Strategies to facilitate community-based health care for severely and persistently mentally ill persons
- Authors: Shasha, Nontembeko Grycelda
- Date: 2015
- Subjects: Mentally ill -- Rehabilitation , Community mental health services , Community mental health services -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3755 , vital:20461
- Description: The goal of mental health delivery system is to allow the individual with severe and persistent mental illness to live and function effectively in the community and to ensure that the consumers and their families have access to accurate information that promotes learning, self-monitoring and accountability (Stuart & Laraia, 2005:710). In community-based health care, the persons living with severe and persistent mental illness (SPMI) are in their natural environment in the context of the family and the community. The goals of care are focused around maximizing the person living with SPMI’s quality of life (Hunt, 2001:15-16). In South Africa, an integrated package of essential Primary Health Care (PHC) services has been made available to the entire population in order to provide the solid foundation of a single unified health care service (Department of Health, 2000:4). The assessment of health care needs of persons living with SPMI is a dynamic on-going process that is used to collect information, recognise changes, analyse needs and plan health care to provide baseline information to help evaluate the physiological and psychological normality and functional capacity of persons with SPMI (Hunt, 2001:100). There is insufficient information from the Department of Health to either satisfy the enquiry of whether the health care needs of persons living with SPMI are being met comprehensively or whether the practitioners rendering community-based health care are knowledgeable and comply with PHC norms and standards developed by this Department. The researcher is interested in understanding how the persons living with SPMI and their families experience the community-based health care provided by PHC nurses. The purpose of this research study is to develop strategies that would assist the PHC nurses in the selected rural areas of the Eastern Cape to facilitate community-based health care and to render a health care service relevant to the health care needs of the persons living with SPMI and their families. To achieve the objective of the study, the research design was based on a qualitative, exploratory, descriptive, contextual research approach. Phase one includes describing and selecting the research population and the sampling process prior to conducting the field work which comprises individual interviews with persons living with SPMI and their families as well as PHC nurses. According to Dickoff, James and Weidenbach (1968:422) and Chinn and Kramer (1995:78), this strategy involves identifying concepts from fieldwork and creating conceptual meaning to provide a foundation for developing strategies to facilitate community-based care for persons living with mental illness. Phase two of the research design will focus on development of conceptual framework in order to allow better understanding of the phenomenon of interest, as the major concepts will be simplified by connecting all related concepts together by means of statements. This was done by making use of the themes identified during data analysis and the literature sources used throughout this research process. The evaluation criteria of Chinn and Kramer (2008:237-248) were used to evaluate the strategies. It is therefore concluded that the researcher succeeded in achieving the purpose of this study because strategies which were understandable, clear, applicable and relevant to the nursing practice have been developed for use by Department of Health and Primary Health Care to facilitate the multifaceted role of the PHC nurses.
- Full Text:
- Date Issued: 2015
- Authors: Shasha, Nontembeko Grycelda
- Date: 2015
- Subjects: Mentally ill -- Rehabilitation , Community mental health services , Community mental health services -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3755 , vital:20461
- Description: The goal of mental health delivery system is to allow the individual with severe and persistent mental illness to live and function effectively in the community and to ensure that the consumers and their families have access to accurate information that promotes learning, self-monitoring and accountability (Stuart & Laraia, 2005:710). In community-based health care, the persons living with severe and persistent mental illness (SPMI) are in their natural environment in the context of the family and the community. The goals of care are focused around maximizing the person living with SPMI’s quality of life (Hunt, 2001:15-16). In South Africa, an integrated package of essential Primary Health Care (PHC) services has been made available to the entire population in order to provide the solid foundation of a single unified health care service (Department of Health, 2000:4). The assessment of health care needs of persons living with SPMI is a dynamic on-going process that is used to collect information, recognise changes, analyse needs and plan health care to provide baseline information to help evaluate the physiological and psychological normality and functional capacity of persons with SPMI (Hunt, 2001:100). There is insufficient information from the Department of Health to either satisfy the enquiry of whether the health care needs of persons living with SPMI are being met comprehensively or whether the practitioners rendering community-based health care are knowledgeable and comply with PHC norms and standards developed by this Department. The researcher is interested in understanding how the persons living with SPMI and their families experience the community-based health care provided by PHC nurses. The purpose of this research study is to develop strategies that would assist the PHC nurses in the selected rural areas of the Eastern Cape to facilitate community-based health care and to render a health care service relevant to the health care needs of the persons living with SPMI and their families. To achieve the objective of the study, the research design was based on a qualitative, exploratory, descriptive, contextual research approach. Phase one includes describing and selecting the research population and the sampling process prior to conducting the field work which comprises individual interviews with persons living with SPMI and their families as well as PHC nurses. According to Dickoff, James and Weidenbach (1968:422) and Chinn and Kramer (1995:78), this strategy involves identifying concepts from fieldwork and creating conceptual meaning to provide a foundation for developing strategies to facilitate community-based care for persons living with mental illness. Phase two of the research design will focus on development of conceptual framework in order to allow better understanding of the phenomenon of interest, as the major concepts will be simplified by connecting all related concepts together by means of statements. This was done by making use of the themes identified during data analysis and the literature sources used throughout this research process. The evaluation criteria of Chinn and Kramer (2008:237-248) were used to evaluate the strategies. It is therefore concluded that the researcher succeeded in achieving the purpose of this study because strategies which were understandable, clear, applicable and relevant to the nursing practice have been developed for use by Department of Health and Primary Health Care to facilitate the multifaceted role of the PHC nurses.
- Full Text:
- Date Issued: 2015
The contribution of guest houses to economic growth and employment as key components of local economic development in the Eden District Area
- Authors: Ramukumba, Takalani
- Date: 2015
- Subjects: Economic development -- South Africa -- Western Cape , Sustainable tourism -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/5214 , vital:20821
- Description: Tourism has come to be seen as a key driver for local economic development in South Africa, as it provides opportunities for pro-poor and community-based initiatives. On a global scale, the challenges of confronting poverty and unemployment continue to dominate the development agenda. The ability of Local Economic Development (LED) to empower local people has earned favour with national governments and development theorists. The imperative facing South Africa to achieve a more equitable and sustainable economy is essentially the challenge to adopt and implement a development approach that will reduce poverty and unemployment (which are the two key objectives of LED) to the greatest extent. It is within this context that the South African government has sought to incorporate LED into their economic development framework, predominantly through the decentralisation of development control and planning to the local government level. This study examined the contribution of guest houses to economic growth and employment as key components of LED in a sustainable manner. The study revealed that guest houses are playing a key role in the development of the local economy in the Eden district region. Guest houses are providing employment opportunities to the local residents both on a full-time and part-time basis. Further to this, guest houses are buying many locally-produced products and services from local suppliers and this contributes to economic growth of the local economy. However, this study also found that many of the guest houses in the area are not aware of government incentives available to support them and very few of them have made use of these services. This is something that needs to be addressed if these guest houses are to continue to strengthen the local economy and provide employment opportunities in a sustainable manner. The study revealed that many of the guest houses are operating in an environmentally friendly manner and this will ensure their future sustainability. The broader situation and the contribution of the accommodation sector as critical assets in local and national tourism economies has been thoroughly researched in tourism research around the world. Existing work on the accommodation sector in the South African tourism economy is mainly urban-focused and indicates that its local development impacts can be positive albeit not always maximised through local linkages, however, only a limited amount of academic investigations examines the contribution of tourism sub-sectors to economic growth and employment. The authenticity of this study is based on Its contribution which must be viewed in relation to the relatively limited body of literature in the contribution of tourism sub-sectors to economic growth and employment and in this case guest houses as one type of accommodation sub-sector.
- Full Text:
- Date Issued: 2015
- Authors: Ramukumba, Takalani
- Date: 2015
- Subjects: Economic development -- South Africa -- Western Cape , Sustainable tourism -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/5214 , vital:20821
- Description: Tourism has come to be seen as a key driver for local economic development in South Africa, as it provides opportunities for pro-poor and community-based initiatives. On a global scale, the challenges of confronting poverty and unemployment continue to dominate the development agenda. The ability of Local Economic Development (LED) to empower local people has earned favour with national governments and development theorists. The imperative facing South Africa to achieve a more equitable and sustainable economy is essentially the challenge to adopt and implement a development approach that will reduce poverty and unemployment (which are the two key objectives of LED) to the greatest extent. It is within this context that the South African government has sought to incorporate LED into their economic development framework, predominantly through the decentralisation of development control and planning to the local government level. This study examined the contribution of guest houses to economic growth and employment as key components of LED in a sustainable manner. The study revealed that guest houses are playing a key role in the development of the local economy in the Eden district region. Guest houses are providing employment opportunities to the local residents both on a full-time and part-time basis. Further to this, guest houses are buying many locally-produced products and services from local suppliers and this contributes to economic growth of the local economy. However, this study also found that many of the guest houses in the area are not aware of government incentives available to support them and very few of them have made use of these services. This is something that needs to be addressed if these guest houses are to continue to strengthen the local economy and provide employment opportunities in a sustainable manner. The study revealed that many of the guest houses are operating in an environmentally friendly manner and this will ensure their future sustainability. The broader situation and the contribution of the accommodation sector as critical assets in local and national tourism economies has been thoroughly researched in tourism research around the world. Existing work on the accommodation sector in the South African tourism economy is mainly urban-focused and indicates that its local development impacts can be positive albeit not always maximised through local linkages, however, only a limited amount of academic investigations examines the contribution of tourism sub-sectors to economic growth and employment. The authenticity of this study is based on Its contribution which must be viewed in relation to the relatively limited body of literature in the contribution of tourism sub-sectors to economic growth and employment and in this case guest houses as one type of accommodation sub-sector.
- Full Text:
- Date Issued: 2015
The effects of outsourcing practices conducted by organisations in Nairobi
- Authors: Wachira, Wanjungu
- Date: 2015
- Subjects: Contracting out , Industrial management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/4988 , vital:20775
- Description: The purpose of this study is to investigate the relationship between outsourcing and development in Nairobi. The key research question for this study is what are the impacts of outsourcing practices conducted by organisations in Nairobi? Data were obtained from questionnaires distributed in December 2010. A total of 85 profit-making firms in Nairobi with a sample of 165 management employees were selected for this study. The empirical findings obtained relate to four outsourcing theories. Transaction Cost Analysis (TCA) Theory focuses on the cost savings that result from outsourcing. Agency Outsourcing Theory centres on outsourcing firms hiring agents to achieve productivity. Hiring agents may result in permanent staff being retrenched and additional outsourcing personnel being contracted and job creation and/or job loss results. Expectation Confirmation Theory (ECT) emphasises the importance of an outsourcing provider conforming to quality management principles. Resource Based Theory (RBT) proposes that organisations need a collection of resources and capabilities to execute outsourcing successfully. Findings further suggested that outsourcing can yield positive and/or negative outcomes depending on risks encountered, the business environment, company policies, function/s to be outsourced, and the competence and commitment of an outsourcing vendor. To further enhance the positive impact of outsourcing three improvements need to be executed: formulation of standard policies, price regulations, and commitment of outsourcing firms in adhering to set contract deadlines. It is suggested that the following would allow organisations to gain more from outsourcing in the future: the adoption of international/offshore outsourcing practices, more commitment by outsourcing consultants, the standardisation of charges for outsourcing contracts, and the use of new technology that would improve how outsourcing is conducted. It is concluded that the positive impacts of outsourcing would foster development to some extent while the possible negative impact of outsourcing would impede development.
- Full Text:
- Date Issued: 2015
- Authors: Wachira, Wanjungu
- Date: 2015
- Subjects: Contracting out , Industrial management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/4988 , vital:20775
- Description: The purpose of this study is to investigate the relationship between outsourcing and development in Nairobi. The key research question for this study is what are the impacts of outsourcing practices conducted by organisations in Nairobi? Data were obtained from questionnaires distributed in December 2010. A total of 85 profit-making firms in Nairobi with a sample of 165 management employees were selected for this study. The empirical findings obtained relate to four outsourcing theories. Transaction Cost Analysis (TCA) Theory focuses on the cost savings that result from outsourcing. Agency Outsourcing Theory centres on outsourcing firms hiring agents to achieve productivity. Hiring agents may result in permanent staff being retrenched and additional outsourcing personnel being contracted and job creation and/or job loss results. Expectation Confirmation Theory (ECT) emphasises the importance of an outsourcing provider conforming to quality management principles. Resource Based Theory (RBT) proposes that organisations need a collection of resources and capabilities to execute outsourcing successfully. Findings further suggested that outsourcing can yield positive and/or negative outcomes depending on risks encountered, the business environment, company policies, function/s to be outsourced, and the competence and commitment of an outsourcing vendor. To further enhance the positive impact of outsourcing three improvements need to be executed: formulation of standard policies, price regulations, and commitment of outsourcing firms in adhering to set contract deadlines. It is suggested that the following would allow organisations to gain more from outsourcing in the future: the adoption of international/offshore outsourcing practices, more commitment by outsourcing consultants, the standardisation of charges for outsourcing contracts, and the use of new technology that would improve how outsourcing is conducted. It is concluded that the positive impacts of outsourcing would foster development to some extent while the possible negative impact of outsourcing would impede development.
- Full Text:
- Date Issued: 2015
The impact of domain knowledge-driven variable derivation on classifier performance for corporate data mining
- Authors: Welcker, Laura Joana Maria
- Date: 2015
- Subjects: Data mining , Business -- Data processing , Database management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/5009 , vital:20778
- Description: The technological progress in terms of increasing computational power and growing virtual space to collect data offers great potential for businesses to benefit from data mining applications. Data mining can create a competitive advantage for corporations by discovering business relevant information, such as patterns, relationships, and rules. The role of the human user within the data mining process is crucial, which is why the research area of domain knowledge becomes increasingly important. This thesis investigates the impact of domain knowledge-driven variable derivation on classifier performance for corporate data mining. Domain knowledge is defined as methodological, data and business know-how. The thesis investigates the topic from a new perspective by shifting the focus from a one-sided approach, namely a purely analytic or purely theoretical approach towards a target group-oriented (researcher and practitioner) approach which puts the methodological aspect by means of a scientific guideline in the centre of the research. In order to ensure feasibility and practical relevance of the guideline, it is adapted and applied to the requirements of a practical business case. Thus, the thesis examines the topic from both perspectives, a theoretical and practical perspective. Therewith, it overcomes the limitation of a one-sided approach which mostly lacks practical relevance or generalisability of the results. The primary objective of this thesis is to provide a scientific guideline which should enable both practitioners and researchers to move forward the domain knowledge-driven research for variable derivation on a corporate basis. In the theoretical part, a broad overview of the main aspects which are necessary to undertake the research are given, such as the concept of domain knowledge, the data mining task of classification, variable derivation as a subtask of data preparation, and evaluation techniques. This part of the thesis refers to the methodological aspect of domain knowledge. In the practical part, a research design is developed for testing six hypotheses related to domain knowledge-driven variable derivation. The major contribution of the empirical study is concerned with testing the impact of domain knowledge on a real business data set compared to the impact of a standard and randomly derived data set. The business application of the research is a binary classification problem in the domain of an insurance business, which deals with the prediction of damages in legal expenses insurances. Domain knowledge is expressed through deriving the corporate variables by means of the business and data-driven constructive induction strategy. Six variable derivation steps are investigated: normalisation, instance relation, discretisation, categorical encoding, ratio, and multivariate mathematical function. The impact of the domain knowledge is examined by pairwise (with and without derived variables) performance comparisons for five classification techniques (decision trees, naive Bayes, logistic regression, artificial neural networks, k-nearest neighbours). The impact is measured by two classifier performance criteria: sensitivity and area under the ROC-curve (AUC). The McNemar significance test is used to verify the results. Based on the results, two hypotheses are clearly verified and accepted, three hypotheses are partly verified, and one hypothesis had to be rejected on the basis of the case study results. The thesis reveals a significant positive impact of domain knowledge-driven variable derivation on classifier performance for options of all six tested steps. Furthermore, the findings indicate that the classification technique influences the impact of the variable derivation steps, and the bundling of steps has a significant higher performance impact if the variables are derived by using domain knowledge (compared to a non-knowledge application). Finally, the research turns out that an empirical examination of the domain knowledge impact is very complex due to a high level of interaction between the selected research parameters (variable derivation step, classification technique, and performance criteria).
- Full Text:
- Date Issued: 2015
- Authors: Welcker, Laura Joana Maria
- Date: 2015
- Subjects: Data mining , Business -- Data processing , Database management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/5009 , vital:20778
- Description: The technological progress in terms of increasing computational power and growing virtual space to collect data offers great potential for businesses to benefit from data mining applications. Data mining can create a competitive advantage for corporations by discovering business relevant information, such as patterns, relationships, and rules. The role of the human user within the data mining process is crucial, which is why the research area of domain knowledge becomes increasingly important. This thesis investigates the impact of domain knowledge-driven variable derivation on classifier performance for corporate data mining. Domain knowledge is defined as methodological, data and business know-how. The thesis investigates the topic from a new perspective by shifting the focus from a one-sided approach, namely a purely analytic or purely theoretical approach towards a target group-oriented (researcher and practitioner) approach which puts the methodological aspect by means of a scientific guideline in the centre of the research. In order to ensure feasibility and practical relevance of the guideline, it is adapted and applied to the requirements of a practical business case. Thus, the thesis examines the topic from both perspectives, a theoretical and practical perspective. Therewith, it overcomes the limitation of a one-sided approach which mostly lacks practical relevance or generalisability of the results. The primary objective of this thesis is to provide a scientific guideline which should enable both practitioners and researchers to move forward the domain knowledge-driven research for variable derivation on a corporate basis. In the theoretical part, a broad overview of the main aspects which are necessary to undertake the research are given, such as the concept of domain knowledge, the data mining task of classification, variable derivation as a subtask of data preparation, and evaluation techniques. This part of the thesis refers to the methodological aspect of domain knowledge. In the practical part, a research design is developed for testing six hypotheses related to domain knowledge-driven variable derivation. The major contribution of the empirical study is concerned with testing the impact of domain knowledge on a real business data set compared to the impact of a standard and randomly derived data set. The business application of the research is a binary classification problem in the domain of an insurance business, which deals with the prediction of damages in legal expenses insurances. Domain knowledge is expressed through deriving the corporate variables by means of the business and data-driven constructive induction strategy. Six variable derivation steps are investigated: normalisation, instance relation, discretisation, categorical encoding, ratio, and multivariate mathematical function. The impact of the domain knowledge is examined by pairwise (with and without derived variables) performance comparisons for five classification techniques (decision trees, naive Bayes, logistic regression, artificial neural networks, k-nearest neighbours). The impact is measured by two classifier performance criteria: sensitivity and area under the ROC-curve (AUC). The McNemar significance test is used to verify the results. Based on the results, two hypotheses are clearly verified and accepted, three hypotheses are partly verified, and one hypothesis had to be rejected on the basis of the case study results. The thesis reveals a significant positive impact of domain knowledge-driven variable derivation on classifier performance for options of all six tested steps. Furthermore, the findings indicate that the classification technique influences the impact of the variable derivation steps, and the bundling of steps has a significant higher performance impact if the variables are derived by using domain knowledge (compared to a non-knowledge application). Finally, the research turns out that an empirical examination of the domain knowledge impact is very complex due to a high level of interaction between the selected research parameters (variable derivation step, classification technique, and performance criteria).
- Full Text:
- Date Issued: 2015
Ultra-high precision machining of contact lens polymers
- Authors: Olufayo, Oluwole Ayodeji
- Date: 2015
- Subjects: Contact lenses , Polymers
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3001 , vital:20385
- Description: Contact lens manufacture requires a high level of accuracy and surface integrity in the range of a few nanometres. Amidst numerous optical manufacturing techniques, single-point diamond turning is widely employed in the making of contact lenses due to its capability of producing optical surfaces of complex shapes and nanometric accuracy. For process optimisation, it is ideal to assess the effects of various conditions and also establish their relationships with the surface finish. Presently, there is little information available on the performance of single point diamond turning when machining contact lens polymers. Therefore, the research work undertaken herewith is aimed at testing known facts in contact lens diamond turning and investigating the performance of ultra-high precision manufacturing of contact lens polymers. Experimental tests were conducted on Roflufocon E, which is a commercially available contact lens polymer and on Precitech Nanoform Ultra-grind 250 precision machining. Tests were performed at varying cutting feeds, speed and depth of cut. Initial experimental tests investigated the influence of process factors affecting surface finish in the UHPM of lenses. The acquired data were statistically analysed using Response Surface Method (RSM) to create a model of the process. Subsequently, a model which uses Runge-Kutta’s fourth order non-linear finite series scheme was developed and adapted to deduce the force occurring at the tool tip. These forces were also statistically analysed and modelled to also predict the effects process factors have on cutting force. Further experimental tests were aimed at establishing the presence of the triboelectric wear phenomena occurring during polymer machining and identifying the most influential process factors. Results indicate that feed rate is a significant factor in the generation of high optical surface quality. In addition, the depth of cut was identified as a significant factor in the generation of low surface roughness in lenses. The influence some of these process factors had was notably linked to triboelectric effects. This tribological effect was generated from the continuous rubbing action of magnetised chips on the cutting tool. This further stresses the presence of high static charging during cutting. Moderately humid cutting conditions presented an adequate means for static charge control and displayed improved surface finishes. In all experimental tests, the feed rate was identified as the most significant factor within the range of cutting parameters employed. Hence, the results validated the fact that feed rate had a high influence in polymer machining. The work also established the relationship on how surface roughness of an optical lens responded to monitoring signals and parameters such as force, feed, speed and depth of cut during machining and it generated models for prediction of surface finishes and appropriate selection of parameters. Furthermore, the study provides a molecular simulation analysis for validating observed conditions occurring at the nanometric scale in polymer machining. This is novel in molecular polymer modelling. The outcome of this research has contributed significantly to the body of knowledge and has provided basic information in the area of precision manufacturing of optical components of high surface integrity such as contact lenses. The application of the research findings presented here cuts across various fields such as medicine, semi-conductors, aerospace, defence, telecom, lasers, instrumentation and life sciences.
- Full Text:
- Date Issued: 2015
- Authors: Olufayo, Oluwole Ayodeji
- Date: 2015
- Subjects: Contact lenses , Polymers
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/3001 , vital:20385
- Description: Contact lens manufacture requires a high level of accuracy and surface integrity in the range of a few nanometres. Amidst numerous optical manufacturing techniques, single-point diamond turning is widely employed in the making of contact lenses due to its capability of producing optical surfaces of complex shapes and nanometric accuracy. For process optimisation, it is ideal to assess the effects of various conditions and also establish their relationships with the surface finish. Presently, there is little information available on the performance of single point diamond turning when machining contact lens polymers. Therefore, the research work undertaken herewith is aimed at testing known facts in contact lens diamond turning and investigating the performance of ultra-high precision manufacturing of contact lens polymers. Experimental tests were conducted on Roflufocon E, which is a commercially available contact lens polymer and on Precitech Nanoform Ultra-grind 250 precision machining. Tests were performed at varying cutting feeds, speed and depth of cut. Initial experimental tests investigated the influence of process factors affecting surface finish in the UHPM of lenses. The acquired data were statistically analysed using Response Surface Method (RSM) to create a model of the process. Subsequently, a model which uses Runge-Kutta’s fourth order non-linear finite series scheme was developed and adapted to deduce the force occurring at the tool tip. These forces were also statistically analysed and modelled to also predict the effects process factors have on cutting force. Further experimental tests were aimed at establishing the presence of the triboelectric wear phenomena occurring during polymer machining and identifying the most influential process factors. Results indicate that feed rate is a significant factor in the generation of high optical surface quality. In addition, the depth of cut was identified as a significant factor in the generation of low surface roughness in lenses. The influence some of these process factors had was notably linked to triboelectric effects. This tribological effect was generated from the continuous rubbing action of magnetised chips on the cutting tool. This further stresses the presence of high static charging during cutting. Moderately humid cutting conditions presented an adequate means for static charge control and displayed improved surface finishes. In all experimental tests, the feed rate was identified as the most significant factor within the range of cutting parameters employed. Hence, the results validated the fact that feed rate had a high influence in polymer machining. The work also established the relationship on how surface roughness of an optical lens responded to monitoring signals and parameters such as force, feed, speed and depth of cut during machining and it generated models for prediction of surface finishes and appropriate selection of parameters. Furthermore, the study provides a molecular simulation analysis for validating observed conditions occurring at the nanometric scale in polymer machining. This is novel in molecular polymer modelling. The outcome of this research has contributed significantly to the body of knowledge and has provided basic information in the area of precision manufacturing of optical components of high surface integrity such as contact lenses. The application of the research findings presented here cuts across various fields such as medicine, semi-conductors, aerospace, defence, telecom, lasers, instrumentation and life sciences.
- Full Text:
- Date Issued: 2015
Whither South Africa – neoliberalism or an embodied communitarian indigenous ethic?
- Authors: Konik, Inga
- Date: 2015
- Subjects: Neoliberalism -- South Africa Communitarianism , Literature and society South Africa -- Politics and government -- 21st century
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/21656 , vital:29729
- Description: This thesis offers a critique of neoliberal transformation in South Africa, which process results in growing social inequality and political apathy among citizens. Many scholars have made political-economic and historical analyses of the neoliberal transition, emphasizing structural changes at work at a ‘macro’ level. However, little attention has been paid to changes that have taken place in South Africa at the ‘micro’ level – changes to individual subjectivity and gender codes. That said, the thesis opens by summarizing the above mentioned political-economic accounts of neoliberalism in South Africa, because such works are indispensable to understanding how the regime is embedded within and buttressed by major global institutions. Yet, to achieve a holistic grasp of ‘neoliberal South Africa,’ more is needed. A sociological investigation into the impact of neoliberalism on ordinary people’s self-identification uncovers deep cultural reasons for the continued perpetuation of this unjust political-economic system. Only if it can be understood why people comply with the system in the face of suffering, can effective counter-measures be proposed and implemented over time. This thesis is inherently transdisciplinary. The approach rejects the privileging of one discipline over others, and likewise cautions against collapsing or dissolving disciplines into one another. Instead, recognizing the valuable contribution that each discipline can make to critical scrutiny of a particular issue, a form of methodological transversalism is used to bring different disciplines into dialogue with one another. Following this interplay of structural and subjective analysis, the thesis uncovers the role that consumerism plays in the political neutralization of South Africans. Consumer culture, tied as it is to profitable accumulation, instigates the neoliberal ‘values’ of economistic calculation, competition, and social atomization. This ethos is inculcated in individuals, both at work and during leisure hours. Moreover, consumerism derives much of its power from its ‘sexual sell,’ the creation of fashionable and ‘exemplary’ models of masculinity and femininity. In South Africa, these hegemonic gender models serve to instill competitive individualism while derogating indigenous values. The thesis proposes that in order to counter neoliberal hegemony in South Africa, and begin reclaiming the cultural autonomy of its peoples, it is important to invigorate indigenous communitarian practices and norms. The original contribution of this thesis consists in placing the African ethos of ubuntu in transversal dialogue with global ecological feminist voices. Both political perspectives reinforce a liberatory alternative vision for a future based on principles of embodied relationality, care giving and protection of community.
- Full Text:
- Date Issued: 2015
- Authors: Konik, Inga
- Date: 2015
- Subjects: Neoliberalism -- South Africa Communitarianism , Literature and society South Africa -- Politics and government -- 21st century
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/21656 , vital:29729
- Description: This thesis offers a critique of neoliberal transformation in South Africa, which process results in growing social inequality and political apathy among citizens. Many scholars have made political-economic and historical analyses of the neoliberal transition, emphasizing structural changes at work at a ‘macro’ level. However, little attention has been paid to changes that have taken place in South Africa at the ‘micro’ level – changes to individual subjectivity and gender codes. That said, the thesis opens by summarizing the above mentioned political-economic accounts of neoliberalism in South Africa, because such works are indispensable to understanding how the regime is embedded within and buttressed by major global institutions. Yet, to achieve a holistic grasp of ‘neoliberal South Africa,’ more is needed. A sociological investigation into the impact of neoliberalism on ordinary people’s self-identification uncovers deep cultural reasons for the continued perpetuation of this unjust political-economic system. Only if it can be understood why people comply with the system in the face of suffering, can effective counter-measures be proposed and implemented over time. This thesis is inherently transdisciplinary. The approach rejects the privileging of one discipline over others, and likewise cautions against collapsing or dissolving disciplines into one another. Instead, recognizing the valuable contribution that each discipline can make to critical scrutiny of a particular issue, a form of methodological transversalism is used to bring different disciplines into dialogue with one another. Following this interplay of structural and subjective analysis, the thesis uncovers the role that consumerism plays in the political neutralization of South Africans. Consumer culture, tied as it is to profitable accumulation, instigates the neoliberal ‘values’ of economistic calculation, competition, and social atomization. This ethos is inculcated in individuals, both at work and during leisure hours. Moreover, consumerism derives much of its power from its ‘sexual sell,’ the creation of fashionable and ‘exemplary’ models of masculinity and femininity. In South Africa, these hegemonic gender models serve to instill competitive individualism while derogating indigenous values. The thesis proposes that in order to counter neoliberal hegemony in South Africa, and begin reclaiming the cultural autonomy of its peoples, it is important to invigorate indigenous communitarian practices and norms. The original contribution of this thesis consists in placing the African ethos of ubuntu in transversal dialogue with global ecological feminist voices. Both political perspectives reinforce a liberatory alternative vision for a future based on principles of embodied relationality, care giving and protection of community.
- Full Text:
- Date Issued: 2015
A critical analysis of selected literary techniques in P.T. Mtuze’s prose narratives
- Authors: Kondowe, Zandile Ziyanda
- Date: 2016
- Subjects: Xhosa literature -- History and criticism Literary style
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/33217 , vital:32570
- Description: The main purpose of this study is to provide a critical analysis of selected literary techniques in P.T. Mtuze’s prose narratives. This study seeks to analyse his style of writing in all his texts. The aspects of his style under stylistic techniques and criticism will serve as a foundation theory that will link the study to the analysis of definitions and referencing under imagery and its aspects; including humour, satire, idioms, proverbs, literary techniques, and figures of speech. Mtuze is noted as one of the most prolific writers due to his ingenuity in language skills, especially in isiXhosa. Mtuze is one of the best humoristic writers; hence he is popular due to applying humour in the prose works he wrote. This study is divided into seven chapters, and the theory which is used for this study is also scrutinised in order to get a sense of what the author intended to deliver through his texts.
- Full Text:
- Date Issued: 2016
- Authors: Kondowe, Zandile Ziyanda
- Date: 2016
- Subjects: Xhosa literature -- History and criticism Literary style
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/33217 , vital:32570
- Description: The main purpose of this study is to provide a critical analysis of selected literary techniques in P.T. Mtuze’s prose narratives. This study seeks to analyse his style of writing in all his texts. The aspects of his style under stylistic techniques and criticism will serve as a foundation theory that will link the study to the analysis of definitions and referencing under imagery and its aspects; including humour, satire, idioms, proverbs, literary techniques, and figures of speech. Mtuze is noted as one of the most prolific writers due to his ingenuity in language skills, especially in isiXhosa. Mtuze is one of the best humoristic writers; hence he is popular due to applying humour in the prose works he wrote. This study is divided into seven chapters, and the theory which is used for this study is also scrutinised in order to get a sense of what the author intended to deliver through his texts.
- Full Text:
- Date Issued: 2016
A critical analysis of the role of strategic communication in strategic planning : a case study of South African universities
- Authors: Hadji, Mutambuli James
- Date: 2016
- Subjects: Communication in management Business communication Strategic planning
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8209 , vital:31978
- Description: The debate on how the communication function can contribute at a strategic level to organisational success is an on-going one because communicators still need to prove their relevance at the top management level. In general, the contribution of communication as a management function in corporate strategy is not known. It is either considered an afterthought or as an element within other functional departments. In this regard, the purpose of this study was to analyse critically the role of communication in strategic planning at the selected South African universities. To achieve this main objective, institutional theory was applied, as it seeks to affirm the role of communication in decision-making with the intention to be legitimised. In-depth interviews were conducted with senior communicators and strategy planners at six universities on how they approach strategic planning in their respective universities. Significant from the findings was the fact that the South African universities follow the same process for strategic planning. Regarding the role of strategic communication, the findings confirmed literature in the sense that communication practice at functional level has been institutionalised but not at the top management level. It was this study’s finding that university reputation and positioning did not prominently feature in the strategic planning processes. Furthermore, this study found that communicators should play a leading in environmental scanning to identify society, industry and commerce with a view to fine-tune the university’s qualification mix. That is, communicators should provide intelligence on changes in the environment which serve as the basis of the development of university strategies. In other words, they should provide vital information to top management to enable them to take informed strategic decisions. Lastly, it was this study’s finding that communicators should conduct evaluation research to assist top management in comparing the set strategic objectives with actual performance. In addition, the communicators should assist top management in determining corrective actions if need be. In view of these findings, this study developed guidelines that will empower communicators to make a more meaningful contribution in the strategic planning process. Given the paucity of research evidence of strategic communication in a university context, the study provides a better understanding of the theory and practice thereof.
- Full Text:
- Date Issued: 2016
- Authors: Hadji, Mutambuli James
- Date: 2016
- Subjects: Communication in management Business communication Strategic planning
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8209 , vital:31978
- Description: The debate on how the communication function can contribute at a strategic level to organisational success is an on-going one because communicators still need to prove their relevance at the top management level. In general, the contribution of communication as a management function in corporate strategy is not known. It is either considered an afterthought or as an element within other functional departments. In this regard, the purpose of this study was to analyse critically the role of communication in strategic planning at the selected South African universities. To achieve this main objective, institutional theory was applied, as it seeks to affirm the role of communication in decision-making with the intention to be legitimised. In-depth interviews were conducted with senior communicators and strategy planners at six universities on how they approach strategic planning in their respective universities. Significant from the findings was the fact that the South African universities follow the same process for strategic planning. Regarding the role of strategic communication, the findings confirmed literature in the sense that communication practice at functional level has been institutionalised but not at the top management level. It was this study’s finding that university reputation and positioning did not prominently feature in the strategic planning processes. Furthermore, this study found that communicators should play a leading in environmental scanning to identify society, industry and commerce with a view to fine-tune the university’s qualification mix. That is, communicators should provide intelligence on changes in the environment which serve as the basis of the development of university strategies. In other words, they should provide vital information to top management to enable them to take informed strategic decisions. Lastly, it was this study’s finding that communicators should conduct evaluation research to assist top management in comparing the set strategic objectives with actual performance. In addition, the communicators should assist top management in determining corrective actions if need be. In view of these findings, this study developed guidelines that will empower communicators to make a more meaningful contribution in the strategic planning process. Given the paucity of research evidence of strategic communication in a university context, the study provides a better understanding of the theory and practice thereof.
- Full Text:
- Date Issued: 2016
A framework for enhancing trust for improved participation in electronic marketplaces accessed from mobile platforms
- Isabirye, Naomi Nabirye, Von Solms, R
- Authors: Isabirye, Naomi Nabirye , Von Solms, R
- Date: 2016
- Subjects: Information technology -- Economic aspects -- South Africa Agricultural innovations -- South Africa Agricultural systems -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/20019 , vital:29053
- Description: Information and communication technologies (ICTs) have been widely researched as a mechanism for improving the socio-economic status of disadvantaged, rural communities. In order to do this numerous technology-based initiatives have been introduced into disadvantaged, rural communities to assist them in various aspects of their lives. Unfortunately, even when the proposed benefit of a particular technology is clearly evident to its initiators, the adoption by the target users is often uncertain. This has also been the case with e-commerce in agriculture. Despite the numerous benefits of e-commerce for agricultural producers, the uptake has been low. Trust is a critical pre-condition for the adoption of e-marketplaces. E-marketplaces expose consumers to the risk of non-delivery or misrepresentation of goods ordered and the misuse of personal information by external parties. Additionally, the time investment needed to make a shift to e-marketplaces and the opinions of important reference groups affects the user’s willingness to trust and depend on an e-marketplace. This study was undertaken to assess the extent to which rural users with limited ICT experience would trust and, consequently, adopt an e-marketplace to support agricultural trade. A pragmatic philosophy was adopted in this study, indicating that the researcher’s view of reality is founded on the practical implications and outcomes that are observed. This study used a Canonical Action Research strategy to design, develop and deploy a voice based e-marketplace to assist the trading activities of a Western Cape based aloe community. The community was allowed to utilise thee-marketplace over a period of eight weeks. Thereafter, interviews were held with the participants to investigate their perceptions of the technology. As a result, a model proposing the factors that must be in place for trust to be achieved in a voice based e-marketplace was proposed. The study found that the trustworthiness of a technology results from the technology’s technical capability to satisfy the needs of its users reliably. Usability and security were found to be important determinants of the trustworthiness of a technology. Furthermore, the requirements elicitation process was found to be central to achieving trust as it defines the necessary criteria for developing secure, usable, functional, and reliable technologies that meet the needs of their users.
- Full Text:
- Date Issued: 2016
- Authors: Isabirye, Naomi Nabirye , Von Solms, R
- Date: 2016
- Subjects: Information technology -- Economic aspects -- South Africa Agricultural innovations -- South Africa Agricultural systems -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/20019 , vital:29053
- Description: Information and communication technologies (ICTs) have been widely researched as a mechanism for improving the socio-economic status of disadvantaged, rural communities. In order to do this numerous technology-based initiatives have been introduced into disadvantaged, rural communities to assist them in various aspects of their lives. Unfortunately, even when the proposed benefit of a particular technology is clearly evident to its initiators, the adoption by the target users is often uncertain. This has also been the case with e-commerce in agriculture. Despite the numerous benefits of e-commerce for agricultural producers, the uptake has been low. Trust is a critical pre-condition for the adoption of e-marketplaces. E-marketplaces expose consumers to the risk of non-delivery or misrepresentation of goods ordered and the misuse of personal information by external parties. Additionally, the time investment needed to make a shift to e-marketplaces and the opinions of important reference groups affects the user’s willingness to trust and depend on an e-marketplace. This study was undertaken to assess the extent to which rural users with limited ICT experience would trust and, consequently, adopt an e-marketplace to support agricultural trade. A pragmatic philosophy was adopted in this study, indicating that the researcher’s view of reality is founded on the practical implications and outcomes that are observed. This study used a Canonical Action Research strategy to design, develop and deploy a voice based e-marketplace to assist the trading activities of a Western Cape based aloe community. The community was allowed to utilise thee-marketplace over a period of eight weeks. Thereafter, interviews were held with the participants to investigate their perceptions of the technology. As a result, a model proposing the factors that must be in place for trust to be achieved in a voice based e-marketplace was proposed. The study found that the trustworthiness of a technology results from the technology’s technical capability to satisfy the needs of its users reliably. Usability and security were found to be important determinants of the trustworthiness of a technology. Furthermore, the requirements elicitation process was found to be central to achieving trust as it defines the necessary criteria for developing secure, usable, functional, and reliable technologies that meet the needs of their users.
- Full Text:
- Date Issued: 2016
A maturity grid-based method for assessing communication in business-IT alignment
- Authors: Coertze, Jacques Jacobus
- Date: 2016
- Subjects: Business communication , Management information systems
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/6740 , vital:21139
- Description: This thesis reports on the research undertaken to develop a method for organisations to assess human communication between their business and IT personnel as part of business–IT alignment. The research described in this thesis involves (i) a literature review in business–IT alignment and related fields, such as management studies and communication science; (ii) a Delphi study conducted among industry members, practitioners, and academics operating in the IT advisory, auditing and communication disciplines; and (iii) a case study of a public sector organisation in South Africa. By adopting a system-theoretic perspective on communication, this thesis proposes that communication in business–IT alignment can be seen as coordinating behaviour and a series of learning and reflection events, consequently culminating in increased mutual understanding. Various conceptualisations of communication are explored and, together with several industry elicited factors that influence communication in business–IT alignment, are incorporated into a conceptual model informing the assessment method. This research developed, applied, and tested a method whereby organisations can assess the quality of the human communication between their business and IT personnel as part of the business–IT alignment endeavour. The aim of this method is to trigger reflection on communication by considering communication philosophy and practices in business–IT alignment. The method, termed the ‘Business-IT Communication Alignment Maturity Improvement Communication Alignment Maturity Improvement (CAMI) method’, is based on a maturity grid-based approach, which stems originally from process improvement in software development and quality management. This thesis is most closely aligned with the research performed by Maier, Eckert, and Clarkson (2004, 2006), who successfully applied the maturity grid-based approach to investigate, audit and assess communication within the engineering design process. The question addressed in this thesis is whether this approach can be successfully extrapolated to the business–IT alignment context and whether it would yield similar benefits. Furthermore, the issue of whether it would offer a practical method for use in organisations is also addressed. Having applied the CAMI method at a public sector organisation, this thesis proposes that the maturity grid-based approach can indeed be extrapolated to iv the business–IT alignment context, consequently offering a viable and practical method for assessing communication in organisations. In particular, the CAMI method allows organisations to capture both their current and their desired communication situations and to expose discrepancies between the perceptions held by their business and IT personnel. These results form a basis for action planning, strategizing, and, ultimately, interventions for improvement. In conclusion, the thesis discusses further application and extension possibilities for the assessment method.
- Full Text:
- Date Issued: 2016
- Authors: Coertze, Jacques Jacobus
- Date: 2016
- Subjects: Business communication , Management information systems
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/6740 , vital:21139
- Description: This thesis reports on the research undertaken to develop a method for organisations to assess human communication between their business and IT personnel as part of business–IT alignment. The research described in this thesis involves (i) a literature review in business–IT alignment and related fields, such as management studies and communication science; (ii) a Delphi study conducted among industry members, practitioners, and academics operating in the IT advisory, auditing and communication disciplines; and (iii) a case study of a public sector organisation in South Africa. By adopting a system-theoretic perspective on communication, this thesis proposes that communication in business–IT alignment can be seen as coordinating behaviour and a series of learning and reflection events, consequently culminating in increased mutual understanding. Various conceptualisations of communication are explored and, together with several industry elicited factors that influence communication in business–IT alignment, are incorporated into a conceptual model informing the assessment method. This research developed, applied, and tested a method whereby organisations can assess the quality of the human communication between their business and IT personnel as part of the business–IT alignment endeavour. The aim of this method is to trigger reflection on communication by considering communication philosophy and practices in business–IT alignment. The method, termed the ‘Business-IT Communication Alignment Maturity Improvement Communication Alignment Maturity Improvement (CAMI) method’, is based on a maturity grid-based approach, which stems originally from process improvement in software development and quality management. This thesis is most closely aligned with the research performed by Maier, Eckert, and Clarkson (2004, 2006), who successfully applied the maturity grid-based approach to investigate, audit and assess communication within the engineering design process. The question addressed in this thesis is whether this approach can be successfully extrapolated to the business–IT alignment context and whether it would yield similar benefits. Furthermore, the issue of whether it would offer a practical method for use in organisations is also addressed. Having applied the CAMI method at a public sector organisation, this thesis proposes that the maturity grid-based approach can indeed be extrapolated to iv the business–IT alignment context, consequently offering a viable and practical method for assessing communication in organisations. In particular, the CAMI method allows organisations to capture both their current and their desired communication situations and to expose discrepancies between the perceptions held by their business and IT personnel. These results form a basis for action planning, strategizing, and, ultimately, interventions for improvement. In conclusion, the thesis discusses further application and extension possibilities for the assessment method.
- Full Text:
- Date Issued: 2016
Benzoyl isothiocyanates derived ligands as potential HIV-1 protease inhibitors and their reactions with gold ions
- Authors: Odame, Felix
- Date: 2016
- Subjects: HIV (Viruses) -- Enzymes Enzyme inhibitors -- Research , Pharmaceutical chemistry Biochemistry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/33228 , vital:32585
- Description: The synthesis and evaluation of benzoyl isothiocyanate derivatives as potential HIV-1 protease inhibitors is presented. The ligands were first designed to fit the protease active site using Autodock 4.2. The design was based on the deNOVO method of drug design in which the active site coordinates from the crystal structure of protease bound to ritonavir was used. An attempt to access the scaffolds designed initially led to the formation of 2,2,4-trimethyl 2,3-dihydro-1H-1,5-benzodiazepin-5-ium isophthalate and 2-2-(3-methylphenyl-1Hbenzimidazole which could not be converted to the desired intermediate. A further attempt led to formation of amino acid and amino acid ester derivatives of benzoyl isothiocyanates which have been fully characterized and the reasons why the desired intermediates were not readily accessible explained. Scaffolds based on the benzoyl isothiocyanate derivatives of structurally diverse diamines were then screened. Sixty compounds have been synthesized and fully characterized using elemental analysis, spectroscopy, GC-MS and twenty-six crystal structures have been discussed. The DFT transition state studies of 11-phenyl- 1,8,10,12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,5,9,11-pentaene-13-thione (20), N-(1Hbenzimidazol-2-yl)benzamide (21), 3-(1,3-benzothiazol-2-yl)-1-(benzoyl)thiourea (23), and N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene] benzamide (39), have been carried out and their detailed density functional theory reaction mechanism have be computed. The Bernly algorithm was used in the determination of saddle points (transtions states), and the intrinsic reaction coordinates leading to the determination of intermediates were traced and optimized to a global minimum or in some cases a local minimum was obtained. The cell viability tests of diamine derivatives which was done by exposing white blood cells to the compounds (inhibitors) at 37 °C and a pH of 7.4 showed that 1-(4-bromobenzoyl)-3-[2- ({[(4-bromophenyl)formamido]methanethioyl}amino)phenyl]thiourea (46), 1-(3-chloro benzoyl)-3-[2-({[(3-chlorophenyl)formamido]methanethioyl}amino)phenyl]thiourea (48), 1- (3-bromobenzoyl)-3-[2-({[(3-bromophenyl)formamido]methanethioyl}amino)phenyl] thiourea (49) and 3-benzoyl-1-(4-{[(phenylformamido)methanethioyl]amino}butyl)thiourea (54), in that group of compounds were cytotoxic with EC50 values of 17.04 ± 9.75 μM, 69.20± 38.16 μM, 35.90 ± 20.55 μM and 68.37 ± 26.45 μM, respectively. 4-Bromo-N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene] benzamide (32), 4-methoxy-N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene]benzamide (33) and 3-chloro-N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene] benzamide (37) were also cytotoxic giving EC50 values of 45.47 ± 21.92, 45.09 ±13.79 and 74.94 ± 13.17 μM, respectively. 3-(1,3-Benzothiazol-2-yl)-1-(3-bromobenzoyl)thiourea (31) and 3-(1,3-benzothiazoyl-2-yl)-1-(4-nitrobenzoyl)thiourea (30) derivatives were also found to be cytotoxic with EC50 values of 1.207 ± 0.58 and 24.08 ±13.14 nM, respectively. 11-(4-Chlorophenyl-1,8,10, 12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,5,9,11-pentaene-13-thione (12), 11-(4-methoxyphenyl)-1,8,10,12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,9,1-pentaene-13-thione (14), and 11-phenyl-1,8,10,12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,5,9,11-pentaene-13-thione (20), were found to be cytotoxic giving EC50 values of 0.152 ± 0.051, 37.96 ± 21.87 and 5.28 ± 2.95 μM, respectively. In the enzyme inhibition studies compound 49 gave a percentage inhibition of 97.03 ± 10.61% at 100 μM, but the fact that it is cytoxic might make it less useful, whilst compounds 19 and 16 had a percentage inhibition of 59.57 ± 13.59% (4-nitro derivative) and 79.97 ± 11.97% (3-nitro derivative) respectively at 100 μM of inhibitor and 20 μM of enzyme (HIV-1 protease). The results suggests that the presence of the nitro group at position 3 (16) and 4 (19) leads to an increase in activity against HIV-1 protease.
- Full Text:
- Date Issued: 2016
- Authors: Odame, Felix
- Date: 2016
- Subjects: HIV (Viruses) -- Enzymes Enzyme inhibitors -- Research , Pharmaceutical chemistry Biochemistry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/33228 , vital:32585
- Description: The synthesis and evaluation of benzoyl isothiocyanate derivatives as potential HIV-1 protease inhibitors is presented. The ligands were first designed to fit the protease active site using Autodock 4.2. The design was based on the deNOVO method of drug design in which the active site coordinates from the crystal structure of protease bound to ritonavir was used. An attempt to access the scaffolds designed initially led to the formation of 2,2,4-trimethyl 2,3-dihydro-1H-1,5-benzodiazepin-5-ium isophthalate and 2-2-(3-methylphenyl-1Hbenzimidazole which could not be converted to the desired intermediate. A further attempt led to formation of amino acid and amino acid ester derivatives of benzoyl isothiocyanates which have been fully characterized and the reasons why the desired intermediates were not readily accessible explained. Scaffolds based on the benzoyl isothiocyanate derivatives of structurally diverse diamines were then screened. Sixty compounds have been synthesized and fully characterized using elemental analysis, spectroscopy, GC-MS and twenty-six crystal structures have been discussed. The DFT transition state studies of 11-phenyl- 1,8,10,12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,5,9,11-pentaene-13-thione (20), N-(1Hbenzimidazol-2-yl)benzamide (21), 3-(1,3-benzothiazol-2-yl)-1-(benzoyl)thiourea (23), and N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene] benzamide (39), have been carried out and their detailed density functional theory reaction mechanism have be computed. The Bernly algorithm was used in the determination of saddle points (transtions states), and the intrinsic reaction coordinates leading to the determination of intermediates were traced and optimized to a global minimum or in some cases a local minimum was obtained. The cell viability tests of diamine derivatives which was done by exposing white blood cells to the compounds (inhibitors) at 37 °C and a pH of 7.4 showed that 1-(4-bromobenzoyl)-3-[2- ({[(4-bromophenyl)formamido]methanethioyl}amino)phenyl]thiourea (46), 1-(3-chloro benzoyl)-3-[2-({[(3-chlorophenyl)formamido]methanethioyl}amino)phenyl]thiourea (48), 1- (3-bromobenzoyl)-3-[2-({[(3-bromophenyl)formamido]methanethioyl}amino)phenyl] thiourea (49) and 3-benzoyl-1-(4-{[(phenylformamido)methanethioyl]amino}butyl)thiourea (54), in that group of compounds were cytotoxic with EC50 values of 17.04 ± 9.75 μM, 69.20± 38.16 μM, 35.90 ± 20.55 μM and 68.37 ± 26.45 μM, respectively. 4-Bromo-N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene] benzamide (32), 4-methoxy-N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene]benzamide (33) and 3-chloro-N-[(9E)-8,10,17-triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene] benzamide (37) were also cytotoxic giving EC50 values of 45.47 ± 21.92, 45.09 ±13.79 and 74.94 ± 13.17 μM, respectively. 3-(1,3-Benzothiazol-2-yl)-1-(3-bromobenzoyl)thiourea (31) and 3-(1,3-benzothiazoyl-2-yl)-1-(4-nitrobenzoyl)thiourea (30) derivatives were also found to be cytotoxic with EC50 values of 1.207 ± 0.58 and 24.08 ±13.14 nM, respectively. 11-(4-Chlorophenyl-1,8,10, 12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,5,9,11-pentaene-13-thione (12), 11-(4-methoxyphenyl)-1,8,10,12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,9,1-pentaene-13-thione (14), and 11-phenyl-1,8,10,12-tetraazatricyclo[7.4.0.02,7]trideca-2(7),3,5,9,11-pentaene-13-thione (20), were found to be cytotoxic giving EC50 values of 0.152 ± 0.051, 37.96 ± 21.87 and 5.28 ± 2.95 μM, respectively. In the enzyme inhibition studies compound 49 gave a percentage inhibition of 97.03 ± 10.61% at 100 μM, but the fact that it is cytoxic might make it less useful, whilst compounds 19 and 16 had a percentage inhibition of 59.57 ± 13.59% (4-nitro derivative) and 79.97 ± 11.97% (3-nitro derivative) respectively at 100 μM of inhibitor and 20 μM of enzyme (HIV-1 protease). The results suggests that the presence of the nitro group at position 3 (16) and 4 (19) leads to an increase in activity against HIV-1 protease.
- Full Text:
- Date Issued: 2016
Business ethics in Ugandan small and medium-sized enterprises
- Authors: Mayanja, Jamiah
- Date: 2016
- Subjects: Business ethics -- Uganda , Small business -- Uganda
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/8521 , vital:26400
- Description: SMEs have been acknowledged by governments globally as a prime source of economic growth and development. In Africa there has been a noticeable increase in the number of SME establishments. In Uganda, SMEs are the most popular business choice and play a major role in the national economy. Although SMEs significant economic contributions are generally acknowledged, being ethical and successful has become a challenge, as many SMEs in Uganda have not fully adopted and integrated ethics into their business strategies. Understanding the reasons for the increased unethical behaviour in SMEs is central to their continued business success. The primary objective of the study was to investigate the factors that influence ethical business conduct in Ugandan SMEs. From a comprehensive literature review, three main independent variables (staff-, business- and external environment factors) were identified as variables influencing ethical business conduct (dependent variable) of SMEs. A hypothetical model was developed to determine whether the independent variables have an influence on the dependent variable. Twelve hypotheses were formulated to test the relationships between three staff factors, five business factors, four external environment factors and ethical business conduct. The study sought the perceptions of SME owners or managers in the Kampala District and utilised the quantitative research paradigm. A survey was conducted with the aid of a structured self-administered questionnaire distributed by three fieldworkers. A combination of convenience and snowball sampling was utilised. The final sample comprised 384 respondents. The validity of the measuring instrument was ascertained by using exploratory factor analysis. The Cronbach‟s alpha values for reliability were calculated for each of the factors identified during the exploratory factor analysis. A total of ten valid and reliable factors were retained. Pearson product-moment correlation and multiple regression analysis were used to test the correlation and statistical significance of the relationships hypothesised between the various independent and dependent variables. One statistically significant relationship was found between the staff factors (employee attitude) and ethical business conduct. Two statistically significant relationships were found between the business factors (knowledge acquisition and management practices) and ethical business conduct. Three statistically significant relationships were found between the external environment factors (legal requirements, industry norm and media power) and ethical business conduct. External environmental factors seem to have a greater influence on SME ethical business conduct in Uganda. Multivariate Analysis of Variance (MANOVA) was used to identify if significant relationships exist between the eight demographic variables and seven reliable and valid independent variables. Furthermore, post-hoc Scheffé tests identified where the significant differences occurred between the different categories. Cohen‟s d-values were calculated in order to assess the practical significance of the mean scores. A total of twelve practical significant relationships were identified. SME owners or managers should consider employing staff with the right attitude to uphold sound ethical business values. They should implement ethical management practices to promote ethical business conduct amongst employees and ensure that employees are made aware of what is regarded as acceptable ethical business behaviour. SME owners or managers should adhere to legal requirements and industry norms to be known as businesses exhibiting ethical behaviour and utilise media to instil and guide ethical values in employees. Lastly, they must pay attention to the role that demographical variables such as: gender, level of education, current employment status, number of years in business and number of employees, play in behaving ethically in business.
- Full Text:
- Date Issued: 2016
- Authors: Mayanja, Jamiah
- Date: 2016
- Subjects: Business ethics -- Uganda , Small business -- Uganda
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/8521 , vital:26400
- Description: SMEs have been acknowledged by governments globally as a prime source of economic growth and development. In Africa there has been a noticeable increase in the number of SME establishments. In Uganda, SMEs are the most popular business choice and play a major role in the national economy. Although SMEs significant economic contributions are generally acknowledged, being ethical and successful has become a challenge, as many SMEs in Uganda have not fully adopted and integrated ethics into their business strategies. Understanding the reasons for the increased unethical behaviour in SMEs is central to their continued business success. The primary objective of the study was to investigate the factors that influence ethical business conduct in Ugandan SMEs. From a comprehensive literature review, three main independent variables (staff-, business- and external environment factors) were identified as variables influencing ethical business conduct (dependent variable) of SMEs. A hypothetical model was developed to determine whether the independent variables have an influence on the dependent variable. Twelve hypotheses were formulated to test the relationships between three staff factors, five business factors, four external environment factors and ethical business conduct. The study sought the perceptions of SME owners or managers in the Kampala District and utilised the quantitative research paradigm. A survey was conducted with the aid of a structured self-administered questionnaire distributed by three fieldworkers. A combination of convenience and snowball sampling was utilised. The final sample comprised 384 respondents. The validity of the measuring instrument was ascertained by using exploratory factor analysis. The Cronbach‟s alpha values for reliability were calculated for each of the factors identified during the exploratory factor analysis. A total of ten valid and reliable factors were retained. Pearson product-moment correlation and multiple regression analysis were used to test the correlation and statistical significance of the relationships hypothesised between the various independent and dependent variables. One statistically significant relationship was found between the staff factors (employee attitude) and ethical business conduct. Two statistically significant relationships were found between the business factors (knowledge acquisition and management practices) and ethical business conduct. Three statistically significant relationships were found between the external environment factors (legal requirements, industry norm and media power) and ethical business conduct. External environmental factors seem to have a greater influence on SME ethical business conduct in Uganda. Multivariate Analysis of Variance (MANOVA) was used to identify if significant relationships exist between the eight demographic variables and seven reliable and valid independent variables. Furthermore, post-hoc Scheffé tests identified where the significant differences occurred between the different categories. Cohen‟s d-values were calculated in order to assess the practical significance of the mean scores. A total of twelve practical significant relationships were identified. SME owners or managers should consider employing staff with the right attitude to uphold sound ethical business values. They should implement ethical management practices to promote ethical business conduct amongst employees and ensure that employees are made aware of what is regarded as acceptable ethical business behaviour. SME owners or managers should adhere to legal requirements and industry norms to be known as businesses exhibiting ethical behaviour and utilise media to instil and guide ethical values in employees. Lastly, they must pay attention to the role that demographical variables such as: gender, level of education, current employment status, number of years in business and number of employees, play in behaving ethically in business.
- Full Text:
- Date Issued: 2016
Causes of staff turnover in selected departments: province of the Eastern Cape
- Authors: Khelekethe, Eric Phathisile
- Date: 2016
- Subjects: Labor turnover -- South Africa -- Eastern Cape , Employee retention -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/8836 , vital:26434
- Description: This research focused on the impact of staff turnover in selected departments of the Province of the Eastern Cape Province. High staff turnover rate may jeopardise efforts to attain organisational objectives. In addition, `when an organisation loses a critical employee, there is a negative impact, on innovation; consistency in providing service to guests may be jeopardised, and major delays in the delivery of services to customers may occur. The research design used in this study contained elements of both the quantitative and qualitative approaches, which allowed the researcher to use structured questionnaires in data collection, on which space was provided for comments. This study was influenced and shaped by the concerns raised by a number of General Managers in the course of various provincial meetings. The main purpose of this research was to identify retention strategies that could be used by selected departments to reduce the turnover of their talented staff. The research also investigated methods to retain knowledge within departments that could possibly be lost due to a high turnover rate among talented staff. The first step used to resolve the issues discussed above was to conduct a full literature study. The literature study sought to reveal what characteristics were required in the departments that ensured that staff would be happy in those departments and remain there for a long time. The literature study also covered what knowledge management methods could be used in managing valuable knowledge. Secondly, the views of current staff and management of the selected departments on staff and knowledge management strategies were solicited in an empirical study, which involved the completion of structured questionnaires. It is the researcher’s aim that this study will, firstly, contribute to the existing body of knowledge of staff turnover and that the Provincial Departments will take into cognisance the problems that lead to employee turnover. Secondly, that it will contribute to an improvement in employee working conditions in various Provincial Government departments.
- Full Text:
- Date Issued: 2016
- Authors: Khelekethe, Eric Phathisile
- Date: 2016
- Subjects: Labor turnover -- South Africa -- Eastern Cape , Employee retention -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/8836 , vital:26434
- Description: This research focused on the impact of staff turnover in selected departments of the Province of the Eastern Cape Province. High staff turnover rate may jeopardise efforts to attain organisational objectives. In addition, `when an organisation loses a critical employee, there is a negative impact, on innovation; consistency in providing service to guests may be jeopardised, and major delays in the delivery of services to customers may occur. The research design used in this study contained elements of both the quantitative and qualitative approaches, which allowed the researcher to use structured questionnaires in data collection, on which space was provided for comments. This study was influenced and shaped by the concerns raised by a number of General Managers in the course of various provincial meetings. The main purpose of this research was to identify retention strategies that could be used by selected departments to reduce the turnover of their talented staff. The research also investigated methods to retain knowledge within departments that could possibly be lost due to a high turnover rate among talented staff. The first step used to resolve the issues discussed above was to conduct a full literature study. The literature study sought to reveal what characteristics were required in the departments that ensured that staff would be happy in those departments and remain there for a long time. The literature study also covered what knowledge management methods could be used in managing valuable knowledge. Secondly, the views of current staff and management of the selected departments on staff and knowledge management strategies were solicited in an empirical study, which involved the completion of structured questionnaires. It is the researcher’s aim that this study will, firstly, contribute to the existing body of knowledge of staff turnover and that the Provincial Departments will take into cognisance the problems that lead to employee turnover. Secondly, that it will contribute to an improvement in employee working conditions in various Provincial Government departments.
- 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
Effects of grazing and housing management systems on greenhouse gas emissions, blood profiles and meat quality of Nguni goats
- Authors: Tapiwa, Chikwanda Allen
- Date: 2016
- Subjects: Goats Goats -- Feeding and feeds Greenhouse gas mitigation , Grazing -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2314 , vital:27752
- Description: The broad objective of this study was to evaluate the effects of grazing and housing management systems on greenhouse gas emissions, blood profiles and meat quality of Nguni goats. A total of 64 castrated Nguni goats were used and a housing structure was designed to accommodate the goats as well as evaluate effects of type of floor on greenhouse gases, meat quality, blood metabolites and fatty acid profiles. In the first experiment: Forty-eight castrated Nguni goats, at 6-7 months old were used for herding (H) or tethering (T) management systems and randomly allocated to pens with earth (E) or slatted (S) floors. Gas sampling was done using static chambers and analysed using a SRI 8610C gas chromatography machine. The highest CH4 fluxes were from the manure of herded goats on earth floors (HE). The highest CO2 fluxes were from manure of herded goats that were housed on slatted floors (HS): The highest N2O fluxes were from the manure of tethered goats that were sheltered on slatted floors (TS). It was concluded from the first experiment that goat manure is an important source of GHG that is influenced by grazing and floor type management systems. The second experiment was done to evaluate greenhouse gas (GHG) emission from disused (DP) vs occupied goat pens (OP) with earth (EF) or slatted (SF) floors. Eight previously occupied pens were used in this study. Sixteen goats were randomly put in the pens labelled occupied pens with earth floors (OPEF) and occupied pens with slatted floors (OPSF) resulting in four goats per OP. There were month by pen use; month by floor type; and use by floor type interaction effects (P < 0.05) on CH4 production. Floor type, use (DP vs OP) and month affected (P < 0.05) CH4 production. Manure on earth floors of occupied pens (OPEF) emitted the highest (P < 0.05) methane followed by earth floors of disused pens (DPEF). The least CH4 was emitted from DPSF. There was pen use (DP vs OP) by floor type interaction effect (P < 0.05) on CO2 emission. Floor type and pen use affected (P < 0.05) CO2 production. Manure in occupied pens with slatted floors (OPSF) produced the highest CO2 and the least CO2 was from disused pens with slatted floors (DPSF). Floor type and month influenced (P < 0.05) N2O production. It was concluded that continued use of goat pens increased GHG emissions. However, disused goat pens with manure remain an important source of GHG as they continued to emit quantifiable levels of CH4, CO2 and N2O. The third experiment was done to determine the effects of grazing and housing management systems on the concentrations of blood metabolites, activity of creatine kinase, body weight (BW), body condition score (BCS) and carcass characteristics using 48 castrated Nguni goats. Tethered goats had higher (P<0.05): urea, creatinine, total protein, globulin concentrations and more activity of CK than herded goats. On the other hand, herded goats had higher (P<0.05) plasma glucose (H: 3.39±0.020 vs T: 3.23±0.020 mmol/L), serum albumin (H: 15.30±0.147 vs T: 14.82±0.144 g/L) concentration. It was concluded that serum concentrations of all the metabolites and the activity of CK were sensitive to grazing system. Herding of goats promoted more glucose concentration and preservation of muscle protein and hence superior body weights and BCS than tethered goats. The fourth experiment was done to determine the effects of grazing and housing management systems on the activity of creatine kinase (CK) and cortisol concentration, and chevon quality. Further, the effect of muscle type [Muscularis longissimus thoracis et. Lumborum (LTL) and triceps brachii (TB)] on chevon quality was also investigated. Forty eight castrated Nguni goats aged 6- 7 months were randomly allocated to tethering (n=24) and herding (n=24) treatments. Floor type affected meat (P<0.05) pH24. Tethered goats had higher (P < 0.05) L* and CL percent than herded goats. Muscle type had a significant influence (P < 0.05) on a*, WBSF and pH. It was observed and concluded that T resulted in higher L* and more CL percent whilst SF lowered the pH24 of chevon; at the same time meat from the TB muscle was more tender, despite having a higher pH24 and more CL percent relative to LTH cuts. The fifth experiment was done to determine the effect of grazing and floor type on fatty acid composition of chevon from tethered and herded Nguni goats. Floor type had no effect on fatty acid composition. Oleic, stearic, palmitic and linoleic were the major fatty acids. Chevon from tethered goats had higher (P < 0.05) proportions of long chain polyunsaturated fatty acids (PUFAs): eicosapentaenoic, docosapentaenoic, docosahexaenoic, conjugated linoleic acid (CLA) and more total SFA, total PUFA, total Omega- 6 and total omega 3 fatty acids than herded goats. On the other hand, chevon from herded goats had more (P < 0.05) C18:1c9, C18:2t9, 12 (n-6), C20:3c11, 14, 17 (n-3) and total MUFA than tethered goats. However, there was no difference (P > 0.05) in the PUFA: SFA and n-6/n-3 fatty acid ratios between the herded and tethered goats. It was concluded that tethering promoted higher proportions of beneficial PUFAs which were more in TB than LTH muscle. The overall conclusions from the whole study were that goat manure is an important source of GHG with high CH4 being emitted from earth floors of herded goats. High CO2 and N2O are emitted from SF of herded and tethered goats, respectively. There were no major differences in meat quality between herded and tethered goats. However, herding promoted more live weight gain than tethering. On the other hand, tethering promoted more beneficial fatty acids. Therefore depending on the objective of the enterprise, smallholder farmers can safely tether or herd their goats. Further, there is need to develop technologies to harness CH4 from goat manure.
- Full Text:
- Date Issued: 2016
- Authors: Tapiwa, Chikwanda Allen
- Date: 2016
- Subjects: Goats Goats -- Feeding and feeds Greenhouse gas mitigation , Grazing -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2314 , vital:27752
- Description: The broad objective of this study was to evaluate the effects of grazing and housing management systems on greenhouse gas emissions, blood profiles and meat quality of Nguni goats. A total of 64 castrated Nguni goats were used and a housing structure was designed to accommodate the goats as well as evaluate effects of type of floor on greenhouse gases, meat quality, blood metabolites and fatty acid profiles. In the first experiment: Forty-eight castrated Nguni goats, at 6-7 months old were used for herding (H) or tethering (T) management systems and randomly allocated to pens with earth (E) or slatted (S) floors. Gas sampling was done using static chambers and analysed using a SRI 8610C gas chromatography machine. The highest CH4 fluxes were from the manure of herded goats on earth floors (HE). The highest CO2 fluxes were from manure of herded goats that were housed on slatted floors (HS): The highest N2O fluxes were from the manure of tethered goats that were sheltered on slatted floors (TS). It was concluded from the first experiment that goat manure is an important source of GHG that is influenced by grazing and floor type management systems. The second experiment was done to evaluate greenhouse gas (GHG) emission from disused (DP) vs occupied goat pens (OP) with earth (EF) or slatted (SF) floors. Eight previously occupied pens were used in this study. Sixteen goats were randomly put in the pens labelled occupied pens with earth floors (OPEF) and occupied pens with slatted floors (OPSF) resulting in four goats per OP. There were month by pen use; month by floor type; and use by floor type interaction effects (P < 0.05) on CH4 production. Floor type, use (DP vs OP) and month affected (P < 0.05) CH4 production. Manure on earth floors of occupied pens (OPEF) emitted the highest (P < 0.05) methane followed by earth floors of disused pens (DPEF). The least CH4 was emitted from DPSF. There was pen use (DP vs OP) by floor type interaction effect (P < 0.05) on CO2 emission. Floor type and pen use affected (P < 0.05) CO2 production. Manure in occupied pens with slatted floors (OPSF) produced the highest CO2 and the least CO2 was from disused pens with slatted floors (DPSF). Floor type and month influenced (P < 0.05) N2O production. It was concluded that continued use of goat pens increased GHG emissions. However, disused goat pens with manure remain an important source of GHG as they continued to emit quantifiable levels of CH4, CO2 and N2O. The third experiment was done to determine the effects of grazing and housing management systems on the concentrations of blood metabolites, activity of creatine kinase, body weight (BW), body condition score (BCS) and carcass characteristics using 48 castrated Nguni goats. Tethered goats had higher (P<0.05): urea, creatinine, total protein, globulin concentrations and more activity of CK than herded goats. On the other hand, herded goats had higher (P<0.05) plasma glucose (H: 3.39±0.020 vs T: 3.23±0.020 mmol/L), serum albumin (H: 15.30±0.147 vs T: 14.82±0.144 g/L) concentration. It was concluded that serum concentrations of all the metabolites and the activity of CK were sensitive to grazing system. Herding of goats promoted more glucose concentration and preservation of muscle protein and hence superior body weights and BCS than tethered goats. The fourth experiment was done to determine the effects of grazing and housing management systems on the activity of creatine kinase (CK) and cortisol concentration, and chevon quality. Further, the effect of muscle type [Muscularis longissimus thoracis et. Lumborum (LTL) and triceps brachii (TB)] on chevon quality was also investigated. Forty eight castrated Nguni goats aged 6- 7 months were randomly allocated to tethering (n=24) and herding (n=24) treatments. Floor type affected meat (P<0.05) pH24. Tethered goats had higher (P < 0.05) L* and CL percent than herded goats. Muscle type had a significant influence (P < 0.05) on a*, WBSF and pH. It was observed and concluded that T resulted in higher L* and more CL percent whilst SF lowered the pH24 of chevon; at the same time meat from the TB muscle was more tender, despite having a higher pH24 and more CL percent relative to LTH cuts. The fifth experiment was done to determine the effect of grazing and floor type on fatty acid composition of chevon from tethered and herded Nguni goats. Floor type had no effect on fatty acid composition. Oleic, stearic, palmitic and linoleic were the major fatty acids. Chevon from tethered goats had higher (P < 0.05) proportions of long chain polyunsaturated fatty acids (PUFAs): eicosapentaenoic, docosapentaenoic, docosahexaenoic, conjugated linoleic acid (CLA) and more total SFA, total PUFA, total Omega- 6 and total omega 3 fatty acids than herded goats. On the other hand, chevon from herded goats had more (P < 0.05) C18:1c9, C18:2t9, 12 (n-6), C20:3c11, 14, 17 (n-3) and total MUFA than tethered goats. However, there was no difference (P > 0.05) in the PUFA: SFA and n-6/n-3 fatty acid ratios between the herded and tethered goats. It was concluded that tethering promoted higher proportions of beneficial PUFAs which were more in TB than LTH muscle. The overall conclusions from the whole study were that goat manure is an important source of GHG with high CH4 being emitted from earth floors of herded goats. High CO2 and N2O are emitted from SF of herded and tethered goats, respectively. There were no major differences in meat quality between herded and tethered goats. However, herding promoted more live weight gain than tethering. On the other hand, tethering promoted more beneficial fatty acids. Therefore depending on the objective of the enterprise, smallholder farmers can safely tether or herd their goats. Further, there is need to develop technologies to harness CH4 from goat manure.
- Full Text:
- Date Issued: 2016
Electrical power output estimation model for a conical diffuser augmented wind turbine
- Authors: Masukume, Peace-Maker
- Date: 2016
- Subjects: Wind power , Wind turbines , Renewable energy sources
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/1517 , vital:27404
- Description: Energy is integral to the quality of life of any society. However, meeting the demand for energy sustainably is the main challenge facing humanity. In general, non-renewable energy resources are used to supply the ever increasing energy demand. However, the extraction and processing of these resources is accompanied by the production of wastes which are a health hazard and impact negatively on climate change. Considering the finite nature of non-renewable sources, the environmental concerns which are associated with their usage and ensuring energy security, renewable energy sources have been brought in the energy supply chain. Wind energy is one of the renewable energy sources which has been supplying electrical energy to the ever increasing energy demand of humanity. Wind energy technology is a mature technology which over and above the bare (conventional) wind turbine technology has seen the development of duct augmented wind turbines. Ducts are used to encase wind turbine rotors to augment the power output of wind turbines especially in low wind speed areas. Though the technology has been under study for decades now, research indicates that there is no known model to estimate the power output of a diffuser augmented wind turbine. This thesis presents the development of the conical Diffuser Augmented Wind Turbine (DAWT) power output estimation model and its validation.
- Full Text:
- Date Issued: 2016
- Authors: Masukume, Peace-Maker
- Date: 2016
- Subjects: Wind power , Wind turbines , Renewable energy sources
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/1517 , vital:27404
- Description: Energy is integral to the quality of life of any society. However, meeting the demand for energy sustainably is the main challenge facing humanity. In general, non-renewable energy resources are used to supply the ever increasing energy demand. However, the extraction and processing of these resources is accompanied by the production of wastes which are a health hazard and impact negatively on climate change. Considering the finite nature of non-renewable sources, the environmental concerns which are associated with their usage and ensuring energy security, renewable energy sources have been brought in the energy supply chain. Wind energy is one of the renewable energy sources which has been supplying electrical energy to the ever increasing energy demand of humanity. Wind energy technology is a mature technology which over and above the bare (conventional) wind turbine technology has seen the development of duct augmented wind turbines. Ducts are used to encase wind turbine rotors to augment the power output of wind turbines especially in low wind speed areas. Though the technology has been under study for decades now, research indicates that there is no known model to estimate the power output of a diffuser augmented wind turbine. This thesis presents the development of the conical Diffuser Augmented Wind Turbine (DAWT) power output estimation model and its validation.
- 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
Evaluation of flocculating potentials and charecterization of bioflocculants produced by three bacterial isolates from Algoa Bay, South Africa
- Authors: Okaiyeto, Kunle
- Date: 2016
- Subjects: Flocculation Water -- Purification -- Flocculation Water quality management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2633 , vital:27947
- Description: Flocculation has been widely adopted as one of the most effective methods to remove colloidal particles in water or wastewater treatment. Synthetic flocculants are conventionally used because of their high flocculating efficiency and cost-effectiveness. However, they have been reported to have hazardous properties and implicated in some serious health problems including senile dementia and neuro-toxicity, as well as being recalcitrant in the environment. Consequently, efforts are being geared away from the use of synthetic flocculants in water and wastewater treatment. Hence, the need for safe and eco-friendly flocculants has become imperative. Compared with synthetic flocculants, bioflocculants have special advantages such as safety, biodegradability and harmlessness to the environment and humans; attributes which make them potential alternatives in water treatment, downstream as well as fermentation processes. In the current study, the potentials of bacterial isolates recovered from Algoa Bay in the Eastern Cape Province of South Africa for bioflocculant production were investigated. The bacterial isolates were identified by polymerase chain reaction (PCR) as belonging to the Bacillus genus. The analysis of 16S ribosomal deoxyribonucleic acid (rDNA) nucleotide sequence of isolate M72 showed 99 percent similarity to Bacillus toyonensis strain BCT-7112 and was deposited in the GenBank as Bacillus toyonensis strain AEMREG6 with accession number KP406731. Likewise, the 16S rDNA nucleotide sequences of isolates M69 and M67 showed 98 percent sequence similarity to Bacillus licheniformis strain W7 and Bacillus algicola strain QD43 respectively; and M67 isolate was subsequently deposited in the GenBank as Bacillus sp. AEMREG7 with accession number KF933697.1. The results of the nutritional requirements and fermentation conditions revealed that optimum inoculum size for REG-6 production was 4 percent (v/v), while 5 percent (v/v) and 3 percent (v/v) were most favourable for MBF-W7 and MBF-UFH production respectively. Glucose was the best carbon source for the production of bioflocculants (REG-6 and MBF-UFH) by Bacillus toyonensis AEMREG6 and Bacillus sp. AEMREG7 respectively, while maltose supported optimum bioflocculant (MBF-W7) production by Bacillus specie. Inorganic nitrogen (NH4NO3) was the favoured nitrogen source for both REG-6 and MBF-W7 production, while mixed nitrogen sources [yeast extract + urea + (NH4)2SO4] supported the maximum production of MBF-UFH. The initial medium pH for REG-6 was 5, while MBF-W7 and MBF-UFH were both maximally produced at the initial pH of 6. After a 96 h cultivation period under optimal culture conditions, 3.2 g of purified REG-6 with a maximum flocculating activity of 77 percent was recovered from 1 L fermented broth of Bacillus toyonensis AEMREG6. Yields of 3.8 g and 1.6 g pure bioflocculants with the respective highest flocculating activities of 94.9 percent and 83.2 percent were also obtained from 1 L, 72 h-fermented broths of Bacillus licheniformis and Bacillus sp. AEMREG7 respectively. Furthermore, all the three bioflocculants (REG-6, MBF-W7 and MBF-UFH), displayed thermal stability within the temperature range of 50 to 100 oC, with strong flocculating activities of over 80 percent against kaolin suspension over a wide range of pH range (3–11) and relatively low dosage requirements of 0.1-03 mg/ml in the presence of divalent cations in the treatment of kaolin clay suspension and Thyme River waters. Chemical composition analyses of the bioflocculants showed them to be glycoproteins with a predominantly polysaccharide backbones as shown by the following carbohydrate/protein (w/w) ratios: 77.8 percent:11.5 percent (REG-6); 73.7 percent:6.2 percent (MBF-W7) and 76 percent:14 percent (MBF-UFH).
- Full Text:
- Date Issued: 2016
- Authors: Okaiyeto, Kunle
- Date: 2016
- Subjects: Flocculation Water -- Purification -- Flocculation Water quality management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2633 , vital:27947
- Description: Flocculation has been widely adopted as one of the most effective methods to remove colloidal particles in water or wastewater treatment. Synthetic flocculants are conventionally used because of their high flocculating efficiency and cost-effectiveness. However, they have been reported to have hazardous properties and implicated in some serious health problems including senile dementia and neuro-toxicity, as well as being recalcitrant in the environment. Consequently, efforts are being geared away from the use of synthetic flocculants in water and wastewater treatment. Hence, the need for safe and eco-friendly flocculants has become imperative. Compared with synthetic flocculants, bioflocculants have special advantages such as safety, biodegradability and harmlessness to the environment and humans; attributes which make them potential alternatives in water treatment, downstream as well as fermentation processes. In the current study, the potentials of bacterial isolates recovered from Algoa Bay in the Eastern Cape Province of South Africa for bioflocculant production were investigated. The bacterial isolates were identified by polymerase chain reaction (PCR) as belonging to the Bacillus genus. The analysis of 16S ribosomal deoxyribonucleic acid (rDNA) nucleotide sequence of isolate M72 showed 99 percent similarity to Bacillus toyonensis strain BCT-7112 and was deposited in the GenBank as Bacillus toyonensis strain AEMREG6 with accession number KP406731. Likewise, the 16S rDNA nucleotide sequences of isolates M69 and M67 showed 98 percent sequence similarity to Bacillus licheniformis strain W7 and Bacillus algicola strain QD43 respectively; and M67 isolate was subsequently deposited in the GenBank as Bacillus sp. AEMREG7 with accession number KF933697.1. The results of the nutritional requirements and fermentation conditions revealed that optimum inoculum size for REG-6 production was 4 percent (v/v), while 5 percent (v/v) and 3 percent (v/v) were most favourable for MBF-W7 and MBF-UFH production respectively. Glucose was the best carbon source for the production of bioflocculants (REG-6 and MBF-UFH) by Bacillus toyonensis AEMREG6 and Bacillus sp. AEMREG7 respectively, while maltose supported optimum bioflocculant (MBF-W7) production by Bacillus specie. Inorganic nitrogen (NH4NO3) was the favoured nitrogen source for both REG-6 and MBF-W7 production, while mixed nitrogen sources [yeast extract + urea + (NH4)2SO4] supported the maximum production of MBF-UFH. The initial medium pH for REG-6 was 5, while MBF-W7 and MBF-UFH were both maximally produced at the initial pH of 6. After a 96 h cultivation period under optimal culture conditions, 3.2 g of purified REG-6 with a maximum flocculating activity of 77 percent was recovered from 1 L fermented broth of Bacillus toyonensis AEMREG6. Yields of 3.8 g and 1.6 g pure bioflocculants with the respective highest flocculating activities of 94.9 percent and 83.2 percent were also obtained from 1 L, 72 h-fermented broths of Bacillus licheniformis and Bacillus sp. AEMREG7 respectively. Furthermore, all the three bioflocculants (REG-6, MBF-W7 and MBF-UFH), displayed thermal stability within the temperature range of 50 to 100 oC, with strong flocculating activities of over 80 percent against kaolin suspension over a wide range of pH range (3–11) and relatively low dosage requirements of 0.1-03 mg/ml in the presence of divalent cations in the treatment of kaolin clay suspension and Thyme River waters. Chemical composition analyses of the bioflocculants showed them to be glycoproteins with a predominantly polysaccharide backbones as shown by the following carbohydrate/protein (w/w) ratios: 77.8 percent:11.5 percent (REG-6); 73.7 percent:6.2 percent (MBF-W7) and 76 percent:14 percent (MBF-UFH).
- Full Text:
- Date Issued: 2016
Evaluation of the incidence of enteric viruses, Vibrio species and Escherichia coli pathotypes in effluents of two wastewater treatment plants located in Keiskammahoek and Stutterheim in the Eastern Cape Province of South Africa
- Authors: Adefisoye, Martins Ajibade
- Date: 2016
- Subjects: Escherichia coli -- South Africa -- Eastern Cape Water -- Purification -- South Africa -- Eastern Cape Effluent quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/3165 , vital:28328
- Description: South Africa is currently experiencing water shortage crisis, a challenge that has been attributed not only to the scarcity of freshwater, but also to fast degrading water quality. Factors such as rapid urbanisation, population and economic growth, climate change as well as poor operational and maintenance of many of the exisiting water/wastewater treatment facilities have been acknowledged as important contributors to degrading water quality in the country. Untreated or inadequately treated discharged wastewater effluents constitute point source pollution to many freshwater environments in South Africa. Hence, it becomes imperative to evaluate wastewater discharges in other to protect the scarce freshwater resource, the environment and public health. Over a twelve-month sampling period (September 2012 to August 2013), we assessed the bacteriological, virological and physicochemical qualities of the discharged final effluents of two wastewater treatment facilities in the Eastern Cape Province of South Africa. For the physicochemical assessment, a total of 144 final effluent samples were collected from both the final effluent tanks (FE) and the discharge points (DP) of the treatment facilities. Physicochemical parameters including pH, temperature, turbidity, total dissolved solids (TDS), dissolved oxygen (DO), electrical conductivity (EC) and free chlorine concentration were determined on site while biological oxygen demand (BOD), nitrate (NO3-), nitrite (NO2-), phosphate (PO4-) and chemical oxygen demand (COD) were determined in the laboratory. The bacteriological analysis of the samples was done using standard membrane filtration (MF) technique. Bacterial group assessed included: faecal indicator bacteria (faecal coliforms and E. coli) and Vibrio species, while the antibiotic susceptibility profiles of selected E. coli and Vibrio species isolates against some selected antibiotics commonly used in human therapy and veterinary medicine were determind using the standard agar-disc diffusion method. The occurrence and concentrations of human enteric viruses including: human adenovirus (HAdV), hepatitis A virus (HAV) and rotavirus (RoV) in the samples were determined by TaqMan-based real-time polymerase chain reaction (qPCR) following concentration by adsorption-elution method. The physicochemical characteristics of the samples ranged as follows: pH (6.5 – 7.6), TDS (95 – 171 mg/L), EC (134 – 267 μS/cm), temperature (12 – 27 °C), turbidity (1.5 – 65.7 mg/L), free chlorine (0.08 – 0.72 mg/L), DO (2.06 – 9.81 mg/L), BOD (0.13 – 9.81 mg/L), NO3- (0 – 21.5 mg/L), NO2- (0 – 0.72 mg/L), PO4- (0 – 18.3 mg/L) and COD (27 – 680 mg/L). Some of the characteristic such as pH, TDS, EC, temperature, nitrite and DO (on most instances) complied with recommended guidelines. Other characteristics, however, including turbidity, BOD, nitrate, phosphate and COD fell short of the recommended guidelines. All the 48 samples analysed for bacteriological qualities tested positive for the presence of the bacterial groups with significant (P≤0.05) seasonal variation in their densities. Faecal coliforms were detected in counts ranging from 1 CFU/100ml to 2.7 × 104 CFU/100ml. Presumptive E. coli counts ranged generally between 1 CFU/100ml – 1.4 × 105 CFU/100ml while counts of presumptive Vibrio species ranged between 4 CFU/100ml – 1.4 × 104 CFU/100ml. Molecular identification of the presumptive isolates by polymerase chain reactions PCR gave positive reaction rates of 76.2 percent (381/500) and 69.8 percent (279/400) for E.coli and Vibrio species respectively. The antibiotic susceptibility profiling of 205 PCR-confirmed Vibiro isolates against 18 commomly used antibiotics showed resistance frequencies ranging from 0.5 percent (imipenem) to 96.1 percent (penicillin G) at recommended breakpoint concentrations. Eighty-one percent (166/205) of the Vibrio isolates showed multidrug resistance (resistance to 3 or more antibiotics) with the most common multiple antibiotic resistance phenotype (MARP) being AP-T-TM-SMX-PG-NI-PB, occurring in 8 isolates.
- Full Text:
- Date Issued: 2016
- Authors: Adefisoye, Martins Ajibade
- Date: 2016
- Subjects: Escherichia coli -- South Africa -- Eastern Cape Water -- Purification -- South Africa -- Eastern Cape Effluent quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/3165 , vital:28328
- Description: South Africa is currently experiencing water shortage crisis, a challenge that has been attributed not only to the scarcity of freshwater, but also to fast degrading water quality. Factors such as rapid urbanisation, population and economic growth, climate change as well as poor operational and maintenance of many of the exisiting water/wastewater treatment facilities have been acknowledged as important contributors to degrading water quality in the country. Untreated or inadequately treated discharged wastewater effluents constitute point source pollution to many freshwater environments in South Africa. Hence, it becomes imperative to evaluate wastewater discharges in other to protect the scarce freshwater resource, the environment and public health. Over a twelve-month sampling period (September 2012 to August 2013), we assessed the bacteriological, virological and physicochemical qualities of the discharged final effluents of two wastewater treatment facilities in the Eastern Cape Province of South Africa. For the physicochemical assessment, a total of 144 final effluent samples were collected from both the final effluent tanks (FE) and the discharge points (DP) of the treatment facilities. Physicochemical parameters including pH, temperature, turbidity, total dissolved solids (TDS), dissolved oxygen (DO), electrical conductivity (EC) and free chlorine concentration were determined on site while biological oxygen demand (BOD), nitrate (NO3-), nitrite (NO2-), phosphate (PO4-) and chemical oxygen demand (COD) were determined in the laboratory. The bacteriological analysis of the samples was done using standard membrane filtration (MF) technique. Bacterial group assessed included: faecal indicator bacteria (faecal coliforms and E. coli) and Vibrio species, while the antibiotic susceptibility profiles of selected E. coli and Vibrio species isolates against some selected antibiotics commonly used in human therapy and veterinary medicine were determind using the standard agar-disc diffusion method. The occurrence and concentrations of human enteric viruses including: human adenovirus (HAdV), hepatitis A virus (HAV) and rotavirus (RoV) in the samples were determined by TaqMan-based real-time polymerase chain reaction (qPCR) following concentration by adsorption-elution method. The physicochemical characteristics of the samples ranged as follows: pH (6.5 – 7.6), TDS (95 – 171 mg/L), EC (134 – 267 μS/cm), temperature (12 – 27 °C), turbidity (1.5 – 65.7 mg/L), free chlorine (0.08 – 0.72 mg/L), DO (2.06 – 9.81 mg/L), BOD (0.13 – 9.81 mg/L), NO3- (0 – 21.5 mg/L), NO2- (0 – 0.72 mg/L), PO4- (0 – 18.3 mg/L) and COD (27 – 680 mg/L). Some of the characteristic such as pH, TDS, EC, temperature, nitrite and DO (on most instances) complied with recommended guidelines. Other characteristics, however, including turbidity, BOD, nitrate, phosphate and COD fell short of the recommended guidelines. All the 48 samples analysed for bacteriological qualities tested positive for the presence of the bacterial groups with significant (P≤0.05) seasonal variation in their densities. Faecal coliforms were detected in counts ranging from 1 CFU/100ml to 2.7 × 104 CFU/100ml. Presumptive E. coli counts ranged generally between 1 CFU/100ml – 1.4 × 105 CFU/100ml while counts of presumptive Vibrio species ranged between 4 CFU/100ml – 1.4 × 104 CFU/100ml. Molecular identification of the presumptive isolates by polymerase chain reactions PCR gave positive reaction rates of 76.2 percent (381/500) and 69.8 percent (279/400) for E.coli and Vibrio species respectively. The antibiotic susceptibility profiling of 205 PCR-confirmed Vibiro isolates against 18 commomly used antibiotics showed resistance frequencies ranging from 0.5 percent (imipenem) to 96.1 percent (penicillin G) at recommended breakpoint concentrations. Eighty-one percent (166/205) of the Vibrio isolates showed multidrug resistance (resistance to 3 or more antibiotics) with the most common multiple antibiotic resistance phenotype (MARP) being AP-T-TM-SMX-PG-NI-PB, occurring in 8 isolates.
- Full Text:
- Date Issued: 2016
Exploration of Nahoon beach milieu for lignocellulose degrading bacteria and optimizing fermentation conditions for holocellulase production by selected strains
- Authors: Fatokun, Evelyn
- Date: 2016
- Subjects: Lignocellulose Lignocellulose -- Biodegradation Water -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/1529 , vital:27413
- Description: A significant trend in the modern day industrial biotechnology is the utilization and application of renewable resources, and ecofriendly approach to industrial processes and waste management. As a consequence thereof, the biotechnology of holocellulases: cellulase and xylanase and, enzymatic hydrolysis of renewable and abundant lignocellulosic biomass to energy and value added products are rapidly increasing; hence, cost effective enzyme system is imperative. In that context, exploration of microbiota for strains and enzymes with novel industrial properties is vital for efficient and commercially viable enzyme biotechnology. Consequent on the complex characteristics of high salinity, variable pressure, temperature and nutritional conditions, bacterial strains from the marine environment are equipped with enzyme machinery of industrial importance for adaptation and survival. In this study, bacterial strains were isolated form Nahoon beach and optimized for holocellulase production. Three isolates selected for lignocellulolytic potential were identified by 16S ribosomal deoxyribonucleic acid (rDNA) sequence analysis. Isolate FS1k had 98 percent similarity with Streptomyces albidoflavus strain AIH12, was designated as Streptomyces albidoflavus strain SAMRC-UFH5 and deposited in the GenBank with accession number KU171373. Similarly, isolates CS14b and CS22d with respective percentage similarity of 98 and 99 (percent) with Bacillus cereus strains and Streptomyces sp. strain WMMB251 were named Bacillus cereus strain SAMRC-UFH9 and Streptomyces sp. strain SAMRC-UFH6; and were deposited in the GenBank with accession number KX524510 and KU171374 respectively. Optimal pH, temperature and agitation speed for cellulase production by S. albidoflavus strain SAMRC-UFH5, and B. cereus strain SAMRC-UFH9 were 6 and 7; 40 and 30 (°C); and 100 and 150 (rpm) respectively; while xylanase production was optimal at pH, temperature and agitation speed of 8 and 7; 40 and 30 (°C); and 150 and 50 (rpm) respectively. Maximum cellulase activity of 0.26 and 0.061(U/mL) by S. albidoflavus strain SAMRC-UFH5 and B. cereus strain SAMRC-UFH9 were attained at 60 h respectively, while maximal xylanase activity of 18.54 and 16.6 (U/mL) was produced by S. albidoflavus strain SAMRC-UFH5 and B. cereus strain SAMRC-UFH9 at 48 h and 60 h respectively. Furthermore, xylanase production by S. albidoflavus strain SAMRC-UFH5 and B. cereus strain SAMRC-UFH9 was maximally induced by wheat straw and xylan respectively, while cellulase production was best induced by mannose and carboxymethyl cellulose respectively. On the other hand, cellulase and xylanase production by Streptomyces sp. strain SAMRC-UFH6 was optimal at pH, temperature and agitation speed of 7 and 8, 40 °C and 100 rpm, respectively. Highest production of cellulase and xylanase was attained at 84 and 60 h with respective activity of 0.065 and 6.34 (U/mL). In addition, cellulase and xylanase production by the strain was best induced by beechwood xylan. Moreover, xylanase produced by Streptomyces sp. strain SAMRC-UFH6 at optimal conditions was characterized by optimal pH and temperature of 8 and 80-90 °C respectively; retaining over 70 percent activity at pH 5-10 after 1 h and 60 percent of initial activity at 90 °C after 90 min of incubation. In all, optimization improved cellulase and xylanase production yields, being 40 and 95.5, 10.89 and 72.17, and 10 and 115- fold increase by S. albidoflavus strain SAMRC-UFH5, B. cereus strain SAMRC-UFH9 and Streptomyces sp. SAMRC-UFH6 respectively. The results of this study suggest that the marine bacterial strains are resource for holocellulase with industrial applications.
- Full Text:
- Date Issued: 2016
- Authors: Fatokun, Evelyn
- Date: 2016
- Subjects: Lignocellulose Lignocellulose -- Biodegradation Water -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/1529 , vital:27413
- Description: A significant trend in the modern day industrial biotechnology is the utilization and application of renewable resources, and ecofriendly approach to industrial processes and waste management. As a consequence thereof, the biotechnology of holocellulases: cellulase and xylanase and, enzymatic hydrolysis of renewable and abundant lignocellulosic biomass to energy and value added products are rapidly increasing; hence, cost effective enzyme system is imperative. In that context, exploration of microbiota for strains and enzymes with novel industrial properties is vital for efficient and commercially viable enzyme biotechnology. Consequent on the complex characteristics of high salinity, variable pressure, temperature and nutritional conditions, bacterial strains from the marine environment are equipped with enzyme machinery of industrial importance for adaptation and survival. In this study, bacterial strains were isolated form Nahoon beach and optimized for holocellulase production. Three isolates selected for lignocellulolytic potential were identified by 16S ribosomal deoxyribonucleic acid (rDNA) sequence analysis. Isolate FS1k had 98 percent similarity with Streptomyces albidoflavus strain AIH12, was designated as Streptomyces albidoflavus strain SAMRC-UFH5 and deposited in the GenBank with accession number KU171373. Similarly, isolates CS14b and CS22d with respective percentage similarity of 98 and 99 (percent) with Bacillus cereus strains and Streptomyces sp. strain WMMB251 were named Bacillus cereus strain SAMRC-UFH9 and Streptomyces sp. strain SAMRC-UFH6; and were deposited in the GenBank with accession number KX524510 and KU171374 respectively. Optimal pH, temperature and agitation speed for cellulase production by S. albidoflavus strain SAMRC-UFH5, and B. cereus strain SAMRC-UFH9 were 6 and 7; 40 and 30 (°C); and 100 and 150 (rpm) respectively; while xylanase production was optimal at pH, temperature and agitation speed of 8 and 7; 40 and 30 (°C); and 150 and 50 (rpm) respectively. Maximum cellulase activity of 0.26 and 0.061(U/mL) by S. albidoflavus strain SAMRC-UFH5 and B. cereus strain SAMRC-UFH9 were attained at 60 h respectively, while maximal xylanase activity of 18.54 and 16.6 (U/mL) was produced by S. albidoflavus strain SAMRC-UFH5 and B. cereus strain SAMRC-UFH9 at 48 h and 60 h respectively. Furthermore, xylanase production by S. albidoflavus strain SAMRC-UFH5 and B. cereus strain SAMRC-UFH9 was maximally induced by wheat straw and xylan respectively, while cellulase production was best induced by mannose and carboxymethyl cellulose respectively. On the other hand, cellulase and xylanase production by Streptomyces sp. strain SAMRC-UFH6 was optimal at pH, temperature and agitation speed of 7 and 8, 40 °C and 100 rpm, respectively. Highest production of cellulase and xylanase was attained at 84 and 60 h with respective activity of 0.065 and 6.34 (U/mL). In addition, cellulase and xylanase production by the strain was best induced by beechwood xylan. Moreover, xylanase produced by Streptomyces sp. strain SAMRC-UFH6 at optimal conditions was characterized by optimal pH and temperature of 8 and 80-90 °C respectively; retaining over 70 percent activity at pH 5-10 after 1 h and 60 percent of initial activity at 90 °C after 90 min of incubation. In all, optimization improved cellulase and xylanase production yields, being 40 and 95.5, 10.89 and 72.17, and 10 and 115- fold increase by S. albidoflavus strain SAMRC-UFH5, B. cereus strain SAMRC-UFH9 and Streptomyces sp. SAMRC-UFH6 respectively. The results of this study suggest that the marine bacterial strains are resource for holocellulase with industrial applications.
- Full Text:
- Date Issued: 2016