Characterising the stress-life response of mechanical and laser formed titanium components
- Authors: Fidder, Herman
- Date: 2012
- Subjects: Titanium alloys -- Fatigue , Titanium --- Fatigue , Materials -- Mechanical properties
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9634 , http://hdl.handle.net/10948/d1018462
- Description: This dissertation involves the experimental investigation of commercially pure titanium (CP Ti) which was subjected to laser forming and mechanical forming processes. Commercially pure titanium grade 2 was formed to a radius of curvature of approximately 120 mm using three forming procedures, i.e. i) laser forming; ii) mechanical forming (stretched forming) and iii) a combined forming process (laser-mechanical forming). Fatigue testing revealed, for all the forming processes, that samples produced by laser forming performed the best at high load settings. However, mechanically formed specimens performed the best at low load settings, whereas the laser-mechanical process resulted in midway performance between laser and mechanical processing. Considering microstructure vs fatigue; impact vs fatigue; and residual stress vs fatigue; at high load settings it is evident that the microstructure is the dominant contributor to crack initiation and growth. Crack morphology of fatigue samples revealed that secondary cracks (parallel to main crack front) followed the grain boundaries of the Widmanstätten microstructure, whereas irregular secondary cracks grew parallel and through the twinning planes and along the grain boundaries of the equiaxed microstructure. Laser forming resulted in microstructural changes from equiaxed grains to a Widmanstätten structure due to fast cooling rates. Excessive twinning is developed within the equiaxed microstructure after the mechanical forming procedure. This is due to cold working / strain hardening. The combined process shows a combination of equiaxed grains and Widmanstätten microstructure. Residual stress relieved for all forming processes revealed an increase in the magnitude of the residual stress compared to the parent plate and that the maximum values were obtained at the inner radius of curvature (i.e. 118.4 mm). Laser forming revealed the highest values in residual stress whereas the other two processes i.e. mechanical and laser-mechanical forming exhibited an increase midway between the parent plate and laser forming. The second most influential factor with regards to fatigue was the magnitude of the residual stress, especially at medium to low load settings. When considering theoretical models to predict fatigue life it was found that the Goodman model showed the closest relation to the actual fatigue data when considering the entire theoretical curve. Vickers microhardness profiling was applied to the thickness of the samples for the parent plate and all forming processes. No significant hardening occurred due to the forming processes and differences in hardness were considered negligible. Charpy impact testing revealed that the laser formed specimens exhibited the most brittle behaviour when compared to the parent plate results. Mechanical formed specimens showed a slight increase in brittleness compared to parent plate whereas the combined process yielded results midway between the laser and mechanically formed specimens. Mathematical equations are formulated and presented for predicting the fatigue life of CP Ti grade 2 for the parent plate and the three forming processes. This study proved that the laser forming process can be successfully used as a production stage in the forming of CP Ti grade 2.
- Full Text:
- Date Issued: 2012
- Authors: Fidder, Herman
- Date: 2012
- Subjects: Titanium alloys -- Fatigue , Titanium --- Fatigue , Materials -- Mechanical properties
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9634 , http://hdl.handle.net/10948/d1018462
- Description: This dissertation involves the experimental investigation of commercially pure titanium (CP Ti) which was subjected to laser forming and mechanical forming processes. Commercially pure titanium grade 2 was formed to a radius of curvature of approximately 120 mm using three forming procedures, i.e. i) laser forming; ii) mechanical forming (stretched forming) and iii) a combined forming process (laser-mechanical forming). Fatigue testing revealed, for all the forming processes, that samples produced by laser forming performed the best at high load settings. However, mechanically formed specimens performed the best at low load settings, whereas the laser-mechanical process resulted in midway performance between laser and mechanical processing. Considering microstructure vs fatigue; impact vs fatigue; and residual stress vs fatigue; at high load settings it is evident that the microstructure is the dominant contributor to crack initiation and growth. Crack morphology of fatigue samples revealed that secondary cracks (parallel to main crack front) followed the grain boundaries of the Widmanstätten microstructure, whereas irregular secondary cracks grew parallel and through the twinning planes and along the grain boundaries of the equiaxed microstructure. Laser forming resulted in microstructural changes from equiaxed grains to a Widmanstätten structure due to fast cooling rates. Excessive twinning is developed within the equiaxed microstructure after the mechanical forming procedure. This is due to cold working / strain hardening. The combined process shows a combination of equiaxed grains and Widmanstätten microstructure. Residual stress relieved for all forming processes revealed an increase in the magnitude of the residual stress compared to the parent plate and that the maximum values were obtained at the inner radius of curvature (i.e. 118.4 mm). Laser forming revealed the highest values in residual stress whereas the other two processes i.e. mechanical and laser-mechanical forming exhibited an increase midway between the parent plate and laser forming. The second most influential factor with regards to fatigue was the magnitude of the residual stress, especially at medium to low load settings. When considering theoretical models to predict fatigue life it was found that the Goodman model showed the closest relation to the actual fatigue data when considering the entire theoretical curve. Vickers microhardness profiling was applied to the thickness of the samples for the parent plate and all forming processes. No significant hardening occurred due to the forming processes and differences in hardness were considered negligible. Charpy impact testing revealed that the laser formed specimens exhibited the most brittle behaviour when compared to the parent plate results. Mechanical formed specimens showed a slight increase in brittleness compared to parent plate whereas the combined process yielded results midway between the laser and mechanically formed specimens. Mathematical equations are formulated and presented for predicting the fatigue life of CP Ti grade 2 for the parent plate and the three forming processes. This study proved that the laser forming process can be successfully used as a production stage in the forming of CP Ti grade 2.
- Full Text:
- Date Issued: 2012
Characterising the stress-life response of mechanical formed AISI-1008 steel plate components
- Authors: Müller, Ruan
- Date: 2012
- Subjects: Materials -- Fatigue -- Testing , Metals -- Fatigue , Mechanical wear -- Measurement , Mechanical engineering
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9616 , http://hdl.handle.net/10948/d1008102 , Materials -- Fatigue -- Testing , Metals -- Fatigue , Mechanical wear -- Measurement , Mechanical engineering
- Description: The main purpose of this research project was to determine the fatigue-life behaviour of AISI 1008 sheet steel which has been mechanically formed to a radius of curvature of 120mm and then to correlate the fatigue-life behaviour to that of the parent or “as manufactured” material. During the forming process it was felt important to induce plastic strain through stretch-bending by clamping the sides of a plate sample’s (width) edges in the bending fixture before being bent by a single acting mechanical press. It was determined through actual testing that there was a decrease in fatigue-life when the mechanical formed data was compared to fatigue data of the parent material. Standard fatigue mathematical models were used to relate the actual fatigue data. Due to the material being cold formed to a radius of curvature of 120mm, residual stresses induced during the forming process played an essential role during the fatigue-life prediction calculations. The maximum relieved stress in the parent material was compressive in nature having a magnitude of 11percent of the “as manufactured” yield strength (265 MPa). For the mechanical formed material compressive residual stresses were measured on the outer surface while tensile stresses were measured on the inner surface. The difference between actual number of cycles to failure to that calculated using the standard mathematical models for the parent material, ranged between 48 percent and 18 percent and for the mechanical formed samples between 35 percent and 1percent, depending on the strain amplitude used. An important aspect of this study was to determine the criteria required for mathematical modelling of the parent material as testing occurred between the limit of proportionality and yield point. Although this aspect requires further investigation the mathematical results obtained during this study were considered to be acceptable.
- Full Text:
- Date Issued: 2012
- Authors: Müller, Ruan
- Date: 2012
- Subjects: Materials -- Fatigue -- Testing , Metals -- Fatigue , Mechanical wear -- Measurement , Mechanical engineering
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9616 , http://hdl.handle.net/10948/d1008102 , Materials -- Fatigue -- Testing , Metals -- Fatigue , Mechanical wear -- Measurement , Mechanical engineering
- Description: The main purpose of this research project was to determine the fatigue-life behaviour of AISI 1008 sheet steel which has been mechanically formed to a radius of curvature of 120mm and then to correlate the fatigue-life behaviour to that of the parent or “as manufactured” material. During the forming process it was felt important to induce plastic strain through stretch-bending by clamping the sides of a plate sample’s (width) edges in the bending fixture before being bent by a single acting mechanical press. It was determined through actual testing that there was a decrease in fatigue-life when the mechanical formed data was compared to fatigue data of the parent material. Standard fatigue mathematical models were used to relate the actual fatigue data. Due to the material being cold formed to a radius of curvature of 120mm, residual stresses induced during the forming process played an essential role during the fatigue-life prediction calculations. The maximum relieved stress in the parent material was compressive in nature having a magnitude of 11percent of the “as manufactured” yield strength (265 MPa). For the mechanical formed material compressive residual stresses were measured on the outer surface while tensile stresses were measured on the inner surface. The difference between actual number of cycles to failure to that calculated using the standard mathematical models for the parent material, ranged between 48 percent and 18 percent and for the mechanical formed samples between 35 percent and 1percent, depending on the strain amplitude used. An important aspect of this study was to determine the criteria required for mathematical modelling of the parent material as testing occurred between the limit of proportionality and yield point. Although this aspect requires further investigation the mathematical results obtained during this study were considered to be acceptable.
- Full Text:
- Date Issued: 2012
Characterising the structural integrity of mechanical formed low carbon steel
- Authors: Victor, Ngea Njoume
- Date: 2012
- Subjects: Carbon steel , Structural analysis (Engineering) , Steel, Structural
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9627 , http://hdl.handle.net/10948/d1012089 , Carbon steel , Structural analysis (Engineering) , Steel, Structural
- Description: The contribution of the clamping force in the technique used in this study to stretch-bend low carbon steel samples was investigated to support the subsequent changes in the microstructure and properties of the formed material with regard to parent material. Although plastic deformation by cold working is known to induce texture or preferred orientation to the grains of a formed material while decreasing its ductility and increasing the strength, as well as inducing residual stress, it is not known how the different directions (rolling, transverse and oblique/45°) of the sheet steel will respond to this stretch bending technique. The first part of the research work involved a thorough literature review on sheet metal forming processes and their effect on the formed material with interest on the above mentioned directions of the sheet. It became clear from the literature overview that cold working of a material will induce strain-hardening which varies with the magnitude of cold work, resulting in changes in the strength and ductility of the material. Besides, when plastic deformation is not uniform (e.g., tensile and compressive) throughout the entire cross section of the formed part, residual stresses remain in the material with the grains been elongated along the direction of the maximum strain. The main parameters that were considered and controlled in this study are as follows: strain experienced / stress induced into the form sample, the sample direction, the stroke length and the clamping torque, the generated radius of curvature. The chapters that follow the literature review, deal with the set-up of the different equipment used in this study, the specimen preparation as well as the recording, the calculation and interpretation of the results. It was found that the stress magnitude that generated the different radii of curvature (120 mm, 150 mm and 185 mm) was between 1 percent & 13 percent higher than the parent material’s yield strength with the lower stress been associated to the smaller radius of curvature and the higher stress to the higher radius. The stress induced into the sample during forming was not only proportional to the stroke length but also to the distance between the punch’s tip and the sample and the sample to the die’s nadir. The clamping torque adopted was restricted to the manual capacity of the operator who used a preset torque wrench to fasten the plate sample into the jig. Plate samples of low carbon steel were cut to angles of 0°, 45°, and 90° to the rolling direction of the sheet material and stretch-bent on a single-action mechanical press to 120 mm, 150 mm, and 185 mm radii of curvature. The preliminary results indicate that stretch-bent samples had increased hardness to the parent plate, in particular below the surface layers up to around 1.1 mm depth. Since there is a well established relationship between hardness, yield and tensile strengths for steel, the yield and tensile strengths of the formed material were estimated using the Nobre et al [34] incremental relation, which relates the linearity between relative increments of hardness and yield strength. Changes were not noticeable at the microstructural level of the formed samples. Meanwhile, samples from which higher plastic deformation stress values were calculated were not those absorbing higher impact energy when Charpy specimen cut from plate and stretch-bent samples were tested. The maximum relieved residual stress in the parent material was predominantly compressive and represents in magnitude approximately 12 percent (average for the three directions) of its original yield strength. In the stretch-bent samples, the relieved residual stress was compressive in the outer curved section with a magnitude about 50 percent of the parent material yield strength and tensile in the inner curved section with a magnitude approximately 25 percent of the parent material yield strength.
- Full Text:
- Date Issued: 2012
- Authors: Victor, Ngea Njoume
- Date: 2012
- Subjects: Carbon steel , Structural analysis (Engineering) , Steel, Structural
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9627 , http://hdl.handle.net/10948/d1012089 , Carbon steel , Structural analysis (Engineering) , Steel, Structural
- Description: The contribution of the clamping force in the technique used in this study to stretch-bend low carbon steel samples was investigated to support the subsequent changes in the microstructure and properties of the formed material with regard to parent material. Although plastic deformation by cold working is known to induce texture or preferred orientation to the grains of a formed material while decreasing its ductility and increasing the strength, as well as inducing residual stress, it is not known how the different directions (rolling, transverse and oblique/45°) of the sheet steel will respond to this stretch bending technique. The first part of the research work involved a thorough literature review on sheet metal forming processes and their effect on the formed material with interest on the above mentioned directions of the sheet. It became clear from the literature overview that cold working of a material will induce strain-hardening which varies with the magnitude of cold work, resulting in changes in the strength and ductility of the material. Besides, when plastic deformation is not uniform (e.g., tensile and compressive) throughout the entire cross section of the formed part, residual stresses remain in the material with the grains been elongated along the direction of the maximum strain. The main parameters that were considered and controlled in this study are as follows: strain experienced / stress induced into the form sample, the sample direction, the stroke length and the clamping torque, the generated radius of curvature. The chapters that follow the literature review, deal with the set-up of the different equipment used in this study, the specimen preparation as well as the recording, the calculation and interpretation of the results. It was found that the stress magnitude that generated the different radii of curvature (120 mm, 150 mm and 185 mm) was between 1 percent & 13 percent higher than the parent material’s yield strength with the lower stress been associated to the smaller radius of curvature and the higher stress to the higher radius. The stress induced into the sample during forming was not only proportional to the stroke length but also to the distance between the punch’s tip and the sample and the sample to the die’s nadir. The clamping torque adopted was restricted to the manual capacity of the operator who used a preset torque wrench to fasten the plate sample into the jig. Plate samples of low carbon steel were cut to angles of 0°, 45°, and 90° to the rolling direction of the sheet material and stretch-bent on a single-action mechanical press to 120 mm, 150 mm, and 185 mm radii of curvature. The preliminary results indicate that stretch-bent samples had increased hardness to the parent plate, in particular below the surface layers up to around 1.1 mm depth. Since there is a well established relationship between hardness, yield and tensile strengths for steel, the yield and tensile strengths of the formed material were estimated using the Nobre et al [34] incremental relation, which relates the linearity between relative increments of hardness and yield strength. Changes were not noticeable at the microstructural level of the formed samples. Meanwhile, samples from which higher plastic deformation stress values were calculated were not those absorbing higher impact energy when Charpy specimen cut from plate and stretch-bent samples were tested. The maximum relieved residual stress in the parent material was predominantly compressive and represents in magnitude approximately 12 percent (average for the three directions) of its original yield strength. In the stretch-bent samples, the relieved residual stress was compressive in the outer curved section with a magnitude about 50 percent of the parent material yield strength and tensile in the inner curved section with a magnitude approximately 25 percent of the parent material yield strength.
- Full Text:
- Date Issued: 2012
Characteristics of the modern toursist in the Nelson Mandela Metropolitan area
- Authors: Shrosbree, Laura Tania
- Date: 2012
- Subjects: Sustainable tourism -- South Africa -- Nelson Mandela Bay , Tourism -- South Africa -- Nelson Mandela Bay , Tourism -- Social aspects , Civilization, Modern
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9369 , http://hdl.handle.net/10948/d1012110 , Sustainable tourism -- South Africa -- Nelson Mandela Bay , Tourism -- South Africa -- Nelson Mandela Bay , Tourism -- Social aspects , Civilization, Modern
- Description: Until the nineteenth century, travel was undertaken only by the elite. With the introduction of rail, mass travel was available for the first time, and new faraway destinations became accessible to all. During the 20th century travel became more destination-orientated. And now, in the 21st century, travel is a new economy, resulting in the tourism industry. The focus of the tourism industry has shifted from air travel, weekend getaways and day trips, to a total experience of the destination. A new era in tourism has arrived with a new kind of tourism experience, one that is sustainable, socially responsible and flexible. At the forefront of this industry is a tourist who is more educated, experienced, knowledgeable, independent and demanding. This tourist demands new or different products/services, is harder to please than the traditional tourist, is well-informed and knows what he/she wants and where he/she wants to go. This is the modern tourist. The objectives of the study were to identify the typical characteristics of the so-called modern consumer, determine which of these characteristics were prevalent among consumers living in the Nelson Mandela Metropolitan Area and whether these characteristics could be used to cluster respondents into segments. The results of the study will assist organisations, within the tourism industry, in dealing with the changing demands of the modern tourist. The literature study contextualised the modern tourist within the tourism industry and provides an overview of the demographic and behavioural factors, which form the basis of the modern tourist‟s development. The demographic factors discussed were age, education, income, gender and household size. The non demographic factors identified and explained were variety seeking, quest for self-identity, quest for authenticity, knowledgeable, experience sharing and time poor. The empirical information was obtained via self-administered questionnaires. Two hundred useable questionnaires were completed by respondents in the Nelson Mandela Metropolitan Area. Statistica version 10 was used to analyse the data received. The principal component factor analysis yielded six behavioural factors, namely meaningful experiences, time poor, knowledge, authenticity and experience sharing. Until the nineteenth century, travel was undertaken only by the elite. With the introduction of rail, mass travel was available for the first time, and new faraway destinations became accessible to all. During the 20th century travel became more destination-orientated. And now, in the 21st century, travel is a new economy, resulting in the tourism industry. The focus of the tourism industry has shifted from air travel, weekend getaways and day trips, to a total experience of the destination. A new era in tourism has arrived with a new kind of tourism experience, one that is sustainable, socially responsible and flexible. At the forefront of this industry is a tourist who is more educated, experienced, knowledgeable, independent and demanding. This tourist demands new or different products/services, is harder to please than the traditional tourist, is well-informed and knows what he/she wants and where he/she wants to go. This is the modern tourist. The objectives of the study were to identify the typical characteristics of the so-called modern consumer, determine which of these characteristics were prevalent among consumers living in the Nelson Mandela Metropolitan Area and whether these characteristics could be used to cluster respondents into segments. The results of the study will assist organisations, within the tourism industry, in dealing with the changing demands of the modern tourist. The literature study contextualised the modern tourist within the tourism industry and provides an overview of the demographic and behavioural factors, which form the basis of the modern tourist‟s development. The demographic factors discussed were age, education, income, gender and household size. The non demographic factors identified and explained were variety seeking, quest for self-identity, quest for authenticity, knowledgeable, experience sharing and time poor. The empirical information was obtained via self-administered questionnaires. Two hundred useable questionnaires were completed by respondents in the Nelson Mandela Metropolitan Area. Statistica version 10 was used to analyse the data received. The principal component factor analysis yielded six behavioural factors, namely meaningful experiences, time poor, knowledge, authenticity and experience sharing. The data analysis revealed three distinct clusters, namely Postmodernists, Traditionalists and Modernists. Each cluster had unique demographic and behavioural characteristics with the result that modern tourists could be grouped into distinct clusters according to their demographic and behavioural characteristics. This will enable the tourism industry to tailor-make their marketing strategies according to these clusters.he data analysis revealed three distinct clusters, namely Postmodernists, Traditionalists and Modernists. Each cluster had unique demographic and behavioural characteristics with the result that modern tourists could be grouped into distinct clusters according to their demographic and behavioural characteristics. This will enable the tourism industry to tailor-make their marketing strategies according to these clusters.
- Full Text:
- Date Issued: 2012
- Authors: Shrosbree, Laura Tania
- Date: 2012
- Subjects: Sustainable tourism -- South Africa -- Nelson Mandela Bay , Tourism -- South Africa -- Nelson Mandela Bay , Tourism -- Social aspects , Civilization, Modern
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9369 , http://hdl.handle.net/10948/d1012110 , Sustainable tourism -- South Africa -- Nelson Mandela Bay , Tourism -- South Africa -- Nelson Mandela Bay , Tourism -- Social aspects , Civilization, Modern
- Description: Until the nineteenth century, travel was undertaken only by the elite. With the introduction of rail, mass travel was available for the first time, and new faraway destinations became accessible to all. During the 20th century travel became more destination-orientated. And now, in the 21st century, travel is a new economy, resulting in the tourism industry. The focus of the tourism industry has shifted from air travel, weekend getaways and day trips, to a total experience of the destination. A new era in tourism has arrived with a new kind of tourism experience, one that is sustainable, socially responsible and flexible. At the forefront of this industry is a tourist who is more educated, experienced, knowledgeable, independent and demanding. This tourist demands new or different products/services, is harder to please than the traditional tourist, is well-informed and knows what he/she wants and where he/she wants to go. This is the modern tourist. The objectives of the study were to identify the typical characteristics of the so-called modern consumer, determine which of these characteristics were prevalent among consumers living in the Nelson Mandela Metropolitan Area and whether these characteristics could be used to cluster respondents into segments. The results of the study will assist organisations, within the tourism industry, in dealing with the changing demands of the modern tourist. The literature study contextualised the modern tourist within the tourism industry and provides an overview of the demographic and behavioural factors, which form the basis of the modern tourist‟s development. The demographic factors discussed were age, education, income, gender and household size. The non demographic factors identified and explained were variety seeking, quest for self-identity, quest for authenticity, knowledgeable, experience sharing and time poor. The empirical information was obtained via self-administered questionnaires. Two hundred useable questionnaires were completed by respondents in the Nelson Mandela Metropolitan Area. Statistica version 10 was used to analyse the data received. The principal component factor analysis yielded six behavioural factors, namely meaningful experiences, time poor, knowledge, authenticity and experience sharing. Until the nineteenth century, travel was undertaken only by the elite. With the introduction of rail, mass travel was available for the first time, and new faraway destinations became accessible to all. During the 20th century travel became more destination-orientated. And now, in the 21st century, travel is a new economy, resulting in the tourism industry. The focus of the tourism industry has shifted from air travel, weekend getaways and day trips, to a total experience of the destination. A new era in tourism has arrived with a new kind of tourism experience, one that is sustainable, socially responsible and flexible. At the forefront of this industry is a tourist who is more educated, experienced, knowledgeable, independent and demanding. This tourist demands new or different products/services, is harder to please than the traditional tourist, is well-informed and knows what he/she wants and where he/she wants to go. This is the modern tourist. The objectives of the study were to identify the typical characteristics of the so-called modern consumer, determine which of these characteristics were prevalent among consumers living in the Nelson Mandela Metropolitan Area and whether these characteristics could be used to cluster respondents into segments. The results of the study will assist organisations, within the tourism industry, in dealing with the changing demands of the modern tourist. The literature study contextualised the modern tourist within the tourism industry and provides an overview of the demographic and behavioural factors, which form the basis of the modern tourist‟s development. The demographic factors discussed were age, education, income, gender and household size. The non demographic factors identified and explained were variety seeking, quest for self-identity, quest for authenticity, knowledgeable, experience sharing and time poor. The empirical information was obtained via self-administered questionnaires. Two hundred useable questionnaires were completed by respondents in the Nelson Mandela Metropolitan Area. Statistica version 10 was used to analyse the data received. The principal component factor analysis yielded six behavioural factors, namely meaningful experiences, time poor, knowledge, authenticity and experience sharing. The data analysis revealed three distinct clusters, namely Postmodernists, Traditionalists and Modernists. Each cluster had unique demographic and behavioural characteristics with the result that modern tourists could be grouped into distinct clusters according to their demographic and behavioural characteristics. This will enable the tourism industry to tailor-make their marketing strategies according to these clusters.he data analysis revealed three distinct clusters, namely Postmodernists, Traditionalists and Modernists. Each cluster had unique demographic and behavioural characteristics with the result that modern tourists could be grouped into distinct clusters according to their demographic and behavioural characteristics. This will enable the tourism industry to tailor-make their marketing strategies according to these clusters.
- Full Text:
- Date Issued: 2012
Characterization of cell mismatch in photovoltaic modules using electroluminescence and associated electro-optic techniques
- Authors: Crozier, Jacqueline Louise
- Date: 2012
- Subjects: Photovoltaic cells , Solar cells
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10545 , http://hdl.handle.net/10948/d1015059
- Description: Solar cells allow the energy from the sun to be converted into electrical energy; this makes solar energy much more environmentally friendly than fossil fuel energy sources. These solar cells are connected together in a photovoltaic (PV) module to provide the higher current, voltage and power outputs necessary for electrical applications. However, the performance of the PV module is limited by the performance of the individual cells. Cell mismatch occurs when some cells are damaged or shaded and produce lower current output than the other cells in the series connected string. The cell mismatch lowers the module performance and can result in further damage as the weak cells are reverse biased and dissipate heat. Bypass diodes can be connected into the module to increase the module current output and prevent further damage. Since cell mismatch results in a significant decrease in the performance of deployed modules it is important to fully understand and characterise its effect on PV modules. PV modules can be characterised using various techniques, each providing important information about the performance of the module. Most commonly the current-voltage (I-V) characteristic curve of a module is measured in outdoor, fully illuminated conditions. This allows performance parameters such as short circuit current (Isc), open circuit voltage (Voc) and maximum power (Pmax) to be determined. In addition to this the shape of the curve allows device parameters like series and shunt resistances to be determined using parameter extraction algorithms like Particle Swarm Optimisation (PSO). The extracted parameters can be entered into the diode equation to model the I-V curve of the module. The I-V characteristic of the module can also be used to identify poor current producing cells in the module by using the worst-case cell determination method. In this technique a cell is shaded and the greater the drop in current in the whole module the better the current production of the shaded cell. The photoresponse of cells in a module can be determined by the Large-area Light Beam Induced Current (LA-LBIC) technique which involves scanning a module with a laser beam and recording the current generated. Electroluminescence (EL) is emitted by a forward biased PV module and is used to identify defects in cell material. Defects such as cracks and broken fingers can be detected as well as material features such as grain boundaries. These techniques are used to in conjunction to characterise the modules used in this study. The modules investigated in this study each exhibit cell mismatch resulting from different causes. Each module is characterised using a combination of characterisation techniques which allows the effect of cell mismatch be investigated. EL imaging enabled cracks and defects, invisible to the naked eye, to be detected allowing the reduced performance observed in I-V curves to be explained. It was seen that the cracked cells have a significant effect on the current produced by a string, while the effect of delaminated areas is less severe. Hot spots are observed on weak cells indicating they are in reverse bias conditions and will degrade further with time. PSO parameter extraction from I-V curves revealed that the effect of module degradation of device parameters like series and shunt resistances. A module with cracked cells and degradation of the antireflective coating has low shunt resistance indicating current losses due to shunting. Similar shunting is observed in a module with delamination and moisture ingress. The extracted parameters are used to simulate the I-V curves of modules with reasonable fit. The fit could be improved around the “knee” of the I-V curve by improving the methods of parameter extraction. This study has shown the effects of cell mismatch on the performance and I-V curves of the PV modules. The different causes of cell mismatch are discussed and modules with different cell configuration and damage are characterised. The characterisation techniques used on each module provide information about the photoresponse, current generation, material properties and cell defects. A comprehensive understanding of these techniques allows the cell mismatch in the modules to be fully characterized.
- Full Text:
- Date Issued: 2012
- Authors: Crozier, Jacqueline Louise
- Date: 2012
- Subjects: Photovoltaic cells , Solar cells
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10545 , http://hdl.handle.net/10948/d1015059
- Description: Solar cells allow the energy from the sun to be converted into electrical energy; this makes solar energy much more environmentally friendly than fossil fuel energy sources. These solar cells are connected together in a photovoltaic (PV) module to provide the higher current, voltage and power outputs necessary for electrical applications. However, the performance of the PV module is limited by the performance of the individual cells. Cell mismatch occurs when some cells are damaged or shaded and produce lower current output than the other cells in the series connected string. The cell mismatch lowers the module performance and can result in further damage as the weak cells are reverse biased and dissipate heat. Bypass diodes can be connected into the module to increase the module current output and prevent further damage. Since cell mismatch results in a significant decrease in the performance of deployed modules it is important to fully understand and characterise its effect on PV modules. PV modules can be characterised using various techniques, each providing important information about the performance of the module. Most commonly the current-voltage (I-V) characteristic curve of a module is measured in outdoor, fully illuminated conditions. This allows performance parameters such as short circuit current (Isc), open circuit voltage (Voc) and maximum power (Pmax) to be determined. In addition to this the shape of the curve allows device parameters like series and shunt resistances to be determined using parameter extraction algorithms like Particle Swarm Optimisation (PSO). The extracted parameters can be entered into the diode equation to model the I-V curve of the module. The I-V characteristic of the module can also be used to identify poor current producing cells in the module by using the worst-case cell determination method. In this technique a cell is shaded and the greater the drop in current in the whole module the better the current production of the shaded cell. The photoresponse of cells in a module can be determined by the Large-area Light Beam Induced Current (LA-LBIC) technique which involves scanning a module with a laser beam and recording the current generated. Electroluminescence (EL) is emitted by a forward biased PV module and is used to identify defects in cell material. Defects such as cracks and broken fingers can be detected as well as material features such as grain boundaries. These techniques are used to in conjunction to characterise the modules used in this study. The modules investigated in this study each exhibit cell mismatch resulting from different causes. Each module is characterised using a combination of characterisation techniques which allows the effect of cell mismatch be investigated. EL imaging enabled cracks and defects, invisible to the naked eye, to be detected allowing the reduced performance observed in I-V curves to be explained. It was seen that the cracked cells have a significant effect on the current produced by a string, while the effect of delaminated areas is less severe. Hot spots are observed on weak cells indicating they are in reverse bias conditions and will degrade further with time. PSO parameter extraction from I-V curves revealed that the effect of module degradation of device parameters like series and shunt resistances. A module with cracked cells and degradation of the antireflective coating has low shunt resistance indicating current losses due to shunting. Similar shunting is observed in a module with delamination and moisture ingress. The extracted parameters are used to simulate the I-V curves of modules with reasonable fit. The fit could be improved around the “knee” of the I-V curve by improving the methods of parameter extraction. This study has shown the effects of cell mismatch on the performance and I-V curves of the PV modules. The different causes of cell mismatch are discussed and modules with different cell configuration and damage are characterised. The characterisation techniques used on each module provide information about the photoresponse, current generation, material properties and cell defects. A comprehensive understanding of these techniques allows the cell mismatch in the modules to be fully characterized.
- Full Text:
- Date Issued: 2012
Chief executive officer compensation and the effect on company performance in a South African context
- Authors: Bradley, Samuel
- Date: 2012
- Subjects: Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:883 , http://hdl.handle.net/10962/d1001637 , Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Description: The goal of this research was to determine, in a South African context, whether there is any correlation between chief executive officer compensation and the performance of the company. For the purposes of the research , the compensation of chief executive officers was broken down into three components: salary, bonus and "other" remuneration, while company performance was measured on return on equity, return on assets and earnings per share figures. Studies on this topic have been carried out in other countries, most notably in the United States of America and the United Kingdom. It appears that no research of a similar nature has been carried out in South Africa. Data in respect of the forty largest listed companies in South Africa were collected over a period of five years. The econometric models used for the research were based on models identified in the literature study. The data were then analysed for evidence of a correlation between chief executive officer compensation and the performance of the company. The results of this study indicate that there is no linear relationship between chief executive officer compensation and company performance variables. The econometric models did, however, show correlations between certain variables, taking into account the other predictor variables in the model. Evidence of correlations between age and experience and compensation was also found , which may present potential avenues of research to scholars in the future.
- Full Text:
- Date Issued: 2012
- Authors: Bradley, Samuel
- Date: 2012
- Subjects: Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:883 , http://hdl.handle.net/10962/d1001637 , Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Description: The goal of this research was to determine, in a South African context, whether there is any correlation between chief executive officer compensation and the performance of the company. For the purposes of the research , the compensation of chief executive officers was broken down into three components: salary, bonus and "other" remuneration, while company performance was measured on return on equity, return on assets and earnings per share figures. Studies on this topic have been carried out in other countries, most notably in the United States of America and the United Kingdom. It appears that no research of a similar nature has been carried out in South Africa. Data in respect of the forty largest listed companies in South Africa were collected over a period of five years. The econometric models used for the research were based on models identified in the literature study. The data were then analysed for evidence of a correlation between chief executive officer compensation and the performance of the company. The results of this study indicate that there is no linear relationship between chief executive officer compensation and company performance variables. The econometric models did, however, show correlations between certain variables, taking into account the other predictor variables in the model. Evidence of correlations between age and experience and compensation was also found , which may present potential avenues of research to scholars in the future.
- Full Text:
- Date Issued: 2012
Child care workers' management of sexualised behaviour displayed by children in residential child and youth care centres
- Authors: Pietersen, Marisa
- Date: 2012
- Subjects: Child care workers -- South Africa , Child sexual abuse , Sexually abused children -- Care , Child sexual abuse -- Psychological aspects , Children -- Institutional care , Social work with children , Sexually abused children -- Counseling of , Child sexual abuse -- Prevention
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9991 , http://hdl.handle.net/10948/1644 , Child care workers -- South Africa , Child sexual abuse , Sexually abused children -- Care , Child sexual abuse -- Psychological aspects , Children -- Institutional care , Social work with children , Sexually abused children -- Counseling of , Child sexual abuse -- Prevention
- Description: Children have been shown to respond differently to the hurt that they suffer at the hands of others. Some of these responses involve internalised behaviours (i.e., repression of feelings, bodily symptoms, etc.); whilst others hurt manifest as externalised behaviours, such as physical attacks on others. These may include sexualised behaviours. The latter is particularly common amongst (but not restricted to) children who have been sexually abused (The American Psychological Association, 2001). For the purposes of this study a distinction is made between developmentally appropriate sexual behaviour and non normative sexualised behaviour which evoke complaints from and discomfort in those involved in the behaviour. The manifestation of these sexualised behaviours is especially pronounced amongst children in institutional care; and hence, it calls for constructive and effective management by the child care workers who are primarily responsible for their safe care and behaviour modification whilst in the institution. This qualitative study – with an exploratory, descriptive and contextual research design – served to explore how the child care workers’ effective management of such behaviours could be enhanced, so that the emotional wellbeing of both the “offender” and the “perpetrator” of this behaviour can be promoted. A non-probability purposive sampling technique was employed to recruit research participants from three different child and youth care centres in Port Elizabeth. A total number of 10 research participants were involved and data was collected up to the point of data saturation. Thematic content analysis was utilised for the analysis of the data and the necessary strategies were employed to enhance the trustworthiness of the data and to meet all the ethical requirements of the study. The main findings alert to the key requirements of Child and Youth Care Workers; it confirms the occurrence of sexualised behaviours; the urgent need for a consistent approach to the management of such behaviours; and for enhanced team work between the helping professionals in the team. The value of the study is embedded in the contributions it can make to practical interventions for children in institutional care, and to the sparse body of knowledge in this area.
- Full Text:
- Date Issued: 2012
- Authors: Pietersen, Marisa
- Date: 2012
- Subjects: Child care workers -- South Africa , Child sexual abuse , Sexually abused children -- Care , Child sexual abuse -- Psychological aspects , Children -- Institutional care , Social work with children , Sexually abused children -- Counseling of , Child sexual abuse -- Prevention
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9991 , http://hdl.handle.net/10948/1644 , Child care workers -- South Africa , Child sexual abuse , Sexually abused children -- Care , Child sexual abuse -- Psychological aspects , Children -- Institutional care , Social work with children , Sexually abused children -- Counseling of , Child sexual abuse -- Prevention
- Description: Children have been shown to respond differently to the hurt that they suffer at the hands of others. Some of these responses involve internalised behaviours (i.e., repression of feelings, bodily symptoms, etc.); whilst others hurt manifest as externalised behaviours, such as physical attacks on others. These may include sexualised behaviours. The latter is particularly common amongst (but not restricted to) children who have been sexually abused (The American Psychological Association, 2001). For the purposes of this study a distinction is made between developmentally appropriate sexual behaviour and non normative sexualised behaviour which evoke complaints from and discomfort in those involved in the behaviour. The manifestation of these sexualised behaviours is especially pronounced amongst children in institutional care; and hence, it calls for constructive and effective management by the child care workers who are primarily responsible for their safe care and behaviour modification whilst in the institution. This qualitative study – with an exploratory, descriptive and contextual research design – served to explore how the child care workers’ effective management of such behaviours could be enhanced, so that the emotional wellbeing of both the “offender” and the “perpetrator” of this behaviour can be promoted. A non-probability purposive sampling technique was employed to recruit research participants from three different child and youth care centres in Port Elizabeth. A total number of 10 research participants were involved and data was collected up to the point of data saturation. Thematic content analysis was utilised for the analysis of the data and the necessary strategies were employed to enhance the trustworthiness of the data and to meet all the ethical requirements of the study. The main findings alert to the key requirements of Child and Youth Care Workers; it confirms the occurrence of sexualised behaviours; the urgent need for a consistent approach to the management of such behaviours; and for enhanced team work between the helping professionals in the team. The value of the study is embedded in the contributions it can make to practical interventions for children in institutional care, and to the sparse body of knowledge in this area.
- Full Text:
- Date Issued: 2012
Child participation in the evaluation of the school nutrition programme: a case study of eight grade 4 learners in Mqanduli village in the Eastern Cape
- Authors: Maxengana, Nomfundiso
- Date: 2012
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: http://hdl.handle.net/10353/1388 , vital:26551
- Description: This study focuses on child participation in the evaluation of the school nutrition programme. It investigates the SNP exclusively from Grade 4 learners’ perspectives. The main significance of it is that many evaluations of the SNP focus on other stakeholders’ perspectives. The study intends to explore effective methodologies and tools for conducting research with children. Furthermore, this study seeks to contribute to the existing literature on the importance of children’s participation in matters concerning their lives. The study seeks to explore three research questions. Firstly, it seeks to explore how Grade 4 learners describe the purpose of the SNP. Secondly, how do the Grade 4 learners describe their day to day experiences of the SNP. Lastly, how do the Grade 4 learners describe the impact of the SNP. Through this research experience, the study hopes to illuminate recommendations to better align policy and programme design with stated intentions. The study is qualitative, and based on a case study design. The central analysis focuses on eight case studies, each representing the experience of one Grade 4 learner, within the context of two selected schools in the rural areas of Mqanduli. This study underscores the literature on school nutrition programming. Despite severe implementation shortfalls, learners still consider the nutrition programme to be an important aspect of their school day. The experience and analysis of learners in regard to the SNP was relatively consistent. Learners consistently experience the SNP as contributing to temporary hunger alleviation thus enhancing learning capacity. Furthermore, they regarded the SNP to have had positive impact towards enhancing their school attendance and punctuality, and mediation between their home and the school life. The study supports the literature that suggests that, while school nutrition programming represents one of the most promising policy tools for serving the rural poor, unless it is carefully designed to reflect the known requirements of school feeding, the results can be limited. This study further suggests that if a programme is poorly implemented, it runs the risk of undermining the intended policy aims rather than contributing towards their attainment. The study further acknowledges child participation in policy and programme decisions concerning them. The study concludes by making a number of policy and implementation suggestions that may better align policy and practice to the specific context of the rural poor in Mqanduli. While these case studies are too few to suggest generalisability of results, it is hoped that these recommendations will be studied for wider application.
- Full Text:
- Date Issued: 2012
- Authors: Maxengana, Nomfundiso
- Date: 2012
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: http://hdl.handle.net/10353/1388 , vital:26551
- Description: This study focuses on child participation in the evaluation of the school nutrition programme. It investigates the SNP exclusively from Grade 4 learners’ perspectives. The main significance of it is that many evaluations of the SNP focus on other stakeholders’ perspectives. The study intends to explore effective methodologies and tools for conducting research with children. Furthermore, this study seeks to contribute to the existing literature on the importance of children’s participation in matters concerning their lives. The study seeks to explore three research questions. Firstly, it seeks to explore how Grade 4 learners describe the purpose of the SNP. Secondly, how do the Grade 4 learners describe their day to day experiences of the SNP. Lastly, how do the Grade 4 learners describe the impact of the SNP. Through this research experience, the study hopes to illuminate recommendations to better align policy and programme design with stated intentions. The study is qualitative, and based on a case study design. The central analysis focuses on eight case studies, each representing the experience of one Grade 4 learner, within the context of two selected schools in the rural areas of Mqanduli. This study underscores the literature on school nutrition programming. Despite severe implementation shortfalls, learners still consider the nutrition programme to be an important aspect of their school day. The experience and analysis of learners in regard to the SNP was relatively consistent. Learners consistently experience the SNP as contributing to temporary hunger alleviation thus enhancing learning capacity. Furthermore, they regarded the SNP to have had positive impact towards enhancing their school attendance and punctuality, and mediation between their home and the school life. The study supports the literature that suggests that, while school nutrition programming represents one of the most promising policy tools for serving the rural poor, unless it is carefully designed to reflect the known requirements of school feeding, the results can be limited. This study further suggests that if a programme is poorly implemented, it runs the risk of undermining the intended policy aims rather than contributing towards their attainment. The study further acknowledges child participation in policy and programme decisions concerning them. The study concludes by making a number of policy and implementation suggestions that may better align policy and practice to the specific context of the rural poor in Mqanduli. While these case studies are too few to suggest generalisability of results, it is hoped that these recommendations will be studied for wider application.
- Full Text:
- Date Issued: 2012
Children's attitudes towards physical education in selected urban primary schools in Mutare - Zimbabwe
- Authors: Gomwe, Howard
- Date: 2012
- Subjects: Physical education and training -- Zimbabwe , Physical education for children -- Zimbabwe , School children -- Zimbabwe , Exercise for children -- Zimbabwe , Curriculum planning -- Zimbabwe , Primary schools -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc (HMS)
- Identifier: vital:11540 , http://hdl.handle.net/10353/527 , Physical education and training -- Zimbabwe , Physical education for children -- Zimbabwe , School children -- Zimbabwe , Exercise for children -- Zimbabwe , Curriculum planning -- Zimbabwe , Primary schools -- Zimbabwe
- Description: The aim of the study was to evaluate school children’s attitudes towards Physical Education in selected Mutare city schools. In order for the children to benefit from the Physical Education program, the study hypothesized that children must develop the right attitudes towards Physical Education. This observation has also been emphasized in other studies that children, who possess the right attitude towards Physical Education, develop positive attitudes towards physical activities. This suggestion has also been reported by Portman, (2003) and McKenzie (2003) that one of the benefits of Physical Education is sustained participation in physical activities outside the school. This study involved 400 children from Mutare Junior, Chancellor, Zamba, Dangamvura, Sakubva, Chikanga, Mutanda and Murahwa Primary Schools in Mutare city. The children’s age ranged between 12 - 14 years old. The primary data were collected from questionnaires, interviews and focus group discussions, while secondary data were based on related literature review. The results indicated that the teacher, curriculum content and delivery, the learning environment, siblings, type of school, location of residences, proximity of facilities and support from parents were some of the factors associated with children’s attitudes towards Physical Education and Physical Activity at school and home respectively. In many ways, these factors affected children’s sustainable participation in physical activities after school.
- Full Text:
- Date Issued: 2012
- Authors: Gomwe, Howard
- Date: 2012
- Subjects: Physical education and training -- Zimbabwe , Physical education for children -- Zimbabwe , School children -- Zimbabwe , Exercise for children -- Zimbabwe , Curriculum planning -- Zimbabwe , Primary schools -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc (HMS)
- Identifier: vital:11540 , http://hdl.handle.net/10353/527 , Physical education and training -- Zimbabwe , Physical education for children -- Zimbabwe , School children -- Zimbabwe , Exercise for children -- Zimbabwe , Curriculum planning -- Zimbabwe , Primary schools -- Zimbabwe
- Description: The aim of the study was to evaluate school children’s attitudes towards Physical Education in selected Mutare city schools. In order for the children to benefit from the Physical Education program, the study hypothesized that children must develop the right attitudes towards Physical Education. This observation has also been emphasized in other studies that children, who possess the right attitude towards Physical Education, develop positive attitudes towards physical activities. This suggestion has also been reported by Portman, (2003) and McKenzie (2003) that one of the benefits of Physical Education is sustained participation in physical activities outside the school. This study involved 400 children from Mutare Junior, Chancellor, Zamba, Dangamvura, Sakubva, Chikanga, Mutanda and Murahwa Primary Schools in Mutare city. The children’s age ranged between 12 - 14 years old. The primary data were collected from questionnaires, interviews and focus group discussions, while secondary data were based on related literature review. The results indicated that the teacher, curriculum content and delivery, the learning environment, siblings, type of school, location of residences, proximity of facilities and support from parents were some of the factors associated with children’s attitudes towards Physical Education and Physical Activity at school and home respectively. In many ways, these factors affected children’s sustainable participation in physical activities after school.
- Full Text:
- Date Issued: 2012
COIN : a customisable, incentive driven video on demand framework for low-cost IPTV services
- Authors: Musvibe, Ray
- Date: 2012 , 2012-03-02
- Subjects: Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4654 , http://hdl.handle.net/10962/d1006650 , Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Description: There has been a significant rise in the provision of television and video services over IP (IPTV) in recent years. Increasing network capacity and falling bandwidth costs have made it both technically and economically feasible for service providers to deliver IPTV services. Several telecommunications (telco) operators worldwide are rolling out IPTV solutions and view IPTV as a major service differentiator and alternative revenue source. The main challenge that IPTV providers currently face, however, is the increasingly congested television service provider market, which also includes Internet Television. IPTV solutions therefore need strong service differentiators to succeed. IPTV solutions can doubtlessly sell much faster if they are more affordable or low-cost. Advertising has already been used in many service sectors to help lower service costs, including traditional broadcast television. This thesis therefore explores the role that advertising can play in helping to lower the cost of IPTV services and to incentivise IPTV billing. Another approach that IPTV providers can use to help sell their product is by addressing the growing need for control by today's multimedia users. This thesis will therefore explore the varied approaches that can be used to achieve viewer focused IPTV implementations. To further lower the cost of IPTV services, telcos can also turn to low-cost, open source platforms for service delivery. The adoption of low-cost infrastructure by telcos can lead to reduced Capital Expenditure (CAPEX), which in turn can lead to lower service fees, and ultimately to higher subscriptions and revenue. Therefore, in this thesis, the author proposes a CustOmisable, INcentive (COIN) driven Video on Demand (VoD) framework to be developed and deployed using the Mobicents Communication Platform, an open source service creation and execution platform. The COIN framework aims to provide a viewer focused, economically competitive service that combines the potential cost savings of using free and open source software (FOSS), with an innovative, incentive-driven billing approach. This project will also aim to evaluate whether the Mobicents Platform is a suitable service creation and execution platform for the proposed framework. Additionally, the proposed implementation aims to be interoperable with other IPTV implementations, hence shall follow current IPTV standardisation architectures and trends. The service testbed and its implementation are described in detail and only free and open source software is used; this is to enable its easy duplication and extension for future research. , TeX output 2012.03.02:1241 , Adobe Acrobat 9.2 Paper Capture Plug-in
- Full Text:
- Date Issued: 2012
- Authors: Musvibe, Ray
- Date: 2012 , 2012-03-02
- Subjects: Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4654 , http://hdl.handle.net/10962/d1006650 , Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Description: There has been a significant rise in the provision of television and video services over IP (IPTV) in recent years. Increasing network capacity and falling bandwidth costs have made it both technically and economically feasible for service providers to deliver IPTV services. Several telecommunications (telco) operators worldwide are rolling out IPTV solutions and view IPTV as a major service differentiator and alternative revenue source. The main challenge that IPTV providers currently face, however, is the increasingly congested television service provider market, which also includes Internet Television. IPTV solutions therefore need strong service differentiators to succeed. IPTV solutions can doubtlessly sell much faster if they are more affordable or low-cost. Advertising has already been used in many service sectors to help lower service costs, including traditional broadcast television. This thesis therefore explores the role that advertising can play in helping to lower the cost of IPTV services and to incentivise IPTV billing. Another approach that IPTV providers can use to help sell their product is by addressing the growing need for control by today's multimedia users. This thesis will therefore explore the varied approaches that can be used to achieve viewer focused IPTV implementations. To further lower the cost of IPTV services, telcos can also turn to low-cost, open source platforms for service delivery. The adoption of low-cost infrastructure by telcos can lead to reduced Capital Expenditure (CAPEX), which in turn can lead to lower service fees, and ultimately to higher subscriptions and revenue. Therefore, in this thesis, the author proposes a CustOmisable, INcentive (COIN) driven Video on Demand (VoD) framework to be developed and deployed using the Mobicents Communication Platform, an open source service creation and execution platform. The COIN framework aims to provide a viewer focused, economically competitive service that combines the potential cost savings of using free and open source software (FOSS), with an innovative, incentive-driven billing approach. This project will also aim to evaluate whether the Mobicents Platform is a suitable service creation and execution platform for the proposed framework. Additionally, the proposed implementation aims to be interoperable with other IPTV implementations, hence shall follow current IPTV standardisation architectures and trends. The service testbed and its implementation are described in detail and only free and open source software is used; this is to enable its easy duplication and extension for future research. , TeX output 2012.03.02:1241 , Adobe Acrobat 9.2 Paper Capture Plug-in
- Full Text:
- Date Issued: 2012
Communication at the health care coalface: lessons from selected clinics in Port Elizabeth
- Authors: Mbengo, Nomatshawe
- Date: 2012
- Subjects: Communication in medicine -- Research -- South Africa Community health services -- South Africa -- Eastern Cape Social medicine -- Research -- South Africa Medical care -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3591 , http://hdl.handle.net/10962/d1002166
- Description: This thesis analyses the state of health care in South Africa with particular reference to a clinic and the Provincial Hospital in Port Elizabeth, Eastern Cape. The complexities of health care provision in a diverse sociolinguistic environment where certain languages are emphasized over others, forms the cornerstone of the research. The research focuses on health care in a complex multi-cultural environment. The goal of the research is to present a coherent and robust translation framework for the development of suitable materials to enhance communication across language and cultural barriers in the health care sector. A model (based on research completed in the USA) is presented as a possible alternative in the final chapter of the thesis.
- Full Text:
- Date Issued: 2012
- Authors: Mbengo, Nomatshawe
- Date: 2012
- Subjects: Communication in medicine -- Research -- South Africa Community health services -- South Africa -- Eastern Cape Social medicine -- Research -- South Africa Medical care -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3591 , http://hdl.handle.net/10962/d1002166
- Description: This thesis analyses the state of health care in South Africa with particular reference to a clinic and the Provincial Hospital in Port Elizabeth, Eastern Cape. The complexities of health care provision in a diverse sociolinguistic environment where certain languages are emphasized over others, forms the cornerstone of the research. The research focuses on health care in a complex multi-cultural environment. The goal of the research is to present a coherent and robust translation framework for the development of suitable materials to enhance communication across language and cultural barriers in the health care sector. A model (based on research completed in the USA) is presented as a possible alternative in the final chapter of the thesis.
- Full Text:
- Date Issued: 2012
Community development projects and food security: the case of Zanyokwe Irrigation Project Eastern Cape Province, South Africa
- Authors: Ndlovu, Sikhanyiso
- Date: 2012
- Subjects: Community development -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape , Farms Small -- South Africa -- Eastern Cape , Family farms -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Soc Sc (Dev)
- Identifier: vital:11438 , http://hdl.handle.net/10353/d1007226 , Community development -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape , Farms Small -- South Africa -- Eastern Cape , Family farms -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape
- Description: Although food insecurity is said to have decreased in South Africa in the past years particularly at the national level, however, at household level a substantial proportion of households remains at risk of food insecurity and are experiencing hunger particularly in the Eastern Cape Province were poverty is rife. Food insecurity in the Eastern Cape Province is attributed to the fact that agriculture, the mainstay of the rural economy is no longer given the value that it should carry, does not help the situation. Despite much research on food (in) security in South Africa, the link between poverty and household food security is not at all clear. This study seeks to fill this gap specifically by looking at the linkages in the main between food security and poverty especially in the community level. Amidst the various programmes and initiatives that are in place in South Africa, there is continual prevalence of food insecurity facing the majority of South African households. The major aim of this study was therefore to examine the impact of one of these programmes, the Zanyokwe irrigation scheme in enhancing food security not only for the farmers but also for the surrounding communities. This study adopted a qualitative approach to research. The study unearthed that even though Zanyokwe irrigation scheme has played an indispensable role in enhancing food security for the smallholder farmers and the community at large challenges such as market challenges, road infrastructural issues, land tenure issues, lack of proper coordination amongst the farmers as well as farmer empowerment are a major limitation to the growth of the irrigation scheme and the farmers. Thus, the study recommended that farmer support services, training, agriculture subsidies, improved infrastructure as well as addressing market related challenges will go a long way in reducing the plight of the Zanyokwe farmers as well as enhancing food security
- Full Text:
- Date Issued: 2012
- Authors: Ndlovu, Sikhanyiso
- Date: 2012
- Subjects: Community development -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape , Farms Small -- South Africa -- Eastern Cape , Family farms -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Soc Sc (Dev)
- Identifier: vital:11438 , http://hdl.handle.net/10353/d1007226 , Community development -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape , Farms Small -- South Africa -- Eastern Cape , Family farms -- South Africa -- Eastern Cape , Food security -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape
- Description: Although food insecurity is said to have decreased in South Africa in the past years particularly at the national level, however, at household level a substantial proportion of households remains at risk of food insecurity and are experiencing hunger particularly in the Eastern Cape Province were poverty is rife. Food insecurity in the Eastern Cape Province is attributed to the fact that agriculture, the mainstay of the rural economy is no longer given the value that it should carry, does not help the situation. Despite much research on food (in) security in South Africa, the link between poverty and household food security is not at all clear. This study seeks to fill this gap specifically by looking at the linkages in the main between food security and poverty especially in the community level. Amidst the various programmes and initiatives that are in place in South Africa, there is continual prevalence of food insecurity facing the majority of South African households. The major aim of this study was therefore to examine the impact of one of these programmes, the Zanyokwe irrigation scheme in enhancing food security not only for the farmers but also for the surrounding communities. This study adopted a qualitative approach to research. The study unearthed that even though Zanyokwe irrigation scheme has played an indispensable role in enhancing food security for the smallholder farmers and the community at large challenges such as market challenges, road infrastructural issues, land tenure issues, lack of proper coordination amongst the farmers as well as farmer empowerment are a major limitation to the growth of the irrigation scheme and the farmers. Thus, the study recommended that farmer support services, training, agriculture subsidies, improved infrastructure as well as addressing market related challenges will go a long way in reducing the plight of the Zanyokwe farmers as well as enhancing food security
- Full Text:
- Date Issued: 2012
Community development through the ward committee structures in the Northern areas of the Nelson Mandela Bay Municipality
- Authors: Ah Shene, Walter T
- Date: 2012
- Subjects: Community development -- South Africa -- Nelson Mandela Bay Municipality , City council members -- South Africa -- Nelson Mandela Bay Municipality , Municipal government -- South Africa -- Nelson Mandela Bay Municipality , Citizens' advisory committees -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:8274 , http://hdl.handle.net/10948/d1016058
- Description: The purpose of this study was to investigate community development through the ward committee structures in the Northern Areas of the Nelson Mandela Bay Municipality. Community development through the ward committees is the key principle in the democratisation process, as well as the promotion of good governance. Community development is an opportunity for both local government and the community to strengthen the democracy that is being enjoyed; and simultaneously to promote accountability. In terms of the Local Government: Municipal Systems, 2000 (Act 32 of 2000), the role of local communities in the particular interests of their municipality must take place, among other things, by the ward councillor – as well as all other suitable procedures, mechanisms and processes set up by the municipality. Ward committees have the power to advise the ward councillor; and as municipal structures, they must ensure that there is always community participation in the sphere of local government. Community participation gives communities the opportunities to express their views, as well as giving them a sense of ownership. The objectives of the study were: - To determine the roles and responsibilities of the ward councillors in terms of the new developmental mandate (the need to encourage the involvement of communities and organisations in local government matters). - To investigate the relations between ward councillors and their ward committees, and between the offices of ward councillors and the general public. - To examine the extent to which ward councillors in the northern areas of the Nelson Mandela Bay Municipality understand the policy and administrative procedures and processes in the municipality, when addressing issues that affect the community. In order to achieve these objectives, it was necessary to review literature on community participation. An empirical search was conducted in wards 10 and 11 in the Northern Areas of Nelson Mandela Bay Municipality. Recommendations were provided which could assist the municipality to effectively make use of the ward committees and the ward councillors. If implemented, these recommendations could also enhance community development through the ward committee structures. Thus, the relationship between the ward committees and the ward councillor should be harmonious; and subsequently, they should also strengthen trust between them. Then the flow of communication will improve.
- Full Text:
- Date Issued: 2012
- Authors: Ah Shene, Walter T
- Date: 2012
- Subjects: Community development -- South Africa -- Nelson Mandela Bay Municipality , City council members -- South Africa -- Nelson Mandela Bay Municipality , Municipal government -- South Africa -- Nelson Mandela Bay Municipality , Citizens' advisory committees -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:8274 , http://hdl.handle.net/10948/d1016058
- Description: The purpose of this study was to investigate community development through the ward committee structures in the Northern Areas of the Nelson Mandela Bay Municipality. Community development through the ward committees is the key principle in the democratisation process, as well as the promotion of good governance. Community development is an opportunity for both local government and the community to strengthen the democracy that is being enjoyed; and simultaneously to promote accountability. In terms of the Local Government: Municipal Systems, 2000 (Act 32 of 2000), the role of local communities in the particular interests of their municipality must take place, among other things, by the ward councillor – as well as all other suitable procedures, mechanisms and processes set up by the municipality. Ward committees have the power to advise the ward councillor; and as municipal structures, they must ensure that there is always community participation in the sphere of local government. Community participation gives communities the opportunities to express their views, as well as giving them a sense of ownership. The objectives of the study were: - To determine the roles and responsibilities of the ward councillors in terms of the new developmental mandate (the need to encourage the involvement of communities and organisations in local government matters). - To investigate the relations between ward councillors and their ward committees, and between the offices of ward councillors and the general public. - To examine the extent to which ward councillors in the northern areas of the Nelson Mandela Bay Municipality understand the policy and administrative procedures and processes in the municipality, when addressing issues that affect the community. In order to achieve these objectives, it was necessary to review literature on community participation. An empirical search was conducted in wards 10 and 11 in the Northern Areas of Nelson Mandela Bay Municipality. Recommendations were provided which could assist the municipality to effectively make use of the ward committees and the ward councillors. If implemented, these recommendations could also enhance community development through the ward committee structures. Thus, the relationship between the ward committees and the ward councillor should be harmonious; and subsequently, they should also strengthen trust between them. Then the flow of communication will improve.
- Full Text:
- Date Issued: 2012
Community participation in rendering local government services in the Capricon District Municipality
- Selematsela, Lebogang Eunice
- Authors: Selematsela, Lebogang Eunice
- Date: 2012
- Subjects: Public administration -- Citizen participation , Community development , Local government
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9185 , http://hdl.handle.net/10948/d1020191
- Description: This study sought to assess community participation in the rendering of services in the Capricorn District Municipality. The concept of community participation is central in underpinning successful development programmes. However, this is usually undermined in communities where cultural factors and political factors influence decision making. The study was premised on the review of literature and documents as the Researcher believed that more research on the subject matter has been done extensively. Personal interviews were done with officials within the Public Participation units in both the Capricorn District Municipality and its Local Municipalities so as to gain insight as to how implementation of public participation processes is done in the CDM‟s area of jurisdiction. Literature was reviewed in terms of the legislative requirements with regard to the implementation of public participation methods in the Local Government sector. Various documents were reviewed so as to understand what other scholars have written about the subject matter. Personal interviews were done with officials within the Public Participation units in both the Capricorn District Municipality and Its Local Municipalities so as to gain insight as to how implementation of public participation processes is done. An assessment of how Capricorn District Municipality implements public participation methods was done in line with what the legislation provides for as well as what the scholars said about public participation. Gaps in the implementation of such were also identified, wherein recommendations were made on how best Capricorn District Municipality can improve on the public participation processes so as to comply with the legislative requirements.
- Full Text:
- Date Issued: 2012
Community participation in rendering local government services in the Capricon District Municipality
- Authors: Selematsela, Lebogang Eunice
- Date: 2012
- Subjects: Public administration -- Citizen participation , Community development , Local government
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9185 , http://hdl.handle.net/10948/d1020191
- Description: This study sought to assess community participation in the rendering of services in the Capricorn District Municipality. The concept of community participation is central in underpinning successful development programmes. However, this is usually undermined in communities where cultural factors and political factors influence decision making. The study was premised on the review of literature and documents as the Researcher believed that more research on the subject matter has been done extensively. Personal interviews were done with officials within the Public Participation units in both the Capricorn District Municipality and its Local Municipalities so as to gain insight as to how implementation of public participation processes is done in the CDM‟s area of jurisdiction. Literature was reviewed in terms of the legislative requirements with regard to the implementation of public participation methods in the Local Government sector. Various documents were reviewed so as to understand what other scholars have written about the subject matter. Personal interviews were done with officials within the Public Participation units in both the Capricorn District Municipality and Its Local Municipalities so as to gain insight as to how implementation of public participation processes is done. An assessment of how Capricorn District Municipality implements public participation methods was done in line with what the legislation provides for as well as what the scholars said about public participation. Gaps in the implementation of such were also identified, wherein recommendations were made on how best Capricorn District Municipality can improve on the public participation processes so as to comply with the legislative requirements.
- Full Text:
- Date Issued: 2012
Community participation in the decision-making process in Mnquma Local Municipality
- Authors: Mbane, Masibulele
- Date: 2012
- Subjects: Local government -- South Africa -- Eastern Cape -- Citizen participation , Community development -- South Africa -- Citizen participation , Citicen's advisory committees -- South Africa -- Eastern Cape , Political participation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8286 , http://hdl.handle.net/10948/d1018501
- Description: The study investigates community participation in the decision-making processes in Mnquma Local Municipality. The issue of community participation in decision making is receiving attention in South Africa, from both government and civil society sectors. Governments in many parts of the world have begun to take a fresh look at the need for public participation in decision-making processes. The main problem to be addressed in this study is the extent to which the community can be involved in decision making processes in Mnquma Local Municipality. To address the research problem and to achieve the aims of this study, an in depth review of the literature on decision making was done. The empirical search was done by distributing self-administered questionnaires to the participants in Mnquma Local Municipality. The research findings revealed that in Mnquma Local Municipality community participation in decision-making is not effective. Consequently, the delivery of services in this municipality is poor. Another factor that inhibits community participation in the decision making processes in the municipality is that most of the municipal documents are written in English a language in which the majority of the members of the community are not competent in because they are Xhosa speaking people. Recommendations for improved satisfaction in service delivery, communication, consultation, regular meetings, and language were made with regard to community participation in decision making. If these recommendations are implemented, they will assist Mnquma Local Municipality in the area of decision making.
- Full Text:
- Date Issued: 2012
- Authors: Mbane, Masibulele
- Date: 2012
- Subjects: Local government -- South Africa -- Eastern Cape -- Citizen participation , Community development -- South Africa -- Citizen participation , Citicen's advisory committees -- South Africa -- Eastern Cape , Political participation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8286 , http://hdl.handle.net/10948/d1018501
- Description: The study investigates community participation in the decision-making processes in Mnquma Local Municipality. The issue of community participation in decision making is receiving attention in South Africa, from both government and civil society sectors. Governments in many parts of the world have begun to take a fresh look at the need for public participation in decision-making processes. The main problem to be addressed in this study is the extent to which the community can be involved in decision making processes in Mnquma Local Municipality. To address the research problem and to achieve the aims of this study, an in depth review of the literature on decision making was done. The empirical search was done by distributing self-administered questionnaires to the participants in Mnquma Local Municipality. The research findings revealed that in Mnquma Local Municipality community participation in decision-making is not effective. Consequently, the delivery of services in this municipality is poor. Another factor that inhibits community participation in the decision making processes in the municipality is that most of the municipal documents are written in English a language in which the majority of the members of the community are not competent in because they are Xhosa speaking people. Recommendations for improved satisfaction in service delivery, communication, consultation, regular meetings, and language were made with regard to community participation in decision making. If these recommendations are implemented, they will assist Mnquma Local Municipality in the area of decision making.
- Full Text:
- Date Issued: 2012
Comparative in-vitro activities of trimethoprimsulfamethoxazole and the new fluoroquinolones against confirmed extended spectrum beta-lactamase producing Stenotrophomonas maltophilia in Nkonkobe Municipality, Eastern Cape environment
- Adeyemi, Oluwatosin Oluwakemi
- Authors: Adeyemi, Oluwatosin Oluwakemi
- Date: 2012
- Subjects: Antibiotics , Microbial sensitivity tests , Drug resistance in microorganisms , Pathogenic microorganisms , Gram-negative bacterial infections
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11275 , http://hdl.handle.net/10353/d1007576 , Antibiotics , Microbial sensitivity tests , Drug resistance in microorganisms , Pathogenic microorganisms , Gram-negative bacterial infections
- Description: Stenotrophomonas maltophilia is increasingly emerging as an opportunistic pathogen of global concern. Due to its inherent resistance to several classes of antibiotics including carbapenems and its ability to acquire mobile resistance elements, treatment of infections caused by S. maltophilia is a constant challenge for clinicians. Trimethoprim-sulphamethoxazole (TMP-SMX) is the generally accepted antibiotic of choice for the treatment of infections caused by this organism, but resistance to the drug is increasingly being reported; hence, the need for alternative therapeutic options. In this study, the antimicrobial susceptibility profile of 110 commensal S. maltophilia isolates obtained from Nkonkobe municipality, Eastern Cape Province, Republic of South Africa was investigated. Twenty-one antibiotics including TMP-SMX and the newer fluoroquinolones; levofloxacin, gatifloxacin and moxifloxacin were included in the antibiotic panel. About 63.4 percent of the isolates were susceptible to TMP-SMX with a resistance rate of 28.2 percent. The fluoroquinolones were more effective with susceptibilities ranging from 76 percent to 94.7 percent. Resistance to the fluoroquinolones ranged from 1.3 percent to 2.7 percent. Levofloxacin was the most effective fluoroquinolone tested. Phenotypic dectection of extended spectrum β-lactamases (ESBLs) showed double disc synergy test (DDST) positivity in 59.5 percent of the isolates. Cefepime was the most sensitive indicator cephalosporin in the DDST with 77.3 percent of suspected ESBL-producing isolates showing cefepime-clavulanic acid synergy. Isolates exhibited nine different ESBL phenotypes, however, PCR amplification of the bla genes revealed four isolates that possessed genes belonging to the CTX-M group (CTX-M-1 and CTX-M-8 groups). ESBL genes are usually carried on mobile elements such as plasmids and transposons which may also bear genes that mediate resistance to aminoglycosides, tetracyclines, TMP-SMX and fluoroquinolones. ESBL positive isolates appeared more susceptible to the fluoroquinolones compared to TMP-SMX but there was no significant relationship between ESBL production and susceptibility to these drugs (p > 0.05). The newer fluoroquinolones are a possible alternative treatment option for S. maltophilia infections in this environment but further studies and clinical investigations are needed to determine the in vivo efficacy of these drugs.
- Full Text:
- Date Issued: 2012
- Authors: Adeyemi, Oluwatosin Oluwakemi
- Date: 2012
- Subjects: Antibiotics , Microbial sensitivity tests , Drug resistance in microorganisms , Pathogenic microorganisms , Gram-negative bacterial infections
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11275 , http://hdl.handle.net/10353/d1007576 , Antibiotics , Microbial sensitivity tests , Drug resistance in microorganisms , Pathogenic microorganisms , Gram-negative bacterial infections
- Description: Stenotrophomonas maltophilia is increasingly emerging as an opportunistic pathogen of global concern. Due to its inherent resistance to several classes of antibiotics including carbapenems and its ability to acquire mobile resistance elements, treatment of infections caused by S. maltophilia is a constant challenge for clinicians. Trimethoprim-sulphamethoxazole (TMP-SMX) is the generally accepted antibiotic of choice for the treatment of infections caused by this organism, but resistance to the drug is increasingly being reported; hence, the need for alternative therapeutic options. In this study, the antimicrobial susceptibility profile of 110 commensal S. maltophilia isolates obtained from Nkonkobe municipality, Eastern Cape Province, Republic of South Africa was investigated. Twenty-one antibiotics including TMP-SMX and the newer fluoroquinolones; levofloxacin, gatifloxacin and moxifloxacin were included in the antibiotic panel. About 63.4 percent of the isolates were susceptible to TMP-SMX with a resistance rate of 28.2 percent. The fluoroquinolones were more effective with susceptibilities ranging from 76 percent to 94.7 percent. Resistance to the fluoroquinolones ranged from 1.3 percent to 2.7 percent. Levofloxacin was the most effective fluoroquinolone tested. Phenotypic dectection of extended spectrum β-lactamases (ESBLs) showed double disc synergy test (DDST) positivity in 59.5 percent of the isolates. Cefepime was the most sensitive indicator cephalosporin in the DDST with 77.3 percent of suspected ESBL-producing isolates showing cefepime-clavulanic acid synergy. Isolates exhibited nine different ESBL phenotypes, however, PCR amplification of the bla genes revealed four isolates that possessed genes belonging to the CTX-M group (CTX-M-1 and CTX-M-8 groups). ESBL genes are usually carried on mobile elements such as plasmids and transposons which may also bear genes that mediate resistance to aminoglycosides, tetracyclines, TMP-SMX and fluoroquinolones. ESBL positive isolates appeared more susceptible to the fluoroquinolones compared to TMP-SMX but there was no significant relationship between ESBL production and susceptibility to these drugs (p > 0.05). The newer fluoroquinolones are a possible alternative treatment option for S. maltophilia infections in this environment but further studies and clinical investigations are needed to determine the in vivo efficacy of these drugs.
- Full Text:
- Date Issued: 2012
Comparing child justice legislation in South Africa and South Sudan
- Authors: Teny, Jamual Peter Malual
- Date: 2012
- Subjects: Children -- Legal status, laws, etc , Criminal law -- South Africa , Criminal law -- Sudan
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10187 , http://hdl.handle.net/10948/d1020941
- Description: The legal framework and legislation governing the rights of the children have become of great concern in modern societies, particularly, in the area of criminal justice and human rights. The Convention on the Rights of the Child and African Charter on the Rights and Welfare of the Child are basic international and regional conventions regulating the rights of the children and include how to deal with children in conflict with the law. States parties to these conventions are required to take appropriate measures, which includes enactment of legislation to give effect to these rights. Legislative instruments must address the following issues: The principle of the best interest of the child; the age of criminal responsibility; restorative justice; diversion; and the trials of children in conflict with the law. The above-mentioned instrument require and emphasise the use of an alternative approach in respect of the children who are in conflict with law. In this research a comparative approach is used to compare the South African and South Sudanese child justice legislative instruments. The legislative instruments pertaining to child justice in both countries are set out and compared. It is concluded that the South African legislative instruments are more aligned to the Convention on the Rights of the Child and African Charter on the Rights and Welfare of the Child. Recommendations and proposals are made to enact to adopt in South Sudan new legislative measures and provisions aim to afford more protection to children in conflict with the law and to strike a better balance between rights of a child and victim of crimes.
- Full Text:
- Date Issued: 2012
- Authors: Teny, Jamual Peter Malual
- Date: 2012
- Subjects: Children -- Legal status, laws, etc , Criminal law -- South Africa , Criminal law -- Sudan
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10187 , http://hdl.handle.net/10948/d1020941
- Description: The legal framework and legislation governing the rights of the children have become of great concern in modern societies, particularly, in the area of criminal justice and human rights. The Convention on the Rights of the Child and African Charter on the Rights and Welfare of the Child are basic international and regional conventions regulating the rights of the children and include how to deal with children in conflict with the law. States parties to these conventions are required to take appropriate measures, which includes enactment of legislation to give effect to these rights. Legislative instruments must address the following issues: The principle of the best interest of the child; the age of criminal responsibility; restorative justice; diversion; and the trials of children in conflict with the law. The above-mentioned instrument require and emphasise the use of an alternative approach in respect of the children who are in conflict with law. In this research a comparative approach is used to compare the South African and South Sudanese child justice legislative instruments. The legislative instruments pertaining to child justice in both countries are set out and compared. It is concluded that the South African legislative instruments are more aligned to the Convention on the Rights of the Child and African Charter on the Rights and Welfare of the Child. Recommendations and proposals are made to enact to adopt in South Sudan new legislative measures and provisions aim to afford more protection to children in conflict with the law and to strike a better balance between rights of a child and victim of crimes.
- Full Text:
- Date Issued: 2012
Comparison of the prevalence of HIV infection in circumcised and uncircumcised men from Salima District in Malawi
- Authors: Kankuwe, Hector Master
- Date: 2012
- Subjects: HIV infections -- Malawi , Initiation rites -- Malawi
- Language: English
- Type: Thesis , Masters , MSc (Biostatistics and Epidemiology)
- Identifier: vital:11778 , http://hdl.handle.net/10353/462 , HIV infections -- Malawi , Initiation rites -- Malawi
- Description: The overall objective of the study was to investigate the relationship between male circumcision status and HIV infection in men from Salima district in Malawi. A cross-sectional survey-based study of men aged 15 years or more was conducted at three sites in Salima district, each of which targeted 90 participants, half of whom were circumcised and the other half uncircumcised. These participants had already decided on their own to visit HIV Testing and Counseling centres at these sites to know their HIV serostatus. Consenting men were drawn into the study using quota sampling, interviewed through a structured questionnaire in local language and tested for HIV during January and March 2011. Measures of association were performed using analysis of contingency tables and Pearson’s chi-square tests or Fisher’s exact tests for comparison of proportions in STATA version 11.0 and PASW Statistics 18.0 software. Unadjusted odds ratios were used to approximate the direction and strength of association. Further, a multivariable logistic regression model was fit to determine which other variables were significantly associated with HIV infection. The study was approved by University of Fort Hare Interim Research Ethics Committee and National Health Sciences Research Committee in Malawi. The overall prevalence of HIV infection was 11.5 percent. However, it was less than half in circumcised males (7.4 percent) compared with uncircumcised counterparts (15.6 vi percent). While Fisher’s exact test revealed a borderline statistically significant association between male circumcision status and HIV infection (p 0.055), Pearson’s chi-square test showed a stronger significant association between the two variables ( p 0.036). The strength of the association was manifested by the odds of HIV infection being roughly 0.43 times lower for circumcised males than their uncircumcised counterparts with a 95 percent confidence interval of (0.20 0.96). Although the association was maintained after controlling for some variables, it lost statistical significance when adjusted for other variables. A multivariable logistic regression revealed that three other variables had significant associations with HIV infection and these were: falling in the age group of 25 years or more (OR 4.69; p 0.020), having had sex with an HIV positive partner (OR 12.15; p 0.000) and having contracted a sexually transmitted infection (OR 3.25; p 0.032). Male circumcision status is significantly related to HIV infection. Although the study involved a small sample size and undertaken in one district in Malawi, the finding is consistent with existing clinic-based findings in literature that indicate a lower risk of HIV infection in circumcised males than in uncircumcised males. Consequently, male circumcision could be considered if it can prove to be a public health intervention in the Malawi context aimed at reducing the risk of uncircumcised males becoming infected by HIV.
- Full Text:
- Date Issued: 2012
- Authors: Kankuwe, Hector Master
- Date: 2012
- Subjects: HIV infections -- Malawi , Initiation rites -- Malawi
- Language: English
- Type: Thesis , Masters , MSc (Biostatistics and Epidemiology)
- Identifier: vital:11778 , http://hdl.handle.net/10353/462 , HIV infections -- Malawi , Initiation rites -- Malawi
- Description: The overall objective of the study was to investigate the relationship between male circumcision status and HIV infection in men from Salima district in Malawi. A cross-sectional survey-based study of men aged 15 years or more was conducted at three sites in Salima district, each of which targeted 90 participants, half of whom were circumcised and the other half uncircumcised. These participants had already decided on their own to visit HIV Testing and Counseling centres at these sites to know their HIV serostatus. Consenting men were drawn into the study using quota sampling, interviewed through a structured questionnaire in local language and tested for HIV during January and March 2011. Measures of association were performed using analysis of contingency tables and Pearson’s chi-square tests or Fisher’s exact tests for comparison of proportions in STATA version 11.0 and PASW Statistics 18.0 software. Unadjusted odds ratios were used to approximate the direction and strength of association. Further, a multivariable logistic regression model was fit to determine which other variables were significantly associated with HIV infection. The study was approved by University of Fort Hare Interim Research Ethics Committee and National Health Sciences Research Committee in Malawi. The overall prevalence of HIV infection was 11.5 percent. However, it was less than half in circumcised males (7.4 percent) compared with uncircumcised counterparts (15.6 vi percent). While Fisher’s exact test revealed a borderline statistically significant association between male circumcision status and HIV infection (p 0.055), Pearson’s chi-square test showed a stronger significant association between the two variables ( p 0.036). The strength of the association was manifested by the odds of HIV infection being roughly 0.43 times lower for circumcised males than their uncircumcised counterparts with a 95 percent confidence interval of (0.20 0.96). Although the association was maintained after controlling for some variables, it lost statistical significance when adjusted for other variables. A multivariable logistic regression revealed that three other variables had significant associations with HIV infection and these were: falling in the age group of 25 years or more (OR 4.69; p 0.020), having had sex with an HIV positive partner (OR 12.15; p 0.000) and having contracted a sexually transmitted infection (OR 3.25; p 0.032). Male circumcision status is significantly related to HIV infection. Although the study involved a small sample size and undertaken in one district in Malawi, the finding is consistent with existing clinic-based findings in literature that indicate a lower risk of HIV infection in circumcised males than in uncircumcised males. Consequently, male circumcision could be considered if it can prove to be a public health intervention in the Malawi context aimed at reducing the risk of uncircumcised males becoming infected by HIV.
- Full Text:
- Date Issued: 2012
Competence development in marine protected area professionals: a case study of the South African Marine Protected Area Management Training Course (SAMPATC)
- Authors: Lewis, Sebastian Giulio
- Date: 2012
- Subjects: Core competencies Employees -- Training of Marine ecosystem management
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1456 , http://hdl.handle.net/10962/d1003337
- Description: This study reviews a training programme on Marine Protected Area (MPA) management. It notes that although MPAs are well promulgated under legislation, reports have found that there are still key challenges facing the management of these areas. The research examines how the course was developed following the Lemm and Attwood (2003) report and designed to develop competences for effective MPA management. The aim is to identify how a MPA management training course produced competences apposite to the workplace settings of the participants. An interpretive case study method was used, in two phases. The first phase explored salient issues in MPA management in South Africa through analysis of the two key ‘state of MPA management’ reports and interviews with MPA professionals. The second was an analysis of the South African Marine Protected Area Management Training Course. This involved interviews with course designers, a review of the course materials, interviews with past course participants, and an analysis of course evaluations. Evidence emerged that supported the following findings: Challenges and problems facing MPA management still exist. Competence in key areas of MPA management was addressed in an effective work-integrated approach. Social learning was a key process in the development of these competences. The competences articulate well with the workplace of participants. Gaps exist between some of the management issues and the competences developed by the course, and some aspects of the course design are ineffective. From these findings it is concluded that: The course took up the majority of issues in MPA management through the development of key competences. The course design facilitated the development of these competences. The competences developed through the course are relevant to the workplace of MPA professionals. The research found that the course adequately addresses issues in MPA management through the development of competences. Some recommendations for improvements are made.
- Full Text:
- Date Issued: 2012
- Authors: Lewis, Sebastian Giulio
- Date: 2012
- Subjects: Core competencies Employees -- Training of Marine ecosystem management
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1456 , http://hdl.handle.net/10962/d1003337
- Description: This study reviews a training programme on Marine Protected Area (MPA) management. It notes that although MPAs are well promulgated under legislation, reports have found that there are still key challenges facing the management of these areas. The research examines how the course was developed following the Lemm and Attwood (2003) report and designed to develop competences for effective MPA management. The aim is to identify how a MPA management training course produced competences apposite to the workplace settings of the participants. An interpretive case study method was used, in two phases. The first phase explored salient issues in MPA management in South Africa through analysis of the two key ‘state of MPA management’ reports and interviews with MPA professionals. The second was an analysis of the South African Marine Protected Area Management Training Course. This involved interviews with course designers, a review of the course materials, interviews with past course participants, and an analysis of course evaluations. Evidence emerged that supported the following findings: Challenges and problems facing MPA management still exist. Competence in key areas of MPA management was addressed in an effective work-integrated approach. Social learning was a key process in the development of these competences. The competences articulate well with the workplace of participants. Gaps exist between some of the management issues and the competences developed by the course, and some aspects of the course design are ineffective. From these findings it is concluded that: The course took up the majority of issues in MPA management through the development of key competences. The course design facilitated the development of these competences. The competences developed through the course are relevant to the workplace of MPA professionals. The research found that the course adequately addresses issues in MPA management through the development of competences. Some recommendations for improvements are made.
- Full Text:
- Date Issued: 2012
Compositions portfolio
- Authors: Van der Merwe, Steven
- Date: 2012
- Subjects: Composition (Music) , Music -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8517 , http://hdl.handle.net/10948/d1012116 , Composition (Music) , Music -- South Africa
- Description: DVD contains the musical compositions
- Full Text:
- Date Issued: 2012
- Authors: Van der Merwe, Steven
- Date: 2012
- Subjects: Composition (Music) , Music -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8517 , http://hdl.handle.net/10948/d1012116 , Composition (Music) , Music -- South Africa
- Description: DVD contains the musical compositions
- Full Text:
- Date Issued: 2012