Characterization of nickel tetrahydroxy phthalocyanine complexes and the electrocatalytic oxidation of 4-chlorophenol
- Khene, Samson M, Lobb, Kevin A, Nyokong, Tebello
- Authors: Khene, Samson M , Lobb, Kevin A , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263308 , vital:53616 , xlink:href="https://doi.org/10.1016/j.ica.2009.08.019"
- Description: This work reports on the use of nickel(II) tetrahydroxy (NiPc(OH)4) and (poly-Ni(OH)Pc(OH)4) phthalocyanine complexes as films on ordinary poly graphite electrode (OPGE) for the electrochemical oxidation of 4-chlorophenol (4-CP). The NiPc(OH)4 film was electrotransformed to Ni(OH)Pc(OH)4 film in aqueous 0.1 M NaOH solution to the ‘O–Ni–O oxo’ bridge form. The result showed that the Ni(OH)Pc(OH)4 film on OPGE was more electroactive in terms of increase in current and less catalytic in terms of potential compared to the adsorbed NiPc(OH)4 on OPGE. The reactivity of the two molecules was explained by theoretical calculations. The energies of the frontier orbitals of NiPc(OH)4, Ni(OH)Pc(OH)4 and 4-chlorophenol were calculated using density functional theory (DFT) method. The inter molecular hardness (η) and donor–acceptor hardness (ηDA) of Ni(OH)Pc(OH)4, NiPc(OH)4, Ni(OH)Pc(OH)4/4-chlorophenol and NiPc(OH)4/4-chlorophenol were estimated. The Ni(OH)Pc(OH)4, showed stronger interaction with 4-chlorophenol than NiPc(OH)4. DFT method was also used to model IR and Raman spectrum of H2Pc(OH)4 and NiPc(OH)4.
- Full Text:
- Date Issued: 2009
- Authors: Khene, Samson M , Lobb, Kevin A , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263308 , vital:53616 , xlink:href="https://doi.org/10.1016/j.ica.2009.08.019"
- Description: This work reports on the use of nickel(II) tetrahydroxy (NiPc(OH)4) and (poly-Ni(OH)Pc(OH)4) phthalocyanine complexes as films on ordinary poly graphite electrode (OPGE) for the electrochemical oxidation of 4-chlorophenol (4-CP). The NiPc(OH)4 film was electrotransformed to Ni(OH)Pc(OH)4 film in aqueous 0.1 M NaOH solution to the ‘O–Ni–O oxo’ bridge form. The result showed that the Ni(OH)Pc(OH)4 film on OPGE was more electroactive in terms of increase in current and less catalytic in terms of potential compared to the adsorbed NiPc(OH)4 on OPGE. The reactivity of the two molecules was explained by theoretical calculations. The energies of the frontier orbitals of NiPc(OH)4, Ni(OH)Pc(OH)4 and 4-chlorophenol were calculated using density functional theory (DFT) method. The inter molecular hardness (η) and donor–acceptor hardness (ηDA) of Ni(OH)Pc(OH)4, NiPc(OH)4, Ni(OH)Pc(OH)4/4-chlorophenol and NiPc(OH)4/4-chlorophenol were estimated. The Ni(OH)Pc(OH)4, showed stronger interaction with 4-chlorophenol than NiPc(OH)4. DFT method was also used to model IR and Raman spectrum of H2Pc(OH)4 and NiPc(OH)4.
- Full Text:
- Date Issued: 2009
Characterization of polymeric film of a new manganese phthalocyanine complex octa-substituted with 2-diethylaminoethanethiol, and its use for the electrochemical detection of bentazon
- Akinbulu, Isaac A, Nyokong, Tebello
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262568 , vital:53534 , xlink:href="https://doi.org/10.1016/j.electacta.2009.07.074"
- Description: Manganese acetate octakis-(2-diethyaminoethanethiol) phthalocyanine (AcMnODEAETPc) was newly synthesized and characterized by spectroscopic and electrochemical methods. Solution electrochemistry of the complex showed three redox processes assigned to MnIIIPc−1/MnIIIPc−2, MnIIIPc−2/MnIIPc−2 and MnIIPc−2/MnIIPc−3 species. The new molecule was polymerized onto a glassy carbon electrode (GCE) to form thin films of different thickness, giving poly-10-AcMnODEAETPc-GCE, poly-20-AcMnODEAETPc-GCE and poly-30-AcMnODEAETPc-GCE, where 10, 20 and 30 represent the number of voltammetry scans during polymerization. Three distinct redox processes were observed on the modified electrode in 0.1 M phosphate buffer solution, pH 5, which confirmed the formation of the polymer. The current signal due to the herbicide, bentazon, was dependent on film thickness; the best signal was obtained on poly-20-AcMnODEAETPc-GCE while poly-10-AcMnODEAETPc-GCE gave the least signal. However, the signals due to the herbicide were better on the different films compared to the bare electrode. Electrochemical impedance spectroscopy (EIS) technique revealed that differences in film thickness offered different charge transfer resistances, Rct, hence difference in current signals for bentazon oxidation were observed on these films. A Tafel slope of 77 mV/decade, obtained for the herbicide on poly-20-AcMnODEAETPc-GCE, denotes a fast one electron transfer followed by a slow chemical step in the electro-oxidation of bentazon. The voltammetry signals of the herbicide on the films indicated the likely involvement of ring-based redox processes in the detection of the herbicide. A plot of background corrected current response, on this film, versus the concentration of bentazon was linear within the range 50–750 μM with a detection limit of 2.48 × 10−7 M.
- Full Text:
- Date Issued: 2009
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262568 , vital:53534 , xlink:href="https://doi.org/10.1016/j.electacta.2009.07.074"
- Description: Manganese acetate octakis-(2-diethyaminoethanethiol) phthalocyanine (AcMnODEAETPc) was newly synthesized and characterized by spectroscopic and electrochemical methods. Solution electrochemistry of the complex showed three redox processes assigned to MnIIIPc−1/MnIIIPc−2, MnIIIPc−2/MnIIPc−2 and MnIIPc−2/MnIIPc−3 species. The new molecule was polymerized onto a glassy carbon electrode (GCE) to form thin films of different thickness, giving poly-10-AcMnODEAETPc-GCE, poly-20-AcMnODEAETPc-GCE and poly-30-AcMnODEAETPc-GCE, where 10, 20 and 30 represent the number of voltammetry scans during polymerization. Three distinct redox processes were observed on the modified electrode in 0.1 M phosphate buffer solution, pH 5, which confirmed the formation of the polymer. The current signal due to the herbicide, bentazon, was dependent on film thickness; the best signal was obtained on poly-20-AcMnODEAETPc-GCE while poly-10-AcMnODEAETPc-GCE gave the least signal. However, the signals due to the herbicide were better on the different films compared to the bare electrode. Electrochemical impedance spectroscopy (EIS) technique revealed that differences in film thickness offered different charge transfer resistances, Rct, hence difference in current signals for bentazon oxidation were observed on these films. A Tafel slope of 77 mV/decade, obtained for the herbicide on poly-20-AcMnODEAETPc-GCE, denotes a fast one electron transfer followed by a slow chemical step in the electro-oxidation of bentazon. The voltammetry signals of the herbicide on the films indicated the likely involvement of ring-based redox processes in the detection of the herbicide. A plot of background corrected current response, on this film, versus the concentration of bentazon was linear within the range 50–750 μM with a detection limit of 2.48 × 10−7 M.
- Full Text:
- Date Issued: 2009
Children navigating rural poverty: Rural children's use of wild resources to counteract food insecurity in the Eastern Cape, South Africa
- McGarry, Dylan K, Shackleton, Charlie M
- Authors: McGarry, Dylan K , Shackleton, Charlie M
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181191 , vital:43706 , xlink:href="https://doi.org/10.1080/10796120802677594"
- Description: This paper analyzes the role of natural resources in the lives of rural children experiencing heightened vulnerability to poverty and the impact of HIV/AIDS, a subject that previously has been unexplored. The authors highlight wild-food use by rural children as a regular activity that supplements their domestic diets. Over the course of 18 months in the Eastern Cape of South Africa, the authors used a broad quantitative and qualitative methodology to explore the food acquisition and consumption patterns for 850 children. They found that the quality of children's domestic diets was, on average, 60% lower than the Food and Agricultural Organization (FAO) guidelines. This occurred in a population where 62% of the children surveyed were supplementing their diets with wild foods; and 30% with over half their diet supplemented in this way. Significantly, dietary diversity increased by 13% when wild food supplementation occurred. Another result was the commercialization of wild foods (observed among 47% of the children), wherein significantly more vulnerable children sold these foods. Considering the heightened nutritional and energy needs of children, combined with the impact of poverty and HIV/AIDS on household food access, wild foods represent the last freely attainable food sources available to them.
- Full Text:
- Date Issued: 2009
- Authors: McGarry, Dylan K , Shackleton, Charlie M
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181191 , vital:43706 , xlink:href="https://doi.org/10.1080/10796120802677594"
- Description: This paper analyzes the role of natural resources in the lives of rural children experiencing heightened vulnerability to poverty and the impact of HIV/AIDS, a subject that previously has been unexplored. The authors highlight wild-food use by rural children as a regular activity that supplements their domestic diets. Over the course of 18 months in the Eastern Cape of South Africa, the authors used a broad quantitative and qualitative methodology to explore the food acquisition and consumption patterns for 850 children. They found that the quality of children's domestic diets was, on average, 60% lower than the Food and Agricultural Organization (FAO) guidelines. This occurred in a population where 62% of the children surveyed were supplementing their diets with wild foods; and 30% with over half their diet supplemented in this way. Significantly, dietary diversity increased by 13% when wild food supplementation occurred. Another result was the commercialization of wild foods (observed among 47% of the children), wherein significantly more vulnerable children sold these foods. Considering the heightened nutritional and energy needs of children, combined with the impact of poverty and HIV/AIDS on household food access, wild foods represent the last freely attainable food sources available to them.
- Full Text:
- Date Issued: 2009
China in the African mediascape: doing better journalism
- Authors: Banda, Fackson
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454561 , vital:75355 , https://hdl.handle.net/10520/EJC139919
- Description: Chinese assistance to African media is not new. What is different now is that it is being administered in the post-Cold War era with a greater degree of openness, says Fackson Banda.
- Full Text:
- Date Issued: 2009
- Authors: Banda, Fackson
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454561 , vital:75355 , https://hdl.handle.net/10520/EJC139919
- Description: Chinese assistance to African media is not new. What is different now is that it is being administered in the post-Cold War era with a greater degree of openness, says Fackson Banda.
- Full Text:
- Date Issued: 2009
Chromone Studies. Part 17. Tricyclic Scaffolds from Reactions of chromone-3-carbaldehydes and methyl vinyl ketone under Baylis–Hillman conditions
- Ganto, Mlungiseleli M, Molefe, Duduzile M, Lobb, Kevin A, Kaye, Perry T
- Authors: Ganto, Mlungiseleli M , Molefe, Duduzile M , Lobb, Kevin A , Kaye, Perry T
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449321 , vital:74811 , xlink:href="https://doi.org/10.3184/030823409X4652"
- Description: Reaction of a series of chromone-3-carbaldehydes with methyl vinyl ketone under Baylis–Hillman conditions, using 3-hydroxyquinuclidine in chloroform or DABCO in 1-methyl-2-pyrrolidinone, affords unprecedented tricylic chromone derivatives which, depending on the conditions, may be accompanied by the normal Baylis–Hillman products or their respective tricyclic dimers.
- Full Text:
- Date Issued: 2009
- Authors: Ganto, Mlungiseleli M , Molefe, Duduzile M , Lobb, Kevin A , Kaye, Perry T
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449321 , vital:74811 , xlink:href="https://doi.org/10.3184/030823409X4652"
- Description: Reaction of a series of chromone-3-carbaldehydes with methyl vinyl ketone under Baylis–Hillman conditions, using 3-hydroxyquinuclidine in chloroform or DABCO in 1-methyl-2-pyrrolidinone, affords unprecedented tricylic chromone derivatives which, depending on the conditions, may be accompanied by the normal Baylis–Hillman products or their respective tricyclic dimers.
- Full Text:
- Date Issued: 2009
Citizen participation, decentralization and inclusive development : a survey on citizen participation and decentralization in South Africa with specific reference to the Eastern Cape c.2005
- Authors: Robino, Carolina
- Date: 2009
- Subjects: Local government -- Citizen participation , Decentralization in government -- South Africa , Political planning -- Citizen participation , Community development, Urban -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9084 , http://hdl.handle.net/10948/875 , Local government -- Citizen participation , Decentralization in government -- South Africa , Political planning -- Citizen participation , Community development, Urban -- South Africa -- Eastern Cape
- Description: Contemporary debates about development confer a prominent role to citizen participation and decentralization. Growing scepticism about the efficacy of narrowly conceived measures add pressure to reform development both theoretically and in practical terms. There is a greater understanding that ‘traditional’ development approaches and policies need to be reformulated and decentralization and citizen participation have been proposed as remedies to previous development failures. It is frequently argued that citizen participation will improve the efficiency and efficacy of public services. Citizen participation is meant to render local government more accountable and to contribute to deepening democracy, by reinforcing representative democratic institutions with participatory forms. At the same time, decentralization reforms have been proposed as a response to the failures of highly centralized states. From a political perspective, it is argued, decentralization reforms can help the central state gain legitimacy and have been seen as a strategy for maintaining political stability. It has been repeatedly suggested that physical proximity makes it easier for citizens to hold local officials accountable for their performance. From an economic perspective, decentralization can improve the match between the mix of services provided by the public sector and the preferences of the local population. It has also been noted that people are more willing to pay for services that respond to their priorities and that increased competition between local governments generates spaces for more creative responses adapted to local needs. But then, can decentralization and citizen participation live up to the faith and expectations that they have inspired? I argue that the literature commonly over-emphasises the role of citizen participation and decentralization in development and what these processes and reforms can achieve. Much of the evidence is anecdotal in nature and tends to neglect the specific contexts in which these processes take place. Also largely ignored are political economy considerations and a critical exploration of the relationship between these two key words. At best, when their interrelationships are addressed decentralization and citizen participation are conceived as based on a symbiotic relationship. I suggest, however, that the relationship between these two processes is not as straightforward as most of the literature assumes. The meanings of these two key words in current development lexicon are explored and critically assessed. I argue that whether or not the rising prominence of these two words actually means the emergence of a new development agenda is a moot point. It critically depends on the understandings of these ambiguous terms. The thesis adopts a political economy approach. Combined with this is an awareness of the broader historical and socio-economic context in which citizen participation and decentralization take place. The thesis applies these ideas triangulating diverse research methods and data sources. It combines a literature review and documentary analysis, a survey conducted with municipal authorities and civil society organizations in the Eastern Cape as well as structured interviews with Ward councillors and with key informants. From a theoretical perspective, the study lays a foundation for understanding the relationship between development policies outcomes and the nature of citizen participation and decentralization in developing countries. This, in turn, provides a basis from which citizen participation and decentralization in South Africa can be assessed and understood. The thesis presents evidence from a case study of the Eastern Cape, South Africa. By revealing how different dimensions of decentralization and citizen participation operate and intersect, the findings demonstrate, that contrary to common knowledge, citizen participation and decentralization are frequently at odds. Moreover, contrary to frequent statements, the research also shows that opening new spaces for participation in decentralized local governance can result in fewer changes and disappointing results at best, undermining the transformative potential of the concepts of participation and decentralization.
- Full Text:
- Date Issued: 2009
- Authors: Robino, Carolina
- Date: 2009
- Subjects: Local government -- Citizen participation , Decentralization in government -- South Africa , Political planning -- Citizen participation , Community development, Urban -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9084 , http://hdl.handle.net/10948/875 , Local government -- Citizen participation , Decentralization in government -- South Africa , Political planning -- Citizen participation , Community development, Urban -- South Africa -- Eastern Cape
- Description: Contemporary debates about development confer a prominent role to citizen participation and decentralization. Growing scepticism about the efficacy of narrowly conceived measures add pressure to reform development both theoretically and in practical terms. There is a greater understanding that ‘traditional’ development approaches and policies need to be reformulated and decentralization and citizen participation have been proposed as remedies to previous development failures. It is frequently argued that citizen participation will improve the efficiency and efficacy of public services. Citizen participation is meant to render local government more accountable and to contribute to deepening democracy, by reinforcing representative democratic institutions with participatory forms. At the same time, decentralization reforms have been proposed as a response to the failures of highly centralized states. From a political perspective, it is argued, decentralization reforms can help the central state gain legitimacy and have been seen as a strategy for maintaining political stability. It has been repeatedly suggested that physical proximity makes it easier for citizens to hold local officials accountable for their performance. From an economic perspective, decentralization can improve the match between the mix of services provided by the public sector and the preferences of the local population. It has also been noted that people are more willing to pay for services that respond to their priorities and that increased competition between local governments generates spaces for more creative responses adapted to local needs. But then, can decentralization and citizen participation live up to the faith and expectations that they have inspired? I argue that the literature commonly over-emphasises the role of citizen participation and decentralization in development and what these processes and reforms can achieve. Much of the evidence is anecdotal in nature and tends to neglect the specific contexts in which these processes take place. Also largely ignored are political economy considerations and a critical exploration of the relationship between these two key words. At best, when their interrelationships are addressed decentralization and citizen participation are conceived as based on a symbiotic relationship. I suggest, however, that the relationship between these two processes is not as straightforward as most of the literature assumes. The meanings of these two key words in current development lexicon are explored and critically assessed. I argue that whether or not the rising prominence of these two words actually means the emergence of a new development agenda is a moot point. It critically depends on the understandings of these ambiguous terms. The thesis adopts a political economy approach. Combined with this is an awareness of the broader historical and socio-economic context in which citizen participation and decentralization take place. The thesis applies these ideas triangulating diverse research methods and data sources. It combines a literature review and documentary analysis, a survey conducted with municipal authorities and civil society organizations in the Eastern Cape as well as structured interviews with Ward councillors and with key informants. From a theoretical perspective, the study lays a foundation for understanding the relationship between development policies outcomes and the nature of citizen participation and decentralization in developing countries. This, in turn, provides a basis from which citizen participation and decentralization in South Africa can be assessed and understood. The thesis presents evidence from a case study of the Eastern Cape, South Africa. By revealing how different dimensions of decentralization and citizen participation operate and intersect, the findings demonstrate, that contrary to common knowledge, citizen participation and decentralization are frequently at odds. Moreover, contrary to frequent statements, the research also shows that opening new spaces for participation in decentralized local governance can result in fewer changes and disappointing results at best, undermining the transformative potential of the concepts of participation and decentralization.
- Full Text:
- Date Issued: 2009
Civil engineering components for a conceptual elevated light rail transit model with reference to Nelson Mandela Bay
- Authors: Zang, Jin
- Date: 2009
- Subjects: Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9593 , http://hdl.handle.net/10948/769 , Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Description: The increase of motor vehicles, especially in cities, cause transport problems of traffic congestion, vehicle accidents, air pollution and a lack of public spaces. The increasing number of motor vehicles consumes huge amounts of finite petrol energy and emits large amounts of gases that are harmful to the atmosphere and the natural environment. Therefore, the current road transport network is not a sustainable form of public transport for the future. In order to seek a suitable transportation mode, the Infrastructure and Engineering Business Unit of the Nelson Mandela Bay Municipality (NMBM) did some feasibility studies about light rail transit (LRT) from 1984 to 1988. The NMBM-report (1988: 8) concluded that a LRT system would provide the most suitable and primary mode to serve Nelson Mandela Bay (NMB). Although LRT was regarded as the most suitable primary mode of transport at that time (1988), further studies that were reported in 2006 recommended an alternative public transportation system. This research refers to these studies done for the NMB area and other studies and reports for other areas, but focus on the identification of the most suitable civil engineering components for a conceptual elevated light rail transit (ELRT) model. Electrical driven LRT systems have advantages over internal-combustion driven vehicles in terms of environmental protection. Traditional LRT systems are at ground level and are integrated with the existing road network. Some successful LRT systems indicate that the success of LRT systems is mainly dependent on integration with the existing road network. However, the integration of road transport systems with LRT systems cause increased congestion and accidents. An ELRT system can solve these problems. Bangkok has already built an ELRT system to solve its severe traffic congestion. 4 In order to develop a conceptual ELRT model, this research aimed to determine the most suitable civil engineering components for a conceptual ELRT model, including: (i) the most suitable type of bridge foundation; (ii) the most suitable type bridge girder; (iii) the most suitable type of sleeper; and (iv) whether the track should be a ballasted or non-ballasted type. The grounded theory approach was adopted to build up sets of data from which the most suitable components could be selected. In addition, design analyses were done of the various types of components to determine their suitability for a conceptual ELRT model. Experienced engineers and experts were also consulted to identify the most suitable components. After analyses and selection of the most suitable components, outstanding experts were approached to evaluate the components that showed up as the most suitable through the research. The research results indicated that bored and cast-in-place piles, a double-cell trapezoidal segmental box girder, and twin-block sleepers on a non-ballasted sleeper bed are the most suitable civil engineering components.
- Full Text:
- Date Issued: 2009
- Authors: Zang, Jin
- Date: 2009
- Subjects: Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9593 , http://hdl.handle.net/10948/769 , Railroads, Local and light -- South Africa -- Port Elizabeth , Street-railroads -- South Africa -- Port Elizabeth , Local transit -- South Africa -- Port Elizabeth
- Description: The increase of motor vehicles, especially in cities, cause transport problems of traffic congestion, vehicle accidents, air pollution and a lack of public spaces. The increasing number of motor vehicles consumes huge amounts of finite petrol energy and emits large amounts of gases that are harmful to the atmosphere and the natural environment. Therefore, the current road transport network is not a sustainable form of public transport for the future. In order to seek a suitable transportation mode, the Infrastructure and Engineering Business Unit of the Nelson Mandela Bay Municipality (NMBM) did some feasibility studies about light rail transit (LRT) from 1984 to 1988. The NMBM-report (1988: 8) concluded that a LRT system would provide the most suitable and primary mode to serve Nelson Mandela Bay (NMB). Although LRT was regarded as the most suitable primary mode of transport at that time (1988), further studies that were reported in 2006 recommended an alternative public transportation system. This research refers to these studies done for the NMB area and other studies and reports for other areas, but focus on the identification of the most suitable civil engineering components for a conceptual elevated light rail transit (ELRT) model. Electrical driven LRT systems have advantages over internal-combustion driven vehicles in terms of environmental protection. Traditional LRT systems are at ground level and are integrated with the existing road network. Some successful LRT systems indicate that the success of LRT systems is mainly dependent on integration with the existing road network. However, the integration of road transport systems with LRT systems cause increased congestion and accidents. An ELRT system can solve these problems. Bangkok has already built an ELRT system to solve its severe traffic congestion. 4 In order to develop a conceptual ELRT model, this research aimed to determine the most suitable civil engineering components for a conceptual ELRT model, including: (i) the most suitable type of bridge foundation; (ii) the most suitable type bridge girder; (iii) the most suitable type of sleeper; and (iv) whether the track should be a ballasted or non-ballasted type. The grounded theory approach was adopted to build up sets of data from which the most suitable components could be selected. In addition, design analyses were done of the various types of components to determine their suitability for a conceptual ELRT model. Experienced engineers and experts were also consulted to identify the most suitable components. After analyses and selection of the most suitable components, outstanding experts were approached to evaluate the components that showed up as the most suitable through the research. The research results indicated that bored and cast-in-place piles, a double-cell trapezoidal segmental box girder, and twin-block sleepers on a non-ballasted sleeper bed are the most suitable civil engineering components.
- Full Text:
- Date Issued: 2009
Civil liability of an employer for injuries on duty
- Authors: Brandt, Denver Charles
- Date: 2009
- Subjects: Liability (Law) -- South Africa , Employers' liability -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10195 , http://hdl.handle.net/10948/1042 , Liability (Law) -- South Africa , Employers' liability -- South Africa , Labor laws and legislation -- South Africa
- Description: The workplace has evolved dramatically in the past decades. Technology has improved, innovative ways of utilising nuclear power have been developed, new chemicals have been introduced to the market and the adverse effects of other chemicals on both human health and safety and the environment have been discovered. This has influenced the nature of the workplace itself. While employees enjoy a common law right to a safe working environment and health and safety, state intervention currently provides restricted claims to an employee who has sustained injuries or contracted occupational diseases. This thesis explores the effect of section 35 of the Compensation for Occupational Injuries and Diseases Act 130 of 1993 which deprives an employee of its common law right to institute civil action against an employer for an injury sustained or disease contracted during the course and scope of employment. Furthermore, this thesis also explores the marriage between the Occupational Health and Safety Act 89 of 1993 and the Compensation for Occupational Injuries and Diseases Act 130 of 1993 as well as the position of ‘employee’ and ‘employer’ insofar as the scope and application of these two acts are concerned with specific reference to the position of labour broker employees. The use of indemnity clauses and its validity in South Africa will also be explored and discussed. This thesis also dedicates a chapter to the leading case authority of Jooste v Score Supermarket Trading (Pty) Ltd and its effect insofar as the enforcement and application of section 35 of the Compensation for Occupational Injuries and Diseases Act 130 of 1993 is concerned. It is impossible to mention all the changes in the workplace that have occurred in the recent years, and this discussion therefore focuses on the current position of employees who have been deprived of their common law right to institute delictual action for damages resulting from an injury sustained while on duty as well as the impact of the current restrictive claims available to them. Alterations to existing approaches are also proposed to resurrect the common law right of employees to institute action against their employers. , Abstract
- Full Text:
- Date Issued: 2009
- Authors: Brandt, Denver Charles
- Date: 2009
- Subjects: Liability (Law) -- South Africa , Employers' liability -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10195 , http://hdl.handle.net/10948/1042 , Liability (Law) -- South Africa , Employers' liability -- South Africa , Labor laws and legislation -- South Africa
- Description: The workplace has evolved dramatically in the past decades. Technology has improved, innovative ways of utilising nuclear power have been developed, new chemicals have been introduced to the market and the adverse effects of other chemicals on both human health and safety and the environment have been discovered. This has influenced the nature of the workplace itself. While employees enjoy a common law right to a safe working environment and health and safety, state intervention currently provides restricted claims to an employee who has sustained injuries or contracted occupational diseases. This thesis explores the effect of section 35 of the Compensation for Occupational Injuries and Diseases Act 130 of 1993 which deprives an employee of its common law right to institute civil action against an employer for an injury sustained or disease contracted during the course and scope of employment. Furthermore, this thesis also explores the marriage between the Occupational Health and Safety Act 89 of 1993 and the Compensation for Occupational Injuries and Diseases Act 130 of 1993 as well as the position of ‘employee’ and ‘employer’ insofar as the scope and application of these two acts are concerned with specific reference to the position of labour broker employees. The use of indemnity clauses and its validity in South Africa will also be explored and discussed. This thesis also dedicates a chapter to the leading case authority of Jooste v Score Supermarket Trading (Pty) Ltd and its effect insofar as the enforcement and application of section 35 of the Compensation for Occupational Injuries and Diseases Act 130 of 1993 is concerned. It is impossible to mention all the changes in the workplace that have occurred in the recent years, and this discussion therefore focuses on the current position of employees who have been deprived of their common law right to institute delictual action for damages resulting from an injury sustained while on duty as well as the impact of the current restrictive claims available to them. Alterations to existing approaches are also proposed to resurrect the common law right of employees to institute action against their employers. , Abstract
- Full Text:
- Date Issued: 2009
Civil society's quest for democracy in Zimbabwe: origins,barriers and prospects, 1900-2008
- Authors: Magure, Booker
- Date: 2009
- Subjects: Civil Society -- Zimbabwe Zimbabwe -- Politics and government -- 1980 Zimbabwe -- Economic conditions Zimbabwe -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2798 , http://hdl.handle.net/10962/d1003008
- Description: This thesis is a critical examination of the origins, barriers and prospects for a working class-led civil society as it sought to democratise Zimbabwe’s post-colonial state. It is an interdisciplinary but historically informed analysis of how advanced capitalist development promoted the emergence of social movement unionism with a potentiality to advance democracy in Zimbabwe. Despite occurring on a much smaller and thinner scale, the evolution of civil society in colonial Zimbabwe was akin to what happened in 19th century Britain where capitalist expansion presented a foundation for democratisation. However, big underlying barriers exist in Zimbabwe, resulting from various forms of authoritarian structures and forcible mobilisation strategies emanating from colonialism and the protracted war of liberation. ZANU PF’s violent reaction to memory contests by non-participants in the war of liberation seeking an alternative political agenda attest to the controversial and polemical nature of struggles over memory and forgetting in contemporary Zimbabwean politics. These structural impediments forestalled the organic growth of civil society in Zimbabwe, thereby explaining its inchoate status and the failure to significantly determine the course of public policy. While recognising the democratic aspirations and capacities of the working class in precipitating political change, this thesis takes into consideration the impact of other factors on state-society relations. These include deepening state barbarism, globalisation, and technological advances in communication, transnational civil society, a dysfunctional economy, migration and remittances. Finally this thesis presents an optimistic scenario about the prospects for civil society and democratisation in Zimbabwe. I argue that the revival of the productive sectors of the economy can possibly strengthen the labour movement and revive its capacities for ushering in a democracy.
- Full Text:
- Date Issued: 2009
- Authors: Magure, Booker
- Date: 2009
- Subjects: Civil Society -- Zimbabwe Zimbabwe -- Politics and government -- 1980 Zimbabwe -- Economic conditions Zimbabwe -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2798 , http://hdl.handle.net/10962/d1003008
- Description: This thesis is a critical examination of the origins, barriers and prospects for a working class-led civil society as it sought to democratise Zimbabwe’s post-colonial state. It is an interdisciplinary but historically informed analysis of how advanced capitalist development promoted the emergence of social movement unionism with a potentiality to advance democracy in Zimbabwe. Despite occurring on a much smaller and thinner scale, the evolution of civil society in colonial Zimbabwe was akin to what happened in 19th century Britain where capitalist expansion presented a foundation for democratisation. However, big underlying barriers exist in Zimbabwe, resulting from various forms of authoritarian structures and forcible mobilisation strategies emanating from colonialism and the protracted war of liberation. ZANU PF’s violent reaction to memory contests by non-participants in the war of liberation seeking an alternative political agenda attest to the controversial and polemical nature of struggles over memory and forgetting in contemporary Zimbabwean politics. These structural impediments forestalled the organic growth of civil society in Zimbabwe, thereby explaining its inchoate status and the failure to significantly determine the course of public policy. While recognising the democratic aspirations and capacities of the working class in precipitating political change, this thesis takes into consideration the impact of other factors on state-society relations. These include deepening state barbarism, globalisation, and technological advances in communication, transnational civil society, a dysfunctional economy, migration and remittances. Finally this thesis presents an optimistic scenario about the prospects for civil society and democratisation in Zimbabwe. I argue that the revival of the productive sectors of the economy can possibly strengthen the labour movement and revive its capacities for ushering in a democracy.
- Full Text:
- Date Issued: 2009
Clem Sunter's transformational leadership discourse: a linguistic analysis
- Authors: Eley, Georgina Jane
- Date: 2009
- Subjects: Linguistics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/61994 , vital:28093
- Description: Since the 1970s, two distinct leadership styles have been recognised in the fields of business and organisational research - transactional and transformational leadership. Transactional leadership is seen to resemble managerial-type leadership where followers fulfil their duties in return for rewards that satisfy their self-interest, such as pay or promotion. Transformational leadership, as the label suggests, is leadership that is seen to transform followers from their everyday selves to their better selves (Yukl 1998). Transformational leaders motivate followers by appealing to their higher-order needs, offering incentives for compliance such as feelings of personal empowerment, a sense of moral self-actualisation and an emphasis on the individual's contribution to the community at large (Harvey 2004). These leaders have been observed to emerge and thrive within contexts fraught with socio-political and economic turbulence, where they maximise the uncertainty of the environment to instigate change. Transformational leaders are seen to be especially adept at using discourse to foster strong, persuasive interpersonal relations with their followers. This research reports on, particularly, the interpersonal dimension of Clem Sunter's transformational discourse; he being a prominent South African scenario planner and business leader. It is essentially a qualitative study that describes Sunter's discourse in three of his texts written in 1996. The end to Apartheid in 1994 and transition from White to Black governance meant that the socio-political climate of 1996 South Africa was conducive to the rise of a transformational leader like Sunter. Although the country was, ostensibly, a democracy in 1996, much social transformation was still needed at the time Sunter produced his texts. The analysis are grounded mainly in Systemic Functional Linguistics, specifically APPRAISAL theory and, to some extent, Critical Discourse Analysis theory. However, the analyses do not follow a classic CDA analysis approach, but draw rather from more recent CDA work (cf. Fairclough 2003), such as the analysis of value assumption types within the texts. This analysis clearly demonstrates that Sunter's discourse is congruent 11 with the principal insights of transformational leadership. More than this, it is argued that these findings suggest a close link between transformational leadership and the goals of the latest social order of new capitalism, a link not made in the relevant research to date. The analysis of modes of operation of ideology in the texts (cf. Thompson 1990), also deriving from CDA, reinforces this, indicating that Sunter's transformational discourse promotes and maintains the kinds of power inequalities that underpin new capitalism. The APPRAISAL analysis of Affect choices in the text reveals a high frequency of disquiet, i.e. Sunter's discourse is seen to generate feelings of insecurity and fear. This feature, interestingly, is completely inconsistent with current transformational leadership theory, but would have been an effective motivational technique given the instability of the South African socio-political context in 1996. In addition, the APPRAISAL analysis of Judgement reveals that Sunter evokes high levels of tenacity and appeals to readers' morality, ethics and feelings of group-efficacy - all higher-order needs. The argument here too is that the socio-political context enabled Sunter to stimulate disquiet and tenacity in an effective configuration to mobilise change in his reader and promote the goals of new capitalism. The thesis concludes with a reflection on the limitations of the study and makes various recommendations for future research.
- Full Text:
- Date Issued: 2009
- Authors: Eley, Georgina Jane
- Date: 2009
- Subjects: Linguistics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/61994 , vital:28093
- Description: Since the 1970s, two distinct leadership styles have been recognised in the fields of business and organisational research - transactional and transformational leadership. Transactional leadership is seen to resemble managerial-type leadership where followers fulfil their duties in return for rewards that satisfy their self-interest, such as pay or promotion. Transformational leadership, as the label suggests, is leadership that is seen to transform followers from their everyday selves to their better selves (Yukl 1998). Transformational leaders motivate followers by appealing to their higher-order needs, offering incentives for compliance such as feelings of personal empowerment, a sense of moral self-actualisation and an emphasis on the individual's contribution to the community at large (Harvey 2004). These leaders have been observed to emerge and thrive within contexts fraught with socio-political and economic turbulence, where they maximise the uncertainty of the environment to instigate change. Transformational leaders are seen to be especially adept at using discourse to foster strong, persuasive interpersonal relations with their followers. This research reports on, particularly, the interpersonal dimension of Clem Sunter's transformational discourse; he being a prominent South African scenario planner and business leader. It is essentially a qualitative study that describes Sunter's discourse in three of his texts written in 1996. The end to Apartheid in 1994 and transition from White to Black governance meant that the socio-political climate of 1996 South Africa was conducive to the rise of a transformational leader like Sunter. Although the country was, ostensibly, a democracy in 1996, much social transformation was still needed at the time Sunter produced his texts. The analysis are grounded mainly in Systemic Functional Linguistics, specifically APPRAISAL theory and, to some extent, Critical Discourse Analysis theory. However, the analyses do not follow a classic CDA analysis approach, but draw rather from more recent CDA work (cf. Fairclough 2003), such as the analysis of value assumption types within the texts. This analysis clearly demonstrates that Sunter's discourse is congruent 11 with the principal insights of transformational leadership. More than this, it is argued that these findings suggest a close link between transformational leadership and the goals of the latest social order of new capitalism, a link not made in the relevant research to date. The analysis of modes of operation of ideology in the texts (cf. Thompson 1990), also deriving from CDA, reinforces this, indicating that Sunter's transformational discourse promotes and maintains the kinds of power inequalities that underpin new capitalism. The APPRAISAL analysis of Affect choices in the text reveals a high frequency of disquiet, i.e. Sunter's discourse is seen to generate feelings of insecurity and fear. This feature, interestingly, is completely inconsistent with current transformational leadership theory, but would have been an effective motivational technique given the instability of the South African socio-political context in 1996. In addition, the APPRAISAL analysis of Judgement reveals that Sunter evokes high levels of tenacity and appeals to readers' morality, ethics and feelings of group-efficacy - all higher-order needs. The argument here too is that the socio-political context enabled Sunter to stimulate disquiet and tenacity in an effective configuration to mobilise change in his reader and promote the goals of new capitalism. The thesis concludes with a reflection on the limitations of the study and makes various recommendations for future research.
- Full Text:
- Date Issued: 2009
Clustering algorithms and their effect on edge preservation in image compression
- Authors: Ndebele, Nothando Elizabeth
- Date: 2009
- Subjects: Image compression , Vector analysis , Cluster analysis , Cluster anaylsis -- Data processing , Algorithms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5576 , http://hdl.handle.net/10962/d1008210 , Image compression , Vector analysis , Cluster analysis , Cluster anaylsis -- Data processing , Algorithms
- Description: Image compression aims to reduce the amount of data that is stored or transmitted for images. One technique that may be used to this end is vector quantization. Vectors may be used to represent images. Vector quantization reduces the number of vectors required for an image by representing a cluster of similar vectors by one typical vector that is part of a set of vectors referred to as the code book. For compression, for each image vector, only the closest codebook vector is stored or transmitted. For reconstruction, the image vectors are again replaced by the the closest codebook vectors. Hence vector quantization is a lossy compression technique and the quality of the reconstructed image depends strongly on the quality of the codebook. The design of the codebook is therefore an important part of the process. In this thesis we examine three clustering algorithms which can be used for codebook design in image compression: c-means (CM), fuzzy c-means (FCM) and learning vector quantization (LVQ). We give a description of these algorithms and their application to codebook design. Edges are an important part of the visual information contained in an image. It is essential therefore to use codebooks which allow an accurate representation of the edges. One of the shortcomings of using vector quantization is poor edge representation. We therefore carry out experiments using these algorithms to compare their edge preserving qualities. We also investigate the combination of these algorithms with classified vector quantization (CVQ) and the replication method (RM). Both these methods have been suggested as methods for improving edge representation. We use a cross validation approach to estimate the mean squared error to measure the performance of each of the algorithms and the edge preserving methods. The results reflect that the edges are less accurately represented than the non - edge areas when using CM, FCM and LVQ. The advantage of using CVQ is that the time taken for code book design is reduced particularly for CM and FCM. RM is found to be effective where the codebook is trained using a set that has larger proportions of edges than the test set.
- Full Text:
- Date Issued: 2009
- Authors: Ndebele, Nothando Elizabeth
- Date: 2009
- Subjects: Image compression , Vector analysis , Cluster analysis , Cluster anaylsis -- Data processing , Algorithms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5576 , http://hdl.handle.net/10962/d1008210 , Image compression , Vector analysis , Cluster analysis , Cluster anaylsis -- Data processing , Algorithms
- Description: Image compression aims to reduce the amount of data that is stored or transmitted for images. One technique that may be used to this end is vector quantization. Vectors may be used to represent images. Vector quantization reduces the number of vectors required for an image by representing a cluster of similar vectors by one typical vector that is part of a set of vectors referred to as the code book. For compression, for each image vector, only the closest codebook vector is stored or transmitted. For reconstruction, the image vectors are again replaced by the the closest codebook vectors. Hence vector quantization is a lossy compression technique and the quality of the reconstructed image depends strongly on the quality of the codebook. The design of the codebook is therefore an important part of the process. In this thesis we examine three clustering algorithms which can be used for codebook design in image compression: c-means (CM), fuzzy c-means (FCM) and learning vector quantization (LVQ). We give a description of these algorithms and their application to codebook design. Edges are an important part of the visual information contained in an image. It is essential therefore to use codebooks which allow an accurate representation of the edges. One of the shortcomings of using vector quantization is poor edge representation. We therefore carry out experiments using these algorithms to compare their edge preserving qualities. We also investigate the combination of these algorithms with classified vector quantization (CVQ) and the replication method (RM). Both these methods have been suggested as methods for improving edge representation. We use a cross validation approach to estimate the mean squared error to measure the performance of each of the algorithms and the edge preserving methods. The results reflect that the edges are less accurately represented than the non - edge areas when using CM, FCM and LVQ. The advantage of using CVQ is that the time taken for code book design is reduced particularly for CM and FCM. RM is found to be effective where the codebook is trained using a set that has larger proportions of edges than the test set.
- Full Text:
- Date Issued: 2009
Collective forgiving
- Authors: Hamilton, Kelly
- Date: 2009
- Subjects: Forgiveness -- Philosophy Collective behavior -- Philosophy Retribution -- Philosophy Reconciliation -- Philosophy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2709 , http://hdl.handle.net/10962/d1002839
- Description: Forgiveness is traditionally understood as a personal change of heart, in which an individual victim of a wrongdoing overcomes her resentment towards the perpetrator of that wrongdoing. Peter Strawson (1974) famously argued that resentment is a personal participant retributive reactive attitude, and the overcoming of such an attitude through forgiveness is itself a personal reactive attitude – in other words, forgiveness is an affective response to a wrongdoing by an individual victim, that is devoid of a retributive element. Because reactive attitudes are personal, it is argued that collectives – groups of individuals – cannot forgive, since collectives cannot, as collectives, hold reactive attitudes. I argue against this. I show that it is possible for collectives to hold attitudes in a way that is not reducible to individuals holding attitudes as individuals, and yet these attitudes still remain personal. Individuals exist within communities, and are interdependent on one another. Much of an individual‟s beliefs and attitudes depend on the collectives that she is a part of. I argue that an attitude is collective when it is deemed to be the appropriate attitude for members of the collective to hold. Members of the collective will take this attitude on as their own insofar as they identify themselves as members of the collective. Individuals hold the attitude, making the attitude personal, but since the individuals hold the attitude in virtue of their membership to a collective, the attitude is also collective. Given that forgiveness is itself a reactive attitude, and that collectives can hold attitudes, I argue that it is possible for a collective to forgive. Members of a collective will come to forgive when forgiveness is held up as the appropriate attitude for them, and once enough members have taken on the attitude of forgiveness as their own attitude, a collective can be said to have forgiven.
- Full Text:
- Date Issued: 2009
- Authors: Hamilton, Kelly
- Date: 2009
- Subjects: Forgiveness -- Philosophy Collective behavior -- Philosophy Retribution -- Philosophy Reconciliation -- Philosophy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2709 , http://hdl.handle.net/10962/d1002839
- Description: Forgiveness is traditionally understood as a personal change of heart, in which an individual victim of a wrongdoing overcomes her resentment towards the perpetrator of that wrongdoing. Peter Strawson (1974) famously argued that resentment is a personal participant retributive reactive attitude, and the overcoming of such an attitude through forgiveness is itself a personal reactive attitude – in other words, forgiveness is an affective response to a wrongdoing by an individual victim, that is devoid of a retributive element. Because reactive attitudes are personal, it is argued that collectives – groups of individuals – cannot forgive, since collectives cannot, as collectives, hold reactive attitudes. I argue against this. I show that it is possible for collectives to hold attitudes in a way that is not reducible to individuals holding attitudes as individuals, and yet these attitudes still remain personal. Individuals exist within communities, and are interdependent on one another. Much of an individual‟s beliefs and attitudes depend on the collectives that she is a part of. I argue that an attitude is collective when it is deemed to be the appropriate attitude for members of the collective to hold. Members of the collective will take this attitude on as their own insofar as they identify themselves as members of the collective. Individuals hold the attitude, making the attitude personal, but since the individuals hold the attitude in virtue of their membership to a collective, the attitude is also collective. Given that forgiveness is itself a reactive attitude, and that collectives can hold attitudes, I argue that it is possible for a collective to forgive. Members of a collective will come to forgive when forgiveness is held up as the appropriate attitude for them, and once enough members have taken on the attitude of forgiveness as their own attitude, a collective can be said to have forgiven.
- Full Text:
- Date Issued: 2009
Community participation in solid waste management in high-density low-income areas: the case of C-Section in Duncan Village
- Authors: Mazinyo, Sonwabo Perez
- Date: 2009
- Subjects: Refuse and refuse disposal -- South Africa -- Eastern Cape , Sewage disposal -- South Africa -- Eastern Cape , Low-income housing -- South Africa -- Eastern Cape , Social participation -- South Africa -- Eastern Cape , Conflict management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPhil (Environmental Studies)
- Identifier: vital:11875 , http://hdl.handle.net/10353/261 , Refuse and refuse disposal -- South Africa -- Eastern Cape , Sewage disposal -- South Africa -- Eastern Cape , Low-income housing -- South Africa -- Eastern Cape , Social participation -- South Africa -- Eastern Cape , Conflict management -- South Africa -- Eastern Cape
- Description: Solid waste management in high density low-income areas is a problem that manifests itself in ubiquitous illegal dumpsites and unhealthy living environmental conditions. Community participation in solid waste management in Duncan Village, C-Section has been found to be part of the solution to this problem. This study investigates community participation in SWM at household level, community waste project level and at informal salvaging/scavenging level. The integration of community participation into existing Buffalo City Municipality waste management plans and the nature of the relationship between the different interest groups are investigated. This study employs qualitative research methods where interviews and participatory observations are used to investigate key objectives. The nature of the relationships between councillors, C-Section residents and the Buffalo City Municipality Departments are tenuous and fraught with conflicts. These conflicts emerge due to the lack of communication as well as due to the non-integration of the community interest groups‟ views and activities into solid waste management in C-Section. The study suggests that this lack of communication should be addressed and that integrated participation of all stakeholders must be encouraged for effective solid waste management in a high density low-income community.
- Full Text:
- Date Issued: 2009
- Authors: Mazinyo, Sonwabo Perez
- Date: 2009
- Subjects: Refuse and refuse disposal -- South Africa -- Eastern Cape , Sewage disposal -- South Africa -- Eastern Cape , Low-income housing -- South Africa -- Eastern Cape , Social participation -- South Africa -- Eastern Cape , Conflict management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPhil (Environmental Studies)
- Identifier: vital:11875 , http://hdl.handle.net/10353/261 , Refuse and refuse disposal -- South Africa -- Eastern Cape , Sewage disposal -- South Africa -- Eastern Cape , Low-income housing -- South Africa -- Eastern Cape , Social participation -- South Africa -- Eastern Cape , Conflict management -- South Africa -- Eastern Cape
- Description: Solid waste management in high density low-income areas is a problem that manifests itself in ubiquitous illegal dumpsites and unhealthy living environmental conditions. Community participation in solid waste management in Duncan Village, C-Section has been found to be part of the solution to this problem. This study investigates community participation in SWM at household level, community waste project level and at informal salvaging/scavenging level. The integration of community participation into existing Buffalo City Municipality waste management plans and the nature of the relationship between the different interest groups are investigated. This study employs qualitative research methods where interviews and participatory observations are used to investigate key objectives. The nature of the relationships between councillors, C-Section residents and the Buffalo City Municipality Departments are tenuous and fraught with conflicts. These conflicts emerge due to the lack of communication as well as due to the non-integration of the community interest groups‟ views and activities into solid waste management in C-Section. The study suggests that this lack of communication should be addressed and that integrated participation of all stakeholders must be encouraged for effective solid waste management in a high density low-income community.
- Full Text:
- Date Issued: 2009
Comparative electrocatalytic behavior of self-assembled monolayer of thiol derivatised Co (II) phthalocyanines on gold disk, ultramicro cylinder and fiber electrodes
- Nombona, Nolwazi, Geraldo, Daniela A, Hakuzimana, Jean, Schwarz, Anne, Westbroek, Philippe, Nyokong, Tebello
- Authors: Nombona, Nolwazi , Geraldo, Daniela A , Hakuzimana, Jean , Schwarz, Anne , Westbroek, Philippe , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263488 , vital:53632 , xlink:href="https://doi.org/10.1007/s10800-008-9716-y"
- Description: This paper reports on the use of thiol derivatised cobalt phthalocyanines as self assembled monolayers (SAMs) on gold disk electrode, gold ultramicro-cylinder electrode (UMCE) and on gold coated fiber for the detection of L-cysteine. The complexes are peripherally and non-peripherally substituted with phenylthio substituents. The SAM modified electrodes showed enhancement of catalytic currents and overpotential reduction occurred on the gold modified electrodes with different geometries. Electrocatalytic oxidation of L-cysteine on SAM modified gold coated fiber was reported for the first time. The gold coated fiber and ultramicro cylinder electrode were less stable towards the electrocatalytic oxidation of cysteine compared to its oxidation on the gold disk. The gold disk electrode gave better catalytic performance in terms of stability and reduction of overpotential.
- Full Text:
- Date Issued: 2009
- Authors: Nombona, Nolwazi , Geraldo, Daniela A , Hakuzimana, Jean , Schwarz, Anne , Westbroek, Philippe , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263488 , vital:53632 , xlink:href="https://doi.org/10.1007/s10800-008-9716-y"
- Description: This paper reports on the use of thiol derivatised cobalt phthalocyanines as self assembled monolayers (SAMs) on gold disk electrode, gold ultramicro-cylinder electrode (UMCE) and on gold coated fiber for the detection of L-cysteine. The complexes are peripherally and non-peripherally substituted with phenylthio substituents. The SAM modified electrodes showed enhancement of catalytic currents and overpotential reduction occurred on the gold modified electrodes with different geometries. Electrocatalytic oxidation of L-cysteine on SAM modified gold coated fiber was reported for the first time. The gold coated fiber and ultramicro cylinder electrode were less stable towards the electrocatalytic oxidation of cysteine compared to its oxidation on the gold disk. The gold disk electrode gave better catalytic performance in terms of stability and reduction of overpotential.
- Full Text:
- Date Issued: 2009
Comparing and contrasting liberal, communitarian and feminist approaches to resolving tensions between customary and constitutional law: the case of polygamy in Swaziland
- Authors: Manson, Katherine Elizabeth
- Date: 2009
- Subjects: Human rights -- Swaziland Constitutional law -- Swaziland Customary law -- Swaziland Culture and law -- Swaziland Women's rights -- Swaziland Sex discrimination against women -- Swaziland Polygamy -- Swaziland Liberalism Communitarianism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2801 , http://hdl.handle.net/10962/d1003011
- Description: Tensions between the individual rights and freedoms found in constitutional bills of rights and the traditionally prescribed social roles and positions articulated in African customary law systems have often been characterised as tensions between communitarian and liberal philosophies. In particular, the notion of gender equality, which is often a feature of the protections offered by constitutional bills of rights, is seen to be in direct opposition to the overtly patriarchal character of many African customs and traditions. This thesis looks specifically at polygamy, long and widely considered in the West to be an oppressive practice premised on the assumed inferiority of women. The analysis considers the implications of polygamy in a particular cultural context, that of the Kingdom of Swaziland, where the newly instituted constitution is often seen to be incompatible with many aspects of Swazi customary law. Here, the tension between the constitutional commitment to gender equality and the persistence of polygamy as a seemingly discriminatory cultural practice forms a lens through which to view the debate as a whole. The theoretical analysis is supplemented by empirical research sourced from local media archives and in-depth interviews conducted with twelve Swazi women, both unmarried and married in polygamous relationships. Communitarian and liberal approaches to resolving this tension are compared, contrasted and finally critiqued from a feminist standpoint. The feminist critique of both communitarianism and liberalism implies that neither ideology promises much for women and affirms the relatively recent feminist suggestion that the key to resolving tensions between constitutional and customary law in general, and to uplifting the social/legal status of women in particular lies in the enhancement of women’s democratic participation and the improvement of women’s decision-making powers.
- Full Text:
- Date Issued: 2009
- Authors: Manson, Katherine Elizabeth
- Date: 2009
- Subjects: Human rights -- Swaziland Constitutional law -- Swaziland Customary law -- Swaziland Culture and law -- Swaziland Women's rights -- Swaziland Sex discrimination against women -- Swaziland Polygamy -- Swaziland Liberalism Communitarianism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2801 , http://hdl.handle.net/10962/d1003011
- Description: Tensions between the individual rights and freedoms found in constitutional bills of rights and the traditionally prescribed social roles and positions articulated in African customary law systems have often been characterised as tensions between communitarian and liberal philosophies. In particular, the notion of gender equality, which is often a feature of the protections offered by constitutional bills of rights, is seen to be in direct opposition to the overtly patriarchal character of many African customs and traditions. This thesis looks specifically at polygamy, long and widely considered in the West to be an oppressive practice premised on the assumed inferiority of women. The analysis considers the implications of polygamy in a particular cultural context, that of the Kingdom of Swaziland, where the newly instituted constitution is often seen to be incompatible with many aspects of Swazi customary law. Here, the tension between the constitutional commitment to gender equality and the persistence of polygamy as a seemingly discriminatory cultural practice forms a lens through which to view the debate as a whole. The theoretical analysis is supplemented by empirical research sourced from local media archives and in-depth interviews conducted with twelve Swazi women, both unmarried and married in polygamous relationships. Communitarian and liberal approaches to resolving this tension are compared, contrasted and finally critiqued from a feminist standpoint. The feminist critique of both communitarianism and liberalism implies that neither ideology promises much for women and affirms the relatively recent feminist suggestion that the key to resolving tensions between constitutional and customary law in general, and to uplifting the social/legal status of women in particular lies in the enhancement of women’s democratic participation and the improvement of women’s decision-making powers.
- Full Text:
- Date Issued: 2009
Comparing the development of a sample of South African pre-school boys and girls utilizing the Griffiths Mental Development Scales-extended revised
- Authors: Jakins, Tamarin Ashlea
- Date: 2009
- Subjects: Griffiths Scales of Mental Development , Preschool children -- Intelligence testing -- South Africa , Child development -- South Africa , Psychological tests for children -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9904 , http://hdl.handle.net/10948/990 , Griffiths Scales of Mental Development , Preschool children -- Intelligence testing -- South Africa , Child development -- South Africa , Psychological tests for children -- South Africa
- Description: Both children and adults share a common, culturally distinct view of what it means to be male or female. These gender stereotypes are pervasive in society and daily social interactions, and influence all aspects of gender development (Golombok & Fivush, 1994). The inherent physical differences of boys and girls may have triggered the speculation and accompanying myths surrounding the existence of gender differences in childhood development. Many people believe that boys and girls follow a different developmental path that lead to gender differences in intellectual ability. An up-to-date and integrative review of theory and research on gender indicates two opposing perspectives on the topic, with substantial information supporting each view. However, this is the first study to examine and compare a sample of South African pre-school boys and girls from a truly holistic developmental perspective on the recently released Griffiths Mental Development Scales-Extended Revised (GMDS-ER). Developmental theorists have emphasized the profound impact early childhood development has on subsequent development, as it shapes the course of an individual’s life. Contemporary cognitive developmental theories, such as Demetriou’s (2000; 2004) developmental model of cognitive development, advance that child development does not progress in a fixed and predictable manner. Instead, Demetriou proposes that development occurs in a wave-like fashion, where the processes and functions of the various levels of the mind may be at differing points in their cycle of development. When one function progresses to a higher level, it unlocks the possibility for another function to advance to a different point in its cycle (Demetriou et al., 2002). As the significance of understanding the process of early childhood development more fully increases, so does the need to establish with more confidence the value and role of developmental assessment in the early identification of problems. The overall purpose of this study was to generate comparative information regarding the general development of a sample of 5- and 6-year-old South African pre-school boys and girls. Specifically, the study aimed to explore and describe the developmental profiles of pre-school boys and girls within the abovementioned age group with respect to their overall performance on the GMDS-ER as well as their performance on the six Subscales. Then, the mean General Quotients (GQ) and developmental profiles of the pre-school boys and girls obtained on the GMDS-ER were compared. An exploratory-descriptive quantitative research method was used. The sample (N = 64) was selected through a combination of non-probability, purposive and convenience xiii sampling. Within this framework, a between-subjects design in which matching was used to control extraneous variables, was employed. Data was analysed using descriptive statistics and independent sample t-tests to compare the GQs of the gender groups. A Hotellings T2 was used to compare the Subscale profiles. No significant gender differences were found when comparing the overall developmental and Subscale profiles of the boys and girls on the GMDS-ER. However, certain interesting trends did emerge from a review of the findings when compared to the literature review and previous studies. The information generated from this study has contributed to our knowledge base of the performance of South African children on the recently released GMDS-ER.
- Full Text:
- Date Issued: 2009
- Authors: Jakins, Tamarin Ashlea
- Date: 2009
- Subjects: Griffiths Scales of Mental Development , Preschool children -- Intelligence testing -- South Africa , Child development -- South Africa , Psychological tests for children -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9904 , http://hdl.handle.net/10948/990 , Griffiths Scales of Mental Development , Preschool children -- Intelligence testing -- South Africa , Child development -- South Africa , Psychological tests for children -- South Africa
- Description: Both children and adults share a common, culturally distinct view of what it means to be male or female. These gender stereotypes are pervasive in society and daily social interactions, and influence all aspects of gender development (Golombok & Fivush, 1994). The inherent physical differences of boys and girls may have triggered the speculation and accompanying myths surrounding the existence of gender differences in childhood development. Many people believe that boys and girls follow a different developmental path that lead to gender differences in intellectual ability. An up-to-date and integrative review of theory and research on gender indicates two opposing perspectives on the topic, with substantial information supporting each view. However, this is the first study to examine and compare a sample of South African pre-school boys and girls from a truly holistic developmental perspective on the recently released Griffiths Mental Development Scales-Extended Revised (GMDS-ER). Developmental theorists have emphasized the profound impact early childhood development has on subsequent development, as it shapes the course of an individual’s life. Contemporary cognitive developmental theories, such as Demetriou’s (2000; 2004) developmental model of cognitive development, advance that child development does not progress in a fixed and predictable manner. Instead, Demetriou proposes that development occurs in a wave-like fashion, where the processes and functions of the various levels of the mind may be at differing points in their cycle of development. When one function progresses to a higher level, it unlocks the possibility for another function to advance to a different point in its cycle (Demetriou et al., 2002). As the significance of understanding the process of early childhood development more fully increases, so does the need to establish with more confidence the value and role of developmental assessment in the early identification of problems. The overall purpose of this study was to generate comparative information regarding the general development of a sample of 5- and 6-year-old South African pre-school boys and girls. Specifically, the study aimed to explore and describe the developmental profiles of pre-school boys and girls within the abovementioned age group with respect to their overall performance on the GMDS-ER as well as their performance on the six Subscales. Then, the mean General Quotients (GQ) and developmental profiles of the pre-school boys and girls obtained on the GMDS-ER were compared. An exploratory-descriptive quantitative research method was used. The sample (N = 64) was selected through a combination of non-probability, purposive and convenience xiii sampling. Within this framework, a between-subjects design in which matching was used to control extraneous variables, was employed. Data was analysed using descriptive statistics and independent sample t-tests to compare the GQs of the gender groups. A Hotellings T2 was used to compare the Subscale profiles. No significant gender differences were found when comparing the overall developmental and Subscale profiles of the boys and girls on the GMDS-ER. However, certain interesting trends did emerge from a review of the findings when compared to the literature review and previous studies. The information generated from this study has contributed to our knowledge base of the performance of South African children on the recently released GMDS-ER.
- Full Text:
- Date Issued: 2009
Compensation for polarization mode dispersion and nonlinear birefringence in a multichannel optical fibre system
- Authors: Waswa, David Wafula
- Date: 2009
- Subjects: Fiber optics , Nonlinear optics , Polarization (Light)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10375 , http://hdl.handle.net/10948/885 , Fiber optics , Nonlinear optics , Polarization (Light)
- Description: Polarization mode dispersion (PMD) is stochastic in nature and continues evolving in an unpredictable manner according to the changing environment. Nonlinear birefringence in multichannel systems alters the polarization states of the bits, so that they vary from one bit to the next in a way that is difficult to predict. These are the two major signal-impairment effects that are inherent in optical fibre transmission links which can seriously degrade network performance. It is therefore extremely challenging to compensate for both linear and nonlinear birefringence in multichannel systems. The purpose of this thesis is to investigate the interaction between PMD and nonlinear induced birefringence in a fibre with consideration of mode coupling. A sound knowledge of this interaction is necessary in designing a linear and nonlinear polarization mode dispersion compensator for WDM systems, as was successfully carried out in this study. The investigation shows that the effect of nonlinear birefringence alone depolarizes the signal, while in high PMD links where polarization mode coupling is high, the nonlinear birefringence effect couples with second-order PMD such that it may reduce the penalty and improve the signal DOP. Further investigation shows that when nonlinear birefringence becomes significant, asymmetry arises between the two principal axes of the fibre, such that it is only one axis which experiences the effect of nonlinear birefringence. It is found out that along this vii axis, there exists a critical point in pump power where the nonlinear birefringence cancels PMD in the link and improves the signal. An adaptive compensator to cancel PMD and nonlinear birefringence was designed based on feedforward DOP-monitoring signal. The compensator was tested both at laboratory level and on the Telkom buried fibre link and found to be functioning as intended. It was able to adaptively track and compensate PMD in the link in less than a second. The compensator was able to cancel PMD in the link up to a maximum of 30 ps. The compensator improved the DOP of the worst signal by more than 100 percent.
- Full Text:
- Date Issued: 2009
- Authors: Waswa, David Wafula
- Date: 2009
- Subjects: Fiber optics , Nonlinear optics , Polarization (Light)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10375 , http://hdl.handle.net/10948/885 , Fiber optics , Nonlinear optics , Polarization (Light)
- Description: Polarization mode dispersion (PMD) is stochastic in nature and continues evolving in an unpredictable manner according to the changing environment. Nonlinear birefringence in multichannel systems alters the polarization states of the bits, so that they vary from one bit to the next in a way that is difficult to predict. These are the two major signal-impairment effects that are inherent in optical fibre transmission links which can seriously degrade network performance. It is therefore extremely challenging to compensate for both linear and nonlinear birefringence in multichannel systems. The purpose of this thesis is to investigate the interaction between PMD and nonlinear induced birefringence in a fibre with consideration of mode coupling. A sound knowledge of this interaction is necessary in designing a linear and nonlinear polarization mode dispersion compensator for WDM systems, as was successfully carried out in this study. The investigation shows that the effect of nonlinear birefringence alone depolarizes the signal, while in high PMD links where polarization mode coupling is high, the nonlinear birefringence effect couples with second-order PMD such that it may reduce the penalty and improve the signal DOP. Further investigation shows that when nonlinear birefringence becomes significant, asymmetry arises between the two principal axes of the fibre, such that it is only one axis which experiences the effect of nonlinear birefringence. It is found out that along this vii axis, there exists a critical point in pump power where the nonlinear birefringence cancels PMD in the link and improves the signal. An adaptive compensator to cancel PMD and nonlinear birefringence was designed based on feedforward DOP-monitoring signal. The compensator was tested both at laboratory level and on the Telkom buried fibre link and found to be functioning as intended. It was able to adaptively track and compensate PMD in the link in less than a second. The compensator was able to cancel PMD in the link up to a maximum of 30 ps. The compensator improved the DOP of the worst signal by more than 100 percent.
- Full Text:
- Date Issued: 2009
Complexes of the ReO³⁺/Re(CO)₃cores with multidentate N,O-Donor chelates
- Authors: Potgieter, Kim Carey
- Date: 2009
- Subjects: Rhenium , Schiff bases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10387 , http://hdl.handle.net/10948/1225 , Rhenium , Schiff bases
- Description: This study investigates the coordination modes of multidentate N,O-donor ligands toward the [ReVO]3+ and fac-[ReI(CO)3]+ cores. The reactions of trans-[ReOX3(PPh3)2] (X = Cl, Br) with 4-aminoantipyrine (H2pap) were studied, and the complexes cis-[ReX2(pap)(H2pap)(PPh3)](ReO4) were isolated. The X-ray crystal structures show that both complexes display a distorted octahedral geometry around the central rhenium atom, and are mirror images of each other. The ligand pap is coordinated monodentately through the doubly deprotonated amino nitrogen as an imide, and H2pap acts as a neutral bidentate chelate, with coordination through the neutral amino nitrogen and the ketonic oxygen. The attempted synthesis of the potentially hexadentate Schiff base ligand 1,2-bis(2-{(Z)- [(2-hydroxyphenyl)imido]methyl}phenoxy)benzene from the condensation reaction of 2- (2-((2-aminophenoxy)methyl)benzyloxy)benzenamine and salicylaldehyde produced the zwitterion derivative (H2ono) of 2-{(Z)-[2-(hydroxyphenyl)imino]methyl}phenol. The tridentate Schiff bases (Z)-2-(2-aminobenzylideneamino)phenol (H3onn) and (Z)-2-(2- (methylthio)benzylideneamino)phenol (Hons) were prepared in a similar manner. The reaction of H2ono with trans-[ReOBr3(PPh3)2] surprisingly led to the isolation of the rhenium(III) complex [ReBr(PPh3)2(ono)], in which ono acts as a dianionic tridentate ligand. The reaction of H3onn with trans-[ReOBr3(PPh3)2] produced the imidorhenium(V) complex salt [ReBr(PPh3)2(onn)]Br, in which onn is coordinated as a trianionic tridentate imidoiminophenolate. The reaction of Hons with [Re(CO)5Br] led to the further decomposition of the Hons ligand, and the rhenium(I) product fac- [Re(CO)3(ons)(Hno)] (Hno = 2-aminophenol) was isolated, with ons coordinated as a monoanionic bidentate chelate (with a free SCH3 group), and Hno present as a neutral monodentate ligand with coordination through the amino nitrogen atom. Abstract Nelson Mandela Metropolitan University vi The reactions of the potentially hexadentate ligand N,N’-{ethane-1,2- diylbis[nitrilomethylidenebenzene-1,2-diyl]}bis(2-aminobenzeneimine) (H2ted) with rhenium(V) starting materials resulted in the decomposition of the H2ted molecule to give different coordinated multidentate ligands coordinated to the rhenium(V) centers. In the reaction of H2ted with trans-[ReOBr3(PPh3)2] in ethanol, the highly unusual ‘3+3’ complex cation [Re(tnn)(Htnn)]Br2 was isolated, in which tnn is coordinated as a tridentate imido-imino-amine, and Htnn is present as a tridentate monoanionic amidoimino- amine chelate (H2tnn = N-(2-aminophenylmethylidene)ethane-1,2-diamine). With trans-[ReO2(py)4]Cl as starting material, the neutral complex [ReO(dne)] was found, in which the tetradentate chelate dne acts as a triamido-imine. The reaction of cis- [ReO2I(PPh3)2] with H2ted led to the formation of the monocationic complex salt [ReO(ane)]PF6, with ane acting as a tetradentate dianionic diamidodiimine (H2ane = N,N’-bis[(2-aminophenyl)methylidene] ethane-1,2-diamine). The seven-coordinate rhenium(III) complex cation [Re(dhp)(PPh3)2]+ (H2dhp = 2,6-bis(2- hydroxyphenyliminomethyl)pyridine) was isolated as the iodide salt from the reaction of cis-[ReO2I(PPh3)2] with H2dhp in ethanol and as the perrhenate salt from the reaction of trans-[ReOBr3(PPh3)2] with H2dhp in methanol. Both products result from a disproportionation reaction with perrhenate also being produced in the process. The complex fac-[Re(CO)3(H2dhp)Br] was prepared from [Re(CO)5Br] and H2dhp in toluene, where the H2dhp ligand acts as a neutral bidentate NN-donor chelate. The metal is coordinated to three carbonyl donors in a facial orientation, to a neutral imino nitrogen, a pyridinic nitrogen and a bromide.
- Full Text:
- Date Issued: 2009
- Authors: Potgieter, Kim Carey
- Date: 2009
- Subjects: Rhenium , Schiff bases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10387 , http://hdl.handle.net/10948/1225 , Rhenium , Schiff bases
- Description: This study investigates the coordination modes of multidentate N,O-donor ligands toward the [ReVO]3+ and fac-[ReI(CO)3]+ cores. The reactions of trans-[ReOX3(PPh3)2] (X = Cl, Br) with 4-aminoantipyrine (H2pap) were studied, and the complexes cis-[ReX2(pap)(H2pap)(PPh3)](ReO4) were isolated. The X-ray crystal structures show that both complexes display a distorted octahedral geometry around the central rhenium atom, and are mirror images of each other. The ligand pap is coordinated monodentately through the doubly deprotonated amino nitrogen as an imide, and H2pap acts as a neutral bidentate chelate, with coordination through the neutral amino nitrogen and the ketonic oxygen. The attempted synthesis of the potentially hexadentate Schiff base ligand 1,2-bis(2-{(Z)- [(2-hydroxyphenyl)imido]methyl}phenoxy)benzene from the condensation reaction of 2- (2-((2-aminophenoxy)methyl)benzyloxy)benzenamine and salicylaldehyde produced the zwitterion derivative (H2ono) of 2-{(Z)-[2-(hydroxyphenyl)imino]methyl}phenol. The tridentate Schiff bases (Z)-2-(2-aminobenzylideneamino)phenol (H3onn) and (Z)-2-(2- (methylthio)benzylideneamino)phenol (Hons) were prepared in a similar manner. The reaction of H2ono with trans-[ReOBr3(PPh3)2] surprisingly led to the isolation of the rhenium(III) complex [ReBr(PPh3)2(ono)], in which ono acts as a dianionic tridentate ligand. The reaction of H3onn with trans-[ReOBr3(PPh3)2] produced the imidorhenium(V) complex salt [ReBr(PPh3)2(onn)]Br, in which onn is coordinated as a trianionic tridentate imidoiminophenolate. The reaction of Hons with [Re(CO)5Br] led to the further decomposition of the Hons ligand, and the rhenium(I) product fac- [Re(CO)3(ons)(Hno)] (Hno = 2-aminophenol) was isolated, with ons coordinated as a monoanionic bidentate chelate (with a free SCH3 group), and Hno present as a neutral monodentate ligand with coordination through the amino nitrogen atom. Abstract Nelson Mandela Metropolitan University vi The reactions of the potentially hexadentate ligand N,N’-{ethane-1,2- diylbis[nitrilomethylidenebenzene-1,2-diyl]}bis(2-aminobenzeneimine) (H2ted) with rhenium(V) starting materials resulted in the decomposition of the H2ted molecule to give different coordinated multidentate ligands coordinated to the rhenium(V) centers. In the reaction of H2ted with trans-[ReOBr3(PPh3)2] in ethanol, the highly unusual ‘3+3’ complex cation [Re(tnn)(Htnn)]Br2 was isolated, in which tnn is coordinated as a tridentate imido-imino-amine, and Htnn is present as a tridentate monoanionic amidoimino- amine chelate (H2tnn = N-(2-aminophenylmethylidene)ethane-1,2-diamine). With trans-[ReO2(py)4]Cl as starting material, the neutral complex [ReO(dne)] was found, in which the tetradentate chelate dne acts as a triamido-imine. The reaction of cis- [ReO2I(PPh3)2] with H2ted led to the formation of the monocationic complex salt [ReO(ane)]PF6, with ane acting as a tetradentate dianionic diamidodiimine (H2ane = N,N’-bis[(2-aminophenyl)methylidene] ethane-1,2-diamine). The seven-coordinate rhenium(III) complex cation [Re(dhp)(PPh3)2]+ (H2dhp = 2,6-bis(2- hydroxyphenyliminomethyl)pyridine) was isolated as the iodide salt from the reaction of cis-[ReO2I(PPh3)2] with H2dhp in ethanol and as the perrhenate salt from the reaction of trans-[ReOBr3(PPh3)2] with H2dhp in methanol. Both products result from a disproportionation reaction with perrhenate also being produced in the process. The complex fac-[Re(CO)3(H2dhp)Br] was prepared from [Re(CO)5Br] and H2dhp in toluene, where the H2dhp ligand acts as a neutral bidentate NN-donor chelate. The metal is coordinated to three carbonyl donors in a facial orientation, to a neutral imino nitrogen, a pyridinic nitrogen and a bromide.
- Full Text:
- Date Issued: 2009
Compositional varition of the Essential Oils of Artemisia afra Jacq. from three Provinces in South Africa- A Case Study of its safety
- Oyedeji, O A, Afolayan, A J, Hutchings, A
- Authors: Oyedeji, O A , Afolayan, A J , Hutchings, A
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/748 , vital:29679
- Description: In South Africa, Centella asiatica. (L.) Urb is used traditionally for the treatment of various diseases. Analyses of the essential oil of this medicinal plant revealed 11 monoterpenoid hydrocarbons (20.20%), nine oxygenated monoterpenoids (5.46%), 14 sesquiterpenoid hydrocarbons (68.80%), five oxygenated sesquiterpenoids (3.90%), and one sulfide sesquiterpenoid (0.76%). α.-Humulene (21.06%), β.-caryophyllene (19.08%), bicyclogermacrene (11.22%), germacrene B (6.29%), and myrcene (6.55%) were the predominant constitutes. The essential oil extract exhibited a broad spectrum of antibacterial activities against Gram-positive (Bacillus subtilis, Staphylococcus aureus.) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Shigella sonnei.) organisms.
- Full Text: false
- Date Issued: 2009
- Authors: Oyedeji, O A , Afolayan, A J , Hutchings, A
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/748 , vital:29679
- Description: In South Africa, Centella asiatica. (L.) Urb is used traditionally for the treatment of various diseases. Analyses of the essential oil of this medicinal plant revealed 11 monoterpenoid hydrocarbons (20.20%), nine oxygenated monoterpenoids (5.46%), 14 sesquiterpenoid hydrocarbons (68.80%), five oxygenated sesquiterpenoids (3.90%), and one sulfide sesquiterpenoid (0.76%). α.-Humulene (21.06%), β.-caryophyllene (19.08%), bicyclogermacrene (11.22%), germacrene B (6.29%), and myrcene (6.55%) were the predominant constitutes. The essential oil extract exhibited a broad spectrum of antibacterial activities against Gram-positive (Bacillus subtilis, Staphylococcus aureus.) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Shigella sonnei.) organisms.
- Full Text: false
- Date Issued: 2009
Conceptualising the more knowledgeable other within a multi-directional ZPD:
- Authors: Graven, Mellony
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69519 , vital:29545 , https://doi.org/10.1007/s10649-017-9768-1
- Description: From a Marxian/Vygotskian perspective, learning is social in origin and it happens in the presence of others that are more knowledgeable. Extending this view to the learning of mathematics, such learning also becomes inseparable from the presence of others (people and artefacts). Researchers over decades have studied different interactions to see how such learning with others occurs, what is the role of the (more knowledgeable) other, and if at all this role alternates between the participants. In this paper, we looked at a 5-year-old’s (Lila) interaction with her mother (Mellony) and a television remote control as Lila attempted to count in threes using the three by three physical layout of the numbered buttons 1–9 on the remote control. We specifically looked at the emergence of the Zone of Proximal Development (ZPD) as Lila’s attention was caught by the properties of the remote control and by her mother’s questions. We also pay attention to how the role of the more knowledgeable other alternates among the participants. Our findings suggest that Lila, at times, used resources provided by the physical properties of the remote control and sometimes, used resources provided by Mellony to think about the task of counting in threes. In Lila’s interaction, we interpreted a multi-directional ZPD as the role of the more knowledgeable other alternated between Mellony, Lila and the remote control.
- Full Text:
- Date Issued: 2009
- Authors: Graven, Mellony
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69519 , vital:29545 , https://doi.org/10.1007/s10649-017-9768-1
- Description: From a Marxian/Vygotskian perspective, learning is social in origin and it happens in the presence of others that are more knowledgeable. Extending this view to the learning of mathematics, such learning also becomes inseparable from the presence of others (people and artefacts). Researchers over decades have studied different interactions to see how such learning with others occurs, what is the role of the (more knowledgeable) other, and if at all this role alternates between the participants. In this paper, we looked at a 5-year-old’s (Lila) interaction with her mother (Mellony) and a television remote control as Lila attempted to count in threes using the three by three physical layout of the numbered buttons 1–9 on the remote control. We specifically looked at the emergence of the Zone of Proximal Development (ZPD) as Lila’s attention was caught by the properties of the remote control and by her mother’s questions. We also pay attention to how the role of the more knowledgeable other alternates among the participants. Our findings suggest that Lila, at times, used resources provided by the physical properties of the remote control and sometimes, used resources provided by Mellony to think about the task of counting in threes. In Lila’s interaction, we interpreted a multi-directional ZPD as the role of the more knowledgeable other alternated between Mellony, Lila and the remote control.
- Full Text:
- Date Issued: 2009