Mr
Peter Baricholo
(National University of Science and Technology, Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Poster
A coaxial Ar excimer lamp excited by a dielectric barrier discharge has been developed and characterized. The effect of discharge gas pressure on the intensity of the Ar 126 nm VUV emission has been investigated. Intensity of the VUV Ar*2 excimer emission increases with pressure according to a second order polynomial.
Mr
Amanda Sefage
(University of Zululand)
Track A - Condensed Matter Physics and Material Science
Poster
A CdO based LPG gas sensor has been fabricated from the deposition of CdO thin film on a glass substrate by PLD and Sputtering deposition techniques.
The structural, morphological, chemical compositional analysis and gas sensing properties of the CdO thin films is still needed to be characterized by using SEM,XRD,RBS and UV-VIS Spectrometry, etc. The electrical resistance and gas response of...
Mr
Winston Tumps Ireeta
(Nelson Mandela Metropolitan University)
Track C - Lasers, Optics and Spectroscopy
Presentation
The design of modern wavelength-division-multiplexed (WDM) optical transmission systems has made advanced optical modulation formats a key ingredient. In this paper, we show PMD-induced system degradation through simulation. We found out that DQPSK is highly tolerant compared to RZ, however, RZ is more tolerant than NRZ.
Dr
Kurt van der Heyden
(UCT)
Track D1 - Astrophysics
Poster
We will undertake a tiered extragalactic continuum survey with MeerKAT to investigate the evolution of AGN, star-forming galaxies and galaxy clusters from the epoch of reionization through to the present day. Our project will fully utilize MeerKAT’s unique capabilities, namely high-resolution coupled with a large survey speed, to undertake a five-tier survey strategy at 1.4 GHz. The...
Prof.
Diane Grayson
(University of Pretoria)
Track E - Physics Education
Presentation
For many years only about 1/3 of the students who registered for a BEng obtained their degree in four years. Since 1994 a minority of students were registered for a 5-year programme that spread two years over three. But most of these students took longer. In 2010 a new, carefully structured 5-year degree is being offered.
Dr
Sanyasi Sitha
(University of the Witwatersrand)
Track C - Lasers, Optics and Spectroscopy
Poster
We report, till date the highest value of molecular first hyperpolarizability (Second order Nonlinear Optical response) for an organic molecule. Calculation shows that low energy absorption (Far-IR) and large ground to excited state dipole difference, are mainly responsible for such a high value first hyperpolarizability even at the molecular level.
Dr
Jan Greben
(CSIR)
Track G - Theoretical and Computational Physics
Presentation
We develop a bound-state approach in quantum field theory which can be used to give an internal description of dressed quarks. The fermionic and bosonic fields are treated as interdependent. The quark is bound by self-consistent infinite binding potentials. By including general relativity and vacuum energy, we can stabilize this system. The average mass for the light quarks is 3.2 MeV, in...
Mr
Ogbonnaya Okike
(University of KwaZulu-Natal)
Track D2 - Space Science
Presentation
The distribution of the cosmic ray flux over the Earth is not uniform, but the result of complex phenomena within the Sun-Earth environment. A multivariate analysis of non-simultaneous Forbush decreases from an array of cosmic ray detectors will give an indication of the stations' asymptotic cones of acceptance.
Prof.
Moritz Braun
(University of South Africa)
Track G - Theoretical and Computational Physics
Presentation
Solving an effective three-dimensional Schroedinger equation is a key ingredient of computational methods for the calculation of atomic, molecular and solid state properties. However, the presence of Coulomb singularities at the nuclei is a challenge for the convergence of any method. In this contribution a new approach is introduced, which is based on writing the wave function as a...
Ms
Katherine Jefferies
(University of the Witwatersrand)
Track G - Theoretical and Computational Physics
Presentation
The planar limit of the dilatation operator in the SU(2) sector has been studied extensively. In this presentation the exact one loop dilatation operator in the SU(2) sector will be considered. This is achieved by exploiting a new basis, the restricted Schur polynomial, which allows us to sum all higher genus diagrams.
Mr
Chris Rohwer
(Institute of Theoretical Physics, University of Stellenbosch)
Track G - Theoretical and Computational Physics
Presentation
We contrast two equivalent formulations for NCQM position measurement: a constrained local description in position containing additional degrees of freedom, and an unconstrained nonlocal description without nonpositional degrees of freedom. After analysing corresponding classical theories, we demonstrate that the local formulations allow for natural interpretations of NCQM involving additional...
Mr
Bernardt Duvenhage
(Optronic Sensor Systems, Defence Peace Safety and Security, CSIR)
Track C - Lasers, Optics and Spectroscopy
Poster
The main research focus is on developing photon simulation algorithms for modern low cost many-core processor architectures. These algorithms all articulate models which offer efficient simulation of the mechanics of photon-material interactions and radiance transport. This paper focusses on the processor architecture for potentially a more general computational application.
Ms
J D Brand
(Stellenbosch University)
Track G - Theoretical and Computational Physics
Poster
Inspired by known instances of a Quantum Hall Effect without Landau levels, we look for such an effect in a carbon nanotube subjected to a magnetic field that is constant along the axial direction and averages to zero around the tube’s circumference.
Dr
David Dekadjevi
(University of Johannesburg)
Track A - Condensed Matter Physics and Material Science
Presentation
The information revolution, which has modified our way of living over the last few decades, has occurred due to the restless exponential growth of information amount that can be processed, stored, and transferred per unit time and unit area of relevant devices. Nanomagnetism is becoming a very important research area in past decades due to its keyrole in this revolution. The main goal of...
Mr
Bosco Oruru
(University of the Free State)
Track D1 - Astrophysics
Presentation
Using X-ray data from the Swift satellite, we analysed the spectrum of AE Aqr and found that the emission has both thermal and non-thermal components. The latter shows up in the high energy spectral range, and its origin with respect to particle acceleration and synchrotron radiation will be discussed.
Prof.
Diane Grayson
(University of Pretoria)
Track E - Physics Education
Presentation
In 2009 the first cohort of students who wrote the new National Senior Certificate entered South Africa’s universities. Failure rates in the first semester in the sciences were higher than before. A survey conducted with students who moved from BEng to the 4-year BSc reveals what students saw as problems.
Mrs
Malebo Tibane
(University of South Africa)
Track A - Condensed Matter Physics and Material Science
Poster
We investigate the thermal stability at 0 GPa for different phases of PtCr binary alloys. We have detected soft modes at X, G, M and R points of the Brillouin zone from the phonon spectra of Pt3Cr A15 phase. Pt3Cr L12 and PtCr3 A15 are predicted as dynamically stable structures.
Mr
Edwin Mapasha
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Presentation
We study Li on graphene using the VASP code employing the PAW method within the GGA for the exchange-correlation. We give detailed structural and electronic results for various configurations involving Li on the different two-dimensional unit cells. For 100% coverage, we have new results for Li on the on-top site, which suggests a staggered configuration for the lowest energy structure for...
Mr
MOHAMMED SULEIMAN
(University of the Witwatersrand)
Track G - Theoretical and Computational Physics
Poster
The crystal structures and mechanical properties of some late transition metal-nitrides at different stoichiometries and different structures have been investigated using first-principles density-functional theory. Obtained results were compared with theory and with experiment whenever possible.
Mr
Richard Andrew
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Presentation
Silicon and Carbon exist readily in pure form and in the 50/50 combination of Silicon Carbide in cubic and hexagonal forms. Carbon is known to be slightly soluble in Si and vice-versa and the reasons for this are not well known. To investigate this, the stability of various Six-1Cx alloys were investigated with x ranging between 0 and 1.
Mr
Masilu Godfrey Mulaudzi
(Materials Modelling Center - University of Limpopo)
Track A - Condensed Matter Physics and Material Science
Poster
We present an ab-initio study of non-stochiometric mixed iron oxide / sulfide using the virtual crystal approximation (VCA). This allows us to analyse the cell parameter, the bulk modulus and the density of states as a function of sulfur content.
Dr
Walter Meyer
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Poster
The electronic and annealing properties of primary radiation induced defects in Si have been studied by means of density functional theory (DFT) calculations using VASP. The results obtained for different functionals have been compared with each other, with results obtained by other groups and where data is available, to experimental values.
Mr
Teboho Cyprian Motsware
(Student)
Track A - Condensed Matter Physics and Material Science
Presentation
We use DFT calculations within GGA-PBE approximation to investigate the structural and mechanical stability of uranium-aluminium systems. Our results provided excellent heats of formation and predict UAl2 to be more stable, in agreement with experiment. Phonon dispersion spectra confirmed relative structural trend, all three compounds where mechanical stability
Ms
Esther Orisakwe
(University of Witwatersrand)
Track G - Theoretical and Computational Physics
Poster
The structural, elastics, and electronic properties of the advanced metal nitrides M2N3 and their ternary phases are investigated using ab-initio plane wave pseudopotentials under the framework of density functional theory. The relative stability of the ternary phases were also computed. Results obtained were compared with the available experimental and theoretical data.
Mr
Nathan Williams
(Nelson Mandela Metropolitan University)
Track F - Applied and Industrial Physics
Presentation
The monitoring of solar home systems is essential to improve the design and implementation of future systems. This paper discusses problems encountered in accurately measuring PV output power when monitoring systems using pulse width modulation charge controllers. Solutions to these problems are proposed and discussed and results presented.
Mr
Ahmed El-Hussein M.Kamel
(The National Institute of Laser Enhanced Science, Cairo University)
Track C - Lasers, Optics and Spectroscopy
Poster
Fluorescence spectroscopy is an evolving technology that can rapidly differentiate between non neoplastic and malignant tissues. These differences are thought to be due to endogenous fluorophores. This technique is a non-invasive diagnostic tool that can identify diseased tissue sites in vitro and in real time. It could have a major impact on the detection and treatment of cancer. The current...
Dr
Irvy (Igle) Gledhill
(CSIR)
Track F - Applied and Industrial Physics
Presentation
Fifth-generation missiles accelerate up to 100 g in turns, and higher accelerations are expected as agility increases. We have developed the theory of aerodynamics for arbitrary accelerations, and have validated modelling in a Computational Fluid Dynamics code. In this paper we will show fin disruption by strake vortices.
Mrs
Angela Dudley
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
We implement a novel technique to operate a phase-only spatial light modulator (SLM) in amplitude mode, allowing us to reproduce Durnin’s ring slit on a liquid crystal display (LCD). The affects of binary and continuous phase modulations on the structure of a zero-order Bessel beam is investigated.
Mrs
Angela Dudley
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
An interferometer, mimicking an amplitude damping channel for vortex modes, is presented. Experimentally the action of the channel is in good agreement with that predicted theoretically. Since we can characterize the action of the channel on orbital angular momentum states, we propose using it to investigate the dynamics of entanglement.
Mr
Attie Hendriks
(CSIR NLC)
Track C - Lasers, Optics and Spectroscopy
Presentation
Theory presenting amplitude and phase modulation using a phase only spatial light modulator is proposed and experimentally verified. This allows manipulation of any arbitrary light distribution unto developing a transmission function toolbox for quantum experiments.
Mr
Darryl Naidoo
(Council for Scientific and Industrial Research)
Track C - Lasers, Optics and Spectroscopy
Presentation
The oscillating mode in laser resonators is dual-directional between the mirrors. Theory describing the field distributions of the beam are compared and supplemented experimentally. The superposition of two Laguerre-Gaussian modes of opposite azimuthal order allows cylindrical “petal” modes to occur. These modes are achieved experimentally and compared to numerical simulations.
Mr
Hendrik van Zyl
(Stellenbosch University)
Track G - Theoretical and Computational Physics
Presentation
A recursive Green's function algorithm is used to calculate the current transport along the interface of a graphene sheet and a superconductor. The difficulty of hole and particle excitations coupling near the interface is resolved by mapping the Hamiltonian onto another equivalent Hamiltonian that can be represented in the algorithm.
Prof.
Hartmut Winkler
(Dept. Physics, University of Johannesburg)
Track D1 - Astrophysics
Presentation
The author presents first results of a project to digitize and characterise the spectra of over 1000 Seyfert galaxies. Due to the already massive and growing size of the lists of known Seyferts, the project at this stage focuses on the following: (a) objects at redshifts of z < 0.1, and (b) Seyferts with a clearly visible broad-line component at H-beta. Standardised spectra are obtained from...
Dr
Max Chirwa
(Walter Sisulu University)
Track A - Condensed Matter Physics and Material Science
Poster
A sequel to representing elemental sources of magnetic fields as elemental magnetic vector charges is realizing that electric and magnetic dipole moments are different classes of first order moments, each being a pair of allied monopolar moments. This shifts acutely from traditional notions like Dirac's magnetic (scalar) charge.
Mr
Mohau Mateyisi
(Institute of Theoretical Physics, Department of physics, University of Stellenbosch))
Track G - Theoretical and Computational Physics
Presentation
The understanding of mechanical properties of active polymer networks can provide insights on the functioning of a range of biological materials. In this paper we first present a simple model for a network of two flexible polymer filaments connected by a molecular motor cluster and the network ideas are further extend to a multi stranded network. We learn that active network components lead to...
Ms
Patricia Govender
(CSIR DPSS unit)
Track C - Lasers, Optics and Spectroscopy
Presentation
An adapted Michelson interferometric technique was used to measure strain induced birefringence in perspex. The birefringence was then used to determine the Kerr constant in perspex. The result obtained is compared to a polarimetric result and is shown to be a more sophisticated and reliable method.
Ms
Bathusile Masina
(CSIR-National Laser Centre)
Track F - Applied and Industrial Physics
Presentation
In this investigation a polycrystalline diamond (PCD) body produced under High Pressure High Temperature (HTHP) conditions was heated using a CO2 laser. The resultant surface temperature profile was measured optically by using the grey body emission from the PCD. This temperature measurement system allows one to study temperature influenced chemical and mechanical changes to the PCD structure.
Mr
Saturnin OMBINDA-LEMBOUMBA
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
The ultrafast dynamics of Zinc Phthalocyanine was studied using transient absorption pump probe spectroscopy. Zinc Phthalocyanine was excited (pumped) at 672nm and probed by a white light continuum. The pump-probe technique used in this study is described and experimental results obtained are discussed.
Mr
Phuti Ngoepe
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Poster
We report the current-voltage-temperature characteristics of Au/Ni/n-Al0.35Ga0.65N Schottky contacts measured over a wide temperature range. For larger forward bias, the current-voltage characteristics were well described by the thermionic emission model. By means of curve fitting, we could determine the relative contribution of the conduction mechanisms at each temperature.
Mr
Ronald Machaka
(School of Chemical and Metallurgical Engineering, University of the Witwatersrand)
Track F - Applied and Industrial Physics
Presentation
Using the nanoindentation technique and the Oliver & Pharr analysis method of the measured loading and unloading segments of the load-displacement curves, the hardness and Young’s modulus were determined for unirradiated and implanted B6O. The implanted hot-pressed B6O was irradiated with 150 keV fluorine in the dose range of 5 × 1014 to 5 × 1016 ions/cm2 at room temperature. The implanted...
Mr
Gerrit Olivier
(University of Stellenbosch)
Track G - Theoretical and Computational Physics
Poster
The microcanonical entropy s(e,m) as a function of energy e and magnetization m is computed analytically for the anisotropic Heisenberg model with Curie-Weiss-type interactions for anti-ferromagnetic and ferromagnetic cases. The results show non-equivalence of ensembles for certain cases and thermodynamic equivalence to the Ising and Heisenberg models in other cases.
Mr
Gaotsiwe Joel Rampho
(University of South Africa)
Track G - Theoretical and Computational Physics
Presentation
A technique of approximating expectation values of realistic nuclear
Hamiltonian with the antisymmetrised molecular dynamics wave function
is presented. Phenomenological nucleon-nucleon potentials with
analytical expectation values are used for illustration. The results
obtained with the approximation are compared with those obtained with
analytical evaluation.
Dr
Deena Naidoo
(School of Physics, University of the Witwatersrand)
Track E - Physics Education
Presentation
A comparison of the BSc extended and mainstream programmes in Physics at the University of the Witwatersrand are reviewed in order to facilitate possible processes to assist the new cohort of Outcome Based Education learners who generally lack the necessary mathematical and conceptual skills required for university.
Mr
Ignatius John
(CPUT)
Track E - Physics Education
Presentation
Little is known about how fine-grained contextual changes impact student reasoning in the context of DC circuits. We report on a study using an open circuit (battery, single wire, resistive element) in which the resistive element (resistor, heating element, light bulb) and the words (“current’, “charge flow”) are inter-changed.
Dr
Michael Gaylard
(HartRAO)
Track D1 - Astrophysics
Presentation
The laser was invented 50 years ago, but it was preceded six years earlier by the maser - stimulated emission at microwave frequencies - invented by Charles Townes and colleagues. Although it was not known at the time, nature had beaten them to it. Naturally produced masers are found in space, the first being discovered in 1965 by Weaver and colleagues. These masers occur in clouds of gas...
Ms
Andri Prozesky
(Unisa)
Track D1 - Astrophysics
Presentation
The physics of gaseous nebulae is critically examined using modeling software. Certain assumptions that are relevant for the optical spectral lines or low energy levels have been taken for granted to work for radio lines or transitions from high energy levels as well. The validity of these assumptions is tested.
Mr
Kenneth Kgatwane
(University of Limpopo)
Track A - Condensed Matter Physics and Material Science
Poster
MnO2 has found extensive applications as a cathode material in lithium batteries. However MnO2 suffers from structural degradation during charge/discharge which leads to capacity fading. We use atomistic simulation to explore and mitigate this structural collapse by employing novel porous MnO2 nanostructures with defects. The nanostructures are lithiated to simulate charge/discharge.
Mr
Andrew Esau
(NECSA)
Track B - Nuclear, Particle and Radiation Physics
Presentation
In this study we focus on the biological shielding around a 20 MW Oak-Ridge type Materials Testing Reactor. The design of the biological shielding around this type of research reactor was performed at ORNL in the USA in the late 1950s and early 1960s, i.e. in the days before powerful digital computers, powerful codes or accurate cross-section data were available. We investigate several...
Mr
Tjaart Krüger
(VU University Amsterdam)
Track C - Lasers, Optics and Spectroscopy
Presentation
We present a very brief introduction to biophysics – the rapidly developing field that explores physical processes in biological systems – and emphasise the great variety of spectroscopic techniques and applications. The promising role that biophysics can and should play in the context of South African Physics is briefly described.
153.
Calibration of an optoelectronic system for the study of solar blind AlGaN-based UV photodiodes
Mr
Louwrens van Schalkwyk
(Student)
Track F - Applied and Industrial Physics
Presentation
A calibrated optoelectronic system is required for the study of tuneable intrinsically solar blind AlGaN-based ultraviolet (UV) light sensitive photodiodes. The method of calibration is discussed; where by the spectral irradiance of the UV light incident on the photodiodes are calibrated for wavelengths ranging from 200 nm to 400 nm.
Dr
Kittessa Roro
(NLC-CSIR)
Track A - Condensed Matter Physics and Material Science
Poster
Multi-walled carbon nanotube (MWCNT)/Nickel oxide nanocomposites were prepared on aluminum substrates for selective solar absorber applications. MWCNTs are functionalized in order to disperse in water and ethanol. Results from the characterization of the composite samples using techniques such as transmission and scanning electron microscopies will be presented and discussed.
Ms
Pulane Moleme
(University of the Free State)
Track A - Condensed Matter Physics and Material Science
Poster
Cathodoluminescence (CL) of strontium thiogallate doped with cerium was investigated using Auger electron spectroscopy (AES) coupled with CL spectroscopy. The CL data were collected when the samples were irradiated with a beam of electrons accelerated at 1.5 to 2.5 kV. Possible mechanisms of CL degradation are discussed.
Ms
Deanne de Bude
(University of Cape Town)
Track D1 - Astrophysics
Presentation
I present preliminary results of a follow-up study on Dwarf Novae identified by the Catalina Transient Survey. Photometric observations were performed on the 1m and 1.9m reflector telescopes of the South African Astronomical Observatory. The properties determined by this study are vital in understanding binary evolution and constraining binary synthesis models.
Prof.
Eugene van Dyk
(Nelson Mandela Metropolitan University)
Track F - Applied and Industrial Physics
Presentation
Concentrator photovoltaic deals with the focussing of incident sunlight onto solar cells by employing relatively inexpensive optical elements in an attempt to reduce overall photovoltaic system cost. In this study a low concentrator photovoltaic module was designed and constructed to characterize the optics, electrical performance and thermal management.
Mr
SJ Van der Merwe
(University of Pretoria/Hermanus Magnetic Observatory)
Track D2 - Space Science
Presentation
This paper briefly describes a novel approach to characterizing the ionosphere over the South Atlantic Geomagnetic Anomaly using a ship-based dual frequency GPS receiver. Applications include but are not limited to HF propagation path prediction for communication and GPS positioning applications, specifically operating in this zone of abnormal magnetic activity.
Mr
Wilfrid Ndebeka
(University of Stellenbosch)
Track C - Lasers, Optics and Spectroscopy
Presentation
We present measurements of the slope efficiency and the pump power at threshold for a “triple-clad” thulium doped fiber laser, operating at around 2 µm wavelength. We observe fiber laser efficiencies as high as 47 % and output power of 5 W for 20 W of absorbed pump power. The dependence of the laser efficiency on different cooling methods will be discussed.
Mr
Gaotsiwe Joel Rampho
(University of South Africa)
Track G - Theoretical and Computational Physics
Poster
Charge form-factors of three- and four-nucleon systems are extracted
from elastic electron scattering using antisymmetrised molecular
dynamics wave functions. The Hamiltonian of the nuclei is described
with a semi-realistic nucleon-nucleon potential. The results obtained
are compared with some experimental data.
Mr
Michiel De kock
(University of Stellenbosch)
Track B - Nuclear, Particle and Radiation Physics
Presentation
Given a histogram of measurements, we compare the chi-squared goodness-of-fit test and the Kullback-Leibler divergence of different models. We then apply these methods for parameter estimation and relate them to the principle of Maximum Likelihood. These non-Bayesian approaches are finally viewed in the
light of a Bayesian solution.
Dr
SS Pitale
(University of the Free State)
Track A - Condensed Matter Physics and Material Science
Presentation
Luminescence characteristics and surface chemical changes of nanocrystalline Mn doped ZnAl2O4 powder phosphors are presented. X-ray photoelectron spectroscopy (XPS) was used to determine the chemical composition of the possible compounds formed on the surface as a result of the prolonged electron beam exposure. A stable Al2O3 layer was formed on the surface and is possibly contributing to the...
Mrs
Marisa Nickola
(HartRAO and UP)
Track D2 - Space Science
Poster
Optical turbulence, occurring mostly in the planetary boundary layer (PBL), degrades geodetic data. Site characterisation requires knowledge of the vertical distribution of optical turbulence, the CN2 profile. A CN2 profile, obtained by employing a database of turbulence-resolving simulations, is compared with an observational profile.
Ms
Stephanie Smith
(University of the Witwatersrand)
Track G - Theoretical and Computational Physics
Presentation
We develop a collective field theory of single matrix models using the formalism of Jevicki
and Sakita in[1] ('The Quantum Collective Field Method and its Application to the Planar Limit'), with Schur polynomials as collective fields. The highly nontrivial Jacobian
associated with the change of variables required to obtain the collective field Hamiltonian, is found
using group...
Alexander Avdeenkov
(NIThep, Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Presentation
The collisions at ultracold temperatures between diatomic polar molecules in a microwave field with a circular polarization are theoretically analyzed. We demonstrate the possibility of trapping polar molecules in the standing-wave electromagnetic field and a successful evaporative cooling not only for samples of molecules in their absolute ground states but in some rotationally excited...
Ms
Ann Singh
(CSIR,National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Poster
This study aims to extract and compare attenuation coefficients of different liquid skin-like phantoms representing Skin Types I to VI with two methods, Spectrophotometric and Integrating Sphere methods. The correlation between the results of the 2 methods was excellent.
Mr
Jacques Pienaar
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Poster
Deep Level Transient Spectroscopy (DLTS) was used to measure the field enhanced emission rate from a defect introduced in n-type Ge. Nonlinear fits to the models of Pons & Makram-Ebeid (1979) and Ganichev & Prettl (1997) which describe emission due to phonon assisted tunneling were obtained. The model of Pons & Makram-Ebeid predicted the measured emission rate more accurately than Ganichev &...
Ms
Buyisiwe Sondezi-Mhlungu
(University of Johannesburg)
Track A - Condensed Matter Physics and Material Science
Presentation
The magnetic and electronic properties of polycrystalline and single crystal CeAuGe were investigated from magnetic susceptibility and resistivity measurements. Theoretical resistivity fits describing anisotropic ferromagnetism in the ordered region were performed and illustrates how the energy gap in the magnon excitation spectrum decreases as a function of applied magnetic field.
Mr
Bradley Frank
(Astrophysics, Cosmology and Gravity Centre, Department of Astronomy, University of Cape Town)
Track D1 - Astrophysics
Presentation
We present recent results comparing the dynamics of a sample of local galaxies in HI (THINGS) and CO (HERACLES). We will also compare different means of computing velocity fields and verify the interchangeability of HI and CO,
especially for the innermost stellar regions, where HI has a very low surface brightness.
Mr
Adewumi Popoola
(School of Physics, University of the Witwatersrand, Johannesburg)
Track A - Condensed Matter Physics and Material Science
Poster
We have used electronic structure method based upon Density Functional Theory (DFT) formalism to search for new class of high temperature super-alloys. Our search is focused on alloys between the noble metals and aluminum. Over-estimation of the properties of our target alloys was avoided by approximating only the gradient of the exchange and correlation functional. The behavior of each alloy...
Mr
Hannes de Meyer
(University of Pretoria)
Track F - Applied and Industrial Physics
Presentation
An offset capacitor system is used to reduce the signal to noise ratio when measuring capacitance transients in Deep Level Transient Spectroscopy (DLTS) to subtract the equilibrium capacitance of the sample. A LabVIEW routine in conjunction with a computer controlled offset capacitance box was build and compared with a standard set capacitor box.
Ms
GLADYS SONKO
(CSIR)
Track F - Applied and Industrial Physics
Presentation
Contact slip rings have inherent characteristics, e.g. contact wear, that hinder their performance. Alternatives include is the use of inductive or capacitive energy storage for contactless power transfer. We investigated the capacitor as an alternative to the standard inductive type contactless slip rings. The resultant prototype system achieves rotary capacitive power transfer at a system...
Mr
Mabuti Jacob Radebe Radebe
(Necsa)
Track F - Applied and Industrial Physics
Presentation
Neutron imaging is a powerful analytical tool with potential and demonstrated industrial and research application to nondestructively investigate internal properties of matter or end products. Standards, through test samples and methods, are essential for industrial application and internationally uniform platform for practice and facility performance assessment. This PhD subproject is a...
Dr
Teodora Kirova
(National Institute for Theoretical Physics)
Track C - Lasers, Optics and Spectroscopy
Presentation
We present the use of Autler-Townes effect to control the singlet-triplet state character in molecules. In a three-laser excitation scheme in lithium dimer we demonstrate that application of a strong enough coupling field to the singlet component of a singlet-triplet mixed pair leads to significant enhancement in the mixing coefficients and therefore the amount of singlet or triplet character...
Mr
MOHAMED ABDELWAHAB
(uct)
Track G - Theoretical and Computational Physics
Poster
In this paper we studied multi-fluid perturbations to fourth order theories of gravity
in a FLRW background. applying the 1+3 covariant gauge-invariant
formalism of cosmological perturbations and derive a complete set of evolution equations for matter
and curvature inhomogeneities.We then specialize to a radiation-dust
fuid described by barotropic equations of state and apply the...
Mr
Gopolang Mohlabeng
(Student)
Track D1 - Astrophysics
Poster
The identification of dark matter (DM) is one of the most challenging issues of physics today. A theoretical class of candidates involves weakly interacting massive particles (WIMPs) as DM. DM produces sizable fluxes of relativistic electrons and positrons. Observational prospects for the MeerKAT telescope concerning the emission in a few nearby clusters of galaxies are presented.
Mr
Hannes Calitz
(CSIR)
Track C - Lasers, Optics and Spectroscopy
Poster
Recent emission FTIR measurements were done on countermeasure flares using a passive infrared imaging Fourier transform spectrometer. Problems faced during the data analysis, where part of the data signature is located on dead pixels, and the determination of both temperature and emissivity as unknowns, are discussed.
Mr
Abraham van der Linde
(University of the Free State)
, Mr
Daniël Wium
(University of the Free State)
Track D1 - Astrophysics
Poster
A pipeline for reducing optical photometry data is presented. It is set in the IRAF environment and coded using CL scripting. The main focus of the project is to ease and speed-up the reduction of differential photometry data, with aperture- and psf fitting both supported.
Dr
Hermann Uys
(National Laser Centre, CSIR)
Track C - Lasers, Optics and Spectroscopy
Poster
We investigate the decoherence of superpositions of hyperfine states of $^9$Be$^+$ ions due to spontaneous scattering of off-resonant light. We find that, contrary to conventional wisdom, elastic Rayleigh scattering can have majour contributions to decoherence when compared to the effect of inelastic Raman scattering.
Ms
Wendy Williams
(University of Cape Town)
Track D1 - Astrophysics
Presentation
I present results from a deep near-infrared survey of gas-rich galaxies behind the plane of our Galaxy. Accurate surface photometry, with careful attention to star-subtraction, has been performed and total magnitudes have been determined for the sample. This data, combined with existing 21-cm spectra, is used to calculate Tully-Fisher distances.
Mr
M J Daniel Esser
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
We present a continuous-wave slab laser utilising both Ho:YLF and Ho:LuLF as laser gain media. 30 W of output power at 2 µm was demonstrated in a stable concave-plane resonator while 13 W was achieved in a hybrid stable-unstable configuration when pumped with a high-power Tm:YLF slab laser.
Ms
Jesman Changundega
(Nelson Mandela Metropolitan University)
Track C - Lasers, Optics and Spectroscopy
Poster
For the monitoring of a probe’s degree of polarization (DOP), the probe wavelength in a pump-probe Wavelength Division Multiplexed system was fixed while the pump wavelength was varied. Results show the changes in the probe’s (DOP). The minimum DOP over the spectrum for varying Pump power was also analyzed.
Dr
Daniel Wamwangi
(wits university)
Track F - Applied and Industrial Physics
Presentation
Cr3C2 films on Si have been grown by RF sputtering at 0 and -60V bias to observe stress relaxation using surface Brillouin scattering. A RF power of 175W and Ar2 working gas pressure of 5.0 x10-3mBar was used to yield a deposition rate of 0.16nm/s. Surface Brillouin studies on the -60V biased and the unbiased samples show high frequency Sezawa modes indicative of high film quality. The...
Ms
Primrose Nosicelo Njingana
(FHIT)
Track F - Applied and Industrial Physics
Poster
The fabrication of thin solid films was conducted using spray pyrolysis technique where the source solution (Organometallic : Grignard Reagent) was dissolved in diethyl ether and inorganic salts) was sprayed in compressed air for 15 minutes then stop to the heated glass substrate and temperature ranges from 290 oC to 350 oC at the deposition chamber.
Mr
Felix Pagona
(Fort Hare Institute of Technology, Physics Department)
Track F - Applied and Industrial Physics
Poster
Unnecessary temperature fluctuations due to factors such as self heating effect adversely affect performance and stability of anaerobic digesters [1]. A digester will be designed with an automatic temperature regulation mechanism that incorporates sensors, temperature regulator and cooling/heating system, which will be triggered into action upon receiving sensor instructions resulting from...
Dr
Hermann Uys
(National Laser Centre, CSIR)
Track C - Lasers, Optics and Spectroscopy
Presentation
We report a calibrated measurement of 174 yoctonewton $(1\times10^{-24}\; \textnormal{N} = 1\;\textnormal{yN})$, using a cloud of 60 $^9$Be$^+$ ion confined in a Penning ion trap. These measurements suggest that ion traps may form the basis of a new class of ultra-sensitive deployable force sensors.
Dr
Christine Steenkamp
(Laser Research Institute, University of Stellenbosch)
Track C - Lasers, Optics and Spectroscopy
Poster
Twenty rovibronic transitions of the e(v’=5)-X(v’’=0) band of 12C16O for which experimental wavelengths were previously unavailable were recently detected by vacuum ultraviolet laser induced fluorescence excitation spectroscopy. The data is important in astrophysical applications and for comparison to the latest model of 12C16O. The experimental techniques that facilitated these measurements...
Dr
Mark Herbert
(University of the Western Cape)
Track B - Nuclear, Particle and Radiation Physics
Presentation
A neutron spectrometer based on NE230 deuterated liquid scintillator was developed to measure neutron energy spectra in water. Neutron energy spectra were obtained from measurements of pulse height spectra using the Bayesian unfolding code MAXED. Results from measurements made along the beam-axis compare well with Monte Carlo calculations using MCNPX.
Mr
Robert Nshimirimana
(NECSA)
Track F - Applied and Industrial Physics
Presentation
The shape and size of particles are used in prediction of permeability (fluid conductivity) in porous media. This talk demonstrates the capability of a neutron/X-ray tomography imaging system in determination of the shape and the size of particles non-destructively.
Mr
Azwitamisi Eric Mudau
(Defence, Peace, Safety and Security (DPSS), Council for Scientific and Industrial Research (CSIR))
Track C - Lasers, Optics and Spectroscopy
Poster
To determination the temperature using infrared cameras, the following issues need to be addressed, the emissivity of the object and atmospheric path effects. The later is negligible in the setup used. In this paper we present the emissivity of the flame determined from the transmissivity measured using the FTIR Spectroscopy.
Mr
Megersa Wodajo Shura
(NMMU)
Track A - Condensed Matter Physics and Material Science
Poster
Steady state photo-conductivity measurements are used for the determination of the lifetime of excess charge carriers in antimony based semiconductor (i.e. Ga Sb) thin films. The spectral dependence of the lifetime, as well as the dependence of lifetime on the incident photon flux density, the temperature and the doping level is investigated. In order to evaluate the surface and bulk...
Mr
Innocent Mayida
(University of Witwatersrand)
Track B - Nuclear, Particle and Radiation Physics
Poster
The 6 MV EN tanderm accelerator of iThemba LABS (Gauteng) will be used for the measurement of 9Be +9Be elastic scattering.An excitation function and an angular distribution will be measured.The beam development exercise,experimental techniques and new results will be presented.
Dr
Pieter Neethling
(Laser Research Institute, University of Stellenbosch)
Track C - Lasers, Optics and Spectroscopy
Poster
The Laser Research Institute and the CSIR National Laser Centre are developing a high power femtosecond laser system in a joint project with a phased approach. The laser system consists of a fs oscillator and a regenerative amplifier. An OPCPA amplifier and a multi-pass amplifier are under development.
Mr
nicolin govender
(Necsa,UKZN,UJ)
Track B - Nuclear, Particle and Radiation Physics
Presentation
There is a global drive to build new research reactors, currently the calculation of various saftely and perfomance parameters is very time consuming for a single design. In the calculation process there are two classes of solutions , Monte Carlo methods which are accurate and flexible but slow and anyalatical methods which are very fast but not as accurate or flexible. This paper will look at...
Mr
Blaine Blaine B. D. Lomberg
(University of the Western Cape & iThemba LABS)
Track B - Nuclear, Particle and Radiation Physics
Poster
In this paper we describe the development of a beam emittance device with which the quality of ion beams extracted from ion sources will be investigated.
Ms
Victoria Van Kets
(University of Cape Town)
Track C - Lasers, Optics and Spectroscopy
Presentation
Photodynamic therapy (PDT) has recently emerged as a treatment modality for photorejuvenation of the skin. This study is a preliminary investigation into the effect of different light sources to activate hypericin, a plant-derived photosensitizer in primary human dermal fibroblast cells.
Prof.
Erich Friedland
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Presentation
Fuel elements of modern high-temperature nuclear reactors are encapsulated by CVD-layers of pyrolitic carbon and silicon carbide to reduce fission product release. The aim of this study is to obtain information on volume and grain boundary diffusion as well as on the influence of radiation damage. For this purpose relevant isotopes were implanted in poly and single crystalline SiC samples at...
Dr
Kobus Lawrie
(iThemba LABS)
Track B - Nuclear, Particle and Radiation Physics
Poster
New experimental results from a gamma spectroscopic study of Hg-196 reveal two dipole bands, with even and odd parity respectively. One was previously observed, while the other is new. In both cases spin and parity assignments were possible.
Mr
Mira Joele
(University of Stellenbosch/iThemba LABS)
Track B - Nuclear, Particle and Radiation Physics
Presentation
The binary breakup of 12C into 8Be fragments and alpha particles were measured in coincidence in the interaction of 33.3 MeV/nucleon 12C projectiles with 197Au, 93Nb and 12C target nuclei. Preliminary experimental cross-section contributions are extracted for both quasi-elastic and the inelastic break-up processes.
Dr
Frederick David Smit
(iThemba LABS, , PO Box 722, Somerset West 7129, South Africa)
Track B - Nuclear, Particle and Radiation Physics
Presentation
A recent paper by Jenkins et al. suggested that the radioactive decay rate of certain radionuclides may be influenced by the neutrino flux from the Sun which varies with the distance between the Sun and Earth. This paper reports on measurements made at a reactor to test this claim.
Ms
Sharlene-Asia Naicker
(University of KwaZulu-Natal)
Track C - Lasers, Optics and Spectroscopy
Poster
Laser cooling and trapping of atoms have become a significant area of research in physics. Saturation absorption spectroscopy is an important element in the laser cooling setup. We have investigated methods to improve the technique of saturation spectroscopy resulting in resolving hyperfine transitions of rubidium atoms which are concealed by Doppler broadening.
Dr
Fabio Frescura
(U Witwatersrand)
Track D1 - Astrophysics
Poster
Lie Derivatives and Perutbation of Fluid Flows
We describe the use of the Lie derivative for describing perturbations of fluid flows. We apply the methods developed to some elementary problems in the stability of stellar structure, and discuss the advantages and disadvantages of this approach compared with the standard theory.
Mr
Stephen Meyer
(University of Kwazulu-Natal)
Track D2 - Space Science
Presentation
VLF (3-30 kHz) radio waves propagate with little attenuation within the Earth-ionosphere waveguide. There are numerous factors that determine waveguide propagation conditions such as ionospheric free electron density and the conductivity of the Earth’s surface along the propagation path. This paper examines how modifications of these factors alter the propagation of the VLF waves.
Mr
Brian Yalisi
(CSIR, UKZN)
Track F - Applied and Industrial Physics
Presentation
Carbon nanotubes embedded in NiO have been ablated onto aluminium by varying deposition time/thickness using pulsed laser deposition for selective solar absorber coatings. It has been noted that the absorptance increases as the thickness increases for all carbon concentrations. A maximum solar absorptance of 91 % has been achieved so far.
Dr
nadia saoula
(centre de développement des technologies avancées , CDTA)
Track A - Condensed Matter Physics and Material Science
Poster
In this study, we present the effect of the plasma deposition parameters on the properties of Ti/TiC multilayers deposited by RF-Magnetron Sputtering (13.56 MHz) under methan and argon reactive plasma at low pressure. The film depositions have been done on silicon and steel substrates. The attention was given to study the influence of different parameters (deposition time, RF power, and total...
Mr
Andreas Hafver
(Stellenbosch University)
Track G - Theoretical and Computational Physics
Poster
In non-commutative quantum mechanics position space becomes fuzzy. This has implications for the way particles interact. We show that the effective interaction between fermions and bosons is modified, leading to an apparent violation of Pauli’s exclusion principle.
Mr
laveshan nayager
(wits)
Track F - Applied and Industrial Physics
Presentation
We consider ways of increasing efficiency of solar trough receiver pipes by decreasing the leading thermal radiation losses. We study the use of a secondary concentrator, a “solar funnel”, which reduces the area that emits thermal radiation. We further increase efficiency by use of a heat mirror on the glass cover which reflects the thermal radiation being emitted by the receiver pipe back onto itself.
Dr
Charles Sheppard
(Department of Physics, University of Johannesburg)
Track A - Condensed Matter Physics and Material Science
Presentation
The influence of Mo-doping on the first-order Néel transition of a Cr0.975Si0.025 alloy is investigated through electrical resistivity, specific heat and thermal transport measurements. The results suggest the absence of antiferromagnetism in (Cr97.5Si2.5)1-yMoy alloys with y ≥ 0.025.
Prof.
Steven Karataglidis
(University of Johannesburg)
Track B - Nuclear, Particle and Radiation Physics
Presentation
Low-energy nucleon-nucleus elastic scattering involving particle-unbound states in the target spectrum is developed within the framework of a Multi-Channel Algebraic Scattering theory. The effects on the scattering observables when the particle-emission widths are significantly different from zero are discussed.
Mr
Bolade Adewale Adetula
(Northwest university, NECSA)
Track F - Applied and Industrial Physics
Poster
A recently developed sensitivity analysis technique known as Global Sensitivity Analysis (GSA) is based on the High Dimensional Model Representation and functional ANOVA. The efficiency of the different numerical techniques used in the evaluation for GSA, capable to deal with the curse of dimensionality and correlations between inputs, are evaluated.
Ms
Marie Chantal CYULINYANA
(University of the Witwatersrand)
Track F - Applied and Industrial Physics
Presentation
We are considering a solar trough system, with the receiver pipe enclosed in a glass cover under vacuum. We present results for absorption and loss calculations for a general case, and use these to compare two scenarios: 1) receiver pipe is coated with a selective coating, and 2) glass cover is coated with a hot mirror coating. Simulations for both scenarios are presented and compared.
Prof.
Darrell Comins
(University of the Witwatersrand)
Track A - Condensed Matter Physics and Material Science
Presentation
Surface Brillouin scattering is used to determine the velocities of the Rayleigh surface wave, pseudo-surface wave and longitudinal lateral wave measured in the [100] and [110] directions in a (100) surface of single crystal InAs0.91Sb0.09. Explicit secular functions for the wave velocities are used to extract the elastic constants.
Mr
Gibson Peter Nyamuda
(Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Presentation
A femtosecond laser is used to study second harmonic generation in reflection and for the first time in transmission using a silicon membrane sample. The second harmonic signal measured in transmission is higher than expected and a new interpretation of second harmonic generation results from silicon/silicon dioxide interfaces is proposed.
Mr
Peter Baricholo
(National University of Science and Technology, Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Presentation
A bipolar pulsed high voltage and high frequency power supply has been developed to excite a dielectric barrier discharge excimer lamp. Voltage and current signals across the 5 mm electrode gap have been measured. Energy through the gas per pulse has been obtained by integrating the power applied. About 300 μJ of energy per pulse is delivered to the gas.
Mr
Albert Chawanda
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Poster
Ruthenium (Ru) and Iridium (Ir) Schottky barrier diodes were electron beam deposited on (100) n-type germanium. Electrical characterization of these contacts using current-voltage and capacitance-voltage measurements was performed under various annealing conditions. The variation of the electrical properties of these Schottky contacts can be attributed to the combined effects of interfacial...
Mr
Pararajasingham Peratheepan
(Department of Physics, University of Johannesburg, Auckland Park-2006, South Africa)
Track A - Condensed Matter Physics and Material Science
Poster
CexLa(1-x)Ru2Al10 (0.6 x 0.99) has been investigated by means of electrical resistivity, thermal conductivity and thermopower. Temperature dependence of electrical resistivity reveals metal-insulator transition that shifts systematically towards low temperatures with increasing La concentration. Fairly small thermal conductivity and enhanced thermopower are observed for x = 0.95 and 0.99.
Mr
Patrick Nsimama
(The university of the Free State)
Track A - Condensed Matter Physics and Material Science
Presentation
Abstract: SrAl2O4:Eu2+,Dy3+ films ablated in different deposition atmospheres were characterized by Auger electron spectroscopy (AES), scanning electron microscopy (SEM), atomic force microscopy (AFM), and fluorescence spectrophotometer. Superior photoluminescence properties were recorded by films deposited in the different gas atmospheres. Surface morphology played a major role in the...
Mr
E M Benecha
(Physics Department, University of South Africa (UNISA))
Track A - Condensed Matter Physics and Material Science
Presentation
The energetic stability and magnetic ordering properties of 3d transition metals in diamond are investigated using ab initio DFT methods. The divacancy is predicted to be the energetically most favourable site, with Cr, Mn, Fe, Co and Ni having the lowest formation energies. Spin polarised impurity bands are induced in the diamond band gap, suggesting that these elements are likely to order...
Mr
Tshepo Dinoko
(iThemba LABS/University of the western Cape)
Track B - Nuclear, Particle and Radiation Physics
Presentation
Excited states in 155Gd nuclei were populated in the 154Sm (α, 3n) reaction at a beam energy of 33MeV. The aim is to establish firm spin and parity assignments for the many complex rotational bands that have been observed in this nucleus and to observe which couplings are blocked by which quasi-neutrons in order to establish the under lying microstructure of the collective excitations of the...
Mr
Vusi Malaza
(Student)
Track B - Nuclear, Particle and Radiation Physics
Poster
A study of a new type of nuclear transformation referred to as “collinear cluster tri-partition” (CCT) has been conducted. Reliable identification of this unusual decay channels involves measurement of neutron multiplicity. A new time-of-flight spectrometer called the Compact Multi-cluster Event Trigger Array (COMETA) has been designed to measure neutron multiplicity.
Mr
Mathew Moodley
(CSIR)
Track A - Condensed Matter Physics and Material Science
Presentation
In situ optical emission spectroscopy(OES) was used to investigate the spatial and temporal evolution of the electron temperature(Te) of laser induced plasmas in the laser-furnace method of synthesizing single-walled carbon nanotubes (SWCNTs). The intensities of the spectral maps of Te showed a strong temperature dependence. The frequency of sharp fluctuations which appear as hot spots in the...
Mr
Pararajasingham Peratheepan
(Department of Physics, University of Johannesburg, Auckland Park-2006, South Africa)
Track A - Condensed Matter Physics and Material Science
Poster
The magnetic susceptibility and specific heat data are reported for the substitutional compounds CexLa(1-x)Ru2Al10 (x = 0.99, 0.4). With decreasing x, i.e., increasing La doping, the antiferromagnetic-like transition, T0, shifts down systematically to lower temperatures.
Dr
Filippus Roux
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Poster
We numerically investigate the evolution of the optical vortex density in a speckle field after its continuous phase is removed, in other words, after it has been phase corrected. We found that it initially drops to 70% and then increases to 88% of the initial density. The rate of decrease is an order of magnitude faster than the rate of increase.
Ms
Pontsho Sylvia Mbule
(University of the Free State)
Track A - Condensed Matter Physics and Material Science
Presentation
Abstract: Zinc Oxide (ZnO) and lead sulphide (PbS) nanoparticles separately synthesized by a precipitation method were combined by an ex situ route to prepare ZnO-PbS nanocomposites with different molar ratios of ZnO and PbS. Optical properties, structure and morphology of the samples were analyzed and are discussed.
Mr
Sosten Ziuku
(SAIP)
Track F - Applied and Industrial Physics
Poster
In this paper, electrical and exergy analysis of a BIPV generator is presented. Electrical efficiency was found to vary between 13.9% and 17.6% while the indoor Exergy varied from 25.1% to 35.2% between 0900 and 1630hours. Exergy analysis, which deals with maximum energy available from the BIPV generator, gives a more realistic model of the impact that integrated photovoltaic panels have on...
Dr
Shimul Kumar Maharaj
(Hermanus Magnetic Observatory)
Track D2 - Space Science
Presentation
Using the Sagdeev pseudo-potential formalism, the permitted velocity ranges of large amplitude ion-acoustic and electron-acoustic solitons are determined for a plasma comprised of hot and cool electrons, and ions. Adiabatic fluids are used for the cool electrons and the ions, whereas, for the hot electrons, both the cases corresponding to including inertial effects and neglecting the inertia...
Mr
fhumulani nemulodi
(university of cape town)
Track G - Theoretical and Computational Physics
Presentation
From Israel-Sterwart(second order) entropy four-current in kinetic theory, we expand it up to third order in dissipative fluxes, the Viscous stress tensor, heat flux and Viscous pressure. We show the temperature behaviour of our coefficients by ploting them as functions of temperature dependent parameter. Finally we will compare our results with those obtained from Israel-Sterwat theory.
Mr
John Motsoeneng
(University of Pretoria)
Track E - Physics Education
Presentation
Q Motsoeneng, N C Moji, D Dale,T Hlatshwayo and W Mtangi.
An investigation of what happens to the temperature of a mixture of ice and water at zero degrees celsius when left to heat up on its own.Students only learned later that the heat absorbed was used to break the bonds.
Mr
Jean Jacques Kaboko
(University of Johannesburg)
Track C - Lasers, Optics and Spectroscopy
Presentation
In this project, a design and experimental investigation of a Q-switched fiber lasers are presented. Using the Q switched technique, the peak power and time duration of the laser pulses are analyzed as function of repetition rate, pumping power, cavity length and output coupler transmission.
Dr
JUSTICE S.P MLATHO
(NORTH-WEST UNIVERSITY)
Track F - Applied and Industrial Physics
Presentation
A Conical Tube (CT) and two volumetric solar receivers have been designed. The volumetric receivers have maximum efficiencies of 35 % for outlet temperatures (Tout) of 100 oC while that of the CT receiver is 42 %. Thus the CT receiver has best designed.
Mrs
Aletta Karsten
(CSIR, National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
Raytracing computer models are valuable tools to determine the fluence at a specific depth into tissue, but need to be verified before they can be used with confidence. Such a model for skin showed good agreement (within 10%) when compared with images from experiments on solid resin skin simulation phantoms.
Mr
Nkanyiso Mbatha
(UKZN and HMO)
Track D2 - Space Science
Presentation
Using absorption data measured by imaging riometer for ionospheric studies (IRIS) located at the South Africa National Antarctic Expedition (SANAE), Antarctica (72˚S, 3˚W), we extracted the parameters of gravity waves (GW) of periods between 35 and 55 minutes during the period from 16 to 30 September 2002, a period of major sudden stratospheric warming (SSW) in the Southern Hemispheric middle...
Mr
Pieter Barnard
(UOVS)
Track A - Condensed Matter Physics and Material Science
Poster
A method is proposed for the preparation of Fe/S samples using molecular Sulfur to dope Iron samples at high temperatures. Using Fick`s semi-infinite diffusion model the time needed to obtain a certain bulk concentration at a specified temperature is calculated. Experimental results obtained this far confirms the possibility of such an experiment.
Dr
Anton du Plessis
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
Femtosecond laser control of the chemical reaction of CO and H2 is studied. Specific high-value reaction products can possibly be produced selectively, without need for further separation or purification. In this work, we aim at controlling the reaction between CO and H2 to produce hydrocarbon products, of interest to the petrochemicals industry. Preliminary experimental results will be presented.
Dr
Anton du Plessis
(CSIR National Laser Centre)
, Dr
Ted Roberts
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
Femtosecond Laser Induced Breakdown Spectroscopy (femto-LIBS) was applied to a depth profiling problem in 500-micron diameter spheres of ZrO2. The spheres were provided containing silver inside, and in addition they were coated with a thin layer of silver on the surface for this study. This is a feasibility study for diagnosing leakage of radioactive silver through the silicon carbide barrier...
Mr
J P W Diener
(Stellenbosch University)
Track G - Theoretical and Computational Physics
Presentation
The magnetic properties of matter under extreme conditions are of particular importance to understand the neutron star interior. One contributing factor to the neutron star’s magnetic field could be the ferromagnetic phase of nuclear matter. Using a relativistic model we calculated the ferromagnetic phase diagram for dense neutron matter.
Dr
riccardo fantoni
(National Institute of Theoretical Physics (NITheP), South Africa)
Track A - Condensed Matter Physics and Material Science
Presentation
We propose a field theoretical approach to a polymer whose
backbone is made of Janus particles. The field theory is solved using
the saddle point approximation and the Random Phase Approximation
valid for a dense polymer. We calculate the free energy density,
the radius of gyration, and the Janus clusters concentrations.
Mr
Maxwell Jingo
(University of the Witwatersrand, South Africa)
Track B - Nuclear, Particle and Radiation Physics
Poster
A survey of the fine structure of the Isovector Giant Dipole Resonance (IVGDR) was investigated using the newly commissioned zero degree capability of the K = 600 magnetic spectrometer of iThemba LABS. Scattering (p,p') data were obtained over a wide target-mass range, at 200 MeV. Experimental techniques and preliminary results are presented.
Mr
Bongani Ngwenya
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Presentation
We study the impact of C substitutional atoms, B and N atom swapping and vacancies, and some adatoms on electronic and structural properties of boronitrene (2D boron nitride) using the VASP code. The generalized gradient approximation is the initially used exchange correlation functional. Our results show good agreement with literature.
Ms
Emily Aradi
(University of the Witwatersrand)
Track F - Applied and Industrial Physics
Presentation
The structural modification of polycrystalline hexagonal boron nitride implanted with boron and lithium ions at 150keV with various fluences were investigated. This was accomplished by analysis with Raman spectroscopy before and after implantation. Micro-Raman Spectrum showed evidence of implantation induced transformation to c-BN. The shifting of c-BN peak was explained using the phonon...
Mr
Samuel Kofi Fosuhene
(Nelson Mandela Metropolitan University)
Track C - Lasers, Optics and Spectroscopy
Poster
Forward and single-ended Polarization Mode Dispersion (PMD) measurements were performed on a tunable PMD emulator. Selected voltages applied to seven electro-optic polarization rotators altered the mode coupling angles between fixed length polarization maintaining fibres thus changing the emulator’s PMD statistics to mimic different fibre links.
Ms
Denise Dale
(University of Pretoria)
Track E - Physics Education
Presentation
2010 SAIP ABSTRACT
D Dale, N C Moji, Q Motsoeneng, T Hlatshwayo and W Mtangi.
An Investigation of the abilities of students, to infer from an experiment done on the cooling down of hot water to room temperature that the Temperature – time graph of cold water heating up to room temperature will be the opposite. Most students could not accomplish this in a class test.
Ms
Nadine Shuda
(University of Johannesburg)
Track C - Lasers, Optics and Spectroscopy
Poster
The application of the FMCW technique to an optical fiber temperature sensor is investigated and tested experimentally in this project. Multiplexing of the sensor and variation of the sensitivity when parameters are varied is also investigated and simulated.
Dr
Ncholu Manyala
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Presentation
We report pulsed laser deposition synthesis and characterization of polycrystalline Fe1-xCoxSi thin films on Si (111). Ferromagnetism with significant magnetic hysteresis is found for all films including nominally pure FeSi which reveals trasition from paramagnetic and helimagnetic to ferromagnetic for Fe1-xCoxSi for FeSi and Co doped FeSi.
Prof.
Ludwig Combrinck
(HartRAO)
Track D2 - Space Science
Presentation
The accuracy of Space Geodesy techniques have improved to such an extent that routine data analyses need to incorporate the effects of General Relativity Theory (GRT). A comparison between the accelerations perturbing the orbits of the two LAGEOS satellites resulting from GRT and other non-GRT accelerations are made. The analyses of the resulting data have to be done within the framework of a...
Mr
Jean UWAMAHORO
(Hermanus Magnetic Observatory)
Track D2 - Space Science
Presentation
Over a period of 11 years of solar cycle 23 : 1996-2006, the solar sources of 219 geomagnetic storms have been investigated . This investigation focused on a class of coronal mass ejections (CMEs) known as halo CMEs and they subsequent geo-effective conditions in the interplanetary medium. In this paper, we present the results of a statistical analysis of geomagnetic storms solar sources...
Dr
Pierre Cilliers
(Hermanus Magnetic Observatory)
Track D2 - Space Science
Presentation
Marion Island (46d52.740’S, 37d51.442’E), near the edge of the South Atlantic Anomaly, is strategically located for geomagnetic observations. This paper presents the geomagnetic survey done on Marion Island towards the re-establishment of a magnetic observatory to follow up on observations done there during the period 1972 to 1980.
Dr
Bhekumusa Mathe
(University of the Witwatersrand)
Track A - Condensed Matter Physics and Material Science
Presentation
Elastic and stiffness moduli of vertically aligned single-crystal ZnO nanorods grown on Si(001) substrates were determined quantitatively by the surface Brillouin scattering technique. A longitudinal guided mode at 16 – 18 GHz enabled the exact determination of c11 from which c11 and c44 were measured to be 116 GPa and 42.4 GPa respectively, at room temperature.
Mr
Moses Mogotsi
(UCT)
Track D1 - Astrophysics
Poster
The habitability zone is a region where planets can form with suitable conditions for life, these regions can be localized to galactic habitability zones and circumstellar habitability zones. These will be discussed along with the application of habitability models around stars to the planetary systems that have been discovered.
Mr
Wilbert Mtangi
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Poster
Hall effect studies carried out on as-received, melt grown, single crystal ZnO samples show the existence of two shallow donors with energy levels (37.8 ± 0.3) meV and (54.5 ± 0.9) meV. Annealing studies performed on the hydrogen peroxide treated samples reveal the existence of a conductive channel in ZnO.
Mr
DAMILOLA ISAAC ADEBIYI
(TSHWANE UNIVERSITY OF TECHNOLOGY, PRETORIA)
Track C - Lasers, Optics and Spectroscopy
Poster
X12CrNiMo martensitic stainless steel was laser alloyed with Titanium Carbide using a 4.4 kW CW Nd-YAG laser. The microstructure of the MMC was investigated using optical microscopy, X-ray diffraction (XRD) meter and scanning electron microscopy (SEM). A Vickers’s hardness profile-indentations from the surface of the alloyed zone through to the substrate was measured at 100 µm interval using a...
Ms
Ella Linganiso
(Nano-scale transport Physics laboratory, School of Physics and Chemistry)
Track A - Condensed Matter Physics and Material Science
Presentation
Synthesis of thin multi-walled carbon nanotubes uniformly filled with over 40% of iron is reported. Magneto-resistance measurements of these novel nano-materials at low temperatures over a wide range of magnetic field, up to 12 Tesla establish one-dimensional behavior and show their potentials for novel spintronic device applications.
Ms
Thifhelimbilu Daphney Singo
(Student-University of Stellenbosch and iThemba LABS)
Track B - Nuclear, Particle and Radiation Physics
Presentation
A high flux neutron detection system, integrating the neutron converter material 6Li and 12C and a highly sensitive mass spectrometer, is been developed to detect slow and fast neutrons. The reaction rates and neutron flux will be deduced from the analysis of the 4He atoms released with the mass spectrometer.
Mr
Wayne Koen
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
We present a high-power Tm:YLF slab laser double-end-pumped by two 300 W laser diode stacks. The resonator was designed such that the laser emitted at 1890 nm instead of the conventional operating wavelength of 1912 nm. At full incident pump power it delivered up to 189 W of stable output.
Mr
Bertrand SONE
(iThemba LABS-UWC)
Track A - Condensed Matter Physics and Material Science
Presentation
We report for the first time the synthesis of WO3 nanostructured fairly-thin films on transparent glass substrates, this by the low-temperature soft chemistry method of Aqueous Chemical Growth3. The films obtained were structurally and optically characterized. Results on these as well as those on their Hydrogen sensing behaviour as a function of temperature and H2 concentration (in ppm) are reported.
Mr
ZN URGESSA
(Nelosn Mandela Metropolitan University (NMMU))
Track A - Condensed Matter Physics and Material Science
Presentation
Self assembled ZnO nanorods have been synthesized on seeded Si substrate by a simple hydrothermal route, using an ordinary glass beaker at a temperature of 750C. XRD analysis reveals that the as-grown rods have good crystalline quality and are c-axis oriented. SEM also confirms this orientation and shows single rods having hexagonal features and needle-like tips. Photoluminescence spectra...
Mr
Kevindran Govender
(South African Astronomical Observatory)
Track E - Physics Education
Presentation
This non-specialist presentation will discuss South Africa's recent selection as host of the prestigious Office for Astronomy Development, an initiative of the International Astronomical Union (IAU). This office aims to realise the IAU's decadal strategy to take astronomy to the developing world.
Mr
Christoph Hagspihl
(University of Cape Town)
Track D1 - Astrophysics
Poster
Combining information from the OGLE-III and 2MASS surveys, we have identified large amplitude, Mira, variables that lie above the well defined period-luminosity relation. It has been suggested that such stars may get additional luminosity from envelope burning and we propose to investigate this by looking for lithium with SALT.
Mr
Thulani Jili
(University of Zululand)
Track A - Condensed Matter Physics and Material Science
Poster
There is an uncertainty surrounding the generation of defects associated with superionic conductivity in terms of whether these are created at an observed transitional temperature Tc, or at an earlier temperature point. The measured conductivity becomes more pronounced at a temperature coinciding with the deviation of constant lattice parameter from 6.2096 angstrom. The Frenkel pairs...
Mr
Ruan Steyn
(Stellenbosch University)
Track F - Applied and Industrial Physics
Poster
The complementary use of PIXE (particle induced X-ray emission) and EDXRF (energy dispersive X-ray fluorescence) techniques which was implemented to reduce the analysis time at the Van der Graff accelerator (iThemba Labs). Preliminary results of the rock art elemental composition will be presented.
Ms
Cornelia van der Walt
(Department of Physics, University of Cape Town)
Track A - Condensed Matter Physics and Material Science
Poster
Palladium germanide formation is studied in ramped anneals of constant ramp rate using real-time RBS. The resulting data is analysed using both Kissinger analysis and fitting an integral to a single ramped anneal. The activation energies determined by both methods are in good agreement.
Ms
Jocelyn Jardine
(University of Johannesburg)
Track C - Lasers, Optics and Spectroscopy
Poster
Abstract: Since cancer is a result of erroneous regulation of genes, we investigated whether low intensity laser irradiation has an influence on the epigenetic state, specifically global methylation, of the DNA in five different cancer cell lines in vitro. Possible consequences may include changes in gene expression and DNA conformation.
1. Introduction
Photodynamic therapy (PDT) for...
Mr
Charl Jafta
(University of the Free State)
Track A - Condensed Matter Physics and Material Science
Poster
Small concentrations of Sb dopant in Cu can increase the grain boundary energy which suppresses grain growth. XRD results show that after annealing the CuSb alloy, the relative intensities of the (111) and (420) orientations increase. The grain growth results indicate that the Sb inhibits grain growth in Cu and keeps the microstructure intact at higher temperatures.
Mr
Kennedy Muguro
(Department of Physics, Nelson Mandela Metropolitan University)
Track C - Lasers, Optics and Spectroscopy
Poster
Raman gain in fibres of low polarization mode dispersion (PMD) depend on the state of polarization (SOP) of the input signal. During forward pumping a large gain variation is observed for certain SOPs when fibre PMD coefficient is below 0.03 pskm-1/2. The gain difference is small for fibres of relatively high PMD parameter.
Dr
NICHOLAS MAKAU
(MOI UNIVERSITY, ELDORET, KENYA)
Track A - Condensed Matter Physics and Material Science
Presentation
The properties of oxygen atoms on C(111)-(1x1) and the (2x1) reconstructed surfaces have been investigated using DFT. The on-top site is preferred by oxygen atoms on the (1x1) surface, while the bridge site is favourable on the (2x1) reconstructed surface. Other properties like stability and workfunction are also reported.
Ms
Jani Geyer
(NITheP, University of Stellenbosch)
Track G - Theoretical and Computational Physics
Presentation
Using Ginzburg-Landau theory of two band superconductors, we determine
the surface energy between coexisting normal and superconducting solutions at the thermodynamic critical field. Close to the transition temperature, Tc, the two band problem maps onto an effective single band problem. While the order parameters of the two bands may have different amplitudes in the homogeneous bulk, near...
Mr
Matshisa Legodi
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Poster
We systematically annealed Ni/Au and Ir Schottky contacts on Al0.35Ga0.65N in O2. Our Capacitance-Voltage-Frequency (C-V-f) measurements reveal the presence of anomalous peaks at 0.9V for Au/Ni/Al0.35Ga0.65N and at 0.8V and 1.2V for the Ir/Al0.35Ga0.65N contact system. The overall quality of both Schottky systems improves with O2 annealing up to 573K.
Prof.
Karin Pruessner
(School of Physics, University of the Witwatersrand)
Track A - Condensed Matter Physics and Material Science
Presentation
Ni-based superalloy TMS-75 was oxidized at 900°C in air. SEM, TEM and Raman Spectroscopy were used to characterize reaction products. At this temperature, an external non-protective (Ni,Co)O scale plus an extensive internal reaction zone consisting of oxide and nitride phases are formed. Orientation relationships were found between the oxide phases.
Dr
Igor Litvin
(CSIR NLC)
Track C - Lasers, Optics and Spectroscopy
Poster
We report on two resonator systems for producing Bessel–like beams with longitudinally dependent cone angles (LDBLBs). Such beams have extended propagation distances as compared to conventional Bessel–Gauss beams, with a far field pattern that is also Bessel–like in structure (i.e. not an annular ring). The first resonator system is based on a lens doublet with spherical aberration, while the...
Mr
Brian van Soelen
(University of the Free State)
Track D1 - Astrophysics
Presentation
The effect of the infrared excess on inverse Compton gamma-ray production in the pulsar binary system PSR B1259-63/SS 2883 is considered. The infrared excess is calculated using catalogue observations and the exact Compton cross-section is used to calculate the expected gamma-ray spectra for an isotropic distribution of target photon.
Mr
Ronald Rop
(Moi University, Kenya)
Track C - Lasers, Optics and Spectroscopy
Presentation
In this work a spatial light modulator (SLM) and a ring slit are used to generate superpositions of higher-order Bessel beams. We show that even though these fields do not carry any orbital angular momentum (OAM) a rotation in their intensity profile is evident, agreeing well with the theoretical prediction.
Mr
Douglas Clerk
(School of Physics, University of the Witwatersrand)
Track E - Physics Education
Presentation
In this study we report that while test scores continue to indicate that students’ creative problem solving ability lags their ability to perform routine exercises, preliminary data suggest that instructors at both high school level and at university level are perhaps simply not teaching their students creative problem solving.
Ms
Jacqui Crozier
(NMMU)
Track F - Applied and Industrial Physics
Presentation
The mismatch of solar cell currents in a photovoltaic module has a substantial effect on the overall power output of the module. In this study the effects on cell mismatch were examined by characterizing a degraded Edge-defined Film-fed crystalline module and making a comparison with simulated results.
Mr
Timuçin Gülmez
(University Of Johannesburg)
Track A - Condensed Matter Physics and Material Science
Presentation
Dosimetric characteristics of thermoluminescence(TL) material principally depend on kinetic parameters describing the TL mechanism in the phosphor. Therefore, any reliable dosimetric study of new thermoluminescent materials should include the determination of kinetic parameters, order of kinetics b, activation energy E and frequency factor s. In this study, kinetic parameters of Mg2SiO4:Tb...
Mr
Franscious Cummings
(Energy and Processes, Council for Scientific and Industrial Research, Materials Science and Manufacturing, Meiring Naude Road, P.O. Box 395, Pretoria 0001, South Africa)
Track A - Condensed Matter Physics and Material Science
Presentation
This work compares the performance of dye-sensitised solar cells (DSCs) employing films of highly-ordered TiO2 nanotubes to traditional DSCs using films of tightly interconnected TiO2 nanoparticles as the electron transport medium. Moreover, the work investigates whether nanotubes enhance the charge transport phenomena in the cell, thereby producing more efficient DSCs.
Mr
Jakobus Hoffman
(Necsa)
Track F - Applied and Industrial Physics
Presentation
Computer Tomography (CT) has been used extensively in the past to study a variety of samples including coal. This MSc-study will determine the validity of the CT technique specifically with regard to coal research by optimizing a general CT system, characterizing coal non-destructively and observing and studying the gasification process.
Mr
Charles Rigby
(Laser Research Institute, Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Presentation
An experimental setup for laser cooling and trapping of neutral rubidium atoms is being developed. A three dimensional optical molasses in a Maxwell gradient magnetic field is used. The effects of the trap parameters on the number of trapped atoms will be investigated. The current status and recent results are presented.
Mr
Malcolm Govender
(CSIR)
Track C - Lasers, Optics and Spectroscopy
Poster
This work demonstrates a versatile method known as CO2-laser pyrolysis which is used to synthesize high purity tungsten oxide thin films and nanostructures from gaseous-phase precursors. The results will show how laser pyrolysis can be used to control the phase and particle size of tungsten oxides by varying the laser power density and wavelength.
Mr
MALUTA COLBERT MUDAU
(Tshwane University of Technology)
Track A - Condensed Matter Physics and Material Science
Poster
The current investigation deals with laser surface alloying of nickel powder on martensitic stainless steel, the aim was to improve the hardness of the substrate.
Nd-YAG laser was used with argon as shielding gas and process parameters were varied. The characterization of the alloyed surface was carried out by Optical Microscopy (OPM), Scanning Electron Microscopy (SEM/EDS) and X-ray...
Dr
Abayneh Ambushe
(CSIR, National Laser Centre)
Track F - Applied and Industrial Physics
Presentation
Laser-induced breakdown spectroscopy (LIBS) will be used to determine the contents of heavy metals in soils and sediments. LIBS results will be compared with the results obtained by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS).
Dr
Sergey Zemlyanoy
(Joint Institute for Nuclear Research)
Track C - Lasers, Optics and Spectroscopy
Poster
Studies of hyperfine structure and isotope shifts form a bridge between nuclear and atomic physics and serve as a tool for investigation of nuclear properties and basic physical principles. This work presents some recent results on investigation of nuclear shape and size of rare earth isotopes by laser spectroscopy methods at JINR, Dubna.
Mr
Paulus Masiteng
(iThemba LABS/University of the Western Cape)
Track B - Nuclear, Particle and Radiation Physics
Presentation
Lifetimes (τ) of high spin states in 194Tl have been studied using the DSAM technique with the AFRODITE array. The deduced B(M1) and B(E2) transition probabilities suggest that the two negative parity bands in the 194Tl are built on the same configuration and correspond to similar nuclear deformation.
Mr
Johannes Breytenbach
(University of Cape Town)
Track D2 - Space Science
Presentation
The lightning sferic count rate from the VLF receiver at Marion Island is presented. Time variation on short to long scales is investigated, and modeled in terms of lightning activity in the southern hemisphere, taking into account propagation conditions over land, ocean and ice.
Mr
John Bosco Habarulema
(Hermanus Magnetic Observatory, P.O. Box 32, Hermanus 7200, South Africa and Department of Physics and Electronics, Rhodes University, Grahamstown 6140, South Africa)
Track D2 - Space Science
Presentation
This paper compares both linear and non-linear regression modeling techniques in approximating total electron content (TEC). Both techniques have been applied on a similar dataset and verified on an independent but identical dataset to assess the performance of the developed models
Mr
Milton van Rooy
(Stellenbosch University)
Track D1 - Astrophysics
Poster
Neutron star properties are studied and the transition density from the core to the crust is calculated using fifteen parameter sets of the effective Skyrme nucleon-nucleon interaction, within a method called the dynamical method. Results are used to verify published values.
Mr
Andry Fitiavana Rajoelimanana
(South African Astronomical Observatory / University of Cape Town (SAAO/UCT))
Track D1 - Astrophysics
Presentation
We present 16 yr baseline optical lightcurves of Be/X-ray binaries (BeX) in the SMC. All the BeX in our sample display both orbital (usually tens of days) modulation, plus a much longer non-orbital variation on timescales of ~ 200-3000 d. We compare and contrast their behaviour with the prototypical BeX, A0538-66. In addition, the amplitude of their orbital outbursts can vary through the...
Mr
Johan Janse van Rensburg
(University of Pretoria)
Track A - Condensed Matter Physics and Material Science
Presentation
Semiconductor materials have been irradiated with 1.6 MeV protons at a temperature of 25 K after which in situ electrical characterization was performed to study the electrical active defects created during the irradiation. High resolution Laplace-DLTS was used to determine activation energies, capture cross-sections, defect concentrations and defect annealing kinetics.
Mr
Hassan Seed Ahmed
(University of the Free State)
Silica doped with rare-earth ions was synthesized by the sol-gel method. The resulting powders were annealed at 600 and 1000°C. X-ray diffraction spectra indicated that all samples were amorphous. Samples doped with Tb3+ exhibited the brightest luminescence, both when excited with UV light (photoluminescence) and with an electron beam (cathodoluminescence).
Mr
Kamohelo George Tshabalala
(University of the Free State)
Track A - Condensed Matter Physics and Material Science
Presentation
Cerium- and terbium –doped zinc aluminate oxide nanocrystals with a spinel structure were successfully prepared by a combustion method, using urea as fuel. The solid combustion products thus obtained were identified by their characteristic XRD patterns. The fine-particle nature of these powders was investigated using SEM, TEM, and luminescence spectroscopy
Mr
Indrajit Nagpure
(University of the Free State)
Track A - Condensed Matter Physics and Material Science
Presentation
UV photo-excited luminescence from CaQ2 organic phosphors and PMMA based thin films for OLED application has been investigated. The intense emission of the spectrum is assigned to the complex polymer network of the Ca ions in the 1-8 hydroxyl quinoline networks. CaQ2 phosphor was synthesized by the co-precipitation method. The FTIR and photoluminescence (PL) characterization of the phosphors...
Mr
Luyanda Lunga Noto
(University of Free State (Student))
Track A - Condensed Matter Physics and Material Science
Poster
Praseodymium doped calcium titanate phosphors (CaTiO3:Pr) exhibiting red emission are synthesized by using the sol – gel method and the structures were determined using the X-ray diffraction technique. The photoluminescence properties of the CaTiO3:Pr were determined using photoluminescence spectroscopy and cathodoluminescence spectroscopy. Particle morphology was determined using Scanning...
Mrs
ANDO RATSIMBAZAFY
(UNIVERSITY OF WESTERN CAPE)
Track D1 - Astrophysics
Poster
The expansion rate of the Universe can potentially be measured using age-dating of Luminous Red Galaxies (LRGs). We explore the validity of the assumptions implicit in this method using LRGs identified in the Millenium Simulation (MS). We use stellar population modelling and spectral synthesis to estimate the errors on ages that can be expected and discuss optimization of such an experiment....
Mr
Zolile Mguda
(Dept of Astronomy, Astrophysics, Cosmology and Gravity Center University of Cape Town)
Track D1 - Astrophysics
Poster
A comparison of some equilibrium stellar models with stellar pulsation observations is presented. We compare atmosphere models with observations and pulsation models with observed pulsation modes asteroseismology observations
Mr
Oreabetsoe Mosikare
(Council for Scientific and Industrial Research)
Track F - Applied and Industrial Physics
Poster
The Response Amplitude Operator (RAO) theory was used to develop a mathematical model of boat angular motion. Measurements were made on a harbour patrol boat on sea runs off Durban Harbour. Measurements were first calibrated for axis alignment and then analysed using power spectral density techniques. An estimated roll radius of gyration of 0.4 times the breadth of the vessel was used in the...
Mr
Azwitamisi Mudau
(Defence, Peace, Safety and Security, Council for Scientific and Industrial Research)
Track F - Applied and Industrial Physics
Presentation
In laser pyrolysis, temperature measurement and control plays a vital role during the development of nanoparticles. We present the results of temperature measurements using infrared camera on a tungsten hexa-ethoxide pyrolysis flame used to synthesize nanoparticles from laser pyrolysis technique.
Mr
Emmanuel. T Musonza
(University of Cape Town)
Track B - Nuclear, Particle and Radiation Physics
Presentation
A new neutron beam monitoring system was installed at iThemba LABS. The instruments included a parallel plate U238 fission ionization chamber, a gain stabilized NE213 detector which is a high resolution instrument for measuring the spectral distribution of the beam using the time-of-flight method and an NE102 transmission detector. A measurement campaign was successfully performed over three...
Dr
Diethelm Schmieder
(University of Johannesburg)
Track C - Lasers, Optics and Spectroscopy
Poster
Abstract: We have designed an experimental setup to micro machine Fabry-Perot interferometer in silica and sapphire fiber with a Ti:sapphire femtosecond laser and in comparison with a nanosecond Nd:YAG laser at 355 nm. We achieved spot sizes of 5 µm with the Ti:sapphire and 20 µm with the Nd:YAG laser.
Mr
Joseph Sithole
(NRF iThemba Labs)
Track A - Condensed Matter Physics and Material Science
Poster
The optimized and fabricated Zinc Oxide (ZnO) microrods and platelets-based nanostructures were generated using hydrolysis-condensation at mild temperatures. The targeted applications are geared towards ultrasensitive H2 sensors with detection efficiency as low as 2 ppm. The synthesis and optimization strategy as well as experimental results on hydrogen gas sensing are presented.
Mr
Jean de Villiers
(University of South Africa)
Track G - Theoretical and Computational Physics
Poster
The problem of fitting material properties on earth to certain models by analysing returned seismic signals are investigated here. Analysis proceeds with inverse methods. Seismic wave inversion is tackled by minimisation of objective function with respect to model parameters. Absorbing boundary conditions are implemented using an exponentially decaying ansatz.
Mr
Daniel Nhlapo
(North West University, Mafikeng Campus)
Track D1 - Astrophysics
Poster
beta Cephei stars are hot massive B stars that pulsate with periods of between 1.6 and 7.7 hours. They oscillate because of seismic waves that travel through these stars. Seismic waves have been used to infer interior conditions and properties of stars. In order for this technique to be used successively, the pulsation modes need to be identified. In this poster we present a...
Prof.
Rodney Medupe
(North West University, Mafikeng Campus)
Track D1 - Astrophysics
Poster
Medupe et al (2009) presented a new formula for calculating perturbation in flux as a function of wavelength and mode. They suggested that such a formula will be suitable for mode-identification and will be better than currently used formulae because it takes into consideration the shapes of the eigenfunctions in the atmospheres of A stars, and does not depend on many parameters. In this...
Mr
Marius Tchonang Pokaha
(student)
Track D2 - Space Science
Poster
The Corona Ionization (CorIon) Space Propulsion system is a novel electrostatic thruster, which combines the ionization and acceleration steps of conventional technology. The CorIon’s small size and simplicity are advantageous in many situations, such as for satellite station keeping and deep space probes. Experimental results are presented and compared to the theoretical model
Ms
Patricia Skelton
(UNISA)
Track D1 - Astrophysics
Poster
The evolution of contact eclipsing binary stars is uncertain, but some systems undergo orbital period changes that may relate to physical changes in the system. Using ASAS and SuperWASP data, selected EC systems have been modelled using the WD code and an O – C period analysis.
Mr
FJ Kotze
(North-West University)
Track C - Lasers, Optics and Spectroscopy
Poster
The direct excitation of CO2 and CH4 using a nanosecond pulsed laser was investigated for chemical reaction activation. Results from this study show that carbon dioxide and methane can be activated successfully using nanosecond laser pulses at 355 nm. The results collected from the various experiments were used to create a model of the possible reaction mechanisms using Molecular Modelling.
Dr
Jacques Bezuidenhout
(Stellenboch University)
Track E - Physics Education
Presentation
The Faculty of Military Science of Stellenbosch University presents Algebra-based Physics courses to military cadets. The practical component comprises experiments that utilise classical apparatus, as well as more modern computer based experiments. Questionnaires are yearly completed by the students to evaluate the theoretical and practical components of the course. This paper will explore...
Dr
Rapela Maphanga
(University of Limpopo)
Track A - Condensed Matter Physics and Material Science
Poster
The EMD is an intergrowth of pyrolusite and ramsdellite-MnO2 polymorphs. Amorphization and recrystallization technique has been used to generate MnO2 structures and study their structural properties. The simulation methodology involves allowing an amorphous transition, enabling various structural modifications to evolve during simulation in response to lattice misfit and underlying support.
Mr
Karl Möller
(Department of Physics, Stellenbosch University)
Track G - Theoretical and Computational Physics
Presentation
Biological filaments can be linked by active crosslinks. Investigating the dynamical behaviour of a system consisting of a large number of filaments and motors would lead to understanding of dynamical mechanical properties and processes in cells. A single motor crosslinked strand is investigated using a functional integral approach.
Mr
Richard Harris
(UFS/Mintek)
Track A - Condensed Matter Physics and Material Science
Presentation
Pt-Al thin films (Pt25Al75, Pt55Al45 and Pt63Al37) were prepared and heat treated at various annealing- temperatures and times. Elemental maps and depth profiles were obtained with a PHI 700 nanoprobe. A chemical potential Monte Carlo model was developed and simulations were run. Theoretical depth-profiles and microstructures where obtained. Comparisons between experimental and theoretical...
Mr
Mpiana Mulamba Florimond Eugène
(Institut of Theoretical Physics, Department of Physics,Stellenbosch University)
Track G - Theoretical and Computational Physics
Presentation
The partition function for a single polymer winding around a fixed long rode is calculated. The topological invariance for the system is maintained by modelling the polymer as a sequence of connected flexible chains from which Reidemester moves are applied to enumerate all the accessible conformations.
Mr
David de la Rey
(University of KwaZulu-Natal)
Track C - Lasers, Optics and Spectroscopy
Poster
The dynamics of single photon wave packets interacting with beam splitters, mirrors and interferometers is investigated. In the simulation the beam splitters are microscopically as arrays of two level atoms. The non-trivial simulations will be using Modern Graphics Processing Units (GPUs). These devices offer tremendous potential for performance and efficiency.
Ms
Suzanne Theron
(Necsa)
Track B - Nuclear, Particle and Radiation Physics
Presentation
This research focuses on modelling reflectors in typical material testing reactors (MTRs). Equivalence theory is used to homogenise and collapse detailed transport solutions to generate equivalent nodal parameters and albedo boundary conditions, for subsequent use in full core diffusion codes. This study aims to determine if this approach to MTR reflector modelling is an accurate and plausible...
Dr
Hencharl Johan Strauss
(CSIR (National Laser Centre))
Track C - Lasers, Optics and Spectroscopy
Poster
A novel multi-pass Tm:YLF laser was demonstrated with an improvement in efficiency, footprint and cost over two diode stack pumped, single pass systems. We report 100 W of output power from 261 W of incident diode pump power with a slope efficiency of 44%.
Dr
Andrew Collier
(Hermanus Magnetic Observatory)
Track D2 - Space Science
Presentation
The identification of anomalies in time series data depends on a knowledge of the expected “normal” variations in the data. Numerous techniques exist for deriving such Quiet Day Curves (QDCs). A flexible multivariate technique has been developed which generates QDCs which account for seasonal and other variations.
Mrs
Alida Odendaal
(University of the Free State)
Track D1 - Astrophysics
Presentation
Supersoft X-ray sources constitute a fascinating class of X-ray systems. Some of these sources consist of a compact object accreting material from a binary companion. The analysis of X-ray and optical spectra discloses valuable information on the exact nature and temporal variation of the extremely powerful physical processes involved.
Mr
Thuto Makgato
(non member)
Track A - Condensed Matter Physics and Material Science
Presentation
The nanostructuring of diamond and graphite surfaces using highly charged ions is studied. Results are presented in terms of changes in morphology and local electronic states observed using atomic force microscopy (AFM) and scanning and tunnelling microscopy (STM) respectively. Energy dependence of defect formation coupled with the use of advanced nanostructuring facilities such as the...
Dr
Bonex Mwakikunga
(CSIR National Laser Centre)
Track A - Condensed Matter Physics and Material Science
Presentation
Raman spectroscopy of the nano-ribbons, about 10 nm thick as found by AFM, is discussed in the framework of the Richter equation for phonon confinement (1) as modified for thin films by Faucet & Campbell1, (2) as modified by Kim et al2 for slabs and (3) our own modification based on the transformation from the spherical coordinates in the Richter equation to Cartesian coordinates; this being...
Dr
Alexander Karpov
(Flerov Laboratory of Nuclear Reactions, JINR)
Track B - Nuclear, Particle and Radiation Physics
Presentation
The project "Knowledge base on low-energy nuclear physics" allocated in the Web solves the two following problems: 1) Fast and visual getting of experimental data on nuclear structure and cross sections of nuclear reactions, a possibility for processing these data, their comparison and plotting the studied regularities and systematizations. 2) Analysis of experimental data and modeling the...
Mr
Alexander Heidt Heidt
(Laser Research Institute, Physics Department, University of Stellenbosch)
Track C - Lasers, Optics and Spectroscopy
Presentation
We numerically and experimentally investigate supercontinuum (SC) generation in fibers with all-normal group velocity dispersion (GVD) under femtosecond pumping, including photonic crystal fibers (PCF), photonic nanowires and suspended core fibers for octave-spanning recompressible supercontinuum generation in the infrared, visible and ultraviolet spectral regimes.
Mr
Hendrikus Groenewald
(University of Stellenbosch)
Track G - Theoretical and Computational Physics
Poster
Non-commutative field theory is applied to nucleon-nucleon interactions where we assume the spatial coordinates of nucleons do not commute. This assumption leads to the interpretation that nucleons occupy a minimum volume in space which alters our view of NN-interactions. Qualitative descriptions of these interactions are obtained using various approximations.
Mr
Masimba Wellington Paradza
(UCT-CERN)
Track G - Theoretical and Computational Physics
Presentation
The flux corrected transport algorithm FCTHydro provides tools for solving continuity equations.
We study the dynamical evolution of non-ideal fluid dynamics in the non-relativistic limit using the (2+1)D planar geometry. The system studied shall be generalised to simulate relativistic hydrodynamic systems, which are of interest in heavy ion collisions.
Dr
Ilya Sinayskiy
(University of KwaZulu-Natal and National Institute for Theoretical Physics)
Track G - Theoretical and Computational Physics
Presentation
The dynamics of a simple spin chain (three spins) coupled to bosonic baths at different temperatures is studied. The dynamics and temperature dependence of spin-spin entanglement is analyzed. Special attention is given to the entanglement in the stationary state of the system.
Mr
George Chimowa
(University of the Witwatersrand, Nano-scale transport Physics laboratory, School of Physics, P. Bag 3, Wits 2050, Braamfontein, Johannesburg, South Africa.)
Track A - Condensed Matter Physics and Material Science
Presentation
Nanocrystalline diamond films were synthesized by chemical vapor deposition and characterized to explore their potential device applications. Electrical conductivity measurements at low temperatures and high magnetic fields showed weakly localized transport in three dimensions in ultra-nanocrystalline diamond films. Also a semi-classical model is developed to explain their unusual...
Mr
George Bepete
(DST/NRF Centre of Excellence in Strong Materials and Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa)
Track A - Condensed Matter Physics and Material Science
Presentation
A novel photovoltaic device employing poly-3-hexylthiophene attached N-CNTs as active layer, giving Voc > 0.3V and Jsc ~ 1 mA/cm2, at 100 mW/cm2 white light illumination is presented. The polymer attached N-CNTs were produced by polymerizing 3-hexythiophene using FeCl3 catalyst in the presence of functionalized N-CNTs that had been synthesized by the floating catalyst CVD method.
Mr
Bernard Erasmus
(Necsa)
Track B - Nuclear, Particle and Radiation Physics
Presentation
Nuclear reactor core reload calculations are used to determine safety and operational parameters of a nuclear reactor. Accurately determining these parameters plays an important role in the safe operating of a reactor. The OSCAR-4 code was used to simulate reactor reloads, and the simulation results were compared to experimental plant data as verification of the simulation methods.
Mr
Joram Ndayishimye
(Stellenbosch University)
Track B - Nuclear, Particle and Radiation Physics
Presentation
We investigate the nuclear structure and elastic scattering in nuclei (20Ne, 44Ti, 94Mo, and 212Po) using a model of alpha-cluster orbiting a closed shell core. A purely phenomenological cluster-core potential was found to provide a successful description of low lying positive parity spectra, electromagnetic transition strengths of these nuclei and alpha-decay rates of these states in 212Po....
Dr
RAYMOND WALTER SPARROW
(CSIR - SYNTHETIC BIOLOGY ERA (BIOSCIENCES))
Track C - Lasers, Optics and Spectroscopy
Poster
The binding activity of AK1 enzymes in the presence of ATP and deuterated ATP were measured using CD spectroscopy. The data showed conformational changes occurring on the binding of these nucleotides and provided an insight into the possible dynamics of these changes.
Mr
Alpha Hamadou Ibrahim
(CSIR, National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Poster
A numerical procedure is proposed to study the decoherence of the entanglement between a pair of qubits due to atmospheric turbulence. The qubits are photons entangled in terms orbital angular momentum modes and the turbulent atmosphere is modeled with the von Karman-Tatarski spectrum.
Mr
Bhekumuzi Sfundo Khanyile
(University of Fort Hare)
Track D2 - Space Science
Presentation
We present the characteristics of small scale (< 100 km) gravity waves in the lower and upper atmosphere derived from imaging riometer at SANAE (710 S,20 W). FFT technique is used to extract wave parameters of the gravity waves. These waves have horizontal phase speed of 0-250 m/s, horizontal wavelength of 16-30 km and the period of 3-30 min. And the propagation direction is ~ 50 degrees.
Dr
Gunther Kassier
(Stellenbosch University)
Track A - Condensed Matter Physics and Material Science
Presentation
We have constructed an Ultrafast Electron Diffraction setup suitable for studying femtosecond time resolved structural dynamics in solid state matter. The setup has been characterized with respect to its spatial and temporal resolution capability, and measurements confirm that sub-300 femtosecond electron pulses with sufficient spatial resolution capability are achievable.
Mr
Sifiso Senzo Ntshangase
(University of Cape Town / iThemba LABS)
Track B - Nuclear, Particle and Radiation Physics
Presentation
The actinide region attracts considerable interest due to the rich variety of octupole phenomena encountered both theoretically and experimentally[1]. These include octupole vibrational bands which, as a function of neutron number an angular momentum, develop into alternating parity bands that have been interpreted as the onset of octupole deformation, or more recently, in terms of...
Mr
Ross Schultz
(Nelson Mandela Metropolitian University)
Track F - Applied and Industrial Physics
Presentation
Concentrated photovoltaic (CPV) modules are a cost effective alternative flat-plate photovoltaic modules that concentrate the sun onto small, highly efficient solar cells.[1] This paper addresses the design, and characterization of CPV modules that use 39% efficient triple junction solar cells. The optical, electrical and thermal configuration of the module is investigated.
Mr
Thomas Godin
(CIMAP)
Track C - Lasers, Optics and Spectroscopy
Poster
We report measurements of polarisability changes Δα between the excited and ground states of the chromium active ions in a laser material by using two different methods (time-resolved divergence diagnostic, Z-scan techniques). The first one indicates that Δα <0 (converging population lensing), while the second one gives Δα >0 (diverging population lensing). This discrepancy has been resolved...
Mr
Vincent De Comarmond
(WITS)
Track G - Theoretical and Computational Physics
Presentation
For operators of bare dimension of O(N), even in the large N limit the planar approximation is inaccurate. Here we study the anomolous dimension of operators built using two complex N by N matricies Z and Y . A basis for these operators, the restricted Schur polynomials, has been developed in [1]. The present study generalizes the work of [2], which considered operators built using no more than two Ys.
Dr
Izak Snyman
(NITheP)
Track G - Theoretical and Computational Physics
Presentation
A massive two dimensional Dirac particle in a random electrostatic potential is considered. For a ribbon geometry (width << length), the Lyapunov exponent is calculated as a function of ribbon width, for several energies and disorder strengths. Intriguingly, an attempt to demonstrate one parameter scaling is only partially successful.
Ms
Humairah Bassa
(University of KwaZulu-Natal)
Track G - Theoretical and Computational Physics
Presentation
We study the implementation of the Grover Search Algorithm by means of photons that carry orbital angular momentum (OAM) using the one-way quantum computing (1WQC) model. Our setup is related to a corresponding scheme of Zeilinger et al [1], which realizes a two-bit Grover Search by employing the polarization of photons.
[1] Anton Zeilinger et al. Experimental One-way Quantum Computing, ...
Mr
Yogan Naidoo
(University of Johannesburg)
Track C - Lasers, Optics and Spectroscopy
Poster
The operation of a fiber optic gyroscope is demonstrated in this project. A fiber optic gyroscope is designed, constructed and tested and the response of the gyroscope to an input rotation is generated. The experimental setup as well as the results are discussed in this paper.
Anna Kozakiewicz
(Wits)
Track A - Condensed Matter Physics and Material Science
Poster
Abstract: Ion implantation was used to produce nanostructures in MgO, Al2O3 and SiO2. Optical absorption spectra show surface plasmon resonance bands characteristic of the implanted metal ions. Upon annealing in reducing atmospheres the optical response of metal nanostructures changes what is related directly to their morphology, shape and size.
Mr
STEVE LEKEKE MANGENA
(TSHWANE UNIVERSITY OT TECHNOLOGY, PRETORIA)
Track A - Condensed Matter Physics and Material Science
Poster
A 4.4 kW Sinar continuous wave Nd: YAG solid-state laser was used for laser hardening of turbine blade steel (chemical composition: 0.19%C; 0.32%Si; 0.38%Mn; 0.01%P; 0,002%S, 12.72%Cr, 0,41%Ni). The laser processing parameter i.e. scan speed and laser power were varied while the temperature was held constant 1050oC. The characterisation of the hardened surfaces was carried out by Optical...
Dr
JUSTICE S.P MLATHO
(NORTH-WEST UNIVERSITY)
Track F - Applied and Industrial Physics
Presentation
Fluent 6.3 software has been used to optimise the designs of two volumetric receivers. The model results indicate that the use of a wire mesh in these receivers does improve their performance. A wire mesh of porosity 0.95 has also been found to be sufficient to improve the efficiency
Mr
oliver collett
(National Laser Center)
Track C - Lasers, Optics and Spectroscopy
Poster
A laser amplifier model was produced for Ho3+:YLF and used for parametric optimization of the amplifier gain. The interaction is approximated with a rate equation approach. A maximum gain of 2.3 in energy was recorded for the particular model configuration.
Mr
Lerato Shikwambana
(CSIR-NLC)
Track A - Condensed Matter Physics and Material Science
Presentation
A laser pyrolysis (LP) technique was used to synthesisVO2+x nanostructures at a wavelength of 10.6 µm and power density of 2.4 kW/cm2. Scanning electron microscopy (SEM) showed nano-rods with lengths of 185 nm and diameters of 53 nm. Energy dispersive x-ray (EDX) analysis established the presence of vanadium oxide.
Ms
Azwihangwisi Iren Mabuda
(University of Fort Hare)
Track F - Applied and Industrial Physics
Poster
Hydrogen is considered as a novel fuel for the twenty first century, mainly due to its environmentally kindly character. Currently, about 90% of the hydrogen is produced by the reactions of natural gas and steam reforming of light oil fractions. These methods mainly consume fossil fuel as energy source, which is not only full with emission problems, but also fossil fuels are depleting at...
Mr
Nicolas Erasmus
(Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Presentation
Ultrafast electron diffraction is a new and exciting technique which aims to directly observe photo-induced dynamics of solids and molecules on the atomic level (spatially in the Ångström regime and temporally in the femtosecond regime ). This is done by combining two tried-and-trusted techniques, namely static electron diffraction and femtosecond pump-probe spectroscopy.
Mr
Samuel Seshupo Mangwejane
(SAIP)
Track A - Condensed Matter Physics and Material Science
Poster
Studies of low index surfaces of PtSb2 have been carried out using the Density Functional theory to oxidize them and find the stability profiles. Indications are there that the oxygen atom (O) and molecules (O2) prefers to bind with the antimony rather than the platinum atom.
Mr
Prince Olusegun Ogunbade
(University of Pretoria)
Track G - Theoretical and Computational Physics
Presentation
We extend the method for locating spectral points generated by central potentials to the multichannel case. The key to the method is the combination of analytic properties of the Jost matrices and rational parametrization of the S-matrix obtained at real collision energies. An explicit derivation of some symmetry properties of the Jost matrices is given. Numerical examples demonstrate the...
Mr
Tshilidzi Thovhogi
(University of Cape Town)
Track G - Theoretical and Computational Physics
Poster
Ultrarelativistic heavy ion collisions are useful “tools” to investigate the hot and dense nuclear matter. Particle abundances and ratios have been suggested as possible signatures for exotic states and phase transitions in dense nuclear matter. We used a microscopic transport model to calculate the particle ratios and multiplicities from Au-Au collisions, and compared the preliminary results...
Mr
Etienne Koen
(Hermanus Magnetic Observatory)
Track D2 - Space Science
Presentation
PIC simulations are numerical techniques for studying plasma phenomena which do not yield to an analytical solution. These techniques will ultimately used to study chorus emissions which are whistler mode waves propagating through the Earth’s magnetosphere. The two-stream instability is presented as an initial part of the study.
Prof.
Fhatuwani Mundalamo
(Tshwane University of Technology)
Track E - Physics Education
Presentation
This paper reports on the role played by Foundation Physics course in preparing students for first year university physics. The performance of students who enrolled for and those who did not enroll for Foundation Physics after Grade 12 were compared in first year physics. 57 students who enrolled for Foundation Physics before and 107 students who did not enroll for Foundation Physics before...
Mr
Chigomezyo Ngwira
(Rhodes University/Hermanus Magnetic Observatory)
Track D2 - Space Science
Presentation
In this paper, GPS transionospheric signals are used to study phase scintillation observations at the South African Antarctic polar research station. A multi-instrument approach shows that the scintillation events are associated with auroral electron precipitation. It is also demonstrated that substorms play an essential role in the production of scintillation in the high-latitude ionosphere.
Mr
Derek Fish
(Unizul Science Centre)
Track E - Physics Education
Presentation
With the World Cup Soccer the biggest talking point of this year, how can we use it to popularise Physics? This show, developed for Sci-Bono Science Centre in Johannesburg, does just that. Investigating the design of the new "Jabulani" soccer ball, how Beckham manages to "bend it" and why peripheral vision is important for passing, it suggests exciting ways to present practical Physics. The...
Dr
Patience Mthunzi
(CSIR - NLC)
Track C - Lasers, Optics and Spectroscopy
Presentation
Due to their self-renewal and pluripotency characteristics, stem cells possess the potential to dramatically advance current therapies in tissue regeneration and engineering. In this work, we report for the first time that femtosecond laser pulses can be utilised for successful transient photo-transfection and differentiation of mouse embryonic stem cell colonies.
Dr
Ceren Ulusoy
(University of Johannesburg)
Track D1 - Astrophysics
Presentation
In this work; the U, B and V light curves of a β Cephei type variable BW Vulpeculae (BW Vul, HD 199140, B2 III) obtained with photometric observations. Besides obtaining the U, B and V light curves for this star, maxima times were obtained as well. Not only the data have been analysed but also the pulsation mode of BW Vul has been identified by Watson (1988) Method.
As a result of these...
Mr
Sello Manoto
(Doctoral student U.J)
Track C - Lasers, Optics and Spectroscopy
Presentation
Abstract: Photodynamic therapy (PDT) is a minimally invasive therapeutic modality for different cancers. The aim of this study was to determine the phototoxic pattern of Zinc sulfophthalocyanine (ZnPcSmix) photosensitizer in DLD-1 and A549 cells and the extent of PDT using different concentrations of photosensitizer.
Dr
cable moji
(university of pretoria)
Track E - Physics Education
Presentation
New students prefer to be taught through being given formulae, memorizing definitions and working through memorandums of previous question papers. They show arrogant attitude when they are not taught differently, such as in Interactive Inquiry Learning manner. They improve their attitude only when the confronting experiments give plausible answers. This is a conceptual change: accommodation.
Prof.
Ilsa Basson
(University of South Africa)
Track E - Physics Education
Presentation
F for “fail” or “feat”? The “system” of learning Physical Science in South Africa keeps on getting an F for “fail” in spite of various efforts to improving it. Examples will be provided of this failure and some suggestions discussed on the possible achievement of an F for “feat”.
Mr
Sibusiso Mthembu
(Hermanus Magnetic observatory)
Track D2 - Space Science
Presentation
Abstract
The activity of planetary waves and variability of tides in the mesosphere/lower thermosphere (MLT) region was studies using the mesospheric wind velocity. Planetary wave activity observed at the MLT region are the result of upward propagating wave which are excited from the lower region of the atmosphere and sometimes are resulting from tidal modulation at planetary wave. Tidal...
Ms
Sharmini Pillay
(University of KwaZulu-Natal)
Track C - Lasers, Optics and Spectroscopy
Poster
QKD uses quantum mechanics to ensure a secure line of communication between two parties. The implementation of QKD using the BB84 protocol in fibre optic cables is a challenge due to birefringence. However this can now be compensated for in a fibre optic cable, thus allowing polarization encoded QKD in fibre.
Ms
Nametso Mongwaketsi
(iThemba LABS)
Track A - Condensed Matter Physics and Material Science
Poster
Understanding growth mechanism of porphyrins nanorods by self assembly and molecular recognition is essential for their successful implementation in nanodevices. Optical spectroscopy and FTIR were used to investigate growth mechanism immediately after mixing and onwards. These porphyrins nanorods can be organized into structures performing essential light-harvesting and energy transfer roles.
Mr
Hussam Mohammed
(iThemba LABS - UCT)
Track B - Nuclear, Particle and Radiation Physics
Presentation
The level scheme of 195Tl was studied and a few new transitions, belonging to a possible chiral partner band, were found. The measured B(M1)/B(E2) ratios for the partner bands show similarities, in accordance with possible chiral nature. A measurement of the gamma ray intensities is in progress.
Dr
Ben Opperman
(Hermanus Magnetic Observatory)
Track D2 - Space Science
Presentation
South Africa’s bid to host the Square Kilometre array (SKA) radio telescope pivots around a number of crucial factors, including the local ionospheric stability. This study investigates the effects of high energetic, electrically-charged particle precipitation over the South Atlantic Magnetic Anomaly on the stability of the South African ionosphere.
Prof.
Sergei Rakitianski
(University of Pretoria)
Track G - Theoretical and Computational Physics
Presentation
For the Jost-matrix that describes the multi-channel scattering, the energy dependence at all the branching points on the Riemann surface is factorized analytically. The remaining single-valued matrix functions of the energy are expanded in the power-series near an arbitrary point in the complex energy plane. A systematic and accurate procedure has been developed for calculating the expansion...
Mr
chijioke nwosa
(cj)
Track D2 - Space Science
Presentation
Over the past five decades a number of South African institutions have developed capabilities and facilities in various fields of space science and technology. This paper describes an experimental rocket launch project in line with the ongoing South African Space programme.
Mr
Moses Mogotsi
(UCT)
Track D1 - Astrophysics
Presentation
Primordial black holes are believed to have formed from some of the inhomogeneities in the early universe; unlike astrophysical black holes they exhibit a large range of masses. Their mass relation and evaporation via Hawking radiation was explored and a simulation of their numbers as the universe aged was made
Mr
Bishop Mongwane
(Department of astronomy, ACGC, university of Capetown)
Track D1 - Astrophysics
Presentation
The history of entire galaxies is encoded in their spectra.
Thus, from spectra, one can answer questions pertaining to evolutionary histories of galaxies.
Moreover, the Hubble constant can be constrained through spectroscopic ages of red galaxies.
In this work, we analyze how reliably one can age date galaxies, by including the metallicity and star formation history.
Mr
J.P. Kotze
(University of Cape Town)
Track D1 - Astrophysics
Presentation
Strong observational evidence for the transformation of galaxies in dense environments exists. The processes responsible for this transformation remains an open question. We report on the use of the GALEV evolutionary synthesis models as a means to probe galaxy transformation processes in the galaxy cluster Abell 1437.
Mr
Viral Parekh
(Astronomy Department, Astrophysics, Cosmology and Gravity Centre (ACGC), University of Cape Town)
Track D1 - Astrophysics
Presentation
An important aspect of the radio emission from clusters of galaxy is represented as the diffuse radio sources associated with the intracluster medium. These radio sources are known as radio halos, relics and mini halos. The radio halos and relics are indicators of cluster mergers. We are probing the same into the submerger A1437 supercluster.
Ms
VICTORIA NWOSU
(UCT)
Track E - Physics Education
Presentation
EBAPS, a forced-choice instrument designed to probe students' epistemologies, their views about the nature of knowledge and learning in the physical sciences, was administered to groups of senior physics student. The results from preliminary analysis for a group of postgraduate students are presented together with some response data from interviews.
Dr
Iyabo Usman
(iThemba Laboratory for Accelerator Based Sciences, Somerset West 7129, South Africa)
Track B - Nuclear, Particle and Radiation Physics
Presentation
The comparison of proton inelastic scattering from 28Si with data from other probes exciting the Isoscalar Giant Quadrupole Resonance (ISGQR) is investigated. Wavelet coefficients of the ISGQR for the various probes are compared to that of (p,p') using the newly-developed Semblance and Dot product techniques.
Ms
Zara Randriamanakoto
(Astronomy Department, Astrophysics, Cosmology and Gravity Centre, University of Cape Town)
Track D1 - Astrophysics
Presentation
From a deep NIR adaptive optics imaging survey, we present thus-far the first K-band super star cluster (SSC) luminosity function (LF) to probe the formation and evolution of SSCs. Based on the derived LF one can constrain the cluster initial mass function (CIMF). Our preliminary results are in disagreement with theoretical expectations which suggest that SSC LFs should be well fitted by a...
Dr
Hermann Uys
(National Laser Centre, CSIR)
Track C - Lasers, Optics and Spectroscopy
Presentation
We study pulse sequences that dynamically decouple $^9$Be$^+$ ions from their decohering environment. The noise environment the ions see is artificially synthesized to emulate a variety of physical systems. By incorporating measurement feedback, our locally optimized dynamical decoupling sequences (LODD) attain an order of magnitude improved suppression of noise in certain noise environments...
Mr
Geoffrey Okeng'o
(Department of Physics, University of Western Cape and South African Astronomical Observatory)
Track D1 - Astrophysics
Presentation
We use a time-dependent model of turbulent convection which includes turbulent pressure, turbulent diffusion and turbulent viscosity to study stellar pulsations in young brown dwarfs recently proposed by Palla and Baraffe (2005). We find that turbulent pressure dominates in driving the oscillations with growth rates much higher than frozen-in approximation.
Ms
Nicolene Botha
(CSIR, NLC)
Track C - Lasers, Optics and Spectroscopy
Poster
The design of the pulse shaping setup as well as factors taken into account in choosing a specific setup will be discussed. We investigate the generation of simple shaped pulses to test our pulse shaper setup. Difference frequency mixing is used to transfer the pulse shape to the mid-infrared regime.
Mr
Steven Nkosi
(CSIR)
Track A - Condensed Matter Physics and Material Science
Presentation
Several types of Fe-Si mixed oxide composites have been synthesized for biomedical, switching and applications [1, 2]. The synthesis, properties, and environmental applications of nanoscale Iron-based material comparing them with non-nanoscale have already been discussed [3]. In order to enhance the material properties and performance the method of synthesis could have an influence hence the...
Mr
Egmont Rohwer
(Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Presentation
Various derivatives of a zinc phthalocyanine molecule, covalently linked or adsorbed to the surface of carbon nanotubes, are excited at their respective absorption bands to subsequently monitor transmission changes with a delayed probe pulse. The aim is to identify charge separated states, their lifetimes and the pathway of the induced photoreaction.
301.
Quantitative Investigation of Cu/In thin Films Deposited onto SiO2 by Electron Beam Evaporation
Mr
Moshawe Maditi
(UFS)
Track A - Condensed Matter Physics and Material Science
Poster
Thin In/Cu films were grown on a SiO2 substrate. Both In and Cu layers were grown by e-beam evaporation. The films were characterized with X-ray Diffraction (XRD) and Auger Electron Spectroscopy (AES). The In diffused into the Cu layer during evaporation and formed two intermetallic Cu11In9 and CuIn2 phases.
Ms
Ephifani Patricia Boukama-Dzoussi
(University of KwaZulu-Natal)
Track G - Theoretical and Computational Physics
Presentation
In quantum teleportation an unknown quantum state is transferred from one quantum system to another. Here we study a scheme to realise quantum teleportation for qubits with photons carrying orbital angular momentum and discuss the possibility to teleport qutrits.
Dr
Peane Peter Maleka
(iThemba LABS and University of the Western Cape)
Track B - Nuclear, Particle and Radiation Physics
Presentation
The iThemba LABS dam water samples were radiometrically analysed using the low-background high-resolution gamma-ray spectrometry for traces of anthropogenic radionuclides. The samples were prepared in a 1-l Marinelli beaker geometry. Traces of anthropogenic radionuclides have been recorded in samples with activity concentrations ranging from 0.3 to 40 Bq/l.
Ms
Lungiswa Ziwani
(iThemba labs)
Track B - Nuclear, Particle and Radiation Physics
Poster
Samples of canned fruits were liquidised and counted using a HPGe detector system. The acquired gamma-ray spectra were analysed for traces of 137Cs 40K radionuclides and determining the activity concentractions in the samples Results of a detailed investigation optimisation of the methodology limits will be presented for reference material.
Mr
Ronald Machaka
(School of Chemical and Metallurgical Engineering, University of the Witwatersrand)
Track F - Applied and Industrial Physics
Presentation
By means of the application of an efficient fluorescence background suppression scheme, the first-, second-, and higher- order Raman spectra of B6O was obtained, which till now had been deemed un-observable when the 514.5 nm excitation line is used. We report on the analysis, of the the first-order and second-order Raman spectra and compare these to the Raman spectra or other boron-rich ultra-hard...
Dr
Christian Engelbrecht
(University of Johannesburg)
Track D1 - Astrophysics
Presentation
Asteroseismology has evolved into a very active research field in stellar astrophysics. The data from a number of recent ground-based surveys and various satellite missions are opening new windows into our understanding of stellar interiors and dynamics. Some of the more prominent new insights are reviewed.
Mr
David Van Niekerk
(Stellenbosch University)
Track B - Nuclear, Particle and Radiation Physics
Presentation
We have formulated a fully relativistic model for inclusive quasielastic nucleon-nucleus scattering. Using RIA we show how the behaviours of projectile and target can be separated into two independent tensors. Subsequently we investigate the RPWIA as well as DWIA descriptions of the projectile. We also examine the Hartree and the RRPA responses of the target.
Dr
Mikhail Katkov
(Nano-scale transport Physics laboratory, School of Physics, University of the Witwatersrand, P. Bag 3, Wits 2050, Braamfontein, Johannesburg, South Africa)
Track A - Condensed Matter Physics and Material Science
Presentation
A tight-binding model of carbon superlattice structures with randomly distributed hopping parameters is developed to interpret the effective nitrogen doping effect on large transmission coefficients of electrons. The calculated current density explains successfully the device characteristics of multilayered carbon including layered graphene structures at low temperatures and high magnetic fields.
Mr
Lufuno Vhengani
(CSIR, DPSS)
Track D2 - Space Science
Presentation
The success or failure of any earth observation mission depends on the quality of its data. Data quality is assessed by determining the radiometric, spatial, spectral and geometric fidelity of the satellite sensor. The process is termed calval. This paper will describe calval techniques specific to South Africa.
Dr
Hermann Uys
(National Laser Centre, CSIR)
Track C - Lasers, Optics and Spectroscopy
Poster
The design, fabrication and preliminary testing of a chipscale, multi-zone, surface
electrode ion trap is reported. The modular design and fabrication techniques used are anticipated to advance scalability of ion trap quantum computing architectures.
Dr
Siegfried Förtsch
(iThemba LABS)
Track B - Nuclear, Particle and Radiation Physics
Presentation
A Giant Pairing Vibration (GPV) is a collective mode involving two-neutron transfer. This mode which is of fundamental importance, since it is analogous to a giant resonance in the particle-particle channel, has however not yet been detected and important uncertainties concerning its cross section, width and position remain.
Mr
Mhlambululi Mafu
(Centre for Quantum Technology)
Track G - Theoretical and Computational Physics
Presentation
Protocols for quantum communication, particularly for quantum cryptography are considered. The general theory of privacy in quantum communication will be investigated.
Definition, analysis and validation of the security of quantum cryptographic protocols, support the realization of a secure and reliable quantum communication channel between two distant parties
Prof.
Rodney Medupe
(North West University, Mafikeng Campus)
Track D1 - Astrophysics
Presentation
We discuss the physics of p-modes travelling though the atmospheres of A stars. We show how the fluctuations in opacity affects the perturbations in flux and discuss the new formulae we derived that relates the flux perturbations to temperature and opacity perturbations. Our new formula is compared with other formulae that have been used in the studies of the p-modes
Ms
Palesa Molukanele
(CSIR)
Track C - Lasers, Optics and Spectroscopy
Poster
Potential for the selective deactivation of viruses while leaving the sensitive material such as the host cell unharmed was studied using a femtosecond laser system, and preliminary results will be reported.
Mr
Ludwig De Clercq
(NLC)
Track C - Lasers, Optics and Spectroscopy
Presentation
Coherent control of the upper vibrational level populations in the electronic ground state of a polyatomic molecule was simulated. Results indicate that selective excitation of a specific upper state level is possible.
Mr
Sandile Ngcobo
(CSIR)
Track C - Lasers, Optics and Spectroscopy
Poster
A Nd:YVO4 modelocked laser has been constructed using a resonator designed according to the theoretical parameters. The laser produced pulses in the picosecond region with a maximum average output power of 2.8W. Passive modelocking of the Nd:YVO4 laser has been demonstrated using a semiconductor saturable absorber mirror (SESAM).
Dr
Pradip Datta
(iThemba LABS)
Track B - Nuclear, Particle and Radiation Physics
Presentation
This work presents the results obtained from GEANT4 simulation study on TIGRESS type segmented HPGe detector. Unlike the usual Clover detector, TIGRESS detector has both longitudinal and lateral segmentation in each cylindrical crystal. The focus of the present study is to calculate the optimal later segmentation depth in the crystals.
Mr
Cobus Jacobs
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
We present a high energy master oscillator power amplifier consisting of a Holmium-doped slab amplifier, a diode-pumped Thulium-slab pump laser, and a single frequency Ho:YLF ring seed laser. The amplifier delivered up to 210 mJ at 2064 nm with a beam quality factor of M2 ≤ 1.4 in both planes.
Dr
Andrew Collier
(Hermanus Magnetic Observatory)
Track D2 - Space Science
Poster
The annual cycle in lightning activity is driven by the seasonal variation in solar insolation which results from the passage of the Sun back and forth across the tropics. The annual lightning cycle for all countries in Africa is shown to decompose into annual and semi-annual components.
Dr
Michael Gaylard
(HartRAO)
Track D1 - Astrophysics
Poster
Monthly averaged weather parameters for day and night from satellite infrared and microwave data for the areas containing the proposed Square Kilometre Array (SKA) radio telescope core sites in Australia and South Africa are compared.
Mr
Slimane Lafane
(Development centre for advanced technologies)
Track A - Condensed Matter Physics and Material Science
Poster
In this contribution we study the effect of the laser fluence on the stoichiometry and morphology of Sm1-xNdxNiO3 thin films deposited by KrF laser ablation into vacuum. Using an ion probe, the plasma plume front velocity was determined and related to the films properties. Furthermore, the ablated mass was measured and the ablation threshold was determined. Thereby, the optimal laser fluence...
Mr
Mathew Munji
(Nelson Mandela Metropolitan University)
Track F - Applied and Industrial Physics
Presentation
Solar cell device parameters cannot be obtained directly from measured current-voltage (I-V) characteristics as performance parameters such as power output are, but need to be extracted by curve-fitting procedures. This contribution describes and applies a particle swarm optimization (PSO) algorithm to extract solar cell device parameters from I-V curves.
Mr
Sashin Moonsamy
(University of the Witwatersrand)
Track D1 - Astrophysics
Presentation
We review the essential ingredients of Mixing Length Theory and comment on its effectiveness in modeling stellar convection. We discuss also a competing theory of convection known as the Full Spectrum of Turbulence model, and compare it with Mixing Length Theory. We consider some numerical procedures involved in the implementation of these theories.
Ms
Mpho Tshisaphungo
(Hermanus Magnetic Observatory)
Track D2 - Space Science
Presentation
Space weather describes the conditions in space that affect both Earth- and Space bound technological and biological systems. It is a consequence of the behavior of the Sun, the nature of the Earth’s magnetic field and atmosphere, and our location in the solar system. Space weather is one of the principal threats to modern technology. With the increase in technological systems the need for...
Dr
Willy Okullo
(Nelson Mandela Metropolitan University)
Track F - Applied and Industrial Physics
Presentation
We investigated the effects of spectral variation on the performance of photovoltaic modules. To quantitatively correlate device performance to different spectra we measured current-voltage data, global irradiance and the corresponding spectrum at different times. This paper presents a detailed discussion of the correlation of device performance with incident spectrum.
Dr
Marek Gusowski
(Department of Physics University of the Free State)
Track C - Lasers, Optics and Spectroscopy
Poster
The structural and luminescence properties of sodium yttrium fluoride (NaYF4) nanoparticles co-doped with rare earth ions, prepared using a thermal decomposition of fluoracetates precursors, were investigated. Luminescent NaYF4:Er3+ nanoparticles in the range of 8-30 nm were obtained.
Mr
Hendrik Jacobus van Heerden
(University of the Free State)
Track D1 - Astrophysics
Poster
The development of Spica, a custom designed data acquisition and control software package for the Boyden research telescopes will be considered. The motivation for the development of the package as well as the aims and capabilities of the software in terms of the hardware-software interfacing, and the data acquisition and control will be discussed. Results on the implementation and uses will be shown.
Mr
Blessed Muchono
(University of Johannesburg)
Track A - Condensed Matter Physics and Material Science
Presentation
Electrical resistivity and specific heat measurements on a (Cr98.5Al1.5)100-yMoy alloy system are reported. The results indicate that antiferromagnetism is fully suppressed to below 2 K in alloys with y larger than 4.5 at.% Mo. The Sommerfeld electronic specific heat coefficient decreases sharply below this concentration.
Mr
Ngcali Tile
(CSIR NLC)
Track A - Condensed Matter Physics and Material Science
Presentation
C-NiO was spray deposited on large scale aluminium substrate for use as cost-effective selective solar absorbers. These films were characterized structurally and optically. Absorptance of up to 0.8 calculated from UV/Vis spectrophotometry was achieved on these coatings. Their SEM images revealed pores while Raman revealed presence of predominantly graphite carbon.
Mr
NDANDULENI LESLEY LETHOLE
(SAIP)
Track A - Condensed Matter Physics and Material Science
Presentation
On introducing amorphisation recrystallisation methods to LiFePO4, ternaries (FePO4), will be more amenable than the quaternary LiFePO4, since they are less complex. Hence we investigate the stabilities of the different polymorphs of FePO4, before atomistic simulations, by employing the pseudo-potential planewave calculations within the Local Density Approximation (LDA) and pardew-wang...
Dr
Ed Elson
(University of Cape Town + South African Astronomical Observatory)
Track D1 - Astrophysics
Presentation
Star formation is a major driver of galaxy evolution. A suite of star formation models is examined for two atypical star-forming dwarf galaxies in order to quantify the relationships between their star formation activity and the properties of their inter-stellar media. High-quality HI, far infrared and far-ultra violet imaging is used to accomplish this. The star formation threshold of each...
Mr
Kevin Garapo
(Centre for Quantum Technology, University of Kwazulu-Natal.)
Track G - Theoretical and Computational Physics
Presentation
The theory of continuous weak measurement provides a tool to monitor the evolution of the wavefunction of a single quantum system in real time. We study the statistics of continuous monitoring of the position of a particle subject to several potentials.
Mr
Sifiso Senzo Ntshangase
(University of Cape Town / iThemba LABS)
Track B - Nuclear, Particle and Radiation Physics
Presentation
Heavy ion beams at iThemba LABS have been produced in a 10GHz Minimafos Electron Cyclotron Resonance (ECRIS) for the past two decades. The increase in demand for new ion species and high intensity beams from the nuclear physics community has led to a decision to procure a new 2nd generation ECRIS. The source is a room temperature ECRIS based on the Grenoble Test Source (GTS) design.The source...
Dr
Robert Bark
(iThemba LABS)
Track B - Nuclear, Particle and Radiation Physics
Presentation
A proposal to develop a radioactive beam facility at iThemba LABS is being developed. It envisages the addition of a new cyclotron, a k70 negative-ion accelerator. Such an accelerator can supply two beams simultaneously, one to be used for isotope production and neutron therapy, the other to create radioactive ions. These can be post accelerated by the existing SSC accelerator to energies of...
Mr
Solohery M. Randriamampandry
(South African Astronomical Observatory)
Track D1 - Astrophysics
Poster
We carry out a chi-square fitting of Spectral Energy Distributions (SEDs) for a set of 25 star forming galaxies in the X-ray luminous cluster MS 0451.6-0305 at z=0.54. We determine the best-fit parameters to get clues on stellar populations and physical properties of these galaxies. It shows that derived stellar masses are in good agreement with previous estimates from the literature. However,...
Mr
Josias Le Roux
(University of Johannesburg)
Track C - Lasers, Optics and Spectroscopy
Poster
Theory on layout of a fiber laser, how a fiber laser operates and increasing the output power is covered in the paper. The steps followed to increase the output power are discussed, including the experimental results obtained.
Mr
Mahlaga Molepo
(University of the Witwatersrand)
Track G - Theoretical and Computational Physics
Poster
Groundstate and hybrid density functional calculations are used to examine the structural and electronic properties of ZnO under high pressure. The generalized gradient approximation is employed to examine the ground state structural properties while the B3LYP hybrid functional is used for the electronic properties. In agreement with previous studies, it is found that ZnO transforms from the...
Mr
RJ Moloantoa
(University of Limpopo)
Track A - Condensed Matter Physics and Material Science
Poster
Au and Pd doped TiO2 nanocrystals were prepared using sol-gel routes. Scanning Electron Microscopy(SEM) and X-ray diffraction(XRD) techniques were used to characterize the samples. The effects of dopants on the phase transformation and grain growth were investigated. Gold does not affect the anatase-rutile transformation temperature whereas palladium does.
Mr
Gaotsiwe Joel Rampho
(University of South Africa)
Track G - Theoretical and Computational Physics
Poster
Ground-state properties and cluster structure of Helium and Berilium
nuclei are studied with the antisymmetrised molecular dynamics. The
Hamiltonian of the nuclei is described with a semi-realistic
nucleon-nucleon potential. The results obtained are compared with
experimental data
Mr
Tinyiko Maluleke
(Student)
Track B - Nuclear, Particle and Radiation Physics
Poster
Alpha decay characteristics (ground-state masses, Q-values, decay lifetimes and nuclear potentials) have been studied extensively using various methods and models. A computer visualization code will be developed and tested on available experimental data and make predictions for experimentally unexplored region. The final product will be incorporated into low-energy nuclear database.
Ms
ESRA Khaleel
(Stellenbosch University)
Track B - Nuclear, Particle and Radiation Physics
Poster
The AFRODITE and DIAMANT detectors were used to measure the evaporation channels in the 18O+18O reaction. Emission of (p, d, t) and alpha particles were identified with excellent particle identification. The cross sections for evaporation residues production are calculated with the statistical model code CASCADE.
Ms
ESRA Khaleel
(Stellenbosch University)
Track B - Nuclear, Particle and Radiation Physics
Presentation
The AFRODITE and DIAMANT detectors were used to measure the evaporation channels in the 18O+18O reaction. Emission of (p, d, t) and alpha particles were identified with excellent particle identification. The cross sections for evaporation residues production are calculated with the statistical model code CASCADE.
Mr
EDWIN MAGIDIMISHA
(NWU (POTCHEFSTROOM))
Track D2 - Space Science
Presentation
In this work a fully time-dependent cosmic ray model, based on the numerical solution of the Parker transport equation, is used to compute intensities of galactic cosmic rays in the heliosphere. Results are compared to recent observations of charged particles by the Ulysses spacecraft. We show how computed intensities along the Ulysses trajectory vary over a solar cycle and in particular show...
Mr
OBED SHIRINDA
(iThemba LABS/University of the Western Cape)
Track B - Nuclear, Particle and Radiation Physics
Presentation
Characteristic conditions that should be met for two-quasiparticle chiral bands to reach degeneracy were examined using the two-quasiparticle-plus-rotor model for the A ~ 100, 130, 190 mass regions. Previously proposed fingerprints of chirality (like intra- and inter-band B(M1) staggering, energy staggering, etc) were also studied.
Dr
Deon Steyn
(iThemba LABS)
Track F - Applied and Industrial Physics
Presentation
Excitation functions have been measured for the reactions 89Y+p and 93Nb+p and thick-target yield curves have been derived for the production of 88Zr and 89Zr up to 70 MeV. Tandem Nb/Y-targets as well as the extraction of medically-important radio-Zr nuclides from used Nb capsules as a by-product are discussed.
Mr
Sam Ramaila
(University of Johannesburg)
Track E - Physics Education
Presentation
Various strategic interventions to enhance teacher professional development have been proposed over the years. Mentorship itself is a broad concept open to a variety of scholarly interpretations. This presentation reflects more specifically on the creative interaction amongst science teachers working as a community of practice with professional development efforts forming the nexus of this...
Mr
Saleh Khamlich
(Nanoscience)
Track A - Condensed Matter Physics and Material Science
Poster
In view of devicing Chromium III Oxide based photothermal absorbers, the quasi-spherical nano-particles of Cr2O3.nH2O have been synthesized by hydrothermal process. An anomalous thermal hysteresis was detected on Cr2O3.nH2O by using the Electron Spin Resonance Spectroscopy at X-band (9.61 GHz) in the temperature range of 292K–420K. Differential scanning calorimetry (DSC), was used in addition...
Mr
Sabata Moloi
(University of South Africa)
Track A - Condensed Matter Physics and Material Science
Presentation
Current-voltage measurements were carried out on the silicon Schottky diodes in the temperature range of 280–330 K. The results obtained were interpreted in terms of defect levels induced by metal impurities in the energy gap. These levels are responsible for the relaxation behavior of silicon. Properties of these relaxation diodes are not affected by the incident radiation; hence, the diodes...
Ms
Mapule DeGama
(Council for Scientific and Industrial Research (CSIR))
, Ms
Thobeka Wittes
(Council for Scientific and Industrial Research (CSIR))
Track F - Applied and Industrial Physics
Poster
Sol-gel technique was used for fabrication of C-NiO coatings. These coatings are used as selective solar absorbers for solar water heating purposes. A home-test facility was built to test the absorption efficiency of C-NiO coatings, and performances of these coatings were compared to black-paint coating and a non-coated aluminium plate.
Mr
Mohamed Elbasher
(Nuclear Physics Research Group)
Track B - Nuclear, Particle and Radiation Physics
Presentation
A large volume neutron detector was developed to investigate the very selective (3He,n)
reaction. The performance of the detector was tested using muon cosmic rays and neutrons emitted from
the 232Th(4He,xn) reaction.
Mr
Makhangela Mbambo
(University of Fort Hare and Hermanus Magnetic Observatory)
Track D2 - Space Science
Presentation
This paper presents the investigation into the variability of the maximum height of the ionospheric F2 layer (hmF2) over the South African region. The dependence of hmF2 on solar and magnetic activity is also investigated. An initial result shows larger hmF2 variability around midnight than during the day for all seasons.
Dr
Miriam Lemmer
(North-West University (Potchefstroom))
Track E - Physics Education
Presentation
Two questionnaires were administered to probe learners’ preparedness for learning mechanics in Grades 10-12. Firstly the knowledge that 1211 Grade 10 learners acquired in the theme Energy and Change in the previous school phase was determined. A second investigation probed 122 Grade 9 learners’ primordial conceptions regarding motion. The results indicated fragmented, incoherent cognitive...
Mr
Cosmas Mafusire
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
A model is used to calculate the beam quality factor of a laser beam from Zernike coefficients. It is tested by programming aberration coefficients on a laser beam and measuring the beam quality using a Shack-Hartmann wavefront sensor. The two show excellent agreement.
Mr
Fulufhelo Kenneth Maphaha
(University of Kwazulu-Natal)
Track D2 - Space Science
Presentation
On the 09/08/2002 the Cluster spacecrafts footprint where located within the field of view of the Syowa East SuperDARN radar. The variations in the magnetospheric electric field observed by the spacecrafts were compared to the line-of-sight velocity observed by radar. The 3 min delay was observed during magnetosphere-ionosphere coupling.
Mr
Nico Lemmer
(North-West University (Potchefstroom))
Track E - Physics Education
Presentation
Alternative conceptions are a perennial problem in physics education. The problem can be approached from different historically predominant theoretical frameworks, e.g. the empirist-behaviorist and constructivist frameworks. A hypothesis of the learning process in physics is proposed, termed the cognitive refinement model. It identifies three levels of learning, viz. perceptual, conceptual and...
Mr
MOHAMMED KHENFOUCH
((1)Faculty of Sciences Dhar el Mahraz, Lab. of solid state physics, Polymers and nanomaterials group , BP 1796 Atlas Fez 30 000.(2) Nanoscience Laboratories, Materials Physics Dept., iThemba LABS-National Research Foundation, P O Box 722, Somerset West 7129, Faure, South Africa)
Track A - Condensed Matter Physics and Material Science
Poster
With freakishly mobile electrons that can blaze through the material at nearly the speed of light, 100 times faster than electrons can move through silicon, and its amazing mechanical properties, graphene became the rise of future mecha and optoelectronic. The main goal of this work is to confine Graphene nanosheets in polymeric 1-D systems.
Ms
Anne Marie Nzioki
(Centre for Astrophysics, Cosmology and Gravitation, University of Cape Town)
Track D1 - Astrophysics
Presentation
Modifications to General Relativity have been proposed to accommodate recent observations and for the most part, the focus has been on the f(R) theories of gravity. We review the features of f(R) theories of gravity by presenting their theoretical and observational aspects using the covariant approach.
Mrs
Liesl Burger
(National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Poster
We describe design considerations and the steps taken to build a laser resonator with an intracavity spatial light modulator. We then discuss the performance of this laser, with observations and problems specific to this configuration.
Mr
Robert Roelof Joseph van den Heetkamp
(North West University (Mafikeng Campus))
Track F - Applied and Industrial Physics
Poster
To perform test on solar energy components and subsystems, a heliostat with louvered mirror-panels mounted on a turntable has been constructed. This paper discusses the development of the control system to direct the reflected radiation to the laboratory hut in which the systems under test are placed.
Mr
Senzo Miya
(Nelson Mandela Metropolitan University)
Track A - Condensed Matter Physics and Material Science
Presentation
InAs/GaInSb strained layer superlattice structures were discovered to have the same detectivities as HgCdTe ternary alloys of the same threshold energy at room temperature. This makes these superlattices suitable replacements for HgCdTe, which presents some technological difficulties. In this paper the optical and structural properties of GaInSb and GaInSb/GaSb quantum wells grown by...
Mr
Tom Mutabazi
(Astronomy Department, Astrophysics, Cosmology and Gravity Centre (ACGC), University of Cape Town)
Track D1 - Astrophysics
Presentation
Distance measurements to extragalactic sources are a major step towarsds studies in extragalactic astronomy. We here determine the redshift-independent distance to the Norma cluster, and hence the peculiar velocity in the Cosmic Microwave Background radiation rest frame using the Near-infrared Fundamental Plane for early-type galaxies.
Ms
Kaminee Maduray
(CSIR)
Track C - Lasers, Optics and Spectroscopy
Poster
This preliminary photodynamic therapy study investigated the effect of different diode laser powers (mW) for the activation of two photosensitizers (AlTSPc, aluminum tetrasulfonatedphthalocyanine and ZnTSPc, zinc tetrasulfonatedphthalocyanine) in healthy normal fibroblast cells.
Mr
Dawit Worku
(University of Cape Town)
Track G - Theoretical and Computational Physics
Presentation
We analyze recent data on particle production yields which is obtained in collider experiments within the statistical model. We calculate the thermodynamic quantities and speed of sound in a resonance hadron gases, whose mass spectrum is assumed to have hagedorn form. Finally, we compared our results with those obtained from other models.
Mr
Mosebetsi Leotlela
(University of Witwatersrand)
Track F - Applied and Industrial Physics
Poster
The effectiveness of silicon carbide (SiC) to act as a barrier to migration of gaseous fission products (FP) through the (Tri-Isotropic) TRISO coated particle out of the fuel pebble depends on its ability to maintain its crystal structure. However, analyses of irradiated fuel pebbles indicate that the crystal structure of the SiC is greatly affected by the duration of irradiation, irradiation...
Mr
Davison Munyaradzi Murape
(NMMU)
Track A - Condensed Matter Physics and Material Science
Presentation
The effect of sulphur treatment on the electrical and optical properties of Te doped bulk n-GaSb has been studied by current-voltage (IV), capacitance-voltage (CV), photoluminescence (PL) and X-Ray photo-spectroscopy (XPS). Treating the GaSb surface with Na2S:9H2O, (NH4)2S and (NH4)2SO4 resulted in an improvement in the reverse leakage current of up to an order of magnitude for Au/n-GaSb...
Mr
Zakhelumuzi Mesuli Khumalo
(Student)
Track A - Condensed Matter Physics and Material Science
Poster
The study of radiation effects on platinum binary systems has both the fundamental and applied aspects.It is due to the fact that the formation of ordered domains with the super-lattice structure increases the strength and surface hardness and could also have an impact on surface activity and chemical properties.The changes of mechanical, physical and chemical properties caused by radiation...
Prof.
JAPIE ENGELBRECHT
(NMMU)
Track A - Condensed Matter Physics and Material Science
Poster
The influence of dielectric parameters involved in the simulation of the reflectivity in the reststrahlen region of SiC is investigated as a possible cause for the appearance of an anomalous peak in this region of the reflectance spectrum of SiC. Results will be presented and discussed.
Dr
Bakang Moses Mothudi
(University of the Free State)
Track A - Condensed Matter Physics and Material Science
Presentation
BaAl2O4:Eu2+, Nd3+,Gd3+ phosphors prepared at different initiating combustion temperatures (400-1200 oC) were annealed at 400-1200 oC for 3 hours. X-ray diffraction, SEM, FT-IR and Raman were employed to identify the structural phases, surface morphology and vibrational frequencies, respectively,and a 325 nm He-Cd was used for fluorescence measurements.
Ms
Shaimaa Abdalmonem
(National Institute for Laser Enhanced Science)
Track C - Lasers, Optics and Spectroscopy
Poster
Determination of the optical properties of solid and liquid samples has great importance. Since the integrating sphere-based setup is used to measure the amount of reflected and transmitted light by the examined samples, optical properties could be calculated. Our study is a preliminary step toward studying the optical properties of bacterial samples.
Dr
R. Neveling
(iThemba Laboratory for Accelerator Based Sciences, Somerset West 7129, South Africa)
Track B - Nuclear, Particle and Radiation Physics
Presentation
The K600 zero degree facility at iThemba LABS was recently successfully commissioned. The setup and experimental techniques for the high energy resolution measurement of (p,p') and (p,t) reactions at intermediate energies are described, and preliminary results are presented.
Ms
Rosinah Mahlangu
(University of Limpopo)
Track A - Condensed Matter Physics and Material Science
Poster
We investigate the transformation from B2 to B19/B19’ in the PtTi shape memory alloys using density functional theory within the generalized gradient approximation, VASP code [1]. We will present the results on the heats of formation, phonon dispersions and the density of states for the B2, L10, B19 and B19’ PtTi structures. Furthermore, we calculated the lattice expansion for the B2 and L10...
Mr
Deatrick Foster
(South African Astronomical Observatory)
Track D1 - Astrophysics
Presentation
We report on the recent observation of a 115-day modulation in the X-ray flux of the ultraluminous X-ray source (ULX) NGC 5408 X-1, and in particular, the interpretation of this modulation as the orbital period. We suggest that this modulation is more likely superorbital in nature. Comparing the properties of this ULX with those of the prototype micro-quasar SS 433, we argue that NGC 5408...
Mr
Abdul Mirza
(UKZN)
Track F - Applied and Industrial Physics
Presentation
The Centre for Quantum Technology has recently secured the link between the Moses Mabhida Soccer Stadium in Durban with the Joint Operations Centre (JOC) of the province using quantum based encryption systems. The link was used by the eThekwini Municipality during the 2010 FIFA World Cup to encrypt all communication between the stadium and the JOC. This, being the first ever public global...
Mr
Thuso Simon
(Astronomy Department, Astrophysics, Cosmology and Gravity Centre (ACGC), University of Cape Town)
Track D1 - Astrophysics
Poster
The XMM-Newton observatory has 10 years worth of data archives. The data is analyzed by a standard pipeline that does not search for transients. I researched into three different methods which would search for transients and found that the Kuiper test was the most sensitive.
Mr
Ogbonnaya Okike
(University of KwaZulu-Natal)
Track D2 - Space Science
Poster
The source region for whistlers has been hotly contested for many years. This study aims to show what fraction of lightning detected by WWLLN penetrates the ionosphere, and then to tie up individual fractional hop whistlers detected by the DEMETER satellite with whistlers observed on the ground at Tihany, Hungary.
Mr
Roger IANJAMASIMANANA
(Astronomy Department, Astrophysics, Cosmology and Gravity Centre (ACGC), University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa)
Track D1 - Astrophysics
Presentation
We present a novel method to study the relationship between gas content of galaxies, their star formation activity and the phase structure of the ISM. We do this by summing all individual profiles in the data cubes of the THINGS samples.
Mr
Jacob Moloantoa
(University of Limpopo)
, Dr
Thuto Mosuang
(University of Limpopo)
Track G - Theoretical and Computational Physics
Poster
The stability of boron trioxide is studied using the plane wave’s pseudopotentials calculations. The hydrostatic pressure against volume at room temperature is being varied to determine the minimum energy possible for phase transformation. Our results agree well with various boron trioxide calculations and experiments.
Mr
Gashaw Adera
(PhD Student in the area of Theoretical Nuclear Physics at Physics Department University of Stellenbosch)
Track B - Nuclear, Particle and Radiation Physics
Presentation
We present calculations of the quasifree associate production via the neutrino-nucleus weak interaction. Our formalism is done in the relativistic plane wave impulse approximation. In the plane wave limit, the spectator approximation is used to construct the invariant matrix element. The cross section is constructed as the contraction between the leptonic and hadronic tensors. The numerical...
Mr
Polycarp Mabizela
(FHIT)
Track F - Applied and Industrial Physics
Poster
Investigations into the gasification behavior during co-gasification of coal, biomass materials and coal/biomass blends prepared at different ratios (10:90, 20:80, 30:70, 40:60, and 50:50) have been conducted using a Thermogravimetric analysis (TGA) apparatus. Biomasses (pine wood, eucalyptus and cow dung) and coal (bituminous and lignite) were used. Devolatization behavior of different...
Mr
Busiso Mtunzi
(Fort Hare Institute of Technology, University of Fort Hare, Physics Department)
Track F - Applied and Industrial Physics
Poster
The efficiency of photovoltaic module is largely affected by high operating temperatures. This paper discusses the effect of a batch water system on a SP70 photovoltaic module. Heat exchange in the system was noted to take place. Infrared camera, PVPM1000C device, thermocouples and a data logger were used for data collection.
Dr
Ashmore Mawire
(North West University, Mafikeng Campus)
Track F - Applied and Industrial Physics
Presentation
Abstract
Theoretical models of an oil/pebble-bed TES for a solar cooking application are formulated. The experimentally validated models are used to examine the effects of different charging and discharging methods on the thermal performance of the oil/pebble-bed TES system.
Prof.
Muzi Ndwandwe
(University of Zululand)
Track A - Condensed Matter Physics and Material Science
Poster
Solid state compound phase formation has been investigated between thin metal films (Co, Hf, Ni, Pd and Pt) and VO2 substrates using RBS and XRD. The thin-film couples were annealed from 45 min to 1 hr between 400 and 900 degrees centigrade. It was found that Hf reacts with VO2 whereas Co, Ni, Pd and Pt do not. Heats of reaction were calculated for all possible combinations of the vanadium...
Mr
Mandla Msimanga
(iThemba LABS)
Track A - Condensed Matter Physics and Material Science
Presentation
Heavy Ion - Elastic Recoil Detection (HI-ERD) analysis is now a well established ion beam technique in the analysis of thin film materials of technological and medical importance. It is to a large extent the most suitable nuclear analytical technique available for simultaneous identification and quantitative depth profiling of light elements in thin films. This presentation describes a Time of...
Dr
Pieter Neethling
(Laser Research Institute, University of Stellenbosch)
Track C - Lasers, Optics and Spectroscopy
Poster
A SCALLS (Solution Crystallization Analysis by Laser Light Scattering) setup has been improved using 3 lasers with different wavelengths. This improvement allows us to not only determine the temperatures at which crystallization starts to occur, but also to estimate the size of the crystallites (as a function of temperature).
Mr
Gibson Peter Nyamuda
(Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Poster
Stationary, single colour, pump-probe reflectivity measurements were performed for the first time on the silicon/silicon dioxide interface of n-type silicon using a femtosecond laser. The change in the reflected probe beam increased with time of several minutes during irradiation of the sample with a strong pump beam.
Ms
Kerstin Haupt
(LRI, Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Presentation
We will present the current status of our first time resolved electron diffraction experiment, which is the investigation of the structure change of an ultrafast heated thin metal foil. We will show how we produce the required freestanding metal films with a thickness of only a few tens of nanometers.
Dr
Frederick David Smit
(iThemba LABS, , PO Box 722, Somerset West 7129, South Africa)
Track B - Nuclear, Particle and Radiation Physics
Presentation
A many-body approach is used to investigate the regular patterns in scales found in a wavelet analysis of giant resonance fine structure. Our study suggests that the spreading widths of collective excitations in nuclei are determined by the number of fragmentations seen in the power spectrum of the scales.
Dr
Bonex Mwakikunga
(CSIR National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Poster
We report on the first online observation of invisible plumes in the CO2 laser system by use of a CEDIP Instruments Inc. infrared camera. Examples of movie clips of the flame are presented. We also present results of ingenious experiments on spectroscopy of such flames by means of an RS Series of the BOMEM FTIR employing two types of the Cincinnati Electronics Laboratories IR detectors...
Mr
SARIT KUMAR GHOSH
(UNIVERSITY OF JOHANNESBURG)
Track A - Condensed Matter Physics and Material Science
Poster
We present electrical resistivity and dc susceptibility measurements in the range of 1.8-300K on cubic Sm3Ru4Ge13 semiconducting system. At higher temperature the resistivity follows activation type behavior and at lower temperature the onset of antiferromagnetic ordering at TN =5K. On the other hand the susceptibility measurement behaves as a Van-Vleck type paramagnet towards higher...
Dr
Messai Mamo
(Nano-scale transport Physics laboratory, School of Physics and Centre of Excellence in Strong Materials,)
Track A - Condensed Matter Physics and Material Science
Poster
Graphene layers were synthesized chemically and characterized systematically by spectroscopic and microscopic techniques. We study electron transport in these materials at low temperatures as well as at high magnetic fields and compare with device properties of multi-layered carbon films to show their potential in sensor device applications.
Prof.
Hassan BENCHERIF
(Reunion Island University)
Track D2 - Space Science
Presentation
The improvement of the laser sources allows LiDAR to probe an increasing altitude range of the atmosphere with improved vertical and time resolutions. Several methods using LiDAR technique have been developed to retrieve temperature in the UTLS. However, the Rayleigh technique is limited and can not operate below the 30km height, while the vibrational Raman-N2 technique has been developed in...
Dr
Attieh A Al-ghamdi
(Photonics Research Department Manager)
Track C - Lasers, Optics and Spectroscopy
Presentation
The solid state dye laser active medium prepared from Pyrromethene-567 dissolved in ethylene glycol and added in a 2-hydroxyethyl-methacrylate methyl-methacrylate (volume mixture 1:1) copolymerized by gamma irradiation method (GIM). This new method of processability, to the best of our knowledge, is the fastest way in fabricating Polymeric Dye Laser samples so far. In the present work, a cheep...
Mr
Zephania Birech
(laser research institute, university of stellenbosch)
Track C - Lasers, Optics and Spectroscopy
Poster
A robust, inherently phase-stable Two-dimensional electronic spectroscopy setup employing conventional optics and delay stages is introduced. The setup is suitable for use in the ultraviolet, visible and near infrared spectral regimes.
Dr
Magnus Rehn
(UKZN)
Track C - Lasers, Optics and Spectroscopy
Presentation
We report on the latest experimental achievements with ultracold atoms in the Quantum Research group at UKZN. As previously reported, we have cooled a dilute gas of Rubidium atoms to mikroKelvins in the first Magneto Optical Trap in Africa. Currently we are implementing methods for better diagnostics as well as transfer to of cold atoms between different vacuum chambers. Some of the long term...
Mr
Nicolas Erasmus
(Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Poster
Femtosecond electron diffraction in principle allows for the observation of the initial dynamics of photo-induced processes in molecules and condensed phase with atomic spatial and temporal resolution. The method is based on the classical pump-probe spectroscopy with femtosecond laser pulses, but the difference being that the laser probe-pulse is replaced by an ultrashort electron pulse, which...
Mr
Gurthwin Bosman
(Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Presentation
The photoinduced isomerisation reaction of dithizionatophenyl-mercury(II) in solution by femtosecond transient absorption spectroscopy is investigated. The C=N isomerisation from the cis reactant to trans product, results in a significantly red shifted absorption band for the product compared to the reactant. We discuss ultrafast photoinduced isomerisation along a reaction pathway.
Mr
Egmont Rohwer
(Stellenbosch University)
Track C - Lasers, Optics and Spectroscopy
Poster
A detailed overview of the current UTA setup at the LRI is presented in poster format. Specific attention is given to the improvements and alterations made in the past year that has allowed for increased sensitivity, spectral versatility, temporal resolution and operational reliability.
Mr
Pheneas Nkundabakura
(University of the Free State)
Track D1 - Astrophysics
Presentation
The Large Area Telescope (LAT) on board the Fermi/GLAST gamma-ray observatory is a pair conversion gamma-ray telescope sensitive to photon energies between 20 MeV and 300 GeV. With its high sensitivity in point source detection, 25 times more than its predecessor the EGRET, and its improved source localisation, Fermi-LAT has shown that it will address some of the unresolved issues left...
Ms
Kosma von Maltitz
(University of Cape Town)
Track D1 - Astrophysics
Presentation
Our understanding of local galaxy dynamics is hindered by the Milky Way which obscures a large fraction of the sky. I will present the latest evidence from a redshift survey of galaxies in the Vela region, behind the Milky Way, of the existence of a previously an unknown overdensity.
Mr
Frikkie De Beer
(Necsa)
Track F - Applied and Industrial Physics
Presentation
Several invisible phenomena, which are part of our daily lives, are being used consciously or non-consciously to reveal features hidden from eyesight. One such phenomena is penetrating radiation in the form of neutrons, gammas- or X-rays which are continuously being utilized to reveal hidden features, unseen and undetected by the normal human eye of e.g. precious artifacts, fossils and the...
Dr
Ilani Loubser
(North-West University)
Track D1 - Astrophysics
Presentation
I will present results of an ongoing investigation of a large sample of brightest cluster galaxies (BCGs), their properties and the relationships between these and the properties of the host clusters. Here, we compare the stellar population properties derived from high signal-to-noise, optical long-slit spectra with the GALEX ultraviolet (UV) colour measurements for 36 nearby BCGs to...
Prof.
Herbert Weigel Weigel
(Physics Department Stellenbosch University)
Track G - Theoretical and Computational Physics
Presentation
I present a computation of the fermion contribution to the vacuum polarization energy of string-like configurations in a non--Abelian gauge theory. I establish this method by numerically verifying the invariance under (a subset of) local gauge transformations. This also provides further support for the use of spectral methods to compute vacuum polarization energies in general. I confirm that...
Dr
Christine Steenkamp
(Laser Research Institute, University of Stellenbosch)
Track C - Lasers, Optics and Spectroscopy
Poster
A tunable, narrow bandwidth vacuum ultraviolet laser source was applied to fluorescence excitation spectroscopy of four carbon monoxide isotopomers. The high spectral resolution and sensitivity of the technique facilitated detection of the lines of rare isotopomers and forbidden transitions. In this poster we give an overview of results and recent progress.
Mr
Mathew Munji
(Nelson Mandela Metropolitan University)
Track F - Applied and Industrial Physics
Presentation
A Solar-Light Beam Induced Current measurement system was used to identify defects regions in a multi-crystalline silicon cell. A particle swarm optimization algorithm was used to extract device parameters from current-voltage data to determine the variation of the device parameters of the cell at the defect locations.
Mr
Ruan Du Toit
(University of Johanneburg)
Track C - Lasers, Optics and Spectroscopy
Poster
In this paper we describe the hardware, software control and experimental results for an interferometric Bragg writing setup at various written wavelengths within the 1550nm and 1310nm telecommunication windows.
Mrs
Marissa Kotze
(SAAO & UCT)
Track D1 - Astrophysics
Presentation
Certain Low Mass X-ray Binaries show very long-term quasi-periodic modulations in their X-ray lightcurves, as obtained from the All Sky Monitor on board the Rossi X-ray Timing Explorer. This suggests long-term variations in the mass-transfer rate from the donor, possibly as a result of its solar-like magnetic cycles.
Ms
Laura Richter
(Rhodes University)
Track D1 - Astrophysics
Presentation
The two main opposing SiO maser polarisation theories can be tested by comparing the circular polarisation of the v=1 J=1-0 and v=1 J=2-1 SiO maser lines. This requires accurate measurements of the circular polarisation. The spectral line VLBI amplitude calibration method is investigated in light of this requirement.
Mr
Garreth Kemp
(University of Johannesburg)
Track D1 - Astrophysics
Poster
We investigate the canonical quantization of axial and Tkachenko oscillation modes of a vortex lattice in a rotating superfluid. We explore possible links between classical vortex theory and the works of Fetter and Owczarek & Slupski. This investigation may be relevant to the timing and glitch behaviour of neutron stars.
Mr
Steve Meyer
(Hermanus Magnetic Observatory, University of KwaZulu-Natal)
Track D2 - Space Science
Poster
Lightning induced whistler waves are one of the primary drivers of energetic particle loss from the the Earth's radiation belts. WWLLN data is used to create a model of the distribution of lightning in geomagnetic coordinates and derive the flux and spectrum of VLF whistler waves incident on the ionosphere.
Mr
Agboola Teru
(University of Fort Hare)
Track F - Applied and Industrial Physics
Poster
Many wireless sensors are getting smaller due to new solid-state devices, increased precision in fabrication and compact layout techniques. Wireless Sensors have been in use for sometime in different applications. Some of these sensors rely on batteries to power them. This makes it cumbersome if a number of them need to be used in some instances with varying distances. These sensors can be...
Mr
JN Ntimane
(University of Limpopo)
Track A - Condensed Matter Physics and Material Science
Poster
There is a growing interest in nano-materials since they have unique physical and chemical properties. The problem is that they tend to grow at relatively moderate temperatures, with subsequent loss of nano-crystalline behaviour. In this contribution we discuss the effects of incorporating both Y and Al in SnO2 on crystal growth.
Ms
Yaseera Ismail
(CSIR-National Laser Centre)
Track C - Lasers, Optics and Spectroscopy
Presentation
Bessel beams are generated by the propagation of plane waves along a conical surface. Experimentally such beams exist for a finite distance (near-field) however abruptly transforms into an annular ring (far-field). Here we outline a new optical method which allows a Bessel function to exist in the Far-field as the propagation distance tends to infinity.
Dr
Max Chirwa
(Physics Department, Walter Sisulu University)
Track G - Theoretical and Computational Physics
Poster
In a harmonized representation of elemental field sources, those of magnetic fields are elemental magnetic vector charges. This permits a simple illustration that, unlike the gravitational and electric fluxes, the magnetic flux out of any closed surface is zero for any enclosed magnetic source, dipolar or non-dipolar.
