Biological generation of reactive alkaline species and their application in a sustainable bioprocess for the remediation of acid and metal contaminated wastewaters
- Authors: Van Hille, Robert Paul
- Date: 2002
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21049 , http://hdl.handle.net/10962/6129
- Description: This project focused on the development of an integrated biological system for the treatment of acidic and metal-laden effluents, based on the sustainable biological generation of reactive alkaline species. Initial studies concentrated on the binding and accumulation of heavy metals by biomass of the cyanobacteria, Spirulina sp. Metal binding was rapid, with saturation reached in 30 minutes, and followed an affinity series of Pb > Cu > Zn >>Fe. The binding capacity of the Spirulina for each of the metals was relatively low when compared to a range of other biosorbents. The toxicity thresholds of the algae was determined for copper and zinc. These were low (10umoles/g) and as such, the algae were not suitable for application in a treatment system in which they came into direct contact with the toxic metals. The algae were able to increase the pH of the surrounding medium. This occurred as a result of the accumulation of inorganic carbon, from bicarbonate, as a response to low concentrations of carbon dioxide in the medium. The resulting release of a hydroxide ion into solution led to the increase in pH. The increase in pH was shown to be due to a reduction in acidity, rather than an increase in alkalinity. The enzyme carbonic anhydrase was shown to be pivotal in this system. Attempts to determine the enzyme activity directly were unsuccessful, due to the inherent inaccuracy of the assay system. An indirect method of determining enzyme activity, by measuring changes in the carbonate species equilibrium, was developed. Under optimal conditions Spirulina was able to reduce the acidity by an amount equivalent to the addition of 3670umoles NaOH g·' h·'. Predictive modelling showed that this enhanced the potential of the medium to effect metal precipitation. For the algal system to be sustainable, a readily available source of bicarbonate was needed. This was achieved by the oxidation of organic carbon, under sulphidogenic conditions, by a bacterial consortium isolated from the anaerobic component of a facultative pond. The consortium was shown to consist of sulphate reducing (most likely Desulvovibrio and Desulfotomaculum)and acetogenic bacteria. Sulphate removal rates of 500mg 1·' day·' and 135mg 1·' day·' were achieved in a 21 agitated and 281 upflow reactor respectively. The bicarbonate generation rate in the 281 reactor was calculated as 4033umoles 1·' day·', which proved sufficient to act as a feed for the algal system. Sparging the anaerobic digester overflow with air and nitrogen resulted in a reduction in the aqueous sulphide concentration. Using nitrogen, a 70% recovery of sulphide, as H2S gas, was achieved in 60 minutes, while with air, this dropped to 40%, due to the oxidation of the aqueous sulphide. The stripping ofH2S resulted in an increase in pH. The H2S gas was used for the selective precipitation of copper and lead in the integrated system. The dynamics of metal precipitation was investigated. For simple reactions, between individual IV metal and base species, it was possible to generate an accurate predictive model and confirm the precipitating species using wavelength dispersive X-ray spectroscopy (WDS). In more complex systems, where precipitation of the artificial acid mine drainage was examined, the predictive modelling and WDS could not accurately describe the system. The addition of aqueous sulphide to copper and iron resulted in the formation of metastable, amorphous precipitates, which remained in suspension. Ageing of the copper precipitate resulted in the evolution of a stable crystalline structure (covellite) and the aggregation and settling of the precipitate. In the case of iron, the amorphous precipitate underwent oxidation before a stable iron sulphide could evolve and the settled precipitate was an iron oxide or oxyhydroxide. The artificial acid mine drainage was treated with sulphide, hydroxide, anaerobic digester overflow and algal overflow. The best metal removal was achieved with the sulphide and hydroxide, while the algal overflow outperformed the anaerobic digester overflow. The precipitate generated by the addition of sulphide was the most compact, followed by the algal overflow, the anaerobic digester overflow and the hydroxide. Efficient precipitation of all the heavy metals, except manganese, was achieved using the algal overflow at an acidity to alkalinity ratio of 1 :2. This ratio was selected for use in the pilot system. The Spirulina based pilot system was effectively used to treat an effluent from the Black Mountain base metal mine. The necessity to maintain the algae in suspension and avoid biomass washout were practical considerations which counted against this system. The replacement of the Spirulina by Oscillatoria, which adhered to a solid support, overcame these problems. The integrated biological system was able to effectively treat an artificial acid mine drainage for 90 days, reducing the concentration of all metals, except manganese, to below the acceptable environmental risk levels. The treatment of the final effluent in a second anaerobic digester reduced the manganese concentration to 4.5uM and proved that the sulphate reducing bacteria could be cultivated on enriched, partially treated acid mine drainage. The integrated biological treatment system performed well, effectively treating an effluent modelled closely on the quality of the water being discharged from the East Rand Basin. The cost of such a system would be considerably less than a "high tech" physico-chemical system. This, coupled with the potential long term sustainability of a biological system, would make it a potentially attractive option for the treatment of future acid mine drainage discharges.
- Full Text:
- Date Issued: 2002
- Authors: Van Hille, Robert Paul
- Date: 2002
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21049 , http://hdl.handle.net/10962/6129
- Description: This project focused on the development of an integrated biological system for the treatment of acidic and metal-laden effluents, based on the sustainable biological generation of reactive alkaline species. Initial studies concentrated on the binding and accumulation of heavy metals by biomass of the cyanobacteria, Spirulina sp. Metal binding was rapid, with saturation reached in 30 minutes, and followed an affinity series of Pb > Cu > Zn >>Fe. The binding capacity of the Spirulina for each of the metals was relatively low when compared to a range of other biosorbents. The toxicity thresholds of the algae was determined for copper and zinc. These were low (10umoles/g) and as such, the algae were not suitable for application in a treatment system in which they came into direct contact with the toxic metals. The algae were able to increase the pH of the surrounding medium. This occurred as a result of the accumulation of inorganic carbon, from bicarbonate, as a response to low concentrations of carbon dioxide in the medium. The resulting release of a hydroxide ion into solution led to the increase in pH. The increase in pH was shown to be due to a reduction in acidity, rather than an increase in alkalinity. The enzyme carbonic anhydrase was shown to be pivotal in this system. Attempts to determine the enzyme activity directly were unsuccessful, due to the inherent inaccuracy of the assay system. An indirect method of determining enzyme activity, by measuring changes in the carbonate species equilibrium, was developed. Under optimal conditions Spirulina was able to reduce the acidity by an amount equivalent to the addition of 3670umoles NaOH g·' h·'. Predictive modelling showed that this enhanced the potential of the medium to effect metal precipitation. For the algal system to be sustainable, a readily available source of bicarbonate was needed. This was achieved by the oxidation of organic carbon, under sulphidogenic conditions, by a bacterial consortium isolated from the anaerobic component of a facultative pond. The consortium was shown to consist of sulphate reducing (most likely Desulvovibrio and Desulfotomaculum)and acetogenic bacteria. Sulphate removal rates of 500mg 1·' day·' and 135mg 1·' day·' were achieved in a 21 agitated and 281 upflow reactor respectively. The bicarbonate generation rate in the 281 reactor was calculated as 4033umoles 1·' day·', which proved sufficient to act as a feed for the algal system. Sparging the anaerobic digester overflow with air and nitrogen resulted in a reduction in the aqueous sulphide concentration. Using nitrogen, a 70% recovery of sulphide, as H2S gas, was achieved in 60 minutes, while with air, this dropped to 40%, due to the oxidation of the aqueous sulphide. The stripping ofH2S resulted in an increase in pH. The H2S gas was used for the selective precipitation of copper and lead in the integrated system. The dynamics of metal precipitation was investigated. For simple reactions, between individual IV metal and base species, it was possible to generate an accurate predictive model and confirm the precipitating species using wavelength dispersive X-ray spectroscopy (WDS). In more complex systems, where precipitation of the artificial acid mine drainage was examined, the predictive modelling and WDS could not accurately describe the system. The addition of aqueous sulphide to copper and iron resulted in the formation of metastable, amorphous precipitates, which remained in suspension. Ageing of the copper precipitate resulted in the evolution of a stable crystalline structure (covellite) and the aggregation and settling of the precipitate. In the case of iron, the amorphous precipitate underwent oxidation before a stable iron sulphide could evolve and the settled precipitate was an iron oxide or oxyhydroxide. The artificial acid mine drainage was treated with sulphide, hydroxide, anaerobic digester overflow and algal overflow. The best metal removal was achieved with the sulphide and hydroxide, while the algal overflow outperformed the anaerobic digester overflow. The precipitate generated by the addition of sulphide was the most compact, followed by the algal overflow, the anaerobic digester overflow and the hydroxide. Efficient precipitation of all the heavy metals, except manganese, was achieved using the algal overflow at an acidity to alkalinity ratio of 1 :2. This ratio was selected for use in the pilot system. The Spirulina based pilot system was effectively used to treat an effluent from the Black Mountain base metal mine. The necessity to maintain the algae in suspension and avoid biomass washout were practical considerations which counted against this system. The replacement of the Spirulina by Oscillatoria, which adhered to a solid support, overcame these problems. The integrated biological system was able to effectively treat an artificial acid mine drainage for 90 days, reducing the concentration of all metals, except manganese, to below the acceptable environmental risk levels. The treatment of the final effluent in a second anaerobic digester reduced the manganese concentration to 4.5uM and proved that the sulphate reducing bacteria could be cultivated on enriched, partially treated acid mine drainage. The integrated biological treatment system performed well, effectively treating an effluent modelled closely on the quality of the water being discharged from the East Rand Basin. The cost of such a system would be considerably less than a "high tech" physico-chemical system. This, coupled with the potential long term sustainability of a biological system, would make it a potentially attractive option for the treatment of future acid mine drainage discharges.
- Full Text:
- Date Issued: 2002
Biological sulphide oxidation in heterotrophic environments
- Authors: Rein, Neil Berthold
- Date: 2002
- Subjects: Acid mine drainage , Oxidation , Sulfides , Oxidation, Physiological
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3919 , http://hdl.handle.net/10962/d1003978 , Acid mine drainage , Oxidation , Sulfides , Oxidation, Physiological
- Description: Acid mine drainage is a major environmental pollution concern associated with the mining of sulphide-containing ore bodies. Both physicochemical and biological options have been investigated for the treatment of acid mine drainage with recent interest in biological processes targeting low-cost and passive treatment applications. All acid mine drainage biological treatment processes are based to some extent on the activity of sulphate reducing bacteria, and their ability to reduce sulphate to sulphide in the presence of a range of carbon and electron donor sources. A portion of the sulphide produced may be consumed in the precipitation of heavy metals present in the mine drainage. Residual sulphide must be removed, not only due to its toxicity, but especially to prevent its reoxidation to sulphate where salinity reduction is a target of the treatment process. The partial oxidation of sulphide to elemental sulphur is an option that has received considerable attention and both physicochemical and biological options have been investigated. Biological processes have substantial potential cost advantages and run at ambient temperatures and pressures. However, the oxidation of sulphide to elemental sulphur is poised over a narrow redox range and process control to maintain optimum conditions remains a serious problem. In addition little has been reported in the literature on process control of sulphide oxidation to elemental sulphur, in the heterotrophic conditions prevailing in the reaction environment following sulphate reduction. This study undertook an investigation of biological sulphide oxidation under heterotrophic conditions in order to establish the effect of organic compounds on biological sulphide oxidation, and to determine whether the presence of organics, and associated heterotrophic oxygen consumption, may be manipulated to maintain the defined redox conditions required for the production of elemental sulphur. Biological sulphide oxidation under heterotrophic conditions was investigated in a series of flask experiments. Based on these results three different reactor configurations, a Fixed-Film Trickle Filter Reactor, Submerged Fixed-Film Reactor and a Silicone Tubular Reactor were used to investigate sulphur production. The flask studies indicated that organics, and associated heterotrophic metabolism in the presence of excess oxygen in the sulphide oxidation reaction environment, did contribute to the poising of redox conditions and thereby enabling the production of elemental sulphur. While the Fixed-Film Trickle Filter Reactor was found to be redox unstable, probably due to excess oxygen ingress to the system, a reduced oxygen challenge in the Submerged Fixed-Film Reactor configuration was found to be more successful for production of elemental sulphur. However, due to the production of a predominantly filamentous sulphur producing microbial population, recovery of sulphur from the column was intermittent and unpredictable. Extended residence times for produced sulphur on the column increased the likelihood for its eventual oxidation to sulphate. The Silicone Tubular Reactor was found to support a vigorous sulphide oxidising biofilm and produced elemental sulphur effectively. Electron microscopic studies showed that this occurred as both biologically produced sulphur and, probably mainly, as crystalline sulphur in the ortho-rhomic form. Given the linear extension of the sulphur production reaction environment it is was possible to investigate the sequence of the reaction mechanism in grater detail than is possible in mixed systems. Based on these findings a model explaining sulphur production under heterotrophic conditions has been proposed and is presented. The commercial implications of the development have also been noted.
- Full Text:
- Date Issued: 2002
- Authors: Rein, Neil Berthold
- Date: 2002
- Subjects: Acid mine drainage , Oxidation , Sulfides , Oxidation, Physiological
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3919 , http://hdl.handle.net/10962/d1003978 , Acid mine drainage , Oxidation , Sulfides , Oxidation, Physiological
- Description: Acid mine drainage is a major environmental pollution concern associated with the mining of sulphide-containing ore bodies. Both physicochemical and biological options have been investigated for the treatment of acid mine drainage with recent interest in biological processes targeting low-cost and passive treatment applications. All acid mine drainage biological treatment processes are based to some extent on the activity of sulphate reducing bacteria, and their ability to reduce sulphate to sulphide in the presence of a range of carbon and electron donor sources. A portion of the sulphide produced may be consumed in the precipitation of heavy metals present in the mine drainage. Residual sulphide must be removed, not only due to its toxicity, but especially to prevent its reoxidation to sulphate where salinity reduction is a target of the treatment process. The partial oxidation of sulphide to elemental sulphur is an option that has received considerable attention and both physicochemical and biological options have been investigated. Biological processes have substantial potential cost advantages and run at ambient temperatures and pressures. However, the oxidation of sulphide to elemental sulphur is poised over a narrow redox range and process control to maintain optimum conditions remains a serious problem. In addition little has been reported in the literature on process control of sulphide oxidation to elemental sulphur, in the heterotrophic conditions prevailing in the reaction environment following sulphate reduction. This study undertook an investigation of biological sulphide oxidation under heterotrophic conditions in order to establish the effect of organic compounds on biological sulphide oxidation, and to determine whether the presence of organics, and associated heterotrophic oxygen consumption, may be manipulated to maintain the defined redox conditions required for the production of elemental sulphur. Biological sulphide oxidation under heterotrophic conditions was investigated in a series of flask experiments. Based on these results three different reactor configurations, a Fixed-Film Trickle Filter Reactor, Submerged Fixed-Film Reactor and a Silicone Tubular Reactor were used to investigate sulphur production. The flask studies indicated that organics, and associated heterotrophic metabolism in the presence of excess oxygen in the sulphide oxidation reaction environment, did contribute to the poising of redox conditions and thereby enabling the production of elemental sulphur. While the Fixed-Film Trickle Filter Reactor was found to be redox unstable, probably due to excess oxygen ingress to the system, a reduced oxygen challenge in the Submerged Fixed-Film Reactor configuration was found to be more successful for production of elemental sulphur. However, due to the production of a predominantly filamentous sulphur producing microbial population, recovery of sulphur from the column was intermittent and unpredictable. Extended residence times for produced sulphur on the column increased the likelihood for its eventual oxidation to sulphate. The Silicone Tubular Reactor was found to support a vigorous sulphide oxidising biofilm and produced elemental sulphur effectively. Electron microscopic studies showed that this occurred as both biologically produced sulphur and, probably mainly, as crystalline sulphur in the ortho-rhomic form. Given the linear extension of the sulphur production reaction environment it is was possible to investigate the sequence of the reaction mechanism in grater detail than is possible in mixed systems. Based on these findings a model explaining sulphur production under heterotrophic conditions has been proposed and is presented. The commercial implications of the development have also been noted.
- Full Text:
- Date Issued: 2002
Biosulphidogenic hydrolysis of lignin and lignin model compounds
- Authors: Madikane, Mzekelo
- Date: 2002
- Subjects: Lignin Lignin -- Biodegradation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3917 , http://hdl.handle.net/10962/d1003976
- Description: Lignin degradation under biosulphidogenic conditions has not been extensively reported in the literature. Although aerobic degradation of lignin is well documented, anaerobic biodegradation has focused mainly on methanogenic systems with biosulphidogenic systems receiving less attention. Sulphate reducing bacteria are known to generate moderately high levels of both sulphide and alkalinity at room temperatures, and these conditions draw some comparison with the Kraft pulping process. In the Kraft pulping process, lignin is degraded chemically at ±170°C under high sulphide and alkaline conditions and may provide a model for understanding biosulphidogenic lignin degrading activity. The aim of this study was to investigate the biosulphidogenic hydrolysis of lignin within the context of the chemical and biological conditions generated by a mixed sulphate reducing bacteria consortia. Bioreactor studies with a mixed sulphate reducing consortia and pine wood powder (both untreated and depectinated) resulted in the generation of comparable levels of sulphide and alkalinity used in the chemical hydrolysis studies. Aromatic compound yields were between 20 to 50% of the chemical hydrolysis studies. This fluctuation may have been due to the utilization of these aromatic compounds as electron donors by the sulphate reducing consortia as evidenced by the high rate of sulphate reduction in both the untreated and depectinated wood bioreactors. Biodegradation of lignin model compounds was investigated in order to elucidate lignin degradation mechanisms. Both mono-aromatic and dimeric lignin model compounds were used as electron donors and carbon sources for the mixed sulphate reducing consortia. Biodegradation and mass spectrometer analysis of mono-aromatic compounds, ferulic acid and ferulic acid ethyl ester resulted in the production of intermediates such as catechol, cyclohexane carboxylic acid and adipic acid. These intermediates were also observed in the degradation of dimeric ferulic acid. Biodegradation of salicin resulted in the production of salicyl alcohol, ortho-cresol and acetate. Biodegradation of benzylic ether resulted in the production of vanillin and acetate as end products. The results of these studies provide evidence for a biosulphidogenic hydrolysis of lignin, and also the utilisation of lignin-derived aromatic compounds as electron donor sources, by a mixed sulphate reducing consortia.
- Full Text:
- Date Issued: 2002
- Authors: Madikane, Mzekelo
- Date: 2002
- Subjects: Lignin Lignin -- Biodegradation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3917 , http://hdl.handle.net/10962/d1003976
- Description: Lignin degradation under biosulphidogenic conditions has not been extensively reported in the literature. Although aerobic degradation of lignin is well documented, anaerobic biodegradation has focused mainly on methanogenic systems with biosulphidogenic systems receiving less attention. Sulphate reducing bacteria are known to generate moderately high levels of both sulphide and alkalinity at room temperatures, and these conditions draw some comparison with the Kraft pulping process. In the Kraft pulping process, lignin is degraded chemically at ±170°C under high sulphide and alkaline conditions and may provide a model for understanding biosulphidogenic lignin degrading activity. The aim of this study was to investigate the biosulphidogenic hydrolysis of lignin within the context of the chemical and biological conditions generated by a mixed sulphate reducing bacteria consortia. Bioreactor studies with a mixed sulphate reducing consortia and pine wood powder (both untreated and depectinated) resulted in the generation of comparable levels of sulphide and alkalinity used in the chemical hydrolysis studies. Aromatic compound yields were between 20 to 50% of the chemical hydrolysis studies. This fluctuation may have been due to the utilization of these aromatic compounds as electron donors by the sulphate reducing consortia as evidenced by the high rate of sulphate reduction in both the untreated and depectinated wood bioreactors. Biodegradation of lignin model compounds was investigated in order to elucidate lignin degradation mechanisms. Both mono-aromatic and dimeric lignin model compounds were used as electron donors and carbon sources for the mixed sulphate reducing consortia. Biodegradation and mass spectrometer analysis of mono-aromatic compounds, ferulic acid and ferulic acid ethyl ester resulted in the production of intermediates such as catechol, cyclohexane carboxylic acid and adipic acid. These intermediates were also observed in the degradation of dimeric ferulic acid. Biodegradation of salicin resulted in the production of salicyl alcohol, ortho-cresol and acetate. Biodegradation of benzylic ether resulted in the production of vanillin and acetate as end products. The results of these studies provide evidence for a biosulphidogenic hydrolysis of lignin, and also the utilisation of lignin-derived aromatic compounds as electron donor sources, by a mixed sulphate reducing consortia.
- Full Text:
- Date Issued: 2002
Bird Migration: A General Survey, (2nd edn) by P. Berthold: book review
- Authors: Craig, Adrian J F K
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/465300 , vital:76592 , https://hdl.handle.net/10520/EJC17822
- Description: For more than 30 years, Peter Berthold has been involved in research on bird migration. His many publications and reviews make him an ideal candidate to undertake such an overview of the field, and this is now the second edition of a book on a topic that has fascinated naturalists and scientists for centuries.
- Full Text:
- Date Issued: 2002
- Authors: Craig, Adrian J F K
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/465300 , vital:76592 , https://hdl.handle.net/10520/EJC17822
- Description: For more than 30 years, Peter Berthold has been involved in research on bird migration. His many publications and reviews make him an ideal candidate to undertake such an overview of the field, and this is now the second edition of a book on a topic that has fascinated naturalists and scientists for centuries.
- Full Text:
- Date Issued: 2002
Broken vessels : the im-possibility of the art of remembrance and re-collection in the work of Anselm Kiefer, Christian Boltanski, William Kentridge and Santu Mofokeng
- Authors: Belluigi, Dina Zoe
- Date: 2002
- Subjects: History in art Kiefer, Anselm, 1945- Boltanski, Christian, 1944- Kentridge, William, 1955- Mofokeng, Santu, 1956-
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2395 , http://hdl.handle.net/10962/d1002191
- Description: This thesis is structured around investigating the philosophical and aesthetic problematics, politics, and possibilities of representing the past for the purposes of demythifying the present as well as commemorating the losses of history, as explored in the artworks of Anselm Kiefer, Christian Boltanski, William Kentridge and Santu Mofokeng. The first chapter begins with Theodor Adorno’s philosophical understanding of myth and history: how he is influenced by and then develops Karl Marx’s critique of society, Sigmund Freud’s critique of reason and its subject, and particularly Walter Benjamin’s ideas of history as catastrophe, the role of the historian and his messianic materialism. The second section looks at Theodor Adorno’s dialectic of art and society: immanent criticism in aesthetic practice, mimesis, and the shift in conceptions of allegory from Walter Benjamin’s understanding to that of Jacques Derrida. The last section of the chapter looks at Jacques Derrida’s poststructuralist theories against boundary-fixing, within that the ethical relation to the ‘other’ and the theorist/artist as psychic exile. The second chapter deals with the politics of remembrance and representation — beginning with Theodor Adorno’s historic interpretation of the Mosaic law against the making of images and Jean-Francois Lyotard on the im-possibility of representing the unrepresentable. The chapter is divided in two parts between the post-Holocaust European artists Anselm Kiefer and Christian Boltanski, and the post-apartheid South African artists William Kentridge and Santu Mofokeng. It explores, within these artists’ specific contexts, their formal and philosophical approaches to myth and history, and the problematics of image-making, representing the unrepresentable, and commemorating the immemorial. The thesis concludes by considering different conceptions of melancholia as they relate to these artists: the Freudian psychoanalytic approach, Benjamin’s notions of the artist-genius, and Julia Kristeva’s Lacanian reading of the humanist melancholic, concluding with the mythic-historical Kaballist notion of melancholia as the historical burden or responsibility to commemorate loss.
- Full Text:
- Date Issued: 2002
- Authors: Belluigi, Dina Zoe
- Date: 2002
- Subjects: History in art Kiefer, Anselm, 1945- Boltanski, Christian, 1944- Kentridge, William, 1955- Mofokeng, Santu, 1956-
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2395 , http://hdl.handle.net/10962/d1002191
- Description: This thesis is structured around investigating the philosophical and aesthetic problematics, politics, and possibilities of representing the past for the purposes of demythifying the present as well as commemorating the losses of history, as explored in the artworks of Anselm Kiefer, Christian Boltanski, William Kentridge and Santu Mofokeng. The first chapter begins with Theodor Adorno’s philosophical understanding of myth and history: how he is influenced by and then develops Karl Marx’s critique of society, Sigmund Freud’s critique of reason and its subject, and particularly Walter Benjamin’s ideas of history as catastrophe, the role of the historian and his messianic materialism. The second section looks at Theodor Adorno’s dialectic of art and society: immanent criticism in aesthetic practice, mimesis, and the shift in conceptions of allegory from Walter Benjamin’s understanding to that of Jacques Derrida. The last section of the chapter looks at Jacques Derrida’s poststructuralist theories against boundary-fixing, within that the ethical relation to the ‘other’ and the theorist/artist as psychic exile. The second chapter deals with the politics of remembrance and representation — beginning with Theodor Adorno’s historic interpretation of the Mosaic law against the making of images and Jean-Francois Lyotard on the im-possibility of representing the unrepresentable. The chapter is divided in two parts between the post-Holocaust European artists Anselm Kiefer and Christian Boltanski, and the post-apartheid South African artists William Kentridge and Santu Mofokeng. It explores, within these artists’ specific contexts, their formal and philosophical approaches to myth and history, and the problematics of image-making, representing the unrepresentable, and commemorating the immemorial. The thesis concludes by considering different conceptions of melancholia as they relate to these artists: the Freudian psychoanalytic approach, Benjamin’s notions of the artist-genius, and Julia Kristeva’s Lacanian reading of the humanist melancholic, concluding with the mythic-historical Kaballist notion of melancholia as the historical burden or responsibility to commemorate loss.
- Full Text:
- Date Issued: 2002
Building brand loyalty within selected segments of the South African fast moving consumer goods market
- Authors: Terblanche, Etienne
- Date: 2002
- Language: English
- Type: Thesis , Masters , MTech (Marketing)
- Identifier: vital:10774 , http://hdl.handle.net/10948/d1002108
- Description: The rapidly increasing competitiveness within the fast-moving consumer goods (FMCG) market compels an organisation within this market to not only entice consumers to purchase the organisation’s brand, but also to keep these consumers purchasing the brand. It is therefore essential that an organisation creates and maintains loyalty among consumers towards its brand. The objective of the research was to find out what strategies an organisation could implement to achieve and sustain loyalty from current and prospective consumers towards its brand in a highly competitive, FMCG market. The main areas of focus were as follows: Establishing the basis on which consumers differentiate between homogenous products. Determining what strategies an organisation could utilise to ensure that consumers will differentiate its brand from those of competitors. Obtaining relevant information to find out what variables motivate consumers to be brand loyal within the FMCG market. Ascertaining how an organisation could build a brand. Determining how an organisation could maintain brand loyalty from its existing consumers. The research included a study of relevant literature and an empirical study. The aim of the literature study was to obtain a solid base of information and opinions regarding the concepts of brands and building brand loyalty. Making use of structured questionnaires and through performing personal interviews, the empirical study consisted of two aspects. The one aspect was a brand loyalty survey conducted among 303 respondents, and the second aspect was a brand loyalty survey conducted with nine owners or marketers of leading brands. The following were the major findings of the research: Relying on being a leader in price and quality is not enough to ensure that a consumer would continue purchasing an organisation’s brand. A brand is an experience and in order for a consumer to become loyal towards a brand, the consumer should have a host of positive thoughts regarding past experience with the brand. It is essential that organisations within the FMCG market proactively develop and implement strategies aimed at creating and maintaining loyalty towards their brands.
- Full Text:
- Date Issued: 2002
- Authors: Terblanche, Etienne
- Date: 2002
- Language: English
- Type: Thesis , Masters , MTech (Marketing)
- Identifier: vital:10774 , http://hdl.handle.net/10948/d1002108
- Description: The rapidly increasing competitiveness within the fast-moving consumer goods (FMCG) market compels an organisation within this market to not only entice consumers to purchase the organisation’s brand, but also to keep these consumers purchasing the brand. It is therefore essential that an organisation creates and maintains loyalty among consumers towards its brand. The objective of the research was to find out what strategies an organisation could implement to achieve and sustain loyalty from current and prospective consumers towards its brand in a highly competitive, FMCG market. The main areas of focus were as follows: Establishing the basis on which consumers differentiate between homogenous products. Determining what strategies an organisation could utilise to ensure that consumers will differentiate its brand from those of competitors. Obtaining relevant information to find out what variables motivate consumers to be brand loyal within the FMCG market. Ascertaining how an organisation could build a brand. Determining how an organisation could maintain brand loyalty from its existing consumers. The research included a study of relevant literature and an empirical study. The aim of the literature study was to obtain a solid base of information and opinions regarding the concepts of brands and building brand loyalty. Making use of structured questionnaires and through performing personal interviews, the empirical study consisted of two aspects. The one aspect was a brand loyalty survey conducted among 303 respondents, and the second aspect was a brand loyalty survey conducted with nine owners or marketers of leading brands. The following were the major findings of the research: Relying on being a leader in price and quality is not enough to ensure that a consumer would continue purchasing an organisation’s brand. A brand is an experience and in order for a consumer to become loyal towards a brand, the consumer should have a host of positive thoughts regarding past experience with the brand. It is essential that organisations within the FMCG market proactively develop and implement strategies aimed at creating and maintaining loyalty towards their brands.
- Full Text:
- Date Issued: 2002
Building project management within financial institutions, a comparative assessment
- Authors: Van Tonder, Anthony David
- Date: 2002
- Subjects: Project management , Financial institutions -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10893 , http://hdl.handle.net/10948/79 , Project management , Financial institutions -- Management
- Description: The expenditure by financial institutions in South Africa on building projects could conservatively be estimated to total in the region of a billion rand per annum. It is surprising, given the amount of money being spent that there is currently no co-operation between the various financial institutions in the field of building project management. The research in this study found that most financial institutions were not taking into account all the costs and benefits when undertaking a project. When a project is undertaken in this manner, the viability analysis would not be a true reflection of the project being undertaken. The areas which were not taken into account when undertaking a project were the indirect project costs, which included costs like the project management staff themselves. An exception to this was First National Bank Metropolitan Delivery. They followed an outsourcing strategy in terms of their building project management function and the cost of this was known and added into the project cost. In terms of the benefits, this study found that the financial institutions do not take the intangible benefits into account. They do not consider the long term benefits which will be derived as a result of the implementation of a project. Arriving at a model which takes into account these factors, would provide material for a Doctorate thesis.
- Full Text:
- Date Issued: 2002
- Authors: Van Tonder, Anthony David
- Date: 2002
- Subjects: Project management , Financial institutions -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10893 , http://hdl.handle.net/10948/79 , Project management , Financial institutions -- Management
- Description: The expenditure by financial institutions in South Africa on building projects could conservatively be estimated to total in the region of a billion rand per annum. It is surprising, given the amount of money being spent that there is currently no co-operation between the various financial institutions in the field of building project management. The research in this study found that most financial institutions were not taking into account all the costs and benefits when undertaking a project. When a project is undertaken in this manner, the viability analysis would not be a true reflection of the project being undertaken. The areas which were not taken into account when undertaking a project were the indirect project costs, which included costs like the project management staff themselves. An exception to this was First National Bank Metropolitan Delivery. They followed an outsourcing strategy in terms of their building project management function and the cost of this was known and added into the project cost. In terms of the benefits, this study found that the financial institutions do not take the intangible benefits into account. They do not consider the long term benefits which will be derived as a result of the implementation of a project. Arriving at a model which takes into account these factors, would provide material for a Doctorate thesis.
- Full Text:
- Date Issued: 2002
Can formal language planning link to grassroots cultural initiatives?: an informal investigation
- Authors: Wright, Laurence
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:7041 , http://hdl.handle.net/10962/d1007381
- Description: Formal language planning is inevitably a top-down, highly technical process. Success for such planning would seem to depend on engaging productively with existing or readily developed social motivation within the society. This article reports on an informal investigation into how ordinary language practitioners and cultural workers in South Africa view the possibilities of contributing to the country’s emerging language dispensation, what they regard as their most useful possible contributions, and what they expect from the language planners and ‘government’ in support of South Africa’s Language Policy and Plan.
- Full Text:
- Date Issued: 2002
- Authors: Wright, Laurence
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:7041 , http://hdl.handle.net/10962/d1007381
- Description: Formal language planning is inevitably a top-down, highly technical process. Success for such planning would seem to depend on engaging productively with existing or readily developed social motivation within the society. This article reports on an informal investigation into how ordinary language practitioners and cultural workers in South Africa view the possibilities of contributing to the country’s emerging language dispensation, what they regard as their most useful possible contributions, and what they expect from the language planners and ‘government’ in support of South Africa’s Language Policy and Plan.
- Full Text:
- Date Issued: 2002
CANS: Customizable Alarm Notification System, an H. 323 Signalling Service
- Authors: Penton, J , Terzoli, Alfredo
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427562 , vital:72447 , https://www.cs.ru.ac.za/research/g97p5142/Docs/CANSSATNAC2002.pdf
- Description: H. 323 is a standardized signalling protocol for Voice over IP (VoIP) networks, which defines the terminal equipment and services that ena-ble real-time multimedia (data, voice, and video) communication over packetbased networks. One of the major advantages of carrying voice over Computer Networks, as opposed to the traditional SCN, is the pos-sibility of creating a wealth of services and integrating them into the network with minimal time and cost. Among these services, exists a subset that may need to interact at the signalling layer and H. 323 (ver-sion 4) provides mechanisms for this. This paper focuses on an appli-cation that was developed to explore and demonstrate H. 323’s signal-ling service creation and extension mechanisms.
- Full Text:
- Date Issued: 2002
- Authors: Penton, J , Terzoli, Alfredo
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427562 , vital:72447 , https://www.cs.ru.ac.za/research/g97p5142/Docs/CANSSATNAC2002.pdf
- Description: H. 323 is a standardized signalling protocol for Voice over IP (VoIP) networks, which defines the terminal equipment and services that ena-ble real-time multimedia (data, voice, and video) communication over packetbased networks. One of the major advantages of carrying voice over Computer Networks, as opposed to the traditional SCN, is the pos-sibility of creating a wealth of services and integrating them into the network with minimal time and cost. Among these services, exists a subset that may need to interact at the signalling layer and H. 323 (ver-sion 4) provides mechanisms for this. This paper focuses on an appli-cation that was developed to explore and demonstrate H. 323’s signal-ling service creation and extension mechanisms.
- Full Text:
- Date Issued: 2002
Case studies of equivalent fuzzy subgroups of finite abelian groups
- Authors: Ngcibi, Sakhile L
- Date: 2002
- Subjects: Abelian groups , Fuzzy sets
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5401 , http://hdl.handle.net/10962/d1005215 , Abelian groups , Fuzzy sets
- Description: The broad goal is to classify all fuzzy subgroups of a given type of finite group. P.S. Das introduced the ntion of level subgroups to characterize fuzzy subgroups of finite grouops. The notion of equivalence of fuzzy subgroups which is used in this thesis was first introduced by Murali and Makamba. We use this equivalence to charterise fuzzy subgroups of inite Abelian groups (p-groups in particular) for a specified prime p. We characterize some crisp subgroups of p-groups and investigate some cases on equi valent fuzzy subgroups.
- Full Text:
- Date Issued: 2002
- Authors: Ngcibi, Sakhile L
- Date: 2002
- Subjects: Abelian groups , Fuzzy sets
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5401 , http://hdl.handle.net/10962/d1005215 , Abelian groups , Fuzzy sets
- Description: The broad goal is to classify all fuzzy subgroups of a given type of finite group. P.S. Das introduced the ntion of level subgroups to characterize fuzzy subgroups of finite grouops. The notion of equivalence of fuzzy subgroups which is used in this thesis was first introduced by Murali and Makamba. We use this equivalence to charterise fuzzy subgroups of inite Abelian groups (p-groups in particular) for a specified prime p. We characterize some crisp subgroups of p-groups and investigate some cases on equi valent fuzzy subgroups.
- Full Text:
- Date Issued: 2002
Catalytic behaviour of metallophthalocyanines towards the detection of nitric oxide
- Authors: Vilakazi, Lea Sibulelo
- Date: 2002
- Subjects: Electrochemistry Nitric oxide
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4418 , http://hdl.handle.net/10962/d1006852
- Description: Electrocatalytic reduction and oxidation of nitric oxide (NO) using cobalt phthalocyanine complexes have been studied and compared to vitamin B₁₂ and other metallophthalocyanine (MPc) complexes. Modifying a glassy carbon electrode with these complexes resulted in improved sensitivity of the electrode allowing detection of NO to 10⁻⁹ mol dm⁻³. The mechanisms of catalysis were studied. Electrocatalysis of NO involves coordination of NO to the MPc complex. Hence catalytic activity is affected by the nature of the metal center. However coordination of NO to the MPc complex has to be reversible to eliminate poisoning of the electrode. Though FePc gave the best sensitivity and lowered the reduction potential more than CoPc, the strong Fe-NO bond resulted in the poisoning of the electrode hence, rendering the electrode unstable. Rate constants for NO coordination to the MPc complexes were studied. These rates were smaller than the studied NO porphyrin coordination rates. Electrocatalytic reduction of NO using MPc complexes involves a transfer of an electron from the metal center to the NO ligand. Hence, substitution of electron-donating grohps on the cobalt pthalocyanine complex resulted in improved sensitivity and catalytic activity. A CoPc modified microelectrode (11μm) was used to monitor NO in human blood components and to detect NO in a rat brain. Detections of NO were also done in aqueous solutions in the presence of interfering species such as dopamine and serotonin. An interaction between NO and serotonin was observed.
- Full Text:
- Date Issued: 2002
- Authors: Vilakazi, Lea Sibulelo
- Date: 2002
- Subjects: Electrochemistry Nitric oxide
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4418 , http://hdl.handle.net/10962/d1006852
- Description: Electrocatalytic reduction and oxidation of nitric oxide (NO) using cobalt phthalocyanine complexes have been studied and compared to vitamin B₁₂ and other metallophthalocyanine (MPc) complexes. Modifying a glassy carbon electrode with these complexes resulted in improved sensitivity of the electrode allowing detection of NO to 10⁻⁹ mol dm⁻³. The mechanisms of catalysis were studied. Electrocatalysis of NO involves coordination of NO to the MPc complex. Hence catalytic activity is affected by the nature of the metal center. However coordination of NO to the MPc complex has to be reversible to eliminate poisoning of the electrode. Though FePc gave the best sensitivity and lowered the reduction potential more than CoPc, the strong Fe-NO bond resulted in the poisoning of the electrode hence, rendering the electrode unstable. Rate constants for NO coordination to the MPc complexes were studied. These rates were smaller than the studied NO porphyrin coordination rates. Electrocatalytic reduction of NO using MPc complexes involves a transfer of an electron from the metal center to the NO ligand. Hence, substitution of electron-donating grohps on the cobalt pthalocyanine complex resulted in improved sensitivity and catalytic activity. A CoPc modified microelectrode (11μm) was used to monitor NO in human blood components and to detect NO in a rat brain. Detections of NO were also done in aqueous solutions in the presence of interfering species such as dopamine and serotonin. An interaction between NO and serotonin was observed.
- Full Text:
- Date Issued: 2002
Chemical studies of selected chromone derivatives
- Authors: Nchinda, Aloysius Tchangwe
- Date: 2002
- Subjects: Heterocyclic compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4434 , http://hdl.handle.net/10962/d1007442
- Description: This investigation has been geared towards several aspects of chromone chemistry. Selected 2-(N,N-dimethylarnino)chromones have been synthesized via 2-hydroxyacetophenone boron difluoride complex intermediates, and potentiometric analysis of these compounds in ethanolwater has been used to determine the influence of substituents on their basicity. The pKa values have been found to lie within a narrow range (1.92 - 2.52), and the observed substituent effects have been rationalized with the aid of semi-empirical and ab initio molecular orbital calculations. An efficient route has been developed for the synthesis of the naturally-occurring chromone, "granulosin" [7,8-(methylenedioxy)-2-propylchromone], and several C-2 side chain analogues in good yields, by condensing 2'-hydroxy-3',4'-(methylenedioxy)acetophenone with a range of ethyl carboxylate esters. These compounds show significant cytotoxic activity against the brine shrimp, Artemia salina, and two of them, the 2-ethyl and 2-benzyl derivatives also show 100% activity as pesticides on Beet army worms (BAW). Another naturally-occurring chromone derivative, 5-hydroxy-2-isopropyl-7-methoxychromone, and four C-2 side chain analogues have been prepared in moderate yields. These compounds also show significant cytotoxic activity against the brine shrimp, Artemia salina, and it is apparent that the presence of the hydroxyl group at C-5 is critical for such activity. The electronimpact mass spectra of both series of chromone derivatives have been investigated, permitting the elucidation of characteristic fragmentation patterns. In work directed towards the synthesis of potential HIV -1 protease inhibitors, five novel chromone-containing analogues of the clinically useful drug, ritonavir, have been synthesized. The design strategy has involved the coupling of substituted chromone-2- carboxylic acids with a specially prepared, hydroxyethylene dipeptide isostere to afford ritonavir analogues containing chromone termini. An interactive docking procedure has been used to explore the docking of ritonavir and the novel chromone-containing analogues into ' the active site of the enzyme, and has indicated the capacity of the ritonavir analogues to form hydrogen-bonds with the HJV-l enzyme receptor. Various substituted cbromone-3-carbaldehydes, which have been synthesized from the corresponding o-hyclroxyacetophenones using Vilsmeier-Haack methodology, have been examined as substrates for Morita-Baylis-Hillman reactions, using 3-hyclroxyquinuclidine as the catalyst and arcylonitrile and methyl acrylate as the activated alkenes. Optimization of the reaction conditions has permitted efficient conversion of the cbromone-3-carbaldehydes to the Morita-Baylis-Hillman products and, in some cases, dimeric products, within 24 h. Heating of the Morita-Baylis-Hillman products, arising from reactions with methyl acrylate, at 80 ºC for 3 h in the presence of DABCO as catalyst, has been shown to effect transformation to the corresponding dimers in good yield.
- Full Text:
- Date Issued: 2002
- Authors: Nchinda, Aloysius Tchangwe
- Date: 2002
- Subjects: Heterocyclic compounds
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4434 , http://hdl.handle.net/10962/d1007442
- Description: This investigation has been geared towards several aspects of chromone chemistry. Selected 2-(N,N-dimethylarnino)chromones have been synthesized via 2-hydroxyacetophenone boron difluoride complex intermediates, and potentiometric analysis of these compounds in ethanolwater has been used to determine the influence of substituents on their basicity. The pKa values have been found to lie within a narrow range (1.92 - 2.52), and the observed substituent effects have been rationalized with the aid of semi-empirical and ab initio molecular orbital calculations. An efficient route has been developed for the synthesis of the naturally-occurring chromone, "granulosin" [7,8-(methylenedioxy)-2-propylchromone], and several C-2 side chain analogues in good yields, by condensing 2'-hydroxy-3',4'-(methylenedioxy)acetophenone with a range of ethyl carboxylate esters. These compounds show significant cytotoxic activity against the brine shrimp, Artemia salina, and two of them, the 2-ethyl and 2-benzyl derivatives also show 100% activity as pesticides on Beet army worms (BAW). Another naturally-occurring chromone derivative, 5-hydroxy-2-isopropyl-7-methoxychromone, and four C-2 side chain analogues have been prepared in moderate yields. These compounds also show significant cytotoxic activity against the brine shrimp, Artemia salina, and it is apparent that the presence of the hydroxyl group at C-5 is critical for such activity. The electronimpact mass spectra of both series of chromone derivatives have been investigated, permitting the elucidation of characteristic fragmentation patterns. In work directed towards the synthesis of potential HIV -1 protease inhibitors, five novel chromone-containing analogues of the clinically useful drug, ritonavir, have been synthesized. The design strategy has involved the coupling of substituted chromone-2- carboxylic acids with a specially prepared, hydroxyethylene dipeptide isostere to afford ritonavir analogues containing chromone termini. An interactive docking procedure has been used to explore the docking of ritonavir and the novel chromone-containing analogues into ' the active site of the enzyme, and has indicated the capacity of the ritonavir analogues to form hydrogen-bonds with the HJV-l enzyme receptor. Various substituted cbromone-3-carbaldehydes, which have been synthesized from the corresponding o-hyclroxyacetophenones using Vilsmeier-Haack methodology, have been examined as substrates for Morita-Baylis-Hillman reactions, using 3-hyclroxyquinuclidine as the catalyst and arcylonitrile and methyl acrylate as the activated alkenes. Optimization of the reaction conditions has permitted efficient conversion of the cbromone-3-carbaldehydes to the Morita-Baylis-Hillman products and, in some cases, dimeric products, within 24 h. Heating of the Morita-Baylis-Hillman products, arising from reactions with methyl acrylate, at 80 ºC for 3 h in the presence of DABCO as catalyst, has been shown to effect transformation to the corresponding dimers in good yield.
- Full Text:
- Date Issued: 2002
Continuity and generalized continuity in dynamics and other applications
- Authors: Mimna, Roy Allan
- Date: 2002
- Subjects: Topological dynamics -- Research Dynamics -- Mathematical models -- Research Perturbation (Mathematics) Attractors (Mathematics) Baire classes Mathematics -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5404 , http://hdl.handle.net/10962/d1005218
- Description: The topological dynamics of continuous and noncontinuous dynamical systems are investigated. Various definitions of chaos are studied, as well as notions of stability. Results are obtained on asymptotically stable sets and the perturbation stability of such sets. The primary focus is on the traditional point sets of topological dynamics, including the chain recurrent set, omega-limit sets and attractors. The basic setting is that of a continuous function on a compact metric space, sometimes with additional properties on the space. The investigation includes results on the dynamical properties of typical continuous functions in the sense of Baire category. Results are also developed concerning dynamical systems involving quasi-continuous functions. An invariance property for the omega-limit sets of such functions is given. Omega-limit sets are characterized for Riemann integrable derivatives and derivatiyes which are continuous almost everywhere. Techniques used in the investigation and formulation of results include finding theorems which relate the rather disparate notions of dynamical properties and generalized continuity. In addition to dynamical systems, numerous other applications of generalized continuity are imoestigated. Techniques used include application of the Baire Category Theorem and the notion of semi-closure. For example, results are formulated concerning functions determined by dense sets, including separately continuous functions, thus generalizing the classical result for continuous functions on dense subsets of the domain. The uniform boundedness theorem is extended to functions which are not necessarily continuous, including various derivatives. The closed graph theorem is strictly generalized in two separate ways, and applications are presented using these generalizations. An invariance property of separately continuous functions is given. Cluster sets are studied in connection with separate continuity, and various results are presented concerning locally bounded functions.
- Full Text:
- Date Issued: 2002
- Authors: Mimna, Roy Allan
- Date: 2002
- Subjects: Topological dynamics -- Research Dynamics -- Mathematical models -- Research Perturbation (Mathematics) Attractors (Mathematics) Baire classes Mathematics -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5404 , http://hdl.handle.net/10962/d1005218
- Description: The topological dynamics of continuous and noncontinuous dynamical systems are investigated. Various definitions of chaos are studied, as well as notions of stability. Results are obtained on asymptotically stable sets and the perturbation stability of such sets. The primary focus is on the traditional point sets of topological dynamics, including the chain recurrent set, omega-limit sets and attractors. The basic setting is that of a continuous function on a compact metric space, sometimes with additional properties on the space. The investigation includes results on the dynamical properties of typical continuous functions in the sense of Baire category. Results are also developed concerning dynamical systems involving quasi-continuous functions. An invariance property for the omega-limit sets of such functions is given. Omega-limit sets are characterized for Riemann integrable derivatives and derivatiyes which are continuous almost everywhere. Techniques used in the investigation and formulation of results include finding theorems which relate the rather disparate notions of dynamical properties and generalized continuity. In addition to dynamical systems, numerous other applications of generalized continuity are imoestigated. Techniques used include application of the Baire Category Theorem and the notion of semi-closure. For example, results are formulated concerning functions determined by dense sets, including separately continuous functions, thus generalizing the classical result for continuous functions on dense subsets of the domain. The uniform boundedness theorem is extended to functions which are not necessarily continuous, including various derivatives. The closed graph theorem is strictly generalized in two separate ways, and applications are presented using these generalizations. An invariance property of separately continuous functions is given. Cluster sets are studied in connection with separate continuity, and various results are presented concerning locally bounded functions.
- Full Text:
- Date Issued: 2002
Convergence of old and new: a case study analysis of the development online by a South African radio station: Radiosondergrense/www.rsg.co.za
- Authors: Vasques, Vanessa Claudia
- Date: 2002
- Subjects: Radio stations -- South Africa , Radio stations -- South Africa -- Marketing , Radio stations -- Computer network resources , Radiosondergrense
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3498 , http://hdl.handle.net/10962/d1003913 , Radio stations -- South Africa , Radio stations -- South Africa -- Marketing , Radio stations -- Computer network resources , Radiosondergrense
- Description: This thesis is a case study analysis of the dream one radio station had about creating something new and unique on the Internet. RadioSonderGrense (RSG), an Afrikaans South African radio station, saw opportunities for themselves as a radio station on the Internet and put enormous resources and man-power into their venture. Their vision of what the Internet could bring to their radio station, and what they could bring to a website set the ground for creative and innovative thought. This dissertation is an examination of whether the Internet lived up to the expectations RSG had for it, and whether they were able to use their resources (in terms of their audience, their advertisers and the uniqueness of radio) to create something new and never seen before. The foremost aim of this dissertation is to shed some light onto the up-to-now under researched area of why radio stations have begun to develop on the Internet. Through the analysis of RSG, their comes to this subject some new thoughts and ideas about the convergence of these two mediums. RSG, and radio in general, are examined historically, practically and in comparison to the Internet. This is done in order to fully grasp the project that RSG had set for themselves and to realize where they had come from and where they hoped to go. It is argued that although RSG had hoped for great things, their innovative thought was not enough to guarantee them their dreams. They were not able to fully utilize the resources available to them in combination with what the Internet could offer them to fulfill the expectations they had for themselves. The foremost conclusion is that although RSG were able to envisage what the Internet could add to the radio station, they fell short of giving their listeners, users and advertisers a tool which could make the RSG website truly unique. Their website gives the user some interesting and useful applications, but it does not make full use of what the Internet and radio together could create.
- Full Text:
- Date Issued: 2002
- Authors: Vasques, Vanessa Claudia
- Date: 2002
- Subjects: Radio stations -- South Africa , Radio stations -- South Africa -- Marketing , Radio stations -- Computer network resources , Radiosondergrense
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3498 , http://hdl.handle.net/10962/d1003913 , Radio stations -- South Africa , Radio stations -- South Africa -- Marketing , Radio stations -- Computer network resources , Radiosondergrense
- Description: This thesis is a case study analysis of the dream one radio station had about creating something new and unique on the Internet. RadioSonderGrense (RSG), an Afrikaans South African radio station, saw opportunities for themselves as a radio station on the Internet and put enormous resources and man-power into their venture. Their vision of what the Internet could bring to their radio station, and what they could bring to a website set the ground for creative and innovative thought. This dissertation is an examination of whether the Internet lived up to the expectations RSG had for it, and whether they were able to use their resources (in terms of their audience, their advertisers and the uniqueness of radio) to create something new and never seen before. The foremost aim of this dissertation is to shed some light onto the up-to-now under researched area of why radio stations have begun to develop on the Internet. Through the analysis of RSG, their comes to this subject some new thoughts and ideas about the convergence of these two mediums. RSG, and radio in general, are examined historically, practically and in comparison to the Internet. This is done in order to fully grasp the project that RSG had set for themselves and to realize where they had come from and where they hoped to go. It is argued that although RSG had hoped for great things, their innovative thought was not enough to guarantee them their dreams. They were not able to fully utilize the resources available to them in combination with what the Internet could offer them to fulfill the expectations they had for themselves. The foremost conclusion is that although RSG were able to envisage what the Internet could add to the radio station, they fell short of giving their listeners, users and advertisers a tool which could make the RSG website truly unique. Their website gives the user some interesting and useful applications, but it does not make full use of what the Internet and radio together could create.
- Full Text:
- Date Issued: 2002
Counter-hair/gemonies: hair as a site of black identity struggle in post-apartheid South Africa
- Authors: Morey, Yvette Vivienne
- Date: 2002
- Subjects: Hairstyles -- South Africa , Women, Black -- Race identity , Hair -- Social aspects -- South Africa , Beauty, Personal -- Social aspects -- South Africa , Hairdressing of Black people
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3024 , http://hdl.handle.net/10962/d1002533 , Hairstyles -- South Africa , Women, Black -- Race identity , Hair -- Social aspects -- South Africa , Beauty, Personal -- Social aspects -- South Africa , Hairdressing of Black people
- Description: This thesis aims to allow the meanings engendered by various black hairstyle choices to emerge as discursive texts with which to further explore issues of black identity in post-apartheid South Africa. It seeks to identify what, if any, new discursive spaces and possibilities are operational in the post-apartheid capitalist context, and how identities are moulded by, and in tum, influence these possibilities. Operating within a discourse analytic approach, this research did not intend to establish fixed and generalisable notions of identity, but by unpacking the discursive baggage attached to historically loaded subjectivities it is concerned with reflecting identity as an ongoing and reflexive project. Entailing a diverse selection of texts, the analysis includes self-generated texts (stemming from interviews, a focus group and participant observation), and public domain texts (stemming from online and print media articles). Chapters 5 - 9 constitute the textual analysis. Using a consumer hair care product as a text, chapter 5 serves as an introduction to discourses surrounding black hair as a variously constructed object. This focus is concerned, more specifically, with the construction of black hair as a 'natural' object in chapter 6. Chapter 7 examines black hair gemonies and the " problematic classification and de/classification of class and consumer identities. Discourses pertaining to the construction and positioning of gendered and sexual subjectivities are explored in chapter 8. Finally, chapter 9 is concerned with the operations of discourses as they function to construct essentialised or hybrid conceptions of identity. The implications for black identity construction in post-apartheid South Africa are discussed in chapter 10 alongside a deconstruction of the research method and researcher positioning.
- Full Text:
- Date Issued: 2002
- Authors: Morey, Yvette Vivienne
- Date: 2002
- Subjects: Hairstyles -- South Africa , Women, Black -- Race identity , Hair -- Social aspects -- South Africa , Beauty, Personal -- Social aspects -- South Africa , Hairdressing of Black people
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3024 , http://hdl.handle.net/10962/d1002533 , Hairstyles -- South Africa , Women, Black -- Race identity , Hair -- Social aspects -- South Africa , Beauty, Personal -- Social aspects -- South Africa , Hairdressing of Black people
- Description: This thesis aims to allow the meanings engendered by various black hairstyle choices to emerge as discursive texts with which to further explore issues of black identity in post-apartheid South Africa. It seeks to identify what, if any, new discursive spaces and possibilities are operational in the post-apartheid capitalist context, and how identities are moulded by, and in tum, influence these possibilities. Operating within a discourse analytic approach, this research did not intend to establish fixed and generalisable notions of identity, but by unpacking the discursive baggage attached to historically loaded subjectivities it is concerned with reflecting identity as an ongoing and reflexive project. Entailing a diverse selection of texts, the analysis includes self-generated texts (stemming from interviews, a focus group and participant observation), and public domain texts (stemming from online and print media articles). Chapters 5 - 9 constitute the textual analysis. Using a consumer hair care product as a text, chapter 5 serves as an introduction to discourses surrounding black hair as a variously constructed object. This focus is concerned, more specifically, with the construction of black hair as a 'natural' object in chapter 6. Chapter 7 examines black hair gemonies and the " problematic classification and de/classification of class and consumer identities. Discourses pertaining to the construction and positioning of gendered and sexual subjectivities are explored in chapter 8. Finally, chapter 9 is concerned with the operations of discourses as they function to construct essentialised or hybrid conceptions of identity. The implications for black identity construction in post-apartheid South Africa are discussed in chapter 10 alongside a deconstruction of the research method and researcher positioning.
- Full Text:
- Date Issued: 2002
Critical literacy in South Africa : possibilities and constraints in 2002
- Authors: Prinsloo, Jeanne , Janks, H
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6330 , http://hdl.handle.net/10962/d1008475
- Description: This article examines the Curriculum documents produced in South Africa since the election of a democratic government in 1994 in order to consider the possibilities they create for the inclusion of critical literacy in the teaching of home languages. This discussion is set against an analysis of the apartheid curriculum documents prior to 1994 and a consideration of the ongoing inequalities in the provision of human and material resources across the system. Despite real constraints with regard to implementation, it is argued that the new Curriculum effects a significant break with the past and makes a positive contribution to transforming language education.
- Full Text:
- Date Issued: 2002
- Authors: Prinsloo, Jeanne , Janks, H
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6330 , http://hdl.handle.net/10962/d1008475
- Description: This article examines the Curriculum documents produced in South Africa since the election of a democratic government in 1994 in order to consider the possibilities they create for the inclusion of critical literacy in the teaching of home languages. This discussion is set against an analysis of the apartheid curriculum documents prior to 1994 and a consideration of the ongoing inequalities in the provision of human and material resources across the system. Despite real constraints with regard to implementation, it is argued that the new Curriculum effects a significant break with the past and makes a positive contribution to transforming language education.
- Full Text:
- Date Issued: 2002
Curriculum patterning in environmental education: A review of developments in formal education in South Africa
- Authors: Lotz-Sisitka, Heila
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437280 , vital:73365 , ISBN 978-07969-2001-0 , https://www.hsrcpress.ac.za/books/environmental-education-ethics-action-in-southern-africa
- Description: Written by environmental practitioners from across the region, the Monograph is a window onto envi-ronmental challenges in a diversity of African con-texts. These contexts include Malawian officials and community leaders, new to multi-level governance, taking up the challenge of environmental manage-ment in villages and districts; Ugandan small-scale farmers in partnership with NGOs trying to produce sustainably for the household and the international market; and government-civil society partnerships in South Africa, where the political transformation of the education system introduced a focus on envi-ronment and human rights in the national school curriculum.
- Full Text:
- Date Issued: 2002
- Authors: Lotz-Sisitka, Heila
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437280 , vital:73365 , ISBN 978-07969-2001-0 , https://www.hsrcpress.ac.za/books/environmental-education-ethics-action-in-southern-africa
- Description: Written by environmental practitioners from across the region, the Monograph is a window onto envi-ronmental challenges in a diversity of African con-texts. These contexts include Malawian officials and community leaders, new to multi-level governance, taking up the challenge of environmental manage-ment in villages and districts; Ugandan small-scale farmers in partnership with NGOs trying to produce sustainably for the household and the international market; and government-civil society partnerships in South Africa, where the political transformation of the education system introduced a focus on envi-ronment and human rights in the national school curriculum.
- Full Text:
- Date Issued: 2002
Cyclic voltammetric studies of octabutylthiophthalo-cyaninato-cobalt (II) and its self-assembled monolayer (SAM) on gold electrode
- Ozoemena, Kenneth, Westbroek, Philippe, Nyokong, Tebello
- Authors: Ozoemena, Kenneth , Westbroek, Philippe , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289567 , vital:56650 , xlink:href="https://doi.org/10.1142/S1088424602000130"
- Description: The synthesis of thiol-derivatized cobalt phthalocyanine complex, 2,3,9,10,16,17,23,24-octa (butylthiophthalocyaninatocobalt(II) (CoOBTPc) is described. Cyclic voltammetric data of this complex in DMF showed five quasi-reversible and reversible, diffusion-controlled redox couples, comprising both the phthalocyanine ring and central metal redox processes. The CoOBTPc complex forms a self-assembled monolayer (SAM) on gold electrode. The investigation of the integrity of this SAM, using the established cyclic voltammetric methods in aqueous alkaline solutions, gave evidence about the formation of a stable and easily reproducible monolayer. However, due to its susceptibility to destruction via oxidative and reductive desorptions, its potential application as an electrochemical sensor in alkaline pH is limited to a potential window of between −0.20 and +0.55 V vs Ag/AgCl.
- Full Text:
- Date Issued: 2002
- Authors: Ozoemena, Kenneth , Westbroek, Philippe , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289567 , vital:56650 , xlink:href="https://doi.org/10.1142/S1088424602000130"
- Description: The synthesis of thiol-derivatized cobalt phthalocyanine complex, 2,3,9,10,16,17,23,24-octa (butylthiophthalocyaninatocobalt(II) (CoOBTPc) is described. Cyclic voltammetric data of this complex in DMF showed five quasi-reversible and reversible, diffusion-controlled redox couples, comprising both the phthalocyanine ring and central metal redox processes. The CoOBTPc complex forms a self-assembled monolayer (SAM) on gold electrode. The investigation of the integrity of this SAM, using the established cyclic voltammetric methods in aqueous alkaline solutions, gave evidence about the formation of a stable and easily reproducible monolayer. However, due to its susceptibility to destruction via oxidative and reductive desorptions, its potential application as an electrochemical sensor in alkaline pH is limited to a potential window of between −0.20 and +0.55 V vs Ag/AgCl.
- Full Text:
- Date Issued: 2002
De-scribing the Timaeus: a transgression of the (phal) logocentric convention that discourse has only one form, language
- Authors: Ord, Jennifer
- Date: 2002
- Subjects: Discourse analysis , Art -- Philosophy
- Language: English
- Type: Thesis , Masters , MTech (Fine Art)
- Identifier: vital:10763 , http://hdl.handle.net/10948/115 , Discourse analysis , Art -- Philosophy
- Description: Like writing, art making is primarily a means of human expression, a means of communication – both “allow us to categorize our (inner and outer) environment as represented by symbols” (Appignanesi, 1999: 7). Yet it is language in the traditional Western garb of rational, philosophical discourse that has been perceived as the primary means of manifesting knowledge and positing truth, not only regarding the character of human existence, but also the nature of art. This infers the acceptance of both works as literally “truth of things”, and of “a language of reason” that “perfectly represents the real world” (Appignanesi, 1999: 77). Going against the grain of this traditional bias, Jacques Derrida holds that, firstly, “human knowledge is not as controllable or as cogent as Western thinkers would have it”: secondly, that language functions in “subtle and often contradictory ways” thus rendering certainty, truth, and perfect representation ever elusive to us (Lye, 1997: 2); and, thirdly, that “practices of interpretation which include art but are not limited to language, are extended discourses” (Appignanesi, 1999: 79). So, the “work of reason” (or rationalism) in this sense, is no longer the definitive “voice” of authority when it comes to ascribing meaning, proclaiming a message, defining truth, etc. Having the grip of its authority loosened and thus its rigid, imposing borders opened up, the communication of knowledge as a form of “aesthetic fiction” (Megill, 1987: 265) is allowed entry into the rarefied field of philosophical discourse. Moreover, if visual art (one such “aesthetic fiction”) is a process of sign-making, as is written and spoken language; if it therefore constitutes a signifying system, as does written and spoken language (Bal and Bryson in Preziosi, 1998: 242); and, if art is not just about autonomous, in-house formalism, then can it not, in any case, validly offer a form for discourse, albeit a different kind of discourse, a discourse that is not “truth seeking” (Sim, 1992: 33)? Here, the maker of the proposed artwork-asdiscourse would not be attempting to establish the truth or falsity of a philosophical position, but, as Derrida would have it, create a form which, without mimicry, would evocatively allude to Plato, his “deconstructor” and the maker of the proposed artwork. Discourse in this sense, then, would generate “active interpretation… infinite free association” (Megill, 1987: 283), because, as in Derrida’s writing, interpretation no longer aims at “the reconciliation or unification of warring truths (Sim, 1992: 10); in other words, it breaks with the (phal)logocentric tradition of discourse as dialectical and becomes questioning without closure. For visual art to enter the exalted arena of philosophical discourse, it cannot be selfreflexive in the Greenbergian or formalist sense – it has to be about something philosophical and this ‘something’ will be a deconstructive response to Plato’s doctrine of the two worlds in the Timaeus. What I propose presenting, then, is an imagographic rather than (phal)logocentric exposition of philosophical content where the aim is not to shape a certainty or to infer an absolute presence or essence of anything, but rather to suggest traces of the maker of the artwork reading Derrida, reading Plato. The proposed artwork as a response to texts will thus be a “pre-text” of my own endeavour.
- Full Text:
- Date Issued: 2002
- Authors: Ord, Jennifer
- Date: 2002
- Subjects: Discourse analysis , Art -- Philosophy
- Language: English
- Type: Thesis , Masters , MTech (Fine Art)
- Identifier: vital:10763 , http://hdl.handle.net/10948/115 , Discourse analysis , Art -- Philosophy
- Description: Like writing, art making is primarily a means of human expression, a means of communication – both “allow us to categorize our (inner and outer) environment as represented by symbols” (Appignanesi, 1999: 7). Yet it is language in the traditional Western garb of rational, philosophical discourse that has been perceived as the primary means of manifesting knowledge and positing truth, not only regarding the character of human existence, but also the nature of art. This infers the acceptance of both works as literally “truth of things”, and of “a language of reason” that “perfectly represents the real world” (Appignanesi, 1999: 77). Going against the grain of this traditional bias, Jacques Derrida holds that, firstly, “human knowledge is not as controllable or as cogent as Western thinkers would have it”: secondly, that language functions in “subtle and often contradictory ways” thus rendering certainty, truth, and perfect representation ever elusive to us (Lye, 1997: 2); and, thirdly, that “practices of interpretation which include art but are not limited to language, are extended discourses” (Appignanesi, 1999: 79). So, the “work of reason” (or rationalism) in this sense, is no longer the definitive “voice” of authority when it comes to ascribing meaning, proclaiming a message, defining truth, etc. Having the grip of its authority loosened and thus its rigid, imposing borders opened up, the communication of knowledge as a form of “aesthetic fiction” (Megill, 1987: 265) is allowed entry into the rarefied field of philosophical discourse. Moreover, if visual art (one such “aesthetic fiction”) is a process of sign-making, as is written and spoken language; if it therefore constitutes a signifying system, as does written and spoken language (Bal and Bryson in Preziosi, 1998: 242); and, if art is not just about autonomous, in-house formalism, then can it not, in any case, validly offer a form for discourse, albeit a different kind of discourse, a discourse that is not “truth seeking” (Sim, 1992: 33)? Here, the maker of the proposed artwork-asdiscourse would not be attempting to establish the truth or falsity of a philosophical position, but, as Derrida would have it, create a form which, without mimicry, would evocatively allude to Plato, his “deconstructor” and the maker of the proposed artwork. Discourse in this sense, then, would generate “active interpretation… infinite free association” (Megill, 1987: 283), because, as in Derrida’s writing, interpretation no longer aims at “the reconciliation or unification of warring truths (Sim, 1992: 10); in other words, it breaks with the (phal)logocentric tradition of discourse as dialectical and becomes questioning without closure. For visual art to enter the exalted arena of philosophical discourse, it cannot be selfreflexive in the Greenbergian or formalist sense – it has to be about something philosophical and this ‘something’ will be a deconstructive response to Plato’s doctrine of the two worlds in the Timaeus. What I propose presenting, then, is an imagographic rather than (phal)logocentric exposition of philosophical content where the aim is not to shape a certainty or to infer an absolute presence or essence of anything, but rather to suggest traces of the maker of the artwork reading Derrida, reading Plato. The proposed artwork as a response to texts will thus be a “pre-text” of my own endeavour.
- Full Text:
- Date Issued: 2002
Deconstructive discourse analysis: extending the methodological conversation
- Authors: Macleod, Catriona I
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6259 , http://hdl.handle.net/10962/d1007877 , http://journals.sagepub.com/doi/abs/10.1177/008124630203200103
- Description: Discourse analysis is increasingly becoming a methodology of preference amongst qualitative researchers. There is a danger, however, of it being viewed as a bounded and uncontested domain of research practice. As discourse analysis is inextricably linked with theoretical issues, it is a dynamic practice that is constantly in a process of revision. In this paper I reflect on some of the conceptualisations undergirding the notion of discourse – conceptualisations that have important implications in terms of how the practice of discourse analysis proceeds. I highlight some of the dualisms that may plague discourse analysis, and offer some solutions to these. Finally, I outline the deconstructive discourse analysis that I utilised in my doctoral work. The purpose of the latter is not to provide a recipe of methodology, but to illustrate how elements of various theorists’ work (in this case Foucault, Derrida and Parker) may be profitably drawn together to perform specific discourse analytic work. , Rhodes University
- Full Text:
- Date Issued: 2002
- Authors: Macleod, Catriona I
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6259 , http://hdl.handle.net/10962/d1007877 , http://journals.sagepub.com/doi/abs/10.1177/008124630203200103
- Description: Discourse analysis is increasingly becoming a methodology of preference amongst qualitative researchers. There is a danger, however, of it being viewed as a bounded and uncontested domain of research practice. As discourse analysis is inextricably linked with theoretical issues, it is a dynamic practice that is constantly in a process of revision. In this paper I reflect on some of the conceptualisations undergirding the notion of discourse – conceptualisations that have important implications in terms of how the practice of discourse analysis proceeds. I highlight some of the dualisms that may plague discourse analysis, and offer some solutions to these. Finally, I outline the deconstructive discourse analysis that I utilised in my doctoral work. The purpose of the latter is not to provide a recipe of methodology, but to illustrate how elements of various theorists’ work (in this case Foucault, Derrida and Parker) may be profitably drawn together to perform specific discourse analytic work. , Rhodes University
- Full Text:
- Date Issued: 2002