Conveners
Applied Physics
- Alan Matthews
Applied Physics
- Adiel Holtzhausen (Akademia)
Applied Physics
- Ernest van Dyk (NMU)
Applied Physics
- Trevor Derry (Wits)
Applied Physics
- Trevor Derry (Wits)
Applied Physics
- Lucas Erasmus (UFS)
Applied Physics
- Philippe Ferrer (Wits)
Applied Physics
- Nicolas Thantsha
Applied Physics
- Marco Mariola
Applied Physics
- Alan Matthews (UKZN)
Applied Physics
- Tjaart Kruger
Applied Physics
- Alan Matthews (UKZN)
The 20kW prototype parabolic trough was completed and the novel receiver performance measured in a realistic setting, completing a project that has led to this point over many years. The final analysis veers away from the original theoretical description, using a more conventional approach and detailed thermal network, necessitated by the insufficient vacuum levels obtained during testing. We...
Solid carbon nanospheres of ~200 nm diameter have been prepared and then doped by ion implantation, using a specialized end-station adapted for the uniform implantation of powders. Boron, nitrogen and neon ions were chosen initially, the latter for control purposes. Herein, the dependence of the physicochemical properties of solid carbon spheres on the fluence of the implanted ions was...
Lightning-induced damage poses a major threat to infrastructure, particularly in power and telecommunications networks. Accurate current measurements are essential for designing protective systems and assessing damage. While traditional sensors such as shunt resistors and Rogowski coils offer high accuracy, they must be installed at the strike point, making them unsuitable for wide-area...
Artificial Intelligence (AI) classification as a methodology and approach to identify Tuberculosis (TB) in patients has become a topic of increasing interest in the past few decades. This is in large part due to the increasing demand for faster methods of detecting TB to reduce spread. However, such methodologies require large datasets so that algorithms can learn the manifestations of TB in...
The High-Luminosity Large Hadron Collider ย requires precise environmental monitoring in the ATLAS Inner Tracker ย to prevent water condensation that could damage detector electronics. This study focuses on the development and the performance of Fibre Optic Sensor ย packages. Each package is made up of a Long Period Grating sensor ย and two Fibre Bragg Grating sensors for accurate temperature,...
Topology has played a significant role many areas in Physics, ranging from cosmology and condensed matter to high-energy physics and waves. In electromagnetism, one can create an optical Skyrmion through correlations between position and polarization which map from real space to the Poincarรฉ sphere. These topological states of light can be realised in classical laser beams and biphoton...
Energy balance closure is a fundamental principle in micrometeorology, ensuring that all energy fluxes within an ecosystem are properly accounted for. The eddy covariance (EC) method, widely used for measuring land โ atmosphere exchanges of energy and mass, often exhibits energy closure discrepancies, particularly across different timescales. This study investigates ecological year energy...
Quantum electron pumps (QEPs) have become more popular as sources of precision current as the ampere is being redefined in terms of basic constants. As possible platforms for QEPs, this study investigates the fabrication and integration of engineered low-dimensional semiconductor materials, specifically silicon nanowires and Cโโ fullerene nanorods. Through a combination of nanofabrication...
Features such as the omni directional intake, the nozzle-diffuser section as well as the diffuser section of the Increased velocity (INVELOX) wind delivery system augment incident air to a cut in wind speed of most small-scale wind turbines systems. Despite these properties, the INVELOX delivery systems suffers from adverse pressure gradient leading to flow separation within the throat...
Quantum state tomography is an essential technique for characterizing quantum systems. It involves performing projective measurements and computationally reconstructing the density matrix from the measurement data by solving a system of linear equations. The discovery of the HHL algorithm has sparked significant interest in leveraging quantum computers to solve these equations, promising a...
Recognizing quantum phases of matter is a central challenge in quantum many-body physics and quantum machine learning. In this work, we introduce a Novel Quantum Convolutional Neural Network (No-QCNN) architecture tailored for efficient quantum phase recognition and benchmark its performance on IBMโs superconducting quantum hardware. The No-QCNN leverages translationally invariant circuit...
The MinPET research team is developing novel computer-vision capabilities for crushed rock sorting in diamond mines. Traditional diamond extraction methods employ multi-stage rock-crushing where stages are chosen such that a mine's diamond-size distribution is balanced against the crush size at each stage so that an overall acceptable rate of diamond breakage is maintained. Positron emission...
The escalating costs of fossil fuels and the finite nature of accessible reserves the indispensable need of studying alternative energy sources. Organic solar cells present a practical and economical technology for capturing solar energy, utilizing materials that are often both accessible and recyclable. Conventional silicon solar cells demonstrated significant reliability; however, their...
Dye-sensitized solar cells (DSSCs) present a promising photovoltaic technology due to their cost-effectiveness, high efficiency, and flexible device design. DSSCs generally use titanium dioxide (TiOโ) as a photoanode material. Brookite TiO2 phase provides special electrical characteristics fit for maximum solar energy conversion. However, the broad bandgap of bulk TiOโ limits its absorption in...
Firefighting bunker gear provides the first line protection for firefighters during fire conditions. The protective garment is fabricated from superior performance fibres and enhanced by the addition of flame retardants (FRs), which resist ignition and delay flame spread. Flame retardants have been attributed to 15-fold greater escape time for occupants. However, concerns have been emerging on...
In quantum computing a diagrammatic representation of a code is conventionally displayed as a vertical column of qubits that feed from left to right into a network of wires and gates. An alternative view is an array with qubits as a header row for all register eigenstates, with amplitude values as a column on the left. In this view, the action of gates on the register is seen as successive...
Fibre Bragg Gratings (FBGs) have emerged as highly sensitive sensors for monitoring environmental parameters such as temperature, strain, radiation dose, etc. Moreover, they can withstand extreme environments, of interest here, a high radiation dose environment. The goal of this work is to develop reliable sensing instruments for high radiation-hard environments, such as the ATLAS inner...
Environmental vibrations can induce distortions in live fibre optic cables through the elasto-optic effect, leading to changes to both the light's state of polarisation (SOP) and phase. Coherent optical receivers, essential to modern telecommunications, offset these distortions by employing advanced digital signal processing (DSP) techniques to filter out the effects during high-speed data...
The global agriculture sector faces mounting challenges due to climate change, rising atmospheric COโ levels, and increasing food demand from growing urban populations. Greenhouses have emerged as vital solutions to ensure improved food production. In earlier work, a real-time Internet of Things (IoT) sensor network was deployed in a sawtooth-shaped greenhouse to monitor temperature and ...
A simulation of a low-cost PET detector concept is presented. The model is used to evaluate the imaging potential of the proposed detector, to optimise image reconstruction techniques for this design, and to feed back performance metrics to the detector design process.
The PET system was developed with GATE (Geant4 Application for Tomographic Emission), incorporating a detector layout based...
Medical PET is an expensive metabolic imaging technique that has applications in cardiology, oncology and neurology and is primarily limited to high income countries. A low-cost PET detector concept would likely extend its application to middle and low income countries. This work aims to find the optimal physical parameters that minimizes the cost of the detector while still producing...
Optical vorticesโphase and polarization singularitiesโare central to structured light applications, yet their comparative resilience to atmospheric turbulence remains underexplored. This study investigates the robustness of phase versus polarization vortices under Kolmogorov-model turbulence using Laguerre-Gaussian and vector beam superpositions. Vortex dynamics are tracked via phase...
In recent years, Deep Diffractive Neural Networks (D2NNs) have emerged as a powerful tool in optical computing and information processing. These systems utilise consecutive phase modulations to map a set of optical input states defined in one basis, to a new set of target states in an arbitrarily defined basis. Traditionally, the phase masks used to achieve these operations are optimised...
Photovoltaic (PV) module imaging has become a critical tool for assessing the performance, reliability, and degradation of PV modules. Automated imaging systems that use advanced hardware and image processing software tools allow for efficient high-throughput data capture across large-scale solar installations. These systems use different imaging techniques such as visible light (RGB) imaging,...
Solar irradiance modelling is critical for determining local solar energy potential. Several past studies have analysed the more easily attainable Global Horizontal Irradiance (GHI) within Southern Africa. However, less research has been carried out on the physically more useful Direct Normal Irradiance (DNI) and Diffuse Horizontal Irradiance (DHI). This study aims to alleviate this by...
Lithium-ion batteries (LIBs) have revolutionised the automotive industry (mainly electric vehicles)as a sustainable energy storage solution for electric vehicles due to their high-power and energy density. Their widespread adoption is crucial for achieving global decarbonization goals and reducing dependence on fossil fuels. However, the degradation of LIBs over time remains a challenge,...
A significant portion rural Africa still lack access to affordable, sustainable and modern energy, causing a knock-on effect on the development of education, agriculture, healthcare, business and transportation, ultimately lowering the rural quality of life. Towards a sustainable solution in meeting the rural Southern Africa energy demand, there is a need for indigenous development and...
iThemba LABS operates complex scientific equipment including particle accelerators where unexpected failures can disrupt critical experiments for extended periods. We present a predictive maintenance framework based on Vanilla LSTM networks that analyzes multivariate time-series sensor data to anticipate equipment failures. The model was trained on operational data from 2021-2024, monitoring...
This paper proposes a mathematical approach to predict the real-time performance of the small-scale photovoltaic (PV) system mounted at the Arcadia based on the power law model (PLM), commonly used to predict the I-V curves of solar cells in standard test conditions (STC). The shape parameters involved in the PLM known as m and ยต in this study were determined using experimental data collected...
The interaction of high-speed ions with target atoms in solid matter continues to be of both fundamental and practical interest. In materials research and development, one of the key ion-atom interactions of interest is the energy loss of the incident ion to target nuclei and the electron cloud. Accurate theoretical description of ion energy loss processes in matter is key to the development...
Positron emission tomography (PET) is a valuable medical imaging technique widely used in the early diagnosis of cancer, as well as in the assessment of cardiovascular, neurological, and metabolic disorders. PET scanners detect pairs of 511 keV gamma rays emitted via the annihilation of positrons from a radioactive tracer injected into the patient. The industry standard detectors used in these...
Cancer induction and progression have been significant challenges that face humanity. Several procedures and methods have been used to detect the different stages within the clinical setting. However, many of these clinical tests are geared towards biochemical cues. This study studied the inherent nanomechanical properties of two breast and colorectal biopsies. The tissues were obtained from a...
Perovskite materials used for solar cell, demonstrated remarkable PCE, that increased from 3.8% in 2009 to approximately 19.44% in 2019. However, challenges such as stability and scalability remain significant obstacles to commercialization. Improvement of the perovskite solar cell stability includes material composition and crystal quality, using both intrinsic and extrinsic methods....
Partially filled neutron gauge volumes in neutron powder diffraction experiments lead to anomalous shifts in diffraction peak positions. In stress analyses, these shifts create systematic errors in lattice parameter measurements, potentially leading to incorrect interpretations of strain if left uncorrected. This phenomenon is known as the pseudo-strain effect.
The instrumental gauge volume...
Photovoltaic (PV) module characterisation plays an important role in understanding and optimizing the performance of solar PV energy systems. By rigorously analysing various parameters such as power output, efficiency, temperature dependence, spectral response, degradation mechanisms and failure rates researchers can fine-tune PV modules and systems for maximum energy output and durability....
We have studied a Ti6Al4V made by metal injection molding (MIM) using synchrotron X-ray imaging techniques. This alloy has superior mechanical properties compared with other titanium alloys [1]. We have managed to determine the porosity, defects, and the morphology using Computed Tomography and Ptychography.
Fabrication of the alloy was carried out at the Council for Scientific and...
The weather plays a crucial role in decisions that people make on daily basis, especially in the agriculture, transportation, energy sectors. Therefore, accurate and efficient weather forecasting is of utmost significance. Predicting weather patterns has been an endeavor humanity has engaged in since ancient times. Over the years, various approaches have been used to forecast the weather....
In general, a rocket's onboard systems, including payloads, must be harmonized within the overall system. In some cases, payloads with an autonomous power system, including batteries, must be activated shortly before or after launch to keep the mission active for the required time. The sizing of power switches must be done according to the power requirements of the payloads, and it is also...
Many applications exist for structured light. However, a barrier of entry exists for non-experts. Button Optics has created an all-in-one solution for generating different kinds of beams. Over the last year we have created a fully functional product interfacing with cameras and computer software. Moreover, we have expanded our product suite to include a diagnostic device. In this talk I will...
Grating-based X-ray phase contrast imaging using a Talbot-Lau interferometer has emerged as an effective laboratory-based method to visualize specimens with low absorption contrast [1]. This technique enables simultaneous extraction of absorption, phase contrast, and dark-field images from a single dataset. Characterization studies were undertaken to validate and optimize the performance of...
Quantum Machine Learning (QML) lies at the intersection of classical Machine Learning (ML) and Quantum Computing (QC) and is currently experiencing significant growth in terms of both efficiency and applications. This expansion is largely driven by the availability of Noisy Intermediate-Scale Quantum (NISQ) processors, which enable the use of Quantum Computing without needing to tackle the...
