Now showing items 21-30 of 85
Some models of relativistic radiating stars.
In this dissertation we study radiating stars in strong gravitational elds. We generate new classes of exact solutions to the Einstein eld equations and the boundary condition applicable to radiating relativistic stars. ...
Spanning trees : eigenvalues, special numbers, and the tree-cover ratios, asymptotes and areas of graphs.
This dissertation deals with spanning trees associated with graphs. The number of spanning trees of a graph can be found by considering the eigenvalues of the Laplacian matrix associated with that graph. Special classes ...
On the existence of self-dual codes invariant under permutation groups.
Abstract available in PDF file.
Spherically symmetric solutions in relativistic astrophysics.
In this thesis we study classes of static spherically symmetric spacetimes admitting a perfect fluid source, electromagnetic fields and anisotropic pressures. Our intention is to generate exact solutions that model the ...
A classification of second order equations via nonlocal transformations.
The study of second order ordinary differential equations is vital given their proliferation in mechanics. The group theoretic approach devised by Lie is one of the most successful techniques available for ...
Computer analysis of equations using Mathematica.
In this thesis we analyse particular differential equations that arise in physical situations. This is achieved with the aid of the computer software package called Mathematica. We first describe the basic features of ...
Modelling the spatial dynamics of a semi-arid grazing system.
A large proportion of the world's land surface is covered by semi-arid grasslands, and they provide an important source of income as a grazing resource. A more comprehensive understanding of these complex ecosystems is ...
Economic evaluation of management strategies for cattle ranching in semi-arid regions.
Arid and semi-arid regions have increasingly become the subject of much research and debate by scientists. By their very nature, these regions characteristically exhibit extremes which complicate the implementation of ...
The application of the multigrid algorithm to the solution of stiff ordinary differential equations resulting from partial differential equations.
We wish to apply the newly developed multigrid method  to the solution of ODEs resulting from the semi-discretization of time dependent PDEs by the method of lines. In particular, we consider the general form of two ...
Mathematical analysis of tuberculosis vaccine models and control stategies.
The epidemiological study of tuberculosis (TB) has been ongoing for several decades, but the most effective control strategy is yet to be completely understood. The basic reproduction number, R₀, has been found to be ...