"Abject dictatorship of the flesh" : corporeality in the fiction of Patrick White
- Authors: Grogan, Bridget Meredith
- Date: 2013
- Subjects: White, Patrick, 1912-1990 -- Criticism and interpretation Human body in literature Dualism in literature Human body -- Social aspects Body image -- Social aspects Australian fiction -- 20th century -- History and criticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2166 , http://hdl.handle.net/10962/d1001554
- Description: Thesis embargoed for an indefinite period - full text not available
- Full Text: false
- Authors: Grogan, Bridget Meredith
- Date: 2013
- Subjects: White, Patrick, 1912-1990 -- Criticism and interpretation Human body in literature Dualism in literature Human body -- Social aspects Body image -- Social aspects Australian fiction -- 20th century -- History and criticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2166 , http://hdl.handle.net/10962/d1001554
- Description: Thesis embargoed for an indefinite period - full text not available
- Full Text: false
A critical analysis of the grammar of isiXhosa as used in the Revised Union version of the Bible
- Oosthuysen, Jacobus Christiaan
- Authors: Oosthuysen, Jacobus Christiaan
- Date: 2013
- Subjects: Bible -- Xhosa -- Revised Union -- 1942 Xhosa language -- Grammar -- Research Xhosa language -- Texts
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3555 , http://hdl.handle.net/10962/d1001625
- Description: This study provides a description and critical analysis of the grammatical structure of isiXhosa as used in the Revised Union Version of the Bible, published in 1942 and republished in 1975. This translation records what was regarded as proper isiXhosa at the beginning of the 20th century, reflecting the consensus inter alia of prominent isiXhosa writers, such as W.B. Rubusana, J.H. Soga, C. Koti, Y. Mbali and D. D. T. Jabavu, who served on the committee that produced the revision. In this study isiXhosa is described in its own right, without approaching it with preconceived ideas derived from other languages. That is to say this is a phenomenological analysis describing the grammatical structures of isiXhosa as they present themselves to the analyst. It is comprehensive, with no structure being overlooked or being described in such a manner that it complicates an understanding of other structures. In the first chapter the context of the research and a brief outline of the historical growth in understanding the structure of isiXhosa are set out and the goals and the method followed in this study are described. In the following chapters the findings of this study are presented. The initial focus is on isiXhosa phonology and the orthography used to put it to writing. Then isiXhosa morphology and syntax is set out. Initially the substantives, i.e. the nouns and pronouns in their distinctive classes and forms, and how they are qualified, receive attention. Then the predicates are explored, i.e. the verbs and copulatives, as linked to the substantives with concords, and reflecting various moods, tenses, actualities and aspects. Finally attention is given to ideophones and interjections and words that can be grouped together as adverbs, conjunctions, avoidance words and numerals. In the concluding chapter consideration is given to the question of whether this study has in fact achieved the aim of setting out a description of the structure of isiXhosa based solely on the language itself, free of preconceived ideas, and attention is drawn to insights gained in respect of the true nature of the isiXhosa grammatical structures, such as, for example, the variable prefix qualificative nouns, traditionally referred to as adjectives. This study is therefore a revisionist study in the sense that it reinvents isiXhosa as a language in its own right, free from Western influenced perspectives.
- Full Text:
- Authors: Oosthuysen, Jacobus Christiaan
- Date: 2013
- Subjects: Bible -- Xhosa -- Revised Union -- 1942 Xhosa language -- Grammar -- Research Xhosa language -- Texts
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3555 , http://hdl.handle.net/10962/d1001625
- Description: This study provides a description and critical analysis of the grammatical structure of isiXhosa as used in the Revised Union Version of the Bible, published in 1942 and republished in 1975. This translation records what was regarded as proper isiXhosa at the beginning of the 20th century, reflecting the consensus inter alia of prominent isiXhosa writers, such as W.B. Rubusana, J.H. Soga, C. Koti, Y. Mbali and D. D. T. Jabavu, who served on the committee that produced the revision. In this study isiXhosa is described in its own right, without approaching it with preconceived ideas derived from other languages. That is to say this is a phenomenological analysis describing the grammatical structures of isiXhosa as they present themselves to the analyst. It is comprehensive, with no structure being overlooked or being described in such a manner that it complicates an understanding of other structures. In the first chapter the context of the research and a brief outline of the historical growth in understanding the structure of isiXhosa are set out and the goals and the method followed in this study are described. In the following chapters the findings of this study are presented. The initial focus is on isiXhosa phonology and the orthography used to put it to writing. Then isiXhosa morphology and syntax is set out. Initially the substantives, i.e. the nouns and pronouns in their distinctive classes and forms, and how they are qualified, receive attention. Then the predicates are explored, i.e. the verbs and copulatives, as linked to the substantives with concords, and reflecting various moods, tenses, actualities and aspects. Finally attention is given to ideophones and interjections and words that can be grouped together as adverbs, conjunctions, avoidance words and numerals. In the concluding chapter consideration is given to the question of whether this study has in fact achieved the aim of setting out a description of the structure of isiXhosa based solely on the language itself, free of preconceived ideas, and attention is drawn to insights gained in respect of the true nature of the isiXhosa grammatical structures, such as, for example, the variable prefix qualificative nouns, traditionally referred to as adjectives. This study is therefore a revisionist study in the sense that it reinvents isiXhosa as a language in its own right, free from Western influenced perspectives.
- Full Text:
A critical realist exploration of the emergence, development, management and sustainability of a Christian private institution of higher education in Malawi
- Kadyakapita, Mozecie Spector John
- Authors: Kadyakapita, Mozecie Spector John
- Date: 2013 , 2013-03-24
- Subjects: Christian universities and colleges -- Administration -- Research -- Malawi Private universities and colleges -- Administration -- Research -- Malawi Education, Higher -- Administration -- Research -- Malawi Higher education and state -- Research -- Malawi Universities and colleges -- Malawi -- History Educational planning -- Malawi
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1400 , http://hdl.handle.net/10962/d1001818
- Description: This study was prompted by an interest in exploring ways in which the development of private higher education in Malawi could be more sustainable. It examines the challenges that private institutions of higher education face in different contexts and the underlying causes of these challenges. The aim of the study was to explore the emergence of private higher education (PHE) in Malawi, its management, development, the challenges it faces and the generative mechanisms of these challenges. The research is a case study of one of the earliest private institutions of higher education in Malawi. The institution is owned and operated by a Christian church organisation that has been operating a network of private primary and secondary schools and health centres since its establishment in Malawi in the early 1890s. Critical realism is used as an underlabourer for its stance on ontological, epistemological and ethical assumptions of reality and its views on agency and structure. Two theoretical frameworks - complexity theory and transformational leadership theories - are used as lenses to help make sense of the nature of social organisations and also as heuristic devices for organising and making sense of data. Data were collected using qualitative interviews, archival document content analysis and observation. Twenty participants were purposefully selected for interviews. The participants comprised a senior officer at the MoEST headquarters, proprietors, members of the top management team of the institution, administrative assistants, heads of academic and nonacademic departments, teachers and non-teaching staff and students. Abstracted data were analysed using inductive, abductive and retroductive modes of inference. The study established that the emergence of private higher education in Malawi was generated by a number of mechanisms. These include the need to survive the threat to socioeconomic development posed by global trends in scientific and technological issues that heavily rely on access to the knowledge economy; the need to respond to demand for equity and access to higher education; the need to carry out the mission of the Christian church; government’s failure to expand and widen access to higher education; and the agential need to survive economic demands. The research findings indicate that a critical challenge that the emergence of private higher education faced was the lack of adequate and efficient structures and systems in the Ministry of Education, Science and Technology to expeditiously process applications to establish and accredit, monitor and control the development of private higher education institutions. It was also found that the challenges that the private higher education faces include high level of authoritarian governance and management practices, weak institutional management and control systems and structure, secularisation, lack of adequate funds to meet operation and capital development costs, facilities and resources to support teaching – learning functions, learner support facilities and services and a critical shortage of appropriately qualified administrative and academic personnel. The underlying causes of the challenges include the perceived threat to personal power and survival; fear of apostasy and secularisation; cultural values, adverse socioeconomic conditions; lack of diverse sources of funding, ineffective communication skills; weak governance systems and structures; low level of self-control; unfavourable attitudes towards educational institutions and the need to restore equity. To make private institutions of higher learning more sustainable, the study recommends that governance practices be guided by clear structures, policies and guidelines in the interest of transparency and accountability. It also recommends that government works in close partnership with private providers, reviews unfair policies concerning government scholarships, subsidizes the cost of materials for instruction and infrastructure development, and provides technical assistance to prospective and active providers. Lastly, the study recommends that private providers form an association so as to share experiences and to collectively deal with issues of common interest and concern. , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Authors: Kadyakapita, Mozecie Spector John
- Date: 2013 , 2013-03-24
- Subjects: Christian universities and colleges -- Administration -- Research -- Malawi Private universities and colleges -- Administration -- Research -- Malawi Education, Higher -- Administration -- Research -- Malawi Higher education and state -- Research -- Malawi Universities and colleges -- Malawi -- History Educational planning -- Malawi
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1400 , http://hdl.handle.net/10962/d1001818
- Description: This study was prompted by an interest in exploring ways in which the development of private higher education in Malawi could be more sustainable. It examines the challenges that private institutions of higher education face in different contexts and the underlying causes of these challenges. The aim of the study was to explore the emergence of private higher education (PHE) in Malawi, its management, development, the challenges it faces and the generative mechanisms of these challenges. The research is a case study of one of the earliest private institutions of higher education in Malawi. The institution is owned and operated by a Christian church organisation that has been operating a network of private primary and secondary schools and health centres since its establishment in Malawi in the early 1890s. Critical realism is used as an underlabourer for its stance on ontological, epistemological and ethical assumptions of reality and its views on agency and structure. Two theoretical frameworks - complexity theory and transformational leadership theories - are used as lenses to help make sense of the nature of social organisations and also as heuristic devices for organising and making sense of data. Data were collected using qualitative interviews, archival document content analysis and observation. Twenty participants were purposefully selected for interviews. The participants comprised a senior officer at the MoEST headquarters, proprietors, members of the top management team of the institution, administrative assistants, heads of academic and nonacademic departments, teachers and non-teaching staff and students. Abstracted data were analysed using inductive, abductive and retroductive modes of inference. The study established that the emergence of private higher education in Malawi was generated by a number of mechanisms. These include the need to survive the threat to socioeconomic development posed by global trends in scientific and technological issues that heavily rely on access to the knowledge economy; the need to respond to demand for equity and access to higher education; the need to carry out the mission of the Christian church; government’s failure to expand and widen access to higher education; and the agential need to survive economic demands. The research findings indicate that a critical challenge that the emergence of private higher education faced was the lack of adequate and efficient structures and systems in the Ministry of Education, Science and Technology to expeditiously process applications to establish and accredit, monitor and control the development of private higher education institutions. It was also found that the challenges that the private higher education faces include high level of authoritarian governance and management practices, weak institutional management and control systems and structure, secularisation, lack of adequate funds to meet operation and capital development costs, facilities and resources to support teaching – learning functions, learner support facilities and services and a critical shortage of appropriately qualified administrative and academic personnel. The underlying causes of the challenges include the perceived threat to personal power and survival; fear of apostasy and secularisation; cultural values, adverse socioeconomic conditions; lack of diverse sources of funding, ineffective communication skills; weak governance systems and structures; low level of self-control; unfavourable attitudes towards educational institutions and the need to restore equity. To make private institutions of higher learning more sustainable, the study recommends that governance practices be guided by clear structures, policies and guidelines in the interest of transparency and accountability. It also recommends that government works in close partnership with private providers, reviews unfair policies concerning government scholarships, subsidizes the cost of materials for instruction and infrastructure development, and provides technical assistance to prospective and active providers. Lastly, the study recommends that private providers form an association so as to share experiences and to collectively deal with issues of common interest and concern. , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
A social realist account of the tutorial system at the University of Johannesburg
- Authors: Layton, Delia Melanie
- Date: 2013
- Subjects: University of Johannesburg Education, Higher -- South Africa Tutors and tutoring -- South Africa College teaching -- South Africa Archer, Margaret Scotford College student development programs -- South Africa Social realism , Tutorial system
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1314 , http://hdl.handle.net/10962/d1001621
- Description: Using Margaret Archer’s social realist methodology, this study critically examines the construction of the tutorial system in several departments and faculties at the Auckland Park campus of the University of Johannesburg. The purpose of the study is to investigate the extent to which tutorials support the acquisition of programme and disciplinary epistemologies. Social realism calls for analytical dualism of ‘the people’ (agents) from ‘the parts’ (structure and culture). This requires the separate consideration of structures (social systems, rules, roles, practices, policies, institutions, and organisational structures like committees, units, departments, faculties), culture (ideologies, theories, beliefs and values as evidenced in discourses), and agency (people and their ability to act within and upon their own world in terms of their social roles and positions dependent on their ability to activate their emergent properties and powers). Through this investigation, an understanding was gained into how the emergent properties and powers contained within the material, ideational and agential elements helped to generate certain events and practices in the tutorial system. These generative mechanisms were examined to explore whether they enabled or constrained the construction of the tutorial system to provide epistemological access. The study shows that while many official policy documents construct the tutorial system as being an intervention to support academic success, particularly for first-years, there are some tensions within the document discourses, where, on the one hand, student success is constructed in terms of throughput numbers, or, on the other hand, as being about becoming a particular kind of person who is able to access and add to powerful knowledge. Furthermore, the study found that policies are not being consistently implemented. While certain key agents and actors, in the form of management, academics and tutors, were found to be able to overcome constraints and introduce innovative ways of enhancing access to target epistemologies, there is a need for consideration of structural and cultural constraints. For example, structures in the form of funding, venues and timetabling were found to constrain the tutorial system as did some of the discourses in the cultural domain: for example, in the form of certain dominant discourses around teaching and learning, beliefs about the purpose of the tutorial and the relationship between academics and the tutorial system. The study also found that the ontological aspects of ‘learning to be’ were not fore-grounded to any great extent in the ways in which the tutorial system was constructed. There needs to be more consideration of the ontological as well as the epistemological aspects of first-year study so as to take cognisance of the different learning needs of an increasingly diverse student body and to encourage the development of the student agency necessary for a deep engagement with the disciplinary epistemologies.
- Full Text:
- Authors: Layton, Delia Melanie
- Date: 2013
- Subjects: University of Johannesburg Education, Higher -- South Africa Tutors and tutoring -- South Africa College teaching -- South Africa Archer, Margaret Scotford College student development programs -- South Africa Social realism , Tutorial system
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1314 , http://hdl.handle.net/10962/d1001621
- Description: Using Margaret Archer’s social realist methodology, this study critically examines the construction of the tutorial system in several departments and faculties at the Auckland Park campus of the University of Johannesburg. The purpose of the study is to investigate the extent to which tutorials support the acquisition of programme and disciplinary epistemologies. Social realism calls for analytical dualism of ‘the people’ (agents) from ‘the parts’ (structure and culture). This requires the separate consideration of structures (social systems, rules, roles, practices, policies, institutions, and organisational structures like committees, units, departments, faculties), culture (ideologies, theories, beliefs and values as evidenced in discourses), and agency (people and their ability to act within and upon their own world in terms of their social roles and positions dependent on their ability to activate their emergent properties and powers). Through this investigation, an understanding was gained into how the emergent properties and powers contained within the material, ideational and agential elements helped to generate certain events and practices in the tutorial system. These generative mechanisms were examined to explore whether they enabled or constrained the construction of the tutorial system to provide epistemological access. The study shows that while many official policy documents construct the tutorial system as being an intervention to support academic success, particularly for first-years, there are some tensions within the document discourses, where, on the one hand, student success is constructed in terms of throughput numbers, or, on the other hand, as being about becoming a particular kind of person who is able to access and add to powerful knowledge. Furthermore, the study found that policies are not being consistently implemented. While certain key agents and actors, in the form of management, academics and tutors, were found to be able to overcome constraints and introduce innovative ways of enhancing access to target epistemologies, there is a need for consideration of structural and cultural constraints. For example, structures in the form of funding, venues and timetabling were found to constrain the tutorial system as did some of the discourses in the cultural domain: for example, in the form of certain dominant discourses around teaching and learning, beliefs about the purpose of the tutorial and the relationship between academics and the tutorial system. The study also found that the ontological aspects of ‘learning to be’ were not fore-grounded to any great extent in the ways in which the tutorial system was constructed. There needs to be more consideration of the ontological as well as the epistemological aspects of first-year study so as to take cognisance of the different learning needs of an increasingly diverse student body and to encourage the development of the student agency necessary for a deep engagement with the disciplinary epistemologies.
- Full Text:
A study of maximum and minimum operators with applications to piecewise linear payoff functions
- Authors: Seedat, Ebrahim
- Date: 2013
- Subjects: Options (Finance) Piecewise linear topology Geometry, Affine Riesz spaces Lattice theory Algebra, Boolean Pricing , Max and min operators
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:931 , http://hdl.handle.net/10962/d1001457
- Description: The payoff functions of contingent claims (options) of one variable are prominent in Financial Economics and thus assume a fundamental role in option pricing theory. Some of these payoff functions are continuous, piecewise-defined and linear or affine. Such option payoff functions can be analysed in a useful way when they are represented in additive, Boolean normal, graphical and linear form. The issue of converting such payoff functions expressed in the additive, linear or graphical form into an equivalent Boolean normal form, has been considered by several authors for more than half-a-century to better-understand the role of such functions. One aspect of our study is to unify the foregoing different forms of representation, by creating algorithms that convert a payoff function expressed in graphical form into Boolean normal form and then into the additive form and vice versa. Applications of these algorithms are considered in a general theoretical sense and also in the context of specific option contracts wherever relevant. The use of these algorithms have yielded easy computation of the area enclosed by the graph of various functions using min and max operators in several ways, which, in our opinion, are important in option pricing. To summarise, this study effectively dealt with maximum and minimum operators from several perspectives
- Full Text:
- Authors: Seedat, Ebrahim
- Date: 2013
- Subjects: Options (Finance) Piecewise linear topology Geometry, Affine Riesz spaces Lattice theory Algebra, Boolean Pricing , Max and min operators
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:931 , http://hdl.handle.net/10962/d1001457
- Description: The payoff functions of contingent claims (options) of one variable are prominent in Financial Economics and thus assume a fundamental role in option pricing theory. Some of these payoff functions are continuous, piecewise-defined and linear or affine. Such option payoff functions can be analysed in a useful way when they are represented in additive, Boolean normal, graphical and linear form. The issue of converting such payoff functions expressed in the additive, linear or graphical form into an equivalent Boolean normal form, has been considered by several authors for more than half-a-century to better-understand the role of such functions. One aspect of our study is to unify the foregoing different forms of representation, by creating algorithms that convert a payoff function expressed in graphical form into Boolean normal form and then into the additive form and vice versa. Applications of these algorithms are considered in a general theoretical sense and also in the context of specific option contracts wherever relevant. The use of these algorithms have yielded easy computation of the area enclosed by the graph of various functions using min and max operators in several ways, which, in our opinion, are important in option pricing. To summarise, this study effectively dealt with maximum and minimum operators from several perspectives
- Full Text:
A study of the first group of Friars Minor (Franciscans) in South Africa, c. 1932-1960
- Authors: Nogemane, Vumile
- Date: 2013
- Subjects: Franciscans -- South Africa -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2530 , http://hdl.handle.net/10962/d1001859
- Description: In 1932, six Missionary Franciscan Friars from Bavaria came to South Africa at the invitation of Bishop Adalbero Michael Fleischer (1874-1963), a Mariannhill missionary in Natal. His vision was that they would establish a “Franciscan Family” there. Despite this invitation, the Friars were not welcomed by the Mariannhill community and went on to found the Mount Currie Prefecture (Diocese of Kokstad) in 1935. There the Franciscans became involved in the life of the ordinary people, who were otherwise abandoned by the government. Among other activities, they provided schools and gardens, and embarked on skills development projects for the youth. The Holy Cross Sisters - whose arrival in 1926 pre-dated that of the Friars - played a crucial role in these developments. From 1952, their educational work would be supplemented by the medical work of the Franciscan Missionaries of Mary Sisters. The arrival of Irish Franciscans (1946) and English Franciscans (1948) brought tensions and differing interpretations of the form that the vision should take. In addition, the Friars were men of their times and products of their particular backgrounds. For example, while some saw their African converts as equals, others were prejudiced against them. However, this thesis – the work of an “insider” to the faith and to the Order, argues that despite tensions and shortcomings, the settlement, and continuing presence, of the Franciscan Friars and Sisters in the Eastern Cape was an eventual realization of Bishop Fleischer’s vision, even though in a slightly different manner from the original ideal. In the early nineteen sixties a new and powerful spirit invaded the Catholic Church. The Second Vatican Council took place from 1962 to 1965. It may be argued that, from that time onward, the Church has never been the same again. In accordance with this call and invitation of the Second Vatican Council for quite some time it has been my earnest desire to get down into a more in-depth study of the history of the Franciscans in South Africa than that provided by the two existing works on this topic. It is my hope that this thesis will contribute to a soul-searching of the Franciscans as they continue to live and minister to the people of South Africa. This history will hopefully teach us to learn from and be inspired by the great and heroic deeds of our spiritual forebears – our Franciscan brothers and sisters – and also teach us to learn from their mistakes.
- Full Text:
- Authors: Nogemane, Vumile
- Date: 2013
- Subjects: Franciscans -- South Africa -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2530 , http://hdl.handle.net/10962/d1001859
- Description: In 1932, six Missionary Franciscan Friars from Bavaria came to South Africa at the invitation of Bishop Adalbero Michael Fleischer (1874-1963), a Mariannhill missionary in Natal. His vision was that they would establish a “Franciscan Family” there. Despite this invitation, the Friars were not welcomed by the Mariannhill community and went on to found the Mount Currie Prefecture (Diocese of Kokstad) in 1935. There the Franciscans became involved in the life of the ordinary people, who were otherwise abandoned by the government. Among other activities, they provided schools and gardens, and embarked on skills development projects for the youth. The Holy Cross Sisters - whose arrival in 1926 pre-dated that of the Friars - played a crucial role in these developments. From 1952, their educational work would be supplemented by the medical work of the Franciscan Missionaries of Mary Sisters. The arrival of Irish Franciscans (1946) and English Franciscans (1948) brought tensions and differing interpretations of the form that the vision should take. In addition, the Friars were men of their times and products of their particular backgrounds. For example, while some saw their African converts as equals, others were prejudiced against them. However, this thesis – the work of an “insider” to the faith and to the Order, argues that despite tensions and shortcomings, the settlement, and continuing presence, of the Franciscan Friars and Sisters in the Eastern Cape was an eventual realization of Bishop Fleischer’s vision, even though in a slightly different manner from the original ideal. In the early nineteen sixties a new and powerful spirit invaded the Catholic Church. The Second Vatican Council took place from 1962 to 1965. It may be argued that, from that time onward, the Church has never been the same again. In accordance with this call and invitation of the Second Vatican Council for quite some time it has been my earnest desire to get down into a more in-depth study of the history of the Franciscans in South Africa than that provided by the two existing works on this topic. It is my hope that this thesis will contribute to a soul-searching of the Franciscans as they continue to live and minister to the people of South Africa. This history will hopefully teach us to learn from and be inspired by the great and heroic deeds of our spiritual forebears – our Franciscan brothers and sisters – and also teach us to learn from their mistakes.
- Full Text:
Afro-communitarianism and the nature of reconciliation
- Authors: Oelofsen, Rianna
- Date: 2013
- Subjects: Ubuntu (Philosophy) Reconciliation -- South Africa Communitarianism -- Africa Philosophy, African
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2736 , http://hdl.handle.net/10962/d1006809
- Description: In this dissertation I sketch a conception of personhood as understood from within an Afrocommunitarian worldview, and argue that this understanding of personhood has implications for understanding the concept of reconciliation. Understanding ‘being human’ as a collective, communal enterprise has implications for how responsibility, justice, forgiveness and humanization (all cognate concepts of reconciliation) are conceptualized. In line with this understanding of reconciliation and its cognate concepts, I argue that the humanization of self and other (according to the Afrocommunitarian understanding of personhood) is required for addressing the ‘inferiority’ and concurrent ‘superiority’ racial complexes as diagnosed by Franz Fanon and Steve Biko. These complexes reach deeply within individual and collective psyches and political identities, and I argue that political solutions to protracted conflict (in South Africa and other racially charged contexts) which do not address these deeply entrenched pathologies will be inadequate according to an Afrocommunitarian framework.
- Full Text:
- Authors: Oelofsen, Rianna
- Date: 2013
- Subjects: Ubuntu (Philosophy) Reconciliation -- South Africa Communitarianism -- Africa Philosophy, African
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2736 , http://hdl.handle.net/10962/d1006809
- Description: In this dissertation I sketch a conception of personhood as understood from within an Afrocommunitarian worldview, and argue that this understanding of personhood has implications for understanding the concept of reconciliation. Understanding ‘being human’ as a collective, communal enterprise has implications for how responsibility, justice, forgiveness and humanization (all cognate concepts of reconciliation) are conceptualized. In line with this understanding of reconciliation and its cognate concepts, I argue that the humanization of self and other (according to the Afrocommunitarian understanding of personhood) is required for addressing the ‘inferiority’ and concurrent ‘superiority’ racial complexes as diagnosed by Franz Fanon and Steve Biko. These complexes reach deeply within individual and collective psyches and political identities, and I argue that political solutions to protracted conflict (in South Africa and other racially charged contexts) which do not address these deeply entrenched pathologies will be inadequate according to an Afrocommunitarian framework.
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An exploration of conditions enabling and constraining the infusion of service-learning into the curriculum at a South African research led university
- Authors: Hlengwa, Amanda Immaculate
- Date: 2013
- Subjects: Rhodes University -- Curricula -- Evaluation Service learning -- Research -- South Africa Education, Higher -- Curricula -- South Africa -- Evaluation Curriculum planning -- Research -- South Africa Experiential learning -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1888 , http://hdl.handle.net/10962/d1006036
- Description: Drawing on critical realist philosophy as a meta-theoretical framework, this study explores the conditions that enable and constrain the infusion of service-learning in university curricula. In this study, four discipline-based cases are analysed within the context of an overarching case of one South African university. The study reports on case study research into four disciplines, broadly representing the disciplinary array offered at Rhodes University, a small traditional research-intensive university in South Africa – four cases are thus embedded within a larger over-arching case. Margret Archer’s analytical dualism is used as an analytical lens for the inquiry. It offers tools for examining the conditions for the emergence of service learning and the form it takes in each case. Archer’s framework requires the artificial separation of structural, cultural and agential mechanisms for analytical purposes in order to establish the dominant factors impacting on the infusion of service-learning in curricula. An analysis of the interplay between structure, culture and agency uncovers insights into the conditions that enable or constrain the adoption of service learning as a pedagogic tool in specific disciplines. Curriculum decision-making is a central consideration in this study. Basil Bernstein’s theory of cultural transmission provides an external language of description to theorise the pedagogic choices made in specific contexts. This body of theory provides analytical tools for generating nuanced explanations of the significance of knowledge and curriculum structures as enabling and constraining mechanisms when pedagogic decisions are made. The study shows that the nature of the discipline has a significant influence on the emergence of service-learning and the form it takes in each context. Key agents draw on available structural and cultural mechanisms to either maintain the status quo or they exercise their personal properties and powers to mitigate existing conditions. The first case examines the emergence of service-learning in a ‘hard pure’ discipline where structural and cultural conditions constrain the emergence of innovative pedagogic tools. In this case a key agent draws on a confluence of personal, structural and cultural emergent properties to initiate a service-learning course at the honours level. Factors that make service-learning possible in this case include the key agent’s seniority within the institution, his status as a prolific researcher, the possibilities for application of disciplinary knowledge, and a strong institutional discourse of service to society (RU in Society) and an institutional and departmental discourse privileging academic freedom. In the second case the conditions in the ‘hard applied’ discipline are largely enabling, however the emergence of service-learning is facilitated by the interplay of the following agential, structural and cultural emergent properties: corporate agency taking advantage of the outward focus of the discipline (a region in Bernsteinian terms) and drawing on what is termed the RU in Society discourse. The third case represents a ‘soft pure’ discipline, where service-learning does not emerge within the formal curriculum, but in a largely marginalised departmental outreach programme. This discipline is inward facing and although its knowledge base draws on challenges and phenomena in society, it remains at an esoteric level accessible mainly to the discipline community. Agents in this department draw on the insular structure of the discipline, in conjunction with the strong Academic Freedom discourse to develop a form of service-learning that furthers disciplinary aims, albeit within the context of limited engagement beyond the boundaries of the discipline and the institution. In the case of the ‘soft applied’ discipline the structural and cultural conditions are largely enabling. However the emergence of service-learning in this discipline relies on the advocacy of a powerful social agent in the department with an interest in socially equitable practice; she draws on the RU in Society discourse to promote direct engagement with communities beyond the university boundaries. The study is set in a research-intensive university and it is perhaps not surprising that the service-learning courses in three of the four cases are framed by research projects. This suggests that in the context of this kind of institution it may be imperative to draw on research activities as the basis of infusing service-learning in the curriculum. The findings of this study challenge the implicit assumption in policy documents that it is possible to institute service-learning in all disciplines.
- Full Text:
- Authors: Hlengwa, Amanda Immaculate
- Date: 2013
- Subjects: Rhodes University -- Curricula -- Evaluation Service learning -- Research -- South Africa Education, Higher -- Curricula -- South Africa -- Evaluation Curriculum planning -- Research -- South Africa Experiential learning -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1888 , http://hdl.handle.net/10962/d1006036
- Description: Drawing on critical realist philosophy as a meta-theoretical framework, this study explores the conditions that enable and constrain the infusion of service-learning in university curricula. In this study, four discipline-based cases are analysed within the context of an overarching case of one South African university. The study reports on case study research into four disciplines, broadly representing the disciplinary array offered at Rhodes University, a small traditional research-intensive university in South Africa – four cases are thus embedded within a larger over-arching case. Margret Archer’s analytical dualism is used as an analytical lens for the inquiry. It offers tools for examining the conditions for the emergence of service learning and the form it takes in each case. Archer’s framework requires the artificial separation of structural, cultural and agential mechanisms for analytical purposes in order to establish the dominant factors impacting on the infusion of service-learning in curricula. An analysis of the interplay between structure, culture and agency uncovers insights into the conditions that enable or constrain the adoption of service learning as a pedagogic tool in specific disciplines. Curriculum decision-making is a central consideration in this study. Basil Bernstein’s theory of cultural transmission provides an external language of description to theorise the pedagogic choices made in specific contexts. This body of theory provides analytical tools for generating nuanced explanations of the significance of knowledge and curriculum structures as enabling and constraining mechanisms when pedagogic decisions are made. The study shows that the nature of the discipline has a significant influence on the emergence of service-learning and the form it takes in each context. Key agents draw on available structural and cultural mechanisms to either maintain the status quo or they exercise their personal properties and powers to mitigate existing conditions. The first case examines the emergence of service-learning in a ‘hard pure’ discipline where structural and cultural conditions constrain the emergence of innovative pedagogic tools. In this case a key agent draws on a confluence of personal, structural and cultural emergent properties to initiate a service-learning course at the honours level. Factors that make service-learning possible in this case include the key agent’s seniority within the institution, his status as a prolific researcher, the possibilities for application of disciplinary knowledge, and a strong institutional discourse of service to society (RU in Society) and an institutional and departmental discourse privileging academic freedom. In the second case the conditions in the ‘hard applied’ discipline are largely enabling, however the emergence of service-learning is facilitated by the interplay of the following agential, structural and cultural emergent properties: corporate agency taking advantage of the outward focus of the discipline (a region in Bernsteinian terms) and drawing on what is termed the RU in Society discourse. The third case represents a ‘soft pure’ discipline, where service-learning does not emerge within the formal curriculum, but in a largely marginalised departmental outreach programme. This discipline is inward facing and although its knowledge base draws on challenges and phenomena in society, it remains at an esoteric level accessible mainly to the discipline community. Agents in this department draw on the insular structure of the discipline, in conjunction with the strong Academic Freedom discourse to develop a form of service-learning that furthers disciplinary aims, albeit within the context of limited engagement beyond the boundaries of the discipline and the institution. In the case of the ‘soft applied’ discipline the structural and cultural conditions are largely enabling. However the emergence of service-learning in this discipline relies on the advocacy of a powerful social agent in the department with an interest in socially equitable practice; she draws on the RU in Society discourse to promote direct engagement with communities beyond the university boundaries. The study is set in a research-intensive university and it is perhaps not surprising that the service-learning courses in three of the four cases are framed by research projects. This suggests that in the context of this kind of institution it may be imperative to draw on research activities as the basis of infusing service-learning in the curriculum. The findings of this study challenge the implicit assumption in policy documents that it is possible to institute service-learning in all disciplines.
- Full Text:
An investigation into how journalists experience economic and political pressures on their ethical decisions at the Nation Media Group in Kenya
- Authors: Maweu, Jacinta Mwende
- Date: 2013
- Subjects: Nation Media Group Limited Journalists -- Kenya Journalistic ethics -- Kenya Press and politics -- Kenya Journalism -- Economic aspects -- Kenya Journalism -- Political aspects -- Kenya Mass media -- Political aspects -- Kenya Mass media -- Economic aspects -- Kenya Freedom of the press -- Kenya
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3508 , http://hdl.handle.net/10962/d1007583
- Description: This study investigates how journalists experience economic and political pressures on their ethical decisions at the Nation Media Group (NMG) conglomerate in Kenya. The study uses qualitative semi- structured interviews to examine how journalists experience these pressures on their professional ethics as they make their daily decisions. Grounded in the critical political economy of the media tradition, the findings of the study indicate that economic and political pressures from advertisers, shareholders’ interests, the profit motive and the highly ethnicised political environment in Kenya largely compromise the ethical decisions of journalists. The study draws on the work done by Herman and Chomsky in their ‘Propaganda Model’ in which they propose ‘filters’ as the analytical indicators of the forms that political and economic pressures that journalists experience may take. The study explores the ways in which journalists experience these pressures, how they respond to the pressures and the ways in which their responses may compromise their journalism ethics. The findings indicate that aside from the pressures from the primary five filters outlined in the Propaganda Model, ethnicity in Kenyan newsrooms is a key ‘filter’ that may compromise the ethical decisions of journalists at the NMG. The study therefore argues that there is a need to modify the explanatory power of the Propaganda Model when applying it to the Kenyan context to include ethnicity as a ‘sixth filter’ that should be understood in relation to the five primary filters. From the findings, it would seem that the government is no longer a major threat to journalists’ freedom and responsibility in Kenya. Market forces and ethnicity in newsrooms pose the greatest threat to journalists’ freedom and responsibility. The study therefore calls for a revision of the normative framework within which journalists’ and media performance in Kenya is assessed. As the study findings show, the prevailing liberal- democratic model ignores the commercial and economic threats the ‘free market’ poses to journalism ethics as well as ethnicity in newsrooms and only focuses on the media- government relations, treating the government as the major threat to media freedom.
- Full Text:
- Authors: Maweu, Jacinta Mwende
- Date: 2013
- Subjects: Nation Media Group Limited Journalists -- Kenya Journalistic ethics -- Kenya Press and politics -- Kenya Journalism -- Economic aspects -- Kenya Journalism -- Political aspects -- Kenya Mass media -- Political aspects -- Kenya Mass media -- Economic aspects -- Kenya Freedom of the press -- Kenya
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3508 , http://hdl.handle.net/10962/d1007583
- Description: This study investigates how journalists experience economic and political pressures on their ethical decisions at the Nation Media Group (NMG) conglomerate in Kenya. The study uses qualitative semi- structured interviews to examine how journalists experience these pressures on their professional ethics as they make their daily decisions. Grounded in the critical political economy of the media tradition, the findings of the study indicate that economic and political pressures from advertisers, shareholders’ interests, the profit motive and the highly ethnicised political environment in Kenya largely compromise the ethical decisions of journalists. The study draws on the work done by Herman and Chomsky in their ‘Propaganda Model’ in which they propose ‘filters’ as the analytical indicators of the forms that political and economic pressures that journalists experience may take. The study explores the ways in which journalists experience these pressures, how they respond to the pressures and the ways in which their responses may compromise their journalism ethics. The findings indicate that aside from the pressures from the primary five filters outlined in the Propaganda Model, ethnicity in Kenyan newsrooms is a key ‘filter’ that may compromise the ethical decisions of journalists at the NMG. The study therefore argues that there is a need to modify the explanatory power of the Propaganda Model when applying it to the Kenyan context to include ethnicity as a ‘sixth filter’ that should be understood in relation to the five primary filters. From the findings, it would seem that the government is no longer a major threat to journalists’ freedom and responsibility in Kenya. Market forces and ethnicity in newsrooms pose the greatest threat to journalists’ freedom and responsibility. The study therefore calls for a revision of the normative framework within which journalists’ and media performance in Kenya is assessed. As the study findings show, the prevailing liberal- democratic model ignores the commercial and economic threats the ‘free market’ poses to journalism ethics as well as ethnicity in newsrooms and only focuses on the media- government relations, treating the government as the major threat to media freedom.
- Full Text:
An investigation into the representations of environmental issues relating to Lake Victoria, Uganda, and their negotiation by the lakeside communities
- Lwanga, Margaret Jjuuko Nassuna
- Authors: Lwanga, Margaret Jjuuko Nassuna
- Date: 2013
- Subjects: Victoria Voice Victoria, Lake -- Environmental aspects -- Research Lakes -- Environmental aspects -- Research -- Uganda Environmental management -- Research -- Uganda Pollution -- Environmental aspects -- Uganda Radio broadcasting -- Uganda , Uganda CBS , Central Broadcasting Service , Mass media -- Environmental aspects -- Research -- Uganda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3411 , http://hdl.handle.net/10962/d1001577
- Description: The state of the environment is increasingly present as an urgent concern for contemporary political, social, cultural and physical life. Yet the roles of the mass media (radio, television and newspapers) in shaping and influencing crucial public awareness, debates and environmental decision-making remain inadequately understood. Positioned as a critical studies inquiry into media representations and audience reception, this study forms part of a wider project amongst media scholars and culture critics on the relationship between media textual production and consumption. It explores how one radio station in Uganda, Central Broadcasting Service (CBS) radio, represents and constructs the environmental crises faced by Lake Victoria, especially pollution and overfishing. The focus is on the Victoria Voice radio documentaries aired on CBS radio in the year 2005. The study further explores how three lakeside communities negotiate these issues as radio broadcasts. It recognises that while the mass media contribute significantly to creating public awareness about such social concerns, their likelihood of having a direct and predictable impact on social behaviour is slight. The context and the lived experiences at the reception stage where the decisions are made on whether to adopt an innovation are ultimately the factors which impact on how they are negotiated. The thesis is informed by the theoretical and analytical framework of Cultural Studies as well as the Participatory Approach to Communication for Development perspectives. The study is specifically informed by the theories of ‘discourse’ (Foucault, 1980a, 1981) and the ‘circuit of culture’ (du Gay et al., 1997 and Johnson, 1987) and these provided the conceptual framework for investigating the representations, the production and the consumption of media texts. Predominantly qualitative methods have been employed in data collection and analysis. In the first place, a Critical Discourse Analysis (CDA) (Fairclough, 1995a, 1995c) of the radio texts has interrogated the discourses and discursive practices of CBS’ Victoria Voice environmental radio programmes in order to consider its representations of particular issues and consequently the discourses it privileged. Qualitative methods of participant observation, in-depth interviews and focus group discussions were deployed to investigate the negotiation of the texts by the lakeside communities. This research establishes that the Victoria Voice radio texts foreground three contesting types of discourses: the discourse of basic economic survival and livelihoods is articulated largely by the ordinary people, the lakeside communities; the discourse of sustainable development, particularly the protection and sustainability of Lake Victoria, by scientists and environmental experts; and the discourse of modernisation and corporate investment by politicians and/or policy makers and industrialists. The texts, to a large degree, reaffirm the hegemonic relations of power in Ugandan society, and thus contribute to the maintenance of the status quo. The selection of an elite category of informers (scientists, experts, politicians, policy makers) serves to marginalise the less powerful ordinary people (the fisher folk, farmers and other eyewitnesses). The construction of the elite as active and speaking subjects within the various debates introduced in these programmes, for example, works both to obscure and endorse the unequal power relations. At the reception side, while the lakeside communities attest to the relevance of the programmes in providing information on the issues concerning Lake Victoria and other aspects of their livelihood, they also recognise the power relations that underpin the sets of representations. Amongst these sets is government’s complicity with industry, in line with their economic policies and the global capitalist economy, while espousing the rhetoric of nature conservation. The study argues that sustainable solutions for the crises on Lake Victoria should take into account the socio-historical and cultural contexts of the lakeside communities. For the Ugandan media, particularly radio, there is a need to rethink the nature of the coverage, which tends to neglect the contextual factors, such as local socio-economic and cultural factors within which environmental issues and problems occur and which, as this thesis establishes, greatly influences the way people make sense of environmental issues and problems. I posit that the Participatory Approach that seeks to address the communities’ most pressing concerns should be adopted – to include more of the communities’ voices and involve them in the production of radio programmes.
- Full Text:
- Authors: Lwanga, Margaret Jjuuko Nassuna
- Date: 2013
- Subjects: Victoria Voice Victoria, Lake -- Environmental aspects -- Research Lakes -- Environmental aspects -- Research -- Uganda Environmental management -- Research -- Uganda Pollution -- Environmental aspects -- Uganda Radio broadcasting -- Uganda , Uganda CBS , Central Broadcasting Service , Mass media -- Environmental aspects -- Research -- Uganda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3411 , http://hdl.handle.net/10962/d1001577
- Description: The state of the environment is increasingly present as an urgent concern for contemporary political, social, cultural and physical life. Yet the roles of the mass media (radio, television and newspapers) in shaping and influencing crucial public awareness, debates and environmental decision-making remain inadequately understood. Positioned as a critical studies inquiry into media representations and audience reception, this study forms part of a wider project amongst media scholars and culture critics on the relationship between media textual production and consumption. It explores how one radio station in Uganda, Central Broadcasting Service (CBS) radio, represents and constructs the environmental crises faced by Lake Victoria, especially pollution and overfishing. The focus is on the Victoria Voice radio documentaries aired on CBS radio in the year 2005. The study further explores how three lakeside communities negotiate these issues as radio broadcasts. It recognises that while the mass media contribute significantly to creating public awareness about such social concerns, their likelihood of having a direct and predictable impact on social behaviour is slight. The context and the lived experiences at the reception stage where the decisions are made on whether to adopt an innovation are ultimately the factors which impact on how they are negotiated. The thesis is informed by the theoretical and analytical framework of Cultural Studies as well as the Participatory Approach to Communication for Development perspectives. The study is specifically informed by the theories of ‘discourse’ (Foucault, 1980a, 1981) and the ‘circuit of culture’ (du Gay et al., 1997 and Johnson, 1987) and these provided the conceptual framework for investigating the representations, the production and the consumption of media texts. Predominantly qualitative methods have been employed in data collection and analysis. In the first place, a Critical Discourse Analysis (CDA) (Fairclough, 1995a, 1995c) of the radio texts has interrogated the discourses and discursive practices of CBS’ Victoria Voice environmental radio programmes in order to consider its representations of particular issues and consequently the discourses it privileged. Qualitative methods of participant observation, in-depth interviews and focus group discussions were deployed to investigate the negotiation of the texts by the lakeside communities. This research establishes that the Victoria Voice radio texts foreground three contesting types of discourses: the discourse of basic economic survival and livelihoods is articulated largely by the ordinary people, the lakeside communities; the discourse of sustainable development, particularly the protection and sustainability of Lake Victoria, by scientists and environmental experts; and the discourse of modernisation and corporate investment by politicians and/or policy makers and industrialists. The texts, to a large degree, reaffirm the hegemonic relations of power in Ugandan society, and thus contribute to the maintenance of the status quo. The selection of an elite category of informers (scientists, experts, politicians, policy makers) serves to marginalise the less powerful ordinary people (the fisher folk, farmers and other eyewitnesses). The construction of the elite as active and speaking subjects within the various debates introduced in these programmes, for example, works both to obscure and endorse the unequal power relations. At the reception side, while the lakeside communities attest to the relevance of the programmes in providing information on the issues concerning Lake Victoria and other aspects of their livelihood, they also recognise the power relations that underpin the sets of representations. Amongst these sets is government’s complicity with industry, in line with their economic policies and the global capitalist economy, while espousing the rhetoric of nature conservation. The study argues that sustainable solutions for the crises on Lake Victoria should take into account the socio-historical and cultural contexts of the lakeside communities. For the Ugandan media, particularly radio, there is a need to rethink the nature of the coverage, which tends to neglect the contextual factors, such as local socio-economic and cultural factors within which environmental issues and problems occur and which, as this thesis establishes, greatly influences the way people make sense of environmental issues and problems. I posit that the Participatory Approach that seeks to address the communities’ most pressing concerns should be adopted – to include more of the communities’ voices and involve them in the production of radio programmes.
- Full Text:
Application of bidentate N,N'-donor extractants in the hydrometallurgical separation of base metals from an acidic sulfate medium
- Authors: Okewole, Adeleye Ishola
- Date: 2013
- Subjects: Hydrometallurgy Sulfates Nanofibers Electrospinning Sorbents Extraction (Chemistry) Solvent extraction Stereochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4281 , http://hdl.handle.net/10962/d1002610
- Description: Bidentate imidazole-based extractants, 1-octylimidazole-2-aldoxime (OIMOX) and 1-octyl-2-(2′-pyridyl)imidazole (OPIM), along with dinonylnaphthalene sulfonic acid (DNNSA) as a synergist, were investigated as potential selective extractants for Cu²⁺and Ni²⁺ respectively from base metals in a solvent extraction system. The study was extended to evaluate the sorption and separation of Ni²⁺ from other base metals in a solid-solution system using microspherical Merrifield resins and nanofibers functionalized with 2,2′-pyridylimidazole. Copper was effectively separated with OIMOX and DNNSA as extractants from nickel with ΔpH½ ≈1.05 and the extraction order of Cu²⁺ > Ni²⁺ > Zn²⁺ > Cd²⁺> Co²⁺ was achieved as a function of pH. At pH 1.65 the extracted copper, from a synthetic mixture of the base metals reached 90.13(±0.90)%, and through a two-step extraction process 98.22(±0.29)% copper was recovered with negligible nickel and cobalt impurities. Stripping of the copper from the loaded organic phase using TraceSelect sulphuric acid at pH 0.35 yielded 96.60(±0.44)% of the loaded quantity after the second stage of stripping. The separation of Ni²⁺ from the borderline and hard acids; Co²⁺, Cu²⁺, Zn²⁺, Fe2²⁺, Fe²⁺, Mn²⁺, Mg2²⁺ and Ca²⁺ at a pH range of 0.5-3.5 with OPIM and DNNSA was acvieved to the tune of a ΔpH½≈ 1.6 with respect to cobalt from a sulfate and sulfate/chloride media. A three-stage counter-current extraction of Ni²⁺, at the optimized pH of 1.89, from a synthetic mixture of Ni²⁺, Co²⁺ and Cu²⁺, yielded 99.01(±1.79)%. The total co-extracted Cu²⁺ was 48.72(±0.24)% of the original quantity in the mixture, and it was 19.85(±0.28%) for Co²⁺. The co-extracted Cu²⁺ was scrubbed off from the loaded organic phase at pH≈8.5 by using an ammonium buffer, while co-extracted Co²⁺ was selectively and quantitatively stripped with H₂SO₄ at pH 1.64. The total recovery of Ni²⁺ by stripping at pH 0.32 was 94.05(±1.70)%. In the solid-liquid system, Ni²⁺ was separated from Co²⁺, Cu²⁺, and Fe²⁺ with the microspherical resins funtionalised with 2,2′-pyridylimidazole by a separation factor (β) in the range 22-45. Electrospun nanofibers as sorbents yielded high sorption capacity in the range of 0.97 - 1.45 mmol.g⁻¹ for the same metals ions. Thus, 1-octylimidazole-2-aldoxime (OIMOX), and1-octyl-2-(2′-pyridyl)imidazole (OPIM) can be effectively utilized alongside DNNSA as a co-extractant in the separation of Cu²⁺ and Ni²⁺ respectively from base metals in acidic sulfate medium in a solvent extraction process, and the latter as a selective ligand in the solid-liquid separation of Ni²⁺ from Co²⁺, Cu²⁺, and Fe²⁺.
- Full Text:
- Authors: Okewole, Adeleye Ishola
- Date: 2013
- Subjects: Hydrometallurgy Sulfates Nanofibers Electrospinning Sorbents Extraction (Chemistry) Solvent extraction Stereochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4281 , http://hdl.handle.net/10962/d1002610
- Description: Bidentate imidazole-based extractants, 1-octylimidazole-2-aldoxime (OIMOX) and 1-octyl-2-(2′-pyridyl)imidazole (OPIM), along with dinonylnaphthalene sulfonic acid (DNNSA) as a synergist, were investigated as potential selective extractants for Cu²⁺and Ni²⁺ respectively from base metals in a solvent extraction system. The study was extended to evaluate the sorption and separation of Ni²⁺ from other base metals in a solid-solution system using microspherical Merrifield resins and nanofibers functionalized with 2,2′-pyridylimidazole. Copper was effectively separated with OIMOX and DNNSA as extractants from nickel with ΔpH½ ≈1.05 and the extraction order of Cu²⁺ > Ni²⁺ > Zn²⁺ > Cd²⁺> Co²⁺ was achieved as a function of pH. At pH 1.65 the extracted copper, from a synthetic mixture of the base metals reached 90.13(±0.90)%, and through a two-step extraction process 98.22(±0.29)% copper was recovered with negligible nickel and cobalt impurities. Stripping of the copper from the loaded organic phase using TraceSelect sulphuric acid at pH 0.35 yielded 96.60(±0.44)% of the loaded quantity after the second stage of stripping. The separation of Ni²⁺ from the borderline and hard acids; Co²⁺, Cu²⁺, Zn²⁺, Fe2²⁺, Fe²⁺, Mn²⁺, Mg2²⁺ and Ca²⁺ at a pH range of 0.5-3.5 with OPIM and DNNSA was acvieved to the tune of a ΔpH½≈ 1.6 with respect to cobalt from a sulfate and sulfate/chloride media. A three-stage counter-current extraction of Ni²⁺, at the optimized pH of 1.89, from a synthetic mixture of Ni²⁺, Co²⁺ and Cu²⁺, yielded 99.01(±1.79)%. The total co-extracted Cu²⁺ was 48.72(±0.24)% of the original quantity in the mixture, and it was 19.85(±0.28%) for Co²⁺. The co-extracted Cu²⁺ was scrubbed off from the loaded organic phase at pH≈8.5 by using an ammonium buffer, while co-extracted Co²⁺ was selectively and quantitatively stripped with H₂SO₄ at pH 1.64. The total recovery of Ni²⁺ by stripping at pH 0.32 was 94.05(±1.70)%. In the solid-liquid system, Ni²⁺ was separated from Co²⁺, Cu²⁺, and Fe²⁺ with the microspherical resins funtionalised with 2,2′-pyridylimidazole by a separation factor (β) in the range 22-45. Electrospun nanofibers as sorbents yielded high sorption capacity in the range of 0.97 - 1.45 mmol.g⁻¹ for the same metals ions. Thus, 1-octylimidazole-2-aldoxime (OIMOX), and1-octyl-2-(2′-pyridyl)imidazole (OPIM) can be effectively utilized alongside DNNSA as a co-extractant in the separation of Cu²⁺ and Ni²⁺ respectively from base metals in acidic sulfate medium in a solvent extraction process, and the latter as a selective ligand in the solid-liquid separation of Ni²⁺ from Co²⁺, Cu²⁺, and Fe²⁺.
- Full Text:
Aspects of isiXhosa poetry with special reference to poems produced about women
- Jadezweni, Mhlobo Wabantwana
- Authors: Jadezweni, Mhlobo Wabantwana
- Date: 2013
- Subjects: Laudatory poetry, Xhosa African poetry (English) -- History and criticism Women in literature Women and literature -- South Africa African poetry -- Women authors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3616 , http://hdl.handle.net/10962/d1006364
- Description: This study investigates the use of modern and izibongo (praise poetry) techniques in representing women in selected isiXhosa poems. The main interest of the study is to determine whether the same techniques to depict men are used when writing about women. It is also the interest of the study to ascertain how gender issues are dealt with in the selected poems. Seminal studies on izibongo by eminent scholars in this field show a serious lack of critique and little recognition of women in African languages’ poetry in general and in isiXhosa in particular. Pioneering studies in Nguni poetry about women have thus recommended that serious studies on poetry about women be undertaken. The analyses of selected poems by established isiXhosa poets show that modern poetry conventions are significantly used together with izibongo techniques. These techniques are used without any gender differentiation, which is another point of interest of this study. There are however instances where images specific to women are used. Such use has however not been found to be demeaning of women in any way. Poems where modern poetry forms and conventions are used tend to deal with subjects who have international or an urban area background. Even though the modern poetry conventions are used with izibongo techniques the presence of the modern literary conventions is prominent. This is the case particularly with poems about women in politics. That some female poet seems to accept some cultural practices that are viewed to be undermining the status of women does not take away the voice of protest against this oppression by some of the selected poets. These two voices, one of acceptance and the other one of protest are used as a basis for a debate around a need for a literary theory that addresses the question of African culture with special reference to isiXhosa poetry about women. The success of the selected poets with both modern and izibongo techniques is a good sign for the development of isiXhosa poetry in general and isiXhosa poetry about women. It is strongly recommended that continued research of a serious nature concerning poetry about, and produced by women, be undertaken.
- Full Text:
- Authors: Jadezweni, Mhlobo Wabantwana
- Date: 2013
- Subjects: Laudatory poetry, Xhosa African poetry (English) -- History and criticism Women in literature Women and literature -- South Africa African poetry -- Women authors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3616 , http://hdl.handle.net/10962/d1006364
- Description: This study investigates the use of modern and izibongo (praise poetry) techniques in representing women in selected isiXhosa poems. The main interest of the study is to determine whether the same techniques to depict men are used when writing about women. It is also the interest of the study to ascertain how gender issues are dealt with in the selected poems. Seminal studies on izibongo by eminent scholars in this field show a serious lack of critique and little recognition of women in African languages’ poetry in general and in isiXhosa in particular. Pioneering studies in Nguni poetry about women have thus recommended that serious studies on poetry about women be undertaken. The analyses of selected poems by established isiXhosa poets show that modern poetry conventions are significantly used together with izibongo techniques. These techniques are used without any gender differentiation, which is another point of interest of this study. There are however instances where images specific to women are used. Such use has however not been found to be demeaning of women in any way. Poems where modern poetry forms and conventions are used tend to deal with subjects who have international or an urban area background. Even though the modern poetry conventions are used with izibongo techniques the presence of the modern literary conventions is prominent. This is the case particularly with poems about women in politics. That some female poet seems to accept some cultural practices that are viewed to be undermining the status of women does not take away the voice of protest against this oppression by some of the selected poets. These two voices, one of acceptance and the other one of protest are used as a basis for a debate around a need for a literary theory that addresses the question of African culture with special reference to isiXhosa poetry about women. The success of the selected poets with both modern and izibongo techniques is a good sign for the development of isiXhosa poetry in general and isiXhosa poetry about women. It is strongly recommended that continued research of a serious nature concerning poetry about, and produced by women, be undertaken.
- Full Text:
Characterisation of surfaces modified through self-assembled monolayers and click chemistry
- Authors: Coates, Megan Patricia
- Date: 2013
- Subjects: Monomolecular films Gold Adsorption Nanotubes Self-assembly (Chemistry) Self-assembly (Chemistry) Scanning electrochemical microscopy X-ray photoelectron spectroscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4277 , http://hdl.handle.net/10962/d1001684
- Description: Different approaches to surface modification were investigated in this work on gold, glassy carbon, multi-walled carbon nanotube paper and on single-walled carbon nanotubes adsorbed on glassy carbon. These approaches include electrochemical grafting, electropolymerisation, click chemistry, axial ligation, adsorption and self-assembled monolayers. The modified surfaces were characterised using a variety of techniques; predominantly electrochemistry, scanning electrochemical microscopy and X-ray photoelectron spectroscopy. For the formation of self-assembled monolayers on gold, four new manganese(III) phthalocyanines (1a-d), octa-substituted at the peripheral position with pentylthio, decylthio, benzylthio, and phenylthio groups were synthesized and characterised. X-ray photoelectron spectroscopy was used to show the formation of a sulphur-gold bond. A number of approaches using 4-azidoaniline (2a) combined with azide-alkyne click chemistry and electrochemistry were also used to anchor ferrocene and pyridine moieties on to the carbon surfaces, including direct in situ diazotation and grafting, electropolymerisation, and the synthesis of the diazonium salt followed by grafting. Iron phthalocyanine was linked to the pyridine-clicked surfaces through axial ligation, where the strong axial bond formed by the interaction between the central metal and the lone pair of the nitrogen in the pyridine group resulted in stable modified electrodes. The potential of these surfaces for the detection of analytes such as thiocyanate, hydrazine and sulphite are briefly shown as well. This work also describes for the first time the possibility of performing local micro-electrochemical grafting of a gold substrate by 4-azidobenzenediazonium (2b) using scanning electrochemical microscopy in a single and simple one step approach, without complications from adsorption.
- Full Text:
- Authors: Coates, Megan Patricia
- Date: 2013
- Subjects: Monomolecular films Gold Adsorption Nanotubes Self-assembly (Chemistry) Self-assembly (Chemistry) Scanning electrochemical microscopy X-ray photoelectron spectroscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4277 , http://hdl.handle.net/10962/d1001684
- Description: Different approaches to surface modification were investigated in this work on gold, glassy carbon, multi-walled carbon nanotube paper and on single-walled carbon nanotubes adsorbed on glassy carbon. These approaches include electrochemical grafting, electropolymerisation, click chemistry, axial ligation, adsorption and self-assembled monolayers. The modified surfaces were characterised using a variety of techniques; predominantly electrochemistry, scanning electrochemical microscopy and X-ray photoelectron spectroscopy. For the formation of self-assembled monolayers on gold, four new manganese(III) phthalocyanines (1a-d), octa-substituted at the peripheral position with pentylthio, decylthio, benzylthio, and phenylthio groups were synthesized and characterised. X-ray photoelectron spectroscopy was used to show the formation of a sulphur-gold bond. A number of approaches using 4-azidoaniline (2a) combined with azide-alkyne click chemistry and electrochemistry were also used to anchor ferrocene and pyridine moieties on to the carbon surfaces, including direct in situ diazotation and grafting, electropolymerisation, and the synthesis of the diazonium salt followed by grafting. Iron phthalocyanine was linked to the pyridine-clicked surfaces through axial ligation, where the strong axial bond formed by the interaction between the central metal and the lone pair of the nitrogen in the pyridine group resulted in stable modified electrodes. The potential of these surfaces for the detection of analytes such as thiocyanate, hydrazine and sulphite are briefly shown as well. This work also describes for the first time the possibility of performing local micro-electrochemical grafting of a gold substrate by 4-azidobenzenediazonium (2b) using scanning electrochemical microscopy in a single and simple one step approach, without complications from adsorption.
- Full Text:
Climate variability and climate change in water resources management of the Zambezi River basin
- Authors: Tirivarombo, Sithabile
- Date: 2013
- Subjects: Water resources development -- Zambezi River Watershed Climatic changes -- Zambezi River Watershed Water-supply -- Zambezi River Watershed Water-supply -- Political aspects -- Africa, Southern Water rights -- Africa, Southern Water security -- Africa, Southern Rain and rainfall -- Africa, Southern Rainfall probabilities -- Africa, Southern Food security -- Africa, Southern Drought forecasting -- Africa, Southern Watersheds -- Africa, Southern Water supply -- Measurement -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6024 , http://hdl.handle.net/10962/d1002955
- Description: Water is recognised as a key driver for social and economic development in the Zambezi basin. The basin is riparian to eight southern African countries and the transboundary nature of the basin’s water resources can be viewed as an agent of cooperation between the basin countries. It is possible, however, that the same water resource can lead to conflicts between water users. The southern African Water Vision for ‘equitable and sustainable utilisation of water for social, environmental justice and economic benefits for the present and future generations’ calls for an integrated and efficient management of water resources within the basin. Ensuring water and food security in the Zambezi basin is, however, faced with challenges due to high variability in climate and the available water resources. Water resources are under continuous threat from pollution, increased population growth, development and urbanisation as well as global climate change. These factors increase the demand for freshwater resources and have resulted in water being one of the major driving forces for development. The basin is also vulnerable due to lack of adequate financial resources and appropriate water resources infrastructure to enable viable, equitable and sustainable distribution of the water resources. This is in addition to the fact that the basin’s economic mainstay and social well-being are largely dependent on rainfed agriculture. There is also competition among the different water users and this has the potential to generate conflicts, which further hinder the development of water resources in the basin. This thesis has focused on the Zambezi River basin emphasising climate variability and climate change. It is now considered common knowledge that the global climate is changing and that many of the impacts will be felt through water resources. If these predictions are correct then the Zambezi basin is most likely to suffer under such impacts since its economic mainstay is largely determined by the availability of rainfall. It is the belief of this study that in order to ascertain the impacts of climate change, there should be a basis against which this change is evaluated. If we do not know the historical patterns of variability it may be difficult to predict changes in the future climate and in the hydrological resources and it will certainly be difficult to develop appropriate management strategies. Reliable quantitative estimates of water availability are a prerequisite for successful water resource plans. However, such initiatives have been hindered by paucity in data especially in a basin where gauging networks are inadequate and some of them have deteriorated. This is further compounded by shortages in resources, both human and financial, to ensure adequate monitoring. To address the data problems, this study largely relied on global data sets and the CRU TS2.1 rainfall grids were used for a large part of this study. The study starts by assessing the historical variability of rainfall and streamflow in the Zambezi basin and the results are used to inform the prediction of change in the future. Various methods of assessing historical trends were employed and regional drought indices were generated and evaluated against the historical rainfall trends. The study clearly demonstrates that the basin has a high degree of temporal and spatial variability in rainfall and streamflow at inter-annual and multi-decadal scales. The Standardised Precipitation Index, a rainfall based drought index, is used to assess historical drought events in the basin and it is shown that most of the droughts that have occurred were influenced by climatic and hydrological variability. It is concluded, through the evaluation of agricultural maize yields, that the basin’s food security is mostly constrained by the availability of rainfall. Comparing the viability of using a rainfall based index to a soil moisture based index as an agricultural drought indicator, this study concluded that a soil moisture based index is a better indicator since all of the water balance components are considered in the generation of the index. This index presents the actual amount of water available for the plant unlike purely rainfall based indices, that do not account for other components of the water budget that cause water losses. A number of challenges were, however, faced in assessing the variability and historical drought conditions, mainly due to the fact that most parts of the Zambezi basin are ungauged and available data are sparse, short and not continuous (with missing gaps). Hydrological modelling is frequently used to bridge the data gap and to facilitate the quantification of a basin’s hydrology for both gauged and ungauged catchments. The trend has been to use various methods of regionalisation to transfer information from gauged basins, or from basins with adequate physical basin data, to ungauged basins. All this is done to ensure that water resources are accounted for and that the future can be well planned. A number of approaches leading to the evaluation of the basin’s hydrological response to future climate change scenarios are taken. The Pitman rainfall-runoff model has enjoyed wide use as a water resources estimation tool in southern Africa. The model has been calibrated for the Zambezi basin but it should be acknowledged that any hydrological modelling process is characterised by many uncertainties arising from limitations in input data and inherent model structural uncertainty. The calibration process is thus carried out in a manner that embraces some of the uncertainties. Initial ranges of parameter values (maximum and minimum) that incorporate the possible parameter uncertainties are assigned in relation to physical basin properties. These parameter sets are used as input to the uncertainty version of the model to generate behavioural parameter space which is then further modified through manual calibration. The use of parameter ranges initially guided by the basin physical properties generates streamflows that adequately represent the historically observed amounts. This study concludes that the uncertainty framework and the Pitman model perform quite well in the Zambezi basin. Based on assumptions of an intensifying hydrological cycle, climate changes are frequently expected to result in negative impacts on water resources. However, it is important that basin scale assessments are undertaken so that appropriate future management strategies can be developed. To assess the likely changes in the Zambezi basin, the calibrated Pitman model was forced with downscaled and bias corrected GCM data. Three GCMs were used for this study, namely; ECHAM, GFDL and IPSL. The general observation made in this study is that the near future (2046-2065) conditions of the Zambezi basin are expected to remain within the ranges of historically observed variability. The differences between the predictions for the three GCMs are an indication of the uncertainties in the future and it has not been possible to make any firm conclusions about directions of change. It is therefore recommended that future water resources management strategies account for historical patterns of variability, but also for increased uncertainty. Any management strategies that are able to satisfactorily deal with the large variability that is evident from the historical data should be robust enough to account for the near future patterns of water availability predicted by this study. However, the uncertainties in these predictions suggest that improved monitoring systems are required to provide additional data against which future model outputs can be assessed.
- Full Text:
- Authors: Tirivarombo, Sithabile
- Date: 2013
- Subjects: Water resources development -- Zambezi River Watershed Climatic changes -- Zambezi River Watershed Water-supply -- Zambezi River Watershed Water-supply -- Political aspects -- Africa, Southern Water rights -- Africa, Southern Water security -- Africa, Southern Rain and rainfall -- Africa, Southern Rainfall probabilities -- Africa, Southern Food security -- Africa, Southern Drought forecasting -- Africa, Southern Watersheds -- Africa, Southern Water supply -- Measurement -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6024 , http://hdl.handle.net/10962/d1002955
- Description: Water is recognised as a key driver for social and economic development in the Zambezi basin. The basin is riparian to eight southern African countries and the transboundary nature of the basin’s water resources can be viewed as an agent of cooperation between the basin countries. It is possible, however, that the same water resource can lead to conflicts between water users. The southern African Water Vision for ‘equitable and sustainable utilisation of water for social, environmental justice and economic benefits for the present and future generations’ calls for an integrated and efficient management of water resources within the basin. Ensuring water and food security in the Zambezi basin is, however, faced with challenges due to high variability in climate and the available water resources. Water resources are under continuous threat from pollution, increased population growth, development and urbanisation as well as global climate change. These factors increase the demand for freshwater resources and have resulted in water being one of the major driving forces for development. The basin is also vulnerable due to lack of adequate financial resources and appropriate water resources infrastructure to enable viable, equitable and sustainable distribution of the water resources. This is in addition to the fact that the basin’s economic mainstay and social well-being are largely dependent on rainfed agriculture. There is also competition among the different water users and this has the potential to generate conflicts, which further hinder the development of water resources in the basin. This thesis has focused on the Zambezi River basin emphasising climate variability and climate change. It is now considered common knowledge that the global climate is changing and that many of the impacts will be felt through water resources. If these predictions are correct then the Zambezi basin is most likely to suffer under such impacts since its economic mainstay is largely determined by the availability of rainfall. It is the belief of this study that in order to ascertain the impacts of climate change, there should be a basis against which this change is evaluated. If we do not know the historical patterns of variability it may be difficult to predict changes in the future climate and in the hydrological resources and it will certainly be difficult to develop appropriate management strategies. Reliable quantitative estimates of water availability are a prerequisite for successful water resource plans. However, such initiatives have been hindered by paucity in data especially in a basin where gauging networks are inadequate and some of them have deteriorated. This is further compounded by shortages in resources, both human and financial, to ensure adequate monitoring. To address the data problems, this study largely relied on global data sets and the CRU TS2.1 rainfall grids were used for a large part of this study. The study starts by assessing the historical variability of rainfall and streamflow in the Zambezi basin and the results are used to inform the prediction of change in the future. Various methods of assessing historical trends were employed and regional drought indices were generated and evaluated against the historical rainfall trends. The study clearly demonstrates that the basin has a high degree of temporal and spatial variability in rainfall and streamflow at inter-annual and multi-decadal scales. The Standardised Precipitation Index, a rainfall based drought index, is used to assess historical drought events in the basin and it is shown that most of the droughts that have occurred were influenced by climatic and hydrological variability. It is concluded, through the evaluation of agricultural maize yields, that the basin’s food security is mostly constrained by the availability of rainfall. Comparing the viability of using a rainfall based index to a soil moisture based index as an agricultural drought indicator, this study concluded that a soil moisture based index is a better indicator since all of the water balance components are considered in the generation of the index. This index presents the actual amount of water available for the plant unlike purely rainfall based indices, that do not account for other components of the water budget that cause water losses. A number of challenges were, however, faced in assessing the variability and historical drought conditions, mainly due to the fact that most parts of the Zambezi basin are ungauged and available data are sparse, short and not continuous (with missing gaps). Hydrological modelling is frequently used to bridge the data gap and to facilitate the quantification of a basin’s hydrology for both gauged and ungauged catchments. The trend has been to use various methods of regionalisation to transfer information from gauged basins, or from basins with adequate physical basin data, to ungauged basins. All this is done to ensure that water resources are accounted for and that the future can be well planned. A number of approaches leading to the evaluation of the basin’s hydrological response to future climate change scenarios are taken. The Pitman rainfall-runoff model has enjoyed wide use as a water resources estimation tool in southern Africa. The model has been calibrated for the Zambezi basin but it should be acknowledged that any hydrological modelling process is characterised by many uncertainties arising from limitations in input data and inherent model structural uncertainty. The calibration process is thus carried out in a manner that embraces some of the uncertainties. Initial ranges of parameter values (maximum and minimum) that incorporate the possible parameter uncertainties are assigned in relation to physical basin properties. These parameter sets are used as input to the uncertainty version of the model to generate behavioural parameter space which is then further modified through manual calibration. The use of parameter ranges initially guided by the basin physical properties generates streamflows that adequately represent the historically observed amounts. This study concludes that the uncertainty framework and the Pitman model perform quite well in the Zambezi basin. Based on assumptions of an intensifying hydrological cycle, climate changes are frequently expected to result in negative impacts on water resources. However, it is important that basin scale assessments are undertaken so that appropriate future management strategies can be developed. To assess the likely changes in the Zambezi basin, the calibrated Pitman model was forced with downscaled and bias corrected GCM data. Three GCMs were used for this study, namely; ECHAM, GFDL and IPSL. The general observation made in this study is that the near future (2046-2065) conditions of the Zambezi basin are expected to remain within the ranges of historically observed variability. The differences between the predictions for the three GCMs are an indication of the uncertainties in the future and it has not been possible to make any firm conclusions about directions of change. It is therefore recommended that future water resources management strategies account for historical patterns of variability, but also for increased uncertainty. Any management strategies that are able to satisfactorily deal with the large variability that is evident from the historical data should be robust enough to account for the near future patterns of water availability predicted by this study. However, the uncertainties in these predictions suggest that improved monitoring systems are required to provide additional data against which future model outputs can be assessed.
- Full Text:
Coping with HIV and AIDS in marginal communities: a case study of Chivanhu Settlement in Nemanwa, Masvingo, Zimbabwe
- Authors: Makonese, Loveness
- Date: 2013
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3337 , http://hdl.handle.net/10962/d1003744
- Description: This thesis seeks to understand and analyse HIV and AIDS and rural livelihoods in Zimbabwe with particular reference to an isolated and marginalised informal settlement called Chivanhu in Masvingo Province. The focus is specifically on questions around HIV susceptibility, AIDS vulnerability and household resilience. In this regard, it is important to recognise that HIV and AIDS cannot be lumped together as one medical or social condition. Rather, there is a progression from HIV infection to AIDS-related chronic illnesses to possible death, and livelihood strategies often alter along this HIV and AIDS time-line. Zimbabwe for over a decade now has gone through a series of economic and political crises which have impacted detrimentally on both urban and rural livelihoods, even for those households which are not directly affected by the HIV and AIDS pandemic. With the economy in free-fall, households have had to pursue a range of livelihood strategies in order to sustain themselves. These socio-economic conditions have in many ways facilitated susceptibility to HIV infection and vulnerability to AIDS. Many studies have examined this in relation to wellentrenched and stable communities in rural Zimbabwe. But the livelihood dynamics for such communities are significantly different to more unstable and informal settlements like Chivanhu, as thesis seeks to show. At the same time, the thesis offers a longitudinal study which is able to map the changes to the livelihoods of infected and affected households in Chivanhu. Though recognising the debilitating effects of the pandemic on these households, it also raises questions about the possible resilience of certain households despite great adversity. In doing so, it goes beyond the individual and household levels of analysis to consider the role of clusters (or groups of households) in responding to the impacts of HIV and AIDS. In this regard, particular emphasis is placed on gender and orphanhood. In the end, the thesis offers a nuanced analysis of the everyday complexities and challenges for affected households in a marginalised and informal rural community in Zimbabwe and thereby makes a contribution to re-theorising HIV and AIDS and rural livelihoods more broadly.
- Full Text:
- Authors: Makonese, Loveness
- Date: 2013
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3337 , http://hdl.handle.net/10962/d1003744
- Description: This thesis seeks to understand and analyse HIV and AIDS and rural livelihoods in Zimbabwe with particular reference to an isolated and marginalised informal settlement called Chivanhu in Masvingo Province. The focus is specifically on questions around HIV susceptibility, AIDS vulnerability and household resilience. In this regard, it is important to recognise that HIV and AIDS cannot be lumped together as one medical or social condition. Rather, there is a progression from HIV infection to AIDS-related chronic illnesses to possible death, and livelihood strategies often alter along this HIV and AIDS time-line. Zimbabwe for over a decade now has gone through a series of economic and political crises which have impacted detrimentally on both urban and rural livelihoods, even for those households which are not directly affected by the HIV and AIDS pandemic. With the economy in free-fall, households have had to pursue a range of livelihood strategies in order to sustain themselves. These socio-economic conditions have in many ways facilitated susceptibility to HIV infection and vulnerability to AIDS. Many studies have examined this in relation to wellentrenched and stable communities in rural Zimbabwe. But the livelihood dynamics for such communities are significantly different to more unstable and informal settlements like Chivanhu, as thesis seeks to show. At the same time, the thesis offers a longitudinal study which is able to map the changes to the livelihoods of infected and affected households in Chivanhu. Though recognising the debilitating effects of the pandemic on these households, it also raises questions about the possible resilience of certain households despite great adversity. In doing so, it goes beyond the individual and household levels of analysis to consider the role of clusters (or groups of households) in responding to the impacts of HIV and AIDS. In this regard, particular emphasis is placed on gender and orphanhood. In the end, the thesis offers a nuanced analysis of the everyday complexities and challenges for affected households in a marginalised and informal rural community in Zimbabwe and thereby makes a contribution to re-theorising HIV and AIDS and rural livelihoods more broadly.
- Full Text:
Critical studies in carbon electrode materials with applications in the electroanalysis of the mycotoxin citrinin
- Authors: Niland, Michael John
- Date: 2013
- Subjects: Electrodes, Carbon , Mycotoxins
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4555 , http://hdl.handle.net/10962/d1018256
- Description: Guided by increasing legislation, the analysis of food borne toxins, including mycotoxins, seeks to address market related demands for the development of analytical systems to monitor this threat to food security and human health. This Thesis is directed at the assessment of the application of electrochemistry for direct electroanalysis and characterisation of the mycotoxin citrinin (CIT) in aqueous media as well as fundamental investigations of the surface of polished and oxidised glassy carbon electrodes (GCE). This study provides the first known account of CIT detection through electrochemical methods. Although electrochemically active, CIT current responses (Ip) were highly irreproducible at polished GCE with a coefficient of variation (C.V.) of 20.16 %. As stability of Ip across multiple electrode preparations is a key requirement in electroanalysis, investigations were directed at attaining stability in CIT Ip. Achieving stability in CIT Ip was investigated via two approaches, including: accounting for Ip variability between electrode preparations as a result of variable GCE surface conditions as a post-data-acquisition analysis and secondly, removing Ip variability through modification of GCE. Accounting for variability in Ip was investigated through the application of double layer capacitance as an indicator of the activity of an electrode, and in so doing serving as a relative mediator of Ip responses between electrodes. Application of this procedure dropped CIT C.V. to a third of starting value across polished GCE (C.V. = 7.18 %), chemically oxidised GCE (Pi-GCE, C.V = 8.47 %) and functionalised multi-walled carbon nanotube modified GCE (fMWCNT, C.V. = 25.79 %) and was effective with analysis of structurally distinct molecules, 2,4-dimethylaniline (2,4-DMA) and 1,2,4-trihydroxybenzene (Triol). Furthermore, it afforded the ability to determine discreet solution overlapping data sets of Ip. Stabilising Ip through GCE surface modification was achieved by anodic electro-oxidation of GCE and allowed for direct electroanalysis of CIT and subsequent characterisation and analysis of CIT in complex media as it reduced C.V. of CIT Ip to 0.73 %. Fundamental investigations of the electrode surface condition are described such that the source of variability could be identified and the interactions of CIT with the electrode understood. Two surface oxidation techniques were applied in modification of GCE; anodic electro-oxidation (EOx GCE) and chemical oxidation using piranha solution (Pi-GCE), analysis of which has previously not been reported. Fundamental analyses to determine surface morphology and chemistry of Pi-GCE, EOx-GCE and polished GCE were conducted using high resolution scanning electron microscopy (HRSEM), scanning electrochemical microscopy (SECM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR) and via electroanalytical methods. These studies showed that both oxidation procedures introduced a variety of oxide species at GCE surface, and further that the extent of those species was similar with total % O being 27.67 % and 33.47 % at Pi-GCE and EOx-GCE respectively. Although chemically similar, each surface was morphologically distinct. Electrochemical analyses at the surfaces revealed Pi-GCE to behave more similarly to polished GCE than EOx-GCE. As CIT responses were found to be stable at EOx-GCE (C.V. = 0.73 %) as opposed to Pi-GCE (C.V. = 22.87 %), stability of CIT Ip was likely to be as a result of a physical interaction with electrode morphology rather than interaction on a chemical basis. Morphological analyses revealed polished GCE and Pi-GCE to be highly morphologically irregular at the micro-scale. Although comparatively smooth, the surface morphology of EOx-GCE does not account for the stability of Ip. This study thus proposed a theory to describe the mechanism by which the limited conductivity and porosity of EOx-GCE allow for it to provide a relatively stable surface area within the oxide layer, adjacent to the electrode surface, and thus provided a stable platform for electroanalysis. Voltammetric characterization of CIT at EOx-GCE revealed that anodic oxidation in aqueous media involved an uneven number of electrons to protons via an ECE mechanism. This was illustrated to be nt = 2e- accompanied by the transfer of 1H⁺ per molecule oxidised. A proposed reaction scheme for the initial stages of CIT oxidation was suggested to involve both hydroxyl and carboxyl moieties of the CIT molecule. CIT oxidation was shown to arise as a result of a relatively complex mass transport regime which included both adsorptive and diffusive derived Ip₁. The LOD in buffered aqueous media was found to be 16 nM, a highly competitive result in relation to chromatographic techniques. Further application of EOx-GCE in complex media illustrated that CIT associates non-specifically with the components of food samples, primarily proteins. As a result of this, extraction of CIT from such media is mandatory. Liquid-liquid extraction illustrated a recovery in CIT Ip₁ and in so doing provided a means of accurately and sensitively detecting CIT from food samples with an LOD of 20 nM. These responses were corroborated by HPLC analyses on the same extractions and illustrate the applicability of electroanalysis as an analytical technique.
- Full Text:
- Authors: Niland, Michael John
- Date: 2013
- Subjects: Electrodes, Carbon , Mycotoxins
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4555 , http://hdl.handle.net/10962/d1018256
- Description: Guided by increasing legislation, the analysis of food borne toxins, including mycotoxins, seeks to address market related demands for the development of analytical systems to monitor this threat to food security and human health. This Thesis is directed at the assessment of the application of electrochemistry for direct electroanalysis and characterisation of the mycotoxin citrinin (CIT) in aqueous media as well as fundamental investigations of the surface of polished and oxidised glassy carbon electrodes (GCE). This study provides the first known account of CIT detection through electrochemical methods. Although electrochemically active, CIT current responses (Ip) were highly irreproducible at polished GCE with a coefficient of variation (C.V.) of 20.16 %. As stability of Ip across multiple electrode preparations is a key requirement in electroanalysis, investigations were directed at attaining stability in CIT Ip. Achieving stability in CIT Ip was investigated via two approaches, including: accounting for Ip variability between electrode preparations as a result of variable GCE surface conditions as a post-data-acquisition analysis and secondly, removing Ip variability through modification of GCE. Accounting for variability in Ip was investigated through the application of double layer capacitance as an indicator of the activity of an electrode, and in so doing serving as a relative mediator of Ip responses between electrodes. Application of this procedure dropped CIT C.V. to a third of starting value across polished GCE (C.V. = 7.18 %), chemically oxidised GCE (Pi-GCE, C.V = 8.47 %) and functionalised multi-walled carbon nanotube modified GCE (fMWCNT, C.V. = 25.79 %) and was effective with analysis of structurally distinct molecules, 2,4-dimethylaniline (2,4-DMA) and 1,2,4-trihydroxybenzene (Triol). Furthermore, it afforded the ability to determine discreet solution overlapping data sets of Ip. Stabilising Ip through GCE surface modification was achieved by anodic electro-oxidation of GCE and allowed for direct electroanalysis of CIT and subsequent characterisation and analysis of CIT in complex media as it reduced C.V. of CIT Ip to 0.73 %. Fundamental investigations of the electrode surface condition are described such that the source of variability could be identified and the interactions of CIT with the electrode understood. Two surface oxidation techniques were applied in modification of GCE; anodic electro-oxidation (EOx GCE) and chemical oxidation using piranha solution (Pi-GCE), analysis of which has previously not been reported. Fundamental analyses to determine surface morphology and chemistry of Pi-GCE, EOx-GCE and polished GCE were conducted using high resolution scanning electron microscopy (HRSEM), scanning electrochemical microscopy (SECM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR) and via electroanalytical methods. These studies showed that both oxidation procedures introduced a variety of oxide species at GCE surface, and further that the extent of those species was similar with total % O being 27.67 % and 33.47 % at Pi-GCE and EOx-GCE respectively. Although chemically similar, each surface was morphologically distinct. Electrochemical analyses at the surfaces revealed Pi-GCE to behave more similarly to polished GCE than EOx-GCE. As CIT responses were found to be stable at EOx-GCE (C.V. = 0.73 %) as opposed to Pi-GCE (C.V. = 22.87 %), stability of CIT Ip was likely to be as a result of a physical interaction with electrode morphology rather than interaction on a chemical basis. Morphological analyses revealed polished GCE and Pi-GCE to be highly morphologically irregular at the micro-scale. Although comparatively smooth, the surface morphology of EOx-GCE does not account for the stability of Ip. This study thus proposed a theory to describe the mechanism by which the limited conductivity and porosity of EOx-GCE allow for it to provide a relatively stable surface area within the oxide layer, adjacent to the electrode surface, and thus provided a stable platform for electroanalysis. Voltammetric characterization of CIT at EOx-GCE revealed that anodic oxidation in aqueous media involved an uneven number of electrons to protons via an ECE mechanism. This was illustrated to be nt = 2e- accompanied by the transfer of 1H⁺ per molecule oxidised. A proposed reaction scheme for the initial stages of CIT oxidation was suggested to involve both hydroxyl and carboxyl moieties of the CIT molecule. CIT oxidation was shown to arise as a result of a relatively complex mass transport regime which included both adsorptive and diffusive derived Ip₁. The LOD in buffered aqueous media was found to be 16 nM, a highly competitive result in relation to chromatographic techniques. Further application of EOx-GCE in complex media illustrated that CIT associates non-specifically with the components of food samples, primarily proteins. As a result of this, extraction of CIT from such media is mandatory. Liquid-liquid extraction illustrated a recovery in CIT Ip₁ and in so doing provided a means of accurately and sensitively detecting CIT from food samples with an LOD of 20 nM. These responses were corroborated by HPLC analyses on the same extractions and illustrate the applicability of electroanalysis as an analytical technique.
- Full Text:
Drivers of macrophyte assemblages in South African freshwater systems
- Authors: Martin, Grant Douglas
- Date: 2013
- Subjects: Freshwater plants -- South Africa Aquatic weeds -- South Africa Invasive plants -- South Africa Freshwater ecology -- South Africa Biotic communities -- South Africa Maximum entropy method Lagarosiphon major -- South Africa Phytophagous insects -- South Africa Hydrellia -- South Africa Parasitoids -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5621 , http://hdl.handle.net/10962/d1004127
- Description: Potentially damaging submerged invasive freshwater macrophytes have been identified in South African freshwater systems, but have received less attention than their floating counterparts. To ascertain the changes and effects that these species may have on macrophyte ecology, an understanding of the drivers of macrophyte assemblages is essential. The aims of this thesis were to investigate select abiotic and biotic factors driving introduction, establishment and spread of submerged macrophytes in South Africa. Surveys on the status of submerged plant species in South Africa were conducted to find out the distribution and diversity of the species present, imported to, and traded in South Africa. Numerous submerged indigenous and invasive macrophyte locality records were collected during field surveys, of which many were first time records. Pet stores and aquarist trading activities were identified as potential vectors for the spread of submerged macrophytes through online surveys and personal interviews. These results highlighted the potential these species have for continuing to enter, and spread within South African water bodies. Maximum Entropy (MAXENT) is a general-purpose method used to predict or infer distributions from incomplete information, and was used here to predict areas suitable for the establishment of five of these invasive macrophytes. Many systems throughout South Africa, particularly those in the subtropical coastal regions, were found to be climatically suitable for the establishment of Elodea canadensis Michx., Egeria densa Planch., Hydrilla verticillata (L.f.) Royle (all Hydrocharitaceae), Myriophyllum spicatum L. (Haloragaceae), and Cabomba caroliniana Gray (Cabombaceae). Despite the high probability of invasion, facilitated by vectors and suitable climate, South Africa’s rich indigenous submerged aquatic flora may be preventing the establishment of these submerged invasive species. Studies on the competitive interactions between a common indigenous submerged macrophytes, Lagarosiphon major (Roxb.) (Hydrocharitaceae) and M.spicatum, an invasive native to Eurasia, were conducted to ascertain which conditions influence competitive superiority. High sediment nutrient conditions significantly increased the growth rate and competitive ability of both species, while clay sediments significantly increased the competitive ability of L. major over M. spicatum, but sandy sediments improved the competitive ability of M. spicatum. These results highlighted the dynamic changes in competition between submerged species driven by abiotic factors, but did not take into consideration the effect that herbivory, a biotic factor, could have on competition between the two species. The effect of herbivory by phytophagous insects of submerged plant species has been regarded as negligible. To find out what this effect is, multiple field surveys were undertaken throughout South Africa to find natural enemies of indigenous Lagarosiphon species with the aim of identifying such species, and quantifying their influence on plant growth dynamics. Several new phytophagous species were recorded for the first time. An ephydrid fly, Hydrellia lagarosiphon Deeming (Diptera: Ephydridae) was ascertained to be the most ubiquitous and abundant species associated with L. major in South Africa. The influence of herbivory by this fly on the competitive ability of L. major in the presence of M. spicatum was investigated using an inverse linear model, which showed that herbivory by H. lagarosiphon reduced the competitive ability of L. major by approximately five times in favour of M. spicatum. This study served to highlight the importance of herbivory as a driver of submerged aquatic plant dynamics. Current ecological theory emphasises the importance of investigating beyond plant-herbivore interactions, by including multitrophic interactions in community dynamics. Therefore, the potential of parasitism by a parasitoid wasp, Chaenusa luteostigma sp. n. Achterberg (Hymenoptera: Braconidae: Alysiinae) on H. lagarosiphon to shift the competitive interactions between the two plant species was also examined. The addition of the parasitoid reduced the effect of herbivory by the fly on L. major by half, thereby shifting the competitive balance in favour of L. major over M. spicatum. This study provides valuable insight into a selection of drivers of submerged macrophyte assemblages of South Africa. It highlights the precarious position of South African freshwater systems with regard to the potential invasion by damaging submerged invasive species. It also provides interesting insights into the effect of competition, herbivory and parasitism on the establishment and spread of species within submerged freshwater systems. Understanding the different influences could assist managers and policy makers to make validated decisions ensuring the integrity of South African freshwater systems.
- Full Text:
- Authors: Martin, Grant Douglas
- Date: 2013
- Subjects: Freshwater plants -- South Africa Aquatic weeds -- South Africa Invasive plants -- South Africa Freshwater ecology -- South Africa Biotic communities -- South Africa Maximum entropy method Lagarosiphon major -- South Africa Phytophagous insects -- South Africa Hydrellia -- South Africa Parasitoids -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5621 , http://hdl.handle.net/10962/d1004127
- Description: Potentially damaging submerged invasive freshwater macrophytes have been identified in South African freshwater systems, but have received less attention than their floating counterparts. To ascertain the changes and effects that these species may have on macrophyte ecology, an understanding of the drivers of macrophyte assemblages is essential. The aims of this thesis were to investigate select abiotic and biotic factors driving introduction, establishment and spread of submerged macrophytes in South Africa. Surveys on the status of submerged plant species in South Africa were conducted to find out the distribution and diversity of the species present, imported to, and traded in South Africa. Numerous submerged indigenous and invasive macrophyte locality records were collected during field surveys, of which many were first time records. Pet stores and aquarist trading activities were identified as potential vectors for the spread of submerged macrophytes through online surveys and personal interviews. These results highlighted the potential these species have for continuing to enter, and spread within South African water bodies. Maximum Entropy (MAXENT) is a general-purpose method used to predict or infer distributions from incomplete information, and was used here to predict areas suitable for the establishment of five of these invasive macrophytes. Many systems throughout South Africa, particularly those in the subtropical coastal regions, were found to be climatically suitable for the establishment of Elodea canadensis Michx., Egeria densa Planch., Hydrilla verticillata (L.f.) Royle (all Hydrocharitaceae), Myriophyllum spicatum L. (Haloragaceae), and Cabomba caroliniana Gray (Cabombaceae). Despite the high probability of invasion, facilitated by vectors and suitable climate, South Africa’s rich indigenous submerged aquatic flora may be preventing the establishment of these submerged invasive species. Studies on the competitive interactions between a common indigenous submerged macrophytes, Lagarosiphon major (Roxb.) (Hydrocharitaceae) and M.spicatum, an invasive native to Eurasia, were conducted to ascertain which conditions influence competitive superiority. High sediment nutrient conditions significantly increased the growth rate and competitive ability of both species, while clay sediments significantly increased the competitive ability of L. major over M. spicatum, but sandy sediments improved the competitive ability of M. spicatum. These results highlighted the dynamic changes in competition between submerged species driven by abiotic factors, but did not take into consideration the effect that herbivory, a biotic factor, could have on competition between the two species. The effect of herbivory by phytophagous insects of submerged plant species has been regarded as negligible. To find out what this effect is, multiple field surveys were undertaken throughout South Africa to find natural enemies of indigenous Lagarosiphon species with the aim of identifying such species, and quantifying their influence on plant growth dynamics. Several new phytophagous species were recorded for the first time. An ephydrid fly, Hydrellia lagarosiphon Deeming (Diptera: Ephydridae) was ascertained to be the most ubiquitous and abundant species associated with L. major in South Africa. The influence of herbivory by this fly on the competitive ability of L. major in the presence of M. spicatum was investigated using an inverse linear model, which showed that herbivory by H. lagarosiphon reduced the competitive ability of L. major by approximately five times in favour of M. spicatum. This study served to highlight the importance of herbivory as a driver of submerged aquatic plant dynamics. Current ecological theory emphasises the importance of investigating beyond plant-herbivore interactions, by including multitrophic interactions in community dynamics. Therefore, the potential of parasitism by a parasitoid wasp, Chaenusa luteostigma sp. n. Achterberg (Hymenoptera: Braconidae: Alysiinae) on H. lagarosiphon to shift the competitive interactions between the two plant species was also examined. The addition of the parasitoid reduced the effect of herbivory by the fly on L. major by half, thereby shifting the competitive balance in favour of L. major over M. spicatum. This study provides valuable insight into a selection of drivers of submerged macrophyte assemblages of South Africa. It highlights the precarious position of South African freshwater systems with regard to the potential invasion by damaging submerged invasive species. It also provides interesting insights into the effect of competition, herbivory and parasitism on the establishment and spread of species within submerged freshwater systems. Understanding the different influences could assist managers and policy makers to make validated decisions ensuring the integrity of South African freshwater systems.
- Full Text:
Electrocatalytic detection of pesticides with electrodes modified with nanoparticles of phthalocyanines and multiwalled carbon nanotubes
- Authors: Siswana, Msimelelo Patrick
- Date: 2013
- Subjects: Phthalocyanines Pesticides Electrocatalysis Electrochemistry Nanotubes Nanoparticles Transmission electron microscopy Scanning electron microscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4282 , http://hdl.handle.net/10962/d1002613
- Description: Three types of electrodes: carbon paste electrodes modified with nanoparticles of metallophthalocyanines (MPcNP-CPEs, M = Mn, Fe, Ni, Co), basal plane pyrolytic graphite electrodes modified with iron or nickel phthalocyanine nanoparticles and multiwalled carbon nanotube composites (FePcNP/MWCNT-BPPGE or NiPcNP/MWCNT-BPPGE),and basal plane pyrolytic graphite electrodes modified with multiwalled carbon nanotubes and electropolymerized metal tetra-aminophthalocyanines (poly-MTAPc-MWCNT-BPPGE), where M is Mn, Fe, Ni or Co, were prepared. Electrochemical characterizations showed that faster electron transfer kinetics occurred at the NiPcNP/MWCNT-BPPGE than at the FePcNP/MWCNT-BPPGE surface. SEM and electrochemical characterizations of poly-MTAPc-MWCNT-BPPGE showed that MTAPc had been deposited on the MWCNTBPPGE surface, and that the poly-CoTAPc-MWCNT-BPPGE exhibited the fastest electron transfer kinetics of all the poly-MTAPc-MWCNT-BPPGEs. Using amitrole and asulam as test analytes, electrochemical experiments showed that, amongst the CPEs, the FePcNP-CPE and NiPcNP-CPE displayed the most electrocatalytic behavior towards amitrole and asulam oxidation, respectively, and further experiments were done to obtain the electrochemical parameters associated with these electrodes and the corresponding analytes. Although, the FePcNP/MWCNT- BPPGE displayed electrocatalytic behavior towards amitrole oxidation in comparison with the bare BPPGE, it was less electrocatalytic than the FePcNP-CPE in terms of detection potential. The NiPcNP/MWCNT-BPPGE displayed the same detection potential as the NiPcNP-CPE. The poly-FeTAPc-MWCNT-BPPGE exhibited the most electrocatalytic behavior towards amitrole, of all the electrodes investigated, and the poly-CoTAPc-MWCNT-BPPGE displayed the best electrocatalytic behavior towards asulam, amongst the poly-MTAPc-MWCNT-BPPGEs.
- Full Text:
- Authors: Siswana, Msimelelo Patrick
- Date: 2013
- Subjects: Phthalocyanines Pesticides Electrocatalysis Electrochemistry Nanotubes Nanoparticles Transmission electron microscopy Scanning electron microscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4282 , http://hdl.handle.net/10962/d1002613
- Description: Three types of electrodes: carbon paste electrodes modified with nanoparticles of metallophthalocyanines (MPcNP-CPEs, M = Mn, Fe, Ni, Co), basal plane pyrolytic graphite electrodes modified with iron or nickel phthalocyanine nanoparticles and multiwalled carbon nanotube composites (FePcNP/MWCNT-BPPGE or NiPcNP/MWCNT-BPPGE),and basal plane pyrolytic graphite electrodes modified with multiwalled carbon nanotubes and electropolymerized metal tetra-aminophthalocyanines (poly-MTAPc-MWCNT-BPPGE), where M is Mn, Fe, Ni or Co, were prepared. Electrochemical characterizations showed that faster electron transfer kinetics occurred at the NiPcNP/MWCNT-BPPGE than at the FePcNP/MWCNT-BPPGE surface. SEM and electrochemical characterizations of poly-MTAPc-MWCNT-BPPGE showed that MTAPc had been deposited on the MWCNTBPPGE surface, and that the poly-CoTAPc-MWCNT-BPPGE exhibited the fastest electron transfer kinetics of all the poly-MTAPc-MWCNT-BPPGEs. Using amitrole and asulam as test analytes, electrochemical experiments showed that, amongst the CPEs, the FePcNP-CPE and NiPcNP-CPE displayed the most electrocatalytic behavior towards amitrole and asulam oxidation, respectively, and further experiments were done to obtain the electrochemical parameters associated with these electrodes and the corresponding analytes. Although, the FePcNP/MWCNT- BPPGE displayed electrocatalytic behavior towards amitrole oxidation in comparison with the bare BPPGE, it was less electrocatalytic than the FePcNP-CPE in terms of detection potential. The NiPcNP/MWCNT-BPPGE displayed the same detection potential as the NiPcNP-CPE. The poly-FeTAPc-MWCNT-BPPGE exhibited the most electrocatalytic behavior towards amitrole, of all the electrodes investigated, and the poly-CoTAPc-MWCNT-BPPGE displayed the best electrocatalytic behavior towards asulam, amongst the poly-MTAPc-MWCNT-BPPGEs.
- Full Text:
Environmental water quality management of glyphosate-based herbicides in South Africa
- Authors: Mensah, Paul Kojo
- Date: 2013
- Subjects: Water quality management -- South Africa Water quality management -- Environmental Aspects -- South Africa Herbicides -- Environmental aspects -- South Africa Herbicides -- Toxicology -- South Africa Water -- Glyphosate content -- South Africa Water -- Pollution -- South Africa Water quality -- Measurement -- South Africa Water -- Analysis -- South Africa Freshwater ecology -- South Africa Integrated water development -- South Africa Caridina -- Effect of pollution on -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6023 , http://hdl.handle.net/10962/d1001987
- Description: Although the use of pesticides is necessary to meet the socio-economic needs of many developing countries, especially in Africa, side effects of these bio-active chemicals have contributed to contaminating aquatic and terrestrial ecosystems. Environmental water quality degradation by pesticides interferes with ecosystem health and poses numerous risks to aquatic life. In South Africa, glyphosate-based herbicides are frequently used to control weeds and invading alien plants, but ultimately end up in freshwater ecosystems. However, there are no South African-based environmental water quality management strategies to regulate these bio-active chemicals. Therefore, this study sought to provide a sound scientific background for the environmental water quality management of glyphosate-based herbicides in South Africa, by conducting both laboratory and field investigations. In the laboratory investigations, aquatic ecotoxicological methods were used to evaluate responses of the freshwater aquatic shrimp Caridina nilotica exposed to Roundup® at different biological system scales, and the responses of multiple South African aquatic species exposed to Roundup® through species sensitivity distribution (SSD). In the field investigations, the effect of Kilo Max WSG on the physicochemical and biological conditions of three selected sites in the Swartkops River before and after a spray episode by Working for Water were evaluated through biomonitoring, using the South African Scoring System version 5 (SASS5) as a sampling protocol. Both Roundup® and Kilo Max WSG are glyphosate-based herbicides. All the data were subjected to relevant statistical analyses. Findings of this study revealed that Roundup® elicited responses at different biological system scales in C. nilotica, while SSD estimates were used to derive proposed water quality guidelines for glyphosate-based herbicides in South Africa. The biomonitoring revealed that using glyphosate-based herbicides to control water hyacinth within the Swartkops River had a negligible impact on the physicochemical and biological conditions. Based on these findings, a conceptual framework that can be used for the integrated environmental water quality management of glyphosate-based herbicides in South Africa was developed as part of integrated water resource management (IWRM). The combined data sets contribute to a sound scientific basis for the environmental water quality management of glyphosate-based herbicides in South Africa.
- Full Text:
- Authors: Mensah, Paul Kojo
- Date: 2013
- Subjects: Water quality management -- South Africa Water quality management -- Environmental Aspects -- South Africa Herbicides -- Environmental aspects -- South Africa Herbicides -- Toxicology -- South Africa Water -- Glyphosate content -- South Africa Water -- Pollution -- South Africa Water quality -- Measurement -- South Africa Water -- Analysis -- South Africa Freshwater ecology -- South Africa Integrated water development -- South Africa Caridina -- Effect of pollution on -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6023 , http://hdl.handle.net/10962/d1001987
- Description: Although the use of pesticides is necessary to meet the socio-economic needs of many developing countries, especially in Africa, side effects of these bio-active chemicals have contributed to contaminating aquatic and terrestrial ecosystems. Environmental water quality degradation by pesticides interferes with ecosystem health and poses numerous risks to aquatic life. In South Africa, glyphosate-based herbicides are frequently used to control weeds and invading alien plants, but ultimately end up in freshwater ecosystems. However, there are no South African-based environmental water quality management strategies to regulate these bio-active chemicals. Therefore, this study sought to provide a sound scientific background for the environmental water quality management of glyphosate-based herbicides in South Africa, by conducting both laboratory and field investigations. In the laboratory investigations, aquatic ecotoxicological methods were used to evaluate responses of the freshwater aquatic shrimp Caridina nilotica exposed to Roundup® at different biological system scales, and the responses of multiple South African aquatic species exposed to Roundup® through species sensitivity distribution (SSD). In the field investigations, the effect of Kilo Max WSG on the physicochemical and biological conditions of three selected sites in the Swartkops River before and after a spray episode by Working for Water were evaluated through biomonitoring, using the South African Scoring System version 5 (SASS5) as a sampling protocol. Both Roundup® and Kilo Max WSG are glyphosate-based herbicides. All the data were subjected to relevant statistical analyses. Findings of this study revealed that Roundup® elicited responses at different biological system scales in C. nilotica, while SSD estimates were used to derive proposed water quality guidelines for glyphosate-based herbicides in South Africa. The biomonitoring revealed that using glyphosate-based herbicides to control water hyacinth within the Swartkops River had a negligible impact on the physicochemical and biological conditions. Based on these findings, a conceptual framework that can be used for the integrated environmental water quality management of glyphosate-based herbicides in South Africa was developed as part of integrated water resource management (IWRM). The combined data sets contribute to a sound scientific basis for the environmental water quality management of glyphosate-based herbicides in South Africa.
- Full Text:
Estuarine-dependency and multiple habitat use by dusky kob Argyrosomus Japonicus (Pisces: Sciaenidae)
- Authors: Childs, Amber-Robyn
- Date: 2013
- Subjects: Argyrosomus -- Habitat -- South Africa -- Algoa Bay , Argyrosomus -- Behavior -- South Africa -- Algoa Bay , Argyrosomus -- Migration -- South Africa -- Algoa Bay , Estuarine fishes -- South Africa -- Algoa Bay , Habitat selection -- South Africa -- Algoa Bay , Argyrosomus -- South Africa -- Sundays Estuary (Eastern Cape) , Underwater acoustic telemetry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5386 , http://hdl.handle.net/10962/d1020241
- Description: Dusky kob Argyrosomus japonicus is a wide-ranging estuarine-dependent Sciaenid and an important fishery species throughout most of its distribution. It is one of South Africa’s most valuable coastal fishery species. High levels of juvenile exploitation in estuaries and ineffective management regulations have led to stock collapse, highlighting the need to better understand the spatial and temporal aspects of estuarine-dependency and multiple habitat use. Habitat connectivity is a critical property of estuarine-associated fishes and it therefore follows that knowledge of this link is fundamental in understanding population dynamics and the nursery role of estuarine and/or marine habitats. While dusky kob occur in both estuaries and nearshore coastal zones, limited information on connectivity among these habitats exists. The aim of this study is to assess the role of estuarine nursery habitats in the life cycle of the dusky kob by examining multiple habitat connectivity and determining the drivers associated with estuarine use. A total of 96 dusky kob (237–1280 mm total length) were tagged with acoustic transmitters in both the estuarine and marine environments of Algoa Bay, Eastern Cape, South Africa between May 2008 and September 2010. Their movements were monitored using a network of automated data-logging acoustic receivers deployed in the Sundays Estuary, seven neighbouring estuarine habitats, two commercial harbours and various sites within Algoa Bay. And more...
- Full Text:
- Authors: Childs, Amber-Robyn
- Date: 2013
- Subjects: Argyrosomus -- Habitat -- South Africa -- Algoa Bay , Argyrosomus -- Behavior -- South Africa -- Algoa Bay , Argyrosomus -- Migration -- South Africa -- Algoa Bay , Estuarine fishes -- South Africa -- Algoa Bay , Habitat selection -- South Africa -- Algoa Bay , Argyrosomus -- South Africa -- Sundays Estuary (Eastern Cape) , Underwater acoustic telemetry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5386 , http://hdl.handle.net/10962/d1020241
- Description: Dusky kob Argyrosomus japonicus is a wide-ranging estuarine-dependent Sciaenid and an important fishery species throughout most of its distribution. It is one of South Africa’s most valuable coastal fishery species. High levels of juvenile exploitation in estuaries and ineffective management regulations have led to stock collapse, highlighting the need to better understand the spatial and temporal aspects of estuarine-dependency and multiple habitat use. Habitat connectivity is a critical property of estuarine-associated fishes and it therefore follows that knowledge of this link is fundamental in understanding population dynamics and the nursery role of estuarine and/or marine habitats. While dusky kob occur in both estuaries and nearshore coastal zones, limited information on connectivity among these habitats exists. The aim of this study is to assess the role of estuarine nursery habitats in the life cycle of the dusky kob by examining multiple habitat connectivity and determining the drivers associated with estuarine use. A total of 96 dusky kob (237–1280 mm total length) were tagged with acoustic transmitters in both the estuarine and marine environments of Algoa Bay, Eastern Cape, South Africa between May 2008 and September 2010. Their movements were monitored using a network of automated data-logging acoustic receivers deployed in the Sundays Estuary, seven neighbouring estuarine habitats, two commercial harbours and various sites within Algoa Bay. And more...
- Full Text: