The purpose of this study was to extend our current knowledge about what happens in physical science classrooms. The focus was the context of problem tasks. This involved the study of the situations, events and factors that relate to the solving of problem tasks at high school in order to understand their role and nature. e problem tasks that were central to this study were well defined, narrow in focus, and invariably involved the calculation of some quantity through the use of a formula and algebraic manipulation. The main questions that guided the study were as follows: What is happening in physical science classrooms? What is the nature and role of problem solving within this context? What are some of the consequences of organising teaching and learning in this manner? How do external forces influence what happens? The study aimed at describing the activities that the teachers and students were involved in and understanding how they understood their own actions. An interpretive research approach was chosen for this purpose, having as its basis a detailed descriptive foundation using classroom observation. Two high school science classrooms were studied in detail over a period of a year. The data gathered included field notes from over a hundred classroom visits, extensive video and audio records, questionnaires, classroom documents and formal an informal interviews with teachers, students and examiners. Through a process of careful and systematic analysis of the data, six assertions emerged. These assertions are supported by both particular evidence in the form of analytic narrative vignettes, quotes and extracts, and general evidence consisting of frequency data and summary tables. The analysis reveals that problem tasks occupied most of the teaching and learning time, and that the students found this experience of school science boring. Most of the problem tasks were routine in nature and of low conceptual demand. The majority of the students were unable to solve the more difficult tasks encountered in their tests and examinations. In addition, a significant number could not solve the routine problem tasks. This suggests that the predominant instructional strategies were ineffective. It was found that participants had an uncritical belief in the efficacy of teacher explanations and student practice on problem tasks. Further, the participants had different views of the role of problem tasks. A significant finding was that the examination exerted a powerful focusing influence on the classroom environment, the instructional activities and on the problem tasks used . It appeared that the ultimate goal of school physical science was to solve these types of problem task in preparation for the high stakes examination, rather than the learning of science. The study has implications both for practice and for research on the teaching and learning of school physical science. These implications are discussed in terms of instructional strategies aimed at promoting a deeper understanding of physical science. In order to improve practice it is advocated that the role of problem tasks in learning science be made explicit while at the same time new types of instructional task need to be designed to achieve our goals for school science. / Thesis (Ph.D.)-University of Natal, Durban, 1999.

The industrial port of Richards Bay on the eastern seaboard of KwaZulu-Natal, South Africa has undergone rapid growth over the last 25 years. This industrial growth has inevitably led to an increase in the anthropogenic pollutant inputs in the area. However, the degree of this contamination has not previously been assessed not been accompanied by an awareness of its environmental impacts. This project serves to assess the current environmental situation of the area and provide background levels against which the environmental impacts of further growth in the area can be assessed. The main pollution point sources in the area were identified as a pulp and paper plant, a sulfuric acid/fertiliser plant and aluminium smelters. The chemical and physical processes involved within these industries were identified and discussed in detail. The common inorganic pollutants emitted by these industries were identifies as trace metals, sulfur dioxide, NOx gases and fluoride. It was these pollutants that therefore became the focus of this study. Reservoirs within Richards Bay that may become sinks for contamination were identified and water, sediment and soil samples were taken from these reservoirs. The samples were analysed for trace metal contamination, pH, alkalinity and fluoride levels. Analysis of the acidity and alkalinity of water, sediment and soils samples demonstrated that there is presently no long-term acidification of the environment in Richards Bay. The only samples that showed increased acidity were the soils taken from the roadside sites immediately outside the industries. This lack of overall acidification indicates that, at present, there are no detrimental effects of acidic emissions on the hydrosphere and geosphere. Only cursory investigations were conducted into the fluoride levels found in water samples. None of the samples analysed demonstrated detectable amounts of fluoride present. Comprehensive trace metal analyses were performed on the water, sediment and soil samples through the use of ICP-AES. Levels obtained were compared with levels from samples taken from relatively uncontaminated background sites. Trace metal analysis indicated contamination of the freshwater reservoirs when compared with the background, while the soils and saltwater reservoirs remain largely uncontaminated. However, the contaminated areas did not show levels greater than quality guideline concentrations. Further studies should be conducted with regards to the trace metal contamination of the biosphere and the bioavailability of the contaminants already present in the waters, sediments and soils. More detailed investigations should also be conducted into the levels of atmospheric pollutants and fluoride levels in all reservoirs. / Thesis (M.Sc.) - University of KwaZulu-Natal, Pietermaritzburg, 2004.