A lean production approach to materials management in the Nigerian construction industry
- Authors: Albert, Idowu
- Date: 2020
- Subjects: Materials management , Lean manufacturing Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46008 , vital:39408
- Description: The Nigerian Construction Industry faces a problem of poor materials management that leads to, among other things, materials waste, poor quality of work, poor materials flow, project delay and cost overrun. Overcoming these challenges, requires the rethinking the current modus operandi of the Nigerian construction industry. One such method that has been espoused as having potential to improve materials management, and associated challenges is ‘lean production’. This research aimed at deciphering the lean approach to production management with a view of extracting its utility in enhancing materials management in the construction industry. The qualitative method of research inquiry that is rooted in the phenomenological paradigm was employed. The research activities included a comprehensive review of the related literature and study of selected cases. Abuja, the Federal capital territory of Nigeria was the selected geographical scope of the research. Ten case studies were purposefully selected for the study. The research instrument was a tick box used for direct observation. The study revealed that poor materials management has a negative effect on the materials management plan. Moreover, mixing of waste at the site, negates the effort for identification of materials waste streams, and makes it difficult to account for materials waste, as well as implementing a materials waste management policy on sites. The research also found that poor materials management has a significant effect (high, moderate or low) on materials waste, quality of work, materials flow, productivity, project delay, project profitability and accounting for materials. The research has developed a conceptual model for a lean production approach to materials management based on the results and informed by the theoretical framework. The study has achieved its aim of establishing an understanding of the lean production approach to materials management in the Nigerian construction industry. The study recommends that construction professionals should be well informed on the effects of poor materials management.
- Full Text:
- Date Issued: 2020
- Authors: Albert, Idowu
- Date: 2020
- Subjects: Materials management , Lean manufacturing Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46008 , vital:39408
- Description: The Nigerian Construction Industry faces a problem of poor materials management that leads to, among other things, materials waste, poor quality of work, poor materials flow, project delay and cost overrun. Overcoming these challenges, requires the rethinking the current modus operandi of the Nigerian construction industry. One such method that has been espoused as having potential to improve materials management, and associated challenges is ‘lean production’. This research aimed at deciphering the lean approach to production management with a view of extracting its utility in enhancing materials management in the construction industry. The qualitative method of research inquiry that is rooted in the phenomenological paradigm was employed. The research activities included a comprehensive review of the related literature and study of selected cases. Abuja, the Federal capital territory of Nigeria was the selected geographical scope of the research. Ten case studies were purposefully selected for the study. The research instrument was a tick box used for direct observation. The study revealed that poor materials management has a negative effect on the materials management plan. Moreover, mixing of waste at the site, negates the effort for identification of materials waste streams, and makes it difficult to account for materials waste, as well as implementing a materials waste management policy on sites. The research also found that poor materials management has a significant effect (high, moderate or low) on materials waste, quality of work, materials flow, productivity, project delay, project profitability and accounting for materials. The research has developed a conceptual model for a lean production approach to materials management based on the results and informed by the theoretical framework. The study has achieved its aim of establishing an understanding of the lean production approach to materials management in the Nigerian construction industry. The study recommends that construction professionals should be well informed on the effects of poor materials management.
- Full Text:
- Date Issued: 2020
A management model for human settlements: a case study of Nigeria and South Africa
- Authors: Adeniran, Adeleye Ayoade
- Date: 2020
- Subjects: Human settlements -- Nigeria , Human settlements -- South Africa Sustainable development
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/45985 , vital:39403
- Description: Persistent depreciating human settlements is a global challenge, particularly in developing countries and this challenge contributes to the continuously increasing housing gap, despite several novel policies and programmes. Although there is a dearth of research-based literature on human settlements management, studies show that property management, Facility Management, housing management and urban management impact the sustainability of all these built environment milieus which form part of the human settlements’ sub-components. This research aimed at altering the afore-said challenge by exploring the management of human settlements in Nigeria and in South Africa. Philosophically, the research is pragmatic, and it rests on positivist deductive reasoning. The methods used for data collection include a review of literature, collection of archival records, and empirical studies of purposively selected professionals and stakeholders involved in human settlements’ management in Nigeria and in South Africa. The findings indicate that existing human settlements in the case studies are “good” and “acceptable” with the majority adopting an outsourced method of management. Furthermore, the lack of maintenance records, the deficiency in policy monitoring and the training of management and maintenance personnel were the three highest ranking factors indicated to be affecting human settlements management. Moreover, an inhabitant’s income, the time available for management, professional expertise and technology employed for management are recognised as the critical sustainability sub-factors affecting human settlement management. The factor analysis established ownership, human resource and capital, social, legal, technology, economic, physical and environmental factors as vital and very significant in achieving sustainable management of human settlements. The study recommends the professionalisation of the field of human settlements as well as a formulation of management policy among others. The study developed a management model for human settlements, and it advocates that human settlements managers, owners and organisations should apply the model in this study, to improve their human settlement management practices, so as to achieve sustainability, and in essence, Sustainable Development Goal 11. It is hoped that the suggested management model will influence human settlement policy development and review, the designing of human settlement management programmes including the framework for their ongoing monitoring and evaluation. The study furthermore contributes to the development of housing and human settlement curricula and evolving human settlement research in both developed and developing countries.
- Full Text:
- Date Issued: 2020
- Authors: Adeniran, Adeleye Ayoade
- Date: 2020
- Subjects: Human settlements -- Nigeria , Human settlements -- South Africa Sustainable development
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/45985 , vital:39403
- Description: Persistent depreciating human settlements is a global challenge, particularly in developing countries and this challenge contributes to the continuously increasing housing gap, despite several novel policies and programmes. Although there is a dearth of research-based literature on human settlements management, studies show that property management, Facility Management, housing management and urban management impact the sustainability of all these built environment milieus which form part of the human settlements’ sub-components. This research aimed at altering the afore-said challenge by exploring the management of human settlements in Nigeria and in South Africa. Philosophically, the research is pragmatic, and it rests on positivist deductive reasoning. The methods used for data collection include a review of literature, collection of archival records, and empirical studies of purposively selected professionals and stakeholders involved in human settlements’ management in Nigeria and in South Africa. The findings indicate that existing human settlements in the case studies are “good” and “acceptable” with the majority adopting an outsourced method of management. Furthermore, the lack of maintenance records, the deficiency in policy monitoring and the training of management and maintenance personnel were the three highest ranking factors indicated to be affecting human settlements management. Moreover, an inhabitant’s income, the time available for management, professional expertise and technology employed for management are recognised as the critical sustainability sub-factors affecting human settlement management. The factor analysis established ownership, human resource and capital, social, legal, technology, economic, physical and environmental factors as vital and very significant in achieving sustainable management of human settlements. The study recommends the professionalisation of the field of human settlements as well as a formulation of management policy among others. The study developed a management model for human settlements, and it advocates that human settlements managers, owners and organisations should apply the model in this study, to improve their human settlement management practices, so as to achieve sustainability, and in essence, Sustainable Development Goal 11. It is hoped that the suggested management model will influence human settlement policy development and review, the designing of human settlement management programmes including the framework for their ongoing monitoring and evaluation. The study furthermore contributes to the development of housing and human settlement curricula and evolving human settlement research in both developed and developing countries.
- Full Text:
- Date Issued: 2020
A novel, improved throughput bioassay for determining the delative speed of antimalarial drug action using fluorescent vitality probes
- Authors: Laming, Dustin
- Date: 2020
- Subjects: Plasmodium falciparum , Malaria -- Treatment -- Africa , Antimalarials , Malaria vaccine
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/139902 , vital:37810
- Description: Malaria is one of the most prevalent diseases in Africa and Plasmodium falciparum is widely accepted as the most virulent of the malaria parasite species, with a fatality rate of 15 – 20 % of reported cases of infection. While various treatments have been accepted into early stage clinical trials, there has been little progress towards a proven vaccine. Pending a long-term solution, endemic countries rely heavily on the development of innovative drugs that are not only efficacious but are also quick acting. Traditional methods of evaluating antimalarial killing speeds via morphological assessments are inherently flawed by tedious, subjective interpretations of the heterogenous parasite morphology encountered in routine parasite culture conditions. This has led to the introduction of alternative assay formats to determine how rapidly compounds act on parasites in vitro: a parasite reduction ratio (PRR) assay that measures the recovery of parasite cultures from drug exposure; determining the shift in IC50 values of compounds when dose-response assays are carried out for different time periods; a bioluminescence relative rate of kill (BRRoK) assay that compares the extent to which compounds reduce firefly luciferase activity in transgenic parasites. Recent whole cell in vitro screening efforts have resulted in the generation of chemically diverse compound libraries such as the Medicines for Malaria Venture’s Pathogen Box, which houses 125 novel compounds with in vitro antiplasmodial activity. Assessing the relative killing speeds of these compounds would aid prioritizing fast-acting compounds that can be exploited as starting points for further development. This study aimed to develop a bioassay using the calcein-acetoxymethyl and propidium iodide fluorescent vitality probes, which would allow the relative speed of drug action on Plasmodium falciparum malaria parasites to be assessed and ranked in relation to each other using a quantitative, improved throughput approach. Initially applied to human (HeLa) cells, the assay was used to compare the relative speeds of action of 3 potential anti-cancer compounds by fluorescence microscopy. Subsequently adapted to P. falciparum, the assay was able to rank the relative speeds of action of standard antimalarials by fluorescence microscopy and two flow cytometry formats. Application of a multiwell flow cytometer increased throughput and enabled the assessment of experimental compounds, which included a set of artemisinin analogs and 125 antimalarial compounds in the MMV Pathogen Box. The latter culminated in the identification of five rapidly parasiticidal compounds in relation to the other compounds in the library, which may act as benchmark references for future studies and form the basis of the next generation of fast acting antimalarials that could be used to combat modern, resistant malaria.
- Full Text:
- Date Issued: 2020
- Authors: Laming, Dustin
- Date: 2020
- Subjects: Plasmodium falciparum , Malaria -- Treatment -- Africa , Antimalarials , Malaria vaccine
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/139902 , vital:37810
- Description: Malaria is one of the most prevalent diseases in Africa and Plasmodium falciparum is widely accepted as the most virulent of the malaria parasite species, with a fatality rate of 15 – 20 % of reported cases of infection. While various treatments have been accepted into early stage clinical trials, there has been little progress towards a proven vaccine. Pending a long-term solution, endemic countries rely heavily on the development of innovative drugs that are not only efficacious but are also quick acting. Traditional methods of evaluating antimalarial killing speeds via morphological assessments are inherently flawed by tedious, subjective interpretations of the heterogenous parasite morphology encountered in routine parasite culture conditions. This has led to the introduction of alternative assay formats to determine how rapidly compounds act on parasites in vitro: a parasite reduction ratio (PRR) assay that measures the recovery of parasite cultures from drug exposure; determining the shift in IC50 values of compounds when dose-response assays are carried out for different time periods; a bioluminescence relative rate of kill (BRRoK) assay that compares the extent to which compounds reduce firefly luciferase activity in transgenic parasites. Recent whole cell in vitro screening efforts have resulted in the generation of chemically diverse compound libraries such as the Medicines for Malaria Venture’s Pathogen Box, which houses 125 novel compounds with in vitro antiplasmodial activity. Assessing the relative killing speeds of these compounds would aid prioritizing fast-acting compounds that can be exploited as starting points for further development. This study aimed to develop a bioassay using the calcein-acetoxymethyl and propidium iodide fluorescent vitality probes, which would allow the relative speed of drug action on Plasmodium falciparum malaria parasites to be assessed and ranked in relation to each other using a quantitative, improved throughput approach. Initially applied to human (HeLa) cells, the assay was used to compare the relative speeds of action of 3 potential anti-cancer compounds by fluorescence microscopy. Subsequently adapted to P. falciparum, the assay was able to rank the relative speeds of action of standard antimalarials by fluorescence microscopy and two flow cytometry formats. Application of a multiwell flow cytometer increased throughput and enabled the assessment of experimental compounds, which included a set of artemisinin analogs and 125 antimalarial compounds in the MMV Pathogen Box. The latter culminated in the identification of five rapidly parasiticidal compounds in relation to the other compounds in the library, which may act as benchmark references for future studies and form the basis of the next generation of fast acting antimalarials that could be used to combat modern, resistant malaria.
- Full Text:
- Date Issued: 2020
A personality-based surveillance model for Facebook apps
- Authors: Van der Schyff, Karl Izak
- Date: 2020
- Subjects: Facebook (Electronic resource) , Electronic surveillance -- Psychological aspects , Online social networks -- Psychological aspects , Social media -- Psychological aspects , Personality
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145534 , vital:38447
- Description: The surveillance of data through the use of Facebook Apps is an ongoing and persistent problem that impacts millions of users. Nonetheless, limited research has been conducted investigating to what extent a Facebook user’s personality influences their awareness of such surveillance practices. Thus, to understand this situation better, the current study inductively developed four propositions from secondary data sources as part of a detailed content analysis. Spanning three search and analysis phases the content analysis led to the development of the research model. Guided by the propositions and research questions, a questionnaire was developed based on the relevant constructs prescribed by the Theory of Planned Behaviour. This questionnaire was used, and a total of 651 responses were collected from Facebook users over the age of 18 years old and residing in the United States of America. Primary data took place at both a univariate and multivariate level with a specific focus on the development of a structural model. Interpretation of the structural model revealed that out of all the Big Five personality traits, Conscientiousness exhibited the strongest relationship with information security awareness followed by Openness to Experience and Neuroticism, respectively. The results further indicated that the model constructs based on attitude, social norms and awareness significantly influenced the intended use of Facebook Apps. The study also contributes by indicating which personality traits are most vulnerable to Facebook App surveillance. For example, it was found that individuals high in Conscientiousness are the least vulnerable with individuals high in Extraversion being the most vulnerable. Since the results indicate that not all the personality traits are significantly related to the model constructs, additional factors may contribute to App surveillance in this context. Concerning this, factors such as user apathy, information privacy, privacy concerns, control and Facebook dependency are discussed as a means to argue why this might be the case.
- Full Text:
- Date Issued: 2020
- Authors: Van der Schyff, Karl Izak
- Date: 2020
- Subjects: Facebook (Electronic resource) , Electronic surveillance -- Psychological aspects , Online social networks -- Psychological aspects , Social media -- Psychological aspects , Personality
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145534 , vital:38447
- Description: The surveillance of data through the use of Facebook Apps is an ongoing and persistent problem that impacts millions of users. Nonetheless, limited research has been conducted investigating to what extent a Facebook user’s personality influences their awareness of such surveillance practices. Thus, to understand this situation better, the current study inductively developed four propositions from secondary data sources as part of a detailed content analysis. Spanning three search and analysis phases the content analysis led to the development of the research model. Guided by the propositions and research questions, a questionnaire was developed based on the relevant constructs prescribed by the Theory of Planned Behaviour. This questionnaire was used, and a total of 651 responses were collected from Facebook users over the age of 18 years old and residing in the United States of America. Primary data took place at both a univariate and multivariate level with a specific focus on the development of a structural model. Interpretation of the structural model revealed that out of all the Big Five personality traits, Conscientiousness exhibited the strongest relationship with information security awareness followed by Openness to Experience and Neuroticism, respectively. The results further indicated that the model constructs based on attitude, social norms and awareness significantly influenced the intended use of Facebook Apps. The study also contributes by indicating which personality traits are most vulnerable to Facebook App surveillance. For example, it was found that individuals high in Conscientiousness are the least vulnerable with individuals high in Extraversion being the most vulnerable. Since the results indicate that not all the personality traits are significantly related to the model constructs, additional factors may contribute to App surveillance in this context. Concerning this, factors such as user apathy, information privacy, privacy concerns, control and Facebook dependency are discussed as a means to argue why this might be the case.
- Full Text:
- Date Issued: 2020
A psychobiographical case study: Amelia Dyer in a search for glory
- Authors: April, Heather
- Date: 2020
- Subjects: Serial murderers--Psychology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/50857 , vital:43008
- Description: The study is a psychobiographical case study based on the life of a Victorian baby farmer Amelia Dyer (1837-1896). She was executed for the murder of babies who were placed in her care over a period of 30 years. Psychobiography is a qualitative method of enquiry which explores the life of a unique individual subject through the lens of a psychological theory for the purpose of creating a coherent psychological case study. The psychoanalytic theoretical lens of Karen Horney was used to trace the evolution of Amelia Dyer’s sense of self within the Victorian culture of respectability. Baby farming referred to an unregulated business of adoption and fostering of infants, mostly illegitimate infants for a fee. Insufficient social structures and support for unwed mothers and children encouraged the business practice as women had very little choice for childcare. Baby farming was open to abuse and exploitation and hundreds of babies lost their lives due to insufficient care or infanticide. Amelia Dyer showed special talents and creativity from a young age, was ambitious and wanted to be self-reliant in a culture that did not provide women with opportunities to live out their ambitions. Baby farming became a business venture for her in the early stages of her life which later evolved into sadistic abuse and murder of the infants. Her evolution from a creative and hardworking young girl to a sadistic murderer of children is what qualifies her as a suitable subject for the exploration of Karen Horney’s dynamic theory of neuroses and the development of the neurotic self within culture. Extensive biographical data was collected and processed into salient themes. The study integrates the theory of Karen Horney, the life experiences of Amelia Dyer and Victorian respectability and demonstrates the value of using psychobiography as the method of inquiry into the exploration of the unique individual. The findings of the study demonstrated that Amelia Dyer and her social context were inextricably bound by a vicious cycle of psychic and emotional vi conflicts related to fear, control and self-hatred by the internalization of gender stereotypes and norms. The contribution of the study as a whole rests with its demonstration of the value of a holistic and reflexive exploration of the unique individual woman. It demonstrates the value of Horney’s in-depth theoretical understanding of the ambivalent core of selfhood that lies behind observable acts of behavior. The study as a whole contributes towards building upon holistic and integrative therapeutic frameworks in the understanding of diversity amongst women and mothers in culture.
- Full Text:
- Date Issued: 2020
- Authors: April, Heather
- Date: 2020
- Subjects: Serial murderers--Psychology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/50857 , vital:43008
- Description: The study is a psychobiographical case study based on the life of a Victorian baby farmer Amelia Dyer (1837-1896). She was executed for the murder of babies who were placed in her care over a period of 30 years. Psychobiography is a qualitative method of enquiry which explores the life of a unique individual subject through the lens of a psychological theory for the purpose of creating a coherent psychological case study. The psychoanalytic theoretical lens of Karen Horney was used to trace the evolution of Amelia Dyer’s sense of self within the Victorian culture of respectability. Baby farming referred to an unregulated business of adoption and fostering of infants, mostly illegitimate infants for a fee. Insufficient social structures and support for unwed mothers and children encouraged the business practice as women had very little choice for childcare. Baby farming was open to abuse and exploitation and hundreds of babies lost their lives due to insufficient care or infanticide. Amelia Dyer showed special talents and creativity from a young age, was ambitious and wanted to be self-reliant in a culture that did not provide women with opportunities to live out their ambitions. Baby farming became a business venture for her in the early stages of her life which later evolved into sadistic abuse and murder of the infants. Her evolution from a creative and hardworking young girl to a sadistic murderer of children is what qualifies her as a suitable subject for the exploration of Karen Horney’s dynamic theory of neuroses and the development of the neurotic self within culture. Extensive biographical data was collected and processed into salient themes. The study integrates the theory of Karen Horney, the life experiences of Amelia Dyer and Victorian respectability and demonstrates the value of using psychobiography as the method of inquiry into the exploration of the unique individual. The findings of the study demonstrated that Amelia Dyer and her social context were inextricably bound by a vicious cycle of psychic and emotional vi conflicts related to fear, control and self-hatred by the internalization of gender stereotypes and norms. The contribution of the study as a whole rests with its demonstration of the value of a holistic and reflexive exploration of the unique individual woman. It demonstrates the value of Horney’s in-depth theoretical understanding of the ambivalent core of selfhood that lies behind observable acts of behavior. The study as a whole contributes towards building upon holistic and integrative therapeutic frameworks in the understanding of diversity amongst women and mothers in culture.
- Full Text:
- Date Issued: 2020
A psychobiography of Viktor Emil Frankl
- Authors: Bushkin, Hanan
- Date: 2020
- Subjects: Frankl, Viktor Emil
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46440 , vital:39566
- Description: The first study conducted in South Africa of a prominent figure traces back as far as 1939. Since then, extensive research has been done in the field of psychobiography, resulting in a growing interest in this field and evolving into an established research genre in South Africa. Despite the increase in the use of psychobiographies as a research approach internationally and specifically in South Africa, its use is still considered relatively under-utilised and, therefore, the pursuit of further development of psychobiographies in South Africa is required. In light of South Africa’s effort to promote and advance the use of psychobiographies, South African researchers may be motivated to continue studying significant and exceptional lives in South Africa and abroad. Viktor Frankl was selected for this study based on his uniqueness, significance and his interesting life. He is also considered an exceptional individual who has shaped modern psychological thinking. Frankl had written over 40 books on his theory and many studies have been conducted based on his existential theory. Frankl’s contribution to the academic world has been recognised and acknowledged by significant institutions through his own and others’ research. Although much has been written on the life and work of Frankl, none of the literature utilises specific psychological focus and no psychobiographical study of the life of Frankl exists. Therefore, the researcher selected Frankl as the subject for this psychobiography through purposive sampling. The aim of the study was to provide a psychological exploration and description of Frankl’s life against the backdrop of his socio-cultural context. In order to achieve this aim, the researcher employed two psychological frameworks to guide in the description and exploration of his life. The psychological frameworks included Levinson’s life structure theory of adult development and Frankl’s existential theory. The study aimed to describe Frankl’s development with the use of Levinson’s theory while describing how he attained meaning in his life with the use of his own existential theory. Due to the exploratory-descriptive nature of this study, the objective fell within the inductive research approach. The researcher utilised a systematic coding method to arrange the data. The theoretical framework of Levinson’s life structure theory guided the coding system, as well as the key concepts of Frankl’s existential theory. In addition, the researcher utilised Alexander’s guidelines for the extraction of salient data, together with McAdam’s methods and recommendations for managing the data. Lastly, the researcher followed the 12-step method of conducting a psychobiography, as proposed by Du Plessis. Findings from this study found a correlation between Frankl’s life and the eras and transitional periods as theorised by Levinson’s theory. The findings of this study, therefore, support the use of Levinson’s theory with regards to the time frames and its use in understanding Frankl’s development. Also, the researcher found that Levinson’s theory was useful in understanding Frankl’s personality development within his context throughout his lifespan. With regards to Frankl’s existential theory, the researcher found that the use of the theory was suitable in understanding Frankl’s search for meaning. Frankl’s concepts of freedom of will, will to meaning, meaning of life, existential vacuum, supra-meaning, dimensional ontology, the three triads and noö-dynamics assisted in explaining Frankl’s drive to find meaning in his life, take responsibility to attain such meaning and to strive for transcendence beyond his suffering. The researcher found Frankl’s theory useful in explaining his drive, motives, needs and patterns of behaviour within this context. The holistic and integrative approach of the study allowed for an in-depth exploration and description of Frankl’s life and development within his socio-historical context. In addition to contributing to the existing body of knowledge on Frankl, his life and his theory, the study also contributed to the growing field of psychobiographical research. The study acknowledged and highlighted that further in-depth examination of the lives of extraordinary personalities could significantly contribute to psychobiographical studies. Based on the psychological frameworks used to explore and describe Frankl’s life, recommendations are made for future research.
- Full Text:
- Date Issued: 2020
- Authors: Bushkin, Hanan
- Date: 2020
- Subjects: Frankl, Viktor Emil
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46440 , vital:39566
- Description: The first study conducted in South Africa of a prominent figure traces back as far as 1939. Since then, extensive research has been done in the field of psychobiography, resulting in a growing interest in this field and evolving into an established research genre in South Africa. Despite the increase in the use of psychobiographies as a research approach internationally and specifically in South Africa, its use is still considered relatively under-utilised and, therefore, the pursuit of further development of psychobiographies in South Africa is required. In light of South Africa’s effort to promote and advance the use of psychobiographies, South African researchers may be motivated to continue studying significant and exceptional lives in South Africa and abroad. Viktor Frankl was selected for this study based on his uniqueness, significance and his interesting life. He is also considered an exceptional individual who has shaped modern psychological thinking. Frankl had written over 40 books on his theory and many studies have been conducted based on his existential theory. Frankl’s contribution to the academic world has been recognised and acknowledged by significant institutions through his own and others’ research. Although much has been written on the life and work of Frankl, none of the literature utilises specific psychological focus and no psychobiographical study of the life of Frankl exists. Therefore, the researcher selected Frankl as the subject for this psychobiography through purposive sampling. The aim of the study was to provide a psychological exploration and description of Frankl’s life against the backdrop of his socio-cultural context. In order to achieve this aim, the researcher employed two psychological frameworks to guide in the description and exploration of his life. The psychological frameworks included Levinson’s life structure theory of adult development and Frankl’s existential theory. The study aimed to describe Frankl’s development with the use of Levinson’s theory while describing how he attained meaning in his life with the use of his own existential theory. Due to the exploratory-descriptive nature of this study, the objective fell within the inductive research approach. The researcher utilised a systematic coding method to arrange the data. The theoretical framework of Levinson’s life structure theory guided the coding system, as well as the key concepts of Frankl’s existential theory. In addition, the researcher utilised Alexander’s guidelines for the extraction of salient data, together with McAdam’s methods and recommendations for managing the data. Lastly, the researcher followed the 12-step method of conducting a psychobiography, as proposed by Du Plessis. Findings from this study found a correlation between Frankl’s life and the eras and transitional periods as theorised by Levinson’s theory. The findings of this study, therefore, support the use of Levinson’s theory with regards to the time frames and its use in understanding Frankl’s development. Also, the researcher found that Levinson’s theory was useful in understanding Frankl’s personality development within his context throughout his lifespan. With regards to Frankl’s existential theory, the researcher found that the use of the theory was suitable in understanding Frankl’s search for meaning. Frankl’s concepts of freedom of will, will to meaning, meaning of life, existential vacuum, supra-meaning, dimensional ontology, the three triads and noö-dynamics assisted in explaining Frankl’s drive to find meaning in his life, take responsibility to attain such meaning and to strive for transcendence beyond his suffering. The researcher found Frankl’s theory useful in explaining his drive, motives, needs and patterns of behaviour within this context. The holistic and integrative approach of the study allowed for an in-depth exploration and description of Frankl’s life and development within his socio-historical context. In addition to contributing to the existing body of knowledge on Frankl, his life and his theory, the study also contributed to the growing field of psychobiographical research. The study acknowledged and highlighted that further in-depth examination of the lives of extraordinary personalities could significantly contribute to psychobiographical studies. Based on the psychological frameworks used to explore and describe Frankl’s life, recommendations are made for future research.
- Full Text:
- Date Issued: 2020
A Ranking Framework for Higher Education Institutions in South Africa
- Authors: Kanyutu, Teresia Watiri
- Date: 2020
- Subjects: Education, Higher -- South Africa
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/48246 , vital:40746
- Description: In the past 16 years, the use of League Tables and Rankings (LTRs) as a tool to rank or measure the performance of Higher Education Institutions (HEIs) has grown in popularity. As a global practice, LTR outcomes are influencing how policies are developed and implemented within the Higher Education (HE) sector. Studies indicate that based on individual information requirements, HE stakeholders are using LTRs to compare HEIs with each other and make informed comparisons and decisions. University directors use LTRs as a basis for institutional strategic planning, reputation building and policy making, while students use LTRs to compare HEIs and make university of choice decisions. Further studies confirm that governments use LTRs for national higher education policy making, university funding, foreign partnerships and resource allocation. Globally and at a national level, the higher education sector has witnessed policy and structural changes, many of which are due to the increase in the use of international rankings and league tables. Despite the opportunities presented by participating in the production of and using LTRs, the ranking practice is contentious. Amongst the issues disputed by the HE stakeholders are the methodologies and criteria used in the production and publication of LTRs. Higher education experts argue that LTRs tend to favour institutional research output and ignore the teaching and learning function of HEIs. As a result, the ranking criteria differ across the higher education ranking institutions and their publication outcomes, which causes skepticism across the HE sector. Research indicates that these ranking criteria are often discussed from the standpoint of governments, the higher education management and the ranking institutions producing these LTR publications. The opinions of the students on the suitable ranking criteria used by ranking institutions lack. This study aims to address that gap. This study investigates the applicable criteria for ranking HEIs in South Africa, from the perspective of students. Building on the existing ranking criteria for three global and popular ranking institutions namely, Academic Ranking of World Universities (ARWU), Times Higher Education World University Ranking (THEWUR) and Quacquarelli Symonds World University Ranking (QSWUR), the study poses the question; “What framework can be used to rank HEIs in South Africa, from a student’s perspective?” The study argues that although some HEIs in South Africa have in the past and most recently appeared in the global LTRs, the current choice of ranking criteria fails to consider the perspectives of the students, who are major consumers of LTRs and important stakeholders in the HE sector. A positivistic research method was used, based on a review of literature on the current ranking criteria for the selected global ranking institutions. An empirical study was conducted amongst students in a South African Comprehensive University. An online survey was distributed through convenient and snowball sampling, where the students were requested to participate in the survey and share the questionnaire link with others. Eight hundred and eighty six (886) responses were received and used for the data analyses of this study.
- Full Text:
- Date Issued: 2020
- Authors: Kanyutu, Teresia Watiri
- Date: 2020
- Subjects: Education, Higher -- South Africa
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/48246 , vital:40746
- Description: In the past 16 years, the use of League Tables and Rankings (LTRs) as a tool to rank or measure the performance of Higher Education Institutions (HEIs) has grown in popularity. As a global practice, LTR outcomes are influencing how policies are developed and implemented within the Higher Education (HE) sector. Studies indicate that based on individual information requirements, HE stakeholders are using LTRs to compare HEIs with each other and make informed comparisons and decisions. University directors use LTRs as a basis for institutional strategic planning, reputation building and policy making, while students use LTRs to compare HEIs and make university of choice decisions. Further studies confirm that governments use LTRs for national higher education policy making, university funding, foreign partnerships and resource allocation. Globally and at a national level, the higher education sector has witnessed policy and structural changes, many of which are due to the increase in the use of international rankings and league tables. Despite the opportunities presented by participating in the production of and using LTRs, the ranking practice is contentious. Amongst the issues disputed by the HE stakeholders are the methodologies and criteria used in the production and publication of LTRs. Higher education experts argue that LTRs tend to favour institutional research output and ignore the teaching and learning function of HEIs. As a result, the ranking criteria differ across the higher education ranking institutions and their publication outcomes, which causes skepticism across the HE sector. Research indicates that these ranking criteria are often discussed from the standpoint of governments, the higher education management and the ranking institutions producing these LTR publications. The opinions of the students on the suitable ranking criteria used by ranking institutions lack. This study aims to address that gap. This study investigates the applicable criteria for ranking HEIs in South Africa, from the perspective of students. Building on the existing ranking criteria for three global and popular ranking institutions namely, Academic Ranking of World Universities (ARWU), Times Higher Education World University Ranking (THEWUR) and Quacquarelli Symonds World University Ranking (QSWUR), the study poses the question; “What framework can be used to rank HEIs in South Africa, from a student’s perspective?” The study argues that although some HEIs in South Africa have in the past and most recently appeared in the global LTRs, the current choice of ranking criteria fails to consider the perspectives of the students, who are major consumers of LTRs and important stakeholders in the HE sector. A positivistic research method was used, based on a review of literature on the current ranking criteria for the selected global ranking institutions. An empirical study was conducted amongst students in a South African Comprehensive University. An online survey was distributed through convenient and snowball sampling, where the students were requested to participate in the survey and share the questionnaire link with others. Eight hundred and eighty six (886) responses were received and used for the data analyses of this study.
- Full Text:
- Date Issued: 2020
A reappraisal of the origin of the Hotazel Fe-Mn Formation in an evolving early Earth system through the application of mineral-specific geochemistry, speciation techniques and stable isotope systematics
- Authors: Mhlanga, Xolane Reginald
- Date: 2020
- Subjects: Manganese ores -- South Africa -- Hotazel , Manganese ores -- Geology , Iron ores -- South Africa -- Hotazel , Iron ores -- Geology , Geochemistry -- South Africa -- Hotazel , Isotope geology -- South Africa -- Hotazel , Geology, Stratigraphic -- Archaean , Geology, Stratigraphic -- Proterozoic , Transvaal Supergroup (South Africa) , Great Oxidation Event
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146123 , vital:38497
- Description: Marine chemical sediments such as Banded Iron Formations deposited during the Archean-Palaeoproterozoic are studied extensively because they represent a period in the development of the Earth’s early history where the atmospheric O₂ content was below the present levels (PAL) of 21%. Prior to the Great Oxidation Event (GOE) at ca. 2.4 Ga, highly ferruginous and anoxic marine environments were dominated by extensive BIF deposition such as that of the Griqualand West Basin of the Transvaal Supergroup in South Africa. This basin is also thought to record the transition into the first rise of atmospheric O₂ in our planet, from the Koegas Subgroup to the Hotazel Formation dated at ca. 2.43 Ga (Gumsley et al., 2017). Two drill cores from the north eastern part of the Kalahari Manganese Field characterized by a well-preserved and complete intersection of the cyclic Mn-Fe Hotazel Formation were studied at a high resolution (sampled at approximately one-meter interval). Such high-resolution approach is being employed for the first time in this project, capturing in detail the three manganese rich layers intercalated with BIF and the transitions between these lithofacies. The micro-banded BIF is made up of three major phases, namely Fe-Ca-Mg carbonates (ankerite, siderite and calcite), magnetite, and silicates (chert and minor Fe-silicates); laminated transitional lutite consist of mainly hematite, chert and Mn-carbonates, whereas the manganese ore layers are made up of mostly calcic carbonates (Mn-calcite and Ca-kutnahorite) in the form of laminations and ovoids, while Mn-silicates include dominant braunite and lesser friedelite. All three lithofacies are very fine grained (sub-mm scale) and so petrographic and mineralogical observations were obtained mostly through scanning electron microscope analysis for detailed textural relationships with focus on the carbonate fraction. Bulk geochemical studies of the entire stratigraphy of the Hotazel Formation have previously provided great insights into the cyclic nature of the deposit but have not adequately considered the potential of the carbonate fraction of the rocks as a valuable proxy for understanding the chemistry of the primary depositional environment and insights into the redox processes that were at play. This is because these carbonates have always been attributed to diagenetic processes below the sediment-water interface such as microbially-mediated dissimilatory iron/manganese reduction (DIR/DMR) where the precursor/primary Fe-Mn oxyhydroxides have been reduced to result in the minerals observed today. The carbonate fraction of the BIF is made up of ankerite and siderite which co-exist in a chert matrix as anhedral to subhedral grains with no apparent replacement textures. This suggests co-precipitation of the two species which is at apparent odds with classic diagenetic models. Similarly, Mn-carbonates in the hematite lutite and manganese ore (Mn-calcite, kutnahorite, and minor rhodocrosite) co-exist in laminae and ovoids with no textures observed that would suggest an obvious sequential mode of formation during diagenesis. In this light, a carbonate-specific geochemical analysis based on the sequential Fe extraction technique of Poulton and Canfield (2005) was employed to decipher further the cyclic nature of the Hotazel Formation and its primary versus diagenetic controls. Results from the carbonate fraction analysis of the three lithofacies show a clear fractionation of iron and manganese during primary – rather than diagenetic - carbonate precipitation, suggesting a decoupling between DIR and DMR which is ultimately interpreted to have taken place in the water column. Bulk-rock concentration results for minor and trace elements such as Zr, Ti, Sc and Al have been used for the determination of either siliciclastic or volcanic detrital inputs as they are generally immobile in most natural aqueous solutions. These elements are in very low concentrations in all three lithofacies suggesting that the depositional environment had vanishingly small contributions from terrigenous or volcanic detritus. In terms of redox-sensitive transition metals, only Mo and Co appear to show an affinity for high Mn facies in the Hotazel sequence. Cobalt in particular attains a very low abundance in the Hotazel BIF layers at an average of ~ 4 ppm. This is similar to average pre-GOE BIF in South Africa and worldwide. Maxima in Co abundance are associated with transitional hematite lutite and Mn ore layers, but maxima over 100ppm are seen in within the hematite lutite and not within the Mn ore proper where maxima in Mn are recorded. This suggests a clear and direct association with the hematite fraction in the rocks, which is modally much higher in the lutites but drops substantially in the Mn layers themselves. The similarities of bulk-rock BIF and modern-day seawater REE patterns has been used as a key argument for primary controls in REE behaviour and minimal diagenetic modification. Likewise, the three lithofacies of the Hotazel Formation analysed in this study all share similar characteristics with a clear seawater signal through gentle positive slopes in the normalised abundance of LREE versus HREE. Negative Ce anomalies prevail in the entire sample set analysed, which has been interpreted before as a proxy for oxic seawater conditions. However, positive Ce anomalies that are traditionally linked to scavenging and deposition of primary tetravalent Mn oxyhydroxides (e.g., as observed in modern day ferromanganese nodules) are completely absent from the current dataset. The lack of a positive Ce anomaly in the manganese ore and peak Co association with ferric oxides and not with peak Mn, suggests that primary deposition must have occurred within an environment that was not fully oxidizing with respect to manganese. The use of stable isotopes (i.e., C and Fe) was employed to gain insights into redox processes, whether these are thought to have happened below the sediment-water interface or in contemporaneous seawater. At a small scale, all lithofacies of the Hotazel Formation record bulk-rock δ¹³C values that are low and essentially invariant about the average value of -9.5 per mil. This is independent of sharp variations in overall modal mineralogy, relative carbonate abundance and carbonate chemistry, which is clearly difficult to reconcile with in-situ diagenetic processes that predict highly variable δ¹³C signals in response to complex combinations of precursor sediment mineralogy, pore-fluid chemistry, organic carbon supply and open vs closed system diagenesis. At a stratigraphic scale, the carbonate δ¹³C (-5 to -13‰) variations between the different lithologies could instead represent temporal changes in water-column chemistry against well-developed physico-chemical gradients, depth of deposition and biological processes. The low iron isotope values recorded in the hematite lutite and manganese ore samples can be attributed to fractionation effects of initial oxidation of ferrous iron to form Fe-oxyhydroxides in the shallow parts of the basin, from an already isotopically highly depleted aqueous Fe-pool as proposed previously. The slightly higher but still negative bulk-rock δ⁵⁶Fe values of the host BIF can be attributed to water-column Fe isotopic effects at deeper levels between primary Fe oxyhydroxides and an isotopically heavier Fe(II) pool, which was subsequently preserved during diagenetic recrystallization. All above findings were combined into a conceptual model of deposition for the three different lithologies of the Hotazel Formation. The model predicts that free molecular oxygen must have been present within the shallow oceanic environment and implicates both Mn and Fe as active redox “players” compared to classic models that apply to the origin of worldwide BIF prior to the GOE. The deposition of the Hotazel strata is interpreted to have occurred through the following three stages: (1) BIF deposition occurred in a relatively deep oceanic environment above the Ongeluk lavas during marine transgression, where a redoxcline and seawater stratification separated hydrothermally sourced iron and manganese, in response to an active Mn-shuttle mechanism linked to Mn redox cycling. Abundant ferrous iron must have been oxidized by available oxygen but also by oxidised Mn species (MnOOH) and possibly even some soluble Mn(III) complexes. Through this process, Mn(III) was being effectively reduced back into solution along with cobalt(III), as Mn(II) and Co(II) respectively, thus creating maxima in their concentrations. A drawdown of Fe(OH)₃ particles was therefore the only net precipitation mechanism at this stage. Carbonate species of Fe and the abundant magnetite would possibly have formed by reaction between the ferric hydroxides and the deeper Fe(II) pool, while organic matter would also have reacted in the water-column via DIR, accounting for the low δ¹³C signature of Fe carbonate minerals. (2) Hematite lutite formation would have occurred at a relatively shallower environment during marine regression. At this stage, reductive cycling of Fe was minimal in the absence of a deeper Fe(II) reservoir reacting with the ferric primary precipitates. Therefore, DIR progressively gave way to manganese reduction and organic carbon oxidation (DMR), which reduced MnOOH to form Mn(II)-rich carbonates in the form of kutnahorite and Mn-calcite. Co-bearing Fe(OH)₃ would have precipitated and was ultimately preserved as Co-bearing hematite during diagenesis. (3) Deposition of manganese-rich sediment occurred at even shallower oceanic depths (maximum regression) where aerobic organic carbon oxidation replaced DMR, resulting in Ca-rich carbonates such as Mn-bearing calcite and Ca-kutnahorite, yet with a low carbon isotope signature recording aerobic conditions of organic carbon cycling. Mn(III) reduction at this stage was curtailed, leading to massive precipitation of MnOOH which was diagenetically transformed into braunite and friedelite. Simultaneous precipitation of Co-bearing Fe(OH)₃ would have continued but at much more subdued rates. Repeated transgressive-regressive cycles resulted in the cyclic BIF-hematite lutite- manganese ore nature of the Hotazel Formation in an oxidized oceanic environment at the onset of the Great Oxidation Event, which was nonetheless never oxic enough to drive Mn(II) oxidation fully to its tetravalent state. The mineralogy and species-specific geochemistry of the Hotazel strata, and more specifically the carbonate fraction thereof, appear to faithfully capture the chemistry of the primary depositional environment in a progressively evolving Earth System. This project opens the door for more studies focusing on better constraining primary versus diagenetic depositional 2020 Hotazel Fe and Mn deposition mechanisms of iron and manganese during the period leading up to the GOE, and possibly re-defining the significance of Fe and Mn as invaluable redox proxies in a rapidly changing planet.
- Full Text:
- Date Issued: 2020
- Authors: Mhlanga, Xolane Reginald
- Date: 2020
- Subjects: Manganese ores -- South Africa -- Hotazel , Manganese ores -- Geology , Iron ores -- South Africa -- Hotazel , Iron ores -- Geology , Geochemistry -- South Africa -- Hotazel , Isotope geology -- South Africa -- Hotazel , Geology, Stratigraphic -- Archaean , Geology, Stratigraphic -- Proterozoic , Transvaal Supergroup (South Africa) , Great Oxidation Event
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146123 , vital:38497
- Description: Marine chemical sediments such as Banded Iron Formations deposited during the Archean-Palaeoproterozoic are studied extensively because they represent a period in the development of the Earth’s early history where the atmospheric O₂ content was below the present levels (PAL) of 21%. Prior to the Great Oxidation Event (GOE) at ca. 2.4 Ga, highly ferruginous and anoxic marine environments were dominated by extensive BIF deposition such as that of the Griqualand West Basin of the Transvaal Supergroup in South Africa. This basin is also thought to record the transition into the first rise of atmospheric O₂ in our planet, from the Koegas Subgroup to the Hotazel Formation dated at ca. 2.43 Ga (Gumsley et al., 2017). Two drill cores from the north eastern part of the Kalahari Manganese Field characterized by a well-preserved and complete intersection of the cyclic Mn-Fe Hotazel Formation were studied at a high resolution (sampled at approximately one-meter interval). Such high-resolution approach is being employed for the first time in this project, capturing in detail the three manganese rich layers intercalated with BIF and the transitions between these lithofacies. The micro-banded BIF is made up of three major phases, namely Fe-Ca-Mg carbonates (ankerite, siderite and calcite), magnetite, and silicates (chert and minor Fe-silicates); laminated transitional lutite consist of mainly hematite, chert and Mn-carbonates, whereas the manganese ore layers are made up of mostly calcic carbonates (Mn-calcite and Ca-kutnahorite) in the form of laminations and ovoids, while Mn-silicates include dominant braunite and lesser friedelite. All three lithofacies are very fine grained (sub-mm scale) and so petrographic and mineralogical observations were obtained mostly through scanning electron microscope analysis for detailed textural relationships with focus on the carbonate fraction. Bulk geochemical studies of the entire stratigraphy of the Hotazel Formation have previously provided great insights into the cyclic nature of the deposit but have not adequately considered the potential of the carbonate fraction of the rocks as a valuable proxy for understanding the chemistry of the primary depositional environment and insights into the redox processes that were at play. This is because these carbonates have always been attributed to diagenetic processes below the sediment-water interface such as microbially-mediated dissimilatory iron/manganese reduction (DIR/DMR) where the precursor/primary Fe-Mn oxyhydroxides have been reduced to result in the minerals observed today. The carbonate fraction of the BIF is made up of ankerite and siderite which co-exist in a chert matrix as anhedral to subhedral grains with no apparent replacement textures. This suggests co-precipitation of the two species which is at apparent odds with classic diagenetic models. Similarly, Mn-carbonates in the hematite lutite and manganese ore (Mn-calcite, kutnahorite, and minor rhodocrosite) co-exist in laminae and ovoids with no textures observed that would suggest an obvious sequential mode of formation during diagenesis. In this light, a carbonate-specific geochemical analysis based on the sequential Fe extraction technique of Poulton and Canfield (2005) was employed to decipher further the cyclic nature of the Hotazel Formation and its primary versus diagenetic controls. Results from the carbonate fraction analysis of the three lithofacies show a clear fractionation of iron and manganese during primary – rather than diagenetic - carbonate precipitation, suggesting a decoupling between DIR and DMR which is ultimately interpreted to have taken place in the water column. Bulk-rock concentration results for minor and trace elements such as Zr, Ti, Sc and Al have been used for the determination of either siliciclastic or volcanic detrital inputs as they are generally immobile in most natural aqueous solutions. These elements are in very low concentrations in all three lithofacies suggesting that the depositional environment had vanishingly small contributions from terrigenous or volcanic detritus. In terms of redox-sensitive transition metals, only Mo and Co appear to show an affinity for high Mn facies in the Hotazel sequence. Cobalt in particular attains a very low abundance in the Hotazel BIF layers at an average of ~ 4 ppm. This is similar to average pre-GOE BIF in South Africa and worldwide. Maxima in Co abundance are associated with transitional hematite lutite and Mn ore layers, but maxima over 100ppm are seen in within the hematite lutite and not within the Mn ore proper where maxima in Mn are recorded. This suggests a clear and direct association with the hematite fraction in the rocks, which is modally much higher in the lutites but drops substantially in the Mn layers themselves. The similarities of bulk-rock BIF and modern-day seawater REE patterns has been used as a key argument for primary controls in REE behaviour and minimal diagenetic modification. Likewise, the three lithofacies of the Hotazel Formation analysed in this study all share similar characteristics with a clear seawater signal through gentle positive slopes in the normalised abundance of LREE versus HREE. Negative Ce anomalies prevail in the entire sample set analysed, which has been interpreted before as a proxy for oxic seawater conditions. However, positive Ce anomalies that are traditionally linked to scavenging and deposition of primary tetravalent Mn oxyhydroxides (e.g., as observed in modern day ferromanganese nodules) are completely absent from the current dataset. The lack of a positive Ce anomaly in the manganese ore and peak Co association with ferric oxides and not with peak Mn, suggests that primary deposition must have occurred within an environment that was not fully oxidizing with respect to manganese. The use of stable isotopes (i.e., C and Fe) was employed to gain insights into redox processes, whether these are thought to have happened below the sediment-water interface or in contemporaneous seawater. At a small scale, all lithofacies of the Hotazel Formation record bulk-rock δ¹³C values that are low and essentially invariant about the average value of -9.5 per mil. This is independent of sharp variations in overall modal mineralogy, relative carbonate abundance and carbonate chemistry, which is clearly difficult to reconcile with in-situ diagenetic processes that predict highly variable δ¹³C signals in response to complex combinations of precursor sediment mineralogy, pore-fluid chemistry, organic carbon supply and open vs closed system diagenesis. At a stratigraphic scale, the carbonate δ¹³C (-5 to -13‰) variations between the different lithologies could instead represent temporal changes in water-column chemistry against well-developed physico-chemical gradients, depth of deposition and biological processes. The low iron isotope values recorded in the hematite lutite and manganese ore samples can be attributed to fractionation effects of initial oxidation of ferrous iron to form Fe-oxyhydroxides in the shallow parts of the basin, from an already isotopically highly depleted aqueous Fe-pool as proposed previously. The slightly higher but still negative bulk-rock δ⁵⁶Fe values of the host BIF can be attributed to water-column Fe isotopic effects at deeper levels between primary Fe oxyhydroxides and an isotopically heavier Fe(II) pool, which was subsequently preserved during diagenetic recrystallization. All above findings were combined into a conceptual model of deposition for the three different lithologies of the Hotazel Formation. The model predicts that free molecular oxygen must have been present within the shallow oceanic environment and implicates both Mn and Fe as active redox “players” compared to classic models that apply to the origin of worldwide BIF prior to the GOE. The deposition of the Hotazel strata is interpreted to have occurred through the following three stages: (1) BIF deposition occurred in a relatively deep oceanic environment above the Ongeluk lavas during marine transgression, where a redoxcline and seawater stratification separated hydrothermally sourced iron and manganese, in response to an active Mn-shuttle mechanism linked to Mn redox cycling. Abundant ferrous iron must have been oxidized by available oxygen but also by oxidised Mn species (MnOOH) and possibly even some soluble Mn(III) complexes. Through this process, Mn(III) was being effectively reduced back into solution along with cobalt(III), as Mn(II) and Co(II) respectively, thus creating maxima in their concentrations. A drawdown of Fe(OH)₃ particles was therefore the only net precipitation mechanism at this stage. Carbonate species of Fe and the abundant magnetite would possibly have formed by reaction between the ferric hydroxides and the deeper Fe(II) pool, while organic matter would also have reacted in the water-column via DIR, accounting for the low δ¹³C signature of Fe carbonate minerals. (2) Hematite lutite formation would have occurred at a relatively shallower environment during marine regression. At this stage, reductive cycling of Fe was minimal in the absence of a deeper Fe(II) reservoir reacting with the ferric primary precipitates. Therefore, DIR progressively gave way to manganese reduction and organic carbon oxidation (DMR), which reduced MnOOH to form Mn(II)-rich carbonates in the form of kutnahorite and Mn-calcite. Co-bearing Fe(OH)₃ would have precipitated and was ultimately preserved as Co-bearing hematite during diagenesis. (3) Deposition of manganese-rich sediment occurred at even shallower oceanic depths (maximum regression) where aerobic organic carbon oxidation replaced DMR, resulting in Ca-rich carbonates such as Mn-bearing calcite and Ca-kutnahorite, yet with a low carbon isotope signature recording aerobic conditions of organic carbon cycling. Mn(III) reduction at this stage was curtailed, leading to massive precipitation of MnOOH which was diagenetically transformed into braunite and friedelite. Simultaneous precipitation of Co-bearing Fe(OH)₃ would have continued but at much more subdued rates. Repeated transgressive-regressive cycles resulted in the cyclic BIF-hematite lutite- manganese ore nature of the Hotazel Formation in an oxidized oceanic environment at the onset of the Great Oxidation Event, which was nonetheless never oxic enough to drive Mn(II) oxidation fully to its tetravalent state. The mineralogy and species-specific geochemistry of the Hotazel strata, and more specifically the carbonate fraction thereof, appear to faithfully capture the chemistry of the primary depositional environment in a progressively evolving Earth System. This project opens the door for more studies focusing on better constraining primary versus diagenetic depositional 2020 Hotazel Fe and Mn deposition mechanisms of iron and manganese during the period leading up to the GOE, and possibly re-defining the significance of Fe and Mn as invaluable redox proxies in a rapidly changing planet.
- Full Text:
- Date Issued: 2020
A scheduling model for the charging of electric vehicles in photovoltaic powered smart microgrids
- Authors: Nyumbeka, Dumisani Joshua
- Date: 2020
- Subjects: Electric vehicles , Photovoltaic power generation Photovoltaic power generation -- Developing countries
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49259 , vital:41615
- Description: Electric vehicles (EVs) have emerged as a viable option to advance sustainable mobility, but adoption is still relatively low. This has been largely due to the limited range one can travel on a single charge, leading to range anxiety, longer charge cycles and long wait times at charging stations. One solution to range anxiety is to erect charging stations on major roads and urban centres. There is also a lack of real-time information regarding the state of charging stations and charging ports in existing charging infrastructure. To increase the benefit of using EVs, using renewable energy sources, such as photovoltaics (PV) to power EVs, can further increase the benefit of reduced carbon footprint. The main research objective was to design a Charge Scheduling Model for charging EVs using a PV-powered smart microgrid (SMG). The model addresses the lack of an integrated platform where EV drivers can schedule when and where to charge their EVs. The model also reduces the negative effects of the adoption of EVs, including range anxiety. The Charge Scheduling Model was developed using the Design Science Research (DSR) methodology and was the main artefact of the study. A literature study was conducted of research related to SMGs, renewable energy, EVs and scheduling, to identify shortcomings that currently exist in EV charge scheduling (EVCS), and to identify the requirements of a potential solution. The literature study also identified the hard and soft constraints that are unique to EVCS, and the available energy in the SMG was identified as one of the hard constraints. Therefore, an Energy Forecasting Model for forecasting energy generated in PV-powered SMGs was required before the Charge Scheduling Model could be designed. During the first iteration of the design and development activities of DSR, four models were designed and implemented to evaluate their effectiveness in forecasting the energy generated in PV-powered SMGs. The models were Support Vector Regression (SVR), K-Nearest Neighbour (KNN), Decision Trees, and Multilayer Perceptron. In the second iteration, the Charge Scheduling Model was designed, consisting of a Four Layered Architecture and the Three-Phase Data Flow Process. The Charge Scheduling Model was then used to design the EVCS prototype. The implementation of the EVCS prototype followed the incremental prototyping approach, which was used to verify the effectiveness of the model. An artificial-summative evaluation was used to evaluate the design of the Charge Scheduling Model, whereas iterative formative evaluations were conducted during the development of the EVCS prototype. The theoretical contribution of this study is the Charge Scheduling Model, and the EVCS prototype is the practical contribution. The results from both evaluations, i.e. the Energy Forecasting Model and the Charge Scheduling Model, also make a contribution to the body of knowledge of EVs.
- Full Text:
- Date Issued: 2020
- Authors: Nyumbeka, Dumisani Joshua
- Date: 2020
- Subjects: Electric vehicles , Photovoltaic power generation Photovoltaic power generation -- Developing countries
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49259 , vital:41615
- Description: Electric vehicles (EVs) have emerged as a viable option to advance sustainable mobility, but adoption is still relatively low. This has been largely due to the limited range one can travel on a single charge, leading to range anxiety, longer charge cycles and long wait times at charging stations. One solution to range anxiety is to erect charging stations on major roads and urban centres. There is also a lack of real-time information regarding the state of charging stations and charging ports in existing charging infrastructure. To increase the benefit of using EVs, using renewable energy sources, such as photovoltaics (PV) to power EVs, can further increase the benefit of reduced carbon footprint. The main research objective was to design a Charge Scheduling Model for charging EVs using a PV-powered smart microgrid (SMG). The model addresses the lack of an integrated platform where EV drivers can schedule when and where to charge their EVs. The model also reduces the negative effects of the adoption of EVs, including range anxiety. The Charge Scheduling Model was developed using the Design Science Research (DSR) methodology and was the main artefact of the study. A literature study was conducted of research related to SMGs, renewable energy, EVs and scheduling, to identify shortcomings that currently exist in EV charge scheduling (EVCS), and to identify the requirements of a potential solution. The literature study also identified the hard and soft constraints that are unique to EVCS, and the available energy in the SMG was identified as one of the hard constraints. Therefore, an Energy Forecasting Model for forecasting energy generated in PV-powered SMGs was required before the Charge Scheduling Model could be designed. During the first iteration of the design and development activities of DSR, four models were designed and implemented to evaluate their effectiveness in forecasting the energy generated in PV-powered SMGs. The models were Support Vector Regression (SVR), K-Nearest Neighbour (KNN), Decision Trees, and Multilayer Perceptron. In the second iteration, the Charge Scheduling Model was designed, consisting of a Four Layered Architecture and the Three-Phase Data Flow Process. The Charge Scheduling Model was then used to design the EVCS prototype. The implementation of the EVCS prototype followed the incremental prototyping approach, which was used to verify the effectiveness of the model. An artificial-summative evaluation was used to evaluate the design of the Charge Scheduling Model, whereas iterative formative evaluations were conducted during the development of the EVCS prototype. The theoretical contribution of this study is the Charge Scheduling Model, and the EVCS prototype is the practical contribution. The results from both evaluations, i.e. the Energy Forecasting Model and the Charge Scheduling Model, also make a contribution to the body of knowledge of EVs.
- Full Text:
- Date Issued: 2020
A sociological understanding of contemporary child marriage in Mabvuku, Harare, Zimbabwe
- Authors: Madzivire, Shamso Christine
- Date: 2020
- Subjects: Child marriage -- Zimbabwe -- Mabvuku , Child marriage -- Zimbabwe -- Case studies , Shona (African people) -- Social life and customs , Marriage customs and rites -- Zimbabwe , Shona (African people) -- Marriage customs and rites , Marriage -- Zimbabwe
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142566 , vital:38091
- Description: Child marriage is a phenomenon that has been increasingly recognised as a global problem since the late nineteenth century. Since then, scholars across many disciplines along with various agencies such as government bodies and non-governmental organisations have tirelessly engaged in research exploring the causes and consequences of this practice and in developing prevention and mitigation strategies. These research efforts have been concentrated in some parts of the world and not others, with the findings in many cases being generalised problematically across different geographical areas. This thesis stands as a response to the dearth of academic research on child marriage in present-day Zimbabwe and simultaneously highlights the significance of studying the specificities of child marriage under particular historical and spatial conditions. The main objective of this thesis is to explore and understand child marriage as a part of modernday marriage practices in Zimbabwe, through a case study of child marriage in Mabvuku in Harare. In addressing this objective, it is hoped that new ways of thinking around this phenomenon will become evident. In addressing this main objective, the thesis considers the experiences of child brides, the drivers and consequences of child and post-child marriage experiences. It does this seeking to understand child marriage with reference to the types of marital unions which exist amongst Shona people in pre-colonial times and in post-colonial Zimbabwe. The thesis adopts a qualitative research methodology which involved in-depth semistructured interviews with 25 women in Mabvuku who were married before the age of 18, along with focus group discussions with community workers and interviews with pertinent government and non-government representatives. Due to certain challenges with current theorising about child marriage, there is an attempt to build theory by drawing upon in particular the Zimbabwean notion and practice of hunhu. A key conclusion is that child marriage in present-day Zimbabwe is in part a result of family transitions which arose during the time of colonialism and continue to this day.
- Full Text:
- Date Issued: 2020
- Authors: Madzivire, Shamso Christine
- Date: 2020
- Subjects: Child marriage -- Zimbabwe -- Mabvuku , Child marriage -- Zimbabwe -- Case studies , Shona (African people) -- Social life and customs , Marriage customs and rites -- Zimbabwe , Shona (African people) -- Marriage customs and rites , Marriage -- Zimbabwe
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142566 , vital:38091
- Description: Child marriage is a phenomenon that has been increasingly recognised as a global problem since the late nineteenth century. Since then, scholars across many disciplines along with various agencies such as government bodies and non-governmental organisations have tirelessly engaged in research exploring the causes and consequences of this practice and in developing prevention and mitigation strategies. These research efforts have been concentrated in some parts of the world and not others, with the findings in many cases being generalised problematically across different geographical areas. This thesis stands as a response to the dearth of academic research on child marriage in present-day Zimbabwe and simultaneously highlights the significance of studying the specificities of child marriage under particular historical and spatial conditions. The main objective of this thesis is to explore and understand child marriage as a part of modernday marriage practices in Zimbabwe, through a case study of child marriage in Mabvuku in Harare. In addressing this objective, it is hoped that new ways of thinking around this phenomenon will become evident. In addressing this main objective, the thesis considers the experiences of child brides, the drivers and consequences of child and post-child marriage experiences. It does this seeking to understand child marriage with reference to the types of marital unions which exist amongst Shona people in pre-colonial times and in post-colonial Zimbabwe. The thesis adopts a qualitative research methodology which involved in-depth semistructured interviews with 25 women in Mabvuku who were married before the age of 18, along with focus group discussions with community workers and interviews with pertinent government and non-government representatives. Due to certain challenges with current theorising about child marriage, there is an attempt to build theory by drawing upon in particular the Zimbabwean notion and practice of hunhu. A key conclusion is that child marriage in present-day Zimbabwe is in part a result of family transitions which arose during the time of colonialism and continue to this day.
- Full Text:
- Date Issued: 2020
A Strategic Model to Promote University of Choice Decisions among International Students Studying in South Africa
- Authors: Jooste, Carlien
- Date: 2020
- Subjects: Internationalism -- Education (Higher) -- South Africa
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/48191 , vital:40519
- Description: The internationalisation of higher education has become an inevitable focus in the modern day higher education sector. This focus is due to the interconnectedness of society, which is driven by globalisation. The ever-changing landscape of the current global higher education sector has further placed emphasis on self-funding and the corporatisation of higher education institutions (HEIs). This has created competitiveness in the sector for local and international students, which has led to institutions globally and in South Africa, being tasked with the responsibility of being agents of internationalisation. The concept of higher education internationalisation involves internationalisation of the curriculum, cross-continental partnerships, the increase in mobility of staff and students, educational programmes, innovative ways of delivery as well as the need to be globally competitive. Students themselves view international study important as it provides them with a global outlook and international experience. The increased competitiveness in the higher education sector and the need for HEIs to become more autonomous and self-funded, has amplified the need to recruit international students who generate additional income. Furthermore, the strategy to recruit international students has evolved and transformed into a customer-driven strategy to meet the needs of the knowledge economy. To recruit international students, HEIs must invest in marketing and recruitment strategies, which build brand awareness and attract a diverse student body. This study investigates the development of a strategic university of choice model that can assist South African universities in the recruitment of international students by focusing on the factors, which influence a student’s university of choice. This was realised firstly by conducting a pilot study investigating the factors which influence the university of choice of students studying in South Africa. Secondly, the findings of the pilot study, combined with appropriate literature studies were used to develop a questionnaire to aid in determining the factors which influence the university of choice of international students studying in South Africa. Lastly, the findings of the questionnaire were used to draw conclusions and develop a proposed strategic model to promote the university of choice decisions among international students studying in South Africa. This thesis is an exploratory, mono-method quantitative study, which consists of literature reviews and surveys in a cross-sectional timeframe. The literature reviews were conducted on secondary sources to identify the factors that influence university of choice, as well as the marketing and recruitment trends within higher education. The empirical study consisted of a Pilot Study Survey and a Main Study Survey. The measuring instrument was compiled from existing surveys and literature studies. The findings of the Main Study Survey identified the following main factors of influence on university of choice: academic programme, academic quality, visa requirements, country/city attractiveness, English language, financial, International Office, student life, safety and security, university location and university reputation as main factors of influence. Within these main factors, various sub-factors were identified. The findings further illustrated that certain factors were more consultative in nature and provided information, which aided in the decision-making process. These factors are: motives to study/choose a programme, country attributes and influences/recruitment methods. Additionally, a third set of factors deemed to subconsciously influence the student’s decision-making process were identified as background of the student, study level and student type. The study contributes theoretically to Stakeholder Theory and Means-End Theory. Prospective students, who are higher education stakeholders, have diverse information needs and expectations, which will be met through the use of the proposed strategic model. Furthermore, the prospective students’ input will aid in the development of focused, targeted and cost-effective marketing and recruitment strategies, which will in turn meet the needs of universities to recruit a diverse student body.
- Full Text:
- Date Issued: 2020
- Authors: Jooste, Carlien
- Date: 2020
- Subjects: Internationalism -- Education (Higher) -- South Africa
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/48191 , vital:40519
- Description: The internationalisation of higher education has become an inevitable focus in the modern day higher education sector. This focus is due to the interconnectedness of society, which is driven by globalisation. The ever-changing landscape of the current global higher education sector has further placed emphasis on self-funding and the corporatisation of higher education institutions (HEIs). This has created competitiveness in the sector for local and international students, which has led to institutions globally and in South Africa, being tasked with the responsibility of being agents of internationalisation. The concept of higher education internationalisation involves internationalisation of the curriculum, cross-continental partnerships, the increase in mobility of staff and students, educational programmes, innovative ways of delivery as well as the need to be globally competitive. Students themselves view international study important as it provides them with a global outlook and international experience. The increased competitiveness in the higher education sector and the need for HEIs to become more autonomous and self-funded, has amplified the need to recruit international students who generate additional income. Furthermore, the strategy to recruit international students has evolved and transformed into a customer-driven strategy to meet the needs of the knowledge economy. To recruit international students, HEIs must invest in marketing and recruitment strategies, which build brand awareness and attract a diverse student body. This study investigates the development of a strategic university of choice model that can assist South African universities in the recruitment of international students by focusing on the factors, which influence a student’s university of choice. This was realised firstly by conducting a pilot study investigating the factors which influence the university of choice of students studying in South Africa. Secondly, the findings of the pilot study, combined with appropriate literature studies were used to develop a questionnaire to aid in determining the factors which influence the university of choice of international students studying in South Africa. Lastly, the findings of the questionnaire were used to draw conclusions and develop a proposed strategic model to promote the university of choice decisions among international students studying in South Africa. This thesis is an exploratory, mono-method quantitative study, which consists of literature reviews and surveys in a cross-sectional timeframe. The literature reviews were conducted on secondary sources to identify the factors that influence university of choice, as well as the marketing and recruitment trends within higher education. The empirical study consisted of a Pilot Study Survey and a Main Study Survey. The measuring instrument was compiled from existing surveys and literature studies. The findings of the Main Study Survey identified the following main factors of influence on university of choice: academic programme, academic quality, visa requirements, country/city attractiveness, English language, financial, International Office, student life, safety and security, university location and university reputation as main factors of influence. Within these main factors, various sub-factors were identified. The findings further illustrated that certain factors were more consultative in nature and provided information, which aided in the decision-making process. These factors are: motives to study/choose a programme, country attributes and influences/recruitment methods. Additionally, a third set of factors deemed to subconsciously influence the student’s decision-making process were identified as background of the student, study level and student type. The study contributes theoretically to Stakeholder Theory and Means-End Theory. Prospective students, who are higher education stakeholders, have diverse information needs and expectations, which will be met through the use of the proposed strategic model. Furthermore, the prospective students’ input will aid in the development of focused, targeted and cost-effective marketing and recruitment strategies, which will in turn meet the needs of universities to recruit a diverse student body.
- Full Text:
- Date Issued: 2020
A Strategy for good IT Governance in South African Municipalities
- Authors: Sibanda, Mbusi
- Date: 2020
- Subjects: Information technology -- Management -- South Africa
- Language: English
- Type: Thesis , Doctoral , DIT
- Identifier: http://hdl.handle.net/10948/49573 , vital:41737
- Description: Information technology (IT) is widely used in South African municipalities as a tool for enabling business processes and therefore its design and implementation are critical to municipalities delivering on their core mandate of delivering services to their communities. The implementation of IT relies on the adoption of sound IT governance practices, whose outcome is to ensure that municipalities derive value from the use of IT and minimise the risk associated with it. However, the implementation of IT governance has proved to be challenging in most municipalities. This research sought to devise a strategic approach to the effective and viable implementation of IT governance in municipalities in South Africa. The research was carried out by adopting a design science research approach, which is increasingly being used for studies in the IT discipline as it assists in solving problems through the design of innovative artefacts, in this case a strategy for the implementation of IT governance. To address the objectives, the research was carried out through case studies of South African municipalities which enabled a detailed investigation of phenomena in its natural context. The data was collected by means of mixed methods consisting of a literature review, a survey and semi-structured interviews. A literature review connected to the research problem was done in order to identify the present state of the issues and how they have been confronted. A survey was sent out to municipalities, institutions and individuals with a mandate to support municipalities, while semi-structured interviews were conducted in five municipalities, government departments and regulatory bodies. A thematic analysis of the data collected was performed which led to a diagnosis of the issues. These include inadequate IT infrastructure; lack of coordinated external support; inadequate IT skills; lack of strong and committed IT leadership; poor IT controls; and fragmented planning. Guiding policies and a set of coherent actions for solving the issues were developed. This culminated in the devising of a strategy for the coordinated implementation of IT governance in municipalities. The primary contribution of this study is the formulation of a strategy for the sound implementation of IT governance in South African municipalities. The research contends that by identifying the strategic issues facing municipalities and implementing the proposed actions, most of which fall outside the municipalities, a new contribution to knowledge has been made. Accordingly, the strategy facilitates the development of plans that address the root causes of the poor implementation of IT in municipalities.
- Full Text:
- Date Issued: 2020
- Authors: Sibanda, Mbusi
- Date: 2020
- Subjects: Information technology -- Management -- South Africa
- Language: English
- Type: Thesis , Doctoral , DIT
- Identifier: http://hdl.handle.net/10948/49573 , vital:41737
- Description: Information technology (IT) is widely used in South African municipalities as a tool for enabling business processes and therefore its design and implementation are critical to municipalities delivering on their core mandate of delivering services to their communities. The implementation of IT relies on the adoption of sound IT governance practices, whose outcome is to ensure that municipalities derive value from the use of IT and minimise the risk associated with it. However, the implementation of IT governance has proved to be challenging in most municipalities. This research sought to devise a strategic approach to the effective and viable implementation of IT governance in municipalities in South Africa. The research was carried out by adopting a design science research approach, which is increasingly being used for studies in the IT discipline as it assists in solving problems through the design of innovative artefacts, in this case a strategy for the implementation of IT governance. To address the objectives, the research was carried out through case studies of South African municipalities which enabled a detailed investigation of phenomena in its natural context. The data was collected by means of mixed methods consisting of a literature review, a survey and semi-structured interviews. A literature review connected to the research problem was done in order to identify the present state of the issues and how they have been confronted. A survey was sent out to municipalities, institutions and individuals with a mandate to support municipalities, while semi-structured interviews were conducted in five municipalities, government departments and regulatory bodies. A thematic analysis of the data collected was performed which led to a diagnosis of the issues. These include inadequate IT infrastructure; lack of coordinated external support; inadequate IT skills; lack of strong and committed IT leadership; poor IT controls; and fragmented planning. Guiding policies and a set of coherent actions for solving the issues were developed. This culminated in the devising of a strategy for the coordinated implementation of IT governance in municipalities. The primary contribution of this study is the formulation of a strategy for the sound implementation of IT governance in South African municipalities. The research contends that by identifying the strategic issues facing municipalities and implementing the proposed actions, most of which fall outside the municipalities, a new contribution to knowledge has been made. Accordingly, the strategy facilitates the development of plans that address the root causes of the poor implementation of IT in municipalities.
- Full Text:
- Date Issued: 2020
A strategy towards implementing standardised data structures in municipal information systems
- Authors: Koekemoer, Silma Marguerite
- Date: 2020
- Subjects: Data structures (Computer science) , Municipal government -- Data processing Public administration -- Data processing Management information systems
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46064 , vital:39482
- Description: The regulation pertaining to a Standard Chart of Accounts (SCOA) for Municipalities was published in 2014 and is applicable to all 257 municipalities and municipal entities in South Africa. The regulation represents a data classification framework or structure and affects all financial management and internal control systems (FMICS) used by municipalities and municipal entities, and affects key business processes within these organisations. Compliance with the SCOA regulation means that the full municipal accountability cycle should accommodate all seven of the SCOA segments, from the budget through transacting and reporting at the transaction level, with all seven of the segments being embedded in the master data table of the municipal FMICS. While the change to technology and systems may be self-evident, the related business change should not be underestimated. This information technology (IT) driven organisational change across the whole municipal environment represents the research topic and key objective of this research study, namely, a strategy towards implementing standard data structures in municipal IT systems. The study followed a pragmatic philosophy using diagnostic reasoning based on an inductive approach, multiple action research methods and a descriptive case study to derive the proposed implementation strategy. The research subjects, which included 25 pilot municipalities, were studied for the duration of the pilot implementation of the strategy with the objective of identifying and utilising the lessons learnt from their experience to fast track the rollout of the strategy to non-pilot municipalities. The study was limited to the local government environment and to South Africa as a geographic area and involved an accidental sample aligned to the implementation project under investigation. The proposed implementation strategy was, however, of a generic nature and is therefore applicable to any other institution or environment engaged in a similar implementation project. The main contribution of the study is an implementation strategy for standard data structures in municipal financial information systems and which consists of seven diagnostics, 17 guiding policies and 48 coherent actions. The strategy was developed and refined during six cycles of data collection, which were conducted at 25 municipalities actively involved in implementing of the standard data structures. The secondary contributions of the research study include three conference papers and one submission to an academic journal.
- Full Text:
- Date Issued: 2020
- Authors: Koekemoer, Silma Marguerite
- Date: 2020
- Subjects: Data structures (Computer science) , Municipal government -- Data processing Public administration -- Data processing Management information systems
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46064 , vital:39482
- Description: The regulation pertaining to a Standard Chart of Accounts (SCOA) for Municipalities was published in 2014 and is applicable to all 257 municipalities and municipal entities in South Africa. The regulation represents a data classification framework or structure and affects all financial management and internal control systems (FMICS) used by municipalities and municipal entities, and affects key business processes within these organisations. Compliance with the SCOA regulation means that the full municipal accountability cycle should accommodate all seven of the SCOA segments, from the budget through transacting and reporting at the transaction level, with all seven of the segments being embedded in the master data table of the municipal FMICS. While the change to technology and systems may be self-evident, the related business change should not be underestimated. This information technology (IT) driven organisational change across the whole municipal environment represents the research topic and key objective of this research study, namely, a strategy towards implementing standard data structures in municipal IT systems. The study followed a pragmatic philosophy using diagnostic reasoning based on an inductive approach, multiple action research methods and a descriptive case study to derive the proposed implementation strategy. The research subjects, which included 25 pilot municipalities, were studied for the duration of the pilot implementation of the strategy with the objective of identifying and utilising the lessons learnt from their experience to fast track the rollout of the strategy to non-pilot municipalities. The study was limited to the local government environment and to South Africa as a geographic area and involved an accidental sample aligned to the implementation project under investigation. The proposed implementation strategy was, however, of a generic nature and is therefore applicable to any other institution or environment engaged in a similar implementation project. The main contribution of the study is an implementation strategy for standard data structures in municipal financial information systems and which consists of seven diagnostics, 17 guiding policies and 48 coherent actions. The strategy was developed and refined during six cycles of data collection, which were conducted at 25 municipalities actively involved in implementing of the standard data structures. The secondary contributions of the research study include three conference papers and one submission to an academic journal.
- Full Text:
- Date Issued: 2020
A theory-based approach to evaluating a Continuing Teacher Professional Development Programme aimed at strengthening environment and sustainability education
- Authors: Songqwaru, Nonyameko Zintle
- Date: 2020
- Subjects: Fundisa for Change , Environmental education -- South Africa , Teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145267 , vital:38423
- Description: This study uses a theory-based approach to evaluate the Fundisa for Change training programme, a continuing teacher professional development programme aimed at strengthening environment and sustainability education. The aim of the study was to surface assumptions that underpin the design and implementation of the Fundisa for Change training programme. The Fundisa for Change Teacher Education programme is a national collaborative programme that is implemented in all the nine provinces of South Africa. The study reports on the implementation of the programme in five provinces. The study aimed to surface the Fundisa for Change training programme’s implementation theory and programme theory as these affect programme delivery. The Fundisa for Change training programme was implemented in diverse contexts by different facilitators to different participants. To determine how training programme outcomes were achieved, use was made of context-mechanism-outcome (CMO) configurations for each site where the programme was implemented. Data used to construct CMO configurations was generated through document analysis of Fundisa for Change documents, interviews with stakeholders and participants, as well as observations of programme implementation at five sites. There were three phases to data analysis: content analysis of Fundisa for Change documents, content analysis of observation transcripts and use of the CMO configuration, an analytical tool used in realist evaluation. An initial CMO configuration was constructed prior to observing implementation of the programme and a refined CMO configuration for the Fundisa for Change training programme was constructed based on similarities between the CMO configurations constructed for each of the five sites under study. The partnership model of the Fundisa for Change training programme brought diverse expertise and resources (material, cognitive, social and emotional) which were conducive to the achievement of programme outcomes. The programme’s action context (structure, culture, agency and relations) contributed to the achievement of programme outcomes by participants. Participants’ subject content knowledge, teaching practice and assessment practice was enhanced through attending the Fundisa for Change training. On-course tasks were mediated during training and this created opportunities for participants to discuss and reflect on current practice in ways that could lead to a change in practice. In evaluating professional development programmes, an elaborated definition of context in terms of structure, culture, agency and relations enables a comprehensive exploration of potential programme mechanisms that can be activated when programmes are implemented. It is also important to disaggregate resources and reasons when identifying mechanisms as this assists with differentiating between context and mechanisms. The study offers insights into the professional learning of teachers grappling with new content and pedagogical content knowledges related to environment in the context of recent curriculum changes where the South African national school curriculum has come into focus. Environmental education programmes in South Africa have implicitly used a realist approach. This study offers the first substantive professional learning evaluation that develops this approach explicitly using Theory of Change and Realist Evaluation in combination.
- Full Text:
- Date Issued: 2020
- Authors: Songqwaru, Nonyameko Zintle
- Date: 2020
- Subjects: Fundisa for Change , Environmental education -- South Africa , Teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/145267 , vital:38423
- Description: This study uses a theory-based approach to evaluate the Fundisa for Change training programme, a continuing teacher professional development programme aimed at strengthening environment and sustainability education. The aim of the study was to surface assumptions that underpin the design and implementation of the Fundisa for Change training programme. The Fundisa for Change Teacher Education programme is a national collaborative programme that is implemented in all the nine provinces of South Africa. The study reports on the implementation of the programme in five provinces. The study aimed to surface the Fundisa for Change training programme’s implementation theory and programme theory as these affect programme delivery. The Fundisa for Change training programme was implemented in diverse contexts by different facilitators to different participants. To determine how training programme outcomes were achieved, use was made of context-mechanism-outcome (CMO) configurations for each site where the programme was implemented. Data used to construct CMO configurations was generated through document analysis of Fundisa for Change documents, interviews with stakeholders and participants, as well as observations of programme implementation at five sites. There were three phases to data analysis: content analysis of Fundisa for Change documents, content analysis of observation transcripts and use of the CMO configuration, an analytical tool used in realist evaluation. An initial CMO configuration was constructed prior to observing implementation of the programme and a refined CMO configuration for the Fundisa for Change training programme was constructed based on similarities between the CMO configurations constructed for each of the five sites under study. The partnership model of the Fundisa for Change training programme brought diverse expertise and resources (material, cognitive, social and emotional) which were conducive to the achievement of programme outcomes. The programme’s action context (structure, culture, agency and relations) contributed to the achievement of programme outcomes by participants. Participants’ subject content knowledge, teaching practice and assessment practice was enhanced through attending the Fundisa for Change training. On-course tasks were mediated during training and this created opportunities for participants to discuss and reflect on current practice in ways that could lead to a change in practice. In evaluating professional development programmes, an elaborated definition of context in terms of structure, culture, agency and relations enables a comprehensive exploration of potential programme mechanisms that can be activated when programmes are implemented. It is also important to disaggregate resources and reasons when identifying mechanisms as this assists with differentiating between context and mechanisms. The study offers insights into the professional learning of teachers grappling with new content and pedagogical content knowledges related to environment in the context of recent curriculum changes where the South African national school curriculum has come into focus. Environmental education programmes in South Africa have implicitly used a realist approach. This study offers the first substantive professional learning evaluation that develops this approach explicitly using Theory of Change and Realist Evaluation in combination.
- Full Text:
- Date Issued: 2020
A trait-based approach to identify indicators for measuring rocky reef ecosystem condition in South Africa
- Authors: Smit, Kaylee
- Date: 2020
- Subjects: Environmental management -- Evaluation , Environmental monitoring -- Methodology Marine ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49292 , vital:41618
- Description: An important yet challenging task for effective ecosystem-based management of marine ecosystems is the reliable measurement and monitoring of changes in ecosystem condition. In South Africa, the National Biodiversity Assessment (NBA) has relied on cumulative pressure mapping, based on the calculation of cumulative impact scores, as a proxy for measures of marine ecosystem condition. While this method is practical for broad scale assessments where ecological data are lacking, there is a need to groundtruth this approach at local scales using in-situ data. The aim of this thesis was to identify potential indicators that can be used to measure the ecosystem condition of subtidal rocky reefs on the East coast of South Africa to groundtruth national pressure-based condition assessments. This thesis constituted the first attempt to conduct a comprehensive assessment of rocky reef ecosystem condition to validate national pressure-based assessments in South Africa. Based on a comprehensive literature review, a traits-based approach was selected to ensure that ecosystem structure and function were included in condition measurements. Fish and benthic community data were collected using baited remote underwater stereo-video systems (144 video samples) from the Natal Shelf ecoregion. Sampling spanned a gradient of low to high human pressures, which incorporated an effective Marine Protected Area (to define reference conditions), as well as areas exposed to intermediate levels of human pressures and a highly impacted area offshore of a large metropolitan port city. Structural and functional indicators were compared among localities and suitable functional indicators were aggregated into multimetric indices (MMIs) to provide an integrated measurement of ecosystem condition. Approximately 840 benthic biota and 10 400 fish (representing 176 identified fish species) were counted. Results showed that functional indicators, particularly size-based ones, were more effective at detecting changes in ecosystem condition compared with structural indicators based on taxonomy. Reefs in good ecological condition had a higher biomass of target species and a higher proportion of large predatory fish with more adults, compared with impacted areas. Benthic communities, however, appeared less responsive to cumulative pressures. The MMIs, using fish and benthic community data, were used to compare condition categories with those from the NBA. Results showed that the pressure-based assessments provided a reasonable proxy of broad patterns of rocky reef ecosystem condition. However, fine-scale discrepancies between results from the data-driven approach versus the proxy method suggested that broad-scale proxies might overestimate condition in some areas and underestimate it in others. To build on these results, the applicability of structural and functional indicators and MMIs were tested using an independent stereo-BRUVs dataset from the Agulhas Shelf ecoregion. Findings showed that not all MPAs were in good ecological condition compared with adjacent impacted areas, as was estimated by the NBA. However, there is a need to improve the quality of trait data and to test indicators and indices in other ecoregions, ecosystem types and in response to a broader range of improved pressure data. Furthermore, there is a need to apply innovative research to guide the calculation of thresholds for condition categories to advance condition assessments.
- Full Text:
- Date Issued: 2020
- Authors: Smit, Kaylee
- Date: 2020
- Subjects: Environmental management -- Evaluation , Environmental monitoring -- Methodology Marine ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49292 , vital:41618
- Description: An important yet challenging task for effective ecosystem-based management of marine ecosystems is the reliable measurement and monitoring of changes in ecosystem condition. In South Africa, the National Biodiversity Assessment (NBA) has relied on cumulative pressure mapping, based on the calculation of cumulative impact scores, as a proxy for measures of marine ecosystem condition. While this method is practical for broad scale assessments where ecological data are lacking, there is a need to groundtruth this approach at local scales using in-situ data. The aim of this thesis was to identify potential indicators that can be used to measure the ecosystem condition of subtidal rocky reefs on the East coast of South Africa to groundtruth national pressure-based condition assessments. This thesis constituted the first attempt to conduct a comprehensive assessment of rocky reef ecosystem condition to validate national pressure-based assessments in South Africa. Based on a comprehensive literature review, a traits-based approach was selected to ensure that ecosystem structure and function were included in condition measurements. Fish and benthic community data were collected using baited remote underwater stereo-video systems (144 video samples) from the Natal Shelf ecoregion. Sampling spanned a gradient of low to high human pressures, which incorporated an effective Marine Protected Area (to define reference conditions), as well as areas exposed to intermediate levels of human pressures and a highly impacted area offshore of a large metropolitan port city. Structural and functional indicators were compared among localities and suitable functional indicators were aggregated into multimetric indices (MMIs) to provide an integrated measurement of ecosystem condition. Approximately 840 benthic biota and 10 400 fish (representing 176 identified fish species) were counted. Results showed that functional indicators, particularly size-based ones, were more effective at detecting changes in ecosystem condition compared with structural indicators based on taxonomy. Reefs in good ecological condition had a higher biomass of target species and a higher proportion of large predatory fish with more adults, compared with impacted areas. Benthic communities, however, appeared less responsive to cumulative pressures. The MMIs, using fish and benthic community data, were used to compare condition categories with those from the NBA. Results showed that the pressure-based assessments provided a reasonable proxy of broad patterns of rocky reef ecosystem condition. However, fine-scale discrepancies between results from the data-driven approach versus the proxy method suggested that broad-scale proxies might overestimate condition in some areas and underestimate it in others. To build on these results, the applicability of structural and functional indicators and MMIs were tested using an independent stereo-BRUVs dataset from the Agulhas Shelf ecoregion. Findings showed that not all MPAs were in good ecological condition compared with adjacent impacted areas, as was estimated by the NBA. However, there is a need to improve the quality of trait data and to test indicators and indices in other ecoregions, ecosystem types and in response to a broader range of improved pressure data. Furthermore, there is a need to apply innovative research to guide the calculation of thresholds for condition categories to advance condition assessments.
- Full Text:
- Date Issued: 2020
A transportation management framework for the Polokwane local municipality during Zion Christian Church (ZCC) Easter weekend pilgrimage
- Authors: Mathebula, Andrew Mabila
- Date: 2020
- Subjects: Transportation -- Management , Urban transportation -- Planning Urban transportation -- Management Christian pilgrims and pilgrimages
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46152 , vital:39509
- Description: The study investigated the impact of the high volume of vehicular traffic on pilgrims and the community during the Zion Christian Church (ZCC) Easter weekend pilgrimage. The researcher adopted an interpretivist research philosophy, and thus attempted to understand policy, planning, and management of the ZCC Easter pilgrimage through meanings that municipal officials assign to them. The study employed the action research approach by collaborating with the Polokwane Local Municipality (PLM) with a view to evolving lasting solutions to traffic congestion during the Easter weekend. The researchers used the seven-step model proposed by Van Tonder and Dietrichsen (Van Tonder and Dietrichsen, 2008). The justification of the model is that it is aligned with the action research model of Organisational Development (OD). It requires that a diagnosis process should be collaborative and participative towards offering solutions to organisational challenges as opposed to imposing a unilateral theoretical generated solution. This model also fits the ontological stance of the researchers which assumes that reality is co-constructed through engagement with other stakeholders. The researcher conducted semi-structured individual and focus groups discussion (FGD) using openended guides. The data from the informants were collected until a point of saturation. In addition to facilitation FGD discussion, the researcher made his own personal reflection of the participatory action research (PAR). A content analysis method was used to synthesise the qualitative data. The contents were extracted from transcribed interviews. The researcher carefully reviewed the notes several times and coded the notes independently. After that, the researcher coded the codes with each other for any potential contradiction. These codes were converted into themes and sub-themes. The qualitative content analysis process, led by the researcher, was both inductive and deductive. Prior to the inductive process, the researcher listened carefully to the audio recordings transcriptions to get a general understanding of participants’ experiences. The findings indicate that the South African transportation planning approach is ossified and divorced from reality. There is a lacuna to address peak traffic challenges during the Easter weekend and the festive season. It is notable that the government-led seasonal road safety campaigns such as ‘Arrive Alive’ are curiously inadequate to address peak traffic and road accidents challenges in South Africa during the ZCC Easter pilgrimage. The transportation management framework for the PLM as well as a peak traffic standard were developed as part of the study recommendations. These recommendations augur a shift to transport planning in South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Mathebula, Andrew Mabila
- Date: 2020
- Subjects: Transportation -- Management , Urban transportation -- Planning Urban transportation -- Management Christian pilgrims and pilgrimages
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46152 , vital:39509
- Description: The study investigated the impact of the high volume of vehicular traffic on pilgrims and the community during the Zion Christian Church (ZCC) Easter weekend pilgrimage. The researcher adopted an interpretivist research philosophy, and thus attempted to understand policy, planning, and management of the ZCC Easter pilgrimage through meanings that municipal officials assign to them. The study employed the action research approach by collaborating with the Polokwane Local Municipality (PLM) with a view to evolving lasting solutions to traffic congestion during the Easter weekend. The researchers used the seven-step model proposed by Van Tonder and Dietrichsen (Van Tonder and Dietrichsen, 2008). The justification of the model is that it is aligned with the action research model of Organisational Development (OD). It requires that a diagnosis process should be collaborative and participative towards offering solutions to organisational challenges as opposed to imposing a unilateral theoretical generated solution. This model also fits the ontological stance of the researchers which assumes that reality is co-constructed through engagement with other stakeholders. The researcher conducted semi-structured individual and focus groups discussion (FGD) using openended guides. The data from the informants were collected until a point of saturation. In addition to facilitation FGD discussion, the researcher made his own personal reflection of the participatory action research (PAR). A content analysis method was used to synthesise the qualitative data. The contents were extracted from transcribed interviews. The researcher carefully reviewed the notes several times and coded the notes independently. After that, the researcher coded the codes with each other for any potential contradiction. These codes were converted into themes and sub-themes. The qualitative content analysis process, led by the researcher, was both inductive and deductive. Prior to the inductive process, the researcher listened carefully to the audio recordings transcriptions to get a general understanding of participants’ experiences. The findings indicate that the South African transportation planning approach is ossified and divorced from reality. There is a lacuna to address peak traffic challenges during the Easter weekend and the festive season. It is notable that the government-led seasonal road safety campaigns such as ‘Arrive Alive’ are curiously inadequate to address peak traffic and road accidents challenges in South Africa during the ZCC Easter pilgrimage. The transportation management framework for the PLM as well as a peak traffic standard were developed as part of the study recommendations. These recommendations augur a shift to transport planning in South Africa.
- Full Text:
- Date Issued: 2020
Activity of diverse chalcones against several targets: statistical analysis of a high-throughput virtual screen of a custom chalcone library
- Authors: Sarron, Arthur F D
- Date: 2020
- Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116028 , vital:34291
- Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
- Full Text:
- Date Issued: 2020
- Authors: Sarron, Arthur F D
- Date: 2020
- Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116028 , vital:34291
- Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
- Full Text:
- Date Issued: 2020
Addressing flux suppression, radio frequency interference, and selection of optimal solution intervals during radio interferometric calibration
- Authors: Sob, Ulrich Armel Mbou
- Date: 2020
- Subjects: CubiCal (Software) , Radio -- Interference , Imaging systems in astronomy , Algorithms , Astronomical instruments -- Calibration , Astronomy -- Data processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/147714 , vital:38663
- Description: The forthcoming Square Kilometre Array is expected to provide answers to some of the most intriguing questions about our Universe. However, as it is already noticeable from MeerKAT and other precursors, the amounts of data produced by these new instruments are significantly challenging to calibrate and image. Calibration of radio interferometric data is usually biased by incomplete sky models and radio frequency interference (RFI) resulting in calibration artefacts that limit the dynamic range and image fidelity of the resulting images. One of the most noticeable of these artefacts is the formation of spurious sources which causes suppression of real emissions. Fortunately, it has been shown that calibration algorithms employing heavy-tailed likelihood functions are less susceptible to this due to their robustness against outliers. Leveraging on recent developments in the field of complex optimisation, we implement a robust calibration algorithm using a Student’s t likelihood function and Wirtinger derivatives. The new algorithm, dubbed the robust solver, is incorporated as a subroutine into the newly released calibration software package CubiCal. We perform statistical analysis on the distribution of visibilities and provide an insight into the functioning of the robust solver and describe different scenarios where it will improve calibration. We use simulations to show that the robust solver effectively reduces the amount of flux suppressed from unmodelled sources both in direction independent and direction dependent calibration. Furthermore, the robust solver is shown to successfully mitigate the effects of low-level RFI when applied to a simulated and a real VLA dataset. Finally, we demonstrate that there are close links between the amount of flux suppressed from sources, the effects of the RFI and the employed solution interval during radio interferometric calibration. Hence, we investigate the effects of solution intervals and the different factors to consider in order to select adequate solution intervals. Furthermore, we propose a practical brute force method for selecting optimal solution intervals. The proposed method is successfully applied to a VLA dataset.
- Full Text:
- Date Issued: 2020
- Authors: Sob, Ulrich Armel Mbou
- Date: 2020
- Subjects: CubiCal (Software) , Radio -- Interference , Imaging systems in astronomy , Algorithms , Astronomical instruments -- Calibration , Astronomy -- Data processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/147714 , vital:38663
- Description: The forthcoming Square Kilometre Array is expected to provide answers to some of the most intriguing questions about our Universe. However, as it is already noticeable from MeerKAT and other precursors, the amounts of data produced by these new instruments are significantly challenging to calibrate and image. Calibration of radio interferometric data is usually biased by incomplete sky models and radio frequency interference (RFI) resulting in calibration artefacts that limit the dynamic range and image fidelity of the resulting images. One of the most noticeable of these artefacts is the formation of spurious sources which causes suppression of real emissions. Fortunately, it has been shown that calibration algorithms employing heavy-tailed likelihood functions are less susceptible to this due to their robustness against outliers. Leveraging on recent developments in the field of complex optimisation, we implement a robust calibration algorithm using a Student’s t likelihood function and Wirtinger derivatives. The new algorithm, dubbed the robust solver, is incorporated as a subroutine into the newly released calibration software package CubiCal. We perform statistical analysis on the distribution of visibilities and provide an insight into the functioning of the robust solver and describe different scenarios where it will improve calibration. We use simulations to show that the robust solver effectively reduces the amount of flux suppressed from unmodelled sources both in direction independent and direction dependent calibration. Furthermore, the robust solver is shown to successfully mitigate the effects of low-level RFI when applied to a simulated and a real VLA dataset. Finally, we demonstrate that there are close links between the amount of flux suppressed from sources, the effects of the RFI and the employed solution interval during radio interferometric calibration. Hence, we investigate the effects of solution intervals and the different factors to consider in order to select adequate solution intervals. Furthermore, we propose a practical brute force method for selecting optimal solution intervals. The proposed method is successfully applied to a VLA dataset.
- Full Text:
- Date Issued: 2020
An analysis of how visualisation capabilities in dynamic geometric software develop meaning-making of mathematical concepts in selected Grade 11 learners
- Authors: Mavani, Deepack Pravin
- Date: 2020
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa , Mathematics -- Computer programs , Mathematics -- Study and teaching (Secondary) -- South Africa -- Case studies , Mathematics -- Study and teaching -- Activity programs , Educational technology , Visualization
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/143213 , vital:38211
- Description: Visualisation plays a central role in developing mathematical ideas because it can be used to make these ideas explicit and visible, and thus has the potential to advance understanding. This study centred around the GeoGebra Literacy Initiative Project (GLIP), a teacher development initiative in Mthatha that aimed to grow and develop appropriate Information and Communication Technology (ICT) skills in teachers, to harness the teaching and learning potential of GeoGebra. GeoGebra is a dynamic geometric software package that is very interactive and makes use of powerful features to create images which can be moved around the computer screen for mathematical exploration. This research project was located within GLIP and analysed how GeoGebra applets develop conceptual and procedural understanding in selected Grade 11 learners. One aspect of GLIP was for teachers to use GeoGebra applets that they had developed themselves and implemented in their classrooms in pre-determined cycles that were aligned to the curriculum. My study specifically focused on how the selected learners made use of these applets and explored how learning had taken place in terms of developing mathematical meaning-making. This interpretive research study was designed as a case study. The case was a cohort of selected Grade 11 learners who had been taught by GLIP teachers, and my unit of analysis was the learners’ interaction with the applets. A screen capturing software package was used to capture learners’ interactions with the GeoGebra. My data consisted mainly of recorded observations and interviews. An analytical framework derived from the works of Kilpatrick, Swafford, and Findell (2001) and Carter et al. (2009) guided and informed the data analysis of the learners’ activities with the GeoGebra. The theoretical orientation of this study was constructivist learning. An in-depth analysis and detailed descriptions of the participants’ interactions enabled me to gain a comprehensive understanding of their meaning-making processes in a technological classroom context. An analysis across the participants identified distinguishable patterns or differences in the development of the learners’ mathematical proficiency and making sense of mathematical ideas. The research argued that technology enabled visualisation was a powerful tool to not only enrich mathematically activities, but to also enrich conceptual and procedural understanding. The findings recognised that exploration of, or manipulation on mathematical objects in GeoGebra was a key activity in the participants’ meaning-making process. It also enabled learners to offer self-proclaimed theories
- Full Text:
- Date Issued: 2020
- Authors: Mavani, Deepack Pravin
- Date: 2020
- Subjects: Mathematics -- Study and teaching (Secondary) -- South Africa , Mathematics -- Computer programs , Mathematics -- Study and teaching (Secondary) -- South Africa -- Case studies , Mathematics -- Study and teaching -- Activity programs , Educational technology , Visualization
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/143213 , vital:38211
- Description: Visualisation plays a central role in developing mathematical ideas because it can be used to make these ideas explicit and visible, and thus has the potential to advance understanding. This study centred around the GeoGebra Literacy Initiative Project (GLIP), a teacher development initiative in Mthatha that aimed to grow and develop appropriate Information and Communication Technology (ICT) skills in teachers, to harness the teaching and learning potential of GeoGebra. GeoGebra is a dynamic geometric software package that is very interactive and makes use of powerful features to create images which can be moved around the computer screen for mathematical exploration. This research project was located within GLIP and analysed how GeoGebra applets develop conceptual and procedural understanding in selected Grade 11 learners. One aspect of GLIP was for teachers to use GeoGebra applets that they had developed themselves and implemented in their classrooms in pre-determined cycles that were aligned to the curriculum. My study specifically focused on how the selected learners made use of these applets and explored how learning had taken place in terms of developing mathematical meaning-making. This interpretive research study was designed as a case study. The case was a cohort of selected Grade 11 learners who had been taught by GLIP teachers, and my unit of analysis was the learners’ interaction with the applets. A screen capturing software package was used to capture learners’ interactions with the GeoGebra. My data consisted mainly of recorded observations and interviews. An analytical framework derived from the works of Kilpatrick, Swafford, and Findell (2001) and Carter et al. (2009) guided and informed the data analysis of the learners’ activities with the GeoGebra. The theoretical orientation of this study was constructivist learning. An in-depth analysis and detailed descriptions of the participants’ interactions enabled me to gain a comprehensive understanding of their meaning-making processes in a technological classroom context. An analysis across the participants identified distinguishable patterns or differences in the development of the learners’ mathematical proficiency and making sense of mathematical ideas. The research argued that technology enabled visualisation was a powerful tool to not only enrich mathematically activities, but to also enrich conceptual and procedural understanding. The findings recognised that exploration of, or manipulation on mathematical objects in GeoGebra was a key activity in the participants’ meaning-making process. It also enabled learners to offer self-proclaimed theories
- Full Text:
- Date Issued: 2020
An audience perception of pentecostal churches’ television programmes on star times and dstv in lagos, Nigeria
- Authors: Olaoye, Adewale Titus
- Date: 2020
- Subjects: Religious broadcasting -- Christianity Television in religion Mass media in religion
- Language: English
- Type: Thesis , Doctoral , PhD (Communication)
- Identifier: http://hdl.handle.net/10353/11418 , vital:39070
- Description: Pentecostal churches in Nigeria are leveraging traditional and new media technologies such as cable or digital satellite television, to broadcast services and programmes to their regular and a growing community of virtual worshippers. Critics of this type of religious outreach now known as televangelism have challenged its predominant, if not exclusive focus on miracle and prosperity message. Using the mixed-method research design involving focus group discussions, key informant interviews and a survey of 255 respondents, this study sought to ascertain Lagos audiences‘ perceptions of Pentecostal Television programmes on two satellite stations, Start Times and DSTV. The findings revealed that audience members perceive Pentecostal churches programme as primarily focused on converting the audience members to the Christian faith. The result revealed that miracle sessions are a common feature of televangelism. Respondents see the miracles as manipulations largely intended to woo and often, hoodwink audience members. The findings revealed that although some of the Pentecostal churches‘ programmes dwell more on the word of God compared to the mainline churches, the programmes and teachings, however, often tended to promote the leadership of the church and not the gospel of Christ. Generally, the study indicates the majority of the audience members are aware of and identify with the atrocities the Pentecostal Churches are accused of perpetrating through their TV programmes. The findings revealed poor awareness and knowledge about the role of the Nigeria Broadcasting Corporation (NBC). The results suggest participants do not believe the NBC is living up to its responsibilities. The findings of this study highlight the need for the NBC, the Christian Association of Nigeria (CAN) and Pentecostal Fellowship of Nigeria (PFN) to work together in formulating new regulations for controlling religious broadcast on television, Pentecostal TV broadcasts, in particular. This is the only way to safeguard vulnerable members of the audience from being manipulated and brainwashed.
- Full Text:
- Date Issued: 2020
- Authors: Olaoye, Adewale Titus
- Date: 2020
- Subjects: Religious broadcasting -- Christianity Television in religion Mass media in religion
- Language: English
- Type: Thesis , Doctoral , PhD (Communication)
- Identifier: http://hdl.handle.net/10353/11418 , vital:39070
- Description: Pentecostal churches in Nigeria are leveraging traditional and new media technologies such as cable or digital satellite television, to broadcast services and programmes to their regular and a growing community of virtual worshippers. Critics of this type of religious outreach now known as televangelism have challenged its predominant, if not exclusive focus on miracle and prosperity message. Using the mixed-method research design involving focus group discussions, key informant interviews and a survey of 255 respondents, this study sought to ascertain Lagos audiences‘ perceptions of Pentecostal Television programmes on two satellite stations, Start Times and DSTV. The findings revealed that audience members perceive Pentecostal churches programme as primarily focused on converting the audience members to the Christian faith. The result revealed that miracle sessions are a common feature of televangelism. Respondents see the miracles as manipulations largely intended to woo and often, hoodwink audience members. The findings revealed that although some of the Pentecostal churches‘ programmes dwell more on the word of God compared to the mainline churches, the programmes and teachings, however, often tended to promote the leadership of the church and not the gospel of Christ. Generally, the study indicates the majority of the audience members are aware of and identify with the atrocities the Pentecostal Churches are accused of perpetrating through their TV programmes. The findings revealed poor awareness and knowledge about the role of the Nigeria Broadcasting Corporation (NBC). The results suggest participants do not believe the NBC is living up to its responsibilities. The findings of this study highlight the need for the NBC, the Christian Association of Nigeria (CAN) and Pentecostal Fellowship of Nigeria (PFN) to work together in formulating new regulations for controlling religious broadcast on television, Pentecostal TV broadcasts, in particular. This is the only way to safeguard vulnerable members of the audience from being manipulated and brainwashed.
- Full Text:
- Date Issued: 2020