Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 105-111). Also available on the Internet.

The synthesis of bromochloromethane (BCM) in a batch reactor, using phase transfer catalysis, was investigated. During the synthetic procedure, sodium bromide (100.0g, 0.97mol) along with an excess amount of dichloromethane (265.0g, 3.12 mol) was charged to a reactor containing benzyl triethylammonium chloride (13 mmol), dissolved in 50 ml of water. The bench scale reactions were all carried out in a Parr 4520 bench top pressure reactor coupled to a Parr 4841 temperature controller. The method produced a 50.0 percent yield of the product BCM after a reaction time of 12 to 13 hours. The main objective for this investigation was to optimize the abovementioned reaction with respect to yield and reactor throughput. Quantitative analysis of BCM was performed on a Focus Gas Chromatograph, fitted with a flame ionization detector, and a BP20 column (30m × 0,32mm ID × 0,25 mm). Delta software, version 5.0, was applied for data collection and processing. The injector and detector port were set at 250°C and 280°C, respectively. The oven temperature was set and held at 40°C for a period of 2 minutes, then gradually increased at a rate of 10°C/min to 130°C, with the final hold time set for 1 minute. An analytical method for the quantitative analysis of BCM was developed, optimized and validated. Validation of the analytical method commenced over a period of three days, and focussed the following validation parameters: Accuracy, precision, and ruggedness. Statistical evaluation of the results obtained for precision showed that the error between individual injections is less than 2 percent for each component. However, ANOVA analysis showed a significant difference between the mean response factors obtained in the three day period (p-value < 0.05). Thus we could conclude that the response factors had to be determined on each day before quantitatively analyzing samples. The accuracy of the analytical method was assessed by using the percent recovery method. Results obtained showed that a mean percent recovery of 100.18 percent was obtained for BCM, with the absolute bias = 0.0004, and the percent bias = 0.18 percent. Hence the 95 confidence intervals for the percent recovery and percent bias are given by: (Lz, Uz) = (100.56 percent percent 102.15 percent), 13 (LPB, UPB) = (0.56 percent, 2.15 percent), respectively. Since the 95 percent confidence interval for the percent recovery contains 100, or equivalently, the 95 percent confidence interval for percent bias contains 0, the assay method is considered accurate and validated for BCM. In the same manner the accuracy and percent recovery for DCM and DBM was evaluated. The method was found to be accurate and validated for DBM, however, slightly biased in determining the recovered amount of DCM. With the analytical method validated, the batch production process could be evaluated. A total of six process variables, namely reaction time, water amount, temperature, volume of the two phases, stirring rate, and catalyst concentration, were selected for the study. The effects of the individual variables were determined in the classical manner, by varying only the one of interest while keeping all others constant. The experimental data generated was fit to a quadratic response surface model. The profile plots that were obtained from this model allowed a visual representation of the effect of the six variables. The experimental results obtained showed that the reaction follows pseudo zero-order kinetics and that the rate of the reaction is directly proportional to the concentration of the catalyst. The reaction obeys the Arrhenius equation, and the relatively high activation energy of 87kJ.mol -1 signifies that the rate constant is strongly dependent on the temperature of the reaction. The results also showed that the formation of BCM is favoured by an increase in the reaction temperature, catalyst concentration, and a high organic: aqueous phase ratio. Thus the synthesis of BCM using phase transfer catalyst could be optimised, to obtain a 100 percent yield BCM, by increasing both the reaction temperature to 105°C, and the concentration of the phase transfer catalyst -benzyl triethylammonium chloride - to 5.36 mol percent. The reaction time was also reduced to 6 hours.

Submitted to the Faculty of Education in fulfilment of the requirements for the degree of MASTER OF SCIENCE EDUCATION in the Department of Mathematics, Science and Technology (MSTE) at the University of Zululand, 2015. / This study set out to investigate beliefs held by pre service Bachelor of Education (B.Ed) students about the nature of science and science teaching and learning. The research sample comprised one hundred and eighty four (184) third and fourth year (B.Ed) students majoring in mathematics and physical sciences. Data on students’ epistemological beliefs about the nature of science and science teaching and Learning were collected using two questionnaires: The Nature of Science as Argument Questionnaire (NSAAQ) and Beliefs About Reformed Science Teaching and Learning (BARSTL). Furthermore the study sought to find out if those beliefs cohered with the beliefs espoused by the National Curriculum Statement (NCS) for Physical Sciences grades 10-12. The conceptual framework of this study was framed upon the preponderance of literature that carried the view that a teacher’s classroom practices are a consequence of two main dialectic influences: (a) the teacher’s epistemological beliefs about the nature of science, which may be either naïve or sophisticated; and (b) the teacher’s beliefs about teaching and learning, which may be either traditional or reformed. Accordingly, the conceptual framework guiding the study opined that teachers holding naïve beliefs about the nature of science, and those holding traditional notions of teaching and learning will be characterized by teacher-centred instructional approaches, while those holding sophisticated beliefs of the nature of science and a reformed view of teaching and learning will be associated with learner-centred instructional approaches. This study was a case study conducted at a South African university, and involved one hundred and eighty-four third and fourth year students registered for a four-year Bachelor of Education (B.Ed) degree for the Senior and Further Education and Training phase. During these two final years of the programme students are engaged in science enquiry practices in their Methods modules. The participants were registered in physical science and mathematics education. Intact groups were used, so there was no sampling undertaken to select participants. Data were collected by the use of (a) the Nature of Science as Argument Questionnaire (NSAAQ), to determine epistemological beliefs held by the participants about the nature of science, as well as the concurrence of those beliefs with the views about science teaching and learning espoused by the NCS; and (b) the Beliefs about Reformed Science Teaching and Learning (BARSTL) questionnaire, to determine the beliefs held by preservice education students about science teaching and learning. Data analysis involved the use of both descriptive statistical methods to decipher patterns and general trends regarding the epistemological beliefs about science held by participants, and their beliefs about science teaching and learning, as well as inferential statistics to test both a priori and a posteriori hypotheses. Similarly, statistical analysis was carried out to determine whether or not third- and fourth-year pre-service science education students held beliefs about science teaching and learning that were in agreement with the pedagogical content beliefs about science teaching and learning espoused by the NCS. The study found that pre service students held significantly more sophisticated epistemological beliefs about the nature of science at fourth year than at third year level. The results also showed that fourth year students demonstrated a significantly higher level of ‘reformed oriented teaching and learning beliefs’ about science than did the third year students. The results however showed that third and fourth year students held beliefs that were not in line with the beliefs espoused by the National Curriculum Statement (NCS). These results support studies which have found that student teachers become more sophisticated in their epistemological beliefs towards graduation. The findings also showed that the B.Ed programme is succeeding in developing both epistemological beliefs about the nature of science and teaching and learning. The degree to which the programme succeeded in developing these beliefs was however quite small. This study recommends that further investigations be done to determine whether students who hold sophisticated epistemological beliefs about the nature of science and ‘reformed beliefs about science teaching and learning’ also demonstrate superior science teaching skills

A research project submitted in partial fulfilment of the requirements for the degree of Master of Science Education in the Faculty of Science. The University of the Witwatersrand. February 2016 / In South Africa, the new Curriculum Statement and Policy Statement (CAPS) Grades 10- 12 for Physical Sciences emphasizes learners’ use of science process skills. The aim of this study was to evaluate the extent of the use of science process skills by Grade 11 Physical Science learners. It also sought to explore some of the factors associated with poor utilization of SPS by Grade 11 Physical Science learners. The participants were Grade 11 Physical Science learners (n=50) and teachers (n=4) from two schools in the Johannesburg area of the Gauteng Province, South Africa. Quantitative and qualitative data used to evaluate Grade 11 Physical Science learners’ use of science process skills was obtained through use of: a learner Likert questionnaire; teacher and learners’ interviews; and analysis of classroom lesson observations. Quantitative data was analyzed using both descriptive and inferential statistics. Qualitative data was analyzed using a combination of content and interpretive analysis. It was found that for both schools basic science process skills were relatively more frequently utilized compared to integrated skills; with the lower fee paying school showing a poorer utilization of both types of skills. The most utilized basic science process skills were found to be communication, observation, identification, classification, comparison, description and calculation. It was found that the following integrated process skills are poorly utilized by the Grade 11 Physical Science leaners- prediction, constructing hypothesis, relationship between variables, constructing diagrams, and experimentation. Some of the factors found to hamper utilization of science process skills were identified as teacher incompetency, lack of learner interest, poor availability of curriculum resources, and poor teaching practices and learning strategies. It was recommended that the South African CAPS curriculum needs to be revised to put greater emphasis on teaching and assessment of science process skill utilization. Furthermore, it was suggested that teachers need to be professional developed to enhance their capabilities of teaching science process skill utilization. Implications for further studies were fleshed out and discussed.

The purpose of this study is to investigate the effects of using verbal analogies in teaching ninth-grade physical science. The experiment is designed to determine if teaching by analogies is more effective than conventional methods of teaching, and to ascertain the effect of analogies on achievement for different ability levels in different subject areas of physical science.

Call number: LD2668 .R4 1967 L43

This exploratory, descriptive and interpretive study investigated the interactions among learners’ conceptions of the nature of scientific inquiry (NOSI), teachers’ conceptions of NOSI and teacher instructional practices when teaching investigations in Physical Science. The participants were South Africa, Grade 11 learners (n= 167) and teachers (n=5), from five schools in the Johannesburg region of South Africa. The schools were conveniently and purposefully sampled. Learners’ and teachers’ conceptions on six NOSI tenets were investigated. These tenets are: difference between laws and theories; difference between observation and interpretation; there is no one method in science; accurate record keeping, peer review and replicability in science; socially and culturally embeddedness nature of scientific knowledge; and the role of human creativity and imagination in the development of scientific knowledge. Data on learners’ and teachers’ conceptions of the NOSI was obtained through; questionnaires, probes and interviews. Teacher instructional practices were determined using laboratory class observations, questionnaires, teacher and learner interviews, and analysis of instructional materials. The data was quantitatively analyzed using mainly, descriptive statistics, correlations, Regression Analysis and Multivariate Analysis of Variance (MANOVA). Qualitative data was analyzed using a combination of analytic induction and interpretive analysis. The results show that learners’ NOSI conceptions were inconsistent, fragmented and fluid, with the majority of the learners displaying naïve conceptions. Teachers were found to hold mixed NOSI conceptions ranging from static, empiricist-aligned to dynamic, constructivist-oriented. Teacher instructional practices were found to be a repertoire of contrasting methodological approaches lying along a continuum ranging from close-ended inquiry to open-ended inquiry. The study found the interactions between and among the investigated variables to be weak and not direct and simple, but complex and under the governance of a variety of factors in the instructional milieu. Curriculum and assessment demands were found to be major factors possibly responsible for weakening the interactions. For the investigated variables, it is posited that the interaction between variables is under the governance of both the context in which the instruction takes place and some factors already embedded in the teacher’s or learner’s conceptual ecology. Recommendations and implications for the practice of science education and future research are raised and discussed.

Thesis (M. Dev.) -- University of Limpopo, 2018. / School Improvement Plan is introduced to improve learner performance in South Africa. This plan is integrated within the whole School Evaluation so as to enhance the quality of education in the country. Malegale Circuit of Education in Limpopo Province is central to the investigation. In terms of the Whole School Evaluation (WSE) schools are required to annually develop and implement a School Improvement Plan (SIP). As part of a SIP, a school should plan to monitor and examines at regular intervals, whether its practices and learner achievement are undergoing changes.SIP maps out the actions needed to bring about improvement. It is compiled annually after School Self-Evaluation (SSE). The focus areas used by school management teams to draw their School Improvement Plan (SIP) are: basic functionality of the school; leadership, management and communication; governance and relationships; quality of teaching and educators development; curriculum provision and resources; learner achievement; school safety, security and discipline; school infrastructure; and parents and community. It outlines the school’s strategies for improvement and sets clear targets of action. All the schools are obliged to draw their School Improvement Plan (SIP) in the curriculum of every subject. The programme helps in assisting towards improving performance in terms of quality of teaching and learning, educator development, curriculum provision and resources, learner achievement and school infrastructure. The study provides insight into the research design, qualitative case study which includes Semi-structured interviews, Document review, Field notes and Observation and quantitative in the form of questionnaires research paradigms, purposeful sampling, site selection, the participants, and data analysis. The members of the school management teams should be encouraged to implement School Improvement Plan in an effective and professional manner. The members of the school management team should be encouraged to appoint qualified physical science teachers to enhance the impact of whole school evaluation on school improvement plan. Government officials should be encouraged to monitor and evaluate the implementation of the whole school evaluation and school improvement plan, so as to enhance the teaching of Physical Science.

Using emergent inquiry curriculum to explore physical science and measurement.

E. A. Burtt's The Metaphysical Foundations of Modern Physical Science (1924) has been described by H. Floris Cohen, writing on the historiography of the Scientific Revolution in 1994, as the "individual thought of an individual thinker...beyond philosophical or historical currents or fashion." The book is something of a puzzle within the context of American twentieth-century intellectual history and more specifically, of the philosophy and history of science of North America and Europe. / Burtt's inter-disciplinary study---as it would be called today---has proved to be both pioneering and prophetic in its rejection of both scientism and positivism. The thesis examines the author's novel interpretation of Isaac Newton's achievement, as well as that of Newton's predecessors in the Scientific Revolution. Burtt's singular view of the rise of modern science from religious underpinnings was, for the most part, either misunderstood or ignored at the time. In fact, the whole idea of a Scientific Revolution was only introduced into the curriculum at leading American universities following the Second World War, in response to Herbert Butterfield and Alexandre Koyre, both of whom owe unacknowledged debts to Burtt. / The Metaphysical Foundations was conceived in the progressive era of the 1920s, the latter part of the "Golden Age" in American philosophy. The thesis examines the role of innovating intellects such as John Dewey, James Harvey Robinson, and Morris R. Cohen in shaping Burtt's view, described against the background of his studies at Columbia university. Under the sway of pragmatic naturalism, Burtt's interpretation of Newton was part of a grand scheme to develop a new philosophy of mind which he intended would overcome the problems of Cartesian dualism. / The dissertation concludes with an extended analysis of Burtt's public, academic, and personal life based upon archives, correspondence and interviews with those who remember him. It considers his politics of conscience during the Cold War and concludes that integrity combined with the relentless search for philosophic understanding drove his more exotic philosophical quests and steered his personal life, including its tragic dimension, toward simple virtues.