Browsing Philosophiae Doctor - PhD (Physics) by Issue Date
Now showing items 21-40 of 62
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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 ... -
Gamma spectroscopy and lifetime measurements in the doubly-odd 194tl nucleus, revealing possible chiral symmetry breaking
(University of the Western Cape, 2013)In the first experiment high spin states in 194Tl, excited through the 181Ta (18O, 5n) heavyion fusion evaporation reaction were studied using the AFRODITE array at iThemba LABS. The γ-γ coincidences, RAD ratios and linear ... -
In-situ measurements and calculation of radon gas concentration and exhalation from a tailings mine dump
(University of the Western Cape, 2013)In Africa as well as in the world, South Africa plays an important role in the mining industry which dates back almost 120 years. Mining activities in South Africa mainly take place in Gauteng Province. Every year millions ... -
Galaxy Evolution and Cosmology using Supercomputer Simulations by Daniel Cunnama
(University of the Western Cape, 2013)Numerical simulations play a crucial role in testing current cosmological models of the formation and evolution of the cosmic structure observed in the modern Universe. Simulations of the collapse of both baryonic and ... -
Far-infrared-radio relations in clusters and groups at intermediate redshift
(University of the Western Cape, 2014)In this thesis, we present a multi-wavelength analysis of star-forming galaxies to shed new light on the evolution of the far-IR-radio relations in intermediate redshift (0.3 < z < 0.6) galaxy clusters and galaxy groups. ... -
Galaxy evolution and cosmology studies using luminous red galaxies
(University of the Western Cape, 2014)There have been a number of attempts to measure the expansion rate of the Universe using age-dating of Luminous Red Galaxies (LRGs). Assuming that stars in LRGs form at the same time, age-dating of two populations of LRGs ... -
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, ... -
Modelling the growth of large-scale structure with interacting fluids
(University of the Western Cape, 2015)Prevailing astronomical and astrophysical observations suggest that we live in a spatially flat cold dark matter (CDM) universe - currently going through a period of accelerated expansion possibly driven by “dark energy” ... -
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 ... -
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 ... -
Using semantic profiling to characterize pedagogical practices and student learning : a case study in two introductory physics courses
(University of the Western Cape, 2016)Framed by the South African imperative of widening epistemological access to undergraduate science studies, this research takes the form of a case study to investigate the educational affordances of an extended introductory ... -
Imprints of Primordial Non-Gaussianity on Large Scale Structure in the Universe
(University of the Western Cape, 2016)Large scale structure in the universe is one of the most important probing tools for cosmological modelling. Assuming the hot big bang model of the universe, the expansion history has undergone two phases of acceleration. ... -
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 ... -
Transport and thermodynamic properties of rare earth compounds and alloys
(University of the Western Cape, 2017)Rare-earth (RE) elements possess an incompletely lled 4f shell, which is very small compared to typical interatomic distances. As a result of this, RE elements and compounds exhibit characteristic properties, which deviate ... -
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 ... -
Nuclear structure studies in the A=136 region using transfer reactions
(University of the Western Cape, 2018)This thesis describes research work undertaken to study neutron pairing correlations in 136Ba via the 138Ba(p, t) pair transfer reaction and to perform high-precision spectroscopy of low-lying states in 136Cs using the ... -
Neutral hydrogen in galaxies, its content and the effect of environment on its evolution
(University of the Western Cape, 2018)Using two hydrodynamic galaxy formation simulations from the Mufasa project that I helped develop, we aim to better understand the relationship between galaxy evolution and its cold gas content commonly known as the ... -
Test of traditional vibrational wisdom by 2 proton stripping onto targets of 108;110Pd,114Cd,115In
(University of the Western Cape, 2018)The cadmium nuclei have traditionally been regarded as among the best examples of spherical vibrational nuclei. However, advances in nuclear spectroscopy have begun to detail the properties of these nuclei at the two and ... -
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 ...