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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
291

Short-term treatment outcomes of children starting ART in the ICU, general medical wards and outpatient HIV clinics at Red Cross War Memorial Children’s Hospital (RCWMCH): a retrospective cohort study

Pillay, Vashini January 2014 (has links)
Includes bibliographical references. / Short-term treatment outcomes of children starting ART in the ICU, general medical wards and outpatient HIV clinics at Red Cross War Memorial Children’s Hospital (RCWMCH): A Retrospective Cohort Study. Background: Antiretroviral therapy (ART) has proven to decrease morbidity and mortality in HIV-infected children and improve immunologic, virologic and clinical outcomes. As clinical management policies evolved, an emphasis on early infant testing was adopted resulting in an increasing number of children being diagnosed and commenced on therapy before the onset of severe disease progression. However, a fair proportion still remain untested and subsequently present to hospital with advanced immunosuppression and severe disease. Since the advent of the 2013 national Standard Treatment Guidelines which encourage expedited initiation of ART within 7 days of HIV diagnosis in all children under the age of 12 months and in those with advanced immunosuppression, it is likely that many HIV-infected children are being initiated on ART during hospitalisation in South Africa. No local published data on these outcomes exist. We assessed the short-term outcomes of children initiated on ART in the intensive care unit (ICU), general medical wards (GMWs) and outpatient HIV clinics (OHCs) at RCWMCH. Methods: Structured Literature Review A Pubmed search looking at outcomes of treatment naïve HIV-infected children and adolescents up to 19 years of age living in South Africa commenced on 1st line ART regimens in accordance to the national guidelines presiding at the time, over a 10 year period was performed. This served to identify gaps in knowledge around paediatric ART in a South African context warranting further research. Retrospective Cohort Study We conducted a retrospective cohort study of HIV-infected children <13 years of age, commenced on first line ART between January 2008 and December 2011 at RCWMCH. Outcome measures included death, virologic suppression and changes in CD4 count and percentage. Kaplan-Meier estimates, multivariate Cox proportional hazard ratios and logistic regression were used to estimate outcomes 6 months after ART initiation. Results: Structured Literature Review This review identified several knowledge gaps. One of these gaps, the treatment outcomes of children started on ART at different service levels within tertiary health care settings was addressed in our retrospective cohort study and described in section C of this dissertation Retrospective Cohort Study Seven hundred and forty-nine children were included: 106 were commenced on ART in the ICU, 509 in the GMWs and 127 in the OHCs. Four hundred and ninety-two (65.7%) children were <12 months old. Children in the ICU and GMW cohorts were significantly younger than the OHC cohort (median ages: 3 and 5 months respectively vs. 22 months) and had lower WAZ scores (-2.48 and -2.33 respectively vs -1.14). Three hundred and eighty-five (51.4%) children qualified for rapid ART initiation within 7 days of HIV diagnosis or hospitalisation, based on CD4 criteria in the 2013 national Standard Treatment Guidelines. Overall mortality was 6.4% (CI: 4.9 - 8.4). Mortality was significantly higher in the ICU cohort i.e. 14 (13.2%) deaths compared to 28 (5.5%) and 5 (3.9%) deaths in the GMWs and OHCs cohorts, logrank p=0.004. Predictors of mortality included being moderately underweight HR 2.4 (CI: 1.1 – 5.2; p=0.02), severely underweight HR 3.2 (CI: 1.6 – 6.5; p=0.001), absence of caregiver counselling sessions HR 2.9 (CI: 1.4 – 6.0; p=0.005) and ART initiation in ICU HR 2.6 (CI: 1.4 – 4.9; p=0.003). Conclusion: The findings of our retrospective cohort study serve as a basis for understanding the implications of ART initiation in children during hospitalisation.
292

Residence students' perceptions of institutional support for interracial contact at the University of Cape Town

Govender, Advaita January 2008 (has links)
Includes bibliographical references (leaves 93-97). / While inter-racial contact in university settings has been researched previously, the important concept of institutional support has not. This construct was listed by Allport as a necessary condition under which contact will yield positive results i.e. reduced prejudice towards outgroup members. This study investigated University of Cape Town residence students' perceptions of institutional support for inter-racial contact to assess whether such perceived support had a noticeable impact on prejudice measures between students.
293

Aggressive behavior in adolescents with fetal alcohol spectrum disorders

Smith, Keelie January 2013 (has links)
Includes bibliographical references. / Behavioral studies of fetal alcohol spectrum disorders (FASD) have indicated that aggression is common amongst alcohol-exposed adolescents, and that it appears to become more prevalent with age in that population. Such studies have documented the presence of aggression as a behavioral outcome, but have not provided detailed information regarding its presentation, including whether it is proactive or reactive in nature and under which circumstances it arises. Consequently, there is a lack of a theoretical framework within which to understand aggression in FASD. The current research comprised two studies. In Study 1, comorbid developmental disorders that are typically associated with aggression were examined in alcohol-exposed and non-exposed boys and girls. The results indicated a higher prevalence of disruptive behavior disorders, and conduct disorder in particular, amongst the alcohol-exposed boys, and highlighted a significant association between prenatal alcohol exposure and an aggressive subtype of conduct disorder. Based on these findings, Study 2, a multiple-case study, examined the aggressive behaviors of 6 alcohol-exposed and nonexposed adolescents and their classmates.
294

Evaluation of a school-based intervention programme for South African children of divorce

Botha, Cornelius J January 2009 (has links)
Includes bibliographical references (leaves 78-88). / Currently, parental separation in South Africa affects an estimated 30 000 children under the age of 18 annually. These children spend a great part of their day at school where they have to interact with peers and teachers and are expected to perform academically, but parental separation could have a significant impact on their ability to do so. Although research has found that children can be adversely affected by parental divorce, schools in South Africa do not offer any group interventions in an attempt to assist and guide children through what could be an ordeal for them. This study aimed to evaluate the effectiveness of the school-based Children of Divorce Intervention Programme (CODIP) at two South African schools. CODIP is a preventively oriented 12-week group programme for nine to twelve year old children. The aims of the programme are to create a supportive group atmosphere in which children can share divorce-related feelings and clarify misconceptions about divorce. Participants are also taught problem-solving, communication and anger management skills. Twenty-five boys of divorce from two schools (ages 10 to 13 years) were randomly assigned to two experimental groups and one delayed intervention control group. The boys' understanding of divorce was assessed through the completion of the Children's Belief about Parental Separation (CBAPS) scale. The Self Perception Profile for Children (SPPC) was used to assess children's perceptions of themselves, while the Parent-Child Interaction Questionnaire for Children (PACHIQ-R-CH) was employed to determine the boys' perceptions of their families. Questionnaires to determine the boys' general adjustment were completed by the boys, teachers and parents. Boys completed the Strengths and Difficulties Questionnaire (SDQ), teachers the Teacher-Child Rating Scale (T-CRS), the AML-R Behaviour Rating Scale and the SDQ, and parents completed the Parent-Child Rating Scale (P-CRS) and the SDQ.
295

Towards reliable correlation of microporous layer physical characteristics and PEMFC electrochemical performance

Crymble, Gregory A January 2014 (has links)
Includes bibliographical references. / Polymer electrolyte membrane (PEM) fuel cells are promising clean energy alternatives to non - sustainable fossil fuels. During fuel cell operation, external humidification of reactant gases is typically required in order to increase PEM conductivity for improved performance. However, the use of external humidification is costly and increases system complexity. Recently it has been found that by including a cathode microporous layer (MPL) in the membrane electrode assembly (MEA) , performance under dry conditions (no external humidification) can be significantly improved . However, the precise function of the MPL is not well understood and therefore there is little theoretical basis to optimisation of physical properties. One possible reason for this lack of understanding is the absence of a well-established fabrication, characterization and electrochemical testing methodology for MPL research. In particular, current research places little emphasis on the effect of MEA variance on the uncertainty in MPL electrochemical performance results. In this study a methodology is developed for fabricating, characterizing and testing MPLs to accurately correlate physical properties with in-situ electrochemical performance. MPLs of two significantly different thicknesses (approximately 20 and 50 &#956;m in the thickest regions) were fabricated in - house using a doctor blade method and varying the ink composition. The pore structure and thickness of MPLs were characterized by mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM) and X-ray micro computed tomography (&#956;CT).
296

The effect of sludge age and aerobic sludge mass fraction on low F/M filament bulking in intermittent aeration nitrogen removal systems

Warburton, Charles Arthur January 1991 (has links)
Since 1989 a wide ranging program of research has been under way to identify the factors that effect low F/M filament proliferation. Completed work has established an important factor conducive to low F /M filament proliferation - the presence of anoxic and aerobic zones, or, alternating anoxic-aerobic conditions in a system. It was also established that the presence or absence of readily biodegradable COD (RBCOD) or slowly biodegradable COD (SBCOD) were not deciding factors in their proliferation. The research presented in this thesis focuses on the effects of; • sludge age, • magnitude of the aerobic mass fraction, • magnitude of the nitrate concentration during the anoxic period, on the low F /M filaments. The experimental set-up consisted of two intermittently. aerated anoxic-aerobic (20 minute cycles, peak DO 2 to 2,5 mgO/l), single reactor completely mixed continuously fed systems. The experimental investigation was chronologically divided into 3 phases and examined the effect of the following conditions on the low F/M filaments.
297

Advanced water metering and its application in low income communities

Malunga, Masoabi January 2017 (has links)
In South Africa, it is a legislative requirement that all water supply points be metered (van Zyl, 2011). Conventional meters are mostly used as the main means of monitoring water consumption by South African municipalities. In the last two decades, the water metering industry has seen substantial developments with new capabilities added to the conventional water meter, known as advanced meters. These advanced water meters have capability of processing, storing and communicating data without the need of human intervention. As such they come with desirable capabilities for both consumers and municipalities. These include prepaid meters which are special type of advanced water metering technology that is mostly applicable in the low income areas of South Africa. However, advanced water meters have significant drawbacks, such as higher failure rates (due to electronics, batteries and more components), higher purchase and maintenance costs and susceptibility to tampering. It is therefore necessary to make a conscious and informed consideration when deciding on which metering technology to implement for different users. This could be achieved through having a technology evaluation framework. The goal of this research was to develop an evaluation framework to help municipalities in the selection of appropriate advanced water metering technologies for application in low income communities. This goal was achieved through: determining the range of functionality of technologies both available and under development for advanced water metering; documenting case studies of both successful and failed implementation of advanced water meters, including social perception and impacts; developing an evaluation framework that can evaluate advanced water metering; and evaluating on technical, social, economic and environmental grounds. The results from literature and case studies indicate that in low income communities, advanced water metering is mainly implemented for cost recovery purposes. However, some municipalities implement advanced metering schemes for water management and debt recovery. The most advanced water metering technology being installed in low income communities is prepaid meters. Prepaid meters have a potential to fulfill all the range of objectives that municipalities install advanced metering technology for. This technology is found to have high maintenance requirements due to high failure rate. For successful implementation, it is important that municipalities have adequate budget for repairs and maintenance or seek technical support from manufacturers.
298

Performance of gold catalysts for low temperature water gas shift

Roberts, Stephen January 2001 (has links)
Bibliography: leaves 77-81. / The ultimate objective of the study was to investigate the performance of suitably prepared gold catalysts for low temperature water gas shift (LTS) - and more specifically to investigate the performance of these catalysts at temperatures below those traditionally utilised. As opposed to the research undertaken to-date on gold catalysed water gas shift, the reaction was performed, as far as possible, under conditions resembling those found industrially, viz. conditions of temperature, pressure, WHSV and dry feed gas composition typical of those applicable to industrial LTS units. Important to this study was therefore the generation of a comprehensive performance benchmark for the commercially available LTS catalyst, a copper-based material, against which to compare the performance of the gold deposited catalysts. The gold catalysts were prepared by deposition-precipitation, a preparation procedure found to yield nano-sized gold particles, suggested in literature as being crucial for activity, on the metal oxide support. Using this procedure, gold promoted low (copper) and high (iron oxide) temperature shift catalysts and commercial zinc oxide supports were prepared and tested. A wide spectrum of Au particle sizes were prepared on the supports, ranging from approximately 3-500 nm. The gold promoted LTS catalyst was found to exhibit slightly higher activity than the commercially available catalyst at temperatures below the conventional LTS range. It would appear as if gold promotion is advantageous to the industrial catalyst and could impact greatly on LTS catalyst life. Even though substantially less active than the commercial copper catalyst was found, the gold promoted commercial zinc oxide catalyst exhibited significantly higher activity than that previously quoted in literature and better performance than the iron oxide supported catalysts of this study. Consequently, the Au/ZnO system exhibits good potential for further developments in terms of water gas shift conversion.
299

An electrochemical investigation of platinum group minerals

Tadie, Margreth January 2015 (has links)
The Bushveld complex is the largest ore body in the world hosting platinum group elements (PGEs). It is a stratified orebody with three major reefs namely, the Merensky reef, UG2 reef and the Platreef. Platinum and palladium are the most abundant PGEs found in the Bushveld complex. They occur in the form of minerals/mineral phases with elements such as sulphur, tellurium, arsenic and iron. These minerals/mineral phases are associated with base metal sulphides occuring along grain boundaries. Unlike the Merensky and UG2 reef, the Platreef is almost barren of PGE sulphides and the distribution of base metals sulphides and their association with PGMs is erratic. Froth flotation targeted at the recovery of base metal sulphides is implemented in PGM concentrators to concentrate PGMs. Flotation of sulphide minerals is achieved with the use of thiol collectors to create hydrophobicity, and copper sulphate is often used to improve hydrophobicity and therefore recovery. Sodium ethyl xanthate (SEX) and sodium diethyl dithiophosphate (DTP) are commonly used as collectors on PGM concentrators. The erratic mineral variations in the Platreef ore, however, raise the question of the effectiveness of the application of sulphide mineral flotation techniques on this ore. Previous work by Shackleton, (2007) investigated the flotation of PGE tellurides, sulphides and arsenides. The study highlighted that the mechanisms with which these minerals interact with collectors and with copper sulphate was poorly understood. It is as a result of the findings of Shackleton's work that this study aims to elucidate the fundamental interactions of telluride and sulphide PGMs with thiol collectors and with copper sulphate. Subsequently this work also aims to compare the behaviour of these reagents on sulphide PGMs and telluride PGMs.
300

Energy management in industry : a case study on the brewing industry

De Villiers, Mark Graham January 1992 (has links)
The industrial sector is the main energy user in South Africa, using about half the national total, and compared to most other industrialised countries South Africa has a high in_dustrial energy intensity, thus necessitating improved industrial energy management. The malt brewing industry was chosen as a case study industry to illustrate the potential for improved energy management in industry. Ohlsson's brewery in Cape Town was analysed in detail and energy management improvements identified for that brewery were ·expanded to include the malt brewing industry in general, by comparing Ohlsson's brewery to other breweries in South Africa. It was found that energy requirements at Ohlsson's Brewery could be reduced by 12-20%, by the implementation of economically feasible energy management schemes. However, mainly because of discrepancies in coal prices between Ohlsson's Brewery and most other breweries in South Africa, energy requirements for the brewing industry in general can be reduced by 7-13%. This translates to be a monetary saving of R242 000-R486 000/month, which is evenly spread between coal, electricity, and maximum demand savings. No single large energy saving scheme was identified, but the potential. savings are due to a number of schemes. The potential energy savings identified in this study exclude the savings as a result of the implementation of process sensitive schemes, which were considered beyond the scope of this study. Nevertheless some process sensitive schemes, associated with boiling in the brewhouse, could result in substantial savings. The energy usage target identified for South African breweries is higher than current energy requiiements for breweries in the Britain and Germany when climatic and operational constraints are taken into account. This is because Britain and Germany have higher energy costs relative to production costs, government incentive schemes for reducing energy usage, and more stringent environmental legislation often necessitating the recovery of brewhouse vapours.

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