Psychological resilience: the role of unconscious and conscious coping strategies in the mediation of stress in high risk occupational contexts
- Authors: Alexander, Debra Geraldine
- Date: 2002
- Subjects: Hazardous occupations , Teachers -- South Africa -- Job stress , Police -- South Africa -- Job stress , Emergency medical personnel -- South Africa -- Job stress , Stress (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3092 , http://hdl.handle.net/10962/d1003059 , Hazardous occupations , Teachers -- South Africa -- Job stress , Police -- South Africa -- Job stress , Emergency medical personnel -- South Africa -- Job stress , Stress (Psychology)
- Description: This study investigates the role of unconscious and conscious coping strategies in the mediation of stress in high risk occupational contexts. The Social Readjustment Rating Scale, the Multidimensional Coping Inventory and the Defense Style Questionnaires were completed by 194 police, ambulance and teaching personnel. A sample of 37 teachers served as a non high risk occupation control group. Descriptive statistics, regression analysis, analysis of variance, analysis of difference and principal component analysis were performed on the data. Results indicated minimal significant between group differences. Within group variances were yielded. A minor relationship between levels of stress and usage of positive and negative mechanisms was observed. The significance of these findings is discussed and recommendations made for further study.
- Full Text:
- Date Issued: 2002
- Authors: Alexander, Debra Geraldine
- Date: 2002
- Subjects: Hazardous occupations , Teachers -- South Africa -- Job stress , Police -- South Africa -- Job stress , Emergency medical personnel -- South Africa -- Job stress , Stress (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3092 , http://hdl.handle.net/10962/d1003059 , Hazardous occupations , Teachers -- South Africa -- Job stress , Police -- South Africa -- Job stress , Emergency medical personnel -- South Africa -- Job stress , Stress (Psychology)
- Description: This study investigates the role of unconscious and conscious coping strategies in the mediation of stress in high risk occupational contexts. The Social Readjustment Rating Scale, the Multidimensional Coping Inventory and the Defense Style Questionnaires were completed by 194 police, ambulance and teaching personnel. A sample of 37 teachers served as a non high risk occupation control group. Descriptive statistics, regression analysis, analysis of variance, analysis of difference and principal component analysis were performed on the data. Results indicated minimal significant between group differences. Within group variances were yielded. A minor relationship between levels of stress and usage of positive and negative mechanisms was observed. The significance of these findings is discussed and recommendations made for further study.
- Full Text:
- Date Issued: 2002
Removal and recovery of gold and platinum from aqueous solutions utilising the non-viable biomass Asolla filiculoides
- Authors: Antunes, Ana Paula Martins
- Date: 2002
- Subjects: Azolla filiculoides Metal wastes -- Recycling Gold -- Recycling Platinum -- Recycling
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3894 , http://hdl.handle.net/10962/d1003726
- Description: Waste water from the mining industry is generally extremely complex and contains numerous species which influence the adsorption of the metals to any biomass. A variety of factors need to be addressed before treatment is considered viable. It is also beneficial to establish the binding characteristics of the metal of interest to maximise its interaction with the biomass to be utilised. Azalia filiculaides was investigated in the adsorption of gold(III), lead(II), iron(ID), copper(II) and platinum (IV). In batch studies, the optimum biomass and initial gold(III) concentrations were found to be 5 gIL and 8 mgIL respectively. The adsorption of gold(ID) is principally pH-dependent with optimal removal at pH 2. Lead(II), iron(III) and copper(II) did not compete with gold(III) adsorption under equimolar and simulated effluent conditions. Halides, with increasing affinity for gold (chloride < bromide < iodide), can affect gold uptake with the soft base, iodide, exhibiting the most inhibition (25%) and the hard base, chloride, O%. Mercaptoethanol (soft base) showed no interference in gold(III) adsorption while the presence of sulphate (hard base) and sulphite (borderline base) showed that concentrations in excess of 1 0 mM may adversely affect gold(ill) uptake, most likely due to competition for cationic sites on the biomass. Column studies, better suited to high volume treatment, indicated that a flow-rate of 5 mL/min and an initial gold(ill) concentration of 5 mgIL was optimal. Competitive effects between lead, iron, copper and gold again showed little or no interference. The halides, chloride, bromide and iodide, affect gold(ill) uptake similarly to the batch studies, while the bases mercaptoethanol and sulphate minimally affect gold(III) binding with sulphite severely hampering adsorption (70% inhibition). To optimise gold desorption, preliminary batch studies indicated that a ratio of 1:1 of adsorbentdesorbent was optimal, whilst gas purging of thiourea with oxygen, air and nitrogen decreased gold elution in proportion to decreased amounts of oxygen. A series of desorbents were utilised, in column studies, to optimise and determine the speciation of bound gold. The presence of an oxidant with thiourea enhanced desorption greater than 3 fold when compared with thiourea alone. Thiourea desorption studies, aided by the oxidant, suggest that gold is present in the + I and 0 oxidation states. Ultimately thiourea, perchloric acid and hydrochloric acid was found to be the most optimal elutant for gold (J 00% recovery). For selective metal recovery oflead and copper, pre-washing the plant material with water, utilising an acid (0.3 M nitric acid), pumping in an up-flow mode, and recycling the desorbent six times was found to be optimal elutant for gold (J 00% recovery). Cost analysis of utilising elutant versus incinerating the biomass for gold recovery indicated the latter as the most economical. Over a 5 cycle adsorption and desorption series, acid desorption before each adsorption cycle was found to result in greater than 92% desorption for lead and 96% for copper. Gold recovery was 97% with incineration. A preliminary study with gold effluent (Mine C) indicated that nickel and sulphate was removed in batch and column studies. Gold removal was found to be 100% and 4% in batch and column studies respectively. Adsorption of gold in the effluent study was accompanied by the release ofHt. Modifying the plant material with various reagents failed to identify the primary binding sites and the role of polysaccharides, proteins and lipids in gold(ill) uptake. The mode of gold binding is suggested as being initially ionic, this is very rapid, with the interaction of the anionic complex, [AuCI₄]". with the cationic biomass (PH 2). This eventually leads to the displacement of the chloride ligand(s) initiating covalent binding. Spectral studies of the chemical interaction between gold and the representative tannins indicated the protonated hydroxy groups to be responsible. All evidence suggests that the binding mechanisms of gold are not simple. Preliminary adsorption studies of platinum by Azalia filiculaides were conducted. Batch studies indicated that J gIL biomass concentration, initial platinum concentration of 20 mgIL and pH 2 are optimal, while the column studies indicated a flow-rate of! 0 rnL/min and initial platinum concentration of 20 mgIL as optimal. In the platinum effluent study, platinum showed a removal of 23 % and 2 J % for the batch and column studies respectively. Again adsorption was accompanied by //' release. Azalia filiculaides demonstrated its feasibility in the removal of gold and platinum from simulated as well as waste water solutions. Its potential viability as a biosorbent was demonstrated by the high recovery from synthetic solutions of greater than 99% for gold (2-10 mgIL), and greater than 89% for platinum (20 mgIL).
- Full Text:
- Date Issued: 2002
- Authors: Antunes, Ana Paula Martins
- Date: 2002
- Subjects: Azolla filiculoides Metal wastes -- Recycling Gold -- Recycling Platinum -- Recycling
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3894 , http://hdl.handle.net/10962/d1003726
- Description: Waste water from the mining industry is generally extremely complex and contains numerous species which influence the adsorption of the metals to any biomass. A variety of factors need to be addressed before treatment is considered viable. It is also beneficial to establish the binding characteristics of the metal of interest to maximise its interaction with the biomass to be utilised. Azalia filiculaides was investigated in the adsorption of gold(III), lead(II), iron(ID), copper(II) and platinum (IV). In batch studies, the optimum biomass and initial gold(III) concentrations were found to be 5 gIL and 8 mgIL respectively. The adsorption of gold(ID) is principally pH-dependent with optimal removal at pH 2. Lead(II), iron(III) and copper(II) did not compete with gold(III) adsorption under equimolar and simulated effluent conditions. Halides, with increasing affinity for gold (chloride < bromide < iodide), can affect gold uptake with the soft base, iodide, exhibiting the most inhibition (25%) and the hard base, chloride, O%. Mercaptoethanol (soft base) showed no interference in gold(III) adsorption while the presence of sulphate (hard base) and sulphite (borderline base) showed that concentrations in excess of 1 0 mM may adversely affect gold(ill) uptake, most likely due to competition for cationic sites on the biomass. Column studies, better suited to high volume treatment, indicated that a flow-rate of 5 mL/min and an initial gold(ill) concentration of 5 mgIL was optimal. Competitive effects between lead, iron, copper and gold again showed little or no interference. The halides, chloride, bromide and iodide, affect gold(ill) uptake similarly to the batch studies, while the bases mercaptoethanol and sulphate minimally affect gold(III) binding with sulphite severely hampering adsorption (70% inhibition). To optimise gold desorption, preliminary batch studies indicated that a ratio of 1:1 of adsorbentdesorbent was optimal, whilst gas purging of thiourea with oxygen, air and nitrogen decreased gold elution in proportion to decreased amounts of oxygen. A series of desorbents were utilised, in column studies, to optimise and determine the speciation of bound gold. The presence of an oxidant with thiourea enhanced desorption greater than 3 fold when compared with thiourea alone. Thiourea desorption studies, aided by the oxidant, suggest that gold is present in the + I and 0 oxidation states. Ultimately thiourea, perchloric acid and hydrochloric acid was found to be the most optimal elutant for gold (J 00% recovery). For selective metal recovery oflead and copper, pre-washing the plant material with water, utilising an acid (0.3 M nitric acid), pumping in an up-flow mode, and recycling the desorbent six times was found to be optimal elutant for gold (J 00% recovery). Cost analysis of utilising elutant versus incinerating the biomass for gold recovery indicated the latter as the most economical. Over a 5 cycle adsorption and desorption series, acid desorption before each adsorption cycle was found to result in greater than 92% desorption for lead and 96% for copper. Gold recovery was 97% with incineration. A preliminary study with gold effluent (Mine C) indicated that nickel and sulphate was removed in batch and column studies. Gold removal was found to be 100% and 4% in batch and column studies respectively. Adsorption of gold in the effluent study was accompanied by the release ofHt. Modifying the plant material with various reagents failed to identify the primary binding sites and the role of polysaccharides, proteins and lipids in gold(ill) uptake. The mode of gold binding is suggested as being initially ionic, this is very rapid, with the interaction of the anionic complex, [AuCI₄]". with the cationic biomass (PH 2). This eventually leads to the displacement of the chloride ligand(s) initiating covalent binding. Spectral studies of the chemical interaction between gold and the representative tannins indicated the protonated hydroxy groups to be responsible. All evidence suggests that the binding mechanisms of gold are not simple. Preliminary adsorption studies of platinum by Azalia filiculaides were conducted. Batch studies indicated that J gIL biomass concentration, initial platinum concentration of 20 mgIL and pH 2 are optimal, while the column studies indicated a flow-rate of! 0 rnL/min and initial platinum concentration of 20 mgIL as optimal. In the platinum effluent study, platinum showed a removal of 23 % and 2 J % for the batch and column studies respectively. Again adsorption was accompanied by //' release. Azalia filiculaides demonstrated its feasibility in the removal of gold and platinum from simulated as well as waste water solutions. Its potential viability as a biosorbent was demonstrated by the high recovery from synthetic solutions of greater than 99% for gold (2-10 mgIL), and greater than 89% for platinum (20 mgIL).
- Full Text:
- Date Issued: 2002
The development of a marketing plan for an emergency medical service
- Authors: Barley, Kim Wayne
- Date: 2002
- Subjects: Market -- Planning , Emergency medical services , Health facilities -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10853 , http://hdl.handle.net/10948/120 , Market -- Planning , Emergency medical services , Health facilities -- South Africa
- Description: The research problem addressed in this study was to develop a comprehensive marketing plan that would help an emergency medical service (EMS) in the Nelson Mandela Metropolitan Municipality (NMMM), capture a significant market share and gain a competitive advantage over competitors. To achieve this object, a literature study to determine the key components of a marketing plan was undertaken and used as a theoretical model in developing an actual marketing plan. In addition to the literature study, an empirical study was conducted to identify the key issues critical to the development of a marketing plan for the EMS. The survey method used, based on the key components gained from the literature study, consisted of an in-depth scan of the macro-environment and thorough market investigation of the target industry. The investigation involved the general management and senior personnel from the local emergency medical industry, medical aid schemes and private hospitals and clinics delimited in the study. The results of the above literature study were finally combined with the results of the empirical study and a marketing plan for an emergency medical service was developed. This study concludes with recommendations applicable for the implementation of the actual marketing plan.
- Full Text:
- Date Issued: 2002
- Authors: Barley, Kim Wayne
- Date: 2002
- Subjects: Market -- Planning , Emergency medical services , Health facilities -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10853 , http://hdl.handle.net/10948/120 , Market -- Planning , Emergency medical services , Health facilities -- South Africa
- Description: The research problem addressed in this study was to develop a comprehensive marketing plan that would help an emergency medical service (EMS) in the Nelson Mandela Metropolitan Municipality (NMMM), capture a significant market share and gain a competitive advantage over competitors. To achieve this object, a literature study to determine the key components of a marketing plan was undertaken and used as a theoretical model in developing an actual marketing plan. In addition to the literature study, an empirical study was conducted to identify the key issues critical to the development of a marketing plan for the EMS. The survey method used, based on the key components gained from the literature study, consisted of an in-depth scan of the macro-environment and thorough market investigation of the target industry. The investigation involved the general management and senior personnel from the local emergency medical industry, medical aid schemes and private hospitals and clinics delimited in the study. The results of the above literature study were finally combined with the results of the empirical study and a marketing plan for an emergency medical service was developed. This study concludes with recommendations applicable for the implementation of the actual marketing plan.
- Full Text:
- Date Issued: 2002
Broken vessels : the im-possibility of the art of remembrance and re-collection in the work of Anselm Kiefer, Christian Boltanski, William Kentridge and Santu Mofokeng
- Authors: Belluigi, Dina Zoe
- Date: 2002
- Subjects: History in art Kiefer, Anselm, 1945- Boltanski, Christian, 1944- Kentridge, William, 1955- Mofokeng, Santu, 1956-
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2395 , http://hdl.handle.net/10962/d1002191
- Description: This thesis is structured around investigating the philosophical and aesthetic problematics, politics, and possibilities of representing the past for the purposes of demythifying the present as well as commemorating the losses of history, as explored in the artworks of Anselm Kiefer, Christian Boltanski, William Kentridge and Santu Mofokeng. The first chapter begins with Theodor Adorno’s philosophical understanding of myth and history: how he is influenced by and then develops Karl Marx’s critique of society, Sigmund Freud’s critique of reason and its subject, and particularly Walter Benjamin’s ideas of history as catastrophe, the role of the historian and his messianic materialism. The second section looks at Theodor Adorno’s dialectic of art and society: immanent criticism in aesthetic practice, mimesis, and the shift in conceptions of allegory from Walter Benjamin’s understanding to that of Jacques Derrida. The last section of the chapter looks at Jacques Derrida’s poststructuralist theories against boundary-fixing, within that the ethical relation to the ‘other’ and the theorist/artist as psychic exile. The second chapter deals with the politics of remembrance and representation — beginning with Theodor Adorno’s historic interpretation of the Mosaic law against the making of images and Jean-Francois Lyotard on the im-possibility of representing the unrepresentable. The chapter is divided in two parts between the post-Holocaust European artists Anselm Kiefer and Christian Boltanski, and the post-apartheid South African artists William Kentridge and Santu Mofokeng. It explores, within these artists’ specific contexts, their formal and philosophical approaches to myth and history, and the problematics of image-making, representing the unrepresentable, and commemorating the immemorial. The thesis concludes by considering different conceptions of melancholia as they relate to these artists: the Freudian psychoanalytic approach, Benjamin’s notions of the artist-genius, and Julia Kristeva’s Lacanian reading of the humanist melancholic, concluding with the mythic-historical Kaballist notion of melancholia as the historical burden or responsibility to commemorate loss.
- Full Text:
- Date Issued: 2002
- Authors: Belluigi, Dina Zoe
- Date: 2002
- Subjects: History in art Kiefer, Anselm, 1945- Boltanski, Christian, 1944- Kentridge, William, 1955- Mofokeng, Santu, 1956-
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2395 , http://hdl.handle.net/10962/d1002191
- Description: This thesis is structured around investigating the philosophical and aesthetic problematics, politics, and possibilities of representing the past for the purposes of demythifying the present as well as commemorating the losses of history, as explored in the artworks of Anselm Kiefer, Christian Boltanski, William Kentridge and Santu Mofokeng. The first chapter begins with Theodor Adorno’s philosophical understanding of myth and history: how he is influenced by and then develops Karl Marx’s critique of society, Sigmund Freud’s critique of reason and its subject, and particularly Walter Benjamin’s ideas of history as catastrophe, the role of the historian and his messianic materialism. The second section looks at Theodor Adorno’s dialectic of art and society: immanent criticism in aesthetic practice, mimesis, and the shift in conceptions of allegory from Walter Benjamin’s understanding to that of Jacques Derrida. The last section of the chapter looks at Jacques Derrida’s poststructuralist theories against boundary-fixing, within that the ethical relation to the ‘other’ and the theorist/artist as psychic exile. The second chapter deals with the politics of remembrance and representation — beginning with Theodor Adorno’s historic interpretation of the Mosaic law against the making of images and Jean-Francois Lyotard on the im-possibility of representing the unrepresentable. The chapter is divided in two parts between the post-Holocaust European artists Anselm Kiefer and Christian Boltanski, and the post-apartheid South African artists William Kentridge and Santu Mofokeng. It explores, within these artists’ specific contexts, their formal and philosophical approaches to myth and history, and the problematics of image-making, representing the unrepresentable, and commemorating the immemorial. The thesis concludes by considering different conceptions of melancholia as they relate to these artists: the Freudian psychoanalytic approach, Benjamin’s notions of the artist-genius, and Julia Kristeva’s Lacanian reading of the humanist melancholic, concluding with the mythic-historical Kaballist notion of melancholia as the historical burden or responsibility to commemorate loss.
- Full Text:
- Date Issued: 2002
The evaluation of waste minimization/waste treatment strategies for a commercial production process of 4-methyl-3-thiosemicarbazide
- Authors: Bennen, Wilroy
- Date: 2002
- Subjects: Hazardous wastes , Hazardous substances -- Analysis
- Language: English
- Type: Thesis , Masters , MTech (Chemistry)
- Identifier: vital:10951 , http://hdl.handle.net/10948/97 , Hazardous wastes , Hazardous substances -- Analysis
- Description: Chemical synthesis is closely related to waste minimization. There is no chemical process that does not produce waste. The methods used by industry to deal with this waste is a major environmental concern. This thesis describes the laboratory scale waste minimization and waste treatment strategies for the commercial production process of 4-methyl-3-thiosemicarbazide (MTSC). The production process of 4-methyl-3-thiosemicarbazide was investigated with the aim of increasing the isolated yield of MTSC and at the same time decrease the amount and toxicity of effluent obtained. During this study, parameters were investigated such as the use of excess DIPEA and the temperature of the reaction. Preliminary studies clearly showed that both factors have a significant influence on the final yield of the product. The next part of the investigation was to optimize the two parameters influencing the isolated yield of the MTSC. For this investigation, a multi factorial design was used to determine the optimum conditions in the MTSC yield response. From the results obtained, it was clear that the excess of DIPEA and the temperature of the reaction both need to be high to obtain high yields. These theoretical results were confirmed by results obtained practically, where yields of up 82 % were obtained, but it became clear that even higher yields could be obtained since chromatographic results showed yeilds as high as 90 %. The mass balance of the MTSC synthesis showed a loss of approximately 30 grams per reaction. This loss may have an influence on the final yield. The effluent obtained during the synthesis of MTSC was investigated and a waste treatment protocol was established to reduce the high COD value of the MTSC effluent. The protocol consists of two steps used for the clean up of the effluent. The first being a cooling step; the effluent was cooled at 0oC to induce precipitation of a solid, consisting mostly of MTSC. The second step is a high pressure wet oxidation of the effluent with oxygen in a high pressure reactor. The remaining compounds in the effluent were oxidized, resulting in another precipitate, consisting mostly of sulphur. After the oxidation the COD value of the effluent was decreased by 98 % to a value of 0.4 %. The MTSC present in the precipitate obtained after cooling could be isolated and purified, to add to the yield of the synthesis. The sulphur obtained during the oxidation could also be isolated and reused, or sold to prevent it from contaminating the environment.
- Full Text:
- Date Issued: 2002
- Authors: Bennen, Wilroy
- Date: 2002
- Subjects: Hazardous wastes , Hazardous substances -- Analysis
- Language: English
- Type: Thesis , Masters , MTech (Chemistry)
- Identifier: vital:10951 , http://hdl.handle.net/10948/97 , Hazardous wastes , Hazardous substances -- Analysis
- Description: Chemical synthesis is closely related to waste minimization. There is no chemical process that does not produce waste. The methods used by industry to deal with this waste is a major environmental concern. This thesis describes the laboratory scale waste minimization and waste treatment strategies for the commercial production process of 4-methyl-3-thiosemicarbazide (MTSC). The production process of 4-methyl-3-thiosemicarbazide was investigated with the aim of increasing the isolated yield of MTSC and at the same time decrease the amount and toxicity of effluent obtained. During this study, parameters were investigated such as the use of excess DIPEA and the temperature of the reaction. Preliminary studies clearly showed that both factors have a significant influence on the final yield of the product. The next part of the investigation was to optimize the two parameters influencing the isolated yield of the MTSC. For this investigation, a multi factorial design was used to determine the optimum conditions in the MTSC yield response. From the results obtained, it was clear that the excess of DIPEA and the temperature of the reaction both need to be high to obtain high yields. These theoretical results were confirmed by results obtained practically, where yields of up 82 % were obtained, but it became clear that even higher yields could be obtained since chromatographic results showed yeilds as high as 90 %. The mass balance of the MTSC synthesis showed a loss of approximately 30 grams per reaction. This loss may have an influence on the final yield. The effluent obtained during the synthesis of MTSC was investigated and a waste treatment protocol was established to reduce the high COD value of the MTSC effluent. The protocol consists of two steps used for the clean up of the effluent. The first being a cooling step; the effluent was cooled at 0oC to induce precipitation of a solid, consisting mostly of MTSC. The second step is a high pressure wet oxidation of the effluent with oxygen in a high pressure reactor. The remaining compounds in the effluent were oxidized, resulting in another precipitate, consisting mostly of sulphur. After the oxidation the COD value of the effluent was decreased by 98 % to a value of 0.4 %. The MTSC present in the precipitate obtained after cooling could be isolated and purified, to add to the yield of the synthesis. The sulphur obtained during the oxidation could also be isolated and reused, or sold to prevent it from contaminating the environment.
- Full Text:
- Date Issued: 2002
The impact of multi-skilling training on the paintshop production environment and its employees at Volkswagen South Africa (VWSA)
- Authors: Bhika, Chandrika
- Date: 2002
- Subjects: Employees -- Training of , Automobile industry and trade -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10852 , http://hdl.handle.net/10948/130 , Employees -- Training of , Automobile industry and trade -- South Africa -- Eastern Cape
- Description: Global competition and rapid technological change have been the driving forces for a more flexible and competent workforce. Continuous employee training assists organisations to achieve their goals by adding value to their key resources, the human factor. The demand for a more qualified workforce becomes a strategic force in the effort to raise competitiveness. Providing, obtaining and improving the necessary skills are important in responding to a rapidly changing international economy. Life-long learning and continuous skills development are the new requirements imposed by our knowledgeintensive society. The overall purpose of the research was to determine the impact of multi-skilling training (MST) on the paintshop production environment and its employees at Volkswagen South Africa (VWSA). The objectives of this research were to: Identify the elements of multi-skilling training and guidelines for its development and implementation; Critically evaluate the current system; Determine the impact of multi-skilling training on the production environment in the paint shop at VWSA The research methodology for this study comprised the following steps: Firstly, the development and implementation of MST at Volkswagen South Africa was assessed. The elements of MST and its impact on production and the employee worldwide were determined through the literature study. Secondly, the limitations of the current MST system used in the paintshop at Volkswagen South Africa were assessed in an empirical study, which involved completing of questionnaires. The empirical study proved that the current MST system employed in the paintshop at Volkswagen South Africa had assisted in improving production, and increasing the employees’ morale. The final step of this study entailed the formulation of recommendations, which are as follows: · Sufficient time should be allocated for practical training. · Frequent job rotation must be implement ed. · Advanced MST must be implemented after completion of Level Four. · MST should be presented in English, Afrikaans and Xhosa.
- Full Text:
- Date Issued: 2002
- Authors: Bhika, Chandrika
- Date: 2002
- Subjects: Employees -- Training of , Automobile industry and trade -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10852 , http://hdl.handle.net/10948/130 , Employees -- Training of , Automobile industry and trade -- South Africa -- Eastern Cape
- Description: Global competition and rapid technological change have been the driving forces for a more flexible and competent workforce. Continuous employee training assists organisations to achieve their goals by adding value to their key resources, the human factor. The demand for a more qualified workforce becomes a strategic force in the effort to raise competitiveness. Providing, obtaining and improving the necessary skills are important in responding to a rapidly changing international economy. Life-long learning and continuous skills development are the new requirements imposed by our knowledgeintensive society. The overall purpose of the research was to determine the impact of multi-skilling training (MST) on the paintshop production environment and its employees at Volkswagen South Africa (VWSA). The objectives of this research were to: Identify the elements of multi-skilling training and guidelines for its development and implementation; Critically evaluate the current system; Determine the impact of multi-skilling training on the production environment in the paint shop at VWSA The research methodology for this study comprised the following steps: Firstly, the development and implementation of MST at Volkswagen South Africa was assessed. The elements of MST and its impact on production and the employee worldwide were determined through the literature study. Secondly, the limitations of the current MST system used in the paintshop at Volkswagen South Africa were assessed in an empirical study, which involved completing of questionnaires. The empirical study proved that the current MST system employed in the paintshop at Volkswagen South Africa had assisted in improving production, and increasing the employees’ morale. The final step of this study entailed the formulation of recommendations, which are as follows: · Sufficient time should be allocated for practical training. · Frequent job rotation must be implement ed. · Advanced MST must be implemented after completion of Level Four. · MST should be presented in English, Afrikaans and Xhosa.
- Full Text:
- Date Issued: 2002
Design, development and analysis of the friction stir welding process
- Authors: Blignault, Calvin
- Date: 2002
- Subjects: Friction welding
- Language: English
- Type: Thesis , Masters , MTech (Mechanical Engineering)
- Identifier: vital:10809 , http://hdl.handle.net/10948/1350 , Friction welding
- Description: The development of a CNC-based technology FSW machine to accurately produce friction stir weld samples that can be analyzed for research purposes is implemented and discussed. A process diagnosis and control scheme to improve the process monitoring and weld evaluation capabilities of an FSW machine are proposed and implemented. Basic CNC-based hardware implementation such as optical encoders and inverters for process control are explained and verified. The control scheme and framework of interfaces to the digital I/O cards for PC user interface are explained. An advanced monitoring system which senses process performance parameters such as tool temperature, 3-axis tool forces, torque and spindle speed are explained. Mechanical designs and manufacturing techniques such as tool, clamp and backing plate designs are explained and verified. The process parameters for quality optimization are investigated and optimized by making use of Correlation and Regression Analysis. The statistical data and analytical relationships between welding parameters (independent) and each of the performance parameters (dependent) are obtained and used to simulate the machining process. The weld research samples are tested for strength and integrity making use of various scientific testing techniques. The reliability of the samples are also evaluated and compared to that of other institutions. Process variables and the optimum operating range of the Friction Stir Welding machine is determined and a framework for further research into weld quality optimization is set.
- Full Text:
- Date Issued: 2002
- Authors: Blignault, Calvin
- Date: 2002
- Subjects: Friction welding
- Language: English
- Type: Thesis , Masters , MTech (Mechanical Engineering)
- Identifier: vital:10809 , http://hdl.handle.net/10948/1350 , Friction welding
- Description: The development of a CNC-based technology FSW machine to accurately produce friction stir weld samples that can be analyzed for research purposes is implemented and discussed. A process diagnosis and control scheme to improve the process monitoring and weld evaluation capabilities of an FSW machine are proposed and implemented. Basic CNC-based hardware implementation such as optical encoders and inverters for process control are explained and verified. The control scheme and framework of interfaces to the digital I/O cards for PC user interface are explained. An advanced monitoring system which senses process performance parameters such as tool temperature, 3-axis tool forces, torque and spindle speed are explained. Mechanical designs and manufacturing techniques such as tool, clamp and backing plate designs are explained and verified. The process parameters for quality optimization are investigated and optimized by making use of Correlation and Regression Analysis. The statistical data and analytical relationships between welding parameters (independent) and each of the performance parameters (dependent) are obtained and used to simulate the machining process. The weld research samples are tested for strength and integrity making use of various scientific testing techniques. The reliability of the samples are also evaluated and compared to that of other institutions. Process variables and the optimum operating range of the Friction Stir Welding machine is determined and a framework for further research into weld quality optimization is set.
- Full Text:
- Date Issued: 2002
The biotransformation of phenolic pollutants using polyphenol oxidase
- Authors: Boshoff, Aileen
- Date: 2002
- Subjects: Polyphenol oxidase Sewage -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3976 , http://hdl.handle.net/10962/d1004035
- Description: The potential of using mushroom polyphenol oxidase (EC 1.14.18.1) as a biocatalyst for the biotransformation of phenols to produce catechols in an aqueous medium was investigated. Polyphenol oxidase is characterised by two distinct reactions i.e., the ortho-hydroxylation of phenols to catechols (cresolase activity) and the subsequent oxidation of catechols to orthoquinones (catecholase activity). In order to facilitate the development of a process to produce catechols, the accumulation of catechol as a true intermediate product released in the reaction system needed to be investigated, as its release had been disputed due to the oxidation of catechols to o-quinones. Using LC-MS, catechol products were successfully identified as true intermediate products formed during biocatalytic reactions in water.
- Full Text:
- Date Issued: 2002
- Authors: Boshoff, Aileen
- Date: 2002
- Subjects: Polyphenol oxidase Sewage -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3976 , http://hdl.handle.net/10962/d1004035
- Description: The potential of using mushroom polyphenol oxidase (EC 1.14.18.1) as a biocatalyst for the biotransformation of phenols to produce catechols in an aqueous medium was investigated. Polyphenol oxidase is characterised by two distinct reactions i.e., the ortho-hydroxylation of phenols to catechols (cresolase activity) and the subsequent oxidation of catechols to orthoquinones (catecholase activity). In order to facilitate the development of a process to produce catechols, the accumulation of catechol as a true intermediate product released in the reaction system needed to be investigated, as its release had been disputed due to the oxidation of catechols to o-quinones. Using LC-MS, catechol products were successfully identified as true intermediate products formed during biocatalytic reactions in water.
- Full Text:
- Date Issued: 2002
A cyclic approach to business continuity planning
- Authors: Botha, Jacques
- Date: 2002
- Subjects: Data recovery (Computer science) -- Planning , Data protection , Emergency management
- Language: English
- Type: Thesis , Masters , MTech (Information Technology)
- Identifier: vital:10788 , http://hdl.handle.net/10948/81 , Data recovery (Computer science) -- Planning , Data protection , Emergency management
- Description: The Information Technology (IT) industry has grown and has become an integral part in the world of business today. The importance of information, and IT in particular, will in fact only increase with time (von Solms, 1999). For a large group of organizations computer systems form the basis of their day-to-day functioning (Halliday, Badendorst & von Solms, 1996). These systems evolve at an incredible pace and this brings about a greater need for securing them, as well as the organizational information processed, transmitted and stored. This technological evolution brings about new risks for an organization’s systems and information (Halliday et. al., 1996). If IT fails, it means that the business could fail as well, creating a need for more rigorous IT management (International Business Machines Corporation, 2000). For this reason, executive management must be made aware of the potential consequences that a disaster could have on the organisation (Hawkins,Yen & Chou, 2000). A disaster could be any event that would cause a disruption in the normal day-to-day functioning of an organization. Such an event could range from a natural disaster, like a fire, an earthquake or a flood, to something more trivial, like a virus or system malfunction (Hawkins et. al., 2000). During the 1980’s a discipline known as Disaster Recovery Planning (DRP) emerged to protect an organization’s data centre, which was central to the organisation’s IT based structure, from the effects of disasters. This solution, however, focussed only on the protection of the data centre. During the early 1990’s the focus shifted towards distributed computing and client/server technology. Data centre protection and recovery were no longer enough to ensure survival. Organizations needed to ensure the continuation of their mission critical processes to support their continued goal of operations (IBM Global Services, 1999). Organizations now had to ensure that their mission critical functions could continue while the data centre was recovering from a disaster. A different approach was required. It is for this reason that Business Continuity Planning (BCP) was accepted as a formal discipline (IBM Global Services, 1999). To ensure that business continues as usual, an organization must have a plan in place that will help them ensure both the continuation and recovery of critical business processes and the recovery of the data centre, should a disaster strike (Moore, 1995). Wilson (2000) defines a business continuity plan as “a set of procedures developed for the entire enterprise, outlining the actions to be taken by the IT organization, executive staff, and the various business units in order to quickly resume operations in the event of a service interruption or an outage”. With markets being highly competitive as they are, an organization needs a detailed listing of steps to follow to ensure minimal loss due to downtime. This is very important for maintaining its competitive advantage and public stature (Wilson, 2000). The fact that the company’s reputation is at stake requires executive management to take continuity planning very serious (IBM Global Services, 1999). Ensuring continuity of business processes and recovering the IT services of an organization is not the sole responsibility of the IT department. Therefore management should be aware that they could be held liable for any consequences resulting from a disaster (Kearvell-White, 1996). Having a business continuity plan in place is important to the entire organization, as everyone, from executive management to the employees, stands to benefit from it (IBM Global Services, 1999). Despite this, numerous organizations do not have a business continuity plan in place. Organizations neglecting to develop a plan put themselves at tremendous risk and stand to loose everything (Kearvell-White, 1996).
- Full Text:
- Date Issued: 2002
- Authors: Botha, Jacques
- Date: 2002
- Subjects: Data recovery (Computer science) -- Planning , Data protection , Emergency management
- Language: English
- Type: Thesis , Masters , MTech (Information Technology)
- Identifier: vital:10788 , http://hdl.handle.net/10948/81 , Data recovery (Computer science) -- Planning , Data protection , Emergency management
- Description: The Information Technology (IT) industry has grown and has become an integral part in the world of business today. The importance of information, and IT in particular, will in fact only increase with time (von Solms, 1999). For a large group of organizations computer systems form the basis of their day-to-day functioning (Halliday, Badendorst & von Solms, 1996). These systems evolve at an incredible pace and this brings about a greater need for securing them, as well as the organizational information processed, transmitted and stored. This technological evolution brings about new risks for an organization’s systems and information (Halliday et. al., 1996). If IT fails, it means that the business could fail as well, creating a need for more rigorous IT management (International Business Machines Corporation, 2000). For this reason, executive management must be made aware of the potential consequences that a disaster could have on the organisation (Hawkins,Yen & Chou, 2000). A disaster could be any event that would cause a disruption in the normal day-to-day functioning of an organization. Such an event could range from a natural disaster, like a fire, an earthquake or a flood, to something more trivial, like a virus or system malfunction (Hawkins et. al., 2000). During the 1980’s a discipline known as Disaster Recovery Planning (DRP) emerged to protect an organization’s data centre, which was central to the organisation’s IT based structure, from the effects of disasters. This solution, however, focussed only on the protection of the data centre. During the early 1990’s the focus shifted towards distributed computing and client/server technology. Data centre protection and recovery were no longer enough to ensure survival. Organizations needed to ensure the continuation of their mission critical processes to support their continued goal of operations (IBM Global Services, 1999). Organizations now had to ensure that their mission critical functions could continue while the data centre was recovering from a disaster. A different approach was required. It is for this reason that Business Continuity Planning (BCP) was accepted as a formal discipline (IBM Global Services, 1999). To ensure that business continues as usual, an organization must have a plan in place that will help them ensure both the continuation and recovery of critical business processes and the recovery of the data centre, should a disaster strike (Moore, 1995). Wilson (2000) defines a business continuity plan as “a set of procedures developed for the entire enterprise, outlining the actions to be taken by the IT organization, executive staff, and the various business units in order to quickly resume operations in the event of a service interruption or an outage”. With markets being highly competitive as they are, an organization needs a detailed listing of steps to follow to ensure minimal loss due to downtime. This is very important for maintaining its competitive advantage and public stature (Wilson, 2000). The fact that the company’s reputation is at stake requires executive management to take continuity planning very serious (IBM Global Services, 1999). Ensuring continuity of business processes and recovering the IT services of an organization is not the sole responsibility of the IT department. Therefore management should be aware that they could be held liable for any consequences resulting from a disaster (Kearvell-White, 1996). Having a business continuity plan in place is important to the entire organization, as everyone, from executive management to the employees, stands to benefit from it (IBM Global Services, 1999). Despite this, numerous organizations do not have a business continuity plan in place. Organizations neglecting to develop a plan put themselves at tremendous risk and stand to loose everything (Kearvell-White, 1996).
- Full Text:
- Date Issued: 2002
The relationship between the leadership, internal quality, and customer satisfaction levels of dealerships in a South African motor vehicle organisation
- Authors: Botha, Jennifer
- Date: 2002
- Subjects: Consumer satisfaction , Automobile dealers -- South Africa , Industrial productivity , Customer services
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1185 , http://hdl.handle.net/10962/d1002802 , Consumer satisfaction , Automobile dealers -- South Africa , Industrial productivity , Customer services
- Description: This research investigates the relationship between the leadership, internal quality, and customer satisfaction levels in the dealerships of a South African motor vehicle organisation. The Service Profit Chain provides the background theory to this relationship, by suggesting that various factors within the service delivery system of an organisation affect the level of customer satisfaction. From the Service Profit Chain, it is established that two of the prevalent factors affecting customer satisfaction, are leadership and internal quality. The Full Range Leadership Development Theory provides the backdrop for analysing the leadership style of each dealership by using the Multifactor Leadership Questionnaire. The Competence Process forms the theoretical construct against which the internal quality of these dealerships is assessed using the Organisation Competence Analysis Questionnaire. Information was gathered, using these two instruments, from a sample of 85 motor vehicle dealerships within South Africa. The customer satisfaction levels at each of these dealerships, is measured by the motor vehicle organisation’s own instrument, known as the Customer Satisfaction Index. Data obtained from each instrument, for the respective dealerships, was then statistically analysed. However, due to the low reliability of the instruments used in this research, the results of this study indicate that there is no relationship between the leadership, internal quality, and customer satisfaction levels within a South African motor vehicle organisation. Therefore we can conclude that the null hypotheses can not be rejected.
- Full Text:
- Date Issued: 2002
- Authors: Botha, Jennifer
- Date: 2002
- Subjects: Consumer satisfaction , Automobile dealers -- South Africa , Industrial productivity , Customer services
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1185 , http://hdl.handle.net/10962/d1002802 , Consumer satisfaction , Automobile dealers -- South Africa , Industrial productivity , Customer services
- Description: This research investigates the relationship between the leadership, internal quality, and customer satisfaction levels in the dealerships of a South African motor vehicle organisation. The Service Profit Chain provides the background theory to this relationship, by suggesting that various factors within the service delivery system of an organisation affect the level of customer satisfaction. From the Service Profit Chain, it is established that two of the prevalent factors affecting customer satisfaction, are leadership and internal quality. The Full Range Leadership Development Theory provides the backdrop for analysing the leadership style of each dealership by using the Multifactor Leadership Questionnaire. The Competence Process forms the theoretical construct against which the internal quality of these dealerships is assessed using the Organisation Competence Analysis Questionnaire. Information was gathered, using these two instruments, from a sample of 85 motor vehicle dealerships within South Africa. The customer satisfaction levels at each of these dealerships, is measured by the motor vehicle organisation’s own instrument, known as the Customer Satisfaction Index. Data obtained from each instrument, for the respective dealerships, was then statistically analysed. However, due to the low reliability of the instruments used in this research, the results of this study indicate that there is no relationship between the leadership, internal quality, and customer satisfaction levels within a South African motor vehicle organisation. Therefore we can conclude that the null hypotheses can not be rejected.
- Full Text:
- Date Issued: 2002
Effect of selected physical and production traits on the tick burdens of beef cattle
- Authors: Botha, Theunis Christoffel
- Date: 2002
- Subjects: Beef cattle -- Breeding
- Language: English
- Type: Thesis , Masters , MTech (Agricultural Management)
- Identifier: vital:10966 , http://hdl.handle.net/10948/91 , Beef cattle -- Breeding
- Description: The objective of this study was to determine the effect of selected traits such as age, sex, body weight, body length and height, body condition score (BCS), coatscore (CS), skin thickness and average skin surface temperature on tick burdens in beef cattle. Bonsmara cattle (n= 143) were used to measure visible tick counts, body condition score, coat score, skin thickness, body height and length, body weight, body surface temperature, gender and inter calving period. Measurements were taken from April to December. All animals were managed extensively on natural and cultivated pastures near George in the Southern Cape. Female animals had significantly (p<0.05) greater tick infestation (37.98±2.7) compared to male animals (16.52±1.2). Age was a significant factor (p<0.001) with the younger animals below two years having (46.40±5.26) more ticks than those of two years and older (20.15±2.44). A significant negative correlation (p<0.001; -0.29) was reported between the infestation of ticks on the animals and the age of the animal. Animals with an average body weight below 250kg had 42% (p<0.05) more ticks compared to animals with a body weight above 250kg. Age of the animal and weight were highly correlated (r= 0.70); p<0.001), while the correlation between the number of ticks per cow and the mean weight was negatively correlated (r= -0.37; p<0.001). Skin surface temperature significantly influenced tick infestation on the animals (p<0.001). The degree of infestation increased as body surface temperature exceeded 30º C. Coat score, skin thickness, body condition score and inter calving period did not significantly influence tick infestation on the animals. The infestation of ticks on the animals were significantly influenced by body height (p<0.019) and body length (p<0.001). Animals smaller than a 130cm in height had a significantly (p<0.05) greater tick infestation (36.5±5) compared to animals taller than 130cm (21.2±1.5). This trend was also observed for body length. Animals with a body length shorter than 145cm had a greater (p<0.05) average tick infestation of 41.3±4.5 compared to 23.2±1.3 to animals longer than 145cm, indicating a 44% greater tick infestation in favour of the shorter animals. For increased production and tick resistance animals should have smoother coats and be able to dissipate heat effectively.
- Full Text:
- Date Issued: 2002
- Authors: Botha, Theunis Christoffel
- Date: 2002
- Subjects: Beef cattle -- Breeding
- Language: English
- Type: Thesis , Masters , MTech (Agricultural Management)
- Identifier: vital:10966 , http://hdl.handle.net/10948/91 , Beef cattle -- Breeding
- Description: The objective of this study was to determine the effect of selected traits such as age, sex, body weight, body length and height, body condition score (BCS), coatscore (CS), skin thickness and average skin surface temperature on tick burdens in beef cattle. Bonsmara cattle (n= 143) were used to measure visible tick counts, body condition score, coat score, skin thickness, body height and length, body weight, body surface temperature, gender and inter calving period. Measurements were taken from April to December. All animals were managed extensively on natural and cultivated pastures near George in the Southern Cape. Female animals had significantly (p<0.05) greater tick infestation (37.98±2.7) compared to male animals (16.52±1.2). Age was a significant factor (p<0.001) with the younger animals below two years having (46.40±5.26) more ticks than those of two years and older (20.15±2.44). A significant negative correlation (p<0.001; -0.29) was reported between the infestation of ticks on the animals and the age of the animal. Animals with an average body weight below 250kg had 42% (p<0.05) more ticks compared to animals with a body weight above 250kg. Age of the animal and weight were highly correlated (r= 0.70); p<0.001), while the correlation between the number of ticks per cow and the mean weight was negatively correlated (r= -0.37; p<0.001). Skin surface temperature significantly influenced tick infestation on the animals (p<0.001). The degree of infestation increased as body surface temperature exceeded 30º C. Coat score, skin thickness, body condition score and inter calving period did not significantly influence tick infestation on the animals. The infestation of ticks on the animals were significantly influenced by body height (p<0.019) and body length (p<0.001). Animals smaller than a 130cm in height had a significantly (p<0.05) greater tick infestation (36.5±5) compared to animals taller than 130cm (21.2±1.5). This trend was also observed for body length. Animals with a body length shorter than 145cm had a greater (p<0.05) average tick infestation of 41.3±4.5 compared to 23.2±1.3 to animals longer than 145cm, indicating a 44% greater tick infestation in favour of the shorter animals. For increased production and tick resistance animals should have smoother coats and be able to dissipate heat effectively.
- Full Text:
- Date Issued: 2002
The biology and molecular ecology of floating sulphur biofilms
- Authors: Bowker, Michelle Louise
- Date: 2002
- Subjects: Biofilms , Microbial ecology , Sulfur
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4056 , http://hdl.handle.net/10962/d1004117 , Biofilms , Microbial ecology , Sulfur
- Description: Floating sulphur biofilms have been observed to occur on sulphate-containing natural systems and waste stabilization ponds. It has been postulated that these biofilms form on the surface of the water because sulphate reducing bacteria present in the bottom layers of the water body reduce sulphate to sulphide which then diffuses upwards and is oxidized under the correct redox conditions to sulphur by sulphide oxidizing bacteria. Very little information exists on these complex floating systems and in order to study them further, model systems were designed. The Baffle Reactor was successfully used to cultivate floating sulphur biofilms. Conditions within the reactor could be closely scrutinized in the laboratory and it was found that sulphate levels decreased, sulphide levels increased and that sulphur was produced over a period of 2 weeks. The success of this system led to it being scaled-up and currently a method to harvest sulphur from the biofilm is under development. It is thought that biofilms are highly complex, heterogeneous structures with different bacteria distributed in different layers. Preliminary work suggested that bacteria were differentially distributed along nutrient and oxygen gradients within the biofilm. Biofilms are very thin structures and therefore difficult to study and Gradient systems were developed in an attempt to spatially separate the biofilm species into functional layers. Gradient Tubes were designed; these provided a gradient of high-sulphide, low oxygen conditions to high-oxygen, low-sulphide conditions. Bacteria were observed to grow in different layers of these systems. The Gradient Tubes could be sectioned and the chemical characteristics of each section as well as the species present could be determined. Silicon Tubular Bioreactors were also developed and these were very efficient at producing large amounts of sulphur under strictly controlled redox conditions. Microscopy and molecular methods including the amplification of a section of Ribosomal Ribonucleic acid by Polymerase Chain Reaction were used in an attempt to characterize the populations present in these biofilm systems. Denaturing Gradient Gel Electrophoresis was used to create band profiles of the populations; individual bands were excised from the gels and sequenced. Identified species included Ectothiorhodospira sp., Dethiosulfovibrio russensis, Pseudomonas geniculata, Thiobacillus baregensis and Halothiobacillus kellyi.
- Full Text:
- Date Issued: 2002
- Authors: Bowker, Michelle Louise
- Date: 2002
- Subjects: Biofilms , Microbial ecology , Sulfur
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4056 , http://hdl.handle.net/10962/d1004117 , Biofilms , Microbial ecology , Sulfur
- Description: Floating sulphur biofilms have been observed to occur on sulphate-containing natural systems and waste stabilization ponds. It has been postulated that these biofilms form on the surface of the water because sulphate reducing bacteria present in the bottom layers of the water body reduce sulphate to sulphide which then diffuses upwards and is oxidized under the correct redox conditions to sulphur by sulphide oxidizing bacteria. Very little information exists on these complex floating systems and in order to study them further, model systems were designed. The Baffle Reactor was successfully used to cultivate floating sulphur biofilms. Conditions within the reactor could be closely scrutinized in the laboratory and it was found that sulphate levels decreased, sulphide levels increased and that sulphur was produced over a period of 2 weeks. The success of this system led to it being scaled-up and currently a method to harvest sulphur from the biofilm is under development. It is thought that biofilms are highly complex, heterogeneous structures with different bacteria distributed in different layers. Preliminary work suggested that bacteria were differentially distributed along nutrient and oxygen gradients within the biofilm. Biofilms are very thin structures and therefore difficult to study and Gradient systems were developed in an attempt to spatially separate the biofilm species into functional layers. Gradient Tubes were designed; these provided a gradient of high-sulphide, low oxygen conditions to high-oxygen, low-sulphide conditions. Bacteria were observed to grow in different layers of these systems. The Gradient Tubes could be sectioned and the chemical characteristics of each section as well as the species present could be determined. Silicon Tubular Bioreactors were also developed and these were very efficient at producing large amounts of sulphur under strictly controlled redox conditions. Microscopy and molecular methods including the amplification of a section of Ribosomal Ribonucleic acid by Polymerase Chain Reaction were used in an attempt to characterize the populations present in these biofilm systems. Denaturing Gradient Gel Electrophoresis was used to create band profiles of the populations; individual bands were excised from the gels and sequenced. Identified species included Ectothiorhodospira sp., Dethiosulfovibrio russensis, Pseudomonas geniculata, Thiobacillus baregensis and Halothiobacillus kellyi.
- Full Text:
- Date Issued: 2002
A phenomenological investigation of Windhoek Senior Secondary school principals' perceptions and experiences of their leadership roles
- Authors: Boys, Ben
- Date: 2002
- Subjects: School principals -- Namibia Educational leadership -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1700 , http://hdl.handle.net/10962/d1003583
- Description: Namibia, having been a former colony of South Africa, was equally subjected to apartheid laws and practices. Independence, achieved in March 1990, signaled the dawn of a new era of access, equity, quality and democracy in the Namibian education sector. A unified system of educational administration, management, and control was established. The whole educational corps, especially the principals of all our schools, is expected to implement this new system as agents of change. In terms of the vision for a new Namibia, therefore, school principals are seen as occupying positions of central importance. This notion resonates strongly with recent and contemporary leadership thinking. However, a number of concerns prevalent in schools - particularly, increasing student underperformance, worsening disciplinary problems, increasing teenage pregnancy and HIV/AIDS pandemic, teacher qualification, decreasing teacher motivation, lack of training including induction for principals, inadequate support from the top (lack of a support system) and insufficient parental involvement in school matters – make the task of running schools extremely challenging and increasingly complex. How do principals experience these challenges and deal with the complex situations? How do they perceive their role, particularly in light of national aspirations and leadership theory? These are questions I think need to be explored. My research goal was to gain an understanding of Windhoek senior secondary school principals’ perceptions and experiences of their leadership role. My focus was on three purposively selected Windhoek senior secondary school principals representative of both the Namibian ethno-cultural diversity and gender. Data was collected through interviews. I found that the situations in which the principals found themselves during the pre- and post independent periods mainly determined their leadership style and behaviour, however, that did not deter their vision for the transformation of the society, as the ultimate objective and essence of their leadership. The appropriate practicing of their leadership role was being hampered by lack of induction and training, lack of a support system and insufficient parental involvement.
- Full Text:
- Date Issued: 2002
- Authors: Boys, Ben
- Date: 2002
- Subjects: School principals -- Namibia Educational leadership -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1700 , http://hdl.handle.net/10962/d1003583
- Description: Namibia, having been a former colony of South Africa, was equally subjected to apartheid laws and practices. Independence, achieved in March 1990, signaled the dawn of a new era of access, equity, quality and democracy in the Namibian education sector. A unified system of educational administration, management, and control was established. The whole educational corps, especially the principals of all our schools, is expected to implement this new system as agents of change. In terms of the vision for a new Namibia, therefore, school principals are seen as occupying positions of central importance. This notion resonates strongly with recent and contemporary leadership thinking. However, a number of concerns prevalent in schools - particularly, increasing student underperformance, worsening disciplinary problems, increasing teenage pregnancy and HIV/AIDS pandemic, teacher qualification, decreasing teacher motivation, lack of training including induction for principals, inadequate support from the top (lack of a support system) and insufficient parental involvement in school matters – make the task of running schools extremely challenging and increasingly complex. How do principals experience these challenges and deal with the complex situations? How do they perceive their role, particularly in light of national aspirations and leadership theory? These are questions I think need to be explored. My research goal was to gain an understanding of Windhoek senior secondary school principals’ perceptions and experiences of their leadership role. My focus was on three purposively selected Windhoek senior secondary school principals representative of both the Namibian ethno-cultural diversity and gender. Data was collected through interviews. I found that the situations in which the principals found themselves during the pre- and post independent periods mainly determined their leadership style and behaviour, however, that did not deter their vision for the transformation of the society, as the ultimate objective and essence of their leadership. The appropriate practicing of their leadership role was being hampered by lack of induction and training, lack of a support system and insufficient parental involvement.
- Full Text:
- Date Issued: 2002
The effect of energy and protein nutritional levels on production of breeding ostriches
- Authors: Brand, Zanell
- Date: 2002
- Subjects: Ostriches -- Nutrition , Ostriches -- Breeding--South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5805 , http://hdl.handle.net/10962/d1006312 , Ostriches -- Nutrition , Ostriches -- Breeding--South Africa
- Description: Adequate and appropriate nutrition is essential for the production of high quality commercially farmed animal species. Although South Africa has had a well-established ostrich industry for over a century, little information on ostrich nutrition, in particular the specific nutritional requirements at different stages of production, is available. The industry has consequently relied heavily on data derived from poultry and pigs, but this has often proved to be unsatisfactory for ostriches and has resulted in serious nutritional-related problems. Recent studies on the metabolisable energy of specific components of diet formulations and balanced diets have indicated that ostriches have enhanced digestibility compared with poultry and pigs. At the same time, in the present economic climate, it is necessary to find cost-effective diets for breeding birds without compromising egg and chick production. This study primarily assessed the effect of different dietary protein and energy levels on production parameters and body condition of breeding female and male ostriches. The energy content of the diet appears to be the main constraint to egg production and breeders on low energy diets laid fewer eggs and lost more body condition compared with breeders fed higher energy diets. A diet with 8.5 MJ/kg DM and 10% protein with well balanced amino acids appears to be sufficient for female breeders without compromising production and a diet with 7.5 MJ/kg DM and 10% protein appears suitable for breeding male ostriches. Different dietary energy and protein levels similarly had little or no effect on egg quality and composition. This study also assessed the carry-over effect of the nutritional regime in one year on the production in the following breeding season. Females fed diets as low as 7.5 MJ/kg ME in the previous breeding season produced significantly fewer eggs in the next breeding season, which resulted in lower chick production. Energy had no effect on the percentage infertile eggs or on the initial egg weight. Different levels of dietary protein had no effect on egg production, egg weight, fertility, hatchability and initial chick weight.
- Full Text:
- Date Issued: 2002
- Authors: Brand, Zanell
- Date: 2002
- Subjects: Ostriches -- Nutrition , Ostriches -- Breeding--South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5805 , http://hdl.handle.net/10962/d1006312 , Ostriches -- Nutrition , Ostriches -- Breeding--South Africa
- Description: Adequate and appropriate nutrition is essential for the production of high quality commercially farmed animal species. Although South Africa has had a well-established ostrich industry for over a century, little information on ostrich nutrition, in particular the specific nutritional requirements at different stages of production, is available. The industry has consequently relied heavily on data derived from poultry and pigs, but this has often proved to be unsatisfactory for ostriches and has resulted in serious nutritional-related problems. Recent studies on the metabolisable energy of specific components of diet formulations and balanced diets have indicated that ostriches have enhanced digestibility compared with poultry and pigs. At the same time, in the present economic climate, it is necessary to find cost-effective diets for breeding birds without compromising egg and chick production. This study primarily assessed the effect of different dietary protein and energy levels on production parameters and body condition of breeding female and male ostriches. The energy content of the diet appears to be the main constraint to egg production and breeders on low energy diets laid fewer eggs and lost more body condition compared with breeders fed higher energy diets. A diet with 8.5 MJ/kg DM and 10% protein with well balanced amino acids appears to be sufficient for female breeders without compromising production and a diet with 7.5 MJ/kg DM and 10% protein appears suitable for breeding male ostriches. Different dietary energy and protein levels similarly had little or no effect on egg quality and composition. This study also assessed the carry-over effect of the nutritional regime in one year on the production in the following breeding season. Females fed diets as low as 7.5 MJ/kg ME in the previous breeding season produced significantly fewer eggs in the next breeding season, which resulted in lower chick production. Energy had no effect on the percentage infertile eggs or on the initial egg weight. Different levels of dietary protein had no effect on egg production, egg weight, fertility, hatchability and initial chick weight.
- Full Text:
- Date Issued: 2002
The relationship between three anxiety related clusters in projective drawings and anxiety and ego-strength scales of the Minnesota multiphasic personality inventory-2
- Authors: Brink, André
- Date: 2002
- Subjects: Projective techniques , Personality assessment , Personality tests , Anxiety , Minnesota Multiphasic Personality Inventory
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2942 , http://hdl.handle.net/10962/d1002451 , Projective techniques , Personality assessment , Personality tests , Anxiety , Minnesota Multiphasic Personality Inventory
- Description: Based on the shortcomings of past research, the need for understanding and investigation of the general relationship between self-report measures and human figure drawings required understanding and investigation (Riethmiller & Handler, 1997b; Waehler, 1997) while utilising a quantitative, configural scoring approach. Riethmiller and Handler (1997a; 1997b) hypothesised that subjects have one of two typical approach styles to anxiety/stress that influences their execution of the Human Figure Drawing (HFD) Test: “Avoidance” or “Coping” as measured by composite scoring index clusters. They argue that these two approach styles had to be taken into account when investigating anxiety on the HFD Test. According to Handler and Reyher (1965) those who experience more intense anxiety typically rely on an “Avoidant” approach, while those with lower anxiety typically rely on a “Coping” approach. The “Coping” response is hypothesised to suggest good ego-strength, and the “Avoidant” response poor ego-strength. Handler and Reyher (1964; 1965; 1966) also argued that there are two sources of anxiety on projective drawings: internal and external sources of anxiety. They hypothesised that the “External” anxiety cluster (measured by utilising the car drawing) and self-report measures both assess ‘external’ anxiety. Using Handler’s (1967) HFD index scoring manual, this research therefore inve stigated the level of correlation of the two MMPI-2 anxiety scale scores with (a) the hypothesised Stress Approach HFD cluster scores, as well as with (b) the “External” anxiety cluster score, while the hypothesised Stress Approach HFD cluster scores were compared with the (c) MMPI-2 ego strength scale score. The results of the investigated relationships yielded non-significant correlations overall. The differences in nature of the two measurement instruments, and the potential weaknesses of this study, as two likely explanations for these correlations, are discussed. In the consideration of the differences of the two measurement instruments, the weaknesses of SR measures and criterion-related validity are discussed while self- attributed and implicit motives are contrasted with each other. Potential extraneous variables and possible truncated range are discussed as potential weaknesses of this study.
- Full Text:
- Date Issued: 2002
- Authors: Brink, André
- Date: 2002
- Subjects: Projective techniques , Personality assessment , Personality tests , Anxiety , Minnesota Multiphasic Personality Inventory
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2942 , http://hdl.handle.net/10962/d1002451 , Projective techniques , Personality assessment , Personality tests , Anxiety , Minnesota Multiphasic Personality Inventory
- Description: Based on the shortcomings of past research, the need for understanding and investigation of the general relationship between self-report measures and human figure drawings required understanding and investigation (Riethmiller & Handler, 1997b; Waehler, 1997) while utilising a quantitative, configural scoring approach. Riethmiller and Handler (1997a; 1997b) hypothesised that subjects have one of two typical approach styles to anxiety/stress that influences their execution of the Human Figure Drawing (HFD) Test: “Avoidance” or “Coping” as measured by composite scoring index clusters. They argue that these two approach styles had to be taken into account when investigating anxiety on the HFD Test. According to Handler and Reyher (1965) those who experience more intense anxiety typically rely on an “Avoidant” approach, while those with lower anxiety typically rely on a “Coping” approach. The “Coping” response is hypothesised to suggest good ego-strength, and the “Avoidant” response poor ego-strength. Handler and Reyher (1964; 1965; 1966) also argued that there are two sources of anxiety on projective drawings: internal and external sources of anxiety. They hypothesised that the “External” anxiety cluster (measured by utilising the car drawing) and self-report measures both assess ‘external’ anxiety. Using Handler’s (1967) HFD index scoring manual, this research therefore inve stigated the level of correlation of the two MMPI-2 anxiety scale scores with (a) the hypothesised Stress Approach HFD cluster scores, as well as with (b) the “External” anxiety cluster score, while the hypothesised Stress Approach HFD cluster scores were compared with the (c) MMPI-2 ego strength scale score. The results of the investigated relationships yielded non-significant correlations overall. The differences in nature of the two measurement instruments, and the potential weaknesses of this study, as two likely explanations for these correlations, are discussed. In the consideration of the differences of the two measurement instruments, the weaknesses of SR measures and criterion-related validity are discussed while self- attributed and implicit motives are contrasted with each other. Potential extraneous variables and possible truncated range are discussed as potential weaknesses of this study.
- Full Text:
- Date Issued: 2002
The development of a financial plan to partly cover the cost of frail care in a retirement village in George
- Authors: Brink, F J
- Date: 2002
- Subjects: Older people -- Care -- South Africa , Frail elderly -- Medical care -- South Africa -- George , Frail elderly -- Care -- South Africa -- George
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10919 , http://hdl.handle.net/10948/84 , Older people -- Care -- South Africa , Frail elderly -- Medical care -- South Africa -- George , Frail elderly -- Care -- South Africa -- George
- Description: The world population is ageing, and this is also relevant to South Africa. At the same time the potential support ratio (the number of persons aged 15 to 64 years per one older person aged 65 years or older) is falling, and the dependency burden on potential workers increases. To alleviate the financial burden on the aged, and their families, it has become necessary to develop a financial plan to cover the cost of frail care. The overall purpose of this research is to determine whether any financial plans exist which are relevant. If nothing existed, a plan had to be developed. The research methodology for this study comprised the following steps: Firstly, the demographics of the world and South Africa were researched. The concept of frail (long-term) care in the United States of America and New Zealand was investigated to determine what is available. The subsidisation concept of the South African Government towards caring for the elderly was also investigated. Secondly, a questionnaire was sent to the residents of five retirement complexes in George to determine their interest in such a plan. The records of the frail care unit that these residents utilise were analysed to determine the number of residents needing frail care. A comparative study of the cost of frail care in the Southern Cape was undertaken. Thirdly, two options to partly subsidise the cost of frail care were examined, where the first option covers the running cost, and the second option, subsidising one third of the frail care cost, builds up a sustainable fund after the first five year period. The funds of the second option can then be utilised in the subsequent years to increase the subsidisation portion of frail care cost. The final step of this study entailed the formulation of recommendations to implement the frail care nursing levy as soon as possible, with special attention given to the following: a) It must be compulsory for new residents to join the fund. b) A yearly capital amount of R100 000 or more is needed to sustain the fund. c) A contract must be drafted to set out all the rules and regulations to the residents. d) An attitude change amongst some residents is required. Individuals must realise that the success of this plan depends upon themselves and with the necessary support could make a significant contribution towards their own peace of mind if and when frail care is needed.
- Full Text:
- Date Issued: 2002
- Authors: Brink, F J
- Date: 2002
- Subjects: Older people -- Care -- South Africa , Frail elderly -- Medical care -- South Africa -- George , Frail elderly -- Care -- South Africa -- George
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10919 , http://hdl.handle.net/10948/84 , Older people -- Care -- South Africa , Frail elderly -- Medical care -- South Africa -- George , Frail elderly -- Care -- South Africa -- George
- Description: The world population is ageing, and this is also relevant to South Africa. At the same time the potential support ratio (the number of persons aged 15 to 64 years per one older person aged 65 years or older) is falling, and the dependency burden on potential workers increases. To alleviate the financial burden on the aged, and their families, it has become necessary to develop a financial plan to cover the cost of frail care. The overall purpose of this research is to determine whether any financial plans exist which are relevant. If nothing existed, a plan had to be developed. The research methodology for this study comprised the following steps: Firstly, the demographics of the world and South Africa were researched. The concept of frail (long-term) care in the United States of America and New Zealand was investigated to determine what is available. The subsidisation concept of the South African Government towards caring for the elderly was also investigated. Secondly, a questionnaire was sent to the residents of five retirement complexes in George to determine their interest in such a plan. The records of the frail care unit that these residents utilise were analysed to determine the number of residents needing frail care. A comparative study of the cost of frail care in the Southern Cape was undertaken. Thirdly, two options to partly subsidise the cost of frail care were examined, where the first option covers the running cost, and the second option, subsidising one third of the frail care cost, builds up a sustainable fund after the first five year period. The funds of the second option can then be utilised in the subsequent years to increase the subsidisation portion of frail care cost. The final step of this study entailed the formulation of recommendations to implement the frail care nursing levy as soon as possible, with special attention given to the following: a) It must be compulsory for new residents to join the fund. b) A yearly capital amount of R100 000 or more is needed to sustain the fund. c) A contract must be drafted to set out all the rules and regulations to the residents. d) An attitude change amongst some residents is required. Individuals must realise that the success of this plan depends upon themselves and with the necessary support could make a significant contribution towards their own peace of mind if and when frail care is needed.
- Full Text:
- Date Issued: 2002
A case study of the language policy in practice in the foundation phase of schooling
- Authors: Brookes, Margaret Ann
- Date: 2002
- Subjects: Language policy -- South Africa English language -- Study and teaching (Elementary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1442 , http://hdl.handle.net/10962/d1003323
- Description: This interpretative case study takes place in the foundation phase of a previously parallel medium school in the Eastern Cape. Learners from all three major language groups of the province (English, Xhosa and Afrikaans) are enrolled at the school. The study examines the language attitudes of teachers, parents and young learners and records their language practices in the classroom, the wider school environment and at home. Research carried out through this case study found that all stakeholders perceive English as the language of access to improved education and lifestyle. All young learners displayed a positive attitude to multilingualism and were keen to be able to speak all three provincial languages. The attitudes of their parents and teachers however differed from the learners and each other. The teachers and the English speaking parents were primarily concerned with the maintenance of the standards of English. The Afrikaans and Xhosa speaking parents were committed to their children developing proficient English language skills even if this meant supporting the development of their primary language and culture at home. Furthermore it was discovered that little attention had been paid to developing a school language policy in accordance with the new Language in Education Policy of July 1997. This policy promotes an additive approach to bilingualism and seeks to ensure that meaningful access to learning is provided for all children. By suggesting steps that could be taken by this school to develop their own language policy, the study highlights the necessity of recognising and remedying the gaps between policy and practice in the issue of language rights, identity and education in general.
- Full Text:
- Date Issued: 2002
- Authors: Brookes, Margaret Ann
- Date: 2002
- Subjects: Language policy -- South Africa English language -- Study and teaching (Elementary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1442 , http://hdl.handle.net/10962/d1003323
- Description: This interpretative case study takes place in the foundation phase of a previously parallel medium school in the Eastern Cape. Learners from all three major language groups of the province (English, Xhosa and Afrikaans) are enrolled at the school. The study examines the language attitudes of teachers, parents and young learners and records their language practices in the classroom, the wider school environment and at home. Research carried out through this case study found that all stakeholders perceive English as the language of access to improved education and lifestyle. All young learners displayed a positive attitude to multilingualism and were keen to be able to speak all three provincial languages. The attitudes of their parents and teachers however differed from the learners and each other. The teachers and the English speaking parents were primarily concerned with the maintenance of the standards of English. The Afrikaans and Xhosa speaking parents were committed to their children developing proficient English language skills even if this meant supporting the development of their primary language and culture at home. Furthermore it was discovered that little attention had been paid to developing a school language policy in accordance with the new Language in Education Policy of July 1997. This policy promotes an additive approach to bilingualism and seeks to ensure that meaningful access to learning is provided for all children. By suggesting steps that could be taken by this school to develop their own language policy, the study highlights the necessity of recognising and remedying the gaps between policy and practice in the issue of language rights, identity and education in general.
- Full Text:
- Date Issued: 2002
Process for the preparation of vanillin from a mixed m-cresol/p-cresol stream
- Authors: Buddoo, Subash
- Date: 2002
- Subjects: Vanillin
- Language: English
- Type: Thesis , Masters , MTech (Chemistry)
- Identifier: vital:10968 , http://hdl.handle.net/10948/138 , Vanillin
- Description: The Vanillin project was undertaken by AECI as it was believed that with the raw materials available from SASOL i.e. cresols, it would be possible to develop a process that would be globally competitive. A process for preparing both vanillin and ethyl vanillin was developed by AECI’s Research and Development Department using a mixed m- and p-cresol stream as feed. The displacement of bromide by methoxide is very successful when using a dimethyl formamide (DMF)/alcohol solvent system and excellent conversions (>95%) and selectivities (>95%) may be obtained. However, the use of DMF, which poses a serious chronic health risk, is unacceptable in this process since the products are intended for use as food and flavouring chemicals. In view of the above the main objectives of this study were: · To find a suitable alternative solvent system, which could produce comparable results while still being economically viable; · To develop an appropriate experimental protocol in the laboratory based on the alternative solvent system; · To determine the important reaction variables by conducting statistically designed experiments; · To optimise the reaction to produce a reproducible and robust experimental protocol; and · To test the reaction thoroughly at bench-scale level and to obtain experimental data for scale-up to pilot plant The most promising alternative solvent system was a methanol/methyl acetate mixture, which produced satisfactory results in the preliminary assessment (conversion of 98.3% and selectivity of 92.0%). DMA and acetonitrile also produced promising results but were not considered for further investigation because of toxicity and cost issues. A set of statistically designed experiments was carried out on the methanol/methyl acetate solvent system where four variables were tested i.e., substrate concentration, temperature, catalyst loading, and methanol to methyl acetate volume ratio. The experimentally determined response surface model showed that the most important variable was catalyst loading (63.2%) for conversion. With respect to selectivity, the most important variables were catalyst loading (31.9%) and methanol to methyl acetate ratio (33.1%). The optimum reaction conditions were as follows: · Temperature: 120°C · Methanol:methyl acetate: 15:1 vol/vol · Catalyst loading: 8 mol % to substrate · Substrate concentration: 22 %m/m on solvent · Catalyst: Copper(I) bromide · Sodium Equivalents: 2.7 wrt substrate · Time: 3 hours The optimum conditions were tested for reproducibility in a 1 Labmax pressure reactor. Replicated reactions, two at a 10% and two at a 20% substrate concentration gave conversions and selectivities all greater than 90%. Although the reaction mixture was a slurry at these concentrations, the reactions were very fast and virtually complete within the first hour (~95% conversion). Initial scale-up studies were conducted in an 8 Parr reactor where five reactions were carried out using the optimum conditions described above. The conversion of substrate and vanillin selectivity was consistently high and compared favourably to the Labmax reactions. The average conversion was 97.3% (96.3 to 98.5%) at an average selectivity of 98.2% (97.4 to 99.1%). A study of the reaction kinetics confirmed that the reaction was first order with respect to the substrate as a plot of substrate concentration versus reaction rate gave a straight line. The rate constant was calculated as 1.1096 k(h-1). The reaction mechanism proposed for the copper assisted nucleophilic aromatic substitution involves the formation of an adduct between sodium methoxide, methyl acetate and copper(I) bromide. The formation of a transient intermediate with the substrate allows intramolecular delivery of the methoxide ion to the aryl moiety through a CuI – CuIII type cycle.
- Full Text:
- Date Issued: 2002
- Authors: Buddoo, Subash
- Date: 2002
- Subjects: Vanillin
- Language: English
- Type: Thesis , Masters , MTech (Chemistry)
- Identifier: vital:10968 , http://hdl.handle.net/10948/138 , Vanillin
- Description: The Vanillin project was undertaken by AECI as it was believed that with the raw materials available from SASOL i.e. cresols, it would be possible to develop a process that would be globally competitive. A process for preparing both vanillin and ethyl vanillin was developed by AECI’s Research and Development Department using a mixed m- and p-cresol stream as feed. The displacement of bromide by methoxide is very successful when using a dimethyl formamide (DMF)/alcohol solvent system and excellent conversions (>95%) and selectivities (>95%) may be obtained. However, the use of DMF, which poses a serious chronic health risk, is unacceptable in this process since the products are intended for use as food and flavouring chemicals. In view of the above the main objectives of this study were: · To find a suitable alternative solvent system, which could produce comparable results while still being economically viable; · To develop an appropriate experimental protocol in the laboratory based on the alternative solvent system; · To determine the important reaction variables by conducting statistically designed experiments; · To optimise the reaction to produce a reproducible and robust experimental protocol; and · To test the reaction thoroughly at bench-scale level and to obtain experimental data for scale-up to pilot plant The most promising alternative solvent system was a methanol/methyl acetate mixture, which produced satisfactory results in the preliminary assessment (conversion of 98.3% and selectivity of 92.0%). DMA and acetonitrile also produced promising results but were not considered for further investigation because of toxicity and cost issues. A set of statistically designed experiments was carried out on the methanol/methyl acetate solvent system where four variables were tested i.e., substrate concentration, temperature, catalyst loading, and methanol to methyl acetate volume ratio. The experimentally determined response surface model showed that the most important variable was catalyst loading (63.2%) for conversion. With respect to selectivity, the most important variables were catalyst loading (31.9%) and methanol to methyl acetate ratio (33.1%). The optimum reaction conditions were as follows: · Temperature: 120°C · Methanol:methyl acetate: 15:1 vol/vol · Catalyst loading: 8 mol % to substrate · Substrate concentration: 22 %m/m on solvent · Catalyst: Copper(I) bromide · Sodium Equivalents: 2.7 wrt substrate · Time: 3 hours The optimum conditions were tested for reproducibility in a 1 Labmax pressure reactor. Replicated reactions, two at a 10% and two at a 20% substrate concentration gave conversions and selectivities all greater than 90%. Although the reaction mixture was a slurry at these concentrations, the reactions were very fast and virtually complete within the first hour (~95% conversion). Initial scale-up studies were conducted in an 8 Parr reactor where five reactions were carried out using the optimum conditions described above. The conversion of substrate and vanillin selectivity was consistently high and compared favourably to the Labmax reactions. The average conversion was 97.3% (96.3 to 98.5%) at an average selectivity of 98.2% (97.4 to 99.1%). A study of the reaction kinetics confirmed that the reaction was first order with respect to the substrate as a plot of substrate concentration versus reaction rate gave a straight line. The rate constant was calculated as 1.1096 k(h-1). The reaction mechanism proposed for the copper assisted nucleophilic aromatic substitution involves the formation of an adduct between sodium methoxide, methyl acetate and copper(I) bromide. The formation of a transient intermediate with the substrate allows intramolecular delivery of the methoxide ion to the aryl moiety through a CuI – CuIII type cycle.
- Full Text:
- Date Issued: 2002
A historical study of John Graham Lake and South African/United States pentecostalism
- Authors: Burpeau, Kemp Pendleton
- Date: 2002
- Subjects: Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2587 , http://hdl.handle.net/10962/d1006484 , Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Description: American minister John Graham Lake (1870-1935) was a pivotal participant in an era of profound religious and political transition. Surprisingly, Lake's often provocative life had previously been largely neglected as a field of academic inquiry. In the U.S. Lake associated with key Holiness, Wesleyan and Apostolic Faith charismatics like John Alexander Dowie of the Zion City, Illinois Utopia, Charles Parham of the Topeka Revival and William Seymour of the Azusa Street Revival. Lake served as an important intermediary between Parham's often reactionary, white orientation that was unreceptive to an enthusiastic black liturgy and Seymour's expansive African-American egalitarianism expressed through exuberant spirit manifestations. Lake's South African ministry was shaped by his middle class white business background, Azusa Street message and American perspectives. He brought together the faith healing movement inspired by Dutch Reformed minister Andrew Murray, P. Ie Roux's black and white Zion charismatic adherents affiliated with Dowie and the new U.S. Pentecostalism of Parham and Seymour. Lake's African-American influenced Pentecostalism was compatible with indigenous African worship. His emphasis on the spiritual needs of the disempowered found a receptive audience in talented black evangelists Elias Letwaba and Edward Lion. Even though acquainted with Mohandas Gandhi, Lake did not undertake a South African social gospel-type civil protest against societal injustice. In fact, Lake's participation with Afrikaner politicians like Louis Botha in fashioning a segregationist land use law was most troubling. Lake was ambivalent about racial integration. His belief in an egalitarian status for all Christians, his Populist/Progressive ethics and his enthusiastic promotion of women's rights were complicated by his advocacy, or at least tolerance, of some disparate racial treatment in his Apostolic Faith Mission and South African society at large. Lake's paternalism and notion of Westem cultural superiority conflicted with his love of all persons. Lake's otherworldly prioritization of individual spiritualism over a socioeconomic agenda usually stymied activism. His uncharacteristic use of nonviolent protest to protect faith healing formed a remarkable contrast with his reluctance to actively campaign against unequal racial treatment in Africa and America. Historiographical perspectives on Lake range from the saintly pioneer charismatic missionary to the Elmer Gantry type charlatan acting only for personal benefit. Lake was a unique personality with his flamboyant rhetoric, strong convictions and feelings of personal worth. His distinctive Jesus as healing and suffering God theology evidenced both consistency with precedent as well as creative anticipation. Shortcomings resulting from his preference to address social concerns on an individual spiritual rather than societal level, his liberties with truth and his bad business judgments resulting in litigation. Nevertheless, Lake's life demonstrated that a gifted but imperfect instrument could accomplish a meaningful ministry. , Adobe Acrobat Pro 9.5.4 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
- Authors: Burpeau, Kemp Pendleton
- Date: 2002
- Subjects: Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2587 , http://hdl.handle.net/10962/d1006484 , Lake, John G , Pentecostalism -- South Africa , Pentecostalism -- United States , Pentecostals , Christianity and politics -- South Africa
- Description: American minister John Graham Lake (1870-1935) was a pivotal participant in an era of profound religious and political transition. Surprisingly, Lake's often provocative life had previously been largely neglected as a field of academic inquiry. In the U.S. Lake associated with key Holiness, Wesleyan and Apostolic Faith charismatics like John Alexander Dowie of the Zion City, Illinois Utopia, Charles Parham of the Topeka Revival and William Seymour of the Azusa Street Revival. Lake served as an important intermediary between Parham's often reactionary, white orientation that was unreceptive to an enthusiastic black liturgy and Seymour's expansive African-American egalitarianism expressed through exuberant spirit manifestations. Lake's South African ministry was shaped by his middle class white business background, Azusa Street message and American perspectives. He brought together the faith healing movement inspired by Dutch Reformed minister Andrew Murray, P. Ie Roux's black and white Zion charismatic adherents affiliated with Dowie and the new U.S. Pentecostalism of Parham and Seymour. Lake's African-American influenced Pentecostalism was compatible with indigenous African worship. His emphasis on the spiritual needs of the disempowered found a receptive audience in talented black evangelists Elias Letwaba and Edward Lion. Even though acquainted with Mohandas Gandhi, Lake did not undertake a South African social gospel-type civil protest against societal injustice. In fact, Lake's participation with Afrikaner politicians like Louis Botha in fashioning a segregationist land use law was most troubling. Lake was ambivalent about racial integration. His belief in an egalitarian status for all Christians, his Populist/Progressive ethics and his enthusiastic promotion of women's rights were complicated by his advocacy, or at least tolerance, of some disparate racial treatment in his Apostolic Faith Mission and South African society at large. Lake's paternalism and notion of Westem cultural superiority conflicted with his love of all persons. Lake's otherworldly prioritization of individual spiritualism over a socioeconomic agenda usually stymied activism. His uncharacteristic use of nonviolent protest to protect faith healing formed a remarkable contrast with his reluctance to actively campaign against unequal racial treatment in Africa and America. Historiographical perspectives on Lake range from the saintly pioneer charismatic missionary to the Elmer Gantry type charlatan acting only for personal benefit. Lake was a unique personality with his flamboyant rhetoric, strong convictions and feelings of personal worth. His distinctive Jesus as healing and suffering God theology evidenced both consistency with precedent as well as creative anticipation. Shortcomings resulting from his preference to address social concerns on an individual spiritual rather than societal level, his liberties with truth and his bad business judgments resulting in litigation. Nevertheless, Lake's life demonstrated that a gifted but imperfect instrument could accomplish a meaningful ministry. , Adobe Acrobat Pro 9.5.4 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
An investigation into the conflict management styles used in organisations with special reference to some organisations in the northern region of the Eastern Cape Province
- Authors: Bwowe, Patrick W
- Date: 2002
- Subjects: Conflict management -- South Africa -- Eastern Provice
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10911 , http://hdl.handle.net/10948/103 , Conflict management -- South Africa -- Eastern Provice
- Description: common and in most cases unavoidable. Because of this, it has become critical for managers to start evaluating the styles they use in managing conflict and to assess the implications of these styles to the benefits and costs of conflict. In order to meet this challenge, managers must understand the nature, sources and the outcome of conflict. It is by reflecting on the above, that managers may become more informed about the right conflict management approach to apply. This research deals with an investigation into the conflict management styles used by managers in organisations. It seeks to identify the styles currently used and to establish whether there is any correlation between these styles and the conflict management styles identified in the literature survey. The study targeted six health institutions in the Northern Region of the Eastern Cape Province. Findings from the literature study revealed two main approaches to managing conflict. These were: the Resolution and the Stimulating approaches. Five conflict management styles were identified when the resolution technique is used. These included: Collaboration, Avoidance, Accommodating, Compromise and the Dominating styles. Five approaches for stimulating functional conflict in organisations were also identified.They included the following: use of programmed conflict, manipulation of communication channels, encouraging competition among employees, encouraging the use structured debates and changing the organisational structure and culture. A research questionnaire and personal interviews were used for collecting data. The Questionnaire sought to establish the conflict management styles currently used in organisations while the interview’s aim was to probe deeper and to establish the participants’ view of the factors which determine one’s preferred conflict handling style and also to assess to what extent managers understand contemporary approaches to managing conflict such as conflict stimulation. The study revealed that the conflict management styles used by managers are similar to those identified in the literature review. It also emerged that managers are not very knowledgeable about the view of managing conflict by stimulating it. This highlighted the importance for further research into managing conflict by means of the stimulation approach.
- Full Text:
- Date Issued: 2002
- Authors: Bwowe, Patrick W
- Date: 2002
- Subjects: Conflict management -- South Africa -- Eastern Provice
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10911 , http://hdl.handle.net/10948/103 , Conflict management -- South Africa -- Eastern Provice
- Description: common and in most cases unavoidable. Because of this, it has become critical for managers to start evaluating the styles they use in managing conflict and to assess the implications of these styles to the benefits and costs of conflict. In order to meet this challenge, managers must understand the nature, sources and the outcome of conflict. It is by reflecting on the above, that managers may become more informed about the right conflict management approach to apply. This research deals with an investigation into the conflict management styles used by managers in organisations. It seeks to identify the styles currently used and to establish whether there is any correlation between these styles and the conflict management styles identified in the literature survey. The study targeted six health institutions in the Northern Region of the Eastern Cape Province. Findings from the literature study revealed two main approaches to managing conflict. These were: the Resolution and the Stimulating approaches. Five conflict management styles were identified when the resolution technique is used. These included: Collaboration, Avoidance, Accommodating, Compromise and the Dominating styles. Five approaches for stimulating functional conflict in organisations were also identified.They included the following: use of programmed conflict, manipulation of communication channels, encouraging competition among employees, encouraging the use structured debates and changing the organisational structure and culture. A research questionnaire and personal interviews were used for collecting data. The Questionnaire sought to establish the conflict management styles currently used in organisations while the interview’s aim was to probe deeper and to establish the participants’ view of the factors which determine one’s preferred conflict handling style and also to assess to what extent managers understand contemporary approaches to managing conflict such as conflict stimulation. The study revealed that the conflict management styles used by managers are similar to those identified in the literature review. It also emerged that managers are not very knowledgeable about the view of managing conflict by stimulating it. This highlighted the importance for further research into managing conflict by means of the stimulation approach.
- Full Text:
- Date Issued: 2002