Walter Sisulu University
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Synthesis and characterization of high energy milled silicon nanoparticles for electronic applications
Get PDFThis study demonstrates that high energy milling using a planetary disc mill offers a new simple route to the production of polycrystalline silicon nanoparticles which are suitable for electronic applications. By manipulating process variables such as milling duration and mass of the feedstock load, the microstructure of the nanoparticles can be tuned to meet requirements. The internal structure of the nanoparticles prepared by high energy milling was found to predominantly consist of nanocrystalline silicon and their surfaces are characterised by a disordered layer of silicon sub-oxides and an insignificant proportion of fully oxidized silicon. X-ray diffraction (XRD) patterns and Raman spectra were used to calculate the average crystallite size and correlating it to the milling process variables. The surface chemistry of the nanoparticles was elucidated using X-ray photo spectroscopy (XPS) and was also related to the milling parameters. The internal structure, agglomeration and aggregation of the particles were tested using high resolution transmission microscopy (HRTEM) and complemented by scanning electron microscopy (SEM). Conductivity tests were done on the particles to ascertain their suitability for electronic applications. It is demonstrated that the longer the milling time, the smaller the sizes of particles and crystals. The sizes also depended on the mass of feedstock load. 30 g feedstock loads resulted in average nanoparticle size which were 30 - 40 % larger than for 10 g loads. The average size of nanoparticles produced were in the range 50 – 80 nm as measured by SEM. The distribution of the size of particles became less polydisperse with increase in milling time and a reduction in feedstock load. The particles were devoid of significant SiO2 layer and hence were confirmed by conductivity tests to be electrically active. Data from XPS indicate that the silicon nanoparticles have a unique surface chemistry which is consistent with the silicon surfaces being dominantly oxygen terminated.Thesis (Masters) -- Faculty of Commerce and Administration, 202
Attitudes and barriers towards HIV testing services among males aged between 15-49 years at Mzamomhle Township: Buffalo City Metropolitan Municipality
Get PDFThis study delves into the attitudes and obstacles surrounding HIV Testing Services (HTS) among males aged 15 to 49 in Mzamomhle Township, Buffalo City Metropolitan Municipality, South Africa. HIV/AIDS prevalence remains a significant concern, especially in sub-Saharan Africa. Employing a mixed-methods approach with questionnaires and interviews, data was gathered from 106 participants. The findings highlight a range of challenges that impede the accessibility of HTS. These challenges include stigma, concerns about privacy, fears related to testing, limited knowledge, and negative attitudes of staff towards HTS. Despite these challenges, the study reveals that participants generally hold positive attitudes towards HTS. However, there are doubts regarding the efficacy of testing in preventing the transmission of HIV. Privacy concerns emerge prominently, with participants fearing that their status might be disclosed. Stigma also acts as a barrier, as individuals fear potential embarrassment if their status becomes known. To address these issues, several recommendations are proposed. These include the establishment of robust support systems, educational campaigns to empower individuals with knowledge about HTS benefits, and community initiatives to combat negative attitudes towards testing. Furthermore, enhancing healthcare worker training and raising political awareness can contribute to creating a more favourable environment for HTS utilisation. By implementing these recommendations, South Africa can work towards dismantling the barriers that hinder HIV testing and promoting a proactive culture of health-seeking behaviour among men. This effort is essential for reducing HIV transmission rates and achieving global health targets.Thesis (Masters) -- Faculty of Medicine and Health Sciences, 202
Paradoxes of cultural interventions in the fight against HIV/AIDS and other social ills in South Africa
Get PDFRemoval of reactive blue 19 from simulated wastewater using Solanum melongena stalk/MWCNTs: thermodynamics, kinetic, equilibrium and regeneration potentials
No full textIn the present study, a nanocomposite was prepared for the removal of dye from the aqueous phase. In this regard, multiwalled carbon nanotubes (MWCNTs) were anchored on the stalk of Solanum melongena (SMB) to obtain a robust adsorbent with the capacity to eliminate reactive blue 19 (RB19) using the batch adsorptive processes. Solanum melongena stalk decorated with MWCNTs (SMC) and SMB were characterized using Thermogravimetric analysis (TGA), Brunauer–Emmett– Teller (BET), Field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR) analysis. With the exception of solution pH, an increase in contact time, adsorbent dose, initial RB19 concentration, and solution temperature were noticed to elevate the uptake potential of SMB and SMC. Kinetic experimental data for SMB and SMC were consistent with the pseudo-second-order and Elovich model, respectively. The experimental isotherm data obtained for SMB and SMC were best expressed by Freundlich and Langmuir models, respectively. After the fifth adsorption–desorption cycle, SMC exhibited 52% of adsorption efficiency. Hence, SMC can be an auspicious candidate for the efficient adsorption of RB19
Nexus Between Pension Funds and Stock Market Sustainability Development in Nigeria
Get PDFIn the literature, pension funds have been recognized to play a contributory role in the development of capital markets. The importance of institutional investors and pension funds is heightened in the context of developing financial markets in a market-based economy, with studies showing a country’s ability to make large gains from Miami. Nexus Between Pension Funds and Stock Market Sustainability Development in Nigeria pension funds is dependent on financial market structure. However, some notable authors in this field of study have expressed optimism that the pension scheme has the potentialsof mobilizing savings for economic growth. The pension scheme is expected to mobilize savings for capital market development and economic growth. Surprisingly, the various reforms and flexibilities resulted in an 8% rise of annual rate in the pension industry in Africa in which Nigeria in particular, have witnessed a 20% increase in the previous year’s funds (PwC (PricewaterhouseCoopers, 2015). In 2017, approximately USD 41.355 trillion of assets were managed by pension funds (Amadou, 2017; Aminu, 2022; Alehile et al., 2022). As more workers contribute to pensions, assets grow and funds may be invested in areas that facilitate development and enable contributors to earn their benefits. According to the OECD (2021) Global Pension Study, the assets held by pension funds exceeded USD 56 trillion globally, an increase of 11% from the 2019 statistics of which Africa holds about $700 billion. Once more, it was observed that assets from the defined contribution and personal plans grew faster than thos
Natural Resource Rents, Institutional Quality, and Environmental Degradation in Resource-Rich Sub-Saharan African Countries
Get PDFEnvironmental degradation concerns are increasing worldwide. Moreover, in sub-SaharanAfrican countries, these concerns are dominant because of an abundance of natural resources andexhaustion of these natural resources that tend to cause carbon emissions. This has created a hugeinterest among academics in investigating the relationship between natural resources, institutionalquality, and environmental degradation. Since the sub-Saharan countries are resource-rich, the currentstudy investigates how the natural resource rents and institutional quality impacted environmentaldegradation in selected sub-Saharan African countries from 1994 to 2020. Through employing theGMM estimation technique, the findings show that natural rents are positively linked with environ-mental degradation. This is closely related to the Environmental Kuznets Curve (EKC) hypothesis,which stipulates that environmental degradation worsens at the initial stage of the economic develop-ment of developing countries. The study has also found that rules and regulations set by governmentshave not been implemented in a manner that reduces environmental degradation in the region. Worthnoting is that the region should collaborate and design its environmental policies in line with theSustainable Developmental Goals. This is the first step towards environmental sustainability
Trade Openness and Unemployment in Selected Southern African Development Community (SADC) Countries
Get PDFThe relationship between trade openness and unemployment in Southern African Development Community (SADC) countries remains an area of significant interest and concern. While trade openness is often advocated for fostering economic growth and development, its potential effects on employment outcomes are complex and multifaceted. Understanding the nature and nuances of this relationship within the SADC region is crucial for policymakers and stakeholders seeking to design effective strategies that balance the benefits of trade openness with the goals of reducing unemployment and promoting inclusive growth. This study evaluates the effect of trade openness on unemployment in SADC from 1980 to 2019 using panel ARDL (pooled mean group—PMG) estimation techniques. The findings of the study show that trade openness and exports negatively impact unemployment, whereas imports positively affect unemployment in the long run. This suggests that while boosting exports and real trade, openness decreases unemployment, and imports increase job losses in the long run in the SADC region. This calls for more caution on trade openness regarding what to export and import when addressing regional unemployment reduction policies
The Impact of COVID-19 Pandemic in South African Correctional Centres: Challenges and Solutions
Get PDFThe outbreak of COVID-19 was declared a public health emergency of international concern by the World Health Organization (WHO) on 30 January 2020. Many nations, including South Africa, have seen an increase in COVID-19 outbreaks in their population, including those working in and incarcerated in correctional centres. Responding to COVID-19 in correctional centres is a major challenge, particularly due to overcrowding and limited medical resources. This paper uses secondary data to investigate the spread of COVID-19 in South African correctional centres. It focuses on the problems faced by the South African Department of Correctional Services in preventing the spread of COVID-19 in its correctional facilities. The author proposes measures to be followed to prevent the spread of COVID-19 in such facilities. The findings reveal that despite efforts to prevent the spread of COVID-19 in South African correctional centres, the virus spread rapidly among inmates and prison workers
A General Picard-Mann Iterative Method for Approximating Fixed Points of Nonexpansive Mappings with Applications
Get PDFFixed point theory provides an important structure for the study of symmetry in mathe-matics. In this article, a new iterative method (general Picard–Mann) to approximate fixed points of nonexpansive mappings is introduced and studied. We study the stability of this newly established method which we find to be summably almost stable for contractive mappings. A number of weak and strong convergence theorems of such iterative methods are established in the setting of Banach spaces under certain geometrical assumptions. Finally, we present a number of applications to address various important problems (zero of an accretive operator, mixed equilibrium problem, convex optimisation problem, split feasibility problem, periodic solution of a nonlinear evolution equation) appearing in the field of nonlinear analysis
Prevelance of Hepatitis-B Virus Co-Infection Among People Living with HIV in Mthatha Region of South Africa
No full textHepatitis-B virus (HBV) co-infection among people living with HIV (PLWH) is highly endemic in South Africa. Despite the availability of an effective vaccine for the last four decades, chronic HBV infection is a major cause of morbidity and mortality among PLWH. Although the incidence of most opportunistic infections has been reduced in individuals with HIV since the implementation of the universal test and treat program in South Africa, HBV co-infection among PLWH is still accounting for high morbidity and mortality..