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SUMMARY:Effect of chemistry on the small punch creep properties of low car
bon steels
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1237@events.saip.org.za
DESCRIPTION:Speakers: zuko Mthwesi (Rhodes University)\nSmall punch creep
testing (SPCT) is a small-scale short-term (<1000h) test that can be used
to determine the remaining life of power plant materials. The mechanical p
roperty data generated by this new technique needs to be correlated to mor
e established testing techniques such as uni-axial creep testing and ultim
ately to predictions regarding the remaining service life of the plant com
ponent. In this study\, we investigated the microstructure-to-property rel
ationships of service exposed low carbon steels with the view to understan
d the deformation mechanisms operating during this accelerated test. SPCT
were performed on 80 samples taken from an industrial steam-line that oper
ated at 425 °C. The chemical composition of the extracted samples was mea
sured using wet-chemical analysis to quantify the minor elements of carbon
and manganese\, as well as trace elements (P\, Si\, Cr\, Mo\, Ni\, Cu\, A
l). In addition\, graphite formation in the samples was quantified using 3
D X-Ray Tomography. The quantitative data consisting of the creep-life\, c
hemical composition and graphite content were analysed using Pearson’s c
orrelation\, exploratory factor analysis and Bayesian neural networks to d
etermine the relationships between the different variables. The results of
the statistical analysis show that carbon and manganese are strongly posi
tively correlated (>0.50) with creep-life\, while graphite content showed
no relationship with the creep-life measured using SPCT. The graphite cont
ent (>0.50) was strongly positively correlated with both aluminium and sil
icon content. Future work will include quantitative microstructural charac
terisation of the samples\, in order to confirm the proposed deformation m
echanisms.\n\nhttps://events.saip.org.za/event/144/contributions/1237/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1237/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Magnetic properties of a distorted Kagomé lattice: Gd3Os4Al12
DTSTART;VALUE=DATE-TIME:20190710T134000Z
DTEND;VALUE=DATE-TIME:20190710T140000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1238@events.saip.org.za
DESCRIPTION:Speakers: Redrisse Djoumessi Fobasso (University of Johannesbu
rg)\nR-T-X (R= rare-earth\, T= Transition element and X = p-block element)
ternary intermetallic compounds have drawn considerable attention for the
ir diversity of structural and magnetic properties. The rare-earth family
of R3T4X12 type is of particular interest among intermetallics because the
structure contains layers as well as triangular and distorted Kagomé lat
tice features. In this work\, we have synthesized the Gd3Os4Al12 compound
by arc-melting technique. The powder X-ray diffraction spectra with a full
-profile refinement confirm that Gd3Os4Al12 crystallizes in the hexagonal
Gd3Ru4Al12-structure type with space group P63/mmc. The temperature (T) de
pendent dc-magnetic susceptibility (𝜒) reveals that the compound underg
oes ferro- to antiferromagnetic orderings below 30 K. They are consistent
with the phase transitions observed in the specific heat data. The (T) dat
a obey the Curie-Weiss law above 180 K\, with the calculated effective mag
netic moment μeff = 7μB/Gd\, which is slightly smaller than the trivalen
t free-ion value for the Gd ion of 7.9 µB. The obtained positive paramagn
etic Weiss temperature indicates the presence of strong ferromagnetic inte
ractions. The study may contribute towards a better understanding of the p
hysics in Kagomé structure compounds\, since in a frustrated lattice syst
em such as this there are strict constraints imposed upon the magnetic ord
er parameter.\n\nhttps://events.saip.org.za/event/144/contributions/1238/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1238/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quantum secret sharing with graph states
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1239@events.saip.org.za
DESCRIPTION:Speakers: Comfort Sekga (Department of Physics and Astronomy\,
Botswana International University fo Science and Technology\, Private Bag
16 Palapye\, Botswana)\nSecret sharing is an information processing proto
col for managing secret information over multiple parties. The information
is distributed in a way that some subset of the parties referred to as th
e access structure can collaborate to recover the original secret informat
ion\, but all other subsets of parties referred to as adversary structure
gain no information on the secret even with unlimited computing power. The
parties in secret sharing forms a quantum network connected by the optica
l channels. In our work\, we use the graph states formalism to represent t
he distribution of entangled states in a secret sharing protocol whereby t
he communicating parties correspond to the vertices and the optical channe
ls linking them represent the edges. We also demonstrate the use of quantu
m repeaters which links the dealer and the players in our secret sharing s
cheme to address the problems associated with the imperfections in the gen
eration of the entangled states\, as well as noise and loss effects during
the transfer of the states over communication network.\n\nhttps://events.
saip.org.za/event/144/contributions/1239/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1239/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A Case for Physics Content Knowledge and Modeling Pedagogy for Nat
ural Science Teachers
DTSTART;VALUE=DATE-TIME:20190711T082000Z
DTEND;VALUE=DATE-TIME:20190711T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1240@events.saip.org.za
DESCRIPTION:Speakers: Bako Nyikun AUDU (University of the Western Cape)\,
Mark Herbert (University of the Western Cape)\nNegative experiences by lea
rners at the gateway phase (grade 9 to grade 10) due to perceived unintere
sting content in natural sciences or poor teaching on the part of the teac
hers has a detrimental effect on learners. There is evidence that many Nat
ural Science teachers are not trained in the physics content component of
the subject\, Hestenes\, Megowan-Romanowicz\, Popp et al (2011)\, Chisholm
(2012). This has been identified as the major factor affecting learners
’ achievement and interest in the sciences and thus\, deterring learners
from having further interest in physical sciences in the senior high scho
ol phase. Also\, the curriculum structures play an important role as teach
ers enact their understanding of what is to be taught\, and what is to be
learned. The study of Natural Sciences in our high schools is a basic-foun
dation subject for learners who would be going on to do Physical Sciences
as a matric subject. This paper focuses on the effect of a Modeling Instru
ction approach on Pre-Service Teachers’ conceptual understanding of elec
tricity in a PGCE science module. The modeling approach is the teaching wh
ereby a small number of key models of the physics component are explicitly
focused on and developed based on inquiry methodology\, Hestenes et al (2
011)\, Barlow\, Frick\, Barker\, and Phelps (2014). The following question
s were asked\; What are the demographics of the Pre-Service teachers and t
he implications for the teaching of Natural Sciences? What is the effect o
f modeling instruction approach on teacher test scores? An analysis of tes
t scores and a survey of teacher experience was also carried out. The resu
lts of the analysis are discussed. The findings of the study shows there i
s positive outcomes for modelling instruction as a strategy for teaching p
hysics content of Natural Science to Pre-Service Teachers. The researchers
recommend the use of modeling instruction for teaching the physics conten
ts of Natural Sciences to help learners learn science better and to see th
e usefulness of the subject at the Junior High School level.\n\nhttps://ev
ents.saip.org.za/event/144/contributions/1240/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1240/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The teacher development and training program for in-service teache
rs in the Department of Physics and Astronomy at the University of the Wes
tern Cape.
DTSTART;VALUE=DATE-TIME:20190711T080000Z
DTEND;VALUE=DATE-TIME:20190711T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1241@events.saip.org.za
DESCRIPTION:Speakers: Mark Herbert (University of the Western Cape)\nSouth
Africa schools have been in a state of education reform since the mid-nin
eties. At the core of the reform was the establishment of the comprehensiv
e curriculum project named Curriculum 2005. Shortcomings in the Curriculum
2005 resulted in the establishment of the National Curriculum Statement i
n 2008. Curriculum reform as required by the National Curriculum Statement
for Natural and Physical Sciences teachers implied that teachers have to
have a deep understanding of the highly structured content knowledge as we
ll as the pedagogical content knowledge to transform the content for effec
tive teaching\, in particular the physics component of the curricula. Howe
ver research findings have indicated that teachers find the curriculum cha
llenging and that they were concerned that they did not have the necessary
skills to deal with the content. The South Africa Institute of Physics (S
AIP) in its draft document “Strategic Plan on the enhancement of Physics
Training in South Africa” recommended that Physics Departments at South
Africa Universities plays a more active role in teacher development and t
raining. This paper reports on the University of the Western Cape\, Depart
ment of Physics and Astronomy’s teacher development and training program
to help address the curriculum challenges teachers face in terms of the p
hysics content and physics pedagogical content knowledge. An overview of t
he program as well as teachers experiences of the program will be presente
d and discussed.\n\nhttps://events.saip.org.za/event/144/contributions/124
1/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1241/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The two stage test: a form of collaborative and reflective learnin
g
DTSTART;VALUE=DATE-TIME:20190709T132000Z
DTEND;VALUE=DATE-TIME:20190709T134000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1242@events.saip.org.za
DESCRIPTION:Speakers: Mark Herbert (University of the Western Cape)\nThis
paper reports on work that has been done in the Physics and Astronomy Depa
rtment at University of the Western Cape (UWC). The mainstream mechanics p
hysics for first years. The module focuses on improving students’ succes
s by giving them epistemological access to the study of physics. Central t
o the module teaching philosophy and pedagogy is the socio-cultural perspe
ctives on learning in the sciences. This has guided the development of our
intervention strategies to direct students’ learning toward gaining acc
ess to the ‘ways of knowing’ of the discipline. Such perspectives sugg
est that an exclusively individual or cognitivist approach need to be comp
lemented by those that recognize the social contexts in which science lear
ning takes place\, and which places a greater emphasis on learning as part
icipation and identity development. This paper reports on the two-stage te
sts used to support physics learning. The two-stage exam is a way to encou
rage students’ to participate and reflect on their learning by providing
immediate formative and summative assessment of their learning. An overvi
ew of the mainstream mechanics physics first year module teaching and lear
ning approach as well as the results of a survey of students’ experience
s of the two-stage test will be presented and discussed.\n\nhttps://events
.saip.org.za/event/144/contributions/1242/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1242/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Support program for first year main stream student outside the nor
mal lectures and tutorial in the Department of Physics and Astronomy at th
e University of the Western Cape
DTSTART;VALUE=DATE-TIME:20190711T092000Z
DTEND;VALUE=DATE-TIME:20190711T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1243@events.saip.org.za
DESCRIPTION:Speakers: Herbert Mark (University of the Western Cape)\nFirst
year students entering the mainstream undergraduate physics program in th
e Department of Physics and Astronomy at the University of the Western Cap
e are at different level of preparedness which have impact on their learni
ng at the university. In particular\, their learning of physics which infl
uence their retention and performance in the subject and progression in th
eir course of choice. Findings of a survey carried out shows that most stu
dents reported that they find the physics interesting but difficult and th
at they needed more guidance and support in their learning of physics insi
de and outside the lecture periods and tutorial. In response to this\, the
lecturer aligned the curriculum\, i.e. the teaching and learning activiti
es to guide students learning as well as to provide a collaborative and su
pportive learning environment inside and outside the lecture periods and t
utorial. This paper describes the initiatives implemented in the mainstrea
m undergraduate physics program to enhance guidance and support for studen
ts learning physics outside the lecture periods and tutorial. An overview
of the support program as well as the results of a survey of students’ e
xperiences of the support program will be presented and discussed\n\nhttps
://events.saip.org.za/event/144/contributions/1243/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1243/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Can bath-induced coherences be useful for thermodynamic tasks?
DTSTART;VALUE=DATE-TIME:20190710T122000Z
DTEND;VALUE=DATE-TIME:20190710T124000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1244@events.saip.org.za
DESCRIPTION:Speakers: Camille Lombard Latune (UKZN)\nSeveral promising inn
ovations in quantum thermodynamics and more generally in quantum technolog
ies rely on the use of quantum coherences. However\, it is far from obviou
s how coherences\, most of the time assumed to be present initially\, are
supposed to be prepared and what would be the associated energetic and/or
entropic costs. These are important questions which might challenge the re
alisation of these operations or at least their overall energetic efficien
cy (fundamental in thermodynamic tasks). Nevertheless\, it is well-known f
rom superradiance [1] that under\nspecific circumstances coherences can ap
pear naturally in a system interacting with a bath. Focusing on quantum th
ermodynamics\, we ask the following question: can these bath-induced coher
ences be useful for thermodynamic tasks? As a partial answer\, we use the
framework introduced in [2] to investigate the thermodynamic impact of bat
h-induced coherences in the equilibrium process and steady state of degene
rate systems. Focusing on spin (or\ntwo-level atom) ensembles\, we show tw
o promising effects emerging from bath-induced coherences. The first one i
s the mitigation of the bath's action\, tending to preserve the energy and
entropy of the system against the influence of the bath. This mitigation
effect can probably find applications in state protection or state prepara
tion. The second effect is the opposite of the first one\, namely the ampl
ification of the bath's action\, tending to increase the influuence of the
bath on the energy of the system. This amplification effect is promising
for instance for cooling tasks and energy storage in quantum batteries.\n\
nThis work is based upon research supported by the South African Research
Chair Initiative of the Department of Science and Technology and National
Research Foundation.\n\n[1] M. Gross and S. Haroche\, Physics Reports\, 93
\, 301-396 (1982).\n[2] C. L. Latune\, I. Sinayskiy\, F. Petruccione\, Qua
ntum Sci. Technol. 4\, 025005 (2019).\n\nhttps://events.saip.org.za/event/
144/contributions/1244/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1244/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Large magnetocaloric effect in RE2NiSi3 with RE = Dy and Tm
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1245@events.saip.org.za
DESCRIPTION:Speakers: Jean Jules Mboukam (University of Johannesburg)\nThe
intermetallic ternary compounds Dy2NiSi3 and Tm2NiSi3 crystallize in the
AlB2 type of hexagonal structure with the space group P6/mmm. The magnetic
properties were studied by measuring magnetization as a function of tempe
rature (χ(T))\, magnetic field (M(H)) and heat capacity (Cp(T)) in magnet
ic fields up to 7 T. Temperature dependent magnetization and heat capacity
results revealed that Dy2NiSi3 shows an antiferromagnetic ordering with N
éel temperature at around 5.9 K while Tm2NiSi3 does not show any transiti
on above 2 K. The magnetocaloric effect (MCE) of the two compounds have be
en evaluated from isothermal magnetization (M(T\,H)). Maximum values of is
othermal magnetic entropy change (−ΔSM) and adiabatic temperature chang
e are found to be 20.9 J/kg-K and 11.4 K respectively for Dy2NiSi3 and 21.
7 J/kg-K and 13.4 K for Tm2NSi3 for a field change up to 7 T.\n\nhttps://e
vents.saip.org.za/event/144/contributions/1245/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1245/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Structural stability and electronic properties of bulk\, monolayer
and bilayer PtX 2 (X = Se and Te)
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1246@events.saip.org.za
DESCRIPTION:Speakers: Hamza Mohammed (The National Institute for Theoretic
al Physics\, School of Physics and Mandelstam Institute for Theoretical Ph
ysics\, University of the Witwatersrand\, Johannesburg\, Wits 2050\, South
Africa)\nPlatinum dichalcogenides PtSe2 and PtTe2 crystallise in layered
structures. We present density functional theory calculations of the stru
ctural\, stability and electronic properties of the layered bulk\, monolay
er and bilayer platinum dichalcogenides PtSe2 and PtTe2 compounds in the C
dI2 structure\, space group $P\\bar{3}m1$. Our calculations revealed that
these compounds are mechanically and dynamically stable. The investigation
of electronic properties shows that monolayer and bilayer PtSe2 and PtTe2
are indirect band gap semiconductors while the bulk structures are a semi
-metals. The calculated band structure shows that the band gaps decrease w
hen the number of layers increase\, which allows band gap engineering for
optimal photovoltaic applications.\n\nhttps://events.saip.org.za/event/144
/contributions/1246/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1246/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Educational Power of Being wrong
DTSTART;VALUE=DATE-TIME:20190709T154000Z
DTEND;VALUE=DATE-TIME:20190709T160000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1247@events.saip.org.za
DESCRIPTION:Speakers: Peter Horszowski (PERT INDUSTRIALS)\nThis presentati
on is based on my article published as "The Educational power of Being Wro
ng."\n\nI pose the following question: 'Why can you not see color by moonl
ight?'\nand follow a process of scientific conjecture and refutation. I a
sk a similar question on real and virtual images: 'why does a mirror swap
left and right but not up and down?'and conclude with reflections on scien
tific methodology and how this can be distorted by media and special inter
est groups.\n\nhttps://events.saip.org.za/event/144/contributions/1247/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1247/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The influence of ammonium hydroxide solution on ZnAl2O4 nanophosph
or prepared by chemical bath deposition method
DTSTART;VALUE=DATE-TIME:20190712T100000Z
DTEND;VALUE=DATE-TIME:20190712T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1248@events.saip.org.za
DESCRIPTION:Speakers: Motlalepula Rebecca Mhlongo (Sefako Makgatho Health
Sciences University)\nZnAl2O4 powders were prepared by chemical bath depos
ition (CBD) method by varying ammonium hydroxide solution (AHS). The volum
e of the AHS was varied from 5 – 100 mL in order to determine the optimu
m volume that is needed for preparation of ZnAl2O4 powders. The effect of
AHS volume on the structure\, morphology\, and optical properties of ZnAl2
O4 powders was investigated. The X-ray diffraction (XRD) patterns showed t
hat the powder samples correspond to the cubic crystalline ZnAl2O4 phase.
The intensity of the most intense peaks increased with the increase in vol
ume of AHS up to 50 mL. The scanning electron microscopy (SEM) results rev
ealed that the AHS volume does not influence the surface morphology of the
prepared powders. Transmission electron microscopy (TEM) confirmed that t
he prepared samples are in a nanoscale region and cubic. Elemental energy
dispersive (EDS) analysis confirmed the presence of the expected elements.
The ultraviolet - visible (UV – vis) spectra showed that by varying the
volume of AHS influenced the band gap (Eg). The photoluminescence (PL) re
sults revealed that 50 mL has the highest intensity.\n\nhttps://events.sai
p.org.za/event/144/contributions/1248/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1248/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Emission constraints for the white dwarf pulsar via modelling of i
ts phase-resolved polarisation signatures
DTSTART;VALUE=DATE-TIME:20190710T084000Z
DTEND;VALUE=DATE-TIME:20190710T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1249@events.saip.org.za
DESCRIPTION:Speakers: Louis Du Plessis (NWU\, Potchefstroom\, Department o
f Physics)\nMarsh et al. (2016) detected radio and optical pulsations from
the binary system AR Scorpii (AR Sco). This system\, with an orbital peri
od of 3.55h\, is composed of a cool\, low-mass star and a white dwarf wit
h a spin period of 1.95min. X-ray pulsations have also been detected from
this source (Takata et al. 2018). Optical observations by Buckley et al. (
2017) showed that the polarimetric emission from the white dwarf is strong
ly linearly polarised (up to ~ 40%) with periodically changing intensities
. This periodic emission is thought to be powered by the highly magnetised
(5*10^8 G) white dwarf that is spinning down. We fitted a standard rotati
ng vector model to these polarisation emission angle data\, and found a ma
gnetic inclination angle (α~90 °) and an observer angle (ζ~60 °). Usin
g zeta and the mass function from Marsh et al. (2016) we could constrain t
he mass of the white dwarf to M_{WD} = 1.00 ± 0.19. We next applied our m
odel to the orbitally phase-resolved polarisation position angle data from
Potter and Buckley (2018b) to find α and ζ vs. orbital phase. We will p
resent our first results to indicate the evolution of α and ζ vs. orbita
l phase\, thereby constraining the spatial origin of the emission.\n\nhttp
s://events.saip.org.za/event/144/contributions/1249/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1249/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Investigation of beta Ti-Mo phase stability employing the first pr
inciple approach
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1250@events.saip.org.za
DESCRIPTION:Speakers: Velile Mnisi (SMU)\nThe improvement for load bearing
dental and orthopedic implants of Titanium based alloys have become signi
ficant in the medical industry\, due to the increase of knee and hip repla
cement amongst younger individuals and the deterioration of body parts by
increasing human age. Hence the need for developing low modulus Ti-based a
lloys with biocompatible properties and low elastic modulus close to the b
one. This study aims to investigate the stability of Ti-based alloys for b
iomedical applications using the first-principles approach. The stability
of beta Ti100-xMox (x=0-10) alloys was investigated with respect to their
equilibrium lattice parameters\, elastic constants and the density of sta
tes. The study employed the density functional theory within the generali
zed gradient approximation. Addition of the alloying element was achieved
employing the visual crystal approximation embedded in CASTEP. Interesting
ly\, the Mo addition stabilizes the beta phase with an increasing C’ mod
uli and the density of states suggest that the phase is being stabilized a
t a higher content of Mo (20 at.%).\n\nhttps://events.saip.org.za/event/14
4/contributions/1250/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1250/
END:VEVENT
BEGIN:VEVENT
SUMMARY:XRD\, Mössbauer and magnetic study of MxCo1-xFe2O4 (M = Zn or Cd)
nanoparticles
DTSTART;VALUE=DATE-TIME:20190709T102000Z
DTEND;VALUE=DATE-TIME:20190709T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1251@events.saip.org.za
DESCRIPTION:Speakers: Sizwe Masuku (University of Zululand)\nIn the curren
t work the TMxCo1-xFe2O4 (TM = Zn or Cd) nanosized compounds with average
particle size of about 9 nm were synthesized and investigated by Mössbaue
r and magnetization measurements. The concentrations of Zn2+ or Cd2+ ions
and crystallite size have significant effects on the magnetic properties.
The 57Fe Mössbauer spectral studies show ordered magnetic spin state for
x < 0.5 and paramagnetic phase for 0.6 < x < 1.0 compositions. This can be
explained by the weakening of super exchange interactions between the 57F
e nuclei at tetrahedral (A) and octahedral (B) sites due to the increasing
contents of nonmagnetic Zn or Cd atoms. The Mössbauer spectra for Zn- an
d Cd-based compounds are closely related due to the similar electronic con
figuration of Zn2+ and Cd2+ ions. The magnetization data reveal the superp
aramagnetic nature of the compounds investigated. An increase in coercive
fields from about zero at room temperature to ~3 kOe at 10 K due to spin f
reezing has been observed. The temperature dependence of magnetization sho
w blocking temperatures higher than 300 K. The variations of the magnetic
parameters such as saturation magnetization\, coercive fields are discusse
d on the basis of Zn or Cd contents and crystallite size.\n\nhttps://event
s.saip.org.za/event/144/contributions/1251/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1251/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mode-Mixing in Nanoeggs
DTSTART;VALUE=DATE-TIME:20190711T082000Z
DTEND;VALUE=DATE-TIME:20190711T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1252@events.saip.org.za
DESCRIPTION:Speakers: Luke Ugwuoke (Department of Physics\, University of
Pretoria)\nWe present a discussion on the mode-mixing behaviour of dipolar
and quadrupolar modes in gold nanoeggs. Nanoeggs are reduced-symmetry die
lectric core-metallic shell nanostructures capable of supporting hybrid pl
asmonic modes. We investigated theoretically\,\nthe localized surface plas
mon resonances(LSPR) of nanoegg plasmons in both a non-confocal nanorice a
nd a non-concentric nanoshell\, using the Drude model\, the Rayleigh appro
ximation\,\nthe Fröhlich condition\, and the Solid-harmonic addition theo
rem. We show that certain relationships exist between the LSPR of the nano
egg plasmons and between the LSPR of nanoegg plasmons\, nanorice plasmons\
, and nanoshell plasmons. The LSPR of these nanoeggs possess great tunabil
ity at the single particle level and can be explored for biosensing applic
ations.\n\nhttps://events.saip.org.za/event/144/contributions/1252/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1252/
END:VEVENT
BEGIN:VEVENT
SUMMARY:ELECTRON MICROSCOPY ANALYSIS OF NANOCRYSTALLINE DIAMOND LAYERS ON
ZIRLO
DTSTART;VALUE=DATE-TIME:20190712T104000Z
DTEND;VALUE=DATE-TIME:20190712T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1253@events.saip.org.za
DESCRIPTION:Speakers: Samkelo Sinoyolo Ngongo (Nelson Mandela University)\
nThere is a need for additional energy generation capacity in South Africa
\, and the government has identified nuclear power as part of the future e
nergy mix. For safety\, economics and reliability of nuclear energy genera
tion the issues that affects the cladding material (i.e. ZIRLO) such as wa
terside corrosion\, which limits the life time of the fuel tubes\, must be
resolved. Zirconium alloy is the main physical barrier between the coolan
t system and the nuclear fuel(1). Its principal role is to keep the radioa
ctive products produced during the fission process contained in the fuel p
in1. One solution is to find a way to protect the ZIRLO with a protective
coating against oxidation. When oxidation takes place in the waterside of
the zirconium alloy\, hydrogen is released to the coolant and the cladding
material absorb some of it which leads to formation of zirconium hydrides
that are brittle in nature(2).\n\nSince this problem is surface related t
he ideal coating must improve the reaction kinetics of the fuel tubes with
steam. The aim is to suppress hydrogen generation\, since this is related
to hydrogen gas explosions under accident conditions. Diamond is known fo
r its outstanding properties\, such as high thermal conductivity\, low che
mical reactivity\, extreme hardness\, wear resistance and it can withstand
high temperatures (3\, 4). Due to these properties it has been considered
as a material of choice for a large variety of applications (5) especiall
y as a coating material. Since it also has low neutron capture\, diamond i
s a material with applications in the nuclear industry. \n\nThis paper rep
orts on the characterization of a nano crystalline diamond (NCD) layer gro
wn on a ZIRLO surface by microwave plasma-enhanced linear antenna chemical
vapor deposition (MW-LA-PECVD) apparatus. The samples were grown at the M
W-LA-PECVD reactor at the Institute of Physics\, Czech Republic using gas
mixture of Hydrocarbons-Hydrogen. \n\nThe NCD coated samples were sectione
d using a diamond wire saw and mounted using carbon stub. The samples were
then carbon coated and investigated by scanning electron microscopy (SEM)
using secondary electron (SE) imaging. Electron Energy-Loss Spectroscopy
(EELS) was used to confirm whether the coating is diamond or a carbon like
structure. A Helios NanoLab FIB SEM was used to cut transmission electron
microscopy (TEM) lamellae from specific areas of interest. The TEM lamell
ae were investigated in a JEOL 2100 LAB6 TEM operated at 200 kV. \n\nRefer
ences\n1) Kim\, H.H. et al. (2010) J. Mater. Sci. Technol. 26(9) 827-832.
\n2) Motta\, A.T.\, Chen\, L.Q. (2012) J. Min. Met. Mater. Soc. 64 (12). \
n3) Kratochvilova\, I. et al. (2011) J. Mater. Chem. 21 (18248).\n4) Balme
r\, R.S.\, et al. (2009) J. Phys.: Condens. Matter 21 (364221).\n5) Ashche
ulov\, P. et al. (2015) Appl. Surf. Sci 359 621-628.\n\nhttps://events.sai
p.org.za/event/144/contributions/1253/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1253/
END:VEVENT
BEGIN:VEVENT
SUMMARY:NIR imaging analysis of cluster candidates in the Vela Supercluste
r
DTSTART;VALUE=DATE-TIME:20190709T100000Z
DTEND;VALUE=DATE-TIME:20190709T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1254@events.saip.org.za
DESCRIPTION:Speakers: Narges Hatamkhani (University of Cape town)\nThe aim
in this survey is to map the distribution of galaxies in the potential cl
usters that lie within the newly discovered Vela Supercluster (VSCL) found
by Kraan-Korteweg et al. (2017). This supercluster at a redshift of about
18000 km/s appears as extended and massive as the Shapley Supercluster. T
he VSCL is partly hidden in the Zone of Avoidance (ZoA) and so the Near In
frared (NIR) is the most suitable waveband to probe it\, since it is less
affected by the dust in the Milky Way. We use NIR images from the IRSF tel
escope which are $\\sim 2$ magnitude deeper compared to 2MASX. Along with
the spatial distribution\, we also estimate the number density distributio
n and derive the luminosity functions of these prospective clusters\, whic
h allow us to ascertain their masses and quantify their contribution to th
e observed bulk flow.\n\nhttps://events.saip.org.za/event/144/contribution
s/1254/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1254/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Heavy ion beam analysis of ion implanted poly-aniline nano-composi
tes
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1255@events.saip.org.za
DESCRIPTION:Speakers: Dakalo Mashamba (Tshwane University of Technology)\,
Mandla Msimanga (Tshwane University of Technology)\nIon Beam Analysis is
a suite of techniques used to determine elemental composition and depth pr
ofiles of thin film structures. The effectiveness of the analysis is expec
ted to improve with the use of heavy ions due to higher cross sections (su
ch as stopping force and X-ray production). In this project a comparison w
ill be done between analysis with heavy ions and with light ions. The anal
ysis is to be performed as part of the project aimed at developing polymer
based nuclear radiation sensors. Several films of PANI were deposited on
ITO coated PET substrates via spin coating. The films were then implanted
to different doses using 100 keV Ti+ ions to form metal-polymer nanocompos
ites. RBS\, PIXE and ERDA analyses were the carried out at iThemba LABS TA
MS to confirm implant doses and depth profiles.\n\nhttps://events.saip.org
.za/event/144/contributions/1255/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1255/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shaken\, not stirred: Test particles in binary black hole mergers.
DTSTART;VALUE=DATE-TIME:20190711T082000Z
DTEND;VALUE=DATE-TIME:20190711T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1256@events.saip.org.za
DESCRIPTION:Speakers: Pieter Van der Merwe (North-west University\, Center
for Space Research)\nIn 2015 gravitational wave event GW150914 was detect
ed by the advanced Laser Interferometer Gravitational-wave Observatory (aL
IGO)\, with a possible weak transient electromagnetic counterpart GW150914
-GBM detected by the Fermi Gamma-ray Burst Monitor (GBM) 0.4s after the de
tection of the gravitational wave signal. In light of these detections we
simulate the dynamics of test particles in the gravitational potential wel
l of a binary black hole close to its merging phase with the eventual end
goal of simulating the associated electromagnetic\nradiation in binary bla
ck hole systems\, as this could shed light on binary black hole systems as
high-energy accelerators and possible electromagnetic counterparts of bin
ary black hole mergers. The potentials are numerically calculated using ni
te dierence methods\, under the assumption of non-rotating black holes wit
h the post-Newtonian Paczynski-Wiita potential approximation.\n\nhttps://e
vents.saip.org.za/event/144/contributions/1256/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1256/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Optimising the top-quark reconstruction for the W$^\\prime$ search
in the hadronic channel.
DTSTART;VALUE=DATE-TIME:20190711T084000Z
DTEND;VALUE=DATE-TIME:20190711T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1295@events.saip.org.za
DESCRIPTION:Speakers: Fortune Mhlanga (University of the Witwatersrand)\nT
he search for W'->tb decays in the hadronic final states using the full ru
n 2 data\, which was collected by the ATLAS detector at the Large Hadron C
ollider (LHC)\, is on going. This search relies on the optimal identificat
ion of large radius jets that emanates from the top-quark\, hence a study
to find a method that optimizes the top-quark reconstruction has been done
. To conduct this study\, five signal samples with different W$^\\prime$ m
asses were studied. This provides an opportunity to explore different met
hods that yields the highest efficiency of choosing a top-quark jet. The t
ransverse momentum and the invariant mass of the large radius\, and small
radius jets contained within the large radius jet were studied. The curren
t method that is used to choose the top-quark candidate has the efficiency
of 82%\, this study attempts to make improve this efficiency.\n\nhttps://
events.saip.org.za/event/144/contributions/1295/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1295/
END:VEVENT
BEGIN:VEVENT
SUMMARY:FIRST PRINCIPLE STUDY OF HEMATITE (α-Fe2O3) SURFACES STRUCTURE DO
PED WITH TRANSITION METALS
DTSTART;VALUE=DATE-TIME:20190709T084000Z
DTEND;VALUE=DATE-TIME:20190709T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1257@events.saip.org.za
DESCRIPTION:Speakers: CLARENCE VUSI MABASO (STUDENT)\nThe photocatalytic w
ater oxidation activity of hematite (α-Fe2O3) has been greatly enhanced b
y incorporating hematite nanoparticles on the reduced graphene oxide (rGO)
nanosheets. Photoelectrochemical measurement results show that coupling t
he hematite nanoparticles with the rGO greatly increases the photocurrent
and reduces the charge recombination rate. Transient absorption spectrosco
py and time-domain terahertz spectroscopy have provided the direct evidenc
e that the photogenerated electrons have transferred as the mobile carrier
s from α-Fe2O3 to rGO\, which enhances the charge separation and suppress
es the charge recombination. The conduction band edge of α -Fe2O3 is high
ly localized\, leading to a heavy electron effective mass and\, therefore\
, very low electron conductivity. Density functional theory was employed t
o study electronic and optical properties of doped hematite with transitio
n metals. The results showed that the incorporation of Ti and Cr reduces t
he electron effective mass\, which improve the electron conductivity of α
-Fe2O3.\n\nhttps://events.saip.org.za/event/144/contributions/1257/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1257/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nanostructured 2D Ti3C2/NiO composite material as electrode for su
percapacitors applications
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1259@events.saip.org.za
DESCRIPTION:Speakers: Abigail Phori (ordinary member)\nCost-effectiveness
and environmentally friendly nature of the transition metal oxides are som
e motivating factors for their exploration for use as energy storage devic
es applications when compared to other electrode materials. This work repo
rts the successful synthesis of Ti3C2/NiO nanocomposite for application as
supercapacitor electrodes. The as-synthesized material was characterized
by various techniques such as\, Raman spectroscopy\, BET\, SEM\, TEM and X
RD to ascertain the morphological and structural nature of the material. E
lectrochemical characterization of the composite material performed in a t
hree-electrode configuration using 6 M KOH electrolyte reveals high specif
ic capacity and excellent cycling stability with satisfactory capacity ret
ention for over 2000 cycle.\n\nhttps://events.saip.org.za/event/144/contri
butions/1259/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1259/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Costraining f(R)-gravity with cosmological data
DTSTART;VALUE=DATE-TIME:20190711T100000Z
DTEND;VALUE=DATE-TIME:20190711T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1261@events.saip.org.za
DESCRIPTION:Speakers: Renier Hough (North-West University)\nWe are looking
at how to constrain ⨍(R)-modified gravity models\, such as ⨍(R) =βRn
(a toy model) or more realistic ⨍(R)-gravity models like the Starobinsk
y or Hu-Sawicki model\, to cosmological data. We\nused 236 intermediate re
dshift and 123 low redshift Type 1A Supernovae data obtained from the SDSS
-II/SNLS3 Joint Light-curve Analysis (JLA)\, with absolute magnitudes for
the B-filter found on the NASA Extragalactic Database (NED). We then devel
oped a Monte-Carlo Markov Chain (MCMC)-simulation to find the best fit (fi
rstly to the ΛCDM model) to obtain the cosmological parameters (Ωm and
ħ). We then used the concordance model results to constrain the priors fo
r the ⨍(R)-gravity models on the MCMC-simulation. We assumed a flat Univ
erse Ωk = 0 and a radiation density Ωr that is negligible in both the Λ
CDM model and ⨍(R) -gravity models. Thus\, the only difference between t
he ΛCDM model and ⨍(R)-gravity models\, will be Dark Energy and arbitra
ry free parameters. This will tell us if there exist viable ⨍(R)-gravity
models\, when we compare them to the results of the ΛCDM model and thus\
, constraining the generic ⨍(R)-gravity models with cosmological data.\n
\nhttps://events.saip.org.za/event/144/contributions/1261/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1261/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Computational Modelling of Minerals Sulfides
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1262@events.saip.org.za
DESCRIPTION:Speakers: Thabo Letsoalo (University of Limpopo)\nThere are se
veral computational techniques and experimental studied minerals sulfides.
Group of sulfides in nature and significant importance because they serve
as a source of economic for many applications. We used parameterization t
echnique to study chalcopyrite\, pyrite\, marcasite and sulfides minerals
structures using a Density Functional based Tight-Binding (DFTB+). We deve
loped sets of parameters for FeCuS2\, MnS2\, FeS2\, CoS2\, NiS2\, CuS2 and
ZnS2 mineral compounds. However\, S-S interaction pairs produced some goo
d bond lengths\, lattice parameters\, bulk modulus and elastic constant of
minerals sulfides and gave a good agreement of computational-based calcul
ations and experimental results. Density of states (DOS) and band structur
es chalcopyrite (FeCuS2) DFTB+ calculations compare with other results sho
wed that there is no bang gap. Cluster Expansion showed alloyed pyrite wit
h Oxygen are stable phases increased band gap and Monte Carlo indicates th
at the is no phase transition at all different temperature but for photovo
ltaic applications of fabricating pyrite absorber because there is promise
with optimum band gap.\n\nhttps://events.saip.org.za/event/144/contributi
ons/1262/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1262/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Multi-messenger hunts for heavy WIMPs
DTSTART;VALUE=DATE-TIME:20190711T092000Z
DTEND;VALUE=DATE-TIME:20190711T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1263@events.saip.org.za
DESCRIPTION:Speakers: Geoff Beck (University of Witwatersrand)\nThe gold-s
tandard of astronomical WIMP hunting has historically been the ability to
detect dark matter annihilation signals at thermal relic cross-section req
uired to produce the observed cosmological dark matter abundance. A model'
s status becomes dubious if expected emissions are not observed at this po
int\, as a weaker cross-section implies this candidate would not supply th
e bulk of cosmological dark matter. A persistent challenge in this field h
as been in reaching this level of sensitivity when probing models that fea
ture a WIMP mass above 1 TeV. In this talk we discuss recent advances in n
eutrino astronomy that provide new tools to explore the largely uncharted
realm of heavy WIMPs.\n\nhttps://events.saip.org.za/event/144/contribution
s/1263/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1263/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ab-initio studies of sperrylite\, platarsite and pal
ladoarsenide phase stability and surfaces
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1267@events.saip.org.za
DESCRIPTION:Speakers: BRADLEY NEMUTUDI (University of Limpopo)\nComputatio
nal modelling studies of platinum group minerals (PGM): sperrylite (PtAs2)
\, platarsite (PtAsS) and palladoarsenide (Pd2As)\, were carried out to in
vestigatate their stabilities and surfaces. These are paramount to the min
ing industry in South Africa as they are the most extracted minerals in th
e Platreef bushveld complex. In this study we employed the Vienna Ab-initi
o Simulation Package (VASP) along with the projector augmented wave (PAW)
method to investigate the structural stability and surface stabilities of
PtAs2\, PtAsS and Pd2As. In addition\, the phase stability of PtAsS was in
vestigated using cluster expansion\, while the PtAs2 and Pd2As were obtain
ed from phonon dispersions. We found that the calculated lattice parameter
s of the studied structures are in good agreement with the experimental da
ta. The PtAsS cluster expansion showed that all generated structures are t
hermodynamically stable and the phonon showed no soft modes for PtAs2\, Pt
AsS and Pd2As structures. The calculated surface energies indicated that t
he (100) surface for PtAs2\, PtAsS and Pd2As was the most stable amongst t
he low miller index (100)\, (110) and (111) surfaces. As such the (100) su
rface was considered as the working surface for all the surface models. Th
e order of surface energies followed as: (100) < (111) < (110) for PtAs2 a
nd PtAsS and (100) < (110) < (111) for Pd2As. The calculated thermodynamic
al equilibrium morphologies of the relaxed surface structures indicated th
at (100) surface was the most dominate surface for all the studied surface
structures. These findings gave more insights on the stability of these m
inerals and their surface stabilities which may be applicable in their rec
overy.\n\nhttps://events.saip.org.za/event/144/contributions/1267/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1267/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Transport coefficients of relativistic fluids from third order cau
sal theory
DTSTART;VALUE=DATE-TIME:20190709T082000Z
DTEND;VALUE=DATE-TIME:20190709T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1268@events.saip.org.za
DESCRIPTION:Speakers: Mohammed Younus (Nelson Mandela University)\nThird o
rder non-equilibrium fluid dynamics as an extension of Muller-Israel-Stewa
rt theory for dissipative relativistic fluids have been derived using Grad
's 14-moments techniques. We have tried to calculate transport coeffcients
for shear\, bulk pressures and heat flow as well as pressure anisotropy f
or relativistic dissipative fluids.\n\nhttps://events.saip.org.za/event/14
4/contributions/1268/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1268/
END:VEVENT
BEGIN:VEVENT
SUMMARY:MLEM reconstruction of multiple point sources for UCT PET detector
DTSTART;VALUE=DATE-TIME:20190710T134000Z
DTEND;VALUE=DATE-TIME:20190710T140000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1269@events.saip.org.za
DESCRIPTION:Speakers: Moment Mahlangu (University of Cape Town)\nDepartmen
t of Physics\, University of Cape Town\n \nAt UCT\, positron imaging techn
iques are used to investigate systems of flow for science and engineering
applications. As an example\, positron emission tomography (PET) measureme
nts are performed of the distribution of liquid in 2D flowing foams to inv
estigate bubble coalescence in mineral froth flotation. The impact of the
results and the feasibility of more complex measurements\, such as extend
ing the results to 3D and multiphase media\, are limited by the simplicity
of the image reconstruction techniques and uncertainties around the longe
r range of the positron in the gas phase. The goal of this preliminary st
udy is to develop an advanced image reconstruction technique\, namely maxi
mum-likelihood expectation-maximisation (MLEM)\, for the PET camera config
uration at UCT. PET measurements were performed on multiple point surface
s on the surface of a cylinder. The images were reconstructed with both ML
EM and a simple back projection algorithm to ascertain the ability of the
technique to reconstruct three-dimensional images. This is a promising fi
rst step towards the investigation of bubble coalescence in 3D\; the next
stage of which will be achieved with Géant 4 simulation of the PET camera
and a spherical shell radiolabeled with a positron emitting radionuclide.
\n\nhttps://events.saip.org.za/event/144/contributions/1269/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1269/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Experimental validation of the hot mirror system
DTSTART;VALUE=DATE-TIME:20190710T092000Z
DTEND;VALUE=DATE-TIME:20190710T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1296@events.saip.org.za
DESCRIPTION:Speakers: phil ferrer (wits)\nSolar receivers in solar trough
installations are crucial components for transferring the incident solar r
adiation to a working fluid as heat\, which can be used for industrial app
lications or electricity generation. Losses as thermal radiation dominate
at high temperature and must be minimised in an efficient system. Conventi
onally\, this is achieved via a selective coating on the absorber pipe\, b
ut a different approach used by us is to coat the glass sleeve with a heat
mirror substance to quench radiation losses. Such a system can display nu
merous advantages. In this presentation\, I will talk about the theory beh
ind the heat mirror\, how it is implemented in a simulation and how experi
mental results have validated this idea.\n\nhttps://events.saip.org.za/eve
nt/144/contributions/1296/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1296/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stability of Methylammonium Lead Tri-bromide with Diffused Metal E
lectrodes
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1270@events.saip.org.za
DESCRIPTION:Speakers: Juvet Nche Fru (University of Pretoria)\nThe interac
tions between aluminium\, gold\, silver\, tin\, gold/zinc metal electrodes
with methylammonium lead tribromide perovskite were studied. The metals w
ere deposited on the substrates by physical vapour deposition using a resi
stive evaporator. Likewise\, methylammonium lead tri-bromide perovskite th
in films were grown on the deposited metal films by sequential physical va
pour deposition of lead (II) bromide and methylammonium bromide. The stru
ctural and morphological properties were observed over a period of one mon
th. Field emission scanning electron microscopy showed that aluminium reac
ts aggressively with the perovskites immediately after deposition leading
to exfoliation of the grains. X-ray diffraction patterns confirmed that th
e exfoliation was a result formation of alumina in air. On the other hand\
, gold/zinc alloy was relatively stable with methylammonium lead tri-bromi
de. This study paves the way for the selection of electrode metals for sta
ble methylammonium lead tri-bromide perovskites solar cells\n\nhttps://eve
nts.saip.org.za/event/144/contributions/1270/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1270/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Computational modelling as a value-add in materials design and dis
covery
DTSTART;VALUE=DATE-TIME:20190712T070000Z
DTEND;VALUE=DATE-TIME:20190712T080000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1272@events.saip.org.za
DESCRIPTION:Speakers: Rapela Maphanga (CSIR)\nComputer modelling has been
identified as a key area of growth worldwide and is increasingly becoming
a driving force in the discovery and design of novel materials. Currently\
, computer simulation methods are influencing all areas of study\, with a
great impact in condensed matter physics\, materials science\, chemistry a
nd engineering. With the advancement of computing powers\, complex materia
ls and their properties are increasing investigated. Methods at different
spatiotemporal scales such as density functional theory\, molecular dynami
cs\, energy minimization\, many-body perturbation theory\, phase field and
quantum Monte Carlo to continuum macroscopic approaches are employed to s
imulate materials for various applications. The search to improve andoptim
ize properties and structural characterization of materials is a subject o
f intense scrutiny. However\, this has proved challenging because of the c
omplex and preparation-dependent microstructure of many materials. Over th
e last few years\, materials science research have been steadily moving fr
om technique development and determination of fundamental properties towar
ds new materials discovery and design guided by computation\, machine lear
ning and data mining\, also by a closely tied combination of computational
predictions and experimental validation. Thus\, thedesign of materials by
computation is expected to lead to the discovery of new material and rapi
d evolution of new materials into products. This talk will broadly highlig
ht recent advances in materials design and discovery\, including the appli
cation of machine learning techniques in materials science.\n\nhttps://eve
nts.saip.org.za/event/144/contributions/1272/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1272/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A review of progress on third-generation photo-voltaic cells\,
DTSTART;VALUE=DATE-TIME:20190711T070000Z
DTEND;VALUE=DATE-TIME:20190711T080000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1273@events.saip.org.za
DESCRIPTION:Speakers: Alison Walker (Department of Physics University of B
ath\, Bath BA2 7AY\, UK)\nA review progress on third-generation photovolta
ic cells\, are solar cells designed toovercome the Shockley–Queisser lim
it of 31–41% power efficiency for single bandgap solar cells. These cell
s are not widely commercially available unlike silicon p-n junction cells
b("first generation") and thin film cells ("second generation"). Third-gen
eration cells are made using inexpensive and scalable manufacturing techni
ques\, such as solution processing\, but are far less stable than silicon
PV. They are either relatively high in efficiency (perovskites cells) or m
ade from non-toxic materials (organic cells)\, but rarely both. The main f
ocus of my talk will be on how the physics of organic and perovskite cells
determines the strengths and limitations of these two technologies.\n\nht
tps://events.saip.org.za/event/144/contributions/1273/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1273/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Physics outside Academia (Mikhail Sakharov)
DTSTART;VALUE=DATE-TIME:20190712T092000Z
DTEND;VALUE=DATE-TIME:20190712T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1274@events.saip.org.za
DESCRIPTION:https://events.saip.org.za/event/144/contributions/1274/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1274/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Intellectual Property\, Innovation Management and the Role of NIMP
O in Innovation Support in South Africa (NIPO)
DTSTART;VALUE=DATE-TIME:20190712T080000Z
DTEND;VALUE=DATE-TIME:20190712T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1276@events.saip.org.za
DESCRIPTION:https://events.saip.org.za/event/144/contributions/1276/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1276/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Discussion of Improving the Physics in Industry
DTSTART;VALUE=DATE-TIME:20190712T104000Z
DTEND;VALUE=DATE-TIME:20190712T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1277@events.saip.org.za
DESCRIPTION:https://events.saip.org.za/event/144/contributions/1277/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1277/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Finite element modelling of thermal stress on lining of a crucible
furnace
DTSTART;VALUE=DATE-TIME:20190711T092000Z
DTEND;VALUE=DATE-TIME:20190711T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1278@events.saip.org.za
DESCRIPTION:Speakers: Mpho Podile (University of Johanensburg)\nThe object
ives of the research reported herein was to determine the composite wall o
f a crucible furnace for a contained heat and reduced heat loss to the amb
ient using Finite Element Method (FEM) considering transient heat conducti
on. This paper presents findings on heat transfer characteristics of a cru
cible furnace wall designed and constructed for the smelting of aluminium
scraps in artisanal casting of three legged aluminium pots. The approach w
ould be extended to a static kiln cylindrical hollow furnace for clinkers
production from carbonates locally found in remote rural areas. Thermal st
resses experienced by the lining (concrete and ceramic refractory material
s) of crucible furnace was modelled and simulated using finite-element met
hod. The findings permitted to perform the structural analysis for the det
ermination of thermal stress in different working condition and ascertain
the appropriate lining materials for the used heating material (coal\, fir
ewood\, cow dung\, macadamia nut shells\, or a combination of the above).\
n\nhttps://events.saip.org.za/event/144/contributions/1278/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1278/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Analytical modelling of thermal properties of possible fuel materi
als for aluminum smelting
DTSTART;VALUE=DATE-TIME:20190711T102000Z
DTEND;VALUE=DATE-TIME:20190711T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1297@events.saip.org.za
DESCRIPTION:Speakers: Kamanda Janvier (University of Johannesburg)\nMany d
ifferent fueling materials are used in the smelting of aluminum as used by
rural foundry men in rural communities in South Africa. One lists namely
coal\, firewood\, cow dung\, and macadamia nutshells. While emission and h
eat radiation generated due to a poor heat containment leading to a possib
le biodiversity degradation environment pollution and contribution to clim
ate change\, a systematic study on environmental monitoring nor technical
attributes of used or usable fuel materials is not reported. This paper us
es algebraic linear combination of paired possible fuel materials to demon
strate their contribution to the generated heat. Possible emission would b
e studied and their contributions justified in terms weighted average of e
ach component.\n\nhttps://events.saip.org.za/event/144/contributions/1297/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1297/
END:VEVENT
BEGIN:VEVENT
SUMMARY:STABILITY OF EXCITONIC STATES IN AN EXTRINSEC SEMICONDUCTOR USING
FEYNMAN PATH INTEGRALS
DTSTART;VALUE=DATE-TIME:20190710T144000Z
DTEND;VALUE=DATE-TIME:20190710T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1280@events.saip.org.za
DESCRIPTION:Speakers: FOBASSO M F C (UNIVERSITY OF DSCHANG)\nWe investigat
e the stability of excitonic states\, which are pairs of fermionic particl
es\, by using Feynman Path Integrals methods and Grassman algebra that bes
t describes fermions. The system is decoupled using Berezin integral. Work
ing in the reciprocal space allow us to write the total action functional
express in terms of interacting and non-interacting Green functions. This
action functional also reveals the fluctuations arriving during the displa
cement of the exciton in semiconductor. The Bethe Salpeter equation applie
d help to establish the parametrs like polarization\, total energy and den
sity of states. The binding energy is found to be large compare to the ele
ctron-hole unbound energy ending to the stability of the particle. The obt
ained parameters strongly depends on the impurity alowing one to predict a
bout the future of the particle in presence of fluctuations. All these res
ults are confirmed by the diagrams sketched and that could be a predictive
experimental study on the excitonic states. It is demonstrated that the F
eynman diagrams obtained are in accordance with the analytical results and
reveal the fact that the system contains more fluctuations that can predi
ct its stability. This work is a good understanding in donors impurities f
or transport applications of a doped semiconductor.\n\nhttps://events.saip
.org.za/event/144/contributions/1280/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1280/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Analytical and Numerical Approaches to the quantum optical impleme
ntation of Open Quantum Walks
DTSTART;VALUE=DATE-TIME:20190710T124000Z
DTEND;VALUE=DATE-TIME:20190710T130000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1281@events.saip.org.za
DESCRIPTION:Speakers: Ayanda Zungu (Department of Physics\, North-West Uni
versity\, Mafikeng Campus)\nOpen quantum walks (OQWs) have been introduced
as a type of quantum walks which are entirely driven by the dissipative i
nteraction with external environments and are defined in terms of discrete
completely positive maps on graphs [1]. In my talk\, I shall give a brief
overview of the microscopic derivation of OQWs [2] and propose a single a
tom quantum maser scheme [3] that to implement OQWs.\nThe structure of the
proposed scheme is as follows: We consider a low-intensity flow of two-le
vel atoms through a high-quality single mode resonator (Q~10^12) [3]. We a
ssume that the atom-field interaction time is much shorter than the cavity
damping time so that the relaxation of the resonator field mode can be ig
nored while an atom is inside the cavity. While an atom flies through the
cavity\, the Jaynes-Cummings Hamiltonian describes the coupled field-atom
system\, and during the intervals between successive atoms\, the evolution
of the field is governed by the master equation of a damped harmonic osci
llator. Using the small unitary rotations approach and rotating wave appro
ximation the effective dynamics of the system is shown to be an OQW.\n\nKe
ywords: Open quantum walks\; quantum optics\; quantum dynamics engineering
.\n\nReferences:\n \n[1] S. Attal\, F. Petruccione\, C. Sabot and I. Sinay
skiy\, J. Stat. Phys. 147 (2012)\, 832.\n[2] H.P. Breuer\, F. Petruccione\
, The Theory of Open Quantum Systems (Oxford University Press\, Oxford\, 2
002)\n[3] P. Filipowicz\, J. Javanainen\, P. Meystre\, Theory of a microsc
opic maser\, Physical Review A 34(4) (1986) 3077\n\nhttps://events.saip.or
g.za/event/144/contributions/1281/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1281/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effect of temperature and concentration on hematite nanostructures
prepared by chemical spray pyrolysis
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1282@events.saip.org.za
DESCRIPTION:Speakers: Justine Nyarige (University of Pretoria)\nHematite f
ilms were deposited by chemical spray pyrolysis on fluorine doped tin oxid
e at elevated temperatures (250 - 400 ̊C). 0.05 M\, 0.10 M and 0.15 M of
iron(lll)chloride hexahydrate (FeCl3.6H2O) was used as precursors for hem
atite with nitrogen (N2) as the carrier gas. Scanning electron microscopy
of the hematite films showed small grain sizes of < 100 nm\, with a unifo
rm distribution on the film. Raman spectroscopy revealed two A1g and five
Eg symmetrical vibrational phonon modes of hematite. X-ray diffraction re
sults confirmed (104) and (110) which are dominant diffraction peaks assoc
iated with a corundum hexagonal hematite structure. The films exhibited an
indirect band gap varying from 2.31–1.97 eV. The as-prepared hematite f
ilms have a potential application in photoelectrochemical water splitting
to produce hydrogen gas. \nKey-words: Spray pyrolysis\, hematite\, nanost
ructures.\n\nhttps://events.saip.org.za/event/144/contributions/1282/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1282/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Solar Observation\, Space Weather and the Computation of Sunspot D
ynamics
DTSTART;VALUE=DATE-TIME:20190709T092000Z
DTEND;VALUE=DATE-TIME:20190709T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1283@events.saip.org.za
DESCRIPTION:Speakers: Clinton Clinton Denis Stevens (North-West University
(Potchefstroom))\nSolar phenomena such as solar prominences\, -flares and
-coronal mass ejections (collectively known as solar variations) directly
influence our way of life on Earth by impacting its atmosphere\, climate
and magnetic field. Furthermore the success of all scientific endeavours w
ithin the solar system and the prospects of space travel are significantly
impacted by space weather. It is therefore crucial to understand the root
of solar variations to safeguard our way of life on Earth and to circumve
nt the obstacles space weather poses to our aspirations. Solar variations
can directly be linked to regions of intense magnetic activity on the sun
’s surface – known as sunspots. Our understanding of solar variations
can be improved by the observation and computation of the short- and long-
term dynamics of these sunspots. Our methodology and efforts regarding sol
ar observation\, which includes the initial set-up of a solar telescope\,
and the computation of sunspot dynamics will be showcased and its context
with relation to space weather will be presented.\n\nhttps://events.saip.o
rg.za/event/144/contributions/1283/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1283/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Structural and optical properties of hematite films prepared by sp
in coating at varying ramping rates
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1284@events.saip.org.za
DESCRIPTION:Speakers: Pannan Kyesmen (University of Pretoria)\nIn this stu
dy\, we investigated the impact of ramping rate on the structural and opti
cal properties of hematite films prepared by spin coating. Four samples of
hematite films were deposited on FTO substrate at 500°C sintering temper
ature and 1\, 4\, 8 and 12°C ramping rates respectively. XRD studies of t
he films revealed prominent peaks for hematite at (104) and (110) with wea
k reflections at (012)\, (113)\, (024)\, (122) and (310) planes. FE-SEM re
vealed spherical nanoparticles with some agglomeration into larva-shaped n
anostructures. Films prepared at ramping rate of 4°C and higher showed cr
acks on their surfaces which increases with ramping rate. In addition\, us
ing Raman spectroscopy\, increasing the ramping rate resulted in increasin
g red shifting of the optical phonon modes of hematite. Similar pattern of
red shifting of UV-Vis absorption spectra was observed with increasing ra
mping rates. This was attributed to physical defects in the films which ap
peared in form of cracks as a result of increasing ramping rate. The films
could be used as photoanodes in a PEC cell for water splitting and the le
vel of physical defects in the films may impact on their performance.\n\nh
ttps://events.saip.org.za/event/144/contributions/1284/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1284/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Turbulence conditions at the beginning of the space age: a prelimi
nary analysis
DTSTART;VALUE=DATE-TIME:20190709T080000Z
DTEND;VALUE=DATE-TIME:20190709T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1285@events.saip.org.za
DESCRIPTION:Speakers: Carel Pieter Wolmarans (North-West University)\nSola
r cycle 20\, in the mid 1960s\, was very unusual in that the usual cosmic
ray intensity decline towards solar maximum was not accompanied by an incr
ease in heliospheric magnetic field magnitude as seen in subsequent solar
cycles. This presents something of a quandary where cosmic ray modulation
studies are concerned. This study presents a novel investigation of histor
ic magnetic field spacecraft observations from this period\, in an attempt
to increase our understanding of modulation conditions\, particularly tho
se concerning the diffusion of cosmic rays\, during this time. The availab
le magnetic field data in this period have not been previously subjected t
o modern turbulence analyses\, probably due to the high percentage of omis
sions and low cadence of data. This study presents the preliminary results
of an analysis designed to take these challenges into account in order to
study turbulence conditions in this time\, and to compare these condition
s to those present in subsequent solar minima.\n\nhttps://events.saip.org.
za/event/144/contributions/1285/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1285/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sizing optimisation and installation of a stand-alone PV water pum
ping system for irrigation
DTSTART;VALUE=DATE-TIME:20190710T122000Z
DTEND;VALUE=DATE-TIME:20190710T124000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1286@events.saip.org.za
DESCRIPTION:Speakers: Eric Maluta (UNIVEN)\, Livhuwani Masevhe (UNIVEN)\nT
o deal with the shortage in electricity and high diesel costs affects the
pumping requirements of community water supplies and irrigation\; so using
solar energy for water pumping is an alternative to conventional electric
ity and diesel based pumping systems. Solar water pumping is based on phot
ovoltaic (PV) technology that converts solar energy into electrical energy
to run a DC or AC motor based water pump. The use of such a system is app
ropriate since there is a natural relationship between the availability of
solar energy and the water requirement. The current study seeks to establ
ish the optimal sizing and installation of a stand-alone PV water pumping
system to meet the water requirements and the additional electricity load
required in the farm located in Limpopo Province. The water was pumped by
the submersible pump rated at 5.5 kW from the borehole with capacity of ar
ound 15 000 L/h powered by 18 solar panels with a power rating of 350 W fo
r a total of 6.3 kWp. The mathematical model to determine the relation bet
ween water flow rate and PV power will be matched with the data obtained e
xperimentally for future performance predictions in other locations. Furth
ermore\, the performance of the system was verified in terms of meteorolog
ical data.\n\nhttps://events.saip.org.za/event/144/contributions/1286/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1286/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Reconfigurable infrared hyperbolic metasurfaces using phase change
materials
DTSTART;VALUE=DATE-TIME:20190709T092000Z
DTEND;VALUE=DATE-TIME:20190709T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1287@events.saip.org.za
DESCRIPTION:Speakers: yohannes abate (The University of Georgia)\nMetasurf
aces control light propagation at the nanoscale for applications in both f
ree-space\nand surface-confined geometries. However\, dynamically changing
the properties of metasurfaces can be a major challenge. Here we demonstr
ate a reconfigurable hyperbolic\nmetasurface comprised of a heterostructur
e of isotopically enriched hexagonal boron nitride\n(hBN) in direct contac
t with the phase-change material (PCM) single-crystal vanadium\ndioxide (V
O2). Metallic and dielectric domains in VO2 provide spatially localized ch
anges in\nthe local dielectric environment\, enabling launching\, reflecti
on\, and transmission of hyperbolic phonon polaritons (HPhPs) at the PCM d
omain boundaries\, and tuning the wavelength\nof HPhPs propagating in hBN
over these domains by a factor of 1.6. We show that this system\nsupports
in-plane HPhP refraction\, thus providing a prototype for a class of plana
r refractive\noptics. This approach offers reconfigurable control of in-pl
ane HPhP propagation and\nexemplifies a generalizable framework based on c
ombining hyperbolic media and PCMs to\ndesign optical functionality.\n\nht
tps://events.saip.org.za/event/144/contributions/1287/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1287/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cobalt ion implantation induced modification in band gap\, thermal
parameters and lattice strain on RF – magnetron sputter deposited Zinc
Oxide thin films on borosilicate glass
DTSTART;VALUE=DATE-TIME:20190710T122000Z
DTEND;VALUE=DATE-TIME:20190710T124000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1288@events.saip.org.za
DESCRIPTION:Speakers: Olakunle Oluwaleye (University of South Africa)\nMod
ification of transparent conducting oxide (TCO) thin films using transitio
n metal ion beams has received much research focus due to the possibility
of developing diluted magnetic semiconductors (DMSs). DMS materials are po
tential candidates for application in spin based magnetoelectronic and opt
oelectronic nanodevices [1]. This work reports on the effects of Co+ ion i
mplantation on band gap\, thermal parameters lattice strain and grain size
on radio-frequency (RF) magnetron sputter deposited zinc oxide (ZnO) thin
films on borosilicate glass substrate. Zinc oxide is a direct band gap se
miconductor with a large energy gap and a good exciton binding energy\, wh
ich makes ZnO to be used extensively in many applications\, such as in ene
rgy nanodevices and optoelectronics [1].\n ZnO thin films of thickness 120
nm were implanted with 170 keV Co+ ions at different fluences ranging fro
m 5x1015 to 5x1016 ions/cm2 using the 200 kV ion implanter at iThemba LABS
in South Africa. The implanted Co+ ions were seemingly incorporated into
the ZnO matrix as substitutional metallic ions. At high ion fluences\, the
lattice strain was observed to decrease by 10.92%\, while grain size incr
eased by 34.82%. Williamson-Hall analysis in estimation of grain size and
lattice strain of implanted samples showed good agreement with the crystal
lite size estimated using the Debye-Scherrer method. The optical band gaps
of implanted samples\, from UV- visible absorption spectroscopy\, showed
interesting improvement. For the sample implanted to a fluence of 5 x 1016
ions/cm2\, a 7.52% decrease in thermal factor was observed in comparison
with the as-grown sample.\n\n\n[1] Yuksel Koseoglu. Enhanced ferromagnetic
properties of Co-doped ZnO DMS nanoparticles. Journal of Superconductivit
y and Novel Magnetism\, 26:485–489\, 2013.\n\nhttps://events.saip.org.za
/event/144/contributions/1288/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1288/
END:VEVENT
BEGIN:VEVENT
SUMMARY:An investigation into sources of pc5 pulsations during quiet geoma
gnetic conditions
DTSTART;VALUE=DATE-TIME:20190711T092000Z
DTEND;VALUE=DATE-TIME:20190711T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1363@events.saip.org.za
DESCRIPTION:Speakers: Njabulo Mbanjwa (UKZN)\nPc5 pulsations are global ma
gneto-hydrodynamic events in the magnetosphere. We investigate quiet-time
Pc5 pulsation events and their likely excitation mechanisms using SuperDAR
N\, and Omni and GOES satellite data. With the interplanetary magnetic fie
ld (IMF) Bz northward\, we investigate cases where the IMF By component
is positive and negative. We investigate the excitation mechanism of the p
ulsation\, determining its qualitative polarization characteristics. A com
plex demodulation technique is employed to determine the amplitude and pha
se relationship between field components observed by the radars and othe
r data sets\, which gives wave number and phase velocity characteristics o
f pulsations. We investigate magnetic pulsations in the context of MHD the
ory\, grouping them under various source mechanisms to obtain their statis
tical occurrence.\n\nhttps://events.saip.org.za/event/144/contributions/13
63/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1363/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ideas around using Google Earth as a pedagogic tool for teaching w
ave concepts in the era of Industry 4.0
DTSTART;VALUE=DATE-TIME:20190711T084000Z
DTEND;VALUE=DATE-TIME:20190711T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1289@events.saip.org.za
DESCRIPTION:Speakers: Emanuela Carleschi (Department of Physics\, Universi
ty of Johannesburg)\nThe advent of the Fourth Industrial Revolution requir
es physics teachers and lecturers to re-look at the way physics concepts a
re traditionally taught in order to accommodate a more interactive and tec
hnology-focused teaching approach. In most textbooks wave concepts are pre
sented with the aid of diagrams that are usually drawn in a very abstract
way\, i.e. as a mathematical function on a (x\,y) two-dimensional Cartesia
n plane or by means of an oscillating string. This makes it difficult for
students to visualize wave concepts in three-dimensions and to link them t
o phenomena occurring in real life. Technology offers us opportunities to
explore different avenues for teaching wave physics. Google Earth provides
copious examples of water wave phenomena at the surface of rivers\, lakes
and oceans\, that can be used effectively to describe general wave concep
ts such as refraction\, reflection\, diffraction\, interference and Huygen
s’ principle. We present ideas on how to implement Google Earth images i
n the curriculum of the second year undergraduate course on Waves and Opti
cs presented to science majors at the University of Johannesburg. The aim
is to teach students to also use intrinsic quantitative tools in Google Ea
rth to verify fundamental wave laws and equations. The above will be imple
mented in the course as from the 2020 academic year.\n\nhttps://events.sai
p.org.za/event/144/contributions/1289/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1289/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Electrical characterization of n-type silicon diodes semiconductor
material doped with tungsten particles.
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1291@events.saip.org.za
DESCRIPTION:Speakers: Caroline Ratlhagane (Sefako Makgatho Health Sciences
University)\nn-type Silicon has been doped with tungsten particles at ion
energies ranging from 50keV to 150keV\, silicon was then characterised us
ing Rutherford backscattering spectroscopy and depth profiling for the ana
lysis of the doped material. Schottky barrier diodes were fabricated on th
e silicon doped with tungsten particles and those that are not doped\, AuS
b was used as an ohmic while Pd was used as a schottky contact. Current-vo
ltage (I-V) and capacitance-voltage (C-V) measurements were carried out at
room temperature (300K). The parameters studied from I-V measurements wer
e saturation current (Is)\, ideality factor (ɳ) and schottky barrier heig
ht (ΦIV). For the C-V measurements The results show that the diode fabric
ated show typical diode behavior of silicon diodes and the barrier height
is shown to have decreased with the increase in ion energy.\n\nhttps://eve
nts.saip.org.za/event/144/contributions/1291/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1291/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effect of annealing temperature on the structure\, morphology and
luminescence properties of mixed phases SrAl2O4/Sr3Al2O6/SrCO3:0.05% Gd³
⁺ nanopowders prepared by citrate sol-gel method
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1292@events.saip.org.za
DESCRIPTION:Speakers: Clinton Dlamini (SMU)\nMixed phases of SrAl2O4/Sr3Al
2O6/SrCO3:0.05% Gd3+ nanopowders were prepared via citrate sol-gel method.
The effect of annealing temperature (AT) at the fixed dopant concentratio
n (0.05Gd3+) on the structure\, morphology and photoluminescence propertie
s of the nanopowders were investigated. X-ray diffraction (XRD) showed tha
t the prepared nanopowders consist of the mixture of monoclinic (SrAl2O4)\
, cubic (Sr3Al2O6) and orthorhombic (SrCO3) structures. It is revealed tha
t crystallite sizes is influenced by the AT. The scanning electron microsc
ope (SEM) images shows that the AT has an influence on the particle morpho
logy of the prepared nanopowders. Transition electron microscope (TEM) sho
wed that the crystallites sizes are in the nanoscale. The photoluminescenc
e (PL) showed that when samples were excited with 272 nm\, two emission pe
aks at 431 nm (violet) and 541 (green) were observed and they are attribut
ed to the defects level within the alumina (Al2O3). The international comm
ission on Illumination (CIE) colour showed that the samples were in the Vi
olet region and the emission colour cannot be tuned by AT.\n\nhttps://even
ts.saip.org.za/event/144/contributions/1292/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1292/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Independence of Inductive kick on Inductance of a Pulse Induction
Circuit
DTSTART;VALUE=DATE-TIME:20190709T094000Z
DTEND;VALUE=DATE-TIME:20190709T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1293@events.saip.org.za
DESCRIPTION:Speakers: Olanrewaju Wojuola (North-West University)\nIt is co
mmonly believed that inductive kick or back electromotive force (EMF) gene
rated by a coil depends on the magnitude of its inductance. This\, intuiti
vely\, is in line with Faraday’s law of electromagnetic induction. This
work seeks to show that this is not necessarily the case. Starting from ba
sic principles\, this work presents a theoretical analysis which shows tha
t the back EMF generated by a pulse induction coil does not depend on indu
ctance. Rather\, the back EMF is a function of the ratio of the load to t
he coil resistance. The theoretical analysis is supported with results of
circuit simulation and a real-life example confirming the independence of
the back EMF on inductance.\n\nhttps://events.saip.org.za/event/144/contri
butions/1293/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1293/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Phenomenology of axion-photon coupling in the jets of AGNs
DTSTART;VALUE=DATE-TIME:20190710T100000Z
DTEND;VALUE=DATE-TIME:20190710T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1298@events.saip.org.za
DESCRIPTION:Speakers: Ahmed Ayad Mohamed Ali (University of the Witwatersr
and)\nAn outstanding result of modern cosmology is that only a small fract
ion of the total matter content of the universe is made of baryonic matter
\, while the vast majority is constituted by dark matter (DM). However\, t
he nature of such component is still unknown and might be a matter of long
standing controversies. In principle\, the nature of DM can be understood
through looking for light scalar candidates of DM such as axion and axion
-like particles. The axion is a pseudo-Nambu-Goldstone boson that appears
after the spontaneous breaking of the Peccei-Quinn symmetry and it was int
roduced to solve the CP-violation problem of the strong interactions. On t
he other hand\, there are other axion-like particles (ALPs) predicted by m
any extensions of the standard model of particle physics (SM) and they pos
tulated to share the same phenomenology of the axion. The theory\, togethe
r with observational and experimental bounds\, predicts that such axions o
r more generally ALPs are very light and weakly interacting with the SM pa
rticles. Therefore\, we strongly believe that ALPs are highly viable candi
date for cold DM in the universe. If they really exist in nature\, they ar
e expected to couple with photons in the present of an external magnetic f
ield through the Primakoff effect. We will examine the detectability of si
gnals produced by ALP-photon coupling in the highly magnetized environment
of the relativistic jets produced by active galactic nuclei (AGNs).\n\nht
tps://events.saip.org.za/event/144/contributions/1298/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1298/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hydrogen sulphide gas sensing behaviour of ZnO nanoparticles doped
with cobalt and indium.
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1300@events.saip.org.za
DESCRIPTION:Speakers: Mahlatse Manamela (University of Limpopo)\nThe undop
ed\, 5 % (In or Co) single and (In and Co) double doped ZnO nanoparticles
have been successfully synthesised using the ball milling technique. The k
enosistec station equipment was used to probe the sensing properties of th
e doped and undoped ZnO nanoparticles to H2S gas. The current versus time
curves plotted for H2S gas\, show that the undoped dominates sensitivity f
ollowed by the double doped ZnO nanoparticles. Single doped nanoparticles
show poor sensitivity to H2S gas. The undoped ZnO nanoparticles acquire op
timum sensitivity at a concentration of 20 ppm in the temperature 300 oC.
For the double doped ZnO nanoparticles\, the optimum sensitivity is obser
ved at 5 -10 ppm concentration at a temperature range of 200-350 oC. The d
ouble doped ZnO nanoparticles show fast response\, while Co doped ZnO nanp
articles show fast recovery time to H2S gas.\n\nhttps://events.saip.org.za
/event/144/contributions/1300/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1300/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Electrical properties of highly oxygenated silicon diodes for radi
ation detection applications\; overview
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1301@events.saip.org.za
DESCRIPTION:Speakers: Pulane Mokoena (University of South Africa)\nDefects
in silicon are intentionally introduced to improve properties of the mate
rial for fabrication of radiation detectors. These defects are introduced
either by doping or irradiation of silicon. In trying to understand prope
rties of these defects\, it has been found that they interact with impurit
ies naturally present in the silicon\, oxygen\, leading to a change in ele
ctrical properties of the devices fabricated from the material. It is wit
h this reason a study on the effects of oxygen dopants is presented in thi
s work. The study will contribute in enhancing the knowledge in defects i
n silicon that\, in turn\, open new vistas for more highly efficient radia
tion detectors. \n\nKey words: silicon\,defects\,oxygen\,electrical proper
ties\,detectors.\n\nhttps://events.saip.org.za/event/144/contributions/130
1/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1301/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Impact-response study of lattice waves and phonons in metallic fcc
nanoclusters using the Sutton-Chen potential
DTSTART;VALUE=DATE-TIME:20190711T080000Z
DTEND;VALUE=DATE-TIME:20190711T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1302@events.saip.org.za
DESCRIPTION:Speakers: Richard Ocaya (UFS\, Department of Physics)\nWe sugg
est a novel approach to investigate phonon propagation in an FCC lattice t
hrough bond length oscillations in response to a single atom velocity pert
urbation. The lattice is modelled using the Sutton-Chen embedded atom mod
el (EAM) without any energy loss mechanisms. We begin by showing that the
concept of the cut-off distance must be abandoned to meaningfully simulate
the transient behavior of nanoclusters. Oscillations are shown to arise
and propagate through the lattice as a result of the interatomic potentia
l. The waves\, which have fundamental frequency and velocity\, are put int
o the context of Debye theory and are shown to aptly postulate bulk and su
rface phonons. Calculations of the C11\, C12 and C44 directional moduli of
elasticity calculated along the <100>\, <110> and <111> directions on a t
hin\, nanosized slab-shaped Cu lattice consisting of 2281 Cu atoms are in
good agreement with the literature values at the attained simulated temper
ature. We also show how the cluster temperature is affected by the passage
of the wave.\n\nhttps://events.saip.org.za/event/144/contributions/1302/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1302/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Constraining the star formation history with Fermi-LAT observation
s of the gamma-ray opacity of the universe
DTSTART;VALUE=DATE-TIME:20190710T102000Z
DTEND;VALUE=DATE-TIME:20190710T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1303@events.saip.org.za
DESCRIPTION:Speakers: Ashlynn Le Ray (University Of The Witwaterand)\nThe
star formation history (SFH) of the Universe is of fundamental importance
to cosmology\, not only to galactic formation itself but also for ongoing
efforts to determine cosmological parameters and matter content of the Uni
verse. Measurements of the extragalactic background light (EBL) as a funct
ion of redshift can constrain models of the SFH\, including the initial ma
ss function (IMF) and dust extinction. The gamma-ray spectra of AGN allow
us to study the extragalactic background light (EBL) through γ-γ absorp
tion of high-energy photons. In this work\, we will use six generic parame
ter constellations leading to the EBL predictions and compare our results
with EBL predictions calculated from observational data. The optical depth
for γ-rays owing to electron-positron pair production will be determined
for each model and compared to measurements obtained from data.\n\nhttps:
//events.saip.org.za/event/144/contributions/1303/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1303/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Electronic stopping force of 16O and 63Cu ions in Tantalum Nitride
thin films by Time of Flight spectrometry
DTSTART;VALUE=DATE-TIME:20190712T080000Z
DTEND;VALUE=DATE-TIME:20190712T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1364@events.saip.org.za
DESCRIPTION:Speakers: Thabiso Nkwashu (University of South Africa)\nhttps:
//events.saip.org.za/event/144/contributions/1364/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1364/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Internal conversion coefficients from conversion electron sources
DTSTART;VALUE=DATE-TIME:20190712T082000Z
DTEND;VALUE=DATE-TIME:20190712T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1365@events.saip.org.za
DESCRIPTION:Speakers: Bonginkosi Zikhali (University of wersten cape physi
cs)\nhttps://events.saip.org.za/event/144/contributions/1365/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1365/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Analysis of Type 1 diabetes verbal autopsy data by machine learnin
g techniques
DTSTART;VALUE=DATE-TIME:20190709T082000Z
DTEND;VALUE=DATE-TIME:20190709T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1306@events.saip.org.za
DESCRIPTION:Speakers: THOKOZILE MANAKA (LESOTHO)\nBig data is a term used
for data sets with large\, diverse and complex structures that are often q
uite difficult to analyze or visualize using traditional computing methods
and approaches. Machine learning (ML) techniques are effective in analyzi
ng these types of data and extracting information from these types of data
. Large sets of data are generated by health care systems from record keep
ing of patients and this data supports a wide range of medical decisions l
ike population health surveillance and disease management for the overall
improvement of the quality of health care delivery. In areas where there a
re no health registration systems like the rural areas of most underdevelo
ped and developing African countries\, a method of verbal autopsy is relie
d on to give information of a likely cause of death. In this study\, type
1 diabetes (T1DM) verbal autopsy data from MRC/Wits Agincourt Unit was use
d as a test case for applying modern machine learning classification metho
ds to ascertain the cause of death by type 1 diabetes. Machine learning te
chniques of artificial neural networks (ANNs) and random forests (RF) whic
h are realized with a keras and tensorflow front end were used for the cla
ssification task. Machine learning algorithms automatically learn to make
accurate predictions based on past observations by learning patterns in th
e data and for this study\, they learn the features present in diabetic pa
tients and are able to identify patients who actually could have died from
the disease. This is the first study on type 1 diabetes verbal autopsy da
ta by the two machine learning techniques in South Africa.\nThe dataset wa
s negatively skewed and performance metrics of precision\, recall\, confus
ion matrix and the roc-score were used on these classifiers. Results obtai
ned show that the random forest classifier did the classification task of
deaths by diabetes better than the artificial neural network. In particula
r the roc-score compares favourably with the study that was done by two cl
inician specialists in the disease whose study was similar\, ascertaining
the number of deaths by type 1 diabetes from the data.\n\nhttps://events.s
aip.org.za/event/144/contributions/1306/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1306/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Super-Hard Materials of the B-C binary system
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1308@events.saip.org.za
DESCRIPTION:Speakers: Gilbert Samukonga (Copperbelt University)\nA number
of potentially ultra-hard materials were examined using ab-initio methods.
Compound phases of varying lattice stoichiometry in the B-C-N-O quaternar
y system\, in the forms\, C8-xBx (x = 1\, 2\, 3\, 4)\, C7-xBNx (x = 1\, 2\
, 3) and C6-xBNOx (x = 1\, 2) were proposed as possible super-hard materia
ls with useful applications. Cell structures and elastic properties were s
tudied\, systematic trends were established. It was determined that C7B an
d C6BN were mechanically and dynamically stable compounds with potential s
uper-hard characteristics\, C6BN being the harder of the two. \nThe result
s showed a graphical minimum in the effective values of the isotropic shea
r modulus\, G and Young modulus\, E at x = 3 (C5B3) for the C8-xBx materia
ls\, this indicates that a much higher boron concentration\, i.e. with x >
4\, could possibly increase the hardness of these materials\; we present
a more detailed and extended study (x = 1-7) of the C8-xBx materials.\n\nh
ttps://events.saip.org.za/event/144/contributions/1308/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1308/
END:VEVENT
BEGIN:VEVENT
SUMMARY:CsMn4As3: A new layered tetragonal pnictide compound with an antif
erromagnetic ground state
DTSTART;VALUE=DATE-TIME:20190711T082000Z
DTEND;VALUE=DATE-TIME:20190711T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1309@events.saip.org.za
DESCRIPTION:Speakers: Abhishek Pandey (School of Physics\, University of t
he Witwatersrand)\nSearch for new high-Tc superconductors (SCs) got a boos
t in 2008 after the discovery of superconductivity in tetragonal iron-base
d compounds 1111-type LaFeAsO1-xFx and 122-type AFe2As2 (A = Ba\, Sr and C
a). Efforts begun to discover new SCs or their prospective parent compound
s and soon a few other SC families were discovered. Two common ingredients
of the parent compounds of the iron-based SC families were— stacked squ
are lattices of transition-metal ions and inherent antiferromagnetic (AFM)
fluctuations/ordering. We report here the synthesis and properties of a n
ew layered tetragonal transition-metal pnictide compound CsMn4As3. The mat
erial is a small band-gap semiconductor and exhibits an AFM ground state.
Its crystal structure can best described as a completely collapsed variant
of the structure of iron-based pnictide superconductor parent compound Ba
Fe2As2\, where the entire middle layer of cations as well as As anions are
absent. As a result\, the ratio of the tetragonal lattice parameters c/a
is only 2.44 in CsMn4As3 compared to 3.28 in BaFe2As2. Owing to the novelt
y of its transition metal sublattice\, this new addition to the family of
tetragonal materials related to the iron-based superconductors brings pros
pects for doping and pressure studies in the search of new superconducting
phases as well as other exciting correlated-electron properties.\n\nhttps
://events.saip.org.za/event/144/contributions/1309/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1309/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Ab Initio Study of Ti50Pt50-xHfx (x = 6.25\, 18.75\, 25) Poten
tial Shape Memory Alloys
DTSTART;VALUE=DATE-TIME:20190709T092000Z
DTEND;VALUE=DATE-TIME:20190709T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1310@events.saip.org.za
DESCRIPTION:Speakers: Mphamela Enos Baloyi (UL)\nThe ab initio density fun
ctional theory approach was employed to study the effect of Hf addition to
the TiPt binary shape memory alloys (SMAs). SMAs have the ability to reta
in its original shapes after deformation and have been widely used in the
fields of engineering and medicine due to their shape memory effect (SME)
and super-plasticity which are displayed in martensitic transformations. P
reviously\, the B2 TiPt system was reported to be unstable with respect to
negative C′ and phonon soft modes. In this work\, a supercell approach
method in VASP was used to substitute Pt with 6.25\, 18.75 and 25 at.% Hf
in the TiPt. We have found that the calculated heats of formation predicte
d that 6.25 at.% Hf to be thermodynamically stable structures. The calcula
ted elastic properties confirmed stability of the TiPtHf at different conc
entration of Hf content with all the Cij being positive. It is thus observ
ed that Hf addition enhances the stability of the B2 TiPt. Moreover\, phon
on dispersion curves indicated that increasing the Hf content in the syste
m stabilizes the structure with no soft modes observed. These findings sug
gests that Ti50Pt43.75Hf6.25 has shown potential for alloy development wit
h promising industrial application.\n\nhttps://events.saip.org.za/event/14
4/contributions/1310/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1310/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Electronic and Optical Properties of Ru and Pt Doped TiO2 Brookite
Surfaces Using Density Functional Theory
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1311@events.saip.org.za
DESCRIPTION:Speakers: DIMA RATSHILUMELA STEV (CSIR/UNIVEN)\nThe electronic
structures and optical properties of brookite TiO2 (210) surfaces doped w
ith transition metals (Ru and Pt) have been investigated by first-principl
es calculations based on the density functional theory employing generaliz
ed gradient approximation (GGA). The modelled surface structures were cons
tructed from an optimized brookite bulk structure. TiO2 surfaces were dope
d with transition metals\, with one Ti atom replaced by a transition metal
atom. The results indicate that both transition metals doping can narrow
the band gap of TiO2\, leading to the improvement in the photo reactivity
of TiO2. The metal dopants shift the absorption to high wavelengths and im
proves optical absorbance in visible and near-IR region.\n\nhttps://events
.saip.org.za/event/144/contributions/1311/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1311/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The search for a new scalar and a dark force boson
DTSTART;VALUE=DATE-TIME:20190709T102000Z
DTEND;VALUE=DATE-TIME:20190709T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1313@events.saip.org.za
DESCRIPTION:Speakers: Phineas Ntsoele (University of Johannesburg)\nThe La
rge Hadron Collider’s (LHC) most significant discoveries are: firstly a
Higgs Boson (discovered on July 4\, 2012) and secondly no physics beyond t
he Standard Model (BSM). This is despite the fact something BSM is so wel
l motivated from especially astrophysics and theoretical considerations.
Searches must become more powerful and extend to regions not yet covered.
This paper describes a new search for a scalar particle decaying ultimatel
y to Standard Model (SM) leptons\, through a dark vector boson intermediat
e state. The progenitor could be Higgs-like\, but is motivated more genera
lly\, by a dark sector\, a 2HDM type approach\, or the search may simply b
e model independent. The processes under consideration is S → XX → 4l
where X is the dark vector boson Zd and S is the new scalar. The mass rang
e under consideration for the new scalar is from 20 GeV to 1 TeV\, excludi
ng a window around the SM Higgs. The mass range of the dark vector boson i
s from 10 GeV to 500 GeV\, excluding the SM Z. The search will use the av
ailable large dataset the LHC has collected during it’s second run (Run
2) which took place between 2015 and 2018 and has 150 fb-1 of data.. The t
alk discusses the motivation of the analysis\, the search strategy\, and t
he validation of the search strategy.\n\nhttps://events.saip.org.za/event/
144/contributions/1313/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1313/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fabrication of of NV centers in diamond
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1314@events.saip.org.za
DESCRIPTION:Speakers: Nyiku Mahonisi (University of Witwatersrand)\nSolid-
state based single photon systems are at the heart of the second quantum r
evolution. There is great interest in research focusing on structurally em
bedded color centers in diamond\, particularly NV⁻ centers. It has been
shown that the excitation of these color centers generate non-classical st
ates on demand\, applicable in quantum information processes. Consequently
\, the emission properties of NV⁻ centers in diamond has been studied ex
tensively over the years and show great promise in the ongoing pursuit of
successfully manufacturing quantum based technological devices. In this st
udy\, we engineer NV⁻ centers in well-defined isolated regions within a
pure type IIa diamond sample via ion implantation. We then characterize th
e fluorescence and photon distribution from a single fabricated color cent
er. Ultimately\, this will allow us to engineer isolated NV⁻ centers\, d
epending on application\, at desirable regions within a given sample.\n\nh
ttps://events.saip.org.za/event/144/contributions/1314/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1314/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Death of an Outcome Revisited.
DTSTART;VALUE=DATE-TIME:20190711T102000Z
DTEND;VALUE=DATE-TIME:20190711T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1315@events.saip.org.za
DESCRIPTION:Speakers: Douglas Clerk (School of Physics\, University of the
Witwatersrand)\nPrevious studies in which physics examinations at matricu
lation and first-year level have been analysed\, have described evidence o
f a favoured question-type that can be taught explicitly and relatively ea
sily mastered. This favoured question-type typically makes up such a dispr
oportionately large fraction of the marks for an examination that candidat
es can pass the examination without having to demonstrate any real problem
-solving ability. This has been offered as a tentative and partial explana
tion for a perceived weakness in students’ problem-solving ability. Wha
t has not been reported on previously\, is the question of candidate perfo
rmance relative to question-type\, which has in the past been difficult be
cause of lack of access to the relevant data. In the last few years the D
epartment of Basic Education has been publishing “Diagnostic Reports”
of the South African matriculation results each year which have been featu
ring the average marks earned per sub-section by the candidates. This mak
es it possible now to analyse an examination and classify the questions (a
ccording to the typology developed in our earlier studies) and then compar
e the patterns emerging with the average performance of the examination ca
ndidates. The results of this analysis will be presented and discussed.\n
\nhttps://events.saip.org.za/event/144/contributions/1315/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1315/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The effect of varying Cu2+ concentration on the structure and opti
cal properties of BaAl2O4: x% Cu2+ (0 ≤ x ≤ 1) nano-phosphors prepared
using the citrate sol-gel method
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1316@events.saip.org.za
DESCRIPTION:Speakers: Setumo Victor Motloung (SMU)\nBaAl2O4:x% Cu2+ (0 ≤
x ≤ 1) nano-powders were successfully synthesized via citrate sol-gel m
ethod. The X-ray diffraction (XRD) spectrum revealed that the prepared BaA
l2O4:x% Cu2+ samples consists of the hexagonal BaAl2O4. The estimated aver
age crystallite sizes from the XRD and transmission electron microscopy (T
EM) were found to be in the order of 20 nm. The energy dispersive X-ray sp
ectroscopy (EDS) confirmed the presence of all expected elementary composi
tion (Ba\, Al\, O and Cu). The scanning electron microscope (SEM) showed t
hat varying the Cu2+ concentration influence the morphology of the prepare
d nano-phosphor. The photoluminescence (PL) showed the presence of both em
issions from the host material and Cu2+. Two emission peaks located at 440
– 500 and 616 nm were attributed to the intrinsic intraband gap defects
within the host material\, while the emission at 424 – 475 nm were attr
ibuted to arise from the 3d84s1 → 3d9 transition in Cu2+. The critical e
nergy transfer distance (Rc) of Cu2+ ions was found to be 12.01 Å\, sugge
sting that the multipole–multipole interaction (M-MI) caused the concent
ration quenching. The International Commission on Illumination (CIE) colou
r chromaticity showed that varying the Cu2+ doping concentration and excit
ation wavelength significantly influences the emission colour. Thermo stim
ulated luminescence (TSL) shows the present of two glow peaks at 90.5 and
100 °C for the host and doped sample\, respectively.\n\nhttps://events.sa
ip.org.za/event/144/contributions/1316/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1316/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Structural and Dynamical Properties of Pentlandite Nanostructures:
Atomistic Simulation Approach.
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1317@events.saip.org.za
DESCRIPTION:Speakers: Mofuti Mehlape (University Of Limpopo)\nAtomistic si
mulations were carried out to study the melting behaviour of pentlandite n
anostructures\, in order to understand their structural and dynamical prop
erties. Pentlandite is a major precious metals-bearing mineral and plays a
very important role in mining. Precious metal ores co-exists with base me
tals either as solid-solution and intergrowths\, hence rendering its detai
led understanding important for efficient extraction of these precious met
als. This work relates to problems in applied areas such as mineralogy\, g
eophysics and geochemistry\, whereby phase transition is modified by impur
ities\, so there is the additional concern of the effect of temperature. C
omputational modelling technique\, molecular dynamics (MD) was performed t
o provide atomic or molecular level insights of the structural and dynamic
s of pentlandite nanostructures. The effect of temperature on different si
zes of nanostructures was determined via the structural and dynamical prop
erties\; namely radial distribution functions (RDFs)\, variation of energy
as a function of temperature and diffusion coefficients. Both mechanisms
reveal that as a size of nanostructure increases\, the melting temperature
increases.\n\nhttps://events.saip.org.za/event/144/contributions/1317/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1317/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Improving energy density in symmetric supercapacitors from optimiz
ed activated carbon using non-aqueous electrolytes
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1318@events.saip.org.za
DESCRIPTION:Speakers: Tjatji Tjebane (Necsa/UP)\nImproving energy density
in symmetric supercapacitors from optimized activated carbon using non-aqu
eous electrolytes \n\nThe formation mechanism of the porous framework in n
anostructured carbon materials is important in a wide variety of applicati
ons such as in supercapacitors\, gas storage\, adsorbents and catalyst sup
ports. The accessibility to the pore sites by electrolyte ions and gases a
re highly determined by the precise synthesis techniques adopted for these
materials. As such\, biomass waste materials are a good choice for synthe
sis as they are available in abundance and cheap\, while containing high c
arbon content and giving high specific surface area for electrochemical su
percapacitor applications.\nIn this study\, activated carbon (AC) was synt
hesized from renewable plant biomass waste using a chemical vapour deposit
ion (CVD) technique via a pre-hydrothermal conversion step and compactivat
ion along with the fine-tuning of key growth parameters\, including activa
tion time.\nThe textural\, structural and morphological features were inve
stigated by the Brunauer-Emmett-Teller (BET) technique\, X-ray diffraction
(XRD)\, Scanning/Transmission electron microscopy (SEM/TEM) and Energy Di
spersive X-ray Spectroscopy (EDS) characterization. The material tested in
a three-electrode configuration exhibited electric double-layer capacitor
(EDLC) behaviour and working comfortably in KNO3 aqueous electrolyte in b
oth negative and positive operating widow of 0.80 V. The material also exh
ibited higher gravimetric energy of over 55 Wh.kg-1 and gravimetric power
of 700W.kg-1 at 0.5 A.g-1 gravimetric current in ionic liquid electrolyte.
The results from this study provide the pathway into designing hierarchic
ally porous materials from cheap and sustainable sources suitable in high
power energy storage devices. The improvement of the energy densities are
also achieved using of ionic liquid electrolytes.\n\nhttps://events.saip.o
rg.za/event/144/contributions/1318/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1318/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cryogenic ion implantation of Polyethylene Terephthalate thin film
s: structural and electrical properties
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1319@events.saip.org.za
DESCRIPTION:Speakers: Gaopalelwe Motaung (University of South Africa)\nPol
ymer based nanocomposites have attracted a lot of attention in the semicon
ductor industry for many different applications such as sensors\, solar ce
lls\, lighting and display\, to name a few. Polyethylene Terephthalate (PE
T)\, an insulating polymer with electrical conductivity of up to 10-15 S.m
-1 shows desirable electrical characteristics after ion implantation. In t
his work\, 100keV Ti+ and Ar+ ions were cryogenically implanted into Polye
thylene Terephthalate (PET) foils of about 130 µm thickness. The PET sam
ples were then characterized using Fourier-Transform Infrared (FTIR) Spect
roscopy to determine the chemical and molecular structure of implanted spe
cies. UV-Vis was carried out to determine the electronic band gap and XRD
to determine the crystallinity. The electrical properties of the implanted
PET were investigated through current-voltage (I-V) measurements. This pr
esentation describes and explains results of the characterisation measurem
ents with a view to establishing structure-property relationships of the c
ryogenically implanted PET. The ultimate goal of this study is develop pol
ymer based nanocomposites for applications in nuclear and solar radiation
sensor devices.\n\nhttps://events.saip.org.za/event/144/contributions/1319
/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1319/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Composition induced structural evaluation in BO3-3\, PO4-3 and SO4
-2 substituted CaMoO4:Dy3+ phosphors for application in White-Light LEDs
DTSTART;VALUE=DATE-TIME:20190712T102000Z
DTEND;VALUE=DATE-TIME:20190712T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1320@events.saip.org.za
DESCRIPTION:Speakers: Balakrishna Avula (University of Johannesburg)\nA se
ries of novel white light emitting CaMoO4:Dy3+ (1.0 mol %) phosphors subst
ituted with different anionic groups (BO3-3\, PO4-3 and SO4-2) were prepar
ed using a high temperature solid state reaction method. The effects of an
ionic substitution on the crystalline structure and photoluminescence (PL)
properties of the CaMoO4:Dy3+\, CaMoO4-BO3:Dy3+\, CaMoO4-PO4:Dy3+and CaMo
O4-SO4:Dy3+ phosphors were investigated. The X-ray diffraction (XRD) patte
rns confirmed that the phosphors to be crystallized in a pure scheelite-ty
pe tetragonal structure. The field emission scanning electron microscopy (
FE-SEM) images showed that the particles were agglomerated together and th
ey had no definite size. The chemical composition analyses and the electro
nic states were analyzed using the energy-dispersive X-ray spectroscopy (E
DS) and X-ray photoelectron spectroscopy (XPS) respectively. The Fourier t
ransform infrared spectroscopy (FTIR) data supplemented both the XRD and E
DS data by confirming that the stretching mode frequencies were all relate
d to BO3-3\, PO4-3 and SO4-2 except a few absorption peaks ascribed to atm
ospheric moisture and hydrocarbons. The band gaps measured from the ultrav
iolet visible spectroscopy (UV-Vis) data were shown to vary for the differ
ent anionic group systems. The excitation spectra of the phosphors were ch
aracterized by broadband extending from 250 to 500 nm. Upon near-UV excita
tion\, the phosphor emits intense blue and yellow light with a weak red ba
nds\, which originated from 4F9/2→6H15/2\, 6H13/2\, 6H11/2 transitions o
f Dy3+ ion respectively. Furthermore\, high intensity white light color em
ission was achieved by substitution of different anionic groups (BO3-3\, P
O4-3 and SO4-2) into the CaMoO4:Dy3+ phosphors. Among all the studied phos
phors\, the CaMoO4-SO4:Dy3+ phosphor showed the strongest PL emission comp
ared to all other phosphors suggesting that it is a promising potential ca
ndidate for red emission in the near UV excited white LED applications.\n\
nhttps://events.saip.org.za/event/144/contributions/1320/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1320/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Neutrino detections in Tidal disruption events.
DTSTART;VALUE=DATE-TIME:20190711T094000Z
DTEND;VALUE=DATE-TIME:20190711T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1321@events.saip.org.za
DESCRIPTION:Speakers: Omphile Rabyang (Centre for space research\, North W
est University\, Potchefstroom Campus)\nThe recent detection of astrophysi
cal very-high-energy neutrinos by IceCube has spurred an intensive search
for their sources. As a possible sources of VHE neutrinos\, tidal disrupti
on events (TDEs) have been suggested. Here we investigate a jetted TDE- S
wift J1644+57 which is the best measured TDE in multiple wavebands- as a c
andidate astrophysical neutrino source. TDEs occur when a star approaches
a massive black hole located at the centre of a galaxy. If the tidal radiu
s is larger than the Swarzschild radius of the SMBH this leads to tidal f
orces violently disrupting the star. Matter accretes on the SMBH and produ
ces luminous and long-lasting flares. We investigate the neutrino producti
on in the TDE emission region using a hadronic code developed by Boettcher
et al (2013). This is done through a parameter study which leads to a pro
duction of fits for the spectral energy distribution (SED) of the source
and evaluated the expected neutrino detection rate by IceCube. We present
a parameter study of how the expected neutrino detection rate depends on v
arious source parameters.\n\nhttps://events.saip.org.za/event/144/contribu
tions/1321/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1321/
END:VEVENT
BEGIN:VEVENT
SUMMARY:ION-IMPLANTED POLYANILINE THIN FILMS FOR RADIATION SENSING APPLICA
TIONS
DTSTART;VALUE=DATE-TIME:20190709T094000Z
DTEND;VALUE=DATE-TIME:20190709T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1322@events.saip.org.za
DESCRIPTION:Speakers: matome Matome (University of South Africa)\nPolymer
based electronics is an emerging technology that is focused on developing
electronic devices using semiconducting polymers that can potentially repl
ace silicon based electronics. Polymer based electronics materials are rel
atively cheaper to synthesize and are mechanically flexible compared to si
licon. Metal-polymer nanocomposites\, for example\, have distinctive elect
rical\, optical and morphological properties that can be useful for device
applications. However\, fabrication-structure-property relationships of t
hese materials are not yet fully understood\, and this warrants further in
vestigative studies. In this work\, ppolyaniline thin films were prepared
and deposited on an ITO/PET substrate using a spin coater. The prepared fi
lms were amorphous in nature\, with nanoparticles that were spherical in s
hape. The size of the nanoparticles was varying from 7.0 to 269 nm with me
an particle size of 194.4 nm. The films were then implanted at cryogenic t
emperature with 50-keV Cu+ ions to different fluences of 0.5x1016\, 1.0x10
16\, 3.0x1016 and 5.0x1016 ions/cm2 to form Cu+-PANI nanocomposite films.
Different characterisation techniques were used to investigate a change in
structural\, optical and electrical properties of the films due to ion im
plantation. Moreover\, the optical band gap and the resistance of the film
s were found to decrease drastically at low fluence\, followed by an infin
itesimal decrease at high fluences. The results\, in general\, indicate th
at implantation by copper ions to high fluences can be used as an effectiv
e tool to tailor properties of the material so that it becomes resistant t
o change. This stability is suitable for the material to be used for fabri
cation of the current and future radiation sensors.\n\nhttps://events.saip
.org.za/event/144/contributions/1322/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1322/
END:VEVENT
BEGIN:VEVENT
SUMMARY:ASTRO & SPACE AGM
DTSTART;VALUE=DATE-TIME:20190710T120000Z
DTEND;VALUE=DATE-TIME:20190710T132000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1323@events.saip.org.za
DESCRIPTION:Speakers: Zama Thobeka Katamzi-Joseph (South African National
Space Agency)\nhttps://events.saip.org.za/event/144/contributions/1323/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1323/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fabrication of inorganic quantum dots (QDs) sensitizer absorbers t
hermalized from lead dithiocarbamates single-source precursors complexes
DTSTART;VALUE=DATE-TIME:20190710T130000Z
DTEND;VALUE=DATE-TIME:20190710T132000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1325@events.saip.org.za
DESCRIPTION:Speakers: Mojeed Adedoyin Agoro (University of Fort Hare)\nSol
ar cell sensitizer absorbers of inorganic quantum dots (QDs) has shown gre
at potential in photovoltaic application. The use of quantum dots as an i
mproved absorber layer in photochemical solar cells has attained a noble g
round\, where essential electron and hole generation occurs. Herein\, we
demonstrate the synthesis and characterization of metal sulphides nanopar
ticles\, prepared from dithiocarbamates complexes of Pb(II) using single-s
ource precursors technique. PbS QDs nanocrystals were measured by SEM/EDS
\, HRTEM\, UV-Vis\, PL\, FTIR and Raman. Thermal studies through TGA perf
ormed in a range temperatures of (30 to 900°C). The result of HRTEM anal
ysis revealed crystallite sizes ranges of 1.82 – 5.95. Raman spectra sho
wed the presence of Raman active modes\, while PL analysis has affirmed th
e presence of emissions peaks around 460 nm. Their peak of emission frequ
encies is very sensitive to size\, shape and composition to match the sola
r spectrum of colours of light they absorb. This outcome features the suc
cessful preparation of single-source precursors of PbS nanoparticles.\n\nh
ttps://events.saip.org.za/event/144/contributions/1325/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1325/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atomistic Simulation Studies of Layered Li2MnO3 Nanospherical Cath
ode Materials
DTSTART;VALUE=DATE-TIME:20190710T084000Z
DTEND;VALUE=DATE-TIME:20190710T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1326@events.saip.org.za
DESCRIPTION:Speakers: Nkgaphe Tsebesebe (University of Limpopo)\nLi-excess
Mn-based materials are potential candidates for the next generation of ca
thode materials owing to their high discharge capacity (>200 mAh/g). This
drives the interest for the intercalation/deintercalation processes using
host electrodes with dimensions at the nanoscale\, as this is sufficiently
quick to deliver the power required from Li-ion batteries. The favorable
material Li2MnO3 is known to be electrochemically inactive in the parent b
ulk form\, and can be rendered Li-active by leaching Li from the structure
. However the structural configuration and nucleation process of Li2MnO3 h
ave not been documented\, particularly during the cycling process. The cur
rent study employs the molecular dynamics (MD) DL_POLY code to generate th
e nanoparticles using amorphization and recrystallization (A&R) technique
under microcanonical and canonical ensembles (NVE and NVT)\, respectively.
Nanoparticles were deintercalated to delineate the charging process and i
nvestigate new possible Li-Mn-O intermediate phases that may emanate in th
e Li2MnO3 → LiMnO2 tie-line. The microstructural snapshots depict the fo
rmation of intermediate structures due to Li extraction and O loss. Furthe
rmore\, XRDs for intermediate structures shows the emergence of new peaks
together with the main characteristics’ peaks of the Li2MnO3. Here it is
shown that structural complexity evolves during synthesis – specificall
y\, during the nucleation and crystallization process with microstructural
features such as grain-boundaries (Li2MnO3\, Li1.50MnO2.5 and LiMnO2)\, d
islocations and intrinsic point defects (Li2MnO3). Findings of this work d
emonstrate how the deintercalation results affect the structural transitio
n of the Li2MnO3 cathode material\, and shed valuable details about the in
termediate structural transformations that transpire during cycling.\n\nht
tps://events.saip.org.za/event/144/contributions/1326/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1326/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sol-gel synthesis and characterization of Er3+ doped and Yb3+ co-d
oped TiO2 nanoparticles
DTSTART;VALUE=DATE-TIME:20190709T100000Z
DTEND;VALUE=DATE-TIME:20190709T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1327@events.saip.org.za
DESCRIPTION:Speakers: Tsholo Talane (TUT)\nNew enhanced novel phosphors wi
th high efficiency\, persistent luminescence lifetime and intensity are ne
eded for the development of various nano-technologically advancing industr
ies. In this respect\, this study will discuss the basic information on tr
ivalent rare earth ions photoluminescence emission (down and up conversion
emissions) in the UV/Vis/NIR regime and optical band-gap tuning based on
rare earth ions doping and co-doping. Erbium-doped ytterbium co-doped tita
nium dioxide (TiO2) nanoparticles were prepared via sol-gel synthesis meth
od. The sample characterization was mainly focused on the comparison of t
he undoped and doped TiO2 samples. The phase analysis and particle sizes o
f TiO2: Er3+ and TiO2: Er3+-Yb3+ nanocrystals were determined using an x-r
ay diffractometer (XRD) and transmission electron microscopy (TEM). The x-
ray diffraction patterns confirmed the formation of an anatase TiO2 phase.
UV/Vis spectroscopy was used to measure the reflectance characteristics o
f the sample\, and the band gap was extrapolated from Kubelka-Munk relatio
n. Phonon quantification in TiO2 was achieved using Fourier transform infr
ared (FT-IR) spectroscopy. The XPS technique was employed to confirm the f
ormation of various defects. A laser beam with 980 nm wavelength was used
to irradiate the sample\, and the displayed emission lines of TiO2: Er3+ i
n the visible region of the electromagnetic spectrum confirmed up-conversi
on luminescence. Enhancement of up-conversion luminescence intensity due t
o Yb3+ co-doping was observed\, indicating an efficient Yb-Er energy trans
fer process.\n\nhttps://events.saip.org.za/event/144/contributions/1327/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1327/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Computational modelling of TiO2/SnO2 interfaces for energy storage
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1328@events.saip.org.za
DESCRIPTION:Speakers: Prettier Maleka (Council for Scientific and Industri
al Research (CSIR))\nEnergy storage devices such as rechargeable lithium-i
on batteries are considered as reliable energy storage devices for portabl
e electronic devices\, electric vehicles and key enabling devices. This is
due to their high energy density\, lightweight\, long lifetime\, environm
ental benignity and high efficiency. In this work\, we make use of hybrid
density functional theory to study the electronic properties of (1 1 0) an
d (1 0 1) TiO2 and SnO2 interfaces. Tin oxide has been considered as one o
f the most appealing and promising materials with high theoretical capacit
y for anode materials used for lithium-ion batteries whereas TiO2 provides
SnO2 with secondary structure protection in the SnO2/TiO2 interfaces. A d
etailed analysis was conducted from first principles calculations by makin
g use of plane-wave pseudopotential density functional theory within the g
eneralised approximation for the exchange-correlation functional. It was f
ound that the band positions of both TiO2/SnO2 interfaces change as compar
ed to individual systems and become broader. Also the electronic propertie
s were investigated\, i.e. analysis of the total and projected density of
states\, and charge density differences of the TiO2/SnO2 interfaces. The f
indings provide a useful information on understanding the interfacial mech
anisms for energy storage materials.\n\nhttps://events.saip.org.za/event/1
44/contributions/1328/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1328/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Theory of equation of state and transport coefficients for relativ
istic hydrodynamics in Heavy Ion Collisions and Binary Neutron Star Collis
ions
DTSTART;VALUE=DATE-TIME:20190709T102000Z
DTEND;VALUE=DATE-TIME:20190709T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1329@events.saip.org.za
DESCRIPTION:Speakers: Azwinndini Muronga (Nelson Mandela University)\nI wi
ll give a review of the nuclear equation of state and transport properties
of matter in heavy ion collisions (HIC) and binary neutron star collision
s. I will also point out the significance of the equation of state (EoS) a
nd transport coefficients for HIC and astrophysical observables. \nI will
try to focus on general methods and principles but also touch on specific
open questions for future research.\n\nThe observation of Neutron Stars an
d Binary Neutron Star Collisions allows us to constrain the equation of st
ate(Eos) and transport coefficients of the dense matter well beyond the de
nsities available in earth laboratories such as those colliding heavy ions
. \nThe recent observation of gravitational waves GW170817 and its electro
magnetic counterparts allows us to constrain the dense matter Eos and tran
sport coefficients in new and complementary ways. \n\nThe macroscopic prop
erties of neutron stars depend on how sub-atomic particles interact in the
ir interiors. These interactions are encoded in the equation of state and
transport coefficients.\n\nFinally\, I will briefly comment on gravitation
al waves as a signature of quark matter formation in LIGO and SALT/MeerKAT
/SKA detection and observations.\n\nhttps://events.saip.org.za/event/144/c
ontributions/1329/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1329/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simulated synthesis of Li-intercalated layered (Li2MnO3)-spinel (L
iMn2O4) composite nanoarchitectures.
DTSTART;VALUE=DATE-TIME:20190710T094000Z
DTEND;VALUE=DATE-TIME:20190710T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1330@events.saip.org.za
DESCRIPTION:Speakers: DONALD HLUNGWANI (UL)\nThe layered-spinel composites
are amongst the utmost propitious cathode materials with potential to adv
ance lithium ion batteries\, to date. They demonstrate tremendous improvem
ent on structural stability\, cycling performance and higher specific capa
city\, > 250 mAh/g. Recent studies have focused mainly on enhancing the sp
ecific capacity of these layered-spinel composites. However\, there is lim
ited knowledge on how incorporating such layered-spinel composite electrod
es affects the working voltage of lithium ion batteries. In this study\, m
olecular dynamics (MD) method was employed to generate nanospherical layer
ed (Li2MnO3) - spinel (LiMn2O4) composite\, with different lithium concent
rations. The simulations yielded crystalline nanospheres with grain-bounda
ries except that of Li1.6Mn2O4. RDF graphs were plotted for all systems an
d confirmed complete crystallisation of all structures. XRDs indicated the
existence of layered Li2MnO3\, spinel LiMn2O4 and spinel Mn3O4. Increases
in Li-content resulted in a decrease in Mn3O4 concentration. Frenkel defe
cts and grain boundaries were observed. The simulated layered-spinel compo
nents exist in all lithiated structures.\n\nhttps://events.saip.org.za/eve
nt/144/contributions/1330/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1330/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The potential and effect of diffusion capacitance on fast point-by
-point Current-Voltage measurements of photovoltaic cells in LBIC
DTSTART;VALUE=DATE-TIME:20190710T102000Z
DTEND;VALUE=DATE-TIME:20190710T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1332@events.saip.org.za
DESCRIPTION:Speakers: Frederik Vorster (NMMU)\nThe use of the Light Beam I
nduced Current (LBIC) measurement technique to study the spatial distribut
ion of performance-limiting defects in photovoltaic (PV) cells is well est
ablished. The point-by-point current-voltage (I-V) measurements that are
measured when scanning a light beam across a PV cell are used to extract a
nd map comparative device and performance parameters qualitatively. The w
ell-known capacitive hysteresis effect caused by a rapidly changing bias w
hen fast I-V measurements are made is also observed during spot-illuminate
d LBIC I-V measurements. Fast I-V measurements are necessary to reduce the
total LBIC scan time when more than 10 000 I-V measurements are done per
square centimetre of cell area. Normally care needs to be taken to avoid
erroneous parameter extractions due to this hysteresis effect. This paper
details diffusion capacitance that gives rise to the hysteresis effect an
d its link with the density of charge carriers generated by the LBIC beam
probe. The results show that in addition to extracted I-V parameters\, the
spatially distributed diffusion capacitance measurements may be developed
as a useful tool to augment normal LBIC I-V measurements to map and ident
ify performance limiting defects and perturbations present in PV cells.\n\
nhttps://events.saip.org.za/event/144/contributions/1332/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1332/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Are we giving our students more than we should?
DTSTART;VALUE=DATE-TIME:20190709T150000Z
DTEND;VALUE=DATE-TIME:20190709T152000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1333@events.saip.org.za
DESCRIPTION:Speakers: Buyi Sondezi (University of Johannesburg)\nStudents
’ performance is the main concern of most of the lecturers and facilitat
ors. In seeking ways to improve their understanding\, a number of interven
tions have been employed\, which include increasing contact time\, employi
ng additional tutors and one-on-one students to tutor/lecturer consultatio
n. All of these efforts have yielded some improvements to a certain degree
\, but are they giving maximum output in accordance to the efforts and inp
uts made? In an endeavor to constantly work for maximum throughput and inc
reased pass rate\, peer teaching\, students’ presentations\, projects an
d portfolios have been implemented as teaching methods and the outcomes ha
ve been assessed and analysed. Here we report on the observations of these
alternative efforts of enhancing teaching\, learning and understanding of
concepts at the undergraduate level.\n\nhttps://events.saip.org.za/event/
144/contributions/1333/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1333/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Photovoltaic array performance parameter extraction using only Max
imum Power Point Traced data
DTSTART;VALUE=DATE-TIME:20190710T104000Z
DTEND;VALUE=DATE-TIME:20190710T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1334@events.saip.org.za
DESCRIPTION:Speakers: ANESU CHITURA (UNIVERSITY OF FORT HARE)\nIn order to
observe PV characteristics\, there is need for highly sophisticated and e
xpensive equipment. These characteristics inform the user by offering a re
view of the state of the photovoltaic (PV) system under different weather
conditions. PV Array Current-Voltage (I-V) measurements require skilled p
ersonnel\, expensive equipment and isolation circuitry\, which may be intr
icate and demanding to handle. Literature has not sufficiently shed light
on how I-V parameters and thus the I-V curve can be obtained using only a
small part on the curve. The maximum power point tracker (MPPT) charge co
ntroller performs its function by continuously hovering about the knee of
the I-V curve and therefore the short circuit current\, open circuit volta
ge as well as maximum power can be obtained. In this paper\, MPPT data is
used and then a graph is fitted onto it. The resulting PV parameters obta
ined are used to extrapolate and obtain the full curve. The fitted curve
is compared and analyzed against the measured data. The research will pav
e the way into the use of the MPPT charge controller as a MPPT Performance
I-V tracer.\n\nhttps://events.saip.org.za/event/144/contributions/1334/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1334/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Investigating the Feasibility of using Neutron Activation to Measu
re Elemental Pollution in the Richards Bay Area
DTSTART;VALUE=DATE-TIME:20190710T144000Z
DTEND;VALUE=DATE-TIME:20190710T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1335@events.saip.org.za
DESCRIPTION:Speakers: Sizwe Mhlongo (University of the Western Cape)\nThe
Neutron Activation Analysis technique is one of the most reliable techniqu
es that can be used to analyze various materials in all phases (solid\, li
quid and gaseous). According to literature\, the technique (when using the
traditional approach of employing thermal neutrons) is sensitive to about
78 elements of the periodic table\, and can be used to simultaneously ana
lyze up to 35 elements. In this study\, the feasibility of using the techn
ique for routine elemental pollution measurements is investigated using FL
UKA simulations and experiments. The study area is Richards Bay\, a town i
n the Nothern Coast of the province of KwaZulu-Natal. The area has various
heavy industrial activities\, including aluminum smelting\, sand dune min
ing\, phosphate fertilizer production\, operation of a kraft process paper
mill and a ferrochrome plant. Studies conducted by Masok et al. (Masok et
al.\, 2016) found that heavy metals such as Arsenic (As)\, Manganese (Mn)
and Cadmium (Cd) were the main water contaminants\, with Mn being above t
he target water quality range (TWQR). The elements of interest\, which are
typical pollutants from the industries mentioned are Mn\, Pb\, Cr\, Fe\,
Ni\, Cd\, Sr and Zn. In this study environmental samples and certified ref
erence materials were irradiated using fast neutrons\, their spectra were
measured and analyzed. The experimental results of the water CRM showed ve
ry few peaks\, excluding background\, while the soil CRM showed more peaks
of the activated elements\, albeit with very low count rates. Among the f
ew elements that were identified are Al\, Mn and As.\n\nhttps://events.sai
p.org.za/event/144/contributions/1335/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1335/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Role of Topology in Quantum Communication
DTSTART;VALUE=DATE-TIME:20190710T120000Z
DTEND;VALUE=DATE-TIME:20190710T122000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1336@events.saip.org.za
DESCRIPTION:Speakers: Makhamisa Senekane (Department of Physics and Electr
onics\, National University of Lesotho\, Roma\, Lesotho)\nTopology is a br
anch of mathematics that studies the properties that remain invariant unde
r continuous deformations (deformations that do not include ``cutting'' or
``tearing''). Interest in topological ideas in physics originated in the
field of condensed matter physics with the exploration and discovery of to
pological phases of matter. Furthermore\, topology was adopted in quantum
computation with quantum error correction and topological model of quantum
computation. Recently\, there has been an interest in applying topology t
o photonics\; and this has resulted in the field of topological photonics.
In essence\, topological photonics applies the ideas of topology to the f
ield of photonics. In this paper\, we explore the role of topology in quan
tum communication (quantum communication can be viewed as photonics in qua
ntum regime). In particular\, we explore the effects of topology in freque
ncy-coded quantum key distribution (QKD)\; with focus on topological laser
and topological one-way fiber. Quantum bit error rates (QBER) for topolog
ically-assisted frequency-coded variants of the BB84 and the B92 QKD proto
cols are then analyzed. The results obtained provide a justification for t
he exploration of topology in quantum communication.\n\nhttps://events.sai
p.org.za/event/144/contributions/1336/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1336/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Optical sensitivity of CdS-Au nanocomposites prepared by physical
techniques: pulsed laser deposition and sputter coating.
DTSTART;VALUE=DATE-TIME:20190711T082000Z
DTEND;VALUE=DATE-TIME:20190711T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1337@events.saip.org.za
DESCRIPTION:Speakers: sibusiso nqayi (ufs)\nIn this work we seek to unders
tand the role played by the shape and size of co-catalyst nanoclusters on
the semiconductor surface optical properties. The preparation of nanocompo
sites is of high importance in science and engineering. These are usually
prepared with chemical methods and in this work we also try to counter the
role played by solvents in the preparation of these structures. This is d
one by using two physical techniques: pulsed laser deposition (PLD)\, whic
h is famous for not altering the stoichiometry of materials and sputter co
ating (SPC). The optical sensitivity of semiconductor material is enhanced
by combining them with metal components. \nThe new material performs much
better than the individual components. The presence of the nanoclusters
on the CdS surface attests itself by the enhancement in the absorption int
ensity of the NCs. The ultraviolet-visible (UV-Vis) spectrum of the SPC na
noclusters showed the highest increase\, just as photoluminescence (PL) qu
enching was observed to be the highest for these agglomerated nanoclusters
. This shows the creation of a Schottky junction which allows for the tran
sfer of more electrons from the semiconductor conduction band to the metal
valence band of the SPC NCs.\n\nhttps://events.saip.org.za/event/144/cont
ributions/1337/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1337/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A Deep Learning approach to the search for γγ in association wit
h missing energy at the ATLAS detector
DTSTART;VALUE=DATE-TIME:20190709T104000Z
DTEND;VALUE=DATE-TIME:20190709T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1338@events.saip.org.za
DESCRIPTION:Speakers: Theodore Gaelejwe (University of the Witwatersrand)\
nThe Large Hadron Collider (LHC) generates petabytes of data during each d
ata taking period and machine learning (ML) techniques are required to ana
lyse this data. In particular\, Boosted Decision Trees (BDTs) have been th
e de-facto standard ML tool for this task. However\, in the recent past\,
more modern techniques such as Deep Learning have emerged and there has be
en growing justification for their use in High Energy Physics (HEP). Deep
Neural Networks (DNNs) are known for handling high dimensionality well\, w
hich often characterises ATLAS data and thus making them a suitable tool f
or analysing it. We conduct a comparative study between BDTs and DNNs in c
lassifying signal and background events in the $H \\rightarrow \\gamma\\ga
mma + \\chi $ decay channel. We also consider an unsupervised approach cal
led Weakly Supervised Classification. Preliminary results indicate that DN
Ns perform better than BDTs\, however\, more rigorous testing is still req
uired.\n\nhttps://events.saip.org.za/event/144/contributions/1338/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1338/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Structural and magnetic characterization of Sm3+ ion substituted Z
n-Mn nanoferrites synthesized by glycol-thermal method
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1340@events.saip.org.za
DESCRIPTION:Speakers: T. Amos Nhlapo (Sefako Makgatho Health Sciences Uni
versity)\nZn0.5Mn0.5SmxFe2-xO4 (0 ≤ x ≤ 0.05) fine powders with averag
e crystallite size in the range 12-17 nm were synthesized by glycol-therma
l reaction. The as synthesized compounds were subjected to the annealing p
rocess of 1100 C\, after which the crystallite size increased to about
60 nm. XRD analysis confirmed a single phase cubic spinel structure in all
the compounds investigated. TEM images showed nearly spherical particles
with uniform particle size distributions. The Mössbauer spectrum of Zn0.5
Mn0.5Fe2O4 (x = 0) oxide could be resolved into two quadrupole doublets in
dicative of paramagnetic spin state. Sm3+ substituted Zn0.5Mn0.5SmxFe2-xO4
(0.01≤ x ≤ 0.05) fine powders show weak sextets in addition to broad
doublets attributed to some particles magnetic moments in ordered magnetic
phase. The Mössbauer spectra of the compounds annealed at 1100 C exhi
bit magnetic split sextets indicative of ordered magnetic phase. The compo
unds have small coercive fields and high saturation magnetization (40 emu/
g to 60 emu/g) which reduces with increasing Sm3+ content due to the param
agnetic nature of Sm3+ ions.\n\nhttps://events.saip.org.za/event/144/contr
ibutions/1340/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1340/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Predicting scuffing by modeling bottle movement on a multi-track c
onveyor.
DTSTART;VALUE=DATE-TIME:20190709T100000Z
DTEND;VALUE=DATE-TIME:20190709T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1341@events.saip.org.za
DESCRIPTION:Speakers: Clemens Dempers (Blue Stallion Technologies\, Centre
for Transport Development\, Industrial & Systems Engineering\, University
of Pretoria\, South Africa)\nThe South African beer industry encourage cu
stomers to return empty 750ml beer bottles to retailers and receive a refu
nd for recycled bottles. These bottles are then re-used\, but after multip
le cycles the bottles eventually exhibit visual signs of scuffing – an o
paque ring at the base and sometimes shoulder of the bottle. Scuffing is c
orrelated to bottle explosions during the refilling process. A simulatio
n model is developed to examine the number of collisions and contact durat
ion of bottles on a conveyor system. The model includes bottle-to-bottle\,
and bottle-to-barrier collisions. An initial bottle trajectory visualizat
ion tool developed with Wolfram Mathematica® software will be presented.\
n\nhttps://events.saip.org.za/event/144/contributions/1341/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1341/
END:VEVENT
BEGIN:VEVENT
SUMMARY:On the Effects of Dissipation Range Turbulence on the Perpendicula
r Diffusion Coefficients of Cosmic Ray Electrons
DTSTART;VALUE=DATE-TIME:20190709T102000Z
DTEND;VALUE=DATE-TIME:20190709T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1342@events.saip.org.za
DESCRIPTION:Speakers: Nadine Dempers (North-West University)\nThe perpendi
cular diffusion coefficient (DC) plays a crucial role in the transport of
low-energy cosmic ray electrons\, which include a proportion of solar ener
getic particles\, electrons originating in the Jovian magnetosphere\, and
electrons of galactic origin. In turn\, various properties of heliospheric
magnetic field turbulence have a strong influence on perpendicular DC exp
ressions derived from theory. Deriving such expressions for realistic form
s for turbulence power spectra is\, however\, difficult\, as this involves
dealing with relatively intractable integrals. This study presents such e
xpressions\, derived from the random ballistic decorrelation interpretatio
n of nonlinear guiding center theory and assuming a 2D turbulence power sp
ectrum that includes a dissipation range. These novel results will be comp
ared with previously published perpendicular DCs derived from this theory
which do not include the effects of turbulent dissipation\, and will be us
ed to ascertain the potential effects of dissipation range quantities on t
he perpendicular transport of low-energy electrons in the heliosphere.\n\n
https://events.saip.org.za/event/144/contributions/1342/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1342/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Electroluminescence Module Mismatch Analysis (EMMA)
DTSTART;VALUE=DATE-TIME:20190710T120000Z
DTEND;VALUE=DATE-TIME:20190710T122000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1344@events.saip.org.za
DESCRIPTION:Speakers: Ross Dix-Peek (NMMU)\nElectroluminescence (EL) imagi
ng has been utilised in qualitative characterisation of photovoltaics devi
ces since 2005. It has been utilised quantitatively to determine individua
l cell voltages\, as well as individual cell electrical parameters. Howeve
r\, there has been limited work on the development of an analysis techniqu
e that combines both the individual cell voltages as well as the local opt
o-electric properties of each cell. In this study a technique is proposed
so as to allow for the study of module mismatch\, module degradation and t
he effect of degradation on module mismatch. \nElectroluminescence Module
Mismatch Analysis (EMMA) makes use of voltage-dependent EL imaging to dete
rmine a set of operational voltage mismatch indices. These indices can the
n be used to give an estimated power response of a module under different
irradiance conditions. This paper presents the development of EMMA as a to
ol to assess PV modules on a commercial scale utilising the third generati
on MBJ Mobile Lab.\n\nhttps://events.saip.org.za/event/144/contributions/1
344/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1344/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sythesis and Characterization of NiO thin films and nano-structure
s for gas sensing applications
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1345@events.saip.org.za
DESCRIPTION:Speakers: Prince Mkwae (University of Zululand)\nNiO thin film
s were deposited at different temperatures (RT\,100\, 200\, 350 and 450 de
gree Celsius) using a direct current (DC) sputtering system and then nicke
l oxide nano-structures were synthesized on the deposited NiO film using h
ydrothermal method. The thin films and nano-structures were subjected to v
arious characterization techniques (X-ray diffraction\, Rutherford Back sc
attering Spectroscope\, Raman\, UV-Visible\, Scanning Electron Microscope\
, X-ray Photo electrons Spectrometer). The thin films deposited were found
to be non-crystalline containing amorphous phases. The deposition tempera
ture was found to have no effect on the film thickness\, since all films d
eposited at different temperatures were found to have the same thickness o
f 25nm\, with uniform distribution of particles on the surface as observed
on the Scanning electron microscope (SEM). These NiO thin films were depo
sited for duration of 1 hour. XPS was used to investigate the presence of
Nickel and Oxygen and their oxidation states in as-deposited samples. Gas
sensing properties of NiO films and nano-structures were tested on Nitric
oxide(NO) gas as analyte\, using kenosis Tec gas sensing station.Repeatab
ility and sensitivity of NiO gas sensor was investigated. Short response o
f 1.5 minutes and recovery times of 1.5 -5.1 minutes were observed on nan
o-structures compare to thin films.\n\nhttps://events.saip.org.za/event/14
4/contributions/1345/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1345/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fluctuating Open Heavy Flavour Energy Loss in a Strongly Coupled P
lasma with observables from RHIC and the LHC
DTSTART;VALUE=DATE-TIME:20190709T084000Z
DTEND;VALUE=DATE-TIME:20190709T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1397@events.saip.org.za
DESCRIPTION:Speakers: Blessed Ngwenya (University of Cape Town)\nHeavy ion
collisions at RHIC and at the LHC produce an enormous amount of energy th
at enables the nuclei and its constituent particles to melt\, thus releasi
ng gluons\, quarks and antiquarks\, travelling in different directions wit
h different momenta. Studies of these collisions have shown that low trans
verse momentum observables describe a strongly coupled plasma (quark-gluon
plasma)\, an almost perfect liquid that evolves hydrodynamically and flow
s with almost no viscosity. We make predictions for the suppression of the
heavy flavor mesons that these heavy quarks decay to and thus describe th
e energy loss of these heavy quarks as they interact with the plasma\; we
show that these predictions are in good agreement with experimental data.\
n\nhttps://events.saip.org.za/event/144/contributions/1397/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1397/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Construction and testing of a magneto-optical trap for laser cooli
ng of rubidium atoms
DTSTART;VALUE=DATE-TIME:20190709T104000Z
DTEND;VALUE=DATE-TIME:20190709T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1348@events.saip.org.za
DESCRIPTION:Speakers: Kessie Govender (Cape Peninsula University of Techno
logy)\nCold neutral atoms are currently being used in many areas of quantu
m information processing\, such as single photon sources\, entangled photo
n generation\, quantum simulations involving cold atoms in optical lattice
s\, etc. Atoms are cooled using a device incorporating laser cooling toget
her with magnetic trapping called a magneto-optical trap (MOT). We describ
e in this presentation the basic principles of laser cooling and the desig
n\, construction and testing of the MOT for cooling of neutral rubidium at
oms.\nOur system consists of an octagonal vacuum chamber having a number o
f view ports\, plus vacuum pumps\, piping\, vacuum gauge and valves. Three
stages of pumping are used to reduce the pressure from atmosphere down to
~ 10^(-10) mbar. Rubidium atoms stored in a getter material are released
into the vacuum chamber by means of electrical heating. Three pairs of cou
nter propagating laser beams\, each pair positioned on opposite sides of t
he chamber along three orthogonal axes\, are used for cooling the atoms in
the chamber. Two lasers are used and frequency locked using saturated abs
orption setups and a PID controllers. One laser is frequency locked to the
5S1/2 (F=2) to 5P3/2 (F=3) cooling transition of rubidium 87. Since the a
toms eventually move out of the cooling transition cycle\, another laser i
s locked to the 5S1/2 (F=1) to 5P3/2 (F=2) repumping transition. The coole
d atoms are trapped using a pair of anti-Helmholtz magnetic coils position
ed on either side of the vacuum chamber. Measurements of the cold atoms ha
ve been conducted using CCD cameras. By measuring the fluorescence of the
cooled atoms\, the number density\, size of the atomic cloud\, and tempera
ture are inferred. We provide measurements of these.\n\nhttps://events.sai
p.org.za/event/144/contributions/1348/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1348/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Temperature dependence of local electroluminescence parameters of
crystalline Si Solar cells
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1350@events.saip.org.za
DESCRIPTION:Speakers: Ross Dix-Peek (NMMU)\nElectroluminescence imaging ha
s been utilised in qualitative characterisation of photovoltaics devices s
ince 2005. Since then\, quantitative techniques have been developed. Howev
er\, the temperature dependence of the emission-voltage response (equation
1) of photovoltaic devices has not been studied in-depth. This work inves
tigates the temperature dependence of the proportionality constant and the
luminescence ideality factor. These parameters are dependent on local mat
erial properties such as effective carrier lifetime and dark current densi
ty. Determining these parameters also allows for increased accuracy at det
ermining local junction voltage at a given global voltage.\n\nLocal lumine
scence ideality factor\, has been related to an injection-dependent carrie
r lifetime. Typically\, in multi-crystalline solar cells\, recombination-a
ctive grain boundaries correspond to non-unity luminescence ideality facto
r. This also corresponds to non-unity local bulk recombination ideality fa
ctors.\nThis paper discusses the experimental setup and analysis of bias-a
nd-temperature dependent electroluminescence imaging. This paper presents
the results of the applied technique on a crystalline Si sample and invest
igates the importance of local temperature correction in the determination
of the luminescence parameters.\n\nhttps://events.saip.org.za/event/144/c
ontributions/1350/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1350/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Implementing a robust anti-QCD tagger with mass de-correlated jet
image data
DTSTART;VALUE=DATE-TIME:20190711T082000Z
DTEND;VALUE=DATE-TIME:20190711T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1351@events.saip.org.za
DESCRIPTION:Speakers: Kokotla Rapetsoa (University of Venda)\nWe implement
a robust anti-QCD tagger with mass de-correlating jet image data produced
using the pre-processing method introduced in arXiv: 1903.02032. We take
a unsupervised (where the algorithm is trained on a mixture of signal and
background data to resemble the proportion of signal and background in ATL
AS) and semi-supervised (where data is only trained on background) learni
ng anomaly detection approach using different kinds of autoencoder neural
networks for our tagger. \nWe use jet image data to train our algorithm in
stead of conventional jet observables. The pre-processing steps perform mo
mentum re-scaling to make all jets have the same mass thus mass de-correla
ting the jets\, Lorentz transformation to make all jets have the same ener
gy and remove the residual rotation by applying the Gram-Schmidt on the pl
ane transverse to the jet axis. This is expected to increase the sensitivi
ty of the autoencoder to non-hypothesised resonance and particles as it wi
ll not face the drawback experienced by most machine learning algorithms a
s they tend to learn the non-linear correlation of the jet-mass with other
jet observables.\n\nhttps://events.saip.org.za/event/144/contributions/13
51/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1351/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alloy simulation of iron aluminides intermetallics
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1353@events.saip.org.za
DESCRIPTION:Speakers: Christine Mkhonto (University of Limpopo)\nThe Fe-ri
ch part of the Fe-Al phase diagram has offered an overview regarding its c
apability as a replacement of steel in the application of intermetallic co
mpounds. They are of excellent application in the energy sector\, boilers\
, pipes and automotive parts. These compounds possess good mechanical prop
erties\, low density as well as accessibility of raw material. Thermodynam
ic stability phase diagrams were calculated and elaborated in order to imp
rove the understanding of the corrosion mechanism. We employed VASP code t
o determine the thermodynamic and electronic properties from their equilib
rium lattice constants on each system. In terms of the system stability\,
there exists correlation between the calculated shear modulus (Cʹ) and Gi
bbs energy as well as the XRD pattern which corresponds to the FeAl bcc or
dered compound. It was found that the addition of Pd\, Pt and Ag enhances
the stability at various (FeXAlXM)X compositions. The results obtained ind
icated that Pt substitution stabilised the system more\, followed by Pd wh
erelse Ag showed to be the least in terms of stability.\n\nhttps://events.
saip.org.za/event/144/contributions/1353/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1353/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ab-Initio Investigation of the Electronic Properties of Low
Miller Index Surfaces in LiMn2O4 Spinel.
DTSTART;VALUE=DATE-TIME:20190709T082000Z
DTEND;VALUE=DATE-TIME:20190709T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1354@events.saip.org.za
DESCRIPTION:Speakers: Brian Ramogayana (UL)\nLithium manganese oxide (LiMn
2O4) spinel attracted the most attention as a potential cathode material f
or lithium-ion batteries because of its three-dimensional crystal structur
e that allows a smooth diffusion of Li+ in and out of the material. Howeve
r\, its application as a cathode material is limited by irreversible capac
ity fading due to manganese dissolution\, which is caused by the presence
of the highly corrosive hydrofluoric acid (HF) continuously produced by de
gradation of the common LiPF6-based electrolytes. In this study\, we emplo
y the spin-polarized density functional theory calculations with on-site C
oulomb interactions and long-range dispersion corrections [DFT+U−D3− (
BJ)] to investigate the stability of (001)\, (011) and (111) surfaces. The
surface energies show that the Li-terminated (001) facet is the most stab
le surface\, which is in agreement with the reported literature. To mimic
charge/discharge processes\, delithiated facets were modeled from the most
stable surfaces terminations\, and their stabilities were evaluated by ca
lculating the surface free energies. As compared to the surface energies o
f the pure pristine facets\, we observed an increase in energy during deli
thiation process\, which indicate the destabilization effect. Our findings
on the LiMn2O4 low Miller index surfaces more essential when improving th
e electrochemical performance of secondary lithium-ion batteries.\n\nhttps
://events.saip.org.za/event/144/contributions/1354/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1354/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effect of Co addition on the structural\, electronic and magnetic
properties of Fe16N2 employing first principles approach
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1376@events.saip.org.za
DESCRIPTION:Speakers: Rosinah Modiba (CSIR)\nImprovements in energy effici
ency and reduction of greenhouse gas emissions have been some of the centr
al topics in recent years in environment and climate change. The advantage
s of using permanent magnets in many different types of electromagnetic dr
ive and static magnetic field applications are compelling. It seems demand
is bound to increase substantially in coming years. There are significant
challenges associated with coming up with new alloys or composite materia
ls that can be used for bulk permanent magnets with an energy product in e
xcess of 460 kJ m−3. In this study\, first-principles approach employing
the density of states within the generalised gradient approximation is em
ployed. The structural\, electronic and magnetic properties of Fe16-xN2Co
for the development of permanent magnets are investigated. Firstly\, geome
try optimization was performed to reach the equilibrium state of the struc
tures and the results compared well with the available experimental result
s. Interestingly the density of states at the Fermi level decreases sugges
ting the stability of Fe16N2 with Co addition.\n\nhttps://events.saip.org.
za/event/144/contributions/1376/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1376/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Electrical properties of highly oxygenated silicon diodes.
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1356@events.saip.org.za
DESCRIPTION:Speakers: Pulane Mokoena (University of South Africa)\nDefects
in silicon are intentionally and unintentionally introduced into the surf
ace and bulk of silicon diodes. Defect engineering is the manipulation of
the type\, concentration\, spatial distribution and mobility of defects wi
thin the material. This is done either by metal doping\, impurity doping a
nd by irradiation before the fabrication of the detector. These effects cr
eate a cascade of interactions generating interstitial and vacancy defects
. The defects recombine in a short time and form chemically stable complex
es and clusters of defects. These defects diffuse through the crystal and
react with impurities such as oxygen. \nSome of these defects under irradi
ation have a negative impact on the electrical properties of silicon such
as shorter minority carrier lifetime\, increased leakage current which is
due to introduction of generation centres\, and the introduction of additi
onal space charge density which will cause variations in full depletion vo
ltage of the silicon device. \nThese changes are due to deep level accepto
r-like radiation induced defects such as di-vacancy bonded to oxygen. V2O
is also responsible for the formation of negative space charge under bias.
\nImproved radiation-hardness can be accomplished by the suppression of t
he formation of V2O centres and in highly oxygenated silicon devices. For
radiation-hardness in silicon devices oxygen concentration is around 1018
cm-3 with high resistivity this is to ensure wide depletion zones thus inc
reasing detection efficiency.\n\nKey words: defect formation\, Si electric
al properties\, radiation hardness.\n\nhttps://events.saip.org.za/event/14
4/contributions/1356/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1356/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Equation of State of weak hadron gas from microscopic model
DTSTART;VALUE=DATE-TIME:20190709T080000Z
DTEND;VALUE=DATE-TIME:20190709T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1357@events.saip.org.za
DESCRIPTION:Speakers: Thendo Emmanuel Nemakhavhani (University of Johannes
burg)\nThe Equation of State (EoS) of a hot and dense hadron matter is stu
died using a microscopic transport model which can support the Large Hadro
n Collider energies of up to √(s_nn )= 14 TeV\, namely the Ultra-relativ
istic Quantum Molecular Dynamics (UrQMD). The molecular dynamics simulatio
n is performed for a system of light meson species (π\; ρ\; K) in a box
with periodic boundary conditions. The equilibrium state is investigated b
y studying the chemical equilibrium and the thermal equilibrium of the sys
tem. The particle multiplicity equilibrates with time\, and the energy spe
ctra of different light meson species have the same slopes and common temp
eratures when thermal equilibrium is reached. The solution of the EoS allo
ws for better understanding of the final state of interactions\, which is
dominated by hadrons produced during ultra-relativistic heavy ion collisio
ns.\n\nhttps://events.saip.org.za/event/144/contributions/1357/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1357/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Non-Abelian Corrections for Radiation in QCD
DTSTART;VALUE=DATE-TIME:20190710T102000Z
DTEND;VALUE=DATE-TIME:20190710T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1358@events.saip.org.za
DESCRIPTION:Speakers: William Horowitz (University of Cape Town)\nWe compu
te the emission spectrum of soft and collinear gluon bremsstrahlung radiat
ion associated with the hard scattering of a quark by a gluon in QCD for o
ne\, two\, and three gluons. In QED\, multiple photon emissions are indep
endent\, which is to say they are emitted according to a Poisson distribut
ion. In QCD\, the non-Abelian nature of the theory leads to interactions
between the emitted gluons. Hence the emissions are not independent\, and
there are therefore corrections to the Poisson distribution of these radi
ated particles. We present the first explicit calculation of these correc
tions\, which exploits maximal helicity violation techniques\, and its rel
evance for heavy ion collision phenomenology.\n\nhttps://events.saip.org.z
a/event/144/contributions/1358/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1358/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Unifying Dark Matter and Dark Energy in Chaplygin Gas Cosmology
DTSTART;VALUE=DATE-TIME:20190711T084000Z
DTEND;VALUE=DATE-TIME:20190711T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1359@events.saip.org.za
DESCRIPTION:Speakers: Anna-Mia Swart (North-West University)\nOne of the m
ost active areas of research in cosmology today involves trying to underst
and the nature of dark matter and dark energy. In this work we will look
at the cosmological background expansion of a universe model filled with a
Radiation-Baryon-Chaplygin Gas fluid system. We will show that such a mo
del can solve the dark matter and dark energy problems\, at least at the l
evel of the background expansion.\n\nhttps://events.saip.org.za/event/144/
contributions/1359/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1359/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Basic concepts in Photovoltaic
DTSTART;VALUE=DATE-TIME:20190708T071500Z
DTEND;VALUE=DATE-TIME:20190708T081500Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1361@events.saip.org.za
DESCRIPTION:Speakers: Mmantsae Diale (University of Pretoria)\nhttps://eve
nts.saip.org.za/event/144/contributions/1361/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1361/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effect of Synthesis Approach on the Structural and Optical Propert
ies of Hybrid Perovskite Materials for Photovoltaic Application
DTSTART;VALUE=DATE-TIME:20190712T092000Z
DTEND;VALUE=DATE-TIME:20190712T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1362@events.saip.org.za
DESCRIPTION:Speakers: Akin Olaleru (University of venda\, South Africa)\nH
ybrid perovskite solar cells aroused great interest in the field of photov
oltaics lately due to easy fabrication process\, tunable band gap within t
he visible region\, high absorption coefficients and carrier mobility (164
cm2v-1s-1). In this work\, we studied the effect of two processes on the s
tructural\, thermal and optical properties of the powder perovskite materi
als for the application in photovoltaic cells. The perovskite materials f
or inclusion into solar cells were prepared by one- and two-step solution
process to generate polycrystalline structures with diverse grain sizes. T
he dynamics of the formation of perovskite were monitored by UV-vis spectr
oscopy\, X-ray diffraction and Thermogravimetric analysis. All samples sho
wed an onset of absorption at ~850 nm in good agreement with the band gap
value (~1.55 eV) of the perovskite materials. The samples prepared using t
wo-step solution process resulted in smooth XRD patterns\, hence showing b
etter crystallinity as exhibited by sharp peaks than those for one step pr
ocess. The crystallite size of the samples were in the range of 44-81 nm.
The one-step solution sample showed the highest temperature (~7500 C) of d
ecomposition when compared to the two-step solution samples which an avera
ge decomposed at (~3500 C).\n\nhttps://events.saip.org.za/event/144/contri
butions/1362/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1362/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Unifying the Background with Perturbations in Chaplygin-gas Cosmol
ogy
DTSTART;VALUE=DATE-TIME:20190711T102000Z
DTEND;VALUE=DATE-TIME:20190711T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1382@events.saip.org.za
DESCRIPTION:Speakers: Heba Abdulrahman (North-West University)\nRecently a
generalized Chaplygin gas has been proposed as a unifying solution to the
dark energy and dark matter problems. In this work\, we will study the de
nsity perturbations of a universe filled with radiation\, baryonic matter
and the Chaplygin gas fluid and analyse the implications on large-scale st
ructure. We will then compare our model results with power spectrum of the
observable universe.\n\nhttps://events.saip.org.za/event/144/contribution
s/1382/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1382/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Relativistic Bell correlations and accelerations
DTSTART;VALUE=DATE-TIME:20190710T134000Z
DTEND;VALUE=DATE-TIME:20190710T140000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1367@events.saip.org.za
DESCRIPTION:Speakers: Jonathan Hartman (University of Johannesburg)\nIn qu
antum mechanics\, the phenomenon described by the situation of two particl
es correlated in such a way that when the spin of one is measured\, the ot
her is immediately known\, is called quantum entanglement. This phenomenon
was first described by Einstein in an argument put forth in the now famou
s EPR paper to express his misgivings and what he saw as the fundamental p
roblems with quantum mechanics. Einstein believed that one should be able
to describe the correlations in the context of classical local realism. Th
e debate was largely philosophical until John Bell\, in 1964\, wrote a pap
er that proposed a way to settle the matter experimentally. Bell\, derived
an inequality\, now called the Bell inequality\, which holds for all such
correlations that can be described by classical local realism and put for
ward what is now called Bell’s theorem. Quantum mechanics itself predict
s that Bell’s inequality should be violated\, which it is as shown by ex
periment. However\, Bell only calculated the theorem in the case of non-re
lativistic quantum mechanics. More recently\, there have been some authors
who have found that the Bell correlations would be modified in relativist
ic frames\, although the maximal violation of Bell’s inequality is still
preserved in a different set of directions. The directions in which the m
aximal violation of Bell’s inequality is conserved in the relativistic f
rames are rotated with respect to each other from the usual non-relativist
ic case through an angle called the Wigner angle. The Wigner angle is rela
ted two the velocity of one inertial frame with respect to the centre of m
omentum frame of the two particles. If such an effect on the correlation b
etween the two particles can be observed between two inertial frames then
it stands to reason that a precessional effect could be observed on Bell o
bservables if the particles are accelerating. This precessional effect is
called the Thomas Precession and we argue that we could possibly use it to
detect forces between the particles.\n\nhttps://events.saip.org.za/event/
144/contributions/1367/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1367/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Particle Physics and Climate Change
DTSTART;VALUE=DATE-TIME:20190711T120000Z
DTEND;VALUE=DATE-TIME:20190711T130000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1368@events.saip.org.za
DESCRIPTION:Speakers: Stephan Woodborne (iThemba LABS)\nAccelerator Mass S
pectrometry (AMS) is an applied particle physics technology that is playin
g an important role in understanding the trajectory of climate change in s
outhern Africa. The Inter-governmental Panel on Climate Change (IPCC) advo
cates the use of past climate history as a test of the skill of climate mo
dels\, but the instrumental record of climate variability in southern Afri
ca is short in duration and patchy in distribution. An approach to climate
reconstruction where instrumental records are inadequate is dendrochronol
ogy: the recording of climate in the ring widths of trees\, but in souther
n Africa this approach is limited to short-lived tree species. At iThemba
LABS we have been attempting to reconstruct past climate using the isotopi
c chemistry of wood from long-lived trees. The focus has been on baobab tr
ees that can achieve ages in excess of 1000 years\, but the ring structure
s preserved in the wood are not annually formed. Understanding the growth
structure of the trees is critical to climate reconstruction. By measuring
the rare isotope 14C using AMS it has been possible to radiocarbon date b
aobabs. The approach is complicated by the “Suess Effect” where atmosp
heric 14C levels were diluted by the addition of “14C-dead” fossil fue
l carbon to the atmosphere since the start of the industrial revolution. I
t is also complicated by the effect that above ground nuclear testing had
on 14C concentrations in the atmosphere. These effects are overcome and th
e results show that baobab growth is complex\, but it can be unraveled wit
h AMS dating. By measuring the stable isotope ratios (13C/12C) of the baob
ab wood\, it has been possible to reconstruct rainfall variability over so
uthern Africa from Namibia to Madagascar over the last 600-1000 years. Thi
s record reveals the underlying forcing of climate\, and approximately 4 v
ariables control most of the droughts (including the “day-0” drought i
n Cape Town) in the region. Using this to test climate models shows that t
he models accurately predict the effects of the 4 underlying variable\, an
d so the alarming climate change forecasts for the region should be given
high priority at policy level.\n\nhttps://events.saip.org.za/event/144/con
tributions/1368/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1368/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Synthesis and Characterization of α-Fe2O3 nanorods arrays for Hyd
rogen Production
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1369@events.saip.org.za
DESCRIPTION:Speakers: Cebo Ndlangamandla (University of Zululand)\nSince t
he discovery of Iron Oxide\, several phases of it have been realized. A th
ermodynamic stable phase of Iron Oxide from a natural occurring water phot
o oxidation. This work seeks to enhance the band gap and the conduction ed
ge to the required values in order to attain this phase akaganiete (β-FeO
OH) is hematite (α-Fe2O3) and it has attracted much attention because of
its great advantages\, such as thermal stability\, Photo-corrosive resista
nce and Photo-catalytic. The major advantage of hematite is its ability to
form a 1-D type nanorods structure via self-assembly mechanism. This type
of nanostructure has a better electrical transport property and a band ga
p of 2.2 eV. Therefore\, due to these properties it is a promising candida
te for water splitting application. This work focuses on nanorods of hemat
ite for hydrogen production by splitting of water but the setback is the f
act that the band gap of these rods is limiting the application of it in w
ater splitting. This is due to the fact that water splitting requires a ba
nd gap of 2.46 eV with and without external bias. Therefore\, a blue shif
t of 0.3 to 0.6 eV on the band gap and simultaneous upward shift on the co
nduction edge would make hematite a good candidate.\n\nhttps://events.saip
.org.za/event/144/contributions/1369/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1369/
END:VEVENT
BEGIN:VEVENT
SUMMARY:THE EFFECT OF VARIABLE MICROWAVE POWER ON THE LOW-FIELD ABSORPTION
IN NANO NICKEL ADDED TO YBCO POWDER
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1370@events.saip.org.za
DESCRIPTION:Speakers: Fhulufhelo Nemangwele (University of Venda)\nMeasure
ment of microwave properties of high Tc superconductors (HTSC) has fundame
ntal physical and technological relevance. HTSC are granular in nature and
contain many Josephson junctions or weak links. We have measured the micr
owave response of NI-YBCO powder\, using low field dependent microwave abs
orption (LFDMA) technique. The existence of peaks in LFDMA is well-establi
shed while dependence of peak position (Hm) on temperature is not very dea
r. The origin of LFDMA in HTSC has been a subject of continued debate. The
model proposed by Dulcic et al.\, with modification explains the most of
the observations of LFDMA. The model is based on the microwave loss mechan
ism in the single representative resistively shunted Josephson junction.\n
\nhttps://events.saip.org.za/event/144/contributions/1370/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1370/
END:VEVENT
BEGIN:VEVENT
SUMMARY:High mass VBF Categorization for the four lepton H→ ZZ→ 4l fin
al state with the ATLAS detector
DTSTART;VALUE=DATE-TIME:20190711T094000Z
DTEND;VALUE=DATE-TIME:20190711T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1390@events.saip.org.za
DESCRIPTION:Speakers: Mzwandile Thabede (University of the Witwatersrand)\
nWe Categorize VBF-like events using cut-based approach for njets ≥ 2. T
his study focuses on the VBF signal optimization for the H→ZZ→4l chann
el and the separation of VBF events from the events produced via the gluon
-gluon Fusion (ggF) production mechanism. The study is based on the ATLAS
full Run2 Monte Carlo at the total luminosity of 140 fb-1. Major backgroun
d contribution is from the qq→ZZ→4l as well as the Electro-weak compon
ent of the ZZ backgound which is important in the VBF category. VBF select
ion efficiency and ggF rejection maps are used to find the optimal signal
selection in the VBF production category for four lepton channel.\n\nhttps
://events.saip.org.za/event/144/contributions/1390/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1390/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Higgs Production through Gluon Fusion via intermediate Top quark l
oop
DTSTART;VALUE=DATE-TIME:20190710T104000Z
DTEND;VALUE=DATE-TIME:20190710T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1372@events.saip.org.za
DESCRIPTION:Speakers: Sukanya Sinha (The University of Witwatersrand)\nBeg
inning with a brief discussion on the spontaneous symmetry breaking of glo
bal and local symmetries\, the amplitude for production of Higgs boson via
the most dominant channel\, i.e.\, gluon fusion\, has been calculated. Th
e expression for the amplitude in terms of general arbitrary top quark mas
ses give rise to some dilogarithmic integrals\, which can be difficult to
evaluate\, and hence\, the limit when mass of top quark >> mass of Higgs b
oson has been chosen. It is found out that even for cases in which the mas
s of the top quark is about 30% more than the mass of the Higgs boson\, th
e integral remains almost insensitive to the mass of the top quark\,i.e.\,
with changing top quark mass\, the value of the amplitude remains the sam
e. This validates the calculations done in the selected limit.\n\nhttps://
events.saip.org.za/event/144/contributions/1372/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1372/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Overview of photoemission spectroscopy as a tool for electronic st
ructure investigations of materials
DTSTART;VALUE=DATE-TIME:20190711T092000Z
DTEND;VALUE=DATE-TIME:20190711T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1373@events.saip.org.za
DESCRIPTION:Speakers: Emanuela Carleschi (Department of Physics\, Universi
ty of Johannesburg)\nInvestigating the electronic structure of solid mater
ials is a very powerful tool to get insights into the oxidation state\, co
mposition\, chemical bonding\, binding energies and correlation effects\,
as well as the low-energy electronic band structure and the Fermi surface
of these materials. Such investigations are carried out experimentally by
exploiting a technique named photoemission spectroscopy\, which gives acce
ss to the either the deep core levels\, in case of X-ray photoemission spe
ctroscopy\, or the low-energy valence band states\, in case of UV photoemi
ssion spectroscopy and angle resolved photoemission spectroscopy.\nIn this
lecture\, I will first talk about the basic theoretical principles of thi
s experimental technique\, namely the three-step model of photoemission in
solids\, the single-particle energy diagram\, conservation of energy and
momentum and matrix elements. I will then move on to discussing the featur
es of photoemission spectra that carry the relevant information on the pro
perties of solids\, such as spin-orbit splitting\, chemical shift\, peak l
ine shape and satellites. I will then conclude my presentation by presenti
ng a summary of recent interesting results\, which show that electronic st
ructure investigations find diversified applications in condensed matter p
hysics\, surface science\, nanotechnology\, semiconductor devices\, materi
als engineering\, chemistry\, catalysis\, water purification and geology.\
n\nhttps://events.saip.org.za/event/144/contributions/1373/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1373/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Non-repeating Open Quantum Walks
DTSTART;VALUE=DATE-TIME:20190710T130000Z
DTEND;VALUE=DATE-TIME:20190710T132000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1375@events.saip.org.za
DESCRIPTION:Speakers: Hazmatally Goolam Hossen (UKZN)\nA model of a non-re
peating quantum walk is formulated in 2D using the formalism of Open Quant
um Walks (OQWs) [1]. During the non-repeating quantum walk\, the particle
changes direction at every step and does not go to an already visited site
. To achieve this dynamics of the walker all visited sites are recorded us
ing a memory system. In the model which we developed “quantum coins'' ar
e composed of Kraus operators of the corresponding OQW. The non-repeating
OQW is implemented using the unraveling of the corresponding master equati
on. Quantum trajectories for various number of steps have been generated (
20-2000 steps of the walk). The distributions of non-repeating open quantu
m walks\, non-reversal open quantum walks [2] and open quantum walks are p
roduced using the same randomly generated coins (set of Kraus operators) a
nd compared. It is observed that the non-repeating open quantum walks have
the largest spread of all three.\n\n\n\n[1] S. Attal\, F. Petruccione\, C
. Sabot\, and I. Sinayskiy\, J. Stat. Phys. 147\, 832 (2012).\n\n\n[2] Y.H
. Goolam Hossen\, I. Sinayskiy and F. Petruccione\, Open Sys. & Inf. Dyn.
25\, 4 (2018)\n\n\nKeywords: Self-avoiding walks\, quantum walks\, open qu
antum system\n\nhttps://events.saip.org.za/event/144/contributions/1375/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1375/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Study of lattice defects in BaF2 using positron annihilation and X
-ray diffraction methods at elevated temperatures
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1377@events.saip.org.za
DESCRIPTION:Speakers: Thulani Jili (University of Zululand)\nWe utilized p
ositron annihilation technique in obtaining Doppler broadening spectra in
the temperature range 300 – 900 K. Theoretical approach utilizes the Loc
al Density and the Generalized Gradient Approximations that calculate the
Doppler broadening spectra in the temperature range. We found that the pos
itrons annihilating with barium valence electrons\, especially the 5p and
the 6s electrons\, contribute immensely in the electron-positron annihilat
ion momentum density. At 693 K\, the positron annihilation fraction due to
Ba-atom when anion Frenkel is created\, is found to be 84.44% compare to
15.56% for F-atom. We also noted that for F di-vacancy at 693 K\, the anni
hilation fraction due to 5p and 6s valence and core electrons in Ba increa
ses by 2.13% to 86.57%. The intensity of disordering of fluorine sub-struc
ture is found to increase non-linearly at a temperature from 580 K without
observing any appreciable conductivity. X-ray diffraction method provided
a lattice constant of 0.625 nm at 693 K through which an appreciable smal
l activity in the conductivity is first observed. This is demonstrated thr
ough the correlation between the lattice constants and the conductivity va
lues at elevated temperatures.\n\nhttps://events.saip.org.za/event/144/con
tributions/1377/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1377/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Inquiry based learning in Optics : Study of students’ understand
ing of image formed by a converging lens and concave mirror.
DTSTART;VALUE=DATE-TIME:20190710T120000Z
DTEND;VALUE=DATE-TIME:20190710T122000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1379@events.saip.org.za
DESCRIPTION:Speakers: Martin Tarisai Kudinha (CPUT)\nBoth the lens and mir
ror formulae have the same mathematical representation\, thus student assu
me same physical principles to explain image formation in lens and mirrors
. Although students tend to correctly apply the formulae in solving proble
ms on\nmirrors and lenses\, they usually experience significant difficulti
es and misconceptions regarding the formation of an image by a converging
lens or a concave mirror because of\ntheir inability to transfer informati
on from one domain to a new different situation. Traditional lecture metho
ds have shown to have limited effectiveness in improving student conceptua
l understanding in basic Physics courses. The purpose of this study was to
investigate students’ understanding of image formed by a converging mir
ror and converging lens using an inquiry based method\, a approach which i
s credited as a highly\neffective method of instruction and is gaining wor
ldwide recognition because it encourages students become co-creators of kn
owledge as active participants in the learning process. In\norder to achie
ve the objective of this investigation\, a pilot study was undertaken with
registered students studying Physics at a university of technology in SA.
The students were divided into two groups ( experimental and control) and
null hypotheses hypothesis were tested. Inquiry-based instructed students
performed significantly better than those the instructed by the tradition
al lecture method thus the inquiry based learning proved to be a more effe
ctive method than the later. \n\nKey words : converging lens\, image\, inq
uiry based learning\, lecture method\n\nhttps://events.saip.org.za/event/1
44/contributions/1379/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1379/
END:VEVENT
BEGIN:VEVENT
SUMMARY:An evaluation of the impact of scientific explanation model on pre
-service teachers’ understanding of basic concepts in electricity
DTSTART;VALUE=DATE-TIME:20190711T094000Z
DTEND;VALUE=DATE-TIME:20190711T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1380@events.saip.org.za
DESCRIPTION:Speakers: Mphiriseni Khwanda (University of Johannesburg)\nEle
ctricity as a topic is regarded as challenging worldwide because students
from different countries around the world are reported to have the same pa
ttern of learning difficulties in understanding electricity due to misconc
eptions associated with it. The literature on misconceptions suggested fur
ther research to determine if instructors are able to prescriptively addre
ss students’ misconceptions in such a way that learning is improved sign
ificantly and also if teachers are gathering insights into students’ pre
conceptions and thought processes. The understanding of students’ precon
ceptions and thought processes is believed to be helpful in planning for f
uture interventions. As an attempt to bridge the conceptual gap in student
s’ understanding of basic electric circuits\, literature advised univers
ity lectures to pay more attention into students’ misconceptions by deve
loping instructional strategies or materials that will enhance students’
understanding. In bridging the gap\, a two-tier test was developed guided
by selected designed principles adopted from knowledge building theory. T
he current study explored the impact of the scientific explanation model a
s an instructional strategy\, on bridging the conceptual gap about some ba
sic concepts of the DC circuit.\n\nhttps://events.saip.org.za/event/144/co
ntributions/1380/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1380/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Energy losses and propagation times of solar energetic particles
DTSTART;VALUE=DATE-TIME:20190709T094000Z
DTEND;VALUE=DATE-TIME:20190709T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1383@events.saip.org.za
DESCRIPTION:Speakers: Jabus van den Berg (North West University)\nThe focu
sed transport of solar energetic particles has received increasingly more
interest in the last couple of years due to upcoming missions to the Sun.
Stochastic differential equations offer a numerically robust way to model
solar energetic particle events\, but very few models exist which utilize
the full capability of this approach. A step is taken towards this goal by
solving the focused transport equation in the spatial dimension along the
Parker magnetic field with stochastic differential equations. This model
includes energy losses and can be used to study propagation times\, topics
which are somewhat unexplored within modelling due to limitations of the
numerical schemes used. The effects of solar wind advection and energy los
ses upon observable characteristics of solar energetic particle events are
explored and it is shown that the neglect of these processes would predic
t incorrect event onset times and peak intensities. Short propagation time
s and little energy losses are found for high energy particles\, as expect
ed. It is found that the average propagation time can be described by the
diffusion approximation for cosmic rays\, while an improved expression is
derived for the average energy loss.\n\nhttps://events.saip.org.za/event/1
44/contributions/1383/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1383/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Studies on Isolation efficiency scale factors using the Tag and Pr
obe method in the H→ZZ→4l channel for the ATLAS detector
DTSTART;VALUE=DATE-TIME:20190711T092000Z
DTEND;VALUE=DATE-TIME:20190711T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1384@events.saip.org.za
DESCRIPTION:Speakers: Onesimo Mtintsilana (University of Witwatersrand)\nI
n this study\, isolation efficiency variations between data and simulation
are corrected so that the Monte Carlo (MC) describes the data as accurate
ly as possible. The corrections applied are translated into scale factors.
Differences between the MC simulation and the data arise not only because
of poor description of the selection efficiencies in the simulation\, but
also due to the fact that the small impurities in the samples have very d
ifferent efficiencies from the bulk. This affects the efficiency extractio
n from the mixed sample if their contribution in the data is not the same
as in the simulation. Results on the scale factors using the Tag and Probe
method will be presented. The Tag and Probe method relies on the stringen
t selection of one of the lepton pairs (named the tag) to ensure they were
correctly reconstructed and belong to the Z decay.\n\nhttps://events.saip
.org.za/event/144/contributions/1384/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1384/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Reliability testing and upgrade of a Low Voltage Power Supply desi
gn for the Front-End Electronics of the ATLAS Tile Calorimeter
DTSTART;VALUE=DATE-TIME:20190710T142000Z
DTEND;VALUE=DATE-TIME:20190710T144000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1386@events.saip.org.za
DESCRIPTION:Speakers: Edward Nkadimeng (University of the Witwatersrand)\n
We present the design of an upgraded switching power supply for the front-
end electronics of the ATLAS hadron TileCal (Tile Calorimeter) at the LHC.
The new design features significant improvements in noise\, improved faul
t detection\, and improved reliability\, while retaining the compact size\
, water-cooling\, output control\, and monitoring features. We discuss the
steps taken to test the quality of the new Tile Low Voltage Power Supplie
s\, using a new type of testing station which is developed at the Universi
ty of Witwatersrand\, and will build upon the previous generation of testi
ng stations used in the initial production of the TileCal system. This par
ticular testing station will power the next generation of upgraded hardwar
e in the TileCal system of ATLAS at CERN.\n\nhttps://events.saip.org.za/ev
ent/144/contributions/1386/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1386/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Search for a new heavy boson in bbyy channel with ATLAS detector
in pp at √ s = 13 TeV
DTSTART;VALUE=DATE-TIME:20190711T100000Z
DTEND;VALUE=DATE-TIME:20190711T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1387@events.saip.org.za
DESCRIPTION:Speakers: Esra Shrif (University of the Witwatersrand)\nWe sea
rch for a new heavy resonance in H→bbyy decay channel.\nThe range of the
heavy boson mass is between [180-1500] GeV. The\nanalysis uses proton-pro
ton collision data with an integrated luminosity of 140 fb−1 recorded at
a centre-of-mass energy of 13 TeV with the ATLAS detector. In this work\,
we discuss event selections and signal optimisation. In addition\, we com
pare data to state-of-the-art Monte Carlo simulation on the control region
.\n\nhttps://events.saip.org.za/event/144/contributions/1387/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1387/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The impact of the kelvin redefinition on temperature measurements
for meteorology and climatology
DTSTART;VALUE=DATE-TIME:20190711T084000Z
DTEND;VALUE=DATE-TIME:20190711T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1388@events.saip.org.za
DESCRIPTION:Speakers: Nonhlanhla Precious Maphaha (National Metrology Insi
tute of South Africa)\nAll calibrations of thermometers for meteorological
or climatological applications are based on the International Temperature
Scale of 1990\, ITS-90. Based on the best science available in 1990\, ITS
-90 specifies procedures which enable cost-effective calibration of thermo
meters worldwide. In this paper we discuss the impact for meteorology of t
wo recent developments: the forthcoming 2019 redefinition of the kelvin\,
and the emergence of techniques of primary thermometry that have revealed
small errors in ITS-90. \nThe kelvin redefinition. Currently\, the Interna
tional System Units\, the SI\, defines the kelvin (and the degree Celsius)
in terms of the temperature of the triple point of water\, which is assig
ned the exact value of 273.16 K (0.01 °C). From 2019\, the SI definitions
of these units will change such that the kelvin (and the degree Celsius)
will be defined in terms of the average amount of energy that the atoms an
d molecules of a substance possess at a given temperature. This will be ac
hieved by specifying an exact value of the Boltzmann constant\, kB\, in un
its of joules per kelvin. Thus after 2019\, measurements of temperature wi
ll become fundamentally measurements of the energy of molecular motion. Ho
wever\, because thermometers will continue to be calibrated according to t
he procedures specified in ITS-90\, this will have no immediate effect on
the practice of meteorology. \nErrors in ITS-90. Since 1990\, the primary
thermometry technique known as acoustic thermometry has improved to an ext
raordinary extent. Acoustic thermometry measurements are now capable of de
tecting errors in the primary thermometry used to construct ITS-90\, and h
ence in ITS-90 itself. Over the meteorological range these errors are smal
l but they are present in every calibrated thermometer on Earth. The error
s vary approximately linearly between ≈ +0.005 K at ~ +50 °C\, and ≈
-0.003 K at ~-30 °C. Errors of this magnitude are unlikely to concern met
eorologists\, but if there is in future a shift away from ITS-90 to a new
International Temperature Scale\, then the concomitant shifts in practical
temperature calibrations may be just detectable by homogenisation algorit
hms used in climate studies.\n\nhttps://events.saip.org.za/event/144/contr
ibutions/1388/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1388/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Understanding the J/Psi background in top quark events using proto
n-proton collision data at a centre-of-mass energy of 13 TeV in ATLAS
DTSTART;VALUE=DATE-TIME:20190709T092000Z
DTEND;VALUE=DATE-TIME:20190709T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1391@events.saip.org.za
DESCRIPTION:Speakers: Kevin Nicholas Barends (University of Cape Town)\nHi
gh precision measurements of the top quark mass have been widely sought af
ter since the discovery of the top quark. This mass is correlated with the
top quark's decay products and the best current measurements are predomin
antly limited by uncertainties related to the reconstruction of jets. Howe
ver\, there are top quark decay signatures which are largely independent o
f the aforementioned uncertainty but require large amounts of data as they
are produced at a much lower rate than the usual signatures. One of these
decay signatures include a J/Psi meson originating from a B-hadron. The A
TLAS detector cannot identify the exact origin of these J/Psi mesons and t
herefore\, background J/Psi mesons contribute and negatively impact the ma
ss measurement. However\, these background J/Psi contributions can be sepa
rated from signal J/Psi mesons by exploiting the mass of a J/Psi meson and
the unique displaced decay vertex feature of B-hadrons. This paper descri
bes a data-driven technique to determine the contributions from signal and
background J/Psi mesons and highlight kinematic regions which limit the c
ontamination of background J/Psi mesons in preparation for the large datas
et that will be available at the end of the next data-taking period.\n\nht
tps://events.saip.org.za/event/144/contributions/1391/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1391/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Structural\, thermodynamic\, electronic and mechanical properties
of MCO3 (M: Ca\, Mn\, Fe\, Co\, Ni) precursor materials for Li-
ion batteries
DTSTART;VALUE=DATE-TIME:20190709T084000Z
DTEND;VALUE=DATE-TIME:20190709T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1392@events.saip.org.za
DESCRIPTION:Speakers: Mogahabo Morukuladi (UL)\nFirst-principles calculati
ons were carried out on the structural\, thermodynamic\, electronic and me
chanical properties of MCO3 precursor materials at 0 K to investigate thei
r possible application as cathodes in Li-ion batteries. Li-ion batteries a
re the most crucial power sources for portable electronic devices. However
\, their performance greatly depends on the cathode materials\, which serv
es as a host structure for Li ions. We have employed the plane-wave pseudo
potential method framed within the density functional theory (DFT) as impl
emented in the VASP code. The structural lattice parameters were calculate
d to 95% agreement with the experimental data\, ensuring robustness of the
approach employed. The calculated heats of formation are relatively low\,
suggesting thermodynamic stability. The electronic density of states show
ed that CaCO3 and MnCO3 are insulators\, whereas CoCO3 and NiCO3 are semic
onductors. Interestingly FeCO3 is predicted to be metallic\, suggesting g
ood electric conductivity. The phonon dispersion curves showed negative vi
brations in all MCO3 systems\, suggesting mechanical instability.\n\nhttp
s://events.saip.org.za/event/144/contributions/1392/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1392/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Heavy ion beam induced sputtering of thin film TCOs at MeV energie
s.
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1395@events.saip.org.za
DESCRIPTION:Speakers: Grant Tshepo Mafa (Tshwane University of Technology\
, Department of Physics\, P Bag X680\, Pretoria 001\,South Africa & iThemb
a LABS TAMS\, National Research Foundation\, P. Bag 11\, WITS 2050\, Johan
nesburg\, South Africa)\nHeavy ions in Ion Beam Analysis techniques (IBA)
such as MeV SIMS are sometimes limited in their application due to lack of
experimental fundamental ion-atom interaction data. We report on an inves
tigation carried out to measure heavy ion beam sputtering yields due to ir
radiation and irradiation effects on physical properties of Transparent Co
nducting Oxides (TCOs) at MeV energies. Measurements were carried out usin
g the Heavy Ion Elastic Recoil Detection Analysis (ERDA) and Rutherford Ba
ckscattering (RBS) techniques to determine electronic sputtering yields in
Indium Tin Oxide and Zinc Oxide films due to Si and Cu beams of MeV energ
ies. Results of measurements are discussed in the context of possible appl
ications in MeV SIMS analysis.\n\nhttps://events.saip.org.za/event/144/con
tributions/1395/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1395/
END:VEVENT
BEGIN:VEVENT
SUMMARY:DENSITY FUNCTIONAL THEORY STUDY OF COPPER ZINC TIN SULPHIDE (Cu2Zn
SnS4) DOPED WITH CALCIUM AND BARIUM
DTSTART;VALUE=DATE-TIME:20190709T080000Z
DTEND;VALUE=DATE-TIME:20190709T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1396@events.saip.org.za
DESCRIPTION:Speakers: thokozane mlotshwa (saip and nitherp)\nThe sun is th
e most important source of renewable energy today. Producing energy from s
unlight using cheap\, abundant and non-toxic materials is considered a maj
or challenge in the field of solar-electrical energy conversion. To harves
t the solar energy\, a thin film solar cell composed of the Cu2ZnSnS4 (CZT
S) semiconductor is a candidate which can harvest as much energy as possib
le. Its advantage is the optical direct band gap and high absorption coeff
icients. The structural\, electronic and optical properties of doped CZTS
will be calculated using the density functional theory (DFT) as implemente
d in the CASTEP codes. A new doping mechanism will be used to dope by the
alkali earth metals\, Calcium (Ca) and Barium (Ba). The dopants will be pl
aced in the structure rather than replacing one of the atoms. Doping using
the different elements is expected to improve the conversion efficiency o
f the CZTS based solar cells.\n\nhttps://events.saip.org.za/event/144/cont
ributions/1396/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1396/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Searches for Dark Matter via mono-higgs with the ATLAS detector.
DTSTART;VALUE=DATE-TIME:20190709T104000Z
DTEND;VALUE=DATE-TIME:20190709T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1398@events.saip.org.za
DESCRIPTION:Speakers: Karabo Mdluli (University of the Witwatersrand)\nA s
earch for the dark matter in association with the Standard Model like Higg
s boson was performed using up to 37 fb^(-1) pp collision data collected b
y the ATLAS detector at the Large Hadron Collider during 2015–2016 are s
ummarised.\nIn high energy physics\, deep learning is used to increase the
sensitivity of physics analyses and provides a handle to evaluate the per
formance and potential for improvement of traditional physics algorithms.\
nWe use Multivariate Analysis methods to suppress the fake missing transve
rse energy\, using the Boosted Decision Tree we are able to enhance the re
gression performance of typically weak Multivariate Analysis methods for
the dark matter search. In the case of both boosted decision trees the use
of machine learning techniques is found to improve the background rejecti
on and the signal efficiency. Linear correlations between the resulting cl
assifiers and the substructure variables are also presented.\n\nhttps://ev
ents.saip.org.za/event/144/contributions/1398/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1398/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fast ion-acoustic soliton stopbands in plasmas with two-temperatur
e kappa-distributed electrons
DTSTART;VALUE=DATE-TIME:20190710T094000Z
DTEND;VALUE=DATE-TIME:20190710T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1399@events.saip.org.za
DESCRIPTION:Speakers: Shimul Maharaj (South African National Space Agency
(SANSA) Space Science)\nThe existence of stopbands\, which are ranges in s
peed where solitons \ncannot propagate was proposed for the very first tim
e in a study of fast ion-acoustic solitons by Nsengiyumva et al. [1] for a
plasma composed of cold ions\, warm (adiabatic) ions and Boltzmann electr
ons. We recall that the stopbands arise when the warm ion limiting curve
is double-valued in speed over a range of normalised cold ion density valu
es. The current study is a theoretical investigation of stopbands in a pla
sma with cold ions\, warm (adiabatic) ions and two-temperature kappa-distr
ibuted electrons\, having spectral indices κc and κh. The stopbands are
found to widen for decreasing values of κc (κh is fixed) or κh (κc is
fixed)\, until the warm ion limiting curve bifurcates into an upper and lo
wer branch. The stopbands disappear when the warm ion limiting curve becom
es single-valued over the range of cold ion densities for very low values
of the spectral index\, when the proportion of superthermal electrons is s
ignificant. The considered plasma model may be applied to the magnetospher
e of Saturn [2] where two-temperature electron populations which follow ka
ppa distributions exist.\n\n[1] F. Nsengiyumva\, M. A. Hellberg\, F. Verhe
est\, and R. L. Mace\, \nPhys. Plasmas 21\, 102301\, doi: 10.1063/1.489670
7 (2014). \n\n[2] P. Schippers\, M. Blanc\, N. André\, I. Dandouras\, G.
R. Lewis\, L. K. Gilbert\, A. M. Persoon\, N. Krupp\, D. A. Gurnett\, A. J
. Coates\, S. M. Krimigis\, D. T. Young\, and M. K. Dougherty\, \nJ. Geoph
ys. Res. 113\, A07208\,\ndoi: 10.1029/2008JA013098 (2008).\n\nhttps://even
ts.saip.org.za/event/144/contributions/1399/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1399/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mira Variables and the Extragalactic Distance Scale
DTSTART;VALUE=DATE-TIME:20190709T092000Z
DTEND;VALUE=DATE-TIME:20190709T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1400@events.saip.org.za
DESCRIPTION:Speakers: John Menzies (South African Astronomical Observatory
)\nInfrared observations of newly-discovered Mira variables in Local Group
galaxies have shown that they follow a tight period-luminosity relation t
hat can be used to determine a distance to any nearby galaxy found to harb
our such stars. This\npresentation will show the outcome of a campaign wit
h the IRSF telescope at Sutherland and consider the implications of the re
sult for the distance scale in the era of the James Webb Space Telescope d
ue to be launched in the near future.\n\nhttps://events.saip.org.za/event/
144/contributions/1400/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1400/
END:VEVENT
BEGIN:VEVENT
SUMMARY:THE SYNTHESIS AND CHARACTERIZATION OF TUNGSTEN OXIDE WO3 NANOSTRUC
TURES THIN FILMS FOR GAS SENSING APPLICATIONS
DTSTART;VALUE=DATE-TIME:20190710T092000Z
DTEND;VALUE=DATE-TIME:20190710T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1402@events.saip.org.za
DESCRIPTION:Speakers: Thokozani Mpanza (University of Zululand)\nTungsten
oxide (WO3) thin films for gas sensing have been successfully deposited us
ing reactive direct current (DC) magnetron sputtering at different deposit
ion temperatures (300 ºC\, 400 ºC and 500 ºC). The structural\, morphol
ogical properties\, thickness and composition have been investigated using
X-ray diffraction (XRD)\, scanning electron microscopy (SEM) and Rutherfo
rd backscattering spectrometry (RBS) techniques. To investigate the effect
of deposition temperature on the gas sensing properties of deposited thin
films on alumina substrates was conducted using the Kenosistec gas sensin
g unit. WO3 thin film deposited at 500 ºC exhibited a higher response whe
n sensing Nitrogen dioxide (NO2) at room temperature as compared to the th
in films prepared at 300 ºC and 400 ºC\, respectively. However\, as depo
sited WO3 thin films exhibited low sensitivity when sensing reducing gases
such as hydrogen (H2) and ammonia (NH3)\, which was an indication of good
selectivity properties of WO3 related sensors.\n\nhttps://events.saip.org
.za/event/144/contributions/1402/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1402/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Counter-electrojet occurrence as observed from C/NOFS satellite an
d ground-based magnetometer data over the African and American sectors
DTSTART;VALUE=DATE-TIME:20190711T094000Z
DTEND;VALUE=DATE-TIME:20190711T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1403@events.saip.org.za
DESCRIPTION:Speakers: John Bosco Habarulema (South African National Space
Agency)\nAn analysis of the counter-electrojet occurrence (CEJ) during 200
8-2014 is presented for the African and American sectors based on local da
ytime (0700-1700 LT) observations from the Communications and Navigation O
utage Forecasting System (C/NOFS) vertical ion plasma drift (equivalent to
vertical E × B at altitude of about 400 km) and ground-based magnetomete
rs. Using quiet time (Kp≤3) data\, differences and/or similarities betwe
en the two datasets with reference to local time and seasonal dependence a
re established. For the first time\, it is shown that C/NOFS satellite dat
a is consistent with magnetometer observations in identifying CEJ occurren
ces during all seasons\, although it depicts higher CEJ occurrence rate. W
ith respect to local time\, C/NOFS satellite also reveals more CEJ events
than magnetometer observations despite both datasets showing the similar t
rend in CEJ identification\n\nhttps://events.saip.org.za/event/144/contrib
utions/1403/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1403/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Corrosion Resistance of TiZrN Coatings on ZIRLO Exposed to High-Te
mperature Oxygen
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1404@events.saip.org.za
DESCRIPTION:Speakers: Hlanganani Nyembe (Centre for HRTEM\, Nelson Mandela
University)\nThe focus of this study is to determine the suitability of T
iZrN coatings as a means to enhance the oxidation resistance of zirconium-
alloy fuel claddings for light water nuclear reactors. The TiZrN coatings
were deposited onto flattened ZIRLO tube-sections with a cathodic arc vapo
ur deposition technique. The characterisation was performed using scanning
electron microscopy (SEM) and transmission electron microscopy (TEM) tech
niques in conjunction with energy dispersive X-ray spectroscopy (EDS). The
coatings have a thickness of ~3.8 µm and exhibited a single-phase solid
solution of Ti0.42Zr0.58N with a NaCl-type crystal structure and columnar
nanocrystals. On exposure to air for 0.5 h\, the coatings were effective i
n the protection of ZIRLO against corrosion from 300 to 600 °C. At 700 to
900 °C\, the TiZrN coatings oxidise completely and severe oxidation of t
he ZIRLO beneath was observed. The coatings provided no protection at temp
eratures above 600 °C and accelerated the oxidation rate of ZIRLO. The o
xidation behaviour of the coatings was also investigated at 500 °C in oxy
gen for 24 h. The results indicate that the oxidation rate of TiZrN coatin
gs is much higher than that of the uncoated ZIRLO and the degree depended
on the microstructure of the formed oxide layers. The TiZr – oxide on th
e coating surface is characterised by a porous microstructure which is ass
ociated with a higher oxidation rate exponent. The coatings provided prote
ction for ZIRLO against corrosion for 20 h as oxidation of the underlying
ZIRLO was not observed. The coatings acted as a barrier to block penetrati
on of oxygen ions into the ZIRLO beneath. The premature failure of coating
s which occurred after 24 h was accompanied by severe oxidation of the und
erlying ZIRLO.\n\nhttps://events.saip.org.za/event/144/contributions/1404/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1404/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Industry-Academia Collaborations – Case Study of Diamond Sorting
Industry
DTSTART;VALUE=DATE-TIME:20190712T100000Z
DTEND;VALUE=DATE-TIME:20190712T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1405@events.saip.org.za
DESCRIPTION:Speakers: Simon Connell (University of Johannesburg)\nhttps://
events.saip.org.za/event/144/contributions/1405/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1405/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Search for collective structures in 186Os
DTSTART;VALUE=DATE-TIME:20190710T104000Z
DTEND;VALUE=DATE-TIME:20190710T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1406@events.saip.org.za
DESCRIPTION:Speakers: Linda Mdletshe (iThemba Laboratory for Accelerator B
ased Sciences)\nhttps://events.saip.org.za/event/144/contributions/1406/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1406/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Developing Nuclear Forensics Signatures in the Southern African Re
gion: A case study of South Africa and Namibia
DTSTART;VALUE=DATE-TIME:20190710T100000Z
DTEND;VALUE=DATE-TIME:20190710T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1407@events.saip.org.za
DESCRIPTION:Speakers: Manny Mathuthu (North West University- Mafikeng)\nht
tps://events.saip.org.za/event/144/contributions/1407/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1407/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Angular correlation measurements with a segmented clover detector
DTSTART;VALUE=DATE-TIME:20190710T094000Z
DTEND;VALUE=DATE-TIME:20190710T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1408@events.saip.org.za
DESCRIPTION:Speakers: Sinegugu Happiness Mthembu (iThemba LABS)\nhttps://e
vents.saip.org.za/event/144/contributions/1408/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1408/
END:VEVENT
BEGIN:VEVENT
SUMMARY:New Collective Structures in the Z = 76 Stable Odd Neutron Nucleus
187Os
DTSTART;VALUE=DATE-TIME:20190710T102000Z
DTEND;VALUE=DATE-TIME:20190710T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1409@events.saip.org.za
DESCRIPTION:https://events.saip.org.za/event/144/contributions/1409/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1409/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Toxicity of Natural Radioactivity in Water Samples from a Gold Min
e in Gauteng Province\, South Africa
DTSTART;VALUE=DATE-TIME:20190710T130000Z
DTEND;VALUE=DATE-TIME:20190710T132000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1410@events.saip.org.za
DESCRIPTION:Speakers: Caspah Kamunda (North West University (Mafikeng))\nh
ttps://events.saip.org.za/event/144/contributions/1410/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1410/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Radioactivity assessment of Uranium Isotopes concentration in wate
r sources at and near selected formeruranium mines in the West-Rand area o
f Johannesburg
DTSTART;VALUE=DATE-TIME:20190710T122000Z
DTEND;VALUE=DATE-TIME:20190710T124000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1411@events.saip.org.za
DESCRIPTION:Speakers: Nthabiseng Sylvia Mohlala (University of Witwatersra
nd)\nhttps://events.saip.org.za/event/144/contributions/1411/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1411/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Design of a national indoor radon survey for South African Homes:
review of existing indoor radonconcentration data and associated measureme
nt techniques
DTSTART;VALUE=DATE-TIME:20190710T120000Z
DTEND;VALUE=DATE-TIME:20190710T122000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1412@events.saip.org.za
DESCRIPTION:Speakers: Abbey Maheso (Stellenbosch University)\nhttps://even
ts.saip.org.za/event/144/contributions/1412/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1412/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Study of total\, complete and incomplete fusions
DTSTART;VALUE=DATE-TIME:20190710T092000Z
DTEND;VALUE=DATE-TIME:20190710T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1413@events.saip.org.za
DESCRIPTION:Speakers: Bahati Mukeru (UNISA)\nhttps://events.saip.org.za/ev
ent/144/contributions/1413/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1413/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Determining the Radon Emanation Coefficient for soil sample.
DTSTART;VALUE=DATE-TIME:20190710T124000Z
DTEND;VALUE=DATE-TIME:20190710T130000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1414@events.saip.org.za
DESCRIPTION:Speakers: LEBOGANG PHEFO (UNIVERSITY OF ZULULAND)\nhttps://eve
nts.saip.org.za/event/144/contributions/1414/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1414/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Modelling instruction in ECP
DTSTART;VALUE=DATE-TIME:20190709T134000Z
DTEND;VALUE=DATE-TIME:20190709T140000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1415@events.saip.org.za
DESCRIPTION:Speakers: Ignatius John (Cape Peninsula University of Technolo
gy)\nThis paper describes the practice used in an Extended Curriculum Prog
ram (ECP)\, on DC circuits. ECP is a program to support the first-year uni
versity students\, who qualified for the entry but did not perform well in
the grade 12 national examination\, from under-performing rural community
schools in South Africa. In order to improve the performance of these stu
dents\, the traditional pedagogy replaced with the Modelling Instructions
(Hestenes\, 1987). \nModelling instruction (MI) focuses on student centere
d learning and the teacher acts as a facilitator. Students are trained as
scientists\; they construct\, validate and apply scientific models in a sp
ecific context. Students learn to predict\, design experiments and use mod
els in different situations. Throughout the modelling instruction the teac
her has a definite agenda and specific objectives for every class activity
: concepts and terminology to be introduced\, conclusions to be reached an
d misconceptions to be addressed. The teacher uses Socratic questions and
plays the role of a physics coach rather than a traditional teacher. To th
e students\, the skilled teacher is transparent\, appearing primarily as a
facilitator of student goals and agendas. This talk presents the pedagogy
used in the ECP curriculum and the effects of attitude of students toward
s the new approach.\nThe Aspects of Circuit Questionnaire (ACQ) (John & Al
lie\, 2017) is used to measure the effectiveness of the project and compar
ed with the traditional group.\n\nHestenes\, D. (1987). Toward a modeling
theory of physics instruction. American Journal of Physics\, 55(May)\, 440
–454. \nJohn\, I.\, & Allie\, S. (2017). DC circuits: I . Evidence for f
ine grained contextual dependence. European Journal of Physics\, 38(38).\n
\nhttps://events.saip.org.za/event/144/contributions/1415/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1415/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Investigating the effect of Co addition on the stability of B2 TiP
d system using DFT approach
DTSTART;VALUE=DATE-TIME:20190709T080000Z
DTEND;VALUE=DATE-TIME:20190709T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1416@events.saip.org.za
DESCRIPTION:Speakers: Ramogohlo Diale (University of Limpopo)\nThe TiPd al
loy exhibits thermoelastic martensitic phase transformation above 823 K an
d has potential for high-temperature shape memory applications. Previous s
tudies showed that this alloy is unstable displaying a negative C′ at ro
om temperature. In order to improve their properties\, the effects of part
ial substitution of Pd with Co are being investigated. The structural\, th
ermodynamic and elastic properties of TiPdCo alloys were simulated using f
irst-principle calculations within the generalized gradient approximation
based on density functional theory. The heat of formation increases with a
n increase in Co concentration\, indicating stability at various compositi
ons decrease. The independent elastic constants results revealed that stab
ility is attained at above 31 at. % Co in agreement with the phonon disper
sion curves. The calculated moduli confirm that alloying with Co effective
ly increases hardness and ductility in TiPd systems. These findings can ha
ve important implications for future materials design in aerospace industr
ies.\n\nhttps://events.saip.org.za/event/144/contributions/1416/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1416/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thermal performance analysis of novel alternative designs for para
bolic trough solar collector
DTSTART;VALUE=DATE-TIME:20190710T094000Z
DTEND;VALUE=DATE-TIME:20190710T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1451@events.saip.org.za
DESCRIPTION:Speakers: Khaled Mohamad (Witwatersrand University)\nThe solar
parabolic trough collector is amongst the most mature solar technologies
and becomes more cost-effective in recent years. We build on our previous
work on hot mirrors to study an absorber with a mirrored cavity. The cavit
y absorber for the parabolic trough receiver is designed to reflect solar
radiation back onto the absorber very efficiently\, which would otherwise
be lost. We built a RU in the laboratory to study the thermal performance
for different designs and we companied this study with a mathematical modu
le implemented on a simulation code. In this work\, the simulation and the
experiments show a good agreement\, validating the applicability of the c
ode and the proposed designs.\n\nhttps://events.saip.org.za/event/144/cont
ributions/1451/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1451/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nickel substituted Spinel-type zinc ferrite nanostructures prepare
d by microwave-assisted hydrothermal and their structural\, luminiscence a
nd gas sensing properties.
DTSTART;VALUE=DATE-TIME:20190711T092000Z
DTEND;VALUE=DATE-TIME:20190711T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1417@events.saip.org.za
DESCRIPTION:Speakers: Murendeni Nemufulwi (CSIR/UFS)\nVarious volatile org
anic compound (VOCs) gases are released from a wide range of products comm
only found in buildings resulting in indoor environmental pollution thus p
osing risks to human health. Much attention has been dedicated on developm
ent of spinel-type ferrites as gas sensors for detection of VOCs gases and
environmental monitoring. However\, the growing demand of highly responsi
ve\, selective and stable sensors still persists with the ever growing ind
ustrialization. In this work\, NixZn1-xFe2O4 (x = 0\, 0.1\, 0.3\, 0.4) na
nostructures were facilely prepared using microwave-assisted hydrothermal
technique followed by annealing at 500 °C. The effect of Ni substitution
on the structural and optical properties as well as specific surface area
was investigated through various characterization techniques including sca
nning electron microscopy (SEM)\, transmission electron microscopy (TEM)\,
X-ray diffraction (XRD)\, Brunauer–Emmett–Teller method\, and Photolu
minescence (PL) spectroscopy. Gas sensing performances of the ZnFe2O4 nano
structures were investigated for Acetone (C3H6O)\, Ethanol (C2H6O) methane
(CH4)\, carbon monoxide (CO)\, ammonia (NH3) and hydrogen (H2) gases at a
n optimized operating temperature of 120 °C.\n\nhttps://events.saip.org.z
a/event/144/contributions/1417/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1417/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Structural stability of some graphene oxide formations
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1419@events.saip.org.za
DESCRIPTION:Speakers: malesela walter Makgoba (University of Limpopo)\nThe
classical molecular dynamics was used to study various forms of graphene
oxide possible formations focusing mainly on the structural stability. The
structures were modelled at 300 K through the NVT Evans ensemble. Variati
ons of the total energy against the a-axis was explored in which the equil
ibrium properties were computed. Pair distribution functions as well as st
ructure factors were plotted. In the plots nearest neighbour distances and
their neighbouring number of atoms were obtained. To probe the mobility o
f oxygen in the systems\, the mean square displacements as well as the vel
ocity auto-correlations were plotted.\n\nhttps://events.saip.org.za/event/
144/contributions/1419/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1419/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Equilibrium and electronic properties of cubic copper sulphide
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1420@events.saip.org.za
DESCRIPTION:Speakers: Moshibudi Ramoshaba (University of Limpopo)\nThe equ
ilibrium and electronic properties of the cubic copper sulphide are invest
igated using the full-potential all electrons first principle density func
tional theory. Convincing equilibrium and electronic properties are obtain
ed using the GGA-PBEsol type exchange-correlation functional. Equilibrium
properties suggest the mechanical stability with elastic anisotropy. The e
lectronic band structure and the density of states suggest the material to
be semi-metallic with no energy bap.\n\nhttps://events.saip.org.za/event/
144/contributions/1420/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1420/
END:VEVENT
BEGIN:VEVENT
SUMMARY:FIRST-PRINCIPLE STUDIES ON THE STRUCTURAL\, ELECTRONIC AND MECHANI
CAL PROPERTIES OF L10 FePt
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1421@events.saip.org.za
DESCRIPTION:Speakers: NDANDULENI LESLEY LETHOLE (University of Limpopo)\nB
imetallic FePt nanoparticles with L10 structure have recently gained a lot
of consideration in practical applications for solid-state devices\, stor
age of ultra-high density magnetic data and biomedicine. This is due to th
eir high magnetic anisotropy\, high magnetocrystalline anisotropy\, high d
ensity\, and high coercivity. These materials are also considered as nanoc
atalysts for growth of carbon nanotubes of different chiralities. In order
gain knowledge on the structural\, electronic and mechanical properties o
f FePt\, we have carried out first-principle calculations to determine the
equilibrium lattice parameters\, band structure\, density of states\, ela
stic and vibrational properties 0 K. We have employed the plane-wave pseud
opotential method framed within the density functional Theory (DFT) as imp
lemented in VASP code. The Perdew−Burke−Ernzerhof (PBE) exchange-corre
lation functional is used with the Hubbard U-correction in the rotationall
y invariant form to address the self-interaction energy. The calculated eq
uilibrium lattice parameters were found to be in good agreement with the e
xperimental data to within 1 %\, validating the approach employed. The ele
ctronic band structure and density of states have shown that FePt is metal
lic\, due to the absence of energy band gap around the level. The bulk (20
9 GPa) and shear (261 GPa) moduli are relatively large\, suggesting high h
ardness and stiffness. Finally\, all elastic constants are positive and ph
onon dispersion curves shows no negative vibrations\, suggesting mechanica
l stability.\n\nhttps://events.saip.org.za/event/144/contributions/1421/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1421/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Perceptions of preservice teachers on the impact of the use of med
ia in the teaching and learning of Physical Science in schools
DTSTART;VALUE=DATE-TIME:20190711T100000Z
DTEND;VALUE=DATE-TIME:20190711T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1422@events.saip.org.za
DESCRIPTION:Speakers: Itumeleng Phage (Central university of Technology\,
Free State)\nTeaching and learning media is one form of teaching strategie
s also known as instructional media. Instructional media influence and aff
ect the way and how physical science is taught in schools. This survey stu
dy was conducted with pre-service teachers to investigate their perception
on the impact of instructional media in the teaching and learning of phys
ical science in schools. The participants were tasked to use teaching and
media strategy during their practice teaching period in schools and make o
bservation on that. They were then asked to deliberate\, on their return b
ack to campus\, what effect it had in their teaching of the subject or sub
ject content or topics. Initially they had mixed feeling about the concept
but finally they saw and agreed on its benefits after learning of how a
constructivist approach enhance learners’ understanding of the concept.
Though some say it consumed too much time of the lesson as learners tend t
o get excited and give their own views and argue about them\, it is good a
pproach to build on to what the learners already know and diffuse their mi
sconceptions and myths about the topic of the day. they also agreed that i
t applies in almost all the physical science topics. The approach just nee
ded a teacher-controlled environment to direct and limit the learners’ r
esponse without degrading them or depriving or suppressing them of their o
pinions. Consequently\, they agreed that learners learn best when they are
actively involved with the teacher facilitating the learning and explaini
ng the science concepts’ meaning and laws to arrive to the point or supp
ort their responses and allay their misconceptions. That means the teachin
g will be learner-centered and it helps the learner enjoy the lesson\, und
erstand concepts better and be interested in the subject and subject field
s and careers.\n\nhttps://events.saip.org.za/event/144/contributions/1422/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1422/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geometry and Electronic Properties of TinPt (n = 2−7) Clusters:
A Density Functional Theory Study
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1423@events.saip.org.za
DESCRIPTION:Speakers: Tshegofatso Michael Phaahla (University of Limpopo)\
nNanoscale clusters are considered a new phase of matter\, being the bridg
e between atoms and the bulk. They form part of extensive research due to
their various potential applications. There is considerable interest in th
e structures and properties of nanoscale clusters\, for example\, being us
ed as finely divided metal catalysts\, particularly for bimetallic cluster
s\, which offer the opportunity of tuning their activity and selectivity.
To date\, much work has been concentrated on small clusters of late transi
tion metals™\, namely\, noble and platinum metals\, while little has bee
n done for the early transition metals. Among TM clusters\, the reactivity
of titanium clusters is not fully understood due to the complexity of the
almost empty d band\, which provides unique bonding properties. In this s
tudy\, we investigate the structures and electronic properties of TinPt (n
= 2−7) clusters using density functional theory with the generalized gr
adient approximations (PBEsol and PBEsol0). The stability of the clusters
is also studied whereby the consistency of TinPt (n = 2-7) clusters with p
ure Tin (n = 2-7) clusters is considered. PBEsol was found to be overestim
ating the energies of the clusters.\n\nhttps://events.saip.org.za/event/14
4/contributions/1423/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1423/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Electronic and vibrational stability of M9S8 (M= Ir\, Rh\,) pentla
ndite-like structures: ab-initio study.
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1424@events.saip.org.za
DESCRIPTION:Speakers: Kgwajana Barnard Molala (UL)\nMetal sulphides are im
portant in many fields of science such as in metallurgy\, materials scienc
e\, geochemistry\, physics\, geology and chemistry. They serve as a sourc
e of the world’s precious metal-bearing minerals that are economically a
nd industrially significant. The Bushveld Complex has the largest concentr
ation of platinum group elements (PGEs) which are hosted in the base metal
sulphides (BMS). Pentlandite minerals are known to host such precious met
als\, either as solid solutions or as intergrowths. The existence of the P
GEs in pentlandite structure is a promising formation of new pentlandite-l
ike system. Thus there is a need to investigate the formation and stabilit
y of Ir9S8 and Rh9S8 in pentlandite-like structures. In this study ab-init
io density functional theory was used to investigate phase stabilities of
Ir9S8 and Rh9S8 pentlandite-like systems. The calculated elastic constant
of the systems were found to satisfy the mechanical stability of cubic sys
tems. Furthermore\, the heat of formations calculated were found to be ne
gative\, suggesting stability. The density of states of showed high stabil
ity in these systems as their Fermi energy falls into the pseudo-gap\, thi
s is in agreement with previous work. Moreover\, their phonon dispersion c
urves appeared to have no negative frequencies (soft modes)\, hence they a
re vibrational stable. These findings provided new knowledge that establis
hes the stability of the PGEs existence in pentlandite-like structure that
could be applicable in geological search of such phases.\n\nhttps://event
s.saip.org.za/event/144/contributions/1424/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1424/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Novel Fibre Bragg Grating Based All Optical OADM for Flexible Spec
trum Channel Reservation to Minimize Optical Cross Talk in WDM optical com
munication networks
DTSTART;VALUE=DATE-TIME:20190711T080000Z
DTEND;VALUE=DATE-TIME:20190711T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1426@events.saip.org.za
DESCRIPTION:Speakers: Dlamini Phumla (Nelson Mandela University)\nFlexible
spectrum has been proposed as a spectrally efficient networking technolog
y that effectively supports dynamically varying traffic demands. With the
Wavelength division multiplexing (WDM) optical networks ability to provide
increased capacity and efficient spectral resource utilization it can be
used to reserve channels to improve the quality of service in big data tra
nsmission. Optical add-drop multiplexer (OADM) is key components for add o
r drop wavelengths in high bit rate optical networks providing channel res
ervation as a mechanism for minimizing optical cross talk. In this work\,
a Fibre Bragg Grating based OADM was developed and functionality was exper
imentally demonstrated for an OADM configured from an FBG fibre and two ci
rculators. The vertical-cavity surface-emitting laser (VCSEL) was transmit
ted along the FBG engraved fibre as it can be tuned to lase at a wavelengt
h satisfying the Bragg Conditions. as the FBG is mainly used in sensor app
lication with less stringent requirements and in WDM systems the wavelengt
h is specified. The OADM performance measurement in a 25 km single mode fi
bre transmission line\, for 3 × 50 GHz channels wavelength division multi
plexing (WDM) network are reported. Results show that quality of service m
easured as Bit Error Rate (BER) of the proposed OADM channel reservation a
re lower and provided better performance than the existing WDM optical net
works. Furthermore\, the OADM fulfils the full width at half maximum (FWHM
) requirement for wavelength-division multiplexers (WDMs) according to the
International Telecommunication Union (i.e.\, FWHM < 0.4 nm).\n\nhttps://
events.saip.org.za/event/144/contributions/1426/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1426/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Magnetic and thermodynamic properties of the CeIrGa4 compound.
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1427@events.saip.org.za
DESCRIPTION:Speakers: P.M Mabidi (University of Johannesburg)\nA polycryst
alline sample of CeIrGa4 was prepared by an arc-melting technique using hi
gh-purity elemental constituent elements on a water-cooled copper plate un
der ultra-high pure argon atmosphere. This compound crystallizes in an ort
horhombic structure having the CeOsGa4 structure type belonging to the spa
ce group Pmma [1]. The sample was characterized by powder X-ray diffractio
n spectra which were refined using EXPO software\, where the lattice param
eters were found to be\; a = 9.456(3) Å\, b = 8.726 (2) Å and c = 7.547
(3) Å. In this work\, we study the physical and magnetic properties of th
is compound\, by heat capacity Cp(T)\, magnetization M(B)\, magnetic susce
ptibility χ(T) and electrical resistivity ρ(T). In the χ(T) results a C
urie-Weiss behaviour is followed above 50 K\, yielding an effective magnet
ic moment\, eff = 2.43 (2) B/mol-Ce\, which is close to the theoret
ical value for a free Ce3+ ion. This indicates that Ce3+ is the only magne
tic species in this compound. The paramagnetic Weiss temperature is p =
− 97.42 (2) K. The negative value of the Weiss temperature indicates th
at AFM interactions dominate. The magnetization shows typical paramagnetic
behaviour above 15 K\, where M is linear in B up to 8 T. However\, in the
T = 2 K isotherm a strong curvilinear behaviour is observed with a weak t
endency towards saturation and a steep rise in M at very small fields. Thi
s suggests a possible phase transition at very low T in this compound\, ev
en though our maximum field extracts only about 0.5 µB/Ce. The electrical
resistivity follows a ρ(T) ~ - log(T) behaviour below room temperature w
hich is in evidence of incoherent Kondo scattering effects in this compoun
d. A coherence or Kondo-lattice peak in ρ(T) develops at 90 K\, below whi
ch ρ decreases sharply. Above 2 K\, ρ(T) shows an anomalous near – lin
ear rise with temperature. The electronic specific heat\, Cp(T)/ T increas
es sharply below 10 K to reach a very high value of 600 mJ/mol.K2 at 2 K.
Our interpretation of the physics in CeIrGa4 is that this is a new exampl
e of a strongly correlated\, Kondo- lattice system. Future studies will fo
cus upon the low temperature region to search for a possible magnetic phas
e transition.\n\nReferences\n[1] M. Schlüter and W. Jeitschko\, Z. Anorg.
Allg. Chem. 628\, 628 (2002).\n\nhttps://events.saip.org.za/event/144/con
tributions/1427/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1427/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Growth of Silicon Carbide nanoparticles by thermal annealing of e-
beam deposited SiC/Pd thin films on c-Si substrate
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1429@events.saip.org.za
DESCRIPTION:Speakers: Mamogo Masenya (iThemba LABS/University of the Weste
rn Cape)\nSilicon Carbide (SiC) nanostructures are well known for their su
perior mechanical properties\, high thermal conductivity\, low thermal-exp
ansion coefficient\, good thermal-shock resistance\, chemical stability\,
and electron affinity which make them excellent candidates for work in har
sh environments [1]. Silicon carbide nanoparticles were grown via thermal
annealing of electron-beam deposited SiC/Pd thin films on crystalline sili
con (c-Si) substrate in vacuum at 800 0C. Scanning electron microscopy (SE
M) analysis of the as-deposited samples showed a uniform surface with smal
l grains while annealed films showed formation of islands that grew larger
as SiC thickness increased. Rutherford Backscattering Spectrometry (RBS)
and Energy-dispersive X-ray Spectroscopy (EDX) confirmed the presence of P
d\, Si\, C and O on the nano-islands. Fourier Transform Infrared Spectrosc
opy (FTIR) confirmed the 3C-SiC polytype.\n\nhttps://events.saip.org.za/ev
ent/144/contributions/1429/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1429/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effects of scattering parameters on charge-sign-dependent cosmic r
ay modulation.
DTSTART;VALUE=DATE-TIME:20190709T104000Z
DTEND;VALUE=DATE-TIME:20190709T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1430@events.saip.org.za
DESCRIPTION:Speakers: Mabedle Ngobeni (North West University)\nA comprehen
sive three-dimensional numerical drift model is used to compute the modula
tion of cosmic ray protons and anti-protons in the heliosphere. This is do
ne using the latest development in diffusion coefficients and cosmic ray i
nterstellar spectra. Emphasis is placed on the effects of the spatial and
rigidity dependence of the scattering parameter (ωτ)\, with ω the gyro-
frequency and τ a time scale defined by diffusive scattering\, on the dri
ft coefficient in the modulation of the mentioned species. A comparison of
the numerical modelling of the ratio of anti-protons to protons obtained
from different scenarios of ωτ is made over a solar cycle. This charge-s
ign-dependent modulation study should assist in establishing the amount of
drifts present at the Earth from solar minimum to maximum solar activity
in both magnetic cycles.\n\nhttps://events.saip.org.za/event/144/contribut
ions/1430/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1430/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Wonderful” Stars
DTSTART;VALUE=DATE-TIME:20190709T070000Z
DTEND;VALUE=DATE-TIME:20190709T080000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1431@events.saip.org.za
DESCRIPTION:Speakers: Patricia Whitelock (SAAO and UCT)\nAs stars like the
Sun age they undergo various dramatic changes. I will review what we know
about the last stage of stellar evolution that is powered by nuclear fusi
on\; know as the Asymptotic Giant Branch (AGB) phase. These extraordinary
stars can be intrinsically a thousand times brighter than the Sun\, and ar
e a major source of elements\, such as carbon\, that will form new planets
and even contribute to living creatures. The mass-loss process by which t
his material leaves the star is still poorly understood and is a focus of
new theory and a variety of observations using telescopes around the world
\, including those in South Africa\, and in space. A subgroup of these AGB
Stars\, the Miras (Latin for wonderful)\, are strongly variable\, regular
ly changing their visual light output by a factor as much as a thousand ti
mes\, on time scales ranging from one hundred to several thousand days. T
hese Miras also have properties that make them useful distance indicators\
, as observations from SAAO have demonstrated. They will potentially be i
mportant to future studies of the distance scale of the universe using the
James Webb Space Telescope and the next generation of extremely large gro
und-based telescopes.\n\nhttps://events.saip.org.za/event/144/contribution
s/1431/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1431/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Molecular Finite Element Density Functional Calculations employing
a Cusp Factor
DTSTART;VALUE=DATE-TIME:20190711T084000Z
DTEND;VALUE=DATE-TIME:20190711T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1432@events.saip.org.za
DESCRIPTION:Speakers: Moritz Braun (University of South Africa)\nFinite el
ement calculations have been performed in Cartesian coordinates using the
density functional approach\nfor a number of small molecules. In order to
aid convergence \nof the orbitals and total energies a suitable cusp fact
or was employed\, such that the resulting effective potential is non-singu
lar at all nuclei. The resulting total energies\nand densities were compa
red with those obtained using the Gaussian basis set package NWChem and
excellent agreement was found.\n\nhttps://events.saip.org.za/event/144/con
tributions/1432/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1432/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Study of structural damage in InGaN thin films due to Cu ion irrad
iation
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1433@events.saip.org.za
DESCRIPTION:Speakers: Joshua Khoele (iThemba LABS)\nThe influence of erbiu
m (Er+) ion irradiation on the structural modification in indium gallium n
itride (InGaN) thin films is studied by a combination of Rutherford backsc
attering spectrometry and channeling (RBS/C) and Raman spectroscopy. Epita
xial InGaN thin films\, with thicknesses of 20 nm\, grown on sapphire subs
trates with gallium nitride (GaN) buffer layers\, were irradiated with 170
keV Er+ ions at fluences of 1 x 1014\, 5 x 1014 and 1 x 1015 ions/cm2 at
room temperature. Structural properties of the films were investigated to
understand the effects of ion fluence on the irradiated thin films. RBS/C
results show that the calculated channelling minimum yield (Χmin) of the
films decreases with increasing ion fluence\, indicating that the crystall
ine quality of the InGaN thin films has improved. However\, at high fluenc
es RBS results exhibit sputtering of the InGaN layer. Results of this stud
y confirms that the previously observed re-crystallization in InGaN films
after ion beam irradiation [1] does not seem to depend on ion beam type or
energy and this may have beneficial implications for control of irradiati
on-induced improvement in InGaN thin films.\n\n[1] Madhuku\, M.\, Husnain\
, G.\, Ahmad\, I.\, Saleem\, H (2015): Irradiation-induced improvement in
crystalline quality of epitaxially grown InGaN thin films: A preliminary s
tudy. In: Proceedings of SAIP2014\, the 59th Annual Conference of the Sout
h African Institute of Physics\, edited by Chris Engelbrecht and Steven Ka
rataglidis (University of Johannesburg)\, 059-065.\n\nhttps://events.saip.
org.za/event/144/contributions/1433/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1433/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The effect of iron-particles on the electrical properties of n-GaS
b semiconductor material
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1434@events.saip.org.za
DESCRIPTION:Speakers: ABONGILE BELE (Sefako Makgatho Health Sciences Unive
rsity)\nSemiconductor material are characterized with the Schottky barrier
diodes (SBDs) as a basic structure. The study was conducted in order to c
heck the effect of iron particles on the electrical properties of Gallium
antimonide (GaSb) semiconductor material. Gallium Antimonide (GaSb) was im
planted with iron particles at various ion fluences ranging from 1.2 × 10
^15 to 1.2 × 10^17 cm^-2 while keeping the ion energy at 90 keV. Aluminiu
m (Al) Schottky barrier diodes (SBDs) were fabricated on Te-doped n-type G
allium Antimonide implanted with Fe+ at various fluences. Structural and e
lectrical properties have been investigated using the Raman spectroscopy a
nd I-V characterization. I-V measurements were performed for all the sampl
es. Raman spectroscopy shows a slight amorphization at fluences higher tha
n 1.2 x 10^15 cm^-2. The ideality factor (n) increased from 1.3 for the un
doped to 2.0 for 1.2 x 10^17 cm^-2. The barrier height was found to decrea
se from 0.735 eV for 1.2 x 10^17 cm^-2 to 0.653 eV for 1.2 x 10^17 cm^-2.
Generally\, the barrier height decreased with the increasing doping fluenc
es while the ideality factor increased with the increasing doping fluences
.\n\nhttps://events.saip.org.za/event/144/contributions/1434/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1434/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Extensions of THERMUS and its Applications in High Energy Particle
collisions
DTSTART;VALUE=DATE-TIME:20190709T094000Z
DTEND;VALUE=DATE-TIME:20190709T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1435@events.saip.org.za
DESCRIPTION:Speakers: DAWIT WORKU (Cape Peninsula University of Technology
)\, Jean Cleymans (University of Cape Town)\, Masimba Wellington Paradza (
UCT-CERN)\nWe have analyzed and discussed the hadronic abundances measured
in Au-Au\, p-p and Pb-Pb collisions at RHIC and LHC experiments using THE
RMUS. The results were obtained with two particle data tables\, and their
differences were explained. In particular\, the data from the RHIC experim
ent for Au-Au collisions at 130 GeV and 200 GeV were discussed and analyze
d. Similarly\, using the preliminary particle yield results of p-p collisi
ons at 0.9 TeV and 7 TeV as well as Pb-Pb collision at 2.76 TeV particle y
ield calculations were presented and the thermodynamic parameters were obt
ained from the fits.\n\nhttps://events.saip.org.za/event/144/contributions
/1435/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1435/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Computer simulation study of HF molecule adsorption on TiO2 rutile
surfaces
DTSTART;VALUE=DATE-TIME:20190710T120000Z
DTEND;VALUE=DATE-TIME:20190710T122000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1436@events.saip.org.za
DESCRIPTION:Speakers: DAVID TSHWANE (UNIVERSITY OF LIMPOPO/CSIR)\nHydroflu
oric acid is a candidate that can be used for etching metal oxide surface
due to its strong corrosive qualities\, However\, etching phenomenon is no
t well understood at the atomistic level. Investigation of HF interaction
with TiO2 rutile lower surface index is important for enhancing the etchin
g mechanism. Adsorption geometries and energies of HF on TiO2 rutile lower
surface index have therefore been investigated using density functional t
heory employing CASTEP code. It was found that HF chemically adsorbed on T
iO2 surfaces to form Ti-F bond and hydroxyl molecule. The surface (110) wa
s found to be more active in HF adsorption with lower adsorption energy an
d large charge transfer. In addition\, all these surfaces found to have hi
gher adsorption ability with the increasing number of HF molecules. Charge
analysis indicated that the dissociated of F atom attract electrons and i
nduced the work function due to the higher electronegativity of fluorine a
tom. This gives evidence that the adsorption of HF molecules on TiO2 surfa
ces is by chemisorption.\n\nhttps://events.saip.org.za/event/144/contribut
ions/1436/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1436/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Multi-instrument observations of atmospheric gravity waves over So
uth Africa.
DTSTART;VALUE=DATE-TIME:20190711T100000Z
DTEND;VALUE=DATE-TIME:20190711T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1437@events.saip.org.za
DESCRIPTION:Speakers: Zama Thobeka Katamzi-Joseph (South African National
Space Agency)\nAtmospheric gravity waves (AGWs) were observed over South A
frica during the recovery phases of coronal mass ejection (CME) and corota
ting interaction region (CIR) driven storms on 3 Aug 2016 and 31 Jan 2017
respectively. The characteristics of the AGWs are determined from observat
ions of intensity of the 630 nm airglow images\, global positioning system
s (GPS) total electron content (TEC) and SWARM electron density. The AGWs
were found to be propagating in the westerly directions with velocity of 9
5-162 m/s. Ionosonde ionograms indicate presence of spread F with observat
ions of AGWs which indicate Perkins instability played a role in the occur
rence of spread F with AGWs as the source of the instability.\n\nhttps://e
vents.saip.org.za/event/144/contributions/1437/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1437/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Observations of large-scale AGWs/TIDs during enhanced auroral acti
vity on 6 January 2014
DTSTART;VALUE=DATE-TIME:20190711T102000Z
DTEND;VALUE=DATE-TIME:20190711T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1438@events.saip.org.za
DESCRIPTION:Speakers: Zama Thobeka Katamzi-Joseph (South African National
Space Agency)\nObservations of large-scale atmospheric gravity waves/trave
ling ionospheric disturbances (AGWs/TIDs) from measurements of\nGlobal Pos
itioning System (GPS) total electron content (TEC) and Fabry–Perot Inter
ferometer’s (FPI’s) intensity of oxygen red line\nemission at 630 nm m
easurements over Svalbard on the night of 6 January 2014 are reported here
. TEC large-scale TIDs have primary periods ranging between 29 and 65 min
and propagate at a mean horizontal velocity of 749–761 m/s with azimuth
of 345–347 deg (which corresponds to poleward propagation direction). On
the other hand\, FPI large-scale AGWs have larger periods of 42–142 min
. These large-scale AGWs/TIDs were linked to enhanced auroral activity ide
ntified from co-located all-sky camera and IMAGE magnetometers. Similar pe
riods\, speed and poleward propagation were found for the all-sky camera (
60–97 min and 823 m/s) and the IMAGE magnetometers (32–53 min and 708
m/s) observations. Joule heating or/and particle precipitation as a result
of auroral energy injection were identified as likely generation mechanis
ms for these disturbances.\n\nhttps://events.saip.org.za/event/144/contrib
utions/1438/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1438/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Influence of Surface Kinetics and Induced Defects on Gas Sensing C
haracteristics of TiO2 nanostructures
DTSTART;VALUE=DATE-TIME:20190710T124000Z
DTEND;VALUE=DATE-TIME:20190710T130000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1439@events.saip.org.za
DESCRIPTION:Speakers: zamaswazi portia Tshabalala (DST/CSIR National Centr
e for Nano-Structured Materials\, Council for Scientific and Industrial Re
search\, Pretoria\, 0001\, South Africa)\nOver the years\, a lot of resear
chers have invested their attention and time in investigating and improvin
g chemical gas sensors as they have extensive applications in variety of f
ields such as air quality and environmental monitoring\, mining\, oil and
automobile industry\, food safety\, medical diagnosis and monitoring. Ther
e is a high demand for accurate\, fast\, stable and portable devices that
rises with technology advances and wide application fields. Enhanced sensi
tivity\, fast response\, total recovery\, and good selectivity are the mai
n characteristics of a good sensor. Titanium dioxide (TiO2) nanostructures
display great potential as gas sensor due to the presence of intrinsic po
int defects such as oxygen vacancies (Ov) and Ti interstitials (Tii) which
play a key role in enhancing the electrical\, chemical and optical proper
ties of the materials at the nanoscale. In this study\, we report on the u
ltra-high sensitive and selective thermally treated TiO2 nanostructures sy
nthesized via hydrothermal method. The findings displayed that as the anne
aling temperature increased\, crystallinity improved and phase totally tra
nsformed from amorphous\, anatase and pure rutile at 900 ˚C. Moreover the
morphology transforms from spherical flower-like nanostructures to rod-li
ke structure. BET surface area decreases with temperature however the poro
sity improves from mesoporous to microporous structures. XPS displayed imp
rovement in Ti3+ and F+ centres which contribute to gas sensing properties
towards volatile organic compounds (VOCs) hence we proposed sensing mecha
nism based on surface porosity and induced defects due to lattice expansio
n and contraction\n\nhttps://events.saip.org.za/event/144/contributions/14
39/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1439/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Energy management strategy for a remote area power system in rural
application
DTSTART;VALUE=DATE-TIME:20190710T084000Z
DTEND;VALUE=DATE-TIME:20190710T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1442@events.saip.org.za
DESCRIPTION:Speakers: Mnoneleli Govuzela (Nelson Mandela University)\nRemo
te area power systems that are based on renewable energy sources have prov
en to be an effective way of providing energy and improve livelihoods in r
emote rural areas. However\, the stochastic behaviour of renewable energy
sources (i.e. solar) and consumption by energy users leads to a mismatch b
etween generation and consumption. To mitigate these effects\, energy stor
age systems such as batteries are necessary to improve the system efficien
cy\, to store excess energy and to maintain the quality of the grid voltag
e during instances of power fluctuations. Therefore\, an optimal energy ma
nagement strategy for control and coordination of energy flows to maintain
healthy battery state of charge and improve its lifetime is required. \nA
grid-ready microgrid system that is configured for rapid deployment in ru
ral applications was developed and deployed at Nelson Mandela University O
utdoor Research Facility. The microgrid is powered by two photovoltaic (PV
) energy generators\, namely\, 1.57KW_p DC coupled monocrystalline silicon
and 3.2KW_p AC coupled polycrystalline silicon arrays. The balance of sys
tem consists of a 5000VA EasySolar bi-directional grid forming inverter p
lus MPPT charge controller from Victron Energy and a Sunny Boy 3000TL grid
-tied inverter (AC side) from SMA. The loads were prepared using programm
able loads connected to the EasySolar inverter distribution boards and con
trolled using a LabVIEW program. Literature based consumption profiles of
various levels (low\, medium and high) for a simulated village were devel
oped and tested on the microgrid.\nIn this paper\, preliminary results bef
ore fully simulating the village are presented on the monitoring of the mi
crogrid system’s ability to coordinate energy flows and maintain a healt
hy state of charge. An investigation of the effects of different consumpti
ons by typical household appliances on the microgrid was carried out durin
g sunny and cloudy days. The effectiveness of a user compliance-based ener
gy management strategy on maintaining grid integrity and a healthy state o
f charge was shown. In addition it has also been demonstrated that consist
ent remote monitoring is an effective way of managing system abuse by user
s.\n\nhttps://events.saip.org.za/event/144/contributions/1442/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1442/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Probing the DA and EoR Using Differential Observations of the SZE-
21cm
DTSTART;VALUE=DATE-TIME:20190709T104000Z
DTEND;VALUE=DATE-TIME:20190709T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1445@events.saip.org.za
DESCRIPTION:Speakers: Charles takalana (University of the Witwatersrand)\n
Probing the Dark ages (DA) and the Epoch of reionization (EoR)\, remains o
ne of the challenges facing modern cosmology. Numerous probes have been pr
oposed for exploration of these epochs and efforts are already under-way t
o detect signatures from them through observations of the 21cm cosmologica
l signal\, which corresponds to the 21cm transition of atomic hydrogen. Re
cently the EDGES collaboration claimed the detection of an absorption feat
ure of the global 21cm background signal centered at 78 MHz. When compared
to the standard 21cm models this feature appears at the correct frequency
(corresponding to a redshift range of z = (15-20)) but it is larger by a
factor of about two in amplitude. This work explores a recently proposed p
robe for the DA and EoR called the SZE-21cm\, we simulate differential obs
ervations towards and away galaxy clusters using the standard 21cm models.
The SZE-21cm presents advantages as it is a differential measure of the C
MB spectrum on and off an area of the sky containing the cosmic structure
under study\, it is as a result not affected by large-scale foregrounds in
observations at low-frequency. We show that observations of SZE-21cm can
be carried out with radio interferometers at frequencies between 50 MHz an
d 250 MHz and used to establish the global properties of the 21cm backgrou
nd spectrum. Noting that detection towards an individual cluster may be ch
allenging we demonstrate how computing the signal for multiple cluster sam
ples may be beneficial and propose the use of the SZE-21cm to test results
of current and upcoming experiments such as EDGES.\n\nhttps://events.saip
.org.za/event/144/contributions/1445/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1445/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quantum effects in the brain: a review of possible mechanisms
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1446@events.saip.org.za
DESCRIPTION:Speakers: Betony Adams (UKZN)\nIn the mid-1990s Hameroff and P
enrose proposed that quantum effects played a role in the nature of consci
ousness. The theory\, known as orchestrated objective reduction\, involves
proteins called microtubules\, which form part of the cytoskeleton of euk
aryotic cells. The theory was largely dismissed due to the fact that quant
um effects were thought unlikely to occur in biological systems\, which ar
e warm and wet and subject to decoherence. There has since been some evide
nce that biological systems may display quantum properties\, particularly
with respect to photosynthesis\, a process fundamental to life on earth. Q
uantum effects are also possibly at play in other biological processes suc
h as avian migration and olfaction. A more recent review of orchestrated o
bjective reduction outlines the experimental discovery of quantum coherenc
e in microtubules. The microtubule mechanism of quantum consciousness has
been joined by other theories of quantum cognition. In 2014 it was propose
d that general anaesthetic\, which switches off consciousness\, does this
through quantum means\, by causing changes in electron spin. A claim suppo
rted by experiments conducted on fruit flies. In 2015 Matthew Fisher outli
ned a mechanism for quantum computation in the brain using Posner molecule
s. Even more recently it has been shown that humans can sense magnetic fie
lds\, specifically that the human brain registers changes in earth strengt
h magnetic fields. It is possible that this effect might be mediated by th
e radical pair mechanism\, which has been investigated in the context of b
irds’ ability to utilise the earth’s magnetic field. This review aims
to investigate the current argument for the role of quantum effects in the
brain and how fully the theory is supported by convincing experimental ev
idence.\n\nhttps://events.saip.org.za/event/144/contributions/1446/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1446/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Room temperature adsorption of ammonia gas on zinc oxide and zinc
oxide–carbon nanostructures hybrid
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1447@events.saip.org.za
DESCRIPTION:Speakers: Puleng Mbuyisa (University of Zululand)\nThe absorpt
ion and desorption properties of ammonia gas on wurzite Zinc Oxide nanorod
s (ZnO NRs) and Zinc oxide-Carbon nanostructures (ZnO-CNs) hybrid where st
udies by fast acquisition x-ray photoemission spectroscopy (XPS). Chemires
istor sensors were made out of the ZnO NRs and ZnO-CNs hybrid and the sens
ors were exposed to ammonia gas at varies concentrations. Ammonia gas was
found to chemisorb on the hybrid structure by forming amine groups while o
n the NRs first physisorbed on the NRs surface and then dissociates by deh
ydrogenation to form chemisorbed decomposition NHX species. However the ch
emisorption was beam induced. The hybrid showed a ~ 4.5 higher sensitivity
to ammonia as compared to the ZnO NRs sensor but a slower recovery time.
The enhanced response and slow desorption of the ZnO-CNs hybrid can be att
ributed to the strong interaction of the hybrid with ammonia gas i.e the d
ifferent adsorption surface chemistry of C (chemisorption) and ZnO (physis
orption)\, and also to the increased surface to volume ratio of the CNDs.\
n\nhttps://events.saip.org.za/event/144/contributions/1447/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1447/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Coalescence Rate of Binary Neutron Stars and Black Hole-Neutro
n Star Systems
DTSTART;VALUE=DATE-TIME:20190710T082000Z
DTEND;VALUE=DATE-TIME:20190710T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1449@events.saip.org.za
DESCRIPTION:Speakers: Lutendo Nyadzani (Centre for Astro-Particle Physics
and Department of Physics\, University of Johannesburg\, Auckland Park 200
6\, South Africa)\nWhen two compact objects such as black holes\, white dw
arfs\, and neutron stars orbit a common centre of gravity\, they emit ener
gy in the form of gravitational waves (GW). The emission of GW will result
in the two objects coalescing. In this work\, we present the empirical ca
lculation of the coalescence rate of binary neutron stars. We have include
d new important results in our input physics in order to obtain more relia
ble estimates of the merging time-scales. We obtain the galactic rate usin
g a sample of known binary neutron stars and black holes in our galaxy. Th
e galactic rate is then extrapolated to the local universe.\n\nhttps://eve
nts.saip.org.za/event/144/contributions/1449/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1449/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Financing a Start-up and the Role of National Empowerment Fund in
Entrepreneurship Support in South Africa (NEF Rep)
DTSTART;VALUE=DATE-TIME:20190712T084000Z
DTEND;VALUE=DATE-TIME:20190712T092000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1450@events.saip.org.za
DESCRIPTION:https://events.saip.org.za/event/144/contributions/1450/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1450/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A 2+1D Monte Carlo generator for Jets in Heavy Ion Collisions
DTSTART;VALUE=DATE-TIME:20190710T084000Z
DTEND;VALUE=DATE-TIME:20190710T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1452@events.saip.org.za
DESCRIPTION:Speakers: Isobel Kolbe (University of Cape Town)\nAt the Large
Hadron Collider (LHC) in Geneva\, Switzerland and the Relativistic Heavy
Ion Collider (RHIC) at Brookhaven National Laboratory in the United States
\, it is widely believed that a new state of matter\, the Quark-Gluon Plas
ma (QGP)\, is routinely created by colliding the nuclei of heavy elements
such as gold or lead at nearly the speed of light. In head-on collisions b
etween heavy nucleii\, it is not uncommon to create tens of thousands of p
articles and the patterns they produce in the detectors can be very comple
x. In order to connect theoretical predictions to experimental measurement
s\, it is useful to create a computer algorithm which uses Monte Carlo tec
hniques to simulate the collisions. Such ‘Monte Carlo Generators (MCG)
’ may be programmed\nto contain much of the known physics\, but the deve
lopment of MCG’s in heavy ion physics has been hampered by the complexit
y of the interplay between different physics effects. Heavy-ion MCG’s ha
ve\, therefore\, often been forced to make simplifying assumptions. JEWEL
is one such an MCG\, attempting to focus primarily on the physics of highl
y energetic particles that traverse the QGP. We present an extension of JE
WEL which allows JEWEL to consider a dynamical background which evolves in
time and has no symmetry in the plain transverse to the beam direction. W
e also show preliminary results from a variety of analyses.\n\nhttps://eve
nts.saip.org.za/event/144/contributions/1452/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1452/
END:VEVENT
BEGIN:VEVENT
SUMMARY:DPCMM AGM
DTSTART;VALUE=DATE-TIME:20190711T100000Z
DTEND;VALUE=DATE-TIME:20190711T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1454@events.saip.org.za
DESCRIPTION:Speakers: Rudolph Erasmus (University of the Witwatersrand)\nh
ttps://events.saip.org.za/event/144/contributions/1454/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1454/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Real-time Performance Control and Monitoring for the PPr-TDAQ inte
gration of ATLAS Upgrades for HL-LHC
DTSTART;VALUE=DATE-TIME:20190710T140000Z
DTEND;VALUE=DATE-TIME:20190710T142000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1458@events.saip.org.za
DESCRIPTION:Speakers: Mpho Gift Doctor Gololo (Witwatersrand University)\n
A major upgrade to the High Luminosity Large Hardon Collider (HL-LHC)will
increase the instantaneous luminosity by a factor 5 compared to the LHC.A
complete redesign of the electronic system is required for new radiation l
ev-els\, data bandwidth as well as the clock distribution. A large amount
of dataacquired from the detector requires high-throughput electron
ics for accuratedata processing. The upgrade of this technology involve
s the integration of Pre-Processor (PPr) and the Trigger Data Acquis
ition (TDAQ) system for high-throughput electronics. The PPr module h
as already been designed that will beintegrated with other modules such as
Adavnced Telecommunication Comput-ing Architecture (ATCA) system and AMC
(Advanced Mezzanine Card) carrierfor the full operation of the high-throug
hput electronics. This paper presentsthe real-time control and performanc
e of the PPr-TDAQ integration using soft-ware and firmware mechanisms impl
emented on the PPr. The communicationwith the PPr is implemented through
the ATCA shell manager to monitor thehealth status of the system. The fin
al design will be capable to operate up to8 complete modules and will be c
omposed of an ATCA carrier with four AMCslots which will host the CPMs.\n\
nhttps://events.saip.org.za/event/144/contributions/1458/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1458/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A Deployable Modular Mini-Grid for Electrification in Rural Areas
DTSTART;VALUE=DATE-TIME:20190710T082000Z
DTEND;VALUE=DATE-TIME:20190710T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1459@events.saip.org.za
DESCRIPTION:Speakers: Ross Schultz (nmu)\nWith the challenge of supplying
electricity to rural regions in South Africa\, where the logistical cost o
f installing a utility line is not economically viable\, photovoltaics (PV
) for power generation offers a solution to rural electrification. However
\, pervious pilot projects executed by government and private institutes u
tilized only DC systems for electrification in typical “solar home syste
ms”. These systems only allowed for battery charging\, and in some cases
transporting of batteries between households and a charging station. In a
ddition\, the use of DC powered appliances is expensive\, and does not tru
ly allow for uninterrupted electrification. The deployment of the designed
modular hub units will effectively provide AC power to the households and
improve livelihoods of the residents.\nThis paper discusses the design an
d implementation of an experimental modular mini-grid for AC electrificati
on in remote rural areas. The mini-grid system comprises of AC and DC coup
led photovoltaic systems sized for optimal power generation. The heart of
the mini-grid is the deployable hub unit that comprise of a DC PV system c
oupled to the inverter system. These units can provide up to 4 households
at a local site. A network is created by coupling more of the hub units to
gether\, which in turn\, communicate with each other and manage the energy
flow to the connected households. The linking of this network to a larger
AC coupled PV system aids to increased generation capacity and meet highe
r instantaneous load draws. The DC and AC systems work together to meet th
e required loads and effectively charge the battery banks.\nThis paper dis
cusses the mini-grid configuration and uses the pilot installation at the
Nelson Mandela University study energy flow and consumption. This is achi
eved by using programmable loads that simulate the consumption profiles of
4 rural households that make up a mini-grid unit. The generation profile
information obtained is then used for design optimization and identify acc
eptable power use assignment for end users.\n\nhttps://events.saip.org.za/
event/144/contributions/1459/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1459/
END:VEVENT
BEGIN:VEVENT
SUMMARY:APPLIED PHYSICS AGM
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1460@events.saip.org.za
DESCRIPTION:Speakers: phil ferrer (wits)\nhttps://events.saip.org.za/event
/144/contributions/1460/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1460/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Exploration of intermediate phases that form during lithium and ox
ygen extraction from the Li2MnO3 nanoporous cathode material
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1461@events.saip.org.za
DESCRIPTION:Speakers: Tshidi Malibe (University of Limpopo)\nLi2MnO3 has b
een classified as an active intercalation host material for lithium ion ba
tteries (LIBs) due to its large specific capacity. However\, its degradati
on nature reported to be due to oxygen loss and phase transformation durin
g cycling hinders its practical application. Furthermore\, the mechanism b
ehind the degradation has not been fully understood. As such\, studying th
e crystal growth process of these intermediate phases during charging is o
f great significance. In this work the simultaneous removal of oxygen and
lithium from the nano-Li2MnO3 will be studied in a quest to explore the fo
rmation of different intermediate structures. Molecular dynamics simulatio
ns was used to carry out the spontaneous crystal growth of the nanoporous
structures. The NVE ensemble was used in amorphisation and NVT for recryst
allisation during the crystal growth. Our results reveal highly defective
structures which are vacancy driven\, and the atomic substitutions are not
ed in the layers. Furthermore\, the XRDs and microstructures reveal the fo
rmation of layered and spinel-type structures as the lithium and oxygen co
ntent decreased.\n\nhttps://events.saip.org.za/event/144/contributions/146
1/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1461/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effects of Gadolinium dopant on electrical characterization of p-t
ype Silicon diodes
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1462@events.saip.org.za
DESCRIPTION:Speakers: Thokozane Moses Sithole (University of South Africa)
\nSithole TM and Moloi SJ\nUniversity of South Africa\, Department of Phys
ics\, P.O. Box 392\, Pretoria 0003\,\nSouth Africa.\nEmail: sthokozanemose
s@gmail.com\n\nAbstract: The aim of this paper is to improve the radiation
-hardness of silicon diodes. The schottky diodes were fabricated on undope
d and gadolinium doped p-type silicon. The electrical properties of the di
odes were studied using the current-voltage (I-V) and capacitance-voltage
(C-V) techniques. The results show that the silicon diodes have become rel
axation-like after doping hence the device shows Ohmic behaviour. This is
in concurrence with the presence of the ‘midgap defect’ in gold and pl
atinum doped devices from literature [1-4]. Erbium and niobium doped silic
on have been found to have similar results as gold and platinum. Relaxatio
n material is radiation-hard since the effects of radiation on the device
are suppressed. From the preliminary results gadolinium doped silicon show
s Ohmic behaviour which has been found to enhance the performance of the d
iodes in radiation-hard particle detectors. \n\nKeywords: Silicon\, gadoli
nium doped diodes\, I-V and C-V\, radiation-hard.\n \nReferences: \n[1] Kw
on Y K\, Ishikawa T and Kuwano H J. Appl. Phys. 1987\; 61 1055.\n[2] Msima
nga M\, McPherson M and Theron C Radiation Physics and Chemistry 2004\; 71
733.\n[3] McPherson M\, Sloan T and Jones B K J. Phys. D: Appl. Phys. 199
7\; 30 3028.\n[4] Moloi S J and McPherson M Physica B 2009\; 404 3922.\n\n
https://events.saip.org.za/event/144/contributions/1462/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1462/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Elastic and Thermal properties of phase change materials (PCM): Sb
2Te3 and Ge1Sb4Te7
DTSTART;VALUE=DATE-TIME:20190709T104000Z
DTEND;VALUE=DATE-TIME:20190709T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1463@events.saip.org.za
DESCRIPTION:Speakers: Phuti Balty Tjale (School of Physics\, University of
the Witwatersrand\, Private Bag 3\, 2050 WITS)\nIntensive interest on Ge-
Sb-Te (GST) based alloys is driven by their outstanding electrical and opt
ical properties which makes them excellent candidates for universal nonvol
atile memory applications\, also known as the phase change random access m
emory (PCRAM). The operating principle of the PCM is based on the rapid it
erative reversible transition between two structural phases after a thresh
old voltage. However\, their thermal conductivity is critical to device pe
rformance since it determines the resistance drift during the cyclic joule
heating of the sandwiched active layer. Very few studies have been report
ed on the elastic and thermal properties of ternary alloys formed from GeT
e and Sb2Te3 building blocks. In this work\, thin films of Sb2Te3 and Ge1S
b4Te7 deposited by RF magnetron are investigated to establish the dependen
ce of acoustic hardening on Sb2Te3 rich phase change alloy. Using the meas
ured elastic properties and acoustic phonon velocities\, the dependence of
thermal conductivity on the Sb2Te3 fraction in Ge1Sb4Te7 by surface Brill
ouin scattering based on the minimum conductivity model is established.\n\
nhttps://events.saip.org.za/event/144/contributions/1463/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1463/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Migration behavior of palladium implanted into glassy carbon
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1464@events.saip.org.za
DESCRIPTION:Speakers: Tasabeeh Alabid Osman Jafer (University of Pretoria)
\nMigration behavior of palladium (Pd) in glassy carbon was investigated u
sing Rutherford backscattering spectrometry (RBS)\, scanning electron micr
oscopy (SEM) and Raman spectroscopy. Pd ions of 200 keV were implanted int
o glassy carbon samples to a fluence of 1×10^16 cm-2 at room temperature.
Some of the implanted samples were annealed in temperature ranging from 1
00 to 1000 oC in steps of 100 oC for 5 hours. Implantation of Pd amorphize
d Gc.\nDiffusion of Pd began after annealing at 400 oC and become more pro
nounced with increasing temperature. At 600 oC it was accompanied by 10% l
oss of Pd while at above 600 oC it was accompanied by loss and peak shift
towards the surface. From the peaks broadening the diffusion were estimate
d in the temperature range from 600 to 1000 oC.\n\nhttps://events.saip.org
.za/event/144/contributions/1464/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1464/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Observations of a kink-unstable coronal loop using DKIST/DL-NIRSP
and Hinode/EIS
DTSTART;VALUE=DATE-TIME:20190709T084000Z
DTEND;VALUE=DATE-TIME:20190709T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1477@events.saip.org.za
DESCRIPTION:Speakers: G. J. J. Botha (Northumbria University)\nA 3D non-er
uptive kink-unstable coronal flux rope is simulated by solving numerically
the nonlinear magnetohydrodynamic equations with parallel thermal conduct
ion. The time evolution from the initial unstable equilibrium is forward m
odelled by generating synthetic spectral intensity maps as observed by DKI
ST/DL-NIRSP and Hinode/EIS using the CHIANTI database. The predicted signa
tures of the new ground-based Daniel K Inouye Solar Telescope (DKIST) in t
he coronal off-limb mode of its Diffraction Limited Near Infrared Spectrop
olarimeter (DL-NIRSP) instrument are compared and contrasted with signatur
es from the Hinode satellite’s EUV Imaging Spectrometer (EIS). The reco
nstructed observations show detailed\, fine-scale structure and exhibit si
gnatures of wave propagation\, redistribution of heat\, flows\, and fine-s
cale bursts.\n\nhttps://events.saip.org.za/event/144/contributions/1477/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1477/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effect of swift heavy ion irradiation on the migration behavior of
strontium implanted into polycrystalline SiC
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1466@events.saip.org.za
DESCRIPTION:Speakers: Hesham Abdelbagi Ali Abdelbagi (University of Pretor
ia)\nThe influence of swift heavy ion (SHI) irradiation on the microstruct
ure and the strontium (Sr) migration behavior of Sr implanted into polycry
stalline SiC were investigated using Rutherford backscattering spectrometr
y (RBS)\, Raman spectroscopy and scanning electron microscopy (SEM). The a
s-implanted and SHIs irradiated samples were vacuum annealed from 1100 to
1500 oC in steps of 100 oC for 5 hours. Implantation of strontium (Sr) amo
rphized the SiC\, while SHIs irradiation of the as-implanted SiC resulted
in limited recrystallization of the initially amorphized SiC. Annealing at
1100 oC already caused recrystallization in both the irradiated and un-ir
radiated but implanted with Sr samples. At 1500 oC\, a carbon layer appear
ed on the surface of the irradiated and un-irradiated but implanted with S
r samples. This was due to the decomposition of the SiC and subsequent sub
limation of silicon leaving a free carbon layer on the surface. SHIs irrad
iation alone induced shift of the implanted Sr toward the surface. This it
may be due to the surface sputtering that caused by SHIs. Annealing the s
amples at 1400 oC caused a release of all implanted strontium in the SHIs
irradiated samples\, while 55% of implanted strontium was released in the
un-irradiated but implanted with Sr samples. The enhanced Sr releasing in
SHIs irradiated samples was explained in terms of the high number of pores
in the irradiated samples compared fewer pores in the un-irradiated but i
mplanted with Sr samples. The results show that more Sr was released in th
e irradiated SiC samples.\n\nhttps://events.saip.org.za/event/144/contribu
tions/1466/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1466/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Structural analysis of Ti/LiCl at different temperatures
DTSTART;VALUE=DATE-TIME:20190710T104000Z
DTEND;VALUE=DATE-TIME:20190710T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1467@events.saip.org.za
DESCRIPTION:Speakers: Andile Mazibuko (University of Limpopo)\nIn this stu
dy we explore an alternative way to maximize Ti production by using LiCl s
alt. We employed the DL_POLY code to understand the interaction of LiCl at
various temperatures in order to achieve Ti that has good properties at h
igh temperatures. The LiCl structure was validated using available experim
ental and ab initio structural data such as elastic constants. The molecul
ar dynamic results of LiCl show that the simulation used is a reliable mod
el of a bulk alkali halide and this model is sufficient to set an environm
ent that will allow to investigate the evolution of titanium. Furthermore\
, the RDF’s of the Ti/LiCl structure depict a change in the morphology o
f the system for all interactions as the temperature is increased. The res
ults of this study might give us more insight on the growth of titanium in
salt mediums and on whether this salt can possibly be used to maximize Ti
production.\n\nhttps://events.saip.org.za/event/144/contributions/1467/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1467/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Differential Privacy Mechanisms for Gentle Measurement
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1468@events.saip.org.za
DESCRIPTION:Speakers: Makhamisa Senekane (Department of Physics and Electr
onics\, National University of Lesotho\, Roma\, Lesotho)\nDifferential pri
vacy is a robust definition of privacy that provides mathematical guarante
es to participants in a statistical database that their privacy would not
be compromised. It has its roots in the field of theoretical computer scie
nce. It has since proven to be a golden standard of data privacy. Recently
\, the connection between this privacy framework and quantum information s
cience has been explored. In this work\, we analyze and explore the connec
tion between differential privacy and gentle measurement\, using two diffe
rential privacy mechanism\, namely\; Exponential and Poisson-Binomial mech
anisms. The results obtained from this work provide evidence for viability
of investigating the connection between differential privacy mechanisms a
nd gentle measurement.\n\nhttps://events.saip.org.za/event/144/contributio
ns/1468/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1468/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Theoretical modelling of a new class of anisotropic compact stella
r model compatible with observational data
DTSTART;VALUE=DATE-TIME:20190711T080000Z
DTEND;VALUE=DATE-TIME:20190711T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1471@events.saip.org.za
DESCRIPTION:Speakers: Shyam Das (P. D. Women's College\, Jalpaiguri\, Indi
a)\nIn this paper\, a physically motivated form of one of the metric poten
tial and a specific choice of the anisotropy has been utilized to obtain c
losed-form solutions of the Einstein field equation for a spherically symm
etric anisotropic matter distribution. This class of solution has been use
d to develop viable models for observed pulsars. The exterior spacetime is
assumed as described by the exterior Schwarzschild solution. The model pa
rameters have been determined from the smooth matching of the interior to
the exterior Schwarzschild spacetime metric and utilizing the condition th
at radial pressure is zero across the boundary. The physical acceptability
of the developed model has been examined in detail by making use of the c
urrent estimated mass and radius of a known pulsar namely\, 4U1820 − 30.
The gross physical nature of the observed pulsar has been analyzed graphi
cally. The stability of the model is also discussed given causality condit
ions\, adiabatic index and under the forces acting on the system. To show
that this model is compatible with observational data\, few more pulsars h
ave been considered\, and all the requirements of a realistic star are hig
hlighted. Also\, the mass-radius (M − R) relationship of compact stellar
objects analyzed.\n\nhttps://events.saip.org.za/event/144/contributions/1
471/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1471/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A non-minimal composite Higgs model
DTSTART;VALUE=DATE-TIME:20190710T094000Z
DTEND;VALUE=DATE-TIME:20190710T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1473@events.saip.org.za
DESCRIPTION:Speakers: Lara Mason (SA-CERN)\nComposite Higgs studies\, wher
e the Higgs boson emerges as a pseudo-Nambu-Goldstone boson after the brea
king of the global symmetry group\, present a BSM solution to issues such
as the hierarchy problem. In such models\, the Higgs is described as a bou
nd state of a confining "strong" force. Here\, we investigate the phenomen
ology of a model with a non-minimal group structure\, where the Yukawa cou
plings are generated through the partial compositeness mechanism. This lea
ds to a spectrum of composite fermion partners\, the lightest of which is
the top partner.\n\nhttps://events.saip.org.za/event/144/contributions/147
3/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1473/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Structural\, Mössbauer\, magnetic and optical studies of Sn0.2Fex
Cr1.8−xO3 nano oxides prepared by reflux and pressure reactor methods
DTSTART;VALUE=DATE-TIME:20190710T142000Z
DTEND;VALUE=DATE-TIME:20190710T144000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1475@events.saip.org.za
DESCRIPTION:Speakers: Nzundu Tony Nsio (University of Namibia)\nWe have in
vestigated the properties of Sn0.2FexCr1.8−xO3 synthesized directly from
high purity metal by reflux and by pressure reactor process. These alloys
series were synthesized at low reaction temperature of about 100 ℃ usin
g hydrothermal methods. XRD analysis for the samples synthesized in a stir
red pressure reactor and in a reflux indicate the basic corundum structure
for the compositions after annealing at 600 ℃. TEM experiment indicate
a similar trend for both methods of preparation with a particle size for s
amples prepared in a pressure reactor slightly reduced compared to that sy
nthesized in a reflux. No appreciable difference was observed on the magne
tic properties of the two sets of samples. Particle sizes and chemical dis
order are shown to play critical roles in influencing the properties of th
e nanomaterials. The 57Fe Mӧssbauer spectra measured at room temperature
are well fitted by two magnetic components that range from two sextets for
Fe-rich nanomaterials to two doublets for Cr-rich ones.\n\nhttps://events
.saip.org.za/event/144/contributions/1475/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1475/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Structural and optical studies of tin iron chromium nano oxides
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1476@events.saip.org.za
DESCRIPTION:Speakers: Didier Mbela Kalengay (University of Namibia)\nIn th
e present study\, we have synthesized Sn0.2Fe0.9Cr0.9O3 nano oxides. Singl
e phase corundum -like structure and nanophase structure of the as-synthes
ized sample were confirmed by X-ray diffraction (XRD) and by transmission
electron microscope (TEM). The results show that the produced powders have
grain size of approximately 32 nm. Using the result of the UV-Vis spectro
meter\, we were able to determine the energy band gaps of 3.1 and 5.2 eV\,
when nanoparticles diluted in iron standard and in deionised water respec
tively.\n\nhttps://events.saip.org.za/event/144/contributions/1476/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1476/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Onset of 2D magnetic reconnection in the solar photosphere\, chrom
osphere and corona
DTSTART;VALUE=DATE-TIME:20190709T082000Z
DTEND;VALUE=DATE-TIME:20190709T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1478@events.saip.org.za
DESCRIPTION:Speakers: G. J. J. Botha (Northumbria University\, UK)\n2D rec
onnection is studied numerically in the context of various atmospheric lay
ers in the Sun: the fully ionized coronal plasma\; the partially ionized c
hromospheric plasma\; the almost-neutral photospheric plasma. Numerical si
mulations solve the compressible\, resistive magnetohydrodynamic equations
\, with reconnection triggered by driving external flows perpendicularly t
owards an equilibrium Harris current sheet. The inflow velocity controls t
he rate of flux entering the reconnection region. In the corona the electr
ic field rises sharply (indicative of reconnection) for a range of velocit
y drivers. In the photosphere reconnection occurs only when the inflow app
roaches the local Alfven velocity. Ambipolar diffusion alters the structur
e of the current density in the chromosphere.\n\nhttps://events.saip.org.z
a/event/144/contributions/1478/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1478/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nanocrystalline Silicon Devices for Radiation Sensing Applications
DTSTART;VALUE=DATE-TIME:20190710T124000Z
DTEND;VALUE=DATE-TIME:20190710T130000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1479@events.saip.org.za
DESCRIPTION:Speakers: DUKE OEBA (University of South Africa)\nNanocrystall
ine silicon detectors show radiation sensing at a faster response and high
ratios of photo detectivity which are qualities that are desired for radi
ation detection. In this research\, nanocrystalline silicon was grown and
characterized to determine its structural\, morphological and elemental co
mposition. A comprehensive review of the temperature dependence of current
-voltage (I-V) measurements that were carried out on Schottky diodes fabri
cated on undoped and niobium-doped n-type nanocrystalline silicon. The I-V
measurements were carried out within a temperature range of 20K to 360K.
Additionally\, investigations were done on the temperature dependence of t
he saturation current\, the Schottky barrier height and the ideality facto
r. The results of this work are in agreement with those reported on the ex
isting literature. Niobium induces deep defect levels within the mid gap o
f nanocrystalline silicon material to act as generation-recombination cent
ers. The defects compensate charge carriers to turn the nanocrystalline si
licon into relaxation material. Radiation detectors fabricated from relaxa
tion materials are characterized by ohmic behavior and high resistivity du
e to recombination of charge carrier by the midgap levels. Thus\, the devi
ce can be used as a radiation- hard detector in a high energy physics expe
riments.\n\nhttps://events.saip.org.za/event/144/contributions/1479/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1479/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The interpretation of broadband data from radio pulsars
DTSTART;VALUE=DATE-TIME:20190710T082000Z
DTEND;VALUE=DATE-TIME:20190710T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1482@events.saip.org.za
DESCRIPTION:Speakers: Isabella Rammala (Rhodes university)\nProfiles from
radio pulsars typically show a strong dependence on observing frequency. T
his depends both on the intrinsic radio emission mechanism\, as well as th
e interaction of the radio waves with the interstellar medium (ISM) that l
ies between the pulsars and our detectors on Earth\, due mostly to the eff
ects of dispersion and scattering. The aim of our project is to study how
to best extract information on pulsar profiles and the ISM\, using the wid
e frequency bands that are typical of radio telescopes today. We make use
of radio pulsar emission models to simulate pulse profiles. Basic radio pu
lsar geometry is used\, assuming that pulsar emission comes from a set of
open magnetic-field lines above the neutron star’s surface\, with high f
requencies emitted in regions closer to the neutron star and low frequenci
es from high altitudes further up the field lines. Depending on the line-o
f-sight cut and the radio frequency of observation\, which are both chosen
for each simulation\, the generated profile may comprise of overlapping c
omponents that are approximated to first order as Gaussians. With this inf
ormation we simulate pulse profiles representing data from telescopes obse
rving at various centre frequency bands\, covering bands from 30 MHz up to
1.7 GHz\, and with a variety of corresponding bandwidths for each pulsar
beam model. The results show that intrinsic profile evolution with frequen
cy can be interpreted as an additional component to the dispersion measure
(DM)\, the frequency dependent delay of the radio emission normally assoc
iated with dispersion in the ISM. In addition\, this DM correction will be
frequency dependent\, unlike the ISM induced DM. We discuss the systemati
cs introduced to pulsar data due to this effect.\n\nhttps://events.saip.or
g.za/event/144/contributions/1482/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1482/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Material composition and thermal analysis of bunker gears used by
firefighters in the City of Johannesburg
DTSTART;VALUE=DATE-TIME:20190711T100000Z
DTEND;VALUE=DATE-TIME:20190711T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1484@events.saip.org.za
DESCRIPTION:Speakers: Vinvent Mokoana (Tshwane University of Technology an
d City of Johannesburg EMS)\nFirefighters are constantly exposed to open f
lames and extreme heated conditions during fires and as a result use firef
ighting protective clothing (bunker gear) for protection. Firefighting pro
tective clothing derives its heat withstanding strength from the flame ret
ardants added in the manufacturing process. However\, some flame retardant
s\, including chlorinated and brominated flame retardants\, have been foun
d to be harmful to humans and the environment. Five (5) new and three (3)
used bunker gears used in the City of Johannesburg were investigated and f
ound to contain brominated flame retardants (BFRs)\, particularly polybrom
inated flame retardants (PBDEs) and hexabromocyclododecane (HBCDD). X-ray
fluorescence (XRF) scanning measurements showed that all the samples conta
ined significant amount of BFRs. Bromine content in the XRF ranged from 44
4 to 20 367 µg/g. Gas Chromatography-Mass Spectrometer (GC-MS) was used t
o validate the XRF results. BFRs\, particularly PBDEs and HBCDD\, were det
ected in all samples with concentrations ranging from 261.61 to 1001.77 µ
g/g and 0.01 to 0.07 µg/g\, respectively. The flame retardants’ impact
on thermal performance of the garments was investigated using the Cone Cal
orimeter under 50 and 75 kW.m-2 external heat fluxes. Measured Cone Calori
meter parameters were used to model indices such as the fire growth rate (
FIGRA). The average FIGRA was found to be 1.88 ± 0.44 kW.s-1 (5 new bunke
r gears) and 2.63 ± 0.37 kW.s-1 (3 old/used bunker gears) for external ir
radiation flux of 50 kW.m-2. Smoke growth rate (SMOGRA) of the bunker gear
s were 3.12 ± 0.34 and 4.96 ± 0.59 m2.s-2\, respectively for new and use
d gears under 50 kW.m-2 irradiation and 13.26 ± 3.63 and 14.60 ± 2.37 m2
.s-2 under 75 kW.m-2 heat fluxes. Further links between the fire retardant
s and the measured thermal parameters will be presented.\n\nhttps://events
.saip.org.za/event/144/contributions/1484/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1484/
END:VEVENT
BEGIN:VEVENT
SUMMARY:SKA HCD Programme and Research Highlights:Dr Mthuthuzeli Zamxaka
DTSTART;VALUE=DATE-TIME:20190712T083000Z
DTEND;VALUE=DATE-TIME:20190712T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1485@events.saip.org.za
DESCRIPTION:https://events.saip.org.za/event/144/contributions/1485/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1485/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Solving differential equations of Quantum Mechanics in 1 D and 2
D using Sinc functions employing Python and Numpy.
DTSTART;VALUE=DATE-TIME:20190711T094000Z
DTEND;VALUE=DATE-TIME:20190711T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1486@events.saip.org.za
DESCRIPTION:Speakers: OBIAGELI LOVENDA EZENWACHUKWU (UNIVERSITY OF SOUTH A
FRICA (UNISA))\nThe Schroedinger equation in one and two dimensions is sol
ved using sinc functions\, applying the variational principle and employi
ng Python and Numpy. Our goal is to examine how the sinc function method
performs with respect to its convergence rate. The python codes are tes
ted with the quantum harmonic oscillator potential and Morse potential\, f
or which analytical solutions are available.\nIt is found that the method
converges quickly.\n\nhttps://events.saip.org.za/event/144/contributions/1
486/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1486/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Top-quark background estimation for physics Beyond Standard Model
in the dilepton and jets final state with the ATLAS detector
DTSTART;VALUE=DATE-TIME:20190711T080000Z
DTEND;VALUE=DATE-TIME:20190711T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1487@events.saip.org.za
DESCRIPTION:Speakers: Jeremiah Monnakgotla (University of the Witwatersran
d)\nThis analysis presents the top-quark background estimation for the $H\
\rightarrow Sh$ channel using the full Run-2 data\, corresponding to an in
tegrated luminosity of 139 fb$^{-1}$ of $pp$ collisions at $\\sqrt{s}=$13
TeV.$~$The final state for this analysis is formed by two oppositely-charg
ed leptons ($e^{\\pm}\\mu^{\\mp}\,\\mu^{\\pm}e^{\\mp}\,e^{\\pm}\\mu^{\\mp}
+ \\mu^{\\pm}e^{\\mp}$) and jets. In this analysis the dominant Standard M
odel background are the top-quark processes ($t\\bar{t}$ and $Wt$). The to
p control/validation regions are defined in the 1 b-jet and 2 b-jets phase
space\, respectively. The construction of the top-quark validation region
is defined to correct the Monte Carlo mismodeling observed in the lepton
ic kinematics. Finally\, the derived normalization factor in the top-quark
control region is applied in the top-quark processes in both the control
region and the signal region.\n\nhttps://events.saip.org.za/event/144/cont
ributions/1487/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1487/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effect of annealing at different time interval on the structure\,
morphology and optical properties of MgAl2O4:0.1% Mn2+ nanophosphors
DTSTART;VALUE=DATE-TIME:20190710T100000Z
DTEND;VALUE=DATE-TIME:20190710T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1488@events.saip.org.za
DESCRIPTION:Speakers: Clinton Dlamini (SMU)\nIn this study\, manganese dop
ed magnesium aluminate nanopowders (MgAl2O4:0.1% Mn2+) were prepared by ci
trate sol-gel. The effect of annealing period/time (AP) at a fixed anneali
ng temperature (800 oC) and dopant concentration (0.1% Mn2+) on the struct
ure\, particle morphology and photoluminescence properties of the nanopowd
ers were investigated. X-ray powder diffraction (XRD) results showed that
the crystalline quality and crystallite sizes of the powders were not infl
uenced by varying the AP. Doping with 0.1% Mn2+ did not influence the crys
tal structure of the un-doped material. The scanning electron microscope (
SEM) images suggested that doping and AP does not influence the particle m
orphology of the nanopowders. Transition electron microscopy (TEM) image s
uggested that the crystallite sizes were in the nanoscale. Photoluminescen
ce (PL) results showed two emission peaks located at around 413 and 655 nm
respectively. The 413 nm emission peak is attributed to the defects level
within the un-doped material. On the other hand\, the 655 nm emission pea
k is attributed to the (4T1 → 6A1) transitions of Mn2+. The CIE coordina
tes results showed that the emission colour change from bluish to the viol
et region when increasing AP.\n\nhttps://events.saip.org.za/event/144/cont
ributions/1488/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1488/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Deep r-band imaging of CLoGS galaxy groups
DTSTART;VALUE=DATE-TIME:20190709T102000Z
DTEND;VALUE=DATE-TIME:20190709T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1496@events.saip.org.za
DESCRIPTION:Speakers: Sumari Hattingh (North-West University)\nGalaxy grou
ps offer an excellent opportunity to study the impact of galaxies on their
intergalactic medium (IGM)\, and vice versa\, as the galaxy's heating pro
cess effects are more visible due to the groups' lower density and mass co
mpared to clusters of galaxies. This project is part of an optical observ
ational campaign to observe the Complete Local-Volume Groups Sample (CLoGS
)\, which is a statistically-complete sample of 53 groups within 80 Mpc\,
with radio observations (GMRT & VLA)\, X-ray bands\, and sub-mm (IRAM-30m)
data already available for the entire sample. \n\nFor this project\, we a
re interested in the surface brightness profiles of the central\, dominant
elliptical galaxies in the groups\, to obtain stellar mass profiles and s
tructural parameters e.g. size of the cores of the galaxies. Here\, we pr
esent Multi-Gaussian Expansion (MGE) fits to the r-band (or equivalent) im
ages of 35 central group galaxies\, from archival Hubble Space Telescope (
HST) imaging and MegaCam / Canada-France-Hawaii Telescope (CFHT) r-band im
ages. For 12 groups\, we also present new CFHT MegaCam observations obtai
ned in 2018/2019.\n\nhttps://events.saip.org.za/event/144/contributions/14
96/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1496/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Light Dependent Energy Regulation in Phycobilisomes of Cyanobacter
ia
DTSTART;VALUE=DATE-TIME:20190709T102000Z
DTEND;VALUE=DATE-TIME:20190709T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1490@events.saip.org.za
DESCRIPTION:Speakers: Tesfaye Gonfa (University of Pretoria)\nSynechocysti
s PCC6803 (Synechocystis) are species of Cyanobacteria capable of oxygenic
photosynthesis. Phycobilisomes (PBs) are large peripheral light-harvestin
g antenna complexes located on the thylakoid membrane. PBs absorb light an
d transfer the energy to the reaction centers of Photosystem I and II. An
intact PB contains a total of 396 pigment-protein complexes. A single pigm
ent-protein complex is made of a phycocyanobilin pigment attached to a pol
ypeptide chain with a covalent bond. In Synechocystis\, the PBs have a hem
i-discoidal shape with six phycocyanin (PC) cylindrical rods radiating out
wards from an allophycocyanin (APC) core. The energy absorbed by pigment-p
rotein complexes of the PBs is transmitted to special core pigment complex
es\, ApcE and ApcD\, known as terminal emitters. ApcE is a pigmented core-
membrane linker that stabilizes the complete structure of the PBs. Recent
Single Molecule Spectroscopy (SMS) studies on PBs (Gwizdala et al.\, 2016\
; Krüger et al.\, 2019) have shown the existence of energy regulation rel
ated to blinking. Upon illumination\, the PBs switch reversibly between 'b
right' emissive\, unquenched states and 'dark' quenched states. As the int
ensity of excitation light increases\, the frequency of switching between
unquenched and quenched states increases. However\, the switching to quenc
hed states dominates at higher intensities and the PBs dissipate excess en
ergy as heat in a quenched state. The exact mechanisms underlying the ener
gy regulation are still unknown. Here we present the first single-molecule
investigation of PBs from mutant Synechocystis that lack the terminal emi
tter pigments ApcD or ApcE to reveal the origins of light-dependent energy
regulation.\n\nhttps://events.saip.org.za/event/144/contributions/1490/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1490/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effect of structural phase transition of GdCrO4 to GdCrO3 on magne
tism
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1491@events.saip.org.za
DESCRIPTION:Speakers: Bincy Susan Jacobs (University Of Johannesburg)\nRar
e-earth orthochromites (RCrO3) with orthorhombically distorted perovskite
(ABO3) structure exhibit a wealth of magnetic phenomena such as temperatur
e-induced magnetization reversal (TMR)\, spin-reorientation (SR)\, spin-fl
ipping (SF)\, and exchange-bias (EB). These occur as a result of magnetic
interactions among the cations such as Cr3+–Cr3+\, Cr3+–R3+ and R3+–
R3+\, where R is the rare earth element\, such as Gd\, Sm\, Tm [1]. Rare-e
arth orthochromites also form a class of magnetoelectric multiferroics whi
ch exhibit the coexistence of ferroelectric and magnetic orders [1]. Some
of these materials\, such as single crystalline GdCrO3\, exhibit a giant m
agnetic entropy change (ΔSm) at a reasonable magnetic field\, making it a
potential candidate for the application in magnetic refrigeration [2]. TM
R and EB have been reported in several RCrO3 compounds due to the competit
ion between the R3+ moment and the canted weak ferromagnetic (FM) componen
t of Cr3+ ions [3]. In the present work\, GdCrO4 samples were obtained usi
ng sol-gel technique [4]. X-ray diffraction technique was used to identify
the phase of the samples. The as synthesized samples were amorphous in na
ture showing a broad hump. Calcination of the samples at 630 °C led to Gd
CrO4 phase formation [5]. Further calcination of the samples at 1030 °C f
or 1 hour led to the decomposition of GdCrO4 into GdCrO3. Upon heat treatm
ent\, the Cr5+ oxidation state in the GdCrO4-zircon phase reduces to the r
elatively stable Cr3+ together with oxygen loss to stabilize the GdCrO3 pe
rovskite-structure [5]. The role of thermal decomposition of GdCrO4 to GdC
rO3 on crystal structure and magnetic transitions\, studied using XRD and
vibrating sample magnetometer (VSM)\, will be discussed. Magnetization mea
surements as a function of temperature (M-T) with different probing magnet
ic fields were carried out to locate the various magnetic transitions in t
he samples under different measurement protocols such as zero field cooled
(ZFC)\, field cool cooling (FCC) and field cool warming (FCW). Anomalies
in the M-T curves observed at T ≈ 10 K and T ≈ 170 K correspond to spi
n - flip and Néel transitions\, respectively. This is in agreement with p
reviously reported values [1]. The hysteresis loops measured across the tr
ansition temperatures validate the magnetic transitions as observed in the
M-T curves. \n\nReferences\n[1] S. Mahana\, U. Manju and D. Topwal\, J.
Phys. D: Appl. Phys. 51 (2018) 305002.\n[2] L. Yin\, J. Yang\, X. Kan\, W.
Song\, J. Dai and Y. Sun\, J. Appl. Phys. 117 (2015)133901.\n[3] B.B. Das
h and S. Ravi\, Solid State Sciences 83 (2018) 192.\n[4] P. Mohanty\, A.R.
E. Prinsloo\, B.P. Doyle\, E. Carleschi\, C.J. Sheppard\, AIP Advances 8 (
2018) 056424.\n[5] A. J. Dossantos-Garcıa\, E. Climent-Pascual\, J.M. Gal
lardo-Amores\, M. G. Rabie\, Y. Doi\, J. Romero de Paz\, B. Beuneu\, R. Sa
ez-Puche\, Journal of Solid State Chemistry 194 (2012) 119.\n\nhttps://eve
nts.saip.org.za/event/144/contributions/1491/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1491/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Discrimination of Signal-Background events with Supervised and Sem
i-Supervised Machine Learning in the search for bosons decaying to Z + γ
final state
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1492@events.saip.org.za
DESCRIPTION:Speakers: Nkateko Baloyi (University of the Witwatersrand)\nTh
e amount of data produced in the Large Hadron Collider requires modern tec
hniques to improve the processing\, classification and regression tasks. I
n this study\, we develop machine learning algorithms that can learn patte
rns in the data and lead to accurate discrimination of Signal and Backgrou
nd in the search for new bosons decaying into Z + γ final state. The tool
kit for multivariate analysis\, scikit-learn boosted decision trees and de
ep neural networks with tensorflow are employed in this study and compared
against each other to find the technique that best improves the quality o
f the signal in the search for new bosons.\n\nhttps://events.saip.org.za/e
vent/144/contributions/1492/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1492/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Correlation of Thermal Imaging and Current-Voltage characteristics
of PV module strings
DTSTART;VALUE=DATE-TIME:20190710T080000Z
DTEND;VALUE=DATE-TIME:20190710T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1493@events.saip.org.za
DESCRIPTION:Speakers: Monphias Vumbugwa (Nelson Mandela University)\nTherm
al infra-red (TIR) imaging is a fast and inexpensive technique for detecti
ng defects in Photovoltaic (PV) modules in large-scale solar PV plants. Ab
normalities in the current-voltage (I-V) curve of a module string can be i
ndicative of an underperforming module in the string. The physical locatio
n of this fault can only be identified by performing electrical measuremen
ts on each module in the string. Since it is not practical and feasible to
measure I-V curves for individual modules in a large PV plant\, correlati
ng the thermal signatures with electrical I-V parameters of module strings
makes it possible to identify and understand the effects of the thermal a
nomalies on the performance of modules in large PV plants. In this study c
opper-indium-gallium-deselenide (CIGS) and multi-crystalline Silicon (mc-S
i) modules in an operational PV system were investigated and TIR images co
rrelated with electrical performance. Thermal anomalies resulting from mod
ule defects were identified and their effect on performance determined. Re
sults show that a single defect such as a crack in one of the modules in a
string can result in a power loss greater than 8%. In addition to power l
oss\, defects that result in areas of increased temperature or “hotspots
” also pose a fire hazard on power plants. Furthermore\, this work has a
direct impact on the improvement of the operation and performance in PV p
lants.\n\nhttps://events.saip.org.za/event/144/contributions/1493/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1493/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Study of Microwave Power Effect and Anisotropic Effect in Ba0.
34K0.64Fe2As2 (BaK122) Superconducting Single Crystal Using Non-Resonant
Microwave Absorption Technique.
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1497@events.saip.org.za
DESCRIPTION:Speakers: Tshiwela caroline Ramashitja (Department of physics\
, University of South Africa \, Private Bag X6\, Florida 1710\, South Afri
ca)\nNon resonant microwave absorption technique at liquid helium temperat
ure has been used to study the microwave power effect and anisotropic effe
ct on the hysteresis loops of superconducting BaK122 single crystals measu
red at 9.4GHz below Tc (32 K). We have found a striking microwave power ef
fect on the hysteresis loops that were measured and a strong anisotropy wa
s found for the two distinct cases where magnetic field applied parallel a
nd perpendicular to the Iron Arsenide plane. We interpret the wide and nar
row hysteresis loops as due to the microwave power induced phase locking o
f several numbers of junctions into coherent groups and then the destructi
on of the phase locking by the applied DC field leading to the fluxon mot
ion \, which gives the loss in individual junctions belonging to these oth
erwise coherent groups.\n\nhttps://events.saip.org.za/event/144/contributi
ons/1497/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1497/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Response surface methodology optimization of adsorption and kineti
cs of Ca removal from aqueous solution using macadamia nutshell biochar
DTSTART;VALUE=DATE-TIME:20190711T094000Z
DTEND;VALUE=DATE-TIME:20190711T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1498@events.saip.org.za
DESCRIPTION:Speakers: Antoine Antoine F. Mulaba-Bafubiandi (University of
Johannesburg)\nResponse surface methodology optimization of adsorption and
kinetics of Ca removal from aqueous solution using macadamia nutshell bio
char\n\nAntoine F. Mulaba – Bafubiandi\, Reason Sithole and Sobowale Sun
day Samuel\n\nMineral Processing and Technology Research Center\, Departme
nt of Metallurgy\, School of Mining \, Metallurgy and Chemical Engineering
\, Faculty of Engineering and The Built Environment\, University of Johann
esburg\, PO BOX 17011 Doornfontein\, Johannesburg 2028\, South Africa.\n\n
Macadamia nutshells collected from Nelspruit (Mpumalanga) were pyrolyzed u
sing a tube furnace and microwave heating process. The produced biochar wa
s activated chemically with varying concentrations of HCL\, H2SO4\, H3PO4
and HNO3 to improve their adsorption ability. The optimised removal of cal
cium from a gold elution effluent is the focus of the project. This paper
reports on the use of response surface methodology to optimise the adsorpt
ion isotherm of the calcium removal from aqueous solutions generated to mi
mic the plant effluent. The kinetics study complements the paper. BET\, SE
M\, TGA FTIR\, XRF and XRD were utilised to characterise both the as-recei
ved nutshells\, the produced biochar and the Ca-loaded activated biochar.
The behaviour in an attrition test as well as their proximate analysis dat
a will be discussed in the light of the optimised Ca removal. The collecte
d Ca adsorption parameters will be validated using the response surface me
thodology.\n\nKeywords: Isotherms of adsorption\, biochar\, macadamia nuts
hells\, kinetics study\n\nhttps://events.saip.org.za/event/144/contributio
ns/1498/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1498/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simulation of the ATLAS ITk Strip Endcap Modules for Testbeam Reco
nstruction and Analysis
DTSTART;VALUE=DATE-TIME:20190709T094000Z
DTEND;VALUE=DATE-TIME:20190709T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1499@events.saip.org.za
DESCRIPTION:Speakers: Ryan Atkin (University of Cape Town)\nThe Large Hadr
on Collider (LHC) is planned to be upgraded to the High Luminosity LHC (HL
-LHC)\, which will increase the number of particles passing through the de
tectors. This will require the detectors to be upgraded in order to cope w
ith the large increase in data collection and radiation as well as improvi
ng the tracking and particle reconstruction in the higher occupancy enviro
nment. A major upgrade to the ATLAS detector will be replacing the current
Inner Detector (ID) with a fully silicon semiconductor based Inner Tracke
r (ITk). The sensors in the ITk strip forward region will use radial geome
tries\, however the current testbeam simulation and reconstruction package
s are designed with cartesian geometries. Presented is the work behind imp
lementing a radial geometry and charge propagation for one of the ITk stri
p forward sensors\, the R0 module\, in these testbeam software packages. T
he data from the EUDET testbeam telescope at DESY\, Hamburg\, and the simu
lated data both undergo the same reconstruction and a comparison between t
he two is then performed.\n\nhttps://events.saip.org.za/event/144/contribu
tions/1499/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1499/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Unraveling the combined influence of Oxygen vacancies and function
al pillared effect on scalable Ni-Co LDH based high performance supercapac
itor electrode materials properties
DTSTART;VALUE=DATE-TIME:20190711T080000Z
DTEND;VALUE=DATE-TIME:20190711T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1501@events.saip.org.za
DESCRIPTION:Speakers: GAYI NYONGOMBE EKAMBO (UNISA)\nThe increasing enviro
nmental challenges such as the rise of global warming and the depletion of
fossil fuels triggered the in studying various clean energy technologies.
Such\, including fuel cells\, solar\, wind\, geothermal and tidal power.
The energy produced by these systems requires an energy storage device\, f
or the energy to be used over a long period. Modern energy storage devices
include supercapacitors Lithium-ion batteries and molten salt\, just to
mention a few. Amongst them\, the supercapacitors have the highest energy
density\, long lifespan and allow safe operation. \n\nIn the present stud
y\, we have developed electrode material for supercapacitors by combining
both the pillar effect and oxygen vacancies via strategic annealing temper
ature of scalable NiCo-LDH resulting to the enhancement of supercapacitors
performance. \n\nthe as-obtained NiCo-LDH was successfully synthesized\,
having the diffraction peaks centered at 12.28°\, 24.67°\, 33°\, 36.41
° and 59°. The peaks were assigned relative to the standard card (JCPDS
no. 14-0191)\, and corresponded to (003)\, (006)\, (009)\, (012) and (110)
plane of hydrotalcite- like LDH.\n\nhttps://events.saip.org.za/event/144/
contributions/1501/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1501/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Title: Facile sensing characteristics of V2O5 nanostructured elect
rode from experimental and first principle approach.
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1502@events.saip.org.za
DESCRIPTION:Speakers: Amos Akande (Dept. of Physics\, University of Limpop
o\, DST/CSIR National Centre for Nano-Structured Materials\, P O Box 395\,
Pretoria 0001\, South Africa)\nTo build an efficient and reliable nano-ga
s sensing device\, critical study and analysis of the sensing material in
terms of the parameters such as sensitivity and selectivity is a key requi
rement. In this study\, experimental sensing performance of dopantless V2
O5 to NH3 gas and its density functional facile properties are presented.
The V2O5 sample material was synthesized from NH3VO4 via CVD at 400 ˚C un
der N2 flow for 12 h. Micro- and nano- structural and morphological charac
terizations revealed the material’s structure as polycrystalline V2O5 na
norods. The material was tested for gas sensing application under differen
t levels of NH3 flow. A linear sensitivity % with respect to the levels of
NH3 concentration was observed. Furthermore\, we also observed optimal se
nsor response at the operating temperature of 400 ˚C. Atomistic density
functional calculations of adsorption energies for different numbers of NH
3 gas molecules were performed on (001) and (110) surfaces of the V2O5 str
ucture. High adsorption was observed in the case of the perpendicular plan
e\; (001) surface compared with the parallel coordinated (110). The result
s suggest that\, although the orientation has almost equal probability in
(001) and (110)\, the (001) is more selective to NH3 than (110). Absolute
value of adsorption energy per molecule with respect to different numbers
of molecule does not only simulate the experimental sensitivity profile bu
t also establish the high selective ability of (001) surface to NH3.\n\nht
tps://events.saip.org.za/event/144/contributions/1502/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1502/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Perspectives on the Crystal Growth of Oxygen and Manganese Compens
ated Li-Rich Layered Nanoparticles
DTSTART;VALUE=DATE-TIME:20190712T094000Z
DTEND;VALUE=DATE-TIME:20190712T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1503@events.saip.org.za
DESCRIPTION:Speakers: Raesibe Sylvia Ledwaba (University of Limpopo)\nThe
charge compensation of both transition metal (Mn) and oxygen in the redox
reactions has driven possession of high specific capacity in Li-rich layer
ed oxide. Although these Li-rich electrodes could achieve higher reversibl
e capacity in energy storage systems due to the oxygen anion participating
in electrochemical reaction\, that is not the case because of the irrever
sible oxygen reaction that occurs during the initial charge cycle\, result
ing in structural instability due to oxygen evolution and phase transition
. This study shows the impact of transition metal and oxygen compensation
during nucleation and crystal growth of layered nanospherical particles.
Snapshots for the Mn-compensated nanosphere display a multi-grained crysta
l with grain boundaries and clusters of Li-O. On the contrary\, the oxygen
-compensated nanosphere resulted in single crystals with minimized oxygen
loss. Microstructures derived from the oxygen compensated structure illust
rate domination of layered LiMnO2 polymorph whilst the loss of oxygen in M
n-compensated nanostructure promotes formation of a spinel phase owing to
Mn3+ atoms migrating to the Li-layers. Understanding such reactions will c
ontribute immensely to the design of high capacity lithium ion batteries f
or large scale applications.\n\nhttps://events.saip.org.za/event/144/contr
ibutions/1503/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1503/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A re-look at the sequence of concepts in our curriculum
DTSTART;VALUE=DATE-TIME:20190709T152000Z
DTEND;VALUE=DATE-TIME:20190709T154000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1504@events.saip.org.za
DESCRIPTION:Speakers: Buyi Sondezi (University of Johannesburg)\, Paul Mol
efe (University of Johannesburg)\nThe concepts and topics in introductory
first-year physics textbooks are arranged in a certain manner of which has
been traditionally followed in delivering lecturers. These topics and con
cepts help to strengthen students’ critical thinking and problem-solving
skills while introducing them to many topics they will learn in more deta
ils in later modules in physics. Most often\, mechanics topics are follow
ing the traditional norm\, in fact\, this curriculum sequence has not been
altered in decades. After a number of observations and studies into the u
nderstanding and assimilation of some first year important topics such as
vectors\, there was a need to re-look at the lecturing sequence. Is there
a reason for this? There are many other questions that arise pertaining to
these mechanics topics in physics. These questions include: Does taking t
he mechanics' module sequence “out of order” have an impact on student
learning in physics? What topics should be taught first? When should thes
e topics be taught? This paper will address some of these questions by loo
king at students’ performance in the mechanics' module and qualitatively
using open-ended questionnaires.\n\nhttps://events.saip.org.za/event/144/
contributions/1504/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1504/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simulations in large N gauge theories with finite chemical potenti
al
DTSTART;VALUE=DATE-TIME:20190709T100000Z
DTEND;VALUE=DATE-TIME:20190709T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1505@events.saip.org.za
DESCRIPTION:Speakers: PAllab BAsu (Senior Lecturer)\nUsing complex Langevi
n dynamics and stochastic quantization we examine the phase structure of a
large N unitary matrix model at low temperature with finite quark chemica
l potential. This model is obtained as the low temperature effective theor
y of QCD with N number of colors and N_f number of quark flavors. We simul
ate several observables of the model\, including Polyakov lines and quark
number density\, for large N and N f . The action is manifestly complex an
d thus the dominant contributions to the path integral come from the space
of complexified gauge field configurations. For this reason\, the Polyako
v line eigenvalues lie off the unit circle and out in the complex plane. A
distinct feature of this model\, the occurrence of a series of Gross-Witt
en-Wadia transitions\, as a function of the quark chemical potential\, is
reproduced using complex Langevin simulations.\n\nhttps://events.saip.org.
za/event/144/contributions/1505/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1505/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Assessment of Remaining Life and Microstructure Degradation of Cre
ep Exposed High – Pressure Rotor Steels
DTSTART;VALUE=DATE-TIME:20190710T140000Z
DTEND;VALUE=DATE-TIME:20190710T142000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1506@events.saip.org.za
DESCRIPTION:Speakers: Hlanganani Nyembe (Centre for HRTEM\, Nelson Mandela
University)\nA remaining life assessment and microstructural ageing study
was performed on a high-pressure turbine rotor belonging to a 200 MW coal
-fired power plant unit. The rotor consists of 1CrMoV steel that operated
for more than 100 kh\, under a pressure of 10.55 MPa and a temperature of
520 °C. Core samples were removed from the high stressed geometry areas o
f the rotor by a plug sampling and hydro – pillar repair welding process
. Light microscopy was used to map out creep voids and cracks which form a
s a consequence of the reduction in creep-strength due to microstructural
degradation. Hardness testing was performed to estimate the extent of dama
ge undergone by the rotor. Two methods were used for estimating creep rema
ining life\; creep – cavitation model and a hardness based model. Furthe
rmore\, scanning electron microscopy and transmission electron microscopy
techniques were used to quantitatively evaluate the microstructural ageing
to corroborate the results for accumulated creep damage obtained based on
the creep void and hardness measurements.\n\nhttps://events.saip.org.za/e
vent/144/contributions/1506/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1506/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Long-term cosmic-ray modulation: a multi-decade approach
DTSTART;VALUE=DATE-TIME:20190709T100000Z
DTEND;VALUE=DATE-TIME:20190709T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1507@events.saip.org.za
DESCRIPTION:Speakers: KATLEGO MOLOTO (NORTH WEST UNIVERSITY)\nA simplified
ab initio approach is followed to model cosmic-ray (CR) modulation from f
irst principles\, using a novel time-dependent three-dimensional stochasti
c solver of the Parker transport equation\, taking into account the variou
s processes that modulate the intensities of these cosmic rays on their wa
y to the inner heliosphere\, and thus to Earth. This approach focuses on
the effects of temporal changes in both the larger scale quantities such a
s the heliospheric magnetic field\, heliospheric tilt angle and the solar
wind\, and in the small scale quantities such as the magnetic variance and
and correlation scales\, on computed CR intensity spectra. This study sys
tematically demonstrates how salient features in cosmic-ray modulation ari
se due to changes in these quantities\n\nhttps://events.saip.org.za/event/
144/contributions/1507/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1507/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Physics student teachers’ perceptions\, experiences and their as
sessment of the teacher education programme. A case study of one South Afr
ican University
DTSTART;VALUE=DATE-TIME:20190710T124000Z
DTEND;VALUE=DATE-TIME:20190710T130000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1508@events.saip.org.za
DESCRIPTION:Speakers: Paul Molefe (University of Johannesburg)\nAn investi
gation aimed at identifying and explaining physics student teachers’ per
ceptions\, experiences and their assessment of the teacher education progr
amme at one of the South African University was done. The main objectives
of the study included\, to assess the student teachers’ expectations whe
n joining the programme. Student teachers’ experiences as they progress
in their teaching programme were identified. Their views on how to improve
the teachers’ education program for physical science teachers are of gr
eat importance. \nA qualitative approach was used to collect data using op
en ended questionnaires and focus group discussion. The outcome of this st
udy shows that student teachers trainees do not receive adequate and appro
priate preparations from high school. Their home faculty does not effectiv
ely allow them to get a good training to teach physical science at high sc
hool level.\n\nhttps://events.saip.org.za/event/144/contributions/1508/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1508/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Materials for hybrid organic-inorganic devices
DTSTART;VALUE=DATE-TIME:20190708T114500Z
DTEND;VALUE=DATE-TIME:20190708T124500Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1513@events.saip.org.za
DESCRIPTION:https://events.saip.org.za/event/144/contributions/1513/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1513/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Reporting on the Southern African Reference Energy Yield Network S
ystem (SAREYNS)
DTSTART;VALUE=DATE-TIME:20190710T100000Z
DTEND;VALUE=DATE-TIME:20190710T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1514@events.saip.org.za
DESCRIPTION:Speakers: Ross Schultz (NMU)\nPhotovoltaics (PV) has been reco
gnized as one of the major renewable energy sources for utility-scale powe
r generation in South Africa that can potentially meet the shortfall in ge
neration\, which ESKOM currently cannot provide. However\, to assure the m
aximum energy yield for a given PV system within a deployed climatic regio
n\, long-term reliable performance data of the various technologies need t
o be obtained. This paper discusses the comparison of performance data fro
m various PV technologies operating within the Southern Africa Reference E
nergy Yield Network System (SAREYNS) and highlights their importance in de
cision making for PV system deployment. The analysis performed on the vari
ous datasets helps to determine the most suitable PV technology in their r
espective region in terms of actual energy yield and specific yield. Compa
ring these energy yield datasets within the network database\, a yield for
ecasting platform for both emerging and current operational PV plants is a
vailable. \nIn addition to forecasting\, the identification and tracking o
f progressive module degradation can be determined. Comparing these datase
ts\, the PV technologies showed specific preferences for the various regio
ns\, and under identical solar isolation\, the effect of spectral content
on the technology performance was also observed.\n\nhttps://events.saip.or
g.za/event/144/contributions/1514/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1514/
END:VEVENT
BEGIN:VEVENT
SUMMARY:African Astronomical Society & IAU GA2024
DTSTART;VALUE=DATE-TIME:20190712T080000Z
DTEND;VALUE=DATE-TIME:20190712T083000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1515@events.saip.org.za
DESCRIPTION:Speakers: Douglas Takalani Nemaungani (Acting Chief Director)\
nhttps://events.saip.org.za/event/144/contributions/1515/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1515/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Multi-wavelength study of large-scale outflows from the Circinus g
alaxy
DTSTART;VALUE=DATE-TIME:20190709T094000Z
DTEND;VALUE=DATE-TIME:20190709T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1516@events.saip.org.za
DESCRIPTION:Speakers: Rozeena Ebrahim (School of Physics\, University of t
he Witwatersrand\, Johannesburg)\nThe Circinus galaxy is a composite starb
urst/Seyfert galaxy which features 3 kpc scale radio lobe outflows along i
ts minor axis. It is located 4 Mpc away\, which makes it a unique target t
o study the physical nature of these outflows. Our task will be to investi
gate whether they originate from star formation or jets that resulted from
an active galactic core. The MeerKAT array can perform 20 arcsecond resol
ution radio observations\, which is in the observed range of the arcminute
lobes of the Circinus galaxy. In this work\, a multiwavelength analysis o
f the radio lobe structures will be conducted using MeerKAT and Fermi-LAT
data\, which will aid in the understanding of the origin of these structur
es. The results can then be compared to the star-formation driven Fermi bu
bbles in the Milky Way\, which have also been observed in both the gamma-r
ay and the radio bands to determine any possible connections to these stru
ctures.\n\nhttps://events.saip.org.za/event/144/contributions/1516/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1516/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The effects of drifting warm ions on fast ion-acoustic soliton sto
pbands
DTSTART;VALUE=DATE-TIME:20190710T100000Z
DTEND;VALUE=DATE-TIME:20190710T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1517@events.saip.org.za
DESCRIPTION:Speakers: Shimul Maharaj (South African National Space Agency
(SANSA) Space Science)\nThe effects of the inclusion of finite drift speed
for the warm ions on fast ion-acoustic soliton stopbands is theoretically
investigated \nin a plasma which is composed of cold ions\, warm (adiabat
ic) ions and Boltzmann electrons. The stopbands are intermediate ranges in
speed for which solitons cannot propagate\, yet soliton propagation is st
ill possible for lower and higher speeds. For warm ions which are drifting
along the direction of wave propagation\, increasing beam speed results i
n the widening of the stopbands over the range of cold ion densities. The
stopbands are not supported when the warm ion limiting curve is single-val
ued over the range of cold ion densities for a sufficiently large value of
the drift speed. Negative values for the beam speed for warm ions which a
re drifting anti-parallel to the direction of wave propagation\, have the
effect of narrowing the stopbands over the range of cold ion densities whe
n the drift speed increases. The considered plasma model may be applicable
to conditions in the solar wind where differences between the bulk speeds
of the heavier helium ions and protons can arise under some circumstances
[1]. \n\n[1] K. W. Ogilvie\, J. Geophys. Res. 80\, 1335-1338\, doi:10.102
9/JA080i010p01335 (1975).\n\nhttps://events.saip.org.za/event/144/contribu
tions/1517/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1517/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Opacities to very high energy gamma rays in the blazar jets
DTSTART;VALUE=DATE-TIME:20190710T094000Z
DTEND;VALUE=DATE-TIME:20190710T100000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1538@events.saip.org.za
DESCRIPTION:Speakers: Mfuphi Ntshatsha (University of Johannesburg)\nSome
of the brightest\, in electromagnetic radiation\, objects in the universe
are surprisingly not only stars but galaxies. Active galaxies\, at their c
ore\, have supermassive black holes which accelerate charged particles alo
ng an axis. The acceleration of these particles results in various emissio
n processes. The emission is propagated in jets whose cones lie along this
axis and is observable across the entire electromagnetic spectrum at rela
tively high intensities. We present here the attenuation\, through photon-
photon pair production\, of the high energy radiation (gamma-rays) of quas
ars as it propagates through its own low-energy ambient radiation gas (the
so-called broad-line region)\, the cosmic x-ray background and the cosmic
microwave background.\n\nhttps://events.saip.org.za/event/144/contributio
ns/1538/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1538/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cosmic radiation and space exploration
DTSTART;VALUE=DATE-TIME:20190710T092000Z
DTEND;VALUE=DATE-TIME:20190710T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1518@events.saip.org.za
DESCRIPTION:Speakers: Du Toit Strauss (Centre for Space Research\, North-W
est University)\nWe live in an interesting time of space exploration\; NAS
A is planning to return to the moon in 2024 and a permanently crewed lunar
outpost also in the pipeline. This is part of a renewed drive to land the
first humans on Mars in the 2030's. Private companies\, such as SpaceX\,
also have such plans in place. A major obstacle to long-term crewed missio
ns outside the protective shielding provided by the Earth's magnetic field
and atmosphere is\, however\, the potentially high level of exposure to g
alactic and solar cosmic rays. Here\, we discuss the origin and levels of
radiation at and above aviation altitudes\, as well as the potential dange
rs that astronauts experience as a result of varying ionizing radiation le
vels in interplanetary space. We will discuss our current efforts in forec
asting any enhanced levels of radiation produced during solar transient ev
ents\, including forecasting of the related dosimetric quantities.\n\nhttp
s://events.saip.org.za/event/144/contributions/1518/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1518/
END:VEVENT
BEGIN:VEVENT
SUMMARY:First principle studies on lattice thermal conductivity and therm
oelectric properties of LiYSe2
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1519@events.saip.org.za
DESCRIPTION:Speakers: Elkana Rugut (University of the Witwatersrand)\nTher
moelectric materials can convert heat into electricity and thermoelectric
devices can play an important role in the efficient use of energy. In this
study\, we investigate structural\, dynamical and mechanical stability of
LiYSe2 alongside its lattice thermal conductivity and thermoelectric prop
erties for the first time. The ability of a material to be a applied as t
he active component in the design of a thermoelectric device is based on t
he magnitude of its figure of merit\, ZT\, which includes information on t
he lattice and electronic transport properties. Given the difficulties of
directly measuring ZT experimentally\, we computed its value within densit
y functional theory using linearized Boltzmann transport equations in a re
laxation time approximation.\n\nhttps://events.saip.org.za/event/144/contr
ibutions/1519/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1519/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effects of spin parameters variation on the structural and optical
properties of spin coated polyaniline thin films
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1522@events.saip.org.za
DESCRIPTION:Speakers: Ingrid Segola (Tshwane University of Techonology/iTh
emba LABS)\nIn this study\, polyaniline thin films of various thicknesses
on a silicon (Si) substrate were deposited by electrospinning polyaniline-
emeraldine base (PANI (EB)) solution obtained by mixing PANI with the solv
ent DMSO (Di-methyl sulphur dioxide). Different thicknesses of the films w
ere obtained by varying the spin coating time\, while uniformity was inves
tigated by varying spin coating speed. The constant flow of the solution w
as maintained at all times\, resulting in the constant dropping of the sol
ution on the substrate. Rutherford backscattering spectrometry (RBS) was u
sed to determine the thickness and stoichiometry of the films for the diff
erent spin times and speeds. The crystal structure investigation was done
using an X-ray diffractometer (XRD)\, while Fourier transmittance infrared
spectroscopy (FTIR) was used to measure the consistency of the molecular
structure and structural transformations of the thin films. UV-vis was use
d to measure the optical transmission of the thin films which resulted in
the evaluation of band gap using Swanepoel's envelope method for different
thicknesses.\n\nhttps://events.saip.org.za/event/144/contributions/1522/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1522/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Luminescence and structural properties of Fe3+ doped ZnAl2O4: the
influence of charge imbalance
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1523@events.saip.org.za
DESCRIPTION:Speakers: SIMON OGUGUA (UNIVERSITY OF THE FREE STATE)\nIntrodu
ction \nKeeping in mind that the unit cell of spinal ZnAl2O4 is made of te
trahedral and octahedral sites\, of which upon doping shows different char
acteristics. Zn2+ occupies the tetrahedral sites\, while Al3+ occupies the
octahedral sites. When doped with Fe3+\, ZnAl2O4 is characterized by two
broad emissions with maxima around 485 and 730 nm [1]. To maintain electri
cal neutrality\, charge balancing should be taking into consideration when
doping ZnAl2O4\, since charge imbalance can lead to charge defects within
the material\, which can create non-radiative luminescence centers in the
material. We have prepared sets of ZnAl2O4 doped Fe3+ phosphors. To inves
tigate the effect of charge imbalance on the luminescence properties of th
e phosphors\, Fe3+ was used to substitute Zn2+ in one instance and Al3+ in
another instance. The site occupancy of the Fe3+ ion was investigated. \n
\n Results \nThe two sets of phosphors are represented by the gener
al formula ZnAl(2-x) Fe_x^(3+)O4 (Fe3+ substituting Al3+) and Zn(1-x)Fe_x^
(3+)Al2O4 (Fe3+ substituting Zn2+). The structure\, morphology and the ele
mental compositions of the phosphors were determined using X-ray diffracti
on\, field emission scanning electron spectroscopy and energy dispersive X
-ray spectroscopy\, respectively. The elemental composition\, chemical and
electronic states of the phosphors were analyzed using X-ray photoelectro
n spectroscopy. Both photoluminescence (PL)\, and cathodoluminescence prop
erties of the phosphors were also studied. The luminescence studies showed
that the ZnAl(2-x) Fe_x^(3+)O4 phosphors have superior luminescence than
the Zn(1-x)Fe_x^(3+)Al2O4 phosphors\, as expected. The band gaps of the ph
osphors were determined from the diffuse reflectance data. \n\n3. Referenc
e\n[1] N. Pathak\, S.K. Gupta\, K. Sanyal\, M. Kumar\, R.M. Kadama and V.
Natarajan. Dalton Trans. 43 (2014) 9313.\n\nhttps://events.saip.org.za/eve
nt/144/contributions/1523/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1523/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Comparative study of machine learning techniques in the search for
dark matter candidates associated with missing transverse energy
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1539@events.saip.org.za
DESCRIPTION:Speakers: Audrey Thabang Magabe (University of the Witwatersra
nd)\nThe Large Hadron Collider generates experimental data that consists o
f signal and background events. In order to further analyse the data\, it
is highly desirable to optimally discriminate between signal and backgroun
d events. We conduct a comparative study between supervised and semi-super
vised machine learning techniques in classifying between signal\nand backg
round events in H → γγ + χ decay channel.\n\nhttps://events.saip.org.
za/event/144/contributions/1539/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1539/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Astronomical opportunities for HBU's
DTSTART;VALUE=DATE-TIME:20190710T080000Z
DTEND;VALUE=DATE-TIME:20190710T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1525@events.saip.org.za
DESCRIPTION:Speakers: Thulani Jili (University of Zululand)\nMore than two
decades after the birth of South Africa's democracy we find ourselves in
an exciting era for astronomy in South Africa. The MeerKAT and SALT telesc
opes are producing world class science\, the number of astronomers in the
country are steadily growing\, government funding is significant\, and hun
dreds of students are finding opportunities within the broad scientific an
d technical disciplines associated with flagship astronomy projects. Howev
er\, there is still a clear gap between those universities that are active
beneficiaries of South Africa's investment in astronomy\, and the many ot
her universities in the country. At a glance it is evident that South Afri
ca's Historically Black Universities (HBUs) have not reaped large benefit
from the astronomy field. Partly due to the pressing need for transformati
on within the astronomy field\, students from Physics Departments at HBUs
often feed into human capital development programmes\, taking potential sk
ills away from their home institutions. There is thus a clear need to buil
d stronger partnerships between the astronomy community and South Africa's
HBUs\, both in order to more effectively transform the demographics of th
e field\, and to build scientific human capacity that remains at and benef
its those institutions. The Office of Astronomy for Development (OAD) has
been working with the University of Zululand for several years to explore
how astronomy could bring benefit to the university\, primarily through th
e Physics Department. Initiatives include capacity development workshops\;
small telescope\, robotic telescope and Virtual Observatory training\; as
tronomy outreach\; and the potential development of new telescope site whi
ch would have a combined research\, training and community development pur
pose. The long term perspective is that such initiatives can be replicated
in HBUs in South Africa and universities across the African continent\, w
here there may be active Physics departments\, but minimal astronomy activ
ities.\n\nhttps://events.saip.org.za/event/144/contributions/1525/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1525/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Astrophysical Transients with MeerKAT and MeerLICHT
DTSTART;VALUE=DATE-TIME:20190709T084000Z
DTEND;VALUE=DATE-TIME:20190709T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1527@events.saip.org.za
DESCRIPTION:Speakers: Patrick Woudt (Department of Astronomy\, University
of Cape Town)\nIn July 2018\, MeerKAT was inaugurated and started its scie
nce mission. One of the 5-year legacy programs on MeerKAT is the ThunderKA
T large survey project which aims to find\, identify and understand high e
nergy astrophysical processes via their radio emission. This is achieved t
hrough a program of surveying and monitoring Galactic synchrotron transien
ts (X-ray binaries\, Cataclysmic variables\, Supernova and Gamma-ray burst
s). Out of the ThunderKAT collaboration emerged a novel concept of real-ti
me simultaneous radio and optical monitoring of the MeerKAT sky to fully c
haracterise radio transients discovered in the data stream. Thus a new opt
ical wide field telescope (MeerLICHT) was funded and constructed\, and ina
ugurated in Sutherland in May 2018. MeerLICHT will provide simultaneous ni
ght time optical data for all MeerKAT pointings. In this presentation we
will give an overview of some of the first scientific results from MeerKAT
and MeerLICHT related to astrophysical transients.\n\nhttps://events.saip
.org.za/event/144/contributions/1527/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1527/
END:VEVENT
BEGIN:VEVENT
SUMMARY:NUCLEAR PRP AGM
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T140500Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1528@events.saip.org.za
DESCRIPTION:Speakers: Bruce Mellado (University of the Witwatersrand)\nhtt
ps://events.saip.org.za/event/144/contributions/1528/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1528/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Theoretical Division AGM
DTSTART;VALUE=DATE-TIME:20190711T100000Z
DTEND;VALUE=DATE-TIME:20190711T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1529@events.saip.org.za
DESCRIPTION:Speakers: Kristian Müller-Nedebock (University of Stellenbosc
h)\nhttps://events.saip.org.za/event/144/contributions/1529/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1529/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fluka Monte Carlo simulation of gamma photon transport through a d
istillation column\, designed usingChemSep software
DTSTART;VALUE=DATE-TIME:20190710T080000Z
DTEND;VALUE=DATE-TIME:20190710T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1531@events.saip.org.za
DESCRIPTION:Speakers: Witness Chirume (National University of Science and
Technology)\nhttps://events.saip.org.za/event/144/contributions/1531/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1531/
END:VEVENT
BEGIN:VEVENT
SUMMARY:An overview of iThemba LABS cyclotrons and ion sources
DTSTART;VALUE=DATE-TIME:20190709T080000Z
DTEND;VALUE=DATE-TIME:20190709T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1532@events.saip.org.za
DESCRIPTION:Speakers: Muneer Sakildien (iThemba LABS)\nhttps://events.saip
.org.za/event/144/contributions/1532/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1532/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Production of metal ion beams with the iThemba LABS ECR ion source
DTSTART;VALUE=DATE-TIME:20190709T082000Z
DTEND;VALUE=DATE-TIME:20190709T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1533@events.saip.org.za
DESCRIPTION:Speakers: Joele Mira (iThemba LABS)\nhttps://events.saip.org.z
a/event/144/contributions/1533/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1533/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Calculation of the Higgs mass in GHU: SU(3)W × SU(3)C
DTSTART;VALUE=DATE-TIME:20190710T092000Z
DTEND;VALUE=DATE-TIME:20190710T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1534@events.saip.org.za
DESCRIPTION:Speakers: Alan Cornell (University of Johannesburg)\nWe discus
s the computation of the Coleman Weinberg effective potential in an SU(3)W
× SU(3)C gauge Higgs model in five dimensions. We attempt to compute the
Higgs mass in this model\, where we had previously calculated the unifica
tion of the gauge and top-like Yukawa couplings.\n\nhttps://events.saip.or
g.za/event/144/contributions/1534/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1534/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Monte-Carlo Shielding Calculations for a 10-MeV Electron Accelerat
or in Botswana
DTSTART;VALUE=DATE-TIME:20190710T082000Z
DTEND;VALUE=DATE-TIME:20190710T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1535@events.saip.org.za
DESCRIPTION:Speakers: Otsile Tikologo (BIUST)\nhttps://events.saip.org.za/
event/144/contributions/1535/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1535/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Geant4 in a new role – Reactor Physics
DTSTART;VALUE=DATE-TIME:20190710T084000Z
DTEND;VALUE=DATE-TIME:20190710T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1536@events.saip.org.za
DESCRIPTION:Speakers: Simon Connell (University of Johannesburg)\nhttps://
events.saip.org.za/event/144/contributions/1536/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1536/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Computational investigation of Structural\, Electronic\, and Mecha
nical Properties of Spinel LiMn2O4
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1540@events.saip.org.za
DESCRIPTION:Speakers: Brian Ramogayana (UL)\nOver the last decade\, energy
storage became one of the greatest challenges mainly because of natural d
epleting recourses and enhanced technology. Several investigations have be
en made in the quest of alternative energy sources\, which are renewable\,
rechargeable and sustainable to current technologies. Lithium-ion batteri
es appeared as a promising energy source in low-carbon electricity and ele
ctric vehicles. However\, one of the major difficulties for improving the
performance of lithium-ion batteries required to meet the increasing deman
d for energy storage devices is the development of efficient and stable ca
thode materials. In particular\, lithium manganese oxide spinel has attrac
ted the most attention as potential cathode material because of its three-
dimensional crystal structure that allows a reversible Li+ diffusion. In t
his study\, we employ the Density Functional Theory (DFT) to investigate t
he stability of the LiMn2O4 spinel bulk through structural\, electronic an
d mechanical properties. The pristine bulk structure was found to be a mag
netic semiconductor with a direct band gap of 0.041 eV. The Density of Sta
tes (DOS) indicated that the structure is metallic\, which is in agreement
with the reported literature. The phonon dispersion curves show that the
spinel bulk structure is stable\, since there is no imaginary frequencies.
Our findings give insight on the electronic properties and spinel stabili
ty of the bulk structure.\n\nhttps://events.saip.org.za/event/144/contribu
tions/1540/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1540/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Teaching Problem Solving: The "10 Commandments" Approach
DTSTART;VALUE=DATE-TIME:20190709T144000Z
DTEND;VALUE=DATE-TIME:20190709T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1541@events.saip.org.za
DESCRIPTION:Speakers: Noluvuyo Matiwane (Rhodes University)\nExpertise in
physics problem-solving has been identified as one of the most crucial tan
gible skills that a physics graduate should develop [1\,2]. An important o
bjective in physics teaching is to promote good problem solving skills. Th
e Physics Education Research group at Rhodes University has developed a pr
oblem-solving framework which has been used to create an innovative way of
teaching first-year physics. The framework incorporates a dynamic iterati
ve process consisting of 3 fundamental tasks each consisting of a number o
f elements or activities that have been packaged together as a set of “1
0 Commandments” of problem-solving. This has led to significant structur
al changes to the physics first-year curriculum\, where problem-solving is
being explicitly taught. The project aims to evaluate the impact of the f
ramework on students’ problem-solving cababilities\n\nReferences\n\nCoun
cil on higher education\, South African Institute of physics\, 2015. Revie
w of undergraduate education in public higher education institutions.\n\nA
dams\, Wendy J.\, Wieman\, Carl E.\, 2015. Analyzing the many skills invol
ved in solving complex physics problems. American Journal of Physics 83 45
9-467.\n\nhttps://events.saip.org.za/event/144/contributions/1541/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1541/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anomalies in the production of leptons at the LHC
DTSTART;VALUE=DATE-TIME:20190711T104000Z
DTEND;VALUE=DATE-TIME:20190711T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1542@events.saip.org.za
DESCRIPTION:Speakers: Bruce Mellado (University of the Witwatersrand)\nBas
ed on a number of features from proton-proton collisions taken during data
Run 1 data taking period at the LHC\, a boson with a mass around the EW
scale was postulated such that a significant fraction of its decays would
entail the Standard Model (SM) Higgs boson and an additional scalar\, S. O
ne of the phenomenological implications of a simplified model\, where S is
treated a SM Higgs boson\, is the anomalous production of high transverse
momentum leptons. A combined study of Run 1 and Run 2 data are indicative
of very significant discrepancies between data and SM Monte Carlos in a v
ariety of final states involving multiple leptons with and without b-quark
s. These discrepancies appear in corners of the phase-space where differen
t SM processes dominate\, indicating that the potential mismodeling of a p
articular SM process is unlikely to explain them. Systematic uncertainties
from the prediction of SM processes evaluated with currently available to
ols seem unable to explain away these discrepancies. The internal consiste
ncy of these anomalies and their interpretation in the framework of the or
iginal hypothesis will be quantified. The potential connection with the mu
on g-2 anomaly is also be discussed.\n\nhttps://events.saip.org.za/event/1
44/contributions/1542/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1542/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Application of the adiabatic compression scenario to the radio rel
ic in the galaxy cluster A3411-3412
DTSTART;VALUE=DATE-TIME:20190710T104000Z
DTEND;VALUE=DATE-TIME:20190710T110000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1543@events.saip.org.za
DESCRIPTION:Speakers: Charissa Button (University of the Witwatersrand)\nR
adio relics are non-thermal\, steep-spectrum (α < -1) diffuse radio sourc
es found in the peripheral regions of galaxy clusters. The emission is pro
duced through synchrotron radiation as relativistic electrons (γ >> 1000)
move in helical paths through the magnetic fields of the intracluster med
ium (ICM). As the time it would take for the electrons to diffuse over a d
istance greater than 50 kpc from any compact source is longer than their r
adiative lifetime of approximately 0.1 Gyr\, the electrons have probably b
een injected or (re)accelerated close to where the emission is observed. R
adio relics are widely considered to have originated in intracluster shock
waves\, since studies have shown that relics seem to trace shock fronts.
Although diffusive shock acceleration (DSA) has been widely used to explai
n the origin of relics\, it is inefficient at low Mach numbers and other m
echanisms such as adiabatic compression of fossil relativistic electrons a
re also present in these structures. In this project we apply the adiabati
c compression model in an attempt to explain the spatial structure of the
spectral index that is observed in the relic hosted in the merging galaxy
cluster Abell 3411-3412.\n\nhttps://events.saip.org.za/event/144/contribut
ions/1543/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1543/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stress-Induced Structural Changes of Lithiated Li1+xMn2O4 (0 ≤ x
≤ 1) Nanoporous Electrode Materials
DTSTART;VALUE=DATE-TIME:20190710T102000Z
DTEND;VALUE=DATE-TIME:20190710T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1544@events.saip.org.za
DESCRIPTION:Speakers: Beauty Shibiri (University of Limpopo)\nOptimising t
he performance potential in terms of voltage and capacity of Li-ion batter
ies requires understanding of both electrochemical and mechanical properti
es of a material. Molecular dynamics (MD) methods are capable of informing
the time dependent properties such as amorphisation and recrystallisation
(A+R) which can provide understanding of microstructural evolution. As su
ch\, MD simulations employing the DL_POLY code were carried out to investi
gate the effect of lithiation on the Li-Mn-O nanoporous materials under th
e NST ensemble. The Li-Mn-O nanoporous structures were obtained from spont
aneous recrystallisation\, during which various lithiated structures yield
ed to single or multigrained crystals. Furthermore\, microstructural analy
sis depicted evolution of composites of spinel-layered components with def
ects. The XRDs analysis also confirmed the co-existence of spinel with lay
ered structures owing to the characteristic/signature peaks of both polymo
rphs. Furthermore\, the increment of Li content resulted in volume change
in the nanoporous structures resulting in inward expansion within their po
res. This may be ascribed to the flexible nature of nanoporous materials a
ttributed to the hollow channels.\n\nhttps://events.saip.org.za/event/144/
contributions/1544/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1544/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Students’ approaches to solving problems kinematic problems
DTSTART;VALUE=DATE-TIME:20190709T130000Z
DTEND;VALUE=DATE-TIME:20190709T132000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1545@events.saip.org.za
DESCRIPTION:Speakers: Mark Herbert (University of the Western Cape)\nThe p
urpose of this research study is to investigate how to address the under-p
reparedness of students entering first year physics in South African unive
rsities\, particularly with regard to their competence in solving kinemati
cs problems. Previous studies show that the best tool for changing and exp
anding the conceptual understanding of a learner is problem solving\; it a
ssists a learner in dealing with new and unfamiliar concepts. These studie
s have also shown that cooperative learning helps students to share knowle
dge with each other. This research study thus investigated students’ app
roaches in solving kinematic problems and also observed the effects of exp
ert problem-solving approaches and cooperative learning on the performance
and results obtained by students in the first-year mainstream physics at
the University of the Western Cape. The findings of the study will be pres
ented and discussed.\n\nhttps://events.saip.org.za/event/144/contributions
/1545/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1545/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Density Functional theory study of optical and electronic properti
es of (TiO2)n=5\,8\,68 clusters for application in organic and hybrid org
anic-inorganic solar cells
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1546@events.saip.org.za
DESCRIPTION:Speakers: Ife Fortunate Elegbeleye (University of Venda)\nA ra
nge of solution processed organic and hybrid organic−inorganic solar cel
ls\, such as dye-sensitized solar cells and bulk heterojunction organic so
lar cells have been intensely developed in the past two decades. TiO2 is w
idely employed as electron transporting material in nanostructured TiO2 pe
rovskite-sensitized solar cells and semiconductor in dye sensitized solar
cell. Understanding the optical and electronic mechanisms that govern char
ge separation\, transport and recombination in these devices will enhance
their power to current conversion efficiencies under illumination to sunli
ght. In this work\, DFT with PBE functional computational approach was use
d through various computational softwares which are CASTEP\, GPAW and AVO
GADRO within an atomic simulation environment to explore the optical and e
lectronic properties of three modelled TiO2 brookite clusters which are T
i5O10\, Ti8O16 and Ti68O136 for application in organic and hybrid organic
-inorganic solar cells. The simulated optical absorption spectrum for (TiO
2)5 and (TiO2)8 cluster shows excitation around 200 nm to 400 nm but\, (Ti
O2)8 cluster shows higher absorbance than the corresponding (TiO2)5 cluste
r. The density of states and the projected density of states of (TiO2)5\,
(TiO2)8 and (TiO2)68 clusters were computed using GPAW and PBE exchange c
orrelation functional to further understand their electronic structure. Th
e density of states spectrum reveals surface valence and conduction bands
separated by a band gap of 1.10 eV\, 2.31 eV and 1.37 eV for (TiO2)5\, (Ti
O2)8 and (TiO2)68 clusters respectively. The projected density of states s
pectrum reveals 2p atomic orbitals contributing mostly to the highest occu
pied valence band (VB) state\, whereas the lowest unoccupied state of the
conduction band is mainly dominated by the contributions of titanium 3d at
omic orbitals. Our findings generally shows that the optical and electroni
c properties of TiO2 cluster varies with the size of the cluster.\n\nKeywo
rds: Density Functional theory\, Titanium dioxide\, optical properties\, e
lectronic properties\, hybrid solar cells.\n\nhttps://events.saip.org.za/e
vent/144/contributions/1546/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1546/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Analysis of a deep neural network for missing transverse momentum
reconstruction with the ATLAS detector
DTSTART;VALUE=DATE-TIME:20190709T100000Z
DTEND;VALUE=DATE-TIME:20190709T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1547@events.saip.org.za
DESCRIPTION:Speakers: Matthew Leigh (University of Cape Town)\nThe missing
transverse momentum ($E_T^{miss}$) of a $pp$ collision is an important ob
servable as it serves as a proxy for the transverse momentum carried away
by undetectable particles. In addition to Standard Model neutrinos\, there
exist many theorised particles which would not leave any signals in a det
ector. Therefore\, measuring $E_T^{miss}$ with high degrees of accuracy is
critical for the understanding many physical processes which take place a
t the LHC\, in the Standard Model and beyond. ATLAS currently utilises sev
eral working points to reconstruct the $E_T^{miss}$ of the hard-scatter in
teraction using only the observed objects. The optimal choice of working p
oint depends strongly on the event topology. The aim of this project is to
investigate the use of a deep neural network\, trained using Monte-Carlo
samples\, to develop a more accurate $E_T^{miss}$ reconstruction\, which i
s independent of topology and more resilient to pile-up effects. We demons
trate how the network improves $E_T^{miss}$ accuracy in both simulated and
real data\, and how this new method might assist in searches for physics
beyond the Standard Model.\n\nhttps://events.saip.org.za/event/144/contrib
utions/1547/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1547/
END:VEVENT
BEGIN:VEVENT
SUMMARY:First Principle Study of Metal Oxide 110 &beta\;-MO2 (M
= Ti\, Mn\, V) Surfaces Stability and their Interaction with Li2O2
DTSTART;VALUE=DATE-TIME:20190710T080000Z
DTEND;VALUE=DATE-TIME:20190710T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1548@events.saip.org.za
DESCRIPTION:Speakers: Percy Ngobeni (UL)\nMetal-air batteries are viewed a
s the next generation energy storage devices due to their high energy dens
ity and environmental friendliness. However\, they suffer from production
of unstable discharge products which leads to capacity fading of the batte
ry. Several catalysts have been used to improve Oxygen Reduction Reaction
(ORR) and Oxygen Evolution Reaction (OER) which will yield stable discharg
e product. In this study\, Density functional theory (DFT) is employed to
investigate the relative stability of metal oxide catalysts\,(110) β-MO2
surfaces. Electronic and structural stability of clean and Li-O adsorbed s
urfaces such as elastic constants\, phonon dispersions\, density of states
and band structures are investigated. The phonon dispersion curves show t
hat clean β-TiO2 surface is the most stable structure since it does not d
isplay vibrations in the negative frequencies along the Γ region in Brill
ouin zone. The electronic band structures calculated indicate the absence
of gap at fermi level of all the surfaces that are adsorbed with lithium a
nd oxygen\, thus they are all metallic. These findings are important in im
proving the cycling performance of Li-air battery and give insight on the
reactivity of (110) β-MO2 surfaces with lithium and oxygen.\n\nhttps://ev
ents.saip.org.za/event/144/contributions/1548/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1548/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Computational modelling on Stability of Solid Electrolytes in Magn
esium ion batteries
DTSTART;VALUE=DATE-TIME:20190710T082000Z
DTEND;VALUE=DATE-TIME:20190710T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1549@events.saip.org.za
DESCRIPTION:Speakers: Khumbulani Tibane (UL)\nDeveloping new battery techn
ologies to sustain the ever growing demand of energy storage constitutes o
ne of the greatest scientific and societal challenges of the century. Lith
ium-ion batteries (LIBs) are at the center of energy revolution\, they pow
er millions of portable electronics and electric vehicles. Li ion’s succ
ess is in part due to the remarkable mobility of Li+ in many solids. Fast
Li-ion transport enables intercalation electrodes\, in which charge is sto
red by moving the ions in and out of crystal structures. A technology that
has the potential to alleviate resource issues with Li-ion systems and fu
rther increase the energy density is Mg2+ intercalation systems. Replacing
Li with safer and earth abundant Mg has the advantage of doubling the tot
al charge per ion\, resulting in larger theoretical volumetric capacity co
mpared with typical LIB. Most importantly\, in Mg batteries\, the anode is
constituted by energy dense Mg metal notably surpassing the theoretical v
olumetric energy density of the current graphitic anode of LIB and even th
at of lithium metal. In this study we investigate by using first principle
calculations within generalized gradient approximation the stability of M
gSc2S4 and MgSc2Se4 structures. The lattice parameters are in good agreeme
nt with experimental studies. The heats of formation indicate that the str
uctures are stable. Calculated elastic properties shows that structures ar
e mechanically stable.\n\nhttps://events.saip.org.za/event/144/contributio
ns/1549/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1549/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Point defects in cubic Boron Nitride(c-BN)
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1550@events.saip.org.za
DESCRIPTION:Speakers: Magopa Tshepho Mcdonald Kekana (University of Limpop
o)\nPoint defects in cubic boron nitride are being investigated using the
classical molecular dynamics and the rigid Tersoff potentials. In the proc
ess\, the stability\, the structural properties and lattice vacancies are
being explored. The formulation uses the NVT Evans ensemble to obtain radi
al distribution functions and the defect energies for boron and nitrogen v
acancies. Boron and nitrogen vacancy defect energies are calculated relati
ve to bulk c-BN total energies. The results suggest that the nitrogen vaca
ncy is more stable compared to the boron vacancy.\n\nhttps://events.saip.o
rg.za/event/144/contributions/1550/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1550/
END:VEVENT
BEGIN:VEVENT
SUMMARY:WATER ADSORPTION ON PtAs2 (111) SURFACE: A GENERAL PICTURE FROM DE
NSITY FUNCTIONAL THEORIES
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1552@events.saip.org.za
DESCRIPTION:Speakers: Susan Ndou (University Of Limpopo)\nMost of the worl
d’s supply of platinum and palladium and associated elements comes from
mines within four major layered igneous intrusions: the Bushveld Complex i
n South Africa\, the Stillwater Complex in the USA\, the Great Dyke in Zim
babwe and the Noril’sk-Talnakh Complexes in Russia. The predominant PGM
in the mined area of the Platreef and Merenskyite of the Bush complex in S
outh Africa are (Pd\,Pt)(Bi\,Te)2\, PtTe2\, PtAs2\, and Pd2As\, respective
ly. The high concentrations of these minerals make it necessary to explore
opportunities to maximize the recovery these minerals by flotation. The i
nteraction of these mineral with xanthates\, whereby the mineral surface i
s rendered hydrophobic and gas bubbles can adhere to the surface\, has bee
n utilized for many years in practical flotation systems\, but this may no
t be the optimal approach. Industrial mineralogical studies have found pla
tinum group minerals\, such as Sperrylite (PtAs2) to be poorly recovered d
uring flotation. Research on the flotation behaviour of Sperrylite mineral
is very limited\, due to their small size (<10μm)\, and also the scarcit
y of individual grains contribute to the complexity of studying fundamenta
l interactions. This study employs ab-initio method to investigate the eff
ect of water molecule on the low index surfaces of PtAs2. The convergent t
est of slab thickness\, vacuum width between slabs and surface relaxation
were carried out in order to obtain meaningful results. The results of the
adsorption of water molecules on the low index surfaces (100)\, (110) and
(111) are presented and discussed and compared with the available experim
ent.\n\nhttps://events.saip.org.za/event/144/contributions/1552/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1552/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dark matter in the Randall-Sundrum model
DTSTART;VALUE=DATE-TIME:20190710T080000Z
DTEND;VALUE=DATE-TIME:20190710T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1554@events.saip.org.za
DESCRIPTION:Speakers: Mukesh Kumar (University of the Witwatersrand)\nWe c
onsider simplified dark matter models (DM) interacting gravitationally wit
h the Standard Model particles in a Randall-Sundrum (RS) frame work. In th
is frame work the DM particles interact through the exchange of spin-2 Kal
uza-Klein (KK) gravitons in the $s$-channel with the SM particles. The par
ameter space of RS model with universal couplings to SM particles is known
to be strongly constrained from the LHC data. We are thus led to consider
models with non-universal couplings. The first model we consider in this
study is a top-philic graviton model in which only the right-handed top qu
arks are taken to interact strongly with the gravitons. In the second lept
on-philic model\, we assume that only the right-handed charged leptons int
eract strongly with the gravitons. We extend the study to include not only
the scalar\, vector and spin-1/2 fermions but also spin-3/2 fermionic dar
k matter. We find that there is a large parameter space in these benchmar
k models where it is possible to achieve the observed relic density consis
tent with the direct and indirect searches.\n\nhttps://events.saip.org.za/
event/144/contributions/1554/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1554/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Structural\, electronic and optical properties of rare-earth coppe
r chalcogenides LaCuX2 (X = S\, Se): A first principles study
DTSTART;VALUE=DATE-TIME:20190711T130000Z
DTEND;VALUE=DATE-TIME:20190711T150000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1556@events.saip.org.za
DESCRIPTION:Speakers: Abdu Barde (The National Institute for Theoretical P
hysics\, School of Physics and Mandelstam Institute for Theoretical Physic
s\, University of the Witwatersrand\, Johannesburg\, Wits 2050\, South Afr
ica)\nStructural\, electronic and optical properties of rare-earth copper
chalcogenides LaCuX2 (X = S\, Se) were investigated with density fuctional
theory (DFT). The calculated structural properties agree resonably well w
ith previous results and experimental data. Elastic constants satisfy the
stability conditions for monoclinic structures\, wich confirms mechanical
stability for the compounds. Modified Becker Johnson (MBJ) potential band
structure and density of state calculation reveals that LaCuX2 (X = S\, Se
) are indirect band gap semiconductors with DFT energy gaps between 1.30 t
o 1.50 eV. The fundemental gaps were determined at G0W0 level of approxima
tion\, while optical parameters such as dieclectric functions\, refractive
indices\, energy loss functions and absorption coefficients were examined
by solving the Bether Selpater equation. From the results obtained\, LaCu
X2 are stable compounds and posses energy gaps suitable for photovoltaic a
pplications.\n\nhttps://events.saip.org.za/event/144/contributions/1556/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1556/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Orbitally-Modulated X-ray and Gamma-ray Emission from Millisecond
Pulsar Binaries
DTSTART;VALUE=DATE-TIME:20190710T092000Z
DTEND;VALUE=DATE-TIME:20190710T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1557@events.saip.org.za
DESCRIPTION:Speakers: Christian van der Merwe (North-West University\, Cen
tre for Space Research)\nBlack widow and redback systems are compact binar
ies in which the pulsar heats and may even ablate its low-mass companion b
y its intense wind of relativistic particles and emission. The pulsar wind
drives mass loss from the companion\, and an intra-binary shock forms as
a site of particle acceleration. Radio\, optical and X-ray follow-up of un
identified Fermi Large Area Telescope (LAT) sources has expanded the numbe
r of these systems from four to nearly 30. We model the X-ray and gamma-ra
y spectral components from nearby 'spider binaries'\, including diffusion\
, convection and radiative energy losses in an axially-symmetric\, steady-
state approach. The code simultaneously yields energy-dependent light curv
es and orbital phase-resolved spectra. Using parameter studies and fitting
X-ray and gamma-ray spectra and light curves\, we constrain certain model
parameters and estimate the very-high-energy gamma-ray flux for two promi
sing sources. We find that nearby binaries that are in a 'flaring state' a
re promising targets for the future Cherenkov Telescope Array (CTA)\, and
may also be detectable by H.E.S.S. for optimistic parameter choices. Const
raining the inverse Compton emission via such observations will probe the
particle acceleration in the shock as well as the pulsar wind content.\n\n
https://events.saip.org.za/event/144/contributions/1557/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1557/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Automation of next-to-leading order computations in QCD of the WWj
j Background for the Dilepton Final State
DTSTART;VALUE=DATE-TIME:20190711T102000Z
DTEND;VALUE=DATE-TIME:20190711T104000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1558@events.saip.org.za
DESCRIPTION:Speakers: Lebohang Mokoena (University of the Witwatersrand)\n
A study is performed for the autonomous computation for cross section at t
he next-to- leading order in QCD for the WWjj background. The WWjj process
is described and simulated using MadGraph with aMC@NLO framework\, partic
ularly suited for its parallel computation in Standard Model as well as Be
yond the Standard Model theories. Interfacing with PYTHIA8 and HERWIG++ in
leading order and next- to-leading order allows for parton shower calcula
tions. The study presents different distributions measured in our phase sp
ace characterized by the kinematic and energy behaviour of the process.\n\
nhttps://events.saip.org.za/event/144/contributions/1558/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1558/
END:VEVENT
BEGIN:VEVENT
SUMMARY:An effective solution to a many-bodied problem in first-year physi
cs
DTSTART;VALUE=DATE-TIME:20190709T140000Z
DTEND;VALUE=DATE-TIME:20190709T142000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1559@events.saip.org.za
DESCRIPTION:Speakers: Ross Dix-Peek (NMMU)\nAt Nelson Mandela University (
previously NMMU) over the past 4 years\, the first-year Physics student nu
mbers in the main stream courses have gone from 140 students to over 500.
This has strained the lab capacity\, equipment and staff of the department
. Late 2017\, it was apparent that the current system would not be able to
support the influx of students from the new Bachelor of Engineering Techn
ology course offered by the university. In response to this\, a document w
as drawn up based upon the SAIP Benchmark Statement. This document was ent
itled ‘Graduate Skills and Attributes Framework’. It outlined the skil
ls and attributes the department deemed important for Physics students to
attain during their studies. The entire practical course was overhauled. P
racticals were selected and redesigned to not only improve the efficiency
of delivery but to focus on specific skill development. The total number o
f practicals decreased within the introduction of a week dedicated to the
pre-practical preparation and assessment of the students. Post-practical a
ssessment was also included so to ensure each students engagement of the p
ractical.\n\nThis paper discusses the developed First Year Practical Cours
e within the Physics Department at Nelson Mandela University. The paper fo
cuses on the benefit of an online system for pre-and-post practical assess
ment and problems associated with the new system.\n\nhttps://events.saip.o
rg.za/event/144/contributions/1559/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1559/
END:VEVENT
BEGIN:VEVENT
SUMMARY:On the combined analysis of luminescence for thermal assistance an
d thermal quenching
DTSTART;VALUE=DATE-TIME:20190711T084000Z
DTEND;VALUE=DATE-TIME:20190711T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1560@events.saip.org.za
DESCRIPTION:Speakers: Makaiko Chithambo (Rhodes University)\nIf the emissi
on of luminescence is affected by thermal assistance\, and if the total pr
obability of emission 1/τ is modulated by a Boltzmann factor exp(- Ε
α/ κΤ) where Εα is the activation energy of thermal assistance\, t
he overall probability of optically stimulated luminescence emission can b
e expressed for n electron traps as:\n\n1/τ = [1/τrαd + ν exp( - ΔΕ
/ κΤ) ] Π ni exp ( - Εαi /κΤ)\n\n\nwhere Τrαd is the radiative
lifetime\, and are as previously defined\, υ is the activation energy
for thermal assistance for the electron trap and the number of electro
n traps contributing to the process [1]. We will examine how to quantify
thermal effects in cases where the luminescence ensues with very high effi
ciency such that any little additional component due to thermal assistance
and any loss due to non-radiative transitions is masked.\nReferences\n1
Chithambo\, M.L.\, Costin\, G.\, 2017. Temperature-dependence of time-r
esolved optically stimulated luminescence and composition heterogeneity of
synthetic -Al2O3:C. J. Lumin. 182\, 252-262.\n\nhttps://events.saip.or
g.za/event/144/contributions/1560/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1560/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Explaining muon $g-2$ in a 2HDM+S model
DTSTART;VALUE=DATE-TIME:20190710T100000Z
DTEND;VALUE=DATE-TIME:20190710T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1561@events.saip.org.za
DESCRIPTION:Speakers: Mukesh Kumar (University of the Witwatersrand)\nThe
disagreement between experimental and Standard Model prediction of muon an
omalous magnetic moment at the level of 3-4$\\sigma$ is well known. In a t
wo Higgs doublet model with a singlet scalar (2HDM+S)\, we investigate the
possible parameter space of all four types of this model to explain this
discrepancy. Further we also analyse the sizeable effect of electric dipol
e moment within this model.\n\nhttps://events.saip.org.za/event/144/contri
butions/1561/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1561/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A radiative transfer model for hydrogen recombination line masers
DTSTART;VALUE=DATE-TIME:20190709T082000Z
DTEND;VALUE=DATE-TIME:20190709T084000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1562@events.saip.org.za
DESCRIPTION:Speakers: Andri Prozesky (Unisa)\nAstronomical masers occur wh
en radiation is amplified by the process of stimulated emission over long
path lengths\, producing line emission that is much brighter than spectral
lines produced by spontaneous transitions. Molecular astronomical masers
have proven to be a useful tool to probe conditions in a wide variety of a
stronomical sources. Masers are also produced by atomic hydrogen formed by
recombination in sufficiently dense H II regions. These hydrogen recombin
ation line (HRL) masers have been observed in a handful of objects to date
and the analysis of the atomic physics involved have been rudimentary. In
this work a new model of HRL masers is presented which uses an nl-method
model to describe the atomic populations interacting with free-free radiat
ion from the plasma\, and an escape probability framework to deal with rad
iative transfer effects. The importance of including the collisions betwee
n angular momentum quantum states and the free-free emission in models of
HRL masers are demonstrated. The model is used to describe the general beh
aviour of radiative transfer of HRLs and to investigate the conditions und
er which HRL masers form. The model results show good agreement with obser
vations collected over a broad range of frequencies.\n\nhttps://events.sai
p.org.za/event/144/contributions/1562/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1562/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A study on High School Learners’ Apathy to Physics Subject – C
ase Study Of High Schools in Kano Municipality\, Kano State Nigeria.
DTSTART;VALUE=DATE-TIME:20190710T122000Z
DTEND;VALUE=DATE-TIME:20190710T124000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1563@events.saip.org.za
DESCRIPTION:Speakers: Itegbeyogene Ezekiel (National Centre for Technology
Management\, North West Zonal Office\, Kano State\, Nigeria)\nPhysics con
cepts form a strong background in Science\, Technology and Engineering edu
cation (STE). High school learners’ interest in Physics could significan
tly improve the enrollment and graduation figures in STE and Mathematics (
STEM) professions at the tertiary level of education. This study tries to
investigate the factors that could significantly enhance learners’ inter
est in Physics especially in the northern part of Nigeria where student en
rollments are generally very low. Questionnaires were administered to some
selected high schools learners in Kano State Municipality of Nigeria. Fac
tors such as methods of teaching Physics\, the quality of teachers\, labor
atory setups\, cultural and subject orientation among other factors have b
een elucidated and found to have a strong correlation to learners’ apath
y for Physics.\n\nhttps://events.saip.org.za/event/144/contributions/1563/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1563/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Physics of new materials for nano-sensors and photovoltaics
DTSTART;VALUE=DATE-TIME:20190708T093500Z
DTEND;VALUE=DATE-TIME:20190708T103500Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1565@events.saip.org.za
DESCRIPTION:Speakers: Bonex Mwakikunga (CSIR National Laser Centre)\nhttps
://events.saip.org.za/event/144/contributions/1565/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1565/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Review of organic solar cells Historical perspective Recent develo
pment and concept improvement
DTSTART;VALUE=DATE-TIME:20190708T081500Z
DTEND;VALUE=DATE-TIME:20190708T091500Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1566@events.saip.org.za
DESCRIPTION:https://events.saip.org.za/event/144/contributions/1566/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1566/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Bottomonia Suppression in Heavy-Ion Collisions from AdS/CFT
DTSTART;VALUE=DATE-TIME:20190709T092000Z
DTEND;VALUE=DATE-TIME:20190709T094000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1567@events.saip.org.za
DESCRIPTION:Speakers: Nadia Barnard (University of Cape Town)\nWe compute
for the first time the suppression of bottomonia in a strongly coupled QGP
and compare the results to those from a weakly coupled QGP and to data. U
sing imaginary time techniques we numerically determine the real and imagi
nary parts of the binding energy of ground state bottomonia in a potential
computed from AdS/CFT and another computed from pQCD. We implement the co
mplex binding energies in a suppression model to determine the $\\Upsilon$
(1S) nuclear modification factor in $\\sqrt{s}_{NN}=2.76$ TeV Pb+Pb collis
ions. This simplest strong-coupling\, $p_T$-independent potential leads to
a significant oversuppression of $\\Upsilon$(1S) compared to data while t
he results from the pQCD-derived potential are consistent with data. We al
so investigate the validity of using complex heavy quark potentials from A
dS/CFT for all quark separation $r$ by independently computing the meson s
pectrum using semiclassical\, rotating open strings attached to the D7-bra
ne.\n\nhttps://events.saip.org.za/event/144/contributions/1567/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1567/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Opening and welcome
DTSTART;VALUE=DATE-TIME:20190708T070000Z
DTEND;VALUE=DATE-TIME:20190708T071500Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1568@events.saip.org.za
DESCRIPTION:Speakers: Nnditshedzeni Eric Maluta (University of Venda)\nhtt
ps://events.saip.org.za/event/144/contributions/1568/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1568/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Storms from the Sun: The Science of Space Weather
DTSTART;VALUE=DATE-TIME:20190709T120000Z
DTEND;VALUE=DATE-TIME:20190709T130000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1569@events.saip.org.za
DESCRIPTION:Speakers: Patricia Doherty (Institute for Scientific Research)
\nSpace Weather is an emerging field of space science that studies how the
Sun influences the Earth’s space environment and the impacts of those i
nteractions on technology and society. Some of the most intense interactio
ns can damage our Earth-orbiting commercial and scientific satellites\; th
reaten astronaut safety\; introduce high levels of radiation for crews and
passengers in flights crossing over the poles\; disrupt electric power gr
ids\, oil pipelines and the reliability and accuracy of global communicati
ons and navigation systems\, including Global Navigation Satellite Systems
(GNSS). With society’s ever-increasing dependence on space-based techno
logy\, it is important to enhance public awareness of Space Weather\, its
potential impacts and what governments are doing to enhance forecasting an
d mitigation of its most damaging effects. This presentation will introduc
e the basic physical concepts of the source of Space\nWeather. This includ
es information on the Sun\, solar wind\, eruptive solar phenomena\, magnet
osphere\, ionosphere and geomagnetic induction. The presentation will cont
inue with a view of the impacts of Space Weather on technological systems
in space and on the ground. Finally\, we will introduce plans to advance f
orecasting capabilities and mitigation of Space Weather.\n\nhttps://events
.saip.org.za/event/144/contributions/1569/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1569/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Reporting on the findings of Physics scientometric study: Prof Joh
an Mouton
DTSTART;VALUE=DATE-TIME:20190712T092000Z
DTEND;VALUE=DATE-TIME:20190712T102000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1570@events.saip.org.za
DESCRIPTION:https://events.saip.org.za/event/144/contributions/1570/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1570/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Physics for all: Rebuilding our community for everyone
DTSTART;VALUE=DATE-TIME:20190710T070000Z
DTEND;VALUE=DATE-TIME:20190710T080000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1571@events.saip.org.za
DESCRIPTION:Speakers: Kate Shaw (CERN)\nPhysics is an objective and precis
e science. We are careful to not allow our or anyone else's personal biase
s\, emotions\, or cultural influences to effect interpretations of data\,
characterising the scientific method. However\, in the past\, and it could
be argued still today\, we do allow these vices to affect the way we thin
k about the people doing science\, be them ourselves or others. This can c
ause problems for minority groups in physics\, such as women\, by not only
encountering prejudice\, and from lack of confidence\, but also due to sy
stems that were designed to suit a specific type of scientist\, traditiona
lly who are male. There are many other factors that cross-correlate\, such
as economic background\, geographic location\, and ethnicity\, that have
similar battles but manifested in different ways. This talk will explore t
hese issues\, with some focus on South Africa\, and look to how we can bec
ome more scientific\, in our approach to people\, as we are to our data.\n
\nhttps://events.saip.org.za/event/144/contributions/1571/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1571/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quantum Metamaterials: The past\, current and future perspective o
n quantum communication and information science.
DTSTART;VALUE=DATE-TIME:20190710T130000Z
DTEND;VALUE=DATE-TIME:20190710T132000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1572@events.saip.org.za
DESCRIPTION:Speakers: Solomon Uriri (Center for Quantum technology\, Unive
rsity of KwaZulu-Natal)\nMetamaterials are artificial engineered periodic
structures with exceptional optical properties that are not found in conve
ntional materials. As a result of the material unique optical properties\
, new ways of controlling and manipulating light at the nanoscale is now p
ossible. Thus\, leading to many applications most particularly to quantum
communication and information processing. Other notable applications where
quantum metamaterials have been used include sensing and metrology\, ener
gy harvesting\, electromagnetic cloak and super-resolution imaging. Quantu
m metamaterials have been used in addition with other nano-photonics devic
es to enable on-chip photonic circuitry\, quantum reconfigurable devices a
nd to perform quantum state engineering task. Using metamaterial at the qu
antum scale is still relatively new and research in this direction is rapi
dly growing. This study briefly reviews the current and future state of qu
antum metamaterials with applications to quantum communication and informa
tion processing.\n\nhttps://events.saip.org.za/event/144/contributions/157
2/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1572/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Beam intensity improvement of high energy heavy ions beams at iThe
mba LABS
DTSTART;VALUE=DATE-TIME:20190709T084000Z
DTEND;VALUE=DATE-TIME:20190709T090000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1573@events.saip.org.za
DESCRIPTION:Speakers: fhumulani nemulodi (iThemba LABS)\nhttps://events.sa
ip.org.za/event/144/contributions/1573/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1573/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Investigating thermal and non-thermal emission in novae
DTSTART;VALUE=DATE-TIME:20190709T080000Z
DTEND;VALUE=DATE-TIME:20190709T082000Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1574@events.saip.org.za
DESCRIPTION:Speakers: Miriam Mumbua Nyamai (University of Cape Town)\nA no
va eruption occurs on the surface of a white dwarf following extensive acc
retion of material from a less evolved companion star. Their study provide
s an opportunity to understand the emission processes of expelled material
and high-energy emitting shocks among others. Modelling radio observation
s as an expanding gas emitting free-free emission give insights to ejected
mass\, the velocity of the remnant and kinetic energy of the outburst. Th
e environments surrounding novae in these models are assumed to be of low
densities allowing the envelope to expand freely. However\, novae surround
ed by dense 'embedded' environments similar to recurrent novae\, interacti
on with the ejecta gives rise to synchrotron emission which in some cases
is the dominant emission. We present the case of nova V445 Puppis where th
e radio light curve is multi-peaked and dominated by synchrotron emission.
We model the emission as arising from the interaction of nova ejecta with
regions of enhanced densities (shells) in the circumstellar material to d
etermine the amount of mass ejected and energy of the explosion. Most radi
o models assume the material to be spherical. However\, imaging shows evid
ence of polar and equatorial flows in novae. We apply bipolar models to es
timate the ejected mass of V339 Del outburst and compare with theoretical
predictions.\n\nhttps://events.saip.org.za/event/144/contributions/1574/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1574/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Closing Remarks
DTSTART;VALUE=DATE-TIME:20190708T134500Z
DTEND;VALUE=DATE-TIME:20190708T140500Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1575@events.saip.org.za
DESCRIPTION:Speakers: Tshifhiwa Solomon Ravhengani (University of Venda)\n
https://events.saip.org.za/event/144/contributions/1575/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1575/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Renewable Energy Markets and technologies: An overview
DTSTART;VALUE=DATE-TIME:20190708T124500Z
DTEND;VALUE=DATE-TIME:20190708T134500Z
DTSTAMP;VALUE=DATE-TIME:20260813T210025Z
UID:indico-contribution-144-1576@events.saip.org.za
DESCRIPTION:Speakers: Kittessa Roro (NLC-CSIR)\nhttps://events.saip.org.za
/event/144/contributions/1576/
LOCATION:Polokwane Protea The Ranch Hotel
URL:https://events.saip.org.za/event/144/contributions/1576/
END:VEVENT
END:VCALENDAR