Browsing Philosophiae Doctor - PhD (Physics) by Title
Now showing items 33-52 of 62
-
The observed bispectrum for SKA and other galaxy surveys
(University of the Western Cape, 2019)Next-generation galaxy surveys will usher in a new era of high precision cosmology. They will increasingly rely on the galaxy bispectrum to provide improved constraints on the key parameters of a cosmological model to ... -
Optical modeling of amorphous and metal induced crystallized silicon with an effective medium approximation
(University of the Western Cape, 2009)In this thesis we report on the metal-mediated-thermally induced changes of the structural and optical properties of hydrogenated amorphous silicon deposited by hot-wire CVD, where aluminium and nickel were used to induce ... -
Perturbations of dark energy models
(University of Western Cape, 2012)The growth of structure in the Universe proceeds via the collapse of dark matter and baryons. This process is retarded by dark energy which drives an accelerated expansion of the late Universe. In this thesis we use ... -
Physical properties of vanadium dioxide nanoparticles: application as 1-d nanobelts room temperature for hydrogen gas sensing
(University of the Western Cape, 2013)Transition metal oxides magneli phases present crystallographic shear structure which is of great interest in multiple applications because of their wide range of valence, which is exhibited by the transition metals. The ... -
Physics graduate preparedness for work and society
(University of the Western Cape, 2023)Both internationally and in South Africa, there have been renewed debates about the purposes of higher education and the attributes that should be developed in graduates. In the field of physics, many studies have reported ... -
Probing galaxy evolution below the noise threshold with radio observations
(University of the Western Cape, 2020)The faint radio population consisting of star forming galaxies (SFG) and radio-quiet active galactic nuclei (AGN) is important in the study of galaxy evolution. However, the bulk of the faint population is below the ... -
Probing large-scale structure with the SKAO and other cosmological surveys
(University of the Western Cape, 2022)In recent history there have been several advances in cosmology, which has significantly shaped our understanding of the Universe. The current leading theory is called ΛCDM, which can successfully model the expansion of ... -
Probing the expansion history of the universe using upernovae and Baryon Acoustic Oscillations
(University of the Western Cape, 2016)The standard model of cosmology (the ɅCDM model) has been very successful and is compatible with all observational data up to now. However, it remains an important task to develop and apply null tests of this model. These ... -
Proton conductivity stability studies by modelling
(University of the Western Cape, 2016)In this thesis, some of the challenges experienced by high temperature polymer electrolyte membrane fuel cells are explored through material modelling techniques. A very important aspect for a fuel cell is that it should ... -
Radiometric characterisation of vineyard soils, Western Cape, South Africa
(University of the Western Cape, 2010)This study is aimed at investigating the feasibility of using the radiometric technique as an alternative to traditional methods for determining soil physico-chemical parameters which are important for terroir characterization. ... -
Radiometric investigation of soil and beach sand in Zanzibar
(University of the Western Cape, 2020)This study presents the results of radiometric investigation of soil and beach sand in Zanzibar. The activity concentration of natural radionuclides (40K, and 232Th and 238U decay products) in beach sand and soil samples ... -
Relativistic corrections to the power spectrum
(University of the Western Cape, 2015)The matter power spectrum is key to understanding the growth of large-scale structure in the Universe. Upcoming surveys of galaxies in the optical and HI will probe increasingly large scales, approaching and even exceeding ... -
Silicon nanowires by metal-assisted chemical etching and its incorporation into hybrid solar cells
(University of Western Cape, 2021)The rapid increase in global energy demand in recent decades coupled with the adverse environmental impact of conventional fuels has led to a high demand for alternative energy sources that are sustainable and efficient. ... -
Simulating the neutral hydrogen distribution during cosmic reionization
(University of the Western Cape, 2018)We improve on the physical treatment of ionising source and sink populations in the large scale semi-numerical simulations by implementing new physically motivated parametrizations taken from high-resolution radiative ... -
Spectrally selective AlXOY/Pt/AlXOY solar absorber coatings for high temprature solar-thermal applications
(University of Western Cape, 2014)The limited supply of fossil hydrocarbon resources and the negative impact of CO2 emission on the global environment dictate the increasing usage of renewable energy sources. Concentrating solar power (CSP) systems are the ... -
Structural and gas sensing properties of TiO₂-based (Sn, Mg) nano-structures induced by mechanical milling and annealing
(University of the Western Cape, 2015)Titanium oxynitride has attracted research interest for the fact that it is a bioactive non-toxic material. It is suitable for surface coating of biomaterials and in other applications such as anti-reflective coatings, ... -
Structural and physical properties of ReN i03 (Re=Sm, N d) nanostructured films prepared by Pulsed Laser Deposition
(University of the Western Cape, 2010)Very few systems allow the study of the relationship between structural changes and physical properties in such a clear way as rare earth nickelate ReNi03 perovskites (Re (rare earth) = Pr, Nd, Sm and Gd). Synthesized for ... -
Structure property relationship and thermal stability of organic photovoltaic cells
(University of the Western Cape, 2010)In this thesis, regioregularpoly( 3-hexylthiophene) (rr-P3HT) polymer was used as a light absorption and electron donating material, while the C60 fullerene and its derivative [6,6]-phenyl C61-butyric acid methyl ester ... -
A study of hydrogenated nanocrystalline silicon thin films deposited by hot-wire chemical vapour deposition (HWCVD)
(University of the Western Cape, 2005)In this thesis, intrinsic hydrogenated nanocrystalline silicon thin films for solar cells application have been deposited by means of the hot – wire chemical vapour deposition (HWCVD) technique and have been characterised ... -
Studying chirality in a ~ 100, 130 and 190 mass regions
(University of the Western Cape, 2011)Chirality is a nuclear symmetry which is suggested to occur in nuclei when the total angular momentum of the system has an aplanar orientation [Fra97, Fra01]. It can occur for nuclei with triaxial shape, which have valence ...