Effect of nanoparticles on the photophysicochemical behaviour of metallophthalocyanines
- Moeno, Sharon Keitumetse Gail Mpheletso
- Authors: Moeno, Sharon Keitumetse Gail Mpheletso
- Date: 2011 , 2011-03-30
- Subjects: Phthalocyanines Nanoparticles Photochemistry Quantum dots
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4310 , http://hdl.handle.net/10962/d1004968
- Description: The synthesis, spectroscopic characterization, and studies of the photophysicochemical behaviour of selective anionic, cationic and neutral metallophthallocyanine (MPc) complexes were carried out and the results are presented herein. Studies on the effect of the central metal ion, the solvent used and the presence of nanoparticles on the photophysicochemical properties were conducted. The findings showed that the photophysicochemical parameters were mostly enhanced in the presence of central metal ions of high atomic numbers and also in the presence of nanoparticles. It was also observed that solvents that encouraged the monomericity of the MPc complexes also lead to improved photophysical and photochemical behaviour. CdTe quantum dots (QDs) stabilized with mercaptocarbonic acids were also observed to cause stimulated emission of the MPcs through Förster resonance energy transfer (FRET) thus acting as energy donors while the respective MPc acted as energy acceptors in all the FRET studies. FRET was observed following the photoexcitation of QDs for all monomeric anionic MPcs but it was also shown to occur for some cationic MPcs in organic media. Both the substituent and solvent used were found to exert a strong influence on the occurrence of FRET. Other cationic MPcs however showed different behaviour in the presence of the meraptocarbonic stabilized CdTe QDs; with the cationic porphyrazine giving clear indications of Pc ring reduction. The rest of the cationic MPcs did not give clear evidence of Pc ring reduction, instead they showed signs of aggregate formation possibly from the assembly of electrostatic ion pair complexes which could result in reduction of the quaternized pyridinium ring of the substituent. Both the QDs and the MPc complex emission spectra were significantly quenched for each in the presence of the other. Stern-Volmer quenching studies indicated that both static and dynamic quenching of the QDs in the presence of MPcs took place. The fluorescence lifetimes of the mercaptopropionic acid (MPA) capped CdTe QDs in the presence of various MPc complexes showed quenching of mostly the longer lifetimes of the QDs in the presence of MPcs suggesting that the surface defects and states are involved in the interaction of the QDs and MPcs. An MPc complex terminating in thio tethers was employed in the conjugation to AuNPs. Spectroscopic and microscopic studies confirmed the formation of the MPc-AuNP conjugate which was also shown to exhibit improved photophysicochemical properties compared to the free MPc.
- Full Text:
- Date Issued: 2011
- Authors: Moeno, Sharon Keitumetse Gail Mpheletso
- Date: 2011 , 2011-03-30
- Subjects: Phthalocyanines Nanoparticles Photochemistry Quantum dots
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4310 , http://hdl.handle.net/10962/d1004968
- Description: The synthesis, spectroscopic characterization, and studies of the photophysicochemical behaviour of selective anionic, cationic and neutral metallophthallocyanine (MPc) complexes were carried out and the results are presented herein. Studies on the effect of the central metal ion, the solvent used and the presence of nanoparticles on the photophysicochemical properties were conducted. The findings showed that the photophysicochemical parameters were mostly enhanced in the presence of central metal ions of high atomic numbers and also in the presence of nanoparticles. It was also observed that solvents that encouraged the monomericity of the MPc complexes also lead to improved photophysical and photochemical behaviour. CdTe quantum dots (QDs) stabilized with mercaptocarbonic acids were also observed to cause stimulated emission of the MPcs through Förster resonance energy transfer (FRET) thus acting as energy donors while the respective MPc acted as energy acceptors in all the FRET studies. FRET was observed following the photoexcitation of QDs for all monomeric anionic MPcs but it was also shown to occur for some cationic MPcs in organic media. Both the substituent and solvent used were found to exert a strong influence on the occurrence of FRET. Other cationic MPcs however showed different behaviour in the presence of the meraptocarbonic stabilized CdTe QDs; with the cationic porphyrazine giving clear indications of Pc ring reduction. The rest of the cationic MPcs did not give clear evidence of Pc ring reduction, instead they showed signs of aggregate formation possibly from the assembly of electrostatic ion pair complexes which could result in reduction of the quaternized pyridinium ring of the substituent. Both the QDs and the MPc complex emission spectra were significantly quenched for each in the presence of the other. Stern-Volmer quenching studies indicated that both static and dynamic quenching of the QDs in the presence of MPcs took place. The fluorescence lifetimes of the mercaptopropionic acid (MPA) capped CdTe QDs in the presence of various MPc complexes showed quenching of mostly the longer lifetimes of the QDs in the presence of MPcs suggesting that the surface defects and states are involved in the interaction of the QDs and MPcs. An MPc complex terminating in thio tethers was employed in the conjugation to AuNPs. Spectroscopic and microscopic studies confirmed the formation of the MPc-AuNP conjugate which was also shown to exhibit improved photophysicochemical properties compared to the free MPc.
- Full Text:
- Date Issued: 2011
Effects of polarization in a distributed raman fibre amplifier
- Authors: Muguro, Kennedy Mwaura
- Date: 2011
- Subjects: Fiber optics , Polarization (Light) , Optical communications , Optical amplifiers , Raman effect
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10544 , http://hdl.handle.net/10948/d1014621
- Description: The need to exploit the large fibre bandwidth and increase the reach has seen the application of the Raman fibre amplifier (RFA) become indispensable in modern light wave systems. The success and resilience of RFAs in optical communication is deeply rooted in their unique optical properties and new technologies which have allowed the amplifier to come of age. However, the full potential of RFAs in optical communication and other applications are yet to be realized. More so are its polarization properties which still remain largely unexploited and have not been fully understood. In this work, fundamental issues regarding distributed RFA have been investigated with the aim of acquiring a better understanding of the amplifier polarization characteristics which have potential applications. In particular the effects of polarization mode dispersion (PMD) and polarization dependent loss (PDL) have been demonstrated both by simulation and experiment. The possibility of Raman polarization pulling in single mode fibres (SMFs) has also been addressed. Polarization sensitivity of RFA has been known for a long time but the clear manifestation of it has become evident in the advent of modern low PMD fibre. Unlike EDFAs which make use of special doped fibre, RFAs require no special fibre for operation. Besides, RFA uses a very long length of fibre and as such the fibre polarization characteristics come into play during amplification. In the demonstrations presented in this thesis a fibre of PMD coefficient < 0.05 pskm-1/2 was regarded as low PMD fibre while one having coefficient ≥ 0.05 pskm-1/2 was categorized to have high PMD unless otherwise stated. Several experiments were performed to evaluate the RFA gain characteristics with respect to fibre PMD and the system performance in the presence of noise emanating from amplified spontaneous emission (ASE). Analysis of Raman gain statistics was done for fibres of low and high PMD coefficients. The statistics of PDG and on-off gain were eventually used to demonstrate the extraction of PMD coefficients of fibres between 0.01- 0.1 pskm-1/2 using a forward pumping configuration. It was found that, at increasing pump power a linear relationship exists between forward and backward signal gain on a dB scale. The interaction of PDL and Raman PDG in the presence of PMD were observed at very fundamental level. It was found the presence of PDL serves to reduce the available on-off gain. It was also established that the presence of PMD mediates the interaction between PDG/PDL. When PMD is high it reduces PDG but the presence of PDL introduces a wavelength dependent gain tilting for WDM channels. Further analysis revealed that signal polarization is influenced by the pump SOP due to the pulling effect which is present even at moderate pump power.
- Full Text:
- Date Issued: 2011
- Authors: Muguro, Kennedy Mwaura
- Date: 2011
- Subjects: Fiber optics , Polarization (Light) , Optical communications , Optical amplifiers , Raman effect
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10544 , http://hdl.handle.net/10948/d1014621
- Description: The need to exploit the large fibre bandwidth and increase the reach has seen the application of the Raman fibre amplifier (RFA) become indispensable in modern light wave systems. The success and resilience of RFAs in optical communication is deeply rooted in their unique optical properties and new technologies which have allowed the amplifier to come of age. However, the full potential of RFAs in optical communication and other applications are yet to be realized. More so are its polarization properties which still remain largely unexploited and have not been fully understood. In this work, fundamental issues regarding distributed RFA have been investigated with the aim of acquiring a better understanding of the amplifier polarization characteristics which have potential applications. In particular the effects of polarization mode dispersion (PMD) and polarization dependent loss (PDL) have been demonstrated both by simulation and experiment. The possibility of Raman polarization pulling in single mode fibres (SMFs) has also been addressed. Polarization sensitivity of RFA has been known for a long time but the clear manifestation of it has become evident in the advent of modern low PMD fibre. Unlike EDFAs which make use of special doped fibre, RFAs require no special fibre for operation. Besides, RFA uses a very long length of fibre and as such the fibre polarization characteristics come into play during amplification. In the demonstrations presented in this thesis a fibre of PMD coefficient < 0.05 pskm-1/2 was regarded as low PMD fibre while one having coefficient ≥ 0.05 pskm-1/2 was categorized to have high PMD unless otherwise stated. Several experiments were performed to evaluate the RFA gain characteristics with respect to fibre PMD and the system performance in the presence of noise emanating from amplified spontaneous emission (ASE). Analysis of Raman gain statistics was done for fibres of low and high PMD coefficients. The statistics of PDG and on-off gain were eventually used to demonstrate the extraction of PMD coefficients of fibres between 0.01- 0.1 pskm-1/2 using a forward pumping configuration. It was found that, at increasing pump power a linear relationship exists between forward and backward signal gain on a dB scale. The interaction of PDL and Raman PDG in the presence of PMD were observed at very fundamental level. It was found the presence of PDL serves to reduce the available on-off gain. It was also established that the presence of PMD mediates the interaction between PDG/PDL. When PMD is high it reduces PDG but the presence of PDL introduces a wavelength dependent gain tilting for WDM channels. Further analysis revealed that signal polarization is influenced by the pump SOP due to the pulling effect which is present even at moderate pump power.
- Full Text:
- Date Issued: 2011
Enhancing the role of the Kaizen suggestion tool in South African lean automotive companies of the Eastern Cape
- Authors: Adedeji, Adeyemi Charles
- Date: 2011
- Subjects: Lean manufacturing , Manufacturing processes , Production management -- Mathematical models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8644 , http://hdl.handle.net/10948/d1008157 , Lean manufacturing , Manufacturing processes , Production management -- Mathematical models
- Description: The Toyota manufacturing system, aptly referred to as Lean manufacturing, has received a reasonable appreciation and awareness over the past decade in South African industry. This production phenomenon constitutes an organizational culture that encourages world-class production success through the liberation of factory resources, while employees are empowered and encouraged to contribute ideas for the improvement of processes and products. However, despite lean awareness and the crucial role of employee participation in the suggestion of ideas in world-class organizations, the performance level of lean manufacturing in South African industry is largely devoid of the Kaizen suggestion tool, particularly in the automotive companies of the Eastern Cape. The aim of this research was to proffer appropriate recommendations, improved awareness, understanding and practice for the improvement of the Kaizen suggestion principle in the automotive companies of the Eastern Cape. The research primarily focused on the ‘management/employees’ paradigm within the organisational context. The methodology employed in the study included a thorough review of the relevant literature and a questionnaire, which was developed and administered to both the management and employees of the thirty automotive components suppliers in Eastern Cape. The target companies constituted the units of analyses and therefore provided the opportunity for a detailed investigation of the links between management and employees as well as a submission of ideas for operational and organisational processes as established in the literature review. Epistemologically, the research is objectivist and paradigmically, positivist. However, some qualitative aspects of the data were relevant to the study and, therefore, were used in a complementary manner. The case approach utilized mixed methods by applying a range of data collection techniques and evidence from multiple sources while the sampling technique was sequential, involving both purposive and stratified random sampling. The study reveals the apparent lack of a systematic mechanism for the practice and administration of the Kaizen suggestion tools in most Eastern Cape automotive companies. This demerit is found to have negatively affected maximum employee participation and involvement in organizational decision making within the Province. The study has established a basic level of awareness and understanding among employees / employers relations that the Kaizen suggestion scheme is a vital tool for delivering strategic objectives in the management of decision making and organizational growth. The study strongly advocates the inclusion of employee suggestion systems as part of the organizational process.
- Full Text:
- Date Issued: 2011
- Authors: Adedeji, Adeyemi Charles
- Date: 2011
- Subjects: Lean manufacturing , Manufacturing processes , Production management -- Mathematical models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8644 , http://hdl.handle.net/10948/d1008157 , Lean manufacturing , Manufacturing processes , Production management -- Mathematical models
- Description: The Toyota manufacturing system, aptly referred to as Lean manufacturing, has received a reasonable appreciation and awareness over the past decade in South African industry. This production phenomenon constitutes an organizational culture that encourages world-class production success through the liberation of factory resources, while employees are empowered and encouraged to contribute ideas for the improvement of processes and products. However, despite lean awareness and the crucial role of employee participation in the suggestion of ideas in world-class organizations, the performance level of lean manufacturing in South African industry is largely devoid of the Kaizen suggestion tool, particularly in the automotive companies of the Eastern Cape. The aim of this research was to proffer appropriate recommendations, improved awareness, understanding and practice for the improvement of the Kaizen suggestion principle in the automotive companies of the Eastern Cape. The research primarily focused on the ‘management/employees’ paradigm within the organisational context. The methodology employed in the study included a thorough review of the relevant literature and a questionnaire, which was developed and administered to both the management and employees of the thirty automotive components suppliers in Eastern Cape. The target companies constituted the units of analyses and therefore provided the opportunity for a detailed investigation of the links between management and employees as well as a submission of ideas for operational and organisational processes as established in the literature review. Epistemologically, the research is objectivist and paradigmically, positivist. However, some qualitative aspects of the data were relevant to the study and, therefore, were used in a complementary manner. The case approach utilized mixed methods by applying a range of data collection techniques and evidence from multiple sources while the sampling technique was sequential, involving both purposive and stratified random sampling. The study reveals the apparent lack of a systematic mechanism for the practice and administration of the Kaizen suggestion tools in most Eastern Cape automotive companies. This demerit is found to have negatively affected maximum employee participation and involvement in organizational decision making within the Province. The study has established a basic level of awareness and understanding among employees / employers relations that the Kaizen suggestion scheme is a vital tool for delivering strategic objectives in the management of decision making and organizational growth. The study strongly advocates the inclusion of employee suggestion systems as part of the organizational process.
- Full Text:
- Date Issued: 2011
Evidence-informed clinical guidelines for nursing care practices related to the safety of the mechanically ventilated patient
- Authors: Jordan, Portia Janine
- Date: 2011
- Subjects: Respiratory intensive care -- South Africa -- Port Elizabeth , Respiratory therapy -- South Africa -- Port Elizabeth , Artificial respiration -- South Africa -- Port Elizabeth , Artificial respiration -- Nursing , Respirators (Medical equipment) -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10027 , http://hdl.handle.net/10948/1322 , Respiratory intensive care -- South Africa -- Port Elizabeth , Respiratory therapy -- South Africa -- Port Elizabeth , Artificial respiration -- South Africa -- Port Elizabeth , Artificial respiration -- Nursing , Respirators (Medical equipment) -- South Africa -- Port Elizabeth
- Description: An evidence-based approach to clinical practice aims to deliver appropriate care in an efficient manner to individual patients. This approach entails the integration of research evidence, clinical expertise and the interpretation of patients' needs and perspectives in making decisions about the best care modalities. The increased emphasis internationally on improved patient care and cost effectiveness in health care delivery highlighted the need for quality health services that have to be built upon the use of best evidence to inform practice and patient-care decision-making (McKenna, Ashton and Keeney, 2004:178). Critical care nursing science, a specialised branch of nursing, focusing on the care of the critically ill patient in a designated unit, is no exception to the drive to provide improved quality and cost-effective patient care. Critical care practitioners are seen to have a specialised knowledge base, specific skills in delivering advanced health care and a commitment to serve the critically ill patient. It is expected of them to be aware of new and emerging evidence about health disease processes, treatment modalities and technology used in the critical-care units. Due to the dynamic nature of a critical care unit, it is essential that every practitioner working in the unit, whether a novice professional nurse or senior unit manager, needs to be aware of the current evidence guiding their practices (Elliot, Aitken, Chaboyer, 2007:18). With reference to the critically ill patient who is connected to a mechanical ventilator, practices related to the nursing care of this group of patients, who mostly occupy the critical care units, should be based on the best evidence in order to provide cost-effective and quality care. The research study aimed to explore and describe four identified nursing care practices related to safety of a mechanically ventilated patient as performed by professional nurses in the critical care units in the Nelson Mandela Metropole. The identified nursing-care practices include: endotrachael tube placement verification, endotracheal tube cuff pressure monitoring, endotrachael tube suctioning and mechanical ventilator settings. This objective was operationalized in Stage One of the study, by using a quantitative, explorative, descriptive and contextual approach. A structured questionnaire was utilised to collect data from professional nurses working in critical care units. From the analysed data, it was decided to select the two nursing care practices that were done least according to the best recommended practice, namely endotracheal tube suctioning and endotracheal tube cuff pressure monitoring. Based on the results, systematic reviews were done respectively on the two nursing care practices. On completion of Stage One of the study, evidence-informed clinical guidelines for the two identified nursing care practices were developed. The clinical guidelines were based on the evidence found in conducting the systematic reviews. The draft clinical guidelines were reviewed by an expert panel. Feedback from the reviewers was considered to prepare the final evidence-informed clinical guidelines. Based on the clinical guidelines, two clinical algorithms were developed, which might be used at the patient's bedside and can assist in quick dissemination of the recommendations for practice. Ethical considerations were maintained throughout the study. The quality of the study was ensured in applying the principles of validity and reliability as well as performing a critical appraisal of all data collected during the systematic review. It is envisaged that the study findings be disseminated in the critical care units in the Nelson Mandela Metropole and published in peer reviewed journals.
- Full Text:
- Date Issued: 2011
- Authors: Jordan, Portia Janine
- Date: 2011
- Subjects: Respiratory intensive care -- South Africa -- Port Elizabeth , Respiratory therapy -- South Africa -- Port Elizabeth , Artificial respiration -- South Africa -- Port Elizabeth , Artificial respiration -- Nursing , Respirators (Medical equipment) -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10027 , http://hdl.handle.net/10948/1322 , Respiratory intensive care -- South Africa -- Port Elizabeth , Respiratory therapy -- South Africa -- Port Elizabeth , Artificial respiration -- South Africa -- Port Elizabeth , Artificial respiration -- Nursing , Respirators (Medical equipment) -- South Africa -- Port Elizabeth
- Description: An evidence-based approach to clinical practice aims to deliver appropriate care in an efficient manner to individual patients. This approach entails the integration of research evidence, clinical expertise and the interpretation of patients' needs and perspectives in making decisions about the best care modalities. The increased emphasis internationally on improved patient care and cost effectiveness in health care delivery highlighted the need for quality health services that have to be built upon the use of best evidence to inform practice and patient-care decision-making (McKenna, Ashton and Keeney, 2004:178). Critical care nursing science, a specialised branch of nursing, focusing on the care of the critically ill patient in a designated unit, is no exception to the drive to provide improved quality and cost-effective patient care. Critical care practitioners are seen to have a specialised knowledge base, specific skills in delivering advanced health care and a commitment to serve the critically ill patient. It is expected of them to be aware of new and emerging evidence about health disease processes, treatment modalities and technology used in the critical-care units. Due to the dynamic nature of a critical care unit, it is essential that every practitioner working in the unit, whether a novice professional nurse or senior unit manager, needs to be aware of the current evidence guiding their practices (Elliot, Aitken, Chaboyer, 2007:18). With reference to the critically ill patient who is connected to a mechanical ventilator, practices related to the nursing care of this group of patients, who mostly occupy the critical care units, should be based on the best evidence in order to provide cost-effective and quality care. The research study aimed to explore and describe four identified nursing care practices related to safety of a mechanically ventilated patient as performed by professional nurses in the critical care units in the Nelson Mandela Metropole. The identified nursing-care practices include: endotrachael tube placement verification, endotracheal tube cuff pressure monitoring, endotrachael tube suctioning and mechanical ventilator settings. This objective was operationalized in Stage One of the study, by using a quantitative, explorative, descriptive and contextual approach. A structured questionnaire was utilised to collect data from professional nurses working in critical care units. From the analysed data, it was decided to select the two nursing care practices that were done least according to the best recommended practice, namely endotracheal tube suctioning and endotracheal tube cuff pressure monitoring. Based on the results, systematic reviews were done respectively on the two nursing care practices. On completion of Stage One of the study, evidence-informed clinical guidelines for the two identified nursing care practices were developed. The clinical guidelines were based on the evidence found in conducting the systematic reviews. The draft clinical guidelines were reviewed by an expert panel. Feedback from the reviewers was considered to prepare the final evidence-informed clinical guidelines. Based on the clinical guidelines, two clinical algorithms were developed, which might be used at the patient's bedside and can assist in quick dissemination of the recommendations for practice. Ethical considerations were maintained throughout the study. The quality of the study was ensured in applying the principles of validity and reliability as well as performing a critical appraisal of all data collected during the systematic review. It is envisaged that the study findings be disseminated in the critical care units in the Nelson Mandela Metropole and published in peer reviewed journals.
- Full Text:
- Date Issued: 2011
Exploring opportunities for action competence development through learners' participation in waste management activities in selected primary schools in Botswana
- Authors: Silo, Nthalivi
- Date: 2011
- Subjects: Environmental education -- Botswana -- Case studies Environmental education -- Study and teaching (Primary) -- Botswana -- Case studies Environmental education -- Activity programs -- Botswana -- Case studies Student-centered learning -- Botswana -- Case studies Refuse and refuse disposal -- Environmental aspects -- Botswana -- Case studies Active learning -- Botswana -- Case studies Competency-based education -- Botswana -- Case studies Teacher-student relationships -- Botswana -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1541 , http://hdl.handle.net/10962/d1003423
- Description: The broader aim of this study is to probe participation of learners in waste management activities in selected primary schools in Botswana and through these activities, explore opportunities for action competence development. The study starts by tracing and outlining the socio-ecological challenges that confront children and the historical background of learner-centred education which gave rise to an emphasis on learner participation in Botswana education policy. It then maps out the development of children's participation in the global, regional and Botswana contexts by tracing the development of environmental education from early ecological and issue resolution goals of environmental education to sustainable development discourses. The focus is on policy issues and how learner participation has been represented and implemented in environmental education. The study then probes the rhetorical and normalised emphases on participation, and seeks further insight into how learners can be engaged in participatory learning processes that are meaningful, purposeful and that broaden their action competence and civic agency. The study uses the Cultural Historical Activity Theory (CHAT) methodology to build a picture of waste management activity systems in primary schools and to bring to the surface contradictions and tensions in learner participation in these activity systems. These contradictions are used to open up expansive learning participatory processes with learners using the Danish action competence framework. The expansive learning process uses action competence models that provide potential for transformative participation with learners, and new and different opportunities for learner participation. Case study research was used and conducted in the south eastern region of Botswana in three primary schools in three contexts, namely urban, peri-urban and rural. The data was largely generated through focus group interviews during workshops with children and observations of waste management activities. These two methods formed the main data generation methods. They were complemented by semi-structured interviews with teachers, and other actors in the waste management activities, learners' activities and work, learners' notes, photographs and children's drawings as well as show-and-tell explanations by learners. Content analysis and the abductive mode of inference were used to analyse data in all three case studies. Findings from the first phase of the study reveal that participation of learners in waste management activities was largely teacher-directed. This resulted in a mis-match between teachers views of what practices are necessary and important, and children's views of what practices are necessary and important in and for environmental education. Due to culturally and historically formed views of environmental education, the study reveals that teachers wanted children to pick up litter, and this was their primary environmental education concern. Learners on the other hand, identified sanitation management in the school toilets as their primary waste management concern. Teachers had not considered this an environmental education concern. Using the action competence expansive learning approach, the second phase of the study addressed this tension by opening up dialogue between teachers and learners and amongst the learners themselves through an expansive learning process supporting children's participation and action competence development. Through this teacher-learner dialogical engagement, a broader range of possibilities became available and ideas around participation were radically changed. The study further reveals that the achievement of this open dialogue provided for a better relationship within the school community. And with improved communication came better ideas to solve waste management issues that the community still face on a daily basis, such as too much litter. Newly devised solutions were practical and had a broader impact than the initial ones that teachers had always focussed on. They included mobilising the maintenance of toilets, landscaping the school premises and even re-contextualising the litter management that had always caused tensions between learners and teachers. Children seemed to be developing not only a better understanding of the environment, but also developing the ability to resolve conflict amongst themselves and with their elders. By engaging in dialogue with children, they became co-catalysts for change in the school community. This study shows that if children's participation is taken seriously, and if opportunities for dialogue exist between teachers and children, positive changes for a healthier environment can be created in schools. It reveals that children also appeared to be feeling more confident and more equipped to consider changes in their environment outside of the school community. The study further shows that participation in environmental education involves more than cognitive changes as proposed in earlier constructivist literature; it includes in-depth engagement with socio-cultural dynamics and histories in the school context, such as the cultural histories of teachers, schooling and authority structures in the cultural community of the school. The study recommends that there is need to strengthen Teacher Education programmes to develop teaching practices and support for teachers to identify ways of engaging learners' views on issues in the school in open, dialogical ways. Such Teacher Education programmes should deepen teachers' understandings of learners' zone of proximal development (ZPD), demonstrating how dialogue and scaffolding are part of a teacher's role in supporting learning. This is shown in the three case studies that form part of this study. Finally, the study also deepens insights of using the Cultural Historical Activity theory (CHAT) to shed light on issues surrounding learner participation within the socio-cultural and historical environmental education contexts of the schools. The action competence models used in the study provide a tool for revealing forms of learner participation. This tool can be used for critical reflections and monitoring of teaching practices in schools.
- Full Text:
- Date Issued: 2011
- Authors: Silo, Nthalivi
- Date: 2011
- Subjects: Environmental education -- Botswana -- Case studies Environmental education -- Study and teaching (Primary) -- Botswana -- Case studies Environmental education -- Activity programs -- Botswana -- Case studies Student-centered learning -- Botswana -- Case studies Refuse and refuse disposal -- Environmental aspects -- Botswana -- Case studies Active learning -- Botswana -- Case studies Competency-based education -- Botswana -- Case studies Teacher-student relationships -- Botswana -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1541 , http://hdl.handle.net/10962/d1003423
- Description: The broader aim of this study is to probe participation of learners in waste management activities in selected primary schools in Botswana and through these activities, explore opportunities for action competence development. The study starts by tracing and outlining the socio-ecological challenges that confront children and the historical background of learner-centred education which gave rise to an emphasis on learner participation in Botswana education policy. It then maps out the development of children's participation in the global, regional and Botswana contexts by tracing the development of environmental education from early ecological and issue resolution goals of environmental education to sustainable development discourses. The focus is on policy issues and how learner participation has been represented and implemented in environmental education. The study then probes the rhetorical and normalised emphases on participation, and seeks further insight into how learners can be engaged in participatory learning processes that are meaningful, purposeful and that broaden their action competence and civic agency. The study uses the Cultural Historical Activity Theory (CHAT) methodology to build a picture of waste management activity systems in primary schools and to bring to the surface contradictions and tensions in learner participation in these activity systems. These contradictions are used to open up expansive learning participatory processes with learners using the Danish action competence framework. The expansive learning process uses action competence models that provide potential for transformative participation with learners, and new and different opportunities for learner participation. Case study research was used and conducted in the south eastern region of Botswana in three primary schools in three contexts, namely urban, peri-urban and rural. The data was largely generated through focus group interviews during workshops with children and observations of waste management activities. These two methods formed the main data generation methods. They were complemented by semi-structured interviews with teachers, and other actors in the waste management activities, learners' activities and work, learners' notes, photographs and children's drawings as well as show-and-tell explanations by learners. Content analysis and the abductive mode of inference were used to analyse data in all three case studies. Findings from the first phase of the study reveal that participation of learners in waste management activities was largely teacher-directed. This resulted in a mis-match between teachers views of what practices are necessary and important, and children's views of what practices are necessary and important in and for environmental education. Due to culturally and historically formed views of environmental education, the study reveals that teachers wanted children to pick up litter, and this was their primary environmental education concern. Learners on the other hand, identified sanitation management in the school toilets as their primary waste management concern. Teachers had not considered this an environmental education concern. Using the action competence expansive learning approach, the second phase of the study addressed this tension by opening up dialogue between teachers and learners and amongst the learners themselves through an expansive learning process supporting children's participation and action competence development. Through this teacher-learner dialogical engagement, a broader range of possibilities became available and ideas around participation were radically changed. The study further reveals that the achievement of this open dialogue provided for a better relationship within the school community. And with improved communication came better ideas to solve waste management issues that the community still face on a daily basis, such as too much litter. Newly devised solutions were practical and had a broader impact than the initial ones that teachers had always focussed on. They included mobilising the maintenance of toilets, landscaping the school premises and even re-contextualising the litter management that had always caused tensions between learners and teachers. Children seemed to be developing not only a better understanding of the environment, but also developing the ability to resolve conflict amongst themselves and with their elders. By engaging in dialogue with children, they became co-catalysts for change in the school community. This study shows that if children's participation is taken seriously, and if opportunities for dialogue exist between teachers and children, positive changes for a healthier environment can be created in schools. It reveals that children also appeared to be feeling more confident and more equipped to consider changes in their environment outside of the school community. The study further shows that participation in environmental education involves more than cognitive changes as proposed in earlier constructivist literature; it includes in-depth engagement with socio-cultural dynamics and histories in the school context, such as the cultural histories of teachers, schooling and authority structures in the cultural community of the school. The study recommends that there is need to strengthen Teacher Education programmes to develop teaching practices and support for teachers to identify ways of engaging learners' views on issues in the school in open, dialogical ways. Such Teacher Education programmes should deepen teachers' understandings of learners' zone of proximal development (ZPD), demonstrating how dialogue and scaffolding are part of a teacher's role in supporting learning. This is shown in the three case studies that form part of this study. Finally, the study also deepens insights of using the Cultural Historical Activity theory (CHAT) to shed light on issues surrounding learner participation within the socio-cultural and historical environmental education contexts of the schools. The action competence models used in the study provide a tool for revealing forms of learner participation. This tool can be used for critical reflections and monitoring of teaching practices in schools.
- Full Text:
- Date Issued: 2011
Exploring ways of assisting Lesotho educators to offer care and support to children orphaned and rendered vulnerable by HIV and AIDS
- Authors: Ntaote, Grace Makeletso
- Date: 2011
- Subjects: Orphans -- Developing Countries -- Social conditions , HIV infections
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9503 , http://hdl.handle.net/10948/1320 , Orphans -- Developing Countries -- Social conditions , HIV infections
- Description: The HIV and AIDS pandemic has resulted in 14 million children being orphaned worldwide. In Lesotho alone, where this study was carried out, there are about 180 000 of these children (UNAIDS, 2007). Teachers, especially in Lesotho‘s primary schools need to be equipped to better deal with the challenges that result from having these children in their classrooms. At the Lesotho College of Education, where I have worked for 12 years as a teacher educator, pre-service and in-service student teachers are not trained to offer care and support to orphans and vulnerable children. They experience problems in the classroom emanating from the needs of these children. This study followed an action research design to find ways to support teachers to better deal with the issues they face as a result of having orphans and vulnerable children in their classes. Using a qualitative approach, educators perceptions, feelings, attitudes and experiences in dealing with orphans and vulnerable children in their schools were identified, and it became apparent that educators were negatively affected on a personal and professional level. It was concluded that the development of resilience in educators would help them to better cope with orphans and vulnerable children in their classes. The chosen intervention Resilient Educators Programme (REds) was implemented and evaluated and findings revealed that it was beneficial in increasing educator resilience. Recommendations, based on the findings of the study, were made for future teacher education in this area.
- Full Text:
- Date Issued: 2011
- Authors: Ntaote, Grace Makeletso
- Date: 2011
- Subjects: Orphans -- Developing Countries -- Social conditions , HIV infections
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9503 , http://hdl.handle.net/10948/1320 , Orphans -- Developing Countries -- Social conditions , HIV infections
- Description: The HIV and AIDS pandemic has resulted in 14 million children being orphaned worldwide. In Lesotho alone, where this study was carried out, there are about 180 000 of these children (UNAIDS, 2007). Teachers, especially in Lesotho‘s primary schools need to be equipped to better deal with the challenges that result from having these children in their classrooms. At the Lesotho College of Education, where I have worked for 12 years as a teacher educator, pre-service and in-service student teachers are not trained to offer care and support to orphans and vulnerable children. They experience problems in the classroom emanating from the needs of these children. This study followed an action research design to find ways to support teachers to better deal with the issues they face as a result of having orphans and vulnerable children in their classes. Using a qualitative approach, educators perceptions, feelings, attitudes and experiences in dealing with orphans and vulnerable children in their schools were identified, and it became apparent that educators were negatively affected on a personal and professional level. It was concluded that the development of resilience in educators would help them to better cope with orphans and vulnerable children in their classes. The chosen intervention Resilient Educators Programme (REds) was implemented and evaluated and findings revealed that it was beneficial in increasing educator resilience. Recommendations, based on the findings of the study, were made for future teacher education in this area.
- Full Text:
- Date Issued: 2011
Factors contributing to the success of professional and business women in South Africa
- Authors: Doubell, Marianne
- Date: 2011
- Subjects: Women executives -- South Africa , Women in the professions -- South Africa , Businesswomen -- South Africa , Career development -- South Africa , Women in development -- South Africa
- Language: English
- Type: Thesis , Doctoral , DCom
- Identifier: vital:9275 , http://hdl.handle.net/10948/1622 , Women executives -- South Africa , Women in the professions -- South Africa , Businesswomen -- South Africa , Career development -- South Africa , Women in development -- South Africa
- Description: Women remain notably underrepresented in management and leadership positions despite the enactment of Equal Opportunity and Affirmative Action policies. A critical literature review yielded evidence of a multitude of barriers inhibiting women’s career advancement beyond an apparent glass ceiling, but not which of the factors constitute the major barriers. A knowledge gap was further identified in research pertaining to characteristics of successful professional women and the environments that enable them to succeed in their professions. The purpose of the current study is to expand the empirical body of research and knowledge on factors contributing to the success of professional women, and of factors inhibiting the career progression of women in business. The study extends that of Punnett, Duffy, Fox, Gregory, Lituchy, Monserrat, Olivas-Luján and Santos (2006) and of Duffy, Fox, Punnett, Gregory, Lituchy, Monserrat, Olivas-Luján, Santos and Miller (2006), conducted in the Americas, to the South African context. The study suggests a conceptual framework for investigating factors that influence professional success of women. The developed conceptual framework of factors perceived to influence professional success was employed to empirically test the relationships between the variables presented. The empirical data collected was subjected to a series of statistical tests and the results considered in testing the hypotheses. Statistica 10 was employed to analyse the empirical data collected. Univariate and multivariate tests (MANOVA) were employed to determine whether sufficient evidence existed to make conclusions about hypotheses one to five of the study, relating to differences between two success groups of women based on their demographics and the selected variables. Pearson Product Moment Correlation (Pearson r) was employed to determine whether sufficient evidence existed to make conclusions about vi hypotheses six to ten, relating to significant relationships between the selected independent variables for the study and the professional success of women. Professional success was measured as job seniority level. For the pipeline success group, professional success was measured as seniority in relation to years in the employment sector and age. The contribution of the study to management science and possible limitations are discussed and recommendations made for future research. Recommendations for the development of women and for the social transformation of organisations are made. The study identifies a number of internal organisational support factors and government interventions which are recommended for inclusion in development initiatives for the achievement of gender equity.
- Full Text:
- Date Issued: 2011
- Authors: Doubell, Marianne
- Date: 2011
- Subjects: Women executives -- South Africa , Women in the professions -- South Africa , Businesswomen -- South Africa , Career development -- South Africa , Women in development -- South Africa
- Language: English
- Type: Thesis , Doctoral , DCom
- Identifier: vital:9275 , http://hdl.handle.net/10948/1622 , Women executives -- South Africa , Women in the professions -- South Africa , Businesswomen -- South Africa , Career development -- South Africa , Women in development -- South Africa
- Description: Women remain notably underrepresented in management and leadership positions despite the enactment of Equal Opportunity and Affirmative Action policies. A critical literature review yielded evidence of a multitude of barriers inhibiting women’s career advancement beyond an apparent glass ceiling, but not which of the factors constitute the major barriers. A knowledge gap was further identified in research pertaining to characteristics of successful professional women and the environments that enable them to succeed in their professions. The purpose of the current study is to expand the empirical body of research and knowledge on factors contributing to the success of professional women, and of factors inhibiting the career progression of women in business. The study extends that of Punnett, Duffy, Fox, Gregory, Lituchy, Monserrat, Olivas-Luján and Santos (2006) and of Duffy, Fox, Punnett, Gregory, Lituchy, Monserrat, Olivas-Luján, Santos and Miller (2006), conducted in the Americas, to the South African context. The study suggests a conceptual framework for investigating factors that influence professional success of women. The developed conceptual framework of factors perceived to influence professional success was employed to empirically test the relationships between the variables presented. The empirical data collected was subjected to a series of statistical tests and the results considered in testing the hypotheses. Statistica 10 was employed to analyse the empirical data collected. Univariate and multivariate tests (MANOVA) were employed to determine whether sufficient evidence existed to make conclusions about hypotheses one to five of the study, relating to differences between two success groups of women based on their demographics and the selected variables. Pearson Product Moment Correlation (Pearson r) was employed to determine whether sufficient evidence existed to make conclusions about vi hypotheses six to ten, relating to significant relationships between the selected independent variables for the study and the professional success of women. Professional success was measured as job seniority level. For the pipeline success group, professional success was measured as seniority in relation to years in the employment sector and age. The contribution of the study to management science and possible limitations are discussed and recommendations made for future research. Recommendations for the development of women and for the social transformation of organisations are made. The study identifies a number of internal organisational support factors and government interventions which are recommended for inclusion in development initiatives for the achievement of gender equity.
- Full Text:
- Date Issued: 2011
Fundamental investigations into the factors affecting the response of laccase-based electrochemical biosensors
- Authors: Fogel, Ronen
- Date: 2011
- Subjects: Laccase Phenols Biosensors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4073 , http://hdl.handle.net/10962/d1007166
- Description: Given their widespread effects and distribution in both natural and industrial environments, the monitoring of phenolic compounds is of considerable analytical interest. Electrochemical biosensor technologies, in particular those comprising laccase enzymes, afford many potential benefits to address this analytical need. However, several key factors affecting sensor response currently limit their applicability. This Thesis reports on the fabrication and optimisation of an electrochemical laccase-based biosensor towards the application of the monitoring of phenolic compounds. Selected factors considered to affect sensor response were investigated using the optimised biosensor. These included: electrochemical, biochemical and substrate-dependent factors, which were found to intersect in modulating biosensor response signals. Through the application of transducer-dependent and substrate-dependent parameters, the selective and simultaneous detection of a mixture of different phenolic analytes is successfully demonstrated. This Thesis also investigates the use of Quartz-Crystal Microbalance with Dissipation (QCM-D) technology, an analytical technique that measures physical parameters of thin-film structures, towards the successful monitoring of enzyme immobilisation strategies. These strategies are fundamental to the successful fabrication of biosensors, and the real-time monitoring of immobilised film formations is of considerable research interest. In the studies reported on in this Thesis, QCM-D technology was demonstrated to be an effective complementary technology in the prediction of film immobilisation techniques on the resultant biochemical kinetics of immobilised enzymes.
- Full Text:
- Date Issued: 2011
- Authors: Fogel, Ronen
- Date: 2011
- Subjects: Laccase Phenols Biosensors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4073 , http://hdl.handle.net/10962/d1007166
- Description: Given their widespread effects and distribution in both natural and industrial environments, the monitoring of phenolic compounds is of considerable analytical interest. Electrochemical biosensor technologies, in particular those comprising laccase enzymes, afford many potential benefits to address this analytical need. However, several key factors affecting sensor response currently limit their applicability. This Thesis reports on the fabrication and optimisation of an electrochemical laccase-based biosensor towards the application of the monitoring of phenolic compounds. Selected factors considered to affect sensor response were investigated using the optimised biosensor. These included: electrochemical, biochemical and substrate-dependent factors, which were found to intersect in modulating biosensor response signals. Through the application of transducer-dependent and substrate-dependent parameters, the selective and simultaneous detection of a mixture of different phenolic analytes is successfully demonstrated. This Thesis also investigates the use of Quartz-Crystal Microbalance with Dissipation (QCM-D) technology, an analytical technique that measures physical parameters of thin-film structures, towards the successful monitoring of enzyme immobilisation strategies. These strategies are fundamental to the successful fabrication of biosensors, and the real-time monitoring of immobilised film formations is of considerable research interest. In the studies reported on in this Thesis, QCM-D technology was demonstrated to be an effective complementary technology in the prediction of film immobilisation techniques on the resultant biochemical kinetics of immobilised enzymes.
- Full Text:
- Date Issued: 2011
Health information technologies for improved continuity of care: a South African perspective
- Authors: Mostert-Phipps, Nicolette
- Date: 2011
- Subjects: Medical records -- Data processing , Medical technology -- South Africa , Medical innovations -- South Africa , Health -- Information services
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9730 , http://hdl.handle.net/10948/1619 , Medical records -- Data processing , Medical technology -- South Africa , Medical innovations -- South Africa , Health -- Information services
- Description: The fragmented nature of modern health care provision makes it increasingly difficult to achieve continuity of care. This is equally true in the context of the South African healthcare landscape. This results in a strong emphasis on the informational dimension of continuity of care which highlights the importance of the continuity of medical records. Paper-based methods of record keeping are inadequate to support informational continuity of care which leads to an increased interest in electronic methods of record keeping through the adoption of various Health Information Technologies (HITs). This research project investigates the role that various HITs such as Personal Health Records (PHRs), Electronic Medical Records (EMRs), and Health Information Exchanges (HIEs) can play in improving informational continuity of care resulting in the development of a standards-based technological model for the South African healthcare sector. This technological model employs appropriate HITs to address the problem of informational continuity of care in the South African healthcare landscape The benefits that are possible through the adoption of the proposed technological model can only be realized if the proposed HITs are used in a meaningful manner once adopted and implemented. The Delphi method is employed to identify factors that need to be addressed to encourage the adoption and meaningful use of such HITs in the South African healthcare landscape. Lastly, guidelines are formulated to encourage the adoption and meaningful use of HITs in the South African healthcare landscape to improve the continuity of care. The guidelines address both the technological requirements on a high level, as well as the factors that need to be addressed to encourage the adoption and meaningful use of the technological components suggested. These guidelines will play a significant role in raising awareness of the factors that need to be addressed to create an environment conducive to the adoption and meaningful use of appropriate HITs in order to improve the continuity of care in the South African healthcare landscape.
- Full Text:
- Date Issued: 2011
- Authors: Mostert-Phipps, Nicolette
- Date: 2011
- Subjects: Medical records -- Data processing , Medical technology -- South Africa , Medical innovations -- South Africa , Health -- Information services
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9730 , http://hdl.handle.net/10948/1619 , Medical records -- Data processing , Medical technology -- South Africa , Medical innovations -- South Africa , Health -- Information services
- Description: The fragmented nature of modern health care provision makes it increasingly difficult to achieve continuity of care. This is equally true in the context of the South African healthcare landscape. This results in a strong emphasis on the informational dimension of continuity of care which highlights the importance of the continuity of medical records. Paper-based methods of record keeping are inadequate to support informational continuity of care which leads to an increased interest in electronic methods of record keeping through the adoption of various Health Information Technologies (HITs). This research project investigates the role that various HITs such as Personal Health Records (PHRs), Electronic Medical Records (EMRs), and Health Information Exchanges (HIEs) can play in improving informational continuity of care resulting in the development of a standards-based technological model for the South African healthcare sector. This technological model employs appropriate HITs to address the problem of informational continuity of care in the South African healthcare landscape The benefits that are possible through the adoption of the proposed technological model can only be realized if the proposed HITs are used in a meaningful manner once adopted and implemented. The Delphi method is employed to identify factors that need to be addressed to encourage the adoption and meaningful use of such HITs in the South African healthcare landscape. Lastly, guidelines are formulated to encourage the adoption and meaningful use of HITs in the South African healthcare landscape to improve the continuity of care. The guidelines address both the technological requirements on a high level, as well as the factors that need to be addressed to encourage the adoption and meaningful use of the technological components suggested. These guidelines will play a significant role in raising awareness of the factors that need to be addressed to create an environment conducive to the adoption and meaningful use of appropriate HITs in order to improve the continuity of care in the South African healthcare landscape.
- Full Text:
- Date Issued: 2011
Identity, belonging and ecological crisis in South African speculative fiction
- Authors: Steenkamp, Elzette Lorna
- Date: 2011
- Subjects: South African fiction -- History and criticism Identity (Philosophical concept) in literature Group identity in literature Ecology in literature Science fiction, South African -- History and criticism Fantasy fiction, South African -- History and criticism Ecofiction -- History and criticism Ecocriticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2219 , http://hdl.handle.net/10962/d1002262
- Description: This study examines a range of South African speculative novels which situate their narratives in futuristic or ‘alternative’ milieus, exploring how these narratives not only address identity formation in a deeply divided and rapidly changing society, but also the ways in which human beings place themselves in relation to Nature and form notions of ‘ecological’ belonging. It offers close readings of these speculative narratives in order to investigate the ways in which they evince concerns which are rooted in the natural, social and political landscapes which inform them. Specific attention is paid to the texts’ treatment of the intertwined issues of identity, belonging and ecological crisis. This dissertation draws on the fields of Ecocriticism, Postcolonial Studies and Science Fiction Studies, and assumes a culturally specific approach to primary texts while investigating possible cross-cultural commonalities between Afrikaans and English speculative narratives, as well as the cross-fertilisation of global SF/speculative features. It is suggested that South African speculative fiction presents a socio-historically situated, rhizomatic approach to ecology – one that is attuned to the tension between humanistic- and ecological concerns.
- Full Text:
- Date Issued: 2011
- Authors: Steenkamp, Elzette Lorna
- Date: 2011
- Subjects: South African fiction -- History and criticism Identity (Philosophical concept) in literature Group identity in literature Ecology in literature Science fiction, South African -- History and criticism Fantasy fiction, South African -- History and criticism Ecofiction -- History and criticism Ecocriticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2219 , http://hdl.handle.net/10962/d1002262
- Description: This study examines a range of South African speculative novels which situate their narratives in futuristic or ‘alternative’ milieus, exploring how these narratives not only address identity formation in a deeply divided and rapidly changing society, but also the ways in which human beings place themselves in relation to Nature and form notions of ‘ecological’ belonging. It offers close readings of these speculative narratives in order to investigate the ways in which they evince concerns which are rooted in the natural, social and political landscapes which inform them. Specific attention is paid to the texts’ treatment of the intertwined issues of identity, belonging and ecological crisis. This dissertation draws on the fields of Ecocriticism, Postcolonial Studies and Science Fiction Studies, and assumes a culturally specific approach to primary texts while investigating possible cross-cultural commonalities between Afrikaans and English speculative narratives, as well as the cross-fertilisation of global SF/speculative features. It is suggested that South African speculative fiction presents a socio-historically situated, rhizomatic approach to ecology – one that is attuned to the tension between humanistic- and ecological concerns.
- Full Text:
- Date Issued: 2011
Improving organisational effectiveness of public enterprises in Kenya
- Authors: Koigi, Alice Nyambura
- Date: 2011
- Subjects: Organisational effectiveness -- Kenya , Organisational change -- Kenya , Performance (Management) , Government business enterprises -- Kenya -- Management
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8660 , http://hdl.handle.net/10948/1316 , Organisational effectiveness -- Kenya , Organisational change -- Kenya , Performance (Management) , Government business enterprises -- Kenya -- Management
- Description: To achieve effectiveness and efficiency in public enterprises, change is needed. Due to the rapid changing global environment and increasing demand for service delivery, continuous change is needed. Changes have been taking place in the Kenyan public sector since 2003. The public enterprises in Kenya, like in most countries in Sub-Saharan Africa, have been characterised by slow and bureaucratic processes that retard organisational performance. Employees and managers in these enterprises have been perceived as not performing as they should. Kenyan public enterprises are important to the economy of the country. They provide social services to the Kenyan population and employ about 654 200 people. The latter translated in a wage bill of 84 378 million Kenyan Shillings (Ksh 80 = 1 US dollar). There is therefore a need to investigate ways to improve individual and organisational performance, collectively viewed as organisational effectiveness in this study, in these enterprises. It is generally accepted that leadership and organisational culture play a critical role in managing the effectiveness of enterprises. In this study, leadership style (transactional and transformational), leadership personality (Machiavellianism, narcissism, masculinity, femininity, individualism and collectivism) and organisational culture (entrepreneurial and market-orientation), strategic management, corporate ethics are investigated determinants of organisational effectiveness. A survey approach was used to collect data from 670 senior executives from 134 Kenyan public (state) enterprises. Two hundred and fifty-six (256) useful survey responses from 53 public enterprises were received. Structural equation modelling (SEM) statistical technique was used to test the hypothesised relationships between the above-mentioned determinants and the dependent variables (individual performance intention and organisational performance). The descriptive statistics of the raw data were also analysed to ascertain the managers’ perceptions about these determinants in the public enterprises. The empirical results revealed that transformational leadership exerts a positive influence on both organisational performance and individual performance intention; that self-deceptive narcissism motivates individual performance intent but decreases organisational performance; that an entrepreneurial, market and strategic management orientation positively influences organisational performance; and that strategy implementation positively influences individual performance intent. In view of these findings, the study concludes that it is critical that leadership styles and leadership personalities be taken into account in leadership recruitment and development process in Kenya public enterprises. Kenyan public enterprises will also improve their organisational performance if they implement entrepreneurial, market and strategic management principles.
- Full Text:
- Date Issued: 2011
- Authors: Koigi, Alice Nyambura
- Date: 2011
- Subjects: Organisational effectiveness -- Kenya , Organisational change -- Kenya , Performance (Management) , Government business enterprises -- Kenya -- Management
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8660 , http://hdl.handle.net/10948/1316 , Organisational effectiveness -- Kenya , Organisational change -- Kenya , Performance (Management) , Government business enterprises -- Kenya -- Management
- Description: To achieve effectiveness and efficiency in public enterprises, change is needed. Due to the rapid changing global environment and increasing demand for service delivery, continuous change is needed. Changes have been taking place in the Kenyan public sector since 2003. The public enterprises in Kenya, like in most countries in Sub-Saharan Africa, have been characterised by slow and bureaucratic processes that retard organisational performance. Employees and managers in these enterprises have been perceived as not performing as they should. Kenyan public enterprises are important to the economy of the country. They provide social services to the Kenyan population and employ about 654 200 people. The latter translated in a wage bill of 84 378 million Kenyan Shillings (Ksh 80 = 1 US dollar). There is therefore a need to investigate ways to improve individual and organisational performance, collectively viewed as organisational effectiveness in this study, in these enterprises. It is generally accepted that leadership and organisational culture play a critical role in managing the effectiveness of enterprises. In this study, leadership style (transactional and transformational), leadership personality (Machiavellianism, narcissism, masculinity, femininity, individualism and collectivism) and organisational culture (entrepreneurial and market-orientation), strategic management, corporate ethics are investigated determinants of organisational effectiveness. A survey approach was used to collect data from 670 senior executives from 134 Kenyan public (state) enterprises. Two hundred and fifty-six (256) useful survey responses from 53 public enterprises were received. Structural equation modelling (SEM) statistical technique was used to test the hypothesised relationships between the above-mentioned determinants and the dependent variables (individual performance intention and organisational performance). The descriptive statistics of the raw data were also analysed to ascertain the managers’ perceptions about these determinants in the public enterprises. The empirical results revealed that transformational leadership exerts a positive influence on both organisational performance and individual performance intention; that self-deceptive narcissism motivates individual performance intent but decreases organisational performance; that an entrepreneurial, market and strategic management orientation positively influences organisational performance; and that strategy implementation positively influences individual performance intent. In view of these findings, the study concludes that it is critical that leadership styles and leadership personalities be taken into account in leadership recruitment and development process in Kenya public enterprises. Kenyan public enterprises will also improve their organisational performance if they implement entrepreneurial, market and strategic management principles.
- Full Text:
- Date Issued: 2011
Informal cross border trading and poverty reduction in the Southern Africa development community: the case of Zimbabwe
- Authors: Kachere, Wadzanai
- Date: 2011
- Subjects: Poverty -- South Africa , Households -- Zimbabwe , Food supply -- Zimbabwe , Entrepreneurship -- Zimbabwe , Poverty -- Economic aspects -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD (Social Science Dev)
- Identifier: vital:11421 , http://hdl.handle.net/10353/500 , Poverty -- South Africa , Households -- Zimbabwe , Food supply -- Zimbabwe , Entrepreneurship -- Zimbabwe , Poverty -- Economic aspects -- Zimbabwe
- Description: This study investigates the impact of informal cross border trading on poverty reduction in Zimbabwe. In the context of this study, the term Informal Cross Border Trade (ICBT), is used to describe the activities of small entrepreneurs who are involved in buying and selling across national borders. The study focuses on whether the stated activities are lifting those participating out of poverty. The research problem is examined through an assessment of the income levels, assets acquirement, expenditures patterns, food security and family relations. The hypotheses tested in the research are that, “The extent of ICBT is significant in Zimbabwe; ICBT in the Southern Africa region is mainly dominated by women; and that ICBT contributes positively to poverty reduction”. In this context, poverty reduction is said to have occurred when informal cross border trading would have resulted in an improvement in the socio-economic wellbeing of traders‟ households. The Poverty Datum Line (PDL) is used as the measure of households‟ well-being. To assess the impact of ICBT on well-being, a survey was conducted whereby in-depth interviews using the questionnaire method were used to collect primary data. Secondary information was obtained from documentary searches at institutions and also using internet searches. From this study it has been found that ICBT has both positive and negative impacts with regard to social welfare. With regard to economic welfare, based on poverty indicator measures used in the study, ICBT contributes positively to Poverty Reduction. Thus the analysis revealed that informal cross border trade plays an important role in alleviating economic hardships, reducing poverty and enhancing welfare and human development in Zimbabwe.
- Full Text:
- Date Issued: 2011
- Authors: Kachere, Wadzanai
- Date: 2011
- Subjects: Poverty -- South Africa , Households -- Zimbabwe , Food supply -- Zimbabwe , Entrepreneurship -- Zimbabwe , Poverty -- Economic aspects -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD (Social Science Dev)
- Identifier: vital:11421 , http://hdl.handle.net/10353/500 , Poverty -- South Africa , Households -- Zimbabwe , Food supply -- Zimbabwe , Entrepreneurship -- Zimbabwe , Poverty -- Economic aspects -- Zimbabwe
- Description: This study investigates the impact of informal cross border trading on poverty reduction in Zimbabwe. In the context of this study, the term Informal Cross Border Trade (ICBT), is used to describe the activities of small entrepreneurs who are involved in buying and selling across national borders. The study focuses on whether the stated activities are lifting those participating out of poverty. The research problem is examined through an assessment of the income levels, assets acquirement, expenditures patterns, food security and family relations. The hypotheses tested in the research are that, “The extent of ICBT is significant in Zimbabwe; ICBT in the Southern Africa region is mainly dominated by women; and that ICBT contributes positively to poverty reduction”. In this context, poverty reduction is said to have occurred when informal cross border trading would have resulted in an improvement in the socio-economic wellbeing of traders‟ households. The Poverty Datum Line (PDL) is used as the measure of households‟ well-being. To assess the impact of ICBT on well-being, a survey was conducted whereby in-depth interviews using the questionnaire method were used to collect primary data. Secondary information was obtained from documentary searches at institutions and also using internet searches. From this study it has been found that ICBT has both positive and negative impacts with regard to social welfare. With regard to economic welfare, based on poverty indicator measures used in the study, ICBT contributes positively to Poverty Reduction. Thus the analysis revealed that informal cross border trade plays an important role in alleviating economic hardships, reducing poverty and enhancing welfare and human development in Zimbabwe.
- Full Text:
- Date Issued: 2011
Information security service management : a service management approach to information security management
- Authors: Rastogi, Rahul
- Date: 2011
- Subjects: Information technology -- Security measures
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9755 , http://hdl.handle.net/10948/1389 , Information technology -- Security measures
- Description: In today’s world, information and the associated Information Technology are critical assets for many organizations. Any information security breach, or compromise of these assets, can lead to serious implications for organizations that are heavily dependent on these assets. For such organizations, information security becomes vital. Organizations deploy an information security infrastructure for protecting their information assets. This infrastructure consists of policies and controls. Organizations also create an information security management system for managing information security in the organization. While some of the policies and controls are of a purely technical nature, many depend upon the actions of end-users. However, end-users are known to exhibit both compliant and noncompliant behaviours in respect of these information security policies and controls in the organization. Non-compliant information security behaviours of end-users have the potential to lead to information security breaches. Non-compliance thus needs to be controlled. The discipline of information security and its management have evolved over the years. However, the discipline has retained the technology-driven nature of its origin. In this context, the discipline has failed to adequately appreciate the role played by the end-users and the complexities of their behaviour, as it relates to information security policies and controls. The pervasive information security management philosophy is that of treating end-users as the enemy. Compliance is sought to be achieved through awareness programs, rewards, punishments and evermore strict policies and controls. This has led to a bureaucratic information security management approach. The philosophy of treating end-users as the enemy has had an adverse impact on information security in the organization. It can be said that rather than curbing non-compliance by end-users, the present-day bureaucratic approach to information security management has contributed to non-compliance. This thesis calls this the end-user crisis. This research aims at resolving this crisis by identifying an improved approach to information security management in the organization. This research has applied the service management approach to information security management. The resultant Information Security Service Management (ISSM) views end-users as assets and resources, and not as enemies. The central idea of ISSM is that the end-user is to be treated as a customer, whose needs are to be satisfied. This research presents ISSM. This research also presents the various components of ISSM to aid in its implementation in an organization.
- Full Text:
- Date Issued: 2011
- Authors: Rastogi, Rahul
- Date: 2011
- Subjects: Information technology -- Security measures
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9755 , http://hdl.handle.net/10948/1389 , Information technology -- Security measures
- Description: In today’s world, information and the associated Information Technology are critical assets for many organizations. Any information security breach, or compromise of these assets, can lead to serious implications for organizations that are heavily dependent on these assets. For such organizations, information security becomes vital. Organizations deploy an information security infrastructure for protecting their information assets. This infrastructure consists of policies and controls. Organizations also create an information security management system for managing information security in the organization. While some of the policies and controls are of a purely technical nature, many depend upon the actions of end-users. However, end-users are known to exhibit both compliant and noncompliant behaviours in respect of these information security policies and controls in the organization. Non-compliant information security behaviours of end-users have the potential to lead to information security breaches. Non-compliance thus needs to be controlled. The discipline of information security and its management have evolved over the years. However, the discipline has retained the technology-driven nature of its origin. In this context, the discipline has failed to adequately appreciate the role played by the end-users and the complexities of their behaviour, as it relates to information security policies and controls. The pervasive information security management philosophy is that of treating end-users as the enemy. Compliance is sought to be achieved through awareness programs, rewards, punishments and evermore strict policies and controls. This has led to a bureaucratic information security management approach. The philosophy of treating end-users as the enemy has had an adverse impact on information security in the organization. It can be said that rather than curbing non-compliance by end-users, the present-day bureaucratic approach to information security management has contributed to non-compliance. This thesis calls this the end-user crisis. This research aims at resolving this crisis by identifying an improved approach to information security management in the organization. This research has applied the service management approach to information security management. The resultant Information Security Service Management (ISSM) views end-users as assets and resources, and not as enemies. The central idea of ISSM is that the end-user is to be treated as a customer, whose needs are to be satisfied. This research presents ISSM. This research also presents the various components of ISSM to aid in its implementation in an organization.
- Full Text:
- Date Issued: 2011
Intellectualisation of African languages with particular reference to isiXhosa
- Authors: Maseko, Pamela
- Date: 2011
- Subjects: Xhosa language -- Study and teaching -- South Africa , Language and education -- South Africa , African languages
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/58035 , vital:27035
- Description: The research explores the relationship between language and education, and motivates for the intellectualisation of African languages, isiXhosa in particular, and for their use in education. The main rationale behind this is that access to, and success in education can largely be realised if that education is mediated in one’s first language. The thesis discusses works of prominent scholars who have written on the subject - relating cognitive abilities and achievement in education to language in which that education is offered. The lack of terminology in new domains in African languages as barrier to mother tongue education is laid bare by looking specifically at the history of intellectualisation of isiXhosa, from the missionaries in the 1820s up to the new endeavours as recently as 2008. Terminologies that were developed during the Bantu Education era, where development of isiXhosa and other indigenous African languages was accelerated in order to respond to the demands of moedertaal-onderwys (mother tongue education) are surveyed, and the process of their development analysed. Three main terminology lists developed during this period are analysed against terminology development principles, approaches and methods that are seen as a measure to ensure quality terminology development. The efforts of the development of isiXhosa during the post-apartheid South Africa, especially the government-driven initiatives, are also critiqued even though these are not as effective and as extensive, especially in education. The result of this analysis is that African languages and isiXhosa in particular, can be used in scientific disciplines and at the highest levels of education. Its grammar is advanced, and its lexicon is extensive such that new concepts that need to be named can be named, using appropriate term creation strategies. There are also technological tools such as WordSmith tools that can be used that can advance its development, ensuring that the concept represented in the newly-created term is precise, concise and appropriate in terms of its discipline. Therefore it is argued that, in the interim, terminologies should be developed, in various subjects, to support learning, which at this stage is mediated in English, for those students who have other languages as mother tongue. Those terminologies that have been developed in the various historical periods should be collated, revised and brought into the classrooms. The thesis argues that real intellectualisation of isiXhosa and other African languages rests on the use of these languages in classrooms and lecture halls, and in the value that all role players place on these languages.
- Full Text:
- Date Issued: 2011
- Authors: Maseko, Pamela
- Date: 2011
- Subjects: Xhosa language -- Study and teaching -- South Africa , Language and education -- South Africa , African languages
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/58035 , vital:27035
- Description: The research explores the relationship between language and education, and motivates for the intellectualisation of African languages, isiXhosa in particular, and for their use in education. The main rationale behind this is that access to, and success in education can largely be realised if that education is mediated in one’s first language. The thesis discusses works of prominent scholars who have written on the subject - relating cognitive abilities and achievement in education to language in which that education is offered. The lack of terminology in new domains in African languages as barrier to mother tongue education is laid bare by looking specifically at the history of intellectualisation of isiXhosa, from the missionaries in the 1820s up to the new endeavours as recently as 2008. Terminologies that were developed during the Bantu Education era, where development of isiXhosa and other indigenous African languages was accelerated in order to respond to the demands of moedertaal-onderwys (mother tongue education) are surveyed, and the process of their development analysed. Three main terminology lists developed during this period are analysed against terminology development principles, approaches and methods that are seen as a measure to ensure quality terminology development. The efforts of the development of isiXhosa during the post-apartheid South Africa, especially the government-driven initiatives, are also critiqued even though these are not as effective and as extensive, especially in education. The result of this analysis is that African languages and isiXhosa in particular, can be used in scientific disciplines and at the highest levels of education. Its grammar is advanced, and its lexicon is extensive such that new concepts that need to be named can be named, using appropriate term creation strategies. There are also technological tools such as WordSmith tools that can be used that can advance its development, ensuring that the concept represented in the newly-created term is precise, concise and appropriate in terms of its discipline. Therefore it is argued that, in the interim, terminologies should be developed, in various subjects, to support learning, which at this stage is mediated in English, for those students who have other languages as mother tongue. Those terminologies that have been developed in the various historical periods should be collated, revised and brought into the classrooms. The thesis argues that real intellectualisation of isiXhosa and other African languages rests on the use of these languages in classrooms and lecture halls, and in the value that all role players place on these languages.
- Full Text:
- Date Issued: 2011
Intelligent automotive thermal comfort control
- Authors: Kranz, Jürgen
- Date: 2011
- Subjects: Automobiles -- Heating and ventilation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9645 , http://hdl.handle.net/10948/1435 , Automobiles -- Heating and ventilation
- Description: Mobility has become a substantial part in our society. Since we spend a lot of our available time on the road, we expect the automotive environment to provide similar comfort levels than residential buildings. Within this context, this research thesis especially focuses on automotive thermal comfort control. The automotive cabin is a very special environment, which is characterized by extreme inhomogeneity and overall transient behavior. Thermal comfort is a very vague and a very subjective term, which depends on physiological and psychological variables. Theories for thermal comfort in transient environments have not been fully established yet and researchers are still busy with its investigation. At present, automotive industry relies on extensive thermal comfort models, manikins and powerful simulation tools to assess and control thermal comfort. This thesis studies the application of artificial intelligence and proposes a blackbox approach which aims for extracting thermal comfort knowledge directly from human's interaction with the HVAC controls. This methodology avoids the use of human physiological and psychological thermal comfort models and does not require any a-priori knowledge. A novel comfort acquisition tool has been developed and has been integrated into a research vehicle in order to gather the required data for system learning. Data has been collected during spring, autumn and summer conditions in Southern Africa. Methods of data mining have been applied and an intelligent implementation using artificial neural networks has been proposed. The achieved results are promising and allow for about 87 perecent correct classification. It is concluded that methods of artificial intelligence perform well and are far superior compared to conventional approaches. These methods can be used as a powerful tool for the development process of vehicle air-conditioning controls and have great potential for time and cost reduction.
- Full Text:
- Date Issued: 2011
- Authors: Kranz, Jürgen
- Date: 2011
- Subjects: Automobiles -- Heating and ventilation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9645 , http://hdl.handle.net/10948/1435 , Automobiles -- Heating and ventilation
- Description: Mobility has become a substantial part in our society. Since we spend a lot of our available time on the road, we expect the automotive environment to provide similar comfort levels than residential buildings. Within this context, this research thesis especially focuses on automotive thermal comfort control. The automotive cabin is a very special environment, which is characterized by extreme inhomogeneity and overall transient behavior. Thermal comfort is a very vague and a very subjective term, which depends on physiological and psychological variables. Theories for thermal comfort in transient environments have not been fully established yet and researchers are still busy with its investigation. At present, automotive industry relies on extensive thermal comfort models, manikins and powerful simulation tools to assess and control thermal comfort. This thesis studies the application of artificial intelligence and proposes a blackbox approach which aims for extracting thermal comfort knowledge directly from human's interaction with the HVAC controls. This methodology avoids the use of human physiological and psychological thermal comfort models and does not require any a-priori knowledge. A novel comfort acquisition tool has been developed and has been integrated into a research vehicle in order to gather the required data for system learning. Data has been collected during spring, autumn and summer conditions in Southern Africa. Methods of data mining have been applied and an intelligent implementation using artificial neural networks has been proposed. The achieved results are promising and allow for about 87 perecent correct classification. It is concluded that methods of artificial intelligence perform well and are far superior compared to conventional approaches. These methods can be used as a powerful tool for the development process of vehicle air-conditioning controls and have great potential for time and cost reduction.
- Full Text:
- Date Issued: 2011
Investigating the impact of a psychometric assessment technique in the South African automotive industry
- Authors: Piro, Karen
- Date: 2011
- Subjects: Automobile industry and trade -- South Africa -- Employees -- Ability testing , Automobile industry and trade -- South Africa -- Employees -- Training of
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9397 , http://hdl.handle.net/10948/1381 , Automobile industry and trade -- South Africa -- Employees -- Ability testing , Automobile industry and trade -- South Africa -- Employees -- Training of
- Description: This research takes place in a South African multinational automotive industry, which needs to be on the forefront for being globally competitive and sustainable to remain viable in the country. A strategic initiative was embarked upon to identify talent within their staff population, through the psychometric assessment of learning potential. The objective was to identify high potential employees and provide them with the requisite training and development to meet the demands of the rapidly advancing technology. The primary purpose of this study is to investigate the usefulness of the Ability, Process of Information and Learning Battery (APIL) as a psychometric assessment tool for identifying talent, within a heterogeneous workforce. This research adopts a cross-cultural approach as it is comparative in nature and addresses the adequacy of a psychometric instrument in a multicultural context. The Employment Equity Act has transformed the landscape of the use of psychological measurement in South Africa, in that it stipulates that no psychological test that is biased against any cultural group can be used. A sample of 841 heterogeneous staff employees was assessed with three major research objectives: (a) to ensure that the instrument could stand scientific scrutiny thereby complying with the Employment Equity Act; (b) to recommend ways the organisation can identify and understand employees’ talent more holistically; and (c) to manage talent more effectively. The heterogeneous sample was divided into six homogeneous subsets for statistical analysis. This research attempted to answer the first objective through the examination of internal consistency, bias and equivalence of the APIL. Results showed good internal consistency, very good construct equivalence and low item bias, demonstrating the APIL can be applied fairly in a multicultural industrial setting. The second objective was determined by investigating whether significant difference in mean learning potential scores occur among the identified subsets in the sample. Statistical analyses provide clear trend lines indicating that sociopolitical and socioeconomic factors of advantagement and disadvantagement, age and education influence learning potential. However it is also evident that there are individuals across all subsets that demonstrate strong cognitive potential. This supports the rationale on which the APIL was developed, in that it distinguishes people with high learning potential despite the fact that there may be gaps or limitations in skill repertoire due to past disadvantagement. Recommendations to address the third objective is provided by aligning learning potential with the performance management system to provide a holistic overview of the talent composition. This will assist in the identifying of strategic training and development interventions needed at the individual, functional and organisational level, which is key for the South African automotive industry to remain competitive and viable.
- Full Text:
- Date Issued: 2011
- Authors: Piro, Karen
- Date: 2011
- Subjects: Automobile industry and trade -- South Africa -- Employees -- Ability testing , Automobile industry and trade -- South Africa -- Employees -- Training of
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9397 , http://hdl.handle.net/10948/1381 , Automobile industry and trade -- South Africa -- Employees -- Ability testing , Automobile industry and trade -- South Africa -- Employees -- Training of
- Description: This research takes place in a South African multinational automotive industry, which needs to be on the forefront for being globally competitive and sustainable to remain viable in the country. A strategic initiative was embarked upon to identify talent within their staff population, through the psychometric assessment of learning potential. The objective was to identify high potential employees and provide them with the requisite training and development to meet the demands of the rapidly advancing technology. The primary purpose of this study is to investigate the usefulness of the Ability, Process of Information and Learning Battery (APIL) as a psychometric assessment tool for identifying talent, within a heterogeneous workforce. This research adopts a cross-cultural approach as it is comparative in nature and addresses the adequacy of a psychometric instrument in a multicultural context. The Employment Equity Act has transformed the landscape of the use of psychological measurement in South Africa, in that it stipulates that no psychological test that is biased against any cultural group can be used. A sample of 841 heterogeneous staff employees was assessed with three major research objectives: (a) to ensure that the instrument could stand scientific scrutiny thereby complying with the Employment Equity Act; (b) to recommend ways the organisation can identify and understand employees’ talent more holistically; and (c) to manage talent more effectively. The heterogeneous sample was divided into six homogeneous subsets for statistical analysis. This research attempted to answer the first objective through the examination of internal consistency, bias and equivalence of the APIL. Results showed good internal consistency, very good construct equivalence and low item bias, demonstrating the APIL can be applied fairly in a multicultural industrial setting. The second objective was determined by investigating whether significant difference in mean learning potential scores occur among the identified subsets in the sample. Statistical analyses provide clear trend lines indicating that sociopolitical and socioeconomic factors of advantagement and disadvantagement, age and education influence learning potential. However it is also evident that there are individuals across all subsets that demonstrate strong cognitive potential. This supports the rationale on which the APIL was developed, in that it distinguishes people with high learning potential despite the fact that there may be gaps or limitations in skill repertoire due to past disadvantagement. Recommendations to address the third objective is provided by aligning learning potential with the performance management system to provide a holistic overview of the talent composition. This will assist in the identifying of strategic training and development interventions needed at the individual, functional and organisational level, which is key for the South African automotive industry to remain competitive and viable.
- Full Text:
- Date Issued: 2011
Investigation and laboratory tests of sub-economic aluminium resources in China
- Authors: Hu, Sichun
- Date: 2011
- Subjects: Aluminum -- China , Bauxite -- China , Iron -- China , Sulfur -- China , Fertilizers -- China
- Language: English
- Type: Thesis , Doctoral , PhD (Geology)
- Identifier: vital:11520 , http://hdl.handle.net/10353/436 , Aluminum -- China , Bauxite -- China , Iron -- China , Sulfur -- China , Fertilizers -- China
- Description: China, the largest aluminium producer, is seriously lacking of reserves at the present and in the future. However, there are a huge amount of sub-economic aluminium resources (high iron diasporic, low A/S and high iron gibbsite and high sulfur diasporic bauxite), and potassic sandy shale suitable for the extraction of aluminium and the production of potassium and silicon fertilizers if proper metallurgical processes are developed. This study aims to investigate the sub-economic aluminium resources through investigation and identify the right technologies through laboratory tests for metal extraction and utilization of the by-products of K-feldspar sandy shale. The investigation of the sub-economic aluminium resources includes field and site visits and data collection and collation. A series of laboratory scale tests were carried out for different types of bauxite and potassic sandy shale, which includes initial try tests and formal laboratory experiments for optimization of the processes and procedures, and crop planting tests for use of potassium and silicon fertilizers. The successful laboratory tests (technologies) in this study were optimized and proved to be effective. The results showed: 1) Medium temperature metallization roasting and then magnetic separation, and gas reduction metallization roasting and then magnetic separation are effective for processing of the high iron diasporic bauxite; 2) Dry magnetic separation, wet magnetic separation and medium temperature magnetization roasting and then magnetic separation are not effective for processing of the high iron diasporic bauxite; 3) Digestion at atmospheric conditions and high caustic alkali concentration is effective for processing of low A/S and high iron gibbsite bauxite; 4) Desulfurization flotation and desulfurization with barium aluminate are both effective for processing of the high sulfur bauxite. However, each of these methods have their own advantages and disadvantages and must be evaluated; and 5) The soda-lime sintering process is suitable for processing of the Linzhou potassic sandy shale. The aluminium and potassium are extracted and the silicon residues can be used for silicon fertilizer. The results of this study help solve the problem of aluminium reserve shortage. They also open a new way for integrated utilization of other aluminium resources including potassic sandy shale.
- Full Text:
- Date Issued: 2011
- Authors: Hu, Sichun
- Date: 2011
- Subjects: Aluminum -- China , Bauxite -- China , Iron -- China , Sulfur -- China , Fertilizers -- China
- Language: English
- Type: Thesis , Doctoral , PhD (Geology)
- Identifier: vital:11520 , http://hdl.handle.net/10353/436 , Aluminum -- China , Bauxite -- China , Iron -- China , Sulfur -- China , Fertilizers -- China
- Description: China, the largest aluminium producer, is seriously lacking of reserves at the present and in the future. However, there are a huge amount of sub-economic aluminium resources (high iron diasporic, low A/S and high iron gibbsite and high sulfur diasporic bauxite), and potassic sandy shale suitable for the extraction of aluminium and the production of potassium and silicon fertilizers if proper metallurgical processes are developed. This study aims to investigate the sub-economic aluminium resources through investigation and identify the right technologies through laboratory tests for metal extraction and utilization of the by-products of K-feldspar sandy shale. The investigation of the sub-economic aluminium resources includes field and site visits and data collection and collation. A series of laboratory scale tests were carried out for different types of bauxite and potassic sandy shale, which includes initial try tests and formal laboratory experiments for optimization of the processes and procedures, and crop planting tests for use of potassium and silicon fertilizers. The successful laboratory tests (technologies) in this study were optimized and proved to be effective. The results showed: 1) Medium temperature metallization roasting and then magnetic separation, and gas reduction metallization roasting and then magnetic separation are effective for processing of the high iron diasporic bauxite; 2) Dry magnetic separation, wet magnetic separation and medium temperature magnetization roasting and then magnetic separation are not effective for processing of the high iron diasporic bauxite; 3) Digestion at atmospheric conditions and high caustic alkali concentration is effective for processing of low A/S and high iron gibbsite bauxite; 4) Desulfurization flotation and desulfurization with barium aluminate are both effective for processing of the high sulfur bauxite. However, each of these methods have their own advantages and disadvantages and must be evaluated; and 5) The soda-lime sintering process is suitable for processing of the Linzhou potassic sandy shale. The aluminium and potassium are extracted and the silicon residues can be used for silicon fertilizer. The results of this study help solve the problem of aluminium reserve shortage. They also open a new way for integrated utilization of other aluminium resources including potassic sandy shale.
- Full Text:
- Date Issued: 2011
Investigation of antidiabetic properties, mechanisms of action and toxicology of Strychnos Henningsii (GILG) bark
- Authors: Oyewole, Oyedemi Sunday
- Date: 2011
- Subjects: Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Diabetics -- Alternative treatment -- South Africa , Loganiaceae , Lamiaceae , Diabetes , Proteins
- Language: English
- Type: Thesis , Doctoral , PhD (Biochemistry)
- Identifier: vital:11254 , http://hdl.handle.net/10353/d1001070 , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Diabetics -- Alternative treatment -- South Africa , Loganiaceae , Lamiaceae , Diabetes , Proteins
- Description: The apparent reversal of trend from modern drugs to herbal medicine is partly due to the fact that synthetic drugs have always shown adverse reactions and other undesirable side effects. Hence, the use of medicinal plants for the treatment of diseases such as diabetes is very common especially in the rural areas. Majority of these plants are used based on the experience and indigenous knowledge without identification of the therapeutic agents. There is enormous wealth of medicinal plants in the world yet many of them have not been discovered or studied scientifically to substantiate their ethno-medicinal usages. Ethnobotanical study has been the method often used to search for locally important plant species for the discovery of crude drugs with low side effects. An ethnobotanical survey was conducted on the medicinal plants commonly used for the management of diabetes mellitus in Nkonkobe Municipality, Eastern Cape of South Africa. Information was obtained through structured questionnaire administered to traditional healers and herbalists in the region. The study revealed 15 species of plants belonging to 13 families. Strychnos henningsii and Leonotis leonorus among others were repeatedly mentioned by the traditional healers as the two mostly used plants for the management of diabetes mellitus. The infusion and decoction of the roots, leaves and barks of these plants are the methods of preparation. The antioxidant potential of aqueous bark extract of S. henningsii was investigated both in vivo and in vitro using spectroscopic method. The antioxidant activity of the extract against hydrogen peroxide (H2O2), 2,2′-azinobis[3-ethylbenzothiazoline6-sulfonic acid] diammonium salt (ABTS), as well as reducing power was concentration dependent. The extract exhibited lower and average scavenging activities against 1,1diphenyl2picrylhydrazyl (DPPH) and nitric oxide (NO) radicals with IC50 value of 0.739 and 0.49 mg/ml respectively. The administration of the plant extract at 250, 500 and 1000 mg/kg significantly increased the activities of the antioxidant enzymes in the hepatotoxic rats induced with carbon tetrachloride. On the other hand, the stem bark extract had lower effect on lipid peroxidation level except at the dose of 250 mg/kg. The effect of oral administration of S. henningsii extract was evaluated in normal Wistar rats for 28 days. The observed result indicated non- toxic effect of sub-acute administration of plant extract to the animals except at certain doses. This is because, there was no apparent damage to some haematological and biochemical parameters used in assessing organ specific toxicity. However, the alterations observed on platelet, white blood cells and its differentials imply parameter and dose selective toxicity when repeatedly consumed on daily basis at the doses investigated. This study also investigated the antidiabetic activities of the extract at the doses of 125, 250 and 500 mg/kg body weight in diabetic rats induced with streptozotocin -nicotinamide for 15 days. The extract appreciably (P <0.05) reduced the blood glucose level, feed and water intake while the best result was obtained at 250 mg/kg. Similarly, the level of triacylglycerol at the three doses investigated was significantly decreased. In addition, the glucose tolerance was reduced to near normal level after 90 min at certain doses. The clinical significance of the extract on some biochemical and haematological parameters lessen both hepatic and renal damages. Anaemic condition in diabetic animals was also improved after plant extract administration. However, no significant effect was observed in white blood cells and some of its differentials. The extract demonstrated strong glucose utilization in 3T3-L1 cells with a response of 278.63 percent of the control at 12.5μg/ml while that of Chang liver cells was 103.54 percent. The cytotoxicity result revealed non toxic effects of the extract to both cell lines. Treatment of 3T3 L1 cells with the extract did not reduce lipid accumulation. The extract inhibited the activity of α- glucosidase and α- amylase in a concentration dependent manner with IC50 values of 38 μg/ml and 60.9 μg/ml respectively. The percentage protein antiglycation of S. henningsii was 18.4, 38.2 and 61.2 perceent for 0.25, 0.5 and 1 mg/ml respectively while aminoguanidine a known inhibitor of protein glycation was 87.2 percent at 1 mg/ml. The FRAP assay values of the extract was 357.05 μmol Fe (II)/g. The findings from this study support the folkloric usage of this plant for the management of diabetes mellitus in the region.
- Full Text:
- Date Issued: 2011
- Authors: Oyewole, Oyedemi Sunday
- Date: 2011
- Subjects: Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Diabetics -- Alternative treatment -- South Africa , Loganiaceae , Lamiaceae , Diabetes , Proteins
- Language: English
- Type: Thesis , Doctoral , PhD (Biochemistry)
- Identifier: vital:11254 , http://hdl.handle.net/10353/d1001070 , Medicinal plants -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Eastern Cape , Diabetics -- Alternative treatment -- South Africa , Loganiaceae , Lamiaceae , Diabetes , Proteins
- Description: The apparent reversal of trend from modern drugs to herbal medicine is partly due to the fact that synthetic drugs have always shown adverse reactions and other undesirable side effects. Hence, the use of medicinal plants for the treatment of diseases such as diabetes is very common especially in the rural areas. Majority of these plants are used based on the experience and indigenous knowledge without identification of the therapeutic agents. There is enormous wealth of medicinal plants in the world yet many of them have not been discovered or studied scientifically to substantiate their ethno-medicinal usages. Ethnobotanical study has been the method often used to search for locally important plant species for the discovery of crude drugs with low side effects. An ethnobotanical survey was conducted on the medicinal plants commonly used for the management of diabetes mellitus in Nkonkobe Municipality, Eastern Cape of South Africa. Information was obtained through structured questionnaire administered to traditional healers and herbalists in the region. The study revealed 15 species of plants belonging to 13 families. Strychnos henningsii and Leonotis leonorus among others were repeatedly mentioned by the traditional healers as the two mostly used plants for the management of diabetes mellitus. The infusion and decoction of the roots, leaves and barks of these plants are the methods of preparation. The antioxidant potential of aqueous bark extract of S. henningsii was investigated both in vivo and in vitro using spectroscopic method. The antioxidant activity of the extract against hydrogen peroxide (H2O2), 2,2′-azinobis[3-ethylbenzothiazoline6-sulfonic acid] diammonium salt (ABTS), as well as reducing power was concentration dependent. The extract exhibited lower and average scavenging activities against 1,1diphenyl2picrylhydrazyl (DPPH) and nitric oxide (NO) radicals with IC50 value of 0.739 and 0.49 mg/ml respectively. The administration of the plant extract at 250, 500 and 1000 mg/kg significantly increased the activities of the antioxidant enzymes in the hepatotoxic rats induced with carbon tetrachloride. On the other hand, the stem bark extract had lower effect on lipid peroxidation level except at the dose of 250 mg/kg. The effect of oral administration of S. henningsii extract was evaluated in normal Wistar rats for 28 days. The observed result indicated non- toxic effect of sub-acute administration of plant extract to the animals except at certain doses. This is because, there was no apparent damage to some haematological and biochemical parameters used in assessing organ specific toxicity. However, the alterations observed on platelet, white blood cells and its differentials imply parameter and dose selective toxicity when repeatedly consumed on daily basis at the doses investigated. This study also investigated the antidiabetic activities of the extract at the doses of 125, 250 and 500 mg/kg body weight in diabetic rats induced with streptozotocin -nicotinamide for 15 days. The extract appreciably (P <0.05) reduced the blood glucose level, feed and water intake while the best result was obtained at 250 mg/kg. Similarly, the level of triacylglycerol at the three doses investigated was significantly decreased. In addition, the glucose tolerance was reduced to near normal level after 90 min at certain doses. The clinical significance of the extract on some biochemical and haematological parameters lessen both hepatic and renal damages. Anaemic condition in diabetic animals was also improved after plant extract administration. However, no significant effect was observed in white blood cells and some of its differentials. The extract demonstrated strong glucose utilization in 3T3-L1 cells with a response of 278.63 percent of the control at 12.5μg/ml while that of Chang liver cells was 103.54 percent. The cytotoxicity result revealed non toxic effects of the extract to both cell lines. Treatment of 3T3 L1 cells with the extract did not reduce lipid accumulation. The extract inhibited the activity of α- glucosidase and α- amylase in a concentration dependent manner with IC50 values of 38 μg/ml and 60.9 μg/ml respectively. The percentage protein antiglycation of S. henningsii was 18.4, 38.2 and 61.2 perceent for 0.25, 0.5 and 1 mg/ml respectively while aminoguanidine a known inhibitor of protein glycation was 87.2 percent at 1 mg/ml. The FRAP assay values of the extract was 357.05 μmol Fe (II)/g. The findings from this study support the folkloric usage of this plant for the management of diabetes mellitus in the region.
- Full Text:
- Date Issued: 2011
Investigation of photosensitising behaviour of Ni, Pd and Pt phthalocyanines towards phenolic pollutants
- Authors: Ogunbayo, Taofeek Babatunde
- Date: 2011
- Subjects: Phthalocyanines Pollutants Photochemistry Photosensitizing compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4321 , http://hdl.handle.net/10962/d1004979
- Description: Syntheses of various octasubstituted open-shell (Ni(II), Pd(II) and Pt(II)) metallophthalocyanines and their metal-free analogues have been carried out. Spectroscopic characterizations, photophysical and photochemical studies were carried out to determine the effects of these metals on the molecules using the metal-free phthalocyanine analogues as benchmark. Metal-binding studies of few thio-derivatised phthalocyanines were done to increase the number of palladium metal on the phthalocyanine ligands and determine the effect of increasing number of this metal on phthalocyanine properties. Palladium (PdPc) and platinum phthalocyanines (PtPc) gave good triplet and singlet oxygen quantum yields making them suitable for further investigation in application as photosensitisers. Using 4-nitrophenol as model pollutant, photosensitization reactions were carried out under homogenous and heterogeneous conditions. The reactions were monitored using UV-vis spectroscopy. The MPcs were adsorbed on functionalized single wall carbon nanotube (SWCNT-COOH) to form heterogeneous photosensitizers with PtPc failing to adsorb on the SWCNT-COOH. Under the heterogeneous condition, all the PdPcs photosensitization kinetics was consistent with Langmuir-Hinshelwood reaction model. The best photosenstiser, β-palladium dodecylthio phthalocyanine was also deployed in sensitization of oxidation of 4-chlorophenol and pentachlorophenol under homogenous and heterogeneous conditions to establish the ability of the molecules to sensitize oxidation of wide range of phenolic pollutants. Identifications of the products of the reactions were conducted using gas chromatography and high pressure liquid chromatography (HPLC) hyphenated with mass analyzer (LC-MS). Mechanisms of all the reactions were investigated and all the complexes, in spite of reduced lifetime resulting from open-shell nature of the metals, sensitized the reactions through singlet oxygen mediated pathway. All the heterogeneous sensitisers were recyclable in the 4- nitrophenol oxidation but β-palladium dodecylthio phthalocyanine proved unrecyclable in the oxidation of pentachlorophenol.
- Full Text:
- Date Issued: 2011
- Authors: Ogunbayo, Taofeek Babatunde
- Date: 2011
- Subjects: Phthalocyanines Pollutants Photochemistry Photosensitizing compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4321 , http://hdl.handle.net/10962/d1004979
- Description: Syntheses of various octasubstituted open-shell (Ni(II), Pd(II) and Pt(II)) metallophthalocyanines and their metal-free analogues have been carried out. Spectroscopic characterizations, photophysical and photochemical studies were carried out to determine the effects of these metals on the molecules using the metal-free phthalocyanine analogues as benchmark. Metal-binding studies of few thio-derivatised phthalocyanines were done to increase the number of palladium metal on the phthalocyanine ligands and determine the effect of increasing number of this metal on phthalocyanine properties. Palladium (PdPc) and platinum phthalocyanines (PtPc) gave good triplet and singlet oxygen quantum yields making them suitable for further investigation in application as photosensitisers. Using 4-nitrophenol as model pollutant, photosensitization reactions were carried out under homogenous and heterogeneous conditions. The reactions were monitored using UV-vis spectroscopy. The MPcs were adsorbed on functionalized single wall carbon nanotube (SWCNT-COOH) to form heterogeneous photosensitizers with PtPc failing to adsorb on the SWCNT-COOH. Under the heterogeneous condition, all the PdPcs photosensitization kinetics was consistent with Langmuir-Hinshelwood reaction model. The best photosenstiser, β-palladium dodecylthio phthalocyanine was also deployed in sensitization of oxidation of 4-chlorophenol and pentachlorophenol under homogenous and heterogeneous conditions to establish the ability of the molecules to sensitize oxidation of wide range of phenolic pollutants. Identifications of the products of the reactions were conducted using gas chromatography and high pressure liquid chromatography (HPLC) hyphenated with mass analyzer (LC-MS). Mechanisms of all the reactions were investigated and all the complexes, in spite of reduced lifetime resulting from open-shell nature of the metals, sensitized the reactions through singlet oxygen mediated pathway. All the heterogeneous sensitisers were recyclable in the 4- nitrophenol oxidation but β-palladium dodecylthio phthalocyanine proved unrecyclable in the oxidation of pentachlorophenol.
- Full Text:
- Date Issued: 2011
Land use change, landslide occurrence and livelihood strategies on Mount Elgon Slopes, Eastern Uganda
- Authors: Mugagga, Frank
- Date: 2011
- Subjects: Land use -- Uganda -- Mount Elgon National Park , Landslides -- Uganda -- Mount Elgon National Park , Land degradation -- Uganda -- Mount Elgon National Park
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10646 , http://hdl.handle.net/10948/1468 , Land use -- Uganda -- Mount Elgon National Park , Landslides -- Uganda -- Mount Elgon National Park , Land degradation -- Uganda -- Mount Elgon National Park
- Description: An investigation of the relationship between the physical, pedological and anthropogenic influences on landslide occurrence on the midslopes within and outside Mt Elgon National Park was carried out. One of the landslides occurred in a protected pristine forest environment within the Park while the other two were located at sites deforested for cultivation within and outside the National Park. Field based surveys, GIS techniques and laboratory tests were used to collect and analyze the data. A household survey was undertaken to establish the main community livelihood strategies, the drivers of land use change and implications for land degradation on the mid slopes of Mt Elgon. Aerial photographs taken in 1960 and orthophoto maps formed the benchmark for the analysis of the respective land use changes between 1995 and 2006, using 30m Landsat TM and 20m SPOT MS images in IDRISI Andes GIS environment. Landslide sites were mapped using a Magellan Professional MobileMapperTMCX and terrain parameters were derived using a 15M Digital Elevation Model. A hybrid supervised/unsupervised classification approach was employed to generate land cover maps from which the areal extent of three land cover classes (agricultural fields, woodlands and forests) was calculated. Particle size distribution and atterberg limits were used to test the hypothesis that soils at the landslide sites are inherently ‘problem soils’ where slope failure can occur even without human intervention. Shear strength parameters (internal of friction and cohesion) were used calculate the slope factor of safety to ascertain slope stability at pristine and disturbed landslide sites. Results from the socio-economic survey revealed that smallholder subsistence agriculture and encroachment on the National Park resources are the main sources of livelihoods for the communities surrounding the Park. The communities also have a strong socio-cultural attachment to the National Park, as it is the source of items used during traditional rituals like circumcision. Encroachment is driven by the high population pressure and the prevalent political climate. Farmers mainly use slash and burn technique to prepare land for cultivation and those close to the National Park are reluctant to adopt appropriate farming and soil conservation practices due to the uncertainties surrounding their future on such plots. Slash and burn iii techniques were observed to accelerate various forms of erosion including rills, gullies and sheet. Soil and water conservation techniques were mainly practiced on privately owned farms. The period 1960 and 1995 was characterized by minimal land use changes and no encroachment into the designated Mount Elgon National Park. Conversely, the period 1995 – 2006 marked a significant loss of woodlands and forest cover particularly on steep concave slopes (36º – 58º) within the National Park. The land use change trends were attributed to the prevalent land politics and exponential population growth in the region. The encroachment onto the critical slopes was noted to have induced a series of shallow and deep landslides in the area. Deforestation on Mt Elgon was reported to have both onsite and offsite climate variability and implications in the form of drought, heat waves, flash floods, economic dislocation, crop failure and associated malnutrition in surrounding low lying areas. The soils on pristine and disturbed slopes contain high amount of clay (>10 percent), are fine textured (>50 percent of the material passing the 0.075mm sieve) and highly plastic. These soil attributes imply low permeability, excessive water retention and high susceptibility to expansion and sliding. The vertic nature of soils at Nametsi was confirmed by the extremely high plasticity indices (averaging 33percent), while, high liquid limits at Buwabwala (53 percent) and Kitati (59 percent) qualified the soils as vertisols which are associated with landslides. The results point to the fact that soils at landslide sites are inherently ‘problem soils’ where slope failure can occur even without human intervention. Therefore, the hypothesis that soils at three landslide sites are inherently ‘problem soils’ where slope failure can occur even without human intervention is accepted. Notwithstanding the fact that the study was focussed on mid-altitude slopes of Mt Elgon, the results are in tandem with investigations carried out earlier on the lower densely populated slopes, thus confirming the widespread nature of problem soils on Mt Elgon. There is an urgent need to control human population growth and restore forest cover on the heavily deforested steep slopes particularly within the National Park, and restrain communities from encroaching on the pristine slopes of Mt Elgon. This will be achieved if the politicians, Park Authorities and local communities jointly participate in the design and implementation of CFMs. Future research could focus on climate change implications of deforestation of Mt Elgon environments and quantification of carbon loss related to deforestation and soil degradation in the mountain environments.
- Full Text:
- Date Issued: 2011
- Authors: Mugagga, Frank
- Date: 2011
- Subjects: Land use -- Uganda -- Mount Elgon National Park , Landslides -- Uganda -- Mount Elgon National Park , Land degradation -- Uganda -- Mount Elgon National Park
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10646 , http://hdl.handle.net/10948/1468 , Land use -- Uganda -- Mount Elgon National Park , Landslides -- Uganda -- Mount Elgon National Park , Land degradation -- Uganda -- Mount Elgon National Park
- Description: An investigation of the relationship between the physical, pedological and anthropogenic influences on landslide occurrence on the midslopes within and outside Mt Elgon National Park was carried out. One of the landslides occurred in a protected pristine forest environment within the Park while the other two were located at sites deforested for cultivation within and outside the National Park. Field based surveys, GIS techniques and laboratory tests were used to collect and analyze the data. A household survey was undertaken to establish the main community livelihood strategies, the drivers of land use change and implications for land degradation on the mid slopes of Mt Elgon. Aerial photographs taken in 1960 and orthophoto maps formed the benchmark for the analysis of the respective land use changes between 1995 and 2006, using 30m Landsat TM and 20m SPOT MS images in IDRISI Andes GIS environment. Landslide sites were mapped using a Magellan Professional MobileMapperTMCX and terrain parameters were derived using a 15M Digital Elevation Model. A hybrid supervised/unsupervised classification approach was employed to generate land cover maps from which the areal extent of three land cover classes (agricultural fields, woodlands and forests) was calculated. Particle size distribution and atterberg limits were used to test the hypothesis that soils at the landslide sites are inherently ‘problem soils’ where slope failure can occur even without human intervention. Shear strength parameters (internal of friction and cohesion) were used calculate the slope factor of safety to ascertain slope stability at pristine and disturbed landslide sites. Results from the socio-economic survey revealed that smallholder subsistence agriculture and encroachment on the National Park resources are the main sources of livelihoods for the communities surrounding the Park. The communities also have a strong socio-cultural attachment to the National Park, as it is the source of items used during traditional rituals like circumcision. Encroachment is driven by the high population pressure and the prevalent political climate. Farmers mainly use slash and burn technique to prepare land for cultivation and those close to the National Park are reluctant to adopt appropriate farming and soil conservation practices due to the uncertainties surrounding their future on such plots. Slash and burn iii techniques were observed to accelerate various forms of erosion including rills, gullies and sheet. Soil and water conservation techniques were mainly practiced on privately owned farms. The period 1960 and 1995 was characterized by minimal land use changes and no encroachment into the designated Mount Elgon National Park. Conversely, the period 1995 – 2006 marked a significant loss of woodlands and forest cover particularly on steep concave slopes (36º – 58º) within the National Park. The land use change trends were attributed to the prevalent land politics and exponential population growth in the region. The encroachment onto the critical slopes was noted to have induced a series of shallow and deep landslides in the area. Deforestation on Mt Elgon was reported to have both onsite and offsite climate variability and implications in the form of drought, heat waves, flash floods, economic dislocation, crop failure and associated malnutrition in surrounding low lying areas. The soils on pristine and disturbed slopes contain high amount of clay (>10 percent), are fine textured (>50 percent of the material passing the 0.075mm sieve) and highly plastic. These soil attributes imply low permeability, excessive water retention and high susceptibility to expansion and sliding. The vertic nature of soils at Nametsi was confirmed by the extremely high plasticity indices (averaging 33percent), while, high liquid limits at Buwabwala (53 percent) and Kitati (59 percent) qualified the soils as vertisols which are associated with landslides. The results point to the fact that soils at landslide sites are inherently ‘problem soils’ where slope failure can occur even without human intervention. Therefore, the hypothesis that soils at three landslide sites are inherently ‘problem soils’ where slope failure can occur even without human intervention is accepted. Notwithstanding the fact that the study was focussed on mid-altitude slopes of Mt Elgon, the results are in tandem with investigations carried out earlier on the lower densely populated slopes, thus confirming the widespread nature of problem soils on Mt Elgon. There is an urgent need to control human population growth and restore forest cover on the heavily deforested steep slopes particularly within the National Park, and restrain communities from encroaching on the pristine slopes of Mt Elgon. This will be achieved if the politicians, Park Authorities and local communities jointly participate in the design and implementation of CFMs. Future research could focus on climate change implications of deforestation of Mt Elgon environments and quantification of carbon loss related to deforestation and soil degradation in the mountain environments.
- Full Text:
- Date Issued: 2011