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
Assessing the implementation of expanded public works programme in Buffalo City Metropolitan Municipality (2013-2018)
- Authors: Nombebe, Gcobisa
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55107 , vital:49120
- Description: The aim of the study was to evaluate the implementation of the Expanded Public Works Programme (EPWP) in the Buffalo City Metropolitan Municipality (BCMM) between 2013 and 2018. This was necessitated by the common trend observed in the country that, despite many interventions to alleviate poverty, the unemployment rate continues to increase, and poverty remains a challenge. The study was qualitative, and it used secondary data to achieve its objectives. The data was sourced from journals, municipal documents, the national Department of Public Works’ publications, newspapers and many other secondary sources. The results revealed that the EPWP performance in BCMM is greatly influenced by effective performance management systems, proper planning, political impact, training and development, and committed leadership. This was perceived as the first attempt towards improving the EPWP aligned employment statistics in BCMM. These results were found to be very important in helping an organisation to achieve employment targets. Furthermore, the municipality should investigate strengthening its consultative processes to involve the public in the job creation and decision-making processes. , Thesis (MPA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-04
- Authors: Nombebe, Gcobisa
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55107 , vital:49120
- Description: The aim of the study was to evaluate the implementation of the Expanded Public Works Programme (EPWP) in the Buffalo City Metropolitan Municipality (BCMM) between 2013 and 2018. This was necessitated by the common trend observed in the country that, despite many interventions to alleviate poverty, the unemployment rate continues to increase, and poverty remains a challenge. The study was qualitative, and it used secondary data to achieve its objectives. The data was sourced from journals, municipal documents, the national Department of Public Works’ publications, newspapers and many other secondary sources. The results revealed that the EPWP performance in BCMM is greatly influenced by effective performance management systems, proper planning, political impact, training and development, and committed leadership. This was perceived as the first attempt towards improving the EPWP aligned employment statistics in BCMM. These results were found to be very important in helping an organisation to achieve employment targets. Furthermore, the municipality should investigate strengthening its consultative processes to involve the public in the job creation and decision-making processes. , Thesis (MPA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-04
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
Classification and clustering based methods for outlier detection of solar resource data
- Authors: Abrahams, Waldo
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55423 , vital:51996
- Description: Almost 90% of the primary global energy demand is serviced from the burning of fossil fuels (Abas, Kalair & Khan, 2015). Owing to the detrimental environmental impact of this, a global energy transition to the use of renewable energy, including solar energy, is needed (Gielen et al., 2019). An important aspect that inhibits the growth of solar energy is accurate solar resource data. Such data is needed because knowledge of the future reliability and quality of energy production is required to analyse a system’s performance and determine financial implications (Sengupta et al., 2017). Existing methods used to detect outliers in solar resource data do not efficiently identify outliers and an accurate and robust approach is required (Eastwood, 2019). Using simulated and real-world data, this study investigates the use of several classification methods, along with a two-stage clustering-classification approach to accurately identify outliers in solar resource data. The Treebag method proves to be an adequate outlier detection method for solar resource data. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Abrahams, Waldo
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55423 , vital:51996
- Description: Almost 90% of the primary global energy demand is serviced from the burning of fossil fuels (Abas, Kalair & Khan, 2015). Owing to the detrimental environmental impact of this, a global energy transition to the use of renewable energy, including solar energy, is needed (Gielen et al., 2019). An important aspect that inhibits the growth of solar energy is accurate solar resource data. Such data is needed because knowledge of the future reliability and quality of energy production is required to analyse a system’s performance and determine financial implications (Sengupta et al., 2017). Existing methods used to detect outliers in solar resource data do not efficiently identify outliers and an accurate and robust approach is required (Eastwood, 2019). Using simulated and real-world data, this study investigates the use of several classification methods, along with a two-stage clustering-classification approach to accurately identify outliers in solar resource data. The Treebag method proves to be an adequate outlier detection method for solar resource data. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2022
- Full Text:
- Date Issued: 2022-04
Conflict management and transformation within the Evangelical Bible Church of Kwazulu-Natal
- Authors: Mentor, Kurt Raymond
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54870 , vital:48327
- Description: The following treatise is an analysis of conflict management within the Evangelical Bible Church of KwaZulu-Natal (EBC KZN). It focuses on the effectiveness of the management of conflict within the churches of EBC KZN. Over the years, many churches have avoided conflict and conflict management has never been a popular topic in the church. This may be because the church mostly relies on wisdom from God to handle conflict, with few attempts made to learn more about how to handle conflict effectively. A common approach is for the church to wait until conflict builds to a certain level before attempting to resolve it. Many conflicts have spiralled out of control by the time the church responds to issues. Thus, the church needs to address conflict proactively, rather than reactively. In order for the church to be more successful in resolving conflict, the leadership needs to take time to develop effective skills in conflict resolution. This is a proactive way of resolving conflict. This treatise explores the challenges pastors‟ face that inhibits their full potential to manage conflict. It describes the role of the pastors in the process of conflict management among the churches of EBC KZN, investigates the importance of effective conflict management in preventing further conflict, and explores ways of improving the skills of the pastors in conflict management. Like most churches, EBC KZN and its pastors have been called upon to deal with conflict disputes within local churches. Therefore, the researcher worked in partnership with seven pastors of EBC KZN using an analytical approach to explore the management of conflict among their churches. This study made use of qualitative methods of conducting interviews with the seven participants on conflict management in the church. The research revealed that conflict management in EBC KZN is ineffective because of a number of factors; including the lack of training of the pastors in conflict management and comprehensive church guidelines and policies to manage conflict. The researcher recommends that further research be done among the churches and for a proper policy of conflict management to be drawn up. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-04
- Authors: Mentor, Kurt Raymond
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54870 , vital:48327
- Description: The following treatise is an analysis of conflict management within the Evangelical Bible Church of KwaZulu-Natal (EBC KZN). It focuses on the effectiveness of the management of conflict within the churches of EBC KZN. Over the years, many churches have avoided conflict and conflict management has never been a popular topic in the church. This may be because the church mostly relies on wisdom from God to handle conflict, with few attempts made to learn more about how to handle conflict effectively. A common approach is for the church to wait until conflict builds to a certain level before attempting to resolve it. Many conflicts have spiralled out of control by the time the church responds to issues. Thus, the church needs to address conflict proactively, rather than reactively. In order for the church to be more successful in resolving conflict, the leadership needs to take time to develop effective skills in conflict resolution. This is a proactive way of resolving conflict. This treatise explores the challenges pastors‟ face that inhibits their full potential to manage conflict. It describes the role of the pastors in the process of conflict management among the churches of EBC KZN, investigates the importance of effective conflict management in preventing further conflict, and explores ways of improving the skills of the pastors in conflict management. Like most churches, EBC KZN and its pastors have been called upon to deal with conflict disputes within local churches. Therefore, the researcher worked in partnership with seven pastors of EBC KZN using an analytical approach to explore the management of conflict among their churches. This study made use of qualitative methods of conducting interviews with the seven participants on conflict management in the church. The research revealed that conflict management in EBC KZN is ineffective because of a number of factors; including the lack of training of the pastors in conflict management and comprehensive church guidelines and policies to manage conflict. The researcher recommends that further research be done among the churches and for a proper policy of conflict management to be drawn up. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-04
Constructing an intergrated service excellence model for the South African police service
- Authors: Modise, Motsamai John
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55020 , vital:48823
- Description: This study is set within the South African Police Service (SAPS). The purpose of the study is to construct an integrated service excellence model, in order to improve service quality in the South African Police Service as a whole and to continuously improve service excellence in the assistance provided in the Northern Cape in particular. Furthermore, the study was intended to identify gaps in the quality of services provided by the SAPS to the various communities in the Northern Cape. The development of a service excellence model for the assessment of the services provided by the SAPS is justified, because it is an essential means to improving the services rendered, which will be beneficial to both the SAPS and the community. Service failures negatively impact relationships and marketing efforts and thus complicate service providers’ relationship-building efforts. Therefore, service providers endeavour to restore customers’ post-recovery satisfaction through service recovery efforts to retain their customers. However, the influence that customers’ relationship intentions have on this process has not been considered. Previous research on relationship intention in South Africa focussed only on developing a valid and reliable relationship intention measurement scale. This study employed both the quantitative and qualitative research approaches to validate the research questions and authenticate the problem statement. The triangulation approach allowed the researcher to effectively engage the strengths of both research methodologies. The research findings from the empirical survey were statistically analysed using statistical procedures. The data analysis, derived from the qualitative research approach, involved thematic content analysis. The sample populations for the study comprised ward councillors, selected senior officials and community members. For the quantitative approach, questionnaires were distributed to respondents. One-on–one interviews were conducted with senior managers as the qualitative component of the study. , Thesis (PhD) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-04
- Authors: Modise, Motsamai John
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55020 , vital:48823
- Description: This study is set within the South African Police Service (SAPS). The purpose of the study is to construct an integrated service excellence model, in order to improve service quality in the South African Police Service as a whole and to continuously improve service excellence in the assistance provided in the Northern Cape in particular. Furthermore, the study was intended to identify gaps in the quality of services provided by the SAPS to the various communities in the Northern Cape. The development of a service excellence model for the assessment of the services provided by the SAPS is justified, because it is an essential means to improving the services rendered, which will be beneficial to both the SAPS and the community. Service failures negatively impact relationships and marketing efforts and thus complicate service providers’ relationship-building efforts. Therefore, service providers endeavour to restore customers’ post-recovery satisfaction through service recovery efforts to retain their customers. However, the influence that customers’ relationship intentions have on this process has not been considered. Previous research on relationship intention in South Africa focussed only on developing a valid and reliable relationship intention measurement scale. This study employed both the quantitative and qualitative research approaches to validate the research questions and authenticate the problem statement. The triangulation approach allowed the researcher to effectively engage the strengths of both research methodologies. The research findings from the empirical survey were statistically analysed using statistical procedures. The data analysis, derived from the qualitative research approach, involved thematic content analysis. The sample populations for the study comprised ward councillors, selected senior officials and community members. For the quantitative approach, questionnaires were distributed to respondents. One-on–one interviews were conducted with senior managers as the qualitative component of the study. , Thesis (PhD) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-04
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
Cultural perspectives on health decision making of HIV positive Xhosa males
- Tebekana, Aviwe Zuziwe Nomalibongwe
- Authors: Tebekana, Aviwe Zuziwe Nomalibongwe
- Date: 2020-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53769 , vital:45835
- Description: In 1998, following a recommendation made by the United Nations Educational, Scientific and Cultural Organisation (UNESO), the Joint United Nations programme on HIV and AIDS (UNAIDS) adopted a cultural approach to HIV and AIDS prevention and treatment for sustainable development. Cultural identity, values and norms are all influential factors in health decision making and may be especially important in the context of HIV infection. The research aim of this study was to explore and describe the experiences of HIV positive Xhosa males in relation to understanding how cultural identity, cultural values and norms influence the health decision making behaviour of Xhosa males. A qualitative study design was adopted. A descriptive and interpretative approach was applied. Semi-structured interviews were conducted with 10 HIV positive Xhosa males aged 25 to 49 years in four primary healthcare clinics in the Nelson Mandela Bay. Thematic data analysis was utilised to analyse the data through the lens of literature and the bio-ecological model. The data was coded by the researcher and an independent coder. Three themes and six sub themes emerged from the study. Theme one is: significance of culture for HIV positive Xhosa males. Theme two is: perspectives on factors that have an influence on health decision making. Theme three is: perceived beliefs and perceptions about HIV and AIDS in the Xhosa ethnic group. The study indicated that cultural factors such as ancestral beliefs regarding illness, traditional circumcision, initiation school and masculine roles and expectations influenced health decision making of the Xhosa males. In addition, there are other factors that have an influence on health decision making such as psycho-social factors of peer pressure and biological factors which include physical developmental changes. In addition to factors that have an influence to health decision making, it became apparent in the study that there was perceived stigma attached to HIV and AIDS from family members and the Xhosa community. Participants also experienced internalised stigma and expressed a v fear of not having an heir; thus, influencing risk taking health decision in fear of being stigmatised. Perceptions of HIV positive Xhosa males on cultural factors that have an influence on health decision making such as risk behaviour and adherence to treatment are: ancestral belief of protection against illness, traditional circumcision, initiation school and masculine roles and expectations. , Thesis (MA) -- Faculty of Health Sciences, School of Behavioural Sciences, 2020
- Full Text:
- Date Issued: 2020-12
- Authors: Tebekana, Aviwe Zuziwe Nomalibongwe
- Date: 2020-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53769 , vital:45835
- Description: In 1998, following a recommendation made by the United Nations Educational, Scientific and Cultural Organisation (UNESO), the Joint United Nations programme on HIV and AIDS (UNAIDS) adopted a cultural approach to HIV and AIDS prevention and treatment for sustainable development. Cultural identity, values and norms are all influential factors in health decision making and may be especially important in the context of HIV infection. The research aim of this study was to explore and describe the experiences of HIV positive Xhosa males in relation to understanding how cultural identity, cultural values and norms influence the health decision making behaviour of Xhosa males. A qualitative study design was adopted. A descriptive and interpretative approach was applied. Semi-structured interviews were conducted with 10 HIV positive Xhosa males aged 25 to 49 years in four primary healthcare clinics in the Nelson Mandela Bay. Thematic data analysis was utilised to analyse the data through the lens of literature and the bio-ecological model. The data was coded by the researcher and an independent coder. Three themes and six sub themes emerged from the study. Theme one is: significance of culture for HIV positive Xhosa males. Theme two is: perspectives on factors that have an influence on health decision making. Theme three is: perceived beliefs and perceptions about HIV and AIDS in the Xhosa ethnic group. The study indicated that cultural factors such as ancestral beliefs regarding illness, traditional circumcision, initiation school and masculine roles and expectations influenced health decision making of the Xhosa males. In addition, there are other factors that have an influence on health decision making such as psycho-social factors of peer pressure and biological factors which include physical developmental changes. In addition to factors that have an influence to health decision making, it became apparent in the study that there was perceived stigma attached to HIV and AIDS from family members and the Xhosa community. Participants also experienced internalised stigma and expressed a v fear of not having an heir; thus, influencing risk taking health decision in fear of being stigmatised. Perceptions of HIV positive Xhosa males on cultural factors that have an influence on health decision making such as risk behaviour and adherence to treatment are: ancestral belief of protection against illness, traditional circumcision, initiation school and masculine roles and expectations. , Thesis (MA) -- Faculty of Health Sciences, School of Behavioural Sciences, 2020
- Full Text:
- Date Issued: 2020-12
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
Development of a crumb rubber adsorbent for the sorption of lead and copper from waste water: Optimization of sorption in a binary component system
- Authors: Hlabana,Relebohile Gladys
- Date: 2022-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59688 , vital:62356
- Description: Waste tyre is becoming a global environmental problem due to challenges in its disposal management and the fact that it poses fire hazards and metal leaching risk. Waste tyre can also breed mosquitos if it traps water thereby becoming an environmental health problem. There is also a portion of unused tyre in a waste tyre that is valuable and should be recycled. In South Africa waste tyre recycling is in three industries, one of which is crumb rubber where waste tyre is applied into various sized particles called crumb rubber. Crumb rubber can be applied in environmental remediation as an organic and inorganic pollutants’ adsorbent. Considering the fact that South Africa’s environment is loaded with heavy metal pollutants due to contributions by mining and agriculture as examples, it is postulated that crumb rubber produced in South Africa could be used to remediate the environment of these toxic metals. In this study adsorption of Pb (II) and Cu (II) from the synthetic waste water using waste tyre crumb rubber produced in South Africa was studied. Crumb rubber was activated using aqueous NaOH (0.02%) to make crumb rubber wettable followed by it being treated with 0.02 % acidified KMnO4 for modification of its ability to sorp positively charged metal species. Trial sorption experiments on 50 mg / L Cu (II) were successful with sorption of over 70% in 250 minutes. Final optimization of the sorption of combined Pb (II) and Cu (II) was studied using a full factorial design and optimum conditions of sorption were found to be pH 5.4; [metal] 0.617 mmol / L for Pb (II); and pH 5.4; the optimization of Cu (II) was found to be pH 5.4; [metal] 0.777 mmol / L. In Pb (II) sorptions the mechanism of adsorption on the activated crumb rubber was found to be following the Freundlich model indicating that the adsorption seemed to occur on a multilayer adsorbent, while the mechanism of copper(II) adsorption on to the activated crumb rubber was found to be following Langmuir model, indicating that the adsorption seemed to occur on a monolayer. With adsorption percentages ranging from 98.2 % to 100.0 %, for Pb (II), the crumb rubber produced under the conditions of this study, can be used in South Africa for selective removal of Pb (II). , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Hlabana,Relebohile Gladys
- Date: 2022-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59688 , vital:62356
- Description: Waste tyre is becoming a global environmental problem due to challenges in its disposal management and the fact that it poses fire hazards and metal leaching risk. Waste tyre can also breed mosquitos if it traps water thereby becoming an environmental health problem. There is also a portion of unused tyre in a waste tyre that is valuable and should be recycled. In South Africa waste tyre recycling is in three industries, one of which is crumb rubber where waste tyre is applied into various sized particles called crumb rubber. Crumb rubber can be applied in environmental remediation as an organic and inorganic pollutants’ adsorbent. Considering the fact that South Africa’s environment is loaded with heavy metal pollutants due to contributions by mining and agriculture as examples, it is postulated that crumb rubber produced in South Africa could be used to remediate the environment of these toxic metals. In this study adsorption of Pb (II) and Cu (II) from the synthetic waste water using waste tyre crumb rubber produced in South Africa was studied. Crumb rubber was activated using aqueous NaOH (0.02%) to make crumb rubber wettable followed by it being treated with 0.02 % acidified KMnO4 for modification of its ability to sorp positively charged metal species. Trial sorption experiments on 50 mg / L Cu (II) were successful with sorption of over 70% in 250 minutes. Final optimization of the sorption of combined Pb (II) and Cu (II) was studied using a full factorial design and optimum conditions of sorption were found to be pH 5.4; [metal] 0.617 mmol / L for Pb (II); and pH 5.4; the optimization of Cu (II) was found to be pH 5.4; [metal] 0.777 mmol / L. In Pb (II) sorptions the mechanism of adsorption on the activated crumb rubber was found to be following the Freundlich model indicating that the adsorption seemed to occur on a multilayer adsorbent, while the mechanism of copper(II) adsorption on to the activated crumb rubber was found to be following Langmuir model, indicating that the adsorption seemed to occur on a monolayer. With adsorption percentages ranging from 98.2 % to 100.0 %, for Pb (II), the crumb rubber produced under the conditions of this study, can be used in South Africa for selective removal of Pb (II). , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-12
Ecosexual digital war machines: minoritarian environmental desires in the age of new media
- Authors: Weideman, Lisa
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54828 , vital:47915
- Description: Today the (Transnational) State Apparatuses of neoliberal capitalism, ranging from educational institutions to mass media and financial institutions, have effectively created and channelled desires towards consumerism, predicated on resource-extractive practices, within the context of what Gilles Deleuze calls societies of control. This control has also intensified in the digital era, particularly through Internet-based technologies which provide increasingly efficient platforms for the escalation of commodification – ironically, despite the reality of ecological crisis being precipitated by the related extractive practices to the point where it now threatens the continued existence of life on earth. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
- Full Text: false
- Date Issued: 2021-04
- Authors: Weideman, Lisa
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54828 , vital:47915
- Description: Today the (Transnational) State Apparatuses of neoliberal capitalism, ranging from educational institutions to mass media and financial institutions, have effectively created and channelled desires towards consumerism, predicated on resource-extractive practices, within the context of what Gilles Deleuze calls societies of control. This control has also intensified in the digital era, particularly through Internet-based technologies which provide increasingly efficient platforms for the escalation of commodification – ironically, despite the reality of ecological crisis being precipitated by the related extractive practices to the point where it now threatens the continued existence of life on earth. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
- Full Text: false
- Date Issued: 2021-04
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
Effect of fire severity on Afrotemperate forest tree survival
- Authors: Giddey, Brandon Louis
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55385 , vital:51988
- Description: Weather patterns have changed globally with increased fire danger weather conditions, along with poor management and fire suppression, likely contributing to the increase in prevalence of large wildfires. Ecosystems such as temperate broadleaved forests, where fire is limited by climatic conditions, are particularly at risk of altered fire regimes related to climate change. It is thus important to monitor the effects of fire in these ecosystems. Satellite remote sensing is a cost-effective way to assess spatial variability of fire effects on a landscape scale and has become an increasingly used tool for studying fire severity. In the southern Cape of South Africa during October-November 2018, a large wildfire burnt patches of Southern Cape Afrotemperate Forest (hereafter ‘Afrotemperate forest’). This provided an opportunity to investigate the accuracy of a satellite index for fire severity and the effect of fire on Afrotemperate forest survival. The first objective was to verify through field observations the accuracy of the differenced Normalised Burn Ratio (dNBR) as an index of fire severity derived from Sentinel 2 images in Afrotemperate forest. The second objective was to investigate the effect of fire severity and tree size on the post-fire survival of Afrotemperate forest tree species. For the first objective, stem fire severity, estimated from observed damage to the main stem, was recorded for 1 648 trees in 87 plots and linear regression used to test whether the observed measure of fire severity was related to dNBR. For the second objective, stem fire severity and tree survival 19-24 months post-fire were recorded for 40 species and 1 378 trees in 88 plots. Trees were considered to have survived if they resprouted from the main stem or had green foliage in the canopy. The survival response was assessed in relation to stem fire severity and tree size for all trees collectively and for 10 species (with sample size > 40) individually, using logistic regression. A strong linear relationship between dNBR and stem fire severity (r2 = 0.69, p < 0.001) confirmed the accuracy of dNBR as a measure of fire severity in Afrotemperate forest. In the fire investigated, 4 628 ha of Afrotemperate forest burnt of which 67% burnt at low severity, 21% at medium severity and 12% at high severity. The dNBR values associated with fire severity categories were comparable between Afrotemperate and North American forests, suggesting that dNBR values are relatively standard across forest types. Information on the distribution of fire severity facilitates investigation of further questions regarding past and future fire regimes and the fire ecology of Afrotemperate forest. The post-fire survival rate of Afrotemperate forest trees was 45% which is comparable to that in coniferous forests of North America but lower than that in temperate forests of Australia and Portugal and the neighbouring dune thicket which shares several species with Afrotemperate forest. Fire severity had a significant negative effect on survival and tree size a significant positive effect. Total variance explained by the model (for species collectively) was 40.8%, of which fire severity and tree size combined explained 13.2%, and species as random factor, 27.6%. Respective tree species showed differential survival responses – four species showed high survival (> 60% of individuals), while five species showed low survival (< 40%). This study was the first post-fire assessment of the resprouting ability of Afrotemperate forest trees and a third of the trees surveyed (for species collectively) resprouted from the stem. This suggested that resprouting from the stem is a primary means of post-fire recovery in Afrotemperate forest trees, in contrast with previous assertions that several common canopy species, including Podocarpus latifolius, Afrocarpus falcatus, Scutia myrtina, Scolopia mundii and Rapanea melanophloeos, are unable to resprout. Varying resilience to fire among species supports previous suggestions that fire affects species’ composition and diversity in these forests and calls for careful management of fire regimes in the face of global change. , Thesis (MSc) -- Faculty of Science, School of Natural Resource Management, 2022
- Full Text: false
- Date Issued: 2022-04
- Authors: Giddey, Brandon Louis
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55385 , vital:51988
- Description: Weather patterns have changed globally with increased fire danger weather conditions, along with poor management and fire suppression, likely contributing to the increase in prevalence of large wildfires. Ecosystems such as temperate broadleaved forests, where fire is limited by climatic conditions, are particularly at risk of altered fire regimes related to climate change. It is thus important to monitor the effects of fire in these ecosystems. Satellite remote sensing is a cost-effective way to assess spatial variability of fire effects on a landscape scale and has become an increasingly used tool for studying fire severity. In the southern Cape of South Africa during October-November 2018, a large wildfire burnt patches of Southern Cape Afrotemperate Forest (hereafter ‘Afrotemperate forest’). This provided an opportunity to investigate the accuracy of a satellite index for fire severity and the effect of fire on Afrotemperate forest survival. The first objective was to verify through field observations the accuracy of the differenced Normalised Burn Ratio (dNBR) as an index of fire severity derived from Sentinel 2 images in Afrotemperate forest. The second objective was to investigate the effect of fire severity and tree size on the post-fire survival of Afrotemperate forest tree species. For the first objective, stem fire severity, estimated from observed damage to the main stem, was recorded for 1 648 trees in 87 plots and linear regression used to test whether the observed measure of fire severity was related to dNBR. For the second objective, stem fire severity and tree survival 19-24 months post-fire were recorded for 40 species and 1 378 trees in 88 plots. Trees were considered to have survived if they resprouted from the main stem or had green foliage in the canopy. The survival response was assessed in relation to stem fire severity and tree size for all trees collectively and for 10 species (with sample size > 40) individually, using logistic regression. A strong linear relationship between dNBR and stem fire severity (r2 = 0.69, p < 0.001) confirmed the accuracy of dNBR as a measure of fire severity in Afrotemperate forest. In the fire investigated, 4 628 ha of Afrotemperate forest burnt of which 67% burnt at low severity, 21% at medium severity and 12% at high severity. The dNBR values associated with fire severity categories were comparable between Afrotemperate and North American forests, suggesting that dNBR values are relatively standard across forest types. Information on the distribution of fire severity facilitates investigation of further questions regarding past and future fire regimes and the fire ecology of Afrotemperate forest. The post-fire survival rate of Afrotemperate forest trees was 45% which is comparable to that in coniferous forests of North America but lower than that in temperate forests of Australia and Portugal and the neighbouring dune thicket which shares several species with Afrotemperate forest. Fire severity had a significant negative effect on survival and tree size a significant positive effect. Total variance explained by the model (for species collectively) was 40.8%, of which fire severity and tree size combined explained 13.2%, and species as random factor, 27.6%. Respective tree species showed differential survival responses – four species showed high survival (> 60% of individuals), while five species showed low survival (< 40%). This study was the first post-fire assessment of the resprouting ability of Afrotemperate forest trees and a third of the trees surveyed (for species collectively) resprouted from the stem. This suggested that resprouting from the stem is a primary means of post-fire recovery in Afrotemperate forest trees, in contrast with previous assertions that several common canopy species, including Podocarpus latifolius, Afrocarpus falcatus, Scutia myrtina, Scolopia mundii and Rapanea melanophloeos, are unable to resprout. Varying resilience to fire among species supports previous suggestions that fire affects species’ composition and diversity in these forests and calls for careful management of fire regimes in the face of global change. , Thesis (MSc) -- Faculty of Science, School of Natural Resource Management, 2022
- Full Text: false
- Date Issued: 2022-04
Employee Value Proposition (EVP) and employee engagement in a leading South African car rental company
- Authors: Mtati, Yanela
- Date: 2014-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53330 , vital:45134
- Description: The car rental industry in South Africa is a highly competitive sector. The industry’s players are constantly faced with the challenge of finding ways in which to enhance their competitiveness. One of the most important challenges for organisations operating in this industry is to deliver the best service to their customers, hence ensuring they retain customer loyalty, growth and securing future profitability. While a number of competitors may rely on various competitive strategies such as lower prices, it could become increasingly challenging for others to adopt similar approaches without comprising profitability. To overcome this challenge, together with Barloworld, Avis has implemented various employment engagement strategies with the aim of attracting, empowering, and retaining an engaged workforce. Research has shown that employees provide organisations with sustainable competitive advantage. More specifically, it has shown that engaged employees outperform disengaged employees. The differentiating factor for organisations in the pursuit of competitive advantage would therefore be an engaged workforce. In order to remain competitive, Avis realised that their employees area source of competitive advantage. In the year 2013, Avis packaged and introduced EVP as a human resources strategy towards winning an engaged workforce. Some of the objectives for taking on this strategy were to increase job satisfaction and motivation amongst employees and thus result in higher job performance. The main purpose of this study was to measure the impact that the introduction of EVP had on employee engagement at Avis. Introducing a structured EVP plan within this organisation was aimed to increase employee engagement and thus, this study aimed to measure the impact of this intervention. A literature review was conducted to expand on the various definitions of EVP, employee engagement and the elements that influence and impact these variables. This research revealed that engaged employees make positive contributions to key business outcomes such as financial performance, productivity and customer satisfaction. An empirical study was conducted by means of a survey with a questionnaire as data collecting tool. The purpose of the structured questionnaire was to validate the findings obtained from the theoretical overview and to assess employees’ perceptions of the EVP elements, engagement factors and the impact of engagement on the organisational success. The population comprised of 142employeesand 65% a response rate was obtained. The key findings of the study indicated that in general employees are engaged and committed to the vision of the organisation. It also indicated that the introduction of EVP improved the manner in which employees’ viewed their leaders and created a leadership culture that was conducive to the success of the organisation. Furthermore, the study validated the existence of a strong positive relationship between EVP, employee motivation, leadership culture, employee retention, compensation and employee engagement. This study provided direction and feedback in the organisation’s attempt to improve engagement levels and ultimately in the pursuit of competitive advantage. , Thesis (MBA) -- Faculty of Business and Economic Sciences, NMMU Business School, 2014.
- Full Text:
- Date Issued: 2014-12
- Authors: Mtati, Yanela
- Date: 2014-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53330 , vital:45134
- Description: The car rental industry in South Africa is a highly competitive sector. The industry’s players are constantly faced with the challenge of finding ways in which to enhance their competitiveness. One of the most important challenges for organisations operating in this industry is to deliver the best service to their customers, hence ensuring they retain customer loyalty, growth and securing future profitability. While a number of competitors may rely on various competitive strategies such as lower prices, it could become increasingly challenging for others to adopt similar approaches without comprising profitability. To overcome this challenge, together with Barloworld, Avis has implemented various employment engagement strategies with the aim of attracting, empowering, and retaining an engaged workforce. Research has shown that employees provide organisations with sustainable competitive advantage. More specifically, it has shown that engaged employees outperform disengaged employees. The differentiating factor for organisations in the pursuit of competitive advantage would therefore be an engaged workforce. In order to remain competitive, Avis realised that their employees area source of competitive advantage. In the year 2013, Avis packaged and introduced EVP as a human resources strategy towards winning an engaged workforce. Some of the objectives for taking on this strategy were to increase job satisfaction and motivation amongst employees and thus result in higher job performance. The main purpose of this study was to measure the impact that the introduction of EVP had on employee engagement at Avis. Introducing a structured EVP plan within this organisation was aimed to increase employee engagement and thus, this study aimed to measure the impact of this intervention. A literature review was conducted to expand on the various definitions of EVP, employee engagement and the elements that influence and impact these variables. This research revealed that engaged employees make positive contributions to key business outcomes such as financial performance, productivity and customer satisfaction. An empirical study was conducted by means of a survey with a questionnaire as data collecting tool. The purpose of the structured questionnaire was to validate the findings obtained from the theoretical overview and to assess employees’ perceptions of the EVP elements, engagement factors and the impact of engagement on the organisational success. The population comprised of 142employeesand 65% a response rate was obtained. The key findings of the study indicated that in general employees are engaged and committed to the vision of the organisation. It also indicated that the introduction of EVP improved the manner in which employees’ viewed their leaders and created a leadership culture that was conducive to the success of the organisation. Furthermore, the study validated the existence of a strong positive relationship between EVP, employee motivation, leadership culture, employee retention, compensation and employee engagement. This study provided direction and feedback in the organisation’s attempt to improve engagement levels and ultimately in the pursuit of competitive advantage. , Thesis (MBA) -- Faculty of Business and Economic Sciences, NMMU Business School, 2014.
- Full Text:
- Date Issued: 2014-12
Encapsulation of flame retardants for lithium-ion battery safety
- Authors: Ntombela, Nompilo Princess
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55412 , vital:51993
- Description: Lithium-ion technology takes the lead in electric mobility systems, resulting in an increase in the global demand for Li-ion batteries; however, these batteries are associated with numerous safety concerns. Additionally, there are high costs, high energy and power issues which are some of its key limitations. Research efforts are focused on overcoming these obstacles, with different approaches being explored, such as the investigation of more stable salts, modification of active materials and organic solvents, and the use of electrolyte additives. This study focused specifically on electrolyte additives since the electrolyte is one of the most unstable components of the battery. The electrolyte’s decomposition is one of the reactions that occur inside a battery, which may occur due to overcharging or due to an internal short circuit, amongst others. The electrolyte’s decomposition occurs at the early stages of the thermal runaway process and forms part of the reactions that lead to fires and explosions. Thus, this research aims to develop suitable electrolyte additives to improve the safety aspects of Li-ion batteries. Flame retardant additives show great promise in reducing the flammability of the electrolyte in Li-ion batteries, since they serve to suppress the chemical reactions associated with battery ignition. They retard the fires by scavenging the active radical species formed during the decomposition reaction. In this study, the use of flame retardants was investigated. Flame retardant additives have shown to have flame impeding properties inside a battery; however, their direct addition to the electrolyte tends to cause adverse effects on the ionic conductivity and electrochemical performance of the cells. This study investigated an alternative option - the option to microencapsulate such additives into a neutral compound to ensure that the flame retardant has minimal/no effect on the performance of the battery. This investigation looked at tris(2-butoxyethyl) phosphate (TBP) and bis(2,2,2-trifluoroethyl) methylphosphonate (BFP) as flame retardant additives for the electrolyte. The TBP and BFP flame retardants were microencapsulated in poly(urea formaldehyde) (PUF) coating material via in situ polymerization method. The capsules were characterized using various analytical techniques - to prove it was successfully encapsulated. Electrochemical studies were further done on the capsules and neat flame retardants inside a coin cell. Self-extinguishing time (SET), which is the flammability test, proved that the additives have flame retarding abilities. Opto-digital microscopy (DSX) and scanning electron microscopy (SEM) did confirm the spherical shape of the microcapsules, where SEM also showed the smooth outer layer of the microcapsules and its hollow inner side. Fourier transform infrared spectroscopy (FTIR) proved the presence of the TBP and BFP inside the PUF resin by showing that the chemical composition of microcapsules consisted of both the PUF and flame retardant additives. Simultaneous DSC-TGA (DST) was also performed which showed that the microcapsules were stable before 200 °C, which indicates it would not decompose before the thermal runaway events are occurring. TGA analysis did show that the microcapsules underwent multiple decomposition steps upon heating. Additionally, 31P nuclear magnetic resonance (NMR) was used to quantify the amount of flame retardants additives encapsulated inside PUF shell, and also confirmed the stability of the microcapsules for one month in the electrolyte and at temperatures up to 200 °C. The ionic conductivity was vastly decreased when the flame retardants were added directly to the electrolyte. However, adding the flame retardants in a form of capsules had minimal effect on the ionic conductivity. The cycle capacities of the capsules were also improved when the capsules were added to the cell compared to that of neat flame retardants. The same effect was also noticed when doing Electrochemical Impedance Spectroscopy (EIS). This shows that microencapsulation improves the resistance of the cell caused by the flame retardant in comparison to when added directly to the electrolyte of the cell. , Thesis (MSC) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Ntombela, Nompilo Princess
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55412 , vital:51993
- Description: Lithium-ion technology takes the lead in electric mobility systems, resulting in an increase in the global demand for Li-ion batteries; however, these batteries are associated with numerous safety concerns. Additionally, there are high costs, high energy and power issues which are some of its key limitations. Research efforts are focused on overcoming these obstacles, with different approaches being explored, such as the investigation of more stable salts, modification of active materials and organic solvents, and the use of electrolyte additives. This study focused specifically on electrolyte additives since the electrolyte is one of the most unstable components of the battery. The electrolyte’s decomposition is one of the reactions that occur inside a battery, which may occur due to overcharging or due to an internal short circuit, amongst others. The electrolyte’s decomposition occurs at the early stages of the thermal runaway process and forms part of the reactions that lead to fires and explosions. Thus, this research aims to develop suitable electrolyte additives to improve the safety aspects of Li-ion batteries. Flame retardant additives show great promise in reducing the flammability of the electrolyte in Li-ion batteries, since they serve to suppress the chemical reactions associated with battery ignition. They retard the fires by scavenging the active radical species formed during the decomposition reaction. In this study, the use of flame retardants was investigated. Flame retardant additives have shown to have flame impeding properties inside a battery; however, their direct addition to the electrolyte tends to cause adverse effects on the ionic conductivity and electrochemical performance of the cells. This study investigated an alternative option - the option to microencapsulate such additives into a neutral compound to ensure that the flame retardant has minimal/no effect on the performance of the battery. This investigation looked at tris(2-butoxyethyl) phosphate (TBP) and bis(2,2,2-trifluoroethyl) methylphosphonate (BFP) as flame retardant additives for the electrolyte. The TBP and BFP flame retardants were microencapsulated in poly(urea formaldehyde) (PUF) coating material via in situ polymerization method. The capsules were characterized using various analytical techniques - to prove it was successfully encapsulated. Electrochemical studies were further done on the capsules and neat flame retardants inside a coin cell. Self-extinguishing time (SET), which is the flammability test, proved that the additives have flame retarding abilities. Opto-digital microscopy (DSX) and scanning electron microscopy (SEM) did confirm the spherical shape of the microcapsules, where SEM also showed the smooth outer layer of the microcapsules and its hollow inner side. Fourier transform infrared spectroscopy (FTIR) proved the presence of the TBP and BFP inside the PUF resin by showing that the chemical composition of microcapsules consisted of both the PUF and flame retardant additives. Simultaneous DSC-TGA (DST) was also performed which showed that the microcapsules were stable before 200 °C, which indicates it would not decompose before the thermal runaway events are occurring. TGA analysis did show that the microcapsules underwent multiple decomposition steps upon heating. Additionally, 31P nuclear magnetic resonance (NMR) was used to quantify the amount of flame retardants additives encapsulated inside PUF shell, and also confirmed the stability of the microcapsules for one month in the electrolyte and at temperatures up to 200 °C. The ionic conductivity was vastly decreased when the flame retardants were added directly to the electrolyte. However, adding the flame retardants in a form of capsules had minimal effect on the ionic conductivity. The cycle capacities of the capsules were also improved when the capsules were added to the cell compared to that of neat flame retardants. The same effect was also noticed when doing Electrochemical Impedance Spectroscopy (EIS). This shows that microencapsulation improves the resistance of the cell caused by the flame retardant in comparison to when added directly to the electrolyte of the cell. , Thesis (MSC) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
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
Enhancing the provision of social housing through public-private partnerships in Buffalo City Metropolitan Municipality
- Authors: Sobuza, Duduzile
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54806 , vital:47905
- Description: The purpose of this study was to establish the extent to which the provision of social housing can be enhanced through public-private partnerships (PPPs) in the Buffalo City Municipality. A total quality management approach was used as a foundation to understand the application of PPPs in social housing delivery in the Buffalo City Municipality. The study was desktop research to understand the role of PPPs in the provision of social housing. The findings of the study revealed that PPPs provide additional capital for social housing development. The study highlighted that PPPs play a crucial role in providing alternative management and implementation skills as well as offering greater efficiency in the utilisation of financial resources in the delivery of social housing. The findings of the study further revealed that PPPs accelerate social housing delivery through the provision of additional sources of finance where the government is unable to increase public debt to meet investment needs. The study also identified a plethora of constraints that can hinder the adoption of PPP initiatives in social housing delivery. These include capacity constraints, financial constraints, lack of access to land and an unfavourable policy environment. Subsequently, the study advanced a set of recommendations in this regard that includes the creation of transparent and competitive procurement processes, government support in terms of financial incentives, review of the regulatory framework to improve access to land and the regulation of financial services institutions for access to affordable housing credit. , Thesis (MA) -- Faculty of Humanities, Department of Public Management and Leadership , 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Sobuza, Duduzile
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54806 , vital:47905
- Description: The purpose of this study was to establish the extent to which the provision of social housing can be enhanced through public-private partnerships (PPPs) in the Buffalo City Municipality. A total quality management approach was used as a foundation to understand the application of PPPs in social housing delivery in the Buffalo City Municipality. The study was desktop research to understand the role of PPPs in the provision of social housing. The findings of the study revealed that PPPs provide additional capital for social housing development. The study highlighted that PPPs play a crucial role in providing alternative management and implementation skills as well as offering greater efficiency in the utilisation of financial resources in the delivery of social housing. The findings of the study further revealed that PPPs accelerate social housing delivery through the provision of additional sources of finance where the government is unable to increase public debt to meet investment needs. The study also identified a plethora of constraints that can hinder the adoption of PPP initiatives in social housing delivery. These include capacity constraints, financial constraints, lack of access to land and an unfavourable policy environment. Subsequently, the study advanced a set of recommendations in this regard that includes the creation of transparent and competitive procurement processes, government support in terms of financial incentives, review of the regulatory framework to improve access to land and the regulation of financial services institutions for access to affordable housing credit. , Thesis (MA) -- Faculty of Humanities, Department of Public Management and Leadership , 2021
- Full Text:
- Date Issued: 2021-04
Evaluating compliance with supply chain management policies in the public sector
- Authors: Mvanana, Siziwe
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55064 , vital:49027
- Description: Despite reform processes in the employment of Supply Chain Management (SCM) as a strategic tool in the South African public sector, there are predicaments in SCM policies, especially in the public sector. This notwithstanding, research that demystifies the compliance with SCM policies in the public sector. This study evaluate compliance with Supply Chain Management policies in the public sector. The findings of the study revealed that overall the public sector have adopted and implemented the SCM policies. However, SCM policies are sometimes not always aligned with government policies. The most implemented SCM police was demand management, followed by acquisition management. The least implemented policies were logistics, disposal, risk and performance management. No significant differences were observed among the public sector. The public sector face serious SCM challenges in implementing their SCM policies. These challenges stem from: a lack of training for SCM staff, lack of proper capacity, poor planning, and ineffective black economic empowerment in the public sector. Based on the results, there is a need of training for SCM staff, capacity building, better planning interventions, and more effective black economic empowerment. It should be reiterated that the lack of proper SCM policies and procedures are the root cause of problems in service delivery in South Africa. The study concludes by recommending that SCM practitioners should regularly update their SCM policies, ensure proper compliance with the elements of SCM, as well as to source competencies, skills, and knowledge from higher education institutions and private accredited service providers. , Thesis (MPA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-04
- Authors: Mvanana, Siziwe
- Date: 2020-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55064 , vital:49027
- Description: Despite reform processes in the employment of Supply Chain Management (SCM) as a strategic tool in the South African public sector, there are predicaments in SCM policies, especially in the public sector. This notwithstanding, research that demystifies the compliance with SCM policies in the public sector. This study evaluate compliance with Supply Chain Management policies in the public sector. The findings of the study revealed that overall the public sector have adopted and implemented the SCM policies. However, SCM policies are sometimes not always aligned with government policies. The most implemented SCM police was demand management, followed by acquisition management. The least implemented policies were logistics, disposal, risk and performance management. No significant differences were observed among the public sector. The public sector face serious SCM challenges in implementing their SCM policies. These challenges stem from: a lack of training for SCM staff, lack of proper capacity, poor planning, and ineffective black economic empowerment in the public sector. Based on the results, there is a need of training for SCM staff, capacity building, better planning interventions, and more effective black economic empowerment. It should be reiterated that the lack of proper SCM policies and procedures are the root cause of problems in service delivery in South Africa. The study concludes by recommending that SCM practitioners should regularly update their SCM policies, ensure proper compliance with the elements of SCM, as well as to source competencies, skills, and knowledge from higher education institutions and private accredited service providers. , Thesis (MPA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-04
Evaluating the influence of electoral violence on democratic consolidaton in Sub-Saharan Africa: the case of the democratic republic of congo from 2006-2018
- Authors: Poggi, Giovanni
- Date: 2020-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55073 , vital:49035
- Description: The democratic legitimacy of African executives has been called into question substantially over the last decade. Using the Democratic Republic of Congo (DRC) as a case study, this evaluative research seeks to analyse how African executives and political elites continue to play a crucial role in inducing civil unrest and electoral violence. For African democracy to develop, there must be enforced resolutions to eradicate issues facing both procedural and substantive democracy on the continent. This research examined electoral violence and unconstitutional acts that aggravate electoral system abuse and diminish the consolidation of democracy in sub-Saharan African states, in particular the DRC. A specific focus on the leadership of Joseph Kabila in the DRC forms the case study component of this research. In 2016, elections were postponed in the DRC and the DRC’s constitutional court interpreted Article 70 and Article 73 of the constitution in a manner that allowed President Kabila to remain in office until a newly elected president was installed. The court’s ruling and interpretation of Article 70 and Article 73 was an attempt to avoid a power vacuum. The study evaluated the components that trigger the escalation of electoral violence in Sub-Saharan African states. The study reports on different contributory factors, including but not limited to, the impact of predatory and rent-seeking leadership towards electoral manipulation; and the effect of patron-client relations on democratic institutions. Even though elections are not the only indicator of democracy stability in a state, this study demonstrated how electoral violence threatens the consolidation of democracy in sub-Saharan African states, in particular the DRC. In examining electoral violence, a desktop analysis method, which was used in the study, involved the collection of data from existing resources in order to provide a more critical lens to understanding electoral violence in the DRC. The theoretical analysis used in the study is the Höglund (2009) framework on electoral institutions which outlined how political violence remains a pervasive feature in Sub-Saharan countries by linking the framework to patron-clientelism. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-12
- Authors: Poggi, Giovanni
- Date: 2020-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55073 , vital:49035
- Description: The democratic legitimacy of African executives has been called into question substantially over the last decade. Using the Democratic Republic of Congo (DRC) as a case study, this evaluative research seeks to analyse how African executives and political elites continue to play a crucial role in inducing civil unrest and electoral violence. For African democracy to develop, there must be enforced resolutions to eradicate issues facing both procedural and substantive democracy on the continent. This research examined electoral violence and unconstitutional acts that aggravate electoral system abuse and diminish the consolidation of democracy in sub-Saharan African states, in particular the DRC. A specific focus on the leadership of Joseph Kabila in the DRC forms the case study component of this research. In 2016, elections were postponed in the DRC and the DRC’s constitutional court interpreted Article 70 and Article 73 of the constitution in a manner that allowed President Kabila to remain in office until a newly elected president was installed. The court’s ruling and interpretation of Article 70 and Article 73 was an attempt to avoid a power vacuum. The study evaluated the components that trigger the escalation of electoral violence in Sub-Saharan African states. The study reports on different contributory factors, including but not limited to, the impact of predatory and rent-seeking leadership towards electoral manipulation; and the effect of patron-client relations on democratic institutions. Even though elections are not the only indicator of democracy stability in a state, this study demonstrated how electoral violence threatens the consolidation of democracy in sub-Saharan African states, in particular the DRC. In examining electoral violence, a desktop analysis method, which was used in the study, involved the collection of data from existing resources in order to provide a more critical lens to understanding electoral violence in the DRC. The theoretical analysis used in the study is the Höglund (2009) framework on electoral institutions which outlined how political violence remains a pervasive feature in Sub-Saharan countries by linking the framework to patron-clientelism. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
- Full Text:
- Date Issued: 2020-12