Browsing by Author "Fourie, Lionel Fabian"

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    Computational modelling of a hot-wire chemical vapour deposition reactor chamber
    (University of Western Cape, 2020) Fourie, Lionel Fabian; Square, L. C.; Arendse, C. J.
    In this thesis, I explore the subjects of fluid dynamics and the Hot-Wire Chemical Vapour Deposition (HWCVD) process. HWCVD, in its simplicity, is one of the more powerful and elegant deposition techniques available in thin film research which allows for both the growth and post deposition treatments of functional thin films. In the HWCVD process, the quality of the final films is determined by a fixed set of deposition parameters namely: temperature, pressure and the gas flow rate. Finding the optimal combination of these parameters is key to obtaining the desired film specifications during every deposition. Conducting multiple trial experiments to determine said parameters can be expensive and time consuming, this is where simulation methods come into play. One such simulation method is Computational Fluid Dynamics (CFD) modelling
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    Exploring poly (2, 5) benzimidazole enhanced with carbon nanotubes for space applications
    (University of the Western Cape, 2023) Fourie, Lionel Fabian; Square, Lynndle
    This work explores using polymeric materials for space radiation shielding in low-earth orbit. Shielding against radiation is essential on any space mission. Low atomic number materials, such as hydrogen, have shown to be effective in shielding ionising radiation. However, compared to metallic alloys, these materials suer from relatively low mechanical and thermal properties, which limit their application. Aluminium (Al) enjoyed wide use in space applications as a structural and radiation shielding material. However, weight and secondary radiation generation issues have made its use as a shielding material less viable on modern space missions where cost and safety play a crucial role in planning these missions. On modern space missions, conventional shielding materials include Al alloys, high-density polyethylene, and water. The disadvantages include low thermal properties, high atomic numbers, and complex maintenance systems. This lead to exploring other materials that can mitigate some of these drawbacks. A proposed approach to replacing high atomic number metals is deploying hydrogen-rich polymers enhanced with nanofiller materials to form polymer nanocomposites. Poly-mers enhanced with nanofillers can achieve improved physical properties while pro-viding adequate radiation shielding functions at a lower weight with less secondary radiation generation.