Physiological and psychophysical responses of male soldiers to changes in marching gradient, speed and load
- Authors: Todd, Andrew Ivan
- Date: 2002
- Subjects: Soldiers -- South Africa -- Physiology , South Africa Army -- Physical training , Marching -- Physiological aspects , Psychophysiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5129 , http://hdl.handle.net/10962/d1005208 , Soldiers -- South Africa -- Physiology , South Africa Army -- Physical training , Marching -- Physiological aspects , Psychophysiology
- Description: The present study sought to investigate the effects of changes in gradient, under apparently optimal combinations of speed and load, on selected physiological, psychophysical and biophysical responses of military personnel. Subjects (n = 32) were required to march under level (0%), downhill (-10%) and uphill (+10%) conditions. Under each gradient, subjects marched with the following speed-load combinations: 4 km.h-1 carrying 50 kg, 5 km.h-1 carrying 35 kg and 6 km.h-1 carrying 20 kg, a total of nine experimental conditions. Subjects were required to march for six minutes under each condition. Physiological responses (HR, VO2, R, Br, VE, VT, EE) indicated that subjects were not overly taxed by the three speed-load combinations during level marching, which elicited submaximal demands. Furthermore, the results revealed that downhill marching with heavy loads results in similar responses to level marching, while lighter loads may result in significant reductions in physical demands compared to level marching. The physiological responses to uphill marching revealed that subjects were severely physically taxed under these conditions, regardless of speed-load combination. It is unlikely that soldiers would be able to maintain these intensities for an extended period without undue fatigue. It is evident from the psychophysical responses (Rating of Perceived Exertion and Body Discomfort) that subjects perceived the heavy load conditions, regardless of gradient, to be the most stressful on the cardiovascular and muscular systems. The positive gradient conditions also elicited elevated RPE and Body Discomfort responses, while lighter load downhill conditions were perceived to result in the least strain.
- Full Text:
- Date Issued: 2002
- Authors: Todd, Andrew Ivan
- Date: 2002
- Subjects: Soldiers -- South Africa -- Physiology , South Africa Army -- Physical training , Marching -- Physiological aspects , Psychophysiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5129 , http://hdl.handle.net/10962/d1005208 , Soldiers -- South Africa -- Physiology , South Africa Army -- Physical training , Marching -- Physiological aspects , Psychophysiology
- Description: The present study sought to investigate the effects of changes in gradient, under apparently optimal combinations of speed and load, on selected physiological, psychophysical and biophysical responses of military personnel. Subjects (n = 32) were required to march under level (0%), downhill (-10%) and uphill (+10%) conditions. Under each gradient, subjects marched with the following speed-load combinations: 4 km.h-1 carrying 50 kg, 5 km.h-1 carrying 35 kg and 6 km.h-1 carrying 20 kg, a total of nine experimental conditions. Subjects were required to march for six minutes under each condition. Physiological responses (HR, VO2, R, Br, VE, VT, EE) indicated that subjects were not overly taxed by the three speed-load combinations during level marching, which elicited submaximal demands. Furthermore, the results revealed that downhill marching with heavy loads results in similar responses to level marching, while lighter loads may result in significant reductions in physical demands compared to level marching. The physiological responses to uphill marching revealed that subjects were severely physically taxed under these conditions, regardless of speed-load combination. It is unlikely that soldiers would be able to maintain these intensities for an extended period without undue fatigue. It is evident from the psychophysical responses (Rating of Perceived Exertion and Body Discomfort) that subjects perceived the heavy load conditions, regardless of gradient, to be the most stressful on the cardiovascular and muscular systems. The positive gradient conditions also elicited elevated RPE and Body Discomfort responses, while lighter load downhill conditions were perceived to result in the least strain.
- 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
Promotion of liberal values in South African foreign policy : beyond the structural imperatives of the international system?
- Authors: Mkalipi, Zanethemba
- Date: 2002
- Subjects: South Africa -- Foreign relations
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2865 , http://hdl.handle.net/10962/d1007662 , South Africa -- Foreign relations
- Description: The end of the Cold War in the early 1990s led to a multilateral international system no longer divided by contending forces of capitalism and communism. In the context of South Africa, the end of the Cold War occurred at a juncture where the apartheid government was being challenged by pro-democracy forces that have fought against it for decades. The developments in the international system and in the country led to South Africa adopting universal liberal values not only in its constitution, but also in its international relations. Foreign policy documents and statements by the ministry of Foreign Affairs also reflected the country's aspiration of becoming a mediator, a facilitator for democracy and a peacemaker especially in the context of Africa. International expectation mounted as South Africa was perceived as possessing the capacity to act in a manner that advances democratic values and which gives voice to the weak nations of the world. However, the aura of a post-apartheid South Africa that would act not only in its interest, but also in the interest of the world community never fully materialised. South Africa failed to act in a manner consistent with its stated commitment to democratic values when it recognised Peoples Republic of China, an undemocratic and repressive government. It also marched into Lesotho in 1998, resulting in the destabilisation of this tiny Southern African country. These events led to an increasing criticism of the South African government. Some argued that South Africa was still inexperienced given its recent emergence as a world player. Others blamed the inconsistency on a too broad and ambitious foreign policy that set itself for failure. This study seeks to contribute to the conceptual understanding of the debate regarding the ambiguous nature of South Africa's foreign policy behaviour. It situates the conceptualisation of South Africa's foreign policy within the predominant debates in international relations between realism, political structuralism and pluralism. Firstly, it holds that the end of the Cold War and ascendancy of globalist conceptions of international relations did not lead to the inadequacy of political structuralism as an organising framework. Secondly, it attempts to clarify the gap between South Africa's foreign policy and foreign policy behaviour by employing the assumptions advanced by political structuralism, Thirdly, a case study of South Africa's foreign policy towards China, Lesotho, the Great Lakes and Swaziland is carried out. Here it is demonstrated that the ambiguities of South Africa's foreign policy are a function of the constraints imposed by the political and economic structure of the international system, It draws its conclusion by providing methodological recommendations to South Africa's foreign policy makers and future researchers in the field of foreign policy analysis.
- Full Text:
- Date Issued: 2002
- Authors: Mkalipi, Zanethemba
- Date: 2002
- Subjects: South Africa -- Foreign relations
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2865 , http://hdl.handle.net/10962/d1007662 , South Africa -- Foreign relations
- Description: The end of the Cold War in the early 1990s led to a multilateral international system no longer divided by contending forces of capitalism and communism. In the context of South Africa, the end of the Cold War occurred at a juncture where the apartheid government was being challenged by pro-democracy forces that have fought against it for decades. The developments in the international system and in the country led to South Africa adopting universal liberal values not only in its constitution, but also in its international relations. Foreign policy documents and statements by the ministry of Foreign Affairs also reflected the country's aspiration of becoming a mediator, a facilitator for democracy and a peacemaker especially in the context of Africa. International expectation mounted as South Africa was perceived as possessing the capacity to act in a manner that advances democratic values and which gives voice to the weak nations of the world. However, the aura of a post-apartheid South Africa that would act not only in its interest, but also in the interest of the world community never fully materialised. South Africa failed to act in a manner consistent with its stated commitment to democratic values when it recognised Peoples Republic of China, an undemocratic and repressive government. It also marched into Lesotho in 1998, resulting in the destabilisation of this tiny Southern African country. These events led to an increasing criticism of the South African government. Some argued that South Africa was still inexperienced given its recent emergence as a world player. Others blamed the inconsistency on a too broad and ambitious foreign policy that set itself for failure. This study seeks to contribute to the conceptual understanding of the debate regarding the ambiguous nature of South Africa's foreign policy behaviour. It situates the conceptualisation of South Africa's foreign policy within the predominant debates in international relations between realism, political structuralism and pluralism. Firstly, it holds that the end of the Cold War and ascendancy of globalist conceptions of international relations did not lead to the inadequacy of political structuralism as an organising framework. Secondly, it attempts to clarify the gap between South Africa's foreign policy and foreign policy behaviour by employing the assumptions advanced by political structuralism, Thirdly, a case study of South Africa's foreign policy towards China, Lesotho, the Great Lakes and Swaziland is carried out. Here it is demonstrated that the ambiguities of South Africa's foreign policy are a function of the constraints imposed by the political and economic structure of the international system, It draws its conclusion by providing methodological recommendations to South Africa's foreign policy makers and future researchers in the field of foreign policy analysis.
- Full Text:
- Date Issued: 2002
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
Reading William Blake and T.S. Eliot: contrary poets, progressive vision
- Authors: Rayneard, Max James Anthony
- Date: 2002
- Subjects: Blake, William, 1757-1827 -- Criticism and interpretation , Eliot, T. S. (Thomas Stearns), 1888-1965 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2279 , http://hdl.handle.net/10962/d1007545 , Blake, William, 1757-1827 -- Criticism and interpretation , Eliot, T. S. (Thomas Stearns), 1888-1965 -- Criticism and interpretation
- Description: Many critics resort to explaining readers' experiences of poems like William Blake's Jerusalem and T.S. Eliot's Four Quartets in terms of "spirituality" or "religion". These experiences are broadly defined in this thesis as jouissance (after Roland Barthes' essay The Pleasure of the Text) or "experience qua experience". Critical attempts at the reduction of jouissance into abstract constructs serve merely as stopgap measures by which critics might avoid having to account for the limits of their own rational discourse. These poems, in particular, are deliberately structured to preserve the reader's experience of the poem from reduction to any particular meta-discursive construct, including "the spiritual". Through a broad application of Rezeption-Asthetik principles, this thesis demonstrates how the poems are structured to direct readers' faculties to engage with the hypothetical realm within which jouissance occurs, beyond the rationally abstractable. T.S. Eliot's poetic oeuvre appears to chart his growing confidence in non-rational, pre-critical faculties. Through "The Love Song of J. Alfred Prufrock", The Waste Land, and Four Quartets, Eliot's poetry becomes gradually less prescriptive of the terms to which the experience of his poetry might be reduced. In Four Quartets he finally entrusts readers with a great deal of responsibility for "co-creating" the poem's significance. Like T.S . Eliot, although more consistently throughout his oeuvre, William Blake is similarly concerned with the validation of the reader's subjective interpretative/creative faculties. Blake's Jerusalem is carefully structured on various intertwined levels to rouse and exercise in the reader what the poet calls the "All Glorious Imagination" (Keynes 1972: 679). The jouissance of Jerusalem or Four Quartets is located in the reader's efforts to co-create the significance of the poems. It is only during a direct engagement with this process, rather than in subsequent attempts to abstract it, that the "experience qua experience" may be understood.
- Full Text:
- Date Issued: 2002
- Authors: Rayneard, Max James Anthony
- Date: 2002
- Subjects: Blake, William, 1757-1827 -- Criticism and interpretation , Eliot, T. S. (Thomas Stearns), 1888-1965 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2279 , http://hdl.handle.net/10962/d1007545 , Blake, William, 1757-1827 -- Criticism and interpretation , Eliot, T. S. (Thomas Stearns), 1888-1965 -- Criticism and interpretation
- Description: Many critics resort to explaining readers' experiences of poems like William Blake's Jerusalem and T.S. Eliot's Four Quartets in terms of "spirituality" or "religion". These experiences are broadly defined in this thesis as jouissance (after Roland Barthes' essay The Pleasure of the Text) or "experience qua experience". Critical attempts at the reduction of jouissance into abstract constructs serve merely as stopgap measures by which critics might avoid having to account for the limits of their own rational discourse. These poems, in particular, are deliberately structured to preserve the reader's experience of the poem from reduction to any particular meta-discursive construct, including "the spiritual". Through a broad application of Rezeption-Asthetik principles, this thesis demonstrates how the poems are structured to direct readers' faculties to engage with the hypothetical realm within which jouissance occurs, beyond the rationally abstractable. T.S. Eliot's poetic oeuvre appears to chart his growing confidence in non-rational, pre-critical faculties. Through "The Love Song of J. Alfred Prufrock", The Waste Land, and Four Quartets, Eliot's poetry becomes gradually less prescriptive of the terms to which the experience of his poetry might be reduced. In Four Quartets he finally entrusts readers with a great deal of responsibility for "co-creating" the poem's significance. Like T.S . Eliot, although more consistently throughout his oeuvre, William Blake is similarly concerned with the validation of the reader's subjective interpretative/creative faculties. Blake's Jerusalem is carefully structured on various intertwined levels to rouse and exercise in the reader what the poet calls the "All Glorious Imagination" (Keynes 1972: 679). The jouissance of Jerusalem or Four Quartets is located in the reader's efforts to co-create the significance of the poems. It is only during a direct engagement with this process, rather than in subsequent attempts to abstract it, that the "experience qua experience" may be understood.
- Full Text:
- Date Issued: 2002
Reconciling Western and African philosophy : rationality, culture and communitarianism
- Authors: Vitsha, Xolisa
- Date: 2002
- Subjects: Philosophy, African , Africa -- Intellectual life , Philosophy, Comparative , Philosophy , Communitarianism , Self
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2838 , http://hdl.handle.net/10962/d1003807 , Philosophy, African , Africa -- Intellectual life , Philosophy, Comparative , Philosophy , Communitarianism , Self
- Description: This thesis attempts to reconcile Western and African philosophy with specific reference to the issues of rationality, culture and communitarianism. It also discusses the post-Enlightenment, Western philosophical concept of liberal "atomism" and the primacy of the individual and the emergence of a communitarian critique in response. This thesis intends exploring how Western notions of individuality and the communitarian response can be reconciled with contemporary African philosophy and African communitarian thought in particular. To do this, it is necessary to explore the problem of liberal individualism and how African communitarianism might reinforce the Western communitarian critique. African communitarianism has a processual understanding of personhood that underpins its conception of the Self. In contrast to this view, Western communitarianism has a relational conception of the individual Self. Thus, this thesis argues that African communitarianism has a more profound understanding of the constitution of the Self. To demonstrate these claims, this study discusses notions of rationality which inform each of the philosophical traditions. This will enable a comparative analysis of the above-mentioned philosophical traditions with the intention of uncovering the concepts that provide the platform for their reconciliation.
- Full Text:
- Date Issued: 2002
- Authors: Vitsha, Xolisa
- Date: 2002
- Subjects: Philosophy, African , Africa -- Intellectual life , Philosophy, Comparative , Philosophy , Communitarianism , Self
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2838 , http://hdl.handle.net/10962/d1003807 , Philosophy, African , Africa -- Intellectual life , Philosophy, Comparative , Philosophy , Communitarianism , Self
- Description: This thesis attempts to reconcile Western and African philosophy with specific reference to the issues of rationality, culture and communitarianism. It also discusses the post-Enlightenment, Western philosophical concept of liberal "atomism" and the primacy of the individual and the emergence of a communitarian critique in response. This thesis intends exploring how Western notions of individuality and the communitarian response can be reconciled with contemporary African philosophy and African communitarian thought in particular. To do this, it is necessary to explore the problem of liberal individualism and how African communitarianism might reinforce the Western communitarian critique. African communitarianism has a processual understanding of personhood that underpins its conception of the Self. In contrast to this view, Western communitarianism has a relational conception of the individual Self. Thus, this thesis argues that African communitarianism has a more profound understanding of the constitution of the Self. To demonstrate these claims, this study discusses notions of rationality which inform each of the philosophical traditions. This will enable a comparative analysis of the above-mentioned philosophical traditions with the intention of uncovering the concepts that provide the platform for their reconciliation.
- Full Text:
- Date Issued: 2002
Reengineering the business processes in small, medium and micro enterprises (SMME'S) in order to improve profitability
- Authors: Figg, Malcolm John
- Date: 2002
- Subjects: Reengineering (Management)
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10850 , http://hdl.handle.net/10948/112 , Reengineering (Management)
- Description: The research problem addressed in this study was to identify guidelines to improve business processes that will enhance the ability of Small, Medium, and Micro Enterprises (SMME’s) to be able to operate competitively in local and global markets. Reengineering of business processes (BPR) is necessary because of internal factors such as increasing global competition, increasing domestic competition, new technologies, industry overcapacity, shrinking markets and increasing pressure from suppliers. There are also various external factors that influence the necessity to reengineer business processes. These factors include increasing cost structure, declining profitability, declining sales, low productivity, inadequate employee skills and less efficiency in operations. In order to identify guidelines that will enhance SMME’s performance, questionnaires with relevant questions were used . The findings of the literature survey clearly highlights the specific areas where attention is required for improvements.
- Full Text:
- Date Issued: 2002
- Authors: Figg, Malcolm John
- Date: 2002
- Subjects: Reengineering (Management)
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10850 , http://hdl.handle.net/10948/112 , Reengineering (Management)
- Description: The research problem addressed in this study was to identify guidelines to improve business processes that will enhance the ability of Small, Medium, and Micro Enterprises (SMME’s) to be able to operate competitively in local and global markets. Reengineering of business processes (BPR) is necessary because of internal factors such as increasing global competition, increasing domestic competition, new technologies, industry overcapacity, shrinking markets and increasing pressure from suppliers. There are also various external factors that influence the necessity to reengineer business processes. These factors include increasing cost structure, declining profitability, declining sales, low productivity, inadequate employee skills and less efficiency in operations. In order to identify guidelines that will enhance SMME’s performance, questionnaires with relevant questions were used . The findings of the literature survey clearly highlights the specific areas where attention is required for improvements.
- Full Text:
- Date Issued: 2002
Relationship between temparament and linear body parameters of beef cattle under communal grazing system
- Authors: Nekhofhe, Avhasei Justice
- Date: 2002
- Subjects: Cattle , Grazing
- Language: English
- Type: Thesis , Masters , MTech (Agricultural Management)
- Identifier: vital:10965 , http://hdl.handle.net/10948/113 , Cattle , Grazing
- Description: Introduction : Indigenous cattle are mostly reared where the traditional farming is practiced including Northern Region of South Africa. The majority of farmers own Nguni type of cattle although other breeds are found in the region. They perform well under harsh conditions and they seem to produce better under intensive management. However, communal farmers are becoming aware and interested in indigenous breeds especially Nguni cattle type because of their adaptability. Beef cattle production and research require constant movement and handling of livestock (Erf et al., 1992 & Grandin, 1993). Dipping, castration, branding, ear-tagging and counting is commonly practiced as beef cattle management norms hence dehorning are partly practiced as some of the animals had horns which were disturbing them to pass through crushpens and as a result they increased bruising to other animals. At Matatani and Muledzhi areas animals including calves are packed in the crushpens, counted, weighed and temperament traits were also measured on the scale and this is done in order to document the information for this research and future use. Temperament is a behavioural response of animals as handled by man. It is important to be measured in beef cattle farmers under communal grazing conditions as it reduces farmer’s profit and it makes the stock man’s work unpleasant. Therefore, it is also needs to be improved for the improvement of beef cattle schemes. Management system of communal farmers was not conducive to better quality meat due to horns in some animals which ultimately cause bruising in other animals. However, exotic bulls were bought at random for the improvement of other breed types found in these two areas. The focus of this study is almost in Nguni cattle type managed under communal grazing system. Lastly, the purpose of this study is to determine behavioral response of beef cattle under communal management system at their dipping tanks.
- Full Text:
- Date Issued: 2002
- Authors: Nekhofhe, Avhasei Justice
- Date: 2002
- Subjects: Cattle , Grazing
- Language: English
- Type: Thesis , Masters , MTech (Agricultural Management)
- Identifier: vital:10965 , http://hdl.handle.net/10948/113 , Cattle , Grazing
- Description: Introduction : Indigenous cattle are mostly reared where the traditional farming is practiced including Northern Region of South Africa. The majority of farmers own Nguni type of cattle although other breeds are found in the region. They perform well under harsh conditions and they seem to produce better under intensive management. However, communal farmers are becoming aware and interested in indigenous breeds especially Nguni cattle type because of their adaptability. Beef cattle production and research require constant movement and handling of livestock (Erf et al., 1992 & Grandin, 1993). Dipping, castration, branding, ear-tagging and counting is commonly practiced as beef cattle management norms hence dehorning are partly practiced as some of the animals had horns which were disturbing them to pass through crushpens and as a result they increased bruising to other animals. At Matatani and Muledzhi areas animals including calves are packed in the crushpens, counted, weighed and temperament traits were also measured on the scale and this is done in order to document the information for this research and future use. Temperament is a behavioural response of animals as handled by man. It is important to be measured in beef cattle farmers under communal grazing conditions as it reduces farmer’s profit and it makes the stock man’s work unpleasant. Therefore, it is also needs to be improved for the improvement of beef cattle schemes. Management system of communal farmers was not conducive to better quality meat due to horns in some animals which ultimately cause bruising in other animals. However, exotic bulls were bought at random for the improvement of other breed types found in these two areas. The focus of this study is almost in Nguni cattle type managed under communal grazing system. Lastly, the purpose of this study is to determine behavioral response of beef cattle under communal management system at their dipping tanks.
- Full Text:
- Date Issued: 2002
Representations of women in women's magazines
- Authors: Ndzamela, Viwe
- Date: 2002
- Subjects: Women in mass media , Women's periodicals, South African
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3475 , http://hdl.handle.net/10962/d1002930 , Women in mass media , Women's periodicals, South African
- Description: Women’s magazines as a popular form of entertainment are among the media products that have been criticised for misrepresenting women. These popular magazines are often condemned for their failure to represent women in a positive light although they claim to target women as their market. The objective of this research is to assess and analyse representations of women in selected women’s magazines. Because women’s magazines are part of popular culture, which is not only concerned with the production process but also takes into consideration the needs of the readers, the research seeks to find out whether these magazines meet the expectations of its readers. The study is a combination of qualitative analysis, which looks at the frequency and the manner in which women are represented, with a qualitative interpretation of women’s roles within those representations. The issue of representations of women in women’s magazines is a very complex one as magazines, like other cultural texts are open to multiple interpretations. Consequently, multiple conclusions have been reached and the outcome of the study is therefore a series of three conclusions based on feature articles, advertisements and at a theoretical level.
- Full Text:
- Date Issued: 2002
- Authors: Ndzamela, Viwe
- Date: 2002
- Subjects: Women in mass media , Women's periodicals, South African
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3475 , http://hdl.handle.net/10962/d1002930 , Women in mass media , Women's periodicals, South African
- Description: Women’s magazines as a popular form of entertainment are among the media products that have been criticised for misrepresenting women. These popular magazines are often condemned for their failure to represent women in a positive light although they claim to target women as their market. The objective of this research is to assess and analyse representations of women in selected women’s magazines. Because women’s magazines are part of popular culture, which is not only concerned with the production process but also takes into consideration the needs of the readers, the research seeks to find out whether these magazines meet the expectations of its readers. The study is a combination of qualitative analysis, which looks at the frequency and the manner in which women are represented, with a qualitative interpretation of women’s roles within those representations. The issue of representations of women in women’s magazines is a very complex one as magazines, like other cultural texts are open to multiple interpretations. Consequently, multiple conclusions have been reached and the outcome of the study is therefore a series of three conclusions based on feature articles, advertisements and at a theoretical level.
- Full Text:
- Date Issued: 2002
Research projects
- Authors: Thomas, Chacko
- Date: 2002
- Subjects: Mathematics -- Study and teaching -- South Africa Competency-based education -- South Africa Mathematics teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1856 , http://hdl.handle.net/10962/d1004531
- Description: The South African education is undergoing transformation. The introduction of Curriculum 2005 and Outcome Based Education (OBE) are important aspects of this transformation process. The implementation of the new curriculum however, has not been smooth. A lack of adequately qualified and trained teachers and effective learning support materials have been identified as some of the major problems facing the implementation of OBE at school level. Even though the colleges of education in the country were not brought on board in the planning and implementation levels of the new curriculum, they could have played an important role in training of educators and developing learning materials for the successful take off of the new curriculum. In the first research project I look into the preparedness of the Mathematics Department of a college of education in the Eastern Cape towards the implementation of Outcome Based Education. The first part of the research project consists of a literature review on Curriculum 2005, Outcome Based Education and the expectations of teachers in the new curriculum and the research methodologies used. The findings revealed that the department, as a whole, was not adequately prepared for the implementation of outcome-based education even though there were some indications that the department effected some modifications in its curriculum and practice teaching. As an OBE facilitator and a college lecturer, I developed some learning materials in Linear Programming. These activity-oriented materials were based on constructivist principles and were used by my first year Secondary Teachers Diploma students. In the second research project, I reflect on the results of using these learning materials by my students. In the first chapter of the project, the context and background of the research and the reasons for selecting Linear Programming as the topic for preparing the learning material are described. This is followed by a brief overview of constructivism together with a brief explanation of the reasons for considering the material to be constructivist. The research paradigm followed in the project, the research techniques employed in evaluating the learning material and the strengths and weaknesses of the evaluation techniques are given in the next chapter. In the following chapter, the findings from the various data gathering methods and the results of the implementation of the material are described. The concluding chapter presents a critical reflection on the whole process involved in the material development. The post 1994 government in South Africa seems to attach much importance to mathematics, science and technology education. The majority of the population who were previously denied access to these subjects is given more opportunities to learn them. The international Mathematics Union declared 2000 as the World Mathematical Year. One of the aims of the activities organized as part of the celebrations was improving the public image of mathematics to realize the vision of "Mathematics For All". The South African government shows keen interest to improve mathematics education in the country in an attempt to realize the vision of Mathematics For All. Even though the accessibility rate to mathematics has increased, the success rate has not yet increased as anticipated. In this context I, as a post-graduate student in Mathematics Education, thought of /reviewing the concept of Mathematics For All in the South African context. In the third research project, which is a literature review, initially an attempt is made to unpack the concept of Mathematics for ALL. In analyzing the concept, answers are sought for questions like: What is mathematics and why should it be taught? It is followed by a brief review of some goals of mathematics education. Then the current situation of mathematics education in South Africa and the efforts to improve it are also looked at. This is followed by an analysis pf the reasons for the general unpopularity of mathematics. In the concluding part some suggestions for improving mathematics education in the country are given.
- Full Text:
- Date Issued: 2002
- Authors: Thomas, Chacko
- Date: 2002
- Subjects: Mathematics -- Study and teaching -- South Africa Competency-based education -- South Africa Mathematics teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1856 , http://hdl.handle.net/10962/d1004531
- Description: The South African education is undergoing transformation. The introduction of Curriculum 2005 and Outcome Based Education (OBE) are important aspects of this transformation process. The implementation of the new curriculum however, has not been smooth. A lack of adequately qualified and trained teachers and effective learning support materials have been identified as some of the major problems facing the implementation of OBE at school level. Even though the colleges of education in the country were not brought on board in the planning and implementation levels of the new curriculum, they could have played an important role in training of educators and developing learning materials for the successful take off of the new curriculum. In the first research project I look into the preparedness of the Mathematics Department of a college of education in the Eastern Cape towards the implementation of Outcome Based Education. The first part of the research project consists of a literature review on Curriculum 2005, Outcome Based Education and the expectations of teachers in the new curriculum and the research methodologies used. The findings revealed that the department, as a whole, was not adequately prepared for the implementation of outcome-based education even though there were some indications that the department effected some modifications in its curriculum and practice teaching. As an OBE facilitator and a college lecturer, I developed some learning materials in Linear Programming. These activity-oriented materials were based on constructivist principles and were used by my first year Secondary Teachers Diploma students. In the second research project, I reflect on the results of using these learning materials by my students. In the first chapter of the project, the context and background of the research and the reasons for selecting Linear Programming as the topic for preparing the learning material are described. This is followed by a brief overview of constructivism together with a brief explanation of the reasons for considering the material to be constructivist. The research paradigm followed in the project, the research techniques employed in evaluating the learning material and the strengths and weaknesses of the evaluation techniques are given in the next chapter. In the following chapter, the findings from the various data gathering methods and the results of the implementation of the material are described. The concluding chapter presents a critical reflection on the whole process involved in the material development. The post 1994 government in South Africa seems to attach much importance to mathematics, science and technology education. The majority of the population who were previously denied access to these subjects is given more opportunities to learn them. The international Mathematics Union declared 2000 as the World Mathematical Year. One of the aims of the activities organized as part of the celebrations was improving the public image of mathematics to realize the vision of "Mathematics For All". The South African government shows keen interest to improve mathematics education in the country in an attempt to realize the vision of Mathematics For All. Even though the accessibility rate to mathematics has increased, the success rate has not yet increased as anticipated. In this context I, as a post-graduate student in Mathematics Education, thought of /reviewing the concept of Mathematics For All in the South African context. In the third research project, which is a literature review, initially an attempt is made to unpack the concept of Mathematics for ALL. In analyzing the concept, answers are sought for questions like: What is mathematics and why should it be taught? It is followed by a brief review of some goals of mathematics education. Then the current situation of mathematics education in South Africa and the efforts to improve it are also looked at. This is followed by an analysis pf the reasons for the general unpopularity of mathematics. In the concluding part some suggestions for improving mathematics education in the country are given.
- Full Text:
- Date Issued: 2002
Restoring democratic governance in Zimbabwe: a critical investigation of the internet as a possible means of creating new sites of struggle for positive democratic change by Zimbabwean media and activists in Zimbabwe
- Authors: Vennard, Francisca Caroline
- Date: 2002
- Subjects: Zimbabwe -- Politics and government -- 1980- , Internet in publicity , Press and politics -- Zimbabwe , Freedom of the press -- Zimbabwe , Digital media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2837 , http://hdl.handle.net/10962/d1003047 , Zimbabwe -- Politics and government -- 1980- , Internet in publicity , Press and politics -- Zimbabwe , Freedom of the press -- Zimbabwe , Digital media
- Description: This thesis is a reaction to the state of utter lawlessness and the abuse of human rights by those in power in Zimbabwe over the past two years and it investigates the possibility of restoring democratic governance in that country by increasing the freedom of expression and media freedom, which is considered to be one of the most valuable elements in advancing democratization. Its aim is to establish the Internet as the best means possible to increasing media freedom and creating new ‘sites of struggle’ for activists in a context where the substantive freedom of expression does not exist. This in turn is shown to advance levels of democracy. To this end, the value of the freedom of expression to media freedom and the value of the latter to increasing levels of democracy is developed and the lack of democracy in Zimbabwe at all levels of society is considered. The Internet is seen to increase the freedoms of speech and association in new and interesting ways and it is discussed in various examples in which it has already been instrumental in evading the censorship of the media and increasing the ability of activists to express themselves freely and to organize more efficiently. Finally, the resources that Internet technology makes available to African journalists and activists are considered along with lessons gleaned from international examples of successful Internet use and it is shown to already be of use to Zimbabwean journalists and activists as they create to new cyberspaces in which they can struggle for positive democratic change in Zimbabwe. The Internet is also shown to have tremendous potential for future use in that country.
- Full Text:
- Date Issued: 2002
- Authors: Vennard, Francisca Caroline
- Date: 2002
- Subjects: Zimbabwe -- Politics and government -- 1980- , Internet in publicity , Press and politics -- Zimbabwe , Freedom of the press -- Zimbabwe , Digital media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2837 , http://hdl.handle.net/10962/d1003047 , Zimbabwe -- Politics and government -- 1980- , Internet in publicity , Press and politics -- Zimbabwe , Freedom of the press -- Zimbabwe , Digital media
- Description: This thesis is a reaction to the state of utter lawlessness and the abuse of human rights by those in power in Zimbabwe over the past two years and it investigates the possibility of restoring democratic governance in that country by increasing the freedom of expression and media freedom, which is considered to be one of the most valuable elements in advancing democratization. Its aim is to establish the Internet as the best means possible to increasing media freedom and creating new ‘sites of struggle’ for activists in a context where the substantive freedom of expression does not exist. This in turn is shown to advance levels of democracy. To this end, the value of the freedom of expression to media freedom and the value of the latter to increasing levels of democracy is developed and the lack of democracy in Zimbabwe at all levels of society is considered. The Internet is seen to increase the freedoms of speech and association in new and interesting ways and it is discussed in various examples in which it has already been instrumental in evading the censorship of the media and increasing the ability of activists to express themselves freely and to organize more efficiently. Finally, the resources that Internet technology makes available to African journalists and activists are considered along with lessons gleaned from international examples of successful Internet use and it is shown to already be of use to Zimbabwean journalists and activists as they create to new cyberspaces in which they can struggle for positive democratic change in Zimbabwe. The Internet is also shown to have tremendous potential for future use in that country.
- Full Text:
- Date Issued: 2002
Rumours of war : de-constructing media discourses of HIV/AIDS in South Africa
- Authors: Connelly, Mark
- Date: 2002
- Subjects: AIDS (Disease) -- South Africa AIDS (Disease) in mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3177 , http://hdl.handle.net/10962/d1007844
- Description: This paper explores discourses of HIV/AIDS evident in a South African daily newspaper from 1985 to 2000, and discusses the implications of these in terms of the way in which HIV/AIDS is constructed in society. In this paper I utilize a Foucauldian analysis of the relationship between power and knowledge. The discursive framework of the war against HIV/AIDS is used to show how different groups of subjects are positioned in relations of power. Within this the power of western science and medicine is influential and supports and informs other discourses of HIV/AIDS. I argue that the discursive framework constructing HIV/AIDS as a war does far more than provide a useful vehicle within which HIV/AIDS can be understood as it supports certain institutions and groups of people above others. The paper concludes by identifying the silenced voices of women and dissidents, and calling for greater reflection concerning the critical analysis of current issues surrounding HIV/AIDS.
- Full Text:
- Date Issued: 2002
- Authors: Connelly, Mark
- Date: 2002
- Subjects: AIDS (Disease) -- South Africa AIDS (Disease) in mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3177 , http://hdl.handle.net/10962/d1007844
- Description: This paper explores discourses of HIV/AIDS evident in a South African daily newspaper from 1985 to 2000, and discusses the implications of these in terms of the way in which HIV/AIDS is constructed in society. In this paper I utilize a Foucauldian analysis of the relationship between power and knowledge. The discursive framework of the war against HIV/AIDS is used to show how different groups of subjects are positioned in relations of power. Within this the power of western science and medicine is influential and supports and informs other discourses of HIV/AIDS. I argue that the discursive framework constructing HIV/AIDS as a war does far more than provide a useful vehicle within which HIV/AIDS can be understood as it supports certain institutions and groups of people above others. The paper concludes by identifying the silenced voices of women and dissidents, and calling for greater reflection concerning the critical analysis of current issues surrounding HIV/AIDS.
- Full Text:
- Date Issued: 2002
Science for all - myth or reality?: a research project
- Authors: Valiathazhel, James Daniel
- Date: 2002
- Subjects: Science -- Study and teaching -- South Africa Motion -- Study and teaching -- South Africa Physics -- Study and teaching -- South Africa Competency-based education -- South Africa Educational change -- South Africa Technical institutes -- South Africa Technical education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1847 , http://hdl.handle.net/10962/d1004391
- Description: Abstract: Transformation at a historically disadvantaged technikon in South Africa : a research project: South Africa is in the seventh year of democracy. During the first term of office, the ANC government proposed radical shift from the system(s) of education that was/were in existence in this country. A change in the education system in South Africa was inevitable. The ANC government have realised the need and proposed plans for a change in the education system in this country. We might be able to overcome the inequalities of the past and have an education system relevant for all South Africans that promote an equal opportunity for success as envisaged by Outcomes Based Education (OBE). This research project, using a qualitative case study methodology, reports on the readiness of Border Technikon in implementing Outcomes Based Education (OBE) as a teaching/lecturing strategy. Since 1998 Border Technikon organised a series of staff training workshops to empower the academic staff in Outcomes Based Education. A preliminary study on the topic was conducted during 1999, in which questionnaires (to 16 academic staff) and semi-structured interviews (with three academic staff) were used to collect data. During 2000, when the second and final round of this study was conducted semistructured interviews were employed with 4 staff members to gather data. Literature review and document analysis was also part of the research. The analysis of data indicated that the very nature of most of the Technikon Programmes demands an OBE approach in teaching/lecturing and hence OBE based teaching/lecturing is largely practised at Border Technikon. However a few areas of concerns were identified. Some of these concerns were: (i) Technikon employed academic staff (from industry, etc...) with no professional qualification in teaching and it was difficult to provide OBE training to such people and (ii) lack of sufficient support from the Technikon Management might be a cause for the poor attendance of academic staff during the training programme. Another aspect emerged from the data analysis was that all academic staff participated in this study expressed the need for further training in OBE and related topics. Abstract: Science for all - myth or reality?: Different educational projects around the world have made Scientific Literacy a world-wide concern. This study through a literature review shows that Scientific Literacy is a term that has many definitions and interpretations. This literature review reveals that, in the present system Science for All is a myth for various reasons. Governments around the world in general, and South Africa in particular, are in the process of introducing different projects such as the Year of Science and Technology (YEAST), science week and science exhibitions for the purpose of popularising science and technology. The Department of Education in Thailand has modified its education system to accommodate Science for All. In this literature review among other issues the status quo in South African science education and the Thailand model were examined. A few recommendations to achieve Science for All are also included in this project. Abstract: Developing and evaluating the use of learning material in science - a constructivist approach towards learning Newton's laws : a research project: The Government of National Unity in 1994 introduced a new educational policy for South Africa. This represented a shift in paradigm from a transmission mode of teaching and learning to a learner-centred education. The shift marks a transformation from a content-based curriculum to an Outcomes Based Education (OBE). Various authors found that different sections in the Physical Science syllabus in South Africa are often misunderstood by students for different reasons. One of the reasons was that students had their own ideas about laws of nature and these (mis)conceptions were resistant to change. From the literature and from the author's personal experience it was found that Bodies in Motion is a topic that is difficult to conceptualise by students of different age groups. The challenge facing educators is how to tackle this issue. In this research project a diagnostic test is developed and used to identify the topics where students have conceptual problems. To address these problem areas further, concept sheets/work sheets where developed and implemented. The different challenges and tasks given in the work sheets/learning material are organised in such a way as to make the students aware of their own ideas about Bodies in Motion in general and the key-concepts in particular and also to make them aware of the ideas of their peers (group members). It was also aimed at offering the learners the scientific alternative to their own beliefs. At the end, it was discovered that, even though the general understanding of the learners has improved in this topic (namely, Bodies in Motion), their original beliefs were largely unaffected. It is the hope of the researcher that the project would be the basis for further research on the development of learning material in science.
- Full Text:
- Date Issued: 2002
- Authors: Valiathazhel, James Daniel
- Date: 2002
- Subjects: Science -- Study and teaching -- South Africa Motion -- Study and teaching -- South Africa Physics -- Study and teaching -- South Africa Competency-based education -- South Africa Educational change -- South Africa Technical institutes -- South Africa Technical education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1847 , http://hdl.handle.net/10962/d1004391
- Description: Abstract: Transformation at a historically disadvantaged technikon in South Africa : a research project: South Africa is in the seventh year of democracy. During the first term of office, the ANC government proposed radical shift from the system(s) of education that was/were in existence in this country. A change in the education system in South Africa was inevitable. The ANC government have realised the need and proposed plans for a change in the education system in this country. We might be able to overcome the inequalities of the past and have an education system relevant for all South Africans that promote an equal opportunity for success as envisaged by Outcomes Based Education (OBE). This research project, using a qualitative case study methodology, reports on the readiness of Border Technikon in implementing Outcomes Based Education (OBE) as a teaching/lecturing strategy. Since 1998 Border Technikon organised a series of staff training workshops to empower the academic staff in Outcomes Based Education. A preliminary study on the topic was conducted during 1999, in which questionnaires (to 16 academic staff) and semi-structured interviews (with three academic staff) were used to collect data. During 2000, when the second and final round of this study was conducted semistructured interviews were employed with 4 staff members to gather data. Literature review and document analysis was also part of the research. The analysis of data indicated that the very nature of most of the Technikon Programmes demands an OBE approach in teaching/lecturing and hence OBE based teaching/lecturing is largely practised at Border Technikon. However a few areas of concerns were identified. Some of these concerns were: (i) Technikon employed academic staff (from industry, etc...) with no professional qualification in teaching and it was difficult to provide OBE training to such people and (ii) lack of sufficient support from the Technikon Management might be a cause for the poor attendance of academic staff during the training programme. Another aspect emerged from the data analysis was that all academic staff participated in this study expressed the need for further training in OBE and related topics. Abstract: Science for all - myth or reality?: Different educational projects around the world have made Scientific Literacy a world-wide concern. This study through a literature review shows that Scientific Literacy is a term that has many definitions and interpretations. This literature review reveals that, in the present system Science for All is a myth for various reasons. Governments around the world in general, and South Africa in particular, are in the process of introducing different projects such as the Year of Science and Technology (YEAST), science week and science exhibitions for the purpose of popularising science and technology. The Department of Education in Thailand has modified its education system to accommodate Science for All. In this literature review among other issues the status quo in South African science education and the Thailand model were examined. A few recommendations to achieve Science for All are also included in this project. Abstract: Developing and evaluating the use of learning material in science - a constructivist approach towards learning Newton's laws : a research project: The Government of National Unity in 1994 introduced a new educational policy for South Africa. This represented a shift in paradigm from a transmission mode of teaching and learning to a learner-centred education. The shift marks a transformation from a content-based curriculum to an Outcomes Based Education (OBE). Various authors found that different sections in the Physical Science syllabus in South Africa are often misunderstood by students for different reasons. One of the reasons was that students had their own ideas about laws of nature and these (mis)conceptions were resistant to change. From the literature and from the author's personal experience it was found that Bodies in Motion is a topic that is difficult to conceptualise by students of different age groups. The challenge facing educators is how to tackle this issue. In this research project a diagnostic test is developed and used to identify the topics where students have conceptual problems. To address these problem areas further, concept sheets/work sheets where developed and implemented. The different challenges and tasks given in the work sheets/learning material are organised in such a way as to make the students aware of their own ideas about Bodies in Motion in general and the key-concepts in particular and also to make them aware of the ideas of their peers (group members). It was also aimed at offering the learners the scientific alternative to their own beliefs. At the end, it was discovered that, even though the general understanding of the learners has improved in this topic (namely, Bodies in Motion), their original beliefs were largely unaffected. It is the hope of the researcher that the project would be the basis for further research on the development of learning material in science.
- Full Text:
- Date Issued: 2002
Selecting an appropriate process for the formulating of an operations strategy for Bridgestone/Firestone, Port Elizabeth plant, in a changed market environment
- Authors: Jeena, Umesh
- Date: 2002
- Subjects: Tire industry -- South Africa -- Port Elizabeth -- Management , Bridgestone/Firestone (Firm)
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10945 , http://hdl.handle.net/10948/d1011325 , Tire industry -- South Africa -- Port Elizabeth -- Management , Bridgestone/Firestone (Firm)
- Description: The research problem addressed in this study was aimed in assisting the management of Bridgestone/Firestone, Port Elizabeth plant, in selecting an appropriate process for the formulation of an operations strategy. The author embarked on a literature survey to gain understanding of the challenges that are occurring in the market environment. The theories and techniques around operational strategies were extensively researched in an effort to effectively and efficiently assist the management of Firestone in achieving a competitive advantage over rival competitors. Other areas of focus include the content, development, principles and concepts in developing an operations strategy. The author details the process of the formulation of an operations strategy as well as the discussion of four models/procedures deployed in organisations that would enhance strategy formulation. It is evident from the findings of the empirical study that a high percentage of the respondents “agree” that the strategy deployed within Bridgestone/Firestone, Port Elizabeth plant is appropriate, yet an alarmingly high percentage believe it to be “ineffective.
- Full Text:
- Date Issued: 2002
- Authors: Jeena, Umesh
- Date: 2002
- Subjects: Tire industry -- South Africa -- Port Elizabeth -- Management , Bridgestone/Firestone (Firm)
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10945 , http://hdl.handle.net/10948/d1011325 , Tire industry -- South Africa -- Port Elizabeth -- Management , Bridgestone/Firestone (Firm)
- Description: The research problem addressed in this study was aimed in assisting the management of Bridgestone/Firestone, Port Elizabeth plant, in selecting an appropriate process for the formulation of an operations strategy. The author embarked on a literature survey to gain understanding of the challenges that are occurring in the market environment. The theories and techniques around operational strategies were extensively researched in an effort to effectively and efficiently assist the management of Firestone in achieving a competitive advantage over rival competitors. Other areas of focus include the content, development, principles and concepts in developing an operations strategy. The author details the process of the formulation of an operations strategy as well as the discussion of four models/procedures deployed in organisations that would enhance strategy formulation. It is evident from the findings of the empirical study that a high percentage of the respondents “agree” that the strategy deployed within Bridgestone/Firestone, Port Elizabeth plant is appropriate, yet an alarmingly high percentage believe it to be “ineffective.
- Full Text:
- Date Issued: 2002
Self-respecting practical reason: an analysis of self-respect and its implications for practical reason
- Authors: Roberts, Deborah Joan
- Date: 2002
- Subjects: Williams, Bernard Arthur Owen -- Ethics , Ethics, Modern -- 20th century , Self-esteem
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2719 , http://hdl.handle.net/10962/d1002849 , Williams, Bernard Arthur Owen -- Ethics , Ethics, Modern -- 20th century , Self-esteem
- Description: What should I do? As long as I am aware of the relevant facts of the situation and deliberating soundly, Bernard Williams argues that I should do what I want to do. It makes no sense to say that there are reasons that are fixed objects of concern, or values, that exist for an agent regardless of what she is in fact motivated to do. Reasons, for Williams, are hypothetical. I argue that he takes this view of practical reason because of a prior answer to the question “How should I live?”. A universal account of the good life would mean an account of values, or interests, that all human beings should have. Williams thinks it is not possible to give a universal account of the good life for human beings; any such account must be constructed out of the particular reasons of a community. But, he takes a constructivist view of the good life because he thinks that to be universal an account of the good life would have to be objective. Since objectivity cannot be achieved, he argues, neither can universality. Williams is only half right. That objectivity is not possible is inconsequential. A foundation for ethics has to be internal, but this does not preclude it being universal. I develop such a foundation based on the Aristotelian conception of human nature. A life cannot be wholly good if it is not self-respecting. Moreover, self-respect fits the framework for the specification of the good life that this foundation provides: I argue that self-respect can be shown to have a structure which provides an account of real interests - reasons that are objects of fixed concern. As such, reasons recognise rather than construct the good, making categorical reasons possible. A person can have a reason to change or act, even if reason itself cannot effect that change or action. Thus, I can be wrong about what I should do not only by being wrong about what would count as a satisfaction of my interests, but also by being wrong about what my interests are.
- Full Text:
- Date Issued: 2002
- Authors: Roberts, Deborah Joan
- Date: 2002
- Subjects: Williams, Bernard Arthur Owen -- Ethics , Ethics, Modern -- 20th century , Self-esteem
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2719 , http://hdl.handle.net/10962/d1002849 , Williams, Bernard Arthur Owen -- Ethics , Ethics, Modern -- 20th century , Self-esteem
- Description: What should I do? As long as I am aware of the relevant facts of the situation and deliberating soundly, Bernard Williams argues that I should do what I want to do. It makes no sense to say that there are reasons that are fixed objects of concern, or values, that exist for an agent regardless of what she is in fact motivated to do. Reasons, for Williams, are hypothetical. I argue that he takes this view of practical reason because of a prior answer to the question “How should I live?”. A universal account of the good life would mean an account of values, or interests, that all human beings should have. Williams thinks it is not possible to give a universal account of the good life for human beings; any such account must be constructed out of the particular reasons of a community. But, he takes a constructivist view of the good life because he thinks that to be universal an account of the good life would have to be objective. Since objectivity cannot be achieved, he argues, neither can universality. Williams is only half right. That objectivity is not possible is inconsequential. A foundation for ethics has to be internal, but this does not preclude it being universal. I develop such a foundation based on the Aristotelian conception of human nature. A life cannot be wholly good if it is not self-respecting. Moreover, self-respect fits the framework for the specification of the good life that this foundation provides: I argue that self-respect can be shown to have a structure which provides an account of real interests - reasons that are objects of fixed concern. As such, reasons recognise rather than construct the good, making categorical reasons possible. A person can have a reason to change or act, even if reason itself cannot effect that change or action. Thus, I can be wrong about what I should do not only by being wrong about what would count as a satisfaction of my interests, but also by being wrong about what my interests are.
- Full Text:
- Date Issued: 2002
Sensorless speed estimation in three phase induction motors
- Authors: Govindsamy, Matthew
- Date: 2002
- Subjects: Electric motors, induction , Electronic controllers
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10810 , http://hdl.handle.net/10948/139 , Electric motors, induction , Electronic controllers
- Description: This thesis proposes a technique to determine and improve the performance of a sensorless speed estimator for an induction motor based on Motor Current Signature Analysis (MCSA). The theoretical concepts underlying the parameter based observer are developed first and then the model of the observer is built using Simulink. The observer is developed based on Model Reference Adaptive System (MRAS). The dynamic performance of the observer and its behavior due to variation of machine parameters is studied. The error in speed estimated using this observer is shown and the ability of MCSA to retune the rotor speed from the stator current spectrum. The spectrum estimation technique has been implemented using a software routine in Matlab. Both the observer and MCSA techniques were implemented practically on an induction motor. The performance of the combined sensorless speed estimation system was tested and verified.
- Full Text:
- Date Issued: 2002
- Authors: Govindsamy, Matthew
- Date: 2002
- Subjects: Electric motors, induction , Electronic controllers
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10810 , http://hdl.handle.net/10948/139 , Electric motors, induction , Electronic controllers
- Description: This thesis proposes a technique to determine and improve the performance of a sensorless speed estimator for an induction motor based on Motor Current Signature Analysis (MCSA). The theoretical concepts underlying the parameter based observer are developed first and then the model of the observer is built using Simulink. The observer is developed based on Model Reference Adaptive System (MRAS). The dynamic performance of the observer and its behavior due to variation of machine parameters is studied. The error in speed estimated using this observer is shown and the ability of MCSA to retune the rotor speed from the stator current spectrum. The spectrum estimation technique has been implemented using a software routine in Matlab. Both the observer and MCSA techniques were implemented practically on an induction motor. The performance of the combined sensorless speed estimation system was tested and verified.
- Full Text:
- Date Issued: 2002
South African memoirs in a decade of transition: Athol Fugard's Cousins (1994), J.M. Coetzee's Boyhood (1997), and Breyten Breytenbach's Dog Heart (1999)
- Authors: Roux, Christine Ann
- Date: 2002
- Subjects: Autobiography , Fugard, Athol , Coetzee, J. M., 1940 , Breytenbach, Breyten
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2191 , http://hdl.handle.net/10962/d1002233 , Autobiography , Fugard, Athol , Coetzee, J. M., 1940 , Breytenbach, Breyten
- Description: This thesis examines three South African memoirs using M. M. Bakhtin’s theories of the dialogical relationship in language and literature. By offering an alternative to a postmodern or multicultural interpretation of autobiographies, Bakhtin’s precepts, that define a dialogic, help to reframe a way of discussing memoirs and avoiding dead-ends previously arrived at by essayists in James Olney’s 1980 collection. Bakhtin’s ideas discussed here, which include the “once-occurrent moment”, “architectonic contraposition”, ”emotional-volitional tone”, “alibi”, “non-alibi”, and “centripetal” and “centrifugal” force, help to rebuild a discussion based on temporary and evolving self truth rather than fiction, the postmodern interpretation, or confession, the new-age secular spiritualism based on multicultural and politically correct standards. For this, each author’s memoir had to be examined separately and a conclusion was arrived at through inductive analysis. Rather than try to find similar characteristics, I focused on what made each memoir different and unique. Janet Varner Gunn’s Autobiography: Toward A Poetics of Experience (1982) refocused the debate over autobiography on process. The question, what steps did each author take toward writing about himself, led the discussion to an examination of the priorities each author exemplified. Beginning with Fugard who emphasized spatial, concrete, and sensory detail to help him contain his emotional life, the thesis moves on to an examination of Coetzee’s sense of justice. From the physical and intellectual world follows Breytenbach’s spiritual space-making. In each memoir, control of space is evident on different levels of experience. Articulating space inevitably leads to a discussion of boundaries. Here, Charles Taylor’s emphasis on the modern self’s need to articulate a horizon or a framework is helpful in generalizing the effect of the autobiographical process. The conclusion reached is that autobiography is inherently centrifugal: it moves away from the center of cultural thinking because its “truth” bolsters itself on dialogical process which does not depend on a fixed authority but rather on communicative exchange. As an example of exchange, autobiography’s central truth is that it returns to a “unique point of origin”, namely the self, only to reconnect to the other in a potentially eternal exchange of responsiveness moving away from the center.
- Full Text:
- Date Issued: 2002
- Authors: Roux, Christine Ann
- Date: 2002
- Subjects: Autobiography , Fugard, Athol , Coetzee, J. M., 1940 , Breytenbach, Breyten
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2191 , http://hdl.handle.net/10962/d1002233 , Autobiography , Fugard, Athol , Coetzee, J. M., 1940 , Breytenbach, Breyten
- Description: This thesis examines three South African memoirs using M. M. Bakhtin’s theories of the dialogical relationship in language and literature. By offering an alternative to a postmodern or multicultural interpretation of autobiographies, Bakhtin’s precepts, that define a dialogic, help to reframe a way of discussing memoirs and avoiding dead-ends previously arrived at by essayists in James Olney’s 1980 collection. Bakhtin’s ideas discussed here, which include the “once-occurrent moment”, “architectonic contraposition”, ”emotional-volitional tone”, “alibi”, “non-alibi”, and “centripetal” and “centrifugal” force, help to rebuild a discussion based on temporary and evolving self truth rather than fiction, the postmodern interpretation, or confession, the new-age secular spiritualism based on multicultural and politically correct standards. For this, each author’s memoir had to be examined separately and a conclusion was arrived at through inductive analysis. Rather than try to find similar characteristics, I focused on what made each memoir different and unique. Janet Varner Gunn’s Autobiography: Toward A Poetics of Experience (1982) refocused the debate over autobiography on process. The question, what steps did each author take toward writing about himself, led the discussion to an examination of the priorities each author exemplified. Beginning with Fugard who emphasized spatial, concrete, and sensory detail to help him contain his emotional life, the thesis moves on to an examination of Coetzee’s sense of justice. From the physical and intellectual world follows Breytenbach’s spiritual space-making. In each memoir, control of space is evident on different levels of experience. Articulating space inevitably leads to a discussion of boundaries. Here, Charles Taylor’s emphasis on the modern self’s need to articulate a horizon or a framework is helpful in generalizing the effect of the autobiographical process. The conclusion reached is that autobiography is inherently centrifugal: it moves away from the center of cultural thinking because its “truth” bolsters itself on dialogical process which does not depend on a fixed authority but rather on communicative exchange. As an example of exchange, autobiography’s central truth is that it returns to a “unique point of origin”, namely the self, only to reconnect to the other in a potentially eternal exchange of responsiveness moving away from the center.
- Full Text:
- Date Issued: 2002
Speed-related isokinetic and psychophysical responses of female military personnel
- Authors: Kennedy, Dale Charles
- Date: 2002
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:21028 , http://hdl.handle.net/10962/6063
- Description: The present study aims to contribute in an area that has long been neglected, the indigenous female population, about whose physical strength and work-capacity very little is known. Speed-related isokinetic and psychophysical responses of female military personnel were assessed (N=32). Furthermore benchmark data was established for Work-Simulation isokinetic responses where there appears to be limited publication. Analysis of the data showed significant differences in torque, work and power outputs as velocity increased. Only wrench-turning left and right rotation for peak torque and total work did not show significant reductions. Consistency of effort level recorded an average of 72% across the selected isokinetic tests. No discernible morphological and strength expression differences were observed between military office workers and infantry personnel, and no significant correlations were recorded between heart rate and RPE values.
- Full Text:
- Date Issued: 2002
- Authors: Kennedy, Dale Charles
- Date: 2002
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:21028 , http://hdl.handle.net/10962/6063
- Description: The present study aims to contribute in an area that has long been neglected, the indigenous female population, about whose physical strength and work-capacity very little is known. Speed-related isokinetic and psychophysical responses of female military personnel were assessed (N=32). Furthermore benchmark data was established for Work-Simulation isokinetic responses where there appears to be limited publication. Analysis of the data showed significant differences in torque, work and power outputs as velocity increased. Only wrench-turning left and right rotation for peak torque and total work did not show significant reductions. Consistency of effort level recorded an average of 72% across the selected isokinetic tests. No discernible morphological and strength expression differences were observed between military office workers and infantry personnel, and no significant correlations were recorded between heart rate and RPE values.
- Full Text:
- Date Issued: 2002
State or public service broadcasting?: an analysis of the coverage of political issues and debates during an election campaign on television news
- Authors: Macha, Herbert
- Date: 2002
- Subjects: Public service television programs -- Zambia , Television in politics , Television broadcasting of news -- Zambia , Elections -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3502 , http://hdl.handle.net/10962/d1006234 , Public service television programs -- Zambia , Television in politics , Television broadcasting of news -- Zambia , Elections -- Zambia
- Description: Public Service Television remains a key institution of democratisation in the context of emerging democracies in Africa, especially with the advent of liberalisation and commercialisation of the media. The democratic changes taking place in Zambia require a genuine public service broadcasting television that will promote pluralism in the public sphere. Among the many available strategies and mechanisms for fostering a sustainable democratic and cultural environment, public service broadcasting is still the best. This study set out to examine representation of political issues and debates during election campaign on ZNBC television news to assess the extent to which it plays a role as a public broadcaster in the mediation of pluralistic politics. Election news on television, in line with the public sphere argument was found to be essential for investigating the nature of public service television from the point of view of impartiality, universality and diversity. Using both qualitative and quantitative methods the study has confirmed the hypothesis that the role of a public service television in the mediation of pluralistic politics is compromised by ZNBC's partial and unbalanced coverage of elections. As a result ZNBC, as a public service broadcaster is undermining the very democracy it is expected to promote. Public service television should take new forms if it is to be recognised and appreciated by the public as a genuine, open and democratic public sphere. I therefore recommend that a system of license fee for viewers be introduced. Secondly, government should increase funding into public service television to supplement revenue from license fee and advertising. Thirdly, I recommend the appointment of an independent board whose members will be appointed for a fixed term, by public nomination and a process of public hearing, according to publicly available criteria, which guarantees diversity of political, ethnic, social and professional background. Fourthly I suggest the formation of an Election News Coverage Committee comprising of journalists, academicians, the church and civic organisation that will formulate and implement editorial policy on election coverage and above all monitor and the coverage of elections on ZNBC television news.
- Full Text:
- Date Issued: 2002
- Authors: Macha, Herbert
- Date: 2002
- Subjects: Public service television programs -- Zambia , Television in politics , Television broadcasting of news -- Zambia , Elections -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3502 , http://hdl.handle.net/10962/d1006234 , Public service television programs -- Zambia , Television in politics , Television broadcasting of news -- Zambia , Elections -- Zambia
- Description: Public Service Television remains a key institution of democratisation in the context of emerging democracies in Africa, especially with the advent of liberalisation and commercialisation of the media. The democratic changes taking place in Zambia require a genuine public service broadcasting television that will promote pluralism in the public sphere. Among the many available strategies and mechanisms for fostering a sustainable democratic and cultural environment, public service broadcasting is still the best. This study set out to examine representation of political issues and debates during election campaign on ZNBC television news to assess the extent to which it plays a role as a public broadcaster in the mediation of pluralistic politics. Election news on television, in line with the public sphere argument was found to be essential for investigating the nature of public service television from the point of view of impartiality, universality and diversity. Using both qualitative and quantitative methods the study has confirmed the hypothesis that the role of a public service television in the mediation of pluralistic politics is compromised by ZNBC's partial and unbalanced coverage of elections. As a result ZNBC, as a public service broadcaster is undermining the very democracy it is expected to promote. Public service television should take new forms if it is to be recognised and appreciated by the public as a genuine, open and democratic public sphere. I therefore recommend that a system of license fee for viewers be introduced. Secondly, government should increase funding into public service television to supplement revenue from license fee and advertising. Thirdly, I recommend the appointment of an independent board whose members will be appointed for a fixed term, by public nomination and a process of public hearing, according to publicly available criteria, which guarantees diversity of political, ethnic, social and professional background. Fourthly I suggest the formation of an Election News Coverage Committee comprising of journalists, academicians, the church and civic organisation that will formulate and implement editorial policy on election coverage and above all monitor and the coverage of elections on ZNBC television news.
- Full Text:
- Date Issued: 2002
Synthetic approaches to marine labdane diterpenes
- Authors: Wisch, Gregory Albert
- Date: 2002 , 2013-05-10
- Subjects: Diterpenes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4289 , http://hdl.handle.net/10962/d1003131 , Diterpenes
- Description: The work presented in this thesis describes the synthesis of labd-13-en-8ß, 15-diol (46) a stable reduced derivative of an unstable marine natural product aldehyde [8ß-hydroxylabd-13E-en-15-al (6)] isolated by Cimino, et al. from the skin of a Notaspidean mollusc Pleurobranchaea meckelii. The rationale for the synthesis was to provide sufficient 46 for eventual mild oxidation to 6 and investigation of the biological activity of this latter compound. (-)-Sclareol (32), a common diterpene synthetic precursor, was the starting point for the ten step synthesis of 46 described in this thesis. A search of the literature revealed that only one non stereospecific synthesis of 46 had been previously reported. To provide the necessary background to the synthetic component of this thesis, both the occurrence of labdane and ent-labdane in the marine environment and the use of sclareol in the synthesis of marine natural products, was reviewed. The initial step in the synthesis of 46 was the potassium permanganate oxidation of sclareol to give a bisnorlabdane ketone. Reduction of this ketone with lithium aluminium hydride produced a mixture of diols which, through t-butyldimethysilyl triflate protection, afforded a quantitative route to protecting the C-13 ketone in an effort to prevent unwanted intramolecular cyclization reactions. Dehydration of the tertiary alcohol moiety at C-8 with phosphorous oxychloride yielded the Δ⁸·¹⁵ exocyclic alkene required for the next oxidation step. Ozonolysis succeeded in producing the desired C-8 ketone after much deliberation and research into alternative oxidation strategies. Methyl lithium methylation quantitatively afforded the desired a-methyl substitution at C-8, identified at the onset as the key step in the synthesis. Tetra-butylarnmonium fluoride deprotection yielded the 8ß,13-dihydoxylated product, which was in turn subjected to a Swern oxidition to give the desired 8ß-hydroxy-bisnorlabda-13-one. A modified Horner-Wadsworth-Emmons reaction allowed for elaboration at C-13 to yield a to Δ¹³ olefin with a terminal C-15 ethyl ester. Diisobutylaluminium hydride reduction of the ester produced the desired labd-13-en-8ß, 15-diol (46) in a low overall yield of 3.4%. Although opportunities for optimization of at least three steps in the synthesis exist, time constraints prevented both optimization of these steps and an investigation of the oxidation of 46 to 6. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
- Authors: Wisch, Gregory Albert
- Date: 2002 , 2013-05-10
- Subjects: Diterpenes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4289 , http://hdl.handle.net/10962/d1003131 , Diterpenes
- Description: The work presented in this thesis describes the synthesis of labd-13-en-8ß, 15-diol (46) a stable reduced derivative of an unstable marine natural product aldehyde [8ß-hydroxylabd-13E-en-15-al (6)] isolated by Cimino, et al. from the skin of a Notaspidean mollusc Pleurobranchaea meckelii. The rationale for the synthesis was to provide sufficient 46 for eventual mild oxidation to 6 and investigation of the biological activity of this latter compound. (-)-Sclareol (32), a common diterpene synthetic precursor, was the starting point for the ten step synthesis of 46 described in this thesis. A search of the literature revealed that only one non stereospecific synthesis of 46 had been previously reported. To provide the necessary background to the synthetic component of this thesis, both the occurrence of labdane and ent-labdane in the marine environment and the use of sclareol in the synthesis of marine natural products, was reviewed. The initial step in the synthesis of 46 was the potassium permanganate oxidation of sclareol to give a bisnorlabdane ketone. Reduction of this ketone with lithium aluminium hydride produced a mixture of diols which, through t-butyldimethysilyl triflate protection, afforded a quantitative route to protecting the C-13 ketone in an effort to prevent unwanted intramolecular cyclization reactions. Dehydration of the tertiary alcohol moiety at C-8 with phosphorous oxychloride yielded the Δ⁸·¹⁵ exocyclic alkene required for the next oxidation step. Ozonolysis succeeded in producing the desired C-8 ketone after much deliberation and research into alternative oxidation strategies. Methyl lithium methylation quantitatively afforded the desired a-methyl substitution at C-8, identified at the onset as the key step in the synthesis. Tetra-butylarnmonium fluoride deprotection yielded the 8ß,13-dihydoxylated product, which was in turn subjected to a Swern oxidition to give the desired 8ß-hydroxy-bisnorlabda-13-one. A modified Horner-Wadsworth-Emmons reaction allowed for elaboration at C-13 to yield a to Δ¹³ olefin with a terminal C-15 ethyl ester. Diisobutylaluminium hydride reduction of the ester produced the desired labd-13-en-8ß, 15-diol (46) in a low overall yield of 3.4%. Although opportunities for optimization of at least three steps in the synthesis exist, time constraints prevented both optimization of these steps and an investigation of the oxidation of 46 to 6. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002