An investigation into the role of student participation in school governance : a Namibian perspective
- Authors: Shekupakela-Nelulu, Rauna
- Date: 2009
- Subjects: Education and state -- Namibia Education, Secondary -- Namibia Student government -- Namibia Student participation in administration -- Namibia School management and organization -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1923 , http://hdl.handle.net/10962/d1007449
- Description: The issue of student participation in school governance is not a new concept in Namibian schools. Student involvement dates back to the 1970's when the country's administration was under the South African apartheid regime. Back then the involvement of students in school affairs was seen by the regime as a political act and attempts by student leaders to involve themselves in educational issues were often quashed. When the country became independent student representation continued as Student Representative Councils (SRC's), later renamed Learners Representative Councils (LRCs). This study attempted to investigate the perceptions of LRCs and other stakeholders - narnely the school principals and the school board members - of the role of students in school governance. The study was conducted in three Senior Secondary Schools in the Kavango region in Namibia. The research respondents were school principals, chairpersons of the LRCs and one chairperson of a school board. The study was conducted in the interpretive paradigm employing the following three qualitative research methods interviews, observation and document analysis to collect data. Through triangulation it was possible to formulate a rich response to the research question. The study found that, although the notion of student participation in school governance was widely accepted, a number of challenges exist that hamper the effectiveness of LRCs in the schools. It was revealed that there was no national policy docunlent that outlined the roles and function of the LRCs. As a result schools had little direction about the LRCs and subsequently they were given little or no attention by the school authorities. This resulted in misunderstandings and in some cases conflict between learners and the school management. The most significant consequence of these problems was the fact that LRCs were not regarded as true role players in school governance. The study thus recommends that a national policy document that legitimates the role of students in school governance be drafted to provide direction and that schools embark on meaningful training programmes for LRC members. The study also calls for further research to address the gap in literature on this phenomenon, particularly in Namibia.
- Full Text:
- Date Issued: 2009
- Authors: Shekupakela-Nelulu, Rauna
- Date: 2009
- Subjects: Education and state -- Namibia Education, Secondary -- Namibia Student government -- Namibia Student participation in administration -- Namibia School management and organization -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1923 , http://hdl.handle.net/10962/d1007449
- Description: The issue of student participation in school governance is not a new concept in Namibian schools. Student involvement dates back to the 1970's when the country's administration was under the South African apartheid regime. Back then the involvement of students in school affairs was seen by the regime as a political act and attempts by student leaders to involve themselves in educational issues were often quashed. When the country became independent student representation continued as Student Representative Councils (SRC's), later renamed Learners Representative Councils (LRCs). This study attempted to investigate the perceptions of LRCs and other stakeholders - narnely the school principals and the school board members - of the role of students in school governance. The study was conducted in three Senior Secondary Schools in the Kavango region in Namibia. The research respondents were school principals, chairpersons of the LRCs and one chairperson of a school board. The study was conducted in the interpretive paradigm employing the following three qualitative research methods interviews, observation and document analysis to collect data. Through triangulation it was possible to formulate a rich response to the research question. The study found that, although the notion of student participation in school governance was widely accepted, a number of challenges exist that hamper the effectiveness of LRCs in the schools. It was revealed that there was no national policy docunlent that outlined the roles and function of the LRCs. As a result schools had little direction about the LRCs and subsequently they were given little or no attention by the school authorities. This resulted in misunderstandings and in some cases conflict between learners and the school management. The most significant consequence of these problems was the fact that LRCs were not regarded as true role players in school governance. The study thus recommends that a national policy document that legitimates the role of students in school governance be drafted to provide direction and that schools embark on meaningful training programmes for LRC members. The study also calls for further research to address the gap in literature on this phenomenon, particularly in Namibia.
- Full Text:
- Date Issued: 2009
Vocabulary development in a grade 7 class using dictionary skills: an action research project
- Authors: Wells, Stephanie Alice
- Date: 2011
- Subjects: English language -- Study and teaching (Elementary) -- South Africa -- Eastern Cape Vocabulary -- Study and teaching (Elementary) -- South Africa -- Eastern Cape English language Dictionaries -- Polyglot -- Study and teaching (Elementary) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1822 , http://hdl.handle.net/10962/d1003708
- Description: As I was involved as a voluntary, part-time teacher in a local, semi-rural school in the Eastern Cape, South Africa, I became increasingly aware of the learners' lack of English literacy. I therefore decided to do a practical research on vocabulary development, focusing on dictionary skills. In this thesis I describe how I implemented a vocabulary development programme as an Action Research project. My research group was a grade 7 class of English First Additional Language learners who had minimal exposure to English at school and in their communities. The class was a mixture of Afrikaans and isiXhosa home language speakers and the medium of instruction was Afrikaans. The school served a low-income community and was poorly resourced. As dictionary skills is a requirement of the national curriculum, I used 10 time-tabled lessons over a 5 week period to introduce the learners to dictionaries. My data sources were a journal detailing my reflections on each lesson; a video-recording of the lessons; small group interviews after each lesson which were audio-recorded; tasksheets on the work covered in class and questionnaires asking the learners for written responses to the lessons. The class teacher who filmed the lessons was also asked for feedback during and after the programme. My goals were to assess my teaching approach in these circumstances and to what extent the outcomes were positive for the learners. As I had come from a background of English Home Language teaching in good, well-resourced schools I found I had to question many of my assumptions. Although I was an experienced, qualified and confident teacher, I was continually having to reassess my teaching methods which were being challenged by very different classroom conditions. The outcomes of the research show why I was not able to achieve what I had thought I could in the time given.
- Full Text:
- Date Issued: 2011
- Authors: Wells, Stephanie Alice
- Date: 2011
- Subjects: English language -- Study and teaching (Elementary) -- South Africa -- Eastern Cape Vocabulary -- Study and teaching (Elementary) -- South Africa -- Eastern Cape English language Dictionaries -- Polyglot -- Study and teaching (Elementary) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1822 , http://hdl.handle.net/10962/d1003708
- Description: As I was involved as a voluntary, part-time teacher in a local, semi-rural school in the Eastern Cape, South Africa, I became increasingly aware of the learners' lack of English literacy. I therefore decided to do a practical research on vocabulary development, focusing on dictionary skills. In this thesis I describe how I implemented a vocabulary development programme as an Action Research project. My research group was a grade 7 class of English First Additional Language learners who had minimal exposure to English at school and in their communities. The class was a mixture of Afrikaans and isiXhosa home language speakers and the medium of instruction was Afrikaans. The school served a low-income community and was poorly resourced. As dictionary skills is a requirement of the national curriculum, I used 10 time-tabled lessons over a 5 week period to introduce the learners to dictionaries. My data sources were a journal detailing my reflections on each lesson; a video-recording of the lessons; small group interviews after each lesson which were audio-recorded; tasksheets on the work covered in class and questionnaires asking the learners for written responses to the lessons. The class teacher who filmed the lessons was also asked for feedback during and after the programme. My goals were to assess my teaching approach in these circumstances and to what extent the outcomes were positive for the learners. As I had come from a background of English Home Language teaching in good, well-resourced schools I found I had to question many of my assumptions. Although I was an experienced, qualified and confident teacher, I was continually having to reassess my teaching methods which were being challenged by very different classroom conditions. The outcomes of the research show why I was not able to achieve what I had thought I could in the time given.
- Full Text:
- Date Issued: 2011
Family planning : an evaluative study on the attitudes and use of contraceptives by black males in Umtata
- Authors: Madikizela, Nosinodi Alicia
- Date: 1989
- Subjects: Birth control -- South Africa -- Transkei , Transkei (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3278 , http://hdl.handle.net/10962/d1006454 , Birth control -- South Africa -- Transkei , Transkei (South Africa) -- Social conditions
- Description: The purpose of this study is to identify, observe and record the attitudes and use to of contraceptives by black males in Umtata and to investigate the effect of education, urbanisation and age on fertility control. Data was gathered from a sample of adult males who were past the school going age and were employed or working in Umtata and its surburbs, which are Ngangelizwe, Ikwezi, Southernwood, Northcrest, Norwood, Ncambedlana, Nduli Crescent, Fortgale and Hill Crest. Information was also gathered from Nursing officers in charge of family planning service centres in the areas mentioned above. Findings reveal that, although black urbanised educated males in Umtata seem to have accepted the use of contraceptives by themselves and their sexual partners, their patterns of behaviour in relation to fertility control and the value of children to families remains traditional. This contributes to the relatively high fertility rate in the country. Children are an investment for old age. They are also regarded as a security factor against divorce. It is the duty of legally married couples to raise a family with children who will continue to bear the family name. It appears that men are either suspicious of modern contraception if not totally opposed to it. Many still prefer the use of natural methods of contraception. There is thus need for social workers and health planners to recognise and educate males on the use and benefits of modern contraceptives to limit the number of children borne and control periods when they would like to have children. This study will be of value to social welfare services and to family planning nurses who are in direct contact with clients in hospitals and clinics, in their family planning campaigns, when they motivate couples and individuals on the importance of family planning, and also in mother-and-child health services. Educationists, sociologists, psychologists and persons in other fields of study will also benefit from information attained in this survey.
- Full Text:
- Date Issued: 1989
- Authors: Madikizela, Nosinodi Alicia
- Date: 1989
- Subjects: Birth control -- South Africa -- Transkei , Transkei (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3278 , http://hdl.handle.net/10962/d1006454 , Birth control -- South Africa -- Transkei , Transkei (South Africa) -- Social conditions
- Description: The purpose of this study is to identify, observe and record the attitudes and use to of contraceptives by black males in Umtata and to investigate the effect of education, urbanisation and age on fertility control. Data was gathered from a sample of adult males who were past the school going age and were employed or working in Umtata and its surburbs, which are Ngangelizwe, Ikwezi, Southernwood, Northcrest, Norwood, Ncambedlana, Nduli Crescent, Fortgale and Hill Crest. Information was also gathered from Nursing officers in charge of family planning service centres in the areas mentioned above. Findings reveal that, although black urbanised educated males in Umtata seem to have accepted the use of contraceptives by themselves and their sexual partners, their patterns of behaviour in relation to fertility control and the value of children to families remains traditional. This contributes to the relatively high fertility rate in the country. Children are an investment for old age. They are also regarded as a security factor against divorce. It is the duty of legally married couples to raise a family with children who will continue to bear the family name. It appears that men are either suspicious of modern contraception if not totally opposed to it. Many still prefer the use of natural methods of contraception. There is thus need for social workers and health planners to recognise and educate males on the use and benefits of modern contraceptives to limit the number of children borne and control periods when they would like to have children. This study will be of value to social welfare services and to family planning nurses who are in direct contact with clients in hospitals and clinics, in their family planning campaigns, when they motivate couples and individuals on the importance of family planning, and also in mother-and-child health services. Educationists, sociologists, psychologists and persons in other fields of study will also benefit from information attained in this survey.
- Full Text:
- Date Issued: 1989
A standardised protocol for roadkill detection and the determinants of roadkill in the greater Mapungubwe Transfrontier Conservation Area, Limpopo Province, South Africa
- Authors: Collinson, Wendy Jane
- Date: 2013
- Subjects: Roadkill -- South Africa -- Mapungubwe Site , Traffic safety and wildlife -- South Africa -- Mapungubwe Site
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5606 , http://hdl.handle.net/10962/d1002056 , Roadkill -- South Africa -- Mapungubwe Site , Traffic safety and wildlife -- South Africa -- Mapungubwe Site
- Description: Despite evidence suggesting that road traffic is a major threat to biodiversity loss, very little is known about its actual impact on wildlife populations in South Africa. Globally, road density and traffic volumes are increasing, and although huge budgets are devoted to the construction and upgrading of roads, there is little or no allocation to mitigation measures for protecting fauna in most countries, particularly Africa. Further, no global standardised protocol exists for the rapid assessment of roadkill or the most economical and efficient approach for assessing roadkill rates. Using vehicle field trials, the reliability of detecting artificially deployed roadkill was assessed. Roadkill detection rates decreased significantly at speeds >50 km/h and were also significantly influenced by light conditions (i.e. detection success was greater when the sun was high) and the position of the roadkill on the road (i.e. smaller roadkill on verges were often missed). These results suggest that roadkill sampling was most effective between 1.5 hours after dawn and 1.5 hours before dusk and that driving at slower speeds (<50 km.h⁻ₑ) was required to detect roadkill. This protocol was implemented across three ecological seasons on a 100 km paved road and a 20 km unpaved road in the Greater Mapungubwe Transfrontier Conservation Area, Limpopo Province, South Africa. Driven daily over a 120-day period (three periods consisting each of 40 days), a total of 1,027 roadkill were recorded. These comprised 162 species from all terrestrial vertebrate groups with birds being the most commonly encountered roadkill (50% of all incidents). The high numbers of vertebrates identified as roadkill suggests that road traffic could have potentially unsustainable impacts on wildlife populations and hence the biodiversity of the area. Seventeen variables were identified as possible determinants of roadkill occurrence with season, rainfall, minimum and maximum temperature, habitat type, grass height, grass density, fence type and vehicle type significantly influencing roadkill numbers. Significantly more roadkill were detected on the paved road (9.91/100km) than on the unpaved road (1.8/100km) probably because of greater traffic volumes and the increased speed that vehicles travelled on the paved road. Warmer temperatures and increased rainfall in the preceding 24 hours also increased road mortality numbers as animals tended to become more active during these times. Interestingly, more roadkill was detected in open roadside habitats compared to dense roadside habitats on both the paved and unpaved roads and when grass on the roadside verge was of intermediate height. Open habitat possibly may provide a natural corridor for wildlife which ultimately end up on the road. Roadkill numbers increased when certain other physical barriers, such as cattle fences, were present, probably because these barriers were more penetrable than electric fencing. A series of mitigation measures are proposed to reduce the impacts of roads on wildlife in South Africa. These mitigation measures highlight the need to address the balance between the development of a country’s transport infrastructure and the conservation of its fauna. It is important that research on the impacts of roads becomes standardised to enable robust statistical comparisons which will provide a greater understanding of the potential threats to vertebrate biodiversity
- Full Text:
- Date Issued: 2013
- Authors: Collinson, Wendy Jane
- Date: 2013
- Subjects: Roadkill -- South Africa -- Mapungubwe Site , Traffic safety and wildlife -- South Africa -- Mapungubwe Site
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5606 , http://hdl.handle.net/10962/d1002056 , Roadkill -- South Africa -- Mapungubwe Site , Traffic safety and wildlife -- South Africa -- Mapungubwe Site
- Description: Despite evidence suggesting that road traffic is a major threat to biodiversity loss, very little is known about its actual impact on wildlife populations in South Africa. Globally, road density and traffic volumes are increasing, and although huge budgets are devoted to the construction and upgrading of roads, there is little or no allocation to mitigation measures for protecting fauna in most countries, particularly Africa. Further, no global standardised protocol exists for the rapid assessment of roadkill or the most economical and efficient approach for assessing roadkill rates. Using vehicle field trials, the reliability of detecting artificially deployed roadkill was assessed. Roadkill detection rates decreased significantly at speeds >50 km/h and were also significantly influenced by light conditions (i.e. detection success was greater when the sun was high) and the position of the roadkill on the road (i.e. smaller roadkill on verges were often missed). These results suggest that roadkill sampling was most effective between 1.5 hours after dawn and 1.5 hours before dusk and that driving at slower speeds (<50 km.h⁻ₑ) was required to detect roadkill. This protocol was implemented across three ecological seasons on a 100 km paved road and a 20 km unpaved road in the Greater Mapungubwe Transfrontier Conservation Area, Limpopo Province, South Africa. Driven daily over a 120-day period (three periods consisting each of 40 days), a total of 1,027 roadkill were recorded. These comprised 162 species from all terrestrial vertebrate groups with birds being the most commonly encountered roadkill (50% of all incidents). The high numbers of vertebrates identified as roadkill suggests that road traffic could have potentially unsustainable impacts on wildlife populations and hence the biodiversity of the area. Seventeen variables were identified as possible determinants of roadkill occurrence with season, rainfall, minimum and maximum temperature, habitat type, grass height, grass density, fence type and vehicle type significantly influencing roadkill numbers. Significantly more roadkill were detected on the paved road (9.91/100km) than on the unpaved road (1.8/100km) probably because of greater traffic volumes and the increased speed that vehicles travelled on the paved road. Warmer temperatures and increased rainfall in the preceding 24 hours also increased road mortality numbers as animals tended to become more active during these times. Interestingly, more roadkill was detected in open roadside habitats compared to dense roadside habitats on both the paved and unpaved roads and when grass on the roadside verge was of intermediate height. Open habitat possibly may provide a natural corridor for wildlife which ultimately end up on the road. Roadkill numbers increased when certain other physical barriers, such as cattle fences, were present, probably because these barriers were more penetrable than electric fencing. A series of mitigation measures are proposed to reduce the impacts of roads on wildlife in South Africa. These mitigation measures highlight the need to address the balance between the development of a country’s transport infrastructure and the conservation of its fauna. It is important that research on the impacts of roads becomes standardised to enable robust statistical comparisons which will provide a greater understanding of the potential threats to vertebrate biodiversity
- Full Text:
- Date Issued: 2013
African traditional medicine-antiretroviral interactions : effects of Sutherlandia frutescens on the pharmacokinetics of Atazanavir
- Authors: Müller, Adrienne Carmel
- Date: 2011 , 2011-03-28
- Subjects: Antiretroviral agents , Medicinal plants , Traditional medicine , AIDS (Disease) -- Treatment , HIV infections -- Drug therapy , Drug interactions , Pharmacokinetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3859 , http://hdl.handle.net/10962/d1013373
- Description: In response to the urgent call for investigations into antiretroviral (ARV)-African traditional medicine (ATM) interactions, this research was undertaken to ascertain whether chronic administration of the ATM, Sutherlandia frutescens (SF) may alter the bioavailability of the protease inhibitor (PI), atazanavir (ATV), which may impact on the safety or efficacy of the ARV. Prior to investigating a potential interaction between ATV and SF in vitro and in vivo, a high performance liquid chromatography method with ultraviolet detection (HPLC-UV) was developed and validated for the bioanalysis of ATV in human plasma and liver microsomes. An improved and efficient analytical method with minimal use of solvents and short run time was achieved in comparison to methods published in the literature. In addition, the method was selective, linear, accurate and precise for quantitative analysis of ATV in these studies. Molecular docking studies were conducted to compare the binding modes and affinities of ATV and two major SF constituents, Sutherlandioside B and Sutherlandin C, with the efflux transporter, P-glycoprotein (P-gp) and the CYP450 isoenzyme, CYP3A4 to determine the potential for these phytochemicals to competitively inhibit the binding of ATV to these two proteins, which are mediators of absorption and metabolism. These studies revealed that modulation of P-gp transport of ATV by Sutherlandioside B and Sutherlandin C was not likely to occur via competitive inhibition. The results further indicated that weak competitive inhibition of CYP3A4 may possibly occur in the presence of either of these two SF constituents. The Caco-2 cell line was used as an in vitro model of human intestinal absorption. Accumulation studies in these cells were conducted to ascertain whether extracts and constituents of SF have the ability to alter the absorption of ATV. The results showed that the aqueous extract of SF significantly reduced ATV accumulation, suggesting decreased ATV absorption, whilst a triterpenoid glycoside fraction isolated from SF exhibited an opposing effect. Analogous responses were elicited by the aqueous extract and a triterpenoid glycoside fraction in similar accumulation studies in P-gp overexpressing Madin–Darby Canine Kidney Strain II cells (MDCKII-MDR1), which signified that the effects of this extract and component on ATV transport in the Caco-2 cells were P-gp-mediated. The quantitative analysis of ATV in human liver microsomes after co-incubation with extracts and components of SF was conducted to determine the effects of SF on the metabolism of ATV. The aqueous and methanolic extracts of SF inhibited ATV metabolism, whilst the triterpenoid glycoside fraction had a converse effect. Analogous effects by the extracts were demonstrated in experiments conducted in CYP3A4-transfected microsomes, suggesting that the inhibition of ATV metabolism in the liver microsomes by these SF extracts was CYP3A4-mediated. A combination of Sutherlandiosides C and D also inhibited CYP3A4-mediated ATV metabolism, which was in contrast to the response elicited by the triterpenoid fraction in the liver microsomes, where other unidentified compounds, shown to be present therein, may have contributed to the activation of ATV metabolism. The in vitro studies revealed the potential for SF to alter the bioavailability of ATV, therefore a clinical study in which the effect of a multiple dose regimen of SF on the pharmacokinetics (PK) of a single dose of ATV was conducted in healthy male volunteers. The statistical analysis showed that the 90 % confidence intervals around the geometric mean ratios (ATV + SF/ATV alone) for both Cmax and AUC0-24 hours, fell well below the lower limit of the "no-effect" boundary of 0.8 – 1.25, implying that the bioavailability of ATV was significantly reduced in this cohort of subjects. It may thus be concluded that if the reduction in bioavailability observed in this clinical study is found to be clinically relevant, co-administration of SF commercial dosage forms and ATV in HIV/AIDS patients may potentially result in subtherapeutic ATV levels, which may in turn contribute to ATV resistance and/or treatment failure. This research has therefore highlighted the potential risk for toxicity or lack of efficacy of ARV regimens which may result when ATMs and PIs are used concurrently and that patients and health care practitioners alike should be aware of these perils.
- Full Text:
- Date Issued: 2011
- Authors: Müller, Adrienne Carmel
- Date: 2011 , 2011-03-28
- Subjects: Antiretroviral agents , Medicinal plants , Traditional medicine , AIDS (Disease) -- Treatment , HIV infections -- Drug therapy , Drug interactions , Pharmacokinetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3859 , http://hdl.handle.net/10962/d1013373
- Description: In response to the urgent call for investigations into antiretroviral (ARV)-African traditional medicine (ATM) interactions, this research was undertaken to ascertain whether chronic administration of the ATM, Sutherlandia frutescens (SF) may alter the bioavailability of the protease inhibitor (PI), atazanavir (ATV), which may impact on the safety or efficacy of the ARV. Prior to investigating a potential interaction between ATV and SF in vitro and in vivo, a high performance liquid chromatography method with ultraviolet detection (HPLC-UV) was developed and validated for the bioanalysis of ATV in human plasma and liver microsomes. An improved and efficient analytical method with minimal use of solvents and short run time was achieved in comparison to methods published in the literature. In addition, the method was selective, linear, accurate and precise for quantitative analysis of ATV in these studies. Molecular docking studies were conducted to compare the binding modes and affinities of ATV and two major SF constituents, Sutherlandioside B and Sutherlandin C, with the efflux transporter, P-glycoprotein (P-gp) and the CYP450 isoenzyme, CYP3A4 to determine the potential for these phytochemicals to competitively inhibit the binding of ATV to these two proteins, which are mediators of absorption and metabolism. These studies revealed that modulation of P-gp transport of ATV by Sutherlandioside B and Sutherlandin C was not likely to occur via competitive inhibition. The results further indicated that weak competitive inhibition of CYP3A4 may possibly occur in the presence of either of these two SF constituents. The Caco-2 cell line was used as an in vitro model of human intestinal absorption. Accumulation studies in these cells were conducted to ascertain whether extracts and constituents of SF have the ability to alter the absorption of ATV. The results showed that the aqueous extract of SF significantly reduced ATV accumulation, suggesting decreased ATV absorption, whilst a triterpenoid glycoside fraction isolated from SF exhibited an opposing effect. Analogous responses were elicited by the aqueous extract and a triterpenoid glycoside fraction in similar accumulation studies in P-gp overexpressing Madin–Darby Canine Kidney Strain II cells (MDCKII-MDR1), which signified that the effects of this extract and component on ATV transport in the Caco-2 cells were P-gp-mediated. The quantitative analysis of ATV in human liver microsomes after co-incubation with extracts and components of SF was conducted to determine the effects of SF on the metabolism of ATV. The aqueous and methanolic extracts of SF inhibited ATV metabolism, whilst the triterpenoid glycoside fraction had a converse effect. Analogous effects by the extracts were demonstrated in experiments conducted in CYP3A4-transfected microsomes, suggesting that the inhibition of ATV metabolism in the liver microsomes by these SF extracts was CYP3A4-mediated. A combination of Sutherlandiosides C and D also inhibited CYP3A4-mediated ATV metabolism, which was in contrast to the response elicited by the triterpenoid fraction in the liver microsomes, where other unidentified compounds, shown to be present therein, may have contributed to the activation of ATV metabolism. The in vitro studies revealed the potential for SF to alter the bioavailability of ATV, therefore a clinical study in which the effect of a multiple dose regimen of SF on the pharmacokinetics (PK) of a single dose of ATV was conducted in healthy male volunteers. The statistical analysis showed that the 90 % confidence intervals around the geometric mean ratios (ATV + SF/ATV alone) for both Cmax and AUC0-24 hours, fell well below the lower limit of the "no-effect" boundary of 0.8 – 1.25, implying that the bioavailability of ATV was significantly reduced in this cohort of subjects. It may thus be concluded that if the reduction in bioavailability observed in this clinical study is found to be clinically relevant, co-administration of SF commercial dosage forms and ATV in HIV/AIDS patients may potentially result in subtherapeutic ATV levels, which may in turn contribute to ATV resistance and/or treatment failure. This research has therefore highlighted the potential risk for toxicity or lack of efficacy of ARV regimens which may result when ATMs and PIs are used concurrently and that patients and health care practitioners alike should be aware of these perils.
- Full Text:
- Date Issued: 2011
Studies on an autolysin produced by clostridium acetobutylicum
- Authors: Webster, Jocelyn Rowena
- Date: 1981
- Subjects: Clostridium acetobutylicum , Autolysis , Bacteriocins , Proteins -- Synthesis , DNA -- Synthesis , RNA -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3893 , http://hdl.handle.net/10962/d1003724
- Description: An extracellular bacteriocin-like substance produced by Clostridium acetobutylicum was detected during studies on an industrial fermentation process. The bacteriocin-like substance was not inducible by either ultraviolet light or mitomycin C, and its production was not associated with the induction of a protease. Studies on the mode of action of the bacteriocin-like substance indicated that it had no significant effect on DNA, RNA, or protein synthesis, and it did not cause the loss of intracellular ATP. However, the bacteriocin-like substance was able to lyse SDS-treated cells and cell walls of C. acetobutylicum and was identified as an autolysin. Some of the characteristics of this extracellular autolysin were determined, and after purification it was shown to be a glycoprotein with a molecular weight of 28 000.
- Full Text:
- Date Issued: 1981
- Authors: Webster, Jocelyn Rowena
- Date: 1981
- Subjects: Clostridium acetobutylicum , Autolysis , Bacteriocins , Proteins -- Synthesis , DNA -- Synthesis , RNA -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3893 , http://hdl.handle.net/10962/d1003724
- Description: An extracellular bacteriocin-like substance produced by Clostridium acetobutylicum was detected during studies on an industrial fermentation process. The bacteriocin-like substance was not inducible by either ultraviolet light or mitomycin C, and its production was not associated with the induction of a protease. Studies on the mode of action of the bacteriocin-like substance indicated that it had no significant effect on DNA, RNA, or protein synthesis, and it did not cause the loss of intracellular ATP. However, the bacteriocin-like substance was able to lyse SDS-treated cells and cell walls of C. acetobutylicum and was identified as an autolysin. Some of the characteristics of this extracellular autolysin were determined, and after purification it was shown to be a glycoprotein with a molecular weight of 28 000.
- Full Text:
- Date Issued: 1981
An investigation of stakeholder participation and learning in two schools within the Seychelles Eco-School programme
- Authors: Emilie, Shane Antonio
- Date: 2014
- Subjects: Environmental education -- Seychelles Schools -- Environmental aspects -- Seychelles Education, Primary -- Parent participation -- Seychelles Education, Secondary -- Parent participation -- Seychelles Student participation in administration -- Education (Primary) -- Seychelles Student participation in administration -- Education (Secondary) -- Seychelles Student participation in curriculum planning -- Education (Primary) -- Seychelles Student participation in curriculum planning -- Education (Secondary) -- Seychelles Education, Primary -- Seychelles Education, Secondary -- Seychelles
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1969 , http://hdl.handle.net/10962/d1011961
- Description: The aim of this study was to investigate stakeholder participation and learning in the Seychelles Eco-School programme within a primary school context and a secondary school context. Findings from each Eco-School have been presented in two case studies with the goal to explore and describe how teachers, students, parents and organizations are participating and learning in the Eco-School programme. Six elements of school community were used to deepen understanding of the participatory and learning processes in each Eco-School, namely, leadership, management and administration, curriculum planning, teaching and learning, resource use and management, management of physical surrounds of the school and networks and partnerships. Some of the contextual variables in each Eco-School that were constraining and enabling stakeholder participation and learning in the programme have also been explored within this study. Data in this study was generated from historical documents analysed, semi-structured interviews, focus group discussions and field notes. Data was also generated from questionnaires completed by organizations involved in the programme at each Eco- School. Data was analysed in two phases, the first phase involved reading across data generated from the methods mentioned above to organize the data under broad themes in relation to the elements of school community. The second phase of analysis involved the use of the conceptual framework of situating learning in a community of practice to interpret and discuss the participatory and learning processes across the two cases. The study showed that in each Eco-School there is a community of practice with the active involvement of teachers and students and the occasional involvement of parents and organizations. Students and adults are learning as they engage together in classroom and field-work interactions, environmental projects, environmental activities to commemorate environmental theme days, environmental campaigns and co-curricular activities through the practices of each Eco-School community. It was also discovered that students and adults are making different contributions in the Eco-School community based on their level of participation in the programme. It is hoped that the findings in this research contribute information regarding community participation in environmental education programmes like the Seychelles Eco-School programme. In addition, findings will inform the Seychelles Government and its partners to consider the possibility of enhancing school and community partnerships to respond to some of the challenges of participation and learning in the Eco-School programme.
- Full Text:
- Date Issued: 2014
- Authors: Emilie, Shane Antonio
- Date: 2014
- Subjects: Environmental education -- Seychelles Schools -- Environmental aspects -- Seychelles Education, Primary -- Parent participation -- Seychelles Education, Secondary -- Parent participation -- Seychelles Student participation in administration -- Education (Primary) -- Seychelles Student participation in administration -- Education (Secondary) -- Seychelles Student participation in curriculum planning -- Education (Primary) -- Seychelles Student participation in curriculum planning -- Education (Secondary) -- Seychelles Education, Primary -- Seychelles Education, Secondary -- Seychelles
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1969 , http://hdl.handle.net/10962/d1011961
- Description: The aim of this study was to investigate stakeholder participation and learning in the Seychelles Eco-School programme within a primary school context and a secondary school context. Findings from each Eco-School have been presented in two case studies with the goal to explore and describe how teachers, students, parents and organizations are participating and learning in the Eco-School programme. Six elements of school community were used to deepen understanding of the participatory and learning processes in each Eco-School, namely, leadership, management and administration, curriculum planning, teaching and learning, resource use and management, management of physical surrounds of the school and networks and partnerships. Some of the contextual variables in each Eco-School that were constraining and enabling stakeholder participation and learning in the programme have also been explored within this study. Data in this study was generated from historical documents analysed, semi-structured interviews, focus group discussions and field notes. Data was also generated from questionnaires completed by organizations involved in the programme at each Eco- School. Data was analysed in two phases, the first phase involved reading across data generated from the methods mentioned above to organize the data under broad themes in relation to the elements of school community. The second phase of analysis involved the use of the conceptual framework of situating learning in a community of practice to interpret and discuss the participatory and learning processes across the two cases. The study showed that in each Eco-School there is a community of practice with the active involvement of teachers and students and the occasional involvement of parents and organizations. Students and adults are learning as they engage together in classroom and field-work interactions, environmental projects, environmental activities to commemorate environmental theme days, environmental campaigns and co-curricular activities through the practices of each Eco-School community. It was also discovered that students and adults are making different contributions in the Eco-School community based on their level of participation in the programme. It is hoped that the findings in this research contribute information regarding community participation in environmental education programmes like the Seychelles Eco-School programme. In addition, findings will inform the Seychelles Government and its partners to consider the possibility of enhancing school and community partnerships to respond to some of the challenges of participation and learning in the Eco-School programme.
- Full Text:
- Date Issued: 2014
Coping in two cultures: an ecological study of mentally ill people and their families in rural South Africa
- Authors: Cumes, Heide Ulrike
- Date: 1995
- Subjects: Mental illness -- South Africa Xhosa (African people) -- Psychology Xhosa (African people) -- Religion Xhosa (African people) -- Social life and customs
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2958 , http://hdl.handle.net/10962/d1002467
- Description: This study explores severe mental illness in a South African ru~al district, moving, as with a zoom lens, from the macroperspectives of (i) Xhosa culture, and (ii) biomedicine, to the lived experience of the individual. Its methodology, predominantly qualitative, employed anthropological and psychological procedures. The fieldwork (1988-1989)encompassed a three month stay in the village of Msobomvu. Patients continued to be tracked informally until June, 1995. The empirical research has three parts. In part one, the person with a mental illness was contextualized within Xhosa cosmology and social attitudes. The cognitive and social ecologies were tapped through the narratives of high school and university students at different stages of a Western-biased education. Social attitudes regarding mental illness, and confidence in treatment by traditional healers and the hospital, were also evaluated. Traditional attitudes and supernatural beliefs of illness causation persisted in spite of Eurocentric education, with a concurrent increase in the acceptance of Western-type causal explanations commensurate with continued education. Part two considered the the patients in relation to (i) the biomedical framework (the mental and local hospitals), and (ii) their readjustment to the community after hospitalization. Data came from patient charts, interviews with medical staff, and follow-up visits in the villages. Socio-political and economic issues were salient. Part three case-studied people identified by the village residents as having a mental illness. Resources for treatment - traditional healers, mobile clinic, and village health workers - were the focus. The traditional healing system, and biomedicine, were compared for effectiveness, through the course of illness events. While biomedicine was more effective in containing acute psychotic episodes than treatment by the traditional healer, lack of appropriate resources within the biomedical setting had disastrous results for patient compliance and long-term management of the illness, particularly in people with obvious symptoms of bipolar disorder. The mental hospital emerged as an agent of control. While Xhosa culture provided a more tolerant setting for people with a mental illness, the course of severe mental illness was by no means benign, despite research suggesting a more positive outcome for such conditions in the developing world.
- Full Text:
- Date Issued: 1995
- Authors: Cumes, Heide Ulrike
- Date: 1995
- Subjects: Mental illness -- South Africa Xhosa (African people) -- Psychology Xhosa (African people) -- Religion Xhosa (African people) -- Social life and customs
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2958 , http://hdl.handle.net/10962/d1002467
- Description: This study explores severe mental illness in a South African ru~al district, moving, as with a zoom lens, from the macroperspectives of (i) Xhosa culture, and (ii) biomedicine, to the lived experience of the individual. Its methodology, predominantly qualitative, employed anthropological and psychological procedures. The fieldwork (1988-1989)encompassed a three month stay in the village of Msobomvu. Patients continued to be tracked informally until June, 1995. The empirical research has three parts. In part one, the person with a mental illness was contextualized within Xhosa cosmology and social attitudes. The cognitive and social ecologies were tapped through the narratives of high school and university students at different stages of a Western-biased education. Social attitudes regarding mental illness, and confidence in treatment by traditional healers and the hospital, were also evaluated. Traditional attitudes and supernatural beliefs of illness causation persisted in spite of Eurocentric education, with a concurrent increase in the acceptance of Western-type causal explanations commensurate with continued education. Part two considered the the patients in relation to (i) the biomedical framework (the mental and local hospitals), and (ii) their readjustment to the community after hospitalization. Data came from patient charts, interviews with medical staff, and follow-up visits in the villages. Socio-political and economic issues were salient. Part three case-studied people identified by the village residents as having a mental illness. Resources for treatment - traditional healers, mobile clinic, and village health workers - were the focus. The traditional healing system, and biomedicine, were compared for effectiveness, through the course of illness events. While biomedicine was more effective in containing acute psychotic episodes than treatment by the traditional healer, lack of appropriate resources within the biomedical setting had disastrous results for patient compliance and long-term management of the illness, particularly in people with obvious symptoms of bipolar disorder. The mental hospital emerged as an agent of control. While Xhosa culture provided a more tolerant setting for people with a mental illness, the course of severe mental illness was by no means benign, despite research suggesting a more positive outcome for such conditions in the developing world.
- Full Text:
- Date Issued: 1995
An investigation into whether a leadership and management development project changed the perceptions of the educators in a black, disadvantaged school
- Authors: Jaftha, A P
- Date: 2003
- Subjects: University of Port Elizabeth -- Institute for Development Planning and Research Delta Foundation -- Centres of Learning School management and organization -- South Africa Educational leadership -- South Africa Educational change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1620 , http://hdl.handle.net/10962/d1003502
- Description: This study investigates whether a leadership and management development programme changed the management perceptions of the teachers of one of the schools that participated in the programme. The programme seeks to change the organisational culture of schools and develop effective management. The development philosophy of the programme is informed by literature on school effectiveness, organisation development, whole school development and systemic change. My research is conducted in the interpretive paradigm. Interpretive researchers view reality a construct of the human mind, and therefore the way people perceive the world is not necessarily the same since there can be different understandings of what is real. I employ convenience sampling to select the school and purposive sampling to identify my research participants. Whilst overall impression that the data conveys is that much of the programme does not seem to have had a lasting effect on the culture of the school, it nonetheless made an impression on the teachers’ perceptions of management. There clearly seems to be a greater appreciation of participative management processes. The reintroduction of proper prior planning played a decisive role in re-establishing sound work ethics at the school and contributes to a more structured approach to events at the school. Some sort of organisational learning has also been introduced at the school. The realisation on the part of the staff that they now have their destiny in their own hands is an especially critical development. And whilst the vision is not a compelling force in the organisation, it has nevertheless produced some strategic focus at the school. The insights and skills they acquired concerning resource management will also stand them in good stead.
- Full Text:
- Date Issued: 2003
- Authors: Jaftha, A P
- Date: 2003
- Subjects: University of Port Elizabeth -- Institute for Development Planning and Research Delta Foundation -- Centres of Learning School management and organization -- South Africa Educational leadership -- South Africa Educational change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1620 , http://hdl.handle.net/10962/d1003502
- Description: This study investigates whether a leadership and management development programme changed the management perceptions of the teachers of one of the schools that participated in the programme. The programme seeks to change the organisational culture of schools and develop effective management. The development philosophy of the programme is informed by literature on school effectiveness, organisation development, whole school development and systemic change. My research is conducted in the interpretive paradigm. Interpretive researchers view reality a construct of the human mind, and therefore the way people perceive the world is not necessarily the same since there can be different understandings of what is real. I employ convenience sampling to select the school and purposive sampling to identify my research participants. Whilst overall impression that the data conveys is that much of the programme does not seem to have had a lasting effect on the culture of the school, it nonetheless made an impression on the teachers’ perceptions of management. There clearly seems to be a greater appreciation of participative management processes. The reintroduction of proper prior planning played a decisive role in re-establishing sound work ethics at the school and contributes to a more structured approach to events at the school. Some sort of organisational learning has also been introduced at the school. The realisation on the part of the staff that they now have their destiny in their own hands is an especially critical development. And whilst the vision is not a compelling force in the organisation, it has nevertheless produced some strategic focus at the school. The insights and skills they acquired concerning resource management will also stand them in good stead.
- Full Text:
- Date Issued: 2003
The distinction between tax evasion, tax avoidance and tax planning
- Authors: Tarrant, Greg
- Date: 2008
- Subjects: South African Revenue Service , Tax evasion -- South Africa , Tax planning -- South Africa , Income tax -- South Africa , Income tax -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:897 , http://hdl.handle.net/10962/d1004549
- Description: Tax avoidance has been the subject of intense scrutiny lately by both the South African Revenue Service ("the SARS") and the media. This attention stems largely from the recent withdrawal of section 103(1) together with the introduction of section 80A to 80L of the South African Income Tax Act. However, this attention is not limited to South Africa. Revenue authorities worldwide have focused on the task of challenging tax avoidance. The approach of the SARS to tackling tax avoidance has been multi-faceted. In the Discussion Paper on Tax Avoidance and Section 103 (1) of the South African Income Tax Act they begin with a review of the distinction between tax evasion, tax avoidance and tax planning. Following a call for comment the SARS issued an Interim Response followed by the Revised Proposals which culminated in the withdrawal of the longstanding general anti-avoidance rules housed in section 103(1) and the introduction of new and more comprehensive anti-avoidance rules. In addition, the SARS has adopted an ongoing media campaign stressing the importance of paying tax in a country with a large development agenda like that of South Africa, the need for taxpayers to adopt a responsible attitude to the management of tax and the inclusion of responsible tax management as the greatest measure of a taxpayer's corporate and social investment. In tandem with this message the SARS have sought to vilify those taxpayers who engage in tax avoidance. The message is clear: tax avoidance carries reputational risks; those who engage in tax avoidance are unpatriotic or immoral and their actions simply result in an unfair shifting of the tax burden. The SARS is not alone in the above approach. Around the world tax authorities have been echoing the same message. The message appears to be working. Accounting firms speak of a "creeping conservatism" that has pervaded company boardrooms. What is not clear, however, is whether taxpayers, in becoming more conservative, are simply more fully aware of tax risks and are making informed decisions or whether they are simply responding to external events, such as the worldwide focus by revenue authorities and the media on tax avoidance. Whatever the reason, it is now critical, particularly in the case of corporate taxpayers, that their policies for tax and its attendant risks need to be as sophisticated, coherent and transparent as its policies in all other areas involving multiple stakeholders, such as suppliers, customers, staff and investors. How does a company begin to set its tax philosophy and strategic direction or to determine its appetite for risk? A starting point, it is submitted would be a review of the distinction between tax evasion, avoidance and planning with a heightened sensitivity to the unfamiliar ethical, moral and social risks. The goal of this thesis was to clearly define the distinction between tax evasion, tax avoidance and tax planning from a legal interpretive, ethical and historical perspective in order to develop a rudimentary framework for the responsible management of strategic tax decisions, in the light of the new South African general anti-avoidance legislation. The research methodology entails a qualitative research orientation consisting of a critical conceptual analysis of tax evasion and tax avoidance, with a view to establishing a basic framework to be used by taxpayers to make informed decisions on tax matters. The analysis of the distinction in this work culminated in a diagrammatic representation of the distinction between tax evasion, tax avoidance and tax planning emphasising the different types of tax avoidance from least aggressive to the most abusive and from the least objectionable to most objectionable. It is anticipated that a visual representation of the distinction, however flawed, would result in a far more pragmatic tool to taxpayers than a lengthy document. From a glance taxpayers can determine the following: That tax avoidance is legal; that different forms of tax avoidance exist, some forms being more aggressive than others; that aggressive forms of tax avoidance carry reputational risks; and that in certain circumstances aggressive tax avoidance schemes may border on tax evasion. This, it is envisaged, may prompt taxpayers to ask the right questions when faced with an external or in-house tax avoidance arrangement rather than simply blindly accepting or rejecting the arrangement.
- Full Text:
- Date Issued: 2008
- Authors: Tarrant, Greg
- Date: 2008
- Subjects: South African Revenue Service , Tax evasion -- South Africa , Tax planning -- South Africa , Income tax -- South Africa , Income tax -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:897 , http://hdl.handle.net/10962/d1004549
- Description: Tax avoidance has been the subject of intense scrutiny lately by both the South African Revenue Service ("the SARS") and the media. This attention stems largely from the recent withdrawal of section 103(1) together with the introduction of section 80A to 80L of the South African Income Tax Act. However, this attention is not limited to South Africa. Revenue authorities worldwide have focused on the task of challenging tax avoidance. The approach of the SARS to tackling tax avoidance has been multi-faceted. In the Discussion Paper on Tax Avoidance and Section 103 (1) of the South African Income Tax Act they begin with a review of the distinction between tax evasion, tax avoidance and tax planning. Following a call for comment the SARS issued an Interim Response followed by the Revised Proposals which culminated in the withdrawal of the longstanding general anti-avoidance rules housed in section 103(1) and the introduction of new and more comprehensive anti-avoidance rules. In addition, the SARS has adopted an ongoing media campaign stressing the importance of paying tax in a country with a large development agenda like that of South Africa, the need for taxpayers to adopt a responsible attitude to the management of tax and the inclusion of responsible tax management as the greatest measure of a taxpayer's corporate and social investment. In tandem with this message the SARS have sought to vilify those taxpayers who engage in tax avoidance. The message is clear: tax avoidance carries reputational risks; those who engage in tax avoidance are unpatriotic or immoral and their actions simply result in an unfair shifting of the tax burden. The SARS is not alone in the above approach. Around the world tax authorities have been echoing the same message. The message appears to be working. Accounting firms speak of a "creeping conservatism" that has pervaded company boardrooms. What is not clear, however, is whether taxpayers, in becoming more conservative, are simply more fully aware of tax risks and are making informed decisions or whether they are simply responding to external events, such as the worldwide focus by revenue authorities and the media on tax avoidance. Whatever the reason, it is now critical, particularly in the case of corporate taxpayers, that their policies for tax and its attendant risks need to be as sophisticated, coherent and transparent as its policies in all other areas involving multiple stakeholders, such as suppliers, customers, staff and investors. How does a company begin to set its tax philosophy and strategic direction or to determine its appetite for risk? A starting point, it is submitted would be a review of the distinction between tax evasion, avoidance and planning with a heightened sensitivity to the unfamiliar ethical, moral and social risks. The goal of this thesis was to clearly define the distinction between tax evasion, tax avoidance and tax planning from a legal interpretive, ethical and historical perspective in order to develop a rudimentary framework for the responsible management of strategic tax decisions, in the light of the new South African general anti-avoidance legislation. The research methodology entails a qualitative research orientation consisting of a critical conceptual analysis of tax evasion and tax avoidance, with a view to establishing a basic framework to be used by taxpayers to make informed decisions on tax matters. The analysis of the distinction in this work culminated in a diagrammatic representation of the distinction between tax evasion, tax avoidance and tax planning emphasising the different types of tax avoidance from least aggressive to the most abusive and from the least objectionable to most objectionable. It is anticipated that a visual representation of the distinction, however flawed, would result in a far more pragmatic tool to taxpayers than a lengthy document. From a glance taxpayers can determine the following: That tax avoidance is legal; that different forms of tax avoidance exist, some forms being more aggressive than others; that aggressive forms of tax avoidance carry reputational risks; and that in certain circumstances aggressive tax avoidance schemes may border on tax evasion. This, it is envisaged, may prompt taxpayers to ask the right questions when faced with an external or in-house tax avoidance arrangement rather than simply blindly accepting or rejecting the arrangement.
- Full Text:
- Date Issued: 2008
The negotiation process of the EU-SA Trade, Development and Co-operation Agreement: a case of reference for the south?
- Authors: Pillay, Morgenie
- Date: 2003
- Subjects: South Africa -- Foreign economic relations -- European Union countries , European Union countries -- Foreign economic relations -- South Africa , South Africa -- Commerce -- European Union countries , European Union countries -- Commerce -- South Africa , Free trade -- South Africa , Trade regulation -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2821 , http://hdl.handle.net/10962/d1003031 , South Africa -- Foreign economic relations -- European Union countries , European Union countries -- Foreign economic relations -- South Africa , South Africa -- Commerce -- European Union countries , European Union countries -- Commerce -- South Africa , Free trade -- South Africa , Trade regulation -- South Africa
- Description: Overall the conclusions drawn about South Africa’s negotiating style and tactics were arrived at by analysing a number of reports (that closely followed the evolution of the negotiations) and then paralleling this case study’s findings with the conjectures made by the theoretical frameworks (i.e. works by Putnam, Zartmann and Churchmann) about how negotiations proceed. In the final analysis, the findings of this case are intended to provide insight for the south about how to approach any future trade negotiations with the North (or more specifically with the EU).
- Full Text:
- Date Issued: 2003
- Authors: Pillay, Morgenie
- Date: 2003
- Subjects: South Africa -- Foreign economic relations -- European Union countries , European Union countries -- Foreign economic relations -- South Africa , South Africa -- Commerce -- European Union countries , European Union countries -- Commerce -- South Africa , Free trade -- South Africa , Trade regulation -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2821 , http://hdl.handle.net/10962/d1003031 , South Africa -- Foreign economic relations -- European Union countries , European Union countries -- Foreign economic relations -- South Africa , South Africa -- Commerce -- European Union countries , European Union countries -- Commerce -- South Africa , Free trade -- South Africa , Trade regulation -- South Africa
- Description: Overall the conclusions drawn about South Africa’s negotiating style and tactics were arrived at by analysing a number of reports (that closely followed the evolution of the negotiations) and then paralleling this case study’s findings with the conjectures made by the theoretical frameworks (i.e. works by Putnam, Zartmann and Churchmann) about how negotiations proceed. In the final analysis, the findings of this case are intended to provide insight for the south about how to approach any future trade negotiations with the North (or more specifically with the EU).
- Full Text:
- Date Issued: 2003
The independent high rate algal pond as a unit operation in tertiary wastewater treatment
- Authors: Clark, Stewart James
- Date: 2002
- Subjects: Algae -- Biotechnology , Sewage -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4092 , http://hdl.handle.net/10962/d1007805
- Description: The development of the High Rate Algal Pond (HRAP) as an independent tertiary treatment unit operation for phosphate and nitrate removal is reported. A novel Integrated Algal Ponding System (lAPS) design is proposed for nutrient removal from the effluents of both a conventional domestic sewage treatment plant and from an Advanced Integrated Wastewater Ponding System (AIWPS). The viability of an independently operated HRAP has been identified and termed the Independent High Rate Algal Pond (l-HRAP). A 500 m² pilot 1- HRAP was operated in such a way as to facilitate the precipitation of calcium phosphate, known to be controlled by pH (greater than 9.4) and resulting in final phosphate levels of less than 1 mg.L⁻¹ as P0₄-P. The incorporation of the I-HRAP into a denitrification process was also investigated. Continuously fed column reactors, utilising algal biomass as a carbon source, showed that the heterotrophic bacterial community dominant in the anaerobic algal sludge were denitrifying the nitrate in the feed. It was demonstrated that as the cultures were stressed (using increased nitrate concentrations, anaerobiosis and light starvation) total polysaccharide (TPS) concentrations increased, with a notable increase 111 the exopolysaccharide (EPS) fraction. These experiments corroborated the hypothesis that harvested microalgal biomass can be manipulated to produce, and release, exopolymeric substances under stress conditions, and which may serve as carbon source for denitrification. In both batch flask studies and in laboratory-scale reactor systems, harvested microalgal biomass from an HRAP was shown to produce exopolymeric substances under stress conditions. Initial high loading-rates of greater than 20 mg.L⁻¹ NO₃-N resulted in double the amount of exopolysaccharide production than in flasks with initial low loading-rates (less than 5 mg.L⁻¹ NO₃-N). Making use of an upflow anaerobic sludge blanket-type degrading-bed reactor, and an anaerobic, flooded trickle filter (ANTRIC) receiving HRAP effluent, the relationship between denitrification and the changes in polysaccharide content was investigated. This phenomenon has considerable beneficial implications in biological wastewater treatment systems where high nitrate concentration in the final effluent is a potential mitigating factor. Identification of the heterotrophic bacteria active in the denitrification process was attempted. This study presents a first report on the development and operation of the I-HRAP and has been followed by a technical-scale pilot plant evaluation of the process in the tertiary treatment of domestic wastewaters.
- Full Text:
- Date Issued: 2002
- Authors: Clark, Stewart James
- Date: 2002
- Subjects: Algae -- Biotechnology , Sewage -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4092 , http://hdl.handle.net/10962/d1007805
- Description: The development of the High Rate Algal Pond (HRAP) as an independent tertiary treatment unit operation for phosphate and nitrate removal is reported. A novel Integrated Algal Ponding System (lAPS) design is proposed for nutrient removal from the effluents of both a conventional domestic sewage treatment plant and from an Advanced Integrated Wastewater Ponding System (AIWPS). The viability of an independently operated HRAP has been identified and termed the Independent High Rate Algal Pond (l-HRAP). A 500 m² pilot 1- HRAP was operated in such a way as to facilitate the precipitation of calcium phosphate, known to be controlled by pH (greater than 9.4) and resulting in final phosphate levels of less than 1 mg.L⁻¹ as P0₄-P. The incorporation of the I-HRAP into a denitrification process was also investigated. Continuously fed column reactors, utilising algal biomass as a carbon source, showed that the heterotrophic bacterial community dominant in the anaerobic algal sludge were denitrifying the nitrate in the feed. It was demonstrated that as the cultures were stressed (using increased nitrate concentrations, anaerobiosis and light starvation) total polysaccharide (TPS) concentrations increased, with a notable increase 111 the exopolysaccharide (EPS) fraction. These experiments corroborated the hypothesis that harvested microalgal biomass can be manipulated to produce, and release, exopolymeric substances under stress conditions, and which may serve as carbon source for denitrification. In both batch flask studies and in laboratory-scale reactor systems, harvested microalgal biomass from an HRAP was shown to produce exopolymeric substances under stress conditions. Initial high loading-rates of greater than 20 mg.L⁻¹ NO₃-N resulted in double the amount of exopolysaccharide production than in flasks with initial low loading-rates (less than 5 mg.L⁻¹ NO₃-N). Making use of an upflow anaerobic sludge blanket-type degrading-bed reactor, and an anaerobic, flooded trickle filter (ANTRIC) receiving HRAP effluent, the relationship between denitrification and the changes in polysaccharide content was investigated. This phenomenon has considerable beneficial implications in biological wastewater treatment systems where high nitrate concentration in the final effluent is a potential mitigating factor. Identification of the heterotrophic bacteria active in the denitrification process was attempted. This study presents a first report on the development and operation of the I-HRAP and has been followed by a technical-scale pilot plant evaluation of the process in the tertiary treatment of domestic wastewaters.
- Full Text:
- Date Issued: 2002
An ecological study of territoriality in four Cichlid species resident on rocky shores near Monkey Bay, Lake Malawi
- Authors: Sharp, Bradley John
- Date: 1982
- Subjects: Cichlids -- Nyasa, Lake , Cichlids -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5340 , http://hdl.handle.net/10962/d1005927 , Cichlids -- Nyasa, Lake , Cichlids -- Behavior
- Description: This study centres on a diverse assemblage of epilithic algal grazing fish (17 cichlids and 2 cyprinids) found on the rocky shores near Monkey Bay, Lake Malawi. Diet overlap among these species is large, but competitive exclusion is apparently avoided by the species having different feeding structures, behaviour and distribution on the shore. In many respects the ecology and behaviour of the cichlid fishes inhabiting the rocky zones of Lake Malawi parallel those of coral reef fish. In both communities there are species which are highly territorial, resulting in resource subdivision and, in some cases, the development of algal gardens. As this behaviour has not been previously reported for cichlid species, this thesis describes the territoriality of the rock-dwelling cichlids of Monkey Bay, Lake Malawi, and poses three specific questions: 1. What is the function of territoriality? 2. How do the territorial species subdivide the space resource? 3. What prevents one species taking over all the available space? It is suggested that interspecific territoriality evolved in response to a shortage of food, and, at present, serves principally to defend an algal garden i.e. a food supply of high standing crop. The species studied are extremely site specific. The rocky shore is subdivided among the four species according to the rock configuration, size, algal mat composition and position on the shore, of the available sites. An experimental study of the space utilization of the two common territorial species, referred to as 'Pseudotropheus orange cheek' and 'Pseudotropheus aggressive', showed that suitable territory sites are in short supply and that these species are in competition for some sites. These results do not support those of Fryer (1959) who suggested that a superabundance of food enabled fish to coexist by sharing the same food resource. Indeed it now appears that a shortage of food may have been a major driving force during the recent evolution of the species studied.
- Full Text:
- Date Issued: 1982
- Authors: Sharp, Bradley John
- Date: 1982
- Subjects: Cichlids -- Nyasa, Lake , Cichlids -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5340 , http://hdl.handle.net/10962/d1005927 , Cichlids -- Nyasa, Lake , Cichlids -- Behavior
- Description: This study centres on a diverse assemblage of epilithic algal grazing fish (17 cichlids and 2 cyprinids) found on the rocky shores near Monkey Bay, Lake Malawi. Diet overlap among these species is large, but competitive exclusion is apparently avoided by the species having different feeding structures, behaviour and distribution on the shore. In many respects the ecology and behaviour of the cichlid fishes inhabiting the rocky zones of Lake Malawi parallel those of coral reef fish. In both communities there are species which are highly territorial, resulting in resource subdivision and, in some cases, the development of algal gardens. As this behaviour has not been previously reported for cichlid species, this thesis describes the territoriality of the rock-dwelling cichlids of Monkey Bay, Lake Malawi, and poses three specific questions: 1. What is the function of territoriality? 2. How do the territorial species subdivide the space resource? 3. What prevents one species taking over all the available space? It is suggested that interspecific territoriality evolved in response to a shortage of food, and, at present, serves principally to defend an algal garden i.e. a food supply of high standing crop. The species studied are extremely site specific. The rocky shore is subdivided among the four species according to the rock configuration, size, algal mat composition and position on the shore, of the available sites. An experimental study of the space utilization of the two common territorial species, referred to as 'Pseudotropheus orange cheek' and 'Pseudotropheus aggressive', showed that suitable territory sites are in short supply and that these species are in competition for some sites. These results do not support those of Fryer (1959) who suggested that a superabundance of food enabled fish to coexist by sharing the same food resource. Indeed it now appears that a shortage of food may have been a major driving force during the recent evolution of the species studied.
- Full Text:
- Date Issued: 1982
Studies on the metabolism of SKF 525 A|
- Authors: Barber, Peter John
- Date: 1978 , 2013-10-14
- Subjects: Drugs -- Metabolism , Cytochrome P-450
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3835 , http://hdl.handle.net/10962/d1007591 , Drugs -- Metabolism , Cytochrome P-450
- Description: Spectrophotometric studies have been carried out to determine the pH dependence of binding of SKF 525 A, Brietal sodium and carbon monoxide to cytochrome P-450. The optimal pH for metabolic conversion of SKF 525 A has been investigated and this agent and its major metabolite, SKF 8742 A, have been metabolised in vitro by swine and rat hepatic microsomes. A suitable gas liquid chromatography assay has been developed and used to analyse metabolic production. The effects of carbon monoxide, dithiothreitol, n-octylamine and of induction of cytochrome P-450 by phenobarbital on metabolism of SKF 525 A and SKF 8742 A have been investigated. Attempts have been made to synthesise SKF 525 AN-oxide. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1978
- Authors: Barber, Peter John
- Date: 1978 , 2013-10-14
- Subjects: Drugs -- Metabolism , Cytochrome P-450
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3835 , http://hdl.handle.net/10962/d1007591 , Drugs -- Metabolism , Cytochrome P-450
- Description: Spectrophotometric studies have been carried out to determine the pH dependence of binding of SKF 525 A, Brietal sodium and carbon monoxide to cytochrome P-450. The optimal pH for metabolic conversion of SKF 525 A has been investigated and this agent and its major metabolite, SKF 8742 A, have been metabolised in vitro by swine and rat hepatic microsomes. A suitable gas liquid chromatography assay has been developed and used to analyse metabolic production. The effects of carbon monoxide, dithiothreitol, n-octylamine and of induction of cytochrome P-450 by phenobarbital on metabolism of SKF 525 A and SKF 8742 A have been investigated. Attempts have been made to synthesise SKF 525 AN-oxide. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1978
A critical analysis of housing provision, livelihood activities and social reproduction in urban communities in South Africa: the case of Ezamokuhle, Mpumalanga
- Authors: Nkambule, Sipho Jonathan
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7788 , vital:21298
- Description: The post-apartheid South African state has formulated, introduced and implemented nationwide policies and programmes pertaining to urban housing in order to address and tackle the challenges of social reproduction in and for poor urban black communities. This however has been undermined for a number of reasons, such as state incapacities and the state’s neo-liberal overreliance on the market to remedy past injustices. At the same time households, as critical sites of social reproduction in poor urban black communities and under conditions of extreme vulnerability, engage in a range of productive and non-productive activities often in a desperate bid to construct and maintain a semblance of livelihood sustainability. The thesis seeks to critically understand the relationship between state housing programmes and the diverse livelihood activities of poor urban black households in South Africa in the context of an ongoing systemic crisis of social reproduction which exists in these urban communities. This is pursued with specific reference to eZamokuhle Township in Amersfoort, Mpumalanga Province. The thesis is framed conceptually in terms of the notion of social reproduction. In doing so, it brings together two sets of literature which are often disconnected. On the one hand, there is South African literature which critically analyses the post-apartheid state’s housing programmes including the many challenges which exist in this regard. On the other hand, there is literature which considers the urban livelihoods of poor black communities in contemporary South Africa and often from within some kind of livelihoods perspective. The thesis is innovative in bringing these two sets of literature together in terms of the overarching notion of social reproduction and providing, therefore, a more holistic and integrated understanding of the multi-dimensional character of social reproduction. The depth of the crisis of social reproduction in eZamokuhle is explicated and examined in this way but in a manner which articulates the lived experiences and agency of eZamokhule households despite vulnerability constraints and challenges.
- Full Text:
- Date Issued: 2017
- Authors: Nkambule, Sipho Jonathan
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7788 , vital:21298
- Description: The post-apartheid South African state has formulated, introduced and implemented nationwide policies and programmes pertaining to urban housing in order to address and tackle the challenges of social reproduction in and for poor urban black communities. This however has been undermined for a number of reasons, such as state incapacities and the state’s neo-liberal overreliance on the market to remedy past injustices. At the same time households, as critical sites of social reproduction in poor urban black communities and under conditions of extreme vulnerability, engage in a range of productive and non-productive activities often in a desperate bid to construct and maintain a semblance of livelihood sustainability. The thesis seeks to critically understand the relationship between state housing programmes and the diverse livelihood activities of poor urban black households in South Africa in the context of an ongoing systemic crisis of social reproduction which exists in these urban communities. This is pursued with specific reference to eZamokuhle Township in Amersfoort, Mpumalanga Province. The thesis is framed conceptually in terms of the notion of social reproduction. In doing so, it brings together two sets of literature which are often disconnected. On the one hand, there is South African literature which critically analyses the post-apartheid state’s housing programmes including the many challenges which exist in this regard. On the other hand, there is literature which considers the urban livelihoods of poor black communities in contemporary South Africa and often from within some kind of livelihoods perspective. The thesis is innovative in bringing these two sets of literature together in terms of the overarching notion of social reproduction and providing, therefore, a more holistic and integrated understanding of the multi-dimensional character of social reproduction. The depth of the crisis of social reproduction in eZamokuhle is explicated and examined in this way but in a manner which articulates the lived experiences and agency of eZamokhule households despite vulnerability constraints and challenges.
- Full Text:
- Date Issued: 2017
Knowing what we can't believe
- Authors: Viedge, Nikolai
- Date: 2004
- Subjects: Reason , Reasoning , Truth , Explanation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2724 , http://hdl.handle.net/10962/d1002854 , Reason , Reasoning , Truth , Explanation
- Description: The aim of this thesis is to examine what affect, if any, finding an argument both unanswerable yet unbelievable has on three purported first-person doxastic constraints. The three proposed constraints are the principle of truth, the principle of adequate reason and the principle of epistemic explanation. In Chapter 1, I lay out the claim of each of these constraints; differentiate them from one another, examine under what conditions they can be said to apply and provide what I take to be the strongest arguments for each of them. In Chapter 2, I explicate what I mean by finding an argument unanswerable yet unbelievable. In Chapters 3, 4 and 5, I detail how it is that finding an argument unanswerable yet unbelievable could constitute a threat to each of these constraints. I conclude that while the principle of adequate reason is undermined in the face of this threat, both the principle of truth and the principle of epistemic explanation fail to be undermined by this challenge.
- Full Text: false
- Date Issued: 2004
- Authors: Viedge, Nikolai
- Date: 2004
- Subjects: Reason , Reasoning , Truth , Explanation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2724 , http://hdl.handle.net/10962/d1002854 , Reason , Reasoning , Truth , Explanation
- Description: The aim of this thesis is to examine what affect, if any, finding an argument both unanswerable yet unbelievable has on three purported first-person doxastic constraints. The three proposed constraints are the principle of truth, the principle of adequate reason and the principle of epistemic explanation. In Chapter 1, I lay out the claim of each of these constraints; differentiate them from one another, examine under what conditions they can be said to apply and provide what I take to be the strongest arguments for each of them. In Chapter 2, I explicate what I mean by finding an argument unanswerable yet unbelievable. In Chapters 3, 4 and 5, I detail how it is that finding an argument unanswerable yet unbelievable could constitute a threat to each of these constraints. I conclude that while the principle of adequate reason is undermined in the face of this threat, both the principle of truth and the principle of epistemic explanation fail to be undermined by this challenge.
- Full Text: false
- Date Issued: 2004
An investigation into the sensory mechanisms underlying the two point threshold, with particular reference to the practice effect
- Authors: Gradwell, Peter Bertram
- Date: 1971
- Subjects: Sensorimotor integration , Perceptual-motor learning
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3209 , http://hdl.handle.net/10962/d1012085 , Sensorimotor integration , Perceptual-motor learning
- Description: The two point threshold was studied extensively by the psychophysical experimenters of the last century. More recent formulations in signal detection theory have suggested that the statements of these workers about absolute thresholds should be viewed with caution. This study investigates the two point threshold in the light of these formulations, and has two main aims :- (1) To state and deal with the problem of relating a limitation in perceptual ability, such as that which is represented by the two point threshold, to the receptor organisation of the body. (2) To demonstrate a practice effect on the two point threshold, and to consider this in the light of (1) above. To fulfil these two aims, a model of the neural mechanisms underlying the discrimination of two points applied to the skin is proposed, and this is able to accommodate what is known of the two point threshold. Although the model is simple it explicitly accounts for size transfer and the practice effect, and provides some clues as to the type of neural mechanism capable of producing them. The practice effect is demonstrated experimentally, and the results are then referred to the model proposed. The physiology of an organism sets the limits for its behaviour. 'The first aim is thus an important one, in that it considers a specific case of this general problem. And secondly, the practice effect on the two point threshold is typical of a number of fairly simple "learning" phenomena, which are part of the psychologists' study of learning.
- Full Text:
- Date Issued: 1971
- Authors: Gradwell, Peter Bertram
- Date: 1971
- Subjects: Sensorimotor integration , Perceptual-motor learning
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3209 , http://hdl.handle.net/10962/d1012085 , Sensorimotor integration , Perceptual-motor learning
- Description: The two point threshold was studied extensively by the psychophysical experimenters of the last century. More recent formulations in signal detection theory have suggested that the statements of these workers about absolute thresholds should be viewed with caution. This study investigates the two point threshold in the light of these formulations, and has two main aims :- (1) To state and deal with the problem of relating a limitation in perceptual ability, such as that which is represented by the two point threshold, to the receptor organisation of the body. (2) To demonstrate a practice effect on the two point threshold, and to consider this in the light of (1) above. To fulfil these two aims, a model of the neural mechanisms underlying the discrimination of two points applied to the skin is proposed, and this is able to accommodate what is known of the two point threshold. Although the model is simple it explicitly accounts for size transfer and the practice effect, and provides some clues as to the type of neural mechanism capable of producing them. The practice effect is demonstrated experimentally, and the results are then referred to the model proposed. The physiology of an organism sets the limits for its behaviour. 'The first aim is thus an important one, in that it considers a specific case of this general problem. And secondly, the practice effect on the two point threshold is typical of a number of fairly simple "learning" phenomena, which are part of the psychologists' study of learning.
- Full Text:
- Date Issued: 1971
Conscientious objection and the concept of worship
- Authors: Moulder, James Edward
- Date: 1977
- Subjects: Conscientious objectors -- Law and legislation -- South Africa , Conscientious objectors -- South Africa , Conscientious objection , Conscientious objection -- Religious aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2749 , http://hdl.handle.net/10962/d1013555
- Description: [Preface] " ... the focus of this inquiry is limited to some of the connections between conscientious objection in South Africa and the worship and imitation of Christ. More specifically, at the most general level this essay is an attempt to explore six questions: What kind of conscientious objection does South African law allow? Why are some conscientious objectors only conscientious noncombatants? Why are some Christians conscientious noncombatants? Is it appropriate to worship Christ? Does Romans 13 undermine conscientious noncompliance? And is there a prescription for servile compliance? These are, however, not the only questions which are raised in this essay. Nor are they the only questions which can and need to be asked. But they are the questions which interest me. In addition, they have not received as much attention as they deserve".
- Full Text:
- Date Issued: 1977
- Authors: Moulder, James Edward
- Date: 1977
- Subjects: Conscientious objectors -- Law and legislation -- South Africa , Conscientious objectors -- South Africa , Conscientious objection , Conscientious objection -- Religious aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2749 , http://hdl.handle.net/10962/d1013555
- Description: [Preface] " ... the focus of this inquiry is limited to some of the connections between conscientious objection in South Africa and the worship and imitation of Christ. More specifically, at the most general level this essay is an attempt to explore six questions: What kind of conscientious objection does South African law allow? Why are some conscientious objectors only conscientious noncombatants? Why are some Christians conscientious noncombatants? Is it appropriate to worship Christ? Does Romans 13 undermine conscientious noncompliance? And is there a prescription for servile compliance? These are, however, not the only questions which are raised in this essay. Nor are they the only questions which can and need to be asked. But they are the questions which interest me. In addition, they have not received as much attention as they deserve".
- Full Text:
- Date Issued: 1977
Alkane oxidation using metallophthalocyanine as homogeneous catalysts
- Authors: Grootboom, Natasha Denise
- Date: 2002
- Subjects: Oxidation , Alkanes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4449 , http://hdl.handle.net/10962/d1007794
- Description: Iron polychlorophthalocyanine (FePc(Cl)₁₆) and tetrasulfophthalocyanine ([M¹¹TSPc]⁴) complexes of iron, cobalt and manganese are employed as catalysts for the oxidation of cyclohexane using tert-butyl hydroperoxide (TBHP), chloroperoxybenzoic acid (CPBA) and hydrogen peroxide as oxidants. Catalysis using the FePc(Cl)₁₆ was performed in a dimethylformamide:dichloromethane (3 :7) solvent mixture. For the [Fe¹¹TSPc]⁴⁻, [Co¹¹TSPc]⁻ and [Mn¹¹TSPc]⁴⁻catalysts, a water:methanol (1:9) mixture was employed. The products of the catalysis are cyclohexanone, cyclohexanol and cyclohexanediol. The relative percentage yields, percentage selectivity and overall percentage conversion of the products depended on types of oxidant, or catalyst, concentrations of substrate or catalysts and temperature. TBHP was found to be the best oxidant since minimal destruction of the catalyst and higher selectivity in the products were observed when this oxidant was employed. Of the four catalysts investigated [Fe¹¹TSPc]⁴⁻ yielded the highest overall percentage conversion of 20%.The mechanism of the oxidation of cyclohexane in the presence of the FePc(Cl)₁₆ and [M¹¹TSPc]⁴⁻ involves the oxidation of these catalysts, forming an Fe(IlI) phthalocyanine species as an intermediate. Electrocatalysis using [Co¹¹TSPc]⁴⁻ as catalyst, employed an aqueous pH 7 buffer medium for electro-oxidation of 4-pentenoic acid. An enone is suggested as the only oxidation product of 4-pentenoic acid. No degradation of [Co¹¹TSPc]⁴⁻ was observed during the electrocatalytic process. In this process water was used as a source of oxygen therefore eliminating the production of by products from oxidant as in the case of TBHP and CPBA. This system was studied In an attempt to set up conditions for alkane electrocatalytic oxidation.
- Full Text:
- Date Issued: 2002
- Authors: Grootboom, Natasha Denise
- Date: 2002
- Subjects: Oxidation , Alkanes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4449 , http://hdl.handle.net/10962/d1007794
- Description: Iron polychlorophthalocyanine (FePc(Cl)₁₆) and tetrasulfophthalocyanine ([M¹¹TSPc]⁴) complexes of iron, cobalt and manganese are employed as catalysts for the oxidation of cyclohexane using tert-butyl hydroperoxide (TBHP), chloroperoxybenzoic acid (CPBA) and hydrogen peroxide as oxidants. Catalysis using the FePc(Cl)₁₆ was performed in a dimethylformamide:dichloromethane (3 :7) solvent mixture. For the [Fe¹¹TSPc]⁴⁻, [Co¹¹TSPc]⁻ and [Mn¹¹TSPc]⁴⁻catalysts, a water:methanol (1:9) mixture was employed. The products of the catalysis are cyclohexanone, cyclohexanol and cyclohexanediol. The relative percentage yields, percentage selectivity and overall percentage conversion of the products depended on types of oxidant, or catalyst, concentrations of substrate or catalysts and temperature. TBHP was found to be the best oxidant since minimal destruction of the catalyst and higher selectivity in the products were observed when this oxidant was employed. Of the four catalysts investigated [Fe¹¹TSPc]⁴⁻ yielded the highest overall percentage conversion of 20%.The mechanism of the oxidation of cyclohexane in the presence of the FePc(Cl)₁₆ and [M¹¹TSPc]⁴⁻ involves the oxidation of these catalysts, forming an Fe(IlI) phthalocyanine species as an intermediate. Electrocatalysis using [Co¹¹TSPc]⁴⁻ as catalyst, employed an aqueous pH 7 buffer medium for electro-oxidation of 4-pentenoic acid. An enone is suggested as the only oxidation product of 4-pentenoic acid. No degradation of [Co¹¹TSPc]⁴⁻ was observed during the electrocatalytic process. In this process water was used as a source of oxygen therefore eliminating the production of by products from oxidant as in the case of TBHP and CPBA. This system was studied In an attempt to set up conditions for alkane electrocatalytic oxidation.
- Full Text:
- Date Issued: 2002
Investigating the viability and performance of a pilot scale Fly Ash/Lime Filter Tower (FLFT) for greywater treatment and the fate of Triclosan post treatment
- Authors: Nondlazi, Sinoyolo
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63704 , vital:28473
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018
- Authors: Nondlazi, Sinoyolo
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63704 , vital:28473
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2018