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.

The Work and Lives of Street Waste Pickers in Pretoria—A Case Study of Recycling in South Africa’s Urban Informal Economy

Abstract: High levels of unemployment are a permanent feature in the urban areas of many developing countries. South Africa is no exception in this regard. Poverty and hardship caused by unemployment force many participants in the labour market to venture into the urban informal economy in order to survive. The activities of the waste pickers fall within the urban informal economy. In spite of the fact that waste pickers are a common sight in the urban areas of Pretoria and other South African cities, remarkably little is known about them and scant attention is paid to them. The aim of the study was to establish a socio-economic profile of the street waste pickers in Pretoria and to describe the social interaction and relationship dynamics between the waste pickers and their families, each other, the community and buy-back centres. This was done by conducting the first ever empirical study of the street waste pickers in Pretoria. The results revealed that the role of street waste pickers in the broader waste management system is an important public issue that requires urgent attention and appropriate policy responses from policy makers.

Ultrafine Metal Phosphide Nanocrystals in Situ Decorated on Highly Porous Heteroatom-Doped Carbons for Active Electrocatalytic Hydrogen Evolution.

Abstract: In spite of being technologically feasible, electrochemical water reduction to facilitate hydrogen production is confronted with issues mainly due to the lack of affordable and efficient catalysts for the water reduction half reaction. Reported herein is the fabrication of metal phosphides nanocrystals uniformly loaded on highly porous heteroatom-modified carbons through one-step carbonization–phosphization methodology. Remarkably, the well-structured porosity and the increased electrochemically accessible active sites ensure the high catalytic efficiency for electrochemical hydrogen evolution in acidic medium in terms of small onset potentials (33 mV) and large cathodic current density (0.481 mA cm–2), even comparable to the state-of-the-art Pt/C benchmark. The easily prepared composite catalysts of structural and textural peculiarities may serve as promising non-noble metal catalysts for realistic hydrogen evolution.

Preparation and characterization of metals supported on nanostructured TiO2 hollow spheres for production of hydrogen via photocatalytic reforming of glycerol

Abstract: Nanostructured TiO2 hollow spheres (THS) were prepared via a simple hydrothermal method with titanium butoxide, ethanol, urea, and ammonium sulphate. The effects of Ti/ethanol, and reflux temperature on the morphological properties of the nanostructured THS were investigated. An impregnation method was subsequently employed to load metals such as Cu, Co, Cr, Ag, and Ni on the optimized THS, followed by calcination in H2/N2 at 450 °C for 4 h. The morphological properties of the prepared samples were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy (UV/vis). The SEM and TEM pictures showed that the Ti/ethanol ratio of 1:10 resulted in the formation of uniform hollow spheres. The XRD spectre revealed that phase transformation took place as the reflux temperature was increased, with pure anatase TiO2 hollow spheres being formed at 200 °C. The BET surface areas of the calcined photocatalysts were in the range of 80.6–116 m2/g−1. The UV/vis spectra of the photocatalysts showed that loading of transition metals reduced the band gap of the THS. The activities of the prepared catalysts were tested for hydrogen production via photocatalytic reforming of glycerol under solar irradiation. The improved hydrogen evolution from photocatalytic reforming of glycerol was attributed to: the high surface area which enhanced the adsorption of glycerol onto the surface of photocatalysts; high crystallinity and the reduced band gap which improved the solar light harvesting; the hollow chamber within the TiO2 spheres which produced multiple reflection of the light harvested, thus producing efficient electron/hole pair formation; and the detailed composition of the solids retarded the electron/hole recombination by trapping the electrons generated during the photo excitation of the photocatalysts, and thereby promoted their activity.

Gravitational wave extraction and outer boundary conditions by perturbative matching

Abstract: We present a method for extracting gravitational radiation from a three-dimensional numerical relativity simulation and, using the extracted data, to provide outer boundary conditions. The method treats dynamical gravitational variables as nonspherical perturbations of Schwarzschild geometry. We discuss a code which implements this method and present results of tests which have been performed with a three-dimensional numerical relativity code.

A cost-benefit analysis of document management strategies used at a financial institution in Zimbabwe: A case study

Abstract: Background: Choosing a cost-effective document management approach has become a priority to many organisations, especially in view of the rapidly changing technological environment in which information is being created and managed. A literature survey indicated that document management strategies have the potential to provide some substantial cost-saving benefits if they are used judiciously. Objectives: This study investigated a commercial bank’s document management approaches in a bid to ascertain the costs and benefits of each strategy and related issues. Method: A quantitative research approach was employed through a case study which was used to gather data from a sampled population in the bank. Results: The document management approaches used were not coordinated to improve operational efficiency. There were regulations governing documents management. The skills and competences of staff on both document management and cost analysis are limited. That is partly due to limited training opportunities availed to them. That means that economies are not achieved in the management of records. That has a negative impact on the overall efficiency, effectiveness and legal compliance of the banking institution. Conclusion: The financial institutions should create regulations enabling periodical cost-benefit analysis of document management regimes used by the bank at least at quarterly intervals as recommended by the National Archives of Australia. A hybrid approach in managing records is recommended for adoption by the financial institution. There should be on-the-job staff training complimented by attendance at relevant workshops and seminars to improve the staff’s understanding of both the cost-benefit analysis concept and document management.