Characterisation and optimisation of waterjet impact forces and energy parameters during hydroentanglement
- Authors: Moyo, Doice
- Date: 2012
- Subjects: Textile chemistry , Nonwoven fabrics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10453 , http://hdl.handle.net/10948/d1020134
- Description: Hydroentanglement is an important technique of bonding fibres to produce nonwovens using high velocity waterjets as the primary bonding tool. The work reported in this thesis addresses the gap in scientific knowledge and understanding, both theoretical and experimental, related to the impact forces and energy of the waterjets used in the hydroentanglement process. The current study focused on the impact forces and energy involved in, and the optimisation of, the hydroentanglement process. The results of the experimentally measured waterjet impact forces have been used to characterise the waterjets as well as to verify empirically the theoretical models currently available for explaining the mechanics of the hydroentanglement process. Since the process of supplying pressurised waterjets consumes a great deal of energy, the study of energy consumption and efficiency of the system has been critical. A method was proposed and used to determine the coefficients of velocity and water discharge of an industrial machine set-up, helping explain the mechanism of energy transfer during hydroentanglement and to concurrently optimise the process. Furthermore, a response surface experimental design was used to optimise the hydroentanglement of viscose and Polylactic acid (PLA) fibres into nonwovens. The selected Box-Behnken design, with four factors, namely the waterjet force, machine processing speed, input weight and fibre type, was employed to investigate the multivariate process factors and their interactive effects on physical and mechanical properties of nonwovens. Two sets of experiments, the later for validation, were performed to study the energy transfer efficiency. The results of the relative energy transfer to bond the fibrous web showed that it was possible to produce nonwovens using lower input energy without compromising the quality of the products. The optimum waterjet pressure and machine speed used to produce the Abstract nonwoven with the highest tensile strength for the least amount of energy supplied were identified.
- Full Text:
- Date Issued: 2012
- Authors: Moyo, Doice
- Date: 2012
- Subjects: Textile chemistry , Nonwoven fabrics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10453 , http://hdl.handle.net/10948/d1020134
- Description: Hydroentanglement is an important technique of bonding fibres to produce nonwovens using high velocity waterjets as the primary bonding tool. The work reported in this thesis addresses the gap in scientific knowledge and understanding, both theoretical and experimental, related to the impact forces and energy of the waterjets used in the hydroentanglement process. The current study focused on the impact forces and energy involved in, and the optimisation of, the hydroentanglement process. The results of the experimentally measured waterjet impact forces have been used to characterise the waterjets as well as to verify empirically the theoretical models currently available for explaining the mechanics of the hydroentanglement process. Since the process of supplying pressurised waterjets consumes a great deal of energy, the study of energy consumption and efficiency of the system has been critical. A method was proposed and used to determine the coefficients of velocity and water discharge of an industrial machine set-up, helping explain the mechanism of energy transfer during hydroentanglement and to concurrently optimise the process. Furthermore, a response surface experimental design was used to optimise the hydroentanglement of viscose and Polylactic acid (PLA) fibres into nonwovens. The selected Box-Behnken design, with four factors, namely the waterjet force, machine processing speed, input weight and fibre type, was employed to investigate the multivariate process factors and their interactive effects on physical and mechanical properties of nonwovens. Two sets of experiments, the later for validation, were performed to study the energy transfer efficiency. The results of the relative energy transfer to bond the fibrous web showed that it was possible to produce nonwovens using lower input energy without compromising the quality of the products. The optimum waterjet pressure and machine speed used to produce the Abstract nonwoven with the highest tensile strength for the least amount of energy supplied were identified.
- Full Text:
- Date Issued: 2012
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 2,(3)-tetra-(4-oxo-benzamide) phthalocyaninato cobalt (II)—single walled carbon nanotube conjugate platforms and their use in electrocatalysis of amitrole
- Mugadza, Tawanda, Arslanoğlu, Yasin, Nyokong, Tebello
- Authors: Mugadza, Tawanda , Arslanoğlu, Yasin , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244382 , vital:51252 , xlink:href="https://doi.org/10.1016/j.electacta.2012.02.041"
- Description: In this paper we report on the use of carboxylic acid functionalized single walled carbon nanotubes (SWCNT) in the synthesis of 2,(3)-tetra-(4-oxo-benzamide)phthalocyaninato cobalt (II)–single walled carbon nanotube conjugates (CoTOBPc–SWCNT), their characterization and application in the electrocatalytic oxidation of amitrole. Cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy were used for the detection of amitrole on the modified glassy carbon electrode. The catalytic rate constant was 1.6 × 103 M−1 s−1 and the apparent electron rate transfer constant was 1.5 × 10−5 cm s−1. The linear dynamic range was 1.0 × 10−6–3.0 × 10−5 M, with a sensitivity of ∼1.13 A mol−1 L cm−2.
- Full Text:
- Date Issued: 2012
- Authors: Mugadza, Tawanda , Arslanoğlu, Yasin , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244382 , vital:51252 , xlink:href="https://doi.org/10.1016/j.electacta.2012.02.041"
- Description: In this paper we report on the use of carboxylic acid functionalized single walled carbon nanotubes (SWCNT) in the synthesis of 2,(3)-tetra-(4-oxo-benzamide)phthalocyaninato cobalt (II)–single walled carbon nanotube conjugates (CoTOBPc–SWCNT), their characterization and application in the electrocatalytic oxidation of amitrole. Cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy were used for the detection of amitrole on the modified glassy carbon electrode. The catalytic rate constant was 1.6 × 103 M−1 s−1 and the apparent electron rate transfer constant was 1.5 × 10−5 cm s−1. The linear dynamic range was 1.0 × 10−6–3.0 × 10−5 M, with a sensitivity of ∼1.13 A mol−1 L cm−2.
- 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
Chieftainship succession and gender equality in Lesotho: negotiating the right to equality in a jungle of pluralism
- Authors: Juma, Laurence
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127067 , vital:35951 , https://heinonline.org/HOL/Page?handle=hein.journals/tjwl22amp;div=11amp;g_sent=1amp;casa_token=amp;collection=journals
- Description: Women constitute about 51% of Lesotho's population 1 and enjoy a higher literacy rate than men. 2 They are also the backbone of a society that for several hundreds of years provided male labor to South Africa's farms and gold mines.3 However, Basotho women are generally excluded from mainstream politics and are discriminated against in almost all spheres of socioeconomic life. This exclusion, marginalization, and discrimination have been largely blamed on patriarchy and entrenched traditional norms, both of which are sustained by a plural legal system that has seemingly remained insular to developments around the globe. 4
- Full Text:
- Date Issued: 2012
- Authors: Juma, Laurence
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127067 , vital:35951 , https://heinonline.org/HOL/Page?handle=hein.journals/tjwl22amp;div=11amp;g_sent=1amp;casa_token=amp;collection=journals
- Description: Women constitute about 51% of Lesotho's population 1 and enjoy a higher literacy rate than men. 2 They are also the backbone of a society that for several hundreds of years provided male labor to South Africa's farms and gold mines.3 However, Basotho women are generally excluded from mainstream politics and are discriminated against in almost all spheres of socioeconomic life. This exclusion, marginalization, and discrimination have been largely blamed on patriarchy and entrenched traditional norms, both of which are sustained by a plural legal system that has seemingly remained insular to developments around the globe. 4
- 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
China in South Africa: a long affair: Africa rising
- Authors: Wasserman, Herman
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454594 , vital:75358 , https://hdl.handle.net/10520/EJC134108
- Description: Official relations between Africa and China in contemporary times can be seen to have started in 1955 with the first Asian-African Conference in Bandung, Indonesia, aimed at promoting economic and cultural co-operation. The development of China-Africa relations gained impetus when it became clear in the 1990s that to maintain the "roaring pace" of its economic growth as a result of economic reforms, China would need to look for new sources of energy and natural resources - which it found in Africa.
- Full Text:
- Date Issued: 2012
- Authors: Wasserman, Herman
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454594 , vital:75358 , https://hdl.handle.net/10520/EJC134108
- Description: Official relations between Africa and China in contemporary times can be seen to have started in 1955 with the first Asian-African Conference in Bandung, Indonesia, aimed at promoting economic and cultural co-operation. The development of China-Africa relations gained impetus when it became clear in the 1990s that to maintain the "roaring pace" of its economic growth as a result of economic reforms, China would need to look for new sources of energy and natural resources - which it found in Africa.
- Full Text:
- Date Issued: 2012
China-Africa relations: research approaches
- Authors: Simbao, Ruth K
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147503 , vital:38644 , https://doi.org/10.1162/afar.2012.45.2.1
- Description: About to board a plane in Johannesburg, I handed my temporary boarding pass to the flight attendant who exclaimed,“Simbao, you have a fong kong boarding pass!” Fong kong is a slang term used in South Africa meaning fake, cheap, or low quality and is often associated with Chinese imports. In this case, the term was used to refer to a temporary pass issued earlier on my journey that needed to be replaced with a new boarding pass in Johannesburg.
- Full Text:
- Date Issued: 2012
- Authors: Simbao, Ruth K
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147503 , vital:38644 , https://doi.org/10.1162/afar.2012.45.2.1
- Description: About to board a plane in Johannesburg, I handed my temporary boarding pass to the flight attendant who exclaimed,“Simbao, you have a fong kong boarding pass!” Fong kong is a slang term used in South Africa meaning fake, cheap, or low quality and is often associated with Chinese imports. In this case, the term was used to refer to a temporary pass issued earlier on my journey that needed to be replaced with a new boarding pass in Johannesburg.
- Full Text:
- Date Issued: 2012
Chris McGregor, Harry Beckett and Lucky Ranku standing outside a bus
- Date: 2012
- Subjects: McGregor, Chris -- 1936-1990 , Beckett, Harry , Ranku, Lucky , Jazz , Jazz musicians
- Type: Image
- Identifier: vital:13853 , http://hdl.handle.net/10962/d1001687 , McGregor, Chris -- 1936-1990 , Beckett, Harry , Ranku, Lucky , Jazz , Jazz musicians
- Description: Colour photo. From left to right: Lucky Ranku, Harry Beckett and Chris McGregor standing outside a bus.
- Full Text: false
- Date Issued: 2012
- Date: 2012
- Subjects: McGregor, Chris -- 1936-1990 , Beckett, Harry , Ranku, Lucky , Jazz , Jazz musicians
- Type: Image
- Identifier: vital:13853 , http://hdl.handle.net/10962/d1001687 , McGregor, Chris -- 1936-1990 , Beckett, Harry , Ranku, Lucky , Jazz , Jazz musicians
- Description: Colour photo. From left to right: Lucky Ranku, Harry Beckett and Chris McGregor standing outside a bus.
- Full Text: false
- Date Issued: 2012
Civil society and state-centred struggles
- Authors: Helliker, Kirk D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71231 , vital:29821 , https://doi.org/10.1080/02589001.2012.641723
- Description: This article is about civil society and state-centred struggles in contemporary Zimbabwe. I first identify and outline three current understandings of civil society. Two understandings (one Liberal, one Radical) are state-centric and exist firmly within the logic of state discourses and state politics. A third understanding, also Radical, is society-centric and speaks about politics existing at a distance from the state and possibly beyond the boundaries of civil society. This civil society-state discussion frames the second section of the article, which looks specifically at Zimbabwe. It details civil society as contested terrain (from the late 1990s onwards) within the context of a scholarly debate about agrarian transformation and political change. This debate, which reproduces (in theoretical garb) the key political society (or party) fault-lines within Zimbabwean society, has taken place primarily within the restricted confines of state-centred discourses.
- Full Text:
- Date Issued: 2012
- Authors: Helliker, Kirk D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71231 , vital:29821 , https://doi.org/10.1080/02589001.2012.641723
- Description: This article is about civil society and state-centred struggles in contemporary Zimbabwe. I first identify and outline three current understandings of civil society. Two understandings (one Liberal, one Radical) are state-centric and exist firmly within the logic of state discourses and state politics. A third understanding, also Radical, is society-centric and speaks about politics existing at a distance from the state and possibly beyond the boundaries of civil society. This civil society-state discussion frames the second section of the article, which looks specifically at Zimbabwe. It details civil society as contested terrain (from the late 1990s onwards) within the context of a scholarly debate about agrarian transformation and political change. This debate, which reproduces (in theoretical garb) the key political society (or party) fault-lines within Zimbabwean society, has taken place primarily within the restricted confines of state-centred discourses.
- Full Text:
- Date Issued: 2012
Classifying network attack scenarios using an ontology
- Van Heerden, Renier, Irwin, Barry V W, Burke, I D
- Authors: Van Heerden, Renier , Irwin, Barry V W , Burke, I D
- Date: 2012
- Language: English
- Type: Conference paper
- Identifier: vital:6606 , http://hdl.handle.net/10962/d1009326
- Description: This paper presents a methodology using network attack ontology to classify computer-based attacks. Computer network attacks differ in motivation, execution and end result. Because attacks are diverse, no standard classification exists. If an attack could be classified, it could be mitigated accordingly. A taxonomy of computer network attacks forms the basis of the ontology. Most published taxonomies present an attack from either the attacker's or defender's point of view. This taxonomy presents both views. The main taxonomy classes are: Actor, Actor Location, Aggressor, Attack Goal, Attack Mechanism, Attack Scenario, Automation Level, Effects, Motivation, Phase, Scope and Target. The "Actor" class is the entity executing the attack. The "Actor Location" class is the Actor‟s country of origin. The "Aggressor" class is the group instigating an attack. The "Attack Goal" class specifies the attacker‟s goal. The "Attack Mechanism" class defines the attack methodology. The "Automation Level" class indicates the level of human interaction. The "Effects" class describes the consequences of an attack. The "Motivation" class specifies incentives for an attack. The "Scope" class describes the size and utility of the target. The "Target" class is the physical device or entity targeted by an attack. The "Vulnerability" class describes a target vulnerability used by the attacker. The "Phase" class represents an attack model that subdivides an attack into different phases. The ontology was developed using an "Attack Scenario" class, which draws from other classes and can be used to characterize and classify computer network attacks. An "Attack Scenario" consists of phases, has a scope and is attributed to an actor and aggressor which have a goal. The "Attack Scenario" thus represents different classes of attacks. High profile computer network attacks such as Stuxnet and the Estonia attacks can now be been classified through the “Attack Scenario” class.
- Full Text:
- Date Issued: 2012
- Authors: Van Heerden, Renier , Irwin, Barry V W , Burke, I D
- Date: 2012
- Language: English
- Type: Conference paper
- Identifier: vital:6606 , http://hdl.handle.net/10962/d1009326
- Description: This paper presents a methodology using network attack ontology to classify computer-based attacks. Computer network attacks differ in motivation, execution and end result. Because attacks are diverse, no standard classification exists. If an attack could be classified, it could be mitigated accordingly. A taxonomy of computer network attacks forms the basis of the ontology. Most published taxonomies present an attack from either the attacker's or defender's point of view. This taxonomy presents both views. The main taxonomy classes are: Actor, Actor Location, Aggressor, Attack Goal, Attack Mechanism, Attack Scenario, Automation Level, Effects, Motivation, Phase, Scope and Target. The "Actor" class is the entity executing the attack. The "Actor Location" class is the Actor‟s country of origin. The "Aggressor" class is the group instigating an attack. The "Attack Goal" class specifies the attacker‟s goal. The "Attack Mechanism" class defines the attack methodology. The "Automation Level" class indicates the level of human interaction. The "Effects" class describes the consequences of an attack. The "Motivation" class specifies incentives for an attack. The "Scope" class describes the size and utility of the target. The "Target" class is the physical device or entity targeted by an attack. The "Vulnerability" class describes a target vulnerability used by the attacker. The "Phase" class represents an attack model that subdivides an attack into different phases. The ontology was developed using an "Attack Scenario" class, which draws from other classes and can be used to characterize and classify computer network attacks. An "Attack Scenario" consists of phases, has a scope and is attributed to an actor and aggressor which have a goal. The "Attack Scenario" thus represents different classes of attacks. High profile computer network attacks such as Stuxnet and the Estonia attacks can now be been classified through the “Attack Scenario” class.
- 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
Commensal bacteria belonging to the Staphylococcus Acinetobacter and Stenotrophomonas genera as reservoirs of antibiotic resistance determinants in the environment of Nkonkobe Municipality, Eastern Cape Province , South Africa
- Authors: Adegoke, Anthony Ayodeji
- Date: 2012
- Subjects: Acinetobacter infections , Drug resistance in microorganisms , Staphylococcal infections , Bacterial diseases
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/6539 , vital:30551
- Description: A study to assess the potentials of some commensal bacteria that belong to Staphylococcus, Acinetobacter and Stenotrophomonas genera as reservoirs of antibiotic resistance determinants in the environment of Nkonkobe Municipality of the Eastern Cape Province, South Africa, was carried out using standard microbiological and molecular techniques. A total of 120 Staphylococcus isolates which consisted of Staphylococcus haemolyticus (30%), Staphylococcus aureus (23.3%) from pig; Staphylococcus capitis (15%) from goat; Staphylococcus heamolyticus (5%) and Staphylococcus xylosus (15%) from cattle and other Staphylococci (11%) from dead chicken and pigs were isolated. About 23.3% of these isolates were coagulase positive and 76.7% were coagulase negative. This difference in prevalence along coagulase production divide was statistically significant (p < 0.05). Eighty-six Acinetobacter species (Acinetobacter baumannii/calcoaceticus and Acinetobacter haemolyticus) were also isolated from Alice and Fort Beaufort towns samples, while 125 Stenotrophomonas maltophilia isolates were from grass root rhizosphere (96%) and soil butternut root rhizosphere (4%). Between 75-100% of the Staphylococccus species were resistant to Penicillin G, tetracycline, sulphamethaxole and nalidixic acid; about 38 % were methicillin resistant, consisting of 12.6% methicillin resistant Staphylococcus aureus (MRSA) from pig and a total of 12% vancomycin resistant were observed. Also, 12% of the isolates were erythromycin resistant while 40.2 % were resistant to the third generation cephalosporin, ceftazidime. The antibiotic resistance genes vanA, VanB, eryA, eryB, eryC were not detected in all the phenotypically resistant Staphylococccus species, but mec A gene and mph genes were detected. In the Acinetobacter species, a wide range of 30-100% resistance to penicillin G, ceftriazone, nitrofurantoin, erythromycin, and augmentin was observed. Polymerase chain reaction (PCR) revealed the presence of Tet(B) and Tet(39) genes in these species, while Tet (A), Tet(M) and Tet(H) were absent. Also, 9.3% of the Acinetobacter species showed phenotypic production of extended spectrum beta lactamases (ESBLs) while 3.5% were positive for the presence of blaCTX-M-1 genes. The Stenotrophomonas maltophilia isolates showed varying resistance to meropenem (8.9%), cefuroxime (95.6 %), ampicillin-sulbactam (53.9%), ceftazidime (10.7%), cefepime (29.3 %), minocycline (2.2%), kanamycin (56.9%), ofloxacin (2.9%), levofloxacin (1.3%), moxifloxacin (2.8%), ciprofloxacin (24.3%), gatifloxacin (1.3%), polymyxin B (2.9 %), cotrimoxazole (26.1%), trimethoprim (98.6%), aztreonam(58%) and Polymyxin B (2.9 %). The isolates exhibited significant susceptibility to the fluoroquinolones (74.3-94.7 %), polymycin (97.1%) and meropenem (88.1%). Only sul3 genes were the only sulphonamide resistance gene detected among the trimethoprim-sulphamethoxazole resistant isolates. The observed multiple antibiotic resistance indeces (MARI) of >2 for Staphylococcus species, Acinetobacter species and Stenotrophomonas maltophilia suggest that they have arisen from high-risk sources where antibiotics are in constant arbitrary use resulting in high selective pressure. The presence of tetracycline resistance genes in Acinetobacter species justifies the observed phenotypic resistance to oxytetracycline and intermediate resistance to minocycline. High phenotypic resistance and the presence of some resistance genes in Staphylococcus species is a possible threat to public health and suggests animals to be important reservoirs of antibiotic resistance determinants in the environment. Indiscriminate use of antibiotics induces this kind of antibiotic resistance and should be discouraged. Personal hygiene is encouraged as it reduces the load of Acinetobacter species contacted from the environment that may be difficult to control. Commensal Stenotrophomonas maltophilia are as important as their clinical counterparts due to their roles in opportunistic infection, antibiotic resistance and their associated genes, especially sul gene. Personal hygiene is hereby advocated especially when in contact with soil, plants and plants’ rhizospheric soil.
- Full Text:
- Date Issued: 2012
- Authors: Adegoke, Anthony Ayodeji
- Date: 2012
- Subjects: Acinetobacter infections , Drug resistance in microorganisms , Staphylococcal infections , Bacterial diseases
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/6539 , vital:30551
- Description: A study to assess the potentials of some commensal bacteria that belong to Staphylococcus, Acinetobacter and Stenotrophomonas genera as reservoirs of antibiotic resistance determinants in the environment of Nkonkobe Municipality of the Eastern Cape Province, South Africa, was carried out using standard microbiological and molecular techniques. A total of 120 Staphylococcus isolates which consisted of Staphylococcus haemolyticus (30%), Staphylococcus aureus (23.3%) from pig; Staphylococcus capitis (15%) from goat; Staphylococcus heamolyticus (5%) and Staphylococcus xylosus (15%) from cattle and other Staphylococci (11%) from dead chicken and pigs were isolated. About 23.3% of these isolates were coagulase positive and 76.7% were coagulase negative. This difference in prevalence along coagulase production divide was statistically significant (p < 0.05). Eighty-six Acinetobacter species (Acinetobacter baumannii/calcoaceticus and Acinetobacter haemolyticus) were also isolated from Alice and Fort Beaufort towns samples, while 125 Stenotrophomonas maltophilia isolates were from grass root rhizosphere (96%) and soil butternut root rhizosphere (4%). Between 75-100% of the Staphylococccus species were resistant to Penicillin G, tetracycline, sulphamethaxole and nalidixic acid; about 38 % were methicillin resistant, consisting of 12.6% methicillin resistant Staphylococcus aureus (MRSA) from pig and a total of 12% vancomycin resistant were observed. Also, 12% of the isolates were erythromycin resistant while 40.2 % were resistant to the third generation cephalosporin, ceftazidime. The antibiotic resistance genes vanA, VanB, eryA, eryB, eryC were not detected in all the phenotypically resistant Staphylococccus species, but mec A gene and mph genes were detected. In the Acinetobacter species, a wide range of 30-100% resistance to penicillin G, ceftriazone, nitrofurantoin, erythromycin, and augmentin was observed. Polymerase chain reaction (PCR) revealed the presence of Tet(B) and Tet(39) genes in these species, while Tet (A), Tet(M) and Tet(H) were absent. Also, 9.3% of the Acinetobacter species showed phenotypic production of extended spectrum beta lactamases (ESBLs) while 3.5% were positive for the presence of blaCTX-M-1 genes. The Stenotrophomonas maltophilia isolates showed varying resistance to meropenem (8.9%), cefuroxime (95.6 %), ampicillin-sulbactam (53.9%), ceftazidime (10.7%), cefepime (29.3 %), minocycline (2.2%), kanamycin (56.9%), ofloxacin (2.9%), levofloxacin (1.3%), moxifloxacin (2.8%), ciprofloxacin (24.3%), gatifloxacin (1.3%), polymyxin B (2.9 %), cotrimoxazole (26.1%), trimethoprim (98.6%), aztreonam(58%) and Polymyxin B (2.9 %). The isolates exhibited significant susceptibility to the fluoroquinolones (74.3-94.7 %), polymycin (97.1%) and meropenem (88.1%). Only sul3 genes were the only sulphonamide resistance gene detected among the trimethoprim-sulphamethoxazole resistant isolates. The observed multiple antibiotic resistance indeces (MARI) of >2 for Staphylococcus species, Acinetobacter species and Stenotrophomonas maltophilia suggest that they have arisen from high-risk sources where antibiotics are in constant arbitrary use resulting in high selective pressure. The presence of tetracycline resistance genes in Acinetobacter species justifies the observed phenotypic resistance to oxytetracycline and intermediate resistance to minocycline. High phenotypic resistance and the presence of some resistance genes in Staphylococcus species is a possible threat to public health and suggests animals to be important reservoirs of antibiotic resistance determinants in the environment. Indiscriminate use of antibiotics induces this kind of antibiotic resistance and should be discouraged. Personal hygiene is encouraged as it reduces the load of Acinetobacter species contacted from the environment that may be difficult to control. Commensal Stenotrophomonas maltophilia are as important as their clinical counterparts due to their roles in opportunistic infection, antibiotic resistance and their associated genes, especially sul gene. Personal hygiene is hereby advocated especially when in contact with soil, plants and plants’ rhizospheric soil.
- 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