Friction welding of thin walled zircaloy-4 tubes for the nuclear industry
- Authors: Koloi, Nthatisi Dinah
- Date: 2017
- Subjects: Friction welding Zirconium alloys
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/18794 , vital:28724
- Description: This work reports on the process development of solid state welding as an alternative joining process for assembling Zircaloy-4 fuel rod components for the nuclear industry. A typical fuel rod consists of a thin tube that is blocked at both ends by end-caps. The welding of the thin wall tubes onto the end-caps is currently accomplished by employing fusion techniques. Due to limited thin wall Zircaloy-4 tube supplied, preliminary welding was initially performed with thin wall 316L stainless steel tube for the development of a joint geometry and establishment of an experimental welding and testing setup. A suitable joint geometry that would achieve higher static strength equal or above that of the parent material, as well as complete circumferential bonding was investigated through welding a tube on different volume interface geometries of the end-caps. Higher joint efficiency was obtained from a tube-to-tube joint geometry that allowed sufficient frictional heat input at the interface. Consequently, the successful joint geometry was employed to develop a friction welding process for the joining of thin wall Zircaloy-4 tubes. The influential process parameters, axial force, rotational speed and upset distance were varied during the investigation. The completed weld joints were evaluated by visual, metallurgical and mechanical means. Successful welds showed complete circumferential bonding and high joint efficiency that was above the parent plate material as well as parent tube material. The evaluation of the microstructure showed transformation of grain structure on the heat affected zone (HAZ) and friction weld zone when compared to the parent materials. Even though, this work could not resolve inner flash formation, there is enough evidence that friction welding can be used for assembling fuel rod components in the nuclear industry.
- Full Text:
- Date Issued: 2017
- Authors: Koloi, Nthatisi Dinah
- Date: 2017
- Subjects: Friction welding Zirconium alloys
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/18794 , vital:28724
- Description: This work reports on the process development of solid state welding as an alternative joining process for assembling Zircaloy-4 fuel rod components for the nuclear industry. A typical fuel rod consists of a thin tube that is blocked at both ends by end-caps. The welding of the thin wall tubes onto the end-caps is currently accomplished by employing fusion techniques. Due to limited thin wall Zircaloy-4 tube supplied, preliminary welding was initially performed with thin wall 316L stainless steel tube for the development of a joint geometry and establishment of an experimental welding and testing setup. A suitable joint geometry that would achieve higher static strength equal or above that of the parent material, as well as complete circumferential bonding was investigated through welding a tube on different volume interface geometries of the end-caps. Higher joint efficiency was obtained from a tube-to-tube joint geometry that allowed sufficient frictional heat input at the interface. Consequently, the successful joint geometry was employed to develop a friction welding process for the joining of thin wall Zircaloy-4 tubes. The influential process parameters, axial force, rotational speed and upset distance were varied during the investigation. The completed weld joints were evaluated by visual, metallurgical and mechanical means. Successful welds showed complete circumferential bonding and high joint efficiency that was above the parent plate material as well as parent tube material. The evaluation of the microstructure showed transformation of grain structure on the heat affected zone (HAZ) and friction weld zone when compared to the parent materials. Even though, this work could not resolve inner flash formation, there is enough evidence that friction welding can be used for assembling fuel rod components in the nuclear industry.
- Full Text:
- Date Issued: 2017
The effects of vascular targeted bi-functionalized aunps on hepatic lipid metabolism of a diet-induced rats
- Authors: Singo, Dakalo Gladwell
- Date: 2020
- Subjects: Bile acids
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47072 , vital:39780
- Description: Introduction: Obesity is a metabolic disease in which the accumulation of excessive fat in the adipose tissue may interfere with the normal maintenance of a healthy state. However, there is only a limited number of drugs approved for the treatment of obesity. For this purpose, target therapies are receiving more attention as a preferred treatment to reduce the burden of chronic diseases which are associated with the current strategies. Nanotechnology is a highly promising field that offers a nanotechnology-based drug delivery system as a novel means of solving issues associated with the toxicity of conventional anti-obesity drugs. Vascular targeted nanotherapy (targeted bi-functionalized nanoparticles) as a strategy that can overcome the current available anti-obesity drugs. Aim: This study sought to understand the effects of nanotherapy in the hepatic lipid metabolism and secretion of bile acids Research focus: The effects of gold nanotherapy on the bile acid biosynthetic enzymes, transporters and lipogenic enzymes of rats that were on a high fat diet. Conclusion: The study shows low expression in the majority of genes responsible for bile acid synthesis and a lipogenic pathway; therefore, the effects of nanotherapy exhibit low toxicity in the hepatic lipid metabolism.
- Full Text:
- Date Issued: 2020
- Authors: Singo, Dakalo Gladwell
- Date: 2020
- Subjects: Bile acids
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47072 , vital:39780
- Description: Introduction: Obesity is a metabolic disease in which the accumulation of excessive fat in the adipose tissue may interfere with the normal maintenance of a healthy state. However, there is only a limited number of drugs approved for the treatment of obesity. For this purpose, target therapies are receiving more attention as a preferred treatment to reduce the burden of chronic diseases which are associated with the current strategies. Nanotechnology is a highly promising field that offers a nanotechnology-based drug delivery system as a novel means of solving issues associated with the toxicity of conventional anti-obesity drugs. Vascular targeted nanotherapy (targeted bi-functionalized nanoparticles) as a strategy that can overcome the current available anti-obesity drugs. Aim: This study sought to understand the effects of nanotherapy in the hepatic lipid metabolism and secretion of bile acids Research focus: The effects of gold nanotherapy on the bile acid biosynthetic enzymes, transporters and lipogenic enzymes of rats that were on a high fat diet. Conclusion: The study shows low expression in the majority of genes responsible for bile acid synthesis and a lipogenic pathway; therefore, the effects of nanotherapy exhibit low toxicity in the hepatic lipid metabolism.
- Full Text:
- Date Issued: 2020
Cytokine properties of CD23 on human Eosinophilic cells
- Authors: Ferreira, Lauren
- Date: 2007
- Subjects: Cytokines , CD23 antigen , Eosinophil
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10333 , http://hdl.handle.net/10948/503 , http://hdl.handle.net/10948/d1012001 , Cytokines , CD23 antigen , Eosinophil
- Description: CD23, the low affinity IgE receptor, is expressed by various cell types and has numerous functions depending on the form of the protein, its interaction with various ligands and the type of cell involved. CD23 is pivotal in the regulation of IgE, with the soluble form involved in up-regulation, while the membrane bound form is involved in the down-regulation. It is clear why it is believed to be a central molecule in allergic responses, and a therapeutic target for the treatment of allergic disease. In this study a recombinant form of the entire extracellular domain of the protein, exCD23, was produced by PCR cloning and expressed in E. coli. His•Tag™s were introduced onto the C-terminus and N-terminus, respectively, in order to simplify the purification procedure. After renaturation and purification, the recombinant exCD23 bound IgE, indicating its activity. From the IgE binding studies it was established that the position of the tag did not influence the binding. GST•Tagged™ exCD23 was also produced in an attempt to increase the solubility of the recombinant protein, but this proved unsuccessful. Butyrate differentiated EoL-1 cells were treated with the Nterminal His•Tagged™ exCD23, and the protein appeared to suppress the secretion of the constitutively expressed cytokines, especially IL-8 and IFN- , when compared to untreated cells. In addition, treatment of the EoL-1 cells with exCD23 had a significant proliferative effect, but could not induce differentiation of this cell line into mature eosinophilic-like cells.
- Full Text:
- Date Issued: 2007
- Authors: Ferreira, Lauren
- Date: 2007
- Subjects: Cytokines , CD23 antigen , Eosinophil
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10333 , http://hdl.handle.net/10948/503 , http://hdl.handle.net/10948/d1012001 , Cytokines , CD23 antigen , Eosinophil
- Description: CD23, the low affinity IgE receptor, is expressed by various cell types and has numerous functions depending on the form of the protein, its interaction with various ligands and the type of cell involved. CD23 is pivotal in the regulation of IgE, with the soluble form involved in up-regulation, while the membrane bound form is involved in the down-regulation. It is clear why it is believed to be a central molecule in allergic responses, and a therapeutic target for the treatment of allergic disease. In this study a recombinant form of the entire extracellular domain of the protein, exCD23, was produced by PCR cloning and expressed in E. coli. His•Tag™s were introduced onto the C-terminus and N-terminus, respectively, in order to simplify the purification procedure. After renaturation and purification, the recombinant exCD23 bound IgE, indicating its activity. From the IgE binding studies it was established that the position of the tag did not influence the binding. GST•Tagged™ exCD23 was also produced in an attempt to increase the solubility of the recombinant protein, but this proved unsuccessful. Butyrate differentiated EoL-1 cells were treated with the Nterminal His•Tagged™ exCD23, and the protein appeared to suppress the secretion of the constitutively expressed cytokines, especially IL-8 and IFN- , when compared to untreated cells. In addition, treatment of the EoL-1 cells with exCD23 had a significant proliferative effect, but could not induce differentiation of this cell line into mature eosinophilic-like cells.
- Full Text:
- Date Issued: 2007
Constraints in attainment of sustainable human settlements at Kwamaphumulo Local Municipality
- Authors: Sikhosana, Phindokuhle
- Date: 2020
- Subjects: Human settlements , Sustainable development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47181 , vital:39829
- Description: This study sought to investigate the constraints in the attainment of sustainable human settlement in KwaMaphumulo Local Municipality at iLembe District in KwaZulu-Natal, South Africa. The aim of this study was to investigate the constraints that limit the achievement of the ideal of sustainable human settlement development in the KwaMaphumulo Local Municipality. Furthermore, the study sought to determine the impact of these constraints on sustainable development and to proffer measures that can be taken to combat stagnant or underdevelopment in the area. A mixed-method approach is followed in this study, which considers a triangulation of quantitative and qualitative data collection, analysis and interpretation techniques. It is important to note that in the past years since South Africa became a democratic country, there have been countless efforts with regard to overcoming the problems created during the apartheid era. These problems stemmed from a distorted spatial, social, economic and political background that was advocated by both segregationist public policies and the planning systems of the Apartheid Regime. In recent years, South African cities have also been faced with environmental issues, which are imperative to the future development of the country. With all these issues in mind, we see that the many efforts that are put in place by government always fall short of solving the problems. This research report looked at the constraints that affect the KwaMaphumulo Local Municipality in attaining sustainable human settlements and whether the efforts of redistribution and equality have been enough to overcome the problems. The key findings of the study were that constraints in attaining sustainable human settlements in the KwaMaphumulo Local Municipality negatively impacts on the development in the area. The level of services being provided is poor. There is an apparent disconnect between traditional leaders and the municipality councillor as development management and vision are concerned. Furthermore, the development programmes and projects do not seem to address the critical needs of the community. Housing development is narrow minded with a focus on the top structure and a failure to include basic services and infrastructure. Houses built that are financed by subsidies are of poor quality. The latter situation results in more able‐ bodied, skilled and capable people emigrating to developed areas.
- Full Text:
- Date Issued: 2020
- Authors: Sikhosana, Phindokuhle
- Date: 2020
- Subjects: Human settlements , Sustainable development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47181 , vital:39829
- Description: This study sought to investigate the constraints in the attainment of sustainable human settlement in KwaMaphumulo Local Municipality at iLembe District in KwaZulu-Natal, South Africa. The aim of this study was to investigate the constraints that limit the achievement of the ideal of sustainable human settlement development in the KwaMaphumulo Local Municipality. Furthermore, the study sought to determine the impact of these constraints on sustainable development and to proffer measures that can be taken to combat stagnant or underdevelopment in the area. A mixed-method approach is followed in this study, which considers a triangulation of quantitative and qualitative data collection, analysis and interpretation techniques. It is important to note that in the past years since South Africa became a democratic country, there have been countless efforts with regard to overcoming the problems created during the apartheid era. These problems stemmed from a distorted spatial, social, economic and political background that was advocated by both segregationist public policies and the planning systems of the Apartheid Regime. In recent years, South African cities have also been faced with environmental issues, which are imperative to the future development of the country. With all these issues in mind, we see that the many efforts that are put in place by government always fall short of solving the problems. This research report looked at the constraints that affect the KwaMaphumulo Local Municipality in attaining sustainable human settlements and whether the efforts of redistribution and equality have been enough to overcome the problems. The key findings of the study were that constraints in attaining sustainable human settlements in the KwaMaphumulo Local Municipality negatively impacts on the development in the area. The level of services being provided is poor. There is an apparent disconnect between traditional leaders and the municipality councillor as development management and vision are concerned. Furthermore, the development programmes and projects do not seem to address the critical needs of the community. Housing development is narrow minded with a focus on the top structure and a failure to include basic services and infrastructure. Houses built that are financed by subsidies are of poor quality. The latter situation results in more able‐ bodied, skilled and capable people emigrating to developed areas.
- Full Text:
- Date Issued: 2020
Thermal degradation of diamond compacts: a TEM investigation
- Authors: Westraadt, Johan Ewald
- Date: 2011
- Subjects: Materials -- Thermal properties Chemical weathering
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/10829 , vital:26827
- Description: Diamond compacts consist of fine diamond grains bonded together by using high pressure and high temperature. In this study transmission electron microscopy (TEM)was used to study thermal degradation of diamond compacts. Three different types of diamond compacts – namely cobalt polycrystalline diamond (PCD), calcium carbonate PCD, and diamond-SiC composites – were investigated with TEM to understand the processes that occur during synthesis. These compacts were then heated in inert atmospheres and the chemical changes studied with TEM. It was found that PCD, using cobalt as a bonding agent, will degrade after exposure to temperatures above 750ºC. The cobalt pools contain tungsten in solid solution. During heat treatment above 700ºC the solid solution tungsten combines with cobalt and dissolved carbon to form η-phase particles at the cobalt/diamond interface. At higher temperatures or insufficient tungsten levels the rate of dissolved carbon, into the cobalt pool, is too high and the excess carbon will form as graphite in the cobalt pool. Increased levels of solid solution tungsten, in the cobalt, is expected to delay the onset of graphitization in the diamond compact, thereby increasing the thermal stability of the diamond compact. Non-metallic PCD using calcium carbonate as a bonding agent was successfully sintered in this study. TEM revealed similar micro-structural features as in cobalt based PCD. No signs of thermal degradation were found after exposure to 1200ºC in vacuum for this PCD. Contaminants introduced during processing prevented a detailed study of the binder in this system. The effect of substitutional metal atoms and plastic deformation of diamond on the thermal stability of diamond-SiC composites were investigated. A piston cylinder press was developed and used to synthesize diamond-SiC composites with different levels of plastically deformed diamond. It was concluded that substitutional metal atoms and plastic deformation of diamond grains play no role in the thermal degradation of diamond compacts at 750ºC. The thermal degradation of cobalt PCD is therefore completely determined by the cobalt/diamond interaction at 750ºC.
- Full Text:
- Date Issued: 2011
- Authors: Westraadt, Johan Ewald
- Date: 2011
- Subjects: Materials -- Thermal properties Chemical weathering
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/10829 , vital:26827
- Description: Diamond compacts consist of fine diamond grains bonded together by using high pressure and high temperature. In this study transmission electron microscopy (TEM)was used to study thermal degradation of diamond compacts. Three different types of diamond compacts – namely cobalt polycrystalline diamond (PCD), calcium carbonate PCD, and diamond-SiC composites – were investigated with TEM to understand the processes that occur during synthesis. These compacts were then heated in inert atmospheres and the chemical changes studied with TEM. It was found that PCD, using cobalt as a bonding agent, will degrade after exposure to temperatures above 750ºC. The cobalt pools contain tungsten in solid solution. During heat treatment above 700ºC the solid solution tungsten combines with cobalt and dissolved carbon to form η-phase particles at the cobalt/diamond interface. At higher temperatures or insufficient tungsten levels the rate of dissolved carbon, into the cobalt pool, is too high and the excess carbon will form as graphite in the cobalt pool. Increased levels of solid solution tungsten, in the cobalt, is expected to delay the onset of graphitization in the diamond compact, thereby increasing the thermal stability of the diamond compact. Non-metallic PCD using calcium carbonate as a bonding agent was successfully sintered in this study. TEM revealed similar micro-structural features as in cobalt based PCD. No signs of thermal degradation were found after exposure to 1200ºC in vacuum for this PCD. Contaminants introduced during processing prevented a detailed study of the binder in this system. The effect of substitutional metal atoms and plastic deformation of diamond on the thermal stability of diamond-SiC composites were investigated. A piston cylinder press was developed and used to synthesize diamond-SiC composites with different levels of plastically deformed diamond. It was concluded that substitutional metal atoms and plastic deformation of diamond grains play no role in the thermal degradation of diamond compacts at 750ºC. The thermal degradation of cobalt PCD is therefore completely determined by the cobalt/diamond interaction at 750ºC.
- Full Text:
- Date Issued: 2011
Identifying drivers of corporate social responsibility for community involvement
- Authors: Gwama, Mzwandile Sebastian
- Date: 2013
- Subjects: Social responsibility of business , Corporate governance
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/6597 , vital:21124
- Description: Organisations operate under unpredictable business environments. These business environments can be classified into internal and external environments. The decision taken by organisations to allocate resources for CSR depends on business environments. Organisations have no control of external business environments. Global financial crisis is an example of an external business environment of which organisations have no control over. The event in the business environments can influence the organisation to review its CSR operations. The beneficiaries of the organisation's CSR program get affected by such decision reviews and face even bigger challenges.
- Full Text:
- Date Issued: 2013
- Authors: Gwama, Mzwandile Sebastian
- Date: 2013
- Subjects: Social responsibility of business , Corporate governance
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/6597 , vital:21124
- Description: Organisations operate under unpredictable business environments. These business environments can be classified into internal and external environments. The decision taken by organisations to allocate resources for CSR depends on business environments. Organisations have no control of external business environments. Global financial crisis is an example of an external business environment of which organisations have no control over. The event in the business environments can influence the organisation to review its CSR operations. The beneficiaries of the organisation's CSR program get affected by such decision reviews and face even bigger challenges.
- Full Text:
- Date Issued: 2013
Quantification of greenhouse gas fluxes from soil in agricultural fields
- Authors: Nkongolo, Nsalambi Vakanda
- Date: 2010
- Subjects: Greenhouse gases -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10645 , http://hdl.handle.net/10948/1474 , Greenhouse gases -- Environmental aspects
- Description: Field studies were conducted at Lincoln University of Missouri (USA) and Hokkaido University (Japan) to: (i) study the relationships between greenhouse gases emissions and soil properties, (ii) assess the influence of agricultural practices on greenhouse gas fluxes and soil properties and (iii) improve the quantification of greenhouse gases from soil in agricultural fields using geospatial technologies. Results showed that besides soil temperature (T), soil thermal properties such as thermal conductivity (K), resistivity (R) and diffusivity (D) and soil pore spaces indices such as the pore tortuosity factor and the relative gas diffusion coefficient (Ds/Do) are controlling factors for greenhouse gases emissions. Soil thermal properties correlated with greenhouse gases emissions when soil temperature could not. The study has found that predicted Ds/Do and correlate with greenhouse gas fluxes even when the air-filled porosity and the total porosity from which they are predicted did not. We have also showed that Ds/Do and can be predicted quickly from routine measurements of soil water and air and existing diffusivity models found in the literature. Agricultural practices do seriously impact greenhouse gases emissions as showed by the effect of mechanized tillage operations on soil physical properties and greenhouse gas fluxes in a corn and soybean fields. In fact, our results showed that tractor compaction increased soil resistance to penetration, water, bulk density and pore tortuosity while reducing air-filled porosity, total pore space and the soil gas diffusion coefficient. Changes in soil properties resulted in increased CO2, NO and N2O emissions. Finally, our results also confirmed that greenhouse gas fluxes vary tremendously in space and time. As estimates of greenhouse gas emissions are influenced by the data processing approach, differences between the different calculation approaches leads to uncertainty. Thus, techniques for developing better estimates are needed. We have showed that Geographic Information Systems (GIS), Global Positioning System (GPS), computer mapping and geo-statistics are technologies that can be used to better understand systems containing large amounts of spatial and temporal variability. Our GIS-based approach for quantifying CO2, CH4 and N2O fluxes from soil in agricultural fields showed that estimating (extrapolating) total greenhouse gas fluxes using the “standard” approach – multiplying the average flux value by the total field area – results in biased predictions of field total greenhouse gases emissions. In contrast, the GIS-based approach we developed produces an interpolated map portraying the spatial distribution of gas fluxes across the field from point measurements and later process the interpolated map produced to determine flux zones. Furthermore, processing, classification and modeling enables the computation of field total fluxes as the sum of fluxes in different zones, therefore taking into account the spatial variability of greenhouse gas fluxes.
- Full Text:
- Date Issued: 2010
- Authors: Nkongolo, Nsalambi Vakanda
- Date: 2010
- Subjects: Greenhouse gases -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10645 , http://hdl.handle.net/10948/1474 , Greenhouse gases -- Environmental aspects
- Description: Field studies were conducted at Lincoln University of Missouri (USA) and Hokkaido University (Japan) to: (i) study the relationships between greenhouse gases emissions and soil properties, (ii) assess the influence of agricultural practices on greenhouse gas fluxes and soil properties and (iii) improve the quantification of greenhouse gases from soil in agricultural fields using geospatial technologies. Results showed that besides soil temperature (T), soil thermal properties such as thermal conductivity (K), resistivity (R) and diffusivity (D) and soil pore spaces indices such as the pore tortuosity factor and the relative gas diffusion coefficient (Ds/Do) are controlling factors for greenhouse gases emissions. Soil thermal properties correlated with greenhouse gases emissions when soil temperature could not. The study has found that predicted Ds/Do and correlate with greenhouse gas fluxes even when the air-filled porosity and the total porosity from which they are predicted did not. We have also showed that Ds/Do and can be predicted quickly from routine measurements of soil water and air and existing diffusivity models found in the literature. Agricultural practices do seriously impact greenhouse gases emissions as showed by the effect of mechanized tillage operations on soil physical properties and greenhouse gas fluxes in a corn and soybean fields. In fact, our results showed that tractor compaction increased soil resistance to penetration, water, bulk density and pore tortuosity while reducing air-filled porosity, total pore space and the soil gas diffusion coefficient. Changes in soil properties resulted in increased CO2, NO and N2O emissions. Finally, our results also confirmed that greenhouse gas fluxes vary tremendously in space and time. As estimates of greenhouse gas emissions are influenced by the data processing approach, differences between the different calculation approaches leads to uncertainty. Thus, techniques for developing better estimates are needed. We have showed that Geographic Information Systems (GIS), Global Positioning System (GPS), computer mapping and geo-statistics are technologies that can be used to better understand systems containing large amounts of spatial and temporal variability. Our GIS-based approach for quantifying CO2, CH4 and N2O fluxes from soil in agricultural fields showed that estimating (extrapolating) total greenhouse gas fluxes using the “standard” approach – multiplying the average flux value by the total field area – results in biased predictions of field total greenhouse gases emissions. In contrast, the GIS-based approach we developed produces an interpolated map portraying the spatial distribution of gas fluxes across the field from point measurements and later process the interpolated map produced to determine flux zones. Furthermore, processing, classification and modeling enables the computation of field total fluxes as the sum of fluxes in different zones, therefore taking into account the spatial variability of greenhouse gas fluxes.
- Full Text:
- Date Issued: 2010
Strategies schools in a low-socio-economic are used to maintain discipline
- Authors: Manuel, Bianca Winestine
- Date: 2019
- Subjects: Corporal punishment -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/44550 , vital:38143
- Description: The purpose of this study was to investigate the strategies schools use to maintain discipline in a low socio-economic area. Poor discipline in public schools has become a major concern following the abolition of corporal punishment by the National Department of Education. The educational authorities left educators in schools with no constructive alternatives to maintain discipline and alternative strategies had to be found and implemented. Data were collected be means of semi-structured interviews, from principals, educators and school governing body (SGB) members. Three neighbouring high schools in the Northern Areas of Port Elizabeth in the Nelson Mandela Bay District of Education were used. A qualitative research approach was employed in the study. The findings supported the literature that was consulted in that there is a wide range of causes of disciplinary problems in schools. According to the findings, there is a lack of effective strategies to maintain discipline in schools but Bronfenbrenner’s ecological systems theory is in line with the perceptions of the respondents in this study. This study opened a door for further research into effective strategies that are in line with the changing teaching environment in low socio-economic areas. The government should come on board to create an environment to promote the good life for educators and learners. The final outcome of this study focused on strategies that principals, educators and SGB members can use to maintain discipline in low socio-economic areas. These strategies can create an environment that is conducive for teaching and learning, especially in schools situated in low socio-economic areas. These include consistency, parental involvement, detention, suspension and the home environment and socio-economic circumstances. Learners must be disciplined and parents must be involved in the maintenance of discipline in schools situated in low socio-economic areas.
- Full Text:
- Date Issued: 2019
- Authors: Manuel, Bianca Winestine
- Date: 2019
- Subjects: Corporal punishment -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/44550 , vital:38143
- Description: The purpose of this study was to investigate the strategies schools use to maintain discipline in a low socio-economic area. Poor discipline in public schools has become a major concern following the abolition of corporal punishment by the National Department of Education. The educational authorities left educators in schools with no constructive alternatives to maintain discipline and alternative strategies had to be found and implemented. Data were collected be means of semi-structured interviews, from principals, educators and school governing body (SGB) members. Three neighbouring high schools in the Northern Areas of Port Elizabeth in the Nelson Mandela Bay District of Education were used. A qualitative research approach was employed in the study. The findings supported the literature that was consulted in that there is a wide range of causes of disciplinary problems in schools. According to the findings, there is a lack of effective strategies to maintain discipline in schools but Bronfenbrenner’s ecological systems theory is in line with the perceptions of the respondents in this study. This study opened a door for further research into effective strategies that are in line with the changing teaching environment in low socio-economic areas. The government should come on board to create an environment to promote the good life for educators and learners. The final outcome of this study focused on strategies that principals, educators and SGB members can use to maintain discipline in low socio-economic areas. These strategies can create an environment that is conducive for teaching and learning, especially in schools situated in low socio-economic areas. These include consistency, parental involvement, detention, suspension and the home environment and socio-economic circumstances. Learners must be disciplined and parents must be involved in the maintenance of discipline in schools situated in low socio-economic areas.
- Full Text:
- Date Issued: 2019
Aggregate stability, crust formation, steady state infiltration and mode of seedling emergence in soils with various texture and mineralogy
- Authors: Nciizah, Adornis Dakarai
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Crop Science)
- Identifier: vital:11871 , http://hdl.handle.net/10353/d1015539
- Description: The general objective of this study was to quantify the interactive effects of soil texture and mineralogy on soil crusting, infiltration and erosion and the subsequent effects on maize seedling emergence and early development using soils collected from 14 ecotopes in the Eastern Cape Province. The specific objectives were to determine; i) particulate organic matter, soil texture and mineralogy relations, ii) aggregate stability and breakdown mechanisms as affected by soil texture and organic matter, iii) crust formation and steady state infiltration, iv) rainfall pattern effects on crusting, infiltration and erodibility and v) rainfall intensity effects on crusting and mode of seedling emergence. Particulate organic matter (POM) was fractionated into litter POM, coarse POM and fine POM. Both total soil organic matter (SOM) and the POM in each fraction were determined using the weight loss on ignition procedure. Most ecotopes were either sandy loam or sandy clay loam and primary minerals especially quartz dominated the soil mineralogy. The clay content was significantly related to the total SOM (r = 0.78), hematite (r = 0.83) and quartz (r = -0.74). Aggregate stability was determined following methods described by Le Bissonnais (1996) i.e. fast wetting (FW), slow wetting (SW) and wet stirring (WSt). Aggregate breakdown followed the order; slaking < mechanical breakdown < micro-cracking for most ecotopes except Lujiko Leeufontein and Amatola Jozini where SW and WSt resulted in the least MWD respectively. Aggregate stability was significantly correlated to POM only for FW and SW and only positive but not significant for WSt. To study crust formation, aggregate sizes <2, 2 to 3, 3 to 5 mm were exposed to 60 mm hr-1 simulated rainfall. Sieving structural crusts, ~0.2 to ~0.8 mm thick with a surface layer of loose grains overlying a thin plasmic layer, formed in all ecotopes. Crusts with strengths between 0.25 and 3.42 10-4 kg m-2 developed on the <2 mm compared to <2.23 10-4 kg m-2 in the >2 mm aggregates. The reverse occurred in Alice Jozini, which had relatively low clay content of 120 g kg-1. Two significantly different groups of the SSIR were observed. The SSIR was between 1.24 and 3.60 mm hr-1 in the group of ecotopes dominated by primary minerals and relatively lower clay content. In the second group, consisting one ecotope dominated by kaolinite and relatively higher clay content, the SSIR was 15.23 mm hr-1. Rainfall pattern i.e. rainfall applied either as an eight minute single rainstorm (SR) or four-two minute intermittent rainstorms (IR) separated by a 48 h drying period significantly (p < 0.05) affected crust strength, SSIR and erosion. The IR resulted in higher crust strength and SSIR than SR. The effect of rainfall pattern on SSIR was mostly influenced by the primary minerals namely, quartz. Three maize seeds of equal size were planted in plastic pots, pre-wetted by capillary action and then subjected to simulated rainfall at three intensities for 5 min. Rainfall intensity (30, 45 and 60 mm h-1) significantly (P < 0.05) affected crust strength and mean emergence day (MED) but not emergence percentage (EMP) and shoot length (P > 0.05). The 60 mm h-1 rainfall intensity resulted in the highest crust strength and MED.
- Full Text:
- Date Issued: 2014
- Authors: Nciizah, Adornis Dakarai
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Crop Science)
- Identifier: vital:11871 , http://hdl.handle.net/10353/d1015539
- Description: The general objective of this study was to quantify the interactive effects of soil texture and mineralogy on soil crusting, infiltration and erosion and the subsequent effects on maize seedling emergence and early development using soils collected from 14 ecotopes in the Eastern Cape Province. The specific objectives were to determine; i) particulate organic matter, soil texture and mineralogy relations, ii) aggregate stability and breakdown mechanisms as affected by soil texture and organic matter, iii) crust formation and steady state infiltration, iv) rainfall pattern effects on crusting, infiltration and erodibility and v) rainfall intensity effects on crusting and mode of seedling emergence. Particulate organic matter (POM) was fractionated into litter POM, coarse POM and fine POM. Both total soil organic matter (SOM) and the POM in each fraction were determined using the weight loss on ignition procedure. Most ecotopes were either sandy loam or sandy clay loam and primary minerals especially quartz dominated the soil mineralogy. The clay content was significantly related to the total SOM (r = 0.78), hematite (r = 0.83) and quartz (r = -0.74). Aggregate stability was determined following methods described by Le Bissonnais (1996) i.e. fast wetting (FW), slow wetting (SW) and wet stirring (WSt). Aggregate breakdown followed the order; slaking < mechanical breakdown < micro-cracking for most ecotopes except Lujiko Leeufontein and Amatola Jozini where SW and WSt resulted in the least MWD respectively. Aggregate stability was significantly correlated to POM only for FW and SW and only positive but not significant for WSt. To study crust formation, aggregate sizes <2, 2 to 3, 3 to 5 mm were exposed to 60 mm hr-1 simulated rainfall. Sieving structural crusts, ~0.2 to ~0.8 mm thick with a surface layer of loose grains overlying a thin plasmic layer, formed in all ecotopes. Crusts with strengths between 0.25 and 3.42 10-4 kg m-2 developed on the <2 mm compared to <2.23 10-4 kg m-2 in the >2 mm aggregates. The reverse occurred in Alice Jozini, which had relatively low clay content of 120 g kg-1. Two significantly different groups of the SSIR were observed. The SSIR was between 1.24 and 3.60 mm hr-1 in the group of ecotopes dominated by primary minerals and relatively lower clay content. In the second group, consisting one ecotope dominated by kaolinite and relatively higher clay content, the SSIR was 15.23 mm hr-1. Rainfall pattern i.e. rainfall applied either as an eight minute single rainstorm (SR) or four-two minute intermittent rainstorms (IR) separated by a 48 h drying period significantly (p < 0.05) affected crust strength, SSIR and erosion. The IR resulted in higher crust strength and SSIR than SR. The effect of rainfall pattern on SSIR was mostly influenced by the primary minerals namely, quartz. Three maize seeds of equal size were planted in plastic pots, pre-wetted by capillary action and then subjected to simulated rainfall at three intensities for 5 min. Rainfall intensity (30, 45 and 60 mm h-1) significantly (P < 0.05) affected crust strength and mean emergence day (MED) but not emergence percentage (EMP) and shoot length (P > 0.05). The 60 mm h-1 rainfall intensity resulted in the highest crust strength and MED.
- Full Text:
- Date Issued: 2014
Site Fidelity of southern right (Eubalaena australis) and humpback whales (Megaptera novaeangliae) in Algoa Bay, South Africa
- Authors: Drost, Eduard F
- Date: 2016
- Subjects: Marine mammals -- South Africa -- Algoa Bay Southern right whale -- South Africa -- Algoa Bay Humpback whale -- South Africa -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/21735 , vital:29742
- Description: Mysticetes, or baleen whales, make up one of two sub-orders of the Order Cetacea within the Class Mammalia (Drikamer et al, 2013). It contains three families, each characterized by baleen plates (Drikamer et al, 2013). These baleen plates consist of keratin that replaced the tooth structures for feeding in these mammals (Drikamer et al, 2013). Other biological characteristics of these animals include paired external nares (blowholes), a sternum consisting of a single bone, symmetrical skull and the most conspicuous of all, the body length of between ten to thirty metres (Drikamer et al, 2013). It is thought that the size characteristic was probably the main factor when categorising them as cetaceans, with the Latin word ‘Cetus’ referring to ‘sea monster’ (Carnaby, 2006). In this literature review, the focus will fall on two species of mysticetes from separate families, namely that of the southern right whale, Eubalaena australis of the Balaenidae family, and the humpback whale, Megaptera novaeangliae of the Balaenopteridae family. Emphasis in this review will fall on the aspect of site fidelity of the mother-calf pairs.
- Full Text:
- Date Issued: 2016
- Authors: Drost, Eduard F
- Date: 2016
- Subjects: Marine mammals -- South Africa -- Algoa Bay Southern right whale -- South Africa -- Algoa Bay Humpback whale -- South Africa -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/21735 , vital:29742
- Description: Mysticetes, or baleen whales, make up one of two sub-orders of the Order Cetacea within the Class Mammalia (Drikamer et al, 2013). It contains three families, each characterized by baleen plates (Drikamer et al, 2013). These baleen plates consist of keratin that replaced the tooth structures for feeding in these mammals (Drikamer et al, 2013). Other biological characteristics of these animals include paired external nares (blowholes), a sternum consisting of a single bone, symmetrical skull and the most conspicuous of all, the body length of between ten to thirty metres (Drikamer et al, 2013). It is thought that the size characteristic was probably the main factor when categorising them as cetaceans, with the Latin word ‘Cetus’ referring to ‘sea monster’ (Carnaby, 2006). In this literature review, the focus will fall on two species of mysticetes from separate families, namely that of the southern right whale, Eubalaena australis of the Balaenidae family, and the humpback whale, Megaptera novaeangliae of the Balaenopteridae family. Emphasis in this review will fall on the aspect of site fidelity of the mother-calf pairs.
- Full Text:
- Date Issued: 2016
In-betweenness: a postcolonial exploration of sociocultural intergenerational learning through cattle as a medium of cultural expression in Mpembeni, KwaZulu-Natal
- Authors: Masuku, Lynette Sibongile
- Date: 2019
- Subjects: Postcolonialism , Environmental education -- South Africa , Community education -- South Africa -- KwaZulu Natal , Non-formal education -- South Africa -- KwaZulu Natal , Agricultural education -- South Africa -- KwaZulu Natal , Livestock -- Handling -- South Africa -- KwaZulu Natal , Cattle -- Handling -- South Africa -- KwaZulu Natal , Cattle herding -- South Africa -- KwaZulu Natal , Life skills -- Study and teaching -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68181 , vital:29213
- Description: This case study was conducted in a small rural community called Mpembeni, in South Africa’s KwaZulu-Natal province. It was motivated by my observation of high levels of competence in ‘cattle knowledge’ amongst children coupled with a simultaneous failure at school. I view schools as integral parts of the community and consider them as being influenced by the community, which they in turn influence. This study set out to understand that which embodied informal learning in home/pasture-based contexts as well as formalised learning processes in schools. I used Sociocultural theory as the most congruent of educational theories to surface and illuminate the intergenerational learning processes that were taking place in the area. This warranted my use of research investigation methods that could, in non-intrusive ways, expose the everyday community practices that related to cattle as a particular medium of cultural expression. Ethnography, sourced from anthropology, aided by ethnomethods, was not only compatible with my study and the way in which I wanted to write out the research report, but also with my educational theory and its counterhegemonic intents. To understand the colonialities that framed the discord that embodied home and school as learning contexts, I used postcolonial theory, not only as a lens but as a counterhegemonic response. This theory also informed my research methodology as well as afforded me the reflexivity tools for an examination of my own intergenerational learning and the relational identities of myself as ‘Other’ in the lives of the research participants. It further facilitated the exploration of the potential for potential hybrid third spaces within the bubbling meeting nodes of the socio-cultural context of school and home/pasture based settings of learning. I observed cattle herding related practices, interviewed children, their parents and/or carers, dipping tank managers, livestock inspectors, community elders and members. I also analysed some of the written and unwritten content that made up the formal and informal based learning processes and reviewed some of the most recent South African Curriculum Statements and related texts on the representations of cattle. I sought views from teachers on their interactions with the people of Mpembeni, whose children they taught. I also explored axes of tension, silences and presences on anything related to cattle in schools. I argue and make a case for the development of thought by African scholars to advance Africa’s education rather than aid mimicry and the importation of theories of little congruence and relevance to the African context and Africa’s future. The study has made some contributions to new knowledge. This is in its exploration of sociocultural intergenerational methods and techniques that are employed for learning in community contexts, highlighting the importance of surfacing and understanding of children’s knowledge and experiences. The study has gone further to deliberate the in-betweenness of school and home learning environments, highlighting and unsilencing silenced, peripherised, new, old, considered irrelevant in the past, context and time congruent and liberatory knowledges. I propose that the knowledges located in these cleavages of difference be utilised to transform and create learning bridges between home and school environments. I propose that those ways of knowing that see others as nothings, be exposed and unlearned. Methods of learning that naturally unfold at home could be replicated at school with a recognition of the intergenerational methods, techniques, practices and the learning values in a critically constructive manner that narrows difference and othering.
- Full Text:
- Date Issued: 2019
- Authors: Masuku, Lynette Sibongile
- Date: 2019
- Subjects: Postcolonialism , Environmental education -- South Africa , Community education -- South Africa -- KwaZulu Natal , Non-formal education -- South Africa -- KwaZulu Natal , Agricultural education -- South Africa -- KwaZulu Natal , Livestock -- Handling -- South Africa -- KwaZulu Natal , Cattle -- Handling -- South Africa -- KwaZulu Natal , Cattle herding -- South Africa -- KwaZulu Natal , Life skills -- Study and teaching -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68181 , vital:29213
- Description: This case study was conducted in a small rural community called Mpembeni, in South Africa’s KwaZulu-Natal province. It was motivated by my observation of high levels of competence in ‘cattle knowledge’ amongst children coupled with a simultaneous failure at school. I view schools as integral parts of the community and consider them as being influenced by the community, which they in turn influence. This study set out to understand that which embodied informal learning in home/pasture-based contexts as well as formalised learning processes in schools. I used Sociocultural theory as the most congruent of educational theories to surface and illuminate the intergenerational learning processes that were taking place in the area. This warranted my use of research investigation methods that could, in non-intrusive ways, expose the everyday community practices that related to cattle as a particular medium of cultural expression. Ethnography, sourced from anthropology, aided by ethnomethods, was not only compatible with my study and the way in which I wanted to write out the research report, but also with my educational theory and its counterhegemonic intents. To understand the colonialities that framed the discord that embodied home and school as learning contexts, I used postcolonial theory, not only as a lens but as a counterhegemonic response. This theory also informed my research methodology as well as afforded me the reflexivity tools for an examination of my own intergenerational learning and the relational identities of myself as ‘Other’ in the lives of the research participants. It further facilitated the exploration of the potential for potential hybrid third spaces within the bubbling meeting nodes of the socio-cultural context of school and home/pasture based settings of learning. I observed cattle herding related practices, interviewed children, their parents and/or carers, dipping tank managers, livestock inspectors, community elders and members. I also analysed some of the written and unwritten content that made up the formal and informal based learning processes and reviewed some of the most recent South African Curriculum Statements and related texts on the representations of cattle. I sought views from teachers on their interactions with the people of Mpembeni, whose children they taught. I also explored axes of tension, silences and presences on anything related to cattle in schools. I argue and make a case for the development of thought by African scholars to advance Africa’s education rather than aid mimicry and the importation of theories of little congruence and relevance to the African context and Africa’s future. The study has made some contributions to new knowledge. This is in its exploration of sociocultural intergenerational methods and techniques that are employed for learning in community contexts, highlighting the importance of surfacing and understanding of children’s knowledge and experiences. The study has gone further to deliberate the in-betweenness of school and home learning environments, highlighting and unsilencing silenced, peripherised, new, old, considered irrelevant in the past, context and time congruent and liberatory knowledges. I propose that the knowledges located in these cleavages of difference be utilised to transform and create learning bridges between home and school environments. I propose that those ways of knowing that see others as nothings, be exposed and unlearned. Methods of learning that naturally unfold at home could be replicated at school with a recognition of the intergenerational methods, techniques, practices and the learning values in a critically constructive manner that narrows difference and othering.
- Full Text:
- Date Issued: 2019
Substantive equality and affirmative action in the workplace
- Authors: Nconco, Mpumelelo
- Date: 2012
- Subjects: Equality before the law -- South Africa , Discrimination in employment -- Law and legislation -- South Africa , Affirmative action programs -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10196 , http://hdl.handle.net/10948/1617 , Equality before the law -- South Africa , Discrimination in employment -- Law and legislation -- South Africa , Affirmative action programs -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa
- Description: During the apartheid era in South Africa there was an unequivocal commitment to white supremacy, segregation and inequality. Discrimination but not on the basis of race was entrenched by the pre-democratic government. The 1980‟s saw the first steps towards reversing such practices through various measures, in the form of formal equality. Formal equality holds that the state must be act neutrally in relation to its employees and must favour no one above another. It assumes that all people are equal and that inequality can be eradicated simply by treating all people in the same way. Formal equality is therefore blind to structural inequality. Substantive equality in contrast to formal equality holds the value that equality is not simply a matter of likeness, that those who are different should be treated differently. The very essence of equality is to make distinction between groups and individual in order to accommodate their different needs and interests. It considers discrimination against groups which have been historically advantaged to be qualitatively aimed at remedying that disadvantage. The Constitution Act 108 of 1996 confers the right to equal protection and benefit of the law and the right to non discrimination. Prohibition of unfair discrimination in itself is insufficient to achieve true equality in a historically oppressed society. Hard affirmative action measures are required, the Constitution further explicitly endorses such restitutionary measures. Affirmative action is a systematic, planned process whereby the effects of colonialism and racial discrimination are being reversed in all areas if life. It is designed to achieve equal employment opportunities. In order to achieve this goal the barriers of the workplace which restrict employment and progressive opportunities have to be systematically eliminated through proactive programmes. Affirmative action is a delicate instrument of social engineering which must be used with caution. The Employment Equity Act 55 of 1998 gives effect to the constitutional provisions and to regulate affirmative action measures in employment. The Employment Equity Act spells out the beneficiaries, who should do the protection, and advancement and what may happen to employers if they fail to comply in the view of the Director-General of the Labour. However the explicit constitutional and legislative endorsement of affirmative action comes with its controversy and legal challenges and it has been left to the courts to resolve tension on the one hand and to ensure equal treatment on the other. , Abstract
- Full Text:
- Date Issued: 2012
- Authors: Nconco, Mpumelelo
- Date: 2012
- Subjects: Equality before the law -- South Africa , Discrimination in employment -- Law and legislation -- South Africa , Affirmative action programs -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10196 , http://hdl.handle.net/10948/1617 , Equality before the law -- South Africa , Discrimination in employment -- Law and legislation -- South Africa , Affirmative action programs -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa
- Description: During the apartheid era in South Africa there was an unequivocal commitment to white supremacy, segregation and inequality. Discrimination but not on the basis of race was entrenched by the pre-democratic government. The 1980‟s saw the first steps towards reversing such practices through various measures, in the form of formal equality. Formal equality holds that the state must be act neutrally in relation to its employees and must favour no one above another. It assumes that all people are equal and that inequality can be eradicated simply by treating all people in the same way. Formal equality is therefore blind to structural inequality. Substantive equality in contrast to formal equality holds the value that equality is not simply a matter of likeness, that those who are different should be treated differently. The very essence of equality is to make distinction between groups and individual in order to accommodate their different needs and interests. It considers discrimination against groups which have been historically advantaged to be qualitatively aimed at remedying that disadvantage. The Constitution Act 108 of 1996 confers the right to equal protection and benefit of the law and the right to non discrimination. Prohibition of unfair discrimination in itself is insufficient to achieve true equality in a historically oppressed society. Hard affirmative action measures are required, the Constitution further explicitly endorses such restitutionary measures. Affirmative action is a systematic, planned process whereby the effects of colonialism and racial discrimination are being reversed in all areas if life. It is designed to achieve equal employment opportunities. In order to achieve this goal the barriers of the workplace which restrict employment and progressive opportunities have to be systematically eliminated through proactive programmes. Affirmative action is a delicate instrument of social engineering which must be used with caution. The Employment Equity Act 55 of 1998 gives effect to the constitutional provisions and to regulate affirmative action measures in employment. The Employment Equity Act spells out the beneficiaries, who should do the protection, and advancement and what may happen to employers if they fail to comply in the view of the Director-General of the Labour. However the explicit constitutional and legislative endorsement of affirmative action comes with its controversy and legal challenges and it has been left to the courts to resolve tension on the one hand and to ensure equal treatment on the other. , Abstract
- Full Text:
- Date Issued: 2012
Educators'perceptions on the contribution of South African Democratic Teachers' Union to teacher professional development
- Authors: Kwayiba, Xolile Lawrence
- Date: 2015
- Subjects: Teachers' unions Teachers -- In-service training -- South Africa -- Eastern Cape Teachers -- Training of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/6081 , vital:29489
- Description: The purpose of the study was to investigate the educators’ perceptions on the role of the South African Democratic Teachers’ Union (SADTU) in teacher professional development. The study also investigated the Union’s perceived challenges in contributing to teacher professionalism in South Africa, their perceived professional priorities and perceived expectations of teachers. The research genre used for this study was the interpretivism or constructivism paradigm. The qualitative methodology was used and case study employed as the research design of the study. The findings of this study were that SADTU were perceived as militant activists. Their activities were perceived as often very disruptive to education and their role appeared to be more politically focused than educational. They promoted and protected teacher labour rights and interests. However, they had no programme, nor the expertise nor the resources to respond to teachers’ professional development needs. The perceptions about them were that they had minimal or negligible contribution to teacher professional development. SADTU conducted training, but with nothing of value to teacher professional development. The unethical, unconstitutional and professionally non-developmental cadre deployment of SADTU leadership compromised the Union. Another finding was the important role of appropriate continuous professional development programmes in the improvement of the teachers’ own professional development, in the improvement of classroom practices and eventual enhanced learner performance. Inclusive to professional development are educationally good skills and values to colleagues, learners and parents both at school and out of school. Recommendations for SADTU were the: development of a clear programme on Teacher Professional Development; mobilisation of SADTU members towards restoring and enhancing the dignity of the teaching profession; engaging politically in curriculum policymaking to form inclusive professional associations; ending cadre deployment for senior management posts by SADTU leadership; establish development centres for critical maths and science, computers skills and other subjects and resuscitation of teacher colleges.
- Full Text:
- Date Issued: 2015
- Authors: Kwayiba, Xolile Lawrence
- Date: 2015
- Subjects: Teachers' unions Teachers -- In-service training -- South Africa -- Eastern Cape Teachers -- Training of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/6081 , vital:29489
- Description: The purpose of the study was to investigate the educators’ perceptions on the role of the South African Democratic Teachers’ Union (SADTU) in teacher professional development. The study also investigated the Union’s perceived challenges in contributing to teacher professionalism in South Africa, their perceived professional priorities and perceived expectations of teachers. The research genre used for this study was the interpretivism or constructivism paradigm. The qualitative methodology was used and case study employed as the research design of the study. The findings of this study were that SADTU were perceived as militant activists. Their activities were perceived as often very disruptive to education and their role appeared to be more politically focused than educational. They promoted and protected teacher labour rights and interests. However, they had no programme, nor the expertise nor the resources to respond to teachers’ professional development needs. The perceptions about them were that they had minimal or negligible contribution to teacher professional development. SADTU conducted training, but with nothing of value to teacher professional development. The unethical, unconstitutional and professionally non-developmental cadre deployment of SADTU leadership compromised the Union. Another finding was the important role of appropriate continuous professional development programmes in the improvement of the teachers’ own professional development, in the improvement of classroom practices and eventual enhanced learner performance. Inclusive to professional development are educationally good skills and values to colleagues, learners and parents both at school and out of school. Recommendations for SADTU were the: development of a clear programme on Teacher Professional Development; mobilisation of SADTU members towards restoring and enhancing the dignity of the teaching profession; engaging politically in curriculum policymaking to form inclusive professional associations; ending cadre deployment for senior management posts by SADTU leadership; establish development centres for critical maths and science, computers skills and other subjects and resuscitation of teacher colleges.
- Full Text:
- Date Issued: 2015
Hidden presences in the spirituality of the amaXhosa of the Eastern Cape and the impact of Christianity on them
- Authors: Mtuze, P T
- Date: 2000
- Subjects: Spirituality -- South Africa -- Eastern Cape , Xhosa (African people) -- Religion , Missions -- South Africa -- Eastern Cape , Missionaries -- South Africa -- Eastern Cape , Christianity -- South Africa -- Eastern Cape -- History , Christianity and culture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1296 , http://hdl.handle.net/10962/d1015612
- Description: This thesis is an attempt to reopen the debate on the whole question of inculturation in Southern Africa especially in light of the fact that we are now in a multi-lingual and multi-religious state. It is an attempt to rehighlight the plight of the spirituality of the amaXhosa people over the last century when missionary and imperial onslaught relegated it to the doldrums. This plunged the amaXhosa in a crisis that has left them directionless, to put it mildly. This is said because the total onslaught destroyed their self-respect and their identity and begs the question as to whether their acceptability to God was contingent on renouncing their culture especially the hidden presences - Qamata, the living-dead and the notion of evil spirits. It is precisely because of these misconceptions regarding African culture and spirituality that the thesis has a strong expository and apologetic bias primarily aimed to address, and put into proper perspective, the significance of the Supreme Being, the living-dead and the evil spirits in African culture. The issues are discussed within the broader socio-historical context. The thesis is basically comparative in that it uses Celtic spirituality and the approach of the early Celtic church to the question of inculturation as its point of departure and as a foil against which the preposterous actions of the church in Africa should be seen. This comparative element is also reflected in the unmistakable `dichotomy’ of Western religion and African spirituality, or better still, lack of spirituality, that was so fervently maintained by the missionaries and the colonialists alike. It is for this reason that I concur with Chidester (1996:xiv) that `the study of religion must find itself, once again, on the frontier’. The study is informed by this approach right through. It should be stressed, from the outset, that the idea is not comparison in order to satisfy our curiosity, nor is it comparison in order to try to authenticate and vindicate the beleaguered African culture. The central idea of the study is to expose the absurdity of the policies of the past century in this regard. The myth of the pure blooded Christianity is confronted, if not exploded. Several examples of both inculturation and continuities between Christianity and other faiths such as the Jewish founding faith are given. The subtheme of cultural domination subtly spans the whole study culminating in Chapter Four where the blacks begin to appropriate some of the Christian symbols and the whites also begin to assimilate African concepts such as ubuntu.
- Full Text:
- Date Issued: 2000
- Authors: Mtuze, P T
- Date: 2000
- Subjects: Spirituality -- South Africa -- Eastern Cape , Xhosa (African people) -- Religion , Missions -- South Africa -- Eastern Cape , Missionaries -- South Africa -- Eastern Cape , Christianity -- South Africa -- Eastern Cape -- History , Christianity and culture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1296 , http://hdl.handle.net/10962/d1015612
- Description: This thesis is an attempt to reopen the debate on the whole question of inculturation in Southern Africa especially in light of the fact that we are now in a multi-lingual and multi-religious state. It is an attempt to rehighlight the plight of the spirituality of the amaXhosa people over the last century when missionary and imperial onslaught relegated it to the doldrums. This plunged the amaXhosa in a crisis that has left them directionless, to put it mildly. This is said because the total onslaught destroyed their self-respect and their identity and begs the question as to whether their acceptability to God was contingent on renouncing their culture especially the hidden presences - Qamata, the living-dead and the notion of evil spirits. It is precisely because of these misconceptions regarding African culture and spirituality that the thesis has a strong expository and apologetic bias primarily aimed to address, and put into proper perspective, the significance of the Supreme Being, the living-dead and the evil spirits in African culture. The issues are discussed within the broader socio-historical context. The thesis is basically comparative in that it uses Celtic spirituality and the approach of the early Celtic church to the question of inculturation as its point of departure and as a foil against which the preposterous actions of the church in Africa should be seen. This comparative element is also reflected in the unmistakable `dichotomy’ of Western religion and African spirituality, or better still, lack of spirituality, that was so fervently maintained by the missionaries and the colonialists alike. It is for this reason that I concur with Chidester (1996:xiv) that `the study of religion must find itself, once again, on the frontier’. The study is informed by this approach right through. It should be stressed, from the outset, that the idea is not comparison in order to satisfy our curiosity, nor is it comparison in order to try to authenticate and vindicate the beleaguered African culture. The central idea of the study is to expose the absurdity of the policies of the past century in this regard. The myth of the pure blooded Christianity is confronted, if not exploded. Several examples of both inculturation and continuities between Christianity and other faiths such as the Jewish founding faith are given. The subtheme of cultural domination subtly spans the whole study culminating in Chapter Four where the blacks begin to appropriate some of the Christian symbols and the whites also begin to assimilate African concepts such as ubuntu.
- Full Text:
- Date Issued: 2000
Sketch-based digital storyboards and floor plans for authoring computer-generated film pre-visuals
- Authors: Matthews, Timothy
- Date: 2012
- Subjects: Computer graphics , Computer vision
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10463 , http://hdl.handle.net/10948/d1008430 , Computer graphics , Computer vision
- Description: Pre-visualisation is an important tool for planning films during the pre-production phase of filmmaking. Existing pre-visualisation authoring tools do not effectively support the user in authoring pre-visualisations without impairing software usability. These tools require the user to either have programming skills, be experienced in modelling and animation, or use drag-and-drop style interfaces. These interaction methods do not intuitively fit with pre-production activities such as floor planning and storyboarding, and existing tools that apply a storyboarding metaphor do not automatically interpret user sketches. The goal of this research was to investigate how sketch-based user interfaces and methods from computer vision could be used for supporting pre-visualisation authoring using a storyboarding approach. The requirements for such a sketch-based storyboarding tool were determined from literature and an interview with Triggerfish Animation Studios. A framework was developed to support sketch-based pre-visualisation authoring using a storyboarding approach. Algorithms for describing user sketches, recognising objects and performing pose estimation were designed to automatically interpret user sketches. A proof of concept prototype implementation of this framework was evaluated in order to assess its usability benefit. It was found that the participants could author pre-visualisations effectively, efficiently and easily. The results of the usability evaluation also showed that the participants were satisfied with the overall design and usability of the prototype tool. The positive and negative findings of the evaluation were interpreted and combined with existing heuristics in order to create a set of guidelines for designing similar sketch-based pre-visualisation authoring tools that apply the storyboarding approach. The successful implementation of the proof of concept prototype tool provides practical evidence of the feasibility of sketch-based pre-visualisation authoring. The positive results from the usability evaluation established that sketch-based interfacing techniques can be used effectively with a storyboarding approach for authoring pre-visualisations without impairing software usability.
- Full Text:
- Date Issued: 2012
- Authors: Matthews, Timothy
- Date: 2012
- Subjects: Computer graphics , Computer vision
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10463 , http://hdl.handle.net/10948/d1008430 , Computer graphics , Computer vision
- Description: Pre-visualisation is an important tool for planning films during the pre-production phase of filmmaking. Existing pre-visualisation authoring tools do not effectively support the user in authoring pre-visualisations without impairing software usability. These tools require the user to either have programming skills, be experienced in modelling and animation, or use drag-and-drop style interfaces. These interaction methods do not intuitively fit with pre-production activities such as floor planning and storyboarding, and existing tools that apply a storyboarding metaphor do not automatically interpret user sketches. The goal of this research was to investigate how sketch-based user interfaces and methods from computer vision could be used for supporting pre-visualisation authoring using a storyboarding approach. The requirements for such a sketch-based storyboarding tool were determined from literature and an interview with Triggerfish Animation Studios. A framework was developed to support sketch-based pre-visualisation authoring using a storyboarding approach. Algorithms for describing user sketches, recognising objects and performing pose estimation were designed to automatically interpret user sketches. A proof of concept prototype implementation of this framework was evaluated in order to assess its usability benefit. It was found that the participants could author pre-visualisations effectively, efficiently and easily. The results of the usability evaluation also showed that the participants were satisfied with the overall design and usability of the prototype tool. The positive and negative findings of the evaluation were interpreted and combined with existing heuristics in order to create a set of guidelines for designing similar sketch-based pre-visualisation authoring tools that apply the storyboarding approach. The successful implementation of the proof of concept prototype tool provides practical evidence of the feasibility of sketch-based pre-visualisation authoring. The positive results from the usability evaluation established that sketch-based interfacing techniques can be used effectively with a storyboarding approach for authoring pre-visualisations without impairing software usability.
- Full Text:
- Date Issued: 2012
A survey of organizational culture and organizational performance in a manufacturing company
- Authors: Dom, Veliswa Virginia
- Date: 2018
- Subjects: Corporate culture -- South Africa -- Eastern Cape , Organizational behavior -- South Africa -- Eastern Cape , Factories -- South Africa -- Eastern Cape , Analysis of variance , Shift systems -- South Africa -- Eastern Cape , Employees -- Rating of -- South Africa -- Eastern Cape , Competing Values Framework (CVF)
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/61861 , vital:28069
- Description: The purpose of this research was to explore the relationship between organizational culture and organizational performance in a manufacturing company. This company supplies metal products to the motor vehicle manufacturing industry, where the quality and quantity of parts produced is of paramount importance, since the buyers of these products are quality conscious. The organization has three production shifts that rotate each week. Anecdotal observations are that irrespective of the time that a shift operates over the course of the month, the different shifts tend to perform at different levels in terms of quality and quantity of output. This study therefore sought to investigate if these differences between shifts are statistically significant, and if so, whether these shifts also have differences in organizational culture. Components of organizational culture include values, norms, beliefs, attitudes, principles and expectations that give the organization a unique personality and differentiate it from other organizations. While the literature indicates that qualitative or quantitative approaches can be used in organizational culture research, this research adopted the quantitative approach, making use of the Competing Values Framework (CVF). The CVF is a four-category organizational culture typology established by Cameron and Quinn (2006). The framework is based on two dimensions: stability or flexibility of the organization, and external or internal focus. In this research, the CVF was used as a measurement tool to evaluate organizational culture. In order to determine differences in organizational culture between shifts, a survey was undertaken (N=138) which measured employee perceptions pertaining to the existing organizational culture of each of the three production shifts at the company. Secondly, differences in performance between the shifts were examined by using the performance data for a three-month period for each shift in terms of quantity and quality. This data was obtained from the management of the production process at the company. Statistical analysis was done using ANOVA to analyse the differences between the shifts. The findings indicated that the dominant existing organizational culture at the company under investigation is a clan culture. Furthermore, there is a statistically significant difference between the cultures of all the three shifts at the manufacturing company. The results also indicated that there is a statistically significant difference in the quantity and quality of production between the three shifts. In conclusion, the research indicated there are differences in culture and in performance, but given the nature of the data, it was not possible to statistically analyse the relationship between shift culture and performance. However, it is conceivable that cultural differences between shifts may be contributing to performance differences. With regards to further research, it is recommended that this research be extended to other branches of the manufacturing company in other regions, in order to determine whether there are any significant differences in culture and performance between these branches and their shifts. Research could also be extended to other South African organizations to create a sufficiently large sample of shift and/or business units, so as to be able to do statistical analysis of the relationship between culture and performance.
- Full Text:
- Date Issued: 2018
- Authors: Dom, Veliswa Virginia
- Date: 2018
- Subjects: Corporate culture -- South Africa -- Eastern Cape , Organizational behavior -- South Africa -- Eastern Cape , Factories -- South Africa -- Eastern Cape , Analysis of variance , Shift systems -- South Africa -- Eastern Cape , Employees -- Rating of -- South Africa -- Eastern Cape , Competing Values Framework (CVF)
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/61861 , vital:28069
- Description: The purpose of this research was to explore the relationship between organizational culture and organizational performance in a manufacturing company. This company supplies metal products to the motor vehicle manufacturing industry, where the quality and quantity of parts produced is of paramount importance, since the buyers of these products are quality conscious. The organization has three production shifts that rotate each week. Anecdotal observations are that irrespective of the time that a shift operates over the course of the month, the different shifts tend to perform at different levels in terms of quality and quantity of output. This study therefore sought to investigate if these differences between shifts are statistically significant, and if so, whether these shifts also have differences in organizational culture. Components of organizational culture include values, norms, beliefs, attitudes, principles and expectations that give the organization a unique personality and differentiate it from other organizations. While the literature indicates that qualitative or quantitative approaches can be used in organizational culture research, this research adopted the quantitative approach, making use of the Competing Values Framework (CVF). The CVF is a four-category organizational culture typology established by Cameron and Quinn (2006). The framework is based on two dimensions: stability or flexibility of the organization, and external or internal focus. In this research, the CVF was used as a measurement tool to evaluate organizational culture. In order to determine differences in organizational culture between shifts, a survey was undertaken (N=138) which measured employee perceptions pertaining to the existing organizational culture of each of the three production shifts at the company. Secondly, differences in performance between the shifts were examined by using the performance data for a three-month period for each shift in terms of quantity and quality. This data was obtained from the management of the production process at the company. Statistical analysis was done using ANOVA to analyse the differences between the shifts. The findings indicated that the dominant existing organizational culture at the company under investigation is a clan culture. Furthermore, there is a statistically significant difference between the cultures of all the three shifts at the manufacturing company. The results also indicated that there is a statistically significant difference in the quantity and quality of production between the three shifts. In conclusion, the research indicated there are differences in culture and in performance, but given the nature of the data, it was not possible to statistically analyse the relationship between shift culture and performance. However, it is conceivable that cultural differences between shifts may be contributing to performance differences. With regards to further research, it is recommended that this research be extended to other branches of the manufacturing company in other regions, in order to determine whether there are any significant differences in culture and performance between these branches and their shifts. Research could also be extended to other South African organizations to create a sufficiently large sample of shift and/or business units, so as to be able to do statistical analysis of the relationship between culture and performance.
- Full Text:
- Date Issued: 2018
Creating value through customer relationships in the services sector
- Authors: Allie, Hisham
- Date: 2007
- Subjects: Customer services , Value added
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8740 , http://hdl.handle.net/10948/790 , Customer services , Value added
- Description: Many academic studies in the past have focussed on how to create value for businesses in terms of adding profit to the bottom line through performance, and many argue that adding value for the client is also viewed as a profitable business strategy. This strategy translates as a win-win business relationship since long-term relationships ensure customer loyalty, customer retention and repeat business. In the services sector, it is difficult to quantify the worth or value that a particular service has since services are intangible products. The perception of value of such a service is known as “perceived value” since value recognition rests with the consumer who attempts to quantify the worth of that service. It is generally accepted in the services sector that establishing long-term, mutually beneficial, meaningful business relationships add value for the client and helps them to attach a value to the services that company provides. A company cannot establish such relationships without the help of its employees who represents the face of the organisation and implements the value adding strategy on the organisation’s behalf. Recent studies have begun to address this, examining value creation in business relationships in the context of the sale of tangible goods. The process of value creation for customers in services relationships remains underresearched. Perceived value explains why customers choose one particular service over another, why service companies gain competitive advantage by maintaining genuine longterm customer relationships, and why “the personal touch”, created through emotional attributes such as trust, caring and empathy, adds value from customers’ perspective. This dissertation presents a study of perceived value from the perspective of the customer within the context of the delivery of a credence product in a services relationship model. Using grounded theory methodology; following in-depth interviews with consumers of general insurance, a number of customer-value creation dimensions for businesses have been identified. Parallel interviews with members of staff from the supplier company add a further perspective. This research demonstrates how organisations or suppliers in the services industry can add value when delivering a credence product in a services relationship context. It is believed that an understanding of the value-adding dimensions can be implemented to create opportunities to build value for customers, with commensurate benefits for suppliers. Following analysis of the interviews held with each buyer, a total of six value dimensions are identified in the findings chapter. Each dimension is individually described, discussed, and illustrated with quotations from customers and supplier’s staff. Other issues relating to value arising from the interviews are examined in the discussion chapter. Three areas for further research are proposed in the conclusion.
- Full Text:
- Date Issued: 2007
- Authors: Allie, Hisham
- Date: 2007
- Subjects: Customer services , Value added
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8740 , http://hdl.handle.net/10948/790 , Customer services , Value added
- Description: Many academic studies in the past have focussed on how to create value for businesses in terms of adding profit to the bottom line through performance, and many argue that adding value for the client is also viewed as a profitable business strategy. This strategy translates as a win-win business relationship since long-term relationships ensure customer loyalty, customer retention and repeat business. In the services sector, it is difficult to quantify the worth or value that a particular service has since services are intangible products. The perception of value of such a service is known as “perceived value” since value recognition rests with the consumer who attempts to quantify the worth of that service. It is generally accepted in the services sector that establishing long-term, mutually beneficial, meaningful business relationships add value for the client and helps them to attach a value to the services that company provides. A company cannot establish such relationships without the help of its employees who represents the face of the organisation and implements the value adding strategy on the organisation’s behalf. Recent studies have begun to address this, examining value creation in business relationships in the context of the sale of tangible goods. The process of value creation for customers in services relationships remains underresearched. Perceived value explains why customers choose one particular service over another, why service companies gain competitive advantage by maintaining genuine longterm customer relationships, and why “the personal touch”, created through emotional attributes such as trust, caring and empathy, adds value from customers’ perspective. This dissertation presents a study of perceived value from the perspective of the customer within the context of the delivery of a credence product in a services relationship model. Using grounded theory methodology; following in-depth interviews with consumers of general insurance, a number of customer-value creation dimensions for businesses have been identified. Parallel interviews with members of staff from the supplier company add a further perspective. This research demonstrates how organisations or suppliers in the services industry can add value when delivering a credence product in a services relationship context. It is believed that an understanding of the value-adding dimensions can be implemented to create opportunities to build value for customers, with commensurate benefits for suppliers. Following analysis of the interviews held with each buyer, a total of six value dimensions are identified in the findings chapter. Each dimension is individually described, discussed, and illustrated with quotations from customers and supplier’s staff. Other issues relating to value arising from the interviews are examined in the discussion chapter. Three areas for further research are proposed in the conclusion.
- Full Text:
- Date Issued: 2007
The development of a commercial production process for p-menthane-3,8-diol
- Authors: Rust, Nico
- Date: 2009
- Subjects: Insect pests -- Control , Repellents
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:10427 , http://hdl.handle.net/10948/d1018273
- Description: The synthesis of p-menthane-3,8-diol via the acid-catalyzed cyclization of citronellal in a dilute aqueous sulphuric acid medium was investigated using conventional batch and continuous systems in order to develop a commercial production process for said p-menthane-3,8-diol (PMD). The batch studies conducted during the first part of this study showed that the formation of PMD from citronellal occurs via an intra-molecular Prins reaction that results in the formation of both the desired PMD product, as well as the partially hydrated isopulegol. It was shown that the formationof the by- product, PMD-acetal, results from the reaction between an intermediate, 5-methyl-2- isopropylcyclohexanol, and the citronellal starting material, and not from the reaction between PMD and citronellal as previously reported. Kinetic studies confirmed the existence of a complicated kinetic model. The formation of PMD from citronellal displayed typical pseudo first order kinetics up to conversions of 70 after which the kinetic model becomes complicated as the result of the establishment of quasi equilibrium reactions between PMD and isopulegol (dehydration of PMD and hydration of isopulegol) and between PMD the PMD-acetal, both systems being acid catalysed. The PMD-acetal formation reaction appears to be second order with respect to PMD. Scale-up studies of the batch process to 30L and 50L scales showed that it would be extremely difficult to limit the level of PMD-acetal formation below the desired level of 1 percent, even if citronellal conversions are restricted to about 50 percent. During studies conducted on a commercially availablemicro-structured organic synthesis plant (OSP) it was shown that it is possible to perform the PMD reaction as a continuous process. The results obtained showed that the use of a micro-mixer such as the caterpillar micro-mixer did not provide enough residence time in order for desirable conversions (- 40 percent) to be obtained. By combining themicro-mixer with delay-loops of different thicknesses and lengths, and using increasing reaction temperatures, it was shown that the conversion of citronellal could be improved to some extent, but compared poorly to the expected conversions for a well-stirred batch reactor. By packing selected delay loops with inert SiC particles, improved mass transfer was observed between the organic and aqueous phases as reflected in the increased conversion of citronellal. Using the observations that were made during the use of the OSP, a continuous-flow, tubular reactor system was designed and constructed. Advanced statistical techniques were used to investigate the effect of variables such as temperature, acid concentration, reactor length, flow rate and the organic to aqueous ratio on the rate and selectivity of the reaction. Mathematical models were derived for citronellal conversion, yield of PMD and yield of PMD- acetals, and used to predict the concentrations of citronellal, PMD and PMD-acetals at set experimental conditions. The results obtained showed that it was possible to obtain a product which approached desired specifications.Downstream processing of the PMD reaction mixture as it exits the reactor requires phase separation and neutralization of the acid catalyst solution, followed by further work-up to recover unreacted starting material and intermediates for recycle back to the synthesis reactor, followed by purification of crude PMD to the desired specification. The study showed that neutralization, prior or after phase separation, does not affect the selectivity of the PMD to such a great extent, but does influence the relative conversion due to extended contact of the catalyst with the organic phase after the reaction is terminated. Recovery of unreacted citronellal and isopulegol could be achieved by a simple vacuum evaporation step, which may either be carried out in a batch manner using traditional distillation equipment, or in a continuous process using wiped-film (short path) techniques. It was also shown that selective crystallization of PMD from the crude product mixture by addition of a solvent, such as heptanes or hexane proved to be the best way of achieving the desired product specification.
- Full Text:
- Date Issued: 2009
- Authors: Rust, Nico
- Date: 2009
- Subjects: Insect pests -- Control , Repellents
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:10427 , http://hdl.handle.net/10948/d1018273
- Description: The synthesis of p-menthane-3,8-diol via the acid-catalyzed cyclization of citronellal in a dilute aqueous sulphuric acid medium was investigated using conventional batch and continuous systems in order to develop a commercial production process for said p-menthane-3,8-diol (PMD). The batch studies conducted during the first part of this study showed that the formation of PMD from citronellal occurs via an intra-molecular Prins reaction that results in the formation of both the desired PMD product, as well as the partially hydrated isopulegol. It was shown that the formationof the by- product, PMD-acetal, results from the reaction between an intermediate, 5-methyl-2- isopropylcyclohexanol, and the citronellal starting material, and not from the reaction between PMD and citronellal as previously reported. Kinetic studies confirmed the existence of a complicated kinetic model. The formation of PMD from citronellal displayed typical pseudo first order kinetics up to conversions of 70 after which the kinetic model becomes complicated as the result of the establishment of quasi equilibrium reactions between PMD and isopulegol (dehydration of PMD and hydration of isopulegol) and between PMD the PMD-acetal, both systems being acid catalysed. The PMD-acetal formation reaction appears to be second order with respect to PMD. Scale-up studies of the batch process to 30L and 50L scales showed that it would be extremely difficult to limit the level of PMD-acetal formation below the desired level of 1 percent, even if citronellal conversions are restricted to about 50 percent. During studies conducted on a commercially availablemicro-structured organic synthesis plant (OSP) it was shown that it is possible to perform the PMD reaction as a continuous process. The results obtained showed that the use of a micro-mixer such as the caterpillar micro-mixer did not provide enough residence time in order for desirable conversions (- 40 percent) to be obtained. By combining themicro-mixer with delay-loops of different thicknesses and lengths, and using increasing reaction temperatures, it was shown that the conversion of citronellal could be improved to some extent, but compared poorly to the expected conversions for a well-stirred batch reactor. By packing selected delay loops with inert SiC particles, improved mass transfer was observed between the organic and aqueous phases as reflected in the increased conversion of citronellal. Using the observations that were made during the use of the OSP, a continuous-flow, tubular reactor system was designed and constructed. Advanced statistical techniques were used to investigate the effect of variables such as temperature, acid concentration, reactor length, flow rate and the organic to aqueous ratio on the rate and selectivity of the reaction. Mathematical models were derived for citronellal conversion, yield of PMD and yield of PMD- acetals, and used to predict the concentrations of citronellal, PMD and PMD-acetals at set experimental conditions. The results obtained showed that it was possible to obtain a product which approached desired specifications.Downstream processing of the PMD reaction mixture as it exits the reactor requires phase separation and neutralization of the acid catalyst solution, followed by further work-up to recover unreacted starting material and intermediates for recycle back to the synthesis reactor, followed by purification of crude PMD to the desired specification. The study showed that neutralization, prior or after phase separation, does not affect the selectivity of the PMD to such a great extent, but does influence the relative conversion due to extended contact of the catalyst with the organic phase after the reaction is terminated. Recovery of unreacted citronellal and isopulegol could be achieved by a simple vacuum evaporation step, which may either be carried out in a batch manner using traditional distillation equipment, or in a continuous process using wiped-film (short path) techniques. It was also shown that selective crystallization of PMD from the crude product mixture by addition of a solvent, such as heptanes or hexane proved to be the best way of achieving the desired product specification.
- Full Text:
- Date Issued: 2009
Competition and segmentation : an analysis of wage determination and labour adjustments in manufacturing industry
- Authors: McCartan, Patrick John
- Date: 1986
- Subjects: Labour supply , Labour market , Competition , South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:927 , http://hdl.handle.net/10962/d1001453
- Description: The thesis itself proceeds according to the following outline. Chapter One is concerned with the neoclassical theory of the labour market. Three particular models are surveyed all of which attempt to explain wage differentials and labour adjustments within a competitive equilibrium framework. The basic model of the labour market which rests upon the marginal productivity theory of labour demand, the utility-maximising approach to labour supply and the competitive theory of market equilibrium is dealt with first.This is followed by an outline of human capital theory which emphasises the crucial role played by education and training in determining individual earnings . Finally, attention is focused on disequilibrium wage models of adjustment which account for wage dispersion in terms of the amount and quality of information available to transactors in the labour market.(Introduction, p. 3-4)
- Full Text:
- Date Issued: 1986
- Authors: McCartan, Patrick John
- Date: 1986
- Subjects: Labour supply , Labour market , Competition , South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:927 , http://hdl.handle.net/10962/d1001453
- Description: The thesis itself proceeds according to the following outline. Chapter One is concerned with the neoclassical theory of the labour market. Three particular models are surveyed all of which attempt to explain wage differentials and labour adjustments within a competitive equilibrium framework. The basic model of the labour market which rests upon the marginal productivity theory of labour demand, the utility-maximising approach to labour supply and the competitive theory of market equilibrium is dealt with first.This is followed by an outline of human capital theory which emphasises the crucial role played by education and training in determining individual earnings . Finally, attention is focused on disequilibrium wage models of adjustment which account for wage dispersion in terms of the amount and quality of information available to transactors in the labour market.(Introduction, p. 3-4)
- Full Text:
- Date Issued: 1986
The relationship between health and safety and human risk taking behaviour in the South African electrical construction industry
- Authors: Du Toit, Willem Johannes
- Date: 2012
- Subjects: Electrical engineering -- Safety measures , Electrical engineering -- Health aspects , Construction industry -- Safety measures , Psychology, industrial
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9691 , http://hdl.handle.net/10948/d1009529 , Electrical engineering -- Safety measures , Electrical engineering -- Health aspects , Construction industry -- Safety measures , Psychology, industrial
- Description: Mankind, and the development of people, exists due to risk-taking behaviour. It is not that humans should not take risks, but rather the ability to identify the magnitude of risk exposure in order that mankind‟s actions would be so selected as to mitigate exposed risk factors, that no harm should befall them. The approach to health and safety (H&S) has always been to manage H&S environmental factors that could have a negative impact on people, capital, and organisational systems. However, the critical component of human risk-taking behaviour that would have a far greater impact has rarely been acknowledged as part of the drivers that increase risk exposure. Human behaviour is a major contributing factor in accident causation. Although human error cannot be completely eliminated, it should be identified and correctly managed according to each individual‟s risk-taking profile. The reason people decide to take certain risks under certain conditions and the effect it has on H&S management systems is a key component to managing organisational risk exposure. To quantify the value of individual risk-taking behaviour could provide management with better opportunities of lowering the organisational risk exposure. Human risk-taking behaviour is influenced by each individual‟s perception of risk. Such perception of risk will influence decisions on risk-taking behaviour, which in turn is influenced by the individual‟s psychological profile and environmental factors, including character and the impact of a cultural environment. The electrical construction and maintenance industry differs from other similar industries in that the physical entity of electricity requires not only sensory perception for the identification and evaluation of risk factors, but also requires specialised knowledge and testing equipment to evaluate the parameters of electrical installation, plant or equipment. Without such competence, direct exposure to most electrical installations could be fatal. The optimum human resource (HR) solution for managing the risk potential of high risk-taking behaviour is the rating and allocation of specific job tasks that can match and limit the individual potential for risk-taking behaviour and the impact on organisational incident statistics. Maintaining and optimising employee job performance enables organisations to better achieve pre-set goals and missions. Such improvements being a catalyst for better job performance by setting limitations on high risk-taking behaviour, that will improve H&S performance by lowering incident rates.
- Full Text:
- Date Issued: 2012
- Authors: Du Toit, Willem Johannes
- Date: 2012
- Subjects: Electrical engineering -- Safety measures , Electrical engineering -- Health aspects , Construction industry -- Safety measures , Psychology, industrial
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9691 , http://hdl.handle.net/10948/d1009529 , Electrical engineering -- Safety measures , Electrical engineering -- Health aspects , Construction industry -- Safety measures , Psychology, industrial
- Description: Mankind, and the development of people, exists due to risk-taking behaviour. It is not that humans should not take risks, but rather the ability to identify the magnitude of risk exposure in order that mankind‟s actions would be so selected as to mitigate exposed risk factors, that no harm should befall them. The approach to health and safety (H&S) has always been to manage H&S environmental factors that could have a negative impact on people, capital, and organisational systems. However, the critical component of human risk-taking behaviour that would have a far greater impact has rarely been acknowledged as part of the drivers that increase risk exposure. Human behaviour is a major contributing factor in accident causation. Although human error cannot be completely eliminated, it should be identified and correctly managed according to each individual‟s risk-taking profile. The reason people decide to take certain risks under certain conditions and the effect it has on H&S management systems is a key component to managing organisational risk exposure. To quantify the value of individual risk-taking behaviour could provide management with better opportunities of lowering the organisational risk exposure. Human risk-taking behaviour is influenced by each individual‟s perception of risk. Such perception of risk will influence decisions on risk-taking behaviour, which in turn is influenced by the individual‟s psychological profile and environmental factors, including character and the impact of a cultural environment. The electrical construction and maintenance industry differs from other similar industries in that the physical entity of electricity requires not only sensory perception for the identification and evaluation of risk factors, but also requires specialised knowledge and testing equipment to evaluate the parameters of electrical installation, plant or equipment. Without such competence, direct exposure to most electrical installations could be fatal. The optimum human resource (HR) solution for managing the risk potential of high risk-taking behaviour is the rating and allocation of specific job tasks that can match and limit the individual potential for risk-taking behaviour and the impact on organisational incident statistics. Maintaining and optimising employee job performance enables organisations to better achieve pre-set goals and missions. Such improvements being a catalyst for better job performance by setting limitations on high risk-taking behaviour, that will improve H&S performance by lowering incident rates.
- Full Text:
- Date Issued: 2012