Barriers faced by women in public sector leadership roles
- Authors: Khoza, Zelda
- Date: 2024-04
- Subjects: Women construction workers -- South Africa -- Management , Construction industry -- South Africa -- Management , Leadership -- South Africa , Equality
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64599 , vital:73770
- Description: This research aims to analyse barriers that hinder women from occupying senior leadership posi-tions and to identify strategies that can be utilised to enable women to be appointed in these posi-tions at Transnet. The study identifies implementable strategies to assist women who aspire to be part of senior leadership and face barriers that hinder them from progressing to leadership posi-tions. The research adopts a pragmatic research paradigm, including quantitative and qualitative meth-ods, to explain the barriers associated with women advancing to leadership positions within the company. The data was collected through survey questionnaires and in-depth interviews. The analysis indicates that women are still under-represented in Transnet, even though efforts are being made to close this gap. Ineffective implementation of policies, due to lack of facilitating roles by HRM and line managers as expected, and lack of required support from the organisation play a significant role in creating barriers hindering senior leadership positions. The research findings can inform Human Resource Management (HRM) about the need for effec-tive implementation of policies and intensified monitoring to address the identified barriers that hin-der women from occupying senior leadership positions. Transnet should foster an organisational culture to build solid connections and engage diverse stakeholders to increase their impact and access to resources and drive positive organisational change. Transnet can leverage these find-ings to develop programmes and initiatives that support women’s career advancement and skills development. With these findings, Transnet should consider implementing strategies that provide flexible working conditions. Lastly, these findings aid Transnet in providing mentorship to women as a valuable leadership opportunity in the organisation. This study contributes to the existing literature on barriers that hinder women from occupying sen-ior leadership positions within organisations. The study also provides vital insights into the rolling out of women’s development programmes and the encouragement they bring. It offers implications for future research, policy changes, professional practices, and strategies to assist women in lead-ership positions. , Thesis (MSc) -- Faculty of Engineering, the Built Environment and Technology, School of Built Environment and Civil Engineering, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Khoza, Zelda
- Date: 2024-04
- Subjects: Women construction workers -- South Africa -- Management , Construction industry -- South Africa -- Management , Leadership -- South Africa , Equality
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64599 , vital:73770
- Description: This research aims to analyse barriers that hinder women from occupying senior leadership posi-tions and to identify strategies that can be utilised to enable women to be appointed in these posi-tions at Transnet. The study identifies implementable strategies to assist women who aspire to be part of senior leadership and face barriers that hinder them from progressing to leadership posi-tions. The research adopts a pragmatic research paradigm, including quantitative and qualitative meth-ods, to explain the barriers associated with women advancing to leadership positions within the company. The data was collected through survey questionnaires and in-depth interviews. The analysis indicates that women are still under-represented in Transnet, even though efforts are being made to close this gap. Ineffective implementation of policies, due to lack of facilitating roles by HRM and line managers as expected, and lack of required support from the organisation play a significant role in creating barriers hindering senior leadership positions. The research findings can inform Human Resource Management (HRM) about the need for effec-tive implementation of policies and intensified monitoring to address the identified barriers that hin-der women from occupying senior leadership positions. Transnet should foster an organisational culture to build solid connections and engage diverse stakeholders to increase their impact and access to resources and drive positive organisational change. Transnet can leverage these find-ings to develop programmes and initiatives that support women’s career advancement and skills development. With these findings, Transnet should consider implementing strategies that provide flexible working conditions. Lastly, these findings aid Transnet in providing mentorship to women as a valuable leadership opportunity in the organisation. This study contributes to the existing literature on barriers that hinder women from occupying sen-ior leadership positions within organisations. The study also provides vital insights into the rolling out of women’s development programmes and the encouragement they bring. It offers implications for future research, policy changes, professional practices, and strategies to assist women in lead-ership positions. , Thesis (MSc) -- Faculty of Engineering, the Built Environment and Technology, School of Built Environment and Civil Engineering, 2024
- Full Text:
- Date Issued: 2024-04
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
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: 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 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 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
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
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
Estimation of a generalist meso-carnivore (black-backed jackal) population from a fenced protected area
- Davidson-Phillips, Samuel Ralph
- Authors: Davidson-Phillips, Samuel Ralph
- Date: 2024-04
- Subjects: Wildlife conservation , Carnivorous animals -- Conservation , Carnivorous animals -- Ecology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63698 , vital:73589
- Description: Since 2017, landowners, field guides, and management staff have reported large groups of black-backed jackals (Lupullela mesomelas) (here-forward jackal) in the Welgevonden Game Reserve, Limpopo, South Africa. This is linked with several observations of jackals predating on various ungulate species, potentially leading to unintended consequences on prey populations. These observations combined with an apparent poor survival rate of impala (Aepyceros melampus) and continuous declines in their number led to the perception that jackals could be partly responsible. Several studies have attempted to describe the ecological role of jackals within multiple environments, most of which have proven to be variable and context dependent. Human-modified landscapes along with the fencing of protected areas, may have manipulated the role of jackal within these scenarios. Jackals are wide-ranging and generally not confined by fencing, therefore their population trends possibly fluctuate within these anthropogenic landscapes. Re-introduced apex predators have been shown to facilitate food (provision of carrion) and simultaneously suppress jackal (active killing), this, however, remains difficult to predict. Jackals are classified as facultative cooperative hunters, and the term describes how they hunt in groups opportunistically when suitable resources of prey are available. The indication by several studies that jackals do actively predate rather than only scavenge, illustrates that the species has the potential to cause declines in an ungulate population. It therefore appears erroneous to exclude the species in terms of predator-prey relationships, particularly for land managers of fenced protected areas. The first step to any ecological management is the understanding of population size and trends over time. Unfortunately, little to no reliable methods exist to assess or monitor jackal populations. A popular tool for cryptic and wide-ranging terrestrial carnivores is Spatial Capture Recapture (SCR) models, typically through a camera trap array. These often rely on individual identities and an imperfect detection process to derive a statistical estimate of a given area. Jackals have been assumed to be individually unidentifiable and therefore these methods have largely been excluded. To address this a pilot-targeted camera-trap survey was conducted to improve capture and image quality. Following the role of this procedure, semi-automated software was applied to test the feasibility of individual identifications of captured images. This resulted in a subset of 58 right and left identifiable flank images, compiled from the highest graded images (n = 220) using the open-source Interactive Individual IdentificationSystem Beta Contour 3.0 (I3S Contour). I3S Contour assists users by distinguishing between unique contours on independent flanks without omitting observer effort and ranking. The effectiveness of the identification procedure was evaluated using three software tool trials, namely Computer-aided Annotation, Manual Contour Annotation, and Manual Contour Annotation (MA-2), where MA-2 included additional user-defined meta-data to images. Results showed that jackals could be individually identified from camera trap images and thus opened up the use of previously excluded SCR methodologies. Utilising the jackal database derived from the identification procedures described a total of 28 complete identifications (both flanks matched), 32 left-sided and 36 right-sided captures were used. These were derived from two independent survey periods split between seasonality (Winter & Spring). Two SCR methods were compared, namely, the Spatially Explicit Camera Recapture (SECR) and the newly developed Spatial Presence-Absence (SPA) modelling approach. SECR relies on full individual identification linked to spatial locations to derive spatial parameters to estimate population densities. The SECR methodology has been considered the most precise and was thus used as the benchmark. SPA relies on detections only (i.e., without individual identities), along with informative or uninformative priors. This must be across a spatial array that has detectors close enough to allow for simultaneous detections during each occasion (< 24 hours). Comparisons between these model outputs indicated a high degree of confidence interval overlap; however, SPA had a consistently higher posterior mode density estimate (63-64% higher), where the coefficient of variation between outputs also indicated the SPA having a closer relative precision. The targeted survey results for both model outputs for 2021 did not appear unusually high when compared to other studies. To assess the WGR population size over the long term, opportunistic by-catch data from a nine-year leopard (Panthera pardus) camera survey (Panthera organisation) was utilised. Model outputs from each of the years indicated that population estimates remained relatively stable. This was an unexpected result as the SPA densities did not follow the detection observations. This could be attributed to M not being set high enough (200) and the model reaching the limit, resulting in similar outputs between years. An alternative explanation is where the station spacing is larger than the diameter of the home range, which may reduce spatial correlation. , Thesis (MSc) -- Faculty of Science, School of Natural Resource Science & Management, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Davidson-Phillips, Samuel Ralph
- Date: 2024-04
- Subjects: Wildlife conservation , Carnivorous animals -- Conservation , Carnivorous animals -- Ecology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63698 , vital:73589
- Description: Since 2017, landowners, field guides, and management staff have reported large groups of black-backed jackals (Lupullela mesomelas) (here-forward jackal) in the Welgevonden Game Reserve, Limpopo, South Africa. This is linked with several observations of jackals predating on various ungulate species, potentially leading to unintended consequences on prey populations. These observations combined with an apparent poor survival rate of impala (Aepyceros melampus) and continuous declines in their number led to the perception that jackals could be partly responsible. Several studies have attempted to describe the ecological role of jackals within multiple environments, most of which have proven to be variable and context dependent. Human-modified landscapes along with the fencing of protected areas, may have manipulated the role of jackal within these scenarios. Jackals are wide-ranging and generally not confined by fencing, therefore their population trends possibly fluctuate within these anthropogenic landscapes. Re-introduced apex predators have been shown to facilitate food (provision of carrion) and simultaneously suppress jackal (active killing), this, however, remains difficult to predict. Jackals are classified as facultative cooperative hunters, and the term describes how they hunt in groups opportunistically when suitable resources of prey are available. The indication by several studies that jackals do actively predate rather than only scavenge, illustrates that the species has the potential to cause declines in an ungulate population. It therefore appears erroneous to exclude the species in terms of predator-prey relationships, particularly for land managers of fenced protected areas. The first step to any ecological management is the understanding of population size and trends over time. Unfortunately, little to no reliable methods exist to assess or monitor jackal populations. A popular tool for cryptic and wide-ranging terrestrial carnivores is Spatial Capture Recapture (SCR) models, typically through a camera trap array. These often rely on individual identities and an imperfect detection process to derive a statistical estimate of a given area. Jackals have been assumed to be individually unidentifiable and therefore these methods have largely been excluded. To address this a pilot-targeted camera-trap survey was conducted to improve capture and image quality. Following the role of this procedure, semi-automated software was applied to test the feasibility of individual identifications of captured images. This resulted in a subset of 58 right and left identifiable flank images, compiled from the highest graded images (n = 220) using the open-source Interactive Individual IdentificationSystem Beta Contour 3.0 (I3S Contour). I3S Contour assists users by distinguishing between unique contours on independent flanks without omitting observer effort and ranking. The effectiveness of the identification procedure was evaluated using three software tool trials, namely Computer-aided Annotation, Manual Contour Annotation, and Manual Contour Annotation (MA-2), where MA-2 included additional user-defined meta-data to images. Results showed that jackals could be individually identified from camera trap images and thus opened up the use of previously excluded SCR methodologies. Utilising the jackal database derived from the identification procedures described a total of 28 complete identifications (both flanks matched), 32 left-sided and 36 right-sided captures were used. These were derived from two independent survey periods split between seasonality (Winter & Spring). Two SCR methods were compared, namely, the Spatially Explicit Camera Recapture (SECR) and the newly developed Spatial Presence-Absence (SPA) modelling approach. SECR relies on full individual identification linked to spatial locations to derive spatial parameters to estimate population densities. The SECR methodology has been considered the most precise and was thus used as the benchmark. SPA relies on detections only (i.e., without individual identities), along with informative or uninformative priors. This must be across a spatial array that has detectors close enough to allow for simultaneous detections during each occasion (< 24 hours). Comparisons between these model outputs indicated a high degree of confidence interval overlap; however, SPA had a consistently higher posterior mode density estimate (63-64% higher), where the coefficient of variation between outputs also indicated the SPA having a closer relative precision. The targeted survey results for both model outputs for 2021 did not appear unusually high when compared to other studies. To assess the WGR population size over the long term, opportunistic by-catch data from a nine-year leopard (Panthera pardus) camera survey (Panthera organisation) was utilised. Model outputs from each of the years indicated that population estimates remained relatively stable. This was an unexpected result as the SPA densities did not follow the detection observations. This could be attributed to M not being set high enough (200) and the model reaching the limit, resulting in similar outputs between years. An alternative explanation is where the station spacing is larger than the diameter of the home range, which may reduce spatial correlation. , Thesis (MSc) -- Faculty of Science, School of Natural Resource Science & Management, 2024
- Full Text:
- Date Issued: 2024-04
Evaluating elephant, Loxodonta africana, space-use and elephant-linked vegetation change in Liwonde National Park, Malawi
- Authors: Evers, Emma Else Maria
- Date: 2024-04
- Subjects: Elephants -- Nutrition -- Malawi , Ecological heterogeneity , Vegetation and climate
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63744 , vital:73594
- Description: Heterogeneity, the spatio-temporal variation of abiotic and biotic factors, is a key concept that underpins many ecological phenomena and promotes biodiversity. Ecosystem engineers, such as African savanna elephants (hereafter elephant), Loxodonta africana, are organisms capable of affecting heterogeneity through the creation or modification of habitats. Thus, their impacts can have important consequences for ecosystem biodiversity, both positive and negative. Caughley’s “elephant problem” cautions that confined or compressed, growing elephant populations will inevitably lead to a loss of biodiversity. However, a shift in our understanding of elephants suggests that not all elephant impacts lead to negative biodiversity consequences, as long as there is a heterogeneous spread of elephant impacts that allows for spatio-temporal refuges promoting the persistence of both impact-tolerant and impact-intolerant species. To date, little empirical evidence is available in support of managing elephants under this paradigm and few studies are available that infer the consequences of the distribution of elephant impacts on biodiversity. In addition, most studies use parametric statistics that do not account for scale, spatial autocorrelation, or non-stationarity, leading to a misrepresentation of the underlying processes and patterns of drivers of elephant space-use and the consequences of their impacts on biodiversity. Here, I evaluate spatio-temporal patterns and drivers of elephant space-use, and how the distribution of their impacts affects biodiversity through vegetation changes, using a multi-scaled spatial approach, in Liwonde National Park, Malawi. My study demonstrates that elephant space-use in Liwonde is heterogeneous, leading to spatio-temporal variation in the distribution of their impacts, even in a small, fenced reserve. The importance of the drivers of this heterogeneous space-use varied based on the scale of analysis, water was generally important at larger scales while vegetation quality (indexed by NDVI) was more important at smaller scales. When examined using local models, my results suggest that relationships exhibit non-stationarity, what is important in one area of the park is not necessarily important in other areas. The spatio-temporal variation of the inferred impacts of elephants in Liwonde still allowed for spatio-temporal refuges to be created, no clear linear relationship was found between elephant return intervals and woody species structural and functional diversity (indexed by changes in tree cover and changes in annual regrowth using Normalized Difference Vegetation Index as a measure, respectively) throughout the park. My study provides support for adopting the heterogeneity paradigm for managing elephants and demonstrates that not all elephant impacts result in negative vegetation change. I also demonstrate the crucial implications of accounting for scale, non-stationarity, and spatial autocorrelation to evaluate how animals both respond to, and contribute to, environmental heterogeneity. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Evers, Emma Else Maria
- Date: 2024-04
- Subjects: Elephants -- Nutrition -- Malawi , Ecological heterogeneity , Vegetation and climate
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63744 , vital:73594
- Description: Heterogeneity, the spatio-temporal variation of abiotic and biotic factors, is a key concept that underpins many ecological phenomena and promotes biodiversity. Ecosystem engineers, such as African savanna elephants (hereafter elephant), Loxodonta africana, are organisms capable of affecting heterogeneity through the creation or modification of habitats. Thus, their impacts can have important consequences for ecosystem biodiversity, both positive and negative. Caughley’s “elephant problem” cautions that confined or compressed, growing elephant populations will inevitably lead to a loss of biodiversity. However, a shift in our understanding of elephants suggests that not all elephant impacts lead to negative biodiversity consequences, as long as there is a heterogeneous spread of elephant impacts that allows for spatio-temporal refuges promoting the persistence of both impact-tolerant and impact-intolerant species. To date, little empirical evidence is available in support of managing elephants under this paradigm and few studies are available that infer the consequences of the distribution of elephant impacts on biodiversity. In addition, most studies use parametric statistics that do not account for scale, spatial autocorrelation, or non-stationarity, leading to a misrepresentation of the underlying processes and patterns of drivers of elephant space-use and the consequences of their impacts on biodiversity. Here, I evaluate spatio-temporal patterns and drivers of elephant space-use, and how the distribution of their impacts affects biodiversity through vegetation changes, using a multi-scaled spatial approach, in Liwonde National Park, Malawi. My study demonstrates that elephant space-use in Liwonde is heterogeneous, leading to spatio-temporal variation in the distribution of their impacts, even in a small, fenced reserve. The importance of the drivers of this heterogeneous space-use varied based on the scale of analysis, water was generally important at larger scales while vegetation quality (indexed by NDVI) was more important at smaller scales. When examined using local models, my results suggest that relationships exhibit non-stationarity, what is important in one area of the park is not necessarily important in other areas. The spatio-temporal variation of the inferred impacts of elephants in Liwonde still allowed for spatio-temporal refuges to be created, no clear linear relationship was found between elephant return intervals and woody species structural and functional diversity (indexed by changes in tree cover and changes in annual regrowth using Normalized Difference Vegetation Index as a measure, respectively) throughout the park. My study provides support for adopting the heterogeneity paradigm for managing elephants and demonstrates that not all elephant impacts result in negative vegetation change. I also demonstrate the crucial implications of accounting for scale, non-stationarity, and spatial autocorrelation to evaluate how animals both respond to, and contribute to, environmental heterogeneity. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Evaluation of road surface distresses using GPS and GIS techniques: a case study of the City of Johannesburg, South Africa
- Authors: Tsedu, Rinae
- Date: 2024-04
- Subjects: Global Positioning System South Africa -- Johannesburg , Navigation -- Technological innovations , Geographic information systems -- South Africa -- Johannesburg
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64401 , vital:73695
- Description: Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Tsedu, Rinae
- Date: 2024-04
- Subjects: Global Positioning System South Africa -- Johannesburg , Navigation -- Technological innovations , Geographic information systems -- South Africa -- Johannesburg
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64401 , vital:73695
- Description: Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Exploring 3d printing of brass instruments: a comparative study of French horn mouthpieces
- Authors: Barker, Dylan Bruce
- Date: 2024-04
- Subjects: Horn (Musical instrument) , Three-dimensional printing , Instrumentation and orchestration (Band)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62755 , vital:72939
- Description: The French horn is an orchestral instrument with a rich history that spans centuries, undergoing notable transformations in its design and functionality. A short overview of this history is provided in Appendix A. Originating as a simple coil, the French horn has evolved to encompass a complex valve system, multiple harmonic series, and a diverse range of modifications tailored to players' preferences and requirements. These modifications include mutes, grips, extra keys, and even the exploration of different materials for mouthpieces. The use of plastic rims on mouthpieces, for reasons such as allergies, thermal conductivity, and tactile sensation, has already gained traction among horn players (Tuckwell, 2002). In the realm of manufacturing and technology, the concept of additive manufacturing has emerged as a promising avenue. Referred to as the next "industrial revolution” (Berman, 2012), additive manufacturing has become increasingly accessible through desktop-scale 3D printers. This technology offers a viable method for producing cost-effective musical instruments and enhancers without compromising quality (Kantaros, 2018). As evidenced by a 2018 Roundtable report from the South African Parliament, additive manufacturing aligns with the trajectory of the fourth industrial revolution, prompting governments to develop policies and strategies to harness its potential. Given the significance of additive manufacturing, a comprehensive investigation into applying these new technologies for the horn is warranted. Specifically, material choice, quality of sound, and the experience of performing on a printed mouthpiece is investigated and compared to a traditional metal mouthpiece. While the horn is comprised of many individual components, this study relates specifically to the mouthpiece. A brief appraisal of the significance of the mouthpiece will follow in the next section. , Thesis (MMus) -- Faculty of Humanities, School of Visual and Performing Arts, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Barker, Dylan Bruce
- Date: 2024-04
- Subjects: Horn (Musical instrument) , Three-dimensional printing , Instrumentation and orchestration (Band)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/62755 , vital:72939
- Description: The French horn is an orchestral instrument with a rich history that spans centuries, undergoing notable transformations in its design and functionality. A short overview of this history is provided in Appendix A. Originating as a simple coil, the French horn has evolved to encompass a complex valve system, multiple harmonic series, and a diverse range of modifications tailored to players' preferences and requirements. These modifications include mutes, grips, extra keys, and even the exploration of different materials for mouthpieces. The use of plastic rims on mouthpieces, for reasons such as allergies, thermal conductivity, and tactile sensation, has already gained traction among horn players (Tuckwell, 2002). In the realm of manufacturing and technology, the concept of additive manufacturing has emerged as a promising avenue. Referred to as the next "industrial revolution” (Berman, 2012), additive manufacturing has become increasingly accessible through desktop-scale 3D printers. This technology offers a viable method for producing cost-effective musical instruments and enhancers without compromising quality (Kantaros, 2018). As evidenced by a 2018 Roundtable report from the South African Parliament, additive manufacturing aligns with the trajectory of the fourth industrial revolution, prompting governments to develop policies and strategies to harness its potential. Given the significance of additive manufacturing, a comprehensive investigation into applying these new technologies for the horn is warranted. Specifically, material choice, quality of sound, and the experience of performing on a printed mouthpiece is investigated and compared to a traditional metal mouthpiece. While the horn is comprised of many individual components, this study relates specifically to the mouthpiece. A brief appraisal of the significance of the mouthpiece will follow in the next section. , Thesis (MMus) -- Faculty of Humanities, School of Visual and Performing Arts, 2024
- Full Text:
- Date Issued: 2024-04
Exploring resilience of social workers working within the healthcare system in the Nelson Mandela Metropole, South Africa
- Authors: Deliwe, Olwethu Paul
- Date: 2024-04
- Subjects: Social workers -- Port Elizabeth (South Africa) , Resilience (Personality trait) , Health services administration -- Nelson Mandela Bay Municipality (South Africa)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63824 , vital:73617
- Description: Social workers working in the health care setting must respond to complex patient needs, a fast paced and multidisciplinary work environment, that are frequently not experienced as equalising platforms for the social work discipline. This requires a high level of resilience in social workers to remain responsive to compassionate human care, quality service delivery and selfcare. This study aimed to explore the resilience of social workers in the healthcare sector, in order to address the knowledge and practice gap and contribute to a better understanding of mental healthcare needs and coping resources of social workers, working in this field of service. The study was guided by two theoretical frameworks: The ecological systems theory and resilience theory. Informed by a constructivism research paradigm, the study employed semi-structures in-depth research interviews as a method to collect data with eight social workers as research participants, recruited via purposive research sampling from health and mental health care settings. The key findings indicate that social workers experience various challenges at work that leads to burnout as a result of the complex work that they do, and they are required to contain these and be resilient using different mechanism. All the ethical protocols were observed, and the necessary measures taken to enhance the trustworthiness of the study. The findings make a valuable contribution to the curriculum input for social work training and valuable insights for continuous professional development for social work practitioners in the health care sector. , Thesis (MA) -- Faculty of Health Science, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Deliwe, Olwethu Paul
- Date: 2024-04
- Subjects: Social workers -- Port Elizabeth (South Africa) , Resilience (Personality trait) , Health services administration -- Nelson Mandela Bay Municipality (South Africa)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63824 , vital:73617
- Description: Social workers working in the health care setting must respond to complex patient needs, a fast paced and multidisciplinary work environment, that are frequently not experienced as equalising platforms for the social work discipline. This requires a high level of resilience in social workers to remain responsive to compassionate human care, quality service delivery and selfcare. This study aimed to explore the resilience of social workers in the healthcare sector, in order to address the knowledge and practice gap and contribute to a better understanding of mental healthcare needs and coping resources of social workers, working in this field of service. The study was guided by two theoretical frameworks: The ecological systems theory and resilience theory. Informed by a constructivism research paradigm, the study employed semi-structures in-depth research interviews as a method to collect data with eight social workers as research participants, recruited via purposive research sampling from health and mental health care settings. The key findings indicate that social workers experience various challenges at work that leads to burnout as a result of the complex work that they do, and they are required to contain these and be resilient using different mechanism. All the ethical protocols were observed, and the necessary measures taken to enhance the trustworthiness of the study. The findings make a valuable contribution to the curriculum input for social work training and valuable insights for continuous professional development for social work practitioners in the health care sector. , Thesis (MA) -- Faculty of Health Science, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Exploring senior phase teachers’ use of kahoot! Gamification as a formative assessment tool to scaffold mathematical understanding
- Authors: Balele, Silence
- Date: 2024-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423891 , vital:72102
- Description: In South Africa, digital technology, particularly gamification, continues to become an important teaching and learning tool. Its importance lies in scaffolding mathematical understanding, improving the quality of assessment, and developing twenty-first-century technological skills for effective mathematics assessment. To explore this importance, senior phase mathematics teachers are encouraged to adopt gamification technology such as Kahoot! in assessment. The study adopted a case study research design with a interpretivist research paradigm, as this method allows detailed exploration and understanding of a specific context through a close connection with the participants. Data was collected using semi-structured questionnaires, focus group interviews, non-participant observations, and reflective journals. The research involved ten purposively selected senior-phase mathematics teachers from two schools in the Sarah Baartman District, Eastern Cape Province, South Africa. The study drew upon Vygoysky's Sociocultural Theory for its theoretical framework, while the Technological, Pedagogical, and Content Knowledge was used for analysis. The data analysis pursued an inductive approach. Adopting a thematic analysis included coding participant responses, organizing codes into concepts and categories, and developing a theoretical framework from the resultant categories. A four-phase process was involved: coding, conceptualizing, categorizing, and theorizing, was employed. This process and using NVivo software for data organization and management helped identify patterns, themes, and significant concerns surrounding the study's core subject. The findings from the study were as follows: Firstly, it was revealed that most teachers have a positive perception and attitude towards using Kahoot! for formative assessment, believing that it enhances teaching and learning quality. However, they showed scepticism due to insufficient Information and Communication Technologies knowledge and training. Second, teachers' pedagogical and technological experiences were predominantly enjoyable. Kahoot! was accepted as beneficial for promoting collaboration, interaction, and immediate feedback. Third, the study identified enabling and constraining factors in using Kahoot! for formative assessment. The enabling factors include Kahoot!, which was convenient and accessible, promoted immediate feedback and fostered collaboration and interaction. The constraining factors include Information and Communication Technologies and network interference, which posed limitations. The research concluded that Kahoot! as a platform for formative assessment indeed scaffold mathematical understanding. The study recommends increasing teachers' access to educational technology, incorporating continuous professional development programs, providing subject-specific training, and encouraging teachers to adapt to emerging technologies. The study also provided recommendations for future research to explore learner perceptions, employ a mixed methods approach to help quantify learner performance and investigate the pedagogical and technological experiences of senior phase mathematics teachers regarding formative assessment. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Balele, Silence
- Date: 2024-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423891 , vital:72102
- Description: In South Africa, digital technology, particularly gamification, continues to become an important teaching and learning tool. Its importance lies in scaffolding mathematical understanding, improving the quality of assessment, and developing twenty-first-century technological skills for effective mathematics assessment. To explore this importance, senior phase mathematics teachers are encouraged to adopt gamification technology such as Kahoot! in assessment. The study adopted a case study research design with a interpretivist research paradigm, as this method allows detailed exploration and understanding of a specific context through a close connection with the participants. Data was collected using semi-structured questionnaires, focus group interviews, non-participant observations, and reflective journals. The research involved ten purposively selected senior-phase mathematics teachers from two schools in the Sarah Baartman District, Eastern Cape Province, South Africa. The study drew upon Vygoysky's Sociocultural Theory for its theoretical framework, while the Technological, Pedagogical, and Content Knowledge was used for analysis. The data analysis pursued an inductive approach. Adopting a thematic analysis included coding participant responses, organizing codes into concepts and categories, and developing a theoretical framework from the resultant categories. A four-phase process was involved: coding, conceptualizing, categorizing, and theorizing, was employed. This process and using NVivo software for data organization and management helped identify patterns, themes, and significant concerns surrounding the study's core subject. The findings from the study were as follows: Firstly, it was revealed that most teachers have a positive perception and attitude towards using Kahoot! for formative assessment, believing that it enhances teaching and learning quality. However, they showed scepticism due to insufficient Information and Communication Technologies knowledge and training. Second, teachers' pedagogical and technological experiences were predominantly enjoyable. Kahoot! was accepted as beneficial for promoting collaboration, interaction, and immediate feedback. Third, the study identified enabling and constraining factors in using Kahoot! for formative assessment. The enabling factors include Kahoot!, which was convenient and accessible, promoted immediate feedback and fostered collaboration and interaction. The constraining factors include Information and Communication Technologies and network interference, which posed limitations. The research concluded that Kahoot! as a platform for formative assessment indeed scaffold mathematical understanding. The study recommends increasing teachers' access to educational technology, incorporating continuous professional development programs, providing subject-specific training, and encouraging teachers to adapt to emerging technologies. The study also provided recommendations for future research to explore learner perceptions, employ a mixed methods approach to help quantify learner performance and investigate the pedagogical and technological experiences of senior phase mathematics teachers regarding formative assessment. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-04
Exploring the continued importance of technique in the co-production of art with A.I.
- Authors: Venter, Simon Denis
- Date: 2024-04
- Subjects: Art and technology , Mass media and culture , Artificial Intelligence
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63573 , vital:73504
- Description: n Plato’s Republic, artists are criticised for their perceived lack of rationality, since “art encourages and appeals to emotion,” insofar as “its ruling principle is the passions, which in a happy and well-ordered life must be controlled by reason;” indeed, on this basis, “the aesthetic experience” is even said to be “a psychological anarchy, [and] an orgy of misrule” (Collingwood, 1925: 156). However, this reification of reason in Plato’s hypothesized world,1 informed as it was by static hierarchy, has remained dissonant with the path of history toward entropy, as evinced by the chaotic flux of postmodernity. Certainly, this is exemplified in our own postmodern world, characterized as it is by ever greater degrees of disintegration into diversity, as the economic, social, and geo-political orders established in the mid-twentieth century are challenged and transformed into new paradigms through the increasing multiplicity of demands being made on them (Fowlie & Sills, 2011: 120-121). Accordingly, far from being a source of delusion and dissimilation, it could equally be argued that, collectively and individually, artists’ works reflect this kaleidoscopic trace of time more truthfully than the lens of reason, precisely because life – like art – is also largely psychological anarchy and an orgy of misrule. And within this dynamic environment, the reflections of artists, in turn, assume their value, as traces of what, for want of a better term, will henceforth be referred to as living dialogical time. That is, from this perspective, artists are not the political problem Plato suggested them to be, but rather as a whole comprise a reflection of the living dialogical time that, today, recognises itself collectively as humanity. However, while art has always involved material marks, digitality has recently changed this requirement, in ways which have raised a series of important and difficult questions for the world of art. That is, digitality has changed the wall of the cave into the digits of ones and zeros, which are eradicated at the click of an icon, only to be reconstructed at the click of an icon. Thus, the interface between art and digitality involves the former being presented with increasing opportunities for dynamism, but only at the expense of its materiality – insofar as such dynamism requires art to transition to cyber-virtual platforms. But in this regard, it must be remembered that, by definition, an icon is something which connects us to what cannot ever be represented, because it is beyond our everyday living reality, in an atemporal plane. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Venter, Simon Denis
- Date: 2024-04
- Subjects: Art and technology , Mass media and culture , Artificial Intelligence
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63573 , vital:73504
- Description: n Plato’s Republic, artists are criticised for their perceived lack of rationality, since “art encourages and appeals to emotion,” insofar as “its ruling principle is the passions, which in a happy and well-ordered life must be controlled by reason;” indeed, on this basis, “the aesthetic experience” is even said to be “a psychological anarchy, [and] an orgy of misrule” (Collingwood, 1925: 156). However, this reification of reason in Plato’s hypothesized world,1 informed as it was by static hierarchy, has remained dissonant with the path of history toward entropy, as evinced by the chaotic flux of postmodernity. Certainly, this is exemplified in our own postmodern world, characterized as it is by ever greater degrees of disintegration into diversity, as the economic, social, and geo-political orders established in the mid-twentieth century are challenged and transformed into new paradigms through the increasing multiplicity of demands being made on them (Fowlie & Sills, 2011: 120-121). Accordingly, far from being a source of delusion and dissimilation, it could equally be argued that, collectively and individually, artists’ works reflect this kaleidoscopic trace of time more truthfully than the lens of reason, precisely because life – like art – is also largely psychological anarchy and an orgy of misrule. And within this dynamic environment, the reflections of artists, in turn, assume their value, as traces of what, for want of a better term, will henceforth be referred to as living dialogical time. That is, from this perspective, artists are not the political problem Plato suggested them to be, but rather as a whole comprise a reflection of the living dialogical time that, today, recognises itself collectively as humanity. However, while art has always involved material marks, digitality has recently changed this requirement, in ways which have raised a series of important and difficult questions for the world of art. That is, digitality has changed the wall of the cave into the digits of ones and zeros, which are eradicated at the click of an icon, only to be reconstructed at the click of an icon. Thus, the interface between art and digitality involves the former being presented with increasing opportunities for dynamism, but only at the expense of its materiality – insofar as such dynamism requires art to transition to cyber-virtual platforms. But in this regard, it must be remembered that, by definition, an icon is something which connects us to what cannot ever be represented, because it is beyond our everyday living reality, in an atemporal plane. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2024
- Full Text:
- Date Issued: 2024-04