3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item A life cycle analysis and assessment of chemical emulsions(2011-05-24) Ram Reddi, ManogaranThis study utilises the Life Cycle Environmental Management tool, Life cycle Assessment (LCA) to compare the overall environmental impact of the life cycles of three manufactured emulsions. The emulsions - Aquapel, Hi-phase/composite (liquid/solid rosin) - fulfil a specific function as a sizing agent in the cardboard box industry within the confines of South Africa. As the origins and use of these emulsions are different, the impact assessments of each were evaluated. Using the Simapro Impact 2002+ assessment method, the mid-point impact categories show the most significant impacts in descending order to be Toxicity Impacts on terrestrial ecosystems, Respiratory Inorganics, Climate Change and Non Renewable Energy resources. It would appear that toxicity impacts on terrestrial ecosystems, is the most significant impact. Emission of respiratory inorganics followed by effluent treatment, then electricity used in the emulsion process itself has the next highest contribution in all three processes. The higher contribution to respiratory inorganics by the process using liquid rosin is due to a relatively high contribution from the production of tall oil, a relatively energy intensive process. Climate change is the third most significant contribution. Non renewable energy resources for the Aquapel process shows the highest impact because of its raw material, wax. It is also based on a non-renewable energy resource, crude-oil, whilst the raw material for the Hi-phase/composite process, rosin, is bio-based. When comparing the three emulsion processes according to the Impact 2002+ damage or end point impact categories the relative contributions of the processes shows the relatively close performance of the three processes. The liquid rosin process shows slightly higher potential damages in three out of the four damage categories. The explanation for the differences between the systems follows from the explanations given for the mid-point impact categories. The sensitivity analysis for the Aquapel emulsion process shows negative impacts are produced in descending order for liquid effluent in the ecosystem and human health damage categories. For electricity and paraffin wax negative impacts in the human health and climate change damage categories. The best interventions to reduce life cycle damages is to reduce water and electricity consumption and if possible to find a substitute for paraffin wax. For the Hi-phase/composite liquid / solid rosin emulsion process shows negative impacts are produced in descending order for liquid effluent in the ecosystem and human health / climate change and resources damage categories respectively. The electricity and steam used in both the liquid / solid process produce negative impacts in the human health and climate change damage categories. The best interventions to reduce life cycle damages for the rosin emulsion process are to reduce water, electricity and steam consumption.Item The impact of the Gwembe Tonga Development Project on the Gwembe people(2009-06-12T11:41:23Z) Musonda, Brenda LuluABSTRACT The aim of the study is to investigate the impact of the Gwembe Tonga Development Project (GTDP) on the Gwembe Tonga (GT) people. The GT people were displaced in 1956 to pave way for the construction of the Kariba Dam that would increase the electricity supply to the mines in the Copperbelt and farmers. The number of people displaced was 57, 000 and they were not adequately resettled, rehabilitated and compensated. The GTDP was created in 1996 with the main objective to mitigate the negative impacts that the GT people have endured from the time they were displaced to date. A review of international literature on dams has indicated that dam constructions have led to displacement of the poor and marginalized people. Over 40 million people have been displaced worldwide. As shown in the literature review, are case studies that demonstrate the impacts of dams on people. In this study there six countries that have been listed namely India, China, Lesotho, Togo, Mozambique and Zambia. The people in these countries have experienced similar problems in terms of inadequate compensation, resettlement and rehabilitation. It is also noted that these dams leave a negative impact on the local community and environment. Development projects are equated with a general process of modernization where developed nations’ ways of conducting its affairs have been adopted by the developing countries to boost their economic development. This study has also looked at the developmental theories that the developing countries have adopted for economic transformation of both natural and built environments through construction of projects such as dams, roads, irrigation systems, pipelines, and energy resources, aimed eventually at generating and supporting both agricultural and industrial growth, and with them, increased national incomes. These large-scale development projects frequently make references to benefit the general population but experience has shown that the social costs of these projects are often borne by the indigent rural communities.Item The impact of HIV on clinical-microbiologic features and mortality among patients with invasive nontyphoidal Salmonella infection in South Africa(2009-05-18T13:05:35Z) Mtandu, RugolaIntroduction: Nontyphoidal Salmonella (NTS) has been associated with HIV from the outset of the HIV pandemic. The few NTS studies done in Africa and America have not documented the impact of HIV on clinical-microbiologic features and mortality in patients with NTS infection. This study determined the association between HIV serostatus and mortality proportion, clinical presentation, length of hospital stay, frequency of invasive NTS infection recurrence, NTS serotypes and estimated the population attributable fraction of mortality due to HIV among patients with invasive NTS infection in South Africa. Methods: Secondary data from enteric diseases national surveillance in South Africa from 2003 to 2006 were analysed as a cross sectional study. A total of 1 398 subjects with known HIV serostatus were obtained after data cleaning. Data analysis was done in Stata using chi squared test for categorical variables and Wilcoxon rank sum test / Kruskal- Wallis test for continuous variables. Logistic regression models were used to quantify the associations, and adjust for confounders and effect modification. Population attributable fraction was calculated to quantify the impact of HIV on mortality. Results: Majority (82.26%) of patients were HIV positive. The frequency pattern of HIV positive serostatus in different age groups coincided with that of invasive NTS. The overall mortality was 32.00%. HIV positive patients had a higher proportion (35.79 %) of mortality than HIV negative patients (15.55 %) (P<0.001). Fifty five percent of deaths in this study population were attributed to HIV infection. In multivariate models, HIV positive patients were more likely than HIV negative patients to die (OR = 2.50, 95% CI 1.69- 3.70), to develop lower respiratory tract infection (LRTI) (OR = 1.89, 95% CI,1.34- 2.65), to have recurrence of invasive NTS (OR = 3.90, 95% CI 1.41-10.77), to stay less than 16 days in hospitals (OR = 1.61, 95% CI, 1.08-2.40) and to be infected with Salmonella serotype Typhimurium infection (OR = 2.59, 95% CI 1.91-3.51). There were no significant differences in temperature, cardiac arrest, meningitis and site of specimen isolation (p>0.05). Discussion: The major limitation to this study was poor data quality of the surveillance system, including missing HIV serostatus hence the findings cannot be generalized to patients with unknown HIV status. Conclusion: HIV infection is common among patients with invasive NTS and is associated with excess mortality, LRTI, fewer than 16 days of hospital stay, recurrent invasive NTS infection and Salmonella Typhimurium. It is important for clinicians to rule out HIV infection in patients with invasive NTS especially those presenting with LRTI and Salmonella Typhimurium infection in addition to recurrent NTS infection, which is a wellknown feature associated with HIV. Recommendation: Since these patients received antimicrobials and had considerable mortality, the first line treatment of invasive NTS should be reviewed especially to HIV positive patients by investigating resistance patterns and conducting a clinical trial of newer and effective antimicrobials.Item The state of our children's homes: a descriptive study of conditions and resources within childrens homes in the greater Johannesburg area with special reference to the impact of the HIV/AIDS epidemic on these facilities and the training/expertise of caregivers working in these homes(2008-10-15T11:04:04Z) Meiring, Michelle AdrienneINTRODUCTION The HIV epidemic in South Africa has increased not only the number of ill children but also the number of orphans. Although the establishment of orphanages is not sustainable, the number of residential care facilities continues to increase. Many persons working in South African children s homes can testify to the impact HIV has had on this sector, but no studies have actually measured it. AIMS The primary aim of this research was to determine the impact of HIV on the Johannesburg children s homes. The secondary aims were to make recommendations informed by this research to assist children s homes to mitigate the impact and to inform the activities of the Children s Homes Outreach Medical Programme (CHOMP). METHODS A rapid appraisal of all children s homes in the greater Johannesburg was done by means of a telephonic survey. This was followed by an in depth analysis of 24 children s homes through the use of questionnaires, data collection forms, a pop quiz for residential child care workers and the inspection of facilities. RESULTS A total of 115 residential care facilities with a population (excluding the special needs homes) of 5 934 were identified. In a sample of 24 homes, 31,7% of the children were HIV affected and 20% HIV infected. The morbidity rate in the homes was 10%, and 99% of this morbidity was attributable to HIV/AIDS. Over a 6 month period 57 children died in the children s homes, 93% from HIV related conditions.Item Hydraulic and hydrological modelling of the Nyl River floodplain for environmental impact assessment(2006-03-13) Kleynhans, Martin ThomasThere have been various threats from upstream catchment developments to the water supply of the ecologically important Nylsvlei floodplain in South Africa. Hydrological modelling of the catchments and unsteady hydraulic modelling of the floodplain (including measured losses to evapotranspiration and infiltration) with biotic links to Oryza longistaminata revealed that existing developments within the catchments have decreased areas suitable for growth of this plant in the Nylsvley Reserve by 9% on average from 1973/74 to 2000/01 compared to the catchment in a virgin state. Construction of the proposed Olifantspruit Dam with environmental flow releases would have reduced these suitable areas by a further 9% on average. Catchment developments were found to have the greatest impact on floodplain inundation in average to dry years and would also reduce the frequency of occurrence of suitable conditions for growth of Oryza longistaminata.