ResearchSpace

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Welcome to ResearchSpace, the institutional repository of the CSIR. ResearchSpace is an open access electronic archive collecting, preserving and distributing scholarly digital materials created by the CSIR.

Recent Submissions

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Manufacture and testing of ARGUS: A pole climbing surveillance robot

(2024-10) De Ronde, Willis; Bosscha, Peter A; Marais, Stephen T; Pretorius, A

South Africa needs rapidly deployable surveillance in situations such as public marches and periods of unrest. As these events can often last several hours, short-term solutions, such as multi-rotor drones, are generally not feasible. The proposed solution, the Automated Robotic Guardian for Urban Surveillance (ARGUS) platform, is a rapidly deployable pole-climbing robot for surveillance and situational awareness. This paper outlines the system's manufacture, testing, and analysis. The platform was tested under various laboratory and real-world conditions against predefined user specifications. Test results demonstrate that the system can ascend and descend multiple existing pole infrastructures and maintain a hold position without the motors consuming power while on the pole.

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Robotic waste sorting using deep learning

(2024-12) Goorun, Yurisha; Marais, Stephen T; Nicolls, F

The ongoing waste crisis has highlighted the need to address the problem of waste collection and sorting. This paper presents an automated waste sorting system with Deep Learning using a stereoscopic camera and a robotic manipulator. The system can recognise and classify different types of waste and sort them into specific categories by using the robotic arm to improve the recycling process.

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Economic analysis of a hybrid micro-grid with battery energy storage

(2024-10) Ndlovu, Given; Oloo, Fiona RA; Moodaliyar, Sumendran; Hlalele, Thabo G

This paper presents a hybrid microgrid economic model that optimally schedules solar photovoltaic (PV) generation, wind, and battery energy storage power to meet the daily demand of the end-user. The model ensures that the hybrid power plant is fully utilized before acquiring additional power from the grid. An optimal scheduling model with the objective of maximizing the profitability of the hybrid micro-grid operator is evaluated while minimizing the unserved energy to the end-user. The economic scheduling model indicates that by using solar PV, wind, and battery energy storage, the hybrid micro-grid operator can achieve higher profits compared to when using solar PV and wind alone. The overall increase in profit is 3.7 times more than when using solar PV and wind generation, and the load unserved is reduced by 96%. The results show that energy storage can greatly increase profitability while reducing the load unserved.

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Exploring compatibility and accuracy of functionals on structural and electronic properties of manganese oxide cathode materials: A dft and dft+u study

(2024-07) Kgasago, MZ; Ngoepe, PE; Phoshoko, Katlego W; Ledwaba, RS

Lithium manganese oxides (LMO) have gained significant interest as positive electrode materials for lithium-ion batteries, owing to their high capacity and suitability for achieving remarkable energy densities thus positioning them as promising candidates for advancing LIB technology. Among these materials, Li2MnO3 and LiMnO2 exhibit unique structural and electronic properties that are crucial for their performance in LIBs. This study aims to assess the structural and electronic characteristics of layered lithium manganese oxide cathode materials for lithium-ion batteries using DFT-based computational simulations. Through comparison with experimental data, our findings demonstrate the reliability of computational predictions, with calculated lattice parameters showing excellent agreement with measured values (within 0.5% for Li2MnO3 and 3.5% for LiMnO2). Band structure analysis reveals a moderate direct band-gap of approximately 1.439 eV for Li2MnO3, matching the experimental value of 1.64 eV, and 1.379 eV for LiMnO2, aligning closely with the experimental value of 1.58 eV. These findings shows the reliability of computational simulations in predicting the properties of manganese oxide cathode materials for lithium-ion batteries, paving the way for their future implementation as shells in a core-shell design.

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Investigations on the effect of Ni and Ta on the Ti-Pt shape memory alloys for high-temperature applications: First principle approach

(2024-07) Modiba, Rosinah

Ti-Pt alloys have shown the potential to be used at high temperatures due to their high transformation temperatures of above 1000 0C and their shape memory properties. The cubic B2 TiPt alloy was found to be mechanically unstable with a negative shear modulus compared to the commercially used TiNi. In addition, the alloy has been found to exhibit a low shape memory effect which is attributed to low critical stress for slip deformation compared to the stress required for martensitic transformation. To improve the mechanical properties of the TiPt alloys, the addition of Ni and Ta is investigated using the first principle approach. The stability of the alloys is studied in terms of their structural and elastic properties. In addition, the density of states for the alloys is presented.