Information and communication technology driven teaching and learning opportunities in support of environmental education processes: a case of the eno-environment online programme at Treverton Preparatory School, South Africa
- Authors: Snow, Janet P
- Date: 2008
- Subjects: Treverton School (Natal, South Africa) , Environmental education -- South Africa -- Case studies , Sustainable development -- South Africa -- Case studies , Computer-assisted instruction -- South Africa -- Case studies , Education, Preschool -- Computer assisted instruction -- South Africa -- Case studies , Education, Preschool -- South Africa -- Case studies , Early childhood education -- South Africa -- Case studies , Educational technology -- South Africa -- Case studies , Ethnoscience -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1575 , http://hdl.handle.net/10962/d1003457 , Treverton School (Natal, South Africa) , Environmental education -- South Africa -- Case studies , Sustainable development -- South Africa -- Case studies , Computer-assisted instruction -- South Africa -- Case studies , Education, Preschool -- Computer assisted instruction -- South Africa -- Case studies , Education, Preschool -- South Africa -- Case studies , Early childhood education -- South Africa -- Case studies , Educational technology -- South Africa -- Case studies , Ethnoscience -- Study and teaching -- South Africa
- Description: This research looks at a global virtual web-based programme for environmental awareness and education for sustainable development (ENO-Environment Online). It is a case study of Treverton Preparatory school in South Africa, one of several schools where the programme is implemented. One of the themes within the programme (“This is our culture”) is highlighted. A mixed method, interpretive case study methodology is used. Research methods include two focus group interviews with a selected group of learners, observations of four computer-based lessons and one practical session, document analysis of the three forms of learners’ submissions (‘blog’ site submission, presentation of material and ‘chat’ session), and two interviews conducted with the Treverton form teacher and ENO programme co-ordinator. The research views the Treverton ENO activities in relation to: academic rigour in Information and Communication Technology (ICT) use, the teacher’s role in ICT pedagogy, and active learning in ICT applications. As the theme is culturally based with a global perspective, the research also considers these activities from the perspectives of education for cultural knowledge (multicultural education) and in terms of mobilising indigenous knowledge and global education. These perspectives on the ENO activities are analysed in relation to dimensions of teaching and learning guidelines pertinent to Education for Sustainable Development in a southern African context. The research shows that the ENO theme supported a variety of learning contexts, a sense of community, modelling of behaviours and actions, debate, sharing of information and improved communication skills. Learners were exposed to cultural diversity, contradictory cultural values, cultural and global inclusivity. Knowledge of social cultural practices and indigenous knowledge was shared. Academic rigour in the ENO theme was noted with reflection being the predominant activity. Based on these key findings, recommendations to the ENO programme, schools and teachers have been made. These include: exploring possibilities for increasing focus on sustainable development actions, improving access to relevant information, encouraging critical debate and critical engagement with cultural diversity.
- Full Text:
- Date Issued: 2008
- Authors: Snow, Janet P
- Date: 2008
- Subjects: Treverton School (Natal, South Africa) , Environmental education -- South Africa -- Case studies , Sustainable development -- South Africa -- Case studies , Computer-assisted instruction -- South Africa -- Case studies , Education, Preschool -- Computer assisted instruction -- South Africa -- Case studies , Education, Preschool -- South Africa -- Case studies , Early childhood education -- South Africa -- Case studies , Educational technology -- South Africa -- Case studies , Ethnoscience -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1575 , http://hdl.handle.net/10962/d1003457 , Treverton School (Natal, South Africa) , Environmental education -- South Africa -- Case studies , Sustainable development -- South Africa -- Case studies , Computer-assisted instruction -- South Africa -- Case studies , Education, Preschool -- Computer assisted instruction -- South Africa -- Case studies , Education, Preschool -- South Africa -- Case studies , Early childhood education -- South Africa -- Case studies , Educational technology -- South Africa -- Case studies , Ethnoscience -- Study and teaching -- South Africa
- Description: This research looks at a global virtual web-based programme for environmental awareness and education for sustainable development (ENO-Environment Online). It is a case study of Treverton Preparatory school in South Africa, one of several schools where the programme is implemented. One of the themes within the programme (“This is our culture”) is highlighted. A mixed method, interpretive case study methodology is used. Research methods include two focus group interviews with a selected group of learners, observations of four computer-based lessons and one practical session, document analysis of the three forms of learners’ submissions (‘blog’ site submission, presentation of material and ‘chat’ session), and two interviews conducted with the Treverton form teacher and ENO programme co-ordinator. The research views the Treverton ENO activities in relation to: academic rigour in Information and Communication Technology (ICT) use, the teacher’s role in ICT pedagogy, and active learning in ICT applications. As the theme is culturally based with a global perspective, the research also considers these activities from the perspectives of education for cultural knowledge (multicultural education) and in terms of mobilising indigenous knowledge and global education. These perspectives on the ENO activities are analysed in relation to dimensions of teaching and learning guidelines pertinent to Education for Sustainable Development in a southern African context. The research shows that the ENO theme supported a variety of learning contexts, a sense of community, modelling of behaviours and actions, debate, sharing of information and improved communication skills. Learners were exposed to cultural diversity, contradictory cultural values, cultural and global inclusivity. Knowledge of social cultural practices and indigenous knowledge was shared. Academic rigour in the ENO theme was noted with reflection being the predominant activity. Based on these key findings, recommendations to the ENO programme, schools and teachers have been made. These include: exploring possibilities for increasing focus on sustainable development actions, improving access to relevant information, encouraging critical debate and critical engagement with cultural diversity.
- Full Text:
- Date Issued: 2008
A critique of dispute resolution in the public service
- Authors: Smith, Boy Siphiwo
- Date: 2008
- Subjects: Dispute resolution (Law) -- South Africa , Civil service -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10234 , http://hdl.handle.net/10948/754 , Dispute resolution (Law) -- South Africa , Civil service -- South Africa
- Description: Effective, efficient and expeditious resolution of labour disputes plays a crucial role in terms of the realization of one of the primary objectives of the Labour Relations Act (hereinafter referred to as “the Act”) which is the achievement of labour peace. Although there is no proper definition of a dispute offered by the Act, there are several elements raised by authors within the labour relations and labour law fields which constitute a dispute. Two types of disputes are discussed, namely disputes of right (emanating from entitlement) and disputes of interest (based on demands not provided for, and these are also known as disputes based on matters of mutual interests). Labour relations in South Africa has a history that is tarnished by segregation and dualism, where there was a system of labour relations and labour statutes for all races (except for Africans). The first statute dealing somewhat comprehensive with labour disputes, the Industrial Conciliation Act, did not apply to Africans. This situation (exclusion of Africans) prevailed until the early 1980’s. Therefore, although the apartheid system was legislated in 1948, its segregation practices based on race existed long before 1948 and also extended to the workplaces. The turning point in the labour relations arena in South Africa was the appointment of the Wiehahn Commission. As a result of the recommendations by this Commission, African Workers were for the first time included in labour legislation. So, of great interest is the fact that African Workers attained labour rights before the demise of the apartheid system. The birth of the Act with its dispute resolution fora like the Commission for Conciliation, Mediation and Arbitration (hereinafter referred to as “the CCMA”), Bargaining Councils, Labour Court and the Labour Appeal Court, revolutionized dispute resolution in the country. However, there are some challenges that have emerged even within the new system. Prior to 1993, labour relations in the public service, simply just did not exist. This was mainly due to the fact that the public service was excluded from mainstream legal framework governing labour relations. The State was very much in control of what was happening with regards to employment relations in the public service. There were some structures developed for engagement with the State like the Public Service Commission (PSC) which was politicized to push the agenda of apartheid, Public Servants Association (PSA) for White Public Servants, Public Service Union (PSU) for Indian Public Servants and Public Service League for Coloured Public Servants. There was no structure established for African Public Servants though. Nevertheless, these established structures were useless. One of the recommendations of the Wiehahn Commission was the inclusion of public servants within the mainstream labour relations framework and this was never pursued by the then government. It took the wave of strikes in the early 1990’s for the Act to be extended to the public service. Even with the inclusion of public service within the scope of the Act, there are still challenges pertinent to the public service. Central to these challenges is the problem of fragmentation in terms of approach regarding dispute resolution and the fact that there are too many pieces of legislation dealing with dispute resolution. This situation has also resulted in a jurisdictional debacle within the public service. Also, there is a huge challenge in terms of dealing with abscondments / desertion within the public service. In terms of the way forward, there is an initiative to streamline the public service. In this regard, there is a Draft Single Public Service Bill and also the Public Service Amendment Bill.
- Full Text:
- Date Issued: 2008
- Authors: Smith, Boy Siphiwo
- Date: 2008
- Subjects: Dispute resolution (Law) -- South Africa , Civil service -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10234 , http://hdl.handle.net/10948/754 , Dispute resolution (Law) -- South Africa , Civil service -- South Africa
- Description: Effective, efficient and expeditious resolution of labour disputes plays a crucial role in terms of the realization of one of the primary objectives of the Labour Relations Act (hereinafter referred to as “the Act”) which is the achievement of labour peace. Although there is no proper definition of a dispute offered by the Act, there are several elements raised by authors within the labour relations and labour law fields which constitute a dispute. Two types of disputes are discussed, namely disputes of right (emanating from entitlement) and disputes of interest (based on demands not provided for, and these are also known as disputes based on matters of mutual interests). Labour relations in South Africa has a history that is tarnished by segregation and dualism, where there was a system of labour relations and labour statutes for all races (except for Africans). The first statute dealing somewhat comprehensive with labour disputes, the Industrial Conciliation Act, did not apply to Africans. This situation (exclusion of Africans) prevailed until the early 1980’s. Therefore, although the apartheid system was legislated in 1948, its segregation practices based on race existed long before 1948 and also extended to the workplaces. The turning point in the labour relations arena in South Africa was the appointment of the Wiehahn Commission. As a result of the recommendations by this Commission, African Workers were for the first time included in labour legislation. So, of great interest is the fact that African Workers attained labour rights before the demise of the apartheid system. The birth of the Act with its dispute resolution fora like the Commission for Conciliation, Mediation and Arbitration (hereinafter referred to as “the CCMA”), Bargaining Councils, Labour Court and the Labour Appeal Court, revolutionized dispute resolution in the country. However, there are some challenges that have emerged even within the new system. Prior to 1993, labour relations in the public service, simply just did not exist. This was mainly due to the fact that the public service was excluded from mainstream legal framework governing labour relations. The State was very much in control of what was happening with regards to employment relations in the public service. There were some structures developed for engagement with the State like the Public Service Commission (PSC) which was politicized to push the agenda of apartheid, Public Servants Association (PSA) for White Public Servants, Public Service Union (PSU) for Indian Public Servants and Public Service League for Coloured Public Servants. There was no structure established for African Public Servants though. Nevertheless, these established structures were useless. One of the recommendations of the Wiehahn Commission was the inclusion of public servants within the mainstream labour relations framework and this was never pursued by the then government. It took the wave of strikes in the early 1990’s for the Act to be extended to the public service. Even with the inclusion of public service within the scope of the Act, there are still challenges pertinent to the public service. Central to these challenges is the problem of fragmentation in terms of approach regarding dispute resolution and the fact that there are too many pieces of legislation dealing with dispute resolution. This situation has also resulted in a jurisdictional debacle within the public service. Also, there is a huge challenge in terms of dealing with abscondments / desertion within the public service. In terms of the way forward, there is an initiative to streamline the public service. In this regard, there is a Draft Single Public Service Bill and also the Public Service Amendment Bill.
- Full Text:
- Date Issued: 2008
Re-evaluating the law of vicarious liability in South Africa
- Authors: Small, Jonathan Noel
- Date: 2008
- Subjects: Independent contractors -- South Africa Law -- South Africa Torts -- South Africa Courts -- South Africa Jurisdiction -- South Africa International law -- South Africa Roman law Roman-Dutch law
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3704 , http://hdl.handle.net/10962/d1004771
- Description: This thesis is an analysis of the law of vicarious liability and its application within the legal framework of delict in South Africa. A brief overview of the historical development of this branch of law is given, with reference to the influences of Roman, Roman-Dutch and English law. That is followed by an exposition of the 'modem' interpretation of vicarious liability as applied in South African courts, highlighting apparent inconsistencies and the need for reform in what has become a persistently controversial area of law. Specific attention is paid to the so-called 'course and scope enquiry' and to the enduring difficulties associated with attributing liability to employers for the deliberate wrongful conduct of their employees. It is argued that the courts have yet to reach consensus on a general principle capable of being applied to the facts of so-called 'deviation cases', and that consequently the legal divergence on these matters gives rise to uncertainty and concern. It is submitted that the way in which the traditional test for vicarious liability is currently applied fails to give true effect to the policy considerations upon which this branch of law is founded. By way of comparison with the South African position, a detailed account of the law of vicarious liability in comparable foreign jurisdictions is given, with emphasis placed on recent developments in England and the British Commonwealth. The study then moves to an analysis of the various policy considerations behind vicarious liability, with particular attention being paid to the role of risk-related liability and the role of risk-assumption in the 'course and scope' enquiry. A comparative analysis follows, highlighting differences between the approaches of the foreign jurisdictions and that taken by the South African courts. The work concludes with a proposal that the South African courts should broaden the scope of vicarious liability and opt for a model similar to that which has recently been adopted in Canada.
- Full Text:
- Date Issued: 2008
- Authors: Small, Jonathan Noel
- Date: 2008
- Subjects: Independent contractors -- South Africa Law -- South Africa Torts -- South Africa Courts -- South Africa Jurisdiction -- South Africa International law -- South Africa Roman law Roman-Dutch law
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3704 , http://hdl.handle.net/10962/d1004771
- Description: This thesis is an analysis of the law of vicarious liability and its application within the legal framework of delict in South Africa. A brief overview of the historical development of this branch of law is given, with reference to the influences of Roman, Roman-Dutch and English law. That is followed by an exposition of the 'modem' interpretation of vicarious liability as applied in South African courts, highlighting apparent inconsistencies and the need for reform in what has become a persistently controversial area of law. Specific attention is paid to the so-called 'course and scope enquiry' and to the enduring difficulties associated with attributing liability to employers for the deliberate wrongful conduct of their employees. It is argued that the courts have yet to reach consensus on a general principle capable of being applied to the facts of so-called 'deviation cases', and that consequently the legal divergence on these matters gives rise to uncertainty and concern. It is submitted that the way in which the traditional test for vicarious liability is currently applied fails to give true effect to the policy considerations upon which this branch of law is founded. By way of comparison with the South African position, a detailed account of the law of vicarious liability in comparable foreign jurisdictions is given, with emphasis placed on recent developments in England and the British Commonwealth. The study then moves to an analysis of the various policy considerations behind vicarious liability, with particular attention being paid to the role of risk-related liability and the role of risk-assumption in the 'course and scope' enquiry. A comparative analysis follows, highlighting differences between the approaches of the foreign jurisdictions and that taken by the South African courts. The work concludes with a proposal that the South African courts should broaden the scope of vicarious liability and opt for a model similar to that which has recently been adopted in Canada.
- Full Text:
- Date Issued: 2008
Novel camphor derivatives as potential asymmetric alkylation auxiliaries
- Authors: Skiti-Mama, Neliswa
- Date: 2008
- Subjects: Alkylation , Chemistry, Organic
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10372 , http://hdl.handle.net/10948/1077 , Alkylation , Chemistry, Organic
- Description: The investigation has been focussed on the synthesis and characterisation of camphor-derived chiral auxiliaries that incorporate two camphor skeletons and an evaluation of their stereodirecting potential in ester α-benzylation reactions. Two regioisomeric camphorquinone-derived monoketals were synthesised and identified by 1D- and 2D-NMR, and X-ray crystallography. The stereo-directing potential of the alcohols that resulted from reduction of these ketones as chiral auxiliaries in the alkylation of carboxylate ester derivatives has been studied. The diastereoselectivities shown by NMR spectroscopy range from 14- 30 % d.e. for (1R,2 S, 3R) -2 ,2-[ (1R, 2 S, 3R) -bornane-2,3-dioxy] - bornan-3-ol and 68-74 % d.e. for (1R, 2S ,3R) -3 ,3-[ (1R, 2S ,3R) - bornane-2, 3 -dioxy]bornan-2-ol with selectivities that correlate with the size of the alkyl group in the ester moiety. Trapping of the enolates generated from (1R, 2S ,3R)-2, 2 -[(1R,2 S, 3R) -bornane- 2,3-dioxy]bornan-3-yl propanoate afforded both E- and Z-silyl ketene acetal derivatives in the ratio of 64:36 confirming the formation of both possible enolate structures during enolization. Chiral auxiliaries containing a hemiaminal ether blocking group as well as two chiral alcohols containing monothio-ketal blocking groups have also been synthesised. α-Benzylation of their corresponding propanoate esters afforded the alkylated product with disappointingly low diastereos electivities. Asymmetric reduction of α-keto esters attached to (1R, 2 S, 3R) - 2,2- [ (1R,2 S, 3R) -bornane-2, 3 -dioxy]bornan-3-ol and (1R, 2S ,3R) - 3,3- [ (1R,2 S, 3R) -bornane-2, 3 -dioxy]bornan-2-ol with metal hydrides proceeded with selectivities of up to 30 % d.e. Modelling of the keto ester derivatives at DFT levels provided useful insights into possible conformations adopted by the two α-keto esters and hence the preferred face of attack by metal hydride during reduction.
- Full Text:
- Date Issued: 2008
- Authors: Skiti-Mama, Neliswa
- Date: 2008
- Subjects: Alkylation , Chemistry, Organic
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10372 , http://hdl.handle.net/10948/1077 , Alkylation , Chemistry, Organic
- Description: The investigation has been focussed on the synthesis and characterisation of camphor-derived chiral auxiliaries that incorporate two camphor skeletons and an evaluation of their stereodirecting potential in ester α-benzylation reactions. Two regioisomeric camphorquinone-derived monoketals were synthesised and identified by 1D- and 2D-NMR, and X-ray crystallography. The stereo-directing potential of the alcohols that resulted from reduction of these ketones as chiral auxiliaries in the alkylation of carboxylate ester derivatives has been studied. The diastereoselectivities shown by NMR spectroscopy range from 14- 30 % d.e. for (1R,2 S, 3R) -2 ,2-[ (1R, 2 S, 3R) -bornane-2,3-dioxy] - bornan-3-ol and 68-74 % d.e. for (1R, 2S ,3R) -3 ,3-[ (1R, 2S ,3R) - bornane-2, 3 -dioxy]bornan-2-ol with selectivities that correlate with the size of the alkyl group in the ester moiety. Trapping of the enolates generated from (1R, 2S ,3R)-2, 2 -[(1R,2 S, 3R) -bornane- 2,3-dioxy]bornan-3-yl propanoate afforded both E- and Z-silyl ketene acetal derivatives in the ratio of 64:36 confirming the formation of both possible enolate structures during enolization. Chiral auxiliaries containing a hemiaminal ether blocking group as well as two chiral alcohols containing monothio-ketal blocking groups have also been synthesised. α-Benzylation of their corresponding propanoate esters afforded the alkylated product with disappointingly low diastereos electivities. Asymmetric reduction of α-keto esters attached to (1R, 2 S, 3R) - 2,2- [ (1R,2 S, 3R) -bornane-2, 3 -dioxy]bornan-3-ol and (1R, 2S ,3R) - 3,3- [ (1R,2 S, 3R) -bornane-2, 3 -dioxy]bornan-2-ol with metal hydrides proceeded with selectivities of up to 30 % d.e. Modelling of the keto ester derivatives at DFT levels provided useful insights into possible conformations adopted by the two α-keto esters and hence the preferred face of attack by metal hydride during reduction.
- Full Text:
- Date Issued: 2008
Gender and development: a study of the impact of selected cooperatives in the Eastern Cape Province
- Sithole, Noluthando Victoria
- Authors: Sithole, Noluthando Victoria
- Date: 2008
- Subjects: Cooperative societies -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Women in development -- South Africa -- Eastern Cape , Women in cooperative societies -- South Africa -- Eastern Cape , Poverty -- South Africa -- Easttern Cape , Gender identity -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M SW
- Identifier: vital:11752 , http://hdl.handle.net/10353/194 , Cooperative societies -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Women in development -- South Africa -- Eastern Cape , Women in cooperative societies -- South Africa -- Eastern Cape , Poverty -- South Africa -- Easttern Cape , Gender identity -- South Africa -- Eastern Cape
- Description: In 1994 South Africa took a new direction towards democratic governance. This led to a change of government principles and approaches in leading the country. The people became the centre of the country’s development, resulting in the adoption of people-centred development and people-driven strategies. A special focus highlighted women as in the category which had endured poverty the most in South Africa. The South African government, through its various departments, has a responsibility to improve the lives of South Africans, and the Eastern Cape Provincial Department of Social Development is one of the departments which has committed itself towards changing the lives of women in the community. As a strategy to implement community development, the Provincial Department of Social Development is funding women cooperative programmes. Women cooperatives are a relatively new endeavour to address poverty within the democratic South Africa. The study supports the notion and attempts to show the impact that women have on community development. The researcher began studying the trends and realized that the funds allocated and the funding process of community development programmes by Provincial Department of Social Development is not working towards empowering communities. A purposive sampling method was used to select two women cooperative programmes in the Chris Hani District Municipality to explore the role of women in community development in the current context of democracy and social welfare transformation in South Africa; to explore the impact of gender through women cooperatives on community development and to explore strategies for the empowerment of women through community development intervention. The design of the study is qualitative, exploratory and descriptive in nature. The study also adapted evaluation and gender analysis methods to verify the effectiveness of women programmes. The study recommends that women be empowered with skills, knowledge, resources and opportunities to enable them to be more effective in community development.
- Full Text:
- Date Issued: 2008
- Authors: Sithole, Noluthando Victoria
- Date: 2008
- Subjects: Cooperative societies -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Women in development -- South Africa -- Eastern Cape , Women in cooperative societies -- South Africa -- Eastern Cape , Poverty -- South Africa -- Easttern Cape , Gender identity -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M SW
- Identifier: vital:11752 , http://hdl.handle.net/10353/194 , Cooperative societies -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Women in development -- South Africa -- Eastern Cape , Women in cooperative societies -- South Africa -- Eastern Cape , Poverty -- South Africa -- Easttern Cape , Gender identity -- South Africa -- Eastern Cape
- Description: In 1994 South Africa took a new direction towards democratic governance. This led to a change of government principles and approaches in leading the country. The people became the centre of the country’s development, resulting in the adoption of people-centred development and people-driven strategies. A special focus highlighted women as in the category which had endured poverty the most in South Africa. The South African government, through its various departments, has a responsibility to improve the lives of South Africans, and the Eastern Cape Provincial Department of Social Development is one of the departments which has committed itself towards changing the lives of women in the community. As a strategy to implement community development, the Provincial Department of Social Development is funding women cooperative programmes. Women cooperatives are a relatively new endeavour to address poverty within the democratic South Africa. The study supports the notion and attempts to show the impact that women have on community development. The researcher began studying the trends and realized that the funds allocated and the funding process of community development programmes by Provincial Department of Social Development is not working towards empowering communities. A purposive sampling method was used to select two women cooperative programmes in the Chris Hani District Municipality to explore the role of women in community development in the current context of democracy and social welfare transformation in South Africa; to explore the impact of gender through women cooperatives on community development and to explore strategies for the empowerment of women through community development intervention. The design of the study is qualitative, exploratory and descriptive in nature. The study also adapted evaluation and gender analysis methods to verify the effectiveness of women programmes. The study recommends that women be empowered with skills, knowledge, resources and opportunities to enable them to be more effective in community development.
- Full Text:
- Date Issued: 2008
Electrocatalytic detection of amitrole on the multi-walled carbon nanotube–iron (II) tetra-aminophthalocyanine platform
- Siswana, Msimelelo P, Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Siswana, Msimelelo P , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265924 , vital:53901 , xlink:href="https://doi.org/10.3390/s8085096"
- Description: It is shown that iron(II) tetra-aminophthalocyanine complex electropolymerized onto a multi-walled carbon nanotube-modified basal plane pyrolytic graphite electrode greatly enhanced the electrocatalytic detetion of amitrole (a toxic herbicide), resulting in a very low detection limit (0.5 nM) and excellent sensitivity of 8.80±0.44 μA/nM, compared to any known work reported so far. The electrocatalytic detection of amitrole at this electrode occurred at less positive potential (~0.3 V vs Ag|ACl) and also revealed a typical coupled chemical reaction. The mechanism for this response is proposed. The electrode gave satisfactory selectivity to amitrole in the presence of other potential interfering pesticides in aqueous solutions.
- Full Text:
- Date Issued: 2008
- Authors: Siswana, Msimelelo P , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265924 , vital:53901 , xlink:href="https://doi.org/10.3390/s8085096"
- Description: It is shown that iron(II) tetra-aminophthalocyanine complex electropolymerized onto a multi-walled carbon nanotube-modified basal plane pyrolytic graphite electrode greatly enhanced the electrocatalytic detetion of amitrole (a toxic herbicide), resulting in a very low detection limit (0.5 nM) and excellent sensitivity of 8.80±0.44 μA/nM, compared to any known work reported so far. The electrocatalytic detection of amitrole at this electrode occurred at less positive potential (~0.3 V vs Ag|ACl) and also revealed a typical coupled chemical reaction. The mechanism for this response is proposed. The electrode gave satisfactory selectivity to amitrole in the presence of other potential interfering pesticides in aqueous solutions.
- Full Text:
- Date Issued: 2008
Dungamanzi/stirring waters: Tsonga and Shangaan art from southern Africa, Nessa Leibhammer (Ed.): book reviews
- Authors: Simbao, Ruth K
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147358 , vital:38629 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31053
- Description: A woman known as Nkoma We Lwandle (Cow of the Ocean) and a man, Dunga Manzi (Stirring Waters), are remembered as the first Tsonga diviners. Trained by Nzunzu - a powerful water serpent - they were pulled into a lake for a few months and later emerged as influential healers. Such stories (like the one relayed by Dederen of a young girl, Nsatimuni, who also temporarily disappeared into a lake) represent 'death' and 'rebirth', reflecting Arnold van Gennep's (1909) well-known schema of rites de passage: séparation, marge, and agrégation. Separated from daily life, these characters sink into another world where people breathe in water like a foetus in the liquid depths of a womb, evoking impending new birth (p. 171).
- Full Text:
- Date Issued: 2008
- Authors: Simbao, Ruth K
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147358 , vital:38629 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31053
- Description: A woman known as Nkoma We Lwandle (Cow of the Ocean) and a man, Dunga Manzi (Stirring Waters), are remembered as the first Tsonga diviners. Trained by Nzunzu - a powerful water serpent - they were pulled into a lake for a few months and later emerged as influential healers. Such stories (like the one relayed by Dederen of a young girl, Nsatimuni, who also temporarily disappeared into a lake) represent 'death' and 'rebirth', reflecting Arnold van Gennep's (1909) well-known schema of rites de passage: séparation, marge, and agrégation. Separated from daily life, these characters sink into another world where people breathe in water like a foetus in the liquid depths of a womb, evoking impending new birth (p. 171).
- Full Text:
- Date Issued: 2008
An assessment of the role of ward committees in public participation with reference to the Kouga local municipality
- Authors: Simanga, Linda
- Date: 2008
- Subjects: Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:8230 , http://hdl.handle.net/10948/858 , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape
- Description: The Republic of South Africa became a democratic country in 1994 after the historic democratic elections. This year also marks the year when South Africa’s first democratic parliament was convened. The Constitution of the Republic of South Africa Act (no. 108 of 1996) was enacted in 1996. This Constitution provides for the creation of the three spheres of government, namely, the national level, which deals with matters of national importance, the provincial level, which deals with matters of provincial importance, and the local level which deals with matters of local importance. Section 152(1) (e) of the above-mentioned Constitution stipulates that the object of local government, amongst others, is to ensure the involvement of communities and community organizations in the matters of local governance. Section 73 of the Municipal Structures Act (no.117 of 1998) also requires municipalities to establish ward committees in a manner that seeks to enhance participatory democracy at the local level. Municipalities are established in terms of Section 12 of the Municipal Structures Act (no. 117 of 1998), wherein Members of Executive Councils (MEC’s) may, by notice in the Provincial Gazette, establish a municipality in each municipal area which the Demarcation Board demarcates in the province in terms of the Municipal Demarcation Act (no. 27 of 1998). Sections 7 and 8 of the Municipal Structures Act (no. 117 of 1998) further stipulate the categories of municipalities as A, B and C. Category A is a metropolitan municipality with wards and ward committees. B is a local municipality characterized by the existence of wards and ward committees to enhance public participation. C is a district municipality, whose responsibility is to support local municipalities within its area of jurisdiction so that they are self sufficient and can manage their own affairs. This study focuses on the Kouga Local Municipality, which is a Category B Municipality as promulgated by the then MEC for Housing, Local Government and Traditional Affairs, Honourable MEC S. Kwelita in the Provincial Gazette (Gazette No. 1537) dated 23 May 2006. The scenario above indicates that in the Kouga Local Municipality, ward committees are supposed to play a critical role in public participation. The study seeks to assess their role and to establish whether or not the ward committee system is effective in this regard. It is common knowledge that, whilst various pieces of legislation are clear in terms of what the role of ward committees should be, the question remains whether there is any adherence in municipalities to ensure that they fulfill their role in public participation, and hence the study.
- Full Text:
- Date Issued: 2008
- Authors: Simanga, Linda
- Date: 2008
- Subjects: Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:8230 , http://hdl.handle.net/10948/858 , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape
- Description: The Republic of South Africa became a democratic country in 1994 after the historic democratic elections. This year also marks the year when South Africa’s first democratic parliament was convened. The Constitution of the Republic of South Africa Act (no. 108 of 1996) was enacted in 1996. This Constitution provides for the creation of the three spheres of government, namely, the national level, which deals with matters of national importance, the provincial level, which deals with matters of provincial importance, and the local level which deals with matters of local importance. Section 152(1) (e) of the above-mentioned Constitution stipulates that the object of local government, amongst others, is to ensure the involvement of communities and community organizations in the matters of local governance. Section 73 of the Municipal Structures Act (no.117 of 1998) also requires municipalities to establish ward committees in a manner that seeks to enhance participatory democracy at the local level. Municipalities are established in terms of Section 12 of the Municipal Structures Act (no. 117 of 1998), wherein Members of Executive Councils (MEC’s) may, by notice in the Provincial Gazette, establish a municipality in each municipal area which the Demarcation Board demarcates in the province in terms of the Municipal Demarcation Act (no. 27 of 1998). Sections 7 and 8 of the Municipal Structures Act (no. 117 of 1998) further stipulate the categories of municipalities as A, B and C. Category A is a metropolitan municipality with wards and ward committees. B is a local municipality characterized by the existence of wards and ward committees to enhance public participation. C is a district municipality, whose responsibility is to support local municipalities within its area of jurisdiction so that they are self sufficient and can manage their own affairs. This study focuses on the Kouga Local Municipality, which is a Category B Municipality as promulgated by the then MEC for Housing, Local Government and Traditional Affairs, Honourable MEC S. Kwelita in the Provincial Gazette (Gazette No. 1537) dated 23 May 2006. The scenario above indicates that in the Kouga Local Municipality, ward committees are supposed to play a critical role in public participation. The study seeks to assess their role and to establish whether or not the ward committee system is effective in this regard. It is common knowledge that, whilst various pieces of legislation are clear in terms of what the role of ward committees should be, the question remains whether there is any adherence in municipalities to ensure that they fulfill their role in public participation, and hence the study.
- Full Text:
- Date Issued: 2008
Determinants of household food security in the semi-arid areas of Zimbabwe: a case study of irrigation and non-irrigation farmers in Lupane and Hwange districts
- Authors: Sikwela, Misery Mpuzu
- Date: 2008
- Subjects: Food -- Safety measures , Irrigation farming -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11163 , http://hdl.handle.net/10353/90 , Food -- Safety measures , Irrigation farming -- Zimbabwe
- Description: Lupane and Hwange districts fall under natural region IV and V and lie in the semi-arid regions of Zimbabwe with low and erratic mean annual rainfall not exceeding 600mm. Seventy percent of Zimbabwe’s population lives in communal areas, whose livelihood is based on agriculture. The communities in these areas mainly practice mixed farming systems. However, crop production is constrained by water availability and suitable production techniques. As a result households in these areas are experiencing worsening levels of household food insecurity. Two irrigation schemes were identified for this study and these are located in these two districts. Tshongokwe irrigation scheme is located in Lupane district and Lukosi irrigation scheme is located in Hwange district and these irrigation schemes are about 25 hectares in size. Lupane and Hwange districts are considered to be one of the most food insecure areas in the country because of the frequent droughts and unreliable rainfall in the region. The major tool of enquiry in this study was the questionnaire which was used to collect data from the households that farm on irrigated land and those that farm on dryland farming. Household and farm characteristics were collected using structured questionnaires with the help of locally recruited and trained enumerators. Agricultural production, household consumption and marketing of agricultural produce were accessed using the questionnaire to establish problems experienced by farmers. The main objective of this study was to investigate the determinants of household food security using a logistic regression model. The model was initially fitted with thirteen variables, selected from factors identified by previous researchers that affect food security in communal areas. Six variables were found to be significant at 1, 5 and 10 percent significance level and all had the expected signs except farm size. These factors include access to irrigation, farm size, cattle ownership, fertilizer application, household size and per capita aggregate production. The results obtained were further analyzed to compute partial effects on continuous variables and change in probabilities on the discrete variables for the significant factors in the logistic regression model. Analysis of partial effects revealed that household size, farm size, cattle ownership and per capita aggregate production lead to a greater probability of household being food secure. Change in probability results showed that having access to irrigation and using fertilizer can increase the probability of household being food secure The findings of this study highlight a positive and significant relationship between access to irrigation, fertilizer application, cattle ownership, per capita aggregate production to household food security. Household size and farm size have a negative and significant relationship on household food security. This study shows the effectiveness of irrigated farming over dryland farming in the semi-arid areas. The results show increased agricultural production, crop diversification and higher incomes from irrigation farming as compared to dry land farming. Irrigation farming has enabled many households to diversify their source of income and generate more income. Irrigation has enabled households with irrigation not only to feed themselves throughout the year but also to invest on non-agricultural goods and services from incomes received from crop sales Based on the results from the logistic regression model, it can be concluded that household size, farm size, per capita aggregate production, cattle ownership, fertilizer application and access to irrigation have a positive effect on household food security and the magnitude of changes in conditional probabilities have an impact on household food security.
- Full Text:
- Date Issued: 2008
- Authors: Sikwela, Misery Mpuzu
- Date: 2008
- Subjects: Food -- Safety measures , Irrigation farming -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11163 , http://hdl.handle.net/10353/90 , Food -- Safety measures , Irrigation farming -- Zimbabwe
- Description: Lupane and Hwange districts fall under natural region IV and V and lie in the semi-arid regions of Zimbabwe with low and erratic mean annual rainfall not exceeding 600mm. Seventy percent of Zimbabwe’s population lives in communal areas, whose livelihood is based on agriculture. The communities in these areas mainly practice mixed farming systems. However, crop production is constrained by water availability and suitable production techniques. As a result households in these areas are experiencing worsening levels of household food insecurity. Two irrigation schemes were identified for this study and these are located in these two districts. Tshongokwe irrigation scheme is located in Lupane district and Lukosi irrigation scheme is located in Hwange district and these irrigation schemes are about 25 hectares in size. Lupane and Hwange districts are considered to be one of the most food insecure areas in the country because of the frequent droughts and unreliable rainfall in the region. The major tool of enquiry in this study was the questionnaire which was used to collect data from the households that farm on irrigated land and those that farm on dryland farming. Household and farm characteristics were collected using structured questionnaires with the help of locally recruited and trained enumerators. Agricultural production, household consumption and marketing of agricultural produce were accessed using the questionnaire to establish problems experienced by farmers. The main objective of this study was to investigate the determinants of household food security using a logistic regression model. The model was initially fitted with thirteen variables, selected from factors identified by previous researchers that affect food security in communal areas. Six variables were found to be significant at 1, 5 and 10 percent significance level and all had the expected signs except farm size. These factors include access to irrigation, farm size, cattle ownership, fertilizer application, household size and per capita aggregate production. The results obtained were further analyzed to compute partial effects on continuous variables and change in probabilities on the discrete variables for the significant factors in the logistic regression model. Analysis of partial effects revealed that household size, farm size, cattle ownership and per capita aggregate production lead to a greater probability of household being food secure. Change in probability results showed that having access to irrigation and using fertilizer can increase the probability of household being food secure The findings of this study highlight a positive and significant relationship between access to irrigation, fertilizer application, cattle ownership, per capita aggregate production to household food security. Household size and farm size have a negative and significant relationship on household food security. This study shows the effectiveness of irrigated farming over dryland farming in the semi-arid areas. The results show increased agricultural production, crop diversification and higher incomes from irrigation farming as compared to dry land farming. Irrigation farming has enabled many households to diversify their source of income and generate more income. Irrigation has enabled households with irrigation not only to feed themselves throughout the year but also to invest on non-agricultural goods and services from incomes received from crop sales Based on the results from the logistic regression model, it can be concluded that household size, farm size, per capita aggregate production, cattle ownership, fertilizer application and access to irrigation have a positive effect on household food security and the magnitude of changes in conditional probabilities have an impact on household food security.
- Full Text:
- Date Issued: 2008
Manufacturing as a reference for rethinking construction design management
- Authors: Sidloyi, Xabiso
- Date: 2008
- Subjects: Industrial design -- Management , Construction industry -- Management -- South Africa -- Eastern Cape , Architecture -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9667 , http://hdl.handle.net/10948/766 , Industrial design -- Management , Construction industry -- Management -- South Africa -- Eastern Cape , Architecture -- Management
- Description: Design changes due to lack of constructability, cost overruns, delays and dissatisfied clients are but a few problems experienced in construction due to poor management of the design processes. Increased problems, challenges, demands and continuous criticism of the architectural profession has led to increased demand for research into the improvement of design processes. The aims of this research were to determine the adequacy of design management processes used by Eastern Cape (EC) architectural companies and compare these with the design management processes used in manufacturing in order to establish practices, theories, principles, technologies and deliverables that can be transferred from the manufacturing into the construction to improve efficiency of architectural design management. The quantitative research approach was implemented for this research, the questionnaire was designed to acquire primary, factual and attitudinal data from EC architectural companies and secondary data were acquired through a literature review. The results revealed that design management processes, continuous improvement philosophies, lean principles, and Information and Communication Technology (ICT) used by EC architectural companies are not similar to those used in manufacturing. Therefore EC architectural companies could increase their efficiency by adopting some of the design management processes, ICT, continuous improvement philosophies and lean principles originating from the manufacturing industry.
- Full Text:
- Date Issued: 2008
- Authors: Sidloyi, Xabiso
- Date: 2008
- Subjects: Industrial design -- Management , Construction industry -- Management -- South Africa -- Eastern Cape , Architecture -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9667 , http://hdl.handle.net/10948/766 , Industrial design -- Management , Construction industry -- Management -- South Africa -- Eastern Cape , Architecture -- Management
- Description: Design changes due to lack of constructability, cost overruns, delays and dissatisfied clients are but a few problems experienced in construction due to poor management of the design processes. Increased problems, challenges, demands and continuous criticism of the architectural profession has led to increased demand for research into the improvement of design processes. The aims of this research were to determine the adequacy of design management processes used by Eastern Cape (EC) architectural companies and compare these with the design management processes used in manufacturing in order to establish practices, theories, principles, technologies and deliverables that can be transferred from the manufacturing into the construction to improve efficiency of architectural design management. The quantitative research approach was implemented for this research, the questionnaire was designed to acquire primary, factual and attitudinal data from EC architectural companies and secondary data were acquired through a literature review. The results revealed that design management processes, continuous improvement philosophies, lean principles, and Information and Communication Technology (ICT) used by EC architectural companies are not similar to those used in manufacturing. Therefore EC architectural companies could increase their efficiency by adopting some of the design management processes, ICT, continuous improvement philosophies and lean principles originating from the manufacturing industry.
- Full Text:
- Date Issued: 2008
An assessment of the African Peer Review Mechanism with specific reference to South Africa
- Authors: Sibuyi, Lucas Nkosana
- Date: 2008
- Subjects: African Peer Review Mechanism , Peer review -- South Africa , Peer review -- Political aspects -- Africa , African cooperation , Political leadership -- Africa , Africa -- Politics and government -- 1960- , Democratization -- Africa , Civil society -- Africa , Political participation -- Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8242 , http://hdl.handle.net/10948/758 , African Peer Review Mechanism , Peer review -- South Africa , Peer review -- Political aspects -- Africa , African cooperation , Political leadership -- Africa , Africa -- Politics and government -- 1960- , Democratization -- Africa , Civil society -- Africa , Political participation -- Africa
- Description: The Heads of State and Government Implementation Committee (HSGIC) of the New Partnership for Africa’s Development (Nepad) acknowledged and recognised the centrality of good governance within the context of the African Peer Review Mechanism (APRM), an innovative mechanism acceded to by member states of the African Union (AU) as a self- monitoring mechanism for good governance. South Africa is one of the countries which acceded to the APRM in 2003. Accordingly, South Africa appointed a National Governing Council (NGC) under the chairpersonship of the Minister of Public Services and Administration as the focal point to develop a strategy to manage the national APRM process. The NGC was constituted of business, the disabled, civil society, churches, trade unions, government and women’s coalitions thus ensuring all relevant stakeholders are represented. As part of South Africa’s country assessment, questionnaires dealing with the four core thematic areas of the APRM were sent through to the public by community development workers. In addition, four technical assessment agencies were appointed to assist in conducting research on the four thematic areas. The primary objective of this study is to examine the theoretical approach to the study and the African Peer Review Mechanism’s contemporary relevance to South Africa, its intended beneficiaries and an assessment of South Africa for the period 2006. The study revealed that Proportional Representation (PR) and floor-crossing have an impact on the sustainability, relevance, long term development, vibrancy and profundity of constitutional democracy in the country. Clearly, since the dawn of the democratic dispensation in South Africa the electoral system introduced is such that it had to take into account the challenges the country faced during the apartheid system of governance. In this context, enough space for free political competition in the country was created. On the basis of the findings of the study, it is patently clear that the time allocated for the CSAR was minimal and the country should have been given at least two years so that the self assessment could have been extensively done. On the issue of HIV and AIDS and its relationship to socio-economic conditions, it was revealed that the country has a lot to do in this regard. The debilitating effect that HIV and AIDS has on the lives of the citizens requires clarity of policy and strategy, consistency in public communication and the need for sustained partnerships amongst all relevant stakeholders. At another level, there was a call for a basic income grant although government does not necessarily support it. Based on the research findings above, a new research area outlined under recommendations can be conceptualized for further research and it requires some attention.
- Full Text:
- Date Issued: 2008
- Authors: Sibuyi, Lucas Nkosana
- Date: 2008
- Subjects: African Peer Review Mechanism , Peer review -- South Africa , Peer review -- Political aspects -- Africa , African cooperation , Political leadership -- Africa , Africa -- Politics and government -- 1960- , Democratization -- Africa , Civil society -- Africa , Political participation -- Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8242 , http://hdl.handle.net/10948/758 , African Peer Review Mechanism , Peer review -- South Africa , Peer review -- Political aspects -- Africa , African cooperation , Political leadership -- Africa , Africa -- Politics and government -- 1960- , Democratization -- Africa , Civil society -- Africa , Political participation -- Africa
- Description: The Heads of State and Government Implementation Committee (HSGIC) of the New Partnership for Africa’s Development (Nepad) acknowledged and recognised the centrality of good governance within the context of the African Peer Review Mechanism (APRM), an innovative mechanism acceded to by member states of the African Union (AU) as a self- monitoring mechanism for good governance. South Africa is one of the countries which acceded to the APRM in 2003. Accordingly, South Africa appointed a National Governing Council (NGC) under the chairpersonship of the Minister of Public Services and Administration as the focal point to develop a strategy to manage the national APRM process. The NGC was constituted of business, the disabled, civil society, churches, trade unions, government and women’s coalitions thus ensuring all relevant stakeholders are represented. As part of South Africa’s country assessment, questionnaires dealing with the four core thematic areas of the APRM were sent through to the public by community development workers. In addition, four technical assessment agencies were appointed to assist in conducting research on the four thematic areas. The primary objective of this study is to examine the theoretical approach to the study and the African Peer Review Mechanism’s contemporary relevance to South Africa, its intended beneficiaries and an assessment of South Africa for the period 2006. The study revealed that Proportional Representation (PR) and floor-crossing have an impact on the sustainability, relevance, long term development, vibrancy and profundity of constitutional democracy in the country. Clearly, since the dawn of the democratic dispensation in South Africa the electoral system introduced is such that it had to take into account the challenges the country faced during the apartheid system of governance. In this context, enough space for free political competition in the country was created. On the basis of the findings of the study, it is patently clear that the time allocated for the CSAR was minimal and the country should have been given at least two years so that the self assessment could have been extensively done. On the issue of HIV and AIDS and its relationship to socio-economic conditions, it was revealed that the country has a lot to do in this regard. The debilitating effect that HIV and AIDS has on the lives of the citizens requires clarity of policy and strategy, consistency in public communication and the need for sustained partnerships amongst all relevant stakeholders. At another level, there was a call for a basic income grant although government does not necessarily support it. Based on the research findings above, a new research area outlined under recommendations can be conceptualized for further research and it requires some attention.
- Full Text:
- Date Issued: 2008
Connection management applications for high-speed audio networking
- Authors: Sibanda, Phathisile
- Date: 2008 , 2008-03-12
- Subjects: Flash (Computer file) , Computer networks , Computer networks -- Management , Digital communications , Computer sound processing , Sound -- Recording and reproducing -- Digital techniques , Broadcast data systems , C# (Computer program language) , C++ (Computer program language) , ActionScript (Computer program language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4634 , http://hdl.handle.net/10962/d1006532 , Flash (Computer file) , Computer networks , Computer networks -- Management , Digital communications , Computer sound processing , Sound -- Recording and reproducing -- Digital techniques , Broadcast data systems , C# (Computer program language) , C++ (Computer program language) , ActionScript (Computer program language)
- Description: Traditionally, connection management applications (referred to as patchbays) for high-speed audio networking, are predominantly developed using third-generation languages such as C, C# and C++. Due to the rapid increase in distributed audio/video network usage in the world today, connection management applications that control signal routing over these networks have also evolved in complexity to accommodate more functionality. As the result, high-speed audio networking application developers require a tool that will enable them to develop complex connection management applications easily and within the shortest possible time. In addition, this tool should provide them with the reliability and flexibility required to develop applications controlling signal routing in networks carrying real-time data. High-speed audio networks are used for various purposes that include audio/video production and broadcasting. This investigation evaluates the possibility of using Adobe Flash Professional 8, using ActionScript 2.0, for developing connection management applications. Three patchbays, namely the Broadcast patchbay, the Project studio patchbay, and the Hospitality/Convention Centre patchbay were developed and tested for connection management in three sound installation networks, namely the Broadcast network, the Project studio network, and the Hospitality/Convention Centre network. Findings indicate that complex connection management applications can effectively be implemented using the Adobe Flash IDE and ActionScript 2.0.
- Full Text:
- Date Issued: 2008
- Authors: Sibanda, Phathisile
- Date: 2008 , 2008-03-12
- Subjects: Flash (Computer file) , Computer networks , Computer networks -- Management , Digital communications , Computer sound processing , Sound -- Recording and reproducing -- Digital techniques , Broadcast data systems , C# (Computer program language) , C++ (Computer program language) , ActionScript (Computer program language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4634 , http://hdl.handle.net/10962/d1006532 , Flash (Computer file) , Computer networks , Computer networks -- Management , Digital communications , Computer sound processing , Sound -- Recording and reproducing -- Digital techniques , Broadcast data systems , C# (Computer program language) , C++ (Computer program language) , ActionScript (Computer program language)
- Description: Traditionally, connection management applications (referred to as patchbays) for high-speed audio networking, are predominantly developed using third-generation languages such as C, C# and C++. Due to the rapid increase in distributed audio/video network usage in the world today, connection management applications that control signal routing over these networks have also evolved in complexity to accommodate more functionality. As the result, high-speed audio networking application developers require a tool that will enable them to develop complex connection management applications easily and within the shortest possible time. In addition, this tool should provide them with the reliability and flexibility required to develop applications controlling signal routing in networks carrying real-time data. High-speed audio networks are used for various purposes that include audio/video production and broadcasting. This investigation evaluates the possibility of using Adobe Flash Professional 8, using ActionScript 2.0, for developing connection management applications. Three patchbays, namely the Broadcast patchbay, the Project studio patchbay, and the Hospitality/Convention Centre patchbay were developed and tested for connection management in three sound installation networks, namely the Broadcast network, the Project studio network, and the Hospitality/Convention Centre network. Findings indicate that complex connection management applications can effectively be implemented using the Adobe Flash IDE and ActionScript 2.0.
- Full Text:
- Date Issued: 2008
The impact of immigration on the labour market: evidence from South Africa
- Authors: Sibanda, Nomazulu
- Date: 2008
- Subjects: Immigrants -- South Africa , Labor -- South Africa , Labor costs -- South Africa
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11451 , http://hdl.handle.net/10353/207 , Immigrants -- South Africa , Labor -- South Africa , Labor costs -- South Africa
- Description: The impact of immigrants on the labour market in the South African context has always been a long standing issue with both government and natives’ fearing for the latter’s displacement effect, pressure on wages and resources. Migrants are blamed for poor labour market conditions of a host country. Literature reviewed from Africa and elsewhere shows that migrants have negative outcomes on the host country’s labour market. For this study an Error Correction Model on time series data from 1980-2006 has been estimated. The study estimated two models that is the unemployment and the wages models. The variables used for estimation are immigration, inflation and the Gross Domestic Product. The study surprisingly found a positive impact of immigrants on wages but the effect on employment was negative and significant. It is important to note here that the calculated impact is only for the documented immigrants the impact the illegal ones is not known.
- Full Text:
- Date Issued: 2008
- Authors: Sibanda, Nomazulu
- Date: 2008
- Subjects: Immigrants -- South Africa , Labor -- South Africa , Labor costs -- South Africa
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11451 , http://hdl.handle.net/10353/207 , Immigrants -- South Africa , Labor -- South Africa , Labor costs -- South Africa
- Description: The impact of immigrants on the labour market in the South African context has always been a long standing issue with both government and natives’ fearing for the latter’s displacement effect, pressure on wages and resources. Migrants are blamed for poor labour market conditions of a host country. Literature reviewed from Africa and elsewhere shows that migrants have negative outcomes on the host country’s labour market. For this study an Error Correction Model on time series data from 1980-2006 has been estimated. The study estimated two models that is the unemployment and the wages models. The variables used for estimation are immigration, inflation and the Gross Domestic Product. The study surprisingly found a positive impact of immigrants on wages but the effect on employment was negative and significant. It is important to note here that the calculated impact is only for the documented immigrants the impact the illegal ones is not known.
- Full Text:
- Date Issued: 2008
A bioinorganic study of some cobalt(II) Schiff base complexes of variously substituted hydroxybenzaldimines
- Authors: Shaibu, Rafiu Olarewaju
- Date: 2008
- Subjects: Cobalt Schiff bases Artemia Spectrum analysis Ligands -- Analysis Bioinorganic chemistry Antineoplastic agents Cancer -- Chemotherapy Ligands -- Toxicity
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4394 , http://hdl.handle.net/10962/d1006009
- Description: Syntheses of Schiff bases were carried out by reacting salicylaldyhde, ortho-vanillin, para-vanillin or vanillin with aniline, 1-aminonaphthalene, 4- and 3-aminopyridine, and also with 2- and 3-aminomethylpyridine. The various Schiff bases obtained from the condensation reaction were reacted with CoCl₂.6H₂0, triethylamine stripped CoCl₂.6H₂0 or Co(CH₃COO)₂ to form cobalt(Il) complexes of ratio 2:1. The complexes obtained from cobalt chloride designated as the "A series" are of the general formulae ML₂X₂.nH₂0 , (L = Schiff base, X = chlorine) while those obtained from cobalt acetate or triethylamine stripped cobalt chloride denoted as "B" and C" are of the general formulae ML₂. nH₂0. The few complexes that do not follow the general formulae highlighted above are: IA [M(HL)₃.Cl₂], (L = N-phenylsalicylaldimine), 4A = (MLCl₂), (L = N-phenylvanaldiminato), 7 A and 21 A (ML₂), (L = N-naphthyl-o-vanaldiminato, and N-methy-2-pyridylsalicylaldiminato respectively), 8A = MLCI, (L = N-naphthylvanaldiminato), 12A = M₂L₃Cl₂, (L = N-4-pyridylvanaldiminato), 15A (MLCI), (L = N-3-pyridyl-o-vanaldiminato). The ligands and their complexes were characterized using elemental analyses and cobalt analysis using ICP, FT-IR spectroscopy (mid and far-IR), NIR-UV/vis (diffuse reflectance), UV/vis in an aprotic and a protic solvents, while mass spectrometry, ¹HNMR and ¹³CNMR, was used to further characterized the ligands. The tautomeric nature of the Schiff bases were determined by examining the behaviour of Schiff bases and their complexes in a protic (e.g. MeOH) and non-protic (e.g. DMF) polar solvents. The effects of solvents on the electronic behaviour of the compounds were also examined. Using CDCl₃, the NMR technique was further used to confirm the structures of the Schiff bases. The tentative geometry of the complexes was determined using the spectra information obtained from the far infrared and the diffuse reflectance spectroscopy. With few exceptions, most of the "A" series are tetrahedral or distorted tetrahedral, while the "B + C" are octahedral or pseudooctahedral. A small number of complexes are assigned square-planar geometry owing to the characteristic spectral behaviour shown. In order to determine their biological activity, two biological assay methods (antimicrobial testing and brine shrimp lethality assay) were used. Using disc method, the bacteriostatic and fungicidal activities of the various Schiff bases and their respective complexes to Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa as well as Aspergillus niger, were measured and the average inhibition zones are tabulated and analysed. Both the Schiff bases and their complexes showed varying bacteriostatic and fungicidal activity against the bacteria and fungus tested. The inhibition activity is concentration dependent and potential antibiotic and fungicides are identified. To determine the toxicity of the ligands and their corresponding cobalt(II) complexes, brine shrimp lethality assay was used. The LD₅₀ of the tested compounds were calculated and the results obtained were tabulated for comparison.
- Full Text:
- Date Issued: 2008
- Authors: Shaibu, Rafiu Olarewaju
- Date: 2008
- Subjects: Cobalt Schiff bases Artemia Spectrum analysis Ligands -- Analysis Bioinorganic chemistry Antineoplastic agents Cancer -- Chemotherapy Ligands -- Toxicity
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4394 , http://hdl.handle.net/10962/d1006009
- Description: Syntheses of Schiff bases were carried out by reacting salicylaldyhde, ortho-vanillin, para-vanillin or vanillin with aniline, 1-aminonaphthalene, 4- and 3-aminopyridine, and also with 2- and 3-aminomethylpyridine. The various Schiff bases obtained from the condensation reaction were reacted with CoCl₂.6H₂0, triethylamine stripped CoCl₂.6H₂0 or Co(CH₃COO)₂ to form cobalt(Il) complexes of ratio 2:1. The complexes obtained from cobalt chloride designated as the "A series" are of the general formulae ML₂X₂.nH₂0 , (L = Schiff base, X = chlorine) while those obtained from cobalt acetate or triethylamine stripped cobalt chloride denoted as "B" and C" are of the general formulae ML₂. nH₂0. The few complexes that do not follow the general formulae highlighted above are: IA [M(HL)₃.Cl₂], (L = N-phenylsalicylaldimine), 4A = (MLCl₂), (L = N-phenylvanaldiminato), 7 A and 21 A (ML₂), (L = N-naphthyl-o-vanaldiminato, and N-methy-2-pyridylsalicylaldiminato respectively), 8A = MLCI, (L = N-naphthylvanaldiminato), 12A = M₂L₃Cl₂, (L = N-4-pyridylvanaldiminato), 15A (MLCI), (L = N-3-pyridyl-o-vanaldiminato). The ligands and their complexes were characterized using elemental analyses and cobalt analysis using ICP, FT-IR spectroscopy (mid and far-IR), NIR-UV/vis (diffuse reflectance), UV/vis in an aprotic and a protic solvents, while mass spectrometry, ¹HNMR and ¹³CNMR, was used to further characterized the ligands. The tautomeric nature of the Schiff bases were determined by examining the behaviour of Schiff bases and their complexes in a protic (e.g. MeOH) and non-protic (e.g. DMF) polar solvents. The effects of solvents on the electronic behaviour of the compounds were also examined. Using CDCl₃, the NMR technique was further used to confirm the structures of the Schiff bases. The tentative geometry of the complexes was determined using the spectra information obtained from the far infrared and the diffuse reflectance spectroscopy. With few exceptions, most of the "A" series are tetrahedral or distorted tetrahedral, while the "B + C" are octahedral or pseudooctahedral. A small number of complexes are assigned square-planar geometry owing to the characteristic spectral behaviour shown. In order to determine their biological activity, two biological assay methods (antimicrobial testing and brine shrimp lethality assay) were used. Using disc method, the bacteriostatic and fungicidal activities of the various Schiff bases and their respective complexes to Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa as well as Aspergillus niger, were measured and the average inhibition zones are tabulated and analysed. Both the Schiff bases and their complexes showed varying bacteriostatic and fungicidal activity against the bacteria and fungus tested. The inhibition activity is concentration dependent and potential antibiotic and fungicides are identified. To determine the toxicity of the ligands and their corresponding cobalt(II) complexes, brine shrimp lethality assay was used. The LD₅₀ of the tested compounds were calculated and the results obtained were tabulated for comparison.
- Full Text:
- Date Issued: 2008
Links between the local trade in natural products, livelihoods and poverty alleviation in a semi-arid region of South Africa
- Shackleton, Sheona E, Campbell, Bruce, Lotz-Sisitka, Heila, Shackleton, Charlie M
- Authors: Shackleton, Sheona E , Campbell, Bruce , Lotz-Sisitka, Heila , Shackleton, Charlie M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181246 , vital:43712 , xlink:href="https://doi.org/10.1016/j.worlddev.2007.03.003"
- Description: Can the local commercialization of natural products contribute to reduced poverty and vulnerability? Commentary on this issue is mixed, with some observers being quite optimistic, while others hold a counterview. This paper explores the poverty alleviation potential of four products traded in Bushbuckridge, South Africa—traditional brooms, reed mats, woodcraft, and “marula” beer. While key in enhancing the livelihood security of the poorest households, these products were unlikely to provide a route out of poverty for most, although there were exceptions. Incomes often surpassed local wage rates, and some producers obtained returns equivalent to the minimum wage. Non-financial benefits such as the opportunity to work from home were highly rated, and the trade was found to represent a range of livelihood strategies both within and across products.
- Full Text:
- Date Issued: 2008
- Authors: Shackleton, Sheona E , Campbell, Bruce , Lotz-Sisitka, Heila , Shackleton, Charlie M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181246 , vital:43712 , xlink:href="https://doi.org/10.1016/j.worlddev.2007.03.003"
- Description: Can the local commercialization of natural products contribute to reduced poverty and vulnerability? Commentary on this issue is mixed, with some observers being quite optimistic, while others hold a counterview. This paper explores the poverty alleviation potential of four products traded in Bushbuckridge, South Africa—traditional brooms, reed mats, woodcraft, and “marula” beer. While key in enhancing the livelihood security of the poorest households, these products were unlikely to provide a route out of poverty for most, although there were exceptions. Incomes often surpassed local wage rates, and some producers obtained returns equivalent to the minimum wage. Non-financial benefits such as the opportunity to work from home were highly rated, and the trade was found to represent a range of livelihood strategies both within and across products.
- Full Text:
- Date Issued: 2008
Social and ecological trade offs in combating land degradation: The case of invasion by a woody shrub (Euryops floribundus) at Macubeni, South Africa
- Shackleton, Charlie M, Gambiza, James
- Authors: Shackleton, Charlie M , Gambiza, James
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181235 , vital:43711 , xlink:href="https://doi.org/10.1002/ldr.849"
- Description: Woody plant invasions, either of alien or indigenous species, are deemed to result in loss of ecosystem goods and services in many areas throughout the world, resulting in significant degradation and economic costs. Invasion of Euryops floribundus, a species indigenous to South Africa, is perceived to have reduced the grazing available for domestic livestock. Consequently, a programme of manual eradication has been implemented to improve the grazing resource and provide jobs for poverty alleviation. However, there is potential for a conflict of interest as our study shows that almost all households rely on Euryops for fuel and at times fencing material, whereas only a minority of households own livestock. Moreover, comparison of invaded and non-invaded sites indicated that the invaded sites harbour greater plant species richness and higher grass culm density per unit area of grass cover, as well as higher forb and litter cover. While invaded sites had lower grass cover, overall plant cover was no different between invaded and non-invaded sites. Multivariate analysis indicated no obvious differentiation in community composition between invaded and non-invaded areas, suggesting stronger drivers of community composition other than Euryops invasion presumed to be facilitated by the effects of high livestock densities. Overall, our study suggests that the clearing operation may well benefit from a better understanding of the social needs, perceptions of degradation by the various stakeholders and ecological dynamics of the area, especially local reliance on the resources, and the dynamics of the invasion, particularly its extent, rate of spread and susceptibility for re-invasion in the cleared areas.
- Full Text:
- Date Issued: 2008
- Authors: Shackleton, Charlie M , Gambiza, James
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181235 , vital:43711 , xlink:href="https://doi.org/10.1002/ldr.849"
- Description: Woody plant invasions, either of alien or indigenous species, are deemed to result in loss of ecosystem goods and services in many areas throughout the world, resulting in significant degradation and economic costs. Invasion of Euryops floribundus, a species indigenous to South Africa, is perceived to have reduced the grazing available for domestic livestock. Consequently, a programme of manual eradication has been implemented to improve the grazing resource and provide jobs for poverty alleviation. However, there is potential for a conflict of interest as our study shows that almost all households rely on Euryops for fuel and at times fencing material, whereas only a minority of households own livestock. Moreover, comparison of invaded and non-invaded sites indicated that the invaded sites harbour greater plant species richness and higher grass culm density per unit area of grass cover, as well as higher forb and litter cover. While invaded sites had lower grass cover, overall plant cover was no different between invaded and non-invaded sites. Multivariate analysis indicated no obvious differentiation in community composition between invaded and non-invaded areas, suggesting stronger drivers of community composition other than Euryops invasion presumed to be facilitated by the effects of high livestock densities. Overall, our study suggests that the clearing operation may well benefit from a better understanding of the social needs, perceptions of degradation by the various stakeholders and ecological dynamics of the area, especially local reliance on the resources, and the dynamics of the invasion, particularly its extent, rate of spread and susceptibility for re-invasion in the cleared areas.
- Full Text:
- Date Issued: 2008
Household attributes promote diversity of tree holdings in rural areas, South Africa:
- Shackleton, Charlie M, Paumgarten, Fiona, Cocks, Michelle L
- Authors: Shackleton, Charlie M , Paumgarten, Fiona , Cocks, Michelle L
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141301 , vital:37960 , DOI: 10.1007/s10457-007-9066-5
- Description: Trees within the homestead area provide many functions to rural households. However, within the semi-arid regions of southern Africa, there has been only limited examination of the correlates between the socio-economic attributes of rural households and the density, species richness and types of trees they keep. This paper reports on a multivariate analysis of household attributes in relation to homestead tree holdings from six rural villages in South Africa. In terms of density of trees per household, gender of the household head was the only significant correlate, with female-headed households having significantly fewer trees than their male-headed counterparts. This was especially so for the density of indigenous trees.
- Full Text:
- Date Issued: 2008
- Authors: Shackleton, Charlie M , Paumgarten, Fiona , Cocks, Michelle L
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141301 , vital:37960 , DOI: 10.1007/s10457-007-9066-5
- Description: Trees within the homestead area provide many functions to rural households. However, within the semi-arid regions of southern Africa, there has been only limited examination of the correlates between the socio-economic attributes of rural households and the density, species richness and types of trees they keep. This paper reports on a multivariate analysis of household attributes in relation to homestead tree holdings from six rural villages in South Africa. In terms of density of trees per household, gender of the household head was the only significant correlate, with female-headed households having significantly fewer trees than their male-headed counterparts. This was especially so for the density of indigenous trees.
- Full Text:
- Date Issued: 2008
The potential roles of interactions between STAT3, Hsp90, and Hop in the maintenance of self-renewal in mouse embryonic stem cells
- Authors: Setati, Mokgadi Michael
- Date: 2008
- Subjects: Embryonic stem cells , Leukemia inhibitory factor , Cellular signal transduction , Heat shock proteins , Molecular chaperones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3981 , http://hdl.handle.net/10962/d1004040 , Embryonic stem cells , Leukemia inhibitory factor , Cellular signal transduction , Heat shock proteins , Molecular chaperones
- Description: Self-renewal of mouse embryonic stem (mES) cells is dependent upon the presence of leukemia inhibitory factor (LIF). LIF induces tyrosine phosphorylation and nuclear translocation of STAT3 (signal transducer and activator of transcription 3) which is thought to promote self-renewal by inducing key target genes. The molecular chaperone heat shock protein 90 (Hsp90) is involved in signal transduction pathways and regulates STAT3 activity in different cell types. However, the role of Hsp90 in regulating STAT3 activity in mES cells has not previously been investigated. The aim of this study was to investigate if Hsp90 interacts with STAT3 in mES cells and to determine if this interaction is important for the maintenance of self-renewal. It was found that when mES cells were cultured for 24.0 hours in the absence of LIF, the expression levels of total STAT3, tyrosine-phosphorylated STAT3 (pYSTAT3), and the pluripotency marker, Nanog, were down regulated. However, the expression level of Hsp90 was found to be slightly up-regulated over the same period. Significantly, it was found that the amount of STAT3 in differentiating mES cells available for binding to Hsp90 was decreased upon down-regulation of STAT3 by LIF withdrawal. Therefore, STAT3-Hsp90 interactions in mES cells were dependent on the presence of LIF, which suggested that the reduction in STAT3-Hsp90 interaction may have resulted from the low levels of STAT3. Despite a dramatic reduction in the expression levels of pYSTAT3 upon 24.0 hours of culture of mES cells in the presence of the STAT3 tyrosine phosphorylation inhibitor, cucurbitanin I, there was no obvious reduction in the levels of total STAT3, Oct-3/4 or Nanog. These results suggested that the levels of unphosphorylated STAT3 rather than pYSTAT3, maybe more important in the maintenance of mES cells self-renewal.
- Full Text:
- Date Issued: 2008
- Authors: Setati, Mokgadi Michael
- Date: 2008
- Subjects: Embryonic stem cells , Leukemia inhibitory factor , Cellular signal transduction , Heat shock proteins , Molecular chaperones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3981 , http://hdl.handle.net/10962/d1004040 , Embryonic stem cells , Leukemia inhibitory factor , Cellular signal transduction , Heat shock proteins , Molecular chaperones
- Description: Self-renewal of mouse embryonic stem (mES) cells is dependent upon the presence of leukemia inhibitory factor (LIF). LIF induces tyrosine phosphorylation and nuclear translocation of STAT3 (signal transducer and activator of transcription 3) which is thought to promote self-renewal by inducing key target genes. The molecular chaperone heat shock protein 90 (Hsp90) is involved in signal transduction pathways and regulates STAT3 activity in different cell types. However, the role of Hsp90 in regulating STAT3 activity in mES cells has not previously been investigated. The aim of this study was to investigate if Hsp90 interacts with STAT3 in mES cells and to determine if this interaction is important for the maintenance of self-renewal. It was found that when mES cells were cultured for 24.0 hours in the absence of LIF, the expression levels of total STAT3, tyrosine-phosphorylated STAT3 (pYSTAT3), and the pluripotency marker, Nanog, were down regulated. However, the expression level of Hsp90 was found to be slightly up-regulated over the same period. Significantly, it was found that the amount of STAT3 in differentiating mES cells available for binding to Hsp90 was decreased upon down-regulation of STAT3 by LIF withdrawal. Therefore, STAT3-Hsp90 interactions in mES cells were dependent on the presence of LIF, which suggested that the reduction in STAT3-Hsp90 interaction may have resulted from the low levels of STAT3. Despite a dramatic reduction in the expression levels of pYSTAT3 upon 24.0 hours of culture of mES cells in the presence of the STAT3 tyrosine phosphorylation inhibitor, cucurbitanin I, there was no obvious reduction in the levels of total STAT3, Oct-3/4 or Nanog. These results suggested that the levels of unphosphorylated STAT3 rather than pYSTAT3, maybe more important in the maintenance of mES cells self-renewal.
- Full Text:
- Date Issued: 2008
The synthesis and electrochemical behaviour of water soluble manganese phthalocyanines: Anion radical versus Mn(I) species
- Sehlotho, Nthapo, Durmuş, M, Ahsen, N, Nyokong, Tebello
- Authors: Sehlotho, Nthapo , Durmuş, M , Ahsen, N , Nyokong, Tebello
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6596 , http://hdl.handle.net/10962/d1004345
- Description: The following MnPc derivatives were synthesized: 1,(4)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (5a), quaternized 1,(4)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (5b), 2,(3)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (6a) and quaternized 2,(3)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH)(6b). Spectro-electrochemistry shows that the reduction of Mn(II)Pc to Mn(I)Pc occurs only when the complexes are in their quaternized form (5b and 6b). The reduction (to Mn(I)Pc(−2)) of the quaternized form occurs at a lower potential than that (to Mn(II)Pc(−3)) of the unquaternized form. This observation suggests that metal reduction (to Mn(I)Pc(−2)) versus ligand reduction (to Mn(II)Pc(−3)) in Mn(II)Pc complexes depends on the nature of the ring substituents.
- Full Text:
- Date Issued: 2008
- Authors: Sehlotho, Nthapo , Durmuş, M , Ahsen, N , Nyokong, Tebello
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6596 , http://hdl.handle.net/10962/d1004345
- Description: The following MnPc derivatives were synthesized: 1,(4)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (5a), quaternized 1,(4)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (5b), 2,(3)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (6a) and quaternized 2,(3)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH)(6b). Spectro-electrochemistry shows that the reduction of Mn(II)Pc to Mn(I)Pc occurs only when the complexes are in their quaternized form (5b and 6b). The reduction (to Mn(I)Pc(−2)) of the quaternized form occurs at a lower potential than that (to Mn(II)Pc(−3)) of the unquaternized form. This observation suggests that metal reduction (to Mn(I)Pc(−2)) versus ligand reduction (to Mn(II)Pc(−3)) in Mn(II)Pc complexes depends on the nature of the ring substituents.
- Full Text:
- Date Issued: 2008
Electro-catalyzed oxidation of reduced glutathione and 2-mercaptoethanol by cobalt phthalocyanine-containing screen printed graphite electrodes
- Sehlotho, Nthapo, Griveau, Sophie, Ruillé, Nadine, Boujtita, Mohammed, Nyokong, Tebello, Bedioui, Fethi
- Authors: Sehlotho, Nthapo , Griveau, Sophie , Ruillé, Nadine , Boujtita, Mohammed , Nyokong, Tebello , Bedioui, Fethi
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265935 , vital:53902 , xlink:href="https://doi.org/10.1016/j.msec.2007.10.054"
- Description: Electro-catalytic behavior of screen printed graphite electrodes modified with cobalt phthalocyanine (CoPc) towards the oxidation of reduced glutathione (GSH) and 2-mercaptoethanol (2-ME) is reported. We find, by using cyclic voltammetry, that the oxidation of 2-ME occurs at 0.2 V vs Ag/AgCl and − 0.3 vs Ag/AgCl V at pH = 7 and pH = 13, respectively and that of GSH occurs at 0.4 V vs Ag/AgCl and 0.0 V vs Ag/AgCl at pH = 7 and 13, respectively. The electro-catalytic activity depends on the method of electrode modification and the amount of catalyst incorporated in the ink used to fabricate the SPCEs. The highest activity was obtained with electrodes prepared with 2.5% (w:w) of CoPc.
- Full Text:
- Date Issued: 2008
- Authors: Sehlotho, Nthapo , Griveau, Sophie , Ruillé, Nadine , Boujtita, Mohammed , Nyokong, Tebello , Bedioui, Fethi
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265935 , vital:53902 , xlink:href="https://doi.org/10.1016/j.msec.2007.10.054"
- Description: Electro-catalytic behavior of screen printed graphite electrodes modified with cobalt phthalocyanine (CoPc) towards the oxidation of reduced glutathione (GSH) and 2-mercaptoethanol (2-ME) is reported. We find, by using cyclic voltammetry, that the oxidation of 2-ME occurs at 0.2 V vs Ag/AgCl and − 0.3 vs Ag/AgCl V at pH = 7 and pH = 13, respectively and that of GSH occurs at 0.4 V vs Ag/AgCl and 0.0 V vs Ag/AgCl at pH = 7 and 13, respectively. The electro-catalytic activity depends on the method of electrode modification and the amount of catalyst incorporated in the ink used to fabricate the SPCEs. The highest activity was obtained with electrodes prepared with 2.5% (w:w) of CoPc.
- Full Text:
- Date Issued: 2008