The selective dechlorination of poly-chlorophenols
- Authors: Thomas, Maxwell Paul
- Date: 2009
- Subjects: Sewage -- Purification -- Chlorination , Pesticides -- Toxicology , Chlorine -- Toxicology
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:10391 , http://hdl.handle.net/10948/1124 , Sewage -- Purification -- Chlorination , Pesticides -- Toxicology , Chlorine -- Toxicology
- Description: Liquid phase catalytic hydrodechlorinations can provide a convenient and environmentally friendly method for treating organic chlorinated compounds in waste streams generated during the manufacturing of agrochemicals. During such treatment hydrochloric acid is generated as a by-product, which can be easily neutralized employing a base to yield an inorganic salt. This work describes the results obtained during the liquid phase hydrodechlorination of 2,6-dichlorophenol (2,6-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP). The hydrodechlorination of these chlorinated phenolic compounds in a mixture of methanol and water was investigated using supported and unsupported palladium catalysts to yield lower chlorinated phenols or phenol. Various parameters were investigated such as catalyst concentration, ammonium formate concentration, effect of base addition and effect of temperature. During this study two methods of hydrodechlorination were also investigated such as hydride-transfer hydrogenolysis, using ammonium formate, and hydrogenolysis, using dihydrogen. These methods offer a mild treatment in terms of the reaction temperature with temperatures used below 800C. A comparison of the palladium catalyst systems using these methods also showed that Pd/C produced the best results in terms of the hydrodechlorination rate and the selectivity towards phenol. When the ammonium formate method was used, complete hydrodechlorination of both substrates was achieved in 1h of reaction time at a selectivity of 100 percent towards phenol. A comparison of the method using dihydrogen and Pd/C showed that the reaction rate and the selectivity towards phenol during the hydrodechlorination of 2,6-DCP were 87.92 percent and 93.30 percent. Similarly, the reaction rate and selectivity during 2,4,6- TCP hydrodechlorination were 63.77 percent and 70.57 percent. These results were achieved in a reaction time of 3 hours. A high catalyst loading increases the reaction rate at the expense of selectivity, due to the formation of cyclohexanone, formed during further hydrogenation of phenol. The formation of cyclohexanone was limited at high temperatures (ca. 800C) with none detected during the hydrodechlorination of 2,6-DCP and 0.19 percent during the hydrodechlorination of 2,4,6-TCP. Evaluation of the hydrodechlorination parameters showed that the catalytic efficiency of the Pd/C catalysts was inhibited as the reaction proceeded due to the formation of HCl as by-product. A significant increase in the reaction rate was achieved when the reaction was performed in the presence of an inorganic base, which neutralized HCl.
- Full Text:
- Date Issued: 2009
- Authors: Thomas, Maxwell Paul
- Date: 2009
- Subjects: Sewage -- Purification -- Chlorination , Pesticides -- Toxicology , Chlorine -- Toxicology
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:10391 , http://hdl.handle.net/10948/1124 , Sewage -- Purification -- Chlorination , Pesticides -- Toxicology , Chlorine -- Toxicology
- Description: Liquid phase catalytic hydrodechlorinations can provide a convenient and environmentally friendly method for treating organic chlorinated compounds in waste streams generated during the manufacturing of agrochemicals. During such treatment hydrochloric acid is generated as a by-product, which can be easily neutralized employing a base to yield an inorganic salt. This work describes the results obtained during the liquid phase hydrodechlorination of 2,6-dichlorophenol (2,6-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP). The hydrodechlorination of these chlorinated phenolic compounds in a mixture of methanol and water was investigated using supported and unsupported palladium catalysts to yield lower chlorinated phenols or phenol. Various parameters were investigated such as catalyst concentration, ammonium formate concentration, effect of base addition and effect of temperature. During this study two methods of hydrodechlorination were also investigated such as hydride-transfer hydrogenolysis, using ammonium formate, and hydrogenolysis, using dihydrogen. These methods offer a mild treatment in terms of the reaction temperature with temperatures used below 800C. A comparison of the palladium catalyst systems using these methods also showed that Pd/C produced the best results in terms of the hydrodechlorination rate and the selectivity towards phenol. When the ammonium formate method was used, complete hydrodechlorination of both substrates was achieved in 1h of reaction time at a selectivity of 100 percent towards phenol. A comparison of the method using dihydrogen and Pd/C showed that the reaction rate and the selectivity towards phenol during the hydrodechlorination of 2,6-DCP were 87.92 percent and 93.30 percent. Similarly, the reaction rate and selectivity during 2,4,6- TCP hydrodechlorination were 63.77 percent and 70.57 percent. These results were achieved in a reaction time of 3 hours. A high catalyst loading increases the reaction rate at the expense of selectivity, due to the formation of cyclohexanone, formed during further hydrogenation of phenol. The formation of cyclohexanone was limited at high temperatures (ca. 800C) with none detected during the hydrodechlorination of 2,6-DCP and 0.19 percent during the hydrodechlorination of 2,4,6-TCP. Evaluation of the hydrodechlorination parameters showed that the catalytic efficiency of the Pd/C catalysts was inhibited as the reaction proceeded due to the formation of HCl as by-product. A significant increase in the reaction rate was achieved when the reaction was performed in the presence of an inorganic base, which neutralized HCl.
- Full Text:
- Date Issued: 2009
The South African community pharmacist and Type 2 Diabetes Mellitus a pharmaceutical care intervention
- Authors: Hill, Peter William
- Date: 2009
- Subjects: Pharmacist and patient -- South Africa , Pharmaceutical services -- Patients , Pharmaceutical services -- South Africa , Pharmacists -- South Africa , Diabetes -- Treatment -- South Africa , Community health services -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3760 , http://hdl.handle.net/10962/d1003238 , Pharmacist and patient -- South Africa , Pharmaceutical services -- Patients , Pharmaceutical services -- South Africa , Pharmacists -- South Africa , Diabetes -- Treatment -- South Africa , Community health services -- South Africa
- Description: Type 2 diabetes mellitus is a chronic disease of pandemic magnitude, increasingly contributing to the disease burden of countries in the developing world, largely because of the effects of unhealthy lifestyles fuelled by unbridled urbanisation. In certain settings, patients with diabetes are more likely to have a healthcare encounter with a pharmacist than with any other healthcare provider. The overall aim of the study was to investigate the potential of South African community pharmacists to positively influence patient adherence and metabolic control in Type 2 diabetes. The designated primary endpoint was glycated haemoglobin, with the intermediate health outcomes of blood lipids, serum creatinine, blood pressure and body mass index serving as secondary endpoints. Community pharmacists and their associated Type 2 diabetes patients were recruited from areas throughout South Africa using the communication media of various nonstatutory pharmacy organisations. Although 156 pharmacists initially indicated interest in participating in the study, only 28 pharmacists and 153 patients were enrolled prior to baseline data collection. Of these, 16 pharmacists and 57 patients participated in the study for the full twelve months. Baseline clinical and psychosocial data were collected, after which pharmacists and their patients were randomised, nine pharmacists and 34 patients to the intervention group and 8 pharmacists and 27 patients to the control group. The sample size calculation revealed that each group required the participation of a minimum of 35 patients. Control pharmacists were requested to offer standard pharmaceutical care, while the intervention pharmacists were provided with a scope of practice diabetes care plan to guide the diabetes care they were to provide. Data were again collected 12-months postbaseline. At baseline, proportionally more intervention patients (82.4%) than control patients (59.3%) were using only oral anti-diabetes agents (i.e. not in combination with insulin), while insulin usage, either alone or in combination with oral agents was conversely greater in the control group (40.7%) than in the intervention group (17.6%) (Chi-squared test, p=0.013). Approximately half of the patients (53.8% control and 47.1% intervention) reported having their HbA1c levels measured in terms of accepted guidelines. There was no significant difference in HbA1c between the groups at the end of the study (Independent t-test, p=0.514). In the control group, the mean HbA1c increased from 7.3±1.2% to 7.6±1.5%, while for the intervention patients the variable remained almost constant (8.2±2.0% at baseline and 8.2±1.8% at post-baseline). Similarly, there were no significant differences between the groups with regard to any of the designated secondary clinical endpoints. Adherence to medication and self-management recommendations was similarly good for both groups. There were no significant differences between the two groups for any of the other psychosocial variables measured. In conclusion, intervention pharmacists were not able to significantly influence glycaemic control or therapeutic adherence compared to the control pharmacists.
- Full Text:
- Date Issued: 2009
- Authors: Hill, Peter William
- Date: 2009
- Subjects: Pharmacist and patient -- South Africa , Pharmaceutical services -- Patients , Pharmaceutical services -- South Africa , Pharmacists -- South Africa , Diabetes -- Treatment -- South Africa , Community health services -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3760 , http://hdl.handle.net/10962/d1003238 , Pharmacist and patient -- South Africa , Pharmaceutical services -- Patients , Pharmaceutical services -- South Africa , Pharmacists -- South Africa , Diabetes -- Treatment -- South Africa , Community health services -- South Africa
- Description: Type 2 diabetes mellitus is a chronic disease of pandemic magnitude, increasingly contributing to the disease burden of countries in the developing world, largely because of the effects of unhealthy lifestyles fuelled by unbridled urbanisation. In certain settings, patients with diabetes are more likely to have a healthcare encounter with a pharmacist than with any other healthcare provider. The overall aim of the study was to investigate the potential of South African community pharmacists to positively influence patient adherence and metabolic control in Type 2 diabetes. The designated primary endpoint was glycated haemoglobin, with the intermediate health outcomes of blood lipids, serum creatinine, blood pressure and body mass index serving as secondary endpoints. Community pharmacists and their associated Type 2 diabetes patients were recruited from areas throughout South Africa using the communication media of various nonstatutory pharmacy organisations. Although 156 pharmacists initially indicated interest in participating in the study, only 28 pharmacists and 153 patients were enrolled prior to baseline data collection. Of these, 16 pharmacists and 57 patients participated in the study for the full twelve months. Baseline clinical and psychosocial data were collected, after which pharmacists and their patients were randomised, nine pharmacists and 34 patients to the intervention group and 8 pharmacists and 27 patients to the control group. The sample size calculation revealed that each group required the participation of a minimum of 35 patients. Control pharmacists were requested to offer standard pharmaceutical care, while the intervention pharmacists were provided with a scope of practice diabetes care plan to guide the diabetes care they were to provide. Data were again collected 12-months postbaseline. At baseline, proportionally more intervention patients (82.4%) than control patients (59.3%) were using only oral anti-diabetes agents (i.e. not in combination with insulin), while insulin usage, either alone or in combination with oral agents was conversely greater in the control group (40.7%) than in the intervention group (17.6%) (Chi-squared test, p=0.013). Approximately half of the patients (53.8% control and 47.1% intervention) reported having their HbA1c levels measured in terms of accepted guidelines. There was no significant difference in HbA1c between the groups at the end of the study (Independent t-test, p=0.514). In the control group, the mean HbA1c increased from 7.3±1.2% to 7.6±1.5%, while for the intervention patients the variable remained almost constant (8.2±2.0% at baseline and 8.2±1.8% at post-baseline). Similarly, there were no significant differences between the groups with regard to any of the designated secondary clinical endpoints. Adherence to medication and self-management recommendations was similarly good for both groups. There were no significant differences between the two groups for any of the other psychosocial variables measured. In conclusion, intervention pharmacists were not able to significantly influence glycaemic control or therapeutic adherence compared to the control pharmacists.
- Full Text:
- Date Issued: 2009
Tourism policy, biodiversity conservation and management: a case study of the Kruger National Park, South Africa
- Authors: Zhou, Leocadia
- Date: 2009
- Subjects: Biodiversity conservation -- South Africa -- Kruger National Park , Ecosystem management -- South Africa -- Kruger National Park , Tourism -- Government policy -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Geography)
- Identifier: vital:11513 , http://hdl.handle.net/10353/174 , Biodiversity conservation -- South Africa -- Kruger National Park , Ecosystem management -- South Africa -- Kruger National Park , Tourism -- Government policy -- South Africa
- Description: The Kruger National Park (KNP) management has recently made considerable progress in enacting new policies to address biodiversity conservation and management challenges. However, the interlinkages among the new policies to support biodiversity conservation and management have not been evaluated, particularly the principles and approaches, and how these interact in terms of policy decision-making at the economic and political levels. This study seeks to evaluate the interlinkages among the new policies and how they affect one another, as an avenue to promote a more integrated and comprehensive policy implementation. These policies include the tourism policy, the elephant management policy, and the water provision policy. At policy-making level, the integration of these three policies enhances the possibilities for balancing and controlling the pressures exerted on environmental resources. At the implementation level, it offers a framework for the coordination of the interventions of the policies in space so as to recognise and capitalize on their synergies. Given the inevitably multifarious and departmentalized nature of policy formulation in the KNP, there is a need for the analysis of interlinkages amongst policies. The conceptual framework underpinning this study derives much from Briassoulis’ (2004) policy integration. The research utilizes both qualitative and quantitative research methods, and focuses on selected camp sites within the Park. The findings indicate that current procedures for tourism policy-making and implementation are weak, and little is done by way of impact assessment. This has been attributed to the lack of capacity at the KNP. The findings also reconfirm that policy-making is too fragmented. As a result, policy coordination and cooperation among park managers is weak. This study suggests that an environmental policy integration approach can lead to improved policy-making and implementation. Informed by the data collected from interviews, questionnaires and document analyses, a management framework has been developed to demonstrate how an integrated approach to Environmental Policy Integration (EPI) or management can help sustain the practice of wildlife tourism and support biodiversity conservation. It is concluded that greater realisation of integrated policy-making and implementation in the KNP can be achieved by establishing a formal coordinating office. However, a special feature of KNP policy-making is its widespread consultation system that can provide a fertile ground for enhancing EPI.
- Full Text:
- Date Issued: 2009
- Authors: Zhou, Leocadia
- Date: 2009
- Subjects: Biodiversity conservation -- South Africa -- Kruger National Park , Ecosystem management -- South Africa -- Kruger National Park , Tourism -- Government policy -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Geography)
- Identifier: vital:11513 , http://hdl.handle.net/10353/174 , Biodiversity conservation -- South Africa -- Kruger National Park , Ecosystem management -- South Africa -- Kruger National Park , Tourism -- Government policy -- South Africa
- Description: The Kruger National Park (KNP) management has recently made considerable progress in enacting new policies to address biodiversity conservation and management challenges. However, the interlinkages among the new policies to support biodiversity conservation and management have not been evaluated, particularly the principles and approaches, and how these interact in terms of policy decision-making at the economic and political levels. This study seeks to evaluate the interlinkages among the new policies and how they affect one another, as an avenue to promote a more integrated and comprehensive policy implementation. These policies include the tourism policy, the elephant management policy, and the water provision policy. At policy-making level, the integration of these three policies enhances the possibilities for balancing and controlling the pressures exerted on environmental resources. At the implementation level, it offers a framework for the coordination of the interventions of the policies in space so as to recognise and capitalize on their synergies. Given the inevitably multifarious and departmentalized nature of policy formulation in the KNP, there is a need for the analysis of interlinkages amongst policies. The conceptual framework underpinning this study derives much from Briassoulis’ (2004) policy integration. The research utilizes both qualitative and quantitative research methods, and focuses on selected camp sites within the Park. The findings indicate that current procedures for tourism policy-making and implementation are weak, and little is done by way of impact assessment. This has been attributed to the lack of capacity at the KNP. The findings also reconfirm that policy-making is too fragmented. As a result, policy coordination and cooperation among park managers is weak. This study suggests that an environmental policy integration approach can lead to improved policy-making and implementation. Informed by the data collected from interviews, questionnaires and document analyses, a management framework has been developed to demonstrate how an integrated approach to Environmental Policy Integration (EPI) or management can help sustain the practice of wildlife tourism and support biodiversity conservation. It is concluded that greater realisation of integrated policy-making and implementation in the KNP can be achieved by establishing a formal coordinating office. However, a special feature of KNP policy-making is its widespread consultation system that can provide a fertile ground for enhancing EPI.
- Full Text:
- Date Issued: 2009
Women in organisational management in Zimbabwe: theory and practice
- Authors: Zikhali, Whitehead
- Date: 2009
- Subjects: Businesswomen , Discrimination in employment -- Zimbabwe , Women executives -- Zimbabwe , Success in business -- Zimbabwe , Corporate culture -- Zimbabwe , Leadership -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD (Social Science Dev)
- Identifier: vital:11415 , http://hdl.handle.net/10353/d1001185 , Businesswomen , Discrimination in employment -- Zimbabwe , Women executives -- Zimbabwe , Success in business -- Zimbabwe , Corporate culture -- Zimbabwe , Leadership -- Zimbabwe
- Description: The study was premised on the truism that men have historically served in higher echelons of organizational management structures and women are under-represented. The principal objective was to explore the constraints faced by women in accessing higher leadership and senior management positions in public, private and non-governmental organisations in Zimbabwe. This study adopted the triangulation method, that is, qualitative and quantitative approaches. These mixed research methods, were upgraded by the feminist research methodologies, thereby making a contribution in the field of research. The study found out that the constraints that mostly hinder women from accessing leadership and senior management positions in public, private and NGOs were cultural practices, which represent levels of power and control that in turn hinder reforms; and women's socialisation into feminised roles. The study also found out that in most organisations, most females work under male leadership, and this traditional organisational culture, needs to be deconstructed and reversed in order to achieve gender equality. The study recommended for a human centric and integrated organizational management strategy for public, private and NGOs in Zimbabwe. The adoption of a human centric and integrated management approach should aim at gender equity and reduce women's under-representation. A human centred organizational culture has to be practiced, that would create organisational ethos that guide organizational management. An integrated organizational management approach should integrate all systems and processes into one complete framework, enabling people to work as a single unit, unified by organizational goals, shared vision and common values. The system should depend on a balanced mix of the masculine and feminine attributes. The approach should put its weight towards adoption of measures to attract, advance and empower women so as to benefit from their qualifications, experience and talent in a highly competitive environment.
- Full Text:
- Date Issued: 2009
- Authors: Zikhali, Whitehead
- Date: 2009
- Subjects: Businesswomen , Discrimination in employment -- Zimbabwe , Women executives -- Zimbabwe , Success in business -- Zimbabwe , Corporate culture -- Zimbabwe , Leadership -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD (Social Science Dev)
- Identifier: vital:11415 , http://hdl.handle.net/10353/d1001185 , Businesswomen , Discrimination in employment -- Zimbabwe , Women executives -- Zimbabwe , Success in business -- Zimbabwe , Corporate culture -- Zimbabwe , Leadership -- Zimbabwe
- Description: The study was premised on the truism that men have historically served in higher echelons of organizational management structures and women are under-represented. The principal objective was to explore the constraints faced by women in accessing higher leadership and senior management positions in public, private and non-governmental organisations in Zimbabwe. This study adopted the triangulation method, that is, qualitative and quantitative approaches. These mixed research methods, were upgraded by the feminist research methodologies, thereby making a contribution in the field of research. The study found out that the constraints that mostly hinder women from accessing leadership and senior management positions in public, private and NGOs were cultural practices, which represent levels of power and control that in turn hinder reforms; and women's socialisation into feminised roles. The study also found out that in most organisations, most females work under male leadership, and this traditional organisational culture, needs to be deconstructed and reversed in order to achieve gender equality. The study recommended for a human centric and integrated organizational management strategy for public, private and NGOs in Zimbabwe. The adoption of a human centric and integrated management approach should aim at gender equity and reduce women's under-representation. A human centred organizational culture has to be practiced, that would create organisational ethos that guide organizational management. An integrated organizational management approach should integrate all systems and processes into one complete framework, enabling people to work as a single unit, unified by organizational goals, shared vision and common values. The system should depend on a balanced mix of the masculine and feminine attributes. The approach should put its weight towards adoption of measures to attract, advance and empower women so as to benefit from their qualifications, experience and talent in a highly competitive environment.
- Full Text:
- Date Issued: 2009
Teacher educators' interpretation and practice of learner-centred pedagogy : a case study
- Authors: Nyambe, Kamwi John
- Date: 2013-07-16
- Subjects: Bernstein, Basil B Education -- Philosophy Education (Higher) -- Namibia Teacher educators -- Namibia -- Case studies Universities and colleges -- Namibia -- Case studies Teachers -- Traning of -- Namibia -- Case studies Teachers -- In-service training -- Namibia Student-centered learning -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1954 , http://hdl.handle.net/10962/d1008260
- Description: The objective of this study was to understand how teacher educators in a Namibian college of education interpret and practice the learner-centred pedagogy underpinning the Basic Education Teachers Diploma (BETD) program. In order to achieve this objective, a case study approach was adopted, qualitative-interpretive in orientation and drawing upon interviews, naturalistic non-participant observation and document analysis. Bernstein's theory of pedagogy - in particular his notion ofrecontextualization - offered ideas and concepts that were used to generate and analyse data. The data indicated that, at the level of description, teacher educators interpreted leamercentred pedagogy as a pedagogic practice based on weak rules of regulative discourse, or a weak power relation between themselves and their student teachers. The weakening of the rules of regulative discourse and the waning of educator authority were indicated in the interview narratives, which evoked a pedagogic context characterized by a repositioning of the student teacher from the margins to the centre of the classroom, where he or she enjoyed a more active and visible pedagogic position. Contrary to the dis empowering dynamic within classroom practice under the apartheid dispensation, the repositioning of the student teacher suggested a shift of power towards him or her. Similarly, the identification of the teacher educator as afacilitator, which featured prominently in the interview narratives, further suggested a weakening or diminishing of the pedagogic authority of the teacher educator. With regard to rules pertaining to the instructional discourse, the data revealed an interpretation of leamer-centred pedagogy as a pedagogic practice based on strong framing over the selection of discourses, weak framing over pacing, and strong framing over sequencing and criteria for evaluation. When correlated with the interview data, the data generated through lesson observation and teacher educator prepared documents such as lesson plans revealed a disjuncture between teacher educators' ideas about leamer-centred pedagogy and their practice of it. Contrary to the interviews, lesson observation data revealed that teacher educators implemented leamer-centred pedagogy as a pedagogic practice based on strong internal framing over rules of the regulative discourse. Data further indicated strong internal framing over the selection, sequencing, pacing and evaluation. The study concluded that while some teacher educators could produce an accurate interpretation oflearner-centred pedagogy at the level of description, most of them did not do so at the level of practice. Findings revealed structural and personal-psychological factors that constrained teacher educators' recontextualization of the new pedagogy. A narrow understanding of leamercentred pedagogy that concentrated only on changing teacher educators' pedagogical approaches from teacher-centred to learner-centred, while ignoring structural and systematic factors, tended to dominate not only the interview narratives but also official texts. Learner-centred pedagogy was understood as a matter of changing from teachercentredness to leamer-centredness while frame factors, for instance regarding the selection, pacing or sequencing of discourses, still followed the traditional approach. The study recommends the adoption of a systematic and deliberate approach to address the multiplicity of factors involved in enabling teacher educators to interpret and implement leamer-centred pedagogy at the micro-level of their classrooms. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: Nyambe, Kamwi John
- Date: 2013-07-16
- Subjects: Bernstein, Basil B Education -- Philosophy Education (Higher) -- Namibia Teacher educators -- Namibia -- Case studies Universities and colleges -- Namibia -- Case studies Teachers -- Traning of -- Namibia -- Case studies Teachers -- In-service training -- Namibia Student-centered learning -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1954 , http://hdl.handle.net/10962/d1008260
- Description: The objective of this study was to understand how teacher educators in a Namibian college of education interpret and practice the learner-centred pedagogy underpinning the Basic Education Teachers Diploma (BETD) program. In order to achieve this objective, a case study approach was adopted, qualitative-interpretive in orientation and drawing upon interviews, naturalistic non-participant observation and document analysis. Bernstein's theory of pedagogy - in particular his notion ofrecontextualization - offered ideas and concepts that were used to generate and analyse data. The data indicated that, at the level of description, teacher educators interpreted leamercentred pedagogy as a pedagogic practice based on weak rules of regulative discourse, or a weak power relation between themselves and their student teachers. The weakening of the rules of regulative discourse and the waning of educator authority were indicated in the interview narratives, which evoked a pedagogic context characterized by a repositioning of the student teacher from the margins to the centre of the classroom, where he or she enjoyed a more active and visible pedagogic position. Contrary to the dis empowering dynamic within classroom practice under the apartheid dispensation, the repositioning of the student teacher suggested a shift of power towards him or her. Similarly, the identification of the teacher educator as afacilitator, which featured prominently in the interview narratives, further suggested a weakening or diminishing of the pedagogic authority of the teacher educator. With regard to rules pertaining to the instructional discourse, the data revealed an interpretation of leamer-centred pedagogy as a pedagogic practice based on strong framing over the selection of discourses, weak framing over pacing, and strong framing over sequencing and criteria for evaluation. When correlated with the interview data, the data generated through lesson observation and teacher educator prepared documents such as lesson plans revealed a disjuncture between teacher educators' ideas about leamer-centred pedagogy and their practice of it. Contrary to the interviews, lesson observation data revealed that teacher educators implemented leamer-centred pedagogy as a pedagogic practice based on strong internal framing over rules of the regulative discourse. Data further indicated strong internal framing over the selection, sequencing, pacing and evaluation. The study concluded that while some teacher educators could produce an accurate interpretation oflearner-centred pedagogy at the level of description, most of them did not do so at the level of practice. Findings revealed structural and personal-psychological factors that constrained teacher educators' recontextualization of the new pedagogy. A narrow understanding of leamercentred pedagogy that concentrated only on changing teacher educators' pedagogical approaches from teacher-centred to learner-centred, while ignoring structural and systematic factors, tended to dominate not only the interview narratives but also official texts. Learner-centred pedagogy was understood as a matter of changing from teachercentredness to leamer-centredness while frame factors, for instance regarding the selection, pacing or sequencing of discourses, still followed the traditional approach. The study recommends the adoption of a systematic and deliberate approach to address the multiplicity of factors involved in enabling teacher educators to interpret and implement leamer-centred pedagogy at the micro-level of their classrooms. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text: