A spatial assessment of riparian vegetation density and implications for streambank erosion in relation to land tenure in the Mgwalana Catchment, Eastern Cape Province, South Africa
- Authors: Maxama, Asakhile
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53864 , vital:46026
- Description: Riparian vegetation provides an array of various ecosystem functions and has significantly shaped the conditions of catchments. It has strong controls on fluvial geomorphology and erosion processes. The Mgwalana catchment has been intensively studied over the years and the current environmental condition of the study has been linked to land use history. The catchment has been subjected to land use/cover changes (LUCC) over the years. However, spatial variations in riparian vegetation, their implications for stream bank stability and the contribution of land tenure systems to stream channel degradation are poorly understood. The study sought to assess the implications of the spatial variations in riparian vegetation density for stream bank erosion in relation to land tenure on a catchment scale. Land tenure units comprising the catchment of study are traditional and betterment villages (communal lands), and former white commercial farms. A three-pronged approach using GIS and remote sensing, field investigations and laboratory procedures for soil analysis was employed in this study. Variations of riparian vegetation density in the catchment were mapped using ArcGIS for the two land tenure units to assess the spatial variations of riparian density along stream reaches and to determine the spatial relationship between land tenure units and riparian vegetation diminution. Other mapped shape files include sediment accumulation zones to analyse the spatial relationship between riparian vegetation density and sediment sinks. LUCC classification and analysis of the Normalized Difference Vegetation Index (NDVI) were carried out in IDRISI Selva, using Landsat 8 TM imagery of 2018 to represent the current spatial riparian vegetation variations in the catchment. Field investigations were conducted to determine the coupling among hillslope gully erosion, riparian vegetation density and sink areas; and to assess physical characteristics of soil. This would permit an assessment of the implications of riparian vegetation for stream bank erosion and sediment accumulation within the tenure units. Soil samples were taken from scantily and densely vegetated stream reaches, as well as measurements of channel widths and depths. Analyses of soil physical properties viz; grain size distribution, bulk density, soil texture and aggregate stability were done. Results demonstrated that a sparse riparian vegetation distribution was consistent with the communal villages, confined to the upper catchment area. Dense riparian vegetation distribution was consistent with former commercial farms in the lower catchment area. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Maxama, Asakhile
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53864 , vital:46026
- Description: Riparian vegetation provides an array of various ecosystem functions and has significantly shaped the conditions of catchments. It has strong controls on fluvial geomorphology and erosion processes. The Mgwalana catchment has been intensively studied over the years and the current environmental condition of the study has been linked to land use history. The catchment has been subjected to land use/cover changes (LUCC) over the years. However, spatial variations in riparian vegetation, their implications for stream bank stability and the contribution of land tenure systems to stream channel degradation are poorly understood. The study sought to assess the implications of the spatial variations in riparian vegetation density for stream bank erosion in relation to land tenure on a catchment scale. Land tenure units comprising the catchment of study are traditional and betterment villages (communal lands), and former white commercial farms. A three-pronged approach using GIS and remote sensing, field investigations and laboratory procedures for soil analysis was employed in this study. Variations of riparian vegetation density in the catchment were mapped using ArcGIS for the two land tenure units to assess the spatial variations of riparian density along stream reaches and to determine the spatial relationship between land tenure units and riparian vegetation diminution. Other mapped shape files include sediment accumulation zones to analyse the spatial relationship between riparian vegetation density and sediment sinks. LUCC classification and analysis of the Normalized Difference Vegetation Index (NDVI) were carried out in IDRISI Selva, using Landsat 8 TM imagery of 2018 to represent the current spatial riparian vegetation variations in the catchment. Field investigations were conducted to determine the coupling among hillslope gully erosion, riparian vegetation density and sink areas; and to assess physical characteristics of soil. This would permit an assessment of the implications of riparian vegetation for stream bank erosion and sediment accumulation within the tenure units. Soil samples were taken from scantily and densely vegetated stream reaches, as well as measurements of channel widths and depths. Analyses of soil physical properties viz; grain size distribution, bulk density, soil texture and aggregate stability were done. Results demonstrated that a sparse riparian vegetation distribution was consistent with the communal villages, confined to the upper catchment area. Dense riparian vegetation distribution was consistent with former commercial farms in the lower catchment area. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text:
- Date Issued: 2021-12
A value alignment smart city stakeholder model
- Van der Hoogen, Anthea Vivian
- Authors: Van der Hoogen, Anthea Vivian
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54129 , vital:46309
- Description: The concept of a Smart City has evolved over the last three decades and has attracted the increasing interest of the scientific research community. Unfortunately, many Smart City projects and initiatives do not provide the value expected by all the stakeholders. Many of the reasons for this relate to a lack of data management, data integration, data access and stakeholder participation. People are an integral part of any city’s ecosystem, and the Smart City concept was introduced to address the challenges of an ever-growing global population leading to the risk of depletion of economic, environmental and social resources. The problem addressed in this study is based on the challenges preventing the creation of the value of smart cities or stakeholders. Limited research has been published on the status of Smart City initiatives or on the impact of various success factors on the potential value creation for stakeholders including citizens. Studies on initiatives in developing countries, such as South Africa are even less. Whilst some challenges and constraints related to smart cities in Africa have been reported, there are no studies reporting on initiatives across the data value chain that consider all types of stakeholders, nor the impact of these initiatives. This study addressed this gap in research and designed a theoretical Value Alignment Smart City Stakeholder (VASCS) Model based on a Systematic Literature Review and a review of related theories. The model has important components that should form part of any Smart City project or Smart City initiative. These five main components are: 1) nine Smart City dimensions with related success factors; 2) four stakeholder roles (enablers, providers, utilisers and users); 3) the data value chain; and 4) the five phases of stakeholder benefits/value realisation that can be linked to; 5) stakeholder value alignment. This study applied the VASCS Model to Smart City initiatives in two case studies in the Eastern Cape Province of South Africa, which were the Nelson Mandela Bay and Buffalo City to investigate and understand the status of such initiatives and the alignment of value thereof. The stakeholder interviews were conducted in two rounds with various stakeholders of Smart City initiatives, referred to as cases in the two case studies. An expert review of the VASCS Model was conducted with eight experts in the field of Information Systems and Smart Cities. The findings of this review served to confirm the components of the model, with only minor improvements recommended. It was confirmed that all of the components need to be considered in planning Smart City projects. The first round consisted of six interviews with enablers and providers and the second round consisted of 22 interviews with users, utilisers and citizens. The interviews investigated the value and impact experienced by stakeholders of these initiatives, with a particular focus on the users, utilisers and citizens of the cases. The interview data was transcribed and qualitatively analysed by using Atlas.tiand Excel. The data was analysed according to the Technological, Organisational and Environmental theory constructs and other identified themes. The interview analysis findings revealed several drivers for these initiatives, which were primarily cost reduction, integration and quality assurance. The results also highlighted access to resources, such as technical skills as a challenge. Another challenge identified was connectivity related to access to data and the digital and physical divide that can impact decision making. The main benefits of Smart City initiatives highlighted were the provision of infrastructure, education and training and digitalisation. The theoretical contribution of this study is the VASCS Model, which can assist other researchers and practitioners with knowledge of the factors, drivers, challenges and value obtained in Smart City initiatives. The model has two supplementary components: A Stakeholder Classification Model and a Smart City Success Factor Evaluation Template. The practical contribution of this study is the potential use of the VASCS Model by practitioners, city management, researchers and other stakeholders, who can use the model, with the related model and template for planning and evaluating Smart City initiatives. The model can be used to classify the digital activities according to a Smart City’s success factors while evaluating the value created by these activities. The impact of these initiatives can then be assessed through value realisation and alignment for stakeholders. The scientific contribution is the adoption of the model to the cases in the Eastern Cape. To reveal in depth, rich, interview findings that provide important lessons learnt relating to the value created for the stakeholders and the addition of these findings to the body of knowledge. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Van der Hoogen, Anthea Vivian
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54129 , vital:46309
- Description: The concept of a Smart City has evolved over the last three decades and has attracted the increasing interest of the scientific research community. Unfortunately, many Smart City projects and initiatives do not provide the value expected by all the stakeholders. Many of the reasons for this relate to a lack of data management, data integration, data access and stakeholder participation. People are an integral part of any city’s ecosystem, and the Smart City concept was introduced to address the challenges of an ever-growing global population leading to the risk of depletion of economic, environmental and social resources. The problem addressed in this study is based on the challenges preventing the creation of the value of smart cities or stakeholders. Limited research has been published on the status of Smart City initiatives or on the impact of various success factors on the potential value creation for stakeholders including citizens. Studies on initiatives in developing countries, such as South Africa are even less. Whilst some challenges and constraints related to smart cities in Africa have been reported, there are no studies reporting on initiatives across the data value chain that consider all types of stakeholders, nor the impact of these initiatives. This study addressed this gap in research and designed a theoretical Value Alignment Smart City Stakeholder (VASCS) Model based on a Systematic Literature Review and a review of related theories. The model has important components that should form part of any Smart City project or Smart City initiative. These five main components are: 1) nine Smart City dimensions with related success factors; 2) four stakeholder roles (enablers, providers, utilisers and users); 3) the data value chain; and 4) the five phases of stakeholder benefits/value realisation that can be linked to; 5) stakeholder value alignment. This study applied the VASCS Model to Smart City initiatives in two case studies in the Eastern Cape Province of South Africa, which were the Nelson Mandela Bay and Buffalo City to investigate and understand the status of such initiatives and the alignment of value thereof. The stakeholder interviews were conducted in two rounds with various stakeholders of Smart City initiatives, referred to as cases in the two case studies. An expert review of the VASCS Model was conducted with eight experts in the field of Information Systems and Smart Cities. The findings of this review served to confirm the components of the model, with only minor improvements recommended. It was confirmed that all of the components need to be considered in planning Smart City projects. The first round consisted of six interviews with enablers and providers and the second round consisted of 22 interviews with users, utilisers and citizens. The interviews investigated the value and impact experienced by stakeholders of these initiatives, with a particular focus on the users, utilisers and citizens of the cases. The interview data was transcribed and qualitatively analysed by using Atlas.tiand Excel. The data was analysed according to the Technological, Organisational and Environmental theory constructs and other identified themes. The interview analysis findings revealed several drivers for these initiatives, which were primarily cost reduction, integration and quality assurance. The results also highlighted access to resources, such as technical skills as a challenge. Another challenge identified was connectivity related to access to data and the digital and physical divide that can impact decision making. The main benefits of Smart City initiatives highlighted were the provision of infrastructure, education and training and digitalisation. The theoretical contribution of this study is the VASCS Model, which can assist other researchers and practitioners with knowledge of the factors, drivers, challenges and value obtained in Smart City initiatives. The model has two supplementary components: A Stakeholder Classification Model and a Smart City Success Factor Evaluation Template. The practical contribution of this study is the potential use of the VASCS Model by practitioners, city management, researchers and other stakeholders, who can use the model, with the related model and template for planning and evaluating Smart City initiatives. The model can be used to classify the digital activities according to a Smart City’s success factors while evaluating the value created by these activities. The impact of these initiatives can then be assessed through value realisation and alignment for stakeholders. The scientific contribution is the adoption of the model to the cases in the Eastern Cape. To reveal in depth, rich, interview findings that provide important lessons learnt relating to the value created for the stakeholders and the addition of these findings to the body of knowledge. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text:
- Date Issued: 2021-12
Administrative justice and the implementation of the reconstruction and development program in Berlin Town, Eastern Cape
- Authors: Makie, Fundiswa
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54460 , vital:46577
- Description: Housing delivery in South Africa is a crucial and topical issue affecting many citizens. The primary objective of the study was to determine the role of administrative justice in the implementation of the Reconstructive and Development Programme (RDP) in Berlin Town, in the province of the Eastern Cape in South Africa. In addition, the aim of this study was to explore the challenges of RDP housing in the study area, as a way of probing whether housing needs were being met. The study was conducted using a qualitative research methodology in gathering data from Berlin Town residents, Buffalo City Metropolitan Municipality staff and Berlin Town councillors. The data analysis revealed that respondents affirmed the importance of administrative justice and the effective implementation of the RDP with regard to housing. Based on the findings of the study, the researcher recommends that the Buffalo City Metropolitan Municipality prioritise the full implementation of the Integrated Development Plan (IDP) in dealing with the housing backlog and challenges in Berlin Town. Moreover, the findings of this study revealed that it is possible to highlight specific recommendations that can be used by various other local municipalities. Thus, the research study showed that efficient local municipal operations have a direct impact on the delivery of RDP houses. Relating to ethical considerations, the researcher ensured that all the requirements for credible research were met throughout the study. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Makie, Fundiswa
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54460 , vital:46577
- Description: Housing delivery in South Africa is a crucial and topical issue affecting many citizens. The primary objective of the study was to determine the role of administrative justice in the implementation of the Reconstructive and Development Programme (RDP) in Berlin Town, in the province of the Eastern Cape in South Africa. In addition, the aim of this study was to explore the challenges of RDP housing in the study area, as a way of probing whether housing needs were being met. The study was conducted using a qualitative research methodology in gathering data from Berlin Town residents, Buffalo City Metropolitan Municipality staff and Berlin Town councillors. The data analysis revealed that respondents affirmed the importance of administrative justice and the effective implementation of the RDP with regard to housing. Based on the findings of the study, the researcher recommends that the Buffalo City Metropolitan Municipality prioritise the full implementation of the Integrated Development Plan (IDP) in dealing with the housing backlog and challenges in Berlin Town. Moreover, the findings of this study revealed that it is possible to highlight specific recommendations that can be used by various other local municipalities. Thus, the research study showed that efficient local municipal operations have a direct impact on the delivery of RDP houses. Relating to ethical considerations, the researcher ensured that all the requirements for credible research were met throughout the study. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
Applying a systems analysis approach to support marine spatial planning in Algoa Bay, South Africa
- Authors: Vermeulen, Estee Ann
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54121 , vital:46312
- Description: Ocean health provides the foundation for human health through the provisioning of ecosystem services. Increasing demands on ocean space and resources are, however, resulting in a decline in ocean health, with direct and indirect knock-on effects on marine uses and ultimately on human health. In response, there is a growing need to acknowledge and better manage complex human-ocean interactions. This has been recognised in global sustainable development goals and in integrated ocean management processes, leading to widespread endorsement of an ecosystem-based marine spatial planning (MSP) process, including in South Africa. In support of the national MSP process, significant progress has been made in understanding the spatial extent of marine activities and associated marine pressures, but the temporal dynamics of marine activities and interconnections with the marine environment are less well understood. To plan for the growth of marine activities and associated user conflicts, the drivers of these temporal dynamics and associated feedback effects need to be analysed and potential policy and management interventions identified and tested. To support South Africa’s national MSP process, this study adopts a systems analysis approach, using system dynamics modelling, to explore the temporal change in marine uses under alternative growth scenarios in Algoa Bay. Algoa Bay is an appropriate study area because it is experiencing a rapid expansion of marine activities, coupled with a growing uncertainty regarding marine sustainability outcomes. To assist future marine management decisions, the Algoa Marine Systems Analysis Tool (Algoa MSAT) was developed, comprising seven sub-models. Five of the sub-models represent selected marine uses in Algoa Bay, whereas the sixth and seventh integrate the outputs from each marine use in terms of sustainable management indicators (marine health, marine wealth and marine labour). Model development primarily adopted an expert-based model ling approach, although the involvement of stakeholders, through a collaborative modelling process, assisted in integrating knowledge on different marine sectors’ activities, impacts and planning visions into the model framework. Model results were generated under different scenarios to investigate changes in the growth of marine activities and marine sustainability indicators under different levels of ocean governance. Under the baseline (or business-as-usual) model scenario, marine activities were shown to grow increasingly within their respective management limits, with an increase in marine wealth and labour and a consequential decrease in marine health. This scenario particularly highlights that current ocean governance practices are ineffective in sustaining the projected growth of the marine uses, particularly for those that are vulnerable to negative changes in marine health. Conversely, sectors that hold more value in marine wealth and are more resilient to changes in marine health, may continue to grow regardless of negative knock-on effects of the health of the marine environment and on other uses in the bay. This emphasises that an alternative governance strategy is needed to achieve the long-term goal of an ecosystem-based MSP process, as required by South African MSP legislation. To achieve this will require multiple, adaptive cross-sectoral management interventions that are directed towards the ‘deeper leverage points’ that are able to maintain the growth of marine activities within appropriate limits defined by marine health. Using the model interface developed in this project, decision-makers and stakeholders can use the model to explore the temporal dynamics in marine activities under different governance scenarios. Although the model is limited to Algoa Bay, the model boundary can be adapted to assist in marine planning processes at national or trans-national scales. Such analytical assessments and tools are critical to progress the ecosystem-based management approach in MSP, as is required to achieve global sustainable development goals. , Thesis (PhD) -- Faculty of Science, Coastal and Marine Research Unit, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Vermeulen, Estee Ann
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54121 , vital:46312
- Description: Ocean health provides the foundation for human health through the provisioning of ecosystem services. Increasing demands on ocean space and resources are, however, resulting in a decline in ocean health, with direct and indirect knock-on effects on marine uses and ultimately on human health. In response, there is a growing need to acknowledge and better manage complex human-ocean interactions. This has been recognised in global sustainable development goals and in integrated ocean management processes, leading to widespread endorsement of an ecosystem-based marine spatial planning (MSP) process, including in South Africa. In support of the national MSP process, significant progress has been made in understanding the spatial extent of marine activities and associated marine pressures, but the temporal dynamics of marine activities and interconnections with the marine environment are less well understood. To plan for the growth of marine activities and associated user conflicts, the drivers of these temporal dynamics and associated feedback effects need to be analysed and potential policy and management interventions identified and tested. To support South Africa’s national MSP process, this study adopts a systems analysis approach, using system dynamics modelling, to explore the temporal change in marine uses under alternative growth scenarios in Algoa Bay. Algoa Bay is an appropriate study area because it is experiencing a rapid expansion of marine activities, coupled with a growing uncertainty regarding marine sustainability outcomes. To assist future marine management decisions, the Algoa Marine Systems Analysis Tool (Algoa MSAT) was developed, comprising seven sub-models. Five of the sub-models represent selected marine uses in Algoa Bay, whereas the sixth and seventh integrate the outputs from each marine use in terms of sustainable management indicators (marine health, marine wealth and marine labour). Model development primarily adopted an expert-based model ling approach, although the involvement of stakeholders, through a collaborative modelling process, assisted in integrating knowledge on different marine sectors’ activities, impacts and planning visions into the model framework. Model results were generated under different scenarios to investigate changes in the growth of marine activities and marine sustainability indicators under different levels of ocean governance. Under the baseline (or business-as-usual) model scenario, marine activities were shown to grow increasingly within their respective management limits, with an increase in marine wealth and labour and a consequential decrease in marine health. This scenario particularly highlights that current ocean governance practices are ineffective in sustaining the projected growth of the marine uses, particularly for those that are vulnerable to negative changes in marine health. Conversely, sectors that hold more value in marine wealth and are more resilient to changes in marine health, may continue to grow regardless of negative knock-on effects of the health of the marine environment and on other uses in the bay. This emphasises that an alternative governance strategy is needed to achieve the long-term goal of an ecosystem-based MSP process, as required by South African MSP legislation. To achieve this will require multiple, adaptive cross-sectoral management interventions that are directed towards the ‘deeper leverage points’ that are able to maintain the growth of marine activities within appropriate limits defined by marine health. Using the model interface developed in this project, decision-makers and stakeholders can use the model to explore the temporal dynamics in marine activities under different governance scenarios. Although the model is limited to Algoa Bay, the model boundary can be adapted to assist in marine planning processes at national or trans-national scales. Such analytical assessments and tools are critical to progress the ecosystem-based management approach in MSP, as is required to achieve global sustainable development goals. , Thesis (PhD) -- Faculty of Science, Coastal and Marine Research Unit, 2021
- Full Text:
- Date Issued: 2021-12
Assessing service delivery protests in the Nelson Mandela Bay Municipality: the case of Walmer Township
- Authors: Mdanyana, Esethu
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54492 , vital:46609
- Description: In many South Africa’s areas, citizen’s frustration with poor or slow service delivery has resulted in a surge of service delivery protests. Some of these service delivery protests are violent in nature, resulting in the damage of public and private property. Therefore, it is imperative to scrutinize service delivery protests. The South African constitution states that municipalities have the responsibility to make sure that all citizens are provided with services to satisfy their basic needs. These services include water supply, sewage collection and disposal electricity, gas supply health services, roads, storm water drainage, street lighting, municipal parks and recreation. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text: false
- Date Issued: 2021-12
- Authors: Mdanyana, Esethu
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54492 , vital:46609
- Description: In many South Africa’s areas, citizen’s frustration with poor or slow service delivery has resulted in a surge of service delivery protests. Some of these service delivery protests are violent in nature, resulting in the damage of public and private property. Therefore, it is imperative to scrutinize service delivery protests. The South African constitution states that municipalities have the responsibility to make sure that all citizens are provided with services to satisfy their basic needs. These services include water supply, sewage collection and disposal electricity, gas supply health services, roads, storm water drainage, street lighting, municipal parks and recreation. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text: false
- Date Issued: 2021-12
Bicultural voice in three works
- Authors: Nkuna, Musa Duke
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54607 , vital:46769
- Description: This portfolio of compositions is made up of two parts: Part one is a commentary on the works presented in the portfolio. As required by Nelson Mandela University for the degree of DMus, the commentary is a descriptive narrative, rather than an analysis, of the works. It forms a basic guide for the listener as to how these works were conceived and constructed, and how both African and Western music elements have been used in order to achieve a syncretism. My commentary endeavours to show the compositional techniques applied when writing these works, and how my cultural interactions, music training and experience as a professional opera singer influence my compositional output. Part two contains the creative content of the portfolio: a set of scores of the three works themselves, as well as accompanying recordings of these works, with a total duration of ca. 100 minutes of music. It forms the main part of the submission. , Thesis (DMA) -- Faculty of Humanities, Department of Music and Performing Arts, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Nkuna, Musa Duke
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54607 , vital:46769
- Description: This portfolio of compositions is made up of two parts: Part one is a commentary on the works presented in the portfolio. As required by Nelson Mandela University for the degree of DMus, the commentary is a descriptive narrative, rather than an analysis, of the works. It forms a basic guide for the listener as to how these works were conceived and constructed, and how both African and Western music elements have been used in order to achieve a syncretism. My commentary endeavours to show the compositional techniques applied when writing these works, and how my cultural interactions, music training and experience as a professional opera singer influence my compositional output. Part two contains the creative content of the portfolio: a set of scores of the three works themselves, as well as accompanying recordings of these works, with a total duration of ca. 100 minutes of music. It forms the main part of the submission. , Thesis (DMA) -- Faculty of Humanities, Department of Music and Performing Arts, 2021
- Full Text:
- Date Issued: 2021-12
Coordination polymers for denitrogenation of fuel oils
- Authors: Dembaremba, Tendai O
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53630 , vital:45682
- Description: In this thesis, we present adsorptive removal of nitrogen-containing compounds from fuel oil as an alternative to complement conventional hydrotreatment to obtain ultra-low sulfur and nitrogen levels. This is in cognizance of the challenges nitrogen-containing compounds pose to the hydrotreatment process, particularly their inhibition and/or poisoning of the catalysts used in the process, of which basic nitrogen-containing compounds are the major culprits. Selectivity is the biggest challenge for adsorptive removal of nitrogen-containing compounds. We explore reticular synthesis of metal organic frameworks and the use of coordinatively unsaturated metal sites in 1-dimensional coordination polymers to achieve good selectivity for nitrogen-containing compounds. In the first part of the thesis, reticular synthesis of metal organic frameworks to control the size of the cavity, and strategically use the linkers and metal centres was envisaged. In this work we explored variation of the metal centres in the secondary building units (SBUs of the MOFs as the first step to the testing and implementation of the design strategies. Carbazole, representing carbazoles which the major compounds that remain in hydrotreated fuel, was the target compound. Four MOFs of zinc (Zn-CDC-bpe), copper (Cu-CDC-bpe), nickel (Ni-CDC-bpe) and cobalt (Co-CDC-bpe) based on the formation of a dinuclear metal paddlewheel SBUs with the ligand 9H-Carbazole-3,6-dicarboxylic acid (H2CDC) and occupation of the axial positions of the paddlewheel by 1,2-Bis(4-pyridyl)ethane (bpe) to form porous networks were synthesized. A fifth MOF containing only CDC which forms a [Zn4O(O2C-R)5(O2HC-R)] SBU was also synthesized (Zn-CDC). The ligand H2CDC was inspired by the possibility of improving selectivity for carbazole via π–π interactions through the more preferred parallel-offset stacking as well as the possibility for further substitution of the carbazole N-H to add groups that improve selectivity. The sizes of the MOF cavities can then be controlled by choosing different lengths of ligands analogous to 1,2-Bis(4-pyridyl)ethane (bpe), e.g. 4,4’-bipyridine and pyrazine. All the MOFs showed good selectivity of carbazole. The Zn-CDC MOF also had good selectivity for the basic nitrogen-containing compounds tested: quinoline, isoquinoline, quinaldine and 1-naphthylamine. Its uptake of carbazole was also slightly higher. This was attributed to the presence of an unsaturated Zn site in the SBU. Adsorption in all the MOFs was primarily due to physisorption. It was concluded that the role of the metal centre does not play a significant role in the adsorption of carbazole besides providing a template for reticular synthesis. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
- Full Text: false
- Date Issued: 2021-12
- Authors: Dembaremba, Tendai O
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53630 , vital:45682
- Description: In this thesis, we present adsorptive removal of nitrogen-containing compounds from fuel oil as an alternative to complement conventional hydrotreatment to obtain ultra-low sulfur and nitrogen levels. This is in cognizance of the challenges nitrogen-containing compounds pose to the hydrotreatment process, particularly their inhibition and/or poisoning of the catalysts used in the process, of which basic nitrogen-containing compounds are the major culprits. Selectivity is the biggest challenge for adsorptive removal of nitrogen-containing compounds. We explore reticular synthesis of metal organic frameworks and the use of coordinatively unsaturated metal sites in 1-dimensional coordination polymers to achieve good selectivity for nitrogen-containing compounds. In the first part of the thesis, reticular synthesis of metal organic frameworks to control the size of the cavity, and strategically use the linkers and metal centres was envisaged. In this work we explored variation of the metal centres in the secondary building units (SBUs of the MOFs as the first step to the testing and implementation of the design strategies. Carbazole, representing carbazoles which the major compounds that remain in hydrotreated fuel, was the target compound. Four MOFs of zinc (Zn-CDC-bpe), copper (Cu-CDC-bpe), nickel (Ni-CDC-bpe) and cobalt (Co-CDC-bpe) based on the formation of a dinuclear metal paddlewheel SBUs with the ligand 9H-Carbazole-3,6-dicarboxylic acid (H2CDC) and occupation of the axial positions of the paddlewheel by 1,2-Bis(4-pyridyl)ethane (bpe) to form porous networks were synthesized. A fifth MOF containing only CDC which forms a [Zn4O(O2C-R)5(O2HC-R)] SBU was also synthesized (Zn-CDC). The ligand H2CDC was inspired by the possibility of improving selectivity for carbazole via π–π interactions through the more preferred parallel-offset stacking as well as the possibility for further substitution of the carbazole N-H to add groups that improve selectivity. The sizes of the MOF cavities can then be controlled by choosing different lengths of ligands analogous to 1,2-Bis(4-pyridyl)ethane (bpe), e.g. 4,4’-bipyridine and pyrazine. All the MOFs showed good selectivity of carbazole. The Zn-CDC MOF also had good selectivity for the basic nitrogen-containing compounds tested: quinoline, isoquinoline, quinaldine and 1-naphthylamine. Its uptake of carbazole was also slightly higher. This was attributed to the presence of an unsaturated Zn site in the SBU. Adsorption in all the MOFs was primarily due to physisorption. It was concluded that the role of the metal centre does not play a significant role in the adsorption of carbazole besides providing a template for reticular synthesis. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
- Full Text: false
- Date Issued: 2021-12
Corrosion and hydrogen resistant modified zirlo surfaces for nuclear fuel cladding
- Authors: Ngongo, Sinoyolo
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54077 , vital:46252
- Description: Zirconium (Zr) alloys are used as fuel cladding material in all modern water cooled commercial nuclear reactors. Zr alloys have many desirable properties for the nuclear reactor core environment, however, it also has a weakness in that overheated zirconium alloy fuel rods react with hot steam resulting in the release of hydrogen. High temperatures increase the oxidation rate and hence the hydrogen production rate which in turn increase the risk of a hydrogen gas explosion such as what is surmised to have happened in the 2011 Fukushima Daiichi nuclear plant incident. The some of the hydrogen produced will also diffuse into the zirconium alloy and form zirconium hydrides which will weaken the original zirconium alloy material. The development of accident tolerant fuel became a major focus area after the Fukushima event in March 2011 with the U.S. congress directing the U.S. Department of Energy to develop fuel with enhanced accident tolerance at high temperatures. The main objective in the case of zirconium alloy cladding has been the modification of cladding surface layers by coating or doping in order to reduce the oxidation rate and hydrogen generation rate by the reaction of steam with zirconium alloy cladding at high temperatures. This thesis focuses on two surface modifications to decrease the surface corrosion rate of ZIRLOTM (the Zr alloy used in this study) and reduce hydrogen uptake by ZIRLO. The first modification involves an oxidation-resistant nano-crystalline diamond (NCD) film deposited on ZIRLO. The NCD layer was deposited in a microwave plasma-enhanced linear antenna chemical vapor deposition (MW-LA-PECVD) system after immersion of the ZIRLO tubes in a water-based solution containing nanodiamonds. ZIRLO tube samples were coated with 200 nm and 500 nm thick NCD layers. The 200 nm thick NCD coated ZIRLO was kept as control sample whereas the 500 nm thick NCD coated ZIRLO was exposed to steam oxidation at 360 °C for 90 days. The results revealed that the NCD exfoliated in some areas leaving the ZIRLO exposed to the steam. In the areas where the diamond did not exfoliate, the diamond was still attached to the ZIRLO with an amorphous carbon layer present between the NCD and the zirconium oxide layer.The transmission electron microscopy (TEM) results of this study indicate the presence a sp3 – hybridised diamond phase for the NCD layer as well as an intermediate amorphous carbon layer between the NCD and ZrO2 layers. Analyses of the area where the NCD layer had exfoliated showed no evidence of an NCD layer. It is possible that the amorphous carbon layer between the diamond and the zirconium oxide is responsible for weak interfacial bonding leading to partial exfoliation during oxidation in steam 360 °C for 90 days. In the second modification, the effectiveness of a Cr doped ZrO2 layer to reduce the migration rate of hydrogen in ZrO2 was investigated. The ZIRLO tube used for this part of the study did not have a thin oxide passivation surface layer. Two different procedures were used to create chromium doped zirconium oxide surface layers on ZIRLO. The ZIRLO surface was coated with chromium using cathodic arc deposition followed compression plasma flow (CPF) treatment to facilitate intermixing of the Cr and the ZIRLO. In procedure 1, the surface modification was achieved through the incorporation of chromium into the zirconium surface layer using a compression plasma flow (CPF) technique, followed by the oxidation of the chromium doped zirconium. The oxidation process was conducted at 500 °C for 6 hours. In procedure 2, the chromium was incorporated into the zirconium oxide layer again using the CPF technique. Hydrogen desorption was measured from pure ZIRLO and CPF modified samples using a special gas reaction controller system. The key finding of the results is that the chromium doped (incorporated) zirconium oxide layer on ZIRLO sample exhibited the lowest hydrogen desorption rate of all the samples analysed. This indicates that H in the Cr doped zirconium oxide layer had the lowest mobility of all the samples investigated. This is consistent with the theoretical predictions that the doping of ZrO2 by Cr reduces the solubility of hydrogen in ZrO2. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text: false
- Date Issued: 2021-12
- Authors: Ngongo, Sinoyolo
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54077 , vital:46252
- Description: Zirconium (Zr) alloys are used as fuel cladding material in all modern water cooled commercial nuclear reactors. Zr alloys have many desirable properties for the nuclear reactor core environment, however, it also has a weakness in that overheated zirconium alloy fuel rods react with hot steam resulting in the release of hydrogen. High temperatures increase the oxidation rate and hence the hydrogen production rate which in turn increase the risk of a hydrogen gas explosion such as what is surmised to have happened in the 2011 Fukushima Daiichi nuclear plant incident. The some of the hydrogen produced will also diffuse into the zirconium alloy and form zirconium hydrides which will weaken the original zirconium alloy material. The development of accident tolerant fuel became a major focus area after the Fukushima event in March 2011 with the U.S. congress directing the U.S. Department of Energy to develop fuel with enhanced accident tolerance at high temperatures. The main objective in the case of zirconium alloy cladding has been the modification of cladding surface layers by coating or doping in order to reduce the oxidation rate and hydrogen generation rate by the reaction of steam with zirconium alloy cladding at high temperatures. This thesis focuses on two surface modifications to decrease the surface corrosion rate of ZIRLOTM (the Zr alloy used in this study) and reduce hydrogen uptake by ZIRLO. The first modification involves an oxidation-resistant nano-crystalline diamond (NCD) film deposited on ZIRLO. The NCD layer was deposited in a microwave plasma-enhanced linear antenna chemical vapor deposition (MW-LA-PECVD) system after immersion of the ZIRLO tubes in a water-based solution containing nanodiamonds. ZIRLO tube samples were coated with 200 nm and 500 nm thick NCD layers. The 200 nm thick NCD coated ZIRLO was kept as control sample whereas the 500 nm thick NCD coated ZIRLO was exposed to steam oxidation at 360 °C for 90 days. The results revealed that the NCD exfoliated in some areas leaving the ZIRLO exposed to the steam. In the areas where the diamond did not exfoliate, the diamond was still attached to the ZIRLO with an amorphous carbon layer present between the NCD and the zirconium oxide layer.The transmission electron microscopy (TEM) results of this study indicate the presence a sp3 – hybridised diamond phase for the NCD layer as well as an intermediate amorphous carbon layer between the NCD and ZrO2 layers. Analyses of the area where the NCD layer had exfoliated showed no evidence of an NCD layer. It is possible that the amorphous carbon layer between the diamond and the zirconium oxide is responsible for weak interfacial bonding leading to partial exfoliation during oxidation in steam 360 °C for 90 days. In the second modification, the effectiveness of a Cr doped ZrO2 layer to reduce the migration rate of hydrogen in ZrO2 was investigated. The ZIRLO tube used for this part of the study did not have a thin oxide passivation surface layer. Two different procedures were used to create chromium doped zirconium oxide surface layers on ZIRLO. The ZIRLO surface was coated with chromium using cathodic arc deposition followed compression plasma flow (CPF) treatment to facilitate intermixing of the Cr and the ZIRLO. In procedure 1, the surface modification was achieved through the incorporation of chromium into the zirconium surface layer using a compression plasma flow (CPF) technique, followed by the oxidation of the chromium doped zirconium. The oxidation process was conducted at 500 °C for 6 hours. In procedure 2, the chromium was incorporated into the zirconium oxide layer again using the CPF technique. Hydrogen desorption was measured from pure ZIRLO and CPF modified samples using a special gas reaction controller system. The key finding of the results is that the chromium doped (incorporated) zirconium oxide layer on ZIRLO sample exhibited the lowest hydrogen desorption rate of all the samples analysed. This indicates that H in the Cr doped zirconium oxide layer had the lowest mobility of all the samples investigated. This is consistent with the theoretical predictions that the doping of ZrO2 by Cr reduces the solubility of hydrogen in ZrO2. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text: false
- Date Issued: 2021-12
Demarcation of municipalities and service delivery capacity: a case of selected eastern cape municipalities
- Authors: Sokopo, Johannes
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54574 , vital:46715
- Description: The study examines the relationship between demarcation of municipal boundaries and the capacity of a municipality to deliver services. The case of the amalgamation of Baviaans, Camdeboo, and Ikwezi local municipalities which has led to the establishment of the Dr Beyers Naudè Municipality in the Sara Baartman District Municipality in the Eastern Cape has been used to determine this relationship in this study. The amalgamation of these municipalities has led to the redetermination and dismantling of their boundaries and the establishment of the boundaries of the newly created and larger Dr Beyers Naudè Local Municipality. The study investigated whether the demarcation of municipal boundaries has, in this instance, enhanced the capacity of the municipality to deliver basic services. Organisational Theory was used to interpret the amalgamation of municipalities. This theory was used for the theoretical basis of organisational structure and highlighting the need for the alignment of organizational structure with the municipalities’ mandate, of effective and efficient service delivery. The study adopted a qualitative research method and employed a non-probability purposive sampling technique to select participants. Interviews were used for data collection. 38 participants were interviewed, namely 7 councillors, 5 municipal officials, 5 members of the ratepayers’ association and 21 members of the community. Mixed views were expressed by participants regarding the enhancement of the state on basic service delivery after the merger of the three local municipalities. Furthermore, the study did not find evidence of a feasibility study prior to the implementation of the amalgamation process. Subsequently, the study could not find conclusive evidence relating to the enhancement of the capacity of the municipality to deliver services after the redetermination of municipal boundaries. The study recommends, among others, that the demarcation of municipal boundaries should be preceded by an appropriate feasibility study and be done such that there is compliance with the relevant legislation, and it must also have an effective public participation. The study also recommends that the newly established Dr Beyers Naudè Local Municipality should focus on maintaining the service delivery infrastructure it has inherited from the merger of its three predecessor municipalities, enhance public participation in its programmes, and priorities community beneficiation as a critical aspect of its service delivery mandate. , Thesis (PhD) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Sokopo, Johannes
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54574 , vital:46715
- Description: The study examines the relationship between demarcation of municipal boundaries and the capacity of a municipality to deliver services. The case of the amalgamation of Baviaans, Camdeboo, and Ikwezi local municipalities which has led to the establishment of the Dr Beyers Naudè Municipality in the Sara Baartman District Municipality in the Eastern Cape has been used to determine this relationship in this study. The amalgamation of these municipalities has led to the redetermination and dismantling of their boundaries and the establishment of the boundaries of the newly created and larger Dr Beyers Naudè Local Municipality. The study investigated whether the demarcation of municipal boundaries has, in this instance, enhanced the capacity of the municipality to deliver basic services. Organisational Theory was used to interpret the amalgamation of municipalities. This theory was used for the theoretical basis of organisational structure and highlighting the need for the alignment of organizational structure with the municipalities’ mandate, of effective and efficient service delivery. The study adopted a qualitative research method and employed a non-probability purposive sampling technique to select participants. Interviews were used for data collection. 38 participants were interviewed, namely 7 councillors, 5 municipal officials, 5 members of the ratepayers’ association and 21 members of the community. Mixed views were expressed by participants regarding the enhancement of the state on basic service delivery after the merger of the three local municipalities. Furthermore, the study did not find evidence of a feasibility study prior to the implementation of the amalgamation process. Subsequently, the study could not find conclusive evidence relating to the enhancement of the capacity of the municipality to deliver services after the redetermination of municipal boundaries. The study recommends, among others, that the demarcation of municipal boundaries should be preceded by an appropriate feasibility study and be done such that there is compliance with the relevant legislation, and it must also have an effective public participation. The study also recommends that the newly established Dr Beyers Naudè Local Municipality should focus on maintaining the service delivery infrastructure it has inherited from the merger of its three predecessor municipalities, enhance public participation in its programmes, and priorities community beneficiation as a critical aspect of its service delivery mandate. , Thesis (PhD) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
Effect of coal and microalgae biomass co-firing on CO2, SO2 and NOx emissions: An experimental evaluation
- Authors: Magida, Nokuthula Ethel
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53817 , vital:45984
- Description: There is increasingly stringent legislation on the environmental impact of energy production from coal combustion, and this has led to growing pressure to reduce the emission of greenhouse gases (GHGs). Thus, there is a significant need to develop and implement clean coal combustion technologies that would reduce the environmental gas pollutants. For power generation, the co-firing of biomass fuels at conventional coal-fired power stations is recognised as one of the low-cost, low-risk options to achieve significant reductions in GHG emissions. When coal is co-utilized with biomass there is added attractiveness because the biomass is CO2 neutral, and there is interest in using waste biomass and microalgae. Thus, the co-combustion of coal and biomass for energy production results in pollutant reduction, especially in the emissions of NOx, SOx, volatile organic compounds and polyaromatic hydrocarbons. The synergistic activity observed for toxic organic emissions is not well understood and is thought to involve chemical interaction between the volatiles from each fuel coupled with possible catalytic activity from the inorganic constituents of the fuels. The characterization of co-firing products and gases emitted from coal and microalgae (particularly the Scenedesmus strain) co-combustion has received limited attention. Therefore, this study seeks to understand possible interactions occurring during co-combustion of coal and Scenedesmus microalgae (Coalgae®). Additionally, the study aims to determine the effect of co-firing coal and Scenedesmus microalgae on CO2, SO2 and NOx emissions. The term “Coalgae®” refers to the mixture of coal and microalgae biomass. The study looks at physico-thermal characteristics as well as CO2, SO2 and NOx emissions of various coal-microalgae blending ratios by mass; 100:0 (coal), 95:5 (Coalgae® 5%), 90:10 (Coalgae® 10%), 85:15 (Coalgae® 15%) and 80:20 (Coalgae® 20%). Characterization techniques carried out included proximate and ultimate analyses, Fourier-transform infrared (FT-IR) and Scanning electron microscopy and X-ray energy dispersive spectroscopy (SEM/EDS). For combustion studies two techniques were applied. Low heating rate was obtained through a Thermogravimetric-Mass spectrometer analysis (TG-MS). Other combustion experiments were performed on the five lumpy fuels (coal and Coalgae® 5% - 20%) exposed to the flame in a fixed-bed combustion reactor. The emission concentrations of CO2 (%), NOx (ppm) and SO2 (ppm) of coal and Coalgae® blends were measured during the combustion of the five materials using a Lancom 4 portable flue gas analyser. The mass reduction (g) and temperature (°C) at the reactor exit were recorded during the combustion tests to compare the combustion behaviour of the four mixtures to that of raw coal. TG-DTG curves of coal and microalgae confirmed that the combustion behaviour of these materials was different. Coal showed one reaction during the combustion process, while microalgae and the Coalgae® blends showed three reactions. A significant reduction in activation energies of 160.4 kJ/mol, 159.6 kJ/mol, 151.3 kJ/mol, and 134.2 kJ/mol for Coalgae® 5% - Coalgae® 20%, respectively, compared to coal (161.3 kJ/mol) was achieved. The lowering of activation energy could be attributed to the relative fixed carbon content. SEM morphology images of ash obtained from the combustion of coal and Coalgae® 5% - 20% confirmed changes in devolatilization and combustion behaviour of solid raw fuel. The ash of Coalgae® blends had higher fluxing elements (Fe, Ca, K and Mg) than coal and this shows possibility of slagging and fouling in combustion systems. The Coalgae® blends showed a synergistic effect due to different combustion characteristics of coal and Scenedesmus microalgae. The combustion results obtained from the fixed-bed reactor showed significant reductions in concentrations of CO2, SO2 and NOx emissions for Coalgae® blends compared to baseline coal. Microalgae reduced CO2 emissions from baseline coal by 14.9%, 19.5%, 23.5% and 31.4% for Coalgae® 5%, 10%, 15% and 20%, respectively. SO2 reductions of 1.9%, 10.6%, 15.8% and 18.2%, and NOx reductions of 22.4%, 26.1%, 24.4% and 16.9% were achieved with Coalgae® 5%, 10%, 15% and 20%, respectively. Moreover, the combustion efficiency of Coalgae® blends increased significantly by up to 14.5% from baseline coal (86.4%) to Coalgae® 20% (98.9%). Based on the above findings, the co-firing of coal and Scenedesmus microalgae biomass was necessary for the reduction of CO2, SO2, and NOx emissions. As such, Coalgae® blends can be considered as alternative fuels in any coal driven process for energy generation. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Magida, Nokuthula Ethel
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53817 , vital:45984
- Description: There is increasingly stringent legislation on the environmental impact of energy production from coal combustion, and this has led to growing pressure to reduce the emission of greenhouse gases (GHGs). Thus, there is a significant need to develop and implement clean coal combustion technologies that would reduce the environmental gas pollutants. For power generation, the co-firing of biomass fuels at conventional coal-fired power stations is recognised as one of the low-cost, low-risk options to achieve significant reductions in GHG emissions. When coal is co-utilized with biomass there is added attractiveness because the biomass is CO2 neutral, and there is interest in using waste biomass and microalgae. Thus, the co-combustion of coal and biomass for energy production results in pollutant reduction, especially in the emissions of NOx, SOx, volatile organic compounds and polyaromatic hydrocarbons. The synergistic activity observed for toxic organic emissions is not well understood and is thought to involve chemical interaction between the volatiles from each fuel coupled with possible catalytic activity from the inorganic constituents of the fuels. The characterization of co-firing products and gases emitted from coal and microalgae (particularly the Scenedesmus strain) co-combustion has received limited attention. Therefore, this study seeks to understand possible interactions occurring during co-combustion of coal and Scenedesmus microalgae (Coalgae®). Additionally, the study aims to determine the effect of co-firing coal and Scenedesmus microalgae on CO2, SO2 and NOx emissions. The term “Coalgae®” refers to the mixture of coal and microalgae biomass. The study looks at physico-thermal characteristics as well as CO2, SO2 and NOx emissions of various coal-microalgae blending ratios by mass; 100:0 (coal), 95:5 (Coalgae® 5%), 90:10 (Coalgae® 10%), 85:15 (Coalgae® 15%) and 80:20 (Coalgae® 20%). Characterization techniques carried out included proximate and ultimate analyses, Fourier-transform infrared (FT-IR) and Scanning electron microscopy and X-ray energy dispersive spectroscopy (SEM/EDS). For combustion studies two techniques were applied. Low heating rate was obtained through a Thermogravimetric-Mass spectrometer analysis (TG-MS). Other combustion experiments were performed on the five lumpy fuels (coal and Coalgae® 5% - 20%) exposed to the flame in a fixed-bed combustion reactor. The emission concentrations of CO2 (%), NOx (ppm) and SO2 (ppm) of coal and Coalgae® blends were measured during the combustion of the five materials using a Lancom 4 portable flue gas analyser. The mass reduction (g) and temperature (°C) at the reactor exit were recorded during the combustion tests to compare the combustion behaviour of the four mixtures to that of raw coal. TG-DTG curves of coal and microalgae confirmed that the combustion behaviour of these materials was different. Coal showed one reaction during the combustion process, while microalgae and the Coalgae® blends showed three reactions. A significant reduction in activation energies of 160.4 kJ/mol, 159.6 kJ/mol, 151.3 kJ/mol, and 134.2 kJ/mol for Coalgae® 5% - Coalgae® 20%, respectively, compared to coal (161.3 kJ/mol) was achieved. The lowering of activation energy could be attributed to the relative fixed carbon content. SEM morphology images of ash obtained from the combustion of coal and Coalgae® 5% - 20% confirmed changes in devolatilization and combustion behaviour of solid raw fuel. The ash of Coalgae® blends had higher fluxing elements (Fe, Ca, K and Mg) than coal and this shows possibility of slagging and fouling in combustion systems. The Coalgae® blends showed a synergistic effect due to different combustion characteristics of coal and Scenedesmus microalgae. The combustion results obtained from the fixed-bed reactor showed significant reductions in concentrations of CO2, SO2 and NOx emissions for Coalgae® blends compared to baseline coal. Microalgae reduced CO2 emissions from baseline coal by 14.9%, 19.5%, 23.5% and 31.4% for Coalgae® 5%, 10%, 15% and 20%, respectively. SO2 reductions of 1.9%, 10.6%, 15.8% and 18.2%, and NOx reductions of 22.4%, 26.1%, 24.4% and 16.9% were achieved with Coalgae® 5%, 10%, 15% and 20%, respectively. Moreover, the combustion efficiency of Coalgae® blends increased significantly by up to 14.5% from baseline coal (86.4%) to Coalgae® 20% (98.9%). Based on the above findings, the co-firing of coal and Scenedesmus microalgae biomass was necessary for the reduction of CO2, SO2, and NOx emissions. As such, Coalgae® blends can be considered as alternative fuels in any coal driven process for energy generation. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
- Full Text:
- Date Issued: 2021-12
Engineering nanocatalysts using mixed metals for hydrodesulfurization of fuel oil
- Authors: Majodina, Siphumelele
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53861 , vital:46021
- Description: Crude oil is a complex blend containing thousands of hydrocarbons, non-hydrocarbon compounds and heavy metals. These hydrocarbons are mixed with variable quantities of sulfur-, nitrogen-, and oxygen-containing compounds. The combustion of fuel containing organosulfur compounds results in the emission of sulfur oxides (SOx) into the atmosphere. These toxic gases escape into the atmosphere resulting in air pollution, which is a large contributor to global warming. Air pollution also causes pulmonary diseases, allergies and may even lead to human death. It can also cause harm to other living organisms such as animals and food crops. Thus, mandating the reduction of sulfur in organosulfur compounds in fuel to <10 ppmS by the environmental protection agency. Several studies have been conducted to remove sulfur from fuels, most of which have focused on removing refractory sulfur compounds due to the difficulty in removing sulfur in these compounds. However, the currently employed hydrodesulfurization (HDS) catalysts suffer in producing fuels complying with the future standards of fuels quality. Generally, HDS catalysts are made up of metallic components, Co (Ni) and Mo (W), on porous supports, the catalytic activity of these catalysts strongly depends on the amount of NiWS (CoMoS) phases in it and to the extent in which these phases are exposed on the catalyst support surfaces and this is engineered using chelating agents and size of catalysts. To this end, nanosized materials (nanocatalysts) are considered most suitable, as reported active phases of HDS catalysts are exposed, hence improving the hydrodesulfurization of sulfur-containing compounds in fuels. Nanocatalysts results in nanoparticles and when impregnated on a support will results in high surface area, and enhances electronic property, which increases the activity of the catalyst allowing the most refractory sulfur to be removed. The addition of chelating agents such as EDTA, acetic acid, and citric acid further improves the activity of the catalysts by producing more active phases on the catalyst. In this research project, nanocatalysts will be synthesised using mixed metals with and without chelating agents and tested for HDS activity and selectivity towards sulfur using refractory organosulfur compounds in fuels under industrial HDS conditions. This work was divided into two sections, and this dissertation summarizes the research outcomes of each phase. The first section examines the effect of chelating ligands, namely, ethylenediaminetetraacetic acid (EDTA), citric acid (CA), and acetic acid (AA), on CoMo HDS activity and the sulfidation mechanism. In this study, chelating ligands seem to have a beneficial effect on HDS activity. Detailed mechanistic aspects of interactions between chelating ligands and metallic species (Co-chelating ligands) were also studied. Characterization by SC-XRD revealed that the presence of the chelating ligand result in the formation of complex with cobalt, and the effect of this complex was shown by TG-DSC analysis. This showed that the presence of chelating ligand leads a to delay of cobalt sulfidation as the complex decomposes at higher temperatures, which was the main cause of improving HDS activity. It was also shown that chelating ligands play a role in dispersion of metal oxides and sulfided metal oxides (TEM and XPS). XPS results showed low MoS2 phase for CoMo/Al2O3 (45%), while CoMo-EDTA/Al2O3 (63%) catalyst resulted in high MoS2 phases. From all the catalysts, CoMo-CA/Al2O3 (98%) gave the highest catalytic activity, and the increase in activity could be attributed to the formation of octahedral molybdenum oxides as they are easily reducible during sulfidation and result in more dispersed active phases and weak metal-support interaction. The second section examines the effect of a promoter (Rh) and different chelating ligands (EDTA, AA, and CA) on the catalyst RhMo supported with alumina. In this phase, rhodium was used as promoter, the following trend for catalytic activity was observed: RhMo/Al2O3 (88%) > RhMo-AA/Al2O3 (73%) > RhMo-CA/Al2O3 (72%) > RhMo-EDTA/Al2O3 (68%). This could be that the addition of chelating ligand complexed both metallic species retarding sulfidation of both metals, hence lowering the HDS activity. Studies show that it is possible for the citric acid to complex with both promoter and an active metal (Mo), and this might result in the formation of molybdenum dimers, trimers and tetramers which are difficult to sulfide. XPS analysis showed that unchelated catalyst have more MoS2 phases of 63%, hence higher dispersion than the chelated catalyst, this could be the reason for high activity in RhMo/Al2O3 (88%) catalyst. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Majodina, Siphumelele
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53861 , vital:46021
- Description: Crude oil is a complex blend containing thousands of hydrocarbons, non-hydrocarbon compounds and heavy metals. These hydrocarbons are mixed with variable quantities of sulfur-, nitrogen-, and oxygen-containing compounds. The combustion of fuel containing organosulfur compounds results in the emission of sulfur oxides (SOx) into the atmosphere. These toxic gases escape into the atmosphere resulting in air pollution, which is a large contributor to global warming. Air pollution also causes pulmonary diseases, allergies and may even lead to human death. It can also cause harm to other living organisms such as animals and food crops. Thus, mandating the reduction of sulfur in organosulfur compounds in fuel to <10 ppmS by the environmental protection agency. Several studies have been conducted to remove sulfur from fuels, most of which have focused on removing refractory sulfur compounds due to the difficulty in removing sulfur in these compounds. However, the currently employed hydrodesulfurization (HDS) catalysts suffer in producing fuels complying with the future standards of fuels quality. Generally, HDS catalysts are made up of metallic components, Co (Ni) and Mo (W), on porous supports, the catalytic activity of these catalysts strongly depends on the amount of NiWS (CoMoS) phases in it and to the extent in which these phases are exposed on the catalyst support surfaces and this is engineered using chelating agents and size of catalysts. To this end, nanosized materials (nanocatalysts) are considered most suitable, as reported active phases of HDS catalysts are exposed, hence improving the hydrodesulfurization of sulfur-containing compounds in fuels. Nanocatalysts results in nanoparticles and when impregnated on a support will results in high surface area, and enhances electronic property, which increases the activity of the catalyst allowing the most refractory sulfur to be removed. The addition of chelating agents such as EDTA, acetic acid, and citric acid further improves the activity of the catalysts by producing more active phases on the catalyst. In this research project, nanocatalysts will be synthesised using mixed metals with and without chelating agents and tested for HDS activity and selectivity towards sulfur using refractory organosulfur compounds in fuels under industrial HDS conditions. This work was divided into two sections, and this dissertation summarizes the research outcomes of each phase. The first section examines the effect of chelating ligands, namely, ethylenediaminetetraacetic acid (EDTA), citric acid (CA), and acetic acid (AA), on CoMo HDS activity and the sulfidation mechanism. In this study, chelating ligands seem to have a beneficial effect on HDS activity. Detailed mechanistic aspects of interactions between chelating ligands and metallic species (Co-chelating ligands) were also studied. Characterization by SC-XRD revealed that the presence of the chelating ligand result in the formation of complex with cobalt, and the effect of this complex was shown by TG-DSC analysis. This showed that the presence of chelating ligand leads a to delay of cobalt sulfidation as the complex decomposes at higher temperatures, which was the main cause of improving HDS activity. It was also shown that chelating ligands play a role in dispersion of metal oxides and sulfided metal oxides (TEM and XPS). XPS results showed low MoS2 phase for CoMo/Al2O3 (45%), while CoMo-EDTA/Al2O3 (63%) catalyst resulted in high MoS2 phases. From all the catalysts, CoMo-CA/Al2O3 (98%) gave the highest catalytic activity, and the increase in activity could be attributed to the formation of octahedral molybdenum oxides as they are easily reducible during sulfidation and result in more dispersed active phases and weak metal-support interaction. The second section examines the effect of a promoter (Rh) and different chelating ligands (EDTA, AA, and CA) on the catalyst RhMo supported with alumina. In this phase, rhodium was used as promoter, the following trend for catalytic activity was observed: RhMo/Al2O3 (88%) > RhMo-AA/Al2O3 (73%) > RhMo-CA/Al2O3 (72%) > RhMo-EDTA/Al2O3 (68%). This could be that the addition of chelating ligand complexed both metallic species retarding sulfidation of both metals, hence lowering the HDS activity. Studies show that it is possible for the citric acid to complex with both promoter and an active metal (Mo), and this might result in the formation of molybdenum dimers, trimers and tetramers which are difficult to sulfide. XPS analysis showed that unchelated catalyst have more MoS2 phases of 63%, hence higher dispersion than the chelated catalyst, this could be the reason for high activity in RhMo/Al2O3 (88%) catalyst. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
- Full Text:
- Date Issued: 2021-12
Factors influencing first-year students’ career decisions to pursue an IT career
- Authors: Twani, Malibongwe
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54135 , vital:46306
- Description: The process of deciding on a career is a dauntingand life-changing decision,which all scholarshave had to make. Various factors influence a first-year student’s career choice decision and selected field of study. Career decision-making,as a field of study, has been extensivelyresearched,globally. The research studies focusingon IT career choicesof studentshave indicated that scholars choosing careers in Information Technology (IT) are influenced by factors such as salaries, knowledge of career opportunities, the reputation of IT-related fields in society and by parents, teachers and role models. Recent research indicates that exposure to new technologies and programming concepts at the school level can influence a scholar’s IT career choice. Theories relating to career choice have focused on the characteristics of individuals and their environment. Career choice models have identified factors that influenced a student’s career choice.In South Africahowever,there have been limited studies investigating the factors influencing students’ career decisions in choosing careers in Computer Science (CS), Information Systems (IS) and Information Technology (IT)using mixed-methods.This study aims to investigate the factors that influence first-year students’ decisionsin choosing an IT career at the Nelson Mandela University.The research study pursueda pragmatisticapproach,using a mixed-methods approach. In investigating theories andfactors that influence students’ decisionsin choosing IT careers,the study used systematic literature reviews. The decision-making theories and factorsin theliterature review facilitated the creation of the conceptual framework for IT career decision making. A questionnaire was developed and distributed amongst ITand Non-ITfirst-year studentsin 2021. Fourhundredand eightparticipants completed the survey. The data obtained from the survey were statistically analysed, includingdescriptive analysis andExploratory Factor Analysis(EFA). Additionally, inferential statistics were used namely; Correlations, t-test, Confirmatory Factor Analysis(CFA)and Structural Equation Modelling(SEM). The study results wereinterpreted andcompared with iiiotherrelevantstudies. Recommendations were madeto address the factorsthat influencefirst-year students’ IT career decisions.The study highlighted that high academic confidence and personal attributes amongststudents,whowereinvolved at an early age in programming and using computers,chose IT as a career. The study showed significant statistical differences betweenIT and Non-IT groups in perceptions about the IT industry and identifying job title descriptions.Additionally, a significant statistical difference between languages and genders was identified in understanding careers. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Twani, Malibongwe
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54135 , vital:46306
- Description: The process of deciding on a career is a dauntingand life-changing decision,which all scholarshave had to make. Various factors influence a first-year student’s career choice decision and selected field of study. Career decision-making,as a field of study, has been extensivelyresearched,globally. The research studies focusingon IT career choicesof studentshave indicated that scholars choosing careers in Information Technology (IT) are influenced by factors such as salaries, knowledge of career opportunities, the reputation of IT-related fields in society and by parents, teachers and role models. Recent research indicates that exposure to new technologies and programming concepts at the school level can influence a scholar’s IT career choice. Theories relating to career choice have focused on the characteristics of individuals and their environment. Career choice models have identified factors that influenced a student’s career choice.In South Africahowever,there have been limited studies investigating the factors influencing students’ career decisions in choosing careers in Computer Science (CS), Information Systems (IS) and Information Technology (IT)using mixed-methods.This study aims to investigate the factors that influence first-year students’ decisionsin choosing an IT career at the Nelson Mandela University.The research study pursueda pragmatisticapproach,using a mixed-methods approach. In investigating theories andfactors that influence students’ decisionsin choosing IT careers,the study used systematic literature reviews. The decision-making theories and factorsin theliterature review facilitated the creation of the conceptual framework for IT career decision making. A questionnaire was developed and distributed amongst ITand Non-ITfirst-year studentsin 2021. Fourhundredand eightparticipants completed the survey. The data obtained from the survey were statistically analysed, includingdescriptive analysis andExploratory Factor Analysis(EFA). Additionally, inferential statistics were used namely; Correlations, t-test, Confirmatory Factor Analysis(CFA)and Structural Equation Modelling(SEM). The study results wereinterpreted andcompared with iiiotherrelevantstudies. Recommendations were madeto address the factorsthat influencefirst-year students’ IT career decisions.The study highlighted that high academic confidence and personal attributes amongststudents,whowereinvolved at an early age in programming and using computers,chose IT as a career. The study showed significant statistical differences betweenIT and Non-IT groups in perceptions about the IT industry and identifying job title descriptions.Additionally, a significant statistical difference between languages and genders was identified in understanding careers. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text:
- Date Issued: 2021-12
Foraging ecology of Kelp Gulls in natural and anthropogenically modified environments
- Authors: Reusch, Katharina
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54106 , vital:46303
- Description: Humans are having a profound impact on the natural environment through a myriad of activities, such as land use change or direct exploitation of resources. Some species are able to adapt to these changes and thrive in deeply modified environments. They are often considered winners of global change. Among these are Kelp GullsLarus dominicanus in South Africa, which have a generalist foraging nature. Despite their abundance and potential role in the ecosystem, knowledge on their foraging ecology is limited, with no understanding of the role of natural and anthropogenic food resources during breeding. The aim of this thesis was to assess the foraging movements, diet and health of Kelp Gulls breeding in seven different colonies varying in proximity to landfills. GPS loggers were deployed on incubating adults to assess foraging trip patterns, effort, and habitats. Diet and trophic ecology of adults and chicks was determined during the breeding season by combining conventional diet analysis (i.e. stomach content samples and regurgitated pellets) with stable isotope analysis of blood plasma. Finally, population health was estimated using indices of body condition for adults and chicks, and blood and faecal parasites were examined. The first successful tracking data from Kelp Gulls in South Africa revealed that birds from all colonies spent more time foraging in natural environments (marine, coastal and terrestrial) than in anthropogenically modified ones, irrelevant of the distance to the nearest landfill, potentially reflecting prey profitability or availability around thebreeding colonies. Gulls also had higher foraging effort when foraging at sea (longer travelling distance), which might be balanced by foraging on high energy prey in themarine environment (e.g. fish). Diet and trophic ecology data confirmed the wide range of resources Kelp Gulls were capable of exploiting. Anthropogenic items were important food sources at some colonies, while annual differences in trophic level targeted were apparent at some other colonies, possibly reflecting varying predation levels on other seabirds. Diet and trophic ecology generally differed between adults and chicks, with chicks being fed a more marine, i.e. fish, and higher trophic level diet, potentially due to the higher energy content of fish being important for chick growth. Despite differences between colonies in foraging effort and diet, body condition of both adults and chicks was similar across colonies. Birds from one of the urban colonies, foraging at the local landfill, tended to have slightly higher body condition values, possibly due to the high fat content of anthropogenic items, although this was not significant. Blood parasites were very scarce, with only one genus identified, Haemoproteus spp. Parasite abundance was significantly lower in chicks than in adults, implicating that adults might get infected in areas outside the colony. Faecal smears revealed the presence of yeast cells (Candida spp.) in birds, coinciding with higher body condition values, possibly linked to foraging habitat choice, as birds might ingest yeast cells when feeding in urban areas contaminated with human excrement.Kelp Gulls breeding in South Africa forage on a wide variety of resources and habitats, with limited apparent impact on their parasite load and body condition. All colonies foraged to some extend on natural sources, although some colonies located in very urban areas seemed to depend more closely on anthropogenic items as food resource. Therefore, changes in e.g. landfill management might cause changes in population dynamics, with possible repercussions on neighbouring bird populations. Theirgeneralist foraging nature, among others, makes Kelp Gulls winners of global change and is partly responsible for their increased population numbers. As they are often perceived as pests, information on the foraging ecology is important to manage gull populations effectively. , Thesis (PhD) -- Faculty of Sciences, School of Environmental Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Reusch, Katharina
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54106 , vital:46303
- Description: Humans are having a profound impact on the natural environment through a myriad of activities, such as land use change or direct exploitation of resources. Some species are able to adapt to these changes and thrive in deeply modified environments. They are often considered winners of global change. Among these are Kelp GullsLarus dominicanus in South Africa, which have a generalist foraging nature. Despite their abundance and potential role in the ecosystem, knowledge on their foraging ecology is limited, with no understanding of the role of natural and anthropogenic food resources during breeding. The aim of this thesis was to assess the foraging movements, diet and health of Kelp Gulls breeding in seven different colonies varying in proximity to landfills. GPS loggers were deployed on incubating adults to assess foraging trip patterns, effort, and habitats. Diet and trophic ecology of adults and chicks was determined during the breeding season by combining conventional diet analysis (i.e. stomach content samples and regurgitated pellets) with stable isotope analysis of blood plasma. Finally, population health was estimated using indices of body condition for adults and chicks, and blood and faecal parasites were examined. The first successful tracking data from Kelp Gulls in South Africa revealed that birds from all colonies spent more time foraging in natural environments (marine, coastal and terrestrial) than in anthropogenically modified ones, irrelevant of the distance to the nearest landfill, potentially reflecting prey profitability or availability around thebreeding colonies. Gulls also had higher foraging effort when foraging at sea (longer travelling distance), which might be balanced by foraging on high energy prey in themarine environment (e.g. fish). Diet and trophic ecology data confirmed the wide range of resources Kelp Gulls were capable of exploiting. Anthropogenic items were important food sources at some colonies, while annual differences in trophic level targeted were apparent at some other colonies, possibly reflecting varying predation levels on other seabirds. Diet and trophic ecology generally differed between adults and chicks, with chicks being fed a more marine, i.e. fish, and higher trophic level diet, potentially due to the higher energy content of fish being important for chick growth. Despite differences between colonies in foraging effort and diet, body condition of both adults and chicks was similar across colonies. Birds from one of the urban colonies, foraging at the local landfill, tended to have slightly higher body condition values, possibly due to the high fat content of anthropogenic items, although this was not significant. Blood parasites were very scarce, with only one genus identified, Haemoproteus spp. Parasite abundance was significantly lower in chicks than in adults, implicating that adults might get infected in areas outside the colony. Faecal smears revealed the presence of yeast cells (Candida spp.) in birds, coinciding with higher body condition values, possibly linked to foraging habitat choice, as birds might ingest yeast cells when feeding in urban areas contaminated with human excrement.Kelp Gulls breeding in South Africa forage on a wide variety of resources and habitats, with limited apparent impact on their parasite load and body condition. All colonies foraged to some extend on natural sources, although some colonies located in very urban areas seemed to depend more closely on anthropogenic items as food resource. Therefore, changes in e.g. landfill management might cause changes in population dynamics, with possible repercussions on neighbouring bird populations. Theirgeneralist foraging nature, among others, makes Kelp Gulls winners of global change and is partly responsible for their increased population numbers. As they are often perceived as pests, information on the foraging ecology is important to manage gull populations effectively. , Thesis (PhD) -- Faculty of Sciences, School of Environmental Sciences, 2021
- Full Text:
- Date Issued: 2021-12
Ifuthe lenkolo yobuKristu kulwimi lwesiXhosa
- Authors: Mwanda, Siyasanga Pulani
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54511 , vital:46617
- Description: Le ngxongxo iza kuthi ithethe ngefuthe lenkolo yobuKristu kulwimi lwesiXhosa. Akuyomfihlo ukuba ulwimi luthi lukhule okanye ludodobale ngenxa yendlela abantu bolwimi abaphila ngayo notshintsho oluthi lubekho kwindlela abaphila ngayo. AmaXhosa ke athi nawo aziswa kwinkolo yobuKristu. Le ngxoxo iza kuthi icacise ngokuthe gca ithiyori yeSimiyotiki esisiseko sesi sifundo, idakance iizimvo zeengcali zeSimiyotiki, ize ke iveze amagama amatsha ayengekho esiXhoseni mhla mnene, intsusa yalamagama nentsingiselo yawo. Okwesibini izakuthi ivelele intsingiselo yemiqondiso neempawu zobuKristu negalelo lazo kulwimi lwesiXhosa. Okokugqibela iza kuthi iveze izaci namaqhalo esiXhosa angobuKristu. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Mwanda, Siyasanga Pulani
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54511 , vital:46617
- Description: Le ngxongxo iza kuthi ithethe ngefuthe lenkolo yobuKristu kulwimi lwesiXhosa. Akuyomfihlo ukuba ulwimi luthi lukhule okanye ludodobale ngenxa yendlela abantu bolwimi abaphila ngayo notshintsho oluthi lubekho kwindlela abaphila ngayo. AmaXhosa ke athi nawo aziswa kwinkolo yobuKristu. Le ngxoxo iza kuthi icacise ngokuthe gca ithiyori yeSimiyotiki esisiseko sesi sifundo, idakance iizimvo zeengcali zeSimiyotiki, ize ke iveze amagama amatsha ayengekho esiXhoseni mhla mnene, intsusa yalamagama nentsingiselo yawo. Okwesibini izakuthi ivelele intsingiselo yemiqondiso neempawu zobuKristu negalelo lazo kulwimi lwesiXhosa. Okokugqibela iza kuthi iveze izaci namaqhalo esiXhosa angobuKristu. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
- Full Text:
- Date Issued: 2021-12
Igalelo lokutshintsha-tshintsha ulwimi xa kufundiswa isiXhosa kwigumbi lokufundela kwibanga le-12
- Authors: Mini, Nolwandle
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54506 , vital:46619
- Description: Olu phando luza kugxila kwigalelo lokutshintsha kolwimi xa kufundiswa isiXhosa kwizikolo ezifundisa isiXhosa kulwimi olongezelweyo. Lo msebenzi wolu phando usekeleze kwigalelo lokutshintshwa tshintshwa kolwimi xa kufundiswa isiXhosa kwigumbi lokufundela. Olu phando luza Kubeka iliso elibanzi kwindlela ekuhlolwa ngalo ulwimi olongezelweleyo kunye nengxelo yeziphumo zokuphela konyaka wama – 2016 nowama- 2017. Abavavanyi kwingxelo zovavanya zovavanyo bayibeke elubala into yokungaphumeleli kwabafundi ngenxa yefuthe lokungawuvi umbuzo. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
- Full Text: false
- Date Issued: 2021-12
- Authors: Mini, Nolwandle
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54506 , vital:46619
- Description: Olu phando luza kugxila kwigalelo lokutshintsha kolwimi xa kufundiswa isiXhosa kwizikolo ezifundisa isiXhosa kulwimi olongezelweyo. Lo msebenzi wolu phando usekeleze kwigalelo lokutshintshwa tshintshwa kolwimi xa kufundiswa isiXhosa kwigumbi lokufundela. Olu phando luza Kubeka iliso elibanzi kwindlela ekuhlolwa ngalo ulwimi olongezelweleyo kunye nengxelo yeziphumo zokuphela konyaka wama – 2016 nowama- 2017. Abavavanyi kwingxelo zovavanya zovavanyo bayibeke elubala into yokungaphumeleli kwabafundi ngenxa yefuthe lokungawuvi umbuzo. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
- Full Text: false
- Date Issued: 2021-12
In-vitroevaluation of bridelia ferruginea extract gold nanoparticles for the treatment of colon cancer
- Zosela, Itumeleng, Davids, Hajierah
- Authors: Zosela, Itumeleng , Davids, Hajierah
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54124 , vital:46311
- Description: Colorectal cancer (CRC) has become a health burden, being the third common cancer worldwide. Treatment of colorectal cancer is very important to manage the high prevalence rate of this disease. The available treatments for CRC have their drawbacks and side effects. Available treatments of colon cancer include surgery, chemotherapy, and radiation. Due to the side effects associated with these treatments, alternative treatments that pose less side effects are being developed worldwide. Nanotechnologies have gained global consideration due to their potential to improve the current standards and techniques for the diagnosis and treatment. The use of plants for synthesis of gold nanoparticles has opened a new venture of synthesizing environmentally friendly and cost-effective nanoparticles which possess great properties for CRC treatment. The aim of this study was to investigate the use of green synthesized AuNPs from Bridelia ferruginea for potential cancer treatment. In this work study gold nanoparticles were synthesized utilizing Bridelia ferruginea stem bark extract. The nanoparticles were characterized using UV–Vis spectroscopy, Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FTIR) and High-Resolution Transmission Electron Microscopy (HRTEM). The in vitroanti cancer activity of the AuNPs was investigated using Presto Blue assay, cellular morphology, caspase 3/7 assay on the human colon cancer cell line at different times to assess the optimum time for cell death. The cellular uptake and localization of AuNPs was investigated using HRTEM to assess uptake and location of the AuNPs within the cell. Results obtained from this study showed that the AuNP synthesis from Bridellia ferrugenia was successful. The Presto Blue cell viability results showed that the AuNPs reduced cell viability (%) significantly (p<0.05) after 24 h. The optimum treatment time of HT-29 cells with AuNPs was determined to be 24 h. The apoptotic effects of the AuNPs were assessed using Cell Event reagent, and the results from this assay indicated that caspase 3/7 was activated with treatment with AuNPs which induced cell death via apoptosis. The HRTEM results indicated that there was no uptake of AuNP targeting in HT-29 therefore localization could not be determined. It can be concluded that the AuNPs synthesized from Bridellia ferrugenia have anti-cancer properties and are able to induce cell death through apoptosis. Furthermore, this study revealed that optimization of the AuNPs for cellular uptake is needed to further understand the interaction between the nanoparticles and the cells. This will provide more insight on how cellular death is induced by the nanoparticles. , Thesis (MSc) -- Faculty of Science, Department of Biochemistry and Microbiology (including Physiology), 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Zosela, Itumeleng , Davids, Hajierah
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54124 , vital:46311
- Description: Colorectal cancer (CRC) has become a health burden, being the third common cancer worldwide. Treatment of colorectal cancer is very important to manage the high prevalence rate of this disease. The available treatments for CRC have their drawbacks and side effects. Available treatments of colon cancer include surgery, chemotherapy, and radiation. Due to the side effects associated with these treatments, alternative treatments that pose less side effects are being developed worldwide. Nanotechnologies have gained global consideration due to their potential to improve the current standards and techniques for the diagnosis and treatment. The use of plants for synthesis of gold nanoparticles has opened a new venture of synthesizing environmentally friendly and cost-effective nanoparticles which possess great properties for CRC treatment. The aim of this study was to investigate the use of green synthesized AuNPs from Bridelia ferruginea for potential cancer treatment. In this work study gold nanoparticles were synthesized utilizing Bridelia ferruginea stem bark extract. The nanoparticles were characterized using UV–Vis spectroscopy, Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FTIR) and High-Resolution Transmission Electron Microscopy (HRTEM). The in vitroanti cancer activity of the AuNPs was investigated using Presto Blue assay, cellular morphology, caspase 3/7 assay on the human colon cancer cell line at different times to assess the optimum time for cell death. The cellular uptake and localization of AuNPs was investigated using HRTEM to assess uptake and location of the AuNPs within the cell. Results obtained from this study showed that the AuNP synthesis from Bridellia ferrugenia was successful. The Presto Blue cell viability results showed that the AuNPs reduced cell viability (%) significantly (p<0.05) after 24 h. The optimum treatment time of HT-29 cells with AuNPs was determined to be 24 h. The apoptotic effects of the AuNPs were assessed using Cell Event reagent, and the results from this assay indicated that caspase 3/7 was activated with treatment with AuNPs which induced cell death via apoptosis. The HRTEM results indicated that there was no uptake of AuNP targeting in HT-29 therefore localization could not be determined. It can be concluded that the AuNPs synthesized from Bridellia ferrugenia have anti-cancer properties and are able to induce cell death through apoptosis. Furthermore, this study revealed that optimization of the AuNPs for cellular uptake is needed to further understand the interaction between the nanoparticles and the cells. This will provide more insight on how cellular death is induced by the nanoparticles. , Thesis (MSc) -- Faculty of Science, Department of Biochemistry and Microbiology (including Physiology), 2021
- Full Text:
- Date Issued: 2021-12
Inflation, exchange rate and unemployment nexuses in South Africa: lessons from the Inflation Targeting Framework
- Taderera, Christie Simbarashe
- Authors: Taderera, Christie Simbarashe
- Date: 2021-12
- Subjects: Foreign exchange rates -- South Africa , Inflation (Finance) -- South Africa , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54752 , vital:47656
- Description: Unemployment, inflation and exchange rate are key macroeconomic indicators and determinants of the development of a nation, but their relationship remain ambiguous. From the last quarter of 1994 to the same period in 2019, unemployment in South Africa increased from 20 percent to 29.1 percent while over the same period, inflation fell from 15 percent to 4.5 percent. Exchange rate at the same time has increased from 3.55Rand: 1USD to 14.45Rand: 1USD (World Bank Data, 2020). With the adoption of inflation targeting framework as a way of stabilising the general price level which has a trickle effect on unemployment, South Africa has a relatively high unemployment rate of 29.1 percent. This study investigates the relationship between unemployment, inflation and exchange rate in South Africa from 2009 Quarter 1 to 2020 Quarter 1. Furthermore, the study examines the relationship between employment, inflation and exchange rate from 1970 to 2019. Lastly the study investigates the inflation threshold from 1970 to 2019. The study employs the Autoregressive Distributed Lag (ARDL) model and shows that there is no short run and long run relationship between unemployment, inflation and exchange rate. There was however a short run and long run relationship between employment, inflation, exchange rate. In a long run analysis, there is a positive relationship between employment and economic growth for both in the short run and long run. Using the conditional least squares method, an inflation threshold of 5% was found to maximise employment in South Africa vindicating the inflation target of 3-5 percent. Based on the findings of this study, it is recommended that policy measures that increase government expenditure and economic growth be made. Thus, policy makers should increase government expenditure, either by running budget deficits or by collecting more revenue to finance its expenditures so as to increase employment or decrease unemployment without incurring the risk of crowding out. Additionally, from the inflation threshold examination, the current interest rate manipulation by raising or lowering the rate must be used to ensure inflation is kept below 5 per cent. , Thesis (MCom) -- Faculty of Business and Economic Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Taderera, Christie Simbarashe
- Date: 2021-12
- Subjects: Foreign exchange rates -- South Africa , Inflation (Finance) -- South Africa , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54752 , vital:47656
- Description: Unemployment, inflation and exchange rate are key macroeconomic indicators and determinants of the development of a nation, but their relationship remain ambiguous. From the last quarter of 1994 to the same period in 2019, unemployment in South Africa increased from 20 percent to 29.1 percent while over the same period, inflation fell from 15 percent to 4.5 percent. Exchange rate at the same time has increased from 3.55Rand: 1USD to 14.45Rand: 1USD (World Bank Data, 2020). With the adoption of inflation targeting framework as a way of stabilising the general price level which has a trickle effect on unemployment, South Africa has a relatively high unemployment rate of 29.1 percent. This study investigates the relationship between unemployment, inflation and exchange rate in South Africa from 2009 Quarter 1 to 2020 Quarter 1. Furthermore, the study examines the relationship between employment, inflation and exchange rate from 1970 to 2019. Lastly the study investigates the inflation threshold from 1970 to 2019. The study employs the Autoregressive Distributed Lag (ARDL) model and shows that there is no short run and long run relationship between unemployment, inflation and exchange rate. There was however a short run and long run relationship between employment, inflation, exchange rate. In a long run analysis, there is a positive relationship between employment and economic growth for both in the short run and long run. Using the conditional least squares method, an inflation threshold of 5% was found to maximise employment in South Africa vindicating the inflation target of 3-5 percent. Based on the findings of this study, it is recommended that policy measures that increase government expenditure and economic growth be made. Thus, policy makers should increase government expenditure, either by running budget deficits or by collecting more revenue to finance its expenditures so as to increase employment or decrease unemployment without incurring the risk of crowding out. Additionally, from the inflation threshold examination, the current interest rate manipulation by raising or lowering the rate must be used to ensure inflation is kept below 5 per cent. , Thesis (MCom) -- Faculty of Business and Economic Sciences, 2021
- Full Text:
- Date Issued: 2021-12
Investigating customary marriage conflict among the Ndebele speaking people in Mathula Village in Limpopo Province
- Authors: Msiza, Dina
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54504 , vital:46618
- Description: Recognition of Customary Marriages Act of 1998 in South Africa remains one of the greatest initiatives towards equality amongst spouses. However, even with the RCMA of 1998 that is set to regulate customary marriages, customary marriage conflict remains rife across various ethnic groups in South Africa. The RCMA of 1998 leaves a lot of room for interpretation by different cultures and some elements that certain ethnic groups consider as crucial in fulfilling customary marriages are excluded. So, to contribute to Conflict Studies with reference to customary marriage conflict, this study investigated customary marriage conflict among Ndebele speaking people in Mathula Village in Limpopo. The purpose of this study was to investigate the causes of customary marriage among Ndebele speaking people in Mathula Village in Limpopo. Data was collected through semi-structured interviews and analysed through content analysis, coding, and thematic analysis. During the interviews, non-participant observation was used. Purposeful sampling was used to select participants. In the final analysis, this study provides some recommendations with the view of addressing some of the challenges that were identified. Some of the recommendations include that there is a need to rethink the process of customary marriage in relation to the payment of lobola. Further, there is a need for an in-depth research going forward. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Msiza, Dina
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54504 , vital:46618
- Description: Recognition of Customary Marriages Act of 1998 in South Africa remains one of the greatest initiatives towards equality amongst spouses. However, even with the RCMA of 1998 that is set to regulate customary marriages, customary marriage conflict remains rife across various ethnic groups in South Africa. The RCMA of 1998 leaves a lot of room for interpretation by different cultures and some elements that certain ethnic groups consider as crucial in fulfilling customary marriages are excluded. So, to contribute to Conflict Studies with reference to customary marriage conflict, this study investigated customary marriage conflict among Ndebele speaking people in Mathula Village in Limpopo. The purpose of this study was to investigate the causes of customary marriage among Ndebele speaking people in Mathula Village in Limpopo. Data was collected through semi-structured interviews and analysed through content analysis, coding, and thematic analysis. During the interviews, non-participant observation was used. Purposeful sampling was used to select participants. In the final analysis, this study provides some recommendations with the view of addressing some of the challenges that were identified. Some of the recommendations include that there is a need to rethink the process of customary marriage in relation to the payment of lobola. Further, there is a need for an in-depth research going forward. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
Mangrove response to water level changes at the Nxaxo-Ngqusi and St Lucia Estuaries
- Authors: Julie, Corianna Lauren
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53644 , vital:45689
- Description: Water level variability within an estuary can vary as a function of tides (inundation frequency and duration) and rainfall, acting as one of the main determinants of mangrove growth, diversity, productivity, and distribution. Understanding how mangroves respond in estuaries to water level variability provides baseline information which can be used to predict future changes in mangrove growth and distribution in response to this driver This study measured mangrove characteristics (growth, structure, and areal extent) in two estuaries that differed in tidal setting, and thus water variability; the Nxaxo-Ngqusi and St Lucia estuaries, South Africa. These estuaries are part of a long-term monitoring programme (2010 - 2020) that has recorded mangrove responses to environmental changes. At the Nxaxo-Ngqusi Estuary, long-tem sea-level data (2003 – 2018) collected from the nearest tide gauge, and mangrove growth and areal extent were used to assess mangrove characteristics in a permanently open, micro tidal setting.Additionally, short-term water level data (August 2019 – September 2020), measured with in situ loggers, and sediment input at different sites within the mangrove forest, were also measured. Data was collected along the main channel sites, and at previously set up cattle exclusion plots ( browsed and non-browsed sites set to establish the effect of cattle browsing on mangroves). Similarly, at the St Lucia Estuary, long term water level data (2004 – 2020) collected at the bridge in the lower reaches of the estuary by Ezemvelo KZN-Wildlife, and annual mangrove growth, structure and areal extent data were used to assess mangrove characteristics in an estuarine lake that undergoes cycles between hypersaline and freshwater-dominated states. The results showed that mangrove responses to water level changes are complex and depend on several factors such as estuary mouth dynamics, anthropogenic activities, and site-level environmental conditions. The first objective was to compare water level changes and mangrove structure (mangrove height, and pneumatophore characteristics such as height, density and % aerenchyma) and sediment input between different sites at each estuary. Mangrove growth was higher at sites where longer inundation and higher inundation frequency were recorded at the Nxaxo-Ngqusi Estuary. However,longer inundation periods under closed mouth conditions resulted in stunted growth and mangrove dieback at St Lucia Estuary. At the Nxaxo-Ngqusi Estuary, mangroves at the main channel sites, closer to the water’s edge, had an overall higher growth rate (2.8 – 45.9 cm yr-1) than the mangroves found at the browsed (0 – 25 cm yr-1) and non-browsed sites (0 – 25.3 cm yr-1) on the landward edge of the forest. The effect of cattle browsing at these sites forms part of a long-term monitoring programme and this disturbance could have also influenced the results. Mangrove growth rate was higher in years with more rainfall at all sites within the estuary. At the St Lucia Estuary, mangrove growth rate was highest (0.81 cm yr-1) at a lower mean water level range (0.13 – 1.72 m) between 2010 - 2015, and growth rate was lowest (1.3 cm yr-1) in higher mean water level range conditions (0.34 m – 2.18 m) between 2015 – 2020. When water levels increased by up to 1.1 m due to closed mouth conditions, this led to extensive mangrove dieback further upstream by 2015. The maximum tidal flooding depth and inundation period influenced pneumatophore structure (height, density, and % aerenchyma) at the Nxaxo-Ngqusi Estuary. Sediment accumulation was highest at sites with increased pneumatophore density, but accumulation rates at the Nxaxo-Ngqusi Estuary (0.4 – 0.7 g over a high tide lasting 4-5 hours) were low and did not lead to smothering of the pneumatophores. Total sediment accumulation was highest at sites that experienced greater flooding depths. Increased inundation at the St Lucia Estuary caused inundation stress which led to mangrove mortality. This is because these mangroves are found in a closed estuary where increased water levels lead to prolonged submergence of the pneumatophores. A decrease in mangrove area was recorded at both sites. Low rainfall coupled with cattle browsing caused a decrease in mangrove area of 22% between 2009 and 2019, particularly along the mangrove fringe area at the Nxaxo-Ngqusi Estuary. The mangroves at the St Lucia Estuary, however, experienced mangrove dieback at all sites, with Site 1 recording the greatest percentage decrease in area of 71.7 % (loss of 44.76 ha) between 2010 and 2020. This was related to the progressive increase of freshwater input and water level at St Lucia Estuary under closed mouth conditions. The years leading up to 2019 had peaks in water levels at the St Lucia Estuary, with the highest water level of 2.12 m in 2019 since 2002. As a consequence, there was increased reed growth, where reeds expanded by 58% (177 ha) due to the high influx of freshwater, and no tidal exchange, which occurred in conjunction with a loss of 60.% (42 ha) of the original mangrove extent at the St Lucia Estuary. This study shows that increased water level changes (inundation frequency and duration) at the Nxaxo-Ngqusi Estuary maintain healthy mangrove stands. This is in contrast to the St Lucia Estuary, where there was a loss of mangroves as a result of high water levels under closed mouth conditions. Mangrove growth and extent at the Nxaxo-Ngqusi Estuary fluctuated in response to drought, and trampling and browsing by livestock. Extensive inundation and lack of tidal exchange reduced mangrove growth and extent at the St Lucia Estuary, with mangrove dieback occurring at all sites. These two systems are representative of the dynamic conditions found in South African estuaries. These research findings suggest that the continuous effects of climate change on estuarine habitats could result in changes in estuary mouth dynamics, which could impact mangrove growth, structure, and extent. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text: false
- Date Issued: 2021-12
- Authors: Julie, Corianna Lauren
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53644 , vital:45689
- Description: Water level variability within an estuary can vary as a function of tides (inundation frequency and duration) and rainfall, acting as one of the main determinants of mangrove growth, diversity, productivity, and distribution. Understanding how mangroves respond in estuaries to water level variability provides baseline information which can be used to predict future changes in mangrove growth and distribution in response to this driver This study measured mangrove characteristics (growth, structure, and areal extent) in two estuaries that differed in tidal setting, and thus water variability; the Nxaxo-Ngqusi and St Lucia estuaries, South Africa. These estuaries are part of a long-term monitoring programme (2010 - 2020) that has recorded mangrove responses to environmental changes. At the Nxaxo-Ngqusi Estuary, long-tem sea-level data (2003 – 2018) collected from the nearest tide gauge, and mangrove growth and areal extent were used to assess mangrove characteristics in a permanently open, micro tidal setting.Additionally, short-term water level data (August 2019 – September 2020), measured with in situ loggers, and sediment input at different sites within the mangrove forest, were also measured. Data was collected along the main channel sites, and at previously set up cattle exclusion plots ( browsed and non-browsed sites set to establish the effect of cattle browsing on mangroves). Similarly, at the St Lucia Estuary, long term water level data (2004 – 2020) collected at the bridge in the lower reaches of the estuary by Ezemvelo KZN-Wildlife, and annual mangrove growth, structure and areal extent data were used to assess mangrove characteristics in an estuarine lake that undergoes cycles between hypersaline and freshwater-dominated states. The results showed that mangrove responses to water level changes are complex and depend on several factors such as estuary mouth dynamics, anthropogenic activities, and site-level environmental conditions. The first objective was to compare water level changes and mangrove structure (mangrove height, and pneumatophore characteristics such as height, density and % aerenchyma) and sediment input between different sites at each estuary. Mangrove growth was higher at sites where longer inundation and higher inundation frequency were recorded at the Nxaxo-Ngqusi Estuary. However,longer inundation periods under closed mouth conditions resulted in stunted growth and mangrove dieback at St Lucia Estuary. At the Nxaxo-Ngqusi Estuary, mangroves at the main channel sites, closer to the water’s edge, had an overall higher growth rate (2.8 – 45.9 cm yr-1) than the mangroves found at the browsed (0 – 25 cm yr-1) and non-browsed sites (0 – 25.3 cm yr-1) on the landward edge of the forest. The effect of cattle browsing at these sites forms part of a long-term monitoring programme and this disturbance could have also influenced the results. Mangrove growth rate was higher in years with more rainfall at all sites within the estuary. At the St Lucia Estuary, mangrove growth rate was highest (0.81 cm yr-1) at a lower mean water level range (0.13 – 1.72 m) between 2010 - 2015, and growth rate was lowest (1.3 cm yr-1) in higher mean water level range conditions (0.34 m – 2.18 m) between 2015 – 2020. When water levels increased by up to 1.1 m due to closed mouth conditions, this led to extensive mangrove dieback further upstream by 2015. The maximum tidal flooding depth and inundation period influenced pneumatophore structure (height, density, and % aerenchyma) at the Nxaxo-Ngqusi Estuary. Sediment accumulation was highest at sites with increased pneumatophore density, but accumulation rates at the Nxaxo-Ngqusi Estuary (0.4 – 0.7 g over a high tide lasting 4-5 hours) were low and did not lead to smothering of the pneumatophores. Total sediment accumulation was highest at sites that experienced greater flooding depths. Increased inundation at the St Lucia Estuary caused inundation stress which led to mangrove mortality. This is because these mangroves are found in a closed estuary where increased water levels lead to prolonged submergence of the pneumatophores. A decrease in mangrove area was recorded at both sites. Low rainfall coupled with cattle browsing caused a decrease in mangrove area of 22% between 2009 and 2019, particularly along the mangrove fringe area at the Nxaxo-Ngqusi Estuary. The mangroves at the St Lucia Estuary, however, experienced mangrove dieback at all sites, with Site 1 recording the greatest percentage decrease in area of 71.7 % (loss of 44.76 ha) between 2010 and 2020. This was related to the progressive increase of freshwater input and water level at St Lucia Estuary under closed mouth conditions. The years leading up to 2019 had peaks in water levels at the St Lucia Estuary, with the highest water level of 2.12 m in 2019 since 2002. As a consequence, there was increased reed growth, where reeds expanded by 58% (177 ha) due to the high influx of freshwater, and no tidal exchange, which occurred in conjunction with a loss of 60.% (42 ha) of the original mangrove extent at the St Lucia Estuary. This study shows that increased water level changes (inundation frequency and duration) at the Nxaxo-Ngqusi Estuary maintain healthy mangrove stands. This is in contrast to the St Lucia Estuary, where there was a loss of mangroves as a result of high water levels under closed mouth conditions. Mangrove growth and extent at the Nxaxo-Ngqusi Estuary fluctuated in response to drought, and trampling and browsing by livestock. Extensive inundation and lack of tidal exchange reduced mangrove growth and extent at the St Lucia Estuary, with mangrove dieback occurring at all sites. These two systems are representative of the dynamic conditions found in South African estuaries. These research findings suggest that the continuous effects of climate change on estuarine habitats could result in changes in estuary mouth dynamics, which could impact mangrove growth, structure, and extent. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text: false
- Date Issued: 2021-12
Mapping the importance of public participation in the expropriation of land without compensation bill: a case of Silver Town in KwaZakhele, Port Elizabeth
- Authors: Ngwabeni, Siyasanga
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54541 , vital:46686
- Description: The post-1994 era in the South African public imagination was envisaged to herald widespread and transformative efforts to reverse the gross injustices and human rights violations inflicted over many decades of apartheid and colonialism. One of the key measures initiated by the democratic government to drive this nation building project was the land reform programme. The ‘land question’, which is a popular tagline in South Africa when reference is made to land reform, has come to define the general discourse of socioeconomic disadvantage and change in the post-apartheid and post-colonial period – similarly to other former settler colonies in the African continent and the broader Global South. For South Africa though, this specific issue has been characterised by numerous challenges and failures largely at the level of the state, wherein a significant lack of public engagement, public participation and democratic redistribution was not being done according to ‘the will of the people’. On a number of occasions, the South African state has gone on a ‘solo crusade’ to implement the land reform programme under complex conditions that are largely unfavoured by ordinary people ‘on the ground’ – especially those who were the primary victims of land dispossession under colonialism and apartheid. As a result, over the past few years, indigenous black communities across the country especially in (semi)urban and township areas have voluntarily ‘occupied’ land at their own will and sometimes ‘illegally’, as a way to take up settlement space and determine their lives on the land of their birth. Beyond the public discourse of ‘land invasions’ and ‘failed land reform projects’, this study was conducted to closely understand the extent to which public engagement and participation has been integral in the systematic mechanism(s) to transform the patterns of land ownership and control in the democratic South Africa. To do this, the site of KwaZakhele, Silvertown, in Port Elizabeth was selected to conduct the study. This township is an outcome of apartheid geography and land dispossession where many generations of indigenous black people were displaced. Today, it is a struggling community characterised by high rates of poverty and unemployment – and one of its unresolved socio-political issues is the question of the skewed patterns of land ownership in the area. Methodologically, qualitative semi-structured interviews were utilised to conduct the study and the Marxist Concept of Citizenship was selected as a theoretical framework for the study by the researcher. The study has found that, amongst the general legislative and political shortfalls of public participation breakdown, there are other deep seated structural socioeconomic issues that are at the root of the problem – such as economic inequalities and very low prospects of social mobility – which collectively reproduce the persistent inadequacies of political instability and social unrest in the area. The study recommends an astute combination of ‘bottom-up’ active citizenship and major socioeconomic transformation in the area as a systematic and structural mechanism to empower the community of Silvertown to be the champion of its own liberation struggle for the freedom of its people to own land and democratically participate in their own governance, self-determination, and prosperity. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Ngwabeni, Siyasanga
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54541 , vital:46686
- Description: The post-1994 era in the South African public imagination was envisaged to herald widespread and transformative efforts to reverse the gross injustices and human rights violations inflicted over many decades of apartheid and colonialism. One of the key measures initiated by the democratic government to drive this nation building project was the land reform programme. The ‘land question’, which is a popular tagline in South Africa when reference is made to land reform, has come to define the general discourse of socioeconomic disadvantage and change in the post-apartheid and post-colonial period – similarly to other former settler colonies in the African continent and the broader Global South. For South Africa though, this specific issue has been characterised by numerous challenges and failures largely at the level of the state, wherein a significant lack of public engagement, public participation and democratic redistribution was not being done according to ‘the will of the people’. On a number of occasions, the South African state has gone on a ‘solo crusade’ to implement the land reform programme under complex conditions that are largely unfavoured by ordinary people ‘on the ground’ – especially those who were the primary victims of land dispossession under colonialism and apartheid. As a result, over the past few years, indigenous black communities across the country especially in (semi)urban and township areas have voluntarily ‘occupied’ land at their own will and sometimes ‘illegally’, as a way to take up settlement space and determine their lives on the land of their birth. Beyond the public discourse of ‘land invasions’ and ‘failed land reform projects’, this study was conducted to closely understand the extent to which public engagement and participation has been integral in the systematic mechanism(s) to transform the patterns of land ownership and control in the democratic South Africa. To do this, the site of KwaZakhele, Silvertown, in Port Elizabeth was selected to conduct the study. This township is an outcome of apartheid geography and land dispossession where many generations of indigenous black people were displaced. Today, it is a struggling community characterised by high rates of poverty and unemployment – and one of its unresolved socio-political issues is the question of the skewed patterns of land ownership in the area. Methodologically, qualitative semi-structured interviews were utilised to conduct the study and the Marxist Concept of Citizenship was selected as a theoretical framework for the study by the researcher. The study has found that, amongst the general legislative and political shortfalls of public participation breakdown, there are other deep seated structural socioeconomic issues that are at the root of the problem – such as economic inequalities and very low prospects of social mobility – which collectively reproduce the persistent inadequacies of political instability and social unrest in the area. The study recommends an astute combination of ‘bottom-up’ active citizenship and major socioeconomic transformation in the area as a systematic and structural mechanism to empower the community of Silvertown to be the champion of its own liberation struggle for the freedom of its people to own land and democratically participate in their own governance, self-determination, and prosperity. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2021
- Full Text:
- Date Issued: 2021-12