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In this study, a pilot-scale regenerative thermal oxidizer (RTO) was used to test its performance for volatile organic compound (VOC) destruction and degree of thermal energy recovery. The purposes were to improve its performance and establish its operation conditions. The RTO is electrically heated and contains two 0.5 m ¡Ñ 0.5 m ¡Ñ 2.0 m (L ¡Ñ W ¡Ñ H) beds both packed with gravel particles of around 1.16 cm in average diameter to a height of 1.48 m. The bed has a void fraction of 0.405. Experiments include two phases: (1) tests to find the degree of energy conservation and the pressure drop for the air stream with no VOC in the influent air stream, and (2) tests to find the degree of VOC destruction with influent air streams containing one of the three VOCs: trichloroethylene, dichloromethane, and dibutyl ether. Intermediates in the course of VOC destruction were also detected in the second phase experiment. Phase one experiment was conducted for the following conditions: superficial gas velocity (evaluated at ambient temperatures of 26-29oC) Ug = 10-20 m/min, bed shift time ts = 1.5 min, and maximum gravel temperature Tmax = 474-778oC. Results show that the RTO has a thermal recovery efficiency R of over 85% and Ug is the main affecting factor. R is inversely proportional to Ug. Gas pressure drop over the bed height is proportional to the average temperature of the bed gravels. In the phase two experiments, Ug of 10-20 m/min, ts of 1.5 min, and Tmax of 475-487 and 758-778oC were used. Results show that over 90% of the influent VOCs were destructed when Tmax was set in the higher range. However, in the lower Tmax, over 80% destruction was obtained only for dibutyl ether and the VOC destruction was not closely related to Ug. For Tmax = 475-487oC and Ug = 10-20 m/min, complete oxidation products of trichloroethylene and dichloromethane are HCl, CO2, and H2O, and the main intermediates are CO, COCl2, and C2Cl4 (detected only for trichloroethylene). For dibutyl ether, complete oxidation products are CO2, and H2O, and the main intermediates are CO, alkenes, alcohol, alkenes, and acetic acid. For Tmax = 758-778oC and Ug = 10-14.5 m/min, complete oxidation products of trichloroethylene and dichloromethane are HCl, CO2, and H2O, and the main intermediates are CO and COCl2. No acetic acid was detected for dibutyl ether in the higher temperature range. An operation cost of US$ 3.33/(1,000 m3 waste gas) was estimated with the RTO operated in the higher temperatures and a flowrate of 2.5 m3/min (Ug = 10 m/min).

The study examines the Projection method and the simultaneousapproximation-term (SAT) method as boundary treatment for the dynamic beam equation using summation-by-parts (SBP) operators for handling the inner domain. The methods are examined for both the homogeneous constant coefficient case, and the inhomogeneous piecewise constant coefficient case with a coupled interface. The outer boundaries are handled by SAT or Projection, the coupled interfaced is handled by Projection or a mix between Projection and SAT. Solutions are integrated in time with finite central difference schemes and compared to analytical solutions. A convergence study is conducted with respect to the spatial discretization to measure the accuracy, and the stability is examined by numerical simulations of the CFL-condition. The study shows that Projection has the same accuracy as SAT for most boundary conditions while allowing for a larger timestep. A discontinuity in the medium is found to be handled equally accurate by Projection and the Projection and SAT mixture for all but one case studied, where the mixture was slightly more accurate.

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The South African government spends huge sums of funds on schools with an aim to redress past inequalities. Schools receive resource budget allocations to exclusively procure learning materials to ensure that the government’s aim is realised. This study examines availability and enactment of learning materials to enhance effective curriculum delivery. Four township public ordinary primary schools participated in this study. Focus was mainly on Grade 3 home language lessons. I used the case study methods to interview one teacher from each school and scrutinized their documents to establish what learning materials they have in their possession. Additionally I observed and analysed three lessons per educator. Analysis across the cases reveals different collections and variations in usage of learning materials. The former covers the standard, mix and match, and limited collections. Whereas the latter refers to the textbook bound, productive blend and the haphazard approaches. Significantly, the study also explored principles in line with the “ideal teacher”- under which desired results can be achieved.

Magister Artium - MA / There is global interest in teacher education as a strategy for national development. More specifically, emphasis is placed on teachers as the driving force behind educational provision which is central to achieving high standards of learner achievement. This study focused on teacher in-service development and its role for effective teaching and learning towards the holistic development of learners. Extensive social inequalities, along the lines of race, still exist in South Africa almost twenty years into the new dispensation. This is evident by the vast majority of impoverished schools in previously disadvantaged areas. Learners at these schools experience a range of barriers to learning which impede teaching and learning. Consequently, teachers at these schools are confronted with a tensionfilled task: having to be sensitive to the needs of these learners, whilst at the same having to ensure their success. This is reflected in Department of Education (DoE) policies which emphasises principles of social transformation for redress and equity, coupled with the acquisition and application of knowledge and skills for the benefit of individuals in South Africa, as well as global trends. As a quantitative data collection method in this mixed method study, 55 teachers (of which 26 responded) from two schools, were asked to complete a questionnaire on the effectiveness of teacher in-service development programmes towards the holistic development of learners. Qualitative data collection methods entailed interviewing a principal of one of the schools; a social worker from the area; as well as a district officer from the Western Cape Education Department (WCED). In addition, relevant DoE policies were reviewed. Findings reflect that teachers at impoverished schools are confronted with a range of challenges presented by learners in the classrooms. The findings also indicate that even though DoE policies reflect a commitment to teacher development, the in-service programmes offered to teachers mostly do not reflect the needs of teachers for the holistic development of learners. In instances where inservice programmes do assist with the holistic development of learners, findings indicate that the implementation thereof is challenging due to the high teacher: learner ratio and limited resources. Thus, recommendations include the periodic monitoring and review of long-term DoE teacher development initiatives whilst short term measures incorporate giving attention to impediments like lack of parental support and behavioural challenge. Long term measures, which are strongly recommended, encompass systemic change that facilitates the working together of a number of governmental departments. In so doing, educational reform takes on a society wide form, as it is evident that on its own it cannot abate poverty and the related effects. Thus, the DoE’s vision of education for social transformation towards redress and equity, as well as economic growth for individuals and South Africa is more plausible. These recommendations create a vital space for future research.

Philosophiae Doctor - PhD / This research study examines those aspects of Indigenous Knowledge (IK) that could be socially and culturally relevant in the Western Cape Province, South Africa, for teaching meteorological science concepts in a grade 9 Social Science (Geography) classroom using dialogical argumentation as an instructional model (DAIM). The literature reviewed in this study explains the use of argumentation as an instructional method of classroom teaching in particular dialogical argumentation, combined with IKS (Indigenous Knowledge Systems), which in this study is seen as a powerful tool both in enhancing learners’ views and positively identifying indigenous knowledge systems within their own cultures and communities, and as tool that facilitates the learning of (meteorological) literacy and science concepts. With the development of the New Curriculum Statements (NCS) and the Curriculum and Assessment Policy Statements (CAPS) for schools, the Department of Basic Education (DBE) of South Africa acknowledges a strong drive towards recognising and affirming the critical role of IK, especially with respect to science and technology education. The policy suggests that the Department of Education take steps to begin the phased integration of IK into curricula and relevant accreditation frameworks. Using a quasi-experimental research design model, the study employed both quantitative and qualitative methods (mixed-methods) to collect data in two public secondary schools in Cape Town, in the Western Cape Province, South Africa. A survey questionnaire on attitudes towards, and perceptions of high school, of a group of grade 9 learners, as well as their conceptions of weather, was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study. An experimental group (E-group) of learners were exposed to an intervention - the results were recorded against a control group (C-group) that were exposed to no intervention. Both the E-group and C-group were exposed to a Meteorological Literacy Test (MLT) evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks underpinning the study, namely, Toulmin’s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997). The findings of this study revealed that: Firstly, the socio-cultural background of learners has an influence on their conceptions of weather prediction and there was a significant difference between boy’s and girls’ pre-test conceptions about the existence of indigenous knowledge systems within the community they live in. For instance, from the learners’ excerpts, it emerged that the girls presented predominantly rural experiences as opposed to those of the boys which were predominantly from urban settings. Secondly, those E-group learners exposed to the DAIM intervention shifted from being predominantly equipollent to the school science to emergent stances and they found a way of connecting their IK to the school science. The DAIM model which allowed argumentation to occur amongst learners seemed to have enhanced their understanding of the relevance of IK and how its underlying scientific claims relate to that of school science. Thirdly, the argumentation-based instructional model was found to be effective to a certain extent in equipping the in-service teachers with the necessary argumentation skills that could enable them to take part in a meaningful discourse. The study drew on the personal experiences and encounters from a variety of sources. These included storytelling-and sharing, academic talks with local community members recorded during the research journey, formal round table discussion and talks at international and local conferences, conference presentations, informal interviews, indigenous chats at social event-meetings, and shared experiences at IKS training workshops as a facilitator. These encounters lead to the formulation of the research study and occurred throughout the country in various parts of the Southern African continent including: Namibia, Zimbabwe, Malawi, Botswana, Tanzania and Mozambique.

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Mathematics Education / M. Ed. (Mathematics Education)