Conflict management in Kenyan electoral conflict: 2002-2012
- Muhindi, Solomon Peter Kavai
- Authors: Muhindi, Solomon Peter Kavai
- Date: 2016
- Subjects: Conflict management -- Africa Elections -- Kenya Kenya -- Politics and government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/12286 , vital:27051
- Description: In the recent years, majority of African countries have been faced by conflicts during election periods. Some of the electoral related conflicts escalated into violence, and they have been transformed or managed. While other electoral related conflicts have just been prevented during the election periods but remain latent conflicts that would escalate triggered by future elections. This study focuses specifically on electoral conflicts in Kenya and its conflict management perspective from 2002-2013. To transform and manage the conflict, peacebuilding initiatives have been integrated in the study. The prime actors in Kenya electoral conflict includes the; the ruling party coalition, the leading opposition coalition and ethnic groupings affiliated to the ruling party and opposition. Other peripheral actors include: the Independent, Electoral and Boundary Commission (IEBC), the International Criminal Court (ICC) and the judiciary. Triangulation (the combination of two or more methods of collecting and analysing data) has been adopted both in data collection and analysis. Focus group interviews, selected individual interviews, and literature reviews were used to collect data, while research findings were analysed systematically using the constructivist grounded theory. Moreover, the liberal peace theory, Institutionalisation before Liberalisation (IBL) and findings from other researchers like (Elder, Stigant and Claes 2014:1-20), and the Afrobarometer research findings (Kivuva 2015) have been used to authenticate the research findings. Research findings indicates that claims of election rigging, numerous institutional failures, negative ethnicity and economic disparity, among other factors heighten the fear and anxiety that escalates during elections. Towards achieving peacebuilding and sustainable peace, the following reforms were undertaken: constitutional changes and reviews, electoral body reform, judicial reform, pursuit of transitional justice, extensive range of local initiatives reforms and police reforms. However, findings in the study also reveal that despite the latter reforms, peacebuilding measures have been short-term, temporal, and not fully successful, leaving behind a latent conflict that could be triggered again with future electoral conflicts. Besides that, negotiation, dialogue and mediation played a role in restoring trust and confidence in the democratic structures after escalated elections. We also recommend that multi-ethnic composition for electoral coalitions should also be adopted as a means to mitigate ethnic triggered conflicts.
- Full Text:
- Date Issued: 2016
- Authors: Muhindi, Solomon Peter Kavai
- Date: 2016
- Subjects: Conflict management -- Africa Elections -- Kenya Kenya -- Politics and government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/12286 , vital:27051
- Description: In the recent years, majority of African countries have been faced by conflicts during election periods. Some of the electoral related conflicts escalated into violence, and they have been transformed or managed. While other electoral related conflicts have just been prevented during the election periods but remain latent conflicts that would escalate triggered by future elections. This study focuses specifically on electoral conflicts in Kenya and its conflict management perspective from 2002-2013. To transform and manage the conflict, peacebuilding initiatives have been integrated in the study. The prime actors in Kenya electoral conflict includes the; the ruling party coalition, the leading opposition coalition and ethnic groupings affiliated to the ruling party and opposition. Other peripheral actors include: the Independent, Electoral and Boundary Commission (IEBC), the International Criminal Court (ICC) and the judiciary. Triangulation (the combination of two or more methods of collecting and analysing data) has been adopted both in data collection and analysis. Focus group interviews, selected individual interviews, and literature reviews were used to collect data, while research findings were analysed systematically using the constructivist grounded theory. Moreover, the liberal peace theory, Institutionalisation before Liberalisation (IBL) and findings from other researchers like (Elder, Stigant and Claes 2014:1-20), and the Afrobarometer research findings (Kivuva 2015) have been used to authenticate the research findings. Research findings indicates that claims of election rigging, numerous institutional failures, negative ethnicity and economic disparity, among other factors heighten the fear and anxiety that escalates during elections. Towards achieving peacebuilding and sustainable peace, the following reforms were undertaken: constitutional changes and reviews, electoral body reform, judicial reform, pursuit of transitional justice, extensive range of local initiatives reforms and police reforms. However, findings in the study also reveal that despite the latter reforms, peacebuilding measures have been short-term, temporal, and not fully successful, leaving behind a latent conflict that could be triggered again with future electoral conflicts. Besides that, negotiation, dialogue and mediation played a role in restoring trust and confidence in the democratic structures after escalated elections. We also recommend that multi-ethnic composition for electoral coalitions should also be adopted as a means to mitigate ethnic triggered conflicts.
- Full Text:
- Date Issued: 2016
Continuous flow synthesis of silicon compounds as feedstock for solar-grade silicon production
- Authors: Chigondo, Fidelis
- Date: 2016
- Subjects: Silicon -- Synthesis , Homogeneous catalysis
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: http://hdl.handle.net/10948/4529 , vital:20613
- Description: This thesis describes the key steps in the production of high purity (solar-grade) silicon from metallurgical-grade silicon for use in the production of photovoltaic cells as alternative renewable, environmentally benign and cheap energy source. The initial part of the project involves the development and optimization of a small chemical production platform system capable of producing alkoxysilanes from metallurgical-grade silicon as green precursors to solar-grade silicon production. Specifically, the main aim of the study was to synthesize trialkoxysilanes in continuous flow mode, although the synthesis on monosilane was also done in batch mode. The alkoxylation reaction was carried out in a traditional slurry phase batch reactor, packed bed flow tubular reactor and also attempted in a continuous flow falling film tubular reactor. The effect of key parameters which affect the silicon conversion and selectivity for the desired trialkoxysilane were investigated and optimized using ethanol as a reagent model. The synthesis was then extended to the other alcohols namely methanol, n-propanol and n-butanol. Copper catalysts which were tested in the alkoxylation reaction included: CuCl, Cu(OH)2, CuO and CuSO4. CuCl and Cu(OH)2 showed comparable activity in the batch mode but the former was more efficient in the packed bed flow tubular reactor. Cu(OH)2 could be used as a non-halide catalyst but its activity is limited to short reaction cycles (<10 h). The uncatalysed reaction resulted in negligible reaction rates in both types of reactors. High temperature catalyst pre-heating (>500 oC) resulted in a lower rate of reaction and selectivity than when slightly lower temperatures are used (<350 oC) in both reactors, although much difference was noticed in the packed bed flow tubular reactor. Synthesis in the batch reactor needed longer silicon-catalyst activation time, higher pre-heating temperature and higher catalyst amounts as compare to the packed bed flow tubular reactor. Reaction temperature and alcohol flow rate influenced the reaction in both methods. The optimum reaction temperature range and alcohol flow rate was comparable in both reactors (230 to 240 oC) and 0.1mL/min respectively. The effect of alcohol R-group (C1 to C4) on the reaction revealed that conversion and selectivity generally decrease with an increase in carbon chain length in both methods. Ethanol showed highest selectivity (>95% in batch and >97% in flow) and conversion (about 88% in batch and about 64% in flow) as compared to all other alcohols studied showing that it could be the most efficient alkoxylation alcohol for this reaction. Overally, the packed bed flow tubular reactor resulted in higher selectivity to trialkoxysilanes than the batch system. Performing the reaction under pressure resulted in increased conversion but selectivity to the desire trialkoxysilane diminished. Synthesis in a continuous flow falling film tubular reactor was not successful as it resulted in very poor conversion and selectivity. Monosilane was successfully synthesized from the disproportionation of triethoxysilane using homogeneous and heterogeneous catalysts in batch mode. The results obtained from homogeneous catalysis showed that the reaction can be conducted at room temperature. The heterogeneous catalysis method resulted in slow conversion at room temperature but mild heating up to 55 oC greatly improved the reaction. Conducting the reaction under neat conditions produced comparable results to reactions which were carried out using solvents. The disproportionation reaction was best described by the first order kinetic model. The results obtained in this research indicate that the packed bed flow tubular reactor can be utilized with future modifications for continuous flow synthesis of alkoxysilanes as feedstock for the solar-grade silicon production.
- Full Text:
- Date Issued: 2016
- Authors: Chigondo, Fidelis
- Date: 2016
- Subjects: Silicon -- Synthesis , Homogeneous catalysis
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: http://hdl.handle.net/10948/4529 , vital:20613
- Description: This thesis describes the key steps in the production of high purity (solar-grade) silicon from metallurgical-grade silicon for use in the production of photovoltaic cells as alternative renewable, environmentally benign and cheap energy source. The initial part of the project involves the development and optimization of a small chemical production platform system capable of producing alkoxysilanes from metallurgical-grade silicon as green precursors to solar-grade silicon production. Specifically, the main aim of the study was to synthesize trialkoxysilanes in continuous flow mode, although the synthesis on monosilane was also done in batch mode. The alkoxylation reaction was carried out in a traditional slurry phase batch reactor, packed bed flow tubular reactor and also attempted in a continuous flow falling film tubular reactor. The effect of key parameters which affect the silicon conversion and selectivity for the desired trialkoxysilane were investigated and optimized using ethanol as a reagent model. The synthesis was then extended to the other alcohols namely methanol, n-propanol and n-butanol. Copper catalysts which were tested in the alkoxylation reaction included: CuCl, Cu(OH)2, CuO and CuSO4. CuCl and Cu(OH)2 showed comparable activity in the batch mode but the former was more efficient in the packed bed flow tubular reactor. Cu(OH)2 could be used as a non-halide catalyst but its activity is limited to short reaction cycles (<10 h). The uncatalysed reaction resulted in negligible reaction rates in both types of reactors. High temperature catalyst pre-heating (>500 oC) resulted in a lower rate of reaction and selectivity than when slightly lower temperatures are used (<350 oC) in both reactors, although much difference was noticed in the packed bed flow tubular reactor. Synthesis in the batch reactor needed longer silicon-catalyst activation time, higher pre-heating temperature and higher catalyst amounts as compare to the packed bed flow tubular reactor. Reaction temperature and alcohol flow rate influenced the reaction in both methods. The optimum reaction temperature range and alcohol flow rate was comparable in both reactors (230 to 240 oC) and 0.1mL/min respectively. The effect of alcohol R-group (C1 to C4) on the reaction revealed that conversion and selectivity generally decrease with an increase in carbon chain length in both methods. Ethanol showed highest selectivity (>95% in batch and >97% in flow) and conversion (about 88% in batch and about 64% in flow) as compared to all other alcohols studied showing that it could be the most efficient alkoxylation alcohol for this reaction. Overally, the packed bed flow tubular reactor resulted in higher selectivity to trialkoxysilanes than the batch system. Performing the reaction under pressure resulted in increased conversion but selectivity to the desire trialkoxysilane diminished. Synthesis in a continuous flow falling film tubular reactor was not successful as it resulted in very poor conversion and selectivity. Monosilane was successfully synthesized from the disproportionation of triethoxysilane using homogeneous and heterogeneous catalysts in batch mode. The results obtained from homogeneous catalysis showed that the reaction can be conducted at room temperature. The heterogeneous catalysis method resulted in slow conversion at room temperature but mild heating up to 55 oC greatly improved the reaction. Conducting the reaction under neat conditions produced comparable results to reactions which were carried out using solvents. The disproportionation reaction was best described by the first order kinetic model. The results obtained in this research indicate that the packed bed flow tubular reactor can be utilized with future modifications for continuous flow synthesis of alkoxysilanes as feedstock for the solar-grade silicon production.
- Full Text:
- Date Issued: 2016
Customer satisfaction with the guesthouse experience in Ghana
- Authors: Amoah, Felix
- Date: 2016
- Subjects: Consumer satisfaction -- Ghana , Hospitality industry -- Ghana -- Management , Tourism -- Ghana -- Marketing
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: http://hdl.handle.net/10948/6073 , vital:21036
- Description: Guesthouse accommodation plays an important role in Ghana’s hospitality industry and was therefore the focus of this study as little research dealing with guesthouses in Ghana could be found. The number of guesthouses in Ghana continues to grow and they thus represent an important alternative to hotels. However, these establishments seem to perform poorly and face several challenges such as lack of managerial knowledge, insufficiently skilled employees, poor interaction with customers, and criticisms of the provision of low quality service. The main reason for undertaking this research was to provide guesthouse managers in Ghana with information that might assist them in making decisions about the experience they offer. Such knowledge could make this type of accommodation more competitive and eventually help the hospitality sector in Ghana attract tourists and grow. It is imperative that guesthouses focus on the experience they offer, because contemporary tourism and hospitality literature suggest that successful businesses require a shift from functional and financial interests to a more profound focus on total experiences which embody emotional aspects. It is thus argued that, if guesthouse managers in Ghana do not know how their guests perceive their guesthouse experience, they might make costly mistakes and allocate resources to aspects that already provide quality and value in a functional sense, instead of those elements perceived as providing quality and value in the total experience. Two dominating concepts, namely experience quality and experience value, formed the basis of the examination of guests’ experience with the guesthouses in Ghana. In addition, the relationships between the experience and satisfaction were also investigated. Four experience quality dimensions, namely hedonics, peace of mind, involvement, and recognition, and seven value dimensions were examined. The experience value dimensions included atmospherics, enjoyment, entertainment, efficiency, excellence, escape, and economic value. A proportional stratified random sampling procedure was followed to select the guesthouses for the study. Thereafter, a structured questionnaire was distributed to the guesthouse guests selected by means of convenience sampling. Five hundred and forty one useable questionnaires were received. The guesthouse guests formed the primary sampling unit for this study. The results of the empirical study showed a strong positive correlation between all the dimensions of experience quality and experience value, while the factor analysis confirmed that all these dimensions loaded on a single factor. Therefore, experience quality and experience value cannot be separated, and the resulting single multi-dimensional factor was subsequently renamed, overall experience. The results also indicated a positive relationship between hedonics, peace of mind, involvement, recognition, atmospherics, enjoyment, entertainment, efficiency, excellence, escape, economic value, and overall satisfaction. The inferentially established rank-order of the dimensions contributing to satisfaction can guide managers when allocating resources. Overall, atmospherics was ranked first, followed by economic value. Escape was the lowest ranked dimension. In addition, it was found that, except for escape, all the experience dimensions were perceived as basic satisfiers. This implies that guests will be dissatisfied when provision of these dimensions is inadequate. With regard to escape, listed as a performance factor, guests will be satisfied when performance is improved and dissatisfied when performance is low. A positive relationship was also found between overall experience and overall satisfaction. The latter include the likelihood of return and recommending the guesthouse to others. Finally, structural equation modelling confirmed a model representing the 11 experience dimensions (hedonics, peace of mind, involvement, recognition, atmospherics, enjoyment, entertainment, escape, efficiency, excellence, and economic value) and the relationships between overall experience and overall satisfaction pertaining to guesthouses in Ghana.
- Full Text:
- Date Issued: 2016
- Authors: Amoah, Felix
- Date: 2016
- Subjects: Consumer satisfaction -- Ghana , Hospitality industry -- Ghana -- Management , Tourism -- Ghana -- Marketing
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: http://hdl.handle.net/10948/6073 , vital:21036
- Description: Guesthouse accommodation plays an important role in Ghana’s hospitality industry and was therefore the focus of this study as little research dealing with guesthouses in Ghana could be found. The number of guesthouses in Ghana continues to grow and they thus represent an important alternative to hotels. However, these establishments seem to perform poorly and face several challenges such as lack of managerial knowledge, insufficiently skilled employees, poor interaction with customers, and criticisms of the provision of low quality service. The main reason for undertaking this research was to provide guesthouse managers in Ghana with information that might assist them in making decisions about the experience they offer. Such knowledge could make this type of accommodation more competitive and eventually help the hospitality sector in Ghana attract tourists and grow. It is imperative that guesthouses focus on the experience they offer, because contemporary tourism and hospitality literature suggest that successful businesses require a shift from functional and financial interests to a more profound focus on total experiences which embody emotional aspects. It is thus argued that, if guesthouse managers in Ghana do not know how their guests perceive their guesthouse experience, they might make costly mistakes and allocate resources to aspects that already provide quality and value in a functional sense, instead of those elements perceived as providing quality and value in the total experience. Two dominating concepts, namely experience quality and experience value, formed the basis of the examination of guests’ experience with the guesthouses in Ghana. In addition, the relationships between the experience and satisfaction were also investigated. Four experience quality dimensions, namely hedonics, peace of mind, involvement, and recognition, and seven value dimensions were examined. The experience value dimensions included atmospherics, enjoyment, entertainment, efficiency, excellence, escape, and economic value. A proportional stratified random sampling procedure was followed to select the guesthouses for the study. Thereafter, a structured questionnaire was distributed to the guesthouse guests selected by means of convenience sampling. Five hundred and forty one useable questionnaires were received. The guesthouse guests formed the primary sampling unit for this study. The results of the empirical study showed a strong positive correlation between all the dimensions of experience quality and experience value, while the factor analysis confirmed that all these dimensions loaded on a single factor. Therefore, experience quality and experience value cannot be separated, and the resulting single multi-dimensional factor was subsequently renamed, overall experience. The results also indicated a positive relationship between hedonics, peace of mind, involvement, recognition, atmospherics, enjoyment, entertainment, efficiency, excellence, escape, economic value, and overall satisfaction. The inferentially established rank-order of the dimensions contributing to satisfaction can guide managers when allocating resources. Overall, atmospherics was ranked first, followed by economic value. Escape was the lowest ranked dimension. In addition, it was found that, except for escape, all the experience dimensions were perceived as basic satisfiers. This implies that guests will be dissatisfied when provision of these dimensions is inadequate. With regard to escape, listed as a performance factor, guests will be satisfied when performance is improved and dissatisfied when performance is low. A positive relationship was also found between overall experience and overall satisfaction. The latter include the likelihood of return and recommending the guesthouse to others. Finally, structural equation modelling confirmed a model representing the 11 experience dimensions (hedonics, peace of mind, involvement, recognition, atmospherics, enjoyment, entertainment, escape, efficiency, excellence, and economic value) and the relationships between overall experience and overall satisfaction pertaining to guesthouses in Ghana.
- Full Text:
- Date Issued: 2016
Development of a small production platform for citronellal processing
- Mafu, Lubabalo Rowan, Zeelie, Ben
- Authors: Mafu, Lubabalo Rowan , Zeelie, Ben
- Date: 2016
- Subjects: Organic compounds -- Synthesis , Plasticizers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/8488 , vital:26370
- Description: The aim of the project was to develop a small production platform for citronellal processing. The objective of the study was to develop a single continuous flow reactor system for the synthesis of novel derivatives of citronellal and isopulegol. The first step was to develop a continuous flow reactor system for the isopulegol synthesis. The stainless steel tubular fixed-bed reactor equipped with a reaction column (I.D: 9.53 mm and length: 120 mm) was used for the study. The reactor column was packed with H-ZMS-5 zeolite extrusion catalyst. The solvent-free cyclisation reaction of citronellal was investigated and at optimum conditions, 100% of citronellal conversion and almost 100% selectivity towards isopulegol was achieved. A good catalytic performance was observed from the H-ZSM-5 catalyst and proved to be stable for a prolonged reaction time. The second reaction step was to develop a continuous flow reactor system for the synthesis of isopulegyl-ether derivatives. A UniQsis FlowSyn reactor system equipped with a stainless steel reactor column was used for the study. The reactor column was packed with amberlyst-15 dry catalyst. Wherein, n-propanol was employed as a model etherifying agent and as a reaction solvent. At optimum reaction condition, only 30% selectivity of isopulegyl propoxy-ether was achieved. The reaction was found to depend highly on temperature and residence time. The increase of these parameters was found to increase the side reactions and reduced the selectivity of the desired product. Other heterogeneous catalysts such as H-beta zeolite, aluminium pillared clay, Aluminium oxide and H-ZSM-5 were also evaluated in the reaction. Among these catalysts, a catalytic activity was observed with H-beta zeolite (19%) and aluminium pillared clay (5%). Based on these results, none of the evaluated catalysts provided the desired selectivity (greater than 70%) towards the isopulegyl propoxy-ether, therefore the process was not investigated further. In light of this, the isopulegol etherification synthetic route was terminated. Consequently, another analogue of citronellal was used as an alternative intermediate in place of isopulegol, namely para-menthane-3,8-diol (PMD). The initial studies for the synthesis of the novel PMD di-esters from isopulegol were performed in the batch-scale reactor. In a solvent-free reaction, acetic anhydride was initially used as a model acetylating agent. The reaction was performed using polymer-bound scandium triflate (PS-Sc(OTf)3) catalyst. The effect of reaction parameters such as temperature, molar ratio, and reaction time were studied towards the PMD conversion and di-esters selectivity. At optimum reaction conditions, PMD conversion of 70% and di-acetate selectivity of 67% were observed. The reaction was found to follow the zeroth-order kinetics with respect to PMD conversion and obeyed the Arrhenius equation. Other types of di-ester derivatives were synthesized from PMD by varying the carbon chain length of the acetylating agent. The prepared compounds were separated from the product mixtures by vacuum distillation, purified on a column chromatography and characterised by FT-IR, GC-MS, and 1H-NMR, 13C-NMR. The developed methodology was optimised in flow by using an ArrheniumOne microwave-assisted continuous-flow fixed-bed reactor system. A detailed experimental design was used to carry-out the reactions. The reaction parameters such as temperature and flow-rate were studied towards the PMD conversion and di-ester selectivity. From the experimental design analysis, the di-ester selectivity was found to depend highly on the residence time (flow-rate) and significantly on temperature. The PMD conversion and di-ester selectivity were found to increase with decrease in the flow-rate. The conversion and selectivity achieved in the continuous flow process were significantly higher than the achieved in the batch-scale process with respect to the residence time.
- Full Text:
- Date Issued: 2016
- Authors: Mafu, Lubabalo Rowan , Zeelie, Ben
- Date: 2016
- Subjects: Organic compounds -- Synthesis , Plasticizers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/8488 , vital:26370
- Description: The aim of the project was to develop a small production platform for citronellal processing. The objective of the study was to develop a single continuous flow reactor system for the synthesis of novel derivatives of citronellal and isopulegol. The first step was to develop a continuous flow reactor system for the isopulegol synthesis. The stainless steel tubular fixed-bed reactor equipped with a reaction column (I.D: 9.53 mm and length: 120 mm) was used for the study. The reactor column was packed with H-ZMS-5 zeolite extrusion catalyst. The solvent-free cyclisation reaction of citronellal was investigated and at optimum conditions, 100% of citronellal conversion and almost 100% selectivity towards isopulegol was achieved. A good catalytic performance was observed from the H-ZSM-5 catalyst and proved to be stable for a prolonged reaction time. The second reaction step was to develop a continuous flow reactor system for the synthesis of isopulegyl-ether derivatives. A UniQsis FlowSyn reactor system equipped with a stainless steel reactor column was used for the study. The reactor column was packed with amberlyst-15 dry catalyst. Wherein, n-propanol was employed as a model etherifying agent and as a reaction solvent. At optimum reaction condition, only 30% selectivity of isopulegyl propoxy-ether was achieved. The reaction was found to depend highly on temperature and residence time. The increase of these parameters was found to increase the side reactions and reduced the selectivity of the desired product. Other heterogeneous catalysts such as H-beta zeolite, aluminium pillared clay, Aluminium oxide and H-ZSM-5 were also evaluated in the reaction. Among these catalysts, a catalytic activity was observed with H-beta zeolite (19%) and aluminium pillared clay (5%). Based on these results, none of the evaluated catalysts provided the desired selectivity (greater than 70%) towards the isopulegyl propoxy-ether, therefore the process was not investigated further. In light of this, the isopulegol etherification synthetic route was terminated. Consequently, another analogue of citronellal was used as an alternative intermediate in place of isopulegol, namely para-menthane-3,8-diol (PMD). The initial studies for the synthesis of the novel PMD di-esters from isopulegol were performed in the batch-scale reactor. In a solvent-free reaction, acetic anhydride was initially used as a model acetylating agent. The reaction was performed using polymer-bound scandium triflate (PS-Sc(OTf)3) catalyst. The effect of reaction parameters such as temperature, molar ratio, and reaction time were studied towards the PMD conversion and di-esters selectivity. At optimum reaction conditions, PMD conversion of 70% and di-acetate selectivity of 67% were observed. The reaction was found to follow the zeroth-order kinetics with respect to PMD conversion and obeyed the Arrhenius equation. Other types of di-ester derivatives were synthesized from PMD by varying the carbon chain length of the acetylating agent. The prepared compounds were separated from the product mixtures by vacuum distillation, purified on a column chromatography and characterised by FT-IR, GC-MS, and 1H-NMR, 13C-NMR. The developed methodology was optimised in flow by using an ArrheniumOne microwave-assisted continuous-flow fixed-bed reactor system. A detailed experimental design was used to carry-out the reactions. The reaction parameters such as temperature and flow-rate were studied towards the PMD conversion and di-ester selectivity. From the experimental design analysis, the di-ester selectivity was found to depend highly on the residence time (flow-rate) and significantly on temperature. The PMD conversion and di-ester selectivity were found to increase with decrease in the flow-rate. The conversion and selectivity achieved in the continuous flow process were significantly higher than the achieved in the batch-scale process with respect to the residence time.
- Full Text:
- Date Issued: 2016
Digital capital: a mode of bridging capital for immigrant and refugee population
- Authors: Rosendahl, Patricia
- Date: 2016
- Subjects: Social capital (Sociology) -- United States , Immigrants -- United States
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3645 , vital:20449
- Description: The resettlement of immigrant and refugee populations poses specific challenges to new host communities. Municipalities must find resources to assist these populations in transitioning into a new culture. Immediate needs are often adequate housing, health care, and primary schooling. While this transitioning process is still in play, the search for employment begins; often at the cost of consideration of longer-term needs, such as English or other host country language acquisition and planning for long-term career goals. Theorists in the field of social capital postulate that bonding and bridging social capital offers benefits for populations adjusting to new communities. Connections to like-minded individuals or pre-existing ethnic ties (bonding social capital) can provide support important to the well-being of individuals going through difficult social adjustments while connecting with new social groups (bridging social capital) can provide new information leading to expanding opportunities. The concept of bridging social capital for immigrant and refugee populations is the subject of this research study. It is situated within the context of our digital age in which information communication technology (ICT) is the primary mode of access to information and services. For the purpose of this thesis, the capability to exploit this mode of communication is thus identified as “digital capital.” As more and more governmental, educational, and social services are distributed within a technological environment, it is necessary to examine this mode of connection to information as a form of capital which can be viewed in a similar framework to other types of social capital. Access to technology and ICTs has been considered an integral element of the Development Goals as adopted by the United Nations for the Year 2000 Millennium Goals. Though later debates have questioned how ICTs may have benefited development goals, the pervasiveness of this form of information flow continues. Within Development Studies, Sen’s theory on the Capability Approach offers a valuable opportunity of connecting digital capital to development. Just as the Capabilities Approach accommodates the diversity of human values, characteristics, and functionings, so can digital capital provide flexibility through adaptation by the users to tailor the medium to meet specific needs. It is this freedom to adjust to individual needs and goals that allows this mode of bridging capital to hold a distinct advantage for immigrants and refugees who are searching for effective links into new social networks in the job search process. The role of the community college system has been at the forefront of providing educational training and social acclimation for this population in their quest for economic self-sufficiency in the resettlement process. A greater understanding of the role that technology plays in the success of immigrant and refugee resettlement is vitally important for the well-being of communities undergoing dynamic demographic change.
- Full Text:
- Date Issued: 2016
- Authors: Rosendahl, Patricia
- Date: 2016
- Subjects: Social capital (Sociology) -- United States , Immigrants -- United States
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3645 , vital:20449
- Description: The resettlement of immigrant and refugee populations poses specific challenges to new host communities. Municipalities must find resources to assist these populations in transitioning into a new culture. Immediate needs are often adequate housing, health care, and primary schooling. While this transitioning process is still in play, the search for employment begins; often at the cost of consideration of longer-term needs, such as English or other host country language acquisition and planning for long-term career goals. Theorists in the field of social capital postulate that bonding and bridging social capital offers benefits for populations adjusting to new communities. Connections to like-minded individuals or pre-existing ethnic ties (bonding social capital) can provide support important to the well-being of individuals going through difficult social adjustments while connecting with new social groups (bridging social capital) can provide new information leading to expanding opportunities. The concept of bridging social capital for immigrant and refugee populations is the subject of this research study. It is situated within the context of our digital age in which information communication technology (ICT) is the primary mode of access to information and services. For the purpose of this thesis, the capability to exploit this mode of communication is thus identified as “digital capital.” As more and more governmental, educational, and social services are distributed within a technological environment, it is necessary to examine this mode of connection to information as a form of capital which can be viewed in a similar framework to other types of social capital. Access to technology and ICTs has been considered an integral element of the Development Goals as adopted by the United Nations for the Year 2000 Millennium Goals. Though later debates have questioned how ICTs may have benefited development goals, the pervasiveness of this form of information flow continues. Within Development Studies, Sen’s theory on the Capability Approach offers a valuable opportunity of connecting digital capital to development. Just as the Capabilities Approach accommodates the diversity of human values, characteristics, and functionings, so can digital capital provide flexibility through adaptation by the users to tailor the medium to meet specific needs. It is this freedom to adjust to individual needs and goals that allows this mode of bridging capital to hold a distinct advantage for immigrants and refugees who are searching for effective links into new social networks in the job search process. The role of the community college system has been at the forefront of providing educational training and social acclimation for this population in their quest for economic self-sufficiency in the resettlement process. A greater understanding of the role that technology plays in the success of immigrant and refugee resettlement is vitally important for the well-being of communities undergoing dynamic demographic change.
- Full Text:
- Date Issued: 2016
Diversity and ecological role of true crabs (crustacea, brachyura) in the St Lucia Estuary, iSimangaliso Wetland Park, in response to global change
- Authors: Peer, Nasreen
- Date: 2016
- Subjects: Crustacea -- South Africa -- KwaZulu-Natal Crustacea -- South Africa -- Saint Lucia, Lake , Global environmental change
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/45558 , vital:38669
- Description: This work has explored novel concepts of crab vulnerability, recovery and resilience under unprecedented climatic changes in South Africa’s first UNESCO World Heritage Site. By showing how large salinity shifts and prolonged interruption of the marine connection can drastically affect brachyuran diversity and community structure in St. Lucia Lake, the potential cascading effects on ecosystem functioning were estimated. Only 15 crab species were recorded within the system during this study, compared to the 26 species that were known to occur prior to the recent environmental shift (i.e. 58% decline). The impact of this biodiversity collapse has negatively affected the associated mangrove ecosystem in particular, with the entire community of fiddler crabs persisting only in a small area near the estuary mouth. Gut fluorescence measurements have shown that, due to a lack of tidal Influence, their grazing impact on microphytobenthic biomass may become unsustainable. However, although adults are able to survive in this environment, the larvae require a marine connection; and they are thus unable to tolerate the wide fluctuations in salinity currently prevailing in the system. The study concludes that brachyurans are key factors to consider during conservation planning, as they are crucial to maintaining ecosystem function in the face of environmental change. This research is of global relevance, as many similar estuarine and coastal lakes around the world are currently experiencing similar state shifts. All six chapters included in the thesis have already been published in the peer-reviewed literature; and the project results have also earned Nasreen the NRF award of Next-Generation Researcher of the Year for 2015.
- Full Text:
- Date Issued: 2016
- Authors: Peer, Nasreen
- Date: 2016
- Subjects: Crustacea -- South Africa -- KwaZulu-Natal Crustacea -- South Africa -- Saint Lucia, Lake , Global environmental change
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/45558 , vital:38669
- Description: This work has explored novel concepts of crab vulnerability, recovery and resilience under unprecedented climatic changes in South Africa’s first UNESCO World Heritage Site. By showing how large salinity shifts and prolonged interruption of the marine connection can drastically affect brachyuran diversity and community structure in St. Lucia Lake, the potential cascading effects on ecosystem functioning were estimated. Only 15 crab species were recorded within the system during this study, compared to the 26 species that were known to occur prior to the recent environmental shift (i.e. 58% decline). The impact of this biodiversity collapse has negatively affected the associated mangrove ecosystem in particular, with the entire community of fiddler crabs persisting only in a small area near the estuary mouth. Gut fluorescence measurements have shown that, due to a lack of tidal Influence, their grazing impact on microphytobenthic biomass may become unsustainable. However, although adults are able to survive in this environment, the larvae require a marine connection; and they are thus unable to tolerate the wide fluctuations in salinity currently prevailing in the system. The study concludes that brachyurans are key factors to consider during conservation planning, as they are crucial to maintaining ecosystem function in the face of environmental change. This research is of global relevance, as many similar estuarine and coastal lakes around the world are currently experiencing similar state shifts. All six chapters included in the thesis have already been published in the peer-reviewed literature; and the project results have also earned Nasreen the NRF award of Next-Generation Researcher of the Year for 2015.
- Full Text:
- Date Issued: 2016
Effects of lethal management on black-backed jackal population structure and source-sink dynamics
- Authors: Minnie, Liaan
- Date: 2016
- Subjects: Black-backed jackal Carnivorous animals
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/12658 , vital:27104
- Description: Lethal carnivore management, aimed at reducing carnivore impacts, threatens the persistence of carnivores globally. The effects of killing carnivores will depend on their life histories and social structures. Smaller canids, like black-backed jackals (Canis mesomelas), are highly adaptable and display variable population-level responses to mortality sources, which may contribute to their success in fragmented landscapes. Jackals, the dominant predator of livestock in South Africa, are widely hunted to reduce this predation. This hunting is heterogeneous across the landscape, focussed on livestock and game farms, with nature reserves acting as refuges. The aim of this research was to investigate the ecology and population dynamics of jackals in response to heterogeneous anthropogenic mortality. I hypothesized that the spatial variation in hunting results in the formation of a source-sink population structure, which contributes to the persistence of jackals. I addressed this hypothesis by evaluating two criteria, essential for the formation of a source-sink system in larger mammals. Firstly, I confirm that hunting pressures result in the formation of distinct subpopulations with asymmetrical dispersal (i.e. compensatory immigration) from unhunted reserves to neighbouring hunted farms. Secondly, I show that jackal subpopulation display asynchronous demographics, with farm populations displaying a relatively younger age structure and an associated increase in reproductive output (i.e. compensatory reproduction). This confirms the formation of a hunting-induced source-sink system. additionally, I show that jackals have a catholic diet, which confers a level of adaptability to direct (anthropogenic mortality, prey provisioning) and indirect (alteration in prey base) habitat modifications. This dietary flexibility allows jackals to obtain the appropriate resources to achieve reproductive condition. The relatively better body condition of younger jackals in sink habitats allows for compensatory reproduction which contributes to the success of jackals on hunted farms. Based on my findings, I hypothesize that the compensatory life history responses of jackals to anthropogenic mortality may be ascribed to two interconnected mechanism. Dispersal is presumably driven by density-dependent interference competition, as dominant territorial pairs outcompete subordinates in high-density reserve areas, forcing them to disperse onto low-density farms (i.e. ideal despotic model). Additionally, farms likely represent attractive habitats, owing to a reduction in conspecifics and a concomitant increase in resource availability (including anthropogenic resource provisioning). Therefore, dispersing subordinates presumably select for farms which are perceived as good quality habitats, as the high risks of anthropogenic mortality cannot be perceived by dispersing individuals. This results in the formation of an attractive sink or ecological trap. These compensatory processes will continue to counter population management actions as long as recruitment from unmanaged areas persists. This hypothesis provides a conceptual framework for future research directions in understanding jackal persistence and management (i.e. specifically focussing on controlling dispersal) of jackal populations.
- Full Text:
- Date Issued: 2016
- Authors: Minnie, Liaan
- Date: 2016
- Subjects: Black-backed jackal Carnivorous animals
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/12658 , vital:27104
- Description: Lethal carnivore management, aimed at reducing carnivore impacts, threatens the persistence of carnivores globally. The effects of killing carnivores will depend on their life histories and social structures. Smaller canids, like black-backed jackals (Canis mesomelas), are highly adaptable and display variable population-level responses to mortality sources, which may contribute to their success in fragmented landscapes. Jackals, the dominant predator of livestock in South Africa, are widely hunted to reduce this predation. This hunting is heterogeneous across the landscape, focussed on livestock and game farms, with nature reserves acting as refuges. The aim of this research was to investigate the ecology and population dynamics of jackals in response to heterogeneous anthropogenic mortality. I hypothesized that the spatial variation in hunting results in the formation of a source-sink population structure, which contributes to the persistence of jackals. I addressed this hypothesis by evaluating two criteria, essential for the formation of a source-sink system in larger mammals. Firstly, I confirm that hunting pressures result in the formation of distinct subpopulations with asymmetrical dispersal (i.e. compensatory immigration) from unhunted reserves to neighbouring hunted farms. Secondly, I show that jackal subpopulation display asynchronous demographics, with farm populations displaying a relatively younger age structure and an associated increase in reproductive output (i.e. compensatory reproduction). This confirms the formation of a hunting-induced source-sink system. additionally, I show that jackals have a catholic diet, which confers a level of adaptability to direct (anthropogenic mortality, prey provisioning) and indirect (alteration in prey base) habitat modifications. This dietary flexibility allows jackals to obtain the appropriate resources to achieve reproductive condition. The relatively better body condition of younger jackals in sink habitats allows for compensatory reproduction which contributes to the success of jackals on hunted farms. Based on my findings, I hypothesize that the compensatory life history responses of jackals to anthropogenic mortality may be ascribed to two interconnected mechanism. Dispersal is presumably driven by density-dependent interference competition, as dominant territorial pairs outcompete subordinates in high-density reserve areas, forcing them to disperse onto low-density farms (i.e. ideal despotic model). Additionally, farms likely represent attractive habitats, owing to a reduction in conspecifics and a concomitant increase in resource availability (including anthropogenic resource provisioning). Therefore, dispersing subordinates presumably select for farms which are perceived as good quality habitats, as the high risks of anthropogenic mortality cannot be perceived by dispersing individuals. This results in the formation of an attractive sink or ecological trap. These compensatory processes will continue to counter population management actions as long as recruitment from unmanaged areas persists. This hypothesis provides a conceptual framework for future research directions in understanding jackal persistence and management (i.e. specifically focussing on controlling dispersal) of jackal populations.
- Full Text:
- Date Issued: 2016
Emotional intelligence training model for executive leadership in South Africa
- Authors: Els, Deon André
- Date: 2016
- Subjects: Development leadership -- South Africa , Executives -- Training of -- South Africa , Emotional intelligence -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/7398 , vital:21350
- Description: Global leadership crises and increasing executive leadership failures necessitate a new approach to executive leadership development. Globalisation results in new leadership challenges that affect people, the planet and peace across the world. Critical issues include increasing extremism and terrorism, displaced migrants fleeing to stable countries, earth warming and economic decline. The role of the individual executive leader cannot be isolated from human development challenges. Various executive leadership failures and examples of unethical leadership practises, both internationally and in South Africa, place the focus on ethical governance and emotionally matured leadership development. This study follows a nexus, based on a three-stranded cordial link between human development, emotional intelligence and executive leadership. The central themes of the United Nations Human Development’s (UNDP) reports of 1990 to 2009 as well as the Post-United Nations Human Development Report of 2015 form a framework for evaluating the relationship between human development and executive leadership. Although economic growth is central to human development, the development of people through building human capabilities and active participation to improve their lives, are the main goals of the UNDP-2015. The role of executive leadership, leadership derailment and required executive proficiencies and attributes are investigated by evaluating traditional leadership theories and approaches as a lens for investigating leadership development. The positive effect of globalisation is that it affords new approaches and opportunities for executive leadership development. Emotional intelligence-based leadership, including the role of neuro-leadership, is evaluated and an integrative approach that involves the new paradigm of leadership as a response to human development challenges and globalisation is presented. The new paradigm of integrative leadership approaches includes empirical-based authentic leadership, shared leadership and gender-based leadership. The integrative leadership models of Hatala and Passmore are selected as a framework to propose a theoretical emotional intelligence leadership model for this study. New opportunities to develop emotionally intelligent executive leaders include technology-based training, iLeadership and eLeadership in an environment without boundaries. Time constraints are identified as a key obstacle for leadership development. Various training and executive coaching strategies are evaluated and proposed to accelerate leadership development. The link between human development and executive leadership development is proposed by collective leadership approaches towards Corporate Social Responsibilities (CSR) above entrepreneurial acumen and stakeholder involvement. A positivist approach based on quantitative research using Structural Equation Modelling (SEM) is used. The primary research problem is formulated to investigate the multidimensional and complex nature of factors that influence the success of developing emotionally intelligent executive leaders in South Africa. A conceptual theoretical model comprising of factors that influence Human Development and the perceived success of Emotional Intelligence Training is developed. A total of ten independent variables that influence the two mentioned dependent variables are identified. The proposed model and envisaged hypotheses are empirically tested. The study consists of a 73-itemed questionnaire with 360 participants. The sourced data are statically analysed by means of the exploratory factor analysis (EFA) to assess the discriminate validity of the research instrument and to confirm underlying dimensions of the constructs. Cronbach-alpha coefficients are calculated for each of the identified factors by using SEM. The significance of the hypothesised relationships in the revised model is tested. The value of this study’s contribution to the body of knowledge lies within the findings, the proposed Integrative Emotional Intelligence Leadership Model and recommendations for future research. The proposed model identifies practical training approaches to accelerate executive leadership against a background of serious leadership failures in South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Els, Deon André
- Date: 2016
- Subjects: Development leadership -- South Africa , Executives -- Training of -- South Africa , Emotional intelligence -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/7398 , vital:21350
- Description: Global leadership crises and increasing executive leadership failures necessitate a new approach to executive leadership development. Globalisation results in new leadership challenges that affect people, the planet and peace across the world. Critical issues include increasing extremism and terrorism, displaced migrants fleeing to stable countries, earth warming and economic decline. The role of the individual executive leader cannot be isolated from human development challenges. Various executive leadership failures and examples of unethical leadership practises, both internationally and in South Africa, place the focus on ethical governance and emotionally matured leadership development. This study follows a nexus, based on a three-stranded cordial link between human development, emotional intelligence and executive leadership. The central themes of the United Nations Human Development’s (UNDP) reports of 1990 to 2009 as well as the Post-United Nations Human Development Report of 2015 form a framework for evaluating the relationship between human development and executive leadership. Although economic growth is central to human development, the development of people through building human capabilities and active participation to improve their lives, are the main goals of the UNDP-2015. The role of executive leadership, leadership derailment and required executive proficiencies and attributes are investigated by evaluating traditional leadership theories and approaches as a lens for investigating leadership development. The positive effect of globalisation is that it affords new approaches and opportunities for executive leadership development. Emotional intelligence-based leadership, including the role of neuro-leadership, is evaluated and an integrative approach that involves the new paradigm of leadership as a response to human development challenges and globalisation is presented. The new paradigm of integrative leadership approaches includes empirical-based authentic leadership, shared leadership and gender-based leadership. The integrative leadership models of Hatala and Passmore are selected as a framework to propose a theoretical emotional intelligence leadership model for this study. New opportunities to develop emotionally intelligent executive leaders include technology-based training, iLeadership and eLeadership in an environment without boundaries. Time constraints are identified as a key obstacle for leadership development. Various training and executive coaching strategies are evaluated and proposed to accelerate leadership development. The link between human development and executive leadership development is proposed by collective leadership approaches towards Corporate Social Responsibilities (CSR) above entrepreneurial acumen and stakeholder involvement. A positivist approach based on quantitative research using Structural Equation Modelling (SEM) is used. The primary research problem is formulated to investigate the multidimensional and complex nature of factors that influence the success of developing emotionally intelligent executive leaders in South Africa. A conceptual theoretical model comprising of factors that influence Human Development and the perceived success of Emotional Intelligence Training is developed. A total of ten independent variables that influence the two mentioned dependent variables are identified. The proposed model and envisaged hypotheses are empirically tested. The study consists of a 73-itemed questionnaire with 360 participants. The sourced data are statically analysed by means of the exploratory factor analysis (EFA) to assess the discriminate validity of the research instrument and to confirm underlying dimensions of the constructs. Cronbach-alpha coefficients are calculated for each of the identified factors by using SEM. The significance of the hypothesised relationships in the revised model is tested. The value of this study’s contribution to the body of knowledge lies within the findings, the proposed Integrative Emotional Intelligence Leadership Model and recommendations for future research. The proposed model identifies practical training approaches to accelerate executive leadership against a background of serious leadership failures in South Africa.
- Full Text:
- Date Issued: 2016
Establishing the links between performance improvement programmes, maturity and performance to facilitate improvement strategy formulation
- Authors: Ebrahim, Zahier
- Date: 2016
- Subjects: Automobile industry and trade , Lean manufacturing , Organizational effectiveness
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/6865 , vital:21155
- Description: The automotive components manufacturing sector is facing tremendous pressure to remain competitive in a global economy. The application of performance improvement techniques to optimise factor production inputs remains a key strategic mechanism to effect the necessary change towards competitiveness. The high failure rate of these programmes, however, is a risk factor that should be considered by manufacturing firms. The investment into the implementation of these programmes will yield no return if the organisational maturity profile is not considered. The expected gains may not materialise and the execution of critical projects may take much longer than required. It is for this reason that an approach towards selecting the correct Performance Improvement Programme to optimise the performance of companies is a business imperative. Through a better understanding of the relationships between Performance Improvement Programmes and Organisational Maturity Variables, implementation success rates can increase, leading to improved results and sustainability. The approach taken to this research was quantitative in nature. Various descriptive and inferential statistics were applied to the selected respondents from the Eastern Cape automotive sector. The respondents had a working knowledge of Lean Manufacturing, Total Productive Maintenance (TPM) and Six Sigma. The research instrument was administered through an online survey. The research sought to identify whether there was a relationship amongst the variables under the three identified constructs. The research also sought to establish whether there was a difference between the specific Performance Improvement Programmes’ and Organisational Maturity Variables’ relationships. This affirmed the use of a new framework that integrates the programmes on the basis of their relationship to Organisational Maturity Variables. The research also provided insight into the challenges of the industry from a performance perspective and linked these with the relationship between Organisational Maturity Variables and Organisational Performance Variables. This allowed the researcher to include this additional insight as a consideration in the integrated implementation framework developed as part of the research. The results show that good consideration should be given to the Organisational Maturity Variables as these variables are related to the successful adoption of Performance Improvement Programmes. The research also shows that Lean Manufacturing, Total Productive Maintenance and Six Sigma are related to an organisations’ maturity profile in different ways. These results support the integrated Performance Improvement Programme approach, using a common set of tools and selecting the necessary programme specific tools based on a firm’s maturity profile. The research affords industry a framework to aid in decision making considering the relationships tested as part of this research. The linkages between Performance Programmes, Organisational Maturity Variables and Organisational Performance Variables are now more specific in nature.
- Full Text:
- Date Issued: 2016
- Authors: Ebrahim, Zahier
- Date: 2016
- Subjects: Automobile industry and trade , Lean manufacturing , Organizational effectiveness
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/6865 , vital:21155
- Description: The automotive components manufacturing sector is facing tremendous pressure to remain competitive in a global economy. The application of performance improvement techniques to optimise factor production inputs remains a key strategic mechanism to effect the necessary change towards competitiveness. The high failure rate of these programmes, however, is a risk factor that should be considered by manufacturing firms. The investment into the implementation of these programmes will yield no return if the organisational maturity profile is not considered. The expected gains may not materialise and the execution of critical projects may take much longer than required. It is for this reason that an approach towards selecting the correct Performance Improvement Programme to optimise the performance of companies is a business imperative. Through a better understanding of the relationships between Performance Improvement Programmes and Organisational Maturity Variables, implementation success rates can increase, leading to improved results and sustainability. The approach taken to this research was quantitative in nature. Various descriptive and inferential statistics were applied to the selected respondents from the Eastern Cape automotive sector. The respondents had a working knowledge of Lean Manufacturing, Total Productive Maintenance (TPM) and Six Sigma. The research instrument was administered through an online survey. The research sought to identify whether there was a relationship amongst the variables under the three identified constructs. The research also sought to establish whether there was a difference between the specific Performance Improvement Programmes’ and Organisational Maturity Variables’ relationships. This affirmed the use of a new framework that integrates the programmes on the basis of their relationship to Organisational Maturity Variables. The research also provided insight into the challenges of the industry from a performance perspective and linked these with the relationship between Organisational Maturity Variables and Organisational Performance Variables. This allowed the researcher to include this additional insight as a consideration in the integrated implementation framework developed as part of the research. The results show that good consideration should be given to the Organisational Maturity Variables as these variables are related to the successful adoption of Performance Improvement Programmes. The research also shows that Lean Manufacturing, Total Productive Maintenance and Six Sigma are related to an organisations’ maturity profile in different ways. These results support the integrated Performance Improvement Programme approach, using a common set of tools and selecting the necessary programme specific tools based on a firm’s maturity profile. The research affords industry a framework to aid in decision making considering the relationships tested as part of this research. The linkages between Performance Programmes, Organisational Maturity Variables and Organisational Performance Variables are now more specific in nature.
- Full Text:
- Date Issued: 2016
Estuarine species and habitat :distribution and connectivity
- Veldkornet, Dimitri Allastair
- Authors: Veldkornet, Dimitri Allastair
- Date: 2016
- Subjects: Estuarine ecology -- Research -- South Africa Estuarine fishes -- Speciation -- South Africa , Aquatic plants -- South Africa
- Language: English
- Type: Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10948/45388 , vital:38604
- Description: This study explored the distribution of estuarine macrophyte genetic lineages, species and habitats in relation to environmental gradients at various spatial scales. A database was assembled to determine the area and species composition of different estuarine habitats. This can now be used to retrieve information as a baseline for further monitoring and conservation planning. Research has shown that macrophytes occur over a wide range of physiochemical conditions, suggesting that these species have great genetic and phenotypic variation to occupy broad niche ranges. In eight estuaries along the South African coast, sediment and groundwater characteristics were measured in quadrants spanning the salt marsh, ecotone and terrestrial habitats. The results suggested that, in the absence of competition and disturbance at the salt marsh-terrestrial boundary, salt marshes would be unaffected by sea-level rise; and they would migrate landward. However, disturbance at the landward margin of salt marshes has already resulted in changes in species composition and altered environmental conditions. This promotes the encroachment of terrestrial alien invasive plants, leading to a loss of connectivity. A holistic assessment of land-cover changes showed that only 28% of South African estuaries still remain in a natural state. The delineation of all estuaries needs to be consistent and inclusive of all estuarine physical and biological processes, to curb future changes. The research results have been used in national assessments of estuarine health; and they have made a significant contribution to estuary-management plans. In addition, three scientific articles have been published from the thesis; and two more are currently under review.
- Full Text:
- Date Issued: 2016
- Authors: Veldkornet, Dimitri Allastair
- Date: 2016
- Subjects: Estuarine ecology -- Research -- South Africa Estuarine fishes -- Speciation -- South Africa , Aquatic plants -- South Africa
- Language: English
- Type: Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10948/45388 , vital:38604
- Description: This study explored the distribution of estuarine macrophyte genetic lineages, species and habitats in relation to environmental gradients at various spatial scales. A database was assembled to determine the area and species composition of different estuarine habitats. This can now be used to retrieve information as a baseline for further monitoring and conservation planning. Research has shown that macrophytes occur over a wide range of physiochemical conditions, suggesting that these species have great genetic and phenotypic variation to occupy broad niche ranges. In eight estuaries along the South African coast, sediment and groundwater characteristics were measured in quadrants spanning the salt marsh, ecotone and terrestrial habitats. The results suggested that, in the absence of competition and disturbance at the salt marsh-terrestrial boundary, salt marshes would be unaffected by sea-level rise; and they would migrate landward. However, disturbance at the landward margin of salt marshes has already resulted in changes in species composition and altered environmental conditions. This promotes the encroachment of terrestrial alien invasive plants, leading to a loss of connectivity. A holistic assessment of land-cover changes showed that only 28% of South African estuaries still remain in a natural state. The delineation of all estuaries needs to be consistent and inclusive of all estuarine physical and biological processes, to curb future changes. The research results have been used in national assessments of estuarine health; and they have made a significant contribution to estuary-management plans. In addition, three scientific articles have been published from the thesis; and two more are currently under review.
- Full Text:
- Date Issued: 2016
Factors influencing wetland distribution and structure, including ecosystem function of ephemeral wetlands, in Nelson Mandela Bay Municipality (NMBM), South Africa
- Melly, Brigitte Leigh, Gama, Phumelele T
- Authors: Melly, Brigitte Leigh , Gama, Phumelele T
- Date: 2016
- Subjects: Wetland management -- South Africa Wetland ecology -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/11721 , vital:26960
- Description: The Nelson Mandela Bay Municipality (NMBM) is a semi-arid area along the southern coastline of South Africa (SA). Until recently, there was no systematic approach to research on wetland systems in the NMBM. The systematic identification of wetlands was made more difficult by the relatively large number of small, ephemeral systems that can be difficult to delineate. This has meant that fundamental knowledge on wetland distribution, structure and function has been limited and, consequently, management and conservation strategies have been based on knowledge on systems from other regions of the country. Environmental processes occur at different spatial and temporal scales. These processes have an effect on the abiotic factors and biotic structure of wetlands, resulting in inherently complex systems. The location of the NMBM provides a good study area to research some of these environmental and biological attributes at different spatial scales, due to the variability in the underlying geology, geomorphology, vegetation types and the spatial and temporal variability in rainfall, within a relatively small area of 1951 km2. Thus, the aim of this study was to determine the factors influencing wetland distribution, structure and ecosystem functioning within the NMBM. The first Research Objective of work presented here was to identify wetlands using visual interpretation of aerial photographs. A total of 1712 wetlands were identified within the NMBM using aerial photographs, covering an area of 17.88 km2 (Chapter 5). The majority of these wetlands were depressions, seeps and wetland flats. Valley bottom wetlands (channelled and unchannelled) and floodplain wetlands were also identified. A range of wetland sizes was recorded, with 86% of the wetlands being less than 1 ha in size and the largest natural wetland being a floodplain wetland of 57 ha, located south of the Swartkops River. The identified wetlands were used to create a wetland occurrence model using logistic regression (LR) techniques (Chapter 5), in accordance with Objective 2 of the study. An accuracy of 66% was obtained, which was considered acceptable for a semi-arid climate with a relatively high degree of spatial and temporal rainfall variability. The model also highlighted several key environmental variables that are associated with wetland occurrence and distribution at various spatial scales. Some of the important variables included precipitation, evapotranspiration, temperature, flow accumulation and groundwater occurrence. Wetland distribution patterns were described in Chapter 6. Spatial statistics were used to identify whether wetlands are clustered and, therefore, form mosaics within the surrounding landscape (Objective 3). Systems were found to be highly clustered, with 43% of wetlands located within 200 m of another system. Clustering and wetland presence was especially prominent in the southern portion of the Municipality, which is also associated with a higher mean annual precipitation. Smaller wetlands were also significantly more clustered than larger systems (Average Nearest Neighbour statistic, p-value < 0.0001). Average distances also significantly varied according to HGM type, with depressions being the most geographically isolated wetland type compared to the other HGM types. Overall, distances between wetlands indicated good proximal connectivity. Potentially vulnerable areas associated with wetland systems were identified successfully using landscape variables, in accordance with Objective 4. These variables were: land cover, slope gradient, flow accumulation, APAN evaporation, mean annual precipitation (MAP) and annual heat units. The existing Critical Biodiversity Network was also used in connection with these variables to further identify potentially vulnerable areas. The abiotic and biotic characteristics were decribed for three hydrogeomorphic (HGM) types at a total of 46 wetland sites (Chapter 7), as per Objective 5. Depressions, seeps and wetland flats were sampled across the different geological, vegetation and rainfall zones within the NMBM. The wetland sites were delineated up to Level 6 of the Classification System used in SA, and the various abiotic and biotic characteristics of these systems were defined. A total of 307 plant, 144 aquatic macroinvertebrate and 10 tadpole species were identified. Of these species, over 90 species were Eastern Cape and SA endemic species, as well as three threatened species on the IUCN Red List. Multivariate analyses (including Bray-Curtis similarity resemblance analyses, distance-based redundancy analyses, SIMPER analyses and BIOENV analysis in Primer), together with environmental data, were used to define community structure at an HGM level, in accordance with Objective 5. The importance of the spatial scale of the environmental data used to define plant and macroinvertebrate community structure was described in Chapter 7, to address Objective 6. The results showed that both broad-scale and site-level characteristics were important in distinguishing community structure within the HGM types that superseded general location, the sample timing or the stage of inundation. These results also indicated that a combination of both landscape and site-level data are important in defining the community structure in the various HGM types. Some of the important environmental variables that explained some of species assemblages were similar to those in the wetland occurrence model (Chapter 5), with some additional hydrological and soil physico-chemical parameters (e.g. soil electrical conductivity, soil pH, and surface and subsurface water nutrients). These significant variables indicate the complex, multi-scalar role of environmental attributes on wetland distribution, structure and function.
- Full Text:
- Date Issued: 2016
- Authors: Melly, Brigitte Leigh , Gama, Phumelele T
- Date: 2016
- Subjects: Wetland management -- South Africa Wetland ecology -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/11721 , vital:26960
- Description: The Nelson Mandela Bay Municipality (NMBM) is a semi-arid area along the southern coastline of South Africa (SA). Until recently, there was no systematic approach to research on wetland systems in the NMBM. The systematic identification of wetlands was made more difficult by the relatively large number of small, ephemeral systems that can be difficult to delineate. This has meant that fundamental knowledge on wetland distribution, structure and function has been limited and, consequently, management and conservation strategies have been based on knowledge on systems from other regions of the country. Environmental processes occur at different spatial and temporal scales. These processes have an effect on the abiotic factors and biotic structure of wetlands, resulting in inherently complex systems. The location of the NMBM provides a good study area to research some of these environmental and biological attributes at different spatial scales, due to the variability in the underlying geology, geomorphology, vegetation types and the spatial and temporal variability in rainfall, within a relatively small area of 1951 km2. Thus, the aim of this study was to determine the factors influencing wetland distribution, structure and ecosystem functioning within the NMBM. The first Research Objective of work presented here was to identify wetlands using visual interpretation of aerial photographs. A total of 1712 wetlands were identified within the NMBM using aerial photographs, covering an area of 17.88 km2 (Chapter 5). The majority of these wetlands were depressions, seeps and wetland flats. Valley bottom wetlands (channelled and unchannelled) and floodplain wetlands were also identified. A range of wetland sizes was recorded, with 86% of the wetlands being less than 1 ha in size and the largest natural wetland being a floodplain wetland of 57 ha, located south of the Swartkops River. The identified wetlands were used to create a wetland occurrence model using logistic regression (LR) techniques (Chapter 5), in accordance with Objective 2 of the study. An accuracy of 66% was obtained, which was considered acceptable for a semi-arid climate with a relatively high degree of spatial and temporal rainfall variability. The model also highlighted several key environmental variables that are associated with wetland occurrence and distribution at various spatial scales. Some of the important variables included precipitation, evapotranspiration, temperature, flow accumulation and groundwater occurrence. Wetland distribution patterns were described in Chapter 6. Spatial statistics were used to identify whether wetlands are clustered and, therefore, form mosaics within the surrounding landscape (Objective 3). Systems were found to be highly clustered, with 43% of wetlands located within 200 m of another system. Clustering and wetland presence was especially prominent in the southern portion of the Municipality, which is also associated with a higher mean annual precipitation. Smaller wetlands were also significantly more clustered than larger systems (Average Nearest Neighbour statistic, p-value < 0.0001). Average distances also significantly varied according to HGM type, with depressions being the most geographically isolated wetland type compared to the other HGM types. Overall, distances between wetlands indicated good proximal connectivity. Potentially vulnerable areas associated with wetland systems were identified successfully using landscape variables, in accordance with Objective 4. These variables were: land cover, slope gradient, flow accumulation, APAN evaporation, mean annual precipitation (MAP) and annual heat units. The existing Critical Biodiversity Network was also used in connection with these variables to further identify potentially vulnerable areas. The abiotic and biotic characteristics were decribed for three hydrogeomorphic (HGM) types at a total of 46 wetland sites (Chapter 7), as per Objective 5. Depressions, seeps and wetland flats were sampled across the different geological, vegetation and rainfall zones within the NMBM. The wetland sites were delineated up to Level 6 of the Classification System used in SA, and the various abiotic and biotic characteristics of these systems were defined. A total of 307 plant, 144 aquatic macroinvertebrate and 10 tadpole species were identified. Of these species, over 90 species were Eastern Cape and SA endemic species, as well as three threatened species on the IUCN Red List. Multivariate analyses (including Bray-Curtis similarity resemblance analyses, distance-based redundancy analyses, SIMPER analyses and BIOENV analysis in Primer), together with environmental data, were used to define community structure at an HGM level, in accordance with Objective 5. The importance of the spatial scale of the environmental data used to define plant and macroinvertebrate community structure was described in Chapter 7, to address Objective 6. The results showed that both broad-scale and site-level characteristics were important in distinguishing community structure within the HGM types that superseded general location, the sample timing or the stage of inundation. These results also indicated that a combination of both landscape and site-level data are important in defining the community structure in the various HGM types. Some of the important environmental variables that explained some of species assemblages were similar to those in the wetland occurrence model (Chapter 5), with some additional hydrological and soil physico-chemical parameters (e.g. soil electrical conductivity, soil pH, and surface and subsurface water nutrients). These significant variables indicate the complex, multi-scalar role of environmental attributes on wetland distribution, structure and function.
- Full Text:
- Date Issued: 2016
Hate speech as a limitation to freedom of expression
- Authors: Botha, Joanna Catherine
- Date: 2016
- Subjects: Freedom of speech -- South Africa , Hate speech -- South Africa , Civil rights -- South Africa
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: http://hdl.handle.net/10948/9054 , vital:26460
- Description: Hate speech in South Africa creates a tension between the right to freedom of expression and the rights to human dignity and equality. The challenge is to achieve a balance between these competing rights in the context of the divisive past and the transformative constitutional ideal, in which reconciliation and respect for group difference are promoted. Freedom of expression, an individual right, must be construed in light of its underlying values, but regard must also be given to communitarian interests. The constitutional standard draws the initial line. The advocacy of hatred on four grounds and which constitutes incitement to cause harm is not constitutionally protected speech. Such speech undermines nation building, causes acrimony, and is not tolerated in the egalitarian society envisaged by the Constitution. The thesis formulates a principled legislative hate speech framework for South Africa at both human rights and criminal levels within the parameters of the constitutional mandate, as guided by the standard for hate speech restrictions in international law, and the Canadian regulatory model. An essential premise is that regulation requires a multi-faceted balancing enquiry. A holistic approach is proposed where factors such as respect for the dignity of the victims, autonomy for speakers, listeners and the wider community; the causal link between hate speech and hatred in a community; and the desire to achieve a diverse and harmonious society; amongst others, are considered. Failure to regulate hate speech constructively endorses hatemongers and promotes damaging speech at the expense of vulnerable groups. Regulation ensures that law sets the normative benchmark, affirms the protection of vulnerable groups within the social fabric and upholds social cohesion, inclusiveness and the equal citizenship of all individuals in society. The thesis contains a proposal for the enactment of legislation creating a self-standing hate speech crime for the advocacy of extreme hatred, shaped in accordance with international requirements and comparative foreign law, and structured in light of the distinction between hate crime and hate speech. The existing legal framework is unable to provide consistent and fitting redress for the severe harm caused by such speech, namely the fostering of an environment in which the stigmatisation of groups is promoted, their exclusion from society justified and intervention is needed to remedy the escalated levels of hatred and violence between different groups in society. PEPUDA, a remedial statute aimed at promoting transformation and substantive equality, is valuable, but its speech prohibitions are broad and imprecise. Consequently, their effectiveness is compromised and their constitutionality questioned. The thesis proposes recommendations for amendments to sections 7(a), 10(1) and 12 of PEPUDA. The aim is to ensure compliance with the international standard and to foster the optimal regulation of hate speech and other forms of damaging speech, including derogatory racial epithets, which undermine human dignity and equality and threaten national unity. It is intended for the two systems to complement one another and to create a legal framework aimed at addressing hate speech constructively and in context, promoting tolerance, respect for difference, reconciliation and transformation.
- Full Text:
- Date Issued: 2016
- Authors: Botha, Joanna Catherine
- Date: 2016
- Subjects: Freedom of speech -- South Africa , Hate speech -- South Africa , Civil rights -- South Africa
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: http://hdl.handle.net/10948/9054 , vital:26460
- Description: Hate speech in South Africa creates a tension between the right to freedom of expression and the rights to human dignity and equality. The challenge is to achieve a balance between these competing rights in the context of the divisive past and the transformative constitutional ideal, in which reconciliation and respect for group difference are promoted. Freedom of expression, an individual right, must be construed in light of its underlying values, but regard must also be given to communitarian interests. The constitutional standard draws the initial line. The advocacy of hatred on four grounds and which constitutes incitement to cause harm is not constitutionally protected speech. Such speech undermines nation building, causes acrimony, and is not tolerated in the egalitarian society envisaged by the Constitution. The thesis formulates a principled legislative hate speech framework for South Africa at both human rights and criminal levels within the parameters of the constitutional mandate, as guided by the standard for hate speech restrictions in international law, and the Canadian regulatory model. An essential premise is that regulation requires a multi-faceted balancing enquiry. A holistic approach is proposed where factors such as respect for the dignity of the victims, autonomy for speakers, listeners and the wider community; the causal link between hate speech and hatred in a community; and the desire to achieve a diverse and harmonious society; amongst others, are considered. Failure to regulate hate speech constructively endorses hatemongers and promotes damaging speech at the expense of vulnerable groups. Regulation ensures that law sets the normative benchmark, affirms the protection of vulnerable groups within the social fabric and upholds social cohesion, inclusiveness and the equal citizenship of all individuals in society. The thesis contains a proposal for the enactment of legislation creating a self-standing hate speech crime for the advocacy of extreme hatred, shaped in accordance with international requirements and comparative foreign law, and structured in light of the distinction between hate crime and hate speech. The existing legal framework is unable to provide consistent and fitting redress for the severe harm caused by such speech, namely the fostering of an environment in which the stigmatisation of groups is promoted, their exclusion from society justified and intervention is needed to remedy the escalated levels of hatred and violence between different groups in society. PEPUDA, a remedial statute aimed at promoting transformation and substantive equality, is valuable, but its speech prohibitions are broad and imprecise. Consequently, their effectiveness is compromised and their constitutionality questioned. The thesis proposes recommendations for amendments to sections 7(a), 10(1) and 12 of PEPUDA. The aim is to ensure compliance with the international standard and to foster the optimal regulation of hate speech and other forms of damaging speech, including derogatory racial epithets, which undermine human dignity and equality and threaten national unity. It is intended for the two systems to complement one another and to create a legal framework aimed at addressing hate speech constructively and in context, promoting tolerance, respect for difference, reconciliation and transformation.
- Full Text:
- Date Issued: 2016
Higher order modulation formats for high speed optical communication systems with digital signal processing aided receiver
- Chabata, Tichakunda Valentine
- Authors: Chabata, Tichakunda Valentine
- Date: 2016
- Subjects: Optical communications , Modulation (Electronics) , Signal processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/4775 , vital:20677
- Description: The drastic increase in the number of internet users and the general convergence of all other communication systems into an optical system have brought a sharp rise in demand for bandwidth and calls for high capacity transmission networks. Large unamplified transmission reach is another contributor in reducing deployment costs of an optical communication system. Spectrally efficient modulation formats are suggested as a solution to overcome the problems associated with limited channels and bandwidth of dense wavelength division multiplexing (DWDM) optical communication systems. Higher order modulation formats which are considered to be spectrally efficient and can increase the transmission capacity by transmitting more information in the amplitude, phase, polarization or a combination of all was studied. Different detection technologies are to be implemented to suit a particular higher order modulation format. In this research multilevel modulation formats, different detection technologies and a digital signal processing aided receiver were studied in a practical optical transmission system. The work in this thesis started with the implementation of the traditional amplitude shift keying (ASK) modulation and a differential phase shift keying (DPSK) modulation systems as they form the basic building block in the design of higher order modulation formats. Results obtained from using virtual photonics instruments (VPI)simulation software, receiver sensitivity for 10Gbpsnon-return-to-zero (NRZ), amplitude phase shift keying (ASK) and DPSK signals were measured to be -22.7 dBm and -22.0 dBm respectively. Performance comparison for the two modulation formats were done over different transmission distances. ASK also known as On-Off keying (OOK) performed better for shorter lengths whereas DPSK performed better for longer lengths of up to90km.Experimental results on a 10 Gbps NRZ- ASK signal gave a receiver sensitivity of -21.1 dBm from digital signal processing (DSP) aided receiver against -19.8 dBm from the commercial bit error ratio tester (BERT) yielding a small difference of 1.3 dB hence validating the reliability and accuracy of the digital signal processing (DSP) assisted receiver. Traditional direct detection scheme and coherent detection scheme performances were evaluated again on a 10 Gbps NRZ ASK signal. Coherent detection that can achieve a large unamplified transmission reach and has a higher passive optical splitting ratio was first evaluated using the VPI simulation software. Simulation results gave a receiver sensitivity of -30.4 dBm forcoherent detection and -18.3 dBm for direct detection, yielding a gain in receiver sensitivity of 12.1 dB. The complex coherently detected signal, from the experimental setup gave a receiver sensitivity of -20.6 dBm with a gain in receiver sensitivity of 3.5 dBm with respect to direct detection. A multilevel pulse amplitude modulation (4-PAM) that doubles the data rate per channel from10 Gbps to 20 Gbps by transmitting more information in the amplitude of the carrier signal was implemented. This was achieved by modulating the optical amplitude with an electrical four level amplitude shift keyed (ASK) signal. A receiver consisting of a single photodiode, three decision circuits and a decoding logic circuit was used to receive and extract the original transmitted data. A DSP aided receiver was used to evaluate the link performance. A receiver sensitivity of -12.8 dBm is attained with a dispersion penalty of about 7.2 dB after transmission through 25 km of G.652 fibre.
- Full Text:
- Date Issued: 2016
- Authors: Chabata, Tichakunda Valentine
- Date: 2016
- Subjects: Optical communications , Modulation (Electronics) , Signal processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/4775 , vital:20677
- Description: The drastic increase in the number of internet users and the general convergence of all other communication systems into an optical system have brought a sharp rise in demand for bandwidth and calls for high capacity transmission networks. Large unamplified transmission reach is another contributor in reducing deployment costs of an optical communication system. Spectrally efficient modulation formats are suggested as a solution to overcome the problems associated with limited channels and bandwidth of dense wavelength division multiplexing (DWDM) optical communication systems. Higher order modulation formats which are considered to be spectrally efficient and can increase the transmission capacity by transmitting more information in the amplitude, phase, polarization or a combination of all was studied. Different detection technologies are to be implemented to suit a particular higher order modulation format. In this research multilevel modulation formats, different detection technologies and a digital signal processing aided receiver were studied in a practical optical transmission system. The work in this thesis started with the implementation of the traditional amplitude shift keying (ASK) modulation and a differential phase shift keying (DPSK) modulation systems as they form the basic building block in the design of higher order modulation formats. Results obtained from using virtual photonics instruments (VPI)simulation software, receiver sensitivity for 10Gbpsnon-return-to-zero (NRZ), amplitude phase shift keying (ASK) and DPSK signals were measured to be -22.7 dBm and -22.0 dBm respectively. Performance comparison for the two modulation formats were done over different transmission distances. ASK also known as On-Off keying (OOK) performed better for shorter lengths whereas DPSK performed better for longer lengths of up to90km.Experimental results on a 10 Gbps NRZ- ASK signal gave a receiver sensitivity of -21.1 dBm from digital signal processing (DSP) aided receiver against -19.8 dBm from the commercial bit error ratio tester (BERT) yielding a small difference of 1.3 dB hence validating the reliability and accuracy of the digital signal processing (DSP) assisted receiver. Traditional direct detection scheme and coherent detection scheme performances were evaluated again on a 10 Gbps NRZ ASK signal. Coherent detection that can achieve a large unamplified transmission reach and has a higher passive optical splitting ratio was first evaluated using the VPI simulation software. Simulation results gave a receiver sensitivity of -30.4 dBm forcoherent detection and -18.3 dBm for direct detection, yielding a gain in receiver sensitivity of 12.1 dB. The complex coherently detected signal, from the experimental setup gave a receiver sensitivity of -20.6 dBm with a gain in receiver sensitivity of 3.5 dBm with respect to direct detection. A multilevel pulse amplitude modulation (4-PAM) that doubles the data rate per channel from10 Gbps to 20 Gbps by transmitting more information in the amplitude of the carrier signal was implemented. This was achieved by modulating the optical amplitude with an electrical four level amplitude shift keyed (ASK) signal. A receiver consisting of a single photodiode, three decision circuits and a decoding logic circuit was used to receive and extract the original transmitted data. A DSP aided receiver was used to evaluate the link performance. A receiver sensitivity of -12.8 dBm is attained with a dispersion penalty of about 7.2 dB after transmission through 25 km of G.652 fibre.
- Full Text:
- Date Issued: 2016
Impact of a holistic lifestyle management education programme on health and education outcomes of socioeconomically disadvantaged university students
- Authors: Morris-Paxton, Angela Ann
- Date: 2016
- Subjects: College students -- Mental health College students -- Health and hygiene Health promotion
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/11909 , vital:27003
- Description: Disorders of lifestyle are increasing globally; countries in transition are suffering the double burden of both contagious and chronic disorders. The utilization of health education to address these issues has had variable results, but the most successful have incorporated human contact. The aim of this study was to measure the quantitative and qualitative impact of a wellness promotion programme on university students. The objective was to provide a structured facilitated holistic wellness education programme to a sample of socioeconomically disadvantaged students in Higher Education in the Eastern Cape Province, South Africa. Using a pragmatic mixed methodological approach to this critical evaluation, the impact on both wellness and academic progress was measured. Initial demographic data was gathered via a biographical questionnaire, pre- and post-intervention measurement of wellness, using the Wellness Questionnaire for Higher Education, as well as a semi-structured qualitative questionnaire and transcripts of academic results. Quantitative data was analysed using SPSS analysis software and qualitative data using the NVivo analysis package. The findings were that all students improved throughout the year in their overall wellness scores, in particular in areas such as avoiding excessive sun exposure and increasing the amount of physical exercise. This corresponded with an increase in the value that the participants attached to information on these aspects of wellness, which was attributed to the programme. Results revealed that there was a weak correlation between student wellness measured at the year-end and academic success overall, but a strong correlation between student wellness and academic success for the students that gained the highest marks. Analysis of the dimensions of wellness that correlated best with student success revealed that there was a particularly strong correlation between year-end career wellness and year-end academic success. In conclusion it was found that a positive and holistic salutogenic wellness education programme increased levels of student wellness overall, which translated into student academic success. The link between wellness and success was particularly strong in students that gained higher marks. Recommendations include that first-year higher education students receive a positive wellness education programme built into the curriculum of their first year of study and that the overall impact be monitored across a broader spectrum of students over the duration of their diploma or degree programme.
- Full Text:
- Date Issued: 2016
- Authors: Morris-Paxton, Angela Ann
- Date: 2016
- Subjects: College students -- Mental health College students -- Health and hygiene Health promotion
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/11909 , vital:27003
- Description: Disorders of lifestyle are increasing globally; countries in transition are suffering the double burden of both contagious and chronic disorders. The utilization of health education to address these issues has had variable results, but the most successful have incorporated human contact. The aim of this study was to measure the quantitative and qualitative impact of a wellness promotion programme on university students. The objective was to provide a structured facilitated holistic wellness education programme to a sample of socioeconomically disadvantaged students in Higher Education in the Eastern Cape Province, South Africa. Using a pragmatic mixed methodological approach to this critical evaluation, the impact on both wellness and academic progress was measured. Initial demographic data was gathered via a biographical questionnaire, pre- and post-intervention measurement of wellness, using the Wellness Questionnaire for Higher Education, as well as a semi-structured qualitative questionnaire and transcripts of academic results. Quantitative data was analysed using SPSS analysis software and qualitative data using the NVivo analysis package. The findings were that all students improved throughout the year in their overall wellness scores, in particular in areas such as avoiding excessive sun exposure and increasing the amount of physical exercise. This corresponded with an increase in the value that the participants attached to information on these aspects of wellness, which was attributed to the programme. Results revealed that there was a weak correlation between student wellness measured at the year-end and academic success overall, but a strong correlation between student wellness and academic success for the students that gained the highest marks. Analysis of the dimensions of wellness that correlated best with student success revealed that there was a particularly strong correlation between year-end career wellness and year-end academic success. In conclusion it was found that a positive and holistic salutogenic wellness education programme increased levels of student wellness overall, which translated into student academic success. The link between wellness and success was particularly strong in students that gained higher marks. Recommendations include that first-year higher education students receive a positive wellness education programme built into the curriculum of their first year of study and that the overall impact be monitored across a broader spectrum of students over the duration of their diploma or degree programme.
- Full Text:
- Date Issued: 2016
Influence of increased processing speed on the microstructure evolution and mechanical property relationship in friction stir welding of AA5182-H111 (T500)
- Authors: Bernard, Dreyer
- Date: 2016
- Subjects: Friction stir welding , Aluminum alloys -- Welding
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/7322 , vital:21319
- Description: Friction stir welding of 5xxx series aluminium is generally carried out at low travel speeds, which limits the commercial applications of this process. This manuscript discusses the dynamic eformation characteristics of AA5182-H111 (T500), which allowed a travel speed of 1500 mm/min to be realised. This was achieved by using a spindle speed of 500 rev/min; the same as that required to make a weld of 200 mm/min. The thermal cycles, microstructural evolution due to tool / work-piece interaction, and the local microstructural and mechanical properties of the completed weld are discussed for a travel speed for 200 mm/min and 1500 mm/min. At a rate of 200 mm/min, heat generated due to contact between the shoulder and work-piece surface was transferred ahead of the tool, driving dynamic recrystallization which lowered the flow stress. Hereafter the material entered the stir zone where it was extruded around the pin during a process of continuous dynamic crystallization. At a travel speed of 1500 mm/min, the rate of heat conduction ahead of the tool was not rapid enough, and the material was deformed at low temperatures. A low weld pitch rotations per unit length travelled) was required to ensure that the material was sufficiently strained, to allow the formation of geometric necessary boundaries, which resulted in grain subdivision. The number of high angle grain boundaries was increased through subdivision, thus, increasing the nucleation sites for dynamically recrystallized necklace grains to form. In the absence of heat conduction from the shoulder, the high plastic strain ahead of the tool provided the energy required to drive dynamic recrystallization. Heat was generated from the high plastic strain and during recrystallization, where the stored plastic energy was adiabatically released. Once the material entered the stir zone, the high strain rates associated with the tool rotation which drove dynamic recrystallization that allowed the material to reach high levels of strain, resulted significant grain refinement. The weld zone of the 200 mm/min displayed weld a slight increase in yield strength, with respect to the parent material, due to grain refinement to 10 μm, while the yield strength of the 1500 mm/min weld was significantly increased due to grain refinement to 5 μm. The high weld speed did, however, generate high tensile residual stresses. This work is not only significant for the field of friction stir welding, but also in terms of material processing. The dynamic deformation characteristics associated with Al-5Mg-Mn, alloys which was observed ahead of the tool, is of high value in processes where plastic deformation is applied to improve the mechanical properties of these alloys.
- Full Text:
- Date Issued: 2016
- Authors: Bernard, Dreyer
- Date: 2016
- Subjects: Friction stir welding , Aluminum alloys -- Welding
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/7322 , vital:21319
- Description: Friction stir welding of 5xxx series aluminium is generally carried out at low travel speeds, which limits the commercial applications of this process. This manuscript discusses the dynamic eformation characteristics of AA5182-H111 (T500), which allowed a travel speed of 1500 mm/min to be realised. This was achieved by using a spindle speed of 500 rev/min; the same as that required to make a weld of 200 mm/min. The thermal cycles, microstructural evolution due to tool / work-piece interaction, and the local microstructural and mechanical properties of the completed weld are discussed for a travel speed for 200 mm/min and 1500 mm/min. At a rate of 200 mm/min, heat generated due to contact between the shoulder and work-piece surface was transferred ahead of the tool, driving dynamic recrystallization which lowered the flow stress. Hereafter the material entered the stir zone where it was extruded around the pin during a process of continuous dynamic crystallization. At a travel speed of 1500 mm/min, the rate of heat conduction ahead of the tool was not rapid enough, and the material was deformed at low temperatures. A low weld pitch rotations per unit length travelled) was required to ensure that the material was sufficiently strained, to allow the formation of geometric necessary boundaries, which resulted in grain subdivision. The number of high angle grain boundaries was increased through subdivision, thus, increasing the nucleation sites for dynamically recrystallized necklace grains to form. In the absence of heat conduction from the shoulder, the high plastic strain ahead of the tool provided the energy required to drive dynamic recrystallization. Heat was generated from the high plastic strain and during recrystallization, where the stored plastic energy was adiabatically released. Once the material entered the stir zone, the high strain rates associated with the tool rotation which drove dynamic recrystallization that allowed the material to reach high levels of strain, resulted significant grain refinement. The weld zone of the 200 mm/min displayed weld a slight increase in yield strength, with respect to the parent material, due to grain refinement to 10 μm, while the yield strength of the 1500 mm/min weld was significantly increased due to grain refinement to 5 μm. The high weld speed did, however, generate high tensile residual stresses. This work is not only significant for the field of friction stir welding, but also in terms of material processing. The dynamic deformation characteristics associated with Al-5Mg-Mn, alloys which was observed ahead of the tool, is of high value in processes where plastic deformation is applied to improve the mechanical properties of these alloys.
- Full Text:
- Date Issued: 2016
Influence of the macro-economic environment on the construction sector's contribution to the South African economy, 1984 to 2011
- Authors: Babalola, Adewumi Joseph
- Date: 2016
- Subjects: Construction industry -- Economic aspects Economic development Environmental economics
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/5618 , vital:20916
- Description: The construction sector serves as the engine of growth to the South Africa economy because of its catalytic role in the growth and development of the country. This study focuses mainly on the influence of the macro-economic environment on the contribution of the private sector to construction in the South Africa economy from 1984 to 2011. Government construction work is considered to be an injection into the economy; in this regard, state construction is regarded as public investment in the economy; and therefore, it is anti-cyclic (Keynes, 1936). The aim of this study has been to develop an econometric model for predicting the influence of the macroeconomic environment on the contribution of the private sector to the construction sector in the South Africa economy. The research design adopted in this study was an “ex-post facto” type, otherwise known as a causal-comparative design. The data were extracted from the published sources of the South African National Statistics, namely SARB, Stats SA and Quantec SA. The estimation technique used in this study was the ARDL model using quarterly data from 1984 to 2011. This is because in the construction sector, the influence of the independent variables is always felt over time – rather than all at once. The results of this study show that there is a long run causal relationship between inflation rate, interest rate, real exchange rate, GDP and gdp in the construction sector. The descriptive statistical analysis shows that there is a negative relationship between variables inflation rate and interest rate and the private sector spending in construction. However, economic growth as well as growth in the construction sector has a positive relationship with the private sector spending in construction. Likewise, the real exchange rate and labour productivity in construction have a negative relationship with the private sector’s spending in construction and they are statistically insignificant. The variance decomposition analysis show that the private sector spending in construction explains about 75 per cent of it variations, followed by inflation rate that explains 21 per cent on the average; while the remaining variations, comprising about 4 per cent, were shared among the other independent variables, such as GDP, GDP in construction, the interest rate and the real exchange rate. It was discovered that only the inflation rate does Granger-cause the private sector spending in construction. From the finding it can be concluded that inflation rate is a significant explanatory variable in explaining the variation in the dependent variable during period under review. Policy recommendations are as follows: firstly, the monetary authorities in South Africa should embark on sound policies that would bring about low prices of the construction materials. This would ensure growth and development in the construction sector; secondly, a stimulating development plan that would encourage private sector investment in properties and infrastructural development must be instituted; thirdly, an alternative policy to the present inflation targeting is recommended that would bring about low inflation, high growth, low unemployment and stable exchange rate; fourthly, the present policy on interest rate must be reviewed to allow for more participation in construction projects by the private sectors of the economy; fifthly, due to the fact that fluctuation in the crude oil prices in the international market is one of the major factors causing high inflation rate in South Africa, government must source local alternative products that would bring down prices of construction materials.
- Full Text:
- Date Issued: 2016
- Authors: Babalola, Adewumi Joseph
- Date: 2016
- Subjects: Construction industry -- Economic aspects Economic development Environmental economics
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/5618 , vital:20916
- Description: The construction sector serves as the engine of growth to the South Africa economy because of its catalytic role in the growth and development of the country. This study focuses mainly on the influence of the macro-economic environment on the contribution of the private sector to construction in the South Africa economy from 1984 to 2011. Government construction work is considered to be an injection into the economy; in this regard, state construction is regarded as public investment in the economy; and therefore, it is anti-cyclic (Keynes, 1936). The aim of this study has been to develop an econometric model for predicting the influence of the macroeconomic environment on the contribution of the private sector to the construction sector in the South Africa economy. The research design adopted in this study was an “ex-post facto” type, otherwise known as a causal-comparative design. The data were extracted from the published sources of the South African National Statistics, namely SARB, Stats SA and Quantec SA. The estimation technique used in this study was the ARDL model using quarterly data from 1984 to 2011. This is because in the construction sector, the influence of the independent variables is always felt over time – rather than all at once. The results of this study show that there is a long run causal relationship between inflation rate, interest rate, real exchange rate, GDP and gdp in the construction sector. The descriptive statistical analysis shows that there is a negative relationship between variables inflation rate and interest rate and the private sector spending in construction. However, economic growth as well as growth in the construction sector has a positive relationship with the private sector spending in construction. Likewise, the real exchange rate and labour productivity in construction have a negative relationship with the private sector’s spending in construction and they are statistically insignificant. The variance decomposition analysis show that the private sector spending in construction explains about 75 per cent of it variations, followed by inflation rate that explains 21 per cent on the average; while the remaining variations, comprising about 4 per cent, were shared among the other independent variables, such as GDP, GDP in construction, the interest rate and the real exchange rate. It was discovered that only the inflation rate does Granger-cause the private sector spending in construction. From the finding it can be concluded that inflation rate is a significant explanatory variable in explaining the variation in the dependent variable during period under review. Policy recommendations are as follows: firstly, the monetary authorities in South Africa should embark on sound policies that would bring about low prices of the construction materials. This would ensure growth and development in the construction sector; secondly, a stimulating development plan that would encourage private sector investment in properties and infrastructural development must be instituted; thirdly, an alternative policy to the present inflation targeting is recommended that would bring about low inflation, high growth, low unemployment and stable exchange rate; fourthly, the present policy on interest rate must be reviewed to allow for more participation in construction projects by the private sectors of the economy; fifthly, due to the fact that fluctuation in the crude oil prices in the international market is one of the major factors causing high inflation rate in South Africa, government must source local alternative products that would bring down prices of construction materials.
- Full Text:
- Date Issued: 2016
Investigating emerging deleuzoguattarian connections to the environment via information technology
- Authors: Siwak, Jakub
- Date: 2016
- Subjects: Mass media and the environment , Neoliberalism
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/8329 , vital:26343
- Description: This thesis explores whether or not it is possible to positively inflect – via digital means – people’s orientations toward nature through connecting their duration to the time of animals. The thesis opens with an overview of the contemporary environmental crisis, mapping related significant discourses, events and responses from the early 1960s onward. In this regard, after thematizing the relatively ineffective global institutional response to the environmental crisis to date – in spite of both consistent criticisms proffered by a range of stakeholders and widely available information on the scope of current environmental degradation – the lack of any concerted effort to deal with this issue is accounted for in terms of the dimensions of what Kilbourne, Beckmann and Thelen refer to as the ‘Dominant Social Paradigm’ (DSP). However, it is argued that of these dimensions, the technological dimension is most amenable to pro-environmental inflection, particularly through recent developments within information technology. That is, despite the latter being the privileged technology of neoliberalism, and despite the environmental cost of its current material infrastructure, it is also highly unlikely that societies will abandon their dependence on information technology in the near future. Given this, the importance of considering how such technology can be harnessed to positively re-orientate users’ perceptions of the natural world, in a way that also avoids the pitfall of technophilia, is advanced. In terms of this, both positive and negative appraisals of information technology by prominent new media theorists are discussed, and information technology is put forward as a tool that remains indeterminate in terms of its use. After this, and with a view to exploring how the technological dimension of the DSP might possibly be inflected in a pro-environmental manner, the thesis draws on the works of Gilles Deleuze and Félix Guattari who promote desire and difference outside the ambit of capitalism, particularly through desubjectivation in relation to their concept of ‘becoming-animal.’ Finally, after dealing in addition with some potential theoretical challenges to the application of Deleuze’s ideas within the digital realm, focus shifts to three contemporary digital artefacts which have the capacity, albeit to varying degrees, to facilitate a becoming-animal. In this regard, a distinction is made between those artefacts that precipitate first-, second- and third-order hybrid durationality, and it is argued that the latter category presents the greatest promise of interfacing the time of humans with the time of animals.
- Full Text:
- Date Issued: 2016
- Authors: Siwak, Jakub
- Date: 2016
- Subjects: Mass media and the environment , Neoliberalism
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/8329 , vital:26343
- Description: This thesis explores whether or not it is possible to positively inflect – via digital means – people’s orientations toward nature through connecting their duration to the time of animals. The thesis opens with an overview of the contemporary environmental crisis, mapping related significant discourses, events and responses from the early 1960s onward. In this regard, after thematizing the relatively ineffective global institutional response to the environmental crisis to date – in spite of both consistent criticisms proffered by a range of stakeholders and widely available information on the scope of current environmental degradation – the lack of any concerted effort to deal with this issue is accounted for in terms of the dimensions of what Kilbourne, Beckmann and Thelen refer to as the ‘Dominant Social Paradigm’ (DSP). However, it is argued that of these dimensions, the technological dimension is most amenable to pro-environmental inflection, particularly through recent developments within information technology. That is, despite the latter being the privileged technology of neoliberalism, and despite the environmental cost of its current material infrastructure, it is also highly unlikely that societies will abandon their dependence on information technology in the near future. Given this, the importance of considering how such technology can be harnessed to positively re-orientate users’ perceptions of the natural world, in a way that also avoids the pitfall of technophilia, is advanced. In terms of this, both positive and negative appraisals of information technology by prominent new media theorists are discussed, and information technology is put forward as a tool that remains indeterminate in terms of its use. After this, and with a view to exploring how the technological dimension of the DSP might possibly be inflected in a pro-environmental manner, the thesis draws on the works of Gilles Deleuze and Félix Guattari who promote desire and difference outside the ambit of capitalism, particularly through desubjectivation in relation to their concept of ‘becoming-animal.’ Finally, after dealing in addition with some potential theoretical challenges to the application of Deleuze’s ideas within the digital realm, focus shifts to three contemporary digital artefacts which have the capacity, albeit to varying degrees, to facilitate a becoming-animal. In this regard, a distinction is made between those artefacts that precipitate first-, second- and third-order hybrid durationality, and it is argued that the latter category presents the greatest promise of interfacing the time of humans with the time of animals.
- Full Text:
- Date Issued: 2016
Investigating the relationship between mathematical knowledge for teaching and self-efficacy of pre-service mathematical literacy teachers
- Van Zyl, Nicola Stephanie, Van Zyl, Marinda
- Authors: Van Zyl, Nicola Stephanie , Van Zyl, Marinda
- Date: 2016
- Subjects: Mathematics teachers -- South Africa Mathematics -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Doctoral , MEd
- Identifier: http://hdl.handle.net/10948/10849 , vital:26829
- Description: Although a good understanding of mathematical content knowledge is essential for effective mathematics teaching, this might not be enough. Mathematical knowledge for teaching (MKT) requires a kind of depth and detail special to teaching, and involves mathematical reasoning as well as thinking from a learners’ perspective. Educational outcomes are also influenced by teachers’ self-efficacy beliefs regarding their ability to teach effectively. This study was an investigation into the relationship between pre-service teachers’ mathematical knowledge for teaching (MKT) and their mathematical self-efficacy with regard to MKT. Participants in the study were 137 BEd (FET) students at Nelson Mandela Metropolitan University, specializing in Mathematical Literacy as teaching subject. The quantitative data used for the study were gathered using a questionnaire on MKT for the topics number concepts and operations. This questionnaire was designed by Deborah Ball’s Michigan research team, to which I added a question on self-efficacy for every item. An analysis of the data gathered from the questionnaire reveals interesting and disturbing trends. The results suggest that, in more than 80% of the cases, respondents were either completely sure their answer was correct, or tended to think their answer was correct, indicating high levels of self-efficacy. Since only about 40% of answers were in reality correct, this indicates that participants believed their answer to be correct, although their interpretation of the mathematical knowledge for teaching involved was incorrect. Hence: they don’t know that they don’t know! The results of this study suggest that there is a need for educators of teachers to help improve prospective mathematical literacy teachers’ mathematical knowledge for teaching. Pre-service teachers should be taught to use cognitive skills that will raise the likelihood of improved learner understanding. For this, robust understanding of the fundamental mathematics involved is needed, as well as high levels of self-efficacy with regard to the teaching of mathematics.
- Full Text:
- Date Issued: 2016
- Authors: Van Zyl, Nicola Stephanie , Van Zyl, Marinda
- Date: 2016
- Subjects: Mathematics teachers -- South Africa Mathematics -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Doctoral , MEd
- Identifier: http://hdl.handle.net/10948/10849 , vital:26829
- Description: Although a good understanding of mathematical content knowledge is essential for effective mathematics teaching, this might not be enough. Mathematical knowledge for teaching (MKT) requires a kind of depth and detail special to teaching, and involves mathematical reasoning as well as thinking from a learners’ perspective. Educational outcomes are also influenced by teachers’ self-efficacy beliefs regarding their ability to teach effectively. This study was an investigation into the relationship between pre-service teachers’ mathematical knowledge for teaching (MKT) and their mathematical self-efficacy with regard to MKT. Participants in the study were 137 BEd (FET) students at Nelson Mandela Metropolitan University, specializing in Mathematical Literacy as teaching subject. The quantitative data used for the study were gathered using a questionnaire on MKT for the topics number concepts and operations. This questionnaire was designed by Deborah Ball’s Michigan research team, to which I added a question on self-efficacy for every item. An analysis of the data gathered from the questionnaire reveals interesting and disturbing trends. The results suggest that, in more than 80% of the cases, respondents were either completely sure their answer was correct, or tended to think their answer was correct, indicating high levels of self-efficacy. Since only about 40% of answers were in reality correct, this indicates that participants believed their answer to be correct, although their interpretation of the mathematical knowledge for teaching involved was incorrect. Hence: they don’t know that they don’t know! The results of this study suggest that there is a need for educators of teachers to help improve prospective mathematical literacy teachers’ mathematical knowledge for teaching. Pre-service teachers should be taught to use cognitive skills that will raise the likelihood of improved learner understanding. For this, robust understanding of the fundamental mathematics involved is needed, as well as high levels of self-efficacy with regard to the teaching of mathematics.
- Full Text:
- Date Issued: 2016
Isithako sohlahlubo-bunzululwazi-sakhono kwiimbalo zikaSaule: iinoveli ezintathu = decontsructive stylistic critique of Saule' s writings: the case of three novels
- Jaxa, Nontembiso Patricia, Kwatsha, Linda Loretta
- Authors: Jaxa, Nontembiso Patricia , Kwatsha, Linda Loretta
- Date: 2016
- Subjects: Xhosa literature -- Criticism, Textual , Literature -- Black authors -- History and criticism , South African literature -- History and criticism , Saule, N -- Criticism and interpretation , Saule, N -- Literary style
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/7762 , vital:23830
- Description: Kule ngxoxo kuqwalaselwa ukugqwesa kwesiThako Sohlahlubo-buNzululwazi-sakhono kuhlalutyo loncwadi. Olu phando lugxile ekuduliseni ukuba akukho luzalwano luthe ngqo, kwaye lusisigxina phakathi kwegama nentsingiselo, ngenxa yobumbaxa beentsingiselo zegama. Esi siThako siludondolo ekusinyelelwa ngalo kolu phando, ukuqaqambisa ukuba iitekisi azinantsingiselo izinzileyo. Ke ngoko ibe ayinabunyani mpela ingcamango yokuba igama linokunanyatheliswa intsingiselo ethile, ze loo ntsingiselo ibange ubuntsusa. Ingxoxo yophando, iphendula imibuzo ebuza ubuni besiThako Sohlahlubo-buNzululwazi-sakhono, nokuchana kwaso ekuhlalutyeni iitekisi zoncwadi. Imibuzo ikwabuza izizathu zokungazinzi kwentsingiselo yetekisi, nokungabi nakwalatheka ncam kwentsingiselo ajolise kuyo umbhali, ngotolo lwakhe oluluchongo-sigama. Le mibuzo iyaphenduleka kubuthumbu bengxoxo. Ingxoxo idandalazisa ukunzotshoba kwesi siThako kuhlahlubo, kuqanyelwa ngeengcingane zaso eziphambili. Ukuphendulwa kwemibuzo yophando, kufezekisa iinjongo zophando. Iinoveli ezichongelwe uphando, ziinoveli ezintathu zikaSaule, ezizezi: Ukhozi Olumaphiko, Umlimandlela kunye no-Vuleka Mhlaba, azikhethelwanga kuthelekiswa koko kukudandalazisa elubala ukunyanisa kwesiThako Sohlahlubo-buNzululwazi-sakhono, malunga nomba weentsingiselo. Ngazo, kudula ubunyani bophindaphindeko lwegama elinye kwimixholo ngemixholo, lizale iintsingiselo ezahlukileyo. Kanti, kukwadandalaza ukuba intsingiselo yegama ayixhomekekanga kumxholo, iyakwazi ukutyekeza ngaphaya kwawo, liveze nezinye iintsingiselo. Olu phando lungaluncedo kakhulu kubafundi nootitshala kuba kanye luphethe umba wokuhlalutywa kweetekisi, ngendlela ekhuthazwa yiNkcazelo yePolisi yeKharityhulam nokuHlola (2011). Ebethelela ukuba kufundo loncwadi kufuneka abafundi bayiqhaqhe ukuyihlalutya itekisi ukuze kuvele indlela eyakhiwe neyakheke ngayo, oko ke kukuHlahluba. Kanti ke nakubahlohli lungaluncedo kuba lutyhila okuninzi ngesiThako Sohlahlubo-buNzululwazi-sakhono. Ekuxoxeni, isiThako sobuNzululwazi Mlando-mbali, kurhatyulwe kuso, ukuxhasa imiba ethile kuphando. Ingxoxo Yahlulwe yazizahluko ngolu hlobo: Isahluko sokuqala, sidandalazisa ingxubakaxaka ethunuke yandulula uphando olu. Kwabekwa iinjongo, iziphumo-njongo zophando nemibuzo ekuza kucangcathwa kuyo kuphando. Kwaphengululwa iincwadi zeengcali kwisi-Thako Sohlahlubo-buNzululwazi-sakhono, kwarhewulwa nesiThako sobuNzululwazi beeNkumbulo noMlando-mbali. Isahluko sesibini, luphendululo lweencwadi olunzulileyo nolunabileyo, kupendlwa izimvo ezimalunga nobuni besiThako Sohlahlubo-buNzululwazi-sakhono. Kubekelelwa, kucutyungulwa iingcingane zaso, ezibe ludondolo lophando. Isahluko sesithathu, yingxoxo. Kuphicothwa iinoveli ezichongelwe uphando, zihlahlutywa, kusetyenziswa iingcamango neengcingane zesiThako Sohla-hlubo-buNzululwazi-sakhono. Ikakhulu kuqwalaselwa indlela izibini ezichasana ngokulinganayo ezivela ngayo. Kuduliswa ukuminxiselwa kwezo zikwinqanaba elingezantsi. Isahluko sesine, ingxoxo iyaqhuba, kuqwalselwa ukusetyenziswa kwamaze-nge nemiqondiso, neentsingiselo ezivelayo, nokwahluka kwazo, okukhokelela ukuba utekisi ibe nobuvumephika. Isahluko sesihlanu, uphando luqhubeka kudandalaziswa ukusetyenziswa kwezandi, isigama sokuchaza nezafobe, nemifanekiso-ngqondweni eyakhiwa zezi zixhobo zoncwadi, ze kuphendlwe iintsingiselo nefuthe lazo kwitekisi. Isahluko sesithandathu sigxile ekusetyenzisweni kwembali kuncwadi, ngendlela evuselela iinkumbulo. Kuso nakuba kuhlahlutywa kodwa kunce-diswa ngokurhabula kwisiThako sobuNzululwazi beeNkumbulo noMlando-mbali.
- Full Text:
- Date Issued: 2016
- Authors: Jaxa, Nontembiso Patricia , Kwatsha, Linda Loretta
- Date: 2016
- Subjects: Xhosa literature -- Criticism, Textual , Literature -- Black authors -- History and criticism , South African literature -- History and criticism , Saule, N -- Criticism and interpretation , Saule, N -- Literary style
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/7762 , vital:23830
- Description: Kule ngxoxo kuqwalaselwa ukugqwesa kwesiThako Sohlahlubo-buNzululwazi-sakhono kuhlalutyo loncwadi. Olu phando lugxile ekuduliseni ukuba akukho luzalwano luthe ngqo, kwaye lusisigxina phakathi kwegama nentsingiselo, ngenxa yobumbaxa beentsingiselo zegama. Esi siThako siludondolo ekusinyelelwa ngalo kolu phando, ukuqaqambisa ukuba iitekisi azinantsingiselo izinzileyo. Ke ngoko ibe ayinabunyani mpela ingcamango yokuba igama linokunanyatheliswa intsingiselo ethile, ze loo ntsingiselo ibange ubuntsusa. Ingxoxo yophando, iphendula imibuzo ebuza ubuni besiThako Sohlahlubo-buNzululwazi-sakhono, nokuchana kwaso ekuhlalutyeni iitekisi zoncwadi. Imibuzo ikwabuza izizathu zokungazinzi kwentsingiselo yetekisi, nokungabi nakwalatheka ncam kwentsingiselo ajolise kuyo umbhali, ngotolo lwakhe oluluchongo-sigama. Le mibuzo iyaphenduleka kubuthumbu bengxoxo. Ingxoxo idandalazisa ukunzotshoba kwesi siThako kuhlahlubo, kuqanyelwa ngeengcingane zaso eziphambili. Ukuphendulwa kwemibuzo yophando, kufezekisa iinjongo zophando. Iinoveli ezichongelwe uphando, ziinoveli ezintathu zikaSaule, ezizezi: Ukhozi Olumaphiko, Umlimandlela kunye no-Vuleka Mhlaba, azikhethelwanga kuthelekiswa koko kukudandalazisa elubala ukunyanisa kwesiThako Sohlahlubo-buNzululwazi-sakhono, malunga nomba weentsingiselo. Ngazo, kudula ubunyani bophindaphindeko lwegama elinye kwimixholo ngemixholo, lizale iintsingiselo ezahlukileyo. Kanti, kukwadandalaza ukuba intsingiselo yegama ayixhomekekanga kumxholo, iyakwazi ukutyekeza ngaphaya kwawo, liveze nezinye iintsingiselo. Olu phando lungaluncedo kakhulu kubafundi nootitshala kuba kanye luphethe umba wokuhlalutywa kweetekisi, ngendlela ekhuthazwa yiNkcazelo yePolisi yeKharityhulam nokuHlola (2011). Ebethelela ukuba kufundo loncwadi kufuneka abafundi bayiqhaqhe ukuyihlalutya itekisi ukuze kuvele indlela eyakhiwe neyakheke ngayo, oko ke kukuHlahluba. Kanti ke nakubahlohli lungaluncedo kuba lutyhila okuninzi ngesiThako Sohlahlubo-buNzululwazi-sakhono. Ekuxoxeni, isiThako sobuNzululwazi Mlando-mbali, kurhatyulwe kuso, ukuxhasa imiba ethile kuphando. Ingxoxo Yahlulwe yazizahluko ngolu hlobo: Isahluko sokuqala, sidandalazisa ingxubakaxaka ethunuke yandulula uphando olu. Kwabekwa iinjongo, iziphumo-njongo zophando nemibuzo ekuza kucangcathwa kuyo kuphando. Kwaphengululwa iincwadi zeengcali kwisi-Thako Sohlahlubo-buNzululwazi-sakhono, kwarhewulwa nesiThako sobuNzululwazi beeNkumbulo noMlando-mbali. Isahluko sesibini, luphendululo lweencwadi olunzulileyo nolunabileyo, kupendlwa izimvo ezimalunga nobuni besiThako Sohlahlubo-buNzululwazi-sakhono. Kubekelelwa, kucutyungulwa iingcingane zaso, ezibe ludondolo lophando. Isahluko sesithathu, yingxoxo. Kuphicothwa iinoveli ezichongelwe uphando, zihlahlutywa, kusetyenziswa iingcamango neengcingane zesiThako Sohla-hlubo-buNzululwazi-sakhono. Ikakhulu kuqwalaselwa indlela izibini ezichasana ngokulinganayo ezivela ngayo. Kuduliswa ukuminxiselwa kwezo zikwinqanaba elingezantsi. Isahluko sesine, ingxoxo iyaqhuba, kuqwalselwa ukusetyenziswa kwamaze-nge nemiqondiso, neentsingiselo ezivelayo, nokwahluka kwazo, okukhokelela ukuba utekisi ibe nobuvumephika. Isahluko sesihlanu, uphando luqhubeka kudandalaziswa ukusetyenziswa kwezandi, isigama sokuchaza nezafobe, nemifanekiso-ngqondweni eyakhiwa zezi zixhobo zoncwadi, ze kuphendlwe iintsingiselo nefuthe lazo kwitekisi. Isahluko sesithandathu sigxile ekusetyenzisweni kwembali kuncwadi, ngendlela evuselela iinkumbulo. Kuso nakuba kuhlahlutywa kodwa kunce-diswa ngokurhabula kwisiThako sobuNzululwazi beeNkumbulo noMlando-mbali.
- Full Text:
- Date Issued: 2016
Leonotis leonurus: understanding the mechanism of anti-diabetic action and investigating a nano drug delivery system
- Odei-Addo, Frank, Levendal, Ruby-Ann
- Authors: Odei-Addo, Frank , Levendal, Ruby-Ann
- Date: 2016
- Subjects: Diabetes Plant extracts
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/13116 , vital:27153
- Description: Diabetes mellitus is a metabolic disease characterised by hyperglycaemia resulting from defects in insulin secretion, insulin action, or both. The leaf extract of Leonotis leonurus and its active compound marrubiin, have been shown to possess anti-diabetic, antiplatelet, anti-inflammatory and anti-coagulation activity. In the present study, the mechanism by which L. leonurus and marrubiin exert their anti-diabetic properties, the cross-talk between the peripheral tissues and a nano drug delivery system were investigated. Marrubiin in the plant extract was effectively quantified by an optimised reversed phase highperformance liquid chromatography (HPLC) protocol using a pentafluorophenyl (PFP) column with water and acetonitrile (50:50) as mobile phase, and a flow rate of 1ml/min. The chemical structure was determined using liquid chromatography-tandem mass spectroscopy LC-MS/MS. Real-time quantitative polymerase chain reaction (RT-qPCR) gene expression of selected adipokines and proteins implicated in Type-2 diabetes (T2D) were investigated in specific peripheral tissues isolated from an in vivo obese rat model. An in vitro cell culture model was used to determine the crosstalk between the peripheral tissues and pancreatic (INS-1E) β-cells. Various nanoformulations of L. leonurus extract were prepared and their effect on cytotoxicity (in Chang liver and INS-1 cells), insulin-mediated glucose uptake (Change liver cells) and insulin secretion (INS-1) were investigated. The average yield of marrubiin from the plant extract was 10% (n=3), with a molecular mass of 333.20Da and a molecular formula of C20H29O4 +. Results from the in vivo study showed that the L. leonurus extract significantly (p<0.05) enhanced the gene expression of adiponectin, peroxisome proliferator-activated receptor gamma (PPAR-γ), glucokinase (GK), uncoupling protein-2 (UCP-2) and reduced leptin in adipose tissue, but resistin, glucose transporters (GLUT), fatty acid synthase (FAS), insulin receptor substrate -1 (IRS-1) and phosphoenolpyruvate carboxykinase (PEPCK) gene expression were not affected. Marrubiin decreased gene expression of leptin and resistin, and increased IRS-1 and glucokinase in adipose tissue. In liver and muscle tissues, marrubiin and the L. leonurus extract reduced gene expression of PPAR-γ, IRS-1, glucokinase and PEPCK. In the in vitro crosstalk study (under normoglycaemic and hyperglycaemic conditions), conditioned medium from 3T3-L1 cells significantly (p<0.01) enhanced insulin secretion. This was not observed in INS-1E cells exposed to muscle- and liver-conditioned medium, respectively. The in vitro studies using a nanostructured lipid formulation (NLC) of the plant extract was not cytotoxic to either INS-1 and Chang liver cells. The NLC formulation significantly (p<0.05) enhanced glucose uptake in Chang liver cells and improved chronic insulin release in INS-1 cells (p<0.05). Based on the above findings from the in vivo and in vitro studies, both L. leonurus and marrubiin exerted an insulinotropic effect via adipose tissue on pancreatic β-cells. The findings in the in vivo study showed that marrubiin and the L. leonurus extract were employing their major anti-diabetic action via the adipose tissue.
- Full Text:
- Date Issued: 2016
- Authors: Odei-Addo, Frank , Levendal, Ruby-Ann
- Date: 2016
- Subjects: Diabetes Plant extracts
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/13116 , vital:27153
- Description: Diabetes mellitus is a metabolic disease characterised by hyperglycaemia resulting from defects in insulin secretion, insulin action, or both. The leaf extract of Leonotis leonurus and its active compound marrubiin, have been shown to possess anti-diabetic, antiplatelet, anti-inflammatory and anti-coagulation activity. In the present study, the mechanism by which L. leonurus and marrubiin exert their anti-diabetic properties, the cross-talk between the peripheral tissues and a nano drug delivery system were investigated. Marrubiin in the plant extract was effectively quantified by an optimised reversed phase highperformance liquid chromatography (HPLC) protocol using a pentafluorophenyl (PFP) column with water and acetonitrile (50:50) as mobile phase, and a flow rate of 1ml/min. The chemical structure was determined using liquid chromatography-tandem mass spectroscopy LC-MS/MS. Real-time quantitative polymerase chain reaction (RT-qPCR) gene expression of selected adipokines and proteins implicated in Type-2 diabetes (T2D) were investigated in specific peripheral tissues isolated from an in vivo obese rat model. An in vitro cell culture model was used to determine the crosstalk between the peripheral tissues and pancreatic (INS-1E) β-cells. Various nanoformulations of L. leonurus extract were prepared and their effect on cytotoxicity (in Chang liver and INS-1 cells), insulin-mediated glucose uptake (Change liver cells) and insulin secretion (INS-1) were investigated. The average yield of marrubiin from the plant extract was 10% (n=3), with a molecular mass of 333.20Da and a molecular formula of C20H29O4 +. Results from the in vivo study showed that the L. leonurus extract significantly (p<0.05) enhanced the gene expression of adiponectin, peroxisome proliferator-activated receptor gamma (PPAR-γ), glucokinase (GK), uncoupling protein-2 (UCP-2) and reduced leptin in adipose tissue, but resistin, glucose transporters (GLUT), fatty acid synthase (FAS), insulin receptor substrate -1 (IRS-1) and phosphoenolpyruvate carboxykinase (PEPCK) gene expression were not affected. Marrubiin decreased gene expression of leptin and resistin, and increased IRS-1 and glucokinase in adipose tissue. In liver and muscle tissues, marrubiin and the L. leonurus extract reduced gene expression of PPAR-γ, IRS-1, glucokinase and PEPCK. In the in vitro crosstalk study (under normoglycaemic and hyperglycaemic conditions), conditioned medium from 3T3-L1 cells significantly (p<0.01) enhanced insulin secretion. This was not observed in INS-1E cells exposed to muscle- and liver-conditioned medium, respectively. The in vitro studies using a nanostructured lipid formulation (NLC) of the plant extract was not cytotoxic to either INS-1 and Chang liver cells. The NLC formulation significantly (p<0.05) enhanced glucose uptake in Chang liver cells and improved chronic insulin release in INS-1 cells (p<0.05). Based on the above findings from the in vivo and in vitro studies, both L. leonurus and marrubiin exerted an insulinotropic effect via adipose tissue on pancreatic β-cells. The findings in the in vivo study showed that marrubiin and the L. leonurus extract were employing their major anti-diabetic action via the adipose tissue.
- Full Text:
- Date Issued: 2016