Community perceptions on teenage pregnancy: the case of Kamvelihle Township in Nelson Mandela Bay Municipality
- Authors: Mtakati, Faith
- Date: 2024-04
- Subjects: Teenage pregnancy -- South Africa -- Port Elizabeth , Teenage mothers -- South Africa -- Port Elizabeth , Teenagers -- Sexual behavior
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63368 , vital:73263
- Description: Increasingly, teenagers in South Africa get pregnant while studying and this disrupt their schooling program. The above problem in many instances ended up affecting their performance at school and they drop-out of the school. This study investigates the community perceptions on teenage pregnancy in Kamvelihle Township. The study objectives are as follows: to investigate the community perception on teenage pregnancy in Kamvelihle Township, to contribute within the South African Sociological field with specific reference to Kamvelihle Township in the Eastern Cape and to come up with the recommendations with the view to addressing some of the problem in Kamvelihle Township. The research methodology employed in this study is qualitative in approach and it included amongst others, individual interviews using an interview guide containing relevant questions posed to participants. Research ethics protocol has been adhered to from the initial up to the last stages of the study. To supplement the above, relevant secondary sources were consulted ranging from scholarly journal articles as well as scholarly books including other available reading material. In this study, sex education has been used as a conceptual framework to understand the problem of teenage pregnancy in Kamvelihle Township. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Mtakati, Faith
- Date: 2024-04
- Subjects: Teenage pregnancy -- South Africa -- Port Elizabeth , Teenage mothers -- South Africa -- Port Elizabeth , Teenagers -- Sexual behavior
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63368 , vital:73263
- Description: Increasingly, teenagers in South Africa get pregnant while studying and this disrupt their schooling program. The above problem in many instances ended up affecting their performance at school and they drop-out of the school. This study investigates the community perceptions on teenage pregnancy in Kamvelihle Township. The study objectives are as follows: to investigate the community perception on teenage pregnancy in Kamvelihle Township, to contribute within the South African Sociological field with specific reference to Kamvelihle Township in the Eastern Cape and to come up with the recommendations with the view to addressing some of the problem in Kamvelihle Township. The research methodology employed in this study is qualitative in approach and it included amongst others, individual interviews using an interview guide containing relevant questions posed to participants. Research ethics protocol has been adhered to from the initial up to the last stages of the study. To supplement the above, relevant secondary sources were consulted ranging from scholarly journal articles as well as scholarly books including other available reading material. In this study, sex education has been used as a conceptual framework to understand the problem of teenage pregnancy in Kamvelihle Township. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Community violence and mental health symptoms among adolescents in South Africa: a systematic review and meta-analysis
- Authors: Jameson, Stacey
- Date: 2024-04
- Subjects: Violence -- Psychological aspects , Adolescent psychology , Community psychology , Mental health services
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63868 , vital:73621
- Description: There is a global prevalence of youth exposure to community violence. This is notably pronounced in South Africa, where children and adolescents face elevated levels of violence. Existing systematic reviews have predominately focused on international contexts, leaving a gap that requires comprehensive analysis within the South African context to understand the situation in comparison to global trends. The objective of this study was to synthesise the available literature on adolescent exposure to community violence and its impact on mental health outcomes in South Africa. The study aimed to determine the prevalence of such exposure among South African adolescents, explore associated internalising and externalising mental health symptoms, and assess the extent of this relationship. A systematic search of electronic databases was conducted, encompassing studies published between 2010 and 2022. Eighteen studies focusing on adolescents aged 10 to 19 years, investigating exposure to community violence and mental health outcomes were included. Meta-analytical procedures revealed that South African adolescents face elevated levels of both witnessing and direct victimisation of community violence, accompanied by heightened mental health symptoms, particularly in depression and posttraumatic stress disorder. Although a moderate positive correlation between community violence exposure and depression was identified, statistical significance was not achieved. Subgroup analyses, to explore gender as a potential moderating factor was conducted. This study underscores the urgent need for targeted interventions and policy measures to address the impact of community violence on adolescent mental wellbeing in South Africa. These findings contribute to the existing literature by providing an understanding of the situation in the South African context compared to global estimates, offering recommendations for future research to inform more effective public health strategies. , Thesis (MA) -- Faculty of Health Science, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Jameson, Stacey
- Date: 2024-04
- Subjects: Violence -- Psychological aspects , Adolescent psychology , Community psychology , Mental health services
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63868 , vital:73621
- Description: There is a global prevalence of youth exposure to community violence. This is notably pronounced in South Africa, where children and adolescents face elevated levels of violence. Existing systematic reviews have predominately focused on international contexts, leaving a gap that requires comprehensive analysis within the South African context to understand the situation in comparison to global trends. The objective of this study was to synthesise the available literature on adolescent exposure to community violence and its impact on mental health outcomes in South Africa. The study aimed to determine the prevalence of such exposure among South African adolescents, explore associated internalising and externalising mental health symptoms, and assess the extent of this relationship. A systematic search of electronic databases was conducted, encompassing studies published between 2010 and 2022. Eighteen studies focusing on adolescents aged 10 to 19 years, investigating exposure to community violence and mental health outcomes were included. Meta-analytical procedures revealed that South African adolescents face elevated levels of both witnessing and direct victimisation of community violence, accompanied by heightened mental health symptoms, particularly in depression and posttraumatic stress disorder. Although a moderate positive correlation between community violence exposure and depression was identified, statistical significance was not achieved. Subgroup analyses, to explore gender as a potential moderating factor was conducted. This study underscores the urgent need for targeted interventions and policy measures to address the impact of community violence on adolescent mental wellbeing in South Africa. These findings contribute to the existing literature by providing an understanding of the situation in the South African context compared to global estimates, offering recommendations for future research to inform more effective public health strategies. , Thesis (MA) -- Faculty of Health Science, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Comparative study of the effect of iloprost on neuroinflammatory changes in c8-b4 microglial cells and murine model of trypanosomiasis
- Authors: Jacobs, Ashleigh
- Date: 2024-04
- Subjects: Trypanosomiasis -- South Africa , DNA -- Methylation -- Research -- Methodology , Central nervous system -- Diseases , Nervous system -- Degeneration
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64077 , vital:73651
- Description: Neurodegenerative conditions significantly impact well-being and quality of life in individuals with major symptoms including mood disorders, cognitive decline, and psychiatric disturbances, often resulting from neuroinflammation triggered by immune responses to bacterial or parasitic infections such as gram-negative bacteria or Human African Trypanosomiasis. Microglia play a crucial role in both neurotoxicity and cellular processes involved in restoring the neural health. Exploring the therapeutic potential of prostacyclin and its analogues in regulating microglia responses to inflammatory insult and treating Trypanosoma brucei (T.b) infection remains an unexplored area. The aim of this study was to assess the potential neuroprotective effects of Iloprost through comparative analysis of neuroinflammatory responses in both microglial cells exposed to lipopolysaccharide (LPS) and mouse brains infected with T.b brucei. In phase I of this study both resting and LPS treated C8-B4 microglial cells were exposed to varying concentrations of Iloprost. The effects of Iloprost on LPS-induced inflammation were analysed using immunofluorescence to detect microglial activation and differentiate between pro and anti-inflammatory phenotypes. Furthermore, pro and anti-inflammatory cytokine secretion was determined using an ELISA, in addition gene expression analysis was carried out using quantitative polymerase chain reaction (qPCR). Also, DNA methylation status of C8-B4 cells exposed to LPS challenge alone or in combination with various concentrations of Iloprost were determined using bisulfite sequencing technique followed by qPCR. In phase II of the study, a total of twenty-four Albino Swiss male mice (8-10 weeks old) were divided into four treatment groups with 6 mice in each group. All treatment groups except the non-infected control were inoculated with the T.b brucei parasite. One group received a single intraperitoneal injection of Diminazene aceturate (4 mg kg-1) while the remaining group received repeated intraperitoneal injections of Iloprost (200 μg kg-1). On day ten of the study, mouse brains were removed on ice using forceps. The hippocampal tissues were dissected out and processed for quantification of gene expression changes in pro and anti-inflammatory cytokines. Overall, the findings of this study indicate that LPS-induced pro-inflammatory cytokine, TNF-α and IL-1β, secretion and gene expression is down-regulated in C8-B4 microglial cells treated with Iloprost. Furthermore, there was a significant up-regulation in the expression of anti-inflammatory genes, particularly ARG-1, CD206, BDNF and CREB in response to Iloprost treatment following LPS-induced inflammation. This study is also the first to confirm M2 microglial polarization with Iloprost treatment in both resting and LPS treated cells. However, hypermethylation at CREB and BDNF promoter regions was observed 24 hours after Iloprost treatment. Additionally, Iloprost reversed hypomethylation at the BDNF promoter region that had been induced by LPS treatment. The rodent model also indicated a downregulation in the pro-inflammatory cytokine, IL-1β, expression and upregulation of BDNF transcription in T.b brucei infected mice treated with repeated doses of Iloprost. In conclusion, determining the immunomodulatory roles of Iloprost in both in vitro and in vivo models of neuroinflammation could assist in the development of alternative therapy for neurodegenerative disease. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Jacobs, Ashleigh
- Date: 2024-04
- Subjects: Trypanosomiasis -- South Africa , DNA -- Methylation -- Research -- Methodology , Central nervous system -- Diseases , Nervous system -- Degeneration
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64077 , vital:73651
- Description: Neurodegenerative conditions significantly impact well-being and quality of life in individuals with major symptoms including mood disorders, cognitive decline, and psychiatric disturbances, often resulting from neuroinflammation triggered by immune responses to bacterial or parasitic infections such as gram-negative bacteria or Human African Trypanosomiasis. Microglia play a crucial role in both neurotoxicity and cellular processes involved in restoring the neural health. Exploring the therapeutic potential of prostacyclin and its analogues in regulating microglia responses to inflammatory insult and treating Trypanosoma brucei (T.b) infection remains an unexplored area. The aim of this study was to assess the potential neuroprotective effects of Iloprost through comparative analysis of neuroinflammatory responses in both microglial cells exposed to lipopolysaccharide (LPS) and mouse brains infected with T.b brucei. In phase I of this study both resting and LPS treated C8-B4 microglial cells were exposed to varying concentrations of Iloprost. The effects of Iloprost on LPS-induced inflammation were analysed using immunofluorescence to detect microglial activation and differentiate between pro and anti-inflammatory phenotypes. Furthermore, pro and anti-inflammatory cytokine secretion was determined using an ELISA, in addition gene expression analysis was carried out using quantitative polymerase chain reaction (qPCR). Also, DNA methylation status of C8-B4 cells exposed to LPS challenge alone or in combination with various concentrations of Iloprost were determined using bisulfite sequencing technique followed by qPCR. In phase II of the study, a total of twenty-four Albino Swiss male mice (8-10 weeks old) were divided into four treatment groups with 6 mice in each group. All treatment groups except the non-infected control were inoculated with the T.b brucei parasite. One group received a single intraperitoneal injection of Diminazene aceturate (4 mg kg-1) while the remaining group received repeated intraperitoneal injections of Iloprost (200 μg kg-1). On day ten of the study, mouse brains were removed on ice using forceps. The hippocampal tissues were dissected out and processed for quantification of gene expression changes in pro and anti-inflammatory cytokines. Overall, the findings of this study indicate that LPS-induced pro-inflammatory cytokine, TNF-α and IL-1β, secretion and gene expression is down-regulated in C8-B4 microglial cells treated with Iloprost. Furthermore, there was a significant up-regulation in the expression of anti-inflammatory genes, particularly ARG-1, CD206, BDNF and CREB in response to Iloprost treatment following LPS-induced inflammation. This study is also the first to confirm M2 microglial polarization with Iloprost treatment in both resting and LPS treated cells. However, hypermethylation at CREB and BDNF promoter regions was observed 24 hours after Iloprost treatment. Additionally, Iloprost reversed hypomethylation at the BDNF promoter region that had been induced by LPS treatment. The rodent model also indicated a downregulation in the pro-inflammatory cytokine, IL-1β, expression and upregulation of BDNF transcription in T.b brucei infected mice treated with repeated doses of Iloprost. In conclusion, determining the immunomodulatory roles of Iloprost in both in vitro and in vivo models of neuroinflammation could assist in the development of alternative therapy for neurodegenerative disease. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Comparing stable isotope ratios and metal concentrations between components of the benthic food web: a case study of the Swartkops Estuary South Africa
- Authors: Ndoto, Asiphe
- Date: 2024-04
- Subjects: Swartkops River Estuary (South Africa) , Estuarine ecology -- South Africa -- Swartkops River Estuary , Fishes -- Ecology -- South Africa -- Swartkops River Estuary
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64256 , vital:73669
- Description: Estuarine systems are highly productive ecosystems; however, they are subjected to high anthropogenic pressure such as metal contamination and: increased nutrient loads. The contamination sources of metals and nutrients in urban estuaries are derived: from industrial waste. agricultural and urban runoff that flows into estuaries. An example of such a system is the Swartkops Estuary. industry and three wastewater treatment plants within the Swartkops River catchment are major sources of metal. and nutrient pollution, respectively. The metals accumulate in the environment, are biomagnified up the food web, and transferred from one trophic level to another. At lethal concentrations, metals pose a threat to organisms using the estuary by affecting their physiological and biochemical processes. Stable Isotope analysis has proven to be an effective tool for investigating, trophic linkages in the food chain from a variety of environments. By assessing both metals and stable _isotopes in the. estuary it can provide a more robust understanding of the pathway metals accumulate, biomagnified, and transfer from the environment through the estuarine food web. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2024-04
- Authors: Ndoto, Asiphe
- Date: 2024-04
- Subjects: Swartkops River Estuary (South Africa) , Estuarine ecology -- South Africa -- Swartkops River Estuary , Fishes -- Ecology -- South Africa -- Swartkops River Estuary
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64256 , vital:73669
- Description: Estuarine systems are highly productive ecosystems; however, they are subjected to high anthropogenic pressure such as metal contamination and: increased nutrient loads. The contamination sources of metals and nutrients in urban estuaries are derived: from industrial waste. agricultural and urban runoff that flows into estuaries. An example of such a system is the Swartkops Estuary. industry and three wastewater treatment plants within the Swartkops River catchment are major sources of metal. and nutrient pollution, respectively. The metals accumulate in the environment, are biomagnified up the food web, and transferred from one trophic level to another. At lethal concentrations, metals pose a threat to organisms using the estuary by affecting their physiological and biochemical processes. Stable Isotope analysis has proven to be an effective tool for investigating, trophic linkages in the food chain from a variety of environments. By assessing both metals and stable _isotopes in the. estuary it can provide a more robust understanding of the pathway metals accumulate, biomagnified, and transfer from the environment through the estuarine food web. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2024-04
Computer vision as a tool for tracking gastropod chemical trails
- Authors: Viviers, Andre
- Date: 2024-04
- Subjects: Computers , Electronic data processing , Machine learning
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64863 , vital:73934
- Description: The difficulties encountered in previous gastropod research with human intervention (Raw, Miranda, & Perissinotto, 2013) inspired this dissertation. More specifically the tedious task of human intervention in the tracking of gastropod chemical trails, which is a time-consuming and error-prone exercise. In this study, computer vision is proposed as an alternative to human intervention. A machine learning literature review was conducted to identify relevant methodologies and techniques for the research. Furthermore, it investigates data preprocessing techniques on a variety of different data types. This sets the stage for a deeper investigation of techniques used for pre-processing image and video data. Following that, another literature review delved deeper into the computer vision pipeline. The review is divided into two parts: data pre-processing and model training. First, it provides a deeper investigation into relevant data pre-processing techniques for use in constructing a dataset comprised of gastropod images. Following that, it delves into the complexities of training a computer vision model. The study then investigates convolutional neural networks, revealing the neural networks’ suitability in image/video processing. A convolutional neural network is selected as the foundation for the best-effort model. This serves as the foundation for the subsequent experimental research. The first part of the experimental work involves creating a labelled dataset from the video dataset provided by Raw et al. (2013). By employing data preprocessing techniques in a strategic manner, an unlabeled dataset is generated. Then a labelled dataset is generated using a simple K-Means clustering algorithm and manual labelling. Thereafter, a best-effort model is trained to detect gastropods within images using this dataset. After making the labelled dataset, the next step in the exploration is to build a prototype that can find gastropods and draw trace lines based on their movement. Five evaluation runs serve to gauge the prototype’s effectiveness. Videos with varying properties from the original dataset are purposefully chosen for each run. The prototype’s trace lines are compared to the original dataset’s human-drawn pathways. The versatility of the prototype is demonstrated in the final evaluation by generating fine-grained trace lines post-processing. This enables the plot to be adjusted to different parameters based on the characteristics that the resulting plot should have. Through the versatility and accuracy demonstrated by the evaluation runs, this research found that a gastropod tracking solution based on computer vision can alleviate human intervention. The dissertation concludes with a discourse on the lessons learned from the research study. These are presented as guidelines to aid future work in developing a gastropod tracking solution based on computer vision. , Thesis (MIT) -- Faculty of Engineering, the Built Environment, and Technology, School of Information Technology, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Viviers, Andre
- Date: 2024-04
- Subjects: Computers , Electronic data processing , Machine learning
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64863 , vital:73934
- Description: The difficulties encountered in previous gastropod research with human intervention (Raw, Miranda, & Perissinotto, 2013) inspired this dissertation. More specifically the tedious task of human intervention in the tracking of gastropod chemical trails, which is a time-consuming and error-prone exercise. In this study, computer vision is proposed as an alternative to human intervention. A machine learning literature review was conducted to identify relevant methodologies and techniques for the research. Furthermore, it investigates data preprocessing techniques on a variety of different data types. This sets the stage for a deeper investigation of techniques used for pre-processing image and video data. Following that, another literature review delved deeper into the computer vision pipeline. The review is divided into two parts: data pre-processing and model training. First, it provides a deeper investigation into relevant data pre-processing techniques for use in constructing a dataset comprised of gastropod images. Following that, it delves into the complexities of training a computer vision model. The study then investigates convolutional neural networks, revealing the neural networks’ suitability in image/video processing. A convolutional neural network is selected as the foundation for the best-effort model. This serves as the foundation for the subsequent experimental research. The first part of the experimental work involves creating a labelled dataset from the video dataset provided by Raw et al. (2013). By employing data preprocessing techniques in a strategic manner, an unlabeled dataset is generated. Then a labelled dataset is generated using a simple K-Means clustering algorithm and manual labelling. Thereafter, a best-effort model is trained to detect gastropods within images using this dataset. After making the labelled dataset, the next step in the exploration is to build a prototype that can find gastropods and draw trace lines based on their movement. Five evaluation runs serve to gauge the prototype’s effectiveness. Videos with varying properties from the original dataset are purposefully chosen for each run. The prototype’s trace lines are compared to the original dataset’s human-drawn pathways. The versatility of the prototype is demonstrated in the final evaluation by generating fine-grained trace lines post-processing. This enables the plot to be adjusted to different parameters based on the characteristics that the resulting plot should have. Through the versatility and accuracy demonstrated by the evaluation runs, this research found that a gastropod tracking solution based on computer vision can alleviate human intervention. The dissertation concludes with a discourse on the lessons learned from the research study. These are presented as guidelines to aid future work in developing a gastropod tracking solution based on computer vision. , Thesis (MIT) -- Faculty of Engineering, the Built Environment, and Technology, School of Information Technology, 2024
- Full Text:
- Date Issued: 2024-04
Conceptual framework of African immigrant entrepreneurship in South Africa
- Authors: Ngota, Bernard Lama
- Date: 2024-04
- Subjects: Immigrant business enterprises -- South Africa , Entrepreneurship -- South Africa , Foreign workers -- South Africa
- Language: English
- Type: Doctorate theses , text
- Identifier: http://hdl.handle.net/10948/65298 , vital:74090
- Description: Most previous research on immigrant entrepreneurship has focused on investigating and describing immigrant entrepreneurship challenges, characteristics, and drivers of success. Immigrant entrepreneurship research that focuses on Africa, includes the challenges African immigrant entrepreneurs face, and their innate ability to start new ventures in their host countries compared to their native-born counterparts. However, literature on the conceptual framework explaining African immigrant entrepreneurship in South Africa is still nascent. This study assisted to develop a framework that will explain African immigrant entrepreneurship in South Africa. The purpose of this study was to develop a conceptual framework of African immigrant entrepreneurship in South Africa. The aim was achieved through a qualitative research approach that provided insights into African immigrant entrepreneurs and their perceptions thereof; the home country context, the entrepreneur, the resources, business opportunities, the immigrant entrepreneurial ecosystem, new business creation and operations, and the contributions to economic development to the South African economy were explored. Data was collected from a total of twenty-two participants using semi-structured interviews. The interviews were self-administered on a face-to-face contact by the researcher. Participants included African immigrant entrepreneurs; owner/managers and their employees comprised of twelve African immigrant entrepreneurs and ten employees. Data was collected using an interview guide and analysed by means of content and thematic analyses. A conceptual framework of African immigrant entrepreneurship in South Africa was created from the literature, and the collected data was then fitted to match the components of the model. The findings reveal how the different components of home country context, entrepreneur, resources, business opportunity, immigrant entrepreneurial ecosystem, new business creation and operations, were all interlinked to contribute to the economic development of South Africa. Furthermore, the findings revealed that African immigrant social ethnic groups provides support to their members such as “njangi”, loans, emotional support, protection, information, and helping them adjust to their new surroundings. These supports might promote African immigrant entrepreneurship and the creation of a new business in a host country like South Africa. Other findings complement how other employees benefit from African immigrant entrepreneurship in , Thesis (DPhil) -- Faculty of Business and Economic Sciences, School of Management Sciences, 2023 , Most previous research on immigrant entrepreneurship has focused on investigating and describing immigrant entrepreneurship challenges, characteristics, and drivers of success. Immigrant entrepreneurship research that focuses on Africa, includes the challenges African immigrant entrepreneurs face, and their innate ability to start new ventures in their host countries compared to their native-born counterparts. However, literature on the conceptual framework explaining African immigrant entrepreneurship in South Africa is still nascent. This study assisted to develop a framework that will explain African immigrant entrepreneurship in South Africa. The purpose of this study was to develop a conceptual framework of African immigrant entrepreneurship in South Africa. The aim was achieved through a qualitative research approach that provided insights into African immigrant entrepreneurs and their perceptions thereof; the home country context, the entrepreneur, the resources, business opportunities, the immigrant entrepreneurial ecosystem, new business creation and operations, and the contributions to economic development to the South African economy were explored. Data was collected from a total of twenty-two participants using semi-structured interviews. The interviews were self-administered on a face-to-face contact by the researcher. Participants included African immigrant entrepreneurs; owner/managers and their employees comprised of twelve African immigrant entrepreneurs and ten employees. Data was collected using an interview guide and analysed by means of content and thematic analyses. A conceptual framework of African immigrant entrepreneurship in South Africa was created from the literature, and the collected data was then fitted to match the components of the model. The findings reveal how the different components of home country context, entrepreneur, resources, business opportunity, immigrant entrepreneurial ecosystem, new business creation and operations, were all interlinked to contribute to the economic development of South Africa. Furthermore, the findings revealed that African immigrant social ethnic groups provides support to their members such as “njangi”, loans, emotional support, protection, information, and helping them adjust to their new surroundings. These supports might promote African immigrant entrepreneurship and the creation of a new business in a host country like South Africa. Other findings complement how other employees benefit from African immigrant entrepreneurship in South Africa. This was evidence in the entrepreneurs’ responsibilities, improved employees’ skills development, improved employee economic status and improved employee-employer relationships. The proposed framework serves as a valuable resource for scholars and practitioners, especially those involved with the making of legislations in the country. The study recommends that broad-based integrated public policy interventions and strategies be developed and implemented to have a positive impact on the country's economic success in terms of job creation, skills transfer, poverty reduction, and economic growth to achieve the socio-economic well-being of the people.
- Full Text:
- Date Issued: 2024-04
- Authors: Ngota, Bernard Lama
- Date: 2024-04
- Subjects: Immigrant business enterprises -- South Africa , Entrepreneurship -- South Africa , Foreign workers -- South Africa
- Language: English
- Type: Doctorate theses , text
- Identifier: http://hdl.handle.net/10948/65298 , vital:74090
- Description: Most previous research on immigrant entrepreneurship has focused on investigating and describing immigrant entrepreneurship challenges, characteristics, and drivers of success. Immigrant entrepreneurship research that focuses on Africa, includes the challenges African immigrant entrepreneurs face, and their innate ability to start new ventures in their host countries compared to their native-born counterparts. However, literature on the conceptual framework explaining African immigrant entrepreneurship in South Africa is still nascent. This study assisted to develop a framework that will explain African immigrant entrepreneurship in South Africa. The purpose of this study was to develop a conceptual framework of African immigrant entrepreneurship in South Africa. The aim was achieved through a qualitative research approach that provided insights into African immigrant entrepreneurs and their perceptions thereof; the home country context, the entrepreneur, the resources, business opportunities, the immigrant entrepreneurial ecosystem, new business creation and operations, and the contributions to economic development to the South African economy were explored. Data was collected from a total of twenty-two participants using semi-structured interviews. The interviews were self-administered on a face-to-face contact by the researcher. Participants included African immigrant entrepreneurs; owner/managers and their employees comprised of twelve African immigrant entrepreneurs and ten employees. Data was collected using an interview guide and analysed by means of content and thematic analyses. A conceptual framework of African immigrant entrepreneurship in South Africa was created from the literature, and the collected data was then fitted to match the components of the model. The findings reveal how the different components of home country context, entrepreneur, resources, business opportunity, immigrant entrepreneurial ecosystem, new business creation and operations, were all interlinked to contribute to the economic development of South Africa. Furthermore, the findings revealed that African immigrant social ethnic groups provides support to their members such as “njangi”, loans, emotional support, protection, information, and helping them adjust to their new surroundings. These supports might promote African immigrant entrepreneurship and the creation of a new business in a host country like South Africa. Other findings complement how other employees benefit from African immigrant entrepreneurship in , Thesis (DPhil) -- Faculty of Business and Economic Sciences, School of Management Sciences, 2023 , Most previous research on immigrant entrepreneurship has focused on investigating and describing immigrant entrepreneurship challenges, characteristics, and drivers of success. Immigrant entrepreneurship research that focuses on Africa, includes the challenges African immigrant entrepreneurs face, and their innate ability to start new ventures in their host countries compared to their native-born counterparts. However, literature on the conceptual framework explaining African immigrant entrepreneurship in South Africa is still nascent. This study assisted to develop a framework that will explain African immigrant entrepreneurship in South Africa. The purpose of this study was to develop a conceptual framework of African immigrant entrepreneurship in South Africa. The aim was achieved through a qualitative research approach that provided insights into African immigrant entrepreneurs and their perceptions thereof; the home country context, the entrepreneur, the resources, business opportunities, the immigrant entrepreneurial ecosystem, new business creation and operations, and the contributions to economic development to the South African economy were explored. Data was collected from a total of twenty-two participants using semi-structured interviews. The interviews were self-administered on a face-to-face contact by the researcher. Participants included African immigrant entrepreneurs; owner/managers and their employees comprised of twelve African immigrant entrepreneurs and ten employees. Data was collected using an interview guide and analysed by means of content and thematic analyses. A conceptual framework of African immigrant entrepreneurship in South Africa was created from the literature, and the collected data was then fitted to match the components of the model. The findings reveal how the different components of home country context, entrepreneur, resources, business opportunity, immigrant entrepreneurial ecosystem, new business creation and operations, were all interlinked to contribute to the economic development of South Africa. Furthermore, the findings revealed that African immigrant social ethnic groups provides support to their members such as “njangi”, loans, emotional support, protection, information, and helping them adjust to their new surroundings. These supports might promote African immigrant entrepreneurship and the creation of a new business in a host country like South Africa. Other findings complement how other employees benefit from African immigrant entrepreneurship in South Africa. This was evidence in the entrepreneurs’ responsibilities, improved employees’ skills development, improved employee economic status and improved employee-employer relationships. The proposed framework serves as a valuable resource for scholars and practitioners, especially those involved with the making of legislations in the country. The study recommends that broad-based integrated public policy interventions and strategies be developed and implemented to have a positive impact on the country's economic success in terms of job creation, skills transfer, poverty reduction, and economic growth to achieve the socio-economic well-being of the people.
- Full Text:
- Date Issued: 2024-04
Credit accessibility and enabling policies for SMMEs in King Sabata Dalindyebo Local Municipality South Africa
- Authors: Busakwe, Lomso
- Date: 2024-04
- Subjects: Credit -- South Africa -- Eastern Cape , Finance -- South Africa -- Eastern Cape , Small business -- Management -- South Africa -- Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64884 , vital:73938
- Description: Small, medium and micro enterprises contribute significantly to the economy, approximately 34% to South Africa’s Gross Domestic Product. They also play a vital role in the economy as drivers for reducing unemployment. In a modern transforming globe, small, medium and micro enterprises depend on funding. Categorically, credit in South Africa is limited to small, medium and micro enterprises from banks, this has to do with the credit histories, policies and collateral. The issue of policies that make it convenient for Small, medium and micro enterprises to obtain loans have proven to be difficult. These policies aspects have verified to be specifically difficult for regulations meant to increase asset-based total lending. The aim of the study was to assesses the role, adequacy and gaps of current policies to enhance credit accessibility by SMMEs in the KSDLM. The following research objectives are pursued: to identify the challenges faced by small businesses in the KSDLM, specifically from a credit access perspective; to identify the role of policies in assisting SMMEs to access credit for their small businesses in the KSDLM; to identify the policy gaps that hinder access to credit by SMMEs in the KSDLM; to draft a policy framework that enhances access to credit by SMMEs. A mixed method approach was adopted in this study. A questionnaire for quantitative approach, as well as an interview schedule for qualitative approach, was used to collect data. A sample of 145 small, medium, and micro enterprises, as well as 5 financial institutions, was utilised for the study. The study revealed numerous challenges that are hindering small, medium and micro enterprises from accessing credit and they are compliant, lack of proper record keeps, poor adjustment to technology, collateral and stability. Most small, medium and micro enterprises mentioned are facing challenges in accessing credit owing to the policies that are in place that do not cater for all their challenges and shortcomings. The study recommend that the Government can provide financial assistance to small businesses through grants, loans, tax incentives, and subsidies. These initiatives can reduce the financial burden on small businesses, allowing them to invest in growth, innovation and sustainability. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Busakwe, Lomso
- Date: 2024-04
- Subjects: Credit -- South Africa -- Eastern Cape , Finance -- South Africa -- Eastern Cape , Small business -- Management -- South Africa -- Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64884 , vital:73938
- Description: Small, medium and micro enterprises contribute significantly to the economy, approximately 34% to South Africa’s Gross Domestic Product. They also play a vital role in the economy as drivers for reducing unemployment. In a modern transforming globe, small, medium and micro enterprises depend on funding. Categorically, credit in South Africa is limited to small, medium and micro enterprises from banks, this has to do with the credit histories, policies and collateral. The issue of policies that make it convenient for Small, medium and micro enterprises to obtain loans have proven to be difficult. These policies aspects have verified to be specifically difficult for regulations meant to increase asset-based total lending. The aim of the study was to assesses the role, adequacy and gaps of current policies to enhance credit accessibility by SMMEs in the KSDLM. The following research objectives are pursued: to identify the challenges faced by small businesses in the KSDLM, specifically from a credit access perspective; to identify the role of policies in assisting SMMEs to access credit for their small businesses in the KSDLM; to identify the policy gaps that hinder access to credit by SMMEs in the KSDLM; to draft a policy framework that enhances access to credit by SMMEs. A mixed method approach was adopted in this study. A questionnaire for quantitative approach, as well as an interview schedule for qualitative approach, was used to collect data. A sample of 145 small, medium, and micro enterprises, as well as 5 financial institutions, was utilised for the study. The study revealed numerous challenges that are hindering small, medium and micro enterprises from accessing credit and they are compliant, lack of proper record keeps, poor adjustment to technology, collateral and stability. Most small, medium and micro enterprises mentioned are facing challenges in accessing credit owing to the policies that are in place that do not cater for all their challenges and shortcomings. The study recommend that the Government can provide financial assistance to small businesses through grants, loans, tax incentives, and subsidies. These initiatives can reduce the financial burden on small businesses, allowing them to invest in growth, innovation and sustainability. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
Cyber security compliance in South Africa’s maritime sector
- Authors: Steenberg, Wynand
- Date: 2024-04
- Subjects: Computer security -- Management , Computer networks -- Security measures , Cyberspace -- Security measures , Shipping -- Security measures
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/65445 , vital:74152
- Description: Globally, cyber attacks on the maritime industry have escalated exponentially, indicating that cyber security should be an international priority. The majority of maritime digital systems are connected to the cloud through information technologies, creating vulnerability to cyber attacks. Cyber security is critical to protect and ensure resiliency in the maritime industry’s operations. In July 2021, a cyber attack targeted the Transnet National Ports Authority (TNPA) and caused significant disruption to operations at multiple South African ports. Port operations were reduced to manual processes, which resulted in severe congestion. Transnet declared a force majeure during the two weeks it took to reinstate minimal operations. The TNPA cyber attack emphasised the need for effective strategies and procedures to prevent and recover from cyber attacks in the South African maritime industry. As maritime transport contributes significantly to South Africa’s gross domestic product (GDP), the incident had a detrimental effect on the country’s economy. It is, therefore, important to ensure that the South African maritime industry remains aware of the latest strategies and guidelines for cyber risk management. This study set out to establish if South Africa’s maritime industry complies with international standards for cyber risk management by analysing the International Maritime Organization’s (IMO) guidelines for cyber risk management. South Africa’s cyber risk management strategies were evaluated, and recommendations were made to improve the cyber risk management strategies and procedures currently employed in the South African maritime industry. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Steenberg, Wynand
- Date: 2024-04
- Subjects: Computer security -- Management , Computer networks -- Security measures , Cyberspace -- Security measures , Shipping -- Security measures
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/65445 , vital:74152
- Description: Globally, cyber attacks on the maritime industry have escalated exponentially, indicating that cyber security should be an international priority. The majority of maritime digital systems are connected to the cloud through information technologies, creating vulnerability to cyber attacks. Cyber security is critical to protect and ensure resiliency in the maritime industry’s operations. In July 2021, a cyber attack targeted the Transnet National Ports Authority (TNPA) and caused significant disruption to operations at multiple South African ports. Port operations were reduced to manual processes, which resulted in severe congestion. Transnet declared a force majeure during the two weeks it took to reinstate minimal operations. The TNPA cyber attack emphasised the need for effective strategies and procedures to prevent and recover from cyber attacks in the South African maritime industry. As maritime transport contributes significantly to South Africa’s gross domestic product (GDP), the incident had a detrimental effect on the country’s economy. It is, therefore, important to ensure that the South African maritime industry remains aware of the latest strategies and guidelines for cyber risk management. This study set out to establish if South Africa’s maritime industry complies with international standards for cyber risk management by analysing the International Maritime Organization’s (IMO) guidelines for cyber risk management. South Africa’s cyber risk management strategies were evaluated, and recommendations were made to improve the cyber risk management strategies and procedures currently employed in the South African maritime industry. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
Defining and regulating de facto and shadow directors: lessons from New Zealand
- Authors: Botha, Bernardus Hermanus
- Date: 2024-04
- Subjects: Business law , Companies Act 71 of 2008. , Company Management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63059 , vital:73182
- Description: The term ‘director’ is commonly limited to those persons who have been validly appointed as directors. These directors are referred to as de jure directors. However, this is not the only type of director found in practical corporate settings. There are also those who have not been validly appointed as a director, who nonetheless act as directors and who are held out by companies as such. These persons are known as de facto directors. An individual who has not been validly appointed as a director, who is not held out by a company as such, but who still exercises some measure of control over the affairs of a company, is known as a shadow director. The existence of de facto and shadow directors is not peculiar to South Africa. New Zealand has seen fit to regulate de facto and shadow directors and has done so for over 70 years. Owing to the ambiguous wording of the definition of ‘director’ contained in the Companies Act, there is uncertainty whether the current definition in the Companies Act 71 of 2008 extends to de facto and shadow directors. This uncertainty resulted in the non-regulation of these forms of directorship. The Act only applies to those individuals who fall within the definition of ‘director’. The practical effect of this is the absence of clear avenues of accountability to those who occupy a position of power within a company without being appointed as a de jure director. Considering this, the core objectives of this research are to illustrate the far-reaching consequences of the non-regulation of de facto and shadow directors and how this problem may be remedied. , Thesis (LLM) -- Faculty of Law
- Full Text:
- Date Issued: 2024-04
- Authors: Botha, Bernardus Hermanus
- Date: 2024-04
- Subjects: Business law , Companies Act 71 of 2008. , Company Management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63059 , vital:73182
- Description: The term ‘director’ is commonly limited to those persons who have been validly appointed as directors. These directors are referred to as de jure directors. However, this is not the only type of director found in practical corporate settings. There are also those who have not been validly appointed as a director, who nonetheless act as directors and who are held out by companies as such. These persons are known as de facto directors. An individual who has not been validly appointed as a director, who is not held out by a company as such, but who still exercises some measure of control over the affairs of a company, is known as a shadow director. The existence of de facto and shadow directors is not peculiar to South Africa. New Zealand has seen fit to regulate de facto and shadow directors and has done so for over 70 years. Owing to the ambiguous wording of the definition of ‘director’ contained in the Companies Act, there is uncertainty whether the current definition in the Companies Act 71 of 2008 extends to de facto and shadow directors. This uncertainty resulted in the non-regulation of these forms of directorship. The Act only applies to those individuals who fall within the definition of ‘director’. The practical effect of this is the absence of clear avenues of accountability to those who occupy a position of power within a company without being appointed as a de jure director. Considering this, the core objectives of this research are to illustrate the far-reaching consequences of the non-regulation of de facto and shadow directors and how this problem may be remedied. , Thesis (LLM) -- Faculty of Law
- Full Text:
- Date Issued: 2024-04
Development of a numerical geohydrological model for a fractured rock aquifer in the Karoo, near Sutherland, South Africa
- Authors: Maqhubela, Akhona
- Date: 2024-04
- Subjects: Hydrogeology -- South Africa -- Northern Cape , Groundwater -- South Africa -- North Cape -- Management , Evapotranspiration
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64164 , vital:73658
- Description: The regional scale method in groundwater storage observation introduces uncertainties that hinder the evaluation of the remaining lifespan of depleted aquifers. The scarcity of precipitation data presents significant global challenge, especially in semi-arid regions. This study constructs a regional numerical hydrogeological model that identifies the potential impacts of climate change on the water balance for the South African Gravimetric Observation Station in Sutherland. The purpose of this study is to understand mechanisms controlling groundwater in the fractured rock aquifer. The climate data from the Weather forecast data over the last ten years was collected from the South African Weather Service. and groundwater levels data assessed the potential impacts of climate change on water balance components, especially precipitation and evapotranspiration. Precipitation is the primary recharge parameter in this study and had the highest level recorded in winter, with May having the highest precipitation rates of 24,62mm. The instrument conducted two profile investigations in a single day to detect geological abnormalities at various depths, achieving an impressive accuracy of up to 0.001 mV. The fact that groundwater flows from regions of higher hydraulic heads to areas of lower hydraulic charges, confirms that riverbeds in Sutherland act as preferential conduits for subsurface recharge. The profile and processed geophysical maps show low chances of getting groundwater in this observed area due to extensively great depth, approximately 150 – 210 m. The river package from MODFLOW model shows little inflow to the study nearby well locations. These model results showed a negative difference between water flowing in and out of the system of about -7m3 between 2002 and 2020. Groundwater flows faster at borehole five, where the hydraulic conductivity is large. The resulting regional hydrogeological model offered valuable insights into how climate change might influence the distribution and accessibility of groundwater resources. In the context of Sutherland, a negative groundwater budget value signaled that groundwater extraction or consumption surpassed the natural replenishment or recharge of the aquifer. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Maqhubela, Akhona
- Date: 2024-04
- Subjects: Hydrogeology -- South Africa -- Northern Cape , Groundwater -- South Africa -- North Cape -- Management , Evapotranspiration
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64164 , vital:73658
- Description: The regional scale method in groundwater storage observation introduces uncertainties that hinder the evaluation of the remaining lifespan of depleted aquifers. The scarcity of precipitation data presents significant global challenge, especially in semi-arid regions. This study constructs a regional numerical hydrogeological model that identifies the potential impacts of climate change on the water balance for the South African Gravimetric Observation Station in Sutherland. The purpose of this study is to understand mechanisms controlling groundwater in the fractured rock aquifer. The climate data from the Weather forecast data over the last ten years was collected from the South African Weather Service. and groundwater levels data assessed the potential impacts of climate change on water balance components, especially precipitation and evapotranspiration. Precipitation is the primary recharge parameter in this study and had the highest level recorded in winter, with May having the highest precipitation rates of 24,62mm. The instrument conducted two profile investigations in a single day to detect geological abnormalities at various depths, achieving an impressive accuracy of up to 0.001 mV. The fact that groundwater flows from regions of higher hydraulic heads to areas of lower hydraulic charges, confirms that riverbeds in Sutherland act as preferential conduits for subsurface recharge. The profile and processed geophysical maps show low chances of getting groundwater in this observed area due to extensively great depth, approximately 150 – 210 m. The river package from MODFLOW model shows little inflow to the study nearby well locations. These model results showed a negative difference between water flowing in and out of the system of about -7m3 between 2002 and 2020. Groundwater flows faster at borehole five, where the hydraulic conductivity is large. The resulting regional hydrogeological model offered valuable insights into how climate change might influence the distribution and accessibility of groundwater resources. In the context of Sutherland, a negative groundwater budget value signaled that groundwater extraction or consumption surpassed the natural replenishment or recharge of the aquifer. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Development of a numerical geohydrological model for a fractured rock aquifer in the Karoo, near Sutherland, South Africa
- Authors: Maqhubela, Akhona
- Date: 2024-04
- Subjects: Groundwater -- South Africa -- Northern Cape , Hydrogeology -- South Africa -- Northern Cape , Remote sensing , Geographic information systems
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64163 , vital:73659
- Description: The regional scale method in groundwater storage observation introduces uncertainties that hinder the evaluation of the remaining lifespan of depleted aquifers. The scarcity of precipitation data presents significant global challenge, especially in semi-arid regions. This study constructs a regional numerical hydrogeological model that identifies the potential impacts of climate change on the water balance for the South African Gravimetric Observation Station in Sutherland. The purpose of this study is to understand mechanisms controlling groundwater in the fractured rock aquifer. The climate data from the Weather forecast data over the last ten years was collected from the South African Weather Service. and groundwater levels data assessed the potential impacts of climate change on water balance components, especially precipitation and evapotranspiration. Precipitation is the primary recharge parameter in this study and had the highest level recorded in winter, with May having the highest precipitation rates of 24,62mm. The instrument conducted two profile investigations in a single day to detect geological abnormalities at various depths, achieving an impressive accuracy of up to 0.001 mV. The fact that groundwater flows from regions of higher hydraulic heads to areas of lower hydraulic charges, confirms that riverbeds in Sutherland act as preferential conduits for subsurface recharge. The profile and processed geophysical maps show low chances of getting groundwater in this observed area due to extensively great depth, approximately 150 – 210 m. The river package from MODFLOW model shows little inflow to the study nearby well locations. These model results showed a negative difference between water flowing in and out of the system of about -7m3 between 2002 and 2020. Groundwater flows faster at borehole five, where the hydraulic conductivity is large. The resulting regional hydrogeological model offered valuable insights into how climate change might influence the distribution and accessibility of groundwater resources. In the context of Sutherland, a negative groundwater budget value signaled that groundwater extraction or consumption surpassed the natural replenishment or recharge of the aquifer. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2024-04
- Authors: Maqhubela, Akhona
- Date: 2024-04
- Subjects: Groundwater -- South Africa -- Northern Cape , Hydrogeology -- South Africa -- Northern Cape , Remote sensing , Geographic information systems
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64163 , vital:73659
- Description: The regional scale method in groundwater storage observation introduces uncertainties that hinder the evaluation of the remaining lifespan of depleted aquifers. The scarcity of precipitation data presents significant global challenge, especially in semi-arid regions. This study constructs a regional numerical hydrogeological model that identifies the potential impacts of climate change on the water balance for the South African Gravimetric Observation Station in Sutherland. The purpose of this study is to understand mechanisms controlling groundwater in the fractured rock aquifer. The climate data from the Weather forecast data over the last ten years was collected from the South African Weather Service. and groundwater levels data assessed the potential impacts of climate change on water balance components, especially precipitation and evapotranspiration. Precipitation is the primary recharge parameter in this study and had the highest level recorded in winter, with May having the highest precipitation rates of 24,62mm. The instrument conducted two profile investigations in a single day to detect geological abnormalities at various depths, achieving an impressive accuracy of up to 0.001 mV. The fact that groundwater flows from regions of higher hydraulic heads to areas of lower hydraulic charges, confirms that riverbeds in Sutherland act as preferential conduits for subsurface recharge. The profile and processed geophysical maps show low chances of getting groundwater in this observed area due to extensively great depth, approximately 150 – 210 m. The river package from MODFLOW model shows little inflow to the study nearby well locations. These model results showed a negative difference between water flowing in and out of the system of about -7m3 between 2002 and 2020. Groundwater flows faster at borehole five, where the hydraulic conductivity is large. The resulting regional hydrogeological model offered valuable insights into how climate change might influence the distribution and accessibility of groundwater resources. In the context of Sutherland, a negative groundwater budget value signaled that groundwater extraction or consumption surpassed the natural replenishment or recharge of the aquifer. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2024-04
Development of the Zirconium-based metal- organic framework UiO-66 for Adsorption-mediated electrochemical sensing of organonitrogen compounds in fuels
- Authors: Mokgohloa, Mathule Collen
- Date: 2024-04
- Subjects: Electrochemical sensors , Quinoline -- synthesis , Pyridine -- Synthesis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64193 , vital:73663
- Description: The combustion of fuel which contains organonitrogen compounds has led to an increase in atmospheric and environmental levels of nitrogen oxides which are responsible for several environmental, ecological, and human health problems. With increasingly strict environmental regulations and deleterious effects of the nitrogen-containing compounds in fuels, there is a strong need for the removal and detection of nitrogen-containing compounds in fuels to produce fuels with lower levels of nitrogen compounds. The Environmental Protection Agency (EPA) mandated nitrogen content in fossil fuels to be about less than 1 wt%. The existing analytical techniques used for the quantification of nitrogen-containing compounds in fuels include GC-MS, GC-AED, and spectrophotometry. Despite being sensitive and specific, these methods require expensive equipment, highly trained personnel, and time-consuming pre-treatment methods to avoid interferences from similar compounds, and they suffer from analyte loss and inadequate results. Thus, they can only be carried out in the off-site laboratories, hindering them from rapid on-site screening. The metal-organic framework (MOF) UiO-66-NH2 and its composites UiO-66-NH2/GA, and UiO- 66-NH2/GO-NH2 (GA= Graphene aerosol and GO= Graphene oxide) have shown great potentialin the adsorption of organonitrogen compounds like quinoline. However, research in the electrochemical application of these MOFs and their derivatives is limited despite their high surface area, abundant porosity, and increased conductivity. To demonstrate their electrochemical sensing potential, modification of the glassy carbon electrode (GCE) was suggested, which would show a higher degree of association for pyridine and quinoline on modified UiO-66-NH2/GA and UiO-66-NH2/GO-NH2 surfaces, thereby creating a more favourable route for adsorption. This would result in enhanced sensing of pyridine and quinoline in model fuel. Thus, unlike the bare GCE, the fabricated/modified can selectively detect high levels of organonitrogen compounds. In this study, Chapter 3, UiO-66-NH2/GA and UiO-66-NH2/GO-NH2 are prepared via the solvothermal method and then characterized using various spectroscopic and imaging techniques such as Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Ultraviolet-Visible Spectroscopy (UV-VIS), Thermogravimetric Analysis (TGA), X-ray Development of the Zirconium-based metal- organic framework UiO-66 for Adsorption-mediated electrochemical sensing of organonitrogen compounds in fuels. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Mokgohloa, Mathule Collen
- Date: 2024-04
- Subjects: Electrochemical sensors , Quinoline -- synthesis , Pyridine -- Synthesis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64193 , vital:73663
- Description: The combustion of fuel which contains organonitrogen compounds has led to an increase in atmospheric and environmental levels of nitrogen oxides which are responsible for several environmental, ecological, and human health problems. With increasingly strict environmental regulations and deleterious effects of the nitrogen-containing compounds in fuels, there is a strong need for the removal and detection of nitrogen-containing compounds in fuels to produce fuels with lower levels of nitrogen compounds. The Environmental Protection Agency (EPA) mandated nitrogen content in fossil fuels to be about less than 1 wt%. The existing analytical techniques used for the quantification of nitrogen-containing compounds in fuels include GC-MS, GC-AED, and spectrophotometry. Despite being sensitive and specific, these methods require expensive equipment, highly trained personnel, and time-consuming pre-treatment methods to avoid interferences from similar compounds, and they suffer from analyte loss and inadequate results. Thus, they can only be carried out in the off-site laboratories, hindering them from rapid on-site screening. The metal-organic framework (MOF) UiO-66-NH2 and its composites UiO-66-NH2/GA, and UiO- 66-NH2/GO-NH2 (GA= Graphene aerosol and GO= Graphene oxide) have shown great potentialin the adsorption of organonitrogen compounds like quinoline. However, research in the electrochemical application of these MOFs and their derivatives is limited despite their high surface area, abundant porosity, and increased conductivity. To demonstrate their electrochemical sensing potential, modification of the glassy carbon electrode (GCE) was suggested, which would show a higher degree of association for pyridine and quinoline on modified UiO-66-NH2/GA and UiO-66-NH2/GO-NH2 surfaces, thereby creating a more favourable route for adsorption. This would result in enhanced sensing of pyridine and quinoline in model fuel. Thus, unlike the bare GCE, the fabricated/modified can selectively detect high levels of organonitrogen compounds. In this study, Chapter 3, UiO-66-NH2/GA and UiO-66-NH2/GO-NH2 are prepared via the solvothermal method and then characterized using various spectroscopic and imaging techniques such as Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Ultraviolet-Visible Spectroscopy (UV-VIS), Thermogravimetric Analysis (TGA), X-ray Development of the Zirconium-based metal- organic framework UiO-66 for Adsorption-mediated electrochemical sensing of organonitrogen compounds in fuels. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Development of TiO2 nanostructures with a modified energy band gap for hydrogen extraction
- Authors: Mutubuki, Arnold
- Date: 2024-04
- Subjects: Nanostructures , Nanoscience , Nanochemistry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64226 , vital:73666
- Description: A rise in fossil fuel depletion has motivated the research towards alternative, cost effective and clean processes for energy production through renewable sources. The scientific community is currently engaged in extensive research to exploit viable, sustainable methods for generating green hydrogen. Titania (TiO2) is historically the most studied photoactive semiconductor material with great potential in photoelectrochemical water splitting (PECWS), following the discovery by Fujishima and Honda in 1972. TiO2 possesses superior physicochemical characteristics and band gap edges, which enables the semiconductor to effectively facilitate the PECWS process. Efforts are still ongoing to explore alternatives for narrowing the optical band gap energy of TiO2, for an efficient photoelectrode. In this research work, open-ended and well-ordered TiO2 nanotubular arrays were synthesised by a three-step anodization process. The third anodization was crucial to detach the TiO2 thin film from an opaque Ti metal substrate. The free-standing thin films were transferred and pasted onto conductive FTO-coated glass substrates transparent to visible light and annealed at 400 ℃ for crystallisation. The multi-step anodization has shown an improved top tube morphology by eliminating an initiation TiO2 mesh formed when a conventional single-step anodization process is used under similar conditions. To widen the absorption range of the samples, CuO nanosheets were deposited onto nanotubular TiO2/FTO films through successive ionic layer adsorption (SILAR), a wet chemical method. The formation of a CuO/TiO2 nanostructure enhances the transfer of photogenerated carriers, suppressing charge recombination. This research focused on investigating the influence of selected SILAR parameters on the formation of CuO nanostructures. The first was the effect of precursor concentration on the structural, morphological and optical properties of the CuO/TiO2/FTO nanostructured photoelectrode. The effect of the precursor concentration on the structure and morphology was evident in the X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) micrographs. Crystallite sizes of deposited CuO increased from 10.6 nm to 15.7 nm when precursor concentration was varied from 0.02 M to 0.10 M. The UV-visible absorbance results show that an increase in precursor concentration leads to a red shift of both the peak absorbance and edge wavelength of the CuO/TiO2/FTO absorbance spectra. This phenomenon is believed to be caused by the presence of CuO, which exhibits active absorption in the visible spectrum. As evidenced by the study, the continued increase in precursor concentration does not result in a further widening of the absorption band. This is demonstrated by the example of a CuO/TiO2/FTO sample decorated with a 0.2 M precursor. The second was the effect of SILAR immersion cycles on the properties of the CuO/TiO2/FTO nanostructure developed. The increase in the number of immersion cycles led to a notable progression in the adsorption cupric oxide on the TiO2/FTO samples. A redshift in the absorbance peak and edge wavelength is observed in the UV-visible spectra of CuO/TiO2/FTO photoelectrode. The efficacy of the SILAR technique in modifying the absorption band of nanotubular TiO2 thin films has been conclusively demonstrated through comprehensive analysis and correlation of the relationships between the structure and optical properties, as evidenced by the XRD patterns, Raman spectra, SEM, TEM micrographs, and UV-visible absorbance spectra. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Mutubuki, Arnold
- Date: 2024-04
- Subjects: Nanostructures , Nanoscience , Nanochemistry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64226 , vital:73666
- Description: A rise in fossil fuel depletion has motivated the research towards alternative, cost effective and clean processes for energy production through renewable sources. The scientific community is currently engaged in extensive research to exploit viable, sustainable methods for generating green hydrogen. Titania (TiO2) is historically the most studied photoactive semiconductor material with great potential in photoelectrochemical water splitting (PECWS), following the discovery by Fujishima and Honda in 1972. TiO2 possesses superior physicochemical characteristics and band gap edges, which enables the semiconductor to effectively facilitate the PECWS process. Efforts are still ongoing to explore alternatives for narrowing the optical band gap energy of TiO2, for an efficient photoelectrode. In this research work, open-ended and well-ordered TiO2 nanotubular arrays were synthesised by a three-step anodization process. The third anodization was crucial to detach the TiO2 thin film from an opaque Ti metal substrate. The free-standing thin films were transferred and pasted onto conductive FTO-coated glass substrates transparent to visible light and annealed at 400 ℃ for crystallisation. The multi-step anodization has shown an improved top tube morphology by eliminating an initiation TiO2 mesh formed when a conventional single-step anodization process is used under similar conditions. To widen the absorption range of the samples, CuO nanosheets were deposited onto nanotubular TiO2/FTO films through successive ionic layer adsorption (SILAR), a wet chemical method. The formation of a CuO/TiO2 nanostructure enhances the transfer of photogenerated carriers, suppressing charge recombination. This research focused on investigating the influence of selected SILAR parameters on the formation of CuO nanostructures. The first was the effect of precursor concentration on the structural, morphological and optical properties of the CuO/TiO2/FTO nanostructured photoelectrode. The effect of the precursor concentration on the structure and morphology was evident in the X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) micrographs. Crystallite sizes of deposited CuO increased from 10.6 nm to 15.7 nm when precursor concentration was varied from 0.02 M to 0.10 M. The UV-visible absorbance results show that an increase in precursor concentration leads to a red shift of both the peak absorbance and edge wavelength of the CuO/TiO2/FTO absorbance spectra. This phenomenon is believed to be caused by the presence of CuO, which exhibits active absorption in the visible spectrum. As evidenced by the study, the continued increase in precursor concentration does not result in a further widening of the absorption band. This is demonstrated by the example of a CuO/TiO2/FTO sample decorated with a 0.2 M precursor. The second was the effect of SILAR immersion cycles on the properties of the CuO/TiO2/FTO nanostructure developed. The increase in the number of immersion cycles led to a notable progression in the adsorption cupric oxide on the TiO2/FTO samples. A redshift in the absorbance peak and edge wavelength is observed in the UV-visible spectra of CuO/TiO2/FTO photoelectrode. The efficacy of the SILAR technique in modifying the absorption band of nanotubular TiO2 thin films has been conclusively demonstrated through comprehensive analysis and correlation of the relationships between the structure and optical properties, as evidenced by the XRD patterns, Raman spectra, SEM, TEM micrographs, and UV-visible absorbance spectra. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2024
- Full Text:
- Date Issued: 2024-04
Diaspora in Dialogue: An Ontology of Diasporic Subjectivity in the Work of Three Artists Living In-Between South Africa and Zimbabwe
- Nyoni, Vulindlela Philani Elliott
- Authors: Nyoni, Vulindlela Philani Elliott
- Date: 2024-04
- Subjects: Foreign workers -- South Africa , South Africa -- Social conditions , South Africa -- Emigration and immigration
- Language: English
- Type: Doctorate , text
- Identifier: http://hdl.handle.net/10948/62366 , vital:72615
- Description: As a Zimbabwean artist and educator, living and working in South Africa, my daily experience is that of an “in-between” diasporic subjectivity, which is compounded by the discourses around the uneasy reintegration of post-apartheid South Africa into Africa. This context gives rise to the core philosophical aim of this thesis, which is to explore the notion of “diasporic subjectivities” as a philosophical approach to understanding what it means to be in a complex contemporary reality. The notion of diasporic subjectivities works in the same way as that of “queer subjectivities”, which has been used to understand not just gay people but all people. “Diaspora” names people who have moved, migrated, or been scattered away from an established or ancestral homeland, but retain some sense of belonging to this homeland. From an African perspective, I problematise the concept of an established homeland and the settled subjectivities that belong to it, in contrast to which only the diaspora remains in an uncomfortable state of in-betweenness. Instead, I explore a contention among both European and African existentialist philosophers that the condition of not being at home is the fundamental human condition out of which a home must be created. This would mean that the groundlessness, liminality or in-betweenness of being is experienced not just by the diaspora but by all humans. However, importantly, I find that sociocultural differences due to the history of colonialism gives rise to different experiences of homelessness and the groundlessness of being. This makes a distinction necessary, but to avoid the pitfalls of tying this distinction to geographical locations such as Western versus Non-Western or Global North and Global South, I will refer instead to spaces, practices and even individuals, in which there are “mindsets of entitlement” versus “mindsets of disentitlement”. The former refers to the mindset of ownership characteristic of the settled and developed. The latter refers to the mindset of many who feel a sense of unbelonging, due to disenfranchisement and forced disembodiment and dislocation. I have aimed to support the thesis that the groundlessness, liminality or in-betweenness of being is experienced not just by the diaspora but by all humans, in two ways. Firstly, I consider in detail through various means (narratives, personal reflection, investigation of philosophical texts, dialogues), the philosophical concepts of “belonging”, “home” and “nostalgia” as component aspects of an ontology of diasporic subjectivity. In the second part of this study, I engage in an interpretative process, as outlined by Hans-Georg Gadamer, whereby I use this ontology to help me dialogue with artworks produced by three Zimbabwean artists, Ronald Muchatuta, Gerald Machona, and myself (Vulindlela Nyoni), who share the diasporic condition of being Zimbabweans living in-between Zimbabwe and South Africa. The ontology of diasporic subjectivity developed in the first part offers a language with which to dialogue with the artworks or question the way in which the complexities of belonging, home and nostalgia are expressed in the works, while the works in turn help deepen an understanding of diasporic subjectivity. Both philosophies and artworks may function as transformative, practical tools for seeking wisdom, cultivating self-awareness, developing moral character, and living a reflective and examined life. The combination of personal narratives and self-reflexive, philosophical dialogues regarding artworks and art making and its exigencies holds the potential to produce deeper philosophical insights into the fundamentally diasporic human condition. This kind of hybrid research at the interface between philosophy and artistic praxis is accessible to a broad-based audience. It is therefore better able to undo malicious stereotypical associations between émigrés and malignant tropes of societal decay on the African continent and to validate the contributions made by African diaspora to the decolonial project, than neatly distanced academic reflections, which reduce the philosophical impact of transnational migration to measurable motivations and statistics. , Thesis (D.Phil) -- Faculty of Humanities, School of Social Scinces, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Nyoni, Vulindlela Philani Elliott
- Date: 2024-04
- Subjects: Foreign workers -- South Africa , South Africa -- Social conditions , South Africa -- Emigration and immigration
- Language: English
- Type: Doctorate , text
- Identifier: http://hdl.handle.net/10948/62366 , vital:72615
- Description: As a Zimbabwean artist and educator, living and working in South Africa, my daily experience is that of an “in-between” diasporic subjectivity, which is compounded by the discourses around the uneasy reintegration of post-apartheid South Africa into Africa. This context gives rise to the core philosophical aim of this thesis, which is to explore the notion of “diasporic subjectivities” as a philosophical approach to understanding what it means to be in a complex contemporary reality. The notion of diasporic subjectivities works in the same way as that of “queer subjectivities”, which has been used to understand not just gay people but all people. “Diaspora” names people who have moved, migrated, or been scattered away from an established or ancestral homeland, but retain some sense of belonging to this homeland. From an African perspective, I problematise the concept of an established homeland and the settled subjectivities that belong to it, in contrast to which only the diaspora remains in an uncomfortable state of in-betweenness. Instead, I explore a contention among both European and African existentialist philosophers that the condition of not being at home is the fundamental human condition out of which a home must be created. This would mean that the groundlessness, liminality or in-betweenness of being is experienced not just by the diaspora but by all humans. However, importantly, I find that sociocultural differences due to the history of colonialism gives rise to different experiences of homelessness and the groundlessness of being. This makes a distinction necessary, but to avoid the pitfalls of tying this distinction to geographical locations such as Western versus Non-Western or Global North and Global South, I will refer instead to spaces, practices and even individuals, in which there are “mindsets of entitlement” versus “mindsets of disentitlement”. The former refers to the mindset of ownership characteristic of the settled and developed. The latter refers to the mindset of many who feel a sense of unbelonging, due to disenfranchisement and forced disembodiment and dislocation. I have aimed to support the thesis that the groundlessness, liminality or in-betweenness of being is experienced not just by the diaspora but by all humans, in two ways. Firstly, I consider in detail through various means (narratives, personal reflection, investigation of philosophical texts, dialogues), the philosophical concepts of “belonging”, “home” and “nostalgia” as component aspects of an ontology of diasporic subjectivity. In the second part of this study, I engage in an interpretative process, as outlined by Hans-Georg Gadamer, whereby I use this ontology to help me dialogue with artworks produced by three Zimbabwean artists, Ronald Muchatuta, Gerald Machona, and myself (Vulindlela Nyoni), who share the diasporic condition of being Zimbabweans living in-between Zimbabwe and South Africa. The ontology of diasporic subjectivity developed in the first part offers a language with which to dialogue with the artworks or question the way in which the complexities of belonging, home and nostalgia are expressed in the works, while the works in turn help deepen an understanding of diasporic subjectivity. Both philosophies and artworks may function as transformative, practical tools for seeking wisdom, cultivating self-awareness, developing moral character, and living a reflective and examined life. The combination of personal narratives and self-reflexive, philosophical dialogues regarding artworks and art making and its exigencies holds the potential to produce deeper philosophical insights into the fundamentally diasporic human condition. This kind of hybrid research at the interface between philosophy and artistic praxis is accessible to a broad-based audience. It is therefore better able to undo malicious stereotypical associations between émigrés and malignant tropes of societal decay on the African continent and to validate the contributions made by African diaspora to the decolonial project, than neatly distanced academic reflections, which reduce the philosophical impact of transnational migration to measurable motivations and statistics. , Thesis (D.Phil) -- Faculty of Humanities, School of Social Scinces, 2024
- Full Text:
- Date Issued: 2024-04
Discipline and dismissal of employees For testing positive for cannabis
- Authors: Syce, Donato Burchelle
- Date: 2024-04
- Subjects: Occupational health , Cannabis , Substance use
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63071 , vital:73184
- Description: Employers are legally obligated to provide a safe working environment for all employees. They are permitted to enforce rules that regulate the use of cannabis, including a total prohibition thereof in the workplace. Most employers adopt a policy with a zero-tolerance approach to substance abuse in the workplace, especially considering the negative effects of substances. Cannabis is regarded as a drug and the effects of cannabis may negatively affect the health of employees. In most instances, users develop cognitive impairment which may result in decreased working memory function. Therefore, employers must test employees when they suspect that an employee have contravened a workplace policy. There are various tests that can be used to detect THC, the preferred method for testing employees is a urine test. Upon testing an employee, the test may show a positive result for the previous use of cannabis, but it does not determine the level of impairment. However, employers are still required to take the necessary disciplinary action against employees. In the following chapter, I shall discuss the judicial approach towards employees who have tested positive for cannabis. , Thesis (LLM) -- Faculty of Law,(2024)
- Full Text:
- Date Issued: 2024-04
- Authors: Syce, Donato Burchelle
- Date: 2024-04
- Subjects: Occupational health , Cannabis , Substance use
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63071 , vital:73184
- Description: Employers are legally obligated to provide a safe working environment for all employees. They are permitted to enforce rules that regulate the use of cannabis, including a total prohibition thereof in the workplace. Most employers adopt a policy with a zero-tolerance approach to substance abuse in the workplace, especially considering the negative effects of substances. Cannabis is regarded as a drug and the effects of cannabis may negatively affect the health of employees. In most instances, users develop cognitive impairment which may result in decreased working memory function. Therefore, employers must test employees when they suspect that an employee have contravened a workplace policy. There are various tests that can be used to detect THC, the preferred method for testing employees is a urine test. Upon testing an employee, the test may show a positive result for the previous use of cannabis, but it does not determine the level of impairment. However, employers are still required to take the necessary disciplinary action against employees. In the following chapter, I shall discuss the judicial approach towards employees who have tested positive for cannabis. , Thesis (LLM) -- Faculty of Law,(2024)
- Full Text:
- Date Issued: 2024-04
Dislocation imaging of AISI316L stainless steels using electron channeling contrast imaging (ECCI)
- Pullen, Luchian Charton Morne
- Authors: Pullen, Luchian Charton Morne
- Date: 2024-04
- Subjects: Electron microscopy , Microscopy -- Technique
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64301 , vital:73674
- Description: This study investigates the use of electron microscopy to image dislocations in high-temperature steels used in the electrical power generation industry. Dislocations play an important role in the mechanical properties of steels, which continuously evolve during component manufacturing and subsequent in-service exposure due to creep and/or fatigue. The dislocation density of the steels can potentially be used as a fingerprint to identify at-risk components that has either reached end-of-life or that was incorrectly manufactured due to forming or heat treatments. Traditionally, dislocation measurements are performed using transmission electron microscopy (TEM) performed on thin foils samples. However, accurate and precise measurements of the dislocation density in steels using TEM remain a challenge due to the time-consuming nature, small sampling volumes, and effects of sample preparation on the quantitative results. The aim of this study is to evaluate and establish electron channeling contrast imaging (ECCI) as a scanning electron microscopy method of quantifying the dislocation densities of power plant steels. This method can be applied to conventionally polished bulk samples allowing for large areas to be sampled. Samples consisting of AISI316L stainless steel were used as a model alloy (large grain size ~100 μm) to compare dislocation imaging using annular dark field (ADF)-scanning TEM (STEM) and ECCI. Three materials states consisting of a cold drawn rod (high dislocation density), annealed rod (low dislocation density), and an annealed sample subjected to cyclic fatigue testing (medium dislocation density) were investigated. Systematic investigations into the data acquisition parameters showed that an incident beam energy (20 kV), beam current (~4 nA), pixel size (5 nm), and working distance (4-5 mm) on a JEOL7001F SEM fitted with a retractable BSE detector could successfully image the dislocation structures for the material states used in this study. The ECCI technique was successfully used to determine the dislocation density in the three material states and the quantitative results showed similar trends as the ADF-STEM quantification results, but with less effort. Future studies using electron backscattered diffraction (EBSD) orientation mapping combined with electron channeling pattern (ECP) calibrations using a single crystal Si sample will allow for ECCI imaging under controlled grain orientations. Furthermore, accurate image segmentation of dislocations from a micrograph remains a key limitation, which can be improved with the use of advanced image analysis based on deep learning approaches. The quantitative dislocation density techniques demonstrated in this study can be adapted not only for studies of other power plant steels (eg. 9-12% Cr Creep Strength Enhanced Ferritic) but also to other materials systems such as aluminium to study the recrystallization processes during annealing. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2025
- Full Text:
- Date Issued: 2024-04
- Authors: Pullen, Luchian Charton Morne
- Date: 2024-04
- Subjects: Electron microscopy , Microscopy -- Technique
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64301 , vital:73674
- Description: This study investigates the use of electron microscopy to image dislocations in high-temperature steels used in the electrical power generation industry. Dislocations play an important role in the mechanical properties of steels, which continuously evolve during component manufacturing and subsequent in-service exposure due to creep and/or fatigue. The dislocation density of the steels can potentially be used as a fingerprint to identify at-risk components that has either reached end-of-life or that was incorrectly manufactured due to forming or heat treatments. Traditionally, dislocation measurements are performed using transmission electron microscopy (TEM) performed on thin foils samples. However, accurate and precise measurements of the dislocation density in steels using TEM remain a challenge due to the time-consuming nature, small sampling volumes, and effects of sample preparation on the quantitative results. The aim of this study is to evaluate and establish electron channeling contrast imaging (ECCI) as a scanning electron microscopy method of quantifying the dislocation densities of power plant steels. This method can be applied to conventionally polished bulk samples allowing for large areas to be sampled. Samples consisting of AISI316L stainless steel were used as a model alloy (large grain size ~100 μm) to compare dislocation imaging using annular dark field (ADF)-scanning TEM (STEM) and ECCI. Three materials states consisting of a cold drawn rod (high dislocation density), annealed rod (low dislocation density), and an annealed sample subjected to cyclic fatigue testing (medium dislocation density) were investigated. Systematic investigations into the data acquisition parameters showed that an incident beam energy (20 kV), beam current (~4 nA), pixel size (5 nm), and working distance (4-5 mm) on a JEOL7001F SEM fitted with a retractable BSE detector could successfully image the dislocation structures for the material states used in this study. The ECCI technique was successfully used to determine the dislocation density in the three material states and the quantitative results showed similar trends as the ADF-STEM quantification results, but with less effort. Future studies using electron backscattered diffraction (EBSD) orientation mapping combined with electron channeling pattern (ECP) calibrations using a single crystal Si sample will allow for ECCI imaging under controlled grain orientations. Furthermore, accurate image segmentation of dislocations from a micrograph remains a key limitation, which can be improved with the use of advanced image analysis based on deep learning approaches. The quantitative dislocation density techniques demonstrated in this study can be adapted not only for studies of other power plant steels (eg. 9-12% Cr Creep Strength Enhanced Ferritic) but also to other materials systems such as aluminium to study the recrystallization processes during annealing. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2025
- Full Text:
- Date Issued: 2024-04
Early screening for the post intensive care syndrome in a tertiary ICU follow-up clinic in the Eastern Cape
- Authors: van der Merwe, Elizabeth
- Date: 2024-04
- Subjects: Critical care medicine , Post-traumatic stress disorder -- Patients , Psychology, Pathological
- Language: English
- Type: Doctral theses , text
- Identifier: http://hdl.handle.net/10948/63915 , vital:73626
- Description: The Post ICU Syndrome (PICS) is defined as a constellation of new or worsened impairments in physical, cognitive, and/or psychological health which persist after critical care discharge. These deficits are more related to the patients’ intensive care unit (ICU) stay rather than to their original ICU admission diagnosis. Between 25-50% of critical care survivors suffer from PICS. There is a paucity of research on PICS in South Africa (SA). The primary objective of this study is to describe the incidence and co-occurrence of PICS symptoms, as well as the changes in instrumental activities of daily living and life roles in ICU survivors.The study was conducted in a multidisciplinary tertiary ICU in the Eastern Cape. Inclusion criteria were respiratory support for ≥ 48 hours, or a shocked state, and/or organ failure requiring ICU stay for 48 hours. Patients were assessed at six weeks and six months after hospital discharge. Physical impairment was measured by the six-minute walk test and ICU-acquired weakness by the Medical Research Council scale. Instrumental activities of daily living score and employment/educational status were determined. The Hospital Anxiety and Depression Scale and Impact of Event Scale-Revised questionnaires were used as screening tools for significant psychological symptoms. Screening for neurocognitive impairment was performed with the NeuroScreen application and compared to a matched control group. The Short Form-36 Health-Related Quality of Life questionnaire (HRQOL) was used to determine quality of life at baseline and study visits. 107 patients, half of whom had COVID-19, completed the six-month follow-up. Six months after hospital discharge, six out of ten patients were affected by PICS, five out of every ten suffered from physical impairment, four out of every ten reported significant psychological symptoms, with three out of every ten affected by both. Three out of ten experienced significant chronic pain. Overall, six out of every ten patients experienced significant psychological symptoms at either one or both study visits. Only one in ten had psychological symptoms in isolation at six months. Six out of every ten patients reported a significantly lower health-related quality of life at six months as compared to their baseline. Three out of every ten patients had not returned to their previous remunerative work, studying or home making. Neurocognitive impairment in this cohort was not verified, and this may have been due to the selection of the control group. However, there was a significant improvement in neurocognitive functioning from the six-week to the six-month study visits. Only 15% of patients received rehabilitation therapy after hospital discharge. Female sex, a higher co-morbidity score and an admission diagnosis of trauma were predictors of PICS symptoms. COVID-19 was not found to be associated with a higher incidence of PICS. , Thesis (D.Phil) -- Faculty of Health Science, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: van der Merwe, Elizabeth
- Date: 2024-04
- Subjects: Critical care medicine , Post-traumatic stress disorder -- Patients , Psychology, Pathological
- Language: English
- Type: Doctral theses , text
- Identifier: http://hdl.handle.net/10948/63915 , vital:73626
- Description: The Post ICU Syndrome (PICS) is defined as a constellation of new or worsened impairments in physical, cognitive, and/or psychological health which persist after critical care discharge. These deficits are more related to the patients’ intensive care unit (ICU) stay rather than to their original ICU admission diagnosis. Between 25-50% of critical care survivors suffer from PICS. There is a paucity of research on PICS in South Africa (SA). The primary objective of this study is to describe the incidence and co-occurrence of PICS symptoms, as well as the changes in instrumental activities of daily living and life roles in ICU survivors.The study was conducted in a multidisciplinary tertiary ICU in the Eastern Cape. Inclusion criteria were respiratory support for ≥ 48 hours, or a shocked state, and/or organ failure requiring ICU stay for 48 hours. Patients were assessed at six weeks and six months after hospital discharge. Physical impairment was measured by the six-minute walk test and ICU-acquired weakness by the Medical Research Council scale. Instrumental activities of daily living score and employment/educational status were determined. The Hospital Anxiety and Depression Scale and Impact of Event Scale-Revised questionnaires were used as screening tools for significant psychological symptoms. Screening for neurocognitive impairment was performed with the NeuroScreen application and compared to a matched control group. The Short Form-36 Health-Related Quality of Life questionnaire (HRQOL) was used to determine quality of life at baseline and study visits. 107 patients, half of whom had COVID-19, completed the six-month follow-up. Six months after hospital discharge, six out of ten patients were affected by PICS, five out of every ten suffered from physical impairment, four out of every ten reported significant psychological symptoms, with three out of every ten affected by both. Three out of ten experienced significant chronic pain. Overall, six out of every ten patients experienced significant psychological symptoms at either one or both study visits. Only one in ten had psychological symptoms in isolation at six months. Six out of every ten patients reported a significantly lower health-related quality of life at six months as compared to their baseline. Three out of every ten patients had not returned to their previous remunerative work, studying or home making. Neurocognitive impairment in this cohort was not verified, and this may have been due to the selection of the control group. However, there was a significant improvement in neurocognitive functioning from the six-week to the six-month study visits. Only 15% of patients received rehabilitation therapy after hospital discharge. Female sex, a higher co-morbidity score and an admission diagnosis of trauma were predictors of PICS symptoms. COVID-19 was not found to be associated with a higher incidence of PICS. , Thesis (D.Phil) -- Faculty of Health Science, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Economic complexity and inclusive growth in Sub-Saharan Africa: a cross country analysis
- Authors: Maxwele, Chuma
- Date: 2024-04
- Subjects: Gross domestic product , Economic development -- Africa , International trade , Balance of trade -- Africa Africa, Sub-Saharan Africa, Sub-Saharan Africa, Sub-Saharan Africa, Sub-Saharan -- Economic conditions
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/65142 , vital:74037
- Description: The concept of economic complexity is a relatively new term in economics literature, it is used to refer to the magnitude of productive knowledge or capabilities embedded in society. However, because of its potential impact on national prosperity, it is hypothesized that differences in the degree of economic complexity are major factors of inequalities in the growth rates of nations. The approach of economic complexity makes use of fine-grained data on thousands of economic activities to learn both abstract factors of production and the way they combine into thousands of outputs. However, it is only in recent years that studies have started to consider the association between economic complexity and economic growth. As such, there is a lack of robust, vigorous literature that examines the association between economic complexity and inclusive growth, particularly in the context of Sub Sub-Saharan Africa. The extant literature focuses on the relationship between economic complexity and isolated cases of some macroeconomic indicators of growth. As a departure from the existing studies and as a contribution to the field, inclusive growth, in this study, is measured as a composite index from various growth indicators as postulated in the inclusive growth theories and then each indicator is viewed separately. Thus, the general purpose of the study is to investigate the relationship between economic complexity and inclusive growth in Sub Sub-Saharan Africa from 1996 to 2019 2019, which is the primary objective of the study. The first objective of the study is to examine the effect of economic complexity on welfare indicators in Sub Sub-Saharan African countries from 1996 to 2019. In examining the effect, the study employed a Pool Mean Group – Autoregressive Distributive Lag (PMG PMG-ARDL) model. The results of the study reveal that economic complexity, economic growth rate, and terms of trade have a positive and statistically significant long-run impact on welfare in Sub Sub-Saharan Africa. The short-run dynamics reveal that economic complexity negatively and significantly affects welfare. The study's second objective examines the impact of economic complexity on economic indicators in Sub-Saharan African countries from 1996 to 2019. To examine the impact, the study employed the Panel Ordinary Least Square (POLS) model. The results of the study demonstrate that economic complexity, foreign direct investment, inflation, and population growth have a negative and significant impact on the economic index. However, government expenditure demonstrates a positive and significant effect on economic indicators. The third objective of the study examines the effect of economic complexity on human development in Sub Sub-Saharan African countries from 1996 to 2019. In examining the effect, the study employed the Panel Dynamic Ordinary Least Square (DOLS) model for the long-run relationship, and the Generalised Method of Moments (GMM) for the short-run relationship. The results of the long long-run relationship show that economic complexity has a negative impact on human development which is significant at 1 percent. Short Short-run relationships reveal that economic complexity has a positive and insignificant impact on human development. The fourth objective of the study investigates the effect of economic complexity on good governance in Sub Sub-Saharan African countries from 1996 to 2019. The study employed the Pool Mean Group – Autoregressive Distributive Lag (PMG PMG-ARDL) model to investigate the relationship. The PMG PMG-ARDL model results reveal that economic complexity, foreign aid, and the Gini coefficient have a positive and statistically significant long-run impact on good governance in Sub Sub-Saharan Africa. The fifth and last objective of the study investigates the effect of economic complexity on inclusive growth in Sub Sub-Saharan African countries from year 1996 to 2019. To investigate the relationship, the study applied the Panel Vector Autoregressive (P-VAR) model. The results from the grangerGranger-causality test show a unidirectional relationship running from economic complexity to inclusive growth, the panel VAR model reveals that economic complexity has a negative and significant effect on inclusive growth at 10 percent level of significance in Sub Sub-Saharan Africa. The present study investigated five objectives, and out of the five objectives, only two (i.e., Welfare and Good Governance ) have a positive and significant relationship with economic complexity in the long long-run. This implies that with more productive structures, these countries would be in a better position to promote institutional quality and later advance welfare regimes in Sub Sub-Saharan Africa. However, for that goal to be realized, the Sub-Saharan African region should first achieve, or have, a certain level of economic development. , Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Maxwele, Chuma
- Date: 2024-04
- Subjects: Gross domestic product , Economic development -- Africa , International trade , Balance of trade -- Africa Africa, Sub-Saharan Africa, Sub-Saharan Africa, Sub-Saharan Africa, Sub-Saharan -- Economic conditions
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/65142 , vital:74037
- Description: The concept of economic complexity is a relatively new term in economics literature, it is used to refer to the magnitude of productive knowledge or capabilities embedded in society. However, because of its potential impact on national prosperity, it is hypothesized that differences in the degree of economic complexity are major factors of inequalities in the growth rates of nations. The approach of economic complexity makes use of fine-grained data on thousands of economic activities to learn both abstract factors of production and the way they combine into thousands of outputs. However, it is only in recent years that studies have started to consider the association between economic complexity and economic growth. As such, there is a lack of robust, vigorous literature that examines the association between economic complexity and inclusive growth, particularly in the context of Sub Sub-Saharan Africa. The extant literature focuses on the relationship between economic complexity and isolated cases of some macroeconomic indicators of growth. As a departure from the existing studies and as a contribution to the field, inclusive growth, in this study, is measured as a composite index from various growth indicators as postulated in the inclusive growth theories and then each indicator is viewed separately. Thus, the general purpose of the study is to investigate the relationship between economic complexity and inclusive growth in Sub Sub-Saharan Africa from 1996 to 2019 2019, which is the primary objective of the study. The first objective of the study is to examine the effect of economic complexity on welfare indicators in Sub Sub-Saharan African countries from 1996 to 2019. In examining the effect, the study employed a Pool Mean Group – Autoregressive Distributive Lag (PMG PMG-ARDL) model. The results of the study reveal that economic complexity, economic growth rate, and terms of trade have a positive and statistically significant long-run impact on welfare in Sub Sub-Saharan Africa. The short-run dynamics reveal that economic complexity negatively and significantly affects welfare. The study's second objective examines the impact of economic complexity on economic indicators in Sub-Saharan African countries from 1996 to 2019. To examine the impact, the study employed the Panel Ordinary Least Square (POLS) model. The results of the study demonstrate that economic complexity, foreign direct investment, inflation, and population growth have a negative and significant impact on the economic index. However, government expenditure demonstrates a positive and significant effect on economic indicators. The third objective of the study examines the effect of economic complexity on human development in Sub Sub-Saharan African countries from 1996 to 2019. In examining the effect, the study employed the Panel Dynamic Ordinary Least Square (DOLS) model for the long-run relationship, and the Generalised Method of Moments (GMM) for the short-run relationship. The results of the long long-run relationship show that economic complexity has a negative impact on human development which is significant at 1 percent. Short Short-run relationships reveal that economic complexity has a positive and insignificant impact on human development. The fourth objective of the study investigates the effect of economic complexity on good governance in Sub Sub-Saharan African countries from 1996 to 2019. The study employed the Pool Mean Group – Autoregressive Distributive Lag (PMG PMG-ARDL) model to investigate the relationship. The PMG PMG-ARDL model results reveal that economic complexity, foreign aid, and the Gini coefficient have a positive and statistically significant long-run impact on good governance in Sub Sub-Saharan Africa. The fifth and last objective of the study investigates the effect of economic complexity on inclusive growth in Sub Sub-Saharan African countries from year 1996 to 2019. To investigate the relationship, the study applied the Panel Vector Autoregressive (P-VAR) model. The results from the grangerGranger-causality test show a unidirectional relationship running from economic complexity to inclusive growth, the panel VAR model reveals that economic complexity has a negative and significant effect on inclusive growth at 10 percent level of significance in Sub Sub-Saharan Africa. The present study investigated five objectives, and out of the five objectives, only two (i.e., Welfare and Good Governance ) have a positive and significant relationship with economic complexity in the long long-run. This implies that with more productive structures, these countries would be in a better position to promote institutional quality and later advance welfare regimes in Sub Sub-Saharan Africa. However, for that goal to be realized, the Sub-Saharan African region should first achieve, or have, a certain level of economic development. , Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
Effects of foreign capital inflows on human development in Ghana and the mediating role of institutional quality
- Authors: Dadzie, Sylvester Kwesi
- Date: 2024-04
- Subjects: Capital movements -- Ghana , Economic development -- Ghana , Structural equation modeling -- Case studies
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64929 , vital:73987
- Description: The issue of financing for human development has been crucial for governments and stakeholders. The financing mechanisms for human development have been broadly categorised into domestic and foreign. The foreign capital inflows are to complement domestic resources for development. However, despite the heterogeneity of past studies, several studies have proved that with adequate institutional quality, an inflow of finance can positively impact human development. This study sought to examine the effect of foreign capital inflows on human development and the role of institutional quality in Ghana using partial least square structural equation modelling (PLS-SEM) on selected quartered secondary data from 1996 to 2020, primarily incorporating World Development Indicators (WDI) and World Governance Indicators (WGI). It reveals firstly that foreign capital inflows have significant positive influence on institutional quality in Ghana; secondly, institutional quality has insignificant positive effects on human development; thirdly, the direct effects of foreign capital inflows on human development are negative and insignificant. Finally, the effects of foreign capital inflows on human development are not mediated by institutional quality despite the positive effects of institutional quality. The study concludes that institutional quality does not mediate between the effects of foreign capital inflows and human development in Ghana. However, this study recommends that the government design and implement appropriate policies to create an enabling environment to strengthen institutions and regulations while attracting foreign capital as a supplementary source of domestic investment to enhance human development. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Dadzie, Sylvester Kwesi
- Date: 2024-04
- Subjects: Capital movements -- Ghana , Economic development -- Ghana , Structural equation modeling -- Case studies
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64929 , vital:73987
- Description: The issue of financing for human development has been crucial for governments and stakeholders. The financing mechanisms for human development have been broadly categorised into domestic and foreign. The foreign capital inflows are to complement domestic resources for development. However, despite the heterogeneity of past studies, several studies have proved that with adequate institutional quality, an inflow of finance can positively impact human development. This study sought to examine the effect of foreign capital inflows on human development and the role of institutional quality in Ghana using partial least square structural equation modelling (PLS-SEM) on selected quartered secondary data from 1996 to 2020, primarily incorporating World Development Indicators (WDI) and World Governance Indicators (WGI). It reveals firstly that foreign capital inflows have significant positive influence on institutional quality in Ghana; secondly, institutional quality has insignificant positive effects on human development; thirdly, the direct effects of foreign capital inflows on human development are negative and insignificant. Finally, the effects of foreign capital inflows on human development are not mediated by institutional quality despite the positive effects of institutional quality. The study concludes that institutional quality does not mediate between the effects of foreign capital inflows and human development in Ghana. However, this study recommends that the government design and implement appropriate policies to create an enabling environment to strengthen institutions and regulations while attracting foreign capital as a supplementary source of domestic investment to enhance human development. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2024
- Full Text:
- Date Issued: 2024-04
Elephant impacts on plant diversity and structure in the Shamwari Private Game Reserve
- Authors: Halvey, Andrew Lloyd
- Date: 2024-04
- Subjects: Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape , Shamwari Game Reserve (South Africa)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63777 , vital:73597
- Description: Many African landscapes rely on processes such as fire, tree-fall and drought in addition to herbivores to initiate change across the landscape. In the Eastern Cape, elephant have a significant impact on the community structure and diversity of the vegetation they live in. This is most likely the case for the Albany Valley Thicket and azonal riparian vegetation of Shamwari Private Game Reserve, where browsing animals, particularly megaherbivores like the black rhinoceros and elephant, are the main cause of defoliation. The presence of large herbivores creates challenges when it comes to long-term sustainability and biodiversity of the vegetation in Shamwari. Vegetation monitoring provides essential information for effective management of megaherbivores not only in Shamwari but in many other similar reserves. The aim of this study was to design a monitoring plan for the Albany Valley Thicket and riparian vegetation in Shamwari using available vegetation metrics. The vegetation was measured in permanent plots (90 m line intercept analysis per plot) in the Albany Valley Thicket and riparian vegetation of Shamwari. Plot selection was based on thicket structural integrity using NDVI score as a proxy. In all plots, thicket structure was assessed using canopy heights measured every 50 cm along the line. Detrended correspondence analysis of the species abundance data suggested three distinct structural and compositional vegetation states for thicket and riparian vegetation: dense, intermediate and open. Significant relationships between NDVI and vegetation structural metrics across the condition states indicated that NDVI could be used as a proxy for vegetation condition. Vegetation compositional metrics, however, were not always correlated to NDVI and determining species diversity for the vegetation presents additional information useful for monitoring. The monitoring recommended for the reserve is to evaluate vegetation structural integrity annually in summer using NDVI. Areas of change could then be measured for diversity as well as for change in the abundance of selected plant indicator species. This information should be used to initiate management actions if unwanted change has occurred. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Halvey, Andrew Lloyd
- Date: 2024-04
- Subjects: Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape , Shamwari Game Reserve (South Africa)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63777 , vital:73597
- Description: Many African landscapes rely on processes such as fire, tree-fall and drought in addition to herbivores to initiate change across the landscape. In the Eastern Cape, elephant have a significant impact on the community structure and diversity of the vegetation they live in. This is most likely the case for the Albany Valley Thicket and azonal riparian vegetation of Shamwari Private Game Reserve, where browsing animals, particularly megaherbivores like the black rhinoceros and elephant, are the main cause of defoliation. The presence of large herbivores creates challenges when it comes to long-term sustainability and biodiversity of the vegetation in Shamwari. Vegetation monitoring provides essential information for effective management of megaherbivores not only in Shamwari but in many other similar reserves. The aim of this study was to design a monitoring plan for the Albany Valley Thicket and riparian vegetation in Shamwari using available vegetation metrics. The vegetation was measured in permanent plots (90 m line intercept analysis per plot) in the Albany Valley Thicket and riparian vegetation of Shamwari. Plot selection was based on thicket structural integrity using NDVI score as a proxy. In all plots, thicket structure was assessed using canopy heights measured every 50 cm along the line. Detrended correspondence analysis of the species abundance data suggested three distinct structural and compositional vegetation states for thicket and riparian vegetation: dense, intermediate and open. Significant relationships between NDVI and vegetation structural metrics across the condition states indicated that NDVI could be used as a proxy for vegetation condition. Vegetation compositional metrics, however, were not always correlated to NDVI and determining species diversity for the vegetation presents additional information useful for monitoring. The monitoring recommended for the reserve is to evaluate vegetation structural integrity annually in summer using NDVI. Areas of change could then be measured for diversity as well as for change in the abundance of selected plant indicator species. This information should be used to initiate management actions if unwanted change has occurred. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-04