University of South Africa

About: University of South Africa is a education organization based out in Pretoria, South Africa. It is known for research contribution in the topics: Context (language use) & Population. The organization has 8478 authors who have published 19960 publications receiving 237688 citations. The organization is also known as: Unisa.

Spin lattice relaxation of spin‐½ nuclei in solids containing diluted paramagnetic impurity centers. I. Zeeman polarization of nuclear spin system

Abstract: Spin-lattice relaxation mechanisms of nuclear spins in solids in the presence of low concentrations of paramagnetic centers are discussed. Apart from the electron spin-lattice relaxation mechanism, three-spin processes involving two electron spins and a nuclear spin may also play a role in the spin-lattice relaxation of the nuclear spins. Nuclear spins that are close to a paramagnetic impurity center experience large local fields and do not contribute to the NMR signal. Only a small percentage of nuclear spins surrounding an impurity center are polarized directly. The majority of the nuclear spins are polarized by spin diffusion, which is a slow process. A brief overview of a number of paramagnetic impurity centers, which are common in natural diamond, is given and experimental 13C spin-lattice relaxation times for a suite of natural diamonds are compared with calculated values. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson 19A: 20–35, 2003.

Tax compliance obstacles encountered by small and medium enterprises in South Africa

Abstract: It is internationally acknowledged that small and medium enterprises (SMEs) play a vital role in enhancing a country’s economic growth and in creating jobs. It is therefore in the public interest and in the interests of all governments to support SMEs. A study concentrating on the tax function in small and medium manufacturing concerns operating in the Gauteng Province in South Africa was recently undertaken. In this article, which is based on the study, the authors identify the main problem areas that manufacturing SMEs in the Gauteng Province have to cope with in administering government taxes. The article discusses the administration process only, and not the taxes themselves. The authors have identified tax compliance requirements in South Africa as a stumbling block for SMEs. They suggest that the government seriously consider reducing the number of taxes SMEs have to administer, reduce the compliance requirements and make additional tools available to SMEs to assist them in administering taxes.

Rapid microwave-assisted growth of silver nanoparticles on 3D graphene networks for supercapacitor application.

Abstract: Silver nanoparticles (AgNPs) grown on a three dimensional (3d) graphene networks (GNs) has been successfully prepared by an efficient and rapid microwave-assisted growth process to form GNs/AgNPs nanocomposite electrode materials for supercapacitor application. The 3d nature of the used GNs offers a unique architecture, which creates an efficient conduction networks and maximum utilization of space and interface, and acts as a conductive layer for the deposited AgNPs. The electrochemical performances of the fabricated electrode were evaluated by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) tests. Specifically, the optimal GNs/AgNPs nanocomposite exhibits remarkable performances with a high specific capacitance of 528 F g −1 at a current density of 1 A g −1 and excellent capacitance retention of ∼93% after 3000 cycles. Moreover, this microwave-assisted growth strategy of AgNPs is simple and effective, which could be extended to the construction of other three dimensional graphene based metallic composites for energy storage and conversion applications.

The dynamics of corporate governance in South Africa: broad based black economic empowerment and the enhancement of good corporate governance principles

Abstract: This paper illustrates the effect of BBBEE on good corporate governance. Corporate governance and specifically directors’ duties relating to stakeholder protection are focused on. Traditionally, directors are expected to manage a company in the best interests of the shareholders collectively. The question arises as to whether directors should also consider the interests of other stakeholders, inter alia employees, creditors, the environment and the community. The South African Broad Based Black Economic Empowerment Act 53 of 2003, not only aims at correcting racial imbalances, but also strives to promote social investment and the empowerment of communities. By adhering to this act, directors will by implication consider the interests of the community and give effect to the triple-bottom line approach when managing a company. This paper will illustrate the unique dynamics of corporate governance in South Africa.