Account: African Light Source Foundation Trust Account: 10107580045 Bank: Standard Bank, Lynwood Ridge Branch, Branch 05001 SWIFT: SBZA ZA JJ
The time zone is controlled by you as an Indico Setting (top right). The session times will therefore be shifted if you are not set to Central Africa Time (CAT) = GMT+2.
Welcome to the 2024 joint hybrid meeting of the African Light Source (AfLS), the African Physical Society (AfPS), and co-convened with several other Pan African professional science societies. We hope that you will join us as we communicate and celebrate Big Science and Big Goals for Africa!
Advanced light sources support multiple disciplines. We have a vision to establish an advanced light source on the African continent.
Programme Outline
The meeting program will cover a broad range of topics in four different tracks.
Track 1 : AfLS : | 09:00 - 17:30 CAT/GMT+2 |
Track 2 : AfPS : | 09:00 - 17:30 CAT/GMT+2 |
The format of this exciting hybrid meeting will allow attendees to take full advantage of the overlap between the different participating organizations. All registrants will be able to attend sessions in any track with a single registration.
Contributed oral presentations and posters are welcome. Please identify the track of your participation at the registration and abstract submission phases.
The programme details, as they are updated, are available in the Timetable link on the left-hand menu.
Students and Early Career Scientists Welcome
There is a limited amount of financial support for students and early-career professionals for online data packages for the conference. Applicants must first fully register and then apply using the link in the left panel.
Participation
The Joint Organizing Committee of this meeting observes the basic policy of non-discrimination and affirms the right and freedom of scientists to associate in international scientific activity without regard to factors such as ethnic origin, religion, citizenship, language, political stance, gender, sex or age, in accordance with the Statutes of the International Council for Science.
No barriers, which would prevent the participation of bona fide scientists, will exist at this meeting.
Sponsors
From the Chair: AfLS International Conference Organising Committee
Welcome address from the Hosts: Vice-Chancellor of the University of Johannesburg: Prof Letlhokwa Mpedi
The African Physical Society is a non-governmental professional association with the African Association of Physics Students as a subsidiary organization. It provides a forum to bring together for the purposes of networking, collaboration, and advocacy, all the existing national physical societies, The African Physical Society also endeavors to support and represent physicists and physics students working and studying in countries that do not have a national physical society.
The African Light Source (AfLS) project powers the vision for a large scale research infrastructure, known as a light source, in Africa. This super microscope is capable of addressing all the UN SDGs, including Africa specific challenges. It is a premier instrument which can support massive human capacity building and globally competitive research across many disciplines. It also supports innovation, and competitive industry. This contribution reflects on progress over the past year, including the imminent release of the Conceptual Design Report (CDR), and the near final form of the reports from the three Statistic Task Forces (STFs). We will also hear of new partnerships and developing networks at the global level. Notable scientific projects, and major scientific training will be reported on by others. This promises to be a watershed conference, as we reflect on the tremendous progress and achievements. The future holds a developing schedule towards the African Light Source, with professionalisation of the AfLS expected in 2025. We look forward to an excellent conference.
A message from the Director of iThemba LABS, Prof Victor Tshivhase.
Some final comments, logistics, details
Plenary
Qun Shen
Deputy Director for Science and Distinguished Scientist
National Synchrotron Light Source II (NSLS-II)
Brookhaven National Laboratory, Upton, NY 11973, USA
Synchrotron light sources have been developing rapidly since the 1980’s when first dedicated light source facilities started operations. These light sources essentially extend our human vision and allow us to see and investigate tiny things from microstructures to molecules and atoms, in many cases in-situ and under operating conditions. Such research activities have made substantial scientific and technological impacts in such critical areas as clean energy, microelectronics, quantum information, synthesis and manufacturing, human health, and the environment. In addition to direct scientific impacts, the light sources also provide significant indirect broader impacts to our society. These impacts are reflected in business and economic impact to the local community, promoting high-quality education and workforce training and development, and encouraging people working together in a naturally diverse and inclusive light source environment.
National Synchrotron Light Source II (NSLS-II) is a bright synchrotron facility at Brookhaven National Laboratory on Long Island, NY. It provides stable and intense photon beams, from infrared to hard X-rays, experimental capabilities, and data infrastructure to enable multiscale, multimodal, high-resolution studies on diverse systems of materials. In this presentation, I will quickly go through a few research and activity examples from NSLS-II to illustrate their scientific and technological impacts. I will then illustrate on how, in many ways, the local community may benefit from the socioeconomic activities around a light source facility.
National Synchrotron Light Source II is a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704.
Tea
Plenary
Energy and ecological transitions are currently major challenges throughout the world, particularly in Africa, where the effects of global warming are causing enormous damage to environmental and agricultural ecosystems. In addition, the war in Ukraine is demonstrating how important it is for Africa to meet the challenges of energy and food sovereignty through an appropriate approach to the management of the continent's enormous energy sources. Here we address the issues of energy resources in Africa and their geopolitical and geostrategic implications for sustainable development in Africa. We place particular emphasis on the importance of developing renewable energies, and especially on the importance of widespread access to solar energy, which could bring about considerable positive changes in access to energy for all in Africa.
AfLS Contribution
Keratin is a hardy fibrous protein found in all vertebrates with many varying types, and α and β keratin are the most abundant. α-Keratin is found in all vertebrates and consists of α-helix secondary structural elements. In contrast, β-keratin is found only in sauropsids such as reptiles and birds, and is formed out of β-sheet secondary structural elements [1]. Because of their resilient nature, many industries (such as the poultry industry) produce keratin waste, with very few methods to be upcycled.
Thermal degradation methods utilize heat and pressure to break down keratin into nutrient-rich products. These methods are expensive, destroy valued amino acids, and produce toxic gases [2, 3]. Chemical methods are very effective and utilize strong acids and bases to degrade keratin. These methods, however, have a high risk factor for the environment, while only producing low-nutrient products. The last method is enzymatic degradation, in which proteases with the capability to target peptide bonds in keratin are used to degrade keratin into smaller peptides and single amino acids. This method produces nutrient-rich products, including essential amino acids, with minimal risk to the environment. The largest drawback of this method is that very few keratinolytic organisms are known and even fewer stable keratinolytic enzymes identified, with only five known keratinase structures having been solved [1, 2].
The current project is part of the ThermoK consortium and focuses on identifying novel keratinases from the keratinolytic thermophilic organism Fervidobacterium pennivorans, as well as solving their tertiary structures by X-ray crystallography [4]. A novel protease from the S8 family has been isolated and heterologously expressed in E. coli. This protease has shown high levels of keratinolytic activity using both milled feather and keratin azure assays. The tertiary structure of this S8 protease has been solved at a resolution 0f 1.63 Å and possibly matured in the crystallization droplet, as the structure contained the cleaved pro-domain still attached to the catalytic domain. This S8 structure can be used to further elucidate the substrate specificity of keratinases. Understanding the structure-function relationship of this enzyme could aid in the identification of additional keratinases for the upcycling of keratin-laden waste.
[1] J. De Oliveira Martinez, G. Cai, M. Nachtschatt et al. Catalysts 10(2) (2020) 184.
[2] T. Kumar Kumawat, A. Sharma, V. Sharma, et al. Keratin (2018).
[3] M. Brebu, I. Spiridon. Journal of Analytical and Applied Pyrolysis, 91(2) (2011) 288.
[4] R. Javier-Lopez, E. Mandolini, M. Dzhuraeva, K. Bobodzhanova, et al. Microorganisms 11 (2023) 22.
Humanity needs alternative energy solutions as fossil fuels deplete and climate change threatens our world. Solid Oxide Fuel and electrolyzer cells (SOFCs and SOECs) may not solve the problem but provide diversity to the world’s energy sources portfolio, these electrochemical converters improve the efficiency at which we utilise our dwindling resources. SOECs could prove particularly useful in the emerging hydrogen economy. Looking at Lanthanum Molybdate (La2Mo2O9 or LM9) as a more conductive electrolyte than the current industry standard Yttria Stabilised Zirconia in SOFCs could improve this technology. LM9 undergoes an unwanted phase change (from monoclinic to cubic at ~850K) when heating up to operating temperatures (1000K – 1120K). This work aims to stabilise the high-temperature phase of LM9 at room temperature via doping and confirm the structure of the resultant system with high-resolution ambient PXRD from the ESRF ID-31 beamline.
Investigation of Biomimetic Coatings on Glassy Carbon and Ti-6Al-4V Substrates: Impact of Varying Surface Preparation Methods
Unaisa Dockrat1, Johan.B. Malherbe 1, Tshepo.P. Ntsoane2, Thabsile.T. Thabethe1
1Physics Department, University of Pretoria, Hatfield, South Africa.
2Physics Department, South African Nuclear Energy Corporation, Pretoria, South Africa.
Corresponding author: unaisa.dockrat@tuks.co.za
Introduction
Biomimetic coatings, an innovative advancement in biomedical engineering, replicate the intricate mechanisms and superior properties observed in biological systems to enhance the performance, durability, reliability, and biocompatibility of biomedical implants [1-2]. These coatings aim to improve implant integration with the human body, addressing the challenges of traditional coatings like thermally sprayed hydroxyapatite (HAp), which can suffer from inherent residual stress, undesirable thermal products, poor biocompatibility, infection risk, and inadequate tissue integration [2]. By imitating natural biochemical processes, biomimetic coatings with better cellular adhesion, proliferation, and differentiation [3] can be produced. This study explores biomimetic deposition on Ti-6Al-4V (Ti64) and glassy carbon (GC) substrates, pretreated with sandblasting, plasma etching, and polishing, and then immersed in simulated bodily fluid (SBF) for 56 days. The resulting coatings were analyzed using scanning electron microscopy (SEM) for surface morphology, energy-dispersive X-ray spectroscopy (EDS) for elemental analysis, atomic force microscopy (AFM), and X-ray diffraction (XRD) to evaluate their structural and compositional properties.
Results
EDS analysis revealed higher Ca and P on coatings deposited on plasma-etched and polished GC substrates, while sandblasted Ti64 substrates showed higher O, Ca, and P. Plasma-etched GC and sandblasted Ti64 apatite coatings resembled thermally sprayed HAp layers on Ti64, indicating similar elemental compositions. Ti64 substrates subjected to polishing and plasma etching had lower element percentages due to pre-treatment. SEM images showed distinct surface morphologies: GC substrates had tightly packed spherical particles creating a rough texture, while sandblasted Ti64 substrates exhibited densely packed spherical clusters and plasma-etched Ti64 samples had small, uneven clusters forming a porous texture. XRD confirmed coatings on polished and plasma-etched GC and the sandblasted and plasma-etched Ti64 as hydroxyapatite with fine grain size. XRD analysis confirmed all patterns to display distinct peaks corresponding to apatite, confirming successful biomimetic apatite coating formation. The AFM measured the Young's modulus of the coatings and observed values within the range comparable to that of human cortical bone (17–25 GPa) [4]. These findings highlight the success of biomimetic coatings, which indeed produce the apatite coating needed for biomaterial implants. Synchrotron radiation studies will also be carried out to investigate the relationships between coating microstructure, elemental composition, and overall coating stability.
References
[1] Smith, A. M., & Callow, J. A. (2016). Biomimetic Coatings for Biomedical Applications: Advances in Synthesis and Applications. Journal of Biomedical Materials Research Part A, 104(6), 1457-1472. doi:10.1002/jbm.a.35781.
[2] Zhao, L., Wang, H., Huo, K., Cui, L., Zhang, W., Ni, H., ... & Chu, P. K. (2011). Antibacterial nano-structured titanium for biomedical applications. Nanomedicine: Nanotechnology, Biology and Medicine, 7(2), 177-185. doi:10.1016/j.nano.2010.10.004.
[3] Wang, X., Li, Y., Wei, J., & de Groot, K. (2002). Development of biomimetic nano-hydroxyapatite/poly(hexamethylene adipamide) composites. Biomaterials, 23(24), 4787-4791. doi:10.1016/S0142-9612(02)00207-0.
[4] D. T. Reilly and A. H. Burstein, "The elastic and ultimate properties of compact bone tissue," Journal of Biomechanics, vol. 8, no. 6, pp. 393-405, 1975.
Morgan Madhuku1, Rudolph Nchodusup>1, Gillian Arendsesup>1
1 NRF-iThemba LABS, P O Box 722 Somerset West 7129, South Africa
Corresponding author e-mail address: m.madhuku@ilabs.nrf.ac.za
Since its establishment, iThemba Laboratories for Accelerator-based Sciences (iThemba LABS) has advanced knowledge, research, and development in the domains of particle therapy, isotope manufacturing, subatomic physics, and material and environmental sciences. With up to six particle accelerators, it is the only facility of its kind in the southern hemisphere and the premier ion and particle accelerator laboratory on the African continent. iThemba LABS is renowned both domestically and abroad for being a pioneer in the development of isotopes for scientific and medical applications. iThemba LABS serves as a source of inspiration, a career route, and a learning and sharing tool for both high schools and students. In the business community, iThemba LABS is well-known for producing medicinal isotopes and using cutting-edge accelerator technologies. In academia, iThemba LABS is known as the regional hub for South African university researchers in material, particle and nuclear physics.
A quick overview of iThemba LABS, along with the current opportunities that align with its status as an IAEA Collaborating Centre, will be provided.
This study investigates the influence of plasma screening on the relativistic behavior of a hydrogen-like atomic system through the application of a screened Coulomb potential. By accurately solving the Klein-Gordon equation in spherical coordinates, under the assumption that the scalar and vector potentials are equivalent, we get the self-energy spectrum of our system along with its corresponded wave functions.
We study the non relativistic case of a Hydrogen-like atoms in a plasma environment. We use the screened Coulomb potential to model the phenomenon and we write an almost analytical formula for the energies for large wave lengths. We give also a method to compute the critical value of the wave numbers that ionize the atoms.
Plenary
We will discuss the latest efforts in our laboratory to develop highly sensitive methods of microscopy, to go directly inside living cells and uncover the behavior of single biomolecules as they effect their function in transcription. Transcription is the first step in gene expression regulation, during which genetic information on DNA is decoded into RNA transcripts. Methodologically, the so-called live cell single molecule and super-resolution techniques – that break the optical diffraction limit – are revealing with unprecedented spatial and temporal resolutions, novel emergent phenomena inside the living cells. We will discuss our recent discoveries on highly dynamic biomolecular clustering, and phase transitions in vivo. These discoveries are challenging the ‘textbook view’ on how our genome (DNA) is decoded in living cells.
At the heart of materials science studies for next generation materials is an idea that we want to be studying real materials doing real things, often in real devices. In practice, this presents a number of key data analysis and interpretation challenges because it implies we are studying ever more complicated samples, often in complex heterogeneous environments and in time-resolved operando setups, and we are interrogating our data for more and more subtle effects such as microstructures and evolving defects and local structures. Of particular interest is the study of nanomaterials and materials structure on different length-scales. In this talk I will describe various developments that leverage the latest data acquisition and analysis techniques, sometimes powered by artificial intelligence (AI) and machine learning (ML), that reveal how materials behave on ultra-fast (picosecond) time-scales after being hit with a laser. The material studied is a quantum material with a charge-density wave transition, but is a model system that demonstrates an approach that could be used to study chemical reaction coordinates for real processes in sustainable energy, environmental remediation, and health.
AfLS Contribution
Subduction zones link the mass transfer, element cycling and magma differentiation processes in which the release of C-O-H fluids from the slab plays a key role. Geochemical characteristics of basaltic magmas suggest that olivine-poor lithologies like pyroxenites may be produced from the reaction between subducting slab and ambient mantle peridotite in conjunction with variable additions of a hydrous slab component. Numerous experimental data on water solubility in nominally anhydrous minerals (NAMs) are available for hydrous peridotitic and basaltic systems. However, the extent of H migration to the sub-arc mantle wedge from the subducting crust and storage of water in theNAMs present in pyroxenites in presence of both H2O and CO2 are not available. Here we report new partial melting experiments of hydrous carbonated secondary pyroxenite and discuss the partial melt compositions with respect to the genesis of primitive tholeiitic basalts tocalc-alkaline basalts.
High-pressure experiments were performed using a Piston-cylinder apparatus and Platinum/Graphite capsule at 3 GPa and 1350 to 1525°C. A silica-deficient pyroxenite (SPX-15-1) with varying XCO2 [=molar CO2/ (H2O+CO2)] from 0.08 to 0.29 were used as the starting material. To facilitate the growth of single crystals for FTIR analyses, temperature was increased by ~200 °C above the final desired run temperature for 0.5 to 2 hrs to reduce the number of nuclei available for grain growth and finally lower the temperature at 0.4 to 1 °C/min to the final run temperature. Clinopyroxene, orthopyroxene and hydrous carbonated silicate melts (> 30 wt.%) were present in all the experiments in the presence or absence of garnet. Hydrogen incorporation in clinopyroxenes and orthopyroxenes decreases with an increase in the XH2O of pyroxenites and a decrease in Al content in their structure, which suggest Al3+ + H+ substitution. With the increased degree of melting, the partial melt compositions, on volatile-free basis, formed tholeiitic arc basalts to calc-alkaline basalts (45.17 to 51.81 wt.% SiO2, 8.42 to 10.75 wt.% CaO). Comparison of the major element compositions of hydrous carbonated silicate melts (14.85-22.69 wt.% Al2O3, 10.77-15.02 wt.% MgO, CaO/Al2O3 of 0.45-0.67) with natural arc magmas suggest that hydrous carbonated-fluxed melting of secondary pyroxenite over 90 km depth can produce partial melts similar to primitive tholeiitic basalts from Japanese, Sunda and Lesser Antilles arc magmatism.
Synthesis and characterization of Iron tungstate Nanoparticles as a Photocatalyst and Nano-adsorbent
O.J. Ajala1,3, J.O. Tijani1,3, R.B Salau1, A.S. Abdulkareem1,2
1 Department of Chemistry, Federal University of Technology, P. M. B. 65, Bosso Campus, Minna, Niger state, Nigeria.
2 Department of Chemical Engineering, Federal University of Technology, P. M. B. 65, Gidan Kwano Campus, Minna, Niger State, Nigeria.
3 Nanotechnology Research group, Africa Center of Excellence for Mycotoxin and Food Safety, Federal University of Technology, Minna, P. M. B. 65, Niger State, Nigeria.
Abstract
Iron tungstate (FeWO4) nanoparticles were synthesized using a simple sol-gel method, employing sodium tungstate dihydrate and iron(II) sulfate as precursors, with distilled water serving as the solvent. The synthesized nanoparticles underwent a thorough characterization process utilizing various techniques, including Fourier-transform infrared (FTIR) spectroscopy, high-resolution scanning electron microscopy (HRSEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption analysis.
FTIR spectroscopy revealed key vibrational modes: peaks at 771 cm−1 and 948 cm−1 were attributed to O–W–O vibrations and W–O bond stretching, respectively. Additionally, a peak at 567 cm−1 corresponded to Fe–O bending vibrations, while peaks at 3423 cm−1 and 1620 cm−1 were assigned to H–O–H stretching modes and bending vibrations, indicating the presence of free or adsorbed water. HRSEM and HRTEM analyses confirmed that the nanoparticles had an aggregated, spherical morphology. Furthermore, XRD analysis demonstrated the formation of a highly crystalline monoclinic phase of FeWO4 under optimal synthesis conditions: a solution pH of 7, a reaction temperature of 30°C, and a stirring speed of 500 rpm. This comprehensive characterization underscores the successful synthesis of FeWO4 nanoparticles and highlights their potential for various applications across multiple fields.
Andrew Ichoja1, Emmanuel .O.Odoh2 and Emmanuel .O. Adejo3
1,2,3 Federal University of Health Sciences, Department of Physics, Faculty of Science, P.M.B 145 Otukpo, Benue State, Nigeria
Corresponding author; andrew.ichoja@fuhso.edu.ng
1. Abstract
Improved Dy3+ + Sm3+ co-doped strontium magnesium borate glasses with the nominal compositions of 20SrO 10MgO (70 z) B2O3 0.7Dy2O3 zSm2O3 (0.2 z 1.0 mol%) were prepared via the melt-quenching system. The structural property of the quenched glass samples was investigated using X-ray diffraction (XRD). The ultraviolet-visible-near-IR spectroscopy (UV-Vis-NIR) spectra of the glasses exhibited characteristic absorption transitions of Dy3+ and Sm3+ respectively. The photoluminescence (PL) spectra for Dy3+ / Sm3+ co-doped glass system exhibited five emission bands due to the 4F9/26H15/2 (Dy3+), 4F9/26H13/2 (Dy3+), 4G5/26H7/2 (Sm3+), 4G5/26H9/2 (Sm3+) and 4G5/26H11/2 (Sm3+) transitions in Dy3+ and Sm3+, respectively. From the optical absorption measurements, the influence of Dy3+ and Sm3+ on the three Judd-OFelt (JO) intensity parameters (2, 4, 6) were evaluated. The achieved high values of the branching ratio ( 60% and 74%) and stimulated emission cross-section ( 10 1022 cm2) recorded at 4F9/2 6H13/2 and 4G5/2 6H7/2 electronic transitions showed an excellent lasing and optical energy harnessing potentials of the proposed glass compositions.
2. Introduction
Borate glasses are known for remarkable structural and optical properties and are more promising materials than their crystalline equivalent due to their simple and inexpensive production skill, high thermal technology, and good coefficient of incorporation of rare earth [1]. High optical performance arising from the co-doping of rare earths opens new possibilities for various applications of the glass matrix including lasers, biomedicine, sensors, etc. However, the glass system is volatile and unstable hence, the inclusion of alkaline earth metal would enhance its mechanical stability [2]. The newly activated glass composition was prepared using the melt-quenching method. Structural and photoluminescence characteristics of the glass matrix were evaluated using XRD and UV-Vis analysis respectively. The lasing parameters such as stimulated emission cross-section, transition probability, and branching ratio were calculated by equation [3] given by Kindrat
.δ_e (φ^' J^',φJ)=(_p^4)/(8πcn^2 ∆_p ) A_rad (φ^' J^',φJ)
where p is the wavelength at maximum peak, e is the emission cross-section, Arad is the radiative transition probability, and p is the effective bandwidth. The evaluated spectroscopic parameters indicate the possibility of the newly activated glass matrix for technological applications.
3. Results
Fig. 1: The XRD pattern of SrMgB2O3 glasses Fig. 2: The optical absorption spectra of SrMgB2O3 glasses
4. References
[1] H.K. Obayes, H. Wagiran, R. Hussein and M.A. Saeed. Materials and Design 94 (2016) 121 - 131
[2] Y.D. Yiannopolous, G.D.Chryssikos and E.I. Kanitsos. Phys Chem Glasses 42 (2001) 164 - 172
[3] I.I. Kindrat, B.V Padlyak and R. Lisieck. Optical Materials 49 (2015) 241 - 248
In order to implement the process of quantum teleportation, we evaluate quantum information resources through local quantum uncertainty, local quantum Fisher information, and quantum entanglement, as measured by the concurrence of the teleported output state. One of the main challenges of this work lies in the ability to create and analyze local non-classical correlations between the proposed open system and its surrounding environment. Moreover, the considered quantum state will be used as a maximally entangled mixed state as the quantum channel in the process of quantum teleportation. In light of this, we will investigate the impact of intrinsic decoherence on the quantum teleportation protocol. Finally, we assess the fidelity of the process to demonstrate the reliability of transmitting the unknown state.
Tea
Plenary
To be added
AfLS Contribution
Sociality in the vertebrate fossil record is a dynamic and fast-expanding area of research. Natural history observations of living animals are crucial for understanding and categorising sociality, but these observations are not feasible for extinct species. Some monotaxic bonebeds may provide unique opportunities to conceptualise the social behaviours of these extinct animals. An unusual bonebed (SAM-PK-K11289) discovered in the uppermost Permian strata of the Balfour Formation, Karoo Supergroup, in the Eastern Cape presents a window into the sociality of a Late Permian parareptile. The entire bonebed SAM-PKK11289 is dish-shaped, 160 mm long, 85 mm wide and 55 mm thick with an elliptical planimetric shape. We used propagation phase-contrast synchrotron X-ray micro- computed tomography to three-dimensionally reconstruct skeletal elements in SAM-PK-K11289, allowing the taxonomic identification of the individuals in the bonebed as most likely belonging to Owenetta rubidgei. This is the largest aggregation of Owenetta individuals known to date, with a minimum number of 31, based on 314 limb bones. The ontogenetic profile of SAM-PK-K11289 was interpreted by analysing the size distribution of duplicate elements and by making comparisons with other Owenetta and procolophonid specimens. The specimens in the bonebed are all similar in body size and osteologically immature, indicating that they are juveniles. The bonebed occurs in a pedogenically modified ripple cross-laminated siltstone deposited by overbank flooding on a fluvial floodplain that likely contributed to the modification, disturbance and disarticulation of many but not all elements before the bonebed was buried at or very close to the death site. This bonebed provides novel information that directly challenges the popular belief that reptiles and their ancestors are non-social or asocial. Considering the overall circumstances of the bonebed, we hypothesize that Owenetta rubidgei juveniles were socially gregarious and this behaviour may have been induced or influenced by environmental changes during the early extinction phase of the end- Permian mass extinction in the Karoo Basin.
To be added
To be added
Fibre optic sensing (FOS) is being developed for in-core, online, real-time sensing of state parameters for a nuclear reactor at full power. This study focusses on assessing the damage incurred by optical fibres when exposed to a mixed radiation field in a nuclear reactor. Both the high neutron flux and the ionizing radiation in a nuclear reactor can cause physical damage to optical fibres by introducing optical defects through ionization or atomic displacement mechanisms. Such radiation-induced defects can significantly alter the material properties and performance of optical devices. To investigate these effects, different samples of optical fibres were irradiated in the SAFARI-1 Material Test Reactor at the Nuclear Energy Corporation of South Africa (NECSA), with a differential dose up to the cumulative radiation dose (fluence) reaching up to 1 GGy. The SAFARI-1 reactor has a characteristic neutron flux of about 1x1014 n/cm2-s of fast energy neutrons. Silicon dioxide (SiO2) is an organic material extensively used in semiconductor circuits to electrically isolate different conducting regions. Due to its unique properties, SiO2 plays a critical role in wide range of applications, including optical fibres for real-time, online, in-core monitoring of various nuclear reactor parameters, such as temperature, radiation dose, pressure, etc.
Irradiation tests have also been carried out at the IRRAD facility at CERN, up to 1.85 MGy, in in-operando conditions for dose, temperature and humidity sensors, in both radiation hard and radiation soft fibres. This research aims to contribute to the understanding of radiation-induced defects in optical fibres and to support the development of more radiation-resistant materials for FOS nuclear applications. This talk reviews previous x-ray-based studies of radiation damage in fibres, summarizes what is known about the radiation damage effects, and discusses what could be gained from synchrotron-based studies.
Silicon nanoparticles of 2-10 nm size (Si-np) embedded into silicon nitride (Si3N4) thin films (70 nm thick) were synthesized and deposited on polycrystalline silicon wafers through plasma enhanced chemical vapour deposition (PECVD) technique using ammonia (NH3) and silane (SiH4) as precursor reacting gases. A second layer (50 nm) consisting of rare-earth neodymium oxide (Nd2O3) was added onto the Si-np by thermal evaporation. The resulting samples consisting of bilayered coating on Si substrate were assumed to possess photoluminescent properties where Nd2O3 and Si-np elements “cooperate” to emit a stronger signal. The occurrence on the wafer’s surface of Si-np differing in size and the formation of the Nd2O3 layer were supported by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Chemical composition characterisation was done by X-ray photoelectron spectroscopy (XPS) and energy dispersive x-ray spectroscopy (EDS). The devices were finalised by screen-printing the contacts (Ag-Al) on the front face and Al on the rear. Electrical measurements by Hall effect and spectral response were carried out to determine carrier concentrations, mobility of the charge carriers and efficiency of the obtained solar cells.
Investigation into the geological radiation levels and evaluation of hazard parameters in soil and rock specimens taken from mining sites across North-Eastern Nigeria.
Michael C. Ohakwere-Eze1, Musa Nafiu2, Shiv Kumar Singh3, Momoh Kabiru1, and John Simon1
1Department of Physics, Faculty of Science, National Open University of Nigeria.
2Department of Physics, Federal University of Kashere, Gombe State.
3Department of Physics, Federal University of Transportation Daura, Katsina State.
Corresponding author e-mail address: michael.ohakwereze@gmail.com
This research quantitatively evaluates the natural radioactivity levels and geological radiation hazard parameters of soil and rock specimens obtained from mining locations in North-Eastern Nigeria, by means of grammar-ray spectroscopy. There have been potential public health risks associated with the use of soil and rock from mining locations in North-Eastern Nigeria, specifically the study areas. A total of twenty-eight samples were systematically gathered from Nahuta and Kashere locations. Through gamma spectrometry employing a NaI (TI) detector, the natural radioactivity levels of 238U, 232Th and 40K were determined for each and every sample. The findings indicated that the mean activity concentrations of 226Ra, 232Th, and 40K in Nahuta are 46.13±4.78 Bq/Kg, 34.10±3.02 Bq/Kg and 473.94±5.41 Bq/Kg for the soil samples respectively, and 32.91±0.49 Bq/Kg, 40.70±0.41 Bq/Kg, and 578.18±4.28 Bq/Kg for the rock samples respectively. The corresponding mean activity concentrations of 226Ra, 232Th, and 40K in kashere are 17.99±4.18 Bq/Kg, 23.73±1.78Bq/Kg, and 191.65±3.15 Bq/Kg, for the soil samples, and 20.24±3.72 Bq/Kg, 29.09±1.78 Bq/Kg, and 148.36±3.15 Bq/Kg, for the rock samples respectively. An analysis of radiation risk parameters (D, AEDE, Raeq, Hex, Hin, AGDE and ELCR) has been conducted and findings explored. While the samples from the kashere region fall within the international recommended levels, elevated readings of certain radiation health parameters are observed in the Nahuta region, posing serious public health risk due to utilization of the soil and rock from this area in construction activities.
Larger activity concentration values for both soil and rock samples are is found in Nahuta when compared with same for Kashere (Figure 1). In Nahuta, the ranges of radionuclide concentration for 226Ra, 232Th, and 40K are 16.20±4.26 to 53.94±4.72 Bq/Kg with an average 46.13±4.78 Bq/Kg, 13.02±3.32 to 62.71±4.37 with an average 34.10±3.02 Bq/Kg and 76.4±8.44 to 1126.53±8.90 Bq/Kg with an average 473.94±5.41 Bq/Kg, respectively. Conversely, the radionuclide concentration of 226Ra, 232Th, and 40K in Kashere ranges from 17.99±4.18 to 29.56±8.91 Bq/Kg with an average 17.99±4.18 Bq/Kg, 14.60±0.47 to 34.60±0.71 Bq/Kg with an average 23.73±1.78Bq/Kg, and 85.74±6.03 to 316.00±2.99 Bq/Kg with an average 191.65±3.15 Bq/Kg, respectively.
The activity concentration in rock samples is higher in Nahuta, with values for 226Ra, 232Th, and 40K ranging from 9.74±1.26 to 92.78±0.28 Bq/Kg with an average 32.91±0.49 Bq/Kg, 14.33±0.26 to 71.04±0.10 Bq/Kg with an average 40.70±0.41, and 36.67±6.05 to 1136.50±5.54 Bq/Kg with an average 578.18±4.28, respectively. In Kashere, the ranges are 11.07±8.91 to 38.06±0.17 with an average 20.24±3.72 Bq/Kg for 226Ra, 13.47±6.23 to 42.43±0.36 Bq/Kg with an average 29.09±1.78 Bq/Kg for 232Th, and 13.77±2.99 to 326.89±2.33 Bq/Kg with an average 148.36±3.15 Bq/Kg for 40K.
The concentrations of radionuclides 226Ra, 232Th, and 40K in soil and rock samples, as reported by [1], average at 32, 45, and 420 Bq/kg, respectively, worldwide. Analysis indicates that the average radionuclide concentration of 226Ra, 232Th, and 40K in soil and rock samples from kashere region are lower than the global averages, suggesting no imminent radiological threat to the local population. Conversely, the average activity concentration of 226Ra and 40K in soil and rock samples from Nahuta exceeds worldwide averages. These elevated levels are attributed to mining activities in the study area, which is abundant in natural radionuclides.
The calculated mean activity concentration of 226Ra is higher in the soil sample collected from Nahuta compared to Kashere. Nevertheless, compared to Nahuta, Kashere has slightly elevated levels in samples derived from rocks. This implies that the geological formation and mining exploration in Nahuta may have resulted in higher concentrations of radium than in Kashere where the rocks may contain higher concentrations of radium. The mean activity concentrations of 232Th in the soil and rock samples collected from Nahuta are higher than those obtained for Kashere. The higher thorium levels in Nahuta could be explained by the kind of rocks that compose the formations present in the area. The mean activity concentrations of 40K are higher in the soil and rock samples collected from Nahuta as compared to Kashere. Potassium-40 being present in many rocks occurs at higher concentrations in Nahuta, signifying a higher concentration of potassium bearing minerals in the area.
As observed in Figure 1, there are higher concentrations of 226Ra, 232Th, and 40K, particularly in the soil samples obtained from Nahuta, which may pose a radiological health hazard to the inhabitants of the area. This is a health issue because prolonged exposure to these radionuclides contributes to cancer risk and other illnesses. Also, the sampled higher concentrations of these radionuclides suggest the need for environment management and monitoring systems, which should mitigate the impacts of mining and other agricultural activities. The results emphasize the necessity to follow the legal requirements concerning the radiation safety in the region with anthropogenic activities.
Fig. 1. Variation of the mean activity concentrations of 226Ra, 232Th, and 40K given in Bq/Kg for Soil and Rock samples in the study locations.
X-ray detectors play a crucial role in various fields, from medical imaging to high-energy physics. This study focuses on the simulation of both direct and indirect X-ray detectors using the Geant4 toolkit, a Monte Carlo-based software widely used for particle-matter interactions. The direct detector simulation models the immediate conversion of X-rays into electrical signals, while the indirect detector simulates the conversion of X-rays to visible light, followed by an electronic signal generation.
In this work, we present a detailed comparison between direct and indirect X-ray detectors in terms of detection efficiency, spatial resolution, and signal-to-noise ratio, emphasizing the strengths of Monte Carlo simulations for modeling complex detector geometries and interactions. By leveraging the power of Monte Carlo techniques, we are able to precisely simulate photon interactions, charge transport, and the effects of detector materials and structures on performance.
The results demonstrate how Monte Carlo simulations can help optimize detector designs and enhance their performance for specific applications. Furthermore, the adaptability of Geant4 allows for custom detector configurations, making it an invaluable tool for advancing X-ray detection technologies.
We present Fourier–Bessel particle-in-cell (FBPIC) simulation results from a laser wakefield electron accelerator driven by Gaussian (G) and Bessel-Gauss (BG) laser beam. The particle-in-cell simulations show that electron bunch energies of tens of MeV can be obtained, within cm distances to obtain a high-quality beam with low energy spread and low slice emittance.
Formic acid dehydrogenation catalyzed using ruthenium(II) complexes bearing carboxamide ligands: Structural diversity, and mechanistic insights
Pamela. S. Moyo, and Andrew .J Swart
School of Chemistry, University of Witwatersrand Johannesburg, Jorissen St, Braamfontein, Johannesburg, 2017, South Africa
Email: suzzanamoyo@gmail.com, pamela.moyo@wits.ac.za.
Keywords: Homogenous, ruthenium, hydrogen storage, formic acid dehydrogenation
One of the most important societal concerns in light of the growing global population is the search for sustainable energy sources to meet our energy needs.1–2 Fossil fuels like oil, gas and coal are depleting. The direct use of sunlight, wind energy, water power and non-food related biomass is most attractive. The light and wind are not constantly available, and need to be converted into better storable energy vectors.3–4 Most popular hydrogen storage materials are organic compounds, so-called liquid hydrogen carriers (LOHCs). Formic acid (FA) is one of the organic compounds and has recently attracted significant attention as a chemical hydrogen storage medium in which hydrogen is established as a new energy carrier that can be used as a clean energy source because of its favourable properties. Formic acid contains 4.4 wt% of hydrogen, and it is liquid under ambient conditions, allowing it to be handled, stored, and transported easily and safely.5 In this work, ruthenium(II) complexes have been synthesised and characterized using nuclear magnetic resonance spectroscopy 1H NMR, and 13C{1H} NMR infrared spectroscopy, high resolution electrospray ionisation mass spectrometry as well as elemental analysis. These complexes were evaluated as catalyst precursors in the dehydrogenation of formic acid. All the complexes were found to be effective catalyst for the formic acid dehydrogenation under mild conditions.
References
[1] J. Skea, Energy Environ. Sci., 2014, 7, 21–24.
[2] N. Armaroli and V. Balzani, ChemSusChem, 2011, 4, 21–36
[2] P. Moriarty and D. Honnery, Int. J. Hydrogen Energy, 2010, 35, 12374–12380.
[4] S. Koumi Ngoh and D. Njomo, Renewable Sustainable Energy Rev., 2012, 16, 6782–679.
[5] Mellmann, D.; Sponholz, P.; Junge, H.; Beller, M. Chem. Soc. Rev. 2016, 45, 3954-3988.
[6] H. Zhang and P. K. Shen, Chem. Rev., 2012, 112, 2780–2832.
Introduction
Due to over reliance of fossil resources for fuel and chemicals, the resultant global warming and pollution has led to research being conducted on other alternatives for renewable energy and storage systems that can be produced using more sustainable methods. This involves the development of storage systems that have a high energy density and a long-life span (Batteries, supercapacitors and solar cells). Batteries have high energy capacity, but they are limited by their low power density and low cycle life. A supercapacitor possesses unique qualities of high-power density, high cycle stability, and rapid charge-discharge performance but a low energy density.
Supercapacitors can be evaluated based on their electrode material and electrolyte performance. The energy density is largely determined by the electrode materials. As such, studies on improving the performance of electrodes via the development of new electrode materials are increasing. Biomass has been sought as a substrate for carbon electrode materials. This study therefore explores porous carbon derived from Sweet Sorghum Stalk to make supercapacitor electrodes that exhibit long cycling life, high specific capacitance when implored in a two-electrode system.
Fig 1. Galvanostati Charge-Discharge
Fig 2. XRD graphs
Modelling of gold-cyanidation reaction in Percolation Leaching
V. Moyo, L. Robert and O.P. Oladijo*
Department of Chemical, Materials and Metalurgical Engineering, Botswana International University of Science and Technology (BIUST), Palapye
Corresponding author: oladijop@biust.ac.bw
Abstract
At a global scale, depletion of large ore reserves and relative limited operation period of mines has made large investment to be tough to implement. This has prompted the implementation of new sustainability strategies to fulfill the world’s metal demand. Percolation leaching is one of the new sustainability strategies and normally applied as vat leaching in gold extraction process.
The effects of gold leaching parameters namely cyanide concentration, pH and permeability of the fixed ore bed is studied in this work in order to optimize the percolation leaching process. A numerical modelling method is applied to predict the amount of gold remaining in the fixed ore bed after a known time has elapsed. The surface reaction between gold grains and free cyanide ions and aqueous oxygen is modeled based on the framework of the shrinking core model, the internal diffusion of the oxygen through the ash layer is accounted for using the pseudo-steady state mass balance. Other factors incorporated into the model include convective transport of cyanide from the top of the column through the fixed ore bed to the bottom of the column and the amount of unreacted gold particles in the fixed bed ore. The results of the simulation model are then used to analyze, control and optimize the percolation leaching process. This reduces the number of experiments required to achieve the same results.
The model can simulate the overall gold oxidation level as well as the oxidation profile of the gold grains i.e the oxidation depth of gold grains of different sizes and at different locations within the rock particles. The experimental data from laboratory leaching column is used to estimate the model parameters.
The amount of slimes and clays in a specific ore that can reduce the permeability of the ore is also established through column leaching experimental work. This value is an essential input required for efficient permeability of the fixed ore bed. Under these conditions, the fixed bed of ore has a narrow size range which favors efficient percolation of the leaching solution.
Keywords: Percolation leaching, shrinking core model, Parameter estimation,
The establishment of oxygen variation in vat leaching tanks will be investigated. Experiments will be conducted by setting up leaching tanks with ore samples typical of artisanal and small-scale mining. Oxygen concentration and consumption rate will be measured using oxygen meters in different ores. Oxygen is essential during the oxidation of gold and its dissolution in the cyanide solution (Nicol, 2020).
4Au(s)+8CN−(aq) + O2(g)+2H2O(l) → 4Au(CN)2−(aq)+4OH− (aq) (Nourmohamadi & Rezaei, 2023)
Additionally, oxygen is also consumed by competing reactions like cyanocides ( e.g copper). During vat leaching, the process is static and replenishing of used up oxygen is difficult, therefore oxygen is high likely to be insufficient at the bottom of the tank therefore experiments to investigate the concentration of oxygen will be conducted.
Plenary
The Australian Nuclear Science & Technology Organisation (ANSTO) operates, maintains, and develops a wide range of research infrastructure (worth ~$1 billion) for the benefit of all Australians, including some of the largest research facilities in the country. The Lucas Heights campus in Sydney hosts the Australian Centre for Neutron Scattering, the Centre for Accelerator Science and the National Deuteration Facility, while the Clayton campus in Melbourne is home to the 3 GeV Australian Synchrotron Light Source. The Australian Synchrotron generates brilliant beams of infrared and X-ray synchrotron light for use in a vast array of scientific research – studies in radiotherapy, biomedical imaging and 3-D computed tomography; macromolecular crystallography for the study of the biomolecular basis of disease and the development of new medicines; agricultural, environmental and climate change research; studies in advanced electronics and advanced energy materials; planetary sciences; engineering; advanced manufacturing; and cultural heritage studies. The Australian Synchrotron currently hosts over 1000 experiments per annum across its 14 operational beamlines and is currently in the middle of the ~$100 million BRIGHT Program to design, build and commission the new suite of next-generation beamlines at the facility.
This presentation will showcase recent capability upgrades, as well as a range of impactful research outcomes from the Australian Synchrotron in the fields of health, advanced and energy materials, environmental and climate change research, engineering materials and cultural heritage studies. I will also highlight the new research capabilities from our next-generation BRIGHT Beamlines and look to the future of Synchrotron research capabilities for Australia.
Institute of Materials Structure Science is one of the institutes in KEK, and runs a synchrotron facility, Photon Factory (PF), where two synchrotron rings, PF and PF-AR (Advanced Ring) are operated. PF is operated with the beam energy of 2.5 GeV, and PF-AR with 6.5 GeV or 5. 0GeV to provide higher x-ray energy. There are about 50 end stations including 6 x-ray absorption fine structure (XAFS) beamlines: 9A, 9C, 12C, 15A1, AR-NW2A and AR-NW10A.
XAFS is one of the most demanded methods at synchrotrons and is used to study various materials such as catalysts, batteries, functional oxides, semiconductors, minerals and environmental samples. XAFS is usually divided into characteristic two regions, x-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS). XANES is the region of the spectrum from just below the absorption edge to ~50-70 eV above the edge. EXAFS is the other higher energy region above XANES and analysed to investigate local structures of elements of interest, e.g. bond length and coordination number. We will share recent topics of our XAFS studies performed at our facility. In addition, I would suggest potential topics to be studied at the AfLS in the context of natural resources in the African continent.
AfLS Contribution
NEutrons and PHotons Elevating Worldwide Science (NEPHEWS) delivers access to the world-class collective of Europe’s premiere open advanced neutron (N), synchrotron (SR) and free-electron laser (FEL) complementary research infrastructures (RI), to promote curiosity driven excellence in research. In NEPHEWS the RI institute a novel approach with their 40k+ user base of scientists through Users Organisations to provide a user-driven access program targeting new and non-expert communities, with a focus on Widening countries, Ukraine and Africa, a priority. NEPHEWS community building activities in Africa will provide twinning opportunities at RI for experienced researchers, to then act as future ambassadors for SR/FEL and N science in their regions. In-person training opportunities at the HERCULES school for PhD students are available as well as virtual training on SR, FEL and N science inclusive of proposal writing.
A number of initiatives are in progress for creating and enhancing research and training via the utilization of synchrotron light sources and crystallography. For synchrotrons, there are the African Light Source, Greater Caribbean Light Source, and Central Asian Synchrotron Light Source inititiaves. For crystallography research and training hubs, there are X-TechLab in Benin (currently operating), CRXSTAL in Jamaica (soon to be operating), and another being created in Uzbekistan. In this presentation, we will give the latest updates on those initiatives and give projections about future activities.
In this study, we conducted a computational optimization of four designs for CsSnBr3 perovskite solar cells using the SCAPS-1D simulation tool. We explored how variations in the thicknesses of the electron transport layer (ETL), hole transport layer (HTL), and perovskite layer, as well as changes in temperature, series and shunt resistances, and the acceptor doping density of the HTL, influenced key performance metrics such as short-circuit current (Jsc), open-circuit voltage (Voc), fill factor (FF), and power conversion efficiency (PCE). The highest optimized PCE achieved was 31.62%. Moreover, our findings indicated that the PCE values of all CsSnBr3-based solar cell designs developed in this research exceeded those of the previously reported ITO/WS2/CsSnBr3/Cu2O/Au cell, which had the highest recorded PCE for similar devices. Our best-performing structure demonstrated a 9.19% increase in efficiency over the previous record.
Tea
Plenary
The Southern European Thomson back-scattering source for Applied Research (STAR) project, led by INFN and hosted at the University of Calabria (South Italy), represents a cutting-edge platform for producing high-brilliance hard X-ray (up to 350 keV) photon beams through inverse Compton scattering (ICS). With the successful upgrade of its high-energy linac (STAR-HEL) to reach electron beam energies of up to 150 MeV using advanced C-band technology, STAR stands as a model for developing compact, cost-effective high-gradient accelerators to serve user facilities. We illustrate the status of the STAR project and propose leveraging its technological framework to establish the first Compton light source (CLS) on an African university campus or an equivalent regional facility. The development of such a user facility would be a key milestone in the broader roadmap toward realizing the African Light Source (AfLS) project, fostering high-level research and training in accelerator-based science across the continent. The initiative would not only position Africa as a significant player in global scientific research but would also complement existing infrastructure in South Africa, thus strengthening the foundation for collaborative efforts in accelerator and photon science across Africa.
Non-destructive determination of residual stresses in the WC-Co coated systems was exceptionally challenging in that the coatings were only 200 microns thick. The best suited techniques for investigation of WC were diffraction-based strain scanning using penetrating radiation such as thermal neutrons (most penetrating), high energy synchrotron X-rays (100 keV enables 20 micron penetration) and laboratory X-rays (limited to 5 micron penetration). Laboratory X-rays (Necsa, using Co radiation), thermal neutrons (ANSTO, Australia) and X-ray synchrotron (ESRF, France) were successfully employed to resolve the stress conditions. The influences of heat treatment were assessed by stress relief heat treatment of the grit-blasted substrates and coated substrates.
It has been determined that the surface stresses of the coatings exhibited both small compressive and low tensile stresses on the as-sprayed coated samples. After annealing, the stresses became substantially more compressive. The near-surface trends of the grit-blasted substrates were completely relaxed after annealing, with thermal stresses being the dominant mechanism for residual stress induced due to the large difference in the coefficients of thermal expansion (CTE) between the WC coatings and the substrates.
Keyword: X-ray diffraction, Synchrotron XRD, Neutron diffraction, WC-Co coating, HVOF
References:
1. O.P. Oladijo, PhD Thesis, University of the Witwatersrand, 2013.
2. O.P. Oladijo, A.M. Venter, et al, X-ray Diffraction Measurement of Residual Stress in WC-Co Thermally Sprayed Coating onto Metal Substrates, Surface Coating Technology, 206(23) (2012) 4725-4729.
3. A.M. Venter, T. Pirlin, T. Buslap, O.P. Oladijo, et al, Systematic Investigation of Residual Strains Associated with WC-Co Coatings Thermal Sprayed onto Metal Substrate, Surface Coating Technology, 206(19-20) (2012) 4011-4020.
4. A.M. Venter, O.P. Oladijo, et al, Performance Characterisation of Metallic Substrates Coated by HVOF WC-Co, Thin Solid Films, 549 (2013) 330-339.
AfLS Contribution
Carbon dioxide (CO2) is a major greenhouse gas that significantly contributes to climate change, highlighting the urgent need for effective capture and conversion technologies ¹. This research explores the development of palladium-immobilized metal-organic frameworks (MOFs) as catalysts for transforming CO2 into formate, a valuable chemical for various industrial applications ². By utilizing the unique properties of MOFs, such as their high surface area and tunable pore structures, we achieved remarkable CO2 conversion rates at low temperatures ³. The synthesis of palladium@MOF composites was optimized to enhance active site accessibility and improve catalytic efficiency. Experimental results demonstrate that these materials facilitate significant CO2 reduction under mild reaction conditions, showcasing their potential for sustainable CO2 valorisation. The results further indicate that the catalytic activity of homogeneous systems can be improved by incorporating them into MOFs as organic linkers bearing catalytic sites.
References
J. Wang, X. Chen and Y. Zhang, RSC Adv., 2023, 13, 4567-4575.
K. Patel, M. Li and R. Kumar, RSC Adv., 2023, 13, 7890-7898.
L. Yang, S. Gupta and T. Smith, RSC Adv., 2022, 12, 2345-2353.
H. Kim, N. Lee and D. Choi, RSC Adv., 2023, 13, 1122-1130.
Nowadays, one of the most intensive investigation subject in field of materials science is organic-inorganic salts(OIHSs) of owing to their intriguing aesthetic structures and their numerous potential applications as polyfunctional materials [1]. With respect to the very large number of homometallic oxalatometalate(III) salts, the heterometal oxalato-bridged complexes have been much less explored, given the difficulty in controlling the resulting heterometallic arrays[2]. Well-known examples are the 2-D MOFs formulated as (A)[MII/I MIII(ox)3]2-/1- that have been extensively investigated as molecular magnets[3]. Therefore, our interest in this field is a fundamental requirement for gaining some insight into the structural features and the magnetic trend associated with heteropolynuclear oxalato-bridged complexes containing pyridinium derivatives as counter cations. A new heteroheptanuclear oxalato-bridged [K4ICr3III] hybrid salt, (C6H9N2)3[K4Cr3(C2O4)8(H2O)2,5] (1) (C6H9N2+ = 2-amino-3-methylpyridinium cation) has been synthesized using methatesis reaction strategy. It has been characterized by elemental and thermal analyses, IR spectroscopy, single-crystal X-ray diffraction, EPR and variable temperature magnetic susceptibility measurements.
Pyrrole is a 5-membered aromatic nitrogen-containing heterocycle that is present in many natural products, biologically active compounds, and several drugs. Pyrrole derivates have various applications in pharmaceutically active compounds, and they are used as inhibitors for enzymes like reverse transcriptase and cellular DNA polymerase protein kinases. Therefore, Considerable interest has been paid to synthesizing and modifying pyrroles. This study will highlight a newly improved route using synthesized enaminones.1-3
The chemistry of enaminones typically contains the delocalized nucleophilicity of enamines with the delocalized electrophilicity of enones; their versatility as synthetic intermediates provides an excellent scaffold for organic synthesis. Through electrophilic and nucleophilic substitution reactions, enaminones are effective as building blocks in the organic synthesis of acyclic, aromatic, and heterocyclic compounds.4
Compounds were synthesized from refluxing a mixture of acetophenones and DMF-DMA. The reactivity of enaminone towards primary anilines was investigated under acidic conditions. The compounds were confirmed by Nuclear Magnetic Resonance (NMR) and High Resolution Mass Spectroscopy (HRMS).
[1] S. C. Philkhana, F. O. Badmus, I. C. Dos Reis and R. Kartika, Synthesis, 2021, 53, 1531-1555.
[2] I. Siddiqui, D. Kumar and S. Shamim, Journal of Heterocyclic Chemistry, 2013, 50, E111-E115.
[3] D. K. Singh and R. Kumar, Beilstein Journal of Organic Chemistry, 2023, 19, 928-955.
[4] I. J. Amaye, R. D. Haywood, E. M. Mandzo, J. J. Wirick and P. L. Jackson-Ayotunde, Tetrahedron, 2021, 83, 131984.
Abstract
According to Corpinot and Bučar, any reasonable improvement of the physics and chemistry of the solid state requires a theory of molecular packing [1]. In line with this, authors of this study report how lattice theory explains the crystal packing of N, N’-bis(4-chlorophenyl)thiourea N, N- dimethylformamide [2]. Here, we explore the type of crystal packing of the resulting lattice and their contributions to the general stability of the packing arrangement. The significance of this study gives important insights into the relationship between lattice theory and the crystallographic properties of N, N’-bis(4-chlorophenyl)thiourea N, N- dimethylformamide, to improve the understanding of their physical characteristics and potential applications in materials science, medicine, and pharmaceuticals.
References
[1] M. K. Corpinot and D-K. Bučar. Cryst. Growth Des. 19(2019),1426.
[2] A. T. Odularu, P. A. Ajibade, J. Z. Mbese, Opeopuwa O. Oyedeji and H. Puschmann. Open. Chem. 19 (2021) 511.
Plenary
The Synchrotron-light for Experimental Science and Applications in the Middle East (SESAME) is the first synchrotron facility in the Middle East. Its current Members are Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestine and Türkiye. With Brazil, Canada, China (People’s Republic of), the European Organization for Nuclear Research (CERN), the European Union (EU), France, Germany, Greece, Italy, Japan, Kuwait, Portugal, Russian Federation, Spain, Sweden, Switzerland, the United Arab Emirates, the United Kingdom, and the United States of America are observers.
SESAME seeks establishing the Excellency of Science and technology, human capacity building, brain-drain reversal, gender-gap enrichment, and a bridge to understanding in such a tempestuous region. In conjunction with this, the tangible vision that Africa must receive its analogous situation as a leader within the global scientific arenas becomes more evident. The strategic plan is to launch a world-class large scale research infrastructure, heal the brain-drain challenge, address both local and regional concerns, as well as being a vehicle for economy.
In this regard, SESAME is considered as a model in action for the African community. A Memorandum of Understanding has been signed in 2020 with the AfLS Foundation which intrinsically seeks instituting a synchrotron facility in Africa being the only continent that is left behind without such an advanced technology.
The presentation will explore SESAME achievements and challenges, and will emphasize the significant joint efforts between SESAME and the AfLS Foundation Up-to-Date.
X-ray Absorption Fine Structure (XAFS) spectroscopy has emerged as a non-destructive and powerful analytical technique for advancing research not only in physics but also in chemistry, environmental science, biology, archaeology, and, naturally, in the energy domain, offering invaluable insights into the structural, electronic, and chemical properties of materials under realistic conditions. This non-destructive method provides detailed information on the local electronic/atomic environment of elements within a material, capturing changes in oxidation state, coordination geometry, and atomic bonding.
In the energy sector, XAFS plays a key role in the development and optimization of materials for a wide range of applications, including energy storage (batteries, supercapacitors, etc.), energy conversion (fuel cells and solar cells), and catalytic processes for renewable energy production.
In this presentation, a quick description of the experimental setup at the BM08-XAFS/XRF beamline at the Synchrotron-light for Experimental Science and Applications in the Middle East (SESAME) will be shown; a minimum of the XAFS technique basics will be highlighted; and at last, selected examples of research in the field of energy conducted at BM08-XAFS/XRF beamline in SESAME will be illustrated for a clearer and closer picture.
X-ray diffraction (XRD) beamlines are often high-priority facilities due to their broad applications across diverse fields, including materials science, biology, pharmacology, and cultural heritage. The X-ray powder diffraction (XRPD) technique, in particular, is widely used for material phase identification, quantitative phase analysis, microstructural analysis, and kinetic studies. The MS/XPD beamline at SESAME Synchrotron; which started its operational phase in December 2020; is dedicated to XRPD and was the third beamline to open at SESAME.
It is equipped with a two-circle diffractometer and a PILATUS 300K area detector, generously donated by DECTRIS. The beamline covers an energy range of 8-25 keV, achieving an estimated flux of 10¹³ photons/s at 10 keV. This talk will provide an overview of the MS/XPD beamline’s technical specifications, along with selected research examples highlighting some applications in materials science and environmental studies (e.g., water harvesting, energy storage and CO2 storage).
SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) is the only facility of its kind in the Middle East and neighboring regions, officially opened in 2017. Infrared spectromicroscopy was selected as one of the two beamlines to be opened to the general users’ program (the so-called Day-1 beamlines). Being one of the most demanded techniques by various scientific communities in the Middle East, the beamline has been designed and implemented in the framework of a collaboration agreement with the French synchrotron facility, SOLEIL. The presentation highlights the performance of the BM02-IR beamline as well as demonstrating some examples of various scientific case studies.
Tea
Plenary
Over the past decade, the ALBA Synchrotron has become an important pillar of the Spanish and European Research Area, providing research capabilities and a wide range of state-of-the-art instrumentation to a community of more than 8500 academic and industrial users. With its eleven operational experimental beamlines, while three more are being put into operation, and with the creation, in collaboration with other institutions, of an electron microscopy centre, it is an essential tool to address society's most urgent challenges.
ALBA is preparing the leap towards the 4th generation, aiming at increasing its performance, reinforcing its role on the user community and on the industrial use of the instrumentation, as well as its educational vocation and training capacity. ALBA II, which is planned to be fully operative in the 2032, will combine the upgrade to low-emittance storage ring with the construction of three new beamlines, the refurbishment of part of its instrumentation, and the evolution of the data infrastructure.
The impact on the society through the science and innovation that ALBA is enabling will be highlighted during the talk.
This study demonstrates the antifungal and antibacterial potential of isoflavone natural products isolated from the seeds extracts of Millettia thonningii. In an effort to gain bond topological information which may have consequences for the observed bioactivities, the crystal structure of robustic acid was solved and refined using the independent atom as well as the invariom model, and the structures were compared. Robustic acid contains a fused tricyclic unit with a benzopyran moiety, with a phenylene ring substitution on the coumarin ring similar to the alpinumisoflavones isolated from this plant. Two coumarins, robustic acid and thonningine-C isolated from Millettia thonningii, show promising activity against the fungus Candida albicans with minimum fungicidal concentration of 1.0 and 0.5 mg/mL, respectively. Also, at a minimum inhibitory concentration of ~1 mg/mL, alpinumisoflavone and robustic acid were found to be cytotoxic to Staphylococcus aureus (ATCC 25923) showing a zone of inhibition (ZOI) of ~9 mm. Molecular modelling against the putative bio-molecular target, lanosterol 14-demethylase (CYP51), revealed a plausible binding mode for the active compounds, in which the hydroxyl group binds with a methionine backbone carboxylic group blocking access to the iron catalytic site. This binding disrupts the synthesis of several important sterols for the survival of fungi. These compounds offer potential new avenues for targeting fungal and bacteria and could be useful as chemical probes for understanding these pathogens in an effort to overcome drug resistance.
AfLS Contribution
Synchrotron techniques have been used extensively to characterize the structure and interactions of the perovskite crystals and their complexes with both ex situ/in situ approaches. From the Grazing Incident Wide Angle X-ray Scattering/Small Angle X-ray Scattering (GIWAXS/GISAXS), literature reports the chemical pathways from the plumbate intermediates or meta-stable phase to perovskite crystal identified using in situ X-ray diffraction. However, time evolution of crystallization and phase transition in situ cases usually begins with the prepared solvent to inter-mediated complex film and finally to the perovskite crystal. A comprehensive investigation of perovskites crystallization dynamics and morphology evolution from original precursor solution of CH3NH3PbI3 pristine to solid phase crystals operando and in real time shows perovskite crystal intermediate, comprised of an octahedral [PbI6]4+ centre surrounded by cooperative ions. We present an exciting triple cation film degeneration when probed with humidity by GIWAXS and Mirco-Diffraction synchrotron techniques done at Lawrence Berkeley National Laboratory. High resolution Atomic Force Microscopy (AFM) and Scanning Electron Miscrosopy (SEM) gave polymorphy, crystallinity and molecular interactions with good surface morphology from the maps. On elevated Relative Humidities of about 50%, the films segregate back producing intermediate phases from GISAXS and microdiffraction results. We thus propose optimized film formation protocols for high performing perovskites to lucid crystallization pathways and irreversible films used to develop highly efficient and stable photovoltaic devices.
Barium titanate (BaTiO3) has great prospects in integrated and high-performance electro-optic (EO) devices due to its large EO coefficient and its ability to fabricated as thin films on commercially substrates using conventional deposition techniques. However, when grown as films, the EO performance of BaTiO3 considerably degrades with minimal improvement upon adjusting deposition parameters. The aim of this research was to therefore investigate strategies for improving the EO performance of BaTiO3 thin films through manipulation of mechanical and electrical boundary conditions. Films were deposited on LSAT substrates by pulsed laser deposition and laser molecular beam epitaxy. Atomic force microscopy, X-ray diffraction techniques, second-harmonic generation and piezoelectric force microscopy were used for characterization. Mechanical boundary conditions were manipulated by inserting PrScO3 buffer layers of varying thicknesses to modulate epitaxial strains delivered by LSAT to the BaTiO3 epilayer. The films were smooth and single crystalline with a tetragonal phase having a predominantly in-plane domain structure. An effective EO coefficient of 249 pm/V was attained, which is significantly higher compared to films deposited on unbuffered LSAT.
Keywords: ferroelectric; barium titanate; electro-optic effect; pulsed laser deposition, laser molecular beam epitaxy, optical second-harmonic generation
In nuclear reactors, the release of gases from fission products and the accumulation of light and heavy atoms, such as helium, hydrogen and xenon, during operation can significantly alter the structural integrity of reactor materials [1]. These gases may migrate and cluster, forming gas bubbles and inducing stress, which leads to defects within protective layers like silicon carbide (SiC) [2]. SiC, is used in nuclear applications due to its excellent thermal conductivity, mechanical strength, and radiation resistance. However, under extreme irradiation conditions, SiC's structural, chemical, and mechanical properties can degrade [3], reducing its effectiveness as a protective barrier. Understanding SiC’s response to irradiation is crucial for enhancing its performance in high-radiation environments. Hence, this study investigates the effects of room temperature swift heavy ion (SHI) irradiation, using 158 MeV Xe²⁶⁺ ions at fluences of 1×10¹⁰ cm⁻², 1×10¹¹ cm⁻², and 1×10¹³ cm⁻² on polycrystalline 3C-SiC. The primary aim of this research is to evaluate changes in microstructural characteristics and mechanical properties resulting from SHI irradiation.
In this study, Raman spectroscopy, Atomic Force Microscopy (AFM), and Vickers hardness indentation were employed to study the microstructural changes and mechanical properties of the samples. Figure 1 shows Raman spectra before and after irradiation to different fluences. Raman spectroscopy revealed defect production at all irradiation fluence levels, with higher fluences inducing greater damage compared to lower ones. Specifically, irradiation at the highest fluence of 1×10¹³ cm⁻² led to significant defect development, indicating considerable structural disturbance. The longitudinal optical (LO) peak at 965 cm-1 of SiC shifted noticeably towards higher wavenumbers as the fluence increased, signifying the introduction of compressive stress due to ion-induced lattice distortion that alters the atomic arrangement of the SiC crystal structure. Additionally, the transverse optical (TO) to longitudinal optical (LO) intensity ratio increased with higher fluence levels, indicating progressive degradation of the crystal structure and a growing degree of lattice disorder, with defects such as vacancies and interstitials contributing to this disruption.
Hardness measurements showed an initial increase from 29.72 GPa to 37.28 GPa at intermediate fluences, suggesting defect-induced strengthening; however, at the highest fluence, hardness decreased to 30.17 GPa, reflecting the effects of reduced surface roughness from irradiation-induced wear. This interaction between defect accumulation and hardness highlights the effects of ion irradiation on the mechanical properties of SiC, leading to both strengthening and softening behaviors that vary with fluence.
[1]Pratama, A.L. and D. Irwanto. Study on the effects of enrichment and fraction of coated fuel particles on fissile utilization of 100 MWt prismatic-type of high temperature gas reactor. in Journal of Physics: Conference Series. 2020. IOP Publishing.
[2]Guo, J., et al., Extended Development of a Fission Gas Release Behavior Model Inside Spherical Fuel Grains for LWR Reactors. Applied Sciences, 2023. 13(18): p. 10421.
[3]Huang, J., et al., Helium-hydrogen synergistic effects in structural materials under fusion neutron irradiation. Frontiers in Materials, 2022. 9: p. 849115
Manganese steel is a high-carbon alloy known for its exceptional toughness, ductility, and wear resistance. A high manganese grades comprising approximately 22-44% manganese and 1% carbon, exhibits remarkable work-hardening properties, making it ideal for high-impact applications. While the metal grade specification does not indicate any chromium and molybdenum elements, these were found in some melts due to the scrap material used. When in moderate concentrations not to cause significant carbide formation, they influenced the material microstructure, with sub-grains formed within some grains. These carbide formers were also found to be associated with smaller grain structure, which improves the mechanical properties of the material according the Hall-Petch equation. This unique microstructure of manganese steel contributes to its ability to withstand heavy stress and abrasive conditions, commonly found in mining, construction, and rail industries.
Plenary
Solid oxide fuel cells (SOFCs) have emerged as a promising candidate in the search for an efficient and environmentally friendly source of electrical energy. SOFCs offer several benefits over traditional sources of electricity, such as high efficiency and reduced emissions. However, SOFCs have experienced limited commercialization due to short device lifespans and high operating temperatures, the latter feature is largely dictated by the electrolyte material. The quest for improved electrolyte materials, which would ideally exhibit properties such as high phase stability and high ionic conductivity at intermediate temperatures (~650 oC), remains a critical aspect in advancing SOFC performance and application. Advanced synchrotron techniques are required to investigate the local and long-range structural details which determine the overall electrolyte performance. I will present selected work wherein advanced synchrotron techniques at elevated temperatures were used to investigate the structure of bismuth oxide- and lanthanum molybdate-based materials to probe the suitability of these materials as SOFC electrolytes.
This talk presents the crystal structure dynamics as a function of temperature of non-porous borophosphates. Much of the work published on these materials has focused on investigating the synthetic approaches as well as exploring their fascinating structural chemistry. Little has been reported about their thermal expansion behaviour. This thermoresponsive behaviour revealed their thermal stability while serving as a predictive measure of the effects of temperature on other materials properties and subsequent application. The thermal expansion behaviour of the non-porous cristobalite BPO4 phase will be highlighted. BPO4, which crystallizes in the tetragonal lattice, showed a substantial anisotropic expansion in the lattice. This contrasting thermal expansion behaviour along the various axes of the material is related to the temperature variation of the inter-polyhedral angle between adjacent polyhedral in the crystal structure. This talk will also include total scattering data collected at the European Synchrotron Radiation Facility (ESRF), beamline ID22. This analysis is sensitive not only to the average (long-range) material structure but also the local distortions away from the average structure. Results will be reported relating to the total scattering investigation of the thermal expansion of the B-O and P-O bond-lengths in comparison with the values obtained by conventional X-ray diffraction measurements.
In this talk I will briefly present the ESRF which has just celebrated 30 years of user operation. At the ESRF, 20 partner countries, amongst which is South-Africa, join forces to exploit 46 cutting edge beamlines at the forefront of synchrotron technology. I will, in particular, show how the ESRF-EBS (Extremely Brilliant Source), a major upgrade of the facility increasing the brilliance and coherence of the source by two orders of magnitude, is a game changer for the exploration of matter and life from their most intimate mechanisms to entire organs or functioning devices. The talk will be illustrated with recent examples of research carried by South African researchers at the ESRF.
Tea
Plenary
The growth of science and technology is accelerating, with new products and processes being developed in fields such as nanoscience and biotechnology. With this growth, industry is facing increasing pressure to innovate and is discovering that traditional analytical techniques are not answering all of their questions. For example, new materials are being developed daily that may have significantly different properties but are chemically indistinguishable using current analysis techniques. It is crucial for industry to understand these differences and develop these unique properties into new products. Today, industry is turning to new tools to shed light on old, and new, questions.
Industry has discovered the power of synchrotron light source facilities and the vast array of experimental facilities they house. Every year, thousands of researchers from around the world make discoveries that lead to viable products, patents, and technology transfer in areas including:
This presentation will highlight how synchrotron light source facilities engage with and bring value to the private sector, showcasing some of the exciting new science emerging.
ED MITCHELL1
1 European Synchrotron Radiation Facility (Business Development Office, Grenoble, France)
Corresponding author: Ed Mitchell, mitchell@esrf.eu
Keywords: innovation, industry,
Theme: African Light Source session
The European Synchrotron Radiation Facility (ESRF) has worked with industry from even before the first light was delivered in 1994. The ESRF’s Business Development Office (BDO) is now charged with managing interactions with industry from service sales, patents, licences to collaborations and partnerships. The BDO is an internal service of the ESRF, positioned in the Experiments Division. The main activity to date is managing and developing beam time sales, though this is changing. At the ESRF industrial service sales earn about 2.5MEuros annually with the strongest sector being pharma and biotech. One of the current challenges is to deepen our relationship with industry to more than a simple client-supplier relationship. There are many opportunities for this, though grants and networks; the main limitations are in building awareness and understanding in industry (both large and small), and having staff available to do industrial liaison and support work. The presentation will look at the role of industry at the ESRF and how our facilities and expertise support industry research and innovation.
Magnus W. Larsson, Joaquín B. González, Vahid Haghighat, Jackson Silva, Mira Viljanen, Santiago P. Fernandez Bordín, Anuj Prajapati, Samuel A. McDonald, and Kim Nygård
MAX IV Laboratory, Lund University, Sweden
The ForMAX beamline at the MAX IV Laboratory provides multiscale and multimodal structural characterization of hierarchical materials from nm to mm length scales, by combining small- and wide-angle x-ray scattering (SWAXS), scanning SWAXS imaging, and full-field microtomography [1]. The beamline is funded by the Knut and Alice Wallenberg Foundation and industrial partners to advance research and development of sustainable materials and specialty chemicals from forest raw materials, but the beamline is also open for general users within, e.g. materials science, food science, and biomedical imaging. We will present the journey towards a beamline at MAX IV and selected scientific results from the first year of user operation.
[1] K. Nygård et al., J. Synchrotron Rad. 31, 363-377 (2024).
Industry is crucial in the development and utilization of synchrotrons, with expert companies playing a key role in both construction and value creation. Intermediary companies, in particular, facilitate the translation of synchrotron research into tangible benefits for society. This presentation will highlight how these companies enhance the impact of light sources and showcase Momentum Transfer's efforts to revolutionise powder diffraction.
Benefits of synchrotron imaging techniques for material characterization and product testing
Andrea Francesco Ciuffini1, Barbara Fayard1, Jean Doucet1, Caroline Boudou1
1 Novitom, 3 Avenue Doyen Louis Weil F-38000 Grenoble, France
Corresponding author e-mail address: andrea.ciuffini@novitom.com
Novitom is an independent company, specialized in 3D material characterization, NDT and analysis based on advanced imaging techniques including synchrotron technology. As a pioneering service provider, Novitom uses cutting-edge, non-destructive 3D tools, such as 3D micro-imaging and micro-analysis based on state-of-the-art synchrotron technologies, and develops specific measurements and protocols to meet the needs of its customers in terms of material characterization and product/process control.
As service provider specialized in 3D micro-imaging, Novitom was involved, ensuring a flexible-service from one-time to multi-year partnership, in projects that always ensure high value business outcomes. Furthermore, end-to-end innovative solution development for 2D/3D image analysis/treatment, optimization of X ray CT acquisition, in situ testing are topics in which Novitom has been involved in these years.
The services that can be achieved through state-of-the-art synchrotron technologies may be: the use of enhanced phase contrast, local high resolution tomography scans on large samples, the possibility to add instrumentation around the sample, the visualization of highly and poorly absorbent materials, extremely fast acquisitions enabling systematic analyses to control the repeatability or the variability, the use of AI based imaging artefacts correction and the following image analysis.
All these possible improvements with respect to standard techniques allow infinite possibilities which could be exploited by industry. Materials, parts and even biological tissues may be characterized in detail through failure analysis of parts in-service, mimic processes leading to their optimization, describe mechanical behavior of materials.
In these contexts synchrotron tomographic imaging may be used to provide crucial information non-destructively, such as:
• detect the presence on surface or embedded of cracks, their geometrical characteristics, 3D distribution, density, connectivity and their propagation under external stress;
• geometry of the filter particles, statistics on the number of clogged channel, channel fill rate, geometry of an unclogged channel and its walls, validate simulations, describe the mechanisms and nature of clogging;
• volume fraction, orientation, size distribution, distance to closest neighbour of fibres, charges and porosities.
As nanoelectronics push the frontiers of miniaturization, precision, and functionality, advanced material characterization has become critical to driving innovation and maintaining competitiveness in industrial applications. The Platform for Advanced Characterisation - Grenoble (PAC-G), in France, stands at the intersection of scientific discovery and industrial need, offering cutting-edge tools and methodologies tailored for the electronics industry. This presentation will explore how PAC-G empowers industries to harness advanced characterisation technologies for probing materials at the nanoscale levels. With collaborative access to state-of-the-art methods based on synchrotrons X-rays and neutrons. Developed in the framework of the Technological Research Institute (IRT) Nanoelec, PAC-G bridges R&D with practical solutions that enhance material properties, device reliability, and product longevity. Attendees will gain insights into the the platform,that act as a unique Innovation Hub, leverage on the smart specialisation of the Grenoble area, a unique ecosystem dedicated to the industry of semiconductors. We will describe unique industrial case studies and recent advancements that are transforming nanoelectronics characterization on a global scale.
Plenary
This presentation discusses the performance and scientific highlights from Sirius. The Sirius has supported the AfLS for more than a decade, and the presentation also reflects on the role that the Sirius can play to advance synchrotron based science in Africa.
Plenary
Abstract
AlphaFold is a groundbreaking AI tool developed to predict protein structures with remarkable accuracy, yet few scientists based in Africa have received training to use it effectively. From October 7–11, 2024, BioStruct-Africa (www.biostructafrica.org) held a hands-on training workshop in Douala, Cameroon, focused on structural biology. This workshop provided participants with expertise in AlphaFold structural prediction, analysis, interpretation, and utilizing AlphaFold2 models for screening small molecule compound libraries. Such training holds vast potential for advancing drug and vaccine development and fostering sustainable healthcare solutions across the continent. The recent Nobel Prize in Chemistry, partly recognizing AlphaFold’s development, highlights the vital importance of capacity-building efforts in this transformative field.
Schistosomiasis is a devastating parasitic disease caused by the Schistosoma species. It affects over 260 million people worldwide, with the highest morbidity and mortality rates in sub-Saharan Africa. Despite its significant impact on public health, Schistosomiasis remains one of the neglected tropical diseases. Praziquantel (PZQ) is currently the only drug that treats all schistosomiasis infections due to its availability, cost-effectiveness, and minimal side effects. However, recent studies showed the emergence of PZQ-resistant strains due to drug pressure. Exposure of the schistosome parasite to extreme conditions during its developmental stage triggers the expression of heat shock and universal stress proteins. The universal stress G4LZI3 protein has been identified as a potential target for developing new anti-schistosomals. Protein structure is integral to drug design and comprehension of various biological systems and pathways. Hence, X-ray crystallography was employed for the structural determination of this protein, while bioinformatics was used to identify potential polyphenolic compounds with additive ‘druggable’ ROS-scavenging potential to ameliorate anti-schistosomal drug resistance against PZQ.
More so, glycolytic proteins have emerged as possible drug targets and vaccine candidates for treating schistosomiasis. Since proteins do not function alone, disrupting essential protein-protein interactions using small molecule inhibitors has become a more promising approach to resolving drug resistance in diseases. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and Triosephosphate isomerase (TPI) are glycolytic proteins with crucial cooperative role in generating energy for the worm's motility and survival. Therefore, disrupting this critical GAPDH~TPI protein complex should decrease the worms' energy levels, thus creating an unfavourable environment for the parasite to thrive. Raman and UV-vis spectroscopy, coupled with Microscale Thermophoresis were used to investigate this postulated interaction. Virtual screening, molecular docking and molecular dynamics simulation were employed to identify inhibitors against this protein-protein interaction. In vitro screening of these compounds on various stages of the schistosome worms will validate the druggability of these compounds.
AfLS Contribution
Crimean-Congo haemorrhagic fever (CCHF) is a life-threatening anthropo-zoonosis that is characterized by high fatality rates 5-40%. Currently there are no approved vaccines or treatment available. Recently, antibody-based therapies have proved promising approaches to mitigating severe disease caused by other haemorrhagic viruses . CCHFV is made up of two structural glycoproteins, Gc and Gn, the sole targets of neutralizing antibodies and the nucleocapsid protein (NP), which is antigenically well-conserved among different strains. This study seeks to utilize Fluorescence Activated Cell Sorting (FACS) analysis to isolate Gc, Gn and NP targeting resting memory B cells from PBMCs of a convalescent donor.
In this study, Gc and NP were cloned into pcDNA3.1+ and the resulting recombinant plasmids were used to transfect 293-F mammalian cells. Both Gc and NP proteins were purified by affinity chromatography and gel filtration, and the donor serum IgG reactivity to the antigens was measured by ELISA. Gc and NP were further biotinylated in preparation for B cell sorting and verified by ELISA on an avidin coated plate. The donor PBMCs were stained with anti-human APC-Cy7 labeled CD3, CD14, CD16, PE-Cy7 CD19, and IgD-FITC, as well as the Gc/NP-PE/AF647 antigen baits, and the LIVE/DEAD stain prior to loading onto a BDFACS Melody. The total Gc/NP- specific B cells CD19+ were sorted into 96-well plates for cloning and expression of anti-CCHF monoclonal antibodies (mAbs).
CCHFV Gc and NP were successfully cloned, expressed and purified as confirmed by SDS-PAGE and Western blotting. ELISA confirmed the presence of binding anti-CCHF IgG antibodies in donor sera. The biotinylation of both Gc and NP was successful, and these antigens were used to isolate B cell lymphocytes from a South African CCHF survivor to isolate potent and protective mAbs by single-cell analysis.
We have successfully expressed CCHFV Gc and NP which can be used for various applications including antigen-targeted B cell isolation. Furthermore, these antigens constitute valuable reagents for the development of diagnostic assays like ELISA and lateral flow assays which could be useful in low-income sub-Saharan African countries.
ZnO and Zn1-(y+x) O /CuyTix , (Ti, Cu, Cu/Ti-doped ZnO) were synthesized by modified oxalate route using carambola fruit juice as a precipitating agent. The wurtzite hexagonal structure formed saw the space group change from P63mc to p3 with crystallite sizes varying from 15.1 to 17.5 nm. Infrared spectra (IR)of the single molecular precursor, indicated the formation of metallic oxalates. The influence of Cu2+, Ti4+ and Cu2+/Ti4+-doping on the microstructure, morphology and optical properties of the synthesized ZnO was studied. Scanning electron microscope (SEM) confirmed modification of morphology from cuboidal to porous spherical nano structures. The PXRD results revealed an insignificant contraction in cell volume as the dopant elements replaced Zn ions in the microstructure (Ti0.02Cu0.02Zn0.96O, 0.5271nm3 and ZnO, 0.5288 nm3) but improved mechanical properties such as dislocation density, microstrain and specific surface area, and optical properties such as absorbance and optical band gap. Ti0.02Cu0.02Zn0.98O showed a 17.17 % drop in microstrain, 9.63 % drop in dislocation density and 5.61 % increase in specific surface area and decrease in optical band gap within the rang 3.116eV to 2.998eV. Also, EDS results confirmed the incorporation of various dopant ions in the corresponding microstructures of ZnO. The results also revealed a modification in the crystallite size distributions. The new materials (Cu0.42Zn0.58O and Ti0.02Cu0.02Zn0.96O) have exhibited a greater propensity to better, microstructural and optical properties which could improve the electrical properties such as conductivity. Therefore, the newly synthesized samples have been confirmed to have improved mechanical, electrical and optical properties relative to the synthesized Zinc Oxide.
Scheme: Synthesis procedure of the co-doped ZnO by carambola fruit juice coprecipitation route
Tea
Plenary
X-ray computed tomography has proven to be a very useful technique with applications in materials science on carbon fibre composites, lithium-ion battery research, in palaeontology and geology among others. The resolution attainable is limited by lenses and the detectors. However, ptychography is a lens less technique which can ne used to obtain nanometre resolution and allows quantification of the phase. We present the setup of the i13-1 beamline of the Diamond Light Source for ptychography and Bragg coherent diffraction imaging (BCDI). We also present results obtained in the study of a titanium alloy part fabricated using metal injection moulding.
Opportunistic pathogenic fungi cause infectious fungal disease with extremely high mortality rates, especially in immune-compromised patients [1]. Antifungal resistance and multi-drug resistance have emerged against the limited number of clinically used antifungals. Because of the high HIV/AIDS incidence in Sub-Saharan Africa [2], anti-fungal drug resistance is specifically of concern; therefore, there is an urgent need to develop novel therapies.
In this study, sterol C24-methyltransferase (SMT) has been identified as a novel target for anti-fungal drug development. An expression vector library was prepared with SMT genes from four opportunistic pathogenic fungi, heterologously expressed in Escherichia coli and the SMT proteins purified with affinity chromatography. The SMT from Candida albicans was crystallised and diffraction data was collected at the Diamond Light Source synchrotron.
Expression of truncated SMT genes from all four fungi was successful, and the SMT from C. albicans was successfully purified and crystallised; however, diffraction was only observed at low resolution (~7Å). Purification of the SMTs from the other three pathogens is ongoing, and crystallisation of the C. albicans SMT is currently being optimised.
[1] Denning DW (2024) Global incidence and mortality of severe fungal disease. Lancet Infectious Diseases. 24(7):e428-e438.
[2] Dos Santos Abrantes PM, McArthur CP & Africa CWJ (2014). Multi-drug resistant oral Candida species isolated from HIV-positive patients in South Africa and Cameroon. Diagnostic Microbiology and Infectious Disease. 79(2), 222–227.
AfLS Contribution
HIV-1 protease (HIV PR) is an aspartic protease which is considered vital in the cleaving of new viral polyprotein into functional units [1]. These polyproteins are needed in the maturation stage of the viral replication cycle to infect other host cells, this makes the HIV PR a significant drug target for possible therapeutic agents [2]. Due to the distinctive patterns of pharmaceutical drug resistance observed in HIV protease inhibitors, South African HIV-1 subtype C presents its own unique challenges in its management due to lowered drug efficacy [3]. Designing and synthesizing drugs which can adapt to these ever-changing macromolecules has become increasingly important for the management and treatment of patients living with HIV/AIDS. The constituent cis-1-amino-2-indanol has been used as a blueprint for many types of inhibitors including HIV-1 protease and malaria [4].
Cis-1-amino-2-indanol derivatives were synthesized using ketones and aldehydes to produce Schiff base imines to which a series of six compounds were synthesized using one pot synthesis as well as elucidated and characterized by SC-XRD, FTIR and Raman spectroscopy. Using in silico techniques such as molecular docking and dynamics studies the molecules were predicted to behave as dynamic covalent inhibitors which have a high binding affinity for the South African HIV-1 Wild-type C protease, binding to various allosteric sites. The effectiveness of these molecules on the South African HIV-1 Wild-type C protease was evaluated using empirical studies by assessing various kinetic and thermodynamic parameters which can be considered to inhibit proteolytic activity. Additionally, the compounds were also assessed for their cytotoxic effects on Green African monkey kidney cells (Vero cells) to evaluate their respective cytotoxic profiles.
X-ray phase contrast imaging: An alternative approach to laboratory-based sources
Gideon Chinamatira1, Kudakwashe Jakata2, Hillary Masenda1, Josephine Gutekunst3, Anton Du Plessis4,5
1University of the Witwatersrand, 1 Jan Smuts Ave, Braamfontein, Johannesburg, 2000, South Africa
2Diamond Light Source, Harwell Science and Innovation Campus, Fermi Ave, Didcot OX11 0DE, United Kingdom
3Microworks GmbH, Schnetzlerstr. 9, 76137 Karlsruhe, Germany
4Stellenbosch University, 41 Merriman Street, Stellenbosch, Western Cape, South Africa,
5Comet Technologies Canada Inc, Montreal, Canada
Corresponding author e-mail address: gideonchinamatira@gmail.com
Conventional X-ray imaging, based on the absorption of X-rays by various materials, is the standard technique for non-destructive inspection of internal structures. This method is effective for high X-ray attenuation scenarios but encounters limitations when applied to specimens which often exhibit weak absorption contrast due to similar densities among their components [1]. To address this challenge, methods generating radiographic contrast from X-ray phase shifts and scattering have been explored. Among these, grating-based interferometric techniques, specifically the Talbot-Lau interferometer, show significant promise for laboratory-based phase contrast X-ray imaging. This technique employs a series of gratings to create an interference pattern that encodes phase information, enabling the visualization of structures with low absorption contrast [2]. This type of interferometer is particularly suited for use with polychromatic X-ray sources commonly found in laboratory settings due to the introduction of an additional source grating which introduces spatial coherence to the X-ray beam. The spatial coherence is essential for creating well-defined interference patterns downstream in the system setup [3]. In this work, we make use of the Talint-EDU system, a ready to use Talbot-Lau-Interferometer, for implementation to our already existing X-ray computed tomography imaging setup. We conducted a series of characterization experiments to evaluate the effectiveness of our system. These experiments included angular X-ray transmission measurements, system visibility measurements, phase stepping and stability tests, and an assessment of the system's sensitivity as a function of distance from the phase grating. Through these experiments, we were able to optimize the performance of the Talbot-Lau interferometer and ensure reliable imaging results
To demonstrate the capabilities of the system, we obtained preliminary images of a pencil and a circuit board. These images showcase the system's ability to obtain phase contrast, absorption, and dark-field imaging and highlight the potential of the Talbot-Lau interferometer system to overcome the limitations of conventional X-ray imaging offering a powerful tool for applications in various research and industrial environments.
[1] T. Weitkamp, A. Diaz, C. David, F. Pfeiffer, M. Stampanoni, P. Cloetens, and E. Ziegler. X-ray phase imaging with a grating interferometer. Optics Express, 13 (2005) 6296-6304.
[2] H. Wen. Biomedical X-Ray Phase-Contrast Imaging and Tomography. In: P.W. Hawkes, J.C.H. Spence (eds) Springer Handbook of Microscopy. Springer Handbooks. Springer, Cham (2019).
[3] S.A. McDonald, F. Marone, C. Hintermüller, G. Mikuljan, C. David, F. Pfeiffer, and M. Stampanoni. Advanced phase-contrast imaging using a grating interferometer. Journal of Synchrotron Radiation, 16 (2009) 562-572.
Plenary
I will discuss X-ray absorption (XAS) and Resonant inelastic scattering of X-rays (RIXS). There is no practical unified theory for the interpretation of XAS spectra and one-particle models based on Density Functional Theory as well as multiplet model Hamiltonians are used for specific spectra [1,2]. In 2p3d resonant inelastic x-ray scattering (RIXS) one scans through the 2p X-ray absorption edge and measures the low energy excitations. The present experimental resolution of ~20 meV allows the detailed observation of the electronic and magnetic structure. Energy-resolved RIXS to determine the energy positions of the magnons and phonons [3]. Momentum-resolved RIXS can be used to determine the momentum dependence of these excitations, for example the electron-hole pair band structure of LaCoO3 [4].
[1] Core Level Spectroscopy of Solids, Frank de Groot and Akio Kotani (2008)
[2] J. Elec. Spec. 249, 147061 (2021)
[3] Elnaggar et al. Nature Comm 14, 2749 (2023)
[4] Wang et al. Phys. Rev. B. 98, 035149 (2018)
AfLS Contribution
A study aimed at unravelling arsenic (As) speciation in the carbonate sediments and the total suspended particulate (TSP) occurring at the Carletti spring system (CSS), part of the larger Bullicame (Viterbo, Central Italy) system, by means of XAS spectroscopy, has been undertaken.
In the CSS, As occurs as a geogenic anomaly, its mobility and speciation being likely affected by inorganic and/or microbiological processes. The determination of As speciation in the encrustation and TSP, highly diluted samples, is essential to validate the models on the fate of As in this “natural laboratory”.
8 rock and 8 TSP samples were collected in the CSS, following relevant changes in temperature, distance from the spring and physicochemical features of the water/TSP/rock interfaces. All solid samples were analysed, without manipulation, by means of X-ray Absorption Spectroscopy at the As K edge in fluorescence mode and at low temperature (range 77-20 K). Experiments on rock and TSP samples were carried out at two beamlines (BM08 and BM26, respectively) at the ESRF facility.
The main results point to an almost constant As(III) over total As ratio over the whole spring system in the rock samples, As(III) being about 30% of the total Arsenic. Detailed investigation concerned with subsamples discriminated by colour (with reference to different abundances and speciation of co-localised microbiologic populations), finding no apparent changes in As speciation. TSP samples, analysed with a specific procedure due to their ultra-diluted nature, appear also constant and slightly enriched in As(III) with respect to the corresponding rocky samples. These data have to be compared to a water environment, which increases its oxidising potential and its pH while increasing the distance from the spring, as testified from the change of the As(III)/total As ratio from an initial 70% down to a final 40%.
This complex set of experimental results will be discussed on the light of two possible interpretive schemes, i.e. a kinetically constrained precipitation mechanism, and a microbiologically constrained change of As speciation, taking also into account of laboratory reference systems where the inorganic and biotic uptake of As(III) and As(V) were reproduced.
The project focuses on training Machine Learning (ML) algorithms to detect pulmonary Tuberculosis (TB) infections in clinical imaging. We have identified 5 publicly available datasets of TB infected lung radiographs in medical literature. These datasets have been used repeatedly to train ML algorithms to detect TB.1 The main reason for improvements in accuracy of TB detection has been the use of increasingly sophisticated algorithms.1234 To introduce a high volume of new data with known TB indicators, we propose to generate synthetic data from high-resolution digital twin lungs. The study will leverage Hierarchical Phase-Contrast Tomography (HiP-CT) scans which are produced at the European Synchrotron Research Facility (ESRF) beamline BM18. These are high-resolution 3D scans (~20 µm) of whole organs, with regions of sub 2.5 µm resolution. Scans will be taken of ex-vivo healthy and TB-infected lungs. The data will be processed into a large number of 3D models that include a known set of TB indicators. These models will be reprojected into simulated Chest X-rays (CXR) with software using the Geant4 toolkit which simulates the passage of particles through matter. These simulated radiographs with their labelled pathologies will then be used to train classification algorithms for the detection of TB in the lung. This method could be extended to various other organs in future, and as such can assist us in improving the diversity of datasets utilized by the ML community.
Figure 1 is a CXR of a patient infected with TB. The dark region on the left side is a pulmonary cavitation. This occurs when normal lung tissue dies from the infection, thus becoming gas filled. Figure 2 is a demonstration of simulating a CXR using a low-resolution 2D model. The X-rays passing from source to detector interact with several tissue classes and scatter realistically. The detector element can record the X-ray dose absorbed to build a 2D radiograph like in figure 1. We intend to use high resolution HiP-CT data which, due to the non-linear progression of TB, can provide a detailed understanding of the evolution of pathologies down to a cellular level. We aim to combine scans into many digital organs which will exhibit differing presentations of the infection and include truth data allowing optimised training of ML algorithms.
[1] T. Rahman et al., "Reliable Tuberculosis Detection Using Chest X-Ray With Deep Learning, Segmentation and Visualization," 2020, doi: 10.1109/ACCESS.2020.3031384
[2] Showkatian E, Salehi M, Ghaffari H, Reiazi R, Sadighi N. Deep learning-based automatic detection of tuberculosis disease in chest X-ray images. Pol J Radiol. 2022, doi: 10.5114/pjr.2022.113435. PMID: 35280947; PMCID: PMC8906182
[3] Rajesh, T. Babu, R. R. Nair and P. Pechetti, "Detection of Tuberculosis using a Multi-model Classification Approach on CXR Images," 2022, doi: 10.1109/AIDE57180.2022.10060675
[4] D. Capellán-Martín, J. J. Gómez-Valverde, D. Bermejo-Peláez and M. J. Ledesma-Carbayo, "A Lightweight, Rapid and Efficient Deep Convolutional Network for Chest X-Ray Tuberculosis Detection," 2023, doi: 10.1109/ISBI53787.2023.10230500
[5] Ravimohan, S., Kornfeld, H., Weissman, D., & Bisson, G. P. (2018). Tuberculosis and lung damage: from epidemiology to pathophysiology. https://doi.org/10.1183/16000617.0077-2017
Plenary
The value of light source science for agricultural research, and encouraging potential users to increase the use of advanced imaging synchrotron tools, by showcasing leading research in the field.
Tea
We study the non relativistic case of a Hydrogen-like atoms in a plasma environment. We use the screened Coulomb potential to model the phenomenon and we write an almost analytical formula for the energies for large wave lengths. We give also a method to compute the critical value of the wave numbers that ionize the atoms.
Defect complexes have a significant impact on the structural, electronic, optical and electrical properties of semiconductors. Several defect complexes formed by n-type and p-type atoms in Ge have been implemented for the development of improved modern microelectronic devices. However, there is no reported study on the substitutional-interstitial defect complexes formed by trivalent atoms in Ge. This study presents a hybrid density functional theory study of the structural, electronic, formation and defect levels induced by defect complexes in Ge. A crucial understanding of the electrically active defect levels induced by defect complexes in Ge, which could be courted for application in improved Germanium-based microelectronic devices is provided.
15m
Abstract
According to Corpinot and Bučar, any reasonable improvement of the physics and chemistry of the solid state requires a theory of molecular packing [1]. In line with this, authors of this study report how lattice theory explains the crystal packing of N, N’-bis(4-chlorophenyl)thiourea N, N- dimethylformamide [2]. Here, we explore the type of crystal packing of the resulting lattice and their contributions to the general stability of the packing arrangement. The significance of this study gives important insights into the relationship between lattice theory and the crystallographic properties of N, N’-bis(4-chlorophenyl)thiourea N, N- dimethylformamide, to improve the understanding of their physical characteristics and potential applications in materials science, medicine, and pharmaceuticals.
References
[1] M. K. Corpinot and D-K. Bučar. Cryst. Growth Des. 19(2019),1426.
[2] A. T. Odularu, P. A. Ajibade, J. Z. Mbese, Opeopuwa O. Oyedeji and H. Puschmann. Open. Chem. 19 (2021) 511.
This study investigates the influence of plasma screening on the relativistic behavior of a hydrogen-like atomic system through the application of a screened Coulomb potential. By accurately solving the Klein-Gordon equation in spherical coordinates, under the assumption that the scalar and vector potentials are equivalent, we get the self-energy spectrum of our system along with its corresponded wave functions.
Plenary
A descripotion of the history, objectives and futuro of LAMISTAD, a project forestablishing a synchrotron in the Greater Caribbean, will be offered, emphasinzing the challenges and opportunities of this enterprise.
Several Caribbean researchers and students, including from Puerto Rico, have been conducting materials and biological research studies at synchrotron facilities around the world. However, no synchrotron facility exists in the Greater Caribbean Region. A few years ago, a group of international researchers created the Latin American International Synchrotron for Technology, Analysis and Development (LAMISTAD) project with the aim to construct a Greater Caribbean Light Source (GCLS). Several Puerto Rican researchers are participating in the GCLS/LAMISTAD Committee. After the loss of the Arecibo Observatory, Puerto Rico might be a suitable site for a Big Science project such as the establishment of a synchrotron light source on the island. The Puerto Rican Light Source (PULS) initiative was created among Puerto Rican scientists participating in the GCLS/LAMISTAD Committee. Initial discussions about this initiative have been conducted with the Puerto Rico Science, Technology, and Research Trust. A white paper proposing a viability study was prepared. In this presentation the present status of the PULS initiative and possible next steps will be discussed.
Mayra Cuellar-Cruz1, Abel Moreno2
1 Department of Biology Division of Natural and Exact Sciences, University of Guanajuato, Noria alta s/n, Guanajuato 36050, Guanajuato Guanajuato. México.
2 Institute of Chemistry, Universidad Nacional Autónoma de México, Av. Universidad 3000. Mexico City 04510. Mexico.
Corresponding author e-mail address: carcamo@unam.mx
Introduction
This contribution basically deals with the status of the Synchrotron Radiation Facilities in Latin America, and at the same time the importance of the users for applications and development of technology in developing countries. It is described how the Mexican Society of Synchrotron Light (SMLS) was created. The aim of this society was to reinforce the project for the construction of a Mexican Synchrotron Facility in any of the 32 states that form the United States of Mexico.
Finally, an overview of new technologies for the compact sources will be part of the solutions for developing countries that cannot afford the construction of a big facility.
Acknowledgements
One of the authors (AM) acknowledges DGAPA-UNAM project No. PAPIIT IN207922 for the financial support for a recent visit to the compact XFEL facilities inaugurated at the State University of Arizona (USA) to get academic information and based on this talk for the African Conference to face the future of compact sources.
AfLS Contribution
Sotirios Charisopoulos, Danas Ridikas, Alessandro Migliori
Physics Section, Division of Physical and Chemical Sciences
Department of Nuclear Sciences and Applications, International Atomic Energy Agency
Vienna International Centre, PO Box 100, A-1400 Vienna, Austria
Promotion of nuclear applications for peaceful purposes and related capacity building is among the missions of the IAEA. Hereby, accelerator applications is one of the thematic areas, where the IAEA supports its Member States in strengthening their capabilities to adopt and benefit from the usage of accelerators, including synchrotron light sources. For this purpose, the IAEA Physics Section implements various activities to enhance utilization of light sources by enabling facility access for scientists from developing countries through bilateral as well as Collaborating Centre agreements with a number of light sources and through technical support granted through the Technical Cooperation Program.
In this context, the IAEA has recently approved the five-year Interregional TC project INT0104 "Increasing Transnational Cooperation between Light Sources and Diversifying the User Base." This project aims to broaden geographical access to synchrotron light sources and enhance technical expertise among Member States. By fostering collaboration and knowledge exchange, it seeks to empower developing Member States to address industrial and technological challenges, thereby strengthening educational institutions, economies, social structures, and global competitiveness.
A report on IAEA’s activities in support of research and applications using synchrotron-light facilities and increasing their transnational cooperation will be presented.
Emileo Naicker1, Caren Billing1,2, David G. Billing1,2
1 Molecular Science Institute, School of Chemistry,University of the Witwatersrand, Johannesburg, South Africa
2 DSI-NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Private Bag X3, Johannesburg, 2050, South Africa
emileo.naicker1@students.wits.ac.za
Fuel cells provide a way to convert chemical energy into electrical energy. The electrolyte used is one of the components that can be optimized to enhance the operation of the fuel cell. There are different types of electrolytes with the most common electrolyte used being yttrium stabilized zirconia. This work focuses on using doped bismuth oxide as an electrolyte due to its extremely high conductivity in its face centered cubic(fcc) structure while using specific dopants in a triple doped system(Y3+, Ce4+ and Pb2+) to promote certain characteristics with particular focus on Pb2+ for increasing conductivity. Variable Temperature electrochemical impedance spectroscopy (EIS) and Powder x-ray diffraction (PXRD) were both used to determine the conductivity performance and structural stability. It was revealed that increasing the Pb2+ concentration of the system, while fixing the concentration of the other dopants, resulted in increased conductivity. The linearity of both samples on the Arrhenius plots showed that there was not any major phase change. However, it seems that at higher temperatures, lead migrates away from the cubic structure which was revealed with VT-PXRD as the diffraction pattern showed a degradation of the cubic structure and discolouration of sample.
Plenary
The African Light Source Foundation has been engaged in a variety of activities to bring a synchrotron light source facility to the African continent. A milestone along the road to that goal has been the production of a geopolitical conceptual design report that discusses the justification, history, and road ahead for the African Light Source. In this presentation, we will expound upon these items.
Note: Following discussions with Lawrence Norris we would like to submit for two talks. One discussing the UK XFEL Project and Facility Design, and a second discussing the UK XFEL Science Case and notable recent XFEL highlights. However we can deliver this as one talk if the schedule is limited at this stage.
UK XFEL: Overview and Facility Design.
A conceptual design and options analysis (CDOA) is currently being carried out by the UK into the possibility to deliver a next generation XFEL (X-ray Free-Electron Laser). XFELs generate ultra-bright, short pulses of X-rays, allowing for the study of matter at the atomic and molecular level with unprecedented detail. This talk will explore the options and facility design of a potential UK XFEL along with our options for collaborating with existing facilities international, and international partners without XFEL access. We will discuss the conceptual design process, from translating science requirements into specific technical solutions and ultimately into compelling facility proposals. We will present a preliminary design for a UK XFEL– a multi-billion Pound science facility - highlighting key next-generation features and examine top-level design choices. These include multiplexing to enable up to 10 FELs, achieving high peak and average brightness, generating near-transform-limited pulses, reaching high pulse energy and photon energy, incorporating two-colour synchronous sources, enabling high data rates and AI integration, as well as ensuring sustainability throughout. The expected timelines for the project, highlighting the current status of the Conceptual Design and Options Analysis phase, which is expected to be completed by October 2025, will also be discussed along with the plans for subsequent phases of the project.
UK XFEL: Science Case highlights and refresh.
As part of this project we will also review the Science Case for UK XFEL, here we will explore recent scientific advances from XFELs worldwide, highlighting results which strengthen the case for a next-generation UK XFEL facility. We will discuss transformative breakthroughs in several scientific fields, showcasing the power of XFELs to address fundamental questions across the physical, chemical, and life sciences. We will discuss highlights and XFEL applications in our main science areas: Matter in Extreme Conditions, Nano/Quantum Materials, Engineering and Material Applications, Life Sciences, Chemical Sciences and Physical Sciences. And how we have approached engaging with these communities through a series of workshops and townhall discussions over the last 18 months.
AfLS Contribution
Introduction
Recent developments in plasma wakefield technology have enhanced the potential of compact particle accelerators with high energy efficiency and minimal energy spread. At the FLASHForward facility at Deutsches Elektronen-Synchrotron (DESY), researchers have experimentally validated optimal beam loading in a nonlinear plasma wakefield, achieving excellent energy-transfer efficiency and minimal energy spreads [1]. Locating more optimal plasma wakefield acceleration working points virtually is important to increase the efficacy of plasma wakefield acceleration research and consequently to enhance the results of these experiments. By doing this, we can increase the depth of our experimental discoveries and shorten the duration of our investigations.
This study focuses on optimizing three key parameters in virtual FLASHForward: notch width, notch position, and plasma density, crucial for analyzing the witness electron bunch and enhancing the effectiveness of plasma wakefield acceleration. Virtual FLASHForward aims to replicate actual experiments through computational tools Ocelot for beamline tracking and Wake-T for plasma simulations.
Optimization Parameter
The analysis of the witness electron bunch was carried out using an optimization parameter $P$. This parameter $P$ was aimed at making the witness bunch have a very high energy gain, high witness charge, and a low energy spread [1].
\begin{equation}
P = \frac{\Delta E_{\text{acc}}^2 \cdot Q_{\text{acc}}}{\sigma_E}
\end{equation}
where $\Delta E_{\text{acc}}$, $Q_{\text{acc}}$, and $\sigma_E$ represent the energy gain, charge, and energy spread of the witness bunch.
Results
We present the results of the first optimization of plasma wakefield acceleration in virtual FLASHForward, achieving the ideal acceleration regime using a trailing bunch and 500 simulations of a 3D parameter scan varying plasma density, notch position, and width. Points 1 and 2 on the scan show low values for the optimization parameter $P$, indicating insufficient beam loading. At point 3, high plasma densities result in strong acceleration and field flattening with the highest $P$ value. This point represents optimal beam loading with a charge of 59.75 pC, an energy gain of 100 MeV, and an energy spread of 13.44 MeV. This point can be further investigated for more experimental working points at higher plasma density profiles.
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References
[1] Lindstrøm, C. A., Garland, J. M., Schröder, S., Boulton, L., Boyle, G., Chappell, J., ... & Osterhoff, J. (2021). Phys. Rev. Lett. 126, 014801. https://doi.org/10.1103/PhysRevLett.126.014801
Introduction
The flexibility of diarylformamidine ligands to coordinate either as monodentate or as chelating ligands render their respective complexes very promising for application in catalysis [1]. N-hydroxy-N,N’-diarylformamidine complexes have been reported by our research group to be significant initiators in ring opening polymerization [2]. In this work, we explore the synthesis and characterization of hydroxy-N,N’-diarylformamidine derivatives with particular interest in their preferred isomerism in the solid-state.
Results
Symmetrical and Unsymmetrical N-hydroxyformamidines were synthesized and characterized using various spectroscopic techniques. The crystals of the compounds obtained underwent X-ray diffraction analysis, revealing that symmetrical formamidines can adopt both zwitterionic and neutral hydroxy forms, whereas unsymmetrical compounds exclusively adopt the zwitterionic form in solid state. The zwitterions exhibit Zanti isomerism, while the neutral hydroxy forms exhibit Eanti isomerism. Symmetrical and unsymmetrical compounds with smaller substituents tend to form dimeric molecular units, described by an R_2^2 (10) graph set descriptor. In contrast, unsymmetrical compounds with bulkier substituents form chain-like structures. Classical hydrogen bonds (N–H…O, N—H…N, N—H…O, and O–H…N) stabilize the crystal packing in dimeric units, while C–H…O interactions promote packing in chain-forming molecules. Pairwise interaction energy calculations reveal that electrostatic energy (Eele) predominates in the stability of the dimeric pairs, whereas dispersion energy (Edis) is more dominates in chain-like structures.
References
[1] Akpan ED, Ojwach SO, Omondi B, Nyamori VO., New J. Chem. 40 (2016) 3499-3510.
[2] Munzeiwa WA, Omondi B, Nyamori VO, Polyhedron. 138 (2017) 295-305.
Tea
Plenary
The success of the energy transition hinges on the development of efficient energy storage materials and technologies to deal with the intermittency of energy from solar and wind. Metal hydrides (such as LiBH4, NaBH4, KH NaCB11H12, etc.), which are well known for their ability to reversibly store large amounts of hydrogen, have recently emerged as multi-functional energy materials[1-2] This is due to their attractive properties for a variety of energy storage/conversion applications, including reversible hydrogen storage, batteries and fuel cells (as electrodes and solid electrolytes or ionic conductors), superconductivity, and catalysis.[1-2] In all these applications, it is crucial to improve the properties of the pristine metal hydride. In this lecture, I will show how interfacial effects, arising from nanocomposite formation with mesoporous materials (oxides or carbon) can lead to profound improvements in the properties of metal hydrides in energy applications.[3-7] For instance, high hydrogen release/desorption kinetics in hydrogen storage applications and orders of magnitude increase in ionic conductivity for electrochemical applications. Using selected examples from these two applications, I will discuss our recent results on the use of Xray Raman Scattering (XRS) to probe the chemical nature of the metal hydride/oxide and metal hydride/carbon interfaces, and thereby unravel the origin of the profound interface-induced property enhancements in the nanocomposites.[8-10] I will highlight how the fundamental understanding from the XRS studies is beneficial for tuning interface effects, and thereby enabling the design of metal hydride-based nanocomposites with tailor-made properties for energy applications.[1,3-6]
AfLS7 abstract for Oral presentation by Dr T. Ntsoane.
AfLS Contribution
1. Introduction
The seismic model, the Preliminary Reference Earth Model (PREM) [1], provides the profiles of sound velocity and density as a function of depth. Comparing the model with laboratory high-pressure experiments, pure iron cannot explain the sound velocity and density of the PREM core [e.g., 2]. Therefore, the density deficit of the core suggests some light elements may be dissolved in the Earth’s core. Although the density is the property often used for discussing the constituent of the core, we need additional properties such as sound velocities, which are more reliable properties of the core derived from seismology. It is not possible to specify the light elements in the core without information of the sound velocities of iron-light element alloys. However, there are limited measurements of the sound velocity under the core conditions because of the experimental difficulties.
2. Results
We developed techniques to measure the sound velocity at high pressure and temperature by using Inelastic X-ray scattering (IXS) and performed the sound velocity measurements in diamond anvil cell combined with the double-heated laser heating system. The Inelastic X-ray scattering at high-pressure and high-temperature was made at the RIKEN beamline BL43LXU of SPring-8. We doubled the static pressure conditions for IXS and successfully measured the sound velocity of metallic iron at a pressure equivalent to ICB (~330 GPa) and room temperature [3], and iron-nickel-silicon alloys up to the conditions of 130 GPa and 2300 K. These measurements revealed that the vp and vs of the Preliminary reference Earth model (PREM) inner core are 4(±2) % and 36(±17) % slower than those of the pure iron at the center of the core assuming the inner core temperature to be 6000 K. We also estimated the silicon and sulfur contents of the inner core by using the present and previous results on sound velocity measurements of the pure Fe, Fe-Ni-Si alloy, and Fe3S compound at high pressure and temperature. The inner core with the density and sound velocity of the PREM inner core can be explained by addition of 3(±1) wt.% silicon and 3(±2) wt% sulfur to iron‒4~5 wt.% nickel alloy.
This abstract is one of the contributions from Commission of Physics of Minerals (CPM), International Mineralogical Association (IMA).
[1] Dziewonski, A. M. & Anderson, D. L. (1981) Phys. Earth Planet. Inter. 25, 297‒356
[2] Dewaele, A., Loubeyre, P., Occelli, F., Mezouar, M., Dorogokupets, P. I., & Torrent, M. (2006) Physical Review Letters, 97(21), 29–32.
[3] Ikuta D, Ohtani E, Fukui H, Sakai T, Ishikawa D, Baron AQR (2022) Nature Comm. 13:7211
1.Introduction
Ensuring the sustainability of cement production is crucial in the construction sector. One effective approach to achieve this goal is by integrating suitable additives into traditional cement formulations. Layered Double Hydroxides (LDHs) offer promising potential as additives, as they can capture CO$_2$, enhance the carbonation resistance of cement, and remove CO$_2$, SO$_4$$^{2-}$, and Cl⁻ ions that may compromise the durability of cement paste. Classified as ionic solids with a layered structure, LDHs are known as anionic clays with controllable supramolecular structures and unique physicochemical properties, such as anion exchange, which make them particularly attractive in the field of cementitious materials [1,2]. In nature, these minerals are found in ultramafic rocks and form through high-temperature carbonation of spinel-type minerals or low-temperature carbonation of brucite (Mg(OH)$_2$). Investigating the structural evolution, phase transitions, and amorphization conditions of both natural and synthesized LDHs under high pressure using synchrotron light is of significant interest. Pressure-induced irreversible phase transition in hydrotalcite-like minerals comes together with a decrease in electrical resistivity and a progressive amorphization of the crystal structure [3]. Different microstructural characteristics of LDHs evolve as a function of pressure and temperature and influence the interlayer space, which is reflected in an increase in CO$_2$ adsorption [4].
2.Results and discussions
Nano Mg-Al-NO$_3$ LDHs were synthesized using both direct and ultrasound co-precipitation methods. The nanometric size and purity of the LDHs were confirmed through X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR). The ultrasound co-precipitation methods provide nanometric 2D size crystals and high purity of the LDHs species. The initial findings presented here contribute to understanding the precise role of selected nanomaterials in cement paste, particularly regarding how pressure influences their shape memory and the stability of trapped CO$_2$ and other anions responsible for the chemical attack of cement, such as Cl$^-$ and SO$_4$$^{2-}$. At high pressure, the anion absorption increases exponentially [4] and to understand this behaviour, the knowledge of the evolution in interlayer distance and dehydration and dihydroxylation processes of the brucite-type layers is essential. The ongoing HP single-crystal X-ray diffraction (SC-XRD) data will be collected at the ID15B beamline at the European Synchrotron Radiation Facility (ESRF, Grenoble, France) using diamond anvil cell (DAC) and, given the high-resolution and very small size of the beam spot, is being essential to characterize the nanomaterial structure of the synthesized LDHs. These results could also reveal potential adverse effects and aid in refining the procedures for incorporating LDHs additives into cement pastes. This abstract is one of the contributions from Commission of Physics of Minerals (CPM), International Mineralogical Association (IMA).
3.Acknowledgements
This work is funded by the European Union – Next Generation EU under the Italian Ministry of University and Research (MUR) National Innovation Ecosystem grant ECS00000041 - VITALITY - CUP J97G22000170005.
4.References
[1] M.A. Yazdi, E. Gruyaert, K. Van Tittelboom, and N. De Belie. New findings on the contribution of Mg-Al-NO$_3$ layered double hydroxides to the hydration and chloride binding capacity of cement pastes. Cem. Concr. Res.(2023) 163, 107037.
[2] G. Mishr, B. Dash and S. Pandey 2018. Layered double hydroxides: A brief review from fundamentals to application as evolving biomaterials. Appl. Clay Sci., (2018) 153, 172-186.
[3] G. Parthasarathy, M. L. Kantam, B. M. Choudary, and C. V. Reddy. Pressure-induced phase transitions of hydrotalcite by electrical resistivity, structural and thermal studies. Microporous Mesoporous Mater. (2002) 56(2), 147-152.
[4] M. J. Ramírez-Moreno, I. C. Romero-Ibarra,M. A. Hernández-Pérez and Pfeiffer, H. CO$_2$ adsorption at elevated pressure and temperature on Mg–Al layered double hydroxide. Ind. Eng. Chem. Res., 53(19), (2024) 8087-8094.