Browsing Doctoral Degrees (Applied Mathematics) by Title
Now showing items 2746 of 55

Group theoretic approach to heat conducting gravitating systems.
(2013)We study shearfree heat conducting spherically symmetric gravitating fluids defined in four and higher dimensional spacetimes. We analyse models that are both uncharged and charged via the pressure isotropy condition ... 
Initial conditions of the universe : signatures in the cosmic microwave background and baryon acoustic oscillations.
(2012)In this thesis, we investigate the signatures of isocurvature initial conditions in the cosmic microwave background (CMB) through the temperature and polarization anisotropies, and in the largescale structure distribution ... 
Interative approaches to convex feasibility problems.
(2001)Solutions to convex feasibility problems are generally found by iteratively constructing sequences that converge strongly or weakly to it. In this study, four types of iteration schemes are considered in an attempt to ... 
Investigation of gravitational collapse of generalized Vaidya spacetimes.
(2015)In this thesis, we study the gravitational collapse of generalized Vaidya spacetimes which describe a combination of lightlike and timelike matter elds, commonly known as Type I and Type II elds, respectively, in the ... 
Mathematical modeling of cancer treatments and the role of the immune system response to tumor invasion.
(2015)Despite the success of traditional cancer treatments, a definite cure to several cancers does not exist. Further, the traditional cancer treatments are highly toxic and have a relatively low efficacy. Current research ... 
Mathematical models for heat and mass transfer in nanofluid flows.
(2018)The behaviour and evolution of most physical phenomena is often best described using mathematical models in the form of systems of ordinary and partial differential equations. A typical example of such phenomena is the ... 
A modelling approach for determining the freshwater requirements of estuarine macrophytes.
(1998)Increased abstraction of water in the catchment results in a reduced or altered pattern of river flow and this holds serious consequences for the downstream estuarine ecosystem. In South Africa this is a serious concern ... 
Modelling the physical dynamics of estuaries for management.
(1996)South African estuaries are characterised by highly variable inflows owing to the semiarid nature of the land mass which they drain. The interaction of this variability with that of the marine environment (seasonality, ... 
Modelling waterborne diseases.
(2013)Waterborne diseases are among the major health problems threatening the life of individuals globally. This thesis investigates the dynamics of waterborne disease under different conditions and consequently determines ... 
Models in isotropic coordinates with equation of state.
(2014)In this thesis we consider spacetimes which are static and spherically symmetric related to the Einstein and EinsteinMaxwell system of equations in isotropic coordinates. We study both neutral and charged matter ... 
New models for quark stars with charge and anisotropy.
(2014)We find new classes of exact solutions for the EinsteinMaxwell field equations. The solutions are obtained by considering charged anisotropic matter with a linear equation of state consistent with quark stars. The field ... 
New solutions for a radiating star.
(2018) 
Noncircularity of beams in the CMB polarization power spectrum estimation.
(2013)Precise measurements of the Cosmic Microwave Background (CMB) anisotropies have been one of the foremost concerns in modern cosmology as it provides valuable information on the cosmology of the Universe. However, an ... 
A numerical study of heat and mass transfer in nonNewtonian nanofluid models.
(2019)A theoretical study of boundary layer flow, heat and mass transport in nonNewtonian nanofluids is presented. Because of the diversity in the physical structure and properties of nonNewtonian fluids, it is not possible ... 
On new and improved seminumerical techniques for solving nonlinear fluid flow problems.
(2012)Most real world phenomena is modeled by ordinary and/or partial differential equations. Most of these equations are highly nonlinear and exact solutions are not always possible. Exact solutions always give a good account ... 
On paired decoupled quasilinearization methods for solving nonlinear systems of differential equations that model boundary layer fluid flow problems.
(2018)Two numerical methods, namely the spectral quasilinearization method (SQLM) and the spectral local linearization method (SLLM), have been found to be highly efficient methods for solving boundary layer flow problems that ... 
On singularly perturbed problems and exchange of stabilities.
(2015)Singular perturbation theory has been used for about a century to describe models displaying different timescales, that arise in applied sciences; particularly, models displaying two timescales, namely slow time and fast ... 
Optimisation of the population Monte Carlo algorithm : application to cosmology.
(2015)In this thesis we study the Population Monte Carlo (PMC) algorithm and utilise simulations to improve the efficiency of the algorithm by optimising the algorithm parameters. We then ap ply these optimisation results to ...