Characterization of the heat source of thermal aquifers within the Soutpansberg Basin in the Limpopo Province, South Africa: Evidence from geophysical and geological investigations
- Authors: Nyabeze, Peter Kushara
- Date: 2019
- Subjects: Basins (Geology) -- Analysis Geology, Structural -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Geology)
- Identifier: http://hdl.handle.net/10353/15167 , vital:40192
- Description: The research was conducted to contribute towards the knowledge base on the potential for geothermal energy in the Soutpansberg Basin, located in the Limpopo Province of South Africa. The focus area was Siloam, an area that hosts a hottest spring with the highest recorded temperature of 67.5°C. The research involved visits to the Soutpansberg Basin, water sampling, carrying out ground geophysical surveys, and high-level processing of airborne magnetic data to determine depths and temperatures of magnetic sources. The water samples from the hot springs were found to be enriched in sodium, bicarbonate and chlorine with very low concentrations of other element species. The chemical composition of the spring water indicated a source chemistry comprising of the Na-ClHCO3 water assemblage that is a typical signature for deep circulating groundwater of meteoric origin. The circulation depth was inferred to be 2.0 km. The increased resolution of the ground magnetic, electrical resistivity tomography, and electromagnetic conductivity methods data made it possible to delineate subsurface structures at the spring such as dykes, sills, faults and fractures from generated depth models. Modelling of ground magnetic data showed that the Siloam hot spring occurred between two interpreted north dipping dykes approximately 150 m apart. The minimum depth extent of the dykes was interpreted to be 650 m. The magnetic susceptibility values determined from rock measurements and modelling of magnetic data indicated the presence of volcanic and metamorphic rocks. Electromagnetic profiling data showed that there were three main high conductivity zones in the study area with values above 100 mS/m; A central zone associated with the spring; A zone to the south of the spring and a north zone associated with the Siloam Fault. Ground geophysics survey results confirmed the existence of the Siloam Fault. Two artesian boreholes with water warmer than 40 °C were identified to the south of the Siloam hot spring. Both electromagnetic conductivity and electrical resistivity tomography surveys delineated lateral and vertical variation in the bedrock to depths of 40 m to 60 m. Water bearing structures that could be faults, or fractures were identified. Layering due to weathering and water content was found to be in the depth range of 20 m to 40 m. The depths of the potential heat sources were computed from the radially averaged power spectrum of airborne magnetic data for square blocks with side dimensions L of 51 km, 103 km, and 129 km. Spectral analysis based approaches namely Centroid method, Spectral peak method, and the Fractal based approach were used for computing depth and temperatures to heat sources. Airborne magnetic data sets with larger window sizes were preferred for depth computations, as they preserved spectral signatures of deeper sources and reduced the contribution of shallower sources. The size of the data windows did not have a marked effect of depth and temperature values. Shallower magnetic sources depths of approximately 2.0 km were delineated using the Euler deconvolution method. An anticlinal feature at depths of 2.0 to 4.5 km was 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper delineated in the central part of the basin. Spectral analysis results indicated that the depth to the top of magnetic sources was at 3.5 km to 6.2 km; the centroid of the basement at 7.92 km to 13.41 km, and the basal below 11.09 km and 14.08 km. The lower end depth spectrum was determined from application of the Centroid method with the deeper being results from the Fractal based approach. The Spectral peak method was useful for determining the depth to the top of magnetic sources. The temperature of the top of magnetic sources and basement centroid were computed to be in the range 234.00 °C to 281.34 °C. Magnetic source depths and basal temperatures that were in the Curie point range within which rocks lose magnetism due to heat were determined, using a computation approach that utilised fractal parameters, to be 21.39 km and 577.42 °C, respectively. Increasing the value of the fractal parameter β from 0 to 4, had an effect of retaining deeper depths and higher temperatures. The fractal parameter β range of 3 to 4 that gave the Curie point parameters indicated basal rock types with an igneous predisposition. The research highlighted evidence for the existence of the Soutpansberg Basin Geothermal Field (SBGF). The area around Siloam is a potential target for drilling exploration geothermal energy boreholes based on the occurrence of hot springs, shallow heat source depths, anticlinal structure, high formation temperatures, deep circulating water and the achieved Curie point temperature.
- Full Text:
- Date Issued: 2019
- Authors: Nyabeze, Peter Kushara
- Date: 2019
- Subjects: Basins (Geology) -- Analysis Geology, Structural -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Geology)
- Identifier: http://hdl.handle.net/10353/15167 , vital:40192
- Description: The research was conducted to contribute towards the knowledge base on the potential for geothermal energy in the Soutpansberg Basin, located in the Limpopo Province of South Africa. The focus area was Siloam, an area that hosts a hottest spring with the highest recorded temperature of 67.5°C. The research involved visits to the Soutpansberg Basin, water sampling, carrying out ground geophysical surveys, and high-level processing of airborne magnetic data to determine depths and temperatures of magnetic sources. The water samples from the hot springs were found to be enriched in sodium, bicarbonate and chlorine with very low concentrations of other element species. The chemical composition of the spring water indicated a source chemistry comprising of the Na-ClHCO3 water assemblage that is a typical signature for deep circulating groundwater of meteoric origin. The circulation depth was inferred to be 2.0 km. The increased resolution of the ground magnetic, electrical resistivity tomography, and electromagnetic conductivity methods data made it possible to delineate subsurface structures at the spring such as dykes, sills, faults and fractures from generated depth models. Modelling of ground magnetic data showed that the Siloam hot spring occurred between two interpreted north dipping dykes approximately 150 m apart. The minimum depth extent of the dykes was interpreted to be 650 m. The magnetic susceptibility values determined from rock measurements and modelling of magnetic data indicated the presence of volcanic and metamorphic rocks. Electromagnetic profiling data showed that there were three main high conductivity zones in the study area with values above 100 mS/m; A central zone associated with the spring; A zone to the south of the spring and a north zone associated with the Siloam Fault. Ground geophysics survey results confirmed the existence of the Siloam Fault. Two artesian boreholes with water warmer than 40 °C were identified to the south of the Siloam hot spring. Both electromagnetic conductivity and electrical resistivity tomography surveys delineated lateral and vertical variation in the bedrock to depths of 40 m to 60 m. Water bearing structures that could be faults, or fractures were identified. Layering due to weathering and water content was found to be in the depth range of 20 m to 40 m. The depths of the potential heat sources were computed from the radially averaged power spectrum of airborne magnetic data for square blocks with side dimensions L of 51 km, 103 km, and 129 km. Spectral analysis based approaches namely Centroid method, Spectral peak method, and the Fractal based approach were used for computing depth and temperatures to heat sources. Airborne magnetic data sets with larger window sizes were preferred for depth computations, as they preserved spectral signatures of deeper sources and reduced the contribution of shallower sources. The size of the data windows did not have a marked effect of depth and temperature values. Shallower magnetic sources depths of approximately 2.0 km were delineated using the Euler deconvolution method. An anticlinal feature at depths of 2.0 to 4.5 km was 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper delineated in the central part of the basin. Spectral analysis results indicated that the depth to the top of magnetic sources was at 3.5 km to 6.2 km; the centroid of the basement at 7.92 km to 13.41 km, and the basal below 11.09 km and 14.08 km. The lower end depth spectrum was determined from application of the Centroid method with the deeper being results from the Fractal based approach. The Spectral peak method was useful for determining the depth to the top of magnetic sources. The temperature of the top of magnetic sources and basement centroid were computed to be in the range 234.00 °C to 281.34 °C. Magnetic source depths and basal temperatures that were in the Curie point range within which rocks lose magnetism due to heat were determined, using a computation approach that utilised fractal parameters, to be 21.39 km and 577.42 °C, respectively. Increasing the value of the fractal parameter β from 0 to 4, had an effect of retaining deeper depths and higher temperatures. The fractal parameter β range of 3 to 4 that gave the Curie point parameters indicated basal rock types with an igneous predisposition. The research highlighted evidence for the existence of the Soutpansberg Basin Geothermal Field (SBGF). The area around Siloam is a potential target for drilling exploration geothermal energy boreholes based on the occurrence of hot springs, shallow heat source depths, anticlinal structure, high formation temperatures, deep circulating water and the achieved Curie point temperature.
- Full Text:
- Date Issued: 2019
Wild vegetables of the Eastern Cape of South Africa: the nutritional value and domestication of solanum nigrum l
- Authors: Bvenura, Callistus
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Ethnobotany)
- Identifier: vital:11885 , http://hdl.handle.net/10353/d1015514
- Description: An ethnobotanical survey was conducted in Alice and Willowvale in the Nkonkobe and Mbashe municipalities of the Eastern Cape Province, South Africa to identify and document wild vegetables growing in the areas. The survey documented 22 vegetable species belonging to 12 different families. The Amaryllidaceae, Amaranthaceae, Apiaceae, Asteraceae, Caryophyllaceae, Chenopodiaceae, Convolvulaceae, Cruciferae, Cucurbitaceaea, Euphorbiaceae, Tiliaceae, Solanaceae, Polygonaceae and Urticaceae were the families that were recorded. The species were Tulbaghia violacea Harv., Amaranthus blitoides S., Amaranthus blitum L., Amaranthus hybridus L., Centella coriacea Nannfd., Bidens pilosa L, Cotula heterocarpa DC., Sonchus oleraceus L., Galinsoga parviflora Cav., Taraxacum officinale Weber, Hypochaeris radicata L., Stellaria media L., Chenopodium album L., Chenopodium murale L., Ipomoea batatas L., Sisymbrium thellungii O. Schulz, Cucurbita pepo L., Rumex crispus L., Acalypha virginica L., Nicandra physalodes L., Physalis peruviana L., Solanum nigrum L., Urtica urens L. and Corchorus olitorius L. About 27 % of the wild vegetables were native to South Africa and about 45 % were also used as medicinal plants in the areas. Sun drying was the most common method of preserving the wild vegetables for the off season months. This study also revealed that, men and the younger generation knew less about wild vegetables than the women. The study also revealed a loss of knowledge of wild vegetables and their use by the rural dwellers who are more in favour of the exotic types such as spinach and cabbage.
- Full Text:
- Date Issued: 2014
- Authors: Bvenura, Callistus
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Ethnobotany)
- Identifier: vital:11885 , http://hdl.handle.net/10353/d1015514
- Description: An ethnobotanical survey was conducted in Alice and Willowvale in the Nkonkobe and Mbashe municipalities of the Eastern Cape Province, South Africa to identify and document wild vegetables growing in the areas. The survey documented 22 vegetable species belonging to 12 different families. The Amaryllidaceae, Amaranthaceae, Apiaceae, Asteraceae, Caryophyllaceae, Chenopodiaceae, Convolvulaceae, Cruciferae, Cucurbitaceaea, Euphorbiaceae, Tiliaceae, Solanaceae, Polygonaceae and Urticaceae were the families that were recorded. The species were Tulbaghia violacea Harv., Amaranthus blitoides S., Amaranthus blitum L., Amaranthus hybridus L., Centella coriacea Nannfd., Bidens pilosa L, Cotula heterocarpa DC., Sonchus oleraceus L., Galinsoga parviflora Cav., Taraxacum officinale Weber, Hypochaeris radicata L., Stellaria media L., Chenopodium album L., Chenopodium murale L., Ipomoea batatas L., Sisymbrium thellungii O. Schulz, Cucurbita pepo L., Rumex crispus L., Acalypha virginica L., Nicandra physalodes L., Physalis peruviana L., Solanum nigrum L., Urtica urens L. and Corchorus olitorius L. About 27 % of the wild vegetables were native to South Africa and about 45 % were also used as medicinal plants in the areas. Sun drying was the most common method of preserving the wild vegetables for the off season months. This study also revealed that, men and the younger generation knew less about wild vegetables than the women. The study also revealed a loss of knowledge of wild vegetables and their use by the rural dwellers who are more in favour of the exotic types such as spinach and cabbage.
- Full Text:
- Date Issued: 2014
Chemical transformations and phytochemical studies of bioactive components from extracts of Rosmarinus officinalis L
- Authors: Okoh, Omobola Oluranti
- Date: 2010
- Subjects: Essences and essential oils , Rosmarinus , Lamiaceae , Solution (Chemistry) , Extractive distillation , Medicinal plants , Bioactive compounds
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11331 , http://hdl.handle.net/10353/354 , Essences and essential oils , Rosmarinus , Lamiaceae , Solution (Chemistry) , Extractive distillation , Medicinal plants , Bioactive compounds
- Description: Variations in the yield, chemical composition, antibacterial, and antioxidant properties of the essential oils of Rosmarinus officinalis L. cultivated in Alice, Eastern Cape of South Africa over a period of 12 months using the solvent-free microwave extraction and traditional hydrodistillation methods were evaluated. The GC-MS analyses of the essential oils revealed the presence of 33 compounds with 1,8-cineole, a-pinene, camphor, verbenone, bornyl acetate and camphene constituting about 80 percent of the oils throughout the period of investigation, with the solvent-free microwave extraction method generally yielding more of the major components than the hydrodistillation method. Each of the major components of the oils varied in quantity and quality of yield at different periods of the year. The method of extraction and time of harvest are of importance to the quantity and quality of essential oil of Rosmarinus officinalis. Higher amounts of oxygenated monoterpenes such as borneol, camphor, terpene- 4-ol, linalool, a-terpeneol were present in the oil of SFME in comparison with HD. However, HD oil contained more monoterpene hydrocarbons such as a-pinene, camphene, β-pinene, myrcene, a-phellanderene, 1,8-cineole, trans- β-ocimene, γ-teprinene, and cis-sabinene hydrate than SFME extracted oil. Accumulation of monoterpene alcohols and ketones was observed during maturation process of Rosmarinus leaves. Quantitative evaluation of antibacterial activity, minimum inhibitory concentration values were determined using a serial microplate dilution method. The essential oils obtained using both methods of extraction were active against all the bacteria tested at a concentration of 10 mg mL-1. The minimum inhibitory concentrations for the SFME extracted oils ranged between 0.23 and 1.88 mg mL-1, while those of the HD extracted oils varied between 0.94 and 7.5 mg mL-1, thus suggesting that the oil obtained by solvent free microwave extraction was more active against bacteria than the oil obtained through hydrodistillation. The antioxidant and free radical scavenging activity of the obtained oils were tested by means of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH+) assay and β- carotene bleaching test. In the DPPH+ assay, while the free radical scavenging activity of the oil obtained by SFME method showed percentage inhibitions of between 48.8 percent and 67 percent, the HD derived oil showed inhibitions of between 52.2 percent and 65.30 percent at concentrations of 0.33, 0.50 and 1.0 mg mL-1, respectively. In the β-carotene bleaching assay, the percentage inhibition increased with increasing concentration of both oils with a higher antioxidant activity of the oil obtained through the SFME than the HD method. Thin layer chromatography (TLC) was used to analyze the chemical composition of the extracts using three eluent solvent systems of varying polarities i. e. CEF, BEA and EMW and sprayed with vanillin-sulfuric acid. The chemical composition of the different extracts was similar with the exception of methanol and water extracts which had only one or two visible compounds after treating with vanillin-spray reagent. To evaluate the number of antibacterial compounds present in the fractions, bioautography was used against two most important nosocomial microorganisms. S. aureus (Gram positive) and E. coli (Gram negative). Nearly all the crude serial extraction fractions contained compounds that inhibited the growth of E. coli. The hexane extract had the most lines of inhibition followed by ethyl acetate. Bioassay-guided fractionation against E. coli was used to isolate antibacterial compounds. The largest number of antibacterial compounds occurred in the hexane fraction. Furthermore we tried to complete the characterization by extracting and studying other biologically important plant metabolites such as phenolic compounds to evaluate the antioxidant capacity of Rosmarinus extracts.
- Full Text:
- Date Issued: 2010
- Authors: Okoh, Omobola Oluranti
- Date: 2010
- Subjects: Essences and essential oils , Rosmarinus , Lamiaceae , Solution (Chemistry) , Extractive distillation , Medicinal plants , Bioactive compounds
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11331 , http://hdl.handle.net/10353/354 , Essences and essential oils , Rosmarinus , Lamiaceae , Solution (Chemistry) , Extractive distillation , Medicinal plants , Bioactive compounds
- Description: Variations in the yield, chemical composition, antibacterial, and antioxidant properties of the essential oils of Rosmarinus officinalis L. cultivated in Alice, Eastern Cape of South Africa over a period of 12 months using the solvent-free microwave extraction and traditional hydrodistillation methods were evaluated. The GC-MS analyses of the essential oils revealed the presence of 33 compounds with 1,8-cineole, a-pinene, camphor, verbenone, bornyl acetate and camphene constituting about 80 percent of the oils throughout the period of investigation, with the solvent-free microwave extraction method generally yielding more of the major components than the hydrodistillation method. Each of the major components of the oils varied in quantity and quality of yield at different periods of the year. The method of extraction and time of harvest are of importance to the quantity and quality of essential oil of Rosmarinus officinalis. Higher amounts of oxygenated monoterpenes such as borneol, camphor, terpene- 4-ol, linalool, a-terpeneol were present in the oil of SFME in comparison with HD. However, HD oil contained more monoterpene hydrocarbons such as a-pinene, camphene, β-pinene, myrcene, a-phellanderene, 1,8-cineole, trans- β-ocimene, γ-teprinene, and cis-sabinene hydrate than SFME extracted oil. Accumulation of monoterpene alcohols and ketones was observed during maturation process of Rosmarinus leaves. Quantitative evaluation of antibacterial activity, minimum inhibitory concentration values were determined using a serial microplate dilution method. The essential oils obtained using both methods of extraction were active against all the bacteria tested at a concentration of 10 mg mL-1. The minimum inhibitory concentrations for the SFME extracted oils ranged between 0.23 and 1.88 mg mL-1, while those of the HD extracted oils varied between 0.94 and 7.5 mg mL-1, thus suggesting that the oil obtained by solvent free microwave extraction was more active against bacteria than the oil obtained through hydrodistillation. The antioxidant and free radical scavenging activity of the obtained oils were tested by means of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH+) assay and β- carotene bleaching test. In the DPPH+ assay, while the free radical scavenging activity of the oil obtained by SFME method showed percentage inhibitions of between 48.8 percent and 67 percent, the HD derived oil showed inhibitions of between 52.2 percent and 65.30 percent at concentrations of 0.33, 0.50 and 1.0 mg mL-1, respectively. In the β-carotene bleaching assay, the percentage inhibition increased with increasing concentration of both oils with a higher antioxidant activity of the oil obtained through the SFME than the HD method. Thin layer chromatography (TLC) was used to analyze the chemical composition of the extracts using three eluent solvent systems of varying polarities i. e. CEF, BEA and EMW and sprayed with vanillin-sulfuric acid. The chemical composition of the different extracts was similar with the exception of methanol and water extracts which had only one or two visible compounds after treating with vanillin-spray reagent. To evaluate the number of antibacterial compounds present in the fractions, bioautography was used against two most important nosocomial microorganisms. S. aureus (Gram positive) and E. coli (Gram negative). Nearly all the crude serial extraction fractions contained compounds that inhibited the growth of E. coli. The hexane extract had the most lines of inhibition followed by ethyl acetate. Bioassay-guided fractionation against E. coli was used to isolate antibacterial compounds. The largest number of antibacterial compounds occurred in the hexane fraction. Furthermore we tried to complete the characterization by extracting and studying other biologically important plant metabolites such as phenolic compounds to evaluate the antioxidant capacity of Rosmarinus extracts.
- Full Text:
- Date Issued: 2010
Dynamic adaptive cost model for wireless Internet connectivity in African rural communities
- Authors: Sibanda, Khulumani
- Date: 2010
- Subjects: Internet , Community development -- South Africa -- Eastern Cape , Cost effectiveness , Wireless communication systems , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Computer Science)
- Identifier: vital:11389 , http://hdl.handle.net/10353/380 , Internet , Community development -- South Africa -- Eastern Cape , Cost effectiveness , Wireless communication systems , Rural development -- South Africa -- Eastern Cape
- Description: In today’s dynamic technological landscape, wireless communication networks have become an important part of economic development. The emergence of wireless technologies raises hopes to extend communication to remote areas that have not seen any tangible deployment to date. As developing nations pin their hopes to wireless technologies, cost models for wireless communication networks are becoming vital to support the emerging technologies. However, varying cost changes raise critical challenges to the estimation of both capital expenditure and operational expenditure. The network deployment process has numerous events that may cause adjustments to initially estimated project costs. These adjustments are necessary for a cost management plan and this plan includes monitoring cost performance and ensuring that only appropriate changes are made to the network project. The incidents that may cause cost changes can not be entirely predicted as their distribution tend to change dynamically from time to time. Estimating network deployment costs in such a dynamic environment necessitates cost models that can adapt to random occurrence of cost changes. Widely used cost models are usually performed by experienced personnel whose engineering experience is derived from deploying similar networks. In this approach experienced personnel add a certain percentage to the cost estimate to cater for contingency costs. Certainly such an approach depends on individual opinion, making it subjective and void of mathematical estimating relationships which are of paramount importance in ensuring that estimated deployment costs are sufficient to deal with cost uncertainties. We observe that existing approaches can only explore a limited solution space and hence can lead to cost overruns if implemented in dynamically cost changing environments. This thesis presents a wireless communication network deployment cost model that incorporates uncertainties into the final cost estimate. The model is adaptive to unpredictable cost changes since it allows adjustments of confidence levels when calculating contingency costs. This allows dynamically updating the cost changes without the cost model being reconstructed from scratch. We make use of the Poisson process in modeling the occurrence of incidents that are responsible for causing cost changes during network deployment. We also show that the occurrence of the incidents causing cost change are random and tend to follow the Poisson distribution. Using different levels of confidence we model various cost contingencies and make sensitivity analyses to identify the probability of cost overrun when given different contingencies. The dynamic adaptive cost model can be used either at the strategic level to understand the cost of a particular technique or at the operational level, as a way to show how Poisson process in network deployment can compare with engineering experience and other estimating techniques. We believe that the model is useful for remote areas where deployment costs are volatile and the distribution of incidents causing cost change to original cost estimates are diverse and dynamically changing. Further we expect that our research improves the knowledge base of information about the costs for rural communities to connect to the Internet, consequently providing useful input to future policy debates. This work is further poised to be a utility function to help those planning internet infrastructure deployments in least developed regions.
- Full Text:
- Date Issued: 2010
- Authors: Sibanda, Khulumani
- Date: 2010
- Subjects: Internet , Community development -- South Africa -- Eastern Cape , Cost effectiveness , Wireless communication systems , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Computer Science)
- Identifier: vital:11389 , http://hdl.handle.net/10353/380 , Internet , Community development -- South Africa -- Eastern Cape , Cost effectiveness , Wireless communication systems , Rural development -- South Africa -- Eastern Cape
- Description: In today’s dynamic technological landscape, wireless communication networks have become an important part of economic development. The emergence of wireless technologies raises hopes to extend communication to remote areas that have not seen any tangible deployment to date. As developing nations pin their hopes to wireless technologies, cost models for wireless communication networks are becoming vital to support the emerging technologies. However, varying cost changes raise critical challenges to the estimation of both capital expenditure and operational expenditure. The network deployment process has numerous events that may cause adjustments to initially estimated project costs. These adjustments are necessary for a cost management plan and this plan includes monitoring cost performance and ensuring that only appropriate changes are made to the network project. The incidents that may cause cost changes can not be entirely predicted as their distribution tend to change dynamically from time to time. Estimating network deployment costs in such a dynamic environment necessitates cost models that can adapt to random occurrence of cost changes. Widely used cost models are usually performed by experienced personnel whose engineering experience is derived from deploying similar networks. In this approach experienced personnel add a certain percentage to the cost estimate to cater for contingency costs. Certainly such an approach depends on individual opinion, making it subjective and void of mathematical estimating relationships which are of paramount importance in ensuring that estimated deployment costs are sufficient to deal with cost uncertainties. We observe that existing approaches can only explore a limited solution space and hence can lead to cost overruns if implemented in dynamically cost changing environments. This thesis presents a wireless communication network deployment cost model that incorporates uncertainties into the final cost estimate. The model is adaptive to unpredictable cost changes since it allows adjustments of confidence levels when calculating contingency costs. This allows dynamically updating the cost changes without the cost model being reconstructed from scratch. We make use of the Poisson process in modeling the occurrence of incidents that are responsible for causing cost changes during network deployment. We also show that the occurrence of the incidents causing cost change are random and tend to follow the Poisson distribution. Using different levels of confidence we model various cost contingencies and make sensitivity analyses to identify the probability of cost overrun when given different contingencies. The dynamic adaptive cost model can be used either at the strategic level to understand the cost of a particular technique or at the operational level, as a way to show how Poisson process in network deployment can compare with engineering experience and other estimating techniques. We believe that the model is useful for remote areas where deployment costs are volatile and the distribution of incidents causing cost change to original cost estimates are diverse and dynamically changing. Further we expect that our research improves the knowledge base of information about the costs for rural communities to connect to the Internet, consequently providing useful input to future policy debates. This work is further poised to be a utility function to help those planning internet infrastructure deployments in least developed regions.
- Full Text:
- Date Issued: 2010
A longitudinal investigation into employability : student transition and experiences from tertiary education into the labour market
- Authors: Harry, Tinashe Timothy
- Date: 2018
- Subjects: Employability Graduate students Labor market
- Language: English
- Type: Thesis , Doctoral , DCom
- Identifier: http://hdl.handle.net/10353/11053 , vital:37015
- Description: Orientation: Several policies have been formulated by the government to redress the inequalities of apartheid. However, the policies have not yielded any positive results as many graduates from Historically Disadvantaged Institutes (HDIs) continue to struggle in the open labour market as compared to graduates from Historically Advantaged Institutes (HAIs). This has been mainly attributed to the legacy of apartheid in several previous studies. As a result, most of these previously disadvantaged individuals (mostly Black Africans) struggle to make the transition from higher education into the world of work. Research Purpose: This study thus explores the journeys of these Black African students from HDIs to understand the transition and experiences from tertiary education into the labour market. Further, the research sought to understand how these transitions and experiences manifest in a context of high unemployment. Finally, the resolution tactics used by students in such a context are given attention. Research approach, design and method: A longitudinal qualitative approach was deemed appropriate for the study as the aim was to understand the changes that occurred over time. The data was collected over a two-year period. A narrative inquiry was utilized as it allowed the participants to share their perceptions without limitations. A total of 30 participants partook in the study. The participants were selected using a purposive sampling to ensure the right participants were involved in the study. The main criteria for selection to participate was that the participants had to be enrolled with a HDI. Main findings: The narratives of the participants led to the formulation of six main themes that were regarded as affecting the transitions and experiences of the Black graduates from HDIs; namely, (1) socio-economic background, (2) education system, (3) labour market experiences, (4) geographical location, (5) social capital and (6) student resolutions to the challenges of employability. A previously disadvantaged background resulted in the participants being recipients of poor education quality, no social networks or information to navigate the labour market and limited access to the labour market due to secluded residential areas. Subsequently, most participants were unable to take responsibility of enhancing their own employability. Contribution: It is not the sole responsibility of the higher education institutes to produce employable graduates, but it's a process that should also involve government, students and employers. As long as the social inequality remains an issue in the country all the efforts to improve employability and transition into the open labour market will be in vain. Furthermore, employers must work together with higher education institutes by offering programs such as internships and career expos to enhance the employability of the graduates. A Graduate Transition Model (GTM) is suggested based on the findings of this research.
- Full Text:
- Date Issued: 2018
- Authors: Harry, Tinashe Timothy
- Date: 2018
- Subjects: Employability Graduate students Labor market
- Language: English
- Type: Thesis , Doctoral , DCom
- Identifier: http://hdl.handle.net/10353/11053 , vital:37015
- Description: Orientation: Several policies have been formulated by the government to redress the inequalities of apartheid. However, the policies have not yielded any positive results as many graduates from Historically Disadvantaged Institutes (HDIs) continue to struggle in the open labour market as compared to graduates from Historically Advantaged Institutes (HAIs). This has been mainly attributed to the legacy of apartheid in several previous studies. As a result, most of these previously disadvantaged individuals (mostly Black Africans) struggle to make the transition from higher education into the world of work. Research Purpose: This study thus explores the journeys of these Black African students from HDIs to understand the transition and experiences from tertiary education into the labour market. Further, the research sought to understand how these transitions and experiences manifest in a context of high unemployment. Finally, the resolution tactics used by students in such a context are given attention. Research approach, design and method: A longitudinal qualitative approach was deemed appropriate for the study as the aim was to understand the changes that occurred over time. The data was collected over a two-year period. A narrative inquiry was utilized as it allowed the participants to share their perceptions without limitations. A total of 30 participants partook in the study. The participants were selected using a purposive sampling to ensure the right participants were involved in the study. The main criteria for selection to participate was that the participants had to be enrolled with a HDI. Main findings: The narratives of the participants led to the formulation of six main themes that were regarded as affecting the transitions and experiences of the Black graduates from HDIs; namely, (1) socio-economic background, (2) education system, (3) labour market experiences, (4) geographical location, (5) social capital and (6) student resolutions to the challenges of employability. A previously disadvantaged background resulted in the participants being recipients of poor education quality, no social networks or information to navigate the labour market and limited access to the labour market due to secluded residential areas. Subsequently, most participants were unable to take responsibility of enhancing their own employability. Contribution: It is not the sole responsibility of the higher education institutes to produce employable graduates, but it's a process that should also involve government, students and employers. As long as the social inequality remains an issue in the country all the efforts to improve employability and transition into the open labour market will be in vain. Furthermore, employers must work together with higher education institutes by offering programs such as internships and career expos to enhance the employability of the graduates. A Graduate Transition Model (GTM) is suggested based on the findings of this research.
- Full Text:
- Date Issued: 2018
Enhancing parental involvement in children’s academic work: Implications for teaching and learning
- Authors: Fihla, Gcobisa Victoria
- Date: 2018
- Subjects: Education -- Parent participation Parent-teacher relationships Academic achievement
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: http://hdl.handle.net/10353/8042 , vital:31485
- Description: Partnership between schools and parents seems to substandard, leading to both parties questioning each other on why children underperform. Most parents view the school as an instrument for the achievement of children and parents with limited or no education may have little or no interest in supporting children’s academic work. The aim of this study was to investigate how parental involvement in children’s academic work can be enhanced. It focused on three rural secondary schools in the Amathole West Education District in the Eastern Cape Province of South Africa. The study particularly investigated how school schools involved parents in children’s academic work and how they, together with principals, teachers and learners view their involvement in children’s academic work. Guided by Epstein’s theory of parental involvement, this qualitative study was premised on the interpretative paradigm. Face to face interviews and focus group discussions were used to collect data from three high schools in the Amathole West Education District. Purposive sampling was used to select participants who comprised a target population of 24 participants. It emerged from the data that although schools were trying to involve parents in children’s academic work, their activities were uncoordinated, occurred at school level rather than classroom level and focused less on learners’ academic work. Parent’ involvement in their children’s academic work was not touching the real curriculum issues; rather it touched on the outside. The data also showed that parents’ academic statuses influenced their participation as those who had little education seemed to be reluctant to participate on academic issues. The study concludes that there was lack of coordinated strategies by schools to involve parents in children’s academic work. The study, therefore, recommends that Coordinated Grade-based Parent-Teacher Forums be established. This will assist in opening a planform for teachers and parents to engage on teaching and learning discussions and curriculum debates.
- Full Text:
- Date Issued: 2018
- Authors: Fihla, Gcobisa Victoria
- Date: 2018
- Subjects: Education -- Parent participation Parent-teacher relationships Academic achievement
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: http://hdl.handle.net/10353/8042 , vital:31485
- Description: Partnership between schools and parents seems to substandard, leading to both parties questioning each other on why children underperform. Most parents view the school as an instrument for the achievement of children and parents with limited or no education may have little or no interest in supporting children’s academic work. The aim of this study was to investigate how parental involvement in children’s academic work can be enhanced. It focused on three rural secondary schools in the Amathole West Education District in the Eastern Cape Province of South Africa. The study particularly investigated how school schools involved parents in children’s academic work and how they, together with principals, teachers and learners view their involvement in children’s academic work. Guided by Epstein’s theory of parental involvement, this qualitative study was premised on the interpretative paradigm. Face to face interviews and focus group discussions were used to collect data from three high schools in the Amathole West Education District. Purposive sampling was used to select participants who comprised a target population of 24 participants. It emerged from the data that although schools were trying to involve parents in children’s academic work, their activities were uncoordinated, occurred at school level rather than classroom level and focused less on learners’ academic work. Parent’ involvement in their children’s academic work was not touching the real curriculum issues; rather it touched on the outside. The data also showed that parents’ academic statuses influenced their participation as those who had little education seemed to be reluctant to participate on academic issues. The study concludes that there was lack of coordinated strategies by schools to involve parents in children’s academic work. The study, therefore, recommends that Coordinated Grade-based Parent-Teacher Forums be established. This will assist in opening a planform for teachers and parents to engage on teaching and learning discussions and curriculum debates.
- Full Text:
- Date Issued: 2018
The role of African theology and spirituality in bereavement among Xhosa children
- Authors: Diniso Patrick Mncedisi
- Date: 2017
- Subjects: Bereavement in children -- Religious aspects Black theology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17839 , vital:41374
- Description: The background to this study highlights the fact that Xhosa children are not being taken care of during bereavement. There is no theological guidance applied to them, to say the least. There are devotions that are usually conducted by lay preachers (Preachers that are not trained as Pastors/Therapists) who do their utmost best to support bereaved families, and this is done out of love. The challenge, however, is that the language mostly used by these preachers does not seem to accommodate children, as there are expressions that do not make any sense to children such as: tutwini, imela igobele esandleni. These are good and relevant concepts as they underpin the reality of death and the need for comfort during bereavement. However, these need to be communicated in a language that can be understood by children. Due to this identified problem, the researcher deemed it necessary to undertake this study. This study comprises five (5) chapters. In chapter one (1), the researcher focused on the research background and introduction. Chapter two (2) dealt with the literature review of this study. The chapter comprises three sections: generic literature review section, theory base section and primary literature review section. In chapter three (3), the focus is on research methodology and its components. Concepts such as sampling procedures, research instrument and research design are dealt with. In chapter four (4), the researcher dealt with concepts such as data analysis, interpretation and presentation of findings. Chapter five dealt with the research recommendations as per the role of the church (Free Church in Southern Africa [FSA]). The researcher is convinced that this work has done justice in addressing the identified gap in care giving for bereaved Xhosa children. The need for theological guidance for bereaved Xhosa children has been highlighted; findings and practical recommendations have also been presented to meet such a need. These confirmed the need for theological guidance for bereaved Xhosa children. The next section contains the appendix list, namely: appendix one (1), two (2) and three (3).
- Full Text:
- Date Issued: 2017
- Authors: Diniso Patrick Mncedisi
- Date: 2017
- Subjects: Bereavement in children -- Religious aspects Black theology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17839 , vital:41374
- Description: The background to this study highlights the fact that Xhosa children are not being taken care of during bereavement. There is no theological guidance applied to them, to say the least. There are devotions that are usually conducted by lay preachers (Preachers that are not trained as Pastors/Therapists) who do their utmost best to support bereaved families, and this is done out of love. The challenge, however, is that the language mostly used by these preachers does not seem to accommodate children, as there are expressions that do not make any sense to children such as: tutwini, imela igobele esandleni. These are good and relevant concepts as they underpin the reality of death and the need for comfort during bereavement. However, these need to be communicated in a language that can be understood by children. Due to this identified problem, the researcher deemed it necessary to undertake this study. This study comprises five (5) chapters. In chapter one (1), the researcher focused on the research background and introduction. Chapter two (2) dealt with the literature review of this study. The chapter comprises three sections: generic literature review section, theory base section and primary literature review section. In chapter three (3), the focus is on research methodology and its components. Concepts such as sampling procedures, research instrument and research design are dealt with. In chapter four (4), the researcher dealt with concepts such as data analysis, interpretation and presentation of findings. Chapter five dealt with the research recommendations as per the role of the church (Free Church in Southern Africa [FSA]). The researcher is convinced that this work has done justice in addressing the identified gap in care giving for bereaved Xhosa children. The need for theological guidance for bereaved Xhosa children has been highlighted; findings and practical recommendations have also been presented to meet such a need. These confirmed the need for theological guidance for bereaved Xhosa children. The next section contains the appendix list, namely: appendix one (1), two (2) and three (3).
- Full Text:
- Date Issued: 2017
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
An investigation of persistence of rural poverty in South Africa: the case of O.R. Tambo district municipality
- Authors: Kongwa, Kekelwa Samuele
- Date: 2012
- Language: English
- Type: Thesis , Doctoral , PhD (Social Science Dev)
- Identifier: vital:11443 , http://hdl.handle.net/10353/d1007577
- Description: The purpose of this study was an investigation of the reasons for persistent poverty and low level of economic growth and development in the OR Tambo district municipality of the Eastern Cape Province since the advent of democracy in South Africa. To accomplish this objective, a case study of the OR Tambo district municipality was undertaken within the concept of development, seeking to answer three research questions: What are the factors that explain the persistence of poverty in the OR Tambo district municipality? Why is the OR Tambo district municipality the most exposed to poverty in relative and absolute terms? What have state poverty intervention strategies done to alleviate poverty in the OR Tambo district since the advent of democracy in South Africa? Mainly qualitative data collection methods, involving in-depth semi-structured interviews, textual and document analyses, focus group discussions and observations were employed to answer the research questions. A purposive sampling of nineteen participants, supplemented by three focus groups, was selected. The macro-level case study design was supplemented by micro-level documentary evidence on poverty and development. From the synthesised findings of the investigation, twelve causal factors were identified as responsible for persistent poverty and low level of economic growth and development in the OR Tambo district. These included political neglect, agricultural neglect, poor infrastructure, corruption, poor service delivery, poor quality of natural resources, brain drain, migrant labour system, culture of tolerance and conservatism, culture of dependence, no long-term development strategy and globalisation.
- Full Text:
- Date Issued: 2012
- Authors: Kongwa, Kekelwa Samuele
- Date: 2012
- Language: English
- Type: Thesis , Doctoral , PhD (Social Science Dev)
- Identifier: vital:11443 , http://hdl.handle.net/10353/d1007577
- Description: The purpose of this study was an investigation of the reasons for persistent poverty and low level of economic growth and development in the OR Tambo district municipality of the Eastern Cape Province since the advent of democracy in South Africa. To accomplish this objective, a case study of the OR Tambo district municipality was undertaken within the concept of development, seeking to answer three research questions: What are the factors that explain the persistence of poverty in the OR Tambo district municipality? Why is the OR Tambo district municipality the most exposed to poverty in relative and absolute terms? What have state poverty intervention strategies done to alleviate poverty in the OR Tambo district since the advent of democracy in South Africa? Mainly qualitative data collection methods, involving in-depth semi-structured interviews, textual and document analyses, focus group discussions and observations were employed to answer the research questions. A purposive sampling of nineteen participants, supplemented by three focus groups, was selected. The macro-level case study design was supplemented by micro-level documentary evidence on poverty and development. From the synthesised findings of the investigation, twelve causal factors were identified as responsible for persistent poverty and low level of economic growth and development in the OR Tambo district. These included political neglect, agricultural neglect, poor infrastructure, corruption, poor service delivery, poor quality of natural resources, brain drain, migrant labour system, culture of tolerance and conservatism, culture of dependence, no long-term development strategy and globalisation.
- Full Text:
- Date Issued: 2012
Constitutionalism and separation of powers in South Africa after the promulgation of the 1996 constitution : a comparative perspective
- Authors: Ramatsekisa, Tsietsi Given
- Date: 2016
- Subjects: Separation of powers -- South Africa Constitutional law -- South Africa Democracy -- South Africa
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: http://hdl.handle.net/10353/12642 , vital:39295
- Description: Constitutionalism and separation of powers is the most dynamic topic worldwide. Montesquieu, the French philosopher is credited with the doctrine of separation of powers. Various countries adopted the doctrine and modified it, in order to fit their systems of governments. The reason behind is that there is no universally recognized model of separation of powers or one size fit all. Countries apply this doctrine differently in a fashion that fits their domestic laws and constitutional requirements. Montesquieu gave a classic exposition and the rationale for separation of powers in one of his well-celebrated work “The Spirit of Laws”. The concept of separation of powers emerged premised on the theory that the arms of state namely, the judiciary, the legislature and the executive, should operate within their providence without one interfering with the other. From the South African perspective, the Constitution of South Africa of 1996 requires separation of powers even though it is not explicitly so stated in the text. This research examines the unique South African model of separation of powers and how the courts have navigated through it from the time the Constitution was promulgated. It seeks to establish whether or not a South African model of separation of powers has come to the fore. The research further examines the problem of interference amongst the arms of state and mechanism of checks and balances which can be applied to prevent or minimise such interference. In doing so, the study pursued a desktop survey of primary and secondary materials, including scientific literature, legislation, courts’ jurisprudence, and official documents. A comparative perspective was also made in order to learn from the experiences of other jurisdictions where the doctrine is applied. The findings reveal that South Africa has a unique model of separation of powers. The model was learned and enriched from various foreign jurisdictions. The courts have contributed enormously to this model, which contrive to be fluid and living.
- Full Text:
- Date Issued: 2016
- Authors: Ramatsekisa, Tsietsi Given
- Date: 2016
- Subjects: Separation of powers -- South Africa Constitutional law -- South Africa Democracy -- South Africa
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: http://hdl.handle.net/10353/12642 , vital:39295
- Description: Constitutionalism and separation of powers is the most dynamic topic worldwide. Montesquieu, the French philosopher is credited with the doctrine of separation of powers. Various countries adopted the doctrine and modified it, in order to fit their systems of governments. The reason behind is that there is no universally recognized model of separation of powers or one size fit all. Countries apply this doctrine differently in a fashion that fits their domestic laws and constitutional requirements. Montesquieu gave a classic exposition and the rationale for separation of powers in one of his well-celebrated work “The Spirit of Laws”. The concept of separation of powers emerged premised on the theory that the arms of state namely, the judiciary, the legislature and the executive, should operate within their providence without one interfering with the other. From the South African perspective, the Constitution of South Africa of 1996 requires separation of powers even though it is not explicitly so stated in the text. This research examines the unique South African model of separation of powers and how the courts have navigated through it from the time the Constitution was promulgated. It seeks to establish whether or not a South African model of separation of powers has come to the fore. The research further examines the problem of interference amongst the arms of state and mechanism of checks and balances which can be applied to prevent or minimise such interference. In doing so, the study pursued a desktop survey of primary and secondary materials, including scientific literature, legislation, courts’ jurisprudence, and official documents. A comparative perspective was also made in order to learn from the experiences of other jurisdictions where the doctrine is applied. The findings reveal that South Africa has a unique model of separation of powers. The model was learned and enriched from various foreign jurisdictions. The courts have contributed enormously to this model, which contrive to be fluid and living.
- Full Text:
- Date Issued: 2016
Community development education: the integration of individual and collective consciousness for community well-being within a social development paradigm in South Africa
- Authors: Maistry, Savathrie
- Date: 2008
- Subjects: Community development -- South Africa , Social planning -- South Africa , Public welfare -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Development Studies)
- Identifier: vital:11754 , http://hdl.handle.net/10353/182 , Community development -- South Africa , Social planning -- South Africa , Public welfare -- South Africa
- Description: This study focused on community development education and practice for the democratic and transformative South context. Social and community development are relatively new approaches to social welfare and community development is emerging as a discipline and profession to contribute to the goal of developmental social welfare. Community work, albeit to a minimal extent and not community development was viewed as a method of social work during apartheid. With community development being prioritized as an intervention strategy for poverty reduction by the national government, the gap in community development education needs to be addressed. The goal of the study was to develop an undergraduate curriculum framework for community development education that would produce a new generation of ethical community development professionals to contribute to the goal of developmental social welfare. The study focused on the integrated approach to community development education and practice; with education of the student as a whole human being as critical for community development in a transformative South Africa. To achieve its goal, the study identified three themes that were critical to the research: a conceptual framework, clarifying key terms; a curriculum framework for community development education; and qualities and ethics for a new generation of development practitioners. The qualitative study was based in the Eastern Cape Province, South Africa and because of the lack of a referential framework for community development education, the researcher looked towards learning from India which has over fifty years of experience in social and community development education and practice. The state of Kerala established a social development approach in 1957 and was chosen as a learning experience. The state’s Kudumbashree Mission which aims at poverty alleviation through the empowerment of women was chosen as a case study. The integral and values based education system of Sri Sathya Sai University in the state of Andhra Pradesh and the community development education and practice of Loyola College in the state of Kerala were examined. The research design was exploratory, conceptual, descriptive and developmental in nature. The qualitative methodology best suited the nature of this study and a combination of methods to obtain data from a variety of sources across national boundaries was employed. The participants interviewed in both countries were purposively selected for their involvement in social and community development directly as target groups, practitioners, managers and policy makers. The research produced a philosophical and theoretical framework that is unitary and integral and aligned with the current social development policy to guide community development education and practice. The unitary and integral framework encompasses the individual within the family and community context and locates the various dimensions of development such as the social, physical, cultural, psychological, spiritual, political and economical dimensions within a unitary platform. The framework is dominated by the holistic and humanistic philosophies without negating the rational and pragmatic perspectives. In conclusion, the study conceptualizes community development as a natural process; the integration of individual and collective consciousness and an intervention. The outcome of the study is a recommended curriculum framework for community development education that would be of relevance to the Eastern Cape Province in particular and for the South African context generally.
- Full Text:
- Date Issued: 2008
- Authors: Maistry, Savathrie
- Date: 2008
- Subjects: Community development -- South Africa , Social planning -- South Africa , Public welfare -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Development Studies)
- Identifier: vital:11754 , http://hdl.handle.net/10353/182 , Community development -- South Africa , Social planning -- South Africa , Public welfare -- South Africa
- Description: This study focused on community development education and practice for the democratic and transformative South context. Social and community development are relatively new approaches to social welfare and community development is emerging as a discipline and profession to contribute to the goal of developmental social welfare. Community work, albeit to a minimal extent and not community development was viewed as a method of social work during apartheid. With community development being prioritized as an intervention strategy for poverty reduction by the national government, the gap in community development education needs to be addressed. The goal of the study was to develop an undergraduate curriculum framework for community development education that would produce a new generation of ethical community development professionals to contribute to the goal of developmental social welfare. The study focused on the integrated approach to community development education and practice; with education of the student as a whole human being as critical for community development in a transformative South Africa. To achieve its goal, the study identified three themes that were critical to the research: a conceptual framework, clarifying key terms; a curriculum framework for community development education; and qualities and ethics for a new generation of development practitioners. The qualitative study was based in the Eastern Cape Province, South Africa and because of the lack of a referential framework for community development education, the researcher looked towards learning from India which has over fifty years of experience in social and community development education and practice. The state of Kerala established a social development approach in 1957 and was chosen as a learning experience. The state’s Kudumbashree Mission which aims at poverty alleviation through the empowerment of women was chosen as a case study. The integral and values based education system of Sri Sathya Sai University in the state of Andhra Pradesh and the community development education and practice of Loyola College in the state of Kerala were examined. The research design was exploratory, conceptual, descriptive and developmental in nature. The qualitative methodology best suited the nature of this study and a combination of methods to obtain data from a variety of sources across national boundaries was employed. The participants interviewed in both countries were purposively selected for their involvement in social and community development directly as target groups, practitioners, managers and policy makers. The research produced a philosophical and theoretical framework that is unitary and integral and aligned with the current social development policy to guide community development education and practice. The unitary and integral framework encompasses the individual within the family and community context and locates the various dimensions of development such as the social, physical, cultural, psychological, spiritual, political and economical dimensions within a unitary platform. The framework is dominated by the holistic and humanistic philosophies without negating the rational and pragmatic perspectives. In conclusion, the study conceptualizes community development as a natural process; the integration of individual and collective consciousness and an intervention. The outcome of the study is a recommended curriculum framework for community development education that would be of relevance to the Eastern Cape Province in particular and for the South African context generally.
- Full Text:
- Date Issued: 2008
Evaluation and identification of microbial contaminants in polyherbal medicines used for the treatment of tuberculosis in Amathole District Municipality, Eastern Cape Province, South Africa
- Authors: Famewo, Elizabeth Bosede
- Date: 2018
- Subjects: Tuberculosis -- Treatment -- South Africa Mycobacterial diseases -- South Africa -- Eastern Cape Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9680 , vital:34818
- Description: Tuberculosis is caused by Mycobacterium tuberculosis. The emergence of drug-resistant strains of this organism has become a global public health problem. In the continuing search for effective treatment, polyherbal medicines offer a great hope in the development of alternative drugs for the treatment of tuberculosis. The use of herbal formulations for therapeutic purposes has significantly increased in the developed and developing countries because of their curative property, less toxicity and minimal side effects. However, there is little information on their safety and effectiveness in the literature. To address this, polyherbal medicines used for the treatment of tuberculosis in the Eastern Cape Province of South Africa were evaluated. Ethno-medicinal survey was conducted through semi-structured questionnaires coupled with informal conversations with the herbal sellers in five communities in the study area. Bacterial and fungal DNA was extracted from the polyherbal medicines purchased. A fragment of the bacterial 16S rRNA gene and internal transcribed spacer region of the fungal rRNA operon were amplified with universal primers 27F and 518R, and ITS1 and ITS4 respectively. Following standard procedures, the amplicons were finally run on Illumina’s MiSeq platform. Furthermore, the remedies were screened against Mycobacterium tuberculosis H37Rv using Middlebrook 7H9 media and MGIT BACTEC 960 system. Agar dilution method was used to determine the minimum inhibitory concentration (MIC) of the remedies against eight bacteria and three fungi isolates. The herbal preparations were assayed for their toxicity using hatchability success and larval mortality of Artemia salina Leach. Finally, their nutritive properties were analysed using an inductively coupled plasma optical emission spectrometer for mineral analysis while the vitamins were determined using standardized methods A total of nine polyherbal preparations were collected. The herbs used for the preparation of these remedies belong to 20 families. Apiaceae [5(25 percent)] was the most prominent plant family used, followed by Liliaceae [4(20 percent)], Strychnaceae [4(20 percent)], Rutaceae [4(20 percent)] and Hypoxidaceae [3(15 percent)]. The two most frequently used plants were Allium sativum L. (Liliaceae) and Strychnos decussata (Pappe) Gilg. (Strychnaceae). Rhizomes was the most common parts used, followed by the roots and barks. The herbal medicines were prepared mainly by infusion and decoction. The presences of pathogenic and non-pathogenic bacteria were identified in the polyherbal medicines. Generally, the most common bacteria identified from the samples were Bacillus sp., Enterobacter sp., Klebsiella sp., Rahnella sp., Paenibacillus sp., Clostridium sp. and Pantoea sp. The predominant mycoflora obtained belongs to different genera or species of fungi; these include Alternaria, Candida, Ramularia, Cladosporium, Penicillium, Aspergillus and Malassezia. The susceptibility testing revealed that all the remedies contain anti-tubercular activity against M. tuberculosis H37Rv at concentrations below 50 ug/ml. Seven of the polyherbal preparations showed activity at concentrations below 25 ug/ml. The MIC values exhibited inhibitory activity at 1.562 μg/ml. However, isoniazid showed more inhibitory activity against M. tuberculosis at 0.05 μg/ml when compared to the polyherbal remedies. The inhibitory activity of the polyherbal medicines based on the overall MIC revealed that Hogsback first site (HBfs) and Fort Beaufort (FB) remedies were the most active remedies against the bacterial isolates at the concentration of 2.5 mg/mL. Among the nine herbal formulations, only King Williams Town site A (KWTa) remedy showed activity against Aspergillus niger and Aspergillus fumigatus with the MIC valve of 2.5 mg/mL. While King Williams Town site C (KWTc) and Hogsback third site (HBts) had the highest activity at 1.25 mg/mL against Candida albicans, the remaining remedies were active at 2.5 mg/mL. The percentage hatchability of 44.42 percent, 42.96 percent and 39.70 percent were observed in A. salina cysts incubated with herbal preparations from KWTa, HBfs and HBts respectively. The hatching success of the cysts in these remedies was significantly higher than the positive control (nystatin) and the negative control (sea water) at p < 0.05. The mortality of A. salina nauplii incubated in Alice (AL), King Williams Town site B (KWTb) and KWTc remedies were significantly higher than when larvae were incubated in both controls. Based on Meyer’s index, the LD50 of each polyherbal medicine was between 2.9 and 4.0 mg/ml, the LD50 values greater than 1 mg/ml, an indication that they are not toxic. The polyherbal preparations were found to be rich in vitamins and mineral nutrients. Calcium was the highest macronutrient detected while the lowest nutrient was phosphorus. Iron was the highest micronutrient in the majority of the polyherbal preparations while the lowest value was recorded for copper. Vitamin C was absent in the herbal preparations while vitamin A and E were detected. This study provides significant ethno-medicinal information on polyherbal medicines used for the treatment of TB in the study area. The presence of the identified bacteria and fungi in the herbal formulations is a cause for concern. However, the ability of the remedies to possess activity against Mycobacterium tuberculosis and other pathogenic microorganisms associated with tuberculosis infection makes them potential sources of new antimycobacterial agents. Also, they are rich sources of mineral nutrients, and are as well non-toxic, thus, they are safe for consumption. In view of their anti-tubercular properties, this study has provided a better understanding of the reasons why TB-patients make use of these polyherbal formulations. Also, the study supports the folkloric use of polyherbal medicines in the treatment of tuberculosis in the Eastern Cape Province, South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Famewo, Elizabeth Bosede
- Date: 2018
- Subjects: Tuberculosis -- Treatment -- South Africa Mycobacterial diseases -- South Africa -- Eastern Cape Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9680 , vital:34818
- Description: Tuberculosis is caused by Mycobacterium tuberculosis. The emergence of drug-resistant strains of this organism has become a global public health problem. In the continuing search for effective treatment, polyherbal medicines offer a great hope in the development of alternative drugs for the treatment of tuberculosis. The use of herbal formulations for therapeutic purposes has significantly increased in the developed and developing countries because of their curative property, less toxicity and minimal side effects. However, there is little information on their safety and effectiveness in the literature. To address this, polyherbal medicines used for the treatment of tuberculosis in the Eastern Cape Province of South Africa were evaluated. Ethno-medicinal survey was conducted through semi-structured questionnaires coupled with informal conversations with the herbal sellers in five communities in the study area. Bacterial and fungal DNA was extracted from the polyherbal medicines purchased. A fragment of the bacterial 16S rRNA gene and internal transcribed spacer region of the fungal rRNA operon were amplified with universal primers 27F and 518R, and ITS1 and ITS4 respectively. Following standard procedures, the amplicons were finally run on Illumina’s MiSeq platform. Furthermore, the remedies were screened against Mycobacterium tuberculosis H37Rv using Middlebrook 7H9 media and MGIT BACTEC 960 system. Agar dilution method was used to determine the minimum inhibitory concentration (MIC) of the remedies against eight bacteria and three fungi isolates. The herbal preparations were assayed for their toxicity using hatchability success and larval mortality of Artemia salina Leach. Finally, their nutritive properties were analysed using an inductively coupled plasma optical emission spectrometer for mineral analysis while the vitamins were determined using standardized methods A total of nine polyherbal preparations were collected. The herbs used for the preparation of these remedies belong to 20 families. Apiaceae [5(25 percent)] was the most prominent plant family used, followed by Liliaceae [4(20 percent)], Strychnaceae [4(20 percent)], Rutaceae [4(20 percent)] and Hypoxidaceae [3(15 percent)]. The two most frequently used plants were Allium sativum L. (Liliaceae) and Strychnos decussata (Pappe) Gilg. (Strychnaceae). Rhizomes was the most common parts used, followed by the roots and barks. The herbal medicines were prepared mainly by infusion and decoction. The presences of pathogenic and non-pathogenic bacteria were identified in the polyherbal medicines. Generally, the most common bacteria identified from the samples were Bacillus sp., Enterobacter sp., Klebsiella sp., Rahnella sp., Paenibacillus sp., Clostridium sp. and Pantoea sp. The predominant mycoflora obtained belongs to different genera or species of fungi; these include Alternaria, Candida, Ramularia, Cladosporium, Penicillium, Aspergillus and Malassezia. The susceptibility testing revealed that all the remedies contain anti-tubercular activity against M. tuberculosis H37Rv at concentrations below 50 ug/ml. Seven of the polyherbal preparations showed activity at concentrations below 25 ug/ml. The MIC values exhibited inhibitory activity at 1.562 μg/ml. However, isoniazid showed more inhibitory activity against M. tuberculosis at 0.05 μg/ml when compared to the polyherbal remedies. The inhibitory activity of the polyherbal medicines based on the overall MIC revealed that Hogsback first site (HBfs) and Fort Beaufort (FB) remedies were the most active remedies against the bacterial isolates at the concentration of 2.5 mg/mL. Among the nine herbal formulations, only King Williams Town site A (KWTa) remedy showed activity against Aspergillus niger and Aspergillus fumigatus with the MIC valve of 2.5 mg/mL. While King Williams Town site C (KWTc) and Hogsback third site (HBts) had the highest activity at 1.25 mg/mL against Candida albicans, the remaining remedies were active at 2.5 mg/mL. The percentage hatchability of 44.42 percent, 42.96 percent and 39.70 percent were observed in A. salina cysts incubated with herbal preparations from KWTa, HBfs and HBts respectively. The hatching success of the cysts in these remedies was significantly higher than the positive control (nystatin) and the negative control (sea water) at p < 0.05. The mortality of A. salina nauplii incubated in Alice (AL), King Williams Town site B (KWTb) and KWTc remedies were significantly higher than when larvae were incubated in both controls. Based on Meyer’s index, the LD50 of each polyherbal medicine was between 2.9 and 4.0 mg/ml, the LD50 values greater than 1 mg/ml, an indication that they are not toxic. The polyherbal preparations were found to be rich in vitamins and mineral nutrients. Calcium was the highest macronutrient detected while the lowest nutrient was phosphorus. Iron was the highest micronutrient in the majority of the polyherbal preparations while the lowest value was recorded for copper. Vitamin C was absent in the herbal preparations while vitamin A and E were detected. This study provides significant ethno-medicinal information on polyherbal medicines used for the treatment of TB in the study area. The presence of the identified bacteria and fungi in the herbal formulations is a cause for concern. However, the ability of the remedies to possess activity against Mycobacterium tuberculosis and other pathogenic microorganisms associated with tuberculosis infection makes them potential sources of new antimycobacterial agents. Also, they are rich sources of mineral nutrients, and are as well non-toxic, thus, they are safe for consumption. In view of their anti-tubercular properties, this study has provided a better understanding of the reasons why TB-patients make use of these polyherbal formulations. Also, the study supports the folkloric use of polyherbal medicines in the treatment of tuberculosis in the Eastern Cape Province, South Africa.
- Full Text:
- Date Issued: 2018
On the evaluation of spectral effects on photovoltaic modules performance parameters and hotspots in solar cells
- Authors: Simon, Michael
- Date: 2009
- Subjects: Photovoltaic cells , Energy dissipation , Electric power production , Photovoltaic power generation , Solar energy , Spectral energy distribution
- Language: English
- Type: Thesis , Doctoral , PhD (Physics)
- Identifier: vital:11593 , http://hdl.handle.net/10353/257 , Photovoltaic cells , Energy dissipation , Electric power production , Photovoltaic power generation , Solar energy , Spectral energy distribution
- Description: The performance of photovoltaic (PV) modules in terms of their ability to convert incident photon to electrical energy (efficiency) depends mostly on the spectral distribution of incident radiation from the sun. The incident spectrum finally perceived by the module depends strongly on the composition of the medium in which it has traveled. The composition of the earth’s atmosphere, which includes, amongst others, water vapour, gases such as carbon dioxide and oxygen, absorbs or scatters some of the sunlight. The incident solar spectrum is also modified by the diffuse aspect of radiation from the sky which strongly depends on aerosol concentration, cloudiness and local reflection of the earth’s surface. Although it is well known that the changes in outdoor spectrum affect device performance, little work has been conducted to support this theory. This is probably due to lack of spectral data or in certain instances where data is available, little knowledge of interpreting that data. The outdoor spectral data that one obtains in the field does not come clearly for just simple interpretation. Different analytical interpretation procedures have been proposed, all trying to explain and quantify the spectral influence on PV devices. In this study an assessment methodology for evaluating the effects of outdoor spectra on device performance parameters during the course of the day, seasons and or cloudy cover has been developed. The methodology consists of developing a device dependant concept, Weighted Useful Fraction (WUF) using the outdoor measured spectral data. For measuring PV module’s performance parameters, a current-voltage (I-V) tester was developed in order to monitor the performance of six different module technologies. The Gaussian distribution was used to interpret the data. For hot-spot analysis, different techniques were used, which include Infrared thermographic technique for identifying the hot-spots in the solar cells, SEM and EDX techniques. The AES technique was also used in order to identify other elements at hot-spots sites that could not be detected by the EDX technique. iii Results obtained indicate that multicrystalline modules performance is affected by the changes in the outdoor spectrum during summer or winter seasons. The modules prefer a spectrum characterized by WUF = 0.809 during summer season. This spectrum corresponds to AM 2.19 which is different from AM 1.5 used for device ratings. In winter, the mc-Si module’s WUF (0.7125) peaks at 13h00 at a value corresponding to AM 1.83. Although these devices have a wider wavelength range, they respond differently in real outdoor environment. Results for mono – Si module showed that the device performs best at WUF = 0.6457 which corresponds to AM 1.83 during summer season, while it operates optimally under a winter spectrum indicated by WUF of 0.5691 (AM2.58). The seasonal changes resulted in the shift in WUF during day time corresponding to the “preferred” spectrum. This shift indicates that these devices should be rated using AM values that correspond to the WUF values under which the device operates optimally. For poly-Si, it was also observed the WUF values are lower than the other two crystalline-Si counterparts. The pc-Si was observed to prefer a lower AM value indicated by WUF = 0.5813 during winter season while for summer it prefers a spectrum characterized by WUF = 0.5541 at AM 3.36. The performance of the single junction a-Si module degraded by 67 percent after an initial outdoor exposure of 16 kWh/m² while the HIT module did not exhibit the initial degradation regardless of their similarities in material composition. It was established that the WUF before degradation peaks at 15h00 at a value of 0.7130 corresponding to AM 4.50 while the WUF after degradation “prefers” the spectrum (WUF = 0.6578) experienced at 15h30 corresponding to AM value of 5.57. Comparing the before and after degradation scenarios of a-Si:H, it was observed that the device spends less time under the red spectrum which implies that the device “prefers” a full spectrum to operate optimally. The degradation of a-Si:H device revealed that the device spectral response was also shifted by a 7.7 percent after degradation. A higher percentage difference (61.8 percent) for spectral range for the HIT module is observed, but with no effects on device parameters. Seasonal changes (summer/winter) resulted in the outdoor spectrum of CuInSe2 to vary by WUF = 1.5 percent, which resulted in the decrease in Isc. This was ascertained by iv analyzing the percentage change in WUF and evaluating the corresponding change in Isc. The analysis showed that there was a large percentage difference of the module’s Isc as the outdoor spectrum changed during the course of the day. This confirmed that the 17 percent decrease in Isc was due to a WUF of 1.5 percent. In mc-Si solar cells used in this study, it was found that elemental composition across the entire solar cell was not homogenously distributed resulting in high concentration of transition metals which were detected at hot spot areas. The presence of transition metals causes hot-spot formation in crystalline solar cells. Although several transition elements exist at hot-spot regions, the presence of oxygen, carbon, iron and platinum was detected in high concentrations. From this study, it is highly recommended that transition elements and oxygen must be minimized so as to increase the life expectancy of these devices and improve overall systems reliability
- Full Text:
- Date Issued: 2009
- Authors: Simon, Michael
- Date: 2009
- Subjects: Photovoltaic cells , Energy dissipation , Electric power production , Photovoltaic power generation , Solar energy , Spectral energy distribution
- Language: English
- Type: Thesis , Doctoral , PhD (Physics)
- Identifier: vital:11593 , http://hdl.handle.net/10353/257 , Photovoltaic cells , Energy dissipation , Electric power production , Photovoltaic power generation , Solar energy , Spectral energy distribution
- Description: The performance of photovoltaic (PV) modules in terms of their ability to convert incident photon to electrical energy (efficiency) depends mostly on the spectral distribution of incident radiation from the sun. The incident spectrum finally perceived by the module depends strongly on the composition of the medium in which it has traveled. The composition of the earth’s atmosphere, which includes, amongst others, water vapour, gases such as carbon dioxide and oxygen, absorbs or scatters some of the sunlight. The incident solar spectrum is also modified by the diffuse aspect of radiation from the sky which strongly depends on aerosol concentration, cloudiness and local reflection of the earth’s surface. Although it is well known that the changes in outdoor spectrum affect device performance, little work has been conducted to support this theory. This is probably due to lack of spectral data or in certain instances where data is available, little knowledge of interpreting that data. The outdoor spectral data that one obtains in the field does not come clearly for just simple interpretation. Different analytical interpretation procedures have been proposed, all trying to explain and quantify the spectral influence on PV devices. In this study an assessment methodology for evaluating the effects of outdoor spectra on device performance parameters during the course of the day, seasons and or cloudy cover has been developed. The methodology consists of developing a device dependant concept, Weighted Useful Fraction (WUF) using the outdoor measured spectral data. For measuring PV module’s performance parameters, a current-voltage (I-V) tester was developed in order to monitor the performance of six different module technologies. The Gaussian distribution was used to interpret the data. For hot-spot analysis, different techniques were used, which include Infrared thermographic technique for identifying the hot-spots in the solar cells, SEM and EDX techniques. The AES technique was also used in order to identify other elements at hot-spots sites that could not be detected by the EDX technique. iii Results obtained indicate that multicrystalline modules performance is affected by the changes in the outdoor spectrum during summer or winter seasons. The modules prefer a spectrum characterized by WUF = 0.809 during summer season. This spectrum corresponds to AM 2.19 which is different from AM 1.5 used for device ratings. In winter, the mc-Si module’s WUF (0.7125) peaks at 13h00 at a value corresponding to AM 1.83. Although these devices have a wider wavelength range, they respond differently in real outdoor environment. Results for mono – Si module showed that the device performs best at WUF = 0.6457 which corresponds to AM 1.83 during summer season, while it operates optimally under a winter spectrum indicated by WUF of 0.5691 (AM2.58). The seasonal changes resulted in the shift in WUF during day time corresponding to the “preferred” spectrum. This shift indicates that these devices should be rated using AM values that correspond to the WUF values under which the device operates optimally. For poly-Si, it was also observed the WUF values are lower than the other two crystalline-Si counterparts. The pc-Si was observed to prefer a lower AM value indicated by WUF = 0.5813 during winter season while for summer it prefers a spectrum characterized by WUF = 0.5541 at AM 3.36. The performance of the single junction a-Si module degraded by 67 percent after an initial outdoor exposure of 16 kWh/m² while the HIT module did not exhibit the initial degradation regardless of their similarities in material composition. It was established that the WUF before degradation peaks at 15h00 at a value of 0.7130 corresponding to AM 4.50 while the WUF after degradation “prefers” the spectrum (WUF = 0.6578) experienced at 15h30 corresponding to AM value of 5.57. Comparing the before and after degradation scenarios of a-Si:H, it was observed that the device spends less time under the red spectrum which implies that the device “prefers” a full spectrum to operate optimally. The degradation of a-Si:H device revealed that the device spectral response was also shifted by a 7.7 percent after degradation. A higher percentage difference (61.8 percent) for spectral range for the HIT module is observed, but with no effects on device parameters. Seasonal changes (summer/winter) resulted in the outdoor spectrum of CuInSe2 to vary by WUF = 1.5 percent, which resulted in the decrease in Isc. This was ascertained by iv analyzing the percentage change in WUF and evaluating the corresponding change in Isc. The analysis showed that there was a large percentage difference of the module’s Isc as the outdoor spectrum changed during the course of the day. This confirmed that the 17 percent decrease in Isc was due to a WUF of 1.5 percent. In mc-Si solar cells used in this study, it was found that elemental composition across the entire solar cell was not homogenously distributed resulting in high concentration of transition metals which were detected at hot spot areas. The presence of transition metals causes hot-spot formation in crystalline solar cells. Although several transition elements exist at hot-spot regions, the presence of oxygen, carbon, iron and platinum was detected in high concentrations. From this study, it is highly recommended that transition elements and oxygen must be minimized so as to increase the life expectancy of these devices and improve overall systems reliability
- Full Text:
- Date Issued: 2009
Implementation of the policy on religious equity in public schools in the East London Education District : towards a framework for religious diversity
- Makasi, Cordelia Noma-Abysinia
- Authors: Makasi, Cordelia Noma-Abysinia
- Date: 2017
- Subjects: Religious education -- South Africa -- Eastern Cape Religion and state -- South Africa -- Eastern Cape Christianity and politics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/5014 , vital:28935
- Description: The study sought to establish the implementation of the policy on religious equity in public schools in the East London Education district in the Eastern Cape Province of South Africa. Underpinned by Van Meter and Van Horn (2015) with implementation and conceptual theory and also a theory on opportunity to learn and school performance by Van Der Grift and Houtveen(2006), the study was located in the pragmatist research paradigm and followed a mixed methods approach and concurrent triangulation design. The research sampling technique was random for high school learners in selected schools and purposeful for principals, heads of departments, teachers and provincial education officials. Three methods were employed to collect data from selected public schools and from the provincial office namely; semi-structured interviews, individual interviews and observation. Quantitative data were analysed statistically and presented in the form of descriptive statistics. Qualitative data were analysed using the thematic content analysis technique. Major findings of the study are that teachers and principals understood the concept religious equity and had a fair understanding of the policy on religious equity. Schools were predominantly Christian-oriented in terms of religious practices and there were no recorded cases of religious conflict. Learners of minority religions were not compelled to attend Christian religious functions in schools and were allowed to attend their own religious functions outside school. This was established from the fact that participants cited freedom of religion as being exercised in schools. However, it was further established that there was no strategic monitoring and support for teachers in the implementation of religious equity. There were also no deliberate measures and strategies for the implementation of religious equity suggesting challenges and inconsistencies in the implementation of the policy. While there were notable challenges in the implementation of the policy, due to resistance of stakeholders to change, schools had great opportunities which could be utilized to enhance the implementation of the policy on religious equity. The study concludes by noting that, while key policy implementers had an understanding of religious equity, the situation on the ground revealed challenges and inconsistencies in the implementation of the policy which resulted in a Christian-dominated school environment at the expense of minority religions The study recommends, among other things, that that religious equity be adhered to as enshrined in the Constitution of South Africa of 1996 and the South African Schools Act of 1996. The teaching and learning environment should include Religion Education as per prescription by National Policy on Religion Education of 2003, that monitoring and support of teachers be done, and that community involvement with policy development be considered crucial as well as moral education teaching in schools. A framework for enhancing implementation of the policy on religious equity is also proposed.
- Full Text:
- Date Issued: 2017
- Authors: Makasi, Cordelia Noma-Abysinia
- Date: 2017
- Subjects: Religious education -- South Africa -- Eastern Cape Religion and state -- South Africa -- Eastern Cape Christianity and politics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/5014 , vital:28935
- Description: The study sought to establish the implementation of the policy on religious equity in public schools in the East London Education district in the Eastern Cape Province of South Africa. Underpinned by Van Meter and Van Horn (2015) with implementation and conceptual theory and also a theory on opportunity to learn and school performance by Van Der Grift and Houtveen(2006), the study was located in the pragmatist research paradigm and followed a mixed methods approach and concurrent triangulation design. The research sampling technique was random for high school learners in selected schools and purposeful for principals, heads of departments, teachers and provincial education officials. Three methods were employed to collect data from selected public schools and from the provincial office namely; semi-structured interviews, individual interviews and observation. Quantitative data were analysed statistically and presented in the form of descriptive statistics. Qualitative data were analysed using the thematic content analysis technique. Major findings of the study are that teachers and principals understood the concept religious equity and had a fair understanding of the policy on religious equity. Schools were predominantly Christian-oriented in terms of religious practices and there were no recorded cases of religious conflict. Learners of minority religions were not compelled to attend Christian religious functions in schools and were allowed to attend their own religious functions outside school. This was established from the fact that participants cited freedom of religion as being exercised in schools. However, it was further established that there was no strategic monitoring and support for teachers in the implementation of religious equity. There were also no deliberate measures and strategies for the implementation of religious equity suggesting challenges and inconsistencies in the implementation of the policy. While there were notable challenges in the implementation of the policy, due to resistance of stakeholders to change, schools had great opportunities which could be utilized to enhance the implementation of the policy on religious equity. The study concludes by noting that, while key policy implementers had an understanding of religious equity, the situation on the ground revealed challenges and inconsistencies in the implementation of the policy which resulted in a Christian-dominated school environment at the expense of minority religions The study recommends, among other things, that that religious equity be adhered to as enshrined in the Constitution of South Africa of 1996 and the South African Schools Act of 1996. The teaching and learning environment should include Religion Education as per prescription by National Policy on Religion Education of 2003, that monitoring and support of teachers be done, and that community involvement with policy development be considered crucial as well as moral education teaching in schools. A framework for enhancing implementation of the policy on religious equity is also proposed.
- Full Text:
- Date Issued: 2017
A strategic framework for managing and implementation of the intergovernmental relations policy in selected Eastern Cape municipalities
- Authors: Shasha, Zamuxolo
- Date: 2017
- Subjects: Intergovernmental fiscal relations -- South Africa Local government -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8353 , vital:32310
- Description: It is of paramount importance to highlight that the South African government is established in terms of the Constitution of the Republic of South Africa of 1996. Whilst the government of South Africa is one, it consists of three spheres namely; national, provincial and local. These spheres of government are naturally distinctive, interdependent and interrelated. This is expressed in terms of section 41(1) of the Constitution, which requires that there should be co-operation, mutual trust and good faith amongst these three spheres of government. This form of a relationship compels different spheres to inform and consult one another on matters of common interest, co-ordinate their legislation, and adhere to agreed procedures in accordance with the provisions of the constitution which is the supreme law of the Republic. The study sort to find a strategic framework for managing and implementation of the Intergovernmental Relations Policy in Selected Eastern Cape Municipalities. A purposive sampling technique was used to identify the sample elements. The sample was composed of 160 participants and a semi-structured questionnaire was administered to the participants to gather information pertaining the research problem. A mixed research method was used to analyse the data gathered. The sampled respondents were municipal and government employees from various departments who have knowledge of the IGR policy. The study findings pointed out that the current framework on intergovernmental relations was ineffective in the Eastern Cape municipalities that were surveyed. Respondents pointed to a number of shortfalls in the implementation of the intergovernmental relations, which made it ineffective in improving how these municipalities operated and rendered service delivery. A number of factors inhibiting the effectiveness of the intergovernmental relations included lack of communication, poor coordination, lack of clear strategy, poor budgets amongst other factors. Based on the findings of the study, the researcher developed a strategic framework that could be adopted by municipalities in the Eastern Cape. The functionality of this framework would be influenced by the corrective measures taken by the municipalities in addressing the underlying problems of the current intergovernmental relations, as identified by the respondents.
- Full Text: false
- Date Issued: 2017
- Authors: Shasha, Zamuxolo
- Date: 2017
- Subjects: Intergovernmental fiscal relations -- South Africa Local government -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8353 , vital:32310
- Description: It is of paramount importance to highlight that the South African government is established in terms of the Constitution of the Republic of South Africa of 1996. Whilst the government of South Africa is one, it consists of three spheres namely; national, provincial and local. These spheres of government are naturally distinctive, interdependent and interrelated. This is expressed in terms of section 41(1) of the Constitution, which requires that there should be co-operation, mutual trust and good faith amongst these three spheres of government. This form of a relationship compels different spheres to inform and consult one another on matters of common interest, co-ordinate their legislation, and adhere to agreed procedures in accordance with the provisions of the constitution which is the supreme law of the Republic. The study sort to find a strategic framework for managing and implementation of the Intergovernmental Relations Policy in Selected Eastern Cape Municipalities. A purposive sampling technique was used to identify the sample elements. The sample was composed of 160 participants and a semi-structured questionnaire was administered to the participants to gather information pertaining the research problem. A mixed research method was used to analyse the data gathered. The sampled respondents were municipal and government employees from various departments who have knowledge of the IGR policy. The study findings pointed out that the current framework on intergovernmental relations was ineffective in the Eastern Cape municipalities that were surveyed. Respondents pointed to a number of shortfalls in the implementation of the intergovernmental relations, which made it ineffective in improving how these municipalities operated and rendered service delivery. A number of factors inhibiting the effectiveness of the intergovernmental relations included lack of communication, poor coordination, lack of clear strategy, poor budgets amongst other factors. Based on the findings of the study, the researcher developed a strategic framework that could be adopted by municipalities in the Eastern Cape. The functionality of this framework would be influenced by the corrective measures taken by the municipalities in addressing the underlying problems of the current intergovernmental relations, as identified by the respondents.
- Full Text: false
- Date Issued: 2017
Local web news as tools for framing food security: the content analysis of four selected Eastern Cape web newspapers
- Metula , Nolukhanyo Theorida
- Authors: Metula , Nolukhanyo Theorida
- Date: 2019
- Subjects: Food security World Wide Web
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17484 , vital:41080
- Description: This study evaluates how the Eastern Cape local web newspapers frame food security in the Eastern Cape Province. A qualitative content analysis by means of textual analysis was used to evaluate the selected local web newspaper’s content on food security related stories within the period of July-December 2017. The sample was drawn from four Eastern Cape local web newspapers- Daily Dispatch Live, Herald Live, Go and Express and The Talk of the Town. The analysis sought to determine how the selected local web newspapers frame food security concerning food availability, accessibility and affordability in the Eastern Cape Province. Additionally, the study aimed to ascertain the issues about food security that are raised by the Eastern Cape local web newspapers and, to establish the extent to which these Eastern Cape local web newspapers’ framing is helpful in ensuring participation, empowerment and community mobilization for food securing purposes. The results of this study indicate that the local web newspapers frame Eastern Cape Province as untapped food basket. The framing suggests that the Province can leverage its agricultural resources for job creation which will ensure economic growth and food security. The local web newspapers framing suggests that there are numerous channels such as natural food production, livestock production, smallholder farming that can enhance availability and access to affordable food to people in the Eastern Cape Province. The findings revealed that local web newspapers frame increased agricultural production as an important issue that demand serious and urgent attention of the Provincial government as it has the potential of not only ensuring food security but also impacting positively on the income of local farmers. The local web newspapers frame farm attacks, land redistribution and reinstatement as important factors that hinder food production and, ultimately, food security in the Eastern Cape v Province. Furthermore, this study discovered that the frame of references used by the local web newspapers, especially the emphasis on local farming, land redistribution and private sector help to empower and mobilize individuals and communities to participate in food security initiatives. This study concludes that Eastern Cape Local Web Newspapers can be veritable tools to enhance food security channels in the Eastern Cape Province
- Full Text:
- Date Issued: 2019
- Authors: Metula , Nolukhanyo Theorida
- Date: 2019
- Subjects: Food security World Wide Web
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17484 , vital:41080
- Description: This study evaluates how the Eastern Cape local web newspapers frame food security in the Eastern Cape Province. A qualitative content analysis by means of textual analysis was used to evaluate the selected local web newspaper’s content on food security related stories within the period of July-December 2017. The sample was drawn from four Eastern Cape local web newspapers- Daily Dispatch Live, Herald Live, Go and Express and The Talk of the Town. The analysis sought to determine how the selected local web newspapers frame food security concerning food availability, accessibility and affordability in the Eastern Cape Province. Additionally, the study aimed to ascertain the issues about food security that are raised by the Eastern Cape local web newspapers and, to establish the extent to which these Eastern Cape local web newspapers’ framing is helpful in ensuring participation, empowerment and community mobilization for food securing purposes. The results of this study indicate that the local web newspapers frame Eastern Cape Province as untapped food basket. The framing suggests that the Province can leverage its agricultural resources for job creation which will ensure economic growth and food security. The local web newspapers framing suggests that there are numerous channels such as natural food production, livestock production, smallholder farming that can enhance availability and access to affordable food to people in the Eastern Cape Province. The findings revealed that local web newspapers frame increased agricultural production as an important issue that demand serious and urgent attention of the Provincial government as it has the potential of not only ensuring food security but also impacting positively on the income of local farmers. The local web newspapers frame farm attacks, land redistribution and reinstatement as important factors that hinder food production and, ultimately, food security in the Eastern Cape v Province. Furthermore, this study discovered that the frame of references used by the local web newspapers, especially the emphasis on local farming, land redistribution and private sector help to empower and mobilize individuals and communities to participate in food security initiatives. This study concludes that Eastern Cape Local Web Newspapers can be veritable tools to enhance food security channels in the Eastern Cape Province
- Full Text:
- Date Issued: 2019
An analysis of the academic support policies and strategies for underperforming students at Limpopo universities
- Lavhelani, Nyawasedza Phellecy
- Authors: Lavhelani, Nyawasedza Phellecy
- Date: 2017
- Subjects: Compensatory education--South Africa--Limpopo Universities and colleges--South Africa--Limpopo Support services (Management)--South Africa--Limpopo
- Language: English
- Type: Thesis , Doctoral , Public Administration
- Identifier: http://hdl.handle.net/10353/11784 , vital:39106
- Description: The study sought to investigate academic support policies and strategies for underperforming students at Limpopo universities. By focusing on the University of Venda and that of Limpopo (which are located in rural settings), this study will contribute to the body of knowledge addressing the learning needs of underperforming students in resource constrained universities in South Africa. Qualitative research methodology was considered most appropriate in the present study. The researcher used various research instruments as the fact finding strategies. These comprised tools for data collection. The researcher used questionnaires and the survey of secondary sources for data collection. The researcher chose these instruments because this also means discussing the advantages of using questionnaires and reading, for example gaining an in-depth perspective regarding the actual experiences of students who underperform in their studies. The study focused on first year underperforming students, academic support policies and academic support programmes. Permission was sought from the two universities’ Research Departments to conduct this study. Once permission was granted, the questionnaire was sent out to prospective participants. In addition, the researcher involved intra-group despondence analysis. Since the bulk of the data from the questionnaires was qualitative, thematic analysis was utilised. This involved identifying patterns and emerging themes out of the differences and similarities from the despondences’ views. This study was conducted in the Limpopo Province, South Africa, where the two universities are situated.The study population were students, academics, Information Management Officer, CHETL staff and relevant personnel at the Limpopo. Universities. As envisaged, a total of 136 participants were chosen to participate in the study.
- Full Text:
- Date Issued: 2017
- Authors: Lavhelani, Nyawasedza Phellecy
- Date: 2017
- Subjects: Compensatory education--South Africa--Limpopo Universities and colleges--South Africa--Limpopo Support services (Management)--South Africa--Limpopo
- Language: English
- Type: Thesis , Doctoral , Public Administration
- Identifier: http://hdl.handle.net/10353/11784 , vital:39106
- Description: The study sought to investigate academic support policies and strategies for underperforming students at Limpopo universities. By focusing on the University of Venda and that of Limpopo (which are located in rural settings), this study will contribute to the body of knowledge addressing the learning needs of underperforming students in resource constrained universities in South Africa. Qualitative research methodology was considered most appropriate in the present study. The researcher used various research instruments as the fact finding strategies. These comprised tools for data collection. The researcher used questionnaires and the survey of secondary sources for data collection. The researcher chose these instruments because this also means discussing the advantages of using questionnaires and reading, for example gaining an in-depth perspective regarding the actual experiences of students who underperform in their studies. The study focused on first year underperforming students, academic support policies and academic support programmes. Permission was sought from the two universities’ Research Departments to conduct this study. Once permission was granted, the questionnaire was sent out to prospective participants. In addition, the researcher involved intra-group despondence analysis. Since the bulk of the data from the questionnaires was qualitative, thematic analysis was utilised. This involved identifying patterns and emerging themes out of the differences and similarities from the despondences’ views. This study was conducted in the Limpopo Province, South Africa, where the two universities are situated.The study population were students, academics, Information Management Officer, CHETL staff and relevant personnel at the Limpopo. Universities. As envisaged, a total of 136 participants were chosen to participate in the study.
- Full Text:
- Date Issued: 2017
Communal production systems of goats raised by resource-poor farmers in the Eastern Cape Province of South Africa
- Authors: Gwaze, Francisca Rumosa
- Date: 2008
- Subjects: Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11578 , http://hdl.handle.net/10353/172 , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Description: Goats significantly contribute towards the subsistence, economic and social livelihoods of many resource-poor farmers in developing countries, the majority of which own goats. There, however, is dearth of information on communal goat production potential and roles to the rural populace. The broad objective of the study was to evaluate production practices, constraints, production efficiency and to determine nutritional and health status of goats raised by resource-poor communal farmers in the Eastern Cape Province of South Africa. Roles and management systems of goats, goat flock dynamics and, prevalence and loads of gastrointestinal infections and the nutritional status of goats in the study areas were determined. The relationships among body weight, body condition score, faecal egg counts and, haematological and biochemical profiles were also determined. Mean goat flock sizes per household were similar between the two districts studied; Amatole (14.0 ± 0.31) and Alfred Nzo (14.1 ± 1.42). Seventy-nine percent of households in Amatole and 78% in Alfred Nzo kept goats for ceremonies, such as the initiation ceremonies. Goat houses in the two districts were poorly constructed. Thirty two percent of farmers in Alfred Nzo district and 27% in Amatole district reported low buck to doe ratios, suggesting that inbreeding might have been reducing productivity of their flocks. Kid mortality had two major peaks; in May (21%) and in September (21%). Goat production potential (GPP), the proportion of mature and growing goats to the total flock size, was affected by gender of owner of goats. Goats owned by female had a significantly lower GPP value of 0.63 ± 0.015 than goats owned by male farmers (0.70 ± 0.010). Month also significantly affected GPP with the highest (P < 0.05) GPP recorded in May, June and July and the lowest in March and April. Village affected GPP with values for Nkosana and Qawukeni being significantly higher than for Mankone. Goat production potential was also higher (P < 0.05) in small flocks (0.04 ± 0.008) than in large flocks (0.02 ± 0.008). Goat production efficiency (GPE) ranged from 0.11 ± 0.193 in April to 1.55 ± 0.193 in December. The most prevalent gastrointestinal eggs were the strongyle egg type (68.4 ± 8.49 in Qawukeni and 96.1 ± 12.01 in Nkosana) followed by coccidia (53.3 ± 8.76 in Qawukeni and 68.8 ± 8.00 in Mankone). The other identified nematodes were Strongyloides and Trichostrongylus egg types. The trematodes observed were Fasciola and Paramphistomum species. High loads of strongyle eggs were observed in the hot-wet season and the post-rainy season, whilst the other egg types showed a peak in the hot-wet season only. For most of the gastrointestinal parasite eggs, prevalence was higher (P < 0.05) in the sour rangeland compared to the sweet rangeland. Higher (P < 0.05) levels of total protein (TP), globulin, aspartate aminotransferase (AST) and creatinine kinase (CK) levels were recorded in the wet than in the dry season. Body condition scores were positively correlated (P < 0.05) to albumin, body weight and packed cell volume. However, body condition scores were negatively correlated to TP, glucose, alanine transaminase (ALT) and AST. Strongyle egg loads were positively correlated to FAMACHA scores, packed cell volume, body weight and body condition score. The observed high globulin levels suggested a chronic health challenge. Thus, it is fundamental to devise affordable interventions for the control of gastrointestinal parasites in communal goats leading to improved goat productivity and hence rural livelihood
- Full Text:
- Date Issued: 2008
- Authors: Gwaze, Francisca Rumosa
- Date: 2008
- Subjects: Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11578 , http://hdl.handle.net/10353/172 , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Description: Goats significantly contribute towards the subsistence, economic and social livelihoods of many resource-poor farmers in developing countries, the majority of which own goats. There, however, is dearth of information on communal goat production potential and roles to the rural populace. The broad objective of the study was to evaluate production practices, constraints, production efficiency and to determine nutritional and health status of goats raised by resource-poor communal farmers in the Eastern Cape Province of South Africa. Roles and management systems of goats, goat flock dynamics and, prevalence and loads of gastrointestinal infections and the nutritional status of goats in the study areas were determined. The relationships among body weight, body condition score, faecal egg counts and, haematological and biochemical profiles were also determined. Mean goat flock sizes per household were similar between the two districts studied; Amatole (14.0 ± 0.31) and Alfred Nzo (14.1 ± 1.42). Seventy-nine percent of households in Amatole and 78% in Alfred Nzo kept goats for ceremonies, such as the initiation ceremonies. Goat houses in the two districts were poorly constructed. Thirty two percent of farmers in Alfred Nzo district and 27% in Amatole district reported low buck to doe ratios, suggesting that inbreeding might have been reducing productivity of their flocks. Kid mortality had two major peaks; in May (21%) and in September (21%). Goat production potential (GPP), the proportion of mature and growing goats to the total flock size, was affected by gender of owner of goats. Goats owned by female had a significantly lower GPP value of 0.63 ± 0.015 than goats owned by male farmers (0.70 ± 0.010). Month also significantly affected GPP with the highest (P < 0.05) GPP recorded in May, June and July and the lowest in March and April. Village affected GPP with values for Nkosana and Qawukeni being significantly higher than for Mankone. Goat production potential was also higher (P < 0.05) in small flocks (0.04 ± 0.008) than in large flocks (0.02 ± 0.008). Goat production efficiency (GPE) ranged from 0.11 ± 0.193 in April to 1.55 ± 0.193 in December. The most prevalent gastrointestinal eggs were the strongyle egg type (68.4 ± 8.49 in Qawukeni and 96.1 ± 12.01 in Nkosana) followed by coccidia (53.3 ± 8.76 in Qawukeni and 68.8 ± 8.00 in Mankone). The other identified nematodes were Strongyloides and Trichostrongylus egg types. The trematodes observed were Fasciola and Paramphistomum species. High loads of strongyle eggs were observed in the hot-wet season and the post-rainy season, whilst the other egg types showed a peak in the hot-wet season only. For most of the gastrointestinal parasite eggs, prevalence was higher (P < 0.05) in the sour rangeland compared to the sweet rangeland. Higher (P < 0.05) levels of total protein (TP), globulin, aspartate aminotransferase (AST) and creatinine kinase (CK) levels were recorded in the wet than in the dry season. Body condition scores were positively correlated (P < 0.05) to albumin, body weight and packed cell volume. However, body condition scores were negatively correlated to TP, glucose, alanine transaminase (ALT) and AST. Strongyle egg loads were positively correlated to FAMACHA scores, packed cell volume, body weight and body condition score. The observed high globulin levels suggested a chronic health challenge. Thus, it is fundamental to devise affordable interventions for the control of gastrointestinal parasites in communal goats leading to improved goat productivity and hence rural livelihood
- Full Text:
- Date Issued: 2008
A model for secure and usable passphrases for multilingual users
- Authors: Maoneke, Pardon Blessings
- Date: 2019
- Subjects: Computers -- Access control -- Passwords Computer security
- Language: English
- Type: Thesis , Doctoral , PhD (Information Systems)
- Identifier: http://hdl.handle.net/10353/12571 , vital:39289
- Description: Research on more than 100 million passwords that have been leaked to the public domain has uncovered various security limitations associated with user-generated short passwords. Long passwords (passphrases) are considered an alternative solution that could provide a balance between security and usability. However, the literature shows a lack of consistency in the security and usability contributions of passphrases. For example, studies that investigated passphrase security focusing on structural dependencies at character level found passphrases to be secure. Inversely, other research findings suggest that passphrase security could be compromised by the use of predictable grammatical rules, popular words in a natural language and keyboard patterns. This is further exacerbated by research on passphrases that is focused on the Global North. This is a huge concern given that results from inter-cultural studies suggest that local languages do influence password structure and to some extent, password usability and security. To address these gaps in the literature, this study used socio-technical theory which emphasised both the social and technical aspects of the phenomenon under study. Psychological studies show that the memory has limited capacity, something that threatens password usability; hence, the need to utilise information that is already known during password generation. Socio-cultural theory suggests that the information that is already known by users is contextually informed, hence sociocultural theory was applied to understand the contextual factors that could be used to enhance passphrase security and usability. With reference to the Southern African context, this study argues that system designers should take advantage of a multilingual user group and encourage the generation of passphrases that are based on substrings from different languages. This study went on to promote the use of multilingual passphrases instead of emphasising multi-character class passwords. This study was guided by design science research. Participants were invited to take part in a short password and multilingual passphrase generation and recall experiment that was made available using a web-based application. These passwords were generated by participants under pre-specified conditions. Quantitative and qualitative data was gathered. The study findings showed the use of both African and Indo-European languages in multilingual passphrases and short passwords. English oriented passwords and substrings dominated the multilingual passphrase and short password corpora. In addition, some of the short passwords and substrings in the multilingual passphrase corpora were found among the most common passwords of 2016, 2017 and 2018. Usability tests showed that multilingual passphrases are usable, even though they were not easy to create and recall when compared to short passwords. A high rate of password reuse during short password generation by participants might have worked in favour of short passwords. Nonetheless, participants appear to reflect better usability with multilingual passphrases over time due to repeated use. Females struggled to recall short passwords and multilingual passphrases when compared to their male counterparts. Security tests using the Probabilistic Context-Free Grammar suggest that short passwords are weaker, with just more than 50% of the short passwords being guessed, while none 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper of the multilingual passphrases were guessed. Further analysis showed that short passwords that were oriented towards an IndoEuropean language were more easily guessed than African language-oriented short passwords. As such, this study encourages orienting passwords towards African languages while the use of multilingual passphrases is expected to offer more security. The use of African languages and multilingual passphrases by a user group that is biased towards English-oriented passwords could enhance security by increasing the search space.
- Full Text:
- Date Issued: 2019
- Authors: Maoneke, Pardon Blessings
- Date: 2019
- Subjects: Computers -- Access control -- Passwords Computer security
- Language: English
- Type: Thesis , Doctoral , PhD (Information Systems)
- Identifier: http://hdl.handle.net/10353/12571 , vital:39289
- Description: Research on more than 100 million passwords that have been leaked to the public domain has uncovered various security limitations associated with user-generated short passwords. Long passwords (passphrases) are considered an alternative solution that could provide a balance between security and usability. However, the literature shows a lack of consistency in the security and usability contributions of passphrases. For example, studies that investigated passphrase security focusing on structural dependencies at character level found passphrases to be secure. Inversely, other research findings suggest that passphrase security could be compromised by the use of predictable grammatical rules, popular words in a natural language and keyboard patterns. This is further exacerbated by research on passphrases that is focused on the Global North. This is a huge concern given that results from inter-cultural studies suggest that local languages do influence password structure and to some extent, password usability and security. To address these gaps in the literature, this study used socio-technical theory which emphasised both the social and technical aspects of the phenomenon under study. Psychological studies show that the memory has limited capacity, something that threatens password usability; hence, the need to utilise information that is already known during password generation. Socio-cultural theory suggests that the information that is already known by users is contextually informed, hence sociocultural theory was applied to understand the contextual factors that could be used to enhance passphrase security and usability. With reference to the Southern African context, this study argues that system designers should take advantage of a multilingual user group and encourage the generation of passphrases that are based on substrings from different languages. This study went on to promote the use of multilingual passphrases instead of emphasising multi-character class passwords. This study was guided by design science research. Participants were invited to take part in a short password and multilingual passphrase generation and recall experiment that was made available using a web-based application. These passwords were generated by participants under pre-specified conditions. Quantitative and qualitative data was gathered. The study findings showed the use of both African and Indo-European languages in multilingual passphrases and short passwords. English oriented passwords and substrings dominated the multilingual passphrase and short password corpora. In addition, some of the short passwords and substrings in the multilingual passphrase corpora were found among the most common passwords of 2016, 2017 and 2018. Usability tests showed that multilingual passphrases are usable, even though they were not easy to create and recall when compared to short passwords. A high rate of password reuse during short password generation by participants might have worked in favour of short passwords. Nonetheless, participants appear to reflect better usability with multilingual passphrases over time due to repeated use. Females struggled to recall short passwords and multilingual passphrases when compared to their male counterparts. Security tests using the Probabilistic Context-Free Grammar suggest that short passwords are weaker, with just more than 50% of the short passwords being guessed, while none 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper of the multilingual passphrases were guessed. Further analysis showed that short passwords that were oriented towards an IndoEuropean language were more easily guessed than African language-oriented short passwords. As such, this study encourages orienting passwords towards African languages while the use of multilingual passphrases is expected to offer more security. The use of African languages and multilingual passphrases by a user group that is biased towards English-oriented passwords could enhance security by increasing the search space.
- Full Text:
- Date Issued: 2019
Antifugal evaluation and phytochemical analysis of selected medicinal plants used in the treatment of fungal diseases associated with HIV infection in the Eastern Cape Province, South Africa
- Authors: Mbeng, Wilfred Otang
- Date: 2013
- Subjects: Medicinal plants -- ethnobotanical survey , Opportunistic fungal infections , HIV/AIDS -- Cytotoxicity , Eastern Cape -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Botany)
- Identifier: vital:11307 , http://hdl.handle.net/10353/d1006834 , Medicinal plants -- ethnobotanical survey , Opportunistic fungal infections , HIV/AIDS -- Cytotoxicity , Eastern Cape -- South Africa
- Description: Background. As a result of the AIDS pandemic, many people areimmuno compromised andopportunistic fungal infections (OFIs) such as candidiasis are common. Despite the widespread use of medicinal plants in South Africa, there is a dearth of knowledge regarding the use of such plants in the management of these infections. This study evaluates three South African medicinal plants (Arctotis arctotoides, Pittosporum viridiflorum, and Gasteria bicolor) traditionally used in the treatment of OFIs in HIV/AIDS patients, in the Eastern Cape Province, South Africa. Materials and methods. A six-stage process of documentation, evaluation and analysis of results was conducted: (1) Selection of medicinal plants most frequently used in the treatment of OFIs through ethnomedical studies and the survey of specialised literature; (2) Collection and preparation of the extract of each plant; (3) Antifungal evaluation of the crude plant extracts. (4) Phytochemical and antioxidant evaluation of the active crude plant extracts; (5) Cytotoxicity evaluation of the bioactive extracts using the Chang liver cell line, and (6) Statistical analysis of the results. Ethnobotanical information was obtained through interviews with traditional healers and AIDS patients with the aid of semi-structured questionnaires, direct observations and by reviewing studies reported in the literature. Following the approval from the University of Fort Hare‘s Ethics Committee, 101 HIV/AIDS patients were recruited through convenience sampling into an anonymous cross-sectional questionnaire study. The agar diffusion and micro-dilution methods were used to determine the antifungal activities of the hexane, acetone and aqueous extracts of A. arctotoides, G. bicolor and P. viridiflorum against 10 opportunistic fungi.
- Full Text:
- Date Issued: 2013
- Authors: Mbeng, Wilfred Otang
- Date: 2013
- Subjects: Medicinal plants -- ethnobotanical survey , Opportunistic fungal infections , HIV/AIDS -- Cytotoxicity , Eastern Cape -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Botany)
- Identifier: vital:11307 , http://hdl.handle.net/10353/d1006834 , Medicinal plants -- ethnobotanical survey , Opportunistic fungal infections , HIV/AIDS -- Cytotoxicity , Eastern Cape -- South Africa
- Description: Background. As a result of the AIDS pandemic, many people areimmuno compromised andopportunistic fungal infections (OFIs) such as candidiasis are common. Despite the widespread use of medicinal plants in South Africa, there is a dearth of knowledge regarding the use of such plants in the management of these infections. This study evaluates three South African medicinal plants (Arctotis arctotoides, Pittosporum viridiflorum, and Gasteria bicolor) traditionally used in the treatment of OFIs in HIV/AIDS patients, in the Eastern Cape Province, South Africa. Materials and methods. A six-stage process of documentation, evaluation and analysis of results was conducted: (1) Selection of medicinal plants most frequently used in the treatment of OFIs through ethnomedical studies and the survey of specialised literature; (2) Collection and preparation of the extract of each plant; (3) Antifungal evaluation of the crude plant extracts. (4) Phytochemical and antioxidant evaluation of the active crude plant extracts; (5) Cytotoxicity evaluation of the bioactive extracts using the Chang liver cell line, and (6) Statistical analysis of the results. Ethnobotanical information was obtained through interviews with traditional healers and AIDS patients with the aid of semi-structured questionnaires, direct observations and by reviewing studies reported in the literature. Following the approval from the University of Fort Hare‘s Ethics Committee, 101 HIV/AIDS patients were recruited through convenience sampling into an anonymous cross-sectional questionnaire study. The agar diffusion and micro-dilution methods were used to determine the antifungal activities of the hexane, acetone and aqueous extracts of A. arctotoides, G. bicolor and P. viridiflorum against 10 opportunistic fungi.
- Full Text:
- Date Issued: 2013