Women living with HIV/AIDS: a phenomenological intergenerational interpretation of their experiences
- Chisaka, Janet Kaemba Chishimba
- Authors: Chisaka, Janet Kaemba Chishimba
- Date: 2007
- Subjects: AIDS (Disease) in women -- South Africa -- Case studies HIV positive women -- South Africa -- Case studies Poor women -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3307 , http://hdl.handle.net/10962/d1003095
- Description: This study deals with the impact of HIV/AIDS on women living in chronic poverty. The question arises: Do we focus on their HIV/AIDS stories only or do we include their other lived experiences? This phenomenological study, on two sets of three generations of women infected and affected by HIV/AIDS and living in poverty, is an attempt at understanding the way the women experience their lifeworlds, not only their HIV/AIDS stories. One set includes a grandmother, her daughter who is living with full-blown AIDS, and her granddaughter, while the other includes a grandmother, her daughter and her granddaughter infected with HIV. The initial focus of the study was on the women’s HIV/AIDS narratives. However as the study progressed, especially during the interviews, it became apparent that the women’s generational poverty or chronic poverty was of greater concern to them than the HIV/AIDS that they were experiencing. Of the six participants, only one woman centred her life story on HIV/AIDS. This finding echoes other studies on HIV/AIDS among poor women: that chronic poverty is more threatening to the women than the risk or reality of AIDS. As a phenomenological researcher my aim was to focus on the participants’ own interpretations of the studied phenomenon. However, this was inadequate in accounting for the role that social structures play in shaping and informing the women’s subjective consciousness and experience. For this reason, I used feminist ideas to understand and interpret the women’s patriarchal experiences.
- Full Text:
- Date Issued: 2007
Women living with HIV/AIDS: a phenomenological intergenerational interpretation of their experiences
- Authors: Chisaka, Janet Kaemba Chishimba
- Date: 2007
- Subjects: AIDS (Disease) in women -- South Africa -- Case studies HIV positive women -- South Africa -- Case studies Poor women -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3307 , http://hdl.handle.net/10962/d1003095
- Description: This study deals with the impact of HIV/AIDS on women living in chronic poverty. The question arises: Do we focus on their HIV/AIDS stories only or do we include their other lived experiences? This phenomenological study, on two sets of three generations of women infected and affected by HIV/AIDS and living in poverty, is an attempt at understanding the way the women experience their lifeworlds, not only their HIV/AIDS stories. One set includes a grandmother, her daughter who is living with full-blown AIDS, and her granddaughter, while the other includes a grandmother, her daughter and her granddaughter infected with HIV. The initial focus of the study was on the women’s HIV/AIDS narratives. However as the study progressed, especially during the interviews, it became apparent that the women’s generational poverty or chronic poverty was of greater concern to them than the HIV/AIDS that they were experiencing. Of the six participants, only one woman centred her life story on HIV/AIDS. This finding echoes other studies on HIV/AIDS among poor women: that chronic poverty is more threatening to the women than the risk or reality of AIDS. As a phenomenological researcher my aim was to focus on the participants’ own interpretations of the studied phenomenon. However, this was inadequate in accounting for the role that social structures play in shaping and informing the women’s subjective consciousness and experience. For this reason, I used feminist ideas to understand and interpret the women’s patriarchal experiences.
- Full Text:
- Date Issued: 2007
Field and laboratory analyses of manual tasks in the South African automotive industry
- Authors: James, Jonathan Peter
- Date: 2007
- Subjects: Automobile industry and trade -- South Africa -- Safety measures , Human engineering -- South Africa , Automobile industry workers -- South Africa -- Health risk assessment , Industrial safety -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5121 , http://hdl.handle.net/10962/d1005199 , Automobile industry and trade -- South Africa -- Safety measures , Human engineering -- South Africa , Automobile industry workers -- South Africa -- Health risk assessment , Industrial safety -- South Africa
- Description: The present study adopted a “field-laboratory-field” approach in the assessment of the efficacy of ergonomics interventions specific to two selected tasks evaluated in a South African automotive industry. Initial field testing was conducted in an Eastern Cape (South Africa) automotive plant where high risk areas were identified during walkthrough ergonomics surveys in conjunction with interaction with operators. Temporal factors and working postures of 12 industrial workers were recorded and observed, while physiological and perceptual responses were assessed. Two priority areas were focused upon for analysis, namely the Paintshop and Bodyshop with the former identified as being the more taxing of the two tasks. Responses of 30 students participating in rigourously controlled laboratory simulations were subsequently collected while completing the two tasks, namely the Paintshop Trolley Transfer (PTT) and Car Door Carriage (CDC) for participants. Working postures, kinematic, physiological and perceptual responses were assessed pre- and post-intervention. Following the laboratory experimentation a basic re-evaluation was conducted at the plant to assess whether the proposed changes had a positive effect on working postures, physiological and perceptual responses. The results of the preliminary field investigation revealed a prevalence of awkward working postures and excessive manual work in both areas. Laboratory experimentation revealed a notable reduction in task demands pre- versus post-intervention. The PTT mean lean angle for two-handed pre-intervention pulling observations of 23.7° (±3.51) was reduced to 13.9° (±2.21) post-intervention. Low back disorder (LBD) risk was reduced during the two-handed pull intervention (from 36.8% ±8.03 to 21.7% ±5.31). A significant decrement in heart rate responses from 103 bt.min-1 (±11.62) to 93 bt.min[superscript -1] (±11.77) was recorded during the two-handed symmetrical pushing intervention. The electromyography (EMG) responses for one-handed pushing and pulling pre-intervention showed the highest levels of muscular activity in the right medial deltoid due to an awkward and asymmetrical posture. CDC responses demonstrated that minor changes in the storage height of the door resulted in a significant reduction in sagittal flexion from 28.0° (±4.78) to 20.7° (±5.65). Predictions of average probability of LBD risk were significantly reduced from 50.3% (±5.91) to 39.8% (±5.10) for post-intervention car door lifting. In addition, the greatest reduction in EMG activity as a %MVC was achieved during sub-task ii (reduced from 35.1 to 13.7% and 30.5 to 13.9% for left and right erector spinae respectively) which was associated with the introduction of the transfer trolley for the door transfer phase of the CDC. Re-evaluation in the automotive plant revealed that the most notable change has been the implementation of automated ride on trolleys in the Paintshop. The Bodyshop area has also been modified to allow more effective job rotation and the step into the storage bin has been reduced via a “low-cost” stepping platform. Mean heart rate recordings were reduced from 94 (±9.77) bt.min[superscript -1] to 81 (±3.72) bt.min[superscript -1] in the Paintshop. Overall the results demonstrate the effect of “low-cost” interventions in reducing the physical stresses placed on workers in the automotive industry where much of the work is still done manually.
- Full Text:
- Date Issued: 2007
- Authors: James, Jonathan Peter
- Date: 2007
- Subjects: Automobile industry and trade -- South Africa -- Safety measures , Human engineering -- South Africa , Automobile industry workers -- South Africa -- Health risk assessment , Industrial safety -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5121 , http://hdl.handle.net/10962/d1005199 , Automobile industry and trade -- South Africa -- Safety measures , Human engineering -- South Africa , Automobile industry workers -- South Africa -- Health risk assessment , Industrial safety -- South Africa
- Description: The present study adopted a “field-laboratory-field” approach in the assessment of the efficacy of ergonomics interventions specific to two selected tasks evaluated in a South African automotive industry. Initial field testing was conducted in an Eastern Cape (South Africa) automotive plant where high risk areas were identified during walkthrough ergonomics surveys in conjunction with interaction with operators. Temporal factors and working postures of 12 industrial workers were recorded and observed, while physiological and perceptual responses were assessed. Two priority areas were focused upon for analysis, namely the Paintshop and Bodyshop with the former identified as being the more taxing of the two tasks. Responses of 30 students participating in rigourously controlled laboratory simulations were subsequently collected while completing the two tasks, namely the Paintshop Trolley Transfer (PTT) and Car Door Carriage (CDC) for participants. Working postures, kinematic, physiological and perceptual responses were assessed pre- and post-intervention. Following the laboratory experimentation a basic re-evaluation was conducted at the plant to assess whether the proposed changes had a positive effect on working postures, physiological and perceptual responses. The results of the preliminary field investigation revealed a prevalence of awkward working postures and excessive manual work in both areas. Laboratory experimentation revealed a notable reduction in task demands pre- versus post-intervention. The PTT mean lean angle for two-handed pre-intervention pulling observations of 23.7° (±3.51) was reduced to 13.9° (±2.21) post-intervention. Low back disorder (LBD) risk was reduced during the two-handed pull intervention (from 36.8% ±8.03 to 21.7% ±5.31). A significant decrement in heart rate responses from 103 bt.min-1 (±11.62) to 93 bt.min[superscript -1] (±11.77) was recorded during the two-handed symmetrical pushing intervention. The electromyography (EMG) responses for one-handed pushing and pulling pre-intervention showed the highest levels of muscular activity in the right medial deltoid due to an awkward and asymmetrical posture. CDC responses demonstrated that minor changes in the storage height of the door resulted in a significant reduction in sagittal flexion from 28.0° (±4.78) to 20.7° (±5.65). Predictions of average probability of LBD risk were significantly reduced from 50.3% (±5.91) to 39.8% (±5.10) for post-intervention car door lifting. In addition, the greatest reduction in EMG activity as a %MVC was achieved during sub-task ii (reduced from 35.1 to 13.7% and 30.5 to 13.9% for left and right erector spinae respectively) which was associated with the introduction of the transfer trolley for the door transfer phase of the CDC. Re-evaluation in the automotive plant revealed that the most notable change has been the implementation of automated ride on trolleys in the Paintshop. The Bodyshop area has also been modified to allow more effective job rotation and the step into the storage bin has been reduced via a “low-cost” stepping platform. Mean heart rate recordings were reduced from 94 (±9.77) bt.min[superscript -1] to 81 (±3.72) bt.min[superscript -1] in the Paintshop. Overall the results demonstrate the effect of “low-cost” interventions in reducing the physical stresses placed on workers in the automotive industry where much of the work is still done manually.
- Full Text:
- Date Issued: 2007
Improving the levels of cooperation between members of the school management teams
- Authors: Klaas, Andile Jeffrey
- Date: 2007
- Subjects: School management teams -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9539 , http://hdl.handle.net/10948/681 , School management teams -- South Africa
- Description: Schools are directly placed under the care of the school governing bodies and school management teams that manage their day-to-day activities. These school management teams are expected to transform their schools into functioning and effective schools. The sad reality though, is that they are confronted with a huge task of improving cooperation between themselves in order to realise their dream of achieving their shared organizational goals. This interpretive study explores members of the management staff’s subjective experiences and their social world, to provide meaning and understanding of the levels of cooperation among them, and how this can be improved. The main outcomes of the study include: o Promoting conditions that are favourable to the establishment of collaborative practices between members of the management teams. o Fostering cooperation to ensure the development of sustainable capacity and increased energy to solve problems and transform their schools.
- Full Text:
- Date Issued: 2007
- Authors: Klaas, Andile Jeffrey
- Date: 2007
- Subjects: School management teams -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9539 , http://hdl.handle.net/10948/681 , School management teams -- South Africa
- Description: Schools are directly placed under the care of the school governing bodies and school management teams that manage their day-to-day activities. These school management teams are expected to transform their schools into functioning and effective schools. The sad reality though, is that they are confronted with a huge task of improving cooperation between themselves in order to realise their dream of achieving their shared organizational goals. This interpretive study explores members of the management staff’s subjective experiences and their social world, to provide meaning and understanding of the levels of cooperation among them, and how this can be improved. The main outcomes of the study include: o Promoting conditions that are favourable to the establishment of collaborative practices between members of the management teams. o Fostering cooperation to ensure the development of sustainable capacity and increased energy to solve problems and transform their schools.
- Full Text:
- Date Issued: 2007
Optimisation of pharmacological management of diabetes mellitus in a primary health care setting
- Authors: Dickason, Beverley Janine
- Date: 2007
- Subjects: Diabetes , Diabetes -- Treatment
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:10161 , http://hdl.handle.net/10948/846 , http://hdl.handle.net/10948/d1012902 , Diabetes , Diabetes -- Treatment
- Description: Levels of diabetic care in primary health care settings in South Africa have been found to be sub-optimal. Knowledge deficits and inadequate practices have been implicated in the poor quality of local diabetes care. Type 2 diabetes and hypertension are commonly associated chronic conditions hence to optimise diabetic care, tight control of blood pressure is essential. Although guidelines for the overall management of diabetes in a primary health care setting have been published (Working Group of the National Diabetes Advisory Board, 1997; Society for Endocrinology, Metabolism and Diabetes of South Africa, 2002a), adherence to these guidelines has not yet been optimised in the primary health care setting. The objectives of the study were: to design and implement an educational intervention aimed at nursing staff, based on the South African guidelines for type 2 diabetes and hypertension, at a public sector primary health care clinic; to determine the impact of the educational intervention on the level of knowledge and attitudes of the nursing staff, and on the level of diabetic and blood pressure control achieved in the patient population, and to determine the impact of the educational intervention on pharmacological management of patients. A questionnaire was used to quantitatively assess the nursing staffs’ knowledge of the management of type 2 diabetes and hypertension at a primary health care level. A qualitative evaluation of the nursing staff attitudes was obtained using focus group interviews. The educational intervention, in the form of lectures and based on national diabetes and hypertension guidelines (Working Group of the National Diabetes Advisory Board, 1997; Society for Endocrinology, Metabolism and Diabetes of South Africa, 2002a; Milne et al., 2003), was then implemented and directed at the nursing staff at a primary health care clinic. A post-intervention evaluation was performed after four months by repeating the questionnaire and focus group interviews. Comparisons between the pre- and post-intervention questionnaire and focus group interviews evaluated the impact of the educational intervention on the knowledge and attitudes of nursing staff towards the management of type 2 diabetes. Pre- and post-intervention patient data was collected from patient medical files and compared to determine if the management of diabetes and hypertension improved in the patient population after the implementation of the educational intervention. The patient population consisted of 103 patients. The educational intervention resulted in an extremely significant improvement in the level of knowledge of the nursing staff [93 correct responses (28.3 percent; n = 329 (pre-intervention)) vs 223 correct responses (67.8 percent; n = 329 (post-intervention)); p < 0.0001, Fisher’s Exact test]. The educational intervention resulted in improved attitudes of nursing staff towards the management of diabetes. Ideal random blood glucose concentrations improved significantly [16 percent; n = 100 (pre-intervention) vs 22 percent; n = 100 (post-intervention); p = 0.0003; Student t test]. The number of patients with a compromised HbA1c level (> 8 percent) decreased by 2 [51; 49.5 percent, n = 103 (pre-intervention) vs 49, 47.5 percent, n = 103 (post-intervention)] which was not a significant improvement. Ideal blood pressure control improved by one from 38 patients [36.9 percent; n = 103 (pre-intervention)] to 39 patients [37.9 percent; n = 103 (post-intervention)] which was not significant. Optimal change of pharmacological management following the referral of an uncontrolled diabetic patient was only noted for 18 patients (20.2 percent, n = 89) referred in the post-intervention phase. Clinical inertia was identified as a major limitation to the optimisation of diabetes care. Implementation of an educational intervention based on the South African diabetes and hypertension guidelines at a public sector primary health care clinic was successful in improving the knowledge levels and attitudes of nursing staff
- Full Text:
- Date Issued: 2007
- Authors: Dickason, Beverley Janine
- Date: 2007
- Subjects: Diabetes , Diabetes -- Treatment
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:10161 , http://hdl.handle.net/10948/846 , http://hdl.handle.net/10948/d1012902 , Diabetes , Diabetes -- Treatment
- Description: Levels of diabetic care in primary health care settings in South Africa have been found to be sub-optimal. Knowledge deficits and inadequate practices have been implicated in the poor quality of local diabetes care. Type 2 diabetes and hypertension are commonly associated chronic conditions hence to optimise diabetic care, tight control of blood pressure is essential. Although guidelines for the overall management of diabetes in a primary health care setting have been published (Working Group of the National Diabetes Advisory Board, 1997; Society for Endocrinology, Metabolism and Diabetes of South Africa, 2002a), adherence to these guidelines has not yet been optimised in the primary health care setting. The objectives of the study were: to design and implement an educational intervention aimed at nursing staff, based on the South African guidelines for type 2 diabetes and hypertension, at a public sector primary health care clinic; to determine the impact of the educational intervention on the level of knowledge and attitudes of the nursing staff, and on the level of diabetic and blood pressure control achieved in the patient population, and to determine the impact of the educational intervention on pharmacological management of patients. A questionnaire was used to quantitatively assess the nursing staffs’ knowledge of the management of type 2 diabetes and hypertension at a primary health care level. A qualitative evaluation of the nursing staff attitudes was obtained using focus group interviews. The educational intervention, in the form of lectures and based on national diabetes and hypertension guidelines (Working Group of the National Diabetes Advisory Board, 1997; Society for Endocrinology, Metabolism and Diabetes of South Africa, 2002a; Milne et al., 2003), was then implemented and directed at the nursing staff at a primary health care clinic. A post-intervention evaluation was performed after four months by repeating the questionnaire and focus group interviews. Comparisons between the pre- and post-intervention questionnaire and focus group interviews evaluated the impact of the educational intervention on the knowledge and attitudes of nursing staff towards the management of type 2 diabetes. Pre- and post-intervention patient data was collected from patient medical files and compared to determine if the management of diabetes and hypertension improved in the patient population after the implementation of the educational intervention. The patient population consisted of 103 patients. The educational intervention resulted in an extremely significant improvement in the level of knowledge of the nursing staff [93 correct responses (28.3 percent; n = 329 (pre-intervention)) vs 223 correct responses (67.8 percent; n = 329 (post-intervention)); p < 0.0001, Fisher’s Exact test]. The educational intervention resulted in improved attitudes of nursing staff towards the management of diabetes. Ideal random blood glucose concentrations improved significantly [16 percent; n = 100 (pre-intervention) vs 22 percent; n = 100 (post-intervention); p = 0.0003; Student t test]. The number of patients with a compromised HbA1c level (> 8 percent) decreased by 2 [51; 49.5 percent, n = 103 (pre-intervention) vs 49, 47.5 percent, n = 103 (post-intervention)] which was not a significant improvement. Ideal blood pressure control improved by one from 38 patients [36.9 percent; n = 103 (pre-intervention)] to 39 patients [37.9 percent; n = 103 (post-intervention)] which was not significant. Optimal change of pharmacological management following the referral of an uncontrolled diabetic patient was only noted for 18 patients (20.2 percent, n = 89) referred in the post-intervention phase. Clinical inertia was identified as a major limitation to the optimisation of diabetes care. Implementation of an educational intervention based on the South African diabetes and hypertension guidelines at a public sector primary health care clinic was successful in improving the knowledge levels and attitudes of nursing staff
- Full Text:
- Date Issued: 2007
The representation of South African women politicians in the Sunday Times during the 2004 presidential and general elections
- Authors: Katembo, Tina Kabunda
- Date: 2007
- Subjects: Sunday Times (Johannesburg, South Africa) Women politicians -- South Africa Women in mass media Mass media -- Political aspects -- South Africa Elections -- South Africa South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3445 , http://hdl.handle.net/10962/d1002899
- Description: This study analysed the representation of South African women politicians in the Sunday Times’ election news during the 2004 Presidential and general elections, by drawing on perspectives from cultural studies, the constructionist approach to representation and the sociology of news production. Using content analysis and critical discourse analysis, the study found that very few women politicians were used as news actors/sources in the Sunday Times, and that when women politicians were figured, the paper tended to present them in ways that serve to sustain women’s subordinate status in society. Using content analysis, the study analysed 106 news items published between January 1, 2004 and April 30, 2004, and found that of all the 588 identifiable news actors/sources counted, 135 were women and 453 were men. Of these, only 7.67% (or 26) were women politicians and 92.33% (or 313) were men politicians. On average however, the amount of words allocated to a woman politician was more than that allocated to a man politician. The discourse analysis also revealed how the Sunday Times managed to reproduce textually the hegemonic power relations between women and men, by constructing different subject positions for women politicians and men politicians, which generally tended to be negative and positive respectively. In the representation of women politicians, the study revealed patterns that tended to ascribe them negative personality traits, accentuate their passivity and dependency on men, and construct them as incompetent political leaders. This study’s conclusions pose a challenge to the role of the national newspaper in the transformation of gender relations and the promotion of equal access to political and decision-making positions, and to the news media. News discourse, as a social practice, both determines and is determined by the social structure in which it is produced. By systematically reproducing subordinate subject positions for women in the news, the Sunday Times helps to further women’s subordinate status in society. Particularly, as part of the broader social cultural context that is embedded in patriarchal and gender ideologies, the Sunday Times does not merely reflect but actively and effectively constructs the reality it claims to be representing.
- Full Text:
- Date Issued: 2007
- Authors: Katembo, Tina Kabunda
- Date: 2007
- Subjects: Sunday Times (Johannesburg, South Africa) Women politicians -- South Africa Women in mass media Mass media -- Political aspects -- South Africa Elections -- South Africa South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3445 , http://hdl.handle.net/10962/d1002899
- Description: This study analysed the representation of South African women politicians in the Sunday Times’ election news during the 2004 Presidential and general elections, by drawing on perspectives from cultural studies, the constructionist approach to representation and the sociology of news production. Using content analysis and critical discourse analysis, the study found that very few women politicians were used as news actors/sources in the Sunday Times, and that when women politicians were figured, the paper tended to present them in ways that serve to sustain women’s subordinate status in society. Using content analysis, the study analysed 106 news items published between January 1, 2004 and April 30, 2004, and found that of all the 588 identifiable news actors/sources counted, 135 were women and 453 were men. Of these, only 7.67% (or 26) were women politicians and 92.33% (or 313) were men politicians. On average however, the amount of words allocated to a woman politician was more than that allocated to a man politician. The discourse analysis also revealed how the Sunday Times managed to reproduce textually the hegemonic power relations between women and men, by constructing different subject positions for women politicians and men politicians, which generally tended to be negative and positive respectively. In the representation of women politicians, the study revealed patterns that tended to ascribe them negative personality traits, accentuate their passivity and dependency on men, and construct them as incompetent political leaders. This study’s conclusions pose a challenge to the role of the national newspaper in the transformation of gender relations and the promotion of equal access to political and decision-making positions, and to the news media. News discourse, as a social practice, both determines and is determined by the social structure in which it is produced. By systematically reproducing subordinate subject positions for women in the news, the Sunday Times helps to further women’s subordinate status in society. Particularly, as part of the broader social cultural context that is embedded in patriarchal and gender ideologies, the Sunday Times does not merely reflect but actively and effectively constructs the reality it claims to be representing.
- Full Text:
- Date Issued: 2007
Comparative electrooxidation of sulphite by self-assembled monolayers (SAMs) of Co (II), Fe (II), Ni (II) and Mn (III) tetrakis benzylmercapto and dodecylmercapto metallophthalocyanines complexes on gold electrodes
- Agboola, Bolade, Nyokong, Tebello
- Authors: Agboola, Bolade , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281223 , vital:55703 , xlink:href="https://doi.org/10.1016/j.talanta.2006.11.042"
- Description: This work reports on the use of Co(II), Fe(II), Mn(III) and Ni(II) tetrakis benzylmercapto and dodecylmercapto phthalocyanine complexes for gold electrode modification for electrooxidation of sulphite ions. The complexes were successfully used to modify gold electrodes by self-assembled monolayer (SAM) technique. The self-assembled films are stable and showed blocking characteristics towards the following Faradaic processes; gold surface oxidation, underpotential deposition (UPD) of copper and solution redox chemistry of [Fe(H2O)63+]/[Fe(H2O)62+]. All the modified electrodes showed improved catalytic activities than the unmodified gold electrode towards sulphite ion electrooxidation with all the modified electrodes exhibiting high resistance to electrode surface passivation. Better catalytic performance were obtained for the CoPcs, FePcs and MnPcs which have metal based redox processes within the range of the sulphite electrooxidation peak, while the NiPcs which did not show metal based redox reaction performed less. The catalytic current was found to be linear with sulphite ion concentration in the concentration range employed in this work (0.1–1 mM) and sensitivities ranging from 1.68 to 2.96 μA/mM were observed for all the modified electrodes. Mechanisms of the catalytic oxidation of sulphite ions are proposed.
- Full Text:
- Date Issued: 2007
- Authors: Agboola, Bolade , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281223 , vital:55703 , xlink:href="https://doi.org/10.1016/j.talanta.2006.11.042"
- Description: This work reports on the use of Co(II), Fe(II), Mn(III) and Ni(II) tetrakis benzylmercapto and dodecylmercapto phthalocyanine complexes for gold electrode modification for electrooxidation of sulphite ions. The complexes were successfully used to modify gold electrodes by self-assembled monolayer (SAM) technique. The self-assembled films are stable and showed blocking characteristics towards the following Faradaic processes; gold surface oxidation, underpotential deposition (UPD) of copper and solution redox chemistry of [Fe(H2O)63+]/[Fe(H2O)62+]. All the modified electrodes showed improved catalytic activities than the unmodified gold electrode towards sulphite ion electrooxidation with all the modified electrodes exhibiting high resistance to electrode surface passivation. Better catalytic performance were obtained for the CoPcs, FePcs and MnPcs which have metal based redox processes within the range of the sulphite electrooxidation peak, while the NiPcs which did not show metal based redox reaction performed less. The catalytic current was found to be linear with sulphite ion concentration in the concentration range employed in this work (0.1–1 mM) and sensitivities ranging from 1.68 to 2.96 μA/mM were observed for all the modified electrodes. Mechanisms of the catalytic oxidation of sulphite ions are proposed.
- Full Text:
- Date Issued: 2007
The educationally-related challenges faced by teenage mothers on returning to school: a Namibian case study
- Authors: Shaningwa, Lilia Mariro
- Date: 2007
- Subjects: Teenage mothers -- Namibia -- Case studies Teenagers -- Education -- Namibia -- Case studies Education, Secondary -- Namibia -- Case studies Teenage pregnancy -- Namibia -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1506 , http://hdl.handle.net/10962/d1003388
- Description: The study aimed to investigate the educationally-related challenges faced by teenage mothers in coming back to school in two senior schools in the Kavango Education Region. This small-scale study focused on the challenges that influence or affect the academic progress and development of these learners. The study looked at how teenage pregnancy is perceived as a social problem in many countries as well as in Namibia and examined its impact on the educational aspirations of the young mothers. Namibia has a policy in place to cater for the continued education of learners returning to school after the birth of their babies. This policy was analysed and its implementation in the selected schools formed part of the study, The findings revealed that the educational challenges faced by these young women range from social exclusion to the need to manage the dual responsibilities of motherhood and study. The way in which the learners who participated in this study are viewed by their peers and their teachers was found to be influenced by the cultural connotations ascribed to women as soon as they become mothers, a factor that adds to the challenges these learners face when returning to schools. Cultural connotations which perceived a mother as an adult in the society was attached to the change of the behaviours and attitudes of school young mothers. The findings also showed that while these learners tended to be withdrawn in class and were generally unable to participate in extra-mural activities, they none the less were able to compete with their peers in terms of their academic performance. The study revealed that there is no shared understanding of the policy among the participants and that it is not effectively implemented in the schools, nor is it uniformly applied.
- Full Text:
- Date Issued: 2007
- Authors: Shaningwa, Lilia Mariro
- Date: 2007
- Subjects: Teenage mothers -- Namibia -- Case studies Teenagers -- Education -- Namibia -- Case studies Education, Secondary -- Namibia -- Case studies Teenage pregnancy -- Namibia -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1506 , http://hdl.handle.net/10962/d1003388
- Description: The study aimed to investigate the educationally-related challenges faced by teenage mothers in coming back to school in two senior schools in the Kavango Education Region. This small-scale study focused on the challenges that influence or affect the academic progress and development of these learners. The study looked at how teenage pregnancy is perceived as a social problem in many countries as well as in Namibia and examined its impact on the educational aspirations of the young mothers. Namibia has a policy in place to cater for the continued education of learners returning to school after the birth of their babies. This policy was analysed and its implementation in the selected schools formed part of the study, The findings revealed that the educational challenges faced by these young women range from social exclusion to the need to manage the dual responsibilities of motherhood and study. The way in which the learners who participated in this study are viewed by their peers and their teachers was found to be influenced by the cultural connotations ascribed to women as soon as they become mothers, a factor that adds to the challenges these learners face when returning to schools. Cultural connotations which perceived a mother as an adult in the society was attached to the change of the behaviours and attitudes of school young mothers. The findings also showed that while these learners tended to be withdrawn in class and were generally unable to participate in extra-mural activities, they none the less were able to compete with their peers in terms of their academic performance. The study revealed that there is no shared understanding of the policy among the participants and that it is not effectively implemented in the schools, nor is it uniformly applied.
- Full Text:
- Date Issued: 2007
On the microstructure and physical properties of hot pressed (Hf, Ti) C
- Authors: Heiligers, Christiané
- Date: 2007
- Subjects: Transition metal carbides
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10532 , http://hdl.handle.net/10948/523 , http://hdl.handle.net/10948/d1011722 , Transition metal carbides
- Description: The microstructure and physical properties of hot pressed (Hf, Ti) C have been investigated with the aim of producing a cutting tool material with similar hardness to that of WC-Co and TiC-based cermets. Sintered samples were hot pressed from HfC0.7 and TiC0.9 powders using powder metallurgical techniques and the processing cycle was optimized for this system. Ni was used as a binder in selected samples and C black was added to compensate for sub-stoichiometry and to aid in the reduction of oxides formed during milling. Microstructural analyses were performed by scanning and transmission electron microscopy (SEM and TEM) and the composition was determined from X-ray diffraction (XRD) and energy dispersive X-ray spectrometry (EDS). The physical properties measured are density and Vickers hardness, and the indentation fracture toughness was determined using the Shetty formula. The fundamental interactions between HfC, TiC and Ni during hot pressing were investigated and the results obtained used to explain the microstructure that develops in samples made from powder mixtures. The interactions studied are the inter-diffusion of HfC and TiC through the solid state, and the dissolution and re-precipitation rate of the carbides in a liquid Ni binder. EDS analysis revealed that the rate at which Ti diffuses into HfC is higher than the rate at which Hf diffuses into TiC. Upper limits to the diffusion coefficients for these processes are determined and show that solid solution carbides will form from HfC + TiC powder mixtures at 2000 ºC in 1 hour if the average powder particle size is less than 5 μm. The diffusion rates decrease with a decrease in hot pressing temperature but mass transport between the phases can be enhanced by addition of a metallic binder. TEM and EDS analysis shows that Ni wets TiC more efficiently than HfC and that the solubility of TiC in Ni is also higher than that of HfC. The grain size of the carbide phases increases with an increase in the rate at which they dissolve into and re-precipitate from the liquid binder. The crystal structure of the binder phase depends on the concentration of Ti and Hf that remain in the binder after cooling and the carbide phase in which the binder is embedded. Analysis of TEM electron diffraction patterns show that the binder phase consists of cubic solid solutions as well as intermetallic and cubic phases in which atomic ordering is observed.
- Full Text:
- Date Issued: 2007
- Authors: Heiligers, Christiané
- Date: 2007
- Subjects: Transition metal carbides
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10532 , http://hdl.handle.net/10948/523 , http://hdl.handle.net/10948/d1011722 , Transition metal carbides
- Description: The microstructure and physical properties of hot pressed (Hf, Ti) C have been investigated with the aim of producing a cutting tool material with similar hardness to that of WC-Co and TiC-based cermets. Sintered samples were hot pressed from HfC0.7 and TiC0.9 powders using powder metallurgical techniques and the processing cycle was optimized for this system. Ni was used as a binder in selected samples and C black was added to compensate for sub-stoichiometry and to aid in the reduction of oxides formed during milling. Microstructural analyses were performed by scanning and transmission electron microscopy (SEM and TEM) and the composition was determined from X-ray diffraction (XRD) and energy dispersive X-ray spectrometry (EDS). The physical properties measured are density and Vickers hardness, and the indentation fracture toughness was determined using the Shetty formula. The fundamental interactions between HfC, TiC and Ni during hot pressing were investigated and the results obtained used to explain the microstructure that develops in samples made from powder mixtures. The interactions studied are the inter-diffusion of HfC and TiC through the solid state, and the dissolution and re-precipitation rate of the carbides in a liquid Ni binder. EDS analysis revealed that the rate at which Ti diffuses into HfC is higher than the rate at which Hf diffuses into TiC. Upper limits to the diffusion coefficients for these processes are determined and show that solid solution carbides will form from HfC + TiC powder mixtures at 2000 ºC in 1 hour if the average powder particle size is less than 5 μm. The diffusion rates decrease with a decrease in hot pressing temperature but mass transport between the phases can be enhanced by addition of a metallic binder. TEM and EDS analysis shows that Ni wets TiC more efficiently than HfC and that the solubility of TiC in Ni is also higher than that of HfC. The grain size of the carbide phases increases with an increase in the rate at which they dissolve into and re-precipitate from the liquid binder. The crystal structure of the binder phase depends on the concentration of Ti and Hf that remain in the binder after cooling and the carbide phase in which the binder is embedded. Analysis of TEM electron diffraction patterns show that the binder phase consists of cubic solid solutions as well as intermetallic and cubic phases in which atomic ordering is observed.
- Full Text:
- Date Issued: 2007
A methodology for measuring and monitoring IT risk
- Authors: Tansley, Natalie Vanessa
- Date: 2007
- Subjects: Electronic data processing departments -- Security measures , Business -- Data processing -- Security measures , Information resources management , Information technology -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9781 , http://hdl.handle.net/10948/772 , Electronic data processing departments -- Security measures , Business -- Data processing -- Security measures , Information resources management , Information technology -- Security measures
- Description: The primary objective of the research is to develop a methodology for monitoring and measuring IT risks, strictly focusing on internal controls. The research delivers a methodology whereby an organization can measure its system of internal controls, providing assurance that the risks are at an acceptable level. To achieve the primary objective a number of secondary objectives were addressed: What are the drivers forcing organizations to better corporate governance in managing risk? What is IT risk management, specifically focusing on operational risk. What is internal control and specifically focusing on COSO’s internal control process. Investigation of measurement methods, such as, Balance Scorecards, Critical Success Factors, Maturity Models, Key Performance Indicators and Key Goal Indicators. Investigation of various frameworks such as CobiT, COSO and ISO 17799, ITIL and BS 7799 as to how they manage IT risk relating to internal control.
- Full Text:
- Date Issued: 2007
- Authors: Tansley, Natalie Vanessa
- Date: 2007
- Subjects: Electronic data processing departments -- Security measures , Business -- Data processing -- Security measures , Information resources management , Information technology -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9781 , http://hdl.handle.net/10948/772 , Electronic data processing departments -- Security measures , Business -- Data processing -- Security measures , Information resources management , Information technology -- Security measures
- Description: The primary objective of the research is to develop a methodology for monitoring and measuring IT risks, strictly focusing on internal controls. The research delivers a methodology whereby an organization can measure its system of internal controls, providing assurance that the risks are at an acceptable level. To achieve the primary objective a number of secondary objectives were addressed: What are the drivers forcing organizations to better corporate governance in managing risk? What is IT risk management, specifically focusing on operational risk. What is internal control and specifically focusing on COSO’s internal control process. Investigation of measurement methods, such as, Balance Scorecards, Critical Success Factors, Maturity Models, Key Performance Indicators and Key Goal Indicators. Investigation of various frameworks such as CobiT, COSO and ISO 17799, ITIL and BS 7799 as to how they manage IT risk relating to internal control.
- Full Text:
- Date Issued: 2007
An investigation of the sustainability of the Imbewu Project at Phiwe Primary School
- Authors: Maselana, Thobeka
- Date: 2007
- Subjects: Education -- South Africa -- Eastern Cape Sustainable development -- South Africa -- Eastern Cape Project method in teaching -- South Africa -- Eastern Cape School improvement programs -- South Africa -- Eastern Cape -- Case studies Educational change -- South Africa -- Eastern Cape Education and state -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1924 , http://hdl.handle.net/10962/d1007509
- Description: Sustainable development and projects are relatively new terms In the South African context. This study explores these concepts as they relate to a school that is piloting a project in the Eastern Cape. A number of projects have been introduced in disadvantaged schools to redress imbalances of the past. Funders invest a lot of money, but when they leave, schools struggle to sustain these initiatives. This study aims to investigate whether the Imbewu Project, an educational development pilot project meant to improve schools in the Eastern Cape, made provision for long-term sustainability and whether the school sustained the project. Very little research seems to have been conducted on sustainability, especially in South Africa (SA). The study is conducted in the interpretive paradigm. A single case study involving a number of stakeholders at Phiwe Primary School (PPS) was conducted through observations, interviews, focus groups and document analysis. The study found that the action research strategy intended for the project was constrained by the limited time allowed. In addition, the approach did not address processes which are important for sustainability. Also, the cascade approach to learning is not successful in organisations that have not reached the status of being learning organisations. PPS is still struggling to change its culture and therefore one can say that they cannot sustain the changes that are brought by the project. Firstly, they did not involve the parents in most modules as the project suggested. Secondly, some facilitators did not understand the project. Thirdly, although the project provided for monitoring and support, the study found that there was inadequate support from the project team and district officials. There was a shortage of district officials because the Eastern Cape Department of Education did not invest in appointing people that could sustain the project. However, there are areas where the school is doing an outstanding job despite the fact that there was very little support. The school performed well in implementing and sustaining the project in the following areas: learner welfare, community involvement and involvement of staff members in committees.
- Full Text:
- Date Issued: 2007
- Authors: Maselana, Thobeka
- Date: 2007
- Subjects: Education -- South Africa -- Eastern Cape Sustainable development -- South Africa -- Eastern Cape Project method in teaching -- South Africa -- Eastern Cape School improvement programs -- South Africa -- Eastern Cape -- Case studies Educational change -- South Africa -- Eastern Cape Education and state -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1924 , http://hdl.handle.net/10962/d1007509
- Description: Sustainable development and projects are relatively new terms In the South African context. This study explores these concepts as they relate to a school that is piloting a project in the Eastern Cape. A number of projects have been introduced in disadvantaged schools to redress imbalances of the past. Funders invest a lot of money, but when they leave, schools struggle to sustain these initiatives. This study aims to investigate whether the Imbewu Project, an educational development pilot project meant to improve schools in the Eastern Cape, made provision for long-term sustainability and whether the school sustained the project. Very little research seems to have been conducted on sustainability, especially in South Africa (SA). The study is conducted in the interpretive paradigm. A single case study involving a number of stakeholders at Phiwe Primary School (PPS) was conducted through observations, interviews, focus groups and document analysis. The study found that the action research strategy intended for the project was constrained by the limited time allowed. In addition, the approach did not address processes which are important for sustainability. Also, the cascade approach to learning is not successful in organisations that have not reached the status of being learning organisations. PPS is still struggling to change its culture and therefore one can say that they cannot sustain the changes that are brought by the project. Firstly, they did not involve the parents in most modules as the project suggested. Secondly, some facilitators did not understand the project. Thirdly, although the project provided for monitoring and support, the study found that there was inadequate support from the project team and district officials. There was a shortage of district officials because the Eastern Cape Department of Education did not invest in appointing people that could sustain the project. However, there are areas where the school is doing an outstanding job despite the fact that there was very little support. The school performed well in implementing and sustaining the project in the following areas: learner welfare, community involvement and involvement of staff members in committees.
- Full Text:
- Date Issued: 2007
Synthesis of P-Methane-3,8-Diol
- Authors: Mpuhlu, Batsho
- Date: 2007
- Subjects: Insect baits and repellents
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10411 , http://hdl.handle.net/10948/570 , http://hdl.handle.net/10948/d1011717 , Insect baits and repellents
- Description: The synthesis of para-menthane-3,8-diol in a batch reactor was investigated in some detail with the view to evaluate the potential of producing said p-menthane- 3,8-diol in a continuous-flow reactor from the results obtained from the batch process. The methodology used as base for this investigation was a published procedure by Takasago of Japan. The Takasago-method produced 92.3 percent Yield for the product para-menthane-3,8-diol, and 2.7 percent Yield of the by-product, acetal. The objective for this investigation was to produce a minimum p-menthane-3,8- diol content of 97.0 percent and a maximum content of 3.0 percent for the by-product acetal. The batch production process was evaluated in detail using statistical experimental design methodologies. Three process variables, namely catalyst loading, organic/aqueous phase ratio and reaction temperature were selected for the study. The experimental method was based on the Takasago procedure, however the substrate was added as a single slug as opposed to gradual addition method and the reaction period was reduced to 30 minutes. Apart from statistical analysis, mechanistic aspects were also used to interpret the following results. Using a central composite design, three response models (one for the conversion of citronellal, p-menthane-3,8-diol and acetal formation) were determined. An analysis of the response surfaces indicated that, to increase the citronellal conversion all three variables should be increased. To increase the amount of pmenthane- 3,8-diol, the reaction temperature and acid concentration should be increased, but the Aq/org ratio should be decreased as the acid catalyst concentration is increased. To minimize the amount of acetals formed during the reaction, the Aq/org ratio should be decreased; temperature and acid concentration can be decreased or increased. The reaction mechanism suggested that p-menthane-3,8-diol may be formed along two pathways: One pathway directly forms p-menthane-3,8-diol, whilst the second pathway forms the isopulegol first, then proceeds to form product by hydrolysis. The acetal is formed as result of the reaction between unreacted citronellal and p-menthane-3,8-diol. From the design experiments it was suggested that reaction time can be reduced to 8 minutes at reaction temperatures between, 80-85 0C The product and acetal were isolated by simple vacuum evaporation of the low boiling citronellal and isopulegol. Results from recycling the catalyst phase were similar to those of the initial process. The results of this investigation has clearly shown that with a proper understanding of the effect of process variables on the performance of the batch synthesis route, the conversion of this traditionally batch (actually semi-batch) process into a continuous process is quite feasible provided that suitable equipment is available. The most important features required for such equipment would be: Intense mixing throughout the reaction zone so as to maximise the surface area between the two immiscible phases, hence the rate of mass transfer between the two phases; and the ability to run reactions above the boiling point of water. Plans for the further study of the process are already well underway and sections of static mixing tubes have been acquired to build a continuous lab scale tubular reactor that would be capable of providing the level of mixing required.
- Full Text:
- Date Issued: 2007
- Authors: Mpuhlu, Batsho
- Date: 2007
- Subjects: Insect baits and repellents
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10411 , http://hdl.handle.net/10948/570 , http://hdl.handle.net/10948/d1011717 , Insect baits and repellents
- Description: The synthesis of para-menthane-3,8-diol in a batch reactor was investigated in some detail with the view to evaluate the potential of producing said p-menthane- 3,8-diol in a continuous-flow reactor from the results obtained from the batch process. The methodology used as base for this investigation was a published procedure by Takasago of Japan. The Takasago-method produced 92.3 percent Yield for the product para-menthane-3,8-diol, and 2.7 percent Yield of the by-product, acetal. The objective for this investigation was to produce a minimum p-menthane-3,8- diol content of 97.0 percent and a maximum content of 3.0 percent for the by-product acetal. The batch production process was evaluated in detail using statistical experimental design methodologies. Three process variables, namely catalyst loading, organic/aqueous phase ratio and reaction temperature were selected for the study. The experimental method was based on the Takasago procedure, however the substrate was added as a single slug as opposed to gradual addition method and the reaction period was reduced to 30 minutes. Apart from statistical analysis, mechanistic aspects were also used to interpret the following results. Using a central composite design, three response models (one for the conversion of citronellal, p-menthane-3,8-diol and acetal formation) were determined. An analysis of the response surfaces indicated that, to increase the citronellal conversion all three variables should be increased. To increase the amount of pmenthane- 3,8-diol, the reaction temperature and acid concentration should be increased, but the Aq/org ratio should be decreased as the acid catalyst concentration is increased. To minimize the amount of acetals formed during the reaction, the Aq/org ratio should be decreased; temperature and acid concentration can be decreased or increased. The reaction mechanism suggested that p-menthane-3,8-diol may be formed along two pathways: One pathway directly forms p-menthane-3,8-diol, whilst the second pathway forms the isopulegol first, then proceeds to form product by hydrolysis. The acetal is formed as result of the reaction between unreacted citronellal and p-menthane-3,8-diol. From the design experiments it was suggested that reaction time can be reduced to 8 minutes at reaction temperatures between, 80-85 0C The product and acetal were isolated by simple vacuum evaporation of the low boiling citronellal and isopulegol. Results from recycling the catalyst phase were similar to those of the initial process. The results of this investigation has clearly shown that with a proper understanding of the effect of process variables on the performance of the batch synthesis route, the conversion of this traditionally batch (actually semi-batch) process into a continuous process is quite feasible provided that suitable equipment is available. The most important features required for such equipment would be: Intense mixing throughout the reaction zone so as to maximise the surface area between the two immiscible phases, hence the rate of mass transfer between the two phases; and the ability to run reactions above the boiling point of water. Plans for the further study of the process are already well underway and sections of static mixing tubes have been acquired to build a continuous lab scale tubular reactor that would be capable of providing the level of mixing required.
- Full Text:
- Date Issued: 2007
The influences of substitute care on learner motivation
- Authors: Johannes, Arnold Marius
- Date: 2007
- Subjects: Motivation in education , Kinship care -- South Africa , Foster home care -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9479 , http://hdl.handle.net/10948/527 , Motivation in education , Kinship care -- South Africa , Foster home care -- South Africa
- Description: Substitute care is a temporary or permanent placement of children under the supervision of an adult person due to the absence of their biological parents. The escalating divorce rate, increase in extramarital births, high incidence of family violence, the growing number of children orphaned by HIV/AIDS, and the increasing career-orientatedness of parents have led to the development of diverse family structures. Grandparents and other family members are increasingly becoming the primary caretakers for children. Whilst it is generally assumed by society that children’s well-being is better served when they are raised by their biological parents, the purpose of this study is to: • explore what influence substitute care has on learners’ motivation; • formulate guidelines and recommendations for educators to improve the current levels of motivation of learners in substitute care. The literature related to substitute care and motivation were reviewed, with the aim of providing a firm theoretical basis for the study. Concepts related to motivation discussed, included types of and sources of motivation. Concepts related to the second focus of this study included forms of substitute care. Motivational theories related to this study were briefly discussed, namely: the Attribution Theory, the Drive Theory, Goal Theory, and the Self-worth and Selfefficacy Theories. Factors that have a motivational influence on learners, such as acceptance versus rejection, praise versus criticism, success versus failure and positive self-concept versus negative self-concept, were also discussed. A link was then drawn between motivation and substitute care. ii The research design chosen for this study can be described as qualitative, interpretive and constructive in nature. The research study was conducted in two phases: Phase One provided an investigation of the research problem by means of the following open-ended question: What is the influence or impact of your status as a child in substitute care on your motivation? Data were collected by means of eleven unstructured, in-depth personal interviews. Purposeful sampling was undertaken, which included high school learners all in substitute care. Data were analysed, as proposed by the eight steps of Tesch. Discussions between the observer, moderator and an independent re-coder took place to determine the final results of the research through a consensus principle. Key and related concepts were clustered together to formulate themes, categories and sub-categories. The following three themes emerged, based on the results of the data analysis. I. Problems in the close family circle have profound effects on learner motivation. II. Certain motivating forces help learners in substitute care to cope. III. Substitute care does influence learner motivation. Phase Two offered recommendations, derived from the findings of Phase One, to empower teachers in effectively supporting and motivating learners in substitute care. The conclusion was reached that substitute care does have an influence on the motivation of learners. This motivation can either be positive, which means encouraging learners towards their goal, or negative, which implies that it moves learners away from their goal.
- Full Text:
- Date Issued: 2007
- Authors: Johannes, Arnold Marius
- Date: 2007
- Subjects: Motivation in education , Kinship care -- South Africa , Foster home care -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9479 , http://hdl.handle.net/10948/527 , Motivation in education , Kinship care -- South Africa , Foster home care -- South Africa
- Description: Substitute care is a temporary or permanent placement of children under the supervision of an adult person due to the absence of their biological parents. The escalating divorce rate, increase in extramarital births, high incidence of family violence, the growing number of children orphaned by HIV/AIDS, and the increasing career-orientatedness of parents have led to the development of diverse family structures. Grandparents and other family members are increasingly becoming the primary caretakers for children. Whilst it is generally assumed by society that children’s well-being is better served when they are raised by their biological parents, the purpose of this study is to: • explore what influence substitute care has on learners’ motivation; • formulate guidelines and recommendations for educators to improve the current levels of motivation of learners in substitute care. The literature related to substitute care and motivation were reviewed, with the aim of providing a firm theoretical basis for the study. Concepts related to motivation discussed, included types of and sources of motivation. Concepts related to the second focus of this study included forms of substitute care. Motivational theories related to this study were briefly discussed, namely: the Attribution Theory, the Drive Theory, Goal Theory, and the Self-worth and Selfefficacy Theories. Factors that have a motivational influence on learners, such as acceptance versus rejection, praise versus criticism, success versus failure and positive self-concept versus negative self-concept, were also discussed. A link was then drawn between motivation and substitute care. ii The research design chosen for this study can be described as qualitative, interpretive and constructive in nature. The research study was conducted in two phases: Phase One provided an investigation of the research problem by means of the following open-ended question: What is the influence or impact of your status as a child in substitute care on your motivation? Data were collected by means of eleven unstructured, in-depth personal interviews. Purposeful sampling was undertaken, which included high school learners all in substitute care. Data were analysed, as proposed by the eight steps of Tesch. Discussions between the observer, moderator and an independent re-coder took place to determine the final results of the research through a consensus principle. Key and related concepts were clustered together to formulate themes, categories and sub-categories. The following three themes emerged, based on the results of the data analysis. I. Problems in the close family circle have profound effects on learner motivation. II. Certain motivating forces help learners in substitute care to cope. III. Substitute care does influence learner motivation. Phase Two offered recommendations, derived from the findings of Phase One, to empower teachers in effectively supporting and motivating learners in substitute care. The conclusion was reached that substitute care does have an influence on the motivation of learners. This motivation can either be positive, which means encouraging learners towards their goal, or negative, which implies that it moves learners away from their goal.
- Full Text:
- Date Issued: 2007
The development of organisational rights in South Africa
- Authors: Sohena, Siphiwo Clifford
- Date: 2007
- Subjects: Labor unions -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10230 , http://hdl.handle.net/10948/841 , Labor unions -- Law and legislation -- South Africa
- Description: Under the previous Labour Relations Act of 1956, (herein after refered as old LRA) organisational rights in South Africa were conspicuous by their absence. In addition, theright to access was restricted by the Trespass Act No. 6 of 1959, which made it a criminal offence to enter land without thepermission of the owner or lawful occupier, except for a lawful reason. During the 1980’s and the first half of the 1990’s several trade union rights, including the right to engage in collective bargaining were established by the Industrial Court under its unfair labour practice jurisdiction. After 1994, South African courts were bound to uphold the basic rights entrenched in the Constitution, Act No. 108 of 1996, and the new Labour Relations Act, 66 of 1995, (herein after refered as new LRA) was promulgated. A new system of collective bargaining which is voluntary in nature was established in order to level the playing fields between employees and trade unions. The new LRA grants organisational rights to registered trade unions. The aim of this treatise is to consider and evaluate these rights. The main source of organisational rights in international public law is to be found in the International Labour Organisation’s Convention on Freedom of Association. Decisions of the International Labour Organisation’s bodies of supervision and interpretation have upheld the protection of various organisational rights, such as trade union access to the employer’s premises,representation of employees by the officials of their trade union, and the right of union officials to collect union dues. These rights have now been incorporated into our labour law system. In this treatise, the pre-1994 situation and the scenario after the 1994 democratic elections is analysed. The contents of these rights are considered as well as enforcement there-of.
- Full Text:
- Date Issued: 2007
- Authors: Sohena, Siphiwo Clifford
- Date: 2007
- Subjects: Labor unions -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10230 , http://hdl.handle.net/10948/841 , Labor unions -- Law and legislation -- South Africa
- Description: Under the previous Labour Relations Act of 1956, (herein after refered as old LRA) organisational rights in South Africa were conspicuous by their absence. In addition, theright to access was restricted by the Trespass Act No. 6 of 1959, which made it a criminal offence to enter land without thepermission of the owner or lawful occupier, except for a lawful reason. During the 1980’s and the first half of the 1990’s several trade union rights, including the right to engage in collective bargaining were established by the Industrial Court under its unfair labour practice jurisdiction. After 1994, South African courts were bound to uphold the basic rights entrenched in the Constitution, Act No. 108 of 1996, and the new Labour Relations Act, 66 of 1995, (herein after refered as new LRA) was promulgated. A new system of collective bargaining which is voluntary in nature was established in order to level the playing fields between employees and trade unions. The new LRA grants organisational rights to registered trade unions. The aim of this treatise is to consider and evaluate these rights. The main source of organisational rights in international public law is to be found in the International Labour Organisation’s Convention on Freedom of Association. Decisions of the International Labour Organisation’s bodies of supervision and interpretation have upheld the protection of various organisational rights, such as trade union access to the employer’s premises,representation of employees by the officials of their trade union, and the right of union officials to collect union dues. These rights have now been incorporated into our labour law system. In this treatise, the pre-1994 situation and the scenario after the 1994 democratic elections is analysed. The contents of these rights are considered as well as enforcement there-of.
- Full Text:
- Date Issued: 2007
Assessing management competencies in selected Southern Cape Municipalities
- Authors: Krapohl, Johannes
- Date: 2007
- Subjects: Local government -- South Africa , Core competencies , Performance -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8571 , http://hdl.handle.net/10948/797 , Local government -- South Africa , Core competencies , Performance -- Management
- Description: In his 2006 State of the Nation Address, President Thabo Mbeki emphasised the need for the development of managerial competencies and other skills to empower the country’s municipalities to meet the needs of the community (Governance and Administration, 2005). In order to meet the needs of the local community, municipalities need to render effective and efficient services. The lack of relevant managerial competencies adversly influences the municipality’s capacity to deliver the required services. In addition, the uneven distribution of capabilities and capacity across different sections within a municipality also poses a great risk to municipal performance and equitable service provision over the medium term. Notwithstanding progress made to date, service delivery backlogs still exist in key areas that affect the daily lives of the community. Where these backlogs coincide with poor municipal capacity, the result is service failure and a government that is incapable of meeting its goals (Governance and Administration, 2005). The objective of the study is to assess the contemporary management competencies that are required to assist municipal management in addressing the challenges of a dynamic, uncertain and complex Local Government environment. A questionnaire was used to gather the perceptions of 26 senior managers. This sample constituted a response rate of 65 per cent of people employed by municipalities within the Eden District Municipality’s service area. The questionnaires were distributed to the senior managers by means of an identified contact person within each municipality. The empirical findings such as the mean, median, standard deviation and pvalues were calculated by means of MS Excel. The main findings of this research indicated that: • Presently the most developed managerial competencies were selfmanagement, strategic action, planning and administration and communication. • The least developed current competency was global awareness. • The managerial competencies regarded as the most important for the next ten years were planning, administration and strategic action. • Global awareness was regarded as the least important competency for the next ten years. This finding points to the need for developing the global awareness competency to ensure that Municipal Managers are more sensitive to cultural cues and are able to adapt quickly in novel situations.
- Full Text:
- Date Issued: 2007
- Authors: Krapohl, Johannes
- Date: 2007
- Subjects: Local government -- South Africa , Core competencies , Performance -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8571 , http://hdl.handle.net/10948/797 , Local government -- South Africa , Core competencies , Performance -- Management
- Description: In his 2006 State of the Nation Address, President Thabo Mbeki emphasised the need for the development of managerial competencies and other skills to empower the country’s municipalities to meet the needs of the community (Governance and Administration, 2005). In order to meet the needs of the local community, municipalities need to render effective and efficient services. The lack of relevant managerial competencies adversly influences the municipality’s capacity to deliver the required services. In addition, the uneven distribution of capabilities and capacity across different sections within a municipality also poses a great risk to municipal performance and equitable service provision over the medium term. Notwithstanding progress made to date, service delivery backlogs still exist in key areas that affect the daily lives of the community. Where these backlogs coincide with poor municipal capacity, the result is service failure and a government that is incapable of meeting its goals (Governance and Administration, 2005). The objective of the study is to assess the contemporary management competencies that are required to assist municipal management in addressing the challenges of a dynamic, uncertain and complex Local Government environment. A questionnaire was used to gather the perceptions of 26 senior managers. This sample constituted a response rate of 65 per cent of people employed by municipalities within the Eden District Municipality’s service area. The questionnaires were distributed to the senior managers by means of an identified contact person within each municipality. The empirical findings such as the mean, median, standard deviation and pvalues were calculated by means of MS Excel. The main findings of this research indicated that: • Presently the most developed managerial competencies were selfmanagement, strategic action, planning and administration and communication. • The least developed current competency was global awareness. • The managerial competencies regarded as the most important for the next ten years were planning, administration and strategic action. • Global awareness was regarded as the least important competency for the next ten years. This finding points to the need for developing the global awareness competency to ensure that Municipal Managers are more sensitive to cultural cues and are able to adapt quickly in novel situations.
- Full Text:
- Date Issued: 2007
An analysis of the representation of female athletes in selected South African print media from February 2006 to June 2006
- Authors: Jooste, Carlien
- Date: 2007
- Subjects: Women athletes -- South Africa , Athletes in mass media -- South Africa , Mass media and sports -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8374 , http://hdl.handle.net/10948/528 , Women athletes -- South Africa , Athletes in mass media -- South Africa , Mass media and sports -- South Africa
- Description: This thesis attempts to analyse the representation of professional female sport persons in selected South African media. The field of study is located within the ambit of gender and media studies with specific attention to the power of the latter to not only reflect, but actually shape realities and attitudes. Carolyn Byerly and Karen Ross (2004) comment that “the media have the potential not only to reinforce the status quo in power arrangements in society, but also to contribute to new, more egalitarian ones” (2004:24). The core question, then, is to determine whether traditional gender roles are confirmed, or positively shaped, by the way in which the selected media reported on professional women athletes in various sporting codes. As this is a neglected topic in South Africa, the study relied heavily on the research done by various American and European academics. Academics such as Pamela Creedon (1994) and Susan Birrell and Cheryl Cole (1994), found that female athletes are marginalised and stereotyped by the media. Their research also denotes that female athletes are objectified and judged on their looks and dress code instead of their sporting abilities. Female athletes are continuously stereotyped according to societal induced feminine traits. These representations alienate women who do not possess feminine qualities as “the other”, namely falling outside the desirability as determined by sponsorship and an assumed male viewing / reading public. The media further focus more on beautiful, glamorous athletes than female athletes that are less feminine, but with no less achievement and ability. Extensive examples are provided in the treatise of how the selected South African print media misrepresented women in the six month period that was studied. The conclusion is unambiguous: The South African media unfortunately follow the international trend of objectifying women according to male stereotypes. The media that were studied therefore missed an opportunity to shape gender attitudes as they collude with the powerful forces of sponsorship and viewer-ship to reinforce the status quo.
- Full Text:
- Date Issued: 2007
- Authors: Jooste, Carlien
- Date: 2007
- Subjects: Women athletes -- South Africa , Athletes in mass media -- South Africa , Mass media and sports -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8374 , http://hdl.handle.net/10948/528 , Women athletes -- South Africa , Athletes in mass media -- South Africa , Mass media and sports -- South Africa
- Description: This thesis attempts to analyse the representation of professional female sport persons in selected South African media. The field of study is located within the ambit of gender and media studies with specific attention to the power of the latter to not only reflect, but actually shape realities and attitudes. Carolyn Byerly and Karen Ross (2004) comment that “the media have the potential not only to reinforce the status quo in power arrangements in society, but also to contribute to new, more egalitarian ones” (2004:24). The core question, then, is to determine whether traditional gender roles are confirmed, or positively shaped, by the way in which the selected media reported on professional women athletes in various sporting codes. As this is a neglected topic in South Africa, the study relied heavily on the research done by various American and European academics. Academics such as Pamela Creedon (1994) and Susan Birrell and Cheryl Cole (1994), found that female athletes are marginalised and stereotyped by the media. Their research also denotes that female athletes are objectified and judged on their looks and dress code instead of their sporting abilities. Female athletes are continuously stereotyped according to societal induced feminine traits. These representations alienate women who do not possess feminine qualities as “the other”, namely falling outside the desirability as determined by sponsorship and an assumed male viewing / reading public. The media further focus more on beautiful, glamorous athletes than female athletes that are less feminine, but with no less achievement and ability. Extensive examples are provided in the treatise of how the selected South African print media misrepresented women in the six month period that was studied. The conclusion is unambiguous: The South African media unfortunately follow the international trend of objectifying women according to male stereotypes. The media that were studied therefore missed an opportunity to shape gender attitudes as they collude with the powerful forces of sponsorship and viewer-ship to reinforce the status quo.
- Full Text:
- Date Issued: 2007
Making visible constructions of dis/advantage through genealogical investigation: South African schooled literacies
- Authors: Prinsloo, Jeanne
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147869 , vital:38680 , DOI: 10.1080/02560040701398889
- Description: In this paper I assume the relevance of Foucauldian insights for conducting socio-cultural critique and I argue the significance of genealogical work in relation to understanding the present. Thus, I seek both to establish what could constitute a genealogical investigation and to illustrate this by describing and discussing a study, undertaken within a genealogical frame, into literacy practices within a specifically South African context. I investigated the differing schooled literacies in KwaZulu-Natal province in South Africa over three decades along the language lines of Afrikaans, English and Zulu. The findings propose that the differing sets of literacy practices validate different subjects – and that they are implicated in constructing dis/advantage.
- Full Text:
- Date Issued: 2007
- Authors: Prinsloo, Jeanne
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147869 , vital:38680 , DOI: 10.1080/02560040701398889
- Description: In this paper I assume the relevance of Foucauldian insights for conducting socio-cultural critique and I argue the significance of genealogical work in relation to understanding the present. Thus, I seek both to establish what could constitute a genealogical investigation and to illustrate this by describing and discussing a study, undertaken within a genealogical frame, into literacy practices within a specifically South African context. I investigated the differing schooled literacies in KwaZulu-Natal province in South Africa over three decades along the language lines of Afrikaans, English and Zulu. The findings propose that the differing sets of literacy practices validate different subjects – and that they are implicated in constructing dis/advantage.
- Full Text:
- Date Issued: 2007
Severe convective storm risk in the Eastern Cape Province of South Africa
- Authors: Pyle, Desmond Mark
- Date: 2007
- Subjects: Storms -- South Africa -- Eastern Cape Natural disasters -- South Africa -- Eastern Cape Disasters -- South Africa -- Eastern Cape Disaster relief -- South Africa -- Eastern Cape -- Management Meteorology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4853 , http://hdl.handle.net/10962/d1005529
- Description: This study investigates the temporal, spatial and impact characteristics of severe convective storm hazard and risk in the Eastern Cape Province of South Africa. Using historical data on severe convective storms dating from 1897, patterns of the hazard threat and risk to various geographic populations were investigated. A conceptual framework that emphasises the combined role hazard and vulnerability play in defining risk was used for the study. A methodology for ranking the severity of the storms in the historical dataset, based on recorded damage/impact, was specifically developed for the study. It is intended that this methodology will have a potentially wider application and may be adapted to a range of hazard impact and risk studies in South Africa and internationally. The study was undertaken within the context of the South African Disaster Management Act of 2002. Findings of the study show that severe convective storms can occur throughout the province, but there are clearly demarcated areas of higher frequency and concentration. The impact of storms is particularly severe on impoverished and vulnerable rural populations in the eastern parts of the province, where there is an urgent need for building capacity in disaster risk management. A major outcome of the study is the production of a severe convective storm hazard/risk map of the Eastern Cape, which it is hoped will be of benefit to a number of stakeholders in the province, particularly disaster management, but also the South African Weather Service, agricultural organisations, development/planning authorities, educational authorities and risk insurers. It is hoped that this map and the study in general will assist in guiding the operational responses of the various authorities, especially in terms of those interventions aimed at disaster risk reduction in the Eastern Cape.
- Full Text:
- Date Issued: 2007
- Authors: Pyle, Desmond Mark
- Date: 2007
- Subjects: Storms -- South Africa -- Eastern Cape Natural disasters -- South Africa -- Eastern Cape Disasters -- South Africa -- Eastern Cape Disaster relief -- South Africa -- Eastern Cape -- Management Meteorology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4853 , http://hdl.handle.net/10962/d1005529
- Description: This study investigates the temporal, spatial and impact characteristics of severe convective storm hazard and risk in the Eastern Cape Province of South Africa. Using historical data on severe convective storms dating from 1897, patterns of the hazard threat and risk to various geographic populations were investigated. A conceptual framework that emphasises the combined role hazard and vulnerability play in defining risk was used for the study. A methodology for ranking the severity of the storms in the historical dataset, based on recorded damage/impact, was specifically developed for the study. It is intended that this methodology will have a potentially wider application and may be adapted to a range of hazard impact and risk studies in South Africa and internationally. The study was undertaken within the context of the South African Disaster Management Act of 2002. Findings of the study show that severe convective storms can occur throughout the province, but there are clearly demarcated areas of higher frequency and concentration. The impact of storms is particularly severe on impoverished and vulnerable rural populations in the eastern parts of the province, where there is an urgent need for building capacity in disaster risk management. A major outcome of the study is the production of a severe convective storm hazard/risk map of the Eastern Cape, which it is hoped will be of benefit to a number of stakeholders in the province, particularly disaster management, but also the South African Weather Service, agricultural organisations, development/planning authorities, educational authorities and risk insurers. It is hoped that this map and the study in general will assist in guiding the operational responses of the various authorities, especially in terms of those interventions aimed at disaster risk reduction in the Eastern Cape.
- Full Text:
- Date Issued: 2007
A railway terminus for the inner city of Port Elizabeth
- Authors: Scriba, Marco W
- Date: 2007
- Subjects: Railroad terminals -- South Africa -- Port Elizabeth -- Designs and plans , Terminals (Transportation) -- South Africa -- Port Elizabeth -- Designs and plans
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: vital:8154 , http://hdl.handle.net/10948/d1016497
- Description: In the late 1980s people and businesses started to move out of Port Elizabeth's Central District (CBD). Businesses moved to the city's edge establishing new business zones, which in turn threatened the existence of the original CBD. Most inner city buildings became derelict and property prices dropped accordingly. Buildings were neglected and vandalized. This resulted in spaces which were unfit for human habitation and encouraged areas characterized by crime. The regeneration of Port Elizabeth's CDB is very important bacause of its historical value and key position. To build the Metropol the historical ideals of the CDB need to be revitalized, giving the city a administrative and cultural core which is both friendly and safe. A few proposals have been introduced to help uplift areas in the CDB. The latest initiative is the upgrading of Govan Mbeki Street lead by the firm The Matrix. Their aim is to create architecture that creates a more interactive, habitable environment. This would be achieved by more pedestrian orientated spaces, natural landscaping and facilitating vendors and craft markets. Future proposals are the removal of railway lines, the Tank Farm and finally the Ore Dumps to allow the city to expand eastwards. This will allow the city to grow and connect with the seafront and the existing harbour. Consequently the development of a new Railway Terminus is central to the establishment of a bay which is consistent with international standards of key marine cities in the modern world. The old station has a beautiful sense of place in Strand Street, as does the Campanile, which is at the gateway to the harbour. Together they offer a unique experience in this historiacal precinct. This offers new opportunities for tourism and trade and the old station would therefore form part of Port Elizabeth's CDB rejuvenation.
- Full Text:
- Date Issued: 2007
- Authors: Scriba, Marco W
- Date: 2007
- Subjects: Railroad terminals -- South Africa -- Port Elizabeth -- Designs and plans , Terminals (Transportation) -- South Africa -- Port Elizabeth -- Designs and plans
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: vital:8154 , http://hdl.handle.net/10948/d1016497
- Description: In the late 1980s people and businesses started to move out of Port Elizabeth's Central District (CBD). Businesses moved to the city's edge establishing new business zones, which in turn threatened the existence of the original CBD. Most inner city buildings became derelict and property prices dropped accordingly. Buildings were neglected and vandalized. This resulted in spaces which were unfit for human habitation and encouraged areas characterized by crime. The regeneration of Port Elizabeth's CDB is very important bacause of its historical value and key position. To build the Metropol the historical ideals of the CDB need to be revitalized, giving the city a administrative and cultural core which is both friendly and safe. A few proposals have been introduced to help uplift areas in the CDB. The latest initiative is the upgrading of Govan Mbeki Street lead by the firm The Matrix. Their aim is to create architecture that creates a more interactive, habitable environment. This would be achieved by more pedestrian orientated spaces, natural landscaping and facilitating vendors and craft markets. Future proposals are the removal of railway lines, the Tank Farm and finally the Ore Dumps to allow the city to expand eastwards. This will allow the city to grow and connect with the seafront and the existing harbour. Consequently the development of a new Railway Terminus is central to the establishment of a bay which is consistent with international standards of key marine cities in the modern world. The old station has a beautiful sense of place in Strand Street, as does the Campanile, which is at the gateway to the harbour. Together they offer a unique experience in this historiacal precinct. This offers new opportunities for tourism and trade and the old station would therefore form part of Port Elizabeth's CDB rejuvenation.
- Full Text:
- Date Issued: 2007
Isolation of a Clostridium Beijerinckii sLM01 cellulosome and the effect of sulphide on anaerobic digestion
- Authors: Mayende, Lungisa
- Date: 2007
- Subjects: Cellulose , Clostridium , Cellulase , Sulfides
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3973 , http://hdl.handle.net/10962/d1004032 , Cellulose , Clostridium , Cellulase , Sulfides
- Description: Cellulose is the most abundant and the most resistant and stable natural organic compound on earth. Enzyme hydrolysis is difficult because of its insolubility and heterogeneity. Some (anaerobic) microorganisms have overcome this by having a multienzyme system called the cellulosome. The aims of the study were to isolate a mesophilic Clostridium sp. from a biosulphidogenic bioreactor, to purify the cellulosome from this culture, to determine the cellulase and endoglucanase activities using Avicel and carboxymethylcellulose (CMC) as substrates and the dinitrosalicyclic (DNS) method. The organism was identified using 16S rDNA sequence analysis. The sequence obtained indicated that a strain of Clostridium beijerinckii was isolated. The cellulosome was purified from the putative C. beijerinckii sLM01 host culture using affinity chromatography purification and affinity digestion purification procedures. The cellulosomal and non-cellulosomal fractions of C. beijerinckii sLM01 were separated successfully, but the majority of the endoglucanase activity was lost during the Sepharose 4B chromatography step. These cellulosomal and non-cellulosomal fractions were characterised with regards to their pH and temperature optima and effector sensitivity. Increased additions of sulphide activated the cellulase activity of the cellulosomal and non-cellulosomal fractions up to 700 %, while increased additions of sulphate either increased the activity slightly or inhibited it dramatically, depending on the cellulosomal and non-cellulosomal fractions. Increased additions of cellobiose, glucose and acetate inhibited the cellulase and endoglucanase activities. pH optima of 5.0 and 7.5 were observed for cellulases and 5.0 for endoglucanases of the cellulosomal fraction. The noncellulosomal fraction exhibited a pH optimum of 7.5 for both cellulase and endoglucanase activities. Both fractions and enzymes exhibited a temperature optimum of 30 °C. The fundamental knowledge gained from the characterisation was applied to anaerobic digestion, where the effect of sulphide on the rate-limiting step was determined. Sulphide activated cellulase and endoglucanase activities and increased the % chemical oxygen demand (COD) removal rate. Levels of volatile fatty acids (VFAs) were higher in the bioreactor containing sulphide, substrate and C. beijerinckii. Sulphide therefore accelerated the rate-limiting step of anaerobic digestion.
- Full Text:
- Date Issued: 2007
- Authors: Mayende, Lungisa
- Date: 2007
- Subjects: Cellulose , Clostridium , Cellulase , Sulfides
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3973 , http://hdl.handle.net/10962/d1004032 , Cellulose , Clostridium , Cellulase , Sulfides
- Description: Cellulose is the most abundant and the most resistant and stable natural organic compound on earth. Enzyme hydrolysis is difficult because of its insolubility and heterogeneity. Some (anaerobic) microorganisms have overcome this by having a multienzyme system called the cellulosome. The aims of the study were to isolate a mesophilic Clostridium sp. from a biosulphidogenic bioreactor, to purify the cellulosome from this culture, to determine the cellulase and endoglucanase activities using Avicel and carboxymethylcellulose (CMC) as substrates and the dinitrosalicyclic (DNS) method. The organism was identified using 16S rDNA sequence analysis. The sequence obtained indicated that a strain of Clostridium beijerinckii was isolated. The cellulosome was purified from the putative C. beijerinckii sLM01 host culture using affinity chromatography purification and affinity digestion purification procedures. The cellulosomal and non-cellulosomal fractions of C. beijerinckii sLM01 were separated successfully, but the majority of the endoglucanase activity was lost during the Sepharose 4B chromatography step. These cellulosomal and non-cellulosomal fractions were characterised with regards to their pH and temperature optima and effector sensitivity. Increased additions of sulphide activated the cellulase activity of the cellulosomal and non-cellulosomal fractions up to 700 %, while increased additions of sulphate either increased the activity slightly or inhibited it dramatically, depending on the cellulosomal and non-cellulosomal fractions. Increased additions of cellobiose, glucose and acetate inhibited the cellulase and endoglucanase activities. pH optima of 5.0 and 7.5 were observed for cellulases and 5.0 for endoglucanases of the cellulosomal fraction. The noncellulosomal fraction exhibited a pH optimum of 7.5 for both cellulase and endoglucanase activities. Both fractions and enzymes exhibited a temperature optimum of 30 °C. The fundamental knowledge gained from the characterisation was applied to anaerobic digestion, where the effect of sulphide on the rate-limiting step was determined. Sulphide activated cellulase and endoglucanase activities and increased the % chemical oxygen demand (COD) removal rate. Levels of volatile fatty acids (VFAs) were higher in the bioreactor containing sulphide, substrate and C. beijerinckii. Sulphide therefore accelerated the rate-limiting step of anaerobic digestion.
- Full Text:
- Date Issued: 2007
Photocatalysis of 4-nitrophenol using zinc phthalocyanine complexes
- Marais, Eloïse, Klein, Rosalyn, Antunes, Edith M, Nyokong, Tebello
- Authors: Marais, Eloïse , Klein, Rosalyn , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281286 , vital:55709 , xlink:href="https://doi.org/10.1016/j.molcata.2006.07.055"
- Description: Photodegradation of 4-nitrophenol (4-Np) in the presence of zinc tetrasulfophthalocyanine (ZnPcS4), zinc octacarboxyphthalocyanine (ZnPc(COOH)8) and a sulfonated ZnPc containing a mixture of differently sulfonated derivatives (ZnPcSmix), as photocatalysts is reported. ZnPcSmix is the most effective catalyst in terms of a high quantum yield for 4-Np degradation and the stability of the catalyst. However ZnPc(COOH)8 degrades readily during the catalysis, but it has a higher quantum yield (Φ4-Np) for 4-Np degradation than the rest of the complexes. The Φ4-Np values were closely related to the singlet oxygen quantum yields ΦΔ and hence aggregation. The rate constants for the reaction with 4-Np were kr = 0.67 × 106 mol−1 dm3 s−1 for ZnPcSmix and 2.8 × 108 mol−1 dm3 s−1 for ZnPc(COOH)8.
- Full Text:
- Date Issued: 2007
- Authors: Marais, Eloïse , Klein, Rosalyn , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281286 , vital:55709 , xlink:href="https://doi.org/10.1016/j.molcata.2006.07.055"
- Description: Photodegradation of 4-nitrophenol (4-Np) in the presence of zinc tetrasulfophthalocyanine (ZnPcS4), zinc octacarboxyphthalocyanine (ZnPc(COOH)8) and a sulfonated ZnPc containing a mixture of differently sulfonated derivatives (ZnPcSmix), as photocatalysts is reported. ZnPcSmix is the most effective catalyst in terms of a high quantum yield for 4-Np degradation and the stability of the catalyst. However ZnPc(COOH)8 degrades readily during the catalysis, but it has a higher quantum yield (Φ4-Np) for 4-Np degradation than the rest of the complexes. The Φ4-Np values were closely related to the singlet oxygen quantum yields ΦΔ and hence aggregation. The rate constants for the reaction with 4-Np were kr = 0.67 × 106 mol−1 dm3 s−1 for ZnPcSmix and 2.8 × 108 mol−1 dm3 s−1 for ZnPc(COOH)8.
- Full Text:
- Date Issued: 2007