Voltammetric characterization of the self-assembled monolayer (SAM) of octabutylthiophthalocyaninatoiron (II)
- Ozoemena,Kenneth, Nyokong, Tebello
- Authors: Ozoemena,Kenneth , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290419 , vital:56748 , xlink:href="https://doi.org/10.1016/S0013-4686(02)00362-6"
- Description: The fabrication of a self-assembled monolayer (SAM) of 2,3,9,10,16,17,23,24-octa (butylthio)-phthalocyaninatoiron(II) [FePc(SBu)8] on gold electrode is described. The integrity of the SAM, with respect to its ability to block certain Faradaic processes, is interrogated using cyclic voltammetric experiments in aqueous solutions. The experiments show that this SAM provide an excellent blocking capability to the Faradaic processes emanating from gold surface oxidation, underpotential deposition (UPD) of copper and redox chemistry of Fe(NH4)(SO4)2 in HClO4. It is revealed by cyclic voltammetry that an ill-defined reversible couple of the SAM of FePc(SBu)8 can be greatly improved by a simple repetitive cycling of the modified electrode in a DMF solution containing TBAP within a short space of time (ca. 2 min). This ‘activation’ process provides good information concerning the surface coverage and orientation of the monolayer. The reversible redox wave shows a potential shift of about −57 mV per pH in the pH range of 2–9. A preliminary investigation indicates that FePc(SBu)8-SAM modified gold electrode shows electrocatalytic activity toward the oxidation of L-cysteine in acidic medium. The monolayer is stable and easily reproducible. However, due to its susceptibility to destruction via oxidative and reductive desorptions, its potential application as an electrochemical sensor would be much better in acidic and neutral than alkaline environments.
- Full Text:
- Date Issued: 2002
- Authors: Ozoemena,Kenneth , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290419 , vital:56748 , xlink:href="https://doi.org/10.1016/S0013-4686(02)00362-6"
- Description: The fabrication of a self-assembled monolayer (SAM) of 2,3,9,10,16,17,23,24-octa (butylthio)-phthalocyaninatoiron(II) [FePc(SBu)8] on gold electrode is described. The integrity of the SAM, with respect to its ability to block certain Faradaic processes, is interrogated using cyclic voltammetric experiments in aqueous solutions. The experiments show that this SAM provide an excellent blocking capability to the Faradaic processes emanating from gold surface oxidation, underpotential deposition (UPD) of copper and redox chemistry of Fe(NH4)(SO4)2 in HClO4. It is revealed by cyclic voltammetry that an ill-defined reversible couple of the SAM of FePc(SBu)8 can be greatly improved by a simple repetitive cycling of the modified electrode in a DMF solution containing TBAP within a short space of time (ca. 2 min). This ‘activation’ process provides good information concerning the surface coverage and orientation of the monolayer. The reversible redox wave shows a potential shift of about −57 mV per pH in the pH range of 2–9. A preliminary investigation indicates that FePc(SBu)8-SAM modified gold electrode shows electrocatalytic activity toward the oxidation of L-cysteine in acidic medium. The monolayer is stable and easily reproducible. However, due to its susceptibility to destruction via oxidative and reductive desorptions, its potential application as an electrochemical sensor would be much better in acidic and neutral than alkaline environments.
- Full Text:
- Date Issued: 2002
Voltammetric detection of vitamin B1 at carbon paste electrodes and its determination in tablets
- Oni, Joshua, Westbroek, Philippe, Nyokong, Tebello
- Authors: Oni, Joshua , Westbroek, Philippe , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289692 , vital:56663 , xlink:href="https://doi.org/10.1002/1521-4109(200209)14"
- Description: The voltammetric behavior of vitamin B1 in alkaline medium at carbon paste electrode (CPE) is discussed. A method based on cyclic voltammetry for the determination of vitamin B1 at carbon paste electrode modified with manganese phthalocyanine (MnPc-CPE) is presented. In pH 10 buffer, the modified electrode showed catalytic activity towards the oxidation of vitamin B1 by considerably increasing the oxidation current of one of the observed waves compared to the oxidation current obtained at an unmodified electrode. The modified electrode was stable towards the determination of vitamin B1 compared to the unmodified electrode that is completely poisoned after a few scans. A linear relationship between the oxidation current and the concentration of vitamin B1 in solution was observed. The detection limit for vitamin B1 at the modified electrode was of the order of 10−5 mol dm−3. Commercial vitamin B1 tablets were analyzed using the modified electrodes.
- Full Text:
- Date Issued: 2002
- Authors: Oni, Joshua , Westbroek, Philippe , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289692 , vital:56663 , xlink:href="https://doi.org/10.1002/1521-4109(200209)14"
- Description: The voltammetric behavior of vitamin B1 in alkaline medium at carbon paste electrode (CPE) is discussed. A method based on cyclic voltammetry for the determination of vitamin B1 at carbon paste electrode modified with manganese phthalocyanine (MnPc-CPE) is presented. In pH 10 buffer, the modified electrode showed catalytic activity towards the oxidation of vitamin B1 by considerably increasing the oxidation current of one of the observed waves compared to the oxidation current obtained at an unmodified electrode. The modified electrode was stable towards the determination of vitamin B1 compared to the unmodified electrode that is completely poisoned after a few scans. A linear relationship between the oxidation current and the concentration of vitamin B1 in solution was observed. The detection limit for vitamin B1 at the modified electrode was of the order of 10−5 mol dm−3. Commercial vitamin B1 tablets were analyzed using the modified electrodes.
- Full Text:
- Date Issued: 2002
Voltammetric detection of vitamin B1 at carbon paste electrodes and its determination in tablets
- Oni, Joshua, Westbroek, Philippe, Nyokong, Tebello
- Authors: Oni, Joshua , Westbroek, Philippe , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289678 , vital:56662 , xlink:href="https://doi.org/10.1002/1521-4109(200209)14"
- Description: The voltammetric behavior of vitamin B1 in alkaline medium at carbon paste electrode (CPE) is discussed. A method based on cyclic voltammetry for the determination of vitamin B1 at carbon paste electrode modified with manganese phthalocyanine (MnPc-CPE) is presented. In pH 10 buffer, the modified electrode showed catalytic activity towards the oxidation of vitamin B1 by considerably increasing the oxidation current of one of the observed waves compared to the oxidation current obtained at an unmodified electrode. The modified electrode was stable towards the determination of vitamin B1 compared to the unmodified electrode that is completely poisoned after a few scans. A linear relationship between the oxidation current and the concentration of vitamin B1 in solution was observed. The detection limit for vitamin B1 at the modified electrode was of the order of 10−5 mol dm−3. Commercial vitamin B1 tablets were analyzed using the modified electrodes.
- Full Text:
- Date Issued: 2002
- Authors: Oni, Joshua , Westbroek, Philippe , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289678 , vital:56662 , xlink:href="https://doi.org/10.1002/1521-4109(200209)14"
- Description: The voltammetric behavior of vitamin B1 in alkaline medium at carbon paste electrode (CPE) is discussed. A method based on cyclic voltammetry for the determination of vitamin B1 at carbon paste electrode modified with manganese phthalocyanine (MnPc-CPE) is presented. In pH 10 buffer, the modified electrode showed catalytic activity towards the oxidation of vitamin B1 by considerably increasing the oxidation current of one of the observed waves compared to the oxidation current obtained at an unmodified electrode. The modified electrode was stable towards the determination of vitamin B1 compared to the unmodified electrode that is completely poisoned after a few scans. A linear relationship between the oxidation current and the concentration of vitamin B1 in solution was observed. The detection limit for vitamin B1 at the modified electrode was of the order of 10−5 mol dm−3. Commercial vitamin B1 tablets were analyzed using the modified electrodes.
- Full Text:
- Date Issued: 2002
Voluntary associations as schools for democracy? : a case study of the Sibanye Development Project
- Authors: Siwahla, Lindiwe Lillian
- Date: 2002
- Subjects: Sibanye Development Project , Non-governmental organizations , Political participation , Non-governmental organizations--South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2842 , http://hdl.handle.net/10962/d1004778 , Sibanye Development Project , Non-governmental organizations , Political participation , Non-governmental organizations--South Africa
- Description: This is an empirical study of a voluntary association with a view to interrogate the theories of civil society and participation and their practice. These theories came to dominate debate on African politics and democratisation following disappointment with structural approaches to development and democracy. Disenchantment with the state whose role was emphasised by the structural approach led analysts and technocrats to turn their attention to human agency; hence the salience of the idea of popular participation in the public domain, and preoccupation with the idea of strengthening civil society. This trend gained momentum after the 1989 fall of the Berlin Wall and demise of the communist block, and was accompanied by anti-statist sentiments on a global scale. Civil society organisations are seen as schools for democracy and agents of democratic consolidation, and are accordingly expected to perform two major tasks, namely instilling and disseminating a democratic political culture in and among participants and society at large, and promoting good governance. The aim therefore is to take advantage of the supposed intrinsic and utilitarian benefits of participation. As evident in a number of policy documents and legislation, the incumbent South African government embraces the idea of participatory democracy. However, not all analysts share this confidence in the capacity of civil society to perform these tasks. For some analysts public participation does not always have positive intrinsic benefits. Public participation may instead lead to a corrupted political culture deriving from the participants' attempts to survive in a public sphere characterised by manipulation and subtle political control, and it is civil society organisations lacking in organisational strength that are particularly vulnerable. The study revealed that unity between practice and theories of participation and civil society is a complex matter fraught with a number of ambiguities and contradictions. It revealed that though participation in the voluntary association in question does have educative benefits, those benefits do not extend to all the participants. In addition, the quality of that education is contingent upon a number of factors, some internal, others external. The internal and external factors reinforce one another. The internal factors pertain to the organisational dynamics of the voluntary association itself, and the external factors to the nature of the relationship between the voluntary association concerned and public authorities and other civil society organisations. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
- Authors: Siwahla, Lindiwe Lillian
- Date: 2002
- Subjects: Sibanye Development Project , Non-governmental organizations , Political participation , Non-governmental organizations--South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2842 , http://hdl.handle.net/10962/d1004778 , Sibanye Development Project , Non-governmental organizations , Political participation , Non-governmental organizations--South Africa
- Description: This is an empirical study of a voluntary association with a view to interrogate the theories of civil society and participation and their practice. These theories came to dominate debate on African politics and democratisation following disappointment with structural approaches to development and democracy. Disenchantment with the state whose role was emphasised by the structural approach led analysts and technocrats to turn their attention to human agency; hence the salience of the idea of popular participation in the public domain, and preoccupation with the idea of strengthening civil society. This trend gained momentum after the 1989 fall of the Berlin Wall and demise of the communist block, and was accompanied by anti-statist sentiments on a global scale. Civil society organisations are seen as schools for democracy and agents of democratic consolidation, and are accordingly expected to perform two major tasks, namely instilling and disseminating a democratic political culture in and among participants and society at large, and promoting good governance. The aim therefore is to take advantage of the supposed intrinsic and utilitarian benefits of participation. As evident in a number of policy documents and legislation, the incumbent South African government embraces the idea of participatory democracy. However, not all analysts share this confidence in the capacity of civil society to perform these tasks. For some analysts public participation does not always have positive intrinsic benefits. Public participation may instead lead to a corrupted political culture deriving from the participants' attempts to survive in a public sphere characterised by manipulation and subtle political control, and it is civil society organisations lacking in organisational strength that are particularly vulnerable. The study revealed that unity between practice and theories of participation and civil society is a complex matter fraught with a number of ambiguities and contradictions. It revealed that though participation in the voluntary association in question does have educative benefits, those benefits do not extend to all the participants. In addition, the quality of that education is contingent upon a number of factors, some internal, others external. The internal and external factors reinforce one another. The internal factors pertain to the organisational dynamics of the voluntary association itself, and the external factors to the nature of the relationship between the voluntary association concerned and public authorities and other civil society organisations. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
Weaving cloths: Research design in contexts of transformation
- Authors: Lotz-Sisitka, Heila
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184745 , vital:44268 , xlink:href="https://cjee.lakeheadu.ca/article/viewFile/259/136"
- Description: Through storytelling, I apply methodological and epistemological reflexivity to ask questions about the way in which environmental education research is framed in transformational settings. I ask questions about the role of research teachers/supervisors in the “weaving enterprise” or the research process. Do we have the dual task of developing contextually relevant frameworks, and of making sure that these frameworks are not adopted on an “industrial scale”—in other words, as new paradigms which have the potential to narrow research possibilities? The paper concerns itself with a broader question, notably the potentially debilitating effects of mass production of research, or the globalizing of knowledge production. The story I use to raise these, and other questions for consideration by teachers/supervisors of research is a research workers story (my own), constructed between 1992 and 1996, in a context of rapid socio-political and educational transformation in South Africa (Lotz, 1996). In addition to the above, the paper opens a debate about reflexivity as research methodological rigour.
- Full Text:
- Date Issued: 2002
- Authors: Lotz-Sisitka, Heila
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184745 , vital:44268 , xlink:href="https://cjee.lakeheadu.ca/article/viewFile/259/136"
- Description: Through storytelling, I apply methodological and epistemological reflexivity to ask questions about the way in which environmental education research is framed in transformational settings. I ask questions about the role of research teachers/supervisors in the “weaving enterprise” or the research process. Do we have the dual task of developing contextually relevant frameworks, and of making sure that these frameworks are not adopted on an “industrial scale”—in other words, as new paradigms which have the potential to narrow research possibilities? The paper concerns itself with a broader question, notably the potentially debilitating effects of mass production of research, or the globalizing of knowledge production. The story I use to raise these, and other questions for consideration by teachers/supervisors of research is a research workers story (my own), constructed between 1992 and 1996, in a context of rapid socio-political and educational transformation in South Africa (Lotz, 1996). In addition to the above, the paper opens a debate about reflexivity as research methodological rigour.
- Full Text:
- Date Issued: 2002
Women in paid domestic work and their children : an exploratory study
- Authors: Maqungu, Nomzamo Florence
- Date: 2002 , 2013-05-16
- Subjects: Household employees -- South Africa , Women, Black -- Employment -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:711 , http://hdl.handle.net/10962/d1007476 , Household employees -- South Africa , Women, Black -- Employment -- South Africa
- Description: This study explores the views and experiences of domestic workers with regard to service conditions of their occupation, the arrangements they make for the care of their own children and the frequency of contact they make with their children. Data was obtained through use of pre - coded self administered questionnaires which were employed to 50 domestic women who are working in East London and its suburbs and have children under the age of 16 years. Semi-structured interviews were tape recorded and transcribed and the analysis process looked at general trends where qualitative data was obtained. Quantitative data was tabulated in frequency tables and interpreted by means of graphs. The study is pioneering efforts in the Eastern Cape and South Africa in general as well as setting a way forward for further exploration of this subject. It is hoped that the study will make a worthwhile contribution and bring upfront valuable information that could be used when addressing issues of domestic workers. The study also indirectly challenges those professions and disciplines who have been advocating on behalf of domestic workers to mobilize these workers towards taking part in the uplifting of their standards and to fInish up the good work they had already started until their aims have been achieved. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
- Authors: Maqungu, Nomzamo Florence
- Date: 2002 , 2013-05-16
- Subjects: Household employees -- South Africa , Women, Black -- Employment -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:711 , http://hdl.handle.net/10962/d1007476 , Household employees -- South Africa , Women, Black -- Employment -- South Africa
- Description: This study explores the views and experiences of domestic workers with regard to service conditions of their occupation, the arrangements they make for the care of their own children and the frequency of contact they make with their children. Data was obtained through use of pre - coded self administered questionnaires which were employed to 50 domestic women who are working in East London and its suburbs and have children under the age of 16 years. Semi-structured interviews were tape recorded and transcribed and the analysis process looked at general trends where qualitative data was obtained. Quantitative data was tabulated in frequency tables and interpreted by means of graphs. The study is pioneering efforts in the Eastern Cape and South Africa in general as well as setting a way forward for further exploration of this subject. It is hoped that the study will make a worthwhile contribution and bring upfront valuable information that could be used when addressing issues of domestic workers. The study also indirectly challenges those professions and disciplines who have been advocating on behalf of domestic workers to mobilize these workers towards taking part in the uplifting of their standards and to fInish up the good work they had already started until their aims have been achieved. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
Workplace Reorganisation Course
- DITSELA
- Authors: DITSELA
- Date: 2002
- Subjects: Development Institute for Training,Support and Education for Labour (DITSELA)
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/175688 , vital:42606
- Description: This booklet is about the way in which work is being restructured in the workplaces of South Africa. It is the first in a series of booklets dealing with various restructuring issues faced by workers. There are major changes being made in the workplace that impact on the lives of workers. For workers, restructuring brings changes to the way that their workplace is organised and this will impact on their working lives. These changes could hold threats or opportunities for workers. This first book will explain what is meant by restructuring and look at why many companies in South Africa are considering restructuring. It will also look at some trade union strategies around restructuring and some suggestions for negotiating restructuring.
- Full Text:
- Date Issued: 2002
- Authors: DITSELA
- Date: 2002
- Subjects: Development Institute for Training,Support and Education for Labour (DITSELA)
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/175688 , vital:42606
- Description: This booklet is about the way in which work is being restructured in the workplaces of South Africa. It is the first in a series of booklets dealing with various restructuring issues faced by workers. There are major changes being made in the workplace that impact on the lives of workers. For workers, restructuring brings changes to the way that their workplace is organised and this will impact on their working lives. These changes could hold threats or opportunities for workers. This first book will explain what is meant by restructuring and look at why many companies in South Africa are considering restructuring. It will also look at some trade union strategies around restructuring and some suggestions for negotiating restructuring.
- Full Text:
- Date Issued: 2002
Workshop theatre in post-apartheid South Africa : a case study
- Authors: Copteros, Athina
- Date: 2002
- Subjects: Theater -- South Africa , Theater -- Political aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2156 , http://hdl.handle.net/10962/d1007477
- Description: This is a qualitative study exploring the use of workshop theatre in post-apartheid South Africa, with the objective of making a contribution to the knowledge-base regarding its use in current times. Workshop theatre is changing in response to a new socio-political reality and emerging trends in theatre practice. The case study, of developing a play on Oystercatchers with a Grahamstown group of artists, revealed the difficulties and challenges of using workshop theatre in this dynamic context. Data collection included a focus group, observation, reflective discussion and in-depth interviews that were analysed in relation to available literature on workshop theatre in apartheid and post-apartheid South Africa. It is proposed that workshop theatre has continued relevance in post -apartheid South Africa. The process of creating workshop theatre with diverse artists has great potential to transform relationships, address issues of personal identity and to provide an underlying purpose to a workshop theatre -making context.
- Full Text:
- Date Issued: 2002
- Authors: Copteros, Athina
- Date: 2002
- Subjects: Theater -- South Africa , Theater -- Political aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2156 , http://hdl.handle.net/10962/d1007477
- Description: This is a qualitative study exploring the use of workshop theatre in post-apartheid South Africa, with the objective of making a contribution to the knowledge-base regarding its use in current times. Workshop theatre is changing in response to a new socio-political reality and emerging trends in theatre practice. The case study, of developing a play on Oystercatchers with a Grahamstown group of artists, revealed the difficulties and challenges of using workshop theatre in this dynamic context. Data collection included a focus group, observation, reflective discussion and in-depth interviews that were analysed in relation to available literature on workshop theatre in apartheid and post-apartheid South Africa. It is proposed that workshop theatre has continued relevance in post -apartheid South Africa. The process of creating workshop theatre with diverse artists has great potential to transform relationships, address issues of personal identity and to provide an underlying purpose to a workshop theatre -making context.
- Full Text:
- Date Issued: 2002