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- This community is for all faculties and schools' theses and dissertations by masters and doctoral students.
Recent Submissions
Governing Children in Street Situations in Pretoria: Vulnerability and Social Protection in South Africa
(University of the Witwatersrand, Johannesburg, 2022) Matarise, Fungai
The vulnerability of children in post-Apartheid South Africa has been a major issue in social and development policy debates for decades now. Children are situated within the wider notion of “Vulnerable Groups” that is a central tenet in South African public and development policy discourse. This thesis examines the vulnerability of children in street situations as defined in the Children’s Act no. 38. of 2005. Children in street situations are a distinct category of vulnerable children that has experienced and continues to experience countless privations on the streets across South Africa. The issue of children in street situations raises fundamental questions about the political, economic and social aspects of inequality, marginality, and social exclusion in the post-Apartheid state. Hence, a central question in debates surrounding the interventions of state agencies on children in street situations is to consider how social and public policy articulate in concrete ways the country’s commitment to social inclusion, social justice and the fight against inequalities. Yet, with specific reference to children in street situations, little is known about the legal, material and practical governance of these category of children in South Africa. This study examines the governance of Children in Street Situations in Pretoria– the administrative capital of South Africa. The Department of Social Development (DSD) is the main provider for social interventions in the country, including in Pretoria. This is an exploratory study, based on my field research with informants at the Department of Social Development (DSD) and related organisations working on addressing the issue of Children in Street Situations. The study combines data from face to-face interviews with social workers at the DSD and telephone conversations with non governmental organisations (NGOs) personnel alongside textual analysis of official documents, policy reports and guidelines, legal provisions and media reports. Using discourse analysis and a post structural deconstructive approach, the thesis examines and unpacks the value and limits of vulnerability as a critical and core concept in understanding social protection in South Africa’s public and development policy. The thesis argues that a critical approach to the conceptualisation of vulnerability in South African public and development policy is important because it frames the legal and institutional responses to categories of people perceived to be in need of social protection, including children in street situations. The thesis develops this argument empirically by analyzing and discussing the representations of children in street situations in South Africa along mostly negative perceptions of these children and underlines how these representations are important to the framing and practice of social protection in aw, legislation and social policy. Furthermore, in discussing some of the social interventions for children in street situations and the challenges involved for DSD workers, this study also finds that the social problem of children in street situations is defined by ambiguity: among social workers at the DSD there are divergent views on whether these children exist and pose a policy challenge or not. Against a generic conceptualisation of children as similarly characterized by vulnerability, the thesis suggests that a further disaggregation of children in street situations as children in a specific social situation is necessary to appreciate their special vulnerabilities and needs. This fits a purposive response, more effective and targeted initiatives in care and protection that enhance their capabilities and well-being of children in street situations.
Man-The-Shaman is it the Whole Story? A Feminist Perspective on the San Rock Art of Southern Africa
(University of the Witwatersrand, Johannesburg, 1995-06) Stevenson, Judith S.
Ethnographic accounts show that both shamanic and gender rituals play a critical role in San culture. Although 30% of the women and 50% of the men become shamans, the literature investigating San rock art frequently defines 'Man-the-Shaman' and minimizes the feasibility of female depictions of this important social role. Prior rock art research has tended to separate shamanic and gender processes to the impoverishment of both. This dissertation investigates the symbolic connections between these two social spheres, and argues that they are inseparable. Through this examination of gender and shamanic roles in San society this dissertation argues that metaphors reflect these two social spheres. It also argues that metaphors are a way of life which are expressed both in reality and non-reality. With these points in mind, it investigates the role of men and women as related to San rock art through social roles.
The Quantitative Hydrogeological Mapping of Zebediela Estates, Central Transvaal
(University of the Witwatersrand, Johannesburg, 1970-05) Pretorius, Desmond Aubrey
The groundwater system on zebediela Estates, situated along the northern edge of the Springbok Flats in the Central Transvaal, has been studied by physiographic, geologic , geophysical, geochemical, and hydrologic methods . Emphasis has been placed on the subsurface mapping of the spatial distribution patterns of a nvn1ber of hydrogeologic parameters, and computer-based polynomial trend surface analysis has been employed to facilitate the interpretation of the maps. The computer has also been used to determine the general statistics of the frequency distributions of the various parameters and to platform sequential multiple linear regression analysis in an attempt to determine the relationships between the variables . Data arrays of observations, computations, and interpretations have been disp layed in 38 tables in the text and 21 appendices to the text . The distr ibution patterns , in one and two dimensions, have been portrayed in 8 text figures and 117 maps, separate from the t ext. The area studied covers approximate ly 23 square mil es, in which 556, 000 orange trees have been planted on 5800 acres . An average annual amount of 2400 million gallons of water is required to maintain t he operation, and 560 million gallons of this quantity are withdrawn, on the average, each year from boreholes tapping the groundwater resources of the Estates . Up to April, 1969, 315 holes had been drilled, and 151 had become producers at one time or another. In 19 years of exploitation between 1950 and 1968, 10, 600 million gallons of groundwater were withdrawn, at an average rate of 13 million gallons per year per production borehole. The study has shown that the groundwater system supplying this substantial quantity of water consists of two main elements - a piedmont alluvial slope, in which stream channels and paleochannels on coalescing alluvial fans are acting as conduits for the transmistion of water from the intake areas; and an underlying bedrock storage reservoir composed of aquifers of the Transvaal and Karroo sequences . The Malmani dolomite aquifers and the Stormberg basalt aquifers are superior to those of the Wolkberg quartzites, shales, and lavas, and the Stormberg Cave sandstones. It has been possible to distinguish two cycles of Karoo basalts, each of which shows differentiation . The upper cycle is far more important as an aquifer than the lower cycle. The piedmont slope is composed of portions of three alluvial fans , the spines of which have a general southeasterly trend towards the junction of the Nkumpi and Olifant rivers in the valley-flat environment well to the south of the Estates . The upland areas above the apices of the fans embrace the mountain ranges which form the northern rim of the Transvaal Basin, and these uplands have suffered right-lateral movements along extensive east-northeast-trending transcurrent faults which must have continued to be active into recent times in order to displace the stream course on the fans. The fan-head section and portion of the midfan section of the Nkumpi fan, in which the Gompies River is situated, occur over the east-central, eastern, and southeastern parts of the property, and, where underlain by the upper basalt aquifers, constitute the most important source of groundwater on Zebediela Estates. The whole of the fan-head and mid-fan sections of the Mamukebe fan are located in the riorthern, west-central, western, and southwestern localities of the area studied. The fan is much smaller than either of the others, and is underlain by Wolkberg rocks, Cave sandstones, and lower basalts. Its overall groundwater potential is consequently lower than that of either of the other two components of the piedmont slope. Only a very restricted portion of the fan-head section of the Mogoto fan occurs in the extreme northwestern corner of the Estates, where it is underlain by the dolomite aquifer, Its groundwater parameters are consequently very favourable, but the true potential of this fan lies beyond the western boundary of the property. The average yield of boreholes in the upper basalt is 3600 gallons per hour; in the lower basalt, 2000 g.p.h.; in the sandstone, 1500 g.p.h.; in the dolomite, 11,200 g.p.h.; and in the quartzites, 1500 g.p.h. The average yield for all boreholes on the Estates is 4100 gallons per hour. All of these figures are appreciably higher than those for equivalent formations elsewhere in South Africa, testifying to the impoi,tance of the piedmont alluvial slope environment in the overall groundwater system at Zebediela. The average annual recharge of the groundwater reservoirs from all sources has been estimated at 700 million gallons. With the average annual withdrawal being of the order of 560 million gallons, the possibility exists that production from the aquifers can be increased by 25 per cent, without fear of serious, permanent deterioration in the performance of the groundwater system. However, excessive exploitation in times of low recharge might lead to the development of quality h.azards with respect to sodiuum, ehloride, and bicarbonate over the upperbasalts. This possibility does not exist for the remaining aquifers, particularly those in the dolomite, from which relatively pure water is drawn. An added problem in the recharge of the upper basalt aquifer is the contamination of t he groundwater in storage by lithium, brought into the Zebediela groundwater- system by the Nkumpi River, which transmits the element from the granite terrain to the north of the mountainous rim of the Springbok Flats. A new model of groundwater exploration has been devised, based on optimum drilling sites being located where coincidence takes place of piedmont stream channel conduits, dolomite or upper basalt aquifers, and transcurrent fault aquicludes, Results obtained from the employment of this model during two years of drilling subsequent to its development in a preliminary form produced an increase of 14 per cent in the average yield of all boreholes drilled.
Trimetallic nanoparticles immobilised on polymeric membranes for the degradation of organic pollutants in water
(2021) Kgatle, Masako; Moloto, Nosipho; Sikhwivhilu, Keneiloe; Ndlovu, Gebhu
Water is one of the most essential resources in the world, but its scarcity has become an issue of global concern. The scarcity of water is largely the result of climate change, water pollution and increasing population growth which limits the availability of water resources. Moreover, South Africa has been making headlines since 20 IO due to water shortages experienced. It is, therefore crucial to find cost-effective ways to expand the water supply and address the issue of water pollution. This study seeks to tackle the problem of water pollution emanating from textile industries. Over the last few years, nanotechnology and membrane technology have appeared as some of the most widely used methods for the mitigation of water pollution problems. Particularly, nanoscale zerovalent iron (nZVI) has emerged as one of the most broadly used nanoparticles in wastewater treatment and remediation owing to its low-cost and high effectiveness. However, because of its ease of aggregation and consequent loss of reactivity, nZVI is coupled with one or more transition metals to produce multimetallic systems. Nanoparticles alone quickly agglomerate and form large micro-scale particles owing to the magnetic forces thus losing their mobility and chemical reactivity. To avoid these issues, the nanoparticles are stabilized on polymeric membranes. In this study, two trimetallic nanoparticle systems were synthesized, characterized and tested for catalytic activity. The polyvinylpyrrolidone (PVP)-stabilized Fe/Cu/Ag nanoparticles were synthesized by the sodium borohydride chemical reduction method. These nanoparticles were characterized using XRD, XPS, EDX and TEM. The XRD, EDX and XPS techniques showed the presence of all three metals, including iron oxides due to the oxidation of iron in air. The obtained TEM images showed the characteristic core-shell morphology of the nZVI-based nanoparticles. The evaluation of the catalytic activity of the nanoparticles was conducted using methyl orange (MO) dye as the model pollutant and this showed a remarkable degradation efficiency within few minutes. The effect of parameters such as MO solution pH, initial MO dye concentration and nanoparticle dosage in MO degradation was investigated. The nanoparticles were found to have performed better at lower pH, lower initial MO dye concentration and higher nanoparticle dosage. The degradation of MO dye was monitored using UV-Vis analysis and occurred within 1 min. The degradation was found to follow a pseudo first-order kinetic model and was vastly influenced by the studied parameters. The analysis of by-products and reaction pathway were done using LC-MS and this further confirmed that the degradation of MO was indeed rapid. The Fe/Cu/Ag trimetallic nanoparticles were demonstrated as suitable and effectual alternative for the remediation of textile dye wastewater. For the second trimetallic system, three different trimetallic nanoparticles (Fe/(Zn/Ag), Fe/Zn/Ag and Fe/ Ag/Zn) with different metal addition sequences were synthesized. The prepared nanoparticles were characterized using XRD, EDX and TEM analyses. The techniques proved successful synthesis of the nanoparticles and XRD and EDX showed the presence of the three metals together with the oxides. The evaluation of the catalytic reactivity of the nanoparticles was conducted in a series of batch experiments using MO dye as the model pollutant. About 100% of the MO dye was degraded by Fe/ Ag/Zn trimetallic nanoparticles within 1 min and the second-order rate constant obtained was 0.0744 ppm- 1min-\ the rate of reaction was higher than that of the other trimetallic systems. Using Fe/ Ag/Zn trimetallic nanoparticles, parametric tests were conducted at different MO solution pH, initial MO concentration and nanoparticle dosage. The results showed that the reactivity of the Fe/Ag/Zn trimetallic nanoparticles was highly dependent on the aforementioned parameters. Like the Fe/Cu/Ag system, the Fe/Ag/Zn performed better at lower pH, lower initial MO dye concentration and higher nanoparticle dosage. The overall kinetic study showed the removal of MO using Fe/Ag/Zn system to follow a second-order kinetic model. The elucidation of the degradation pathway and MO by-products identification were done using LC-MS and the mechanism of degradation displayed the degradation of methyl orange to proceed via azo-bond cleavage. Moreover, the Fe/ Ag/Zn nanoparticles proved to be effective at degrading methyl orange dye and can be used to treat azo-dye wastewater from textile industries. The Fe/Cu/ Ag trimetallic nanoparticle system was immobilized on a polymethacrylic acid grafted polyethersulfone (PMAA-g-PES) membrane to minimize the issue of recoverability and nanoparticle agglomeration. The nanocomposite membranes were prepared by loading different quantities of Fe/Cu/Ag trimetallic nanoparticles onto the PMAA-g-PES membrane for optimization purposes. Characterization was performed using FTIR, NMR, XPS, SEM/EDS and AFM analyses. The PMAA g-PES and nanocomposite membranes were found to have a porous top layer and a rough surface. Moreover, the addition of nanoparticles did not cause any significant changes in the membrane structure, however, further addition of nano particles led to the blockage of pores. The performance of the synthesized membranes was tested using pure water flux and MO (anionic dye) and methylene blue (MB) (cationic dye) dye removal capacity. The negatively charged membranes were found to have more affinity for MB dye than the MO dye and this was ascribed to the charge interaction between the membrane surface and the dyes. The nanocomposite with 5% Fe/Cu/Ag trimetallic nanoparticle loading on PMAA-g-PES membrane (M4-5% membrane) was found to have the best adsorption capacity with about 60% MB dye removal efficiency. Furthermore, the effect of process parameters such as pH, temperature and H2O2 concentration on the removal of MB was studied. The removal efficiency was found to be higher at higher pH and lower temperature. About 100% removal efficiency was obtained when the process was performed at pH 9 in the presence of H2O2 via adsorption and Fenton degradation. This showed that a hybrid of processes was convenient for the removal of MB dye by adsorption (primarily) and degradation using the nanocomposite membrane. Adsorption equilibrium data were assessed using the Langmuir, Freundlich and Temkin models; the Temkin model was the most convenient to explain the adsorption of MB onto M4-5% membrane. Moreover, lcinetic studies were performed on four kinetic models: pseudo first-order, pseudo second order, intraparticle diffusion and elovich models. The pseudo second-order was found to be the best suitable to explain the adsorption of MB onto M4-5% membrane. Thus, the adsorption of MB onto the nanocomposite membrane is an exothermic chemical process that occurs on a heterogeneous surface. Therefore, the nanocomposite membrane has the prospective to be applied in the removal of cationic textile dyes in the presence of an oxidiser.
Balancing the roles of Employee Aad Primary Child Caregiver: Experiences of Single Mothers formally Employed in Otjiwarongo, Namibia
(University of the Witwatersrand, Johannesburg, 2020) Markus, Julia Ndeyapewa
The number of single mothers entering the workforce is an ever-increasing trend throughout the world, including countries in sub-Saharan Africa, such as Namibia. Usually, single mothers face many challenges fulfilling the roles of employee and primary caregiver simultaneously. Although the challenges experienced by employed, single mothers have been well researched in developed Western and European countries, there is a gap of knowledge regarding how formally employed, single mothers in sub-Saharan Africa, including Namibia, experience trying to balance the responsibilities of employee and primary caregiver of their children. Occupational social workers can play a meaningful role in supporting employees in the workplace, including employed, single mothers who are facing caregiving challenges that are negatively impacting on their work responsibilities. The main aim of this research was thus to explore how employed single mothers in Namibia experience trying to balance the roles of primary caregiver and employee, so that key role players within the workplace, especially occupational social workers, can gain more insight into how these challenges can best be addressed. To realise this aim, a qualitative research approach was adopted using the phenomenological research design. Fifteen employed mothers in Otjiwarongo, a small town of about 28 000 inhabitants in the Otjozondjupa region, were purposively selected as the research sample. Data were gathered by conducting individual interviews with the participants. The research tool was pre-tested with an employed single mother who met the sample selection criteria. Thematic analysis was employed to analyse data. The main findings based on data analysis were that fulfilling the role of mother is difficult when facing work pressure and working long hours. Stress experienced in the work environment is often carried over to the home environment, and vice versa. Focus on work activities can also be undermined when experiencing concerns about the well-being of their children, especially if they are young. Women try to balance their simultaneous roles by employing reliable caregivers to take on the responsibility of caregiving when they are at work. Based on research findings, it is recommended that occupational social workers work towards implementing policy and practice within the work environment that facilitates personal contact between mother and child.