Development of high capacity lithium-manganese-rich cathode materials xLi2MnO3•(1-x)LiMn0.5Ni0.5O2 for lithium ion batteries
- Authors: Rapulenyane, Nomasonto
- Date: 2018
- Subjects: Lithium ion batteries , Electrochemistry Lithium cells
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/34766 , vital:33442
- Description: In this study, a facile synthesis method was developed to produce layered-layered cathode materials with the formula xLi2MnO3•(1-x)LiMO2 (M= Ni and Mn) referred to as lithium-manganese-rich materials for lithium ion batteries. The prepared materials displayed high capacity ≥200 mAh/g at a current density of 20 mA/g in the voltage range of 2.0 V to 4.8 V. In particular the cathode material prepared at pH 10.0 delivered a high initial discharge capacity of 266 mAh/g at 20 mA/g current density and maintained a discharge capacity ≥220 mAh/g at 50 mA/g after 50 cycles. The synthesis method was used to further investigate the effect of lithium ratio in the layered-layered material. Li1+xMn0.6Ni0.2O2, x= 0.2, 0.25, 0.3 and 0.4 cathode materials were produced respectively. The BET surface area analysis results showed that Li1.3Mn0.6Ni0.2O2 material had comparatively higher surface area to the other cathode materials and also delivered good electrochemical results. XPS showed that the cation distribution is affected by the increase in lithium ratio, the Mn4+ percentages decreased significantly with an increase in lithium ratio. All materials peaks deconvoluted into two peaks namely Mn4+ and Mn3+, Li1.3Mn0.6Ni0.2O2 had the highest percentages of the stable Mn4+ 70.8%. Further investigation focused on the effect of the sintering temperature on the structure and the electrochemical performance of Li1+xMn0.6Ni0.2O2, x= 0.25, 0.3 and 0.4 cathode materials. X-ray diffraction showed the same patterns for all cathode materials sintered at 700˚C, 800˚C and 900˚C. Rietveld refined results however, showed that the increase in the sintering temperature, results in a decrease in the Li2MnO3 component percentage in the layered structures. Scanning electron microscopy images further proved that the particle size increases with increasing temperature. The charge–discharge tests of coin cells demonstrated that the materials sintered at 800˚C delivered higher discharge capacities above 200 mAh/g at 20 mA/g current density when compared to the materials made at the lower temperatures. Lastly the cathode material prepared at pH 10.0 was further evaluated in a cell using lithium titanate oxide Li4Ti5O12 as anode material. The cells delivered an initial discharge capacity of 213 mAh/g at 20 mA/g within a voltage range 3.3V-0.5V. The coin cells developed in this work delivered good cycling performance.
- Full Text:
- Date Issued: 2018
- Authors: Rapulenyane, Nomasonto
- Date: 2018
- Subjects: Lithium ion batteries , Electrochemistry Lithium cells
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/34766 , vital:33442
- Description: In this study, a facile synthesis method was developed to produce layered-layered cathode materials with the formula xLi2MnO3•(1-x)LiMO2 (M= Ni and Mn) referred to as lithium-manganese-rich materials for lithium ion batteries. The prepared materials displayed high capacity ≥200 mAh/g at a current density of 20 mA/g in the voltage range of 2.0 V to 4.8 V. In particular the cathode material prepared at pH 10.0 delivered a high initial discharge capacity of 266 mAh/g at 20 mA/g current density and maintained a discharge capacity ≥220 mAh/g at 50 mA/g after 50 cycles. The synthesis method was used to further investigate the effect of lithium ratio in the layered-layered material. Li1+xMn0.6Ni0.2O2, x= 0.2, 0.25, 0.3 and 0.4 cathode materials were produced respectively. The BET surface area analysis results showed that Li1.3Mn0.6Ni0.2O2 material had comparatively higher surface area to the other cathode materials and also delivered good electrochemical results. XPS showed that the cation distribution is affected by the increase in lithium ratio, the Mn4+ percentages decreased significantly with an increase in lithium ratio. All materials peaks deconvoluted into two peaks namely Mn4+ and Mn3+, Li1.3Mn0.6Ni0.2O2 had the highest percentages of the stable Mn4+ 70.8%. Further investigation focused on the effect of the sintering temperature on the structure and the electrochemical performance of Li1+xMn0.6Ni0.2O2, x= 0.25, 0.3 and 0.4 cathode materials. X-ray diffraction showed the same patterns for all cathode materials sintered at 700˚C, 800˚C and 900˚C. Rietveld refined results however, showed that the increase in the sintering temperature, results in a decrease in the Li2MnO3 component percentage in the layered structures. Scanning electron microscopy images further proved that the particle size increases with increasing temperature. The charge–discharge tests of coin cells demonstrated that the materials sintered at 800˚C delivered higher discharge capacities above 200 mAh/g at 20 mA/g current density when compared to the materials made at the lower temperatures. Lastly the cathode material prepared at pH 10.0 was further evaluated in a cell using lithium titanate oxide Li4Ti5O12 as anode material. The cells delivered an initial discharge capacity of 213 mAh/g at 20 mA/g within a voltage range 3.3V-0.5V. The coin cells developed in this work delivered good cycling performance.
- Full Text:
- Date Issued: 2018
Beneficiary perceptions regarding farm worker equity share schemes in South Africa
- Authors: Xolo, Siyavuya Nicholas
- Date: 2018
- Subjects: Investments -- South Africa , Investment analysis Land reform -- South Africa Agricultural laborers -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36323 , vital:33920
- Description: The study aimed to assess beneficiary perceptions regarding farm worker equity share schemes in South Africa. Farm worker equity share schemes started in the early 1990s with the aim of having a special arrangement pertaining to the ownership and operation of a farm between the farmer and the farm workers. This was intended to assist farm workers in not only remaining as farm workers but also to gain ownership of the farm. This could lead to the empowerment of farm workers, better working conditions, improved living standards and their rights to land ownership. Farm worker equity share schemes have been widely reported as having failed to meet their intended objectives, thus, in 2009, the Department of Rural Development and Land Reform initiated a study to assess the implementation of equity share schemes. Although the report was not made public, it reports that out of the 88 equity share schemes at the time, only nine managed to pay dividends ranging from R200 to R2000 per year. As a result, the Department of Rural Development and Land Reform put a moratorium on equity share schemes; this was however removed in 2011. It is against this background that this study was undertaken to assess beneficiaries’ perceptions regarding farm worker equity share schemes in South Africa. A positivistic research paradigm was employed in this study, by means of quantitative research. Secondary data in the form of textbooks, journal articles and Internet sources provided the theoretical framework for this study. Primary data was obtained using the survey method, by means of self-administered structured questionnaires. Convenience and purposive sampling were applied in order to select 20 farms that use equity share schemes. The farms selected for this study were located in the Eastern Cape, Gauteng, Mpumalanga and the Western Cape provinces, covering a variety of farming activities such as citrus fruits, crops, vegetables and wineries. Ideally, a total of 15 farm workers per farm were targeted. However, due to a variation in these farm worker equity share schemes, on some farms less than 15 workers and in others more than 15 workers were selected for the study; this resulted in a total sample size of 341 farm workers. Ten null-hypotheses and a hypothetical model of beneficiary perceptions regarding farm worker equity share schemes were tested. The influence of seven independent variables were tested, these are: stakeholder trust, operational risks, government interventions, two-way communication, farm worker empowerment, training and skills development, and access to resources on farm worker equity share schemes. In addition, the influence of farm worker equity share schemes on three dependent variables, namely, farming performance, sustainability and employee expectations were tested. The Statistica (version 13.2) computer programme was used to analyse the results by means of advanced statistical techniques (such as exploratory factor analysis, regression and correlation analyses) as well as descriptive analysis and frequency distributions. After various statistical procedures, the model was re-specified; some of the variables were then renamed and the hypotheses were adjusted accordingly. The empirical results showed that three key variables to the success of farm worker equity share schemes are stakeholder trust, government interventions and farm owner support. It was determined that these key variables could lead to increased farming performance, farming sustainability and meeting employee expectations. This study provided useful and practical guidelines to farm owners and administrators of equity share schemes, so as to ensure effective strategising that could enhance their competitiveness and long term survival. The findings of this study could inform strategy policy formulation and implementation in the agricultural sector, as pertaining to farm worker equity share schemes. The study used a sound and well-developed research design and methodology, which has been justified and successfully applied to this research; this method can be utilised by other similar studies to conduct empirical research in the field of farm worker equity share schemes. It is envisaged that the results and recommendations of this study could be used to implement effective strategies that could ensure the effective functioning of farm worker equity share schemes in South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Xolo, Siyavuya Nicholas
- Date: 2018
- Subjects: Investments -- South Africa , Investment analysis Land reform -- South Africa Agricultural laborers -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36323 , vital:33920
- Description: The study aimed to assess beneficiary perceptions regarding farm worker equity share schemes in South Africa. Farm worker equity share schemes started in the early 1990s with the aim of having a special arrangement pertaining to the ownership and operation of a farm between the farmer and the farm workers. This was intended to assist farm workers in not only remaining as farm workers but also to gain ownership of the farm. This could lead to the empowerment of farm workers, better working conditions, improved living standards and their rights to land ownership. Farm worker equity share schemes have been widely reported as having failed to meet their intended objectives, thus, in 2009, the Department of Rural Development and Land Reform initiated a study to assess the implementation of equity share schemes. Although the report was not made public, it reports that out of the 88 equity share schemes at the time, only nine managed to pay dividends ranging from R200 to R2000 per year. As a result, the Department of Rural Development and Land Reform put a moratorium on equity share schemes; this was however removed in 2011. It is against this background that this study was undertaken to assess beneficiaries’ perceptions regarding farm worker equity share schemes in South Africa. A positivistic research paradigm was employed in this study, by means of quantitative research. Secondary data in the form of textbooks, journal articles and Internet sources provided the theoretical framework for this study. Primary data was obtained using the survey method, by means of self-administered structured questionnaires. Convenience and purposive sampling were applied in order to select 20 farms that use equity share schemes. The farms selected for this study were located in the Eastern Cape, Gauteng, Mpumalanga and the Western Cape provinces, covering a variety of farming activities such as citrus fruits, crops, vegetables and wineries. Ideally, a total of 15 farm workers per farm were targeted. However, due to a variation in these farm worker equity share schemes, on some farms less than 15 workers and in others more than 15 workers were selected for the study; this resulted in a total sample size of 341 farm workers. Ten null-hypotheses and a hypothetical model of beneficiary perceptions regarding farm worker equity share schemes were tested. The influence of seven independent variables were tested, these are: stakeholder trust, operational risks, government interventions, two-way communication, farm worker empowerment, training and skills development, and access to resources on farm worker equity share schemes. In addition, the influence of farm worker equity share schemes on three dependent variables, namely, farming performance, sustainability and employee expectations were tested. The Statistica (version 13.2) computer programme was used to analyse the results by means of advanced statistical techniques (such as exploratory factor analysis, regression and correlation analyses) as well as descriptive analysis and frequency distributions. After various statistical procedures, the model was re-specified; some of the variables were then renamed and the hypotheses were adjusted accordingly. The empirical results showed that three key variables to the success of farm worker equity share schemes are stakeholder trust, government interventions and farm owner support. It was determined that these key variables could lead to increased farming performance, farming sustainability and meeting employee expectations. This study provided useful and practical guidelines to farm owners and administrators of equity share schemes, so as to ensure effective strategising that could enhance their competitiveness and long term survival. The findings of this study could inform strategy policy formulation and implementation in the agricultural sector, as pertaining to farm worker equity share schemes. The study used a sound and well-developed research design and methodology, which has been justified and successfully applied to this research; this method can be utilised by other similar studies to conduct empirical research in the field of farm worker equity share schemes. It is envisaged that the results and recommendations of this study could be used to implement effective strategies that could ensure the effective functioning of farm worker equity share schemes in South Africa.
- Full Text:
- Date Issued: 2018
Black South African men’s adjustment to divorce: a divorce-stress-adjustment model
- Muchena, Kudakwashe Christopher
- Authors: Muchena, Kudakwashe Christopher
- Date: 2018
- Subjects: Divorce -- Psychological aspects , Social psychology Men -- Psychology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/50121 , vital:42048
- Description: The decision to divorce marks a turning point for each individual involved. It can be viewed as more than just a legal process. From a psychological perspective, it does not matter who initiated the divorce, it always comes with emotional ramifications for all those involved. Statistically there is a high rate of divorce in South Africa and there have been significant shifts in trends over time. However, black South African men’s experience of, action in, and adjustment to divorce has been relatively neglected in the divorce research, yet it is important for understanding contemporary social arrangements and processes, as well as for broadening the understanding of black South African men’s lives. How black South African men describe their situations and respond to marital dissolution may point to their positions in the gender-structured community and to how they interpret the nature of social practice, marriages, divorce and their position in society. The present study aimed at exploring black South African men’s experience of, and adjustment to, divorce. More specifically, the study developed a divorce-stress-adjustment model for divorced black South African men. The theoretical framework underpinning this study was that of Symbolic Interactionism that was complemented and enhanced by Erikson’s Psychosocial Theory, focusing specifically on identity development in adulthood. This was a qualitative study using an Interpretative Phenomenological Analysis (IPA) as both the research design and data analytic theory and process. The eight participants were volunteers who were recruited purposively. In accordance with IPA guidelines, data for the study was collected using biographical questionnaires and semi-structured interviews. The emerging themes were grouped into four superordinate themes, that is, pre-divorce experiences, experiencing divorce, adjustment process and post-divorce experience. Each superordinate theme had corresponding subordinate themes and subthemes. The themes were then used to develop the divorce-stress adjustment model indicating that the experience of divorce is an interconnected process. Weed’s recommendations for interpretative synthesis of interview data were used.
- Full Text:
- Date Issued: 2018
- Authors: Muchena, Kudakwashe Christopher
- Date: 2018
- Subjects: Divorce -- Psychological aspects , Social psychology Men -- Psychology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/50121 , vital:42048
- Description: The decision to divorce marks a turning point for each individual involved. It can be viewed as more than just a legal process. From a psychological perspective, it does not matter who initiated the divorce, it always comes with emotional ramifications for all those involved. Statistically there is a high rate of divorce in South Africa and there have been significant shifts in trends over time. However, black South African men’s experience of, action in, and adjustment to divorce has been relatively neglected in the divorce research, yet it is important for understanding contemporary social arrangements and processes, as well as for broadening the understanding of black South African men’s lives. How black South African men describe their situations and respond to marital dissolution may point to their positions in the gender-structured community and to how they interpret the nature of social practice, marriages, divorce and their position in society. The present study aimed at exploring black South African men’s experience of, and adjustment to, divorce. More specifically, the study developed a divorce-stress-adjustment model for divorced black South African men. The theoretical framework underpinning this study was that of Symbolic Interactionism that was complemented and enhanced by Erikson’s Psychosocial Theory, focusing specifically on identity development in adulthood. This was a qualitative study using an Interpretative Phenomenological Analysis (IPA) as both the research design and data analytic theory and process. The eight participants were volunteers who were recruited purposively. In accordance with IPA guidelines, data for the study was collected using biographical questionnaires and semi-structured interviews. The emerging themes were grouped into four superordinate themes, that is, pre-divorce experiences, experiencing divorce, adjustment process and post-divorce experience. Each superordinate theme had corresponding subordinate themes and subthemes. The themes were then used to develop the divorce-stress adjustment model indicating that the experience of divorce is an interconnected process. Weed’s recommendations for interpretative synthesis of interview data were used.
- Full Text:
- Date Issued: 2018
Investigation of the thermo-chemical behaviour of coal-algae agglomerates
- Authors: Baloyi, Hope
- Date: 2018
- Subjects: Biomass energy , Coal -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23913 , vital:30642
- Description: There is a growing research interest in the co-processing of biomass and coal, with the aim of addressing the negative attributes associated with the thermal processing of coal alone. Biomass feedstocks are regarded as a clean, renewable source, and the co-utilization of biomass feedstocks with coal is deemed to have a potential to reduce emission of pollutants (i.e. NOx and SOx) and volatile organic compounds (VOC’s). Moreover, biomass are thermally reactive and thus facilitate the conversion of coal during co-processing. Biomass material and coal are two autonomous fuel materials with different chemical characteristics and have a dissimilar thermal behaviour making it difficult to achieve chemical interaction between the two solid fuels to contribute to the formation of products. Coalgae® Technology developed at the Nelson Mandela University, involves the biological treatment of coal fines by adsorbing live microalgae biomass (in slurry form) onto waste coal fines to form coal-microalgae agglomerates. This new innovative approach seeks to integrate bio-based feedstock into coal thermal processing and to improve the utilization and thermal efficiency of coal fines as well as the interaction between the volatile components of biomass and coal during thermal processing (e.g. devolatilization), thereby overcoming some of the challenges that confront the co-processing of coal and biomass. Coal fines are low-ranked coals, generally characterized by high contents of sulphur, high ash yields, low calorific values and poor thermal reactivity, and these attributes limits the thermo-chemical processing of the coal fines. Therefore, this investigation was undertaken to assess the thermo-chemical behaviour of coal-microalgae agglomerates, formed by adsorbing live microalgae slurry at varying ratios onto coal fines. For this purpose, the effects of adsorbing microalgae at varying ratios on the chemical characteristics and thermal behaviour of coal fines under pyrolytic conditions were investigated. The primary aim was to assess whether the thermo-chemical behaviour of coal-microalgae agglomerates, formed by adsorption of live microalgae onto fine coal, is substantively modified compared to a simple additive model of the original coal and pre-dried microalgae biomass samples. Results obtained from the proximate analyses performed on an Eltra Thermo-gravimetric analyzer (TGA) thermostep, have shown that the adsorption of microalgae slurry onto coal fines does not possess greater influence in improving the yield of volatiles and ash in coal fines than can be expected from a simple additive model of the original raw materials. Based on the ultimate analyses results, it was found that the adsorption of microalgae slurry resulted in a systematic reduction in the sulphur content, a notable increase in the hydrogen and oxygen contents, however, no significant disparities were found between the measured ultimate properties of coal-microalgae agglomerates as compared to the theoretically-expected ultimate properties from a simple linear combination of parental coal and microalgae biomass. Assessment of the thermal behaviour of parental samples and coal-microalgae agglomerates involved the use non-isothermal (40-900ºC, 20 K/min) thermogravimetry under inert conditions. It was found that the adsorption of microalgae slurry onto coal fines resulted in an improved thermal reactivity of coal fines, although, did not affect the overall pyrolysis characteristics of the coal fines. Comparison of the thermal profiles (measured and calculated TG/DTG curves), revealed that the yield of volatile products during the pyrolysis of coal-microalgae blends do not exceed the expected volatile yields from a simple combination of coal and microalgae biomass. These results suggest that there was no positive or accelerative synergistic interaction between volatile components of adsorbed microalgae and coal fines during pyrolysis. Mild pyrolysis of raw coal and coal-microalgae performed in a fixed-bed reactor furnace (450ºC), resulted in improved yields of Fossil-Bio crude (FBC) oil (derived from coal-microalgae pyrolysis), at increased biomass ratio compared to coal tar. FBC Oil was found to contain relatively high contents of oxygen, hydrogen, and low sulphur content than coal tar. GC-MS analyses showed the presence of a heterocyclic compounds (i.e. Indole and 2, 6 dimethyl pyridine) in the FBC oil and these were not identified in the coal tar. Furthermore, high boiling compounds such as Flourene, pyrene and pentacosane were identified in the coal tar, however not identified in the FBC oil. Simulated distillation results showed notable differences between the FBC oil and coal tar in terms of the distribution of boiling point fractions particularly, high boing point components. Semi-devolatilized chars derived from coal-microalgae agglomerates showed substantial degree of decarboxylation and dehydrogenation compared to the coal chars.
- Full Text:
- Date Issued: 2018
- Authors: Baloyi, Hope
- Date: 2018
- Subjects: Biomass energy , Coal -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23913 , vital:30642
- Description: There is a growing research interest in the co-processing of biomass and coal, with the aim of addressing the negative attributes associated with the thermal processing of coal alone. Biomass feedstocks are regarded as a clean, renewable source, and the co-utilization of biomass feedstocks with coal is deemed to have a potential to reduce emission of pollutants (i.e. NOx and SOx) and volatile organic compounds (VOC’s). Moreover, biomass are thermally reactive and thus facilitate the conversion of coal during co-processing. Biomass material and coal are two autonomous fuel materials with different chemical characteristics and have a dissimilar thermal behaviour making it difficult to achieve chemical interaction between the two solid fuels to contribute to the formation of products. Coalgae® Technology developed at the Nelson Mandela University, involves the biological treatment of coal fines by adsorbing live microalgae biomass (in slurry form) onto waste coal fines to form coal-microalgae agglomerates. This new innovative approach seeks to integrate bio-based feedstock into coal thermal processing and to improve the utilization and thermal efficiency of coal fines as well as the interaction between the volatile components of biomass and coal during thermal processing (e.g. devolatilization), thereby overcoming some of the challenges that confront the co-processing of coal and biomass. Coal fines are low-ranked coals, generally characterized by high contents of sulphur, high ash yields, low calorific values and poor thermal reactivity, and these attributes limits the thermo-chemical processing of the coal fines. Therefore, this investigation was undertaken to assess the thermo-chemical behaviour of coal-microalgae agglomerates, formed by adsorbing live microalgae slurry at varying ratios onto coal fines. For this purpose, the effects of adsorbing microalgae at varying ratios on the chemical characteristics and thermal behaviour of coal fines under pyrolytic conditions were investigated. The primary aim was to assess whether the thermo-chemical behaviour of coal-microalgae agglomerates, formed by adsorption of live microalgae onto fine coal, is substantively modified compared to a simple additive model of the original coal and pre-dried microalgae biomass samples. Results obtained from the proximate analyses performed on an Eltra Thermo-gravimetric analyzer (TGA) thermostep, have shown that the adsorption of microalgae slurry onto coal fines does not possess greater influence in improving the yield of volatiles and ash in coal fines than can be expected from a simple additive model of the original raw materials. Based on the ultimate analyses results, it was found that the adsorption of microalgae slurry resulted in a systematic reduction in the sulphur content, a notable increase in the hydrogen and oxygen contents, however, no significant disparities were found between the measured ultimate properties of coal-microalgae agglomerates as compared to the theoretically-expected ultimate properties from a simple linear combination of parental coal and microalgae biomass. Assessment of the thermal behaviour of parental samples and coal-microalgae agglomerates involved the use non-isothermal (40-900ºC, 20 K/min) thermogravimetry under inert conditions. It was found that the adsorption of microalgae slurry onto coal fines resulted in an improved thermal reactivity of coal fines, although, did not affect the overall pyrolysis characteristics of the coal fines. Comparison of the thermal profiles (measured and calculated TG/DTG curves), revealed that the yield of volatile products during the pyrolysis of coal-microalgae blends do not exceed the expected volatile yields from a simple combination of coal and microalgae biomass. These results suggest that there was no positive or accelerative synergistic interaction between volatile components of adsorbed microalgae and coal fines during pyrolysis. Mild pyrolysis of raw coal and coal-microalgae performed in a fixed-bed reactor furnace (450ºC), resulted in improved yields of Fossil-Bio crude (FBC) oil (derived from coal-microalgae pyrolysis), at increased biomass ratio compared to coal tar. FBC Oil was found to contain relatively high contents of oxygen, hydrogen, and low sulphur content than coal tar. GC-MS analyses showed the presence of a heterocyclic compounds (i.e. Indole and 2, 6 dimethyl pyridine) in the FBC oil and these were not identified in the coal tar. Furthermore, high boiling compounds such as Flourene, pyrene and pentacosane were identified in the coal tar, however not identified in the FBC oil. Simulated distillation results showed notable differences between the FBC oil and coal tar in terms of the distribution of boiling point fractions particularly, high boing point components. Semi-devolatilized chars derived from coal-microalgae agglomerates showed substantial degree of decarboxylation and dehydrogenation compared to the coal chars.
- Full Text:
- Date Issued: 2018
A critical analysis of organisational justice in the South African financial service industry
- Authors: Mrwebi, Viwe
- Date: 2018
- Subjects: Organizational behavior , Financial services industry -- South Africa -- Management Intrinsic motivation Employee retention Labor turnover
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/33065 , vital:32513
- Description: Organisational justice has captured the interest of scholars in recent years since it is associated with the perceptions and reactions of an individual, to the presence of fairness in an organisation. It thus captures what an individual feel or evaluates to be, morally correct rather than viewing it to be something prescriptive. This study was aimed at investigating the extent of organisational justice on organisational citizenship behaviour, ethical behaviour and employee retention in the South African financial services industry. A hypothetical model and measuring instrument was developed in order to investigate factors that may influence the organisational justice in the financial services industry. Six independent variables (trustworthiness of management, employee engagement, reward system, organisational transparency, two-way communication and organisational climate) were identified as variables that have the potential to influence organisational justice (mediating variable). It was also hypothesised that organisational justice) has the potential to affect the dependent variables (organisational citizenship behaviour, ethical behaviour and employee retention). Furthermore, nine null-hypotheses were developed to test the relationship between independent, mediating and dependent variables. All these variables were clearly defined and operationalised with various items that were obtained from other measuring instruments or self-developed items. A quantitative research approach followed. This study made use of the non-probability sampling technique, specifically convenient and judgemental sampling, as there is no data base of financial services firms available in South Africa. A purposive sample of 800 respondents was drawn from four provinces in South Africa. Factor and regression analyses were used to test the significance of the relationship between the various independent and dependent variables. The mediating variable of organisational justice was viewed by respondents as a two-dimensional construct, namely procedural-interactional justice and distributive justice. Consequently, intrinsic rewards, extrinsic rewards, organisational transparency and organisational climate were identified as independent variables that could have an impact on the procedural-interactional justice to predict organisational citizenship behaviour and reputable employee retention in the financial services industry. No relationships were identified between trustworthiness of management and employee engagement and procedural-interactional justice. The independent variables, trustworthiness of management, extrinsic rewards and organisational climate, could have an impact on distributive justice to predict organisational citizenship behaviour and reputable employee retention in the financial services industry. No relationships were identified between employee engagement, intrinsic rewards, organisational transparency and distributive justice. The findings of this study have contributed to the body of knowledge in the financial services literature in South Africa, by developing a theoretical model and a measuring instrument of organisational justice in the financial services industry. The antecedents of organisational justice in the financial services industry are not well documented in literature and findings of this study could thus contribute towards closing this gap in literature. The findings of this study could also inform policy formulation to assist with the implementation of organisational justice programmes in the financial services industry. This study provided useful and very practical guidelines to organisations in order to ensure the effective strategising and management of OJ that could enhance their local and global competitiveness and long-term survival.
- Full Text:
- Date Issued: 2018
- Authors: Mrwebi, Viwe
- Date: 2018
- Subjects: Organizational behavior , Financial services industry -- South Africa -- Management Intrinsic motivation Employee retention Labor turnover
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/33065 , vital:32513
- Description: Organisational justice has captured the interest of scholars in recent years since it is associated with the perceptions and reactions of an individual, to the presence of fairness in an organisation. It thus captures what an individual feel or evaluates to be, morally correct rather than viewing it to be something prescriptive. This study was aimed at investigating the extent of organisational justice on organisational citizenship behaviour, ethical behaviour and employee retention in the South African financial services industry. A hypothetical model and measuring instrument was developed in order to investigate factors that may influence the organisational justice in the financial services industry. Six independent variables (trustworthiness of management, employee engagement, reward system, organisational transparency, two-way communication and organisational climate) were identified as variables that have the potential to influence organisational justice (mediating variable). It was also hypothesised that organisational justice) has the potential to affect the dependent variables (organisational citizenship behaviour, ethical behaviour and employee retention). Furthermore, nine null-hypotheses were developed to test the relationship between independent, mediating and dependent variables. All these variables were clearly defined and operationalised with various items that were obtained from other measuring instruments or self-developed items. A quantitative research approach followed. This study made use of the non-probability sampling technique, specifically convenient and judgemental sampling, as there is no data base of financial services firms available in South Africa. A purposive sample of 800 respondents was drawn from four provinces in South Africa. Factor and regression analyses were used to test the significance of the relationship between the various independent and dependent variables. The mediating variable of organisational justice was viewed by respondents as a two-dimensional construct, namely procedural-interactional justice and distributive justice. Consequently, intrinsic rewards, extrinsic rewards, organisational transparency and organisational climate were identified as independent variables that could have an impact on the procedural-interactional justice to predict organisational citizenship behaviour and reputable employee retention in the financial services industry. No relationships were identified between trustworthiness of management and employee engagement and procedural-interactional justice. The independent variables, trustworthiness of management, extrinsic rewards and organisational climate, could have an impact on distributive justice to predict organisational citizenship behaviour and reputable employee retention in the financial services industry. No relationships were identified between employee engagement, intrinsic rewards, organisational transparency and distributive justice. The findings of this study have contributed to the body of knowledge in the financial services literature in South Africa, by developing a theoretical model and a measuring instrument of organisational justice in the financial services industry. The antecedents of organisational justice in the financial services industry are not well documented in literature and findings of this study could thus contribute towards closing this gap in literature. The findings of this study could also inform policy formulation to assist with the implementation of organisational justice programmes in the financial services industry. This study provided useful and very practical guidelines to organisations in order to ensure the effective strategising and management of OJ that could enhance their local and global competitiveness and long-term survival.
- Full Text:
- Date Issued: 2018
A critical analysis of disaster risk management in local governance with reference to Sarah Baartman District Municipality
- Authors: Oosthuizen, Rene Cheryl
- Date: 2018
- Subjects: Disaster relief -- Citizen participation , Risk management -- South Africa -- Eastern Cape Local government -- South Africa -- Eastern Cape -- Citizen participation Rural development projects -- South Africa -- Eastern Cape Community development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/34487 , vital:33385
- Description: The devastation and destruction caused by natural and man-made disasters have become a global concern, particularly as such disasters affect the most vulnerable in society. The devastation they wreak frequently involves loss of lives and property. Globally, Disaster Management has moved in approach from reactive to proactive. Disaster management is now more than a field of study; it is the application of practices and principles which enable disasters to be managed both prior to and in the aftermath of their occurrence. Disaster risk management is the development approach to Disaster Management. The study addresses the integration of disaster risk management into integrated development planning at the local level in South Africa. The impact of disasters on social and economic development is of special interest. In many instances, resources that have been planned for development have to be diverted for response activities during disasters. Thus, development and disaster risk management are two sides of the same coin and should be dealt with in unison and not separately. There is also now widespread international acknowledgement for the idea of mainstreaming disaster risk management into development planning, particularly at the local level of government. The central argument of this study is that by integrating disaster risk management plans into integrated development plans at the local level, the risks faced by communities can be reduced. Risks can be even further reduced, and development enhanced when communities play an active role in disaster risk management. Within this context, the main objective of the study was to develop a model for integrating disaster risk management plans into integrated development plans at the local level. To achieve this key objective, the study used theoretical and empirical studies. The theoretical aspect focussed on international frameworks and national legislation for Disaster Management. Legislative requirements pertaining to the involvement of communities in integrated development planning were explored, as was the literature on asset-based community development. Empirical research complimented the theoretical research through the use of qualitative methods to collect data. This involved semi-structured interviews with eight government officials involved in provincial, district and municipal Disaster Management programmes, and focus group discussions with sixty ward committee members, so that community viewpoints would be included. The findings of the study reveal that the integration of disaster risk management plans into integrated development plans at the local level can greatly contribute towards reducing the risks faced by communities, especially high-risk communities. The study also revealed that by carefully considering and using community assets, local government could ameliorate the financial effects of Disaster Management and empower communities as first responders. The thesis gives an outline of a model that may be used by local government to integrate risks and community assets into an integrated development plan.
- Full Text:
- Date Issued: 2018
- Authors: Oosthuizen, Rene Cheryl
- Date: 2018
- Subjects: Disaster relief -- Citizen participation , Risk management -- South Africa -- Eastern Cape Local government -- South Africa -- Eastern Cape -- Citizen participation Rural development projects -- South Africa -- Eastern Cape Community development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/34487 , vital:33385
- Description: The devastation and destruction caused by natural and man-made disasters have become a global concern, particularly as such disasters affect the most vulnerable in society. The devastation they wreak frequently involves loss of lives and property. Globally, Disaster Management has moved in approach from reactive to proactive. Disaster management is now more than a field of study; it is the application of practices and principles which enable disasters to be managed both prior to and in the aftermath of their occurrence. Disaster risk management is the development approach to Disaster Management. The study addresses the integration of disaster risk management into integrated development planning at the local level in South Africa. The impact of disasters on social and economic development is of special interest. In many instances, resources that have been planned for development have to be diverted for response activities during disasters. Thus, development and disaster risk management are two sides of the same coin and should be dealt with in unison and not separately. There is also now widespread international acknowledgement for the idea of mainstreaming disaster risk management into development planning, particularly at the local level of government. The central argument of this study is that by integrating disaster risk management plans into integrated development plans at the local level, the risks faced by communities can be reduced. Risks can be even further reduced, and development enhanced when communities play an active role in disaster risk management. Within this context, the main objective of the study was to develop a model for integrating disaster risk management plans into integrated development plans at the local level. To achieve this key objective, the study used theoretical and empirical studies. The theoretical aspect focussed on international frameworks and national legislation for Disaster Management. Legislative requirements pertaining to the involvement of communities in integrated development planning were explored, as was the literature on asset-based community development. Empirical research complimented the theoretical research through the use of qualitative methods to collect data. This involved semi-structured interviews with eight government officials involved in provincial, district and municipal Disaster Management programmes, and focus group discussions with sixty ward committee members, so that community viewpoints would be included. The findings of the study reveal that the integration of disaster risk management plans into integrated development plans at the local level can greatly contribute towards reducing the risks faced by communities, especially high-risk communities. The study also revealed that by carefully considering and using community assets, local government could ameliorate the financial effects of Disaster Management and empower communities as first responders. The thesis gives an outline of a model that may be used by local government to integrate risks and community assets into an integrated development plan.
- Full Text:
- Date Issued: 2018
Prioritisation of spaces and services in on-campus student housing facilities in southern Ghana universities
- Authors: Simpeh, Fredrick
- Date: 2018
- Subjects: Student housing -- Ghana , College students -- Housing -- Ghana Student housing , Facility management -- Ghana Building management -- Ghana
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/35637 , vital:33769
- Description: Student housing facilities (SHFs) are an integral part of universities’ physical facilities. Therefore, the management of SHF should be seen as part of broader university facility management. Moreover, it can be argued that by understanding the requirements of occupants, facility managers would be able to effectively prioritise the spaces and services required in the SHFs. However, studies from many parts of the world, including Ghana, show that users’ requirements and expectations are not duly incorporated into the management process of university building facilities. As a result, users’, in this case students requirements are not well prioritised by facility managers. Thus, the facility departments are unable to adequately provide and deliver SHF spaces and services to meet students’ requirements. With this in mind, this research aimed to develop a prioritisation and a standard SHF frameworks to enhance the provisioning and management of the on-campus SHF spaces and services at southern Ghana universities. The overarching research methodology was subjective. The qualitative method was adopted for the study. The research was conducted within the southern part of Ghana and limited to five universities. A total of ten focus group discussions were carried out in the five universities. Other sources of primary data were interviews and site visit. The study found that washrooms (toilet and bath), sleeping spaces, kitchens, study areas, libraries, sick bays, computer labs, bookshops, drying areas and discussion rooms as well as electricity, water, security, internet, cleaning services, maintenance services, generators, ventilation (fans), health services, library services, electric sockets, study furniture, refuse collection, pest control and fire extinguishers are extremely important spaces and services that students expect to have in a SHF. Furthermore, it was found that only 3 spaces out of the 10 rated as extremely important were rated as basic, whilst 10 out of the 15 services rated as extremely important received a basic priority rating. However, the study also found that some of these extremely important spaces and services such as study areas, computer labs, kitchens and internet were not provided in some SHFs. The study also revealed that students were generally not satisfied with some of the spaces and services that were provided in the SHFs; dissatisfaction was expressed with: the infrequent water supply; the poor condition of washrooms, i.e. bath and toilet facilities; the lack of study areas and also the condition, adequacy and availability of chairs and tables in the study rooms; the slow response of maintenance departments; the poor standard/quality of cleaning and availability of cleaners; the lack of adequate kitchens and the lack of stable internet connectivity. The study has achieved its aim by developing a prioritisation framework as well as an ideal SHF framework to enhance the provision and management of the on-campus SHF spaces and services at southern Ghana universities. It is recommended that SHFs which do not meet average students’ expected standards should be upgraded to meet such standards. The frameworks developed in the study could be used by facility managers or departments as a guide for effective on-campus SHF management.
- Full Text:
- Date Issued: 2018
- Authors: Simpeh, Fredrick
- Date: 2018
- Subjects: Student housing -- Ghana , College students -- Housing -- Ghana Student housing , Facility management -- Ghana Building management -- Ghana
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/35637 , vital:33769
- Description: Student housing facilities (SHFs) are an integral part of universities’ physical facilities. Therefore, the management of SHF should be seen as part of broader university facility management. Moreover, it can be argued that by understanding the requirements of occupants, facility managers would be able to effectively prioritise the spaces and services required in the SHFs. However, studies from many parts of the world, including Ghana, show that users’ requirements and expectations are not duly incorporated into the management process of university building facilities. As a result, users’, in this case students requirements are not well prioritised by facility managers. Thus, the facility departments are unable to adequately provide and deliver SHF spaces and services to meet students’ requirements. With this in mind, this research aimed to develop a prioritisation and a standard SHF frameworks to enhance the provisioning and management of the on-campus SHF spaces and services at southern Ghana universities. The overarching research methodology was subjective. The qualitative method was adopted for the study. The research was conducted within the southern part of Ghana and limited to five universities. A total of ten focus group discussions were carried out in the five universities. Other sources of primary data were interviews and site visit. The study found that washrooms (toilet and bath), sleeping spaces, kitchens, study areas, libraries, sick bays, computer labs, bookshops, drying areas and discussion rooms as well as electricity, water, security, internet, cleaning services, maintenance services, generators, ventilation (fans), health services, library services, electric sockets, study furniture, refuse collection, pest control and fire extinguishers are extremely important spaces and services that students expect to have in a SHF. Furthermore, it was found that only 3 spaces out of the 10 rated as extremely important were rated as basic, whilst 10 out of the 15 services rated as extremely important received a basic priority rating. However, the study also found that some of these extremely important spaces and services such as study areas, computer labs, kitchens and internet were not provided in some SHFs. The study also revealed that students were generally not satisfied with some of the spaces and services that were provided in the SHFs; dissatisfaction was expressed with: the infrequent water supply; the poor condition of washrooms, i.e. bath and toilet facilities; the lack of study areas and also the condition, adequacy and availability of chairs and tables in the study rooms; the slow response of maintenance departments; the poor standard/quality of cleaning and availability of cleaners; the lack of adequate kitchens and the lack of stable internet connectivity. The study has achieved its aim by developing a prioritisation framework as well as an ideal SHF framework to enhance the provision and management of the on-campus SHF spaces and services at southern Ghana universities. It is recommended that SHFs which do not meet average students’ expected standards should be upgraded to meet such standards. The frameworks developed in the study could be used by facility managers or departments as a guide for effective on-campus SHF management.
- Full Text:
- Date Issued: 2018
A programme of academic support for students at the public nursing college of the Eastern Cape Province in South Africa
- Senti, Nomandithini Innocent
- Authors: Senti, Nomandithini Innocent
- Date: 2018
- Subjects: Nursing -- Study and teaching Nursing -- Study and teaching -- Simulation methods
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/10997 , vital:36128
- Description: A comprehensive academic support at the public nursing college is important. Despite this, there is no such support in public nursing colleges in the Eastern Cape Province of South Africa. The aim of the study was to develop an academic support programme for students in order to improve their success in Higher Education. The study endeavoured to answer the following questions: What are the academic support needs of students at the public nursing college in the Eastern Cape of South Africa? What conceptual framework can be developed for the academic support programme of students? What academic support programme can be developed for students at the public nursing college? What guidelines can be developed for implementation of academic support programme of students? The objectives were: to describe academic support needs of students at the public nursing college in the eastern Cape Province of South Africa; to develop a conceptual framework for the academic support programme for students at the public nursing college in the Eastern Cape of South Africa; to develop an academic support programme for students at the public nursing college in the Eastern Cape in south Africa and lastly to describe guidelines for implementation and evaluation of the academic support programme. The research design used in this study was quantitative, qualitative, descriptive, evaluative, and theory generation. The study was conducted according to four phases. Phase one focussed on academic supports needs of the student. Phase two focussed on development of conceptual framework for the students at the public nursing college in Eastern Cape Province. Phase three focussed on the development of the academic support programme for the students, whereas phase four focussed on description of guidelines for implementation and evaluation of the academic support programme. The population of the study consisted of students undergoing training in a four-year programme at the Public Nursing College. The target population was the students in the same programme from level one to level four of training. The sampling technique used was a probability sampling with multi-stage and cluster sampling techniques being utilized. The total sample was n=333 participants. A quantitative self-developed questionnaire was used to collect empirical data. The questionnaire consisted of eight sections. Descriptive data was analysed using Statistic Package of Social Sciences (SPSS) version 24. Exploratory factor analysis was conducted on the descriptive data collected in phase one. Concept analysis and identification were done through the utilisation of exploratory factor analysis. The conceptual framework for the academic support programme was identified through the analysed factors. Fifteen factors were derived from the descriptive data. The conceptual framework of the academic support programme discussed in Chapter 5 was used also in the development of the academic support programme. It is in this chapter that assumptions, context, stakeholders, process, outcome, dynamics and, lastly, the recipient were discussed, along with a description of the programme. The programme was evaluated in accordance with the criteria for programme evaluation. The recommendations brought forward for the academic support programme were: The guidelines have to be tested for the implementation of the programme; benchmarking should be done to compare with other institutions of higher learning regarding their academic support programmes; an academic brochure regarding academic support must be available in the college and should be given to students on arrival as part of a package; and neutral researcher should conduct the same research in the same college.
- Full Text:
- Date Issued: 2018
- Authors: Senti, Nomandithini Innocent
- Date: 2018
- Subjects: Nursing -- Study and teaching Nursing -- Study and teaching -- Simulation methods
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/10997 , vital:36128
- Description: A comprehensive academic support at the public nursing college is important. Despite this, there is no such support in public nursing colleges in the Eastern Cape Province of South Africa. The aim of the study was to develop an academic support programme for students in order to improve their success in Higher Education. The study endeavoured to answer the following questions: What are the academic support needs of students at the public nursing college in the Eastern Cape of South Africa? What conceptual framework can be developed for the academic support programme of students? What academic support programme can be developed for students at the public nursing college? What guidelines can be developed for implementation of academic support programme of students? The objectives were: to describe academic support needs of students at the public nursing college in the eastern Cape Province of South Africa; to develop a conceptual framework for the academic support programme for students at the public nursing college in the Eastern Cape of South Africa; to develop an academic support programme for students at the public nursing college in the Eastern Cape in south Africa and lastly to describe guidelines for implementation and evaluation of the academic support programme. The research design used in this study was quantitative, qualitative, descriptive, evaluative, and theory generation. The study was conducted according to four phases. Phase one focussed on academic supports needs of the student. Phase two focussed on development of conceptual framework for the students at the public nursing college in Eastern Cape Province. Phase three focussed on the development of the academic support programme for the students, whereas phase four focussed on description of guidelines for implementation and evaluation of the academic support programme. The population of the study consisted of students undergoing training in a four-year programme at the Public Nursing College. The target population was the students in the same programme from level one to level four of training. The sampling technique used was a probability sampling with multi-stage and cluster sampling techniques being utilized. The total sample was n=333 participants. A quantitative self-developed questionnaire was used to collect empirical data. The questionnaire consisted of eight sections. Descriptive data was analysed using Statistic Package of Social Sciences (SPSS) version 24. Exploratory factor analysis was conducted on the descriptive data collected in phase one. Concept analysis and identification were done through the utilisation of exploratory factor analysis. The conceptual framework for the academic support programme was identified through the analysed factors. Fifteen factors were derived from the descriptive data. The conceptual framework of the academic support programme discussed in Chapter 5 was used also in the development of the academic support programme. It is in this chapter that assumptions, context, stakeholders, process, outcome, dynamics and, lastly, the recipient were discussed, along with a description of the programme. The programme was evaluated in accordance with the criteria for programme evaluation. The recommendations brought forward for the academic support programme were: The guidelines have to be tested for the implementation of the programme; benchmarking should be done to compare with other institutions of higher learning regarding their academic support programmes; an academic brochure regarding academic support must be available in the college and should be given to students on arrival as part of a package; and neutral researcher should conduct the same research in the same college.
- Full Text:
- Date Issued: 2018
A strategy to enhance the role of the church as a social service delivery agent in fighting poverty in contemporary South Africa
- Lujabe, Busisiwe Tando Tabiso
- Authors: Lujabe, Busisiwe Tando Tabiso
- Date: 2018
- Subjects: Community-based social services Community development
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/17876 , vital:28477
- Description: The possible role and involvement of the Church in social development has reemerged as an important focus of contemporary academic and religious development discourse in South Africa. There are strong voices arguing for churches and other Faith-Based Organisations to be regarded as strategic in contributing to addressing the challenge of poverty as agents of social development. Yet, as church congregations multiply throughout South Africa, they appear to be less responsive to the challenge of poverty facing South African communities, contrary to the rich history of churches in the past. The need for churches to be involved in sustainable community-driven development initiatives to fight poverty in their local communities cannot be denied nor be met with just rhetoric and scholarly dissertations by theologians and academics. The vicious cycle of poverty in our communities must be eradicated as it represents a social injustice in terms of South Africa‘s Constitution and speaks to deep structural inequalities inherent in our society. Whilst researchers have made several proposals for churches to move from social welfare and relief, there appears to be little research with a clear practical strategy which congregations can implement to enhance their social service delivery role from social relief to sustainable community development. This has left a considerable gap which the current research sought to address. This study thus responds to the call by previous research for churches to implement strategies other than mere relief. Hence, this study contributes to the religious development discourse in South Africa, by developing a strategy to enhance Church-based social service delivery initiatives from social relief efforts which are not sustainable, to community development efforts which are sustainable and which will be consistent with the current social development policy context and contextually relevant to the socio-economic challenges of poverty and its consequences in South Africa. The study was conducted in two phases. During phase one, the main purpose was to gain a deeper understanding of the historical and current involvement of the Church in providing social services which address poverty in communities, to enhance understanding of the factors which influence the provision of social services by churches, as well as to understand participants views of how church-based social service delivery can be improved in order to fight poverty. For phase two, the goal was to develop a strategy to enhance church-based social service delivery from being social relief to being community development oriented. The following objectives guided the research process: To review selected and applicable literature to gain a deeper understanding of the historical and current involvement of the Church in the delivery of social services in order to fight poverty; To explore and describe the perceptions of church leaders and congregation members of the historical and current involvement of the Church in the delivery of social services in order to fight poverty; To explore and describe the factors which influence Church-based social service delivery in fighting poverty; To explore the views of church leaders and congregation members on how church-based social service delivery can be improved in their churches to inform the development of a strategy to enhance church-based social service delivery in fighting poverty. This study employed a qualitative research approach grounded in the interpretivist social science paradigm. The qualitative research approach necessitated an exploratory, descriptive and contextual method of inquiry. A descriptive case study method was also used, with the Methodist Church of Southern Africa selected as the main case of focus. The target population in this research comprised of Christian churches with a historical involvement in social service delivery in pre-apartheid South Africa. Purposeful sampling of 5 churches was undertaken, namely; Roman Catholic Church (RCC), Anglican Church (AC), Dutch Reformed Church (DRC), KwaSizabantu Mission (KSB) and Methodist Church of Southern Africa (MCSA). Data collection was conducted in two phases. Phase one comprised a literature review; Phase two comprised gathering empirical evidence by conducting face to face semi-structured interviews with clergy and from conducting one focus group interview with congregants. The information obtained from participants was transcribed, coded and analysed using content analysis and by a computer-assisted qualitative data analysis software (CAQDAS), namely ATLAS.ti. Findings revealed a marked difference between the historical and current churchbased social service delivery suggestive of decline, accompanied by the lack of empowerment opportunities for current church leaders and congregation members in community development facilitation. Further evidence suggest the lack of cooperation between church leaders and congregation members; as well as the lack of sustainability of interventions owing to an absence of resources and the lack of capacity to create sustainable economic opportunities. Findings also revealed that church congregations are rich with people with various assets - skills, strengths, capabilities, passions, gifts, talents in various fields, which they can share with one another as congregations and communities. The discussion of findings reflected that historically, Church-based social service provision involved holistic intervention mechanisms, empowerment, collaborations and sustainability of interventions suggestive of second generation strategies of community development, while currently, Church-based social service provision involves mostly social relief and social welfare efforts suggestive of first generation strategies. The findings suggest a holistic strategy for ―reawakening the co-operativeness‖ of congregations to facilitate sustainable Church-based social service delivery towards fighting poverty in local communities. The strategy which was then developed and described with its sub-strategies, namely: Establishment of collaborative relationships Creation of empowerment opportunities Facilitation of holistic interventions The goal of the strategy is to guide church leaders and congregation members in facilitating sustainable Church-based social service programmes to fight poverty.
- Full Text:
- Date Issued: 2018
- Authors: Lujabe, Busisiwe Tando Tabiso
- Date: 2018
- Subjects: Community-based social services Community development
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/17876 , vital:28477
- Description: The possible role and involvement of the Church in social development has reemerged as an important focus of contemporary academic and religious development discourse in South Africa. There are strong voices arguing for churches and other Faith-Based Organisations to be regarded as strategic in contributing to addressing the challenge of poverty as agents of social development. Yet, as church congregations multiply throughout South Africa, they appear to be less responsive to the challenge of poverty facing South African communities, contrary to the rich history of churches in the past. The need for churches to be involved in sustainable community-driven development initiatives to fight poverty in their local communities cannot be denied nor be met with just rhetoric and scholarly dissertations by theologians and academics. The vicious cycle of poverty in our communities must be eradicated as it represents a social injustice in terms of South Africa‘s Constitution and speaks to deep structural inequalities inherent in our society. Whilst researchers have made several proposals for churches to move from social welfare and relief, there appears to be little research with a clear practical strategy which congregations can implement to enhance their social service delivery role from social relief to sustainable community development. This has left a considerable gap which the current research sought to address. This study thus responds to the call by previous research for churches to implement strategies other than mere relief. Hence, this study contributes to the religious development discourse in South Africa, by developing a strategy to enhance Church-based social service delivery initiatives from social relief efforts which are not sustainable, to community development efforts which are sustainable and which will be consistent with the current social development policy context and contextually relevant to the socio-economic challenges of poverty and its consequences in South Africa. The study was conducted in two phases. During phase one, the main purpose was to gain a deeper understanding of the historical and current involvement of the Church in providing social services which address poverty in communities, to enhance understanding of the factors which influence the provision of social services by churches, as well as to understand participants views of how church-based social service delivery can be improved in order to fight poverty. For phase two, the goal was to develop a strategy to enhance church-based social service delivery from being social relief to being community development oriented. The following objectives guided the research process: To review selected and applicable literature to gain a deeper understanding of the historical and current involvement of the Church in the delivery of social services in order to fight poverty; To explore and describe the perceptions of church leaders and congregation members of the historical and current involvement of the Church in the delivery of social services in order to fight poverty; To explore and describe the factors which influence Church-based social service delivery in fighting poverty; To explore the views of church leaders and congregation members on how church-based social service delivery can be improved in their churches to inform the development of a strategy to enhance church-based social service delivery in fighting poverty. This study employed a qualitative research approach grounded in the interpretivist social science paradigm. The qualitative research approach necessitated an exploratory, descriptive and contextual method of inquiry. A descriptive case study method was also used, with the Methodist Church of Southern Africa selected as the main case of focus. The target population in this research comprised of Christian churches with a historical involvement in social service delivery in pre-apartheid South Africa. Purposeful sampling of 5 churches was undertaken, namely; Roman Catholic Church (RCC), Anglican Church (AC), Dutch Reformed Church (DRC), KwaSizabantu Mission (KSB) and Methodist Church of Southern Africa (MCSA). Data collection was conducted in two phases. Phase one comprised a literature review; Phase two comprised gathering empirical evidence by conducting face to face semi-structured interviews with clergy and from conducting one focus group interview with congregants. The information obtained from participants was transcribed, coded and analysed using content analysis and by a computer-assisted qualitative data analysis software (CAQDAS), namely ATLAS.ti. Findings revealed a marked difference between the historical and current churchbased social service delivery suggestive of decline, accompanied by the lack of empowerment opportunities for current church leaders and congregation members in community development facilitation. Further evidence suggest the lack of cooperation between church leaders and congregation members; as well as the lack of sustainability of interventions owing to an absence of resources and the lack of capacity to create sustainable economic opportunities. Findings also revealed that church congregations are rich with people with various assets - skills, strengths, capabilities, passions, gifts, talents in various fields, which they can share with one another as congregations and communities. The discussion of findings reflected that historically, Church-based social service provision involved holistic intervention mechanisms, empowerment, collaborations and sustainability of interventions suggestive of second generation strategies of community development, while currently, Church-based social service provision involves mostly social relief and social welfare efforts suggestive of first generation strategies. The findings suggest a holistic strategy for ―reawakening the co-operativeness‖ of congregations to facilitate sustainable Church-based social service delivery towards fighting poverty in local communities. The strategy which was then developed and described with its sub-strategies, namely: Establishment of collaborative relationships Creation of empowerment opportunities Facilitation of holistic interventions The goal of the strategy is to guide church leaders and congregation members in facilitating sustainable Church-based social service programmes to fight poverty.
- Full Text:
- Date Issued: 2018
Evaluating the impact of energy policies on sustainable development in South Africa
- Authors: Julius, Ibitoye Oyebanji
- Date: 2018
- Subjects: Energy policy -- South Africa , Sustainable development -- South Africa Renewable energy sources -- South Africa Sustainable living -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30440 , vital:30944
- Description: The unachieved targets of the Millennium Development Goals (MDGs) at the end of 2015 by some developing countries including South Africa, lead to the evolution of the Sustainable Development Goals (SDGs). Ensuring access to sustainable, affordable, and modern energy is one of the 17 SDGs that the countries are expected to achieve before the end of 2030. Green growth is an important strategy for attaining this goal and a pathway to achieving the other goals. Therefore, an empirical study of the impact of energy policies on sustainable development is pertinent. Despite the importance of such research, there exists a gap in the literature relating to green growth and sustainable development from the SDGs point of view. This study fills the existing lacuna by developing an intertemporal holistic model which allows a study of the impact of energy policies on sustainable development in relation to the SDGs. Specifically, this thesis employs the Autoregressive Distributed Lag (ARDL) and Toda-Yamamoto approaches to analyse the long-run relationship and direction of causality respectively between green growth policies and sustainable development in South Africa from 1984 to 2016. This research provides insights into the importance of green growth for factors such as deforestation, fuel exports, energy imports and agricultural development, thus adding to the existing literature on the impact of renewable energy on a country’s social, environmental and economic conditions. Results from the analysis of the long-run relationship between green growth and macroeconomic variables, indicate a positive unidirectional relationship between changes in green growth policies and gross capital formation. This finding suggests that adopting green growth policies leads to increased investments. In contrast, green growth was found to have a negative effect on national income (gross domestic product). However, the Granger causality tests do not establish causality between these variables. Although green growth policies stimulate investments, high start-up costs associated with the implementation of these policies may mean that the resultant higher investments are yet to be translated to higher income levels in the South African economy. The findings indicate a boost in the South African balance of payment within the study period iv iv as evidenced by the positive long-run relationship between green growth policies and fuel exports. Additionally, the results indicate that green growth energy policies have assisted in improving the resilience to international oil price shocks as shown in the negative and significant long-run relationship between green growth and energy imports. With regard to environmental variables, results suggest a substitutability effect between green growth policies and the consumption of non-renewable energy. However, no evidence is found on the impact of green growth policies on the levels of deforestation and carbon dioxide(CO2) emissions, as well as natural resource depletion. In relation to the social variables, adoption of green growth policies was found to lead to improved educational quality, with causality running in both directions. This finding supports the feedback hypothesis. Similarly, green growth policies had a positive impact on agricultural development, again with causality established in both directions. The outcome of the long-run relationship between green energy consumption and unemployment shows that the green growth policies is yet to have a significant impact on unemployment reduction in South Africa. Green growth also has an insignificant and indirect relationship with GDP per capita; this result was affirmed by the absence of causality between GDP per capita and green energy consumption. This research not only makes contributions to the literature on the relevance of green growth policies for achieving economic, social and environmental sustainability, it also suggests possible policy implications which highlight the need for adoption and continued implementation of green growth policies in developing countries such as South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Julius, Ibitoye Oyebanji
- Date: 2018
- Subjects: Energy policy -- South Africa , Sustainable development -- South Africa Renewable energy sources -- South Africa Sustainable living -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30440 , vital:30944
- Description: The unachieved targets of the Millennium Development Goals (MDGs) at the end of 2015 by some developing countries including South Africa, lead to the evolution of the Sustainable Development Goals (SDGs). Ensuring access to sustainable, affordable, and modern energy is one of the 17 SDGs that the countries are expected to achieve before the end of 2030. Green growth is an important strategy for attaining this goal and a pathway to achieving the other goals. Therefore, an empirical study of the impact of energy policies on sustainable development is pertinent. Despite the importance of such research, there exists a gap in the literature relating to green growth and sustainable development from the SDGs point of view. This study fills the existing lacuna by developing an intertemporal holistic model which allows a study of the impact of energy policies on sustainable development in relation to the SDGs. Specifically, this thesis employs the Autoregressive Distributed Lag (ARDL) and Toda-Yamamoto approaches to analyse the long-run relationship and direction of causality respectively between green growth policies and sustainable development in South Africa from 1984 to 2016. This research provides insights into the importance of green growth for factors such as deforestation, fuel exports, energy imports and agricultural development, thus adding to the existing literature on the impact of renewable energy on a country’s social, environmental and economic conditions. Results from the analysis of the long-run relationship between green growth and macroeconomic variables, indicate a positive unidirectional relationship between changes in green growth policies and gross capital formation. This finding suggests that adopting green growth policies leads to increased investments. In contrast, green growth was found to have a negative effect on national income (gross domestic product). However, the Granger causality tests do not establish causality between these variables. Although green growth policies stimulate investments, high start-up costs associated with the implementation of these policies may mean that the resultant higher investments are yet to be translated to higher income levels in the South African economy. The findings indicate a boost in the South African balance of payment within the study period iv iv as evidenced by the positive long-run relationship between green growth policies and fuel exports. Additionally, the results indicate that green growth energy policies have assisted in improving the resilience to international oil price shocks as shown in the negative and significant long-run relationship between green growth and energy imports. With regard to environmental variables, results suggest a substitutability effect between green growth policies and the consumption of non-renewable energy. However, no evidence is found on the impact of green growth policies on the levels of deforestation and carbon dioxide(CO2) emissions, as well as natural resource depletion. In relation to the social variables, adoption of green growth policies was found to lead to improved educational quality, with causality running in both directions. This finding supports the feedback hypothesis. Similarly, green growth policies had a positive impact on agricultural development, again with causality established in both directions. The outcome of the long-run relationship between green energy consumption and unemployment shows that the green growth policies is yet to have a significant impact on unemployment reduction in South Africa. Green growth also has an insignificant and indirect relationship with GDP per capita; this result was affirmed by the absence of causality between GDP per capita and green energy consumption. This research not only makes contributions to the literature on the relevance of green growth policies for achieving economic, social and environmental sustainability, it also suggests possible policy implications which highlight the need for adoption and continued implementation of green growth policies in developing countries such as South Africa.
- Full Text:
- Date Issued: 2018
Productivity and resilience of intertidal resources available to extant human foragers on South Africa’s cape south coast: behavioural implications for early Homo sapiens
- Authors: De Vynck, Jan Carlo
- Date: 2018
- Subjects: Marine invertebrates -- South Africa -- Prehistory , Shellfish -- South Africa -- Prehistory Fishes -- Behavior
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30172 , vital:30854
- Description: Studies of pre-historic lifestyles can be limited by a lack of preserved material and sites and resource misinterpretation is augmented by the vagueness of pre-historic subsistence lifestyles. The present can inform the past and this study‟s ethnoarchaeological approach, through modern analogues, examines productivity, resilience and temporal and spatial size variation of intertidal invertebrates on the Cape‟s south coast. O‟Connell (1995) defined the mutualistic relationship between ethnography and archaeology thus: “Archaeology‟s ultimate aim is understanding past human behaviour by patterns in the form and distribution of objects made or modified by humans in the past and knowledge of human behaviour and its material consequences in the present. The first provides direct evidence of past behaviour; the second, a basis for interpreting that evidence”. Coastal archaeology, specifically the contribution of coastal resources to pre-historic subsistence, has gained increased global interest (Erlandson, 2001; Erlandson and Rick, 2008; Codding et al., 2014). Apart from the high representation of preserved shell in coastal archaeological sites, interest in intertidal resources has also been sparked by their economic value compared to terrestrial resource options. Intertidal resources offer low-risk protein acquisition whereas terrestrial protein can be dangerous to procure. However, in the past intertidal subsistence was thought to offer low caloric yields or unfavourable cost-to-benefit relationships until Meehan (1982) convincingly demonstrated the potential caloric „profit‟ possible from coastal foraging; the Anbarra women of northern Australia were contributing significantly to the overall caloric requirements of those people. In South Africa, two possible evolutionary behavioural hypotheses arose from the addition of intertidal resources to pre-historic diets. As background, it is important to note that the oldest global evidence for shellfish procurement [164 000 years ago (ka)] is found on the Cape‟s south coast (Jerardino and Marean, 2010) and the evidence is enriched by other sites from around 110 ka (Voight, 1973; Thackeray, 1988; Henshilwood et al., 2001; Langejans et al., 2012). Furthermore, this period coincides with the emergence of cognitively modern Homo sapiens as evidenced in xx the palaeoarchives from many sites in the region (d‟Errico et al., 2005; Marean et al., 2007; Wurz, 2008; Henshilwood et al., 2009; Watts, 2010; d‟Errico et al., 2012). These features have greatly enhanced the significance and importance of this area to understanding human evolution. The two hypotheses are centred around the effect that intertidal resources could have had on the emergence of our unique species. The addition of a nutritionally beneficial resource to cognitive development is seen by some (Broadhurst et al., 2002; Parkington, 2010) to have driven this cognitive evolution, where others suggest that resources which are both productive and dependable create pro-social proclivities that drive cognitive development (Whitaker and Byrd, 2014; Marean, 2014) and facilitate the migration of humans (Fa, 2008; Codding et al., 2014). Both hypotheses argue that resources on the Cape‟s coast must have been productive and had to be a frequent addition to diet to underpin brain development. The increased frequency of coastal resource procurement or coastal adaptation is therefore seen as an attribute of, or requisite for our species. This thesis attempts to shed light on the contribution of intertidal resources to prehistoric ‒ especially Middle Stone Age (MSA) – subsistence economy on the Cape‟s south coast and the possible effect thereof on human behavioural evolution. The first aim was to investigate the spatial productivity (once-off patch caloric profitability in numerous patches) of intertidal resources and the environmental and behavioural variables affecting it. The second aim was to investigate the resilience of caloric profitability (numerous harvests in the same patch) of these resources to sustained human predation. Productivity itself cannot affect human temporal social dynamics if the resource is swiftly depleted within a specific patch after one or a few harvests. Archaeological records that show the body size of shellfish decreasing over time are usually interpreted to indicate intensive exploitation and the depletion of these resources, but there may be other explanations for such patterns. Therefore, the third aim was to compare temporal and spatial variations in the body size of Turbo sarmaticus in the MSA, Later Stone Age (LSA) and the present day, in order to investigate whether such variations result from human exploitation or environmental changes.
- Full Text:
- Date Issued: 2018
- Authors: De Vynck, Jan Carlo
- Date: 2018
- Subjects: Marine invertebrates -- South Africa -- Prehistory , Shellfish -- South Africa -- Prehistory Fishes -- Behavior
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30172 , vital:30854
- Description: Studies of pre-historic lifestyles can be limited by a lack of preserved material and sites and resource misinterpretation is augmented by the vagueness of pre-historic subsistence lifestyles. The present can inform the past and this study‟s ethnoarchaeological approach, through modern analogues, examines productivity, resilience and temporal and spatial size variation of intertidal invertebrates on the Cape‟s south coast. O‟Connell (1995) defined the mutualistic relationship between ethnography and archaeology thus: “Archaeology‟s ultimate aim is understanding past human behaviour by patterns in the form and distribution of objects made or modified by humans in the past and knowledge of human behaviour and its material consequences in the present. The first provides direct evidence of past behaviour; the second, a basis for interpreting that evidence”. Coastal archaeology, specifically the contribution of coastal resources to pre-historic subsistence, has gained increased global interest (Erlandson, 2001; Erlandson and Rick, 2008; Codding et al., 2014). Apart from the high representation of preserved shell in coastal archaeological sites, interest in intertidal resources has also been sparked by their economic value compared to terrestrial resource options. Intertidal resources offer low-risk protein acquisition whereas terrestrial protein can be dangerous to procure. However, in the past intertidal subsistence was thought to offer low caloric yields or unfavourable cost-to-benefit relationships until Meehan (1982) convincingly demonstrated the potential caloric „profit‟ possible from coastal foraging; the Anbarra women of northern Australia were contributing significantly to the overall caloric requirements of those people. In South Africa, two possible evolutionary behavioural hypotheses arose from the addition of intertidal resources to pre-historic diets. As background, it is important to note that the oldest global evidence for shellfish procurement [164 000 years ago (ka)] is found on the Cape‟s south coast (Jerardino and Marean, 2010) and the evidence is enriched by other sites from around 110 ka (Voight, 1973; Thackeray, 1988; Henshilwood et al., 2001; Langejans et al., 2012). Furthermore, this period coincides with the emergence of cognitively modern Homo sapiens as evidenced in xx the palaeoarchives from many sites in the region (d‟Errico et al., 2005; Marean et al., 2007; Wurz, 2008; Henshilwood et al., 2009; Watts, 2010; d‟Errico et al., 2012). These features have greatly enhanced the significance and importance of this area to understanding human evolution. The two hypotheses are centred around the effect that intertidal resources could have had on the emergence of our unique species. The addition of a nutritionally beneficial resource to cognitive development is seen by some (Broadhurst et al., 2002; Parkington, 2010) to have driven this cognitive evolution, where others suggest that resources which are both productive and dependable create pro-social proclivities that drive cognitive development (Whitaker and Byrd, 2014; Marean, 2014) and facilitate the migration of humans (Fa, 2008; Codding et al., 2014). Both hypotheses argue that resources on the Cape‟s coast must have been productive and had to be a frequent addition to diet to underpin brain development. The increased frequency of coastal resource procurement or coastal adaptation is therefore seen as an attribute of, or requisite for our species. This thesis attempts to shed light on the contribution of intertidal resources to prehistoric ‒ especially Middle Stone Age (MSA) – subsistence economy on the Cape‟s south coast and the possible effect thereof on human behavioural evolution. The first aim was to investigate the spatial productivity (once-off patch caloric profitability in numerous patches) of intertidal resources and the environmental and behavioural variables affecting it. The second aim was to investigate the resilience of caloric profitability (numerous harvests in the same patch) of these resources to sustained human predation. Productivity itself cannot affect human temporal social dynamics if the resource is swiftly depleted within a specific patch after one or a few harvests. Archaeological records that show the body size of shellfish decreasing over time are usually interpreted to indicate intensive exploitation and the depletion of these resources, but there may be other explanations for such patterns. Therefore, the third aim was to compare temporal and spatial variations in the body size of Turbo sarmaticus in the MSA, Later Stone Age (LSA) and the present day, in order to investigate whether such variations result from human exploitation or environmental changes.
- Full Text:
- Date Issued: 2018
The state of constitutionalism in Uganda: 1962-2018
- Authors: Bashasha, Turyatemba Alex
- Date: 2018
- Subjects: Constitutional history -- Uganda , Constitutional history Constitutional law -- Uganda
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23669 , vital:30596
- Description: This Thesis examines the state of constitutionalism in Uganda between 1962 and 2018. The central question which it seeks to answer is: ‘why did Ugandan governments persistently fail to adhere to the basic requirements of the doctrine of constitutionalism between 1962 and 2018?’ In answering this question, which has challenged and continues to challenge many academicians, politicians, government officials, researchers and the international community alike, the Thesis adopts the Theory of Neo-patrimonialism as a theoretical lens through which the behaviours of the post-independence presidents of Uganda are examined. The Thesis discovers that, indeed, Neo-patrimonialism is a fundamental framework for analysing and explaining constitutionalism in post-independence Uganda. Against this backdrop, the Thesis concludes that, the collective behaviours of Uganda’s post-independence presidents viewed through the lens of neo-patrimonialism are more fundamental in understanding the failure of democracy and good governance in Uganda than the country’s structural problems of constitutionalism. The originality of the Thesis is in: (a) its being the first comprehensive investigation into why Ugandan governments have persistently failed to adhere to the basic requirements of the doctrine of constitutionalism for the entire period of 56 years (1962-2018) of post-independence Uganda; and (b) its being the first study to apply the Theory of Neo-patrimonialism in explaining the volatile nature and state of constitutionalism in Uganda. The contribution of the Thesis to the existing knowledge lies in its; (a) generation of detailed and well-researched information about the volatility of constitutionalism in Uganda between 1962 and 2018, (b) recommendation of strategies that should be adopted to effectively enhance consititutionalism in Uganda, and (c) authentication of the validity of the claims that despite its shortcomings, Neo-patrimonialism is a Theory which not only continues to define and drive African politics but its application can suitably be used to explain the volatile nature of constitutionalism in post-independence Uganda and the rest of Africa.
- Full Text:
- Date Issued: 2018
- Authors: Bashasha, Turyatemba Alex
- Date: 2018
- Subjects: Constitutional history -- Uganda , Constitutional history Constitutional law -- Uganda
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23669 , vital:30596
- Description: This Thesis examines the state of constitutionalism in Uganda between 1962 and 2018. The central question which it seeks to answer is: ‘why did Ugandan governments persistently fail to adhere to the basic requirements of the doctrine of constitutionalism between 1962 and 2018?’ In answering this question, which has challenged and continues to challenge many academicians, politicians, government officials, researchers and the international community alike, the Thesis adopts the Theory of Neo-patrimonialism as a theoretical lens through which the behaviours of the post-independence presidents of Uganda are examined. The Thesis discovers that, indeed, Neo-patrimonialism is a fundamental framework for analysing and explaining constitutionalism in post-independence Uganda. Against this backdrop, the Thesis concludes that, the collective behaviours of Uganda’s post-independence presidents viewed through the lens of neo-patrimonialism are more fundamental in understanding the failure of democracy and good governance in Uganda than the country’s structural problems of constitutionalism. The originality of the Thesis is in: (a) its being the first comprehensive investigation into why Ugandan governments have persistently failed to adhere to the basic requirements of the doctrine of constitutionalism for the entire period of 56 years (1962-2018) of post-independence Uganda; and (b) its being the first study to apply the Theory of Neo-patrimonialism in explaining the volatile nature and state of constitutionalism in Uganda. The contribution of the Thesis to the existing knowledge lies in its; (a) generation of detailed and well-researched information about the volatility of constitutionalism in Uganda between 1962 and 2018, (b) recommendation of strategies that should be adopted to effectively enhance consititutionalism in Uganda, and (c) authentication of the validity of the claims that despite its shortcomings, Neo-patrimonialism is a Theory which not only continues to define and drive African politics but its application can suitably be used to explain the volatile nature of constitutionalism in post-independence Uganda and the rest of Africa.
- Full Text:
- Date Issued: 2018
On the development of ZnO nanorods on silicon substrate for light-emitting diode applications
- Djiokap, Stive Roussel Tankio
- Authors: Djiokap, Stive Roussel Tankio
- Date: 2018
- Subjects: Zinc oxide , Chemical reactions , Compound semiconductors
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/29973 , vital:30802
- Description: The interest in zinc oxide (ZnO), a promising material for blue/ultraviolet light emitting devices, arises from its large exciton binding energy (60 meV). The main challenge associated with this promising compound semiconductor, however, arises from the difficulty to achieve stable and/or reproducible p-type doping. Since silicon (Si) technology still dominates the semiconductor industry, the objective of this thesis is to probe into the possibility of using ZnO nanorods (NRs) on p-type silicon for opto-electronic devices. ZnO NRs have been grown on seeded Si, as well as on nickel oxide (NiO) and aluminum nitride (AlN) coated Si, using a two-step chemical bath deposition (CBD) process. Various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM), have been used to characterize the samples. The electrical characteristics of the heterojunction between the substrate and the ZnO nanostructures were evaluated by current-voltage (I-V) and capacitance-voltage (C-V) measurements. SEM and XRD studies have confirmed that, irrespective of the orientation of the Si substrate (Si (100) and Si (111)), the two-step CBD process yielded NRs that crystallised in the wurtzite structure and exhibited a hexagonal shape. Most of the rods developed perpendicularly to the surface of the substrate, with the orientation and distribution of the rods dictated by the seed layer density. Similarly, irrespective of the substrate, the luminescence of the ZnO nanostructures is dominated by near band edge (NBE) emission in the UV region (~ 3.29 eV) and deep level emission (DLE) in the visible region (2 eV to 2.6 eV). Annealing at moderate temperatures (~ 300 °C) increased the NBE emission and decreased the DLE. The removal of surface adsorbed impurities and enhanced defect passivation by hydrogen are responsible for these changes. The diode characteristics of the ZnO/Si heterojunction was studied by I-V and C-V measurements. Rectification was observed when the Si substrate had a relatively low acceptor density of ~1016 cm-3, while diodes produced on substrate with p ~1018 cm-3 were ohmic. From the C-V analysis the donor density in the ZnO was deduced to be ~1018 cm-3. In the case of rectifying junctions, thermionic emission did not dominate the charge transport. The carrier transport mechanism was therefore probed by the temperature dependent I-V xiii measurements (100 K to 295 K). Defect-assisted multistep tunneling was deduced to dominate in the n-ZnO/p-Si diodes at low forward bias. The band alignment between n-ZnO and p-Si predicts a much smaller barrier for electrons than for holes at the interface, which results in recombination on the Si side of the junction for a forward-biased diode. NiO intermediate layers (formed on Si by the thermal oxidation of Ni) were used to reduce electron injection from ZnO into Si. Scanning probe microscopy (SPM) and XRD analysis showed that while the grain size of the poly-crystalline NiO increased with NiO film thickness, the orientation and distribution of the subsequently grown ZnO nanorods were unaffected by the underlying NiO layer. Also, the photoluminescence response of the ZnO rods remained unchanged. I-V measurements did illustrate rectifying behaviour, with both the forward and reverse currents strongly decreased due to the resistive nature of the NiO. In another attempt at confining electrons to the ZnO side of the junction, AlN-coated Si (111) was used as a substrate for ZnO nanorods. CBD parameters that normally yield nanorods resulted in a plate-like architecture of the ZnO. By modifying the ZnO seed density on the AlN/Si substrate, the rod-like morphology could be recovered. Both the forward and reverse current decreased in these diodes. From studies aimed at identifying the transport mechanism it was concluded that trap-assisted tunnelling, resulting from a high density of defects in the seed layer, dominates in these devices. In conclusion, while no ZnO electroluminescence could be achieved from any of the devices, this study provides insight into the transport mechanisms in n-ZnO/barrier/p-Si heterostructures and highlights the importance of the heterointerface quality for light emitting devices.
- Full Text:
- Date Issued: 2018
- Authors: Djiokap, Stive Roussel Tankio
- Date: 2018
- Subjects: Zinc oxide , Chemical reactions , Compound semiconductors
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/29973 , vital:30802
- Description: The interest in zinc oxide (ZnO), a promising material for blue/ultraviolet light emitting devices, arises from its large exciton binding energy (60 meV). The main challenge associated with this promising compound semiconductor, however, arises from the difficulty to achieve stable and/or reproducible p-type doping. Since silicon (Si) technology still dominates the semiconductor industry, the objective of this thesis is to probe into the possibility of using ZnO nanorods (NRs) on p-type silicon for opto-electronic devices. ZnO NRs have been grown on seeded Si, as well as on nickel oxide (NiO) and aluminum nitride (AlN) coated Si, using a two-step chemical bath deposition (CBD) process. Various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM), have been used to characterize the samples. The electrical characteristics of the heterojunction between the substrate and the ZnO nanostructures were evaluated by current-voltage (I-V) and capacitance-voltage (C-V) measurements. SEM and XRD studies have confirmed that, irrespective of the orientation of the Si substrate (Si (100) and Si (111)), the two-step CBD process yielded NRs that crystallised in the wurtzite structure and exhibited a hexagonal shape. Most of the rods developed perpendicularly to the surface of the substrate, with the orientation and distribution of the rods dictated by the seed layer density. Similarly, irrespective of the substrate, the luminescence of the ZnO nanostructures is dominated by near band edge (NBE) emission in the UV region (~ 3.29 eV) and deep level emission (DLE) in the visible region (2 eV to 2.6 eV). Annealing at moderate temperatures (~ 300 °C) increased the NBE emission and decreased the DLE. The removal of surface adsorbed impurities and enhanced defect passivation by hydrogen are responsible for these changes. The diode characteristics of the ZnO/Si heterojunction was studied by I-V and C-V measurements. Rectification was observed when the Si substrate had a relatively low acceptor density of ~1016 cm-3, while diodes produced on substrate with p ~1018 cm-3 were ohmic. From the C-V analysis the donor density in the ZnO was deduced to be ~1018 cm-3. In the case of rectifying junctions, thermionic emission did not dominate the charge transport. The carrier transport mechanism was therefore probed by the temperature dependent I-V xiii measurements (100 K to 295 K). Defect-assisted multistep tunneling was deduced to dominate in the n-ZnO/p-Si diodes at low forward bias. The band alignment between n-ZnO and p-Si predicts a much smaller barrier for electrons than for holes at the interface, which results in recombination on the Si side of the junction for a forward-biased diode. NiO intermediate layers (formed on Si by the thermal oxidation of Ni) were used to reduce electron injection from ZnO into Si. Scanning probe microscopy (SPM) and XRD analysis showed that while the grain size of the poly-crystalline NiO increased with NiO film thickness, the orientation and distribution of the subsequently grown ZnO nanorods were unaffected by the underlying NiO layer. Also, the photoluminescence response of the ZnO rods remained unchanged. I-V measurements did illustrate rectifying behaviour, with both the forward and reverse currents strongly decreased due to the resistive nature of the NiO. In another attempt at confining electrons to the ZnO side of the junction, AlN-coated Si (111) was used as a substrate for ZnO nanorods. CBD parameters that normally yield nanorods resulted in a plate-like architecture of the ZnO. By modifying the ZnO seed density on the AlN/Si substrate, the rod-like morphology could be recovered. Both the forward and reverse current decreased in these diodes. From studies aimed at identifying the transport mechanism it was concluded that trap-assisted tunnelling, resulting from a high density of defects in the seed layer, dominates in these devices. In conclusion, while no ZnO electroluminescence could be achieved from any of the devices, this study provides insight into the transport mechanisms in n-ZnO/barrier/p-Si heterostructures and highlights the importance of the heterointerface quality for light emitting devices.
- Full Text:
- Date Issued: 2018
Synthesis, characterization and evaluation of photophysical and electrochemical properties of ruthenium(II) complexes for dye-sensitized solar cells
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Date Issued: 2018
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Date Issued: 2018
Development of InSb/GaSb quantum dots by MOVPE
- Authors: Ahia, Chinedu Christian
- Date: 2018
- Subjects: Semiconductors , Quantum electronics Organometallic compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23382 , vital:30537
- Description: There has been an increasing interest in the modification of semiconductor band structures through the reduction of their dimensions, which simultaneously increases the band gap energy of the material and gives rise to flexibility in device properties. Advances in III-V antimony (Sb) based semiconductor fabrication have triggered the quest for extension of the emission/absorption wavelength range of this family of compounds for optoelectronic devices operating in the mid-infrared region of the electromagnetic spectrum. An interesting material system for mid-infrared (MIR) applications is indium antimonide (InSb) quantum dots (QDs) within a gallium antimonide (GaSb) matrix. However, its band alignment and emission wavelength has been the subject of some interest and controversy over the years. This study focuses on the development of InSb/GaSb QDs by metal organic vapour phase epitaxy (MOVPE). The samples were grown on different substrates using various growth parameters in order to vary the size, density and aspect ratio of the dots. Interfacial growth interruptions while flowing various source precursors through the reactor were investigated in order to influence the chemical termination of the surface, and hence the resulting strain in the structures. The samples were characterized using photoluminescence spectroscopy, scanning probe microscopy, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. Likewise, the band alignment, energy levels, and carrier wave functions of the samples in this work were modelled theoretically using the nextnanomat software (version 3.1.0.0). A comparison of growth on two different GaSb substrates [(100) 2° off towards <111>B ± 0.1ᵒ and (111) ± 0.1ᵒ] using similar growth conditions yielded a higher dot density on the (100) substrate compared to the (111) substrate. This was attributed to the presence of terraces/atomic steps induced by the misorientation on the (100) substrate, which invariably gives rise to increased adsorption and an enhanced sticking coefficient of adatoms. Studies on the influence of a buffer layer on the morphology of uncapped dots showed that the shape and size of the dots are sensitive to the thickness of the buffer layer. In some case a corrugated buffer surface resulted, which introduced order in the arrangement of the dots, which formed preferentially inside the troughs. An increase in the V/III ratio from 1.0 to 3.0 was found to reduce the areal density of the QDs, while an analysis of the diameter histograms showed a narrowing of the size distribution with an increase in V/III ratio. The larger size distribution at low V/III was ascribed to the increase in indium species and the increased indium adatom migration length. This leads to increased dot density and nucleation sites, and thus triggers an increase in the conversion of tiny QDs into thermodynamically more suitable larger dots via coalescence. However, as the V/III ratio increased, the number of indium adatoms available for growth on the surface reduced, which automatically led to a decrease in the migration length of indium species which is unfavourable for the production of nucleation sites and to a decrease in dot density. Low growth rates were found to be beneficial for the growth of a high density (~5×1010cm-2) of QDs. Photoluminescence (PL) analysis of the capped samples at low temperature (~10 K), using an excitation power of 2 mW, showed a PL peak at ∼732 meV. Upon an increase in laser power to 120 mW, a blue shift of ∼ 8 meV was noticed. This emission typically persisted up to 60–70 K. An increase in the number of InSb QD-layers, was observed to cause an increase in the luminescence spectral line width and a long-wavelength shift of the PL lines, together with an enhancement in the strength of the PL emission. However, high resolution transmission electron microscopy (HRTEM) of the capped dots revealed the formation of an InGaSb quantum well-like structure, ∼10 nm thick, which was responsible for the PL signal mentioned above. The absence of QDs in the capped sample was attributed to inter-diffusion of Ga and In during the deposition of the cap layer, giving rise to a quantum well (QW) instead of the intended QDs. The presence of threading dislocations and stacking faults were also observed in the TEM micrographs of the samples containing multilayers, which can account for the fast quenching of the PL emission with increasing temperature from these samples. Theoretical simulations of the band alignment, wave functions and energy levels were in good agreement with the data collected from the PL spectra of the samples.
- Full Text:
- Date Issued: 2018
- Authors: Ahia, Chinedu Christian
- Date: 2018
- Subjects: Semiconductors , Quantum electronics Organometallic compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23382 , vital:30537
- Description: There has been an increasing interest in the modification of semiconductor band structures through the reduction of their dimensions, which simultaneously increases the band gap energy of the material and gives rise to flexibility in device properties. Advances in III-V antimony (Sb) based semiconductor fabrication have triggered the quest for extension of the emission/absorption wavelength range of this family of compounds for optoelectronic devices operating in the mid-infrared region of the electromagnetic spectrum. An interesting material system for mid-infrared (MIR) applications is indium antimonide (InSb) quantum dots (QDs) within a gallium antimonide (GaSb) matrix. However, its band alignment and emission wavelength has been the subject of some interest and controversy over the years. This study focuses on the development of InSb/GaSb QDs by metal organic vapour phase epitaxy (MOVPE). The samples were grown on different substrates using various growth parameters in order to vary the size, density and aspect ratio of the dots. Interfacial growth interruptions while flowing various source precursors through the reactor were investigated in order to influence the chemical termination of the surface, and hence the resulting strain in the structures. The samples were characterized using photoluminescence spectroscopy, scanning probe microscopy, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. Likewise, the band alignment, energy levels, and carrier wave functions of the samples in this work were modelled theoretically using the nextnanomat software (version 3.1.0.0). A comparison of growth on two different GaSb substrates [(100) 2° off towards <111>B ± 0.1ᵒ and (111) ± 0.1ᵒ] using similar growth conditions yielded a higher dot density on the (100) substrate compared to the (111) substrate. This was attributed to the presence of terraces/atomic steps induced by the misorientation on the (100) substrate, which invariably gives rise to increased adsorption and an enhanced sticking coefficient of adatoms. Studies on the influence of a buffer layer on the morphology of uncapped dots showed that the shape and size of the dots are sensitive to the thickness of the buffer layer. In some case a corrugated buffer surface resulted, which introduced order in the arrangement of the dots, which formed preferentially inside the troughs. An increase in the V/III ratio from 1.0 to 3.0 was found to reduce the areal density of the QDs, while an analysis of the diameter histograms showed a narrowing of the size distribution with an increase in V/III ratio. The larger size distribution at low V/III was ascribed to the increase in indium species and the increased indium adatom migration length. This leads to increased dot density and nucleation sites, and thus triggers an increase in the conversion of tiny QDs into thermodynamically more suitable larger dots via coalescence. However, as the V/III ratio increased, the number of indium adatoms available for growth on the surface reduced, which automatically led to a decrease in the migration length of indium species which is unfavourable for the production of nucleation sites and to a decrease in dot density. Low growth rates were found to be beneficial for the growth of a high density (~5×1010cm-2) of QDs. Photoluminescence (PL) analysis of the capped samples at low temperature (~10 K), using an excitation power of 2 mW, showed a PL peak at ∼732 meV. Upon an increase in laser power to 120 mW, a blue shift of ∼ 8 meV was noticed. This emission typically persisted up to 60–70 K. An increase in the number of InSb QD-layers, was observed to cause an increase in the luminescence spectral line width and a long-wavelength shift of the PL lines, together with an enhancement in the strength of the PL emission. However, high resolution transmission electron microscopy (HRTEM) of the capped dots revealed the formation of an InGaSb quantum well-like structure, ∼10 nm thick, which was responsible for the PL signal mentioned above. The absence of QDs in the capped sample was attributed to inter-diffusion of Ga and In during the deposition of the cap layer, giving rise to a quantum well (QW) instead of the intended QDs. The presence of threading dislocations and stacking faults were also observed in the TEM micrographs of the samples containing multilayers, which can account for the fast quenching of the PL emission with increasing temperature from these samples. Theoretical simulations of the band alignment, wave functions and energy levels were in good agreement with the data collected from the PL spectra of the samples.
- Full Text:
- Date Issued: 2018
A proposed sustainable funding framework for the public broadcaster in South Africa
- Authors: Nyembezi, Cydric Luvuyo
- Date: 2018
- Subjects: South African Broadcasting Corporation -- Finance , Finance, Public -- South Africa Sustainable development -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/34443 , vital:33379
- Description: Public service broadcasting in South Africa is the responsibility of the South African Broadcasting Corporation (SABC), which is the only national public service broadcaster mandated through the South African Broadcasting Act. Consequently, the SABC is meant to be a tool for information, entertainment and education that is accessible by all citizens, regardless of their social and economic status in the community. However, like all enterprises, the SABC requires a sustainable source of revenue to function effectively. It is of the utmost importance that the SABC has the necessary resources and stable source of revenue to fulfil its public service responsibilities, as a lack of proper resources and insufficient funds can hinder the provision of these services. The global economic crisis has put all public and private sector companies under financial pressure. The effect of this financial pressure was felt by the SABC and led to financial loss, subsequently posing a serious threat to the financial sustainability of the SABC. Given this situation, this study sought to develop a sustainable funding framework by identifying factors that influence the financial sustainability of the public broadcaster in South Africa and to provide alternative strategies for improving the financial sustainability of the public broadcaster in South Africa, which has thus far proved unsustainable and insecure. Past research has focused mainly on defining a public service broadcaster or a public mandate, or considered the future of public service broadcasters. In these past studies, researchers mostly debated the SABC funding challenges without attempting to develop a funding framework for the SABC. To achieve the objectives of this study a quantitative approach using a web-based distribution survey method was adopted to test the hypotheses. The participants were randomly selected in each provincial SABC office from the database of managers, unionised and non-unionised employees, as well as the database list of freelancers. A total of 432 participants, selected through a stratification sampling technique, were considered and 175 respondents completed the survey. However, after data clean-up only 168 respondents’ data was usable. Based on the analysis of various secondary sources, a theoretical framework regarding sustainable funding of the public broadcaster in South Africa was constructed. The proposed theoretical framework indicated that the intervening variable, which is sustainable funding, is possibly influenced by three independent variables namely, internal stakeholders, a competitive environment and the management of resources. The perceived outcomes (dependent variables) of a sustainably funded public broadcaster were identified as customer benefits and organisational performance. The computer programme STATISTICA was used for data analysis. Descriptive statistics was used to summarise the data of the respondents and allow easy interpretation by the researcher. Inferential statistical analysis was used to test for relationships between identified variables using a validity test, reliability test and correlation and regression analysis. The empirical results revealed that sustainable funding formed two separate intervening variables. These variables were renamed sustainable funding enabler and sustainable funding as part of management control. The dependent variable customer benefits and organisational performance also loaded onto a single factor and was renamed organisational outcomes. Given the results, it was determined that internal stakeholders, competitive environment and management of resources have a significant positive influence on the sustainable funding enabler for the public broadcaster. In turn, sustainable funding enabler had a significant positive influence on the organisational outcomes (customer benefits and performance). On the other hand, only the management of resources had a positive influence on sustainable funding as part of management control of the public broadcaster. Furthermore, sustainable funding as part of management control still had a significant positive influence on the organisational outcomes. The majority of the respondents agreed in their responses in relation to the variable items measuring sustainable funding as a part of management control and its influence to the organisational outcomes of the public broadcaster. In conclusion, sustainable funding of the public broadcaster is influenced by the identified variables, namely internal stakeholders, competitive environment and management of resources. In turn, sustainable funding has a positive influence on the organisational outcomes (customer benefits and performance). It is envisaged that the empirical evidence provided in this study will assist the SABC in understanding the factors influencing financial sustainability and thereby assist the organisation during strategy development and decision making. This study provides relevant and practical recommendations that will make the SABC financially sustainable. Finally, the objectives of this study were achieved and the research questions were answered. This study can also act as a foundation for other studies, thereby contributing to the body of knowledge.
- Full Text:
- Date Issued: 2018
- Authors: Nyembezi, Cydric Luvuyo
- Date: 2018
- Subjects: South African Broadcasting Corporation -- Finance , Finance, Public -- South Africa Sustainable development -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/34443 , vital:33379
- Description: Public service broadcasting in South Africa is the responsibility of the South African Broadcasting Corporation (SABC), which is the only national public service broadcaster mandated through the South African Broadcasting Act. Consequently, the SABC is meant to be a tool for information, entertainment and education that is accessible by all citizens, regardless of their social and economic status in the community. However, like all enterprises, the SABC requires a sustainable source of revenue to function effectively. It is of the utmost importance that the SABC has the necessary resources and stable source of revenue to fulfil its public service responsibilities, as a lack of proper resources and insufficient funds can hinder the provision of these services. The global economic crisis has put all public and private sector companies under financial pressure. The effect of this financial pressure was felt by the SABC and led to financial loss, subsequently posing a serious threat to the financial sustainability of the SABC. Given this situation, this study sought to develop a sustainable funding framework by identifying factors that influence the financial sustainability of the public broadcaster in South Africa and to provide alternative strategies for improving the financial sustainability of the public broadcaster in South Africa, which has thus far proved unsustainable and insecure. Past research has focused mainly on defining a public service broadcaster or a public mandate, or considered the future of public service broadcasters. In these past studies, researchers mostly debated the SABC funding challenges without attempting to develop a funding framework for the SABC. To achieve the objectives of this study a quantitative approach using a web-based distribution survey method was adopted to test the hypotheses. The participants were randomly selected in each provincial SABC office from the database of managers, unionised and non-unionised employees, as well as the database list of freelancers. A total of 432 participants, selected through a stratification sampling technique, were considered and 175 respondents completed the survey. However, after data clean-up only 168 respondents’ data was usable. Based on the analysis of various secondary sources, a theoretical framework regarding sustainable funding of the public broadcaster in South Africa was constructed. The proposed theoretical framework indicated that the intervening variable, which is sustainable funding, is possibly influenced by three independent variables namely, internal stakeholders, a competitive environment and the management of resources. The perceived outcomes (dependent variables) of a sustainably funded public broadcaster were identified as customer benefits and organisational performance. The computer programme STATISTICA was used for data analysis. Descriptive statistics was used to summarise the data of the respondents and allow easy interpretation by the researcher. Inferential statistical analysis was used to test for relationships between identified variables using a validity test, reliability test and correlation and regression analysis. The empirical results revealed that sustainable funding formed two separate intervening variables. These variables were renamed sustainable funding enabler and sustainable funding as part of management control. The dependent variable customer benefits and organisational performance also loaded onto a single factor and was renamed organisational outcomes. Given the results, it was determined that internal stakeholders, competitive environment and management of resources have a significant positive influence on the sustainable funding enabler for the public broadcaster. In turn, sustainable funding enabler had a significant positive influence on the organisational outcomes (customer benefits and performance). On the other hand, only the management of resources had a positive influence on sustainable funding as part of management control of the public broadcaster. Furthermore, sustainable funding as part of management control still had a significant positive influence on the organisational outcomes. The majority of the respondents agreed in their responses in relation to the variable items measuring sustainable funding as a part of management control and its influence to the organisational outcomes of the public broadcaster. In conclusion, sustainable funding of the public broadcaster is influenced by the identified variables, namely internal stakeholders, competitive environment and management of resources. In turn, sustainable funding has a positive influence on the organisational outcomes (customer benefits and performance). It is envisaged that the empirical evidence provided in this study will assist the SABC in understanding the factors influencing financial sustainability and thereby assist the organisation during strategy development and decision making. This study provides relevant and practical recommendations that will make the SABC financially sustainable. Finally, the objectives of this study were achieved and the research questions were answered. This study can also act as a foundation for other studies, thereby contributing to the body of knowledge.
- Full Text:
- Date Issued: 2018
Time-driven activity-based costing for small to medium manufacturing enterprises in South Africa: an integrated balanced scorecard approach
- Authors: Reynolds, Arthur
- Date: 2018
- Subjects: Activity-based costing , Managerial accounting Small business -- Finance Small business -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/35125 , vital:33630
- Description: The failure rate of small to medium enterprises in South Africa is very high. This is problematic as there is a large dependence on the ongoing success of small to medium enterprises from the economy and society. Increasing labour costs and inflationary pressure have contributed to the high failure rates of small to medium enterprises. In addition, the manufacturing sector for small to medium enterprises has showed a decline over recent years. There is thus a need to identify and manage the critical success factors (CSFs) for small to medium manufacturing enterprises. The balanced scorecard (BSC) has been used successfully to manage CSFs. Furthermore, research on time-driven activity-based costing (TDABC) has illustrated that this costing system could be implemented successfully at small to medium enterprises across the world to manage costs, and that the BSC could be used successfully together with TDABC. However, research has shown that implementing a BSC at small to medium enterprises could be challenging. As a result, the theory of constraints (TOC) that can be used to explain the phenomenon of constraints of resources is recognised as the underlying theory for this study. The availability of a generic yet adaptable BSC could potentially enable owners and managers of small to medium manufacturing enterprises to manage the CSFs that together with the TDABC system can lower costs and identify unused capacity. This study has developed and implemented a generic TDABC/BSC costing system by investigating literature and conducting a Delphi study and a case study at a small to medium enterprise specialising in manufacturing. Firstly, it was found that a generic BSC for small to medium manufacturing enterprises could be developed by using a Delphi study to create a BSC template with optional key metrics/key performance indicators (KPIs) to suit different types of manufacturing industries. Secondly, it was demonstrated in a case study that TDABC could still be beneficial for a small to medium manufacturing enterprise if focus is only on a single product. Thirdly, it became evident that the system could be used to manage the TOC. Finally, the case study shows that cost savings could be achieved in small to medium enterprise by using the integrated TDABC/BSC costing system and by that increase the success of the business.
- Full Text:
- Date Issued: 2018
- Authors: Reynolds, Arthur
- Date: 2018
- Subjects: Activity-based costing , Managerial accounting Small business -- Finance Small business -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/35125 , vital:33630
- Description: The failure rate of small to medium enterprises in South Africa is very high. This is problematic as there is a large dependence on the ongoing success of small to medium enterprises from the economy and society. Increasing labour costs and inflationary pressure have contributed to the high failure rates of small to medium enterprises. In addition, the manufacturing sector for small to medium enterprises has showed a decline over recent years. There is thus a need to identify and manage the critical success factors (CSFs) for small to medium manufacturing enterprises. The balanced scorecard (BSC) has been used successfully to manage CSFs. Furthermore, research on time-driven activity-based costing (TDABC) has illustrated that this costing system could be implemented successfully at small to medium enterprises across the world to manage costs, and that the BSC could be used successfully together with TDABC. However, research has shown that implementing a BSC at small to medium enterprises could be challenging. As a result, the theory of constraints (TOC) that can be used to explain the phenomenon of constraints of resources is recognised as the underlying theory for this study. The availability of a generic yet adaptable BSC could potentially enable owners and managers of small to medium manufacturing enterprises to manage the CSFs that together with the TDABC system can lower costs and identify unused capacity. This study has developed and implemented a generic TDABC/BSC costing system by investigating literature and conducting a Delphi study and a case study at a small to medium enterprise specialising in manufacturing. Firstly, it was found that a generic BSC for small to medium manufacturing enterprises could be developed by using a Delphi study to create a BSC template with optional key metrics/key performance indicators (KPIs) to suit different types of manufacturing industries. Secondly, it was demonstrated in a case study that TDABC could still be beneficial for a small to medium manufacturing enterprise if focus is only on a single product. Thirdly, it became evident that the system could be used to manage the TOC. Finally, the case study shows that cost savings could be achieved in small to medium enterprise by using the integrated TDABC/BSC costing system and by that increase the success of the business.
- Full Text:
- Date Issued: 2018
Factors affecting effective ecological restoration of Portulacaria afra (spekboom)-rich subtropical thicket and aboveground carbon endpoint projections
- Van der Vyver, Marius Lodewyk
- Authors: Van der Vyver, Marius Lodewyk
- Date: 2018
- Subjects: Restoration ecology , Plant conservation -- South Africa Portulacaria afra -- South Africa Shrubs -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23250 , vital:30468
- Description: Among the requirements to achieve effective ecological restoration on a landscape scale are a scientific underpinning, strong adaptive management and the setting of realistic endpoints. Efficacy and success depend on a complex interplay of factors of both local and regional influence. Biome-wide restoration experiments are rare, but valuable for evaluating efficacy of different protocols according to local context. The Thicket-wide Plot (TWP) experiment was initiated by the Subtropical Thicket Restoration Programme to inform landscape-scale ecological restoration of degraded Portulacaria afra (spekboom)-rich Subtropical Thicket. Thirteen different planting treatments of Portulacaria afra (spekboom) truncheons were planted as replicated rows on 0.25 ha fenced plots across the distribution range of spekboom-rich thicket habitat to better establish effective restoration protocols. I used a rule-based learning ensemble algorithm to evaluate 60 different predictors that potentially impact effective restoration, covering a range of climatic, topographic, edaphic, ecological and management related factors observed at 227 of these TWP plots. Percentage survivorship and aboveground biomass carbon sequestration rate (ABCsr) were taken as proxies for efficacy derived from subsequent monitoring data gathered 2 - 5 years after establishment, and a new allometric model I developed for spekboom. I found herbivory and identification of target habitat the two most important predictors of restoration efficacy, both well within the control of the practitioner. Highest survivorship and ABCsr were associated with larger truncheons planted deeper. The only exception to this pattern was found amongst the two smallest size truncheon categories. The application of external rooting hormone or watering treatment to truncheons were found of no significance to effective restoration, while all the pruned treatments were, in association with lesser planting depth, found to be significantly less effective than untreated truncheons planted deeper. When the restoration protocol is optimal (largest truncheons planted deepest in target habitats and protected from herbivory), my results show higher annual carbon sequestration rates (1.46 - 3.7 t C ha−1 yr−1 in aboveground biomass) than most older restoration sites that have been identified as benchmarks of success. In order to project ABC endpoints, I generated 40 new species-specific allometric models and used them to estimate biomass and carbon of intact and degraded stands on five sites spread out across the region. The highest AGC for stands in both intact and degraded states were estimated at 42.96 t Cha−1 and 12.98 t C ha−1 respectively, and the lowest at 26.32 t C ha−1 and 2.52 t C ha−1. Large canopy dominant (LCD) species contributed the largest AGC portion at three intact stands. The second largest portion was recorded for spekboom. The difference between paired stands on each sample site ranged between 23.8 and 32.8 t C ha−1, which provide a realistic target for biome-wide restoration that, when adopted together with current protocols, may be reached within three decades of inception.
- Full Text:
- Date Issued: 2018
- Authors: Van der Vyver, Marius Lodewyk
- Date: 2018
- Subjects: Restoration ecology , Plant conservation -- South Africa Portulacaria afra -- South Africa Shrubs -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23250 , vital:30468
- Description: Among the requirements to achieve effective ecological restoration on a landscape scale are a scientific underpinning, strong adaptive management and the setting of realistic endpoints. Efficacy and success depend on a complex interplay of factors of both local and regional influence. Biome-wide restoration experiments are rare, but valuable for evaluating efficacy of different protocols according to local context. The Thicket-wide Plot (TWP) experiment was initiated by the Subtropical Thicket Restoration Programme to inform landscape-scale ecological restoration of degraded Portulacaria afra (spekboom)-rich Subtropical Thicket. Thirteen different planting treatments of Portulacaria afra (spekboom) truncheons were planted as replicated rows on 0.25 ha fenced plots across the distribution range of spekboom-rich thicket habitat to better establish effective restoration protocols. I used a rule-based learning ensemble algorithm to evaluate 60 different predictors that potentially impact effective restoration, covering a range of climatic, topographic, edaphic, ecological and management related factors observed at 227 of these TWP plots. Percentage survivorship and aboveground biomass carbon sequestration rate (ABCsr) were taken as proxies for efficacy derived from subsequent monitoring data gathered 2 - 5 years after establishment, and a new allometric model I developed for spekboom. I found herbivory and identification of target habitat the two most important predictors of restoration efficacy, both well within the control of the practitioner. Highest survivorship and ABCsr were associated with larger truncheons planted deeper. The only exception to this pattern was found amongst the two smallest size truncheon categories. The application of external rooting hormone or watering treatment to truncheons were found of no significance to effective restoration, while all the pruned treatments were, in association with lesser planting depth, found to be significantly less effective than untreated truncheons planted deeper. When the restoration protocol is optimal (largest truncheons planted deepest in target habitats and protected from herbivory), my results show higher annual carbon sequestration rates (1.46 - 3.7 t C ha−1 yr−1 in aboveground biomass) than most older restoration sites that have been identified as benchmarks of success. In order to project ABC endpoints, I generated 40 new species-specific allometric models and used them to estimate biomass and carbon of intact and degraded stands on five sites spread out across the region. The highest AGC for stands in both intact and degraded states were estimated at 42.96 t Cha−1 and 12.98 t C ha−1 respectively, and the lowest at 26.32 t C ha−1 and 2.52 t C ha−1. Large canopy dominant (LCD) species contributed the largest AGC portion at three intact stands. The second largest portion was recorded for spekboom. The difference between paired stands on each sample site ranged between 23.8 and 32.8 t C ha−1, which provide a realistic target for biome-wide restoration that, when adopted together with current protocols, may be reached within three decades of inception.
- Full Text:
- Date Issued: 2018
The classification of fuzzy groups of finite cyclic groups Zpn Zqm Zr and Zp1 Zp2 Zpn for distinct prime numbers p; q; r; p1; p2; ; pn and n;m 2 Z+
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
The economic and ecological trade-offs of wetland conversion for development projects: the case of the Kampala–Mukono corridor
- Authors: Wasswa, Hannington
- Date: 2018
- Subjects: Wetland ecology -- Uganda -- Kampala , Wetlands -- Uganda -- Kampala Wetland management -- Uganda -- Kampala Hydrogeology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36409 , vital:33939
- Description: Wetland diminution for development projects (DPs) in the Kampala–Mukono Corridor (KMC) continues to pose threats to the socio-economic and ecological benefits of wetlands because decision-makers and wetland users at various levels often have insufficient knowledge of these benefits. This situation has resulted in unsustainable development decisions that accord little weight to wetlands and have allocated many of them to DPs. In order to inform decision making for optimal development in the KMC, the present study analysed the spatial and temporal wetland loss to DPs, estimated the economic value of the KMC wetlands, and assessed the environmental consequences of wetland conversion for DPs. Sets of ortho-rectified and cloud-free multi-temporal Landsat MSS (1974) and Landsat TM/ETM+ images (30m) for 1986, 2006, and 2013 were analysed in a spatial and temporal framework. The 79m Landsat image (MSS) of 1974 was resampled and later filtered with subsequent 30m images using a majority filter method. An unsupervised classification approach was employed to characterize the wetlands and associated DPs. The classified DPs and wetland cover types were validated by reference to topographical maps (sheets) of 1974 at a scale of 1:50,000 obtained from Uganda Lands and Surveys, apriori knowledge and Google earth images corresponding to the same spatial and temporal frames. The IDRISI Selva-based Markov Chain model was employed to model future wetland loss to DPs. The Total Economic Valuation Approach (TEV) was employed to quantify selected use values of wetland economic benefits using the market price, replacement cost and contingent valuation techniques. The ecological implications of wetland loss focused on soil organic carbon (SOC) and hydrological impacts in the KMC wetlands. The estimated SOC was assessed with climatic data in order to infer the implication of SOC loss for local climate variability. The manual wet chemistry/oxidation method by Walkley-Black (1934) was adopted to estimate SOC in various wetland cover types. Hydrological impact assessments focused on water quality analysis in various wetland cover types, with major parameters being total nitrogen (TN), total phosphorous (TP) total dissolved solids – (TDS) and total suspended sediments (TSS). Hydrologic flow data parameters across the different wetland cover types in the KMC focused on water level, speed, stream width, and bed load. Results from analysis of the spatial-temporal wetland change revealed that by 2013 the KMC wetlands had lost almost half (47%) of their 1974 areal coverage, with 56% of this loss resulting from conversion to DPs. It is projected that 26% of the KMC wetlands will be lost to more DPs by 2040. Wetland loss is attributed to intensified economic activity and preference of Kampala as an industrial zone, weakness in the previous spatial planning of Kampala, and the general lack of information flow to various institutions involved in the establishment of DPs. The KMC wetlands provide a flow of economic benefits at a minimum approximated value of US$ 3,418 / ha / per year. It is revealed that a great deal of these economic benefits (88%) accrues to the local subsistence level in the form of livelihood products, incomes, and employment benefits. The 56% wetlands loss to DPs in the KMC by 2013 brings the minimum economic value lost to US$ 19,311,700 in the sampled wetlands, and projections of future wetland loss put the minimum economic loss at US$ 48,368,118 by 2040. Continuous degradation of these wetlands means serious economic costs to the government and local communities, as reflected in high replacement expenditures for wetland services, foregone incomes, subsistence livelihood support and alternative employment. The highest carbon (C) sinks were identified in forest swamps, palms, thickets and wetlands converted to agriculture, which accounted for 25% of the KMC wetlands by 2013, while the lowest total soil organic carbon (TSOC) range occurred in converted wetland cover types (converted wetlands to industrial and settlements) that occupied 47% of the study area. A general decrease in SOC sequestration from 1974 to 2013 across the KMC wetlands is identified, with the lowest C pool registered in 2013. The dwindling SOC banks are considered to be partly responsible for varying climate and related feedbacks on wetland benefits in the KMC. The hydrologic impacts of wetland loss are felt mainly in converted wetland cover types, in the form of compromised water quality, with increased nutrient pollution and TSS. These all create negative impacts on wetland hydrological services, particularly filtration, flood attenuation, recharge and discharge benefits, all of which have profound effects on biodiversity. There is an urgent need to reduce the scale of wetland diminution in the KMC. This will be achieved if mitigation and conservation measures are undertaken. Mitigation measures should include a revision of development plans, user sensitization on wetland economic values and enforcement of regulatory mechanisms. Conservation strategies should involve the use of economic incentives and disincentives which include: a revision of historic property rights to regulate wetland use, performance bonds or subsidies for environmentally friendly activities and taxes, fees or fines for unacceptable levels of degradation and tradable permits that utilise the concept of ‘wetland banks’ to ensure no further loss of the KMC wetlands to DPs. Future research should focus on modelling the response of wetland ecosystems to multiple threats and management interventions, and on a feasibility study of wetland restoration options and the implications for local people’s livelihoods in the KMC.
- Full Text:
- Date Issued: 2018
- Authors: Wasswa, Hannington
- Date: 2018
- Subjects: Wetland ecology -- Uganda -- Kampala , Wetlands -- Uganda -- Kampala Wetland management -- Uganda -- Kampala Hydrogeology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36409 , vital:33939
- Description: Wetland diminution for development projects (DPs) in the Kampala–Mukono Corridor (KMC) continues to pose threats to the socio-economic and ecological benefits of wetlands because decision-makers and wetland users at various levels often have insufficient knowledge of these benefits. This situation has resulted in unsustainable development decisions that accord little weight to wetlands and have allocated many of them to DPs. In order to inform decision making for optimal development in the KMC, the present study analysed the spatial and temporal wetland loss to DPs, estimated the economic value of the KMC wetlands, and assessed the environmental consequences of wetland conversion for DPs. Sets of ortho-rectified and cloud-free multi-temporal Landsat MSS (1974) and Landsat TM/ETM+ images (30m) for 1986, 2006, and 2013 were analysed in a spatial and temporal framework. The 79m Landsat image (MSS) of 1974 was resampled and later filtered with subsequent 30m images using a majority filter method. An unsupervised classification approach was employed to characterize the wetlands and associated DPs. The classified DPs and wetland cover types were validated by reference to topographical maps (sheets) of 1974 at a scale of 1:50,000 obtained from Uganda Lands and Surveys, apriori knowledge and Google earth images corresponding to the same spatial and temporal frames. The IDRISI Selva-based Markov Chain model was employed to model future wetland loss to DPs. The Total Economic Valuation Approach (TEV) was employed to quantify selected use values of wetland economic benefits using the market price, replacement cost and contingent valuation techniques. The ecological implications of wetland loss focused on soil organic carbon (SOC) and hydrological impacts in the KMC wetlands. The estimated SOC was assessed with climatic data in order to infer the implication of SOC loss for local climate variability. The manual wet chemistry/oxidation method by Walkley-Black (1934) was adopted to estimate SOC in various wetland cover types. Hydrological impact assessments focused on water quality analysis in various wetland cover types, with major parameters being total nitrogen (TN), total phosphorous (TP) total dissolved solids – (TDS) and total suspended sediments (TSS). Hydrologic flow data parameters across the different wetland cover types in the KMC focused on water level, speed, stream width, and bed load. Results from analysis of the spatial-temporal wetland change revealed that by 2013 the KMC wetlands had lost almost half (47%) of their 1974 areal coverage, with 56% of this loss resulting from conversion to DPs. It is projected that 26% of the KMC wetlands will be lost to more DPs by 2040. Wetland loss is attributed to intensified economic activity and preference of Kampala as an industrial zone, weakness in the previous spatial planning of Kampala, and the general lack of information flow to various institutions involved in the establishment of DPs. The KMC wetlands provide a flow of economic benefits at a minimum approximated value of US$ 3,418 / ha / per year. It is revealed that a great deal of these economic benefits (88%) accrues to the local subsistence level in the form of livelihood products, incomes, and employment benefits. The 56% wetlands loss to DPs in the KMC by 2013 brings the minimum economic value lost to US$ 19,311,700 in the sampled wetlands, and projections of future wetland loss put the minimum economic loss at US$ 48,368,118 by 2040. Continuous degradation of these wetlands means serious economic costs to the government and local communities, as reflected in high replacement expenditures for wetland services, foregone incomes, subsistence livelihood support and alternative employment. The highest carbon (C) sinks were identified in forest swamps, palms, thickets and wetlands converted to agriculture, which accounted for 25% of the KMC wetlands by 2013, while the lowest total soil organic carbon (TSOC) range occurred in converted wetland cover types (converted wetlands to industrial and settlements) that occupied 47% of the study area. A general decrease in SOC sequestration from 1974 to 2013 across the KMC wetlands is identified, with the lowest C pool registered in 2013. The dwindling SOC banks are considered to be partly responsible for varying climate and related feedbacks on wetland benefits in the KMC. The hydrologic impacts of wetland loss are felt mainly in converted wetland cover types, in the form of compromised water quality, with increased nutrient pollution and TSS. These all create negative impacts on wetland hydrological services, particularly filtration, flood attenuation, recharge and discharge benefits, all of which have profound effects on biodiversity. There is an urgent need to reduce the scale of wetland diminution in the KMC. This will be achieved if mitigation and conservation measures are undertaken. Mitigation measures should include a revision of development plans, user sensitization on wetland economic values and enforcement of regulatory mechanisms. Conservation strategies should involve the use of economic incentives and disincentives which include: a revision of historic property rights to regulate wetland use, performance bonds or subsidies for environmentally friendly activities and taxes, fees or fines for unacceptable levels of degradation and tradable permits that utilise the concept of ‘wetland banks’ to ensure no further loss of the KMC wetlands to DPs. Future research should focus on modelling the response of wetland ecosystems to multiple threats and management interventions, and on a feasibility study of wetland restoration options and the implications for local people’s livelihoods in the KMC.
- Full Text:
- Date Issued: 2018