Conservation biology and management of the Twee River redfin, Barbus erubescens (Pisces : Cyprinide)
- Authors: Marriott, Michael Stephen
- Date: 1999
- Subjects: Barbus , Cyprinidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5248 , http://hdl.handle.net/10962/d1005091 , Barbus , Cyprinidae
- Description: Agricultural practices and increasing levels of pollution, water abstraction and numbers of predatory exotic fishes gave rise to mounting concern for the survival of the already endangered Twee River redfin, Barbus erubescens. Numbers were believed to be dwindling and an urgent re-assessment of the species' conservation status and major threats was called for. Distribution and estimated numbers of B. erubescens were detennined from a census conducted in the Twee River catclunent, and baseline knowledge of age and growth, reproduction, diet and habitat preferences was gained from biological work on collected specimens. Such understanding was necessary to formullate management ideas. Although an estimated 40% reduction in area of occupancy has occurred in the middle reaches of the Twee River system, the known distribution of B. erubescens was extended into the upper Suurvlei River. Despite fragmentation, surviving redfin populations remained healthy and total population size was estimated at 8400 individuals, 4100 of which were considered mature. Adults preferred pools with water exceeding 1 m in depth and tended to be associated with sandy or boulder substrates. Due to low numbers no such study was conducted on juveniles, although observations indicated a preference for the upper 50 cm of the water column, in or around marginal vegetation. Barbus erubescens spawn in summer and follow an asynchronous, iteroparous pattern. Males and females reach a maximum age of six years, maturing after two years at calculated SL of 45 mm in males and 42 mm in females. The diet was dominated by simulid and ephemeropteran larvae. Although the combined pressures of pesticide and fertiliser use, predation and competition from exotic species have undoubtedly had a negative impact on B. erubescens, the species has maintained viable populations. With continued expansion of these threats the focus of conservation attention may change but, at present, it is most likely agricultural water use, amounting to 7.43 x 10⁶ m³y⁻¹, 15% of the entire catchment production, which poses the greatest immediate threat to the survival of the species. Based on a deteriorating habitat and restricted area of occupancy, B. erubescens was rated Critically Endangered, and it is recommended that a conservation management plan be implemented in the Twee River catchment. The focus of such action should be on genetic preservation, with immediate projects including gamete cryopreservation and captive breeding and rearing programmes. Catchment management, including education and rehabilitation programmes, must be the long-term aim of conservation, to ensure the survival of B. erubescens.
- Full Text:
- Date Issued: 1999
Conservation biology and management of the Twee River redfin, Barbus erubescens (Pisces : Cyprinide)
- Authors: Marriott, Michael Stephen
- Date: 1999
- Subjects: Barbus , Cyprinidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5248 , http://hdl.handle.net/10962/d1005091 , Barbus , Cyprinidae
- Description: Agricultural practices and increasing levels of pollution, water abstraction and numbers of predatory exotic fishes gave rise to mounting concern for the survival of the already endangered Twee River redfin, Barbus erubescens. Numbers were believed to be dwindling and an urgent re-assessment of the species' conservation status and major threats was called for. Distribution and estimated numbers of B. erubescens were detennined from a census conducted in the Twee River catclunent, and baseline knowledge of age and growth, reproduction, diet and habitat preferences was gained from biological work on collected specimens. Such understanding was necessary to formullate management ideas. Although an estimated 40% reduction in area of occupancy has occurred in the middle reaches of the Twee River system, the known distribution of B. erubescens was extended into the upper Suurvlei River. Despite fragmentation, surviving redfin populations remained healthy and total population size was estimated at 8400 individuals, 4100 of which were considered mature. Adults preferred pools with water exceeding 1 m in depth and tended to be associated with sandy or boulder substrates. Due to low numbers no such study was conducted on juveniles, although observations indicated a preference for the upper 50 cm of the water column, in or around marginal vegetation. Barbus erubescens spawn in summer and follow an asynchronous, iteroparous pattern. Males and females reach a maximum age of six years, maturing after two years at calculated SL of 45 mm in males and 42 mm in females. The diet was dominated by simulid and ephemeropteran larvae. Although the combined pressures of pesticide and fertiliser use, predation and competition from exotic species have undoubtedly had a negative impact on B. erubescens, the species has maintained viable populations. With continued expansion of these threats the focus of conservation attention may change but, at present, it is most likely agricultural water use, amounting to 7.43 x 10⁶ m³y⁻¹, 15% of the entire catchment production, which poses the greatest immediate threat to the survival of the species. Based on a deteriorating habitat and restricted area of occupancy, B. erubescens was rated Critically Endangered, and it is recommended that a conservation management plan be implemented in the Twee River catchment. The focus of such action should be on genetic preservation, with immediate projects including gamete cryopreservation and captive breeding and rearing programmes. Catchment management, including education and rehabilitation programmes, must be the long-term aim of conservation, to ensure the survival of B. erubescens.
- Full Text:
- Date Issued: 1999
Constitution of Food and Allied Workers Union As amended at the Bi-Annual National Conference
- Food and Allied Workers Union (FAWU)
- Authors: Food and Allied Workers Union (FAWU)
- Date: 1999
- Subjects: Food and Allied Workers Union
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110099 , vital:33223
- Full Text:
- Date Issued: 1999
- Authors: Food and Allied Workers Union (FAWU)
- Date: 1999
- Subjects: Food and Allied Workers Union
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110099 , vital:33223
- Full Text:
- Date Issued: 1999
Contents : 3 projects
- Authors: Mtongana, Lindile
- Date: 1999
- Subjects: Teachers -- In-service training School management and organization -- Parent participation Education and state -- South Africa Educational law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1462 , http://hdl.handle.net/10962/d1003343
- Description: This project comprises a case study that I conducted at New Horizon High School in Butterworth, a school with a good reputation for its excellent academic standard. It is about Staff Development, which I have identified as the most vital component of effective teaching. Although there is a need to ensure that there is an adequate supply of teachers in schools, the greatest challenge lies in the development of the quality of those who are already in service. This enormous challenge seems to have been forgotten by many school leaders. I hope this study will be beneficial to school principals and teachers who want to be successful in their teaching careers in the 21st century.
- Full Text:
- Date Issued: 1999
- Authors: Mtongana, Lindile
- Date: 1999
- Subjects: Teachers -- In-service training School management and organization -- Parent participation Education and state -- South Africa Educational law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1462 , http://hdl.handle.net/10962/d1003343
- Description: This project comprises a case study that I conducted at New Horizon High School in Butterworth, a school with a good reputation for its excellent academic standard. It is about Staff Development, which I have identified as the most vital component of effective teaching. Although there is a need to ensure that there is an adequate supply of teachers in schools, the greatest challenge lies in the development of the quality of those who are already in service. This enormous challenge seems to have been forgotten by many school leaders. I hope this study will be beneficial to school principals and teachers who want to be successful in their teaching careers in the 21st century.
- Full Text:
- Date Issued: 1999
Creating a Web-based Spatiotemporal GIS using Java and VRML
- Clayton, Peter G, Wells, George C, Preston, Michael
- Authors: Clayton, Peter G , Wells, George C , Preston, Michael
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433413 , vital:72968 , https://www.learntechlib.org/p/7417/
- Description: This paper presents our approach towards creating a Web-based Spatiotemporal Geographic Information System, in particular, the creation of the spatial data set and the component interaction. It explores the possibility of rendering Virtual GIS Worlds in near real time across the WWW using a standard Web browser as the user interface. A" proof of concept" Web-based VGIS application was developed to investigate methods for the efficient transfer of high-bandwidth multimedia GIS content over the WWW, as well as providing a suitable development environment for research into Web-based Temporal GIS. This paper describes how VRML and Java were used to provide the visualisation of virtual worlds, interaction with individual objects inside the virtual world, and the query tools for adding, deleting, selecting or manipulating these objects or their associated attribute data.
- Full Text:
- Date Issued: 1999
- Authors: Clayton, Peter G , Wells, George C , Preston, Michael
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433413 , vital:72968 , https://www.learntechlib.org/p/7417/
- Description: This paper presents our approach towards creating a Web-based Spatiotemporal Geographic Information System, in particular, the creation of the spatial data set and the component interaction. It explores the possibility of rendering Virtual GIS Worlds in near real time across the WWW using a standard Web browser as the user interface. A" proof of concept" Web-based VGIS application was developed to investigate methods for the efficient transfer of high-bandwidth multimedia GIS content over the WWW, as well as providing a suitable development environment for research into Web-based Temporal GIS. This paper describes how VRML and Java were used to provide the visualisation of virtual worlds, interaction with individual objects inside the virtual world, and the query tools for adding, deleting, selecting or manipulating these objects or their associated attribute data.
- Full Text:
- Date Issued: 1999
Cumulative mild head injury in rugby: cognitive test profiles of professional rugby and cricket players
- Authors: Ancer, Ruth Lauren
- Date: 1999
- Subjects: Head -- Wounds and injuries , Rugby football injuries , Cricket injuries , Cognitive therapy , Neuropsychological tests
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2925 , http://hdl.handle.net/10962/d1002434 , Head -- Wounds and injuries , Rugby football injuries , Cricket injuries , Cognitive therapy , Neuropsychological tests
- Description: This study investigates the effects of cumulative concussive and subconcussive mild head injury on the cognitive functioning of professional rugby players. A comprehensive battery of neuropsychological tests was administered to 26 professional rugby players and a noncontact sport control group of 21 professional cricket players. The test performances of the rugby players were compared to those of the cricket players. Within the rugby group, forward and backline players were compared. An analysis of mean score differences between the rugby and cricket group failed to support the presence of brain damage effects in the rugby group. However, there was significantly increased variability of scores for the rugby players compared with the cricket players on tests particularly sensitive to cognitive deficit associated with mild head injury. This invalidates the null indications of average effects, indicating that a notable proportion of rugby players’ performances were falling off relative to the rest of the rugby players on tests vulnerable to the cognitive effects of diffuse brain damage. Mean score comparisons within the rugby group indicated that it was the subgroup of forward players, in particular, whose test performances revealed deficits suggestive of cerebral damage. Specifically, deficits were found in working memory, visuoperceptual tracking, verbal memory and visual memory, a pattern of deficits commensurate with cumulative mild head injury. The theoretical perspectives of Satz’s (1997) Brain Reserve Capacity Theory and Jordan’s (1997) ‘Shuttle’ model of variability are drawn upon in order to elucidate research findings and suggestions for future research are provided.
- Full Text:
- Date Issued: 1999
- Authors: Ancer, Ruth Lauren
- Date: 1999
- Subjects: Head -- Wounds and injuries , Rugby football injuries , Cricket injuries , Cognitive therapy , Neuropsychological tests
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2925 , http://hdl.handle.net/10962/d1002434 , Head -- Wounds and injuries , Rugby football injuries , Cricket injuries , Cognitive therapy , Neuropsychological tests
- Description: This study investigates the effects of cumulative concussive and subconcussive mild head injury on the cognitive functioning of professional rugby players. A comprehensive battery of neuropsychological tests was administered to 26 professional rugby players and a noncontact sport control group of 21 professional cricket players. The test performances of the rugby players were compared to those of the cricket players. Within the rugby group, forward and backline players were compared. An analysis of mean score differences between the rugby and cricket group failed to support the presence of brain damage effects in the rugby group. However, there was significantly increased variability of scores for the rugby players compared with the cricket players on tests particularly sensitive to cognitive deficit associated with mild head injury. This invalidates the null indications of average effects, indicating that a notable proportion of rugby players’ performances were falling off relative to the rest of the rugby players on tests vulnerable to the cognitive effects of diffuse brain damage. Mean score comparisons within the rugby group indicated that it was the subgroup of forward players, in particular, whose test performances revealed deficits suggestive of cerebral damage. Specifically, deficits were found in working memory, visuoperceptual tracking, verbal memory and visual memory, a pattern of deficits commensurate with cumulative mild head injury. The theoretical perspectives of Satz’s (1997) Brain Reserve Capacity Theory and Jordan’s (1997) ‘Shuttle’ model of variability are drawn upon in order to elucidate research findings and suggestions for future research are provided.
- Full Text:
- Date Issued: 1999
Declaration on HIV/AIDS
- Authors: COSATU, SAMWU
- Date: 1999
- Subjects: COSATU, SAMWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/162072 , vital:40754
- Description: This Special Congress of COSATU notes the relentless advance of HIV and AIDS since the 1997 Congress. 3,5 million people in South are infected with the Human Immuno-deficiency Virus (HIV). Life expectant South Africa will reduce to 40-45 over the next ten years and health care costs will be beyond the cape of survivors to pay for. It is now clear that publicity and condom distribution, though important, are enough. This requires a new approach and strategy, based on a partnership between government and society in which the organised working class should play a leading role.
- Full Text:
- Date Issued: 1999
- Authors: COSATU, SAMWU
- Date: 1999
- Subjects: COSATU, SAMWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/162072 , vital:40754
- Description: This Special Congress of COSATU notes the relentless advance of HIV and AIDS since the 1997 Congress. 3,5 million people in South are infected with the Human Immuno-deficiency Virus (HIV). Life expectant South Africa will reduce to 40-45 over the next ten years and health care costs will be beyond the cape of survivors to pay for. It is now clear that publicity and condom distribution, though important, are enough. This requires a new approach and strategy, based on a partnership between government and society in which the organised working class should play a leading role.
- Full Text:
- Date Issued: 1999
Development and characterisation of a membrane gradostat bioreactor for the bioremediation of aromatic pollutants using white rot fungi
- Authors: Leukes, Winston D
- Date: 1999
- Subjects: Aromatic compounds Pollutants Fungi Bioremediation Industrial microbiology Biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4032 , http://hdl.handle.net/10962/d1004092
- Description: Bioremediation of aromatic pollutants using the ligninolytic enzymes of the white rot fungi has been thoroughly researched and has been shown to have considerable potential for industrial application. However, little success in scale-up and industrialisation of this technology has been attained due to problems associated with the continuous production of the pollutant-degrading enzymes using conventional bioreactor systems. The low productivities reported result from the incompatibility of conventional submerged culture reactor techniques with the physiological requirements of these fungi which have evolved on a solid-air interface, viz. wood. The enzymes are also produced only during the stationary phase of growth and can therefore be regarded as secondary metabolites. This study reports the conceptualisation, characterisation and evaluation of a novel bioreactor system as a solution to the continuous production of idiophasic pollutant degrading enzymes by the white rot fungus Phanerochaete chlysosporium. The reactor concept evolved from observation of these fungi in their native state, i. e. the metabolism of lignocellulosic material and involves the immobilisation of the organism onto a capillary ultrafiltration membrane. Nutrient gradients established across the biofilm, an inherent characteristic of fixed bed perfusion reactors, are exploited to provide both nutrient rich and nutrient poor zones across the biofilm. This allows growth or primary metabolism in the nutrient rich zone, pushing older biomass into the nutrient poor zone where secondary metabolism is induced by nutrient starvation. In effect, this represents a transformation of the events of a batch culture from a temporal to a spatial domain, allowing continuous production of secondary metabolites over time. Direct contact of the outer part of the biofilm with an air stream simulated the solid-air interface of the native state of the fungus. In order to facilitate the practical application of the membrane gradostat reactor (MGR) concept, conventional capillary membranes and membrane bioreactor modules were first evaluated. These were found to be unsuitable for application of the MGR concept. However, critical analysis of the shortcomings of the conventional systems resulted in the formulation of a set of design criteria for the development of a suitable membrane and module. These design criteria were satisfied by the development of a novel capillary membrane for membrane bioreactors, as well as a transverse flow membrane module, which is a novel approach in membrane bioreactor configuration. For the physiological characterisation of the MGR concept, a single fibre bioreactor unit was designed, which allowed destructive sampling of the biofilm for analysis. Using this system, it was shown that distinct morphological zones could be observed radially across the mature biofilm obtained through MGR operation. That these morphotypes do represent the temporal events of a typical batch culture in a spatial domain was confirmed by following the morphological changes occurring during batch culture of the immobilised fungus where the onset of primary and secondary metabolic conditions were manipulated through control of the nutrient supply. The different morphotypes were correlated to distinct growth phases by comparison of the morphology to the secretion of known enzymatic markers for secondary metabolism, viz. succinate dehydrogenase and cytochrome C oxidoreductase. Detailed structure-function analysis of the biofilm using transmission electron microscopy and adapted enzyme cytochemical staining techniques showed that the biofilm appeared to operate as a co-ordinated unit, with primary and secondary metabolism apparently linked in one thallus through nutrient translocation. This study provided new insights into the physiology of P. chrysosp,o rium and a detailed descriptive model was formulated which correlates well to existing models of wood degradation by the white rot fungi (WRF). Evaluation of the process on a laboratory scale using a novel transverse flow membrane bioreactor showed that a volumetric productivity of 1916 U.L.⁻¹day⁻¹ for manganese peroxidase, one of the pollutant degrading enzymes, could be attained, corresponding to a final concentration of 2 361 U.L.⁻¹ This may be compared to the best reported system (Moreira el at. 1997), where a volumetric productivity of 202 U.L.⁻¹day⁻¹was achieved with a final concentration of 250 U.L.⁻¹ However, MGR productivity is yet to be subjected to rigorous optimisation studies. The process could be operated continuously for 60 days. However, peak productivity could not be maintained for long periods. This was found to be due to physical phenomena relating to the fluid dynamics of the system which caused fluid flow maldistribution, which would have to be resolved through engineering analysis. In evaluation of the MGR concept for aromatic pollutant removal, in this case ρ- cresol, from growth medium, good performance was also achieved. The VmaxKm calculated by linear regression for the MGR was 0.8 (R² = 0.93), which compared favourably to that reported by Lewandowski et al. (1990), who obtained a Vmax/Km of 0.34 for a packed bed reactor treating chlorophenol. It was concluded that the MGR showed suitable potential to warrant further development, and that the descriptive characterisation of the biofilm physiology provided a sufficient basis for process analysis once engineering aspects ofthe system could be resolved.
- Full Text:
- Date Issued: 1999
- Authors: Leukes, Winston D
- Date: 1999
- Subjects: Aromatic compounds Pollutants Fungi Bioremediation Industrial microbiology Biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4032 , http://hdl.handle.net/10962/d1004092
- Description: Bioremediation of aromatic pollutants using the ligninolytic enzymes of the white rot fungi has been thoroughly researched and has been shown to have considerable potential for industrial application. However, little success in scale-up and industrialisation of this technology has been attained due to problems associated with the continuous production of the pollutant-degrading enzymes using conventional bioreactor systems. The low productivities reported result from the incompatibility of conventional submerged culture reactor techniques with the physiological requirements of these fungi which have evolved on a solid-air interface, viz. wood. The enzymes are also produced only during the stationary phase of growth and can therefore be regarded as secondary metabolites. This study reports the conceptualisation, characterisation and evaluation of a novel bioreactor system as a solution to the continuous production of idiophasic pollutant degrading enzymes by the white rot fungus Phanerochaete chlysosporium. The reactor concept evolved from observation of these fungi in their native state, i. e. the metabolism of lignocellulosic material and involves the immobilisation of the organism onto a capillary ultrafiltration membrane. Nutrient gradients established across the biofilm, an inherent characteristic of fixed bed perfusion reactors, are exploited to provide both nutrient rich and nutrient poor zones across the biofilm. This allows growth or primary metabolism in the nutrient rich zone, pushing older biomass into the nutrient poor zone where secondary metabolism is induced by nutrient starvation. In effect, this represents a transformation of the events of a batch culture from a temporal to a spatial domain, allowing continuous production of secondary metabolites over time. Direct contact of the outer part of the biofilm with an air stream simulated the solid-air interface of the native state of the fungus. In order to facilitate the practical application of the membrane gradostat reactor (MGR) concept, conventional capillary membranes and membrane bioreactor modules were first evaluated. These were found to be unsuitable for application of the MGR concept. However, critical analysis of the shortcomings of the conventional systems resulted in the formulation of a set of design criteria for the development of a suitable membrane and module. These design criteria were satisfied by the development of a novel capillary membrane for membrane bioreactors, as well as a transverse flow membrane module, which is a novel approach in membrane bioreactor configuration. For the physiological characterisation of the MGR concept, a single fibre bioreactor unit was designed, which allowed destructive sampling of the biofilm for analysis. Using this system, it was shown that distinct morphological zones could be observed radially across the mature biofilm obtained through MGR operation. That these morphotypes do represent the temporal events of a typical batch culture in a spatial domain was confirmed by following the morphological changes occurring during batch culture of the immobilised fungus where the onset of primary and secondary metabolic conditions were manipulated through control of the nutrient supply. The different morphotypes were correlated to distinct growth phases by comparison of the morphology to the secretion of known enzymatic markers for secondary metabolism, viz. succinate dehydrogenase and cytochrome C oxidoreductase. Detailed structure-function analysis of the biofilm using transmission electron microscopy and adapted enzyme cytochemical staining techniques showed that the biofilm appeared to operate as a co-ordinated unit, with primary and secondary metabolism apparently linked in one thallus through nutrient translocation. This study provided new insights into the physiology of P. chrysosp,o rium and a detailed descriptive model was formulated which correlates well to existing models of wood degradation by the white rot fungi (WRF). Evaluation of the process on a laboratory scale using a novel transverse flow membrane bioreactor showed that a volumetric productivity of 1916 U.L.⁻¹day⁻¹ for manganese peroxidase, one of the pollutant degrading enzymes, could be attained, corresponding to a final concentration of 2 361 U.L.⁻¹ This may be compared to the best reported system (Moreira el at. 1997), where a volumetric productivity of 202 U.L.⁻¹day⁻¹was achieved with a final concentration of 250 U.L.⁻¹ However, MGR productivity is yet to be subjected to rigorous optimisation studies. The process could be operated continuously for 60 days. However, peak productivity could not be maintained for long periods. This was found to be due to physical phenomena relating to the fluid dynamics of the system which caused fluid flow maldistribution, which would have to be resolved through engineering analysis. In evaluation of the MGR concept for aromatic pollutant removal, in this case ρ- cresol, from growth medium, good performance was also achieved. The VmaxKm calculated by linear regression for the MGR was 0.8 (R² = 0.93), which compared favourably to that reported by Lewandowski et al. (1990), who obtained a Vmax/Km of 0.34 for a packed bed reactor treating chlorophenol. It was concluded that the MGR showed suitable potential to warrant further development, and that the descriptive characterisation of the biofilm physiology provided a sufficient basis for process analysis once engineering aspects ofthe system could be resolved.
- Full Text:
- Date Issued: 1999
Development of a model of performance indicators required for the effective management of South African Universities and Technikons
- Authors: Hutton, Wendy
- Date: 1999
- Subjects: Universities and colleges -- South Africa -- Management , Performance -- Management , Performance standards , Performance -- Measurement
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10826 , http://hdl.handle.net/10948/16 , Universities and colleges -- South Africa -- Management , Performance -- Management , Performance standards , Performance -- Measurement
- Description: Research has been conducted on performance indicators in higher education institutions in a number of countries. However, in South Africa limited research in this field on a national level is available to the management of South African higher education institutions. The change in funding of these institutions has led to performance measurement becoming essential in order to justify the use of public funds. In order to obtain more relevant information about performance indicators in the South African context, a literature study was conducted to develop a questionnaire to test the concurrence of the importance of performance indicators in South African universities and technikons. The findings of the survey shows a high level of concurrence for the performance indicators identified in the literature study.
- Full Text:
- Date Issued: 1999
- Authors: Hutton, Wendy
- Date: 1999
- Subjects: Universities and colleges -- South Africa -- Management , Performance -- Management , Performance standards , Performance -- Measurement
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10826 , http://hdl.handle.net/10948/16 , Universities and colleges -- South Africa -- Management , Performance -- Management , Performance standards , Performance -- Measurement
- Description: Research has been conducted on performance indicators in higher education institutions in a number of countries. However, in South Africa limited research in this field on a national level is available to the management of South African higher education institutions. The change in funding of these institutions has led to performance measurement becoming essential in order to justify the use of public funds. In order to obtain more relevant information about performance indicators in the South African context, a literature study was conducted to develop a questionnaire to test the concurrence of the importance of performance indicators in South African universities and technikons. The findings of the survey shows a high level of concurrence for the performance indicators identified in the literature study.
- Full Text:
- Date Issued: 1999
Development of integrated biological processing for the biodesalination of sulphate- and metal-rich wastewaters
- Authors: Boshoff, Genevieve Ann
- Date: 1999
- Subjects: Sewage -- Purification -- Biological treatment Sulfates Mineral industries -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3899 , http://hdl.handle.net/10962/d1003958
- Description: The substantial pollution threat to the South African environment from acid mine drainage (AMD) effluents has been well documented. Due to the juvenile nature of acidity in these flows, any remediation strategies implemented will need to function effectively and at low cost for long periods of time. The widespread use of sulphate reducing biological systems for the treatment of such effluents, and in particular large volume flows, has been limited. The supply of inexpensive electron donor and carbon sources, as well as appropriate reactor designs capable of handling large volume flows, have been identified as among the principal factors limiting development of this technology. The broad aim of the research programme reported here was to undertake an evaluation of the feasibility of an algal-bacterial integrated ponding system for the treatment of AMD, and the waste stabilisation pond (WSP) as an appropriate reactor design for this application. The study attempted to demonstrate the feasibility of individual unit operations in a proposed process train using complex organic carbon serving as the electron donor source for the sulphate reducing bacteria (SRB). Studies were undertaken as laboratory and pilot-scale investigations. Tannery effluent was shown to be a functional carbon source for biological sulphate reduction, with effective removal of sulphate and organics being recorded. In turn, the use of biological sulphate reduction for the treatment of tannery effluent was demonstrated. Algal biomass was shown in laboratory studies to function as an effective carbon source for biological sulphate reduction. It is known that micro-algae produce large quantities of photosynthate which is released to the growth medium under conditions of physiological stress. The potential for the use of photosynthate production in high rate algal ponding systems and its manipulation and use as a sustainable carbon source for sulphate reduction was investigated. Growth of a mixed culture of Dunaliella under conditions of light, temperature and salinity stress demonstrated production of large quantities of organic carbon. However, growth was inhibited at high temperatures. An elevation of salinity levels led to a decrease in growth of Dunaliella, but to increased organic carbon production. Spirulina spp., on the other hand, grew well at higher temperatures but showed the highest organic carbon production, and release to the medium, under low light conditions. These results led to a proposed process for the integration of algal ponding into an integrated system for the treatment of AMD. The algal biomass may be fed into the anaerobic digester as a carbon source, or it may be passed into a High Rate Algal Pond (HRAP) where it is stressed to enhance the organic carbon content. This can then be fed into the anaerobic digester as a carbon source. The impact of high levels of sulphide in the water feeding to the algal growth compartment was investigated. Spirulina spp. isolated from a tannery waste stabilisation pond was shown to be a sulphidophilic strain of cyanobacterium, capable of being adapted to high concentrations of sulphide. Dunaliella salina on the other hand was less tolerant. These results demonstrated the practical use of algal biomass providing an oxygen-rich cap for odour control on the surface of the facultative pond as well for the secondary treatment of sulphide-rich overflow to the High Rate Algal Pond. The ability of micro-algae to elevate the pH of their surrounding environment was evaluated as a functional precipitant and neutralisation reagent for acidic metal containing wastewater. Spirulina spp. was shown to perform effectively. D. salina was less functional in this environment. Anacystis spp. was effective in elevating the pH of a defined medium as well as a zinc-rich effluent. These results indicated the practicality of a neutralising function for algal ponds in the treatment of AMD. Metal removal in the system was found to be a combined function of sulphide precipitation, removal by binding to micro-algal biomass and extracellular polymeric substances. The feasibility of waste stabilisation ponding technology use for the treatment of large volume AMD effluents was provisionally demonstrated. It was shown that complex carbon sources would be used as efficient electron donors for sulphate reduction. The integration of algal ponding into the system provides for the generation of a sustainable carbon source, odour control with the recycling of oxygen-rich water onto the top of the facultative pond, secondary treatment of the anaerobic digester overflow, and the neutralisation of the incoming acidic effluents and removal of heavy metals. Integration of the individual unit operations, the feasibility of which has been provisionally demonstrated in this study, into a continuous process train is being investigated in follow-upstudies.
- Full Text:
- Date Issued: 1999
- Authors: Boshoff, Genevieve Ann
- Date: 1999
- Subjects: Sewage -- Purification -- Biological treatment Sulfates Mineral industries -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3899 , http://hdl.handle.net/10962/d1003958
- Description: The substantial pollution threat to the South African environment from acid mine drainage (AMD) effluents has been well documented. Due to the juvenile nature of acidity in these flows, any remediation strategies implemented will need to function effectively and at low cost for long periods of time. The widespread use of sulphate reducing biological systems for the treatment of such effluents, and in particular large volume flows, has been limited. The supply of inexpensive electron donor and carbon sources, as well as appropriate reactor designs capable of handling large volume flows, have been identified as among the principal factors limiting development of this technology. The broad aim of the research programme reported here was to undertake an evaluation of the feasibility of an algal-bacterial integrated ponding system for the treatment of AMD, and the waste stabilisation pond (WSP) as an appropriate reactor design for this application. The study attempted to demonstrate the feasibility of individual unit operations in a proposed process train using complex organic carbon serving as the electron donor source for the sulphate reducing bacteria (SRB). Studies were undertaken as laboratory and pilot-scale investigations. Tannery effluent was shown to be a functional carbon source for biological sulphate reduction, with effective removal of sulphate and organics being recorded. In turn, the use of biological sulphate reduction for the treatment of tannery effluent was demonstrated. Algal biomass was shown in laboratory studies to function as an effective carbon source for biological sulphate reduction. It is known that micro-algae produce large quantities of photosynthate which is released to the growth medium under conditions of physiological stress. The potential for the use of photosynthate production in high rate algal ponding systems and its manipulation and use as a sustainable carbon source for sulphate reduction was investigated. Growth of a mixed culture of Dunaliella under conditions of light, temperature and salinity stress demonstrated production of large quantities of organic carbon. However, growth was inhibited at high temperatures. An elevation of salinity levels led to a decrease in growth of Dunaliella, but to increased organic carbon production. Spirulina spp., on the other hand, grew well at higher temperatures but showed the highest organic carbon production, and release to the medium, under low light conditions. These results led to a proposed process for the integration of algal ponding into an integrated system for the treatment of AMD. The algal biomass may be fed into the anaerobic digester as a carbon source, or it may be passed into a High Rate Algal Pond (HRAP) where it is stressed to enhance the organic carbon content. This can then be fed into the anaerobic digester as a carbon source. The impact of high levels of sulphide in the water feeding to the algal growth compartment was investigated. Spirulina spp. isolated from a tannery waste stabilisation pond was shown to be a sulphidophilic strain of cyanobacterium, capable of being adapted to high concentrations of sulphide. Dunaliella salina on the other hand was less tolerant. These results demonstrated the practical use of algal biomass providing an oxygen-rich cap for odour control on the surface of the facultative pond as well for the secondary treatment of sulphide-rich overflow to the High Rate Algal Pond. The ability of micro-algae to elevate the pH of their surrounding environment was evaluated as a functional precipitant and neutralisation reagent for acidic metal containing wastewater. Spirulina spp. was shown to perform effectively. D. salina was less functional in this environment. Anacystis spp. was effective in elevating the pH of a defined medium as well as a zinc-rich effluent. These results indicated the practicality of a neutralising function for algal ponds in the treatment of AMD. Metal removal in the system was found to be a combined function of sulphide precipitation, removal by binding to micro-algal biomass and extracellular polymeric substances. The feasibility of waste stabilisation ponding technology use for the treatment of large volume AMD effluents was provisionally demonstrated. It was shown that complex carbon sources would be used as efficient electron donors for sulphate reduction. The integration of algal ponding into the system provides for the generation of a sustainable carbon source, odour control with the recycling of oxygen-rich water onto the top of the facultative pond, secondary treatment of the anaerobic digester overflow, and the neutralisation of the incoming acidic effluents and removal of heavy metals. Integration of the individual unit operations, the feasibility of which has been provisionally demonstrated in this study, into a continuous process train is being investigated in follow-upstudies.
- Full Text:
- Date Issued: 1999
Dramatic learning : a case study of theatre for development and environmental education
- Authors: Burt, Jane Caroline
- Date: 1999
- Subjects: Drama in education -- South Africa Environmental education -- Study and teaching (Elementary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1501 , http://hdl.handle.net/10962/d1003383
- Description: The aim of my research was to introduce drama, in the form of theatre for development processes, to local Grahamstown Primary School teachers, and to work closely with one teacher to explore theatre for development in the classroom, as a means of introducing both environmental education and learner-centred, constructivist teaching methodologies. I started my research by interviewing Primary School principals as well as sending out questionnaires to teachers, to survey their understanding and practice of drama and environmental education in the school curriculum and to invite them to participate in the research project. In collaboration with Educational Drama and Theatre students, I developed two workshops to introduce theatre for development processes such as image theatre and role-play to the teachers. Nine teachers attended this workshop which was video-taped. After the workshop I gave two lessons at a local school, in partnership with a teacher. Throughout this process I kept a research journal. All action components of the research were followed up with individual interviews, group discussions and a focus group. Although the study gave rise to multiple themes, I chose to highlight two: Firstly, Curriculum 2005 advocates a move towards more learner-centred,constructivist and process-orientated pedagogies. All of the participants in this study, including myself, had intentions of adopting a new approach tq education and teaching but found that we often reverted back to earlier learnt roles of product-orientated, text-based, authoritarian approaches to education which we originally had rejected. Secondly, I reflect on how we set out viewing environmental education, education, drama and research as a process and yet all the participants, including myself, continually tried to 'put on' the perfect performance in the form of a drama, a learning experience and research. This project was a participatory research project. The textwork of the research reflects a post-structural orientation. It has been written in the form of a drama to represent the many voices of the participants, but also to question the role of research in society and make research more accessible to non-academic readers. I also intend to perform the research process at a later stage.
- Full Text:
- Date Issued: 1999
- Authors: Burt, Jane Caroline
- Date: 1999
- Subjects: Drama in education -- South Africa Environmental education -- Study and teaching (Elementary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1501 , http://hdl.handle.net/10962/d1003383
- Description: The aim of my research was to introduce drama, in the form of theatre for development processes, to local Grahamstown Primary School teachers, and to work closely with one teacher to explore theatre for development in the classroom, as a means of introducing both environmental education and learner-centred, constructivist teaching methodologies. I started my research by interviewing Primary School principals as well as sending out questionnaires to teachers, to survey their understanding and practice of drama and environmental education in the school curriculum and to invite them to participate in the research project. In collaboration with Educational Drama and Theatre students, I developed two workshops to introduce theatre for development processes such as image theatre and role-play to the teachers. Nine teachers attended this workshop which was video-taped. After the workshop I gave two lessons at a local school, in partnership with a teacher. Throughout this process I kept a research journal. All action components of the research were followed up with individual interviews, group discussions and a focus group. Although the study gave rise to multiple themes, I chose to highlight two: Firstly, Curriculum 2005 advocates a move towards more learner-centred,constructivist and process-orientated pedagogies. All of the participants in this study, including myself, had intentions of adopting a new approach tq education and teaching but found that we often reverted back to earlier learnt roles of product-orientated, text-based, authoritarian approaches to education which we originally had rejected. Secondly, I reflect on how we set out viewing environmental education, education, drama and research as a process and yet all the participants, including myself, continually tried to 'put on' the perfect performance in the form of a drama, a learning experience and research. This project was a participatory research project. The textwork of the research reflects a post-structural orientation. It has been written in the form of a drama to represent the many voices of the participants, but also to question the role of research in society and make research more accessible to non-academic readers. I also intend to perform the research process at a later stage.
- Full Text:
- Date Issued: 1999
Dreamwork and imaginal healing: the incorporation of artwork in a systematized method of group dreamwork
- Authors: Euvrard, Gwenda Joan
- Date: 1999
- Subjects: Dreams -- Therapeutic use , Art therapy , Jungian psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2972 , http://hdl.handle.net/10962/d1002481 , Dreams -- Therapeutic use , Art therapy , Jungian psychology
- Description: This exploratory study investigated the expansion of an established systematized group dreamwork method (Shuttleworth-Jordan, 1995) to incorporate artwork. The rationale for the addition of artwork was situated firstly, in a poetic Jungian understanding of the image as a holistic "place" of gnosis or transformative healing and, secondly, in an argument that in order to carry the gnostic potential of the image into the lived world, a dreamwork method should involve all four styles of consciousness (thinking, intuition, sensation and feeling). It was considered that the verbal interpretive Shuttleworth-Jordan method would be enhanced by the incorporation of a visual artwork process in order more fully to open the potential of the method for incorporating the nonverbal intuitive, sensation and feeling styles of consciousness. In order to compare the established method (dreamwork Without Art) and the proposed method (dreamwork With Art), two dreamwork workshops were conducted in which all participants experienced all four conditions of the study: Dream Presenter Without Art, Dream Presenter With Art, Group Member Without Art, Group Member With Art. Two levels of assessment were utilized: a quantitative analysis (involving rating scales completed after each dreamwork session), supported by a qualitative analysis (involving written questionnaires completed at the end of the workshops and follow-up interviews conducted a week after completion of the workshops). The results suggested that the incorporation of artwork in the Shuttleworth-Jordan (1995) group dreamwork method enhanced the established method in that a consistent trend of increased involvement in the dreamwork process and increased dreamwork effectiveness was reflected, while no deleterious effects were noted which might detract from the effectiveness of the existing model which had been established in previous research studies. Finally, a refined step-by-step group dreamwork method incorporating artwork was proposed, which included qualitative feedback from the present study.
- Full Text:
- Date Issued: 1999
- Authors: Euvrard, Gwenda Joan
- Date: 1999
- Subjects: Dreams -- Therapeutic use , Art therapy , Jungian psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2972 , http://hdl.handle.net/10962/d1002481 , Dreams -- Therapeutic use , Art therapy , Jungian psychology
- Description: This exploratory study investigated the expansion of an established systematized group dreamwork method (Shuttleworth-Jordan, 1995) to incorporate artwork. The rationale for the addition of artwork was situated firstly, in a poetic Jungian understanding of the image as a holistic "place" of gnosis or transformative healing and, secondly, in an argument that in order to carry the gnostic potential of the image into the lived world, a dreamwork method should involve all four styles of consciousness (thinking, intuition, sensation and feeling). It was considered that the verbal interpretive Shuttleworth-Jordan method would be enhanced by the incorporation of a visual artwork process in order more fully to open the potential of the method for incorporating the nonverbal intuitive, sensation and feeling styles of consciousness. In order to compare the established method (dreamwork Without Art) and the proposed method (dreamwork With Art), two dreamwork workshops were conducted in which all participants experienced all four conditions of the study: Dream Presenter Without Art, Dream Presenter With Art, Group Member Without Art, Group Member With Art. Two levels of assessment were utilized: a quantitative analysis (involving rating scales completed after each dreamwork session), supported by a qualitative analysis (involving written questionnaires completed at the end of the workshops and follow-up interviews conducted a week after completion of the workshops). The results suggested that the incorporation of artwork in the Shuttleworth-Jordan (1995) group dreamwork method enhanced the established method in that a consistent trend of increased involvement in the dreamwork process and increased dreamwork effectiveness was reflected, while no deleterious effects were noted which might detract from the effectiveness of the existing model which had been established in previous research studies. Finally, a refined step-by-step group dreamwork method incorporating artwork was proposed, which included qualitative feedback from the present study.
- Full Text:
- Date Issued: 1999
DSC screening of potential prochlorperazine-excipient interactions in preformulation studies
- Brown, Michael E, Antunes, Edith M, Glass, Beverley M, Lebete, Mosimotsana L, Walker, Roderick B
- Authors: Brown, Michael E , Antunes, Edith M , Glass, Beverley M , Lebete, Mosimotsana L , Walker, Roderick B
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184367 , vital:44212 , xlink:href="https://doi.org/10.1023/A:1010150305542"
- Description: Differential scanning calorimetry was used to examine the thermal behaviour of mixtures of the drug prochlorperazine with standard excipients, to assess potential interactions, and of mixtures with cyclodextrins, to investigate inclusion complexation which could increase the photostability of the drug. For most of the excipients (magnesium stearate, stearic acid, Explotab®, Ac-Di-Sol®, Encompress® and Ludipress®, lactose and Starch 1500) disappearance or broadening of the melting endotherm of the drug indicated interactions. Lubritab® was the only 'inert' excipient tested. Mixtures of prochlorperazine and the cyclodextrins gave incomplete inclusion complexation as shown by only partial disappearance of the melting endotherm of the drug.
- Full Text: false
- Date Issued: 1999
- Authors: Brown, Michael E , Antunes, Edith M , Glass, Beverley M , Lebete, Mosimotsana L , Walker, Roderick B
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184367 , vital:44212 , xlink:href="https://doi.org/10.1023/A:1010150305542"
- Description: Differential scanning calorimetry was used to examine the thermal behaviour of mixtures of the drug prochlorperazine with standard excipients, to assess potential interactions, and of mixtures with cyclodextrins, to investigate inclusion complexation which could increase the photostability of the drug. For most of the excipients (magnesium stearate, stearic acid, Explotab®, Ac-Di-Sol®, Encompress® and Ludipress®, lactose and Starch 1500) disappearance or broadening of the melting endotherm of the drug indicated interactions. Lubritab® was the only 'inert' excipient tested. Mixtures of prochlorperazine and the cyclodextrins gave incomplete inclusion complexation as shown by only partial disappearance of the melting endotherm of the drug.
- Full Text: false
- Date Issued: 1999
Effect of concentration and degree of saturation of topical fluocinonide formulations on in vitro membrane transport and in vivo availability on human skin
- Schwarb, Fabian P, Imanidis, Georgios, Smith, Eric W, Haigh, John M, Surber, Christian
- Authors: Schwarb, Fabian P , Imanidis, Georgios , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1999
- Language: English
- Type: text , Article
- Identifier: vital:6425 , http://hdl.handle.net/10962/d1006560
- Description: Purpose. The thermodynamic acitvity of drugs in topical vehicles is considered to significantly influence topical delivery. In vitro diffusion across a synthetic membrane was shown to be correlated to the degree of saturation of the drug in the applied vehicle and therefore offers a potential for increased topical drug delivery. Fluocinonide a topical corticosteroid, was chosen as a model compound to investigate in vitro and in vivo availability from formulations with different degrees of saturation. Methods. Sub-, as well as, supersaturated drug solutions were prepared using PVP as an antinucleant agent. In vitro membrane diffusion experiments across silicone membrane and in vivo pharmacodynamic activity assessments, using the human skin blanching assay, were carried out. Results. Over the concentration range studied, the in vitro membrane transport of fluocinonide was proportional to the degree of saturation of the respective formulations. The in vivo pharmacodynamic response in the human skin blanching assay was related to the concentration of the drug in the vehicle irrespective of the degree of saturation. Conclusions. From the membrane permeation experiment it can be concluded, that the drug flux might be increased supra-proportionally with increasing donor concentration, drug (super-)saturation (proportional), beyond what would be anticipated based on ideal donor concentration and partition coefficient considerations only. These findings could not be confirmed in the in vivo investigation, probably due to additional vehicle effects (e.g., enhancement, irritation, drug binding) which have to be expected and could have altered the integrity of the stratum corneum and therewith topical bioavailability of the drug.
- Full Text: false
- Date Issued: 1999
- Authors: Schwarb, Fabian P , Imanidis, Georgios , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1999
- Language: English
- Type: text , Article
- Identifier: vital:6425 , http://hdl.handle.net/10962/d1006560
- Description: Purpose. The thermodynamic acitvity of drugs in topical vehicles is considered to significantly influence topical delivery. In vitro diffusion across a synthetic membrane was shown to be correlated to the degree of saturation of the drug in the applied vehicle and therefore offers a potential for increased topical drug delivery. Fluocinonide a topical corticosteroid, was chosen as a model compound to investigate in vitro and in vivo availability from formulations with different degrees of saturation. Methods. Sub-, as well as, supersaturated drug solutions were prepared using PVP as an antinucleant agent. In vitro membrane diffusion experiments across silicone membrane and in vivo pharmacodynamic activity assessments, using the human skin blanching assay, were carried out. Results. Over the concentration range studied, the in vitro membrane transport of fluocinonide was proportional to the degree of saturation of the respective formulations. The in vivo pharmacodynamic response in the human skin blanching assay was related to the concentration of the drug in the vehicle irrespective of the degree of saturation. Conclusions. From the membrane permeation experiment it can be concluded, that the drug flux might be increased supra-proportionally with increasing donor concentration, drug (super-)saturation (proportional), beyond what would be anticipated based on ideal donor concentration and partition coefficient considerations only. These findings could not be confirmed in the in vivo investigation, probably due to additional vehicle effects (e.g., enhancement, irritation, drug binding) which have to be expected and could have altered the integrity of the stratum corneum and therewith topical bioavailability of the drug.
- Full Text: false
- Date Issued: 1999
Effective application of digital printing techniques for fine artists in the South African context
- Authors: Giloi, Susan Louise
- Date: 1999
- Subjects: Photography -- Digital techniques
- Language: English
- Type: Thesis , Masters , MTech (Photography)
- Identifier: vital:10760 , http://hdl.handle.net/10948/15 , Photography -- Digital techniques
- Description: The question to be answered by this research is how would a fine artist working in South Africa, identify and use the correct digital printing techniques to accurately print their work?
- Full Text:
- Date Issued: 1999
- Authors: Giloi, Susan Louise
- Date: 1999
- Subjects: Photography -- Digital techniques
- Language: English
- Type: Thesis , Masters , MTech (Photography)
- Identifier: vital:10760 , http://hdl.handle.net/10948/15 , Photography -- Digital techniques
- Description: The question to be answered by this research is how would a fine artist working in South Africa, identify and use the correct digital printing techniques to accurately print their work?
- Full Text:
- Date Issued: 1999
Effects of zone and wave exposure on population structure and recruitment of the mussel (Perna perna) in South Africa
- Authors: Lindsay, Justin Robert
- Date: 1999
- Subjects: Perna -- South Africa , Perna -- Growth , Mussels -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5685 , http://hdl.handle.net/10962/d1005371 , Perna -- South Africa , Perna -- Growth , Mussels -- South Africa
- Description:
Certain aspects of the population dynamics of the brown mussel, Perna perna, were examined at 18 sites along the south coast of South African. Specifically the effects of wave exposure and tidal height were examined in relation to mussel size, biomass and density. A single set of samples was removed from each of the 18 sites, over three spring tide cycles. Sites were classified as exposed or sheltered prior to sampling. Principal component analysis (PCA) (based on mussel length data) and length frequency histograms revealed that there was a general decrease in the modal size of the adult mussel cohort with an increase in tidal height. The effects of exposure on mussel size decreased higher on the shore. On the exposed low shore the maximum size of mussels had a mean length of 102.3mm and was significantly larger (ANOVA, p<0.0001) than that for mussels on sheltered shores (86.7mm). The difference between mean maximum lengths of mussels on the mid shore was not so great, exposed sites had a average mean maximum length of 79.9, while on the sheltered shores it was 68.4mm. On the high shore the difference between the average mean maximum lengths at exposed and sheltered sites was only 3.9mm. The fact that the effects of exposure were greatest on the low shore was also borne out in the PCA. In this analysis low shore exposed and sheltered zones separated into two groups with little overlap, mid shore exposed and sheltered zones were positioned next to each other, and exposed and sheltered high shore zones were clumped together. Densities of adult mussels (>l5mm) were calculated as real densities from randomly placed quads i.e. not from areas of 100% cover. Density decreased up the shore; low, mid and high shore zones were significantly different from each other (ANOVA , p<0.0001; followed by multiple range tests). There was no significant difference between the densities of mussels at exposed and sheltered sites within each zone (ANOVA, p=0.7155). Recruit (
- Full Text:
- Date Issued: 1999
- Authors: Lindsay, Justin Robert
- Date: 1999
- Subjects: Perna -- South Africa , Perna -- Growth , Mussels -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5685 , http://hdl.handle.net/10962/d1005371 , Perna -- South Africa , Perna -- Growth , Mussels -- South Africa
- Description:
Certain aspects of the population dynamics of the brown mussel, Perna perna, were examined at 18 sites along the south coast of South African. Specifically the effects of wave exposure and tidal height were examined in relation to mussel size, biomass and density. A single set of samples was removed from each of the 18 sites, over three spring tide cycles. Sites were classified as exposed or sheltered prior to sampling. Principal component analysis (PCA) (based on mussel length data) and length frequency histograms revealed that there was a general decrease in the modal size of the adult mussel cohort with an increase in tidal height. The effects of exposure on mussel size decreased higher on the shore. On the exposed low shore the maximum size of mussels had a mean length of 102.3mm and was significantly larger (ANOVA, p<0.0001) than that for mussels on sheltered shores (86.7mm). The difference between mean maximum lengths of mussels on the mid shore was not so great, exposed sites had a average mean maximum length of 79.9, while on the sheltered shores it was 68.4mm. On the high shore the difference between the average mean maximum lengths at exposed and sheltered sites was only 3.9mm. The fact that the effects of exposure were greatest on the low shore was also borne out in the PCA. In this analysis low shore exposed and sheltered zones separated into two groups with little overlap, mid shore exposed and sheltered zones were positioned next to each other, and exposed and sheltered high shore zones were clumped together. Densities of adult mussels (>l5mm) were calculated as real densities from randomly placed quads i.e. not from areas of 100% cover. Density decreased up the shore; low, mid and high shore zones were significantly different from each other (ANOVA , p<0.0001; followed by multiple range tests). There was no significant difference between the densities of mussels at exposed and sheltered sites within each zone (ANOVA, p=0.7155). Recruit (
- Full Text:
- Date Issued: 1999
Electrochemical studies of gold bioaccumulation by yeast cell wall components
- Authors: Lack, Barbara Anne
- Date: 1999
- Subjects: Hydrometallurgy , Electrochemical analysis , Gold ores , Gold
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4311 , http://hdl.handle.net/10962/d1004969 , Hydrometallurgy , Electrochemical analysis , Gold ores , Gold
- Description: Gold, amongst other group 11 metals, was almost certainly one of the first three metals known to man. In addition to the economic importance of the metal, gold has a wide variety of applications in the medical, electrocatalytical and micro-electronics fields. However, the determination of gold ions in solution, with accuracy, precision, sensitivity and selectivity is still an interesting and much debated topic in analytical chemistry. A system whereby gold ions have been successfully detected employing an electrochemical technique, known as stripping voltammetry, has been developed. The electrochemical method was chosen over other available techniques for the sensitivity, particularly at low concentrations, and selectivity properties; notably in the presence of other metal ions. Under acidic conditions, the electrochemical technique was applied and the presence of gold(III), at a concentration of 2.53 x 10⁻⁵ mol dm⁻³ in a mine waste water sample, was detected. Biomass, in particular yeast and algal types, have been successfully employed in extracting low concentrations of gold ions from industrial effluents. The manipulation of the biological facility for mineral interaction, biohydrometallurgy, may yield numerous potential new technologies. South Africa in particular would benefit from this area of research, since the country is a major ore and metal refining country and if the output and the efficiency of the mines could be improved, even by a small percentage, the financial rewards would be vast. In this study, the application of adsorptive cathodic stripping voltammetry (AdCSV) of gold(III) in the presence of various Saccharomyces cerevisiae cell wall components, was investigated to determine which, if any, were involved specifically in the chemical binding of the gold ions. The chitin and mannan extracts showed the most promise with detection limits of 1.10 x 10⁻⁶ mol dm⁻³ and 9 x 10⁻⁹ mol dm⁻³, respectively; employing the AdCSV technique. A modification of the stripping voltammetry technique, Osteryoung square wave stripping voltammetry (OSWSV), provided the lowest detection limit, for gold(IIl) in the presence of mannan, of 1.70 x 10⁻¹¹ mol dm⁻³ ; utilising a modified carbon paste electrode. The detection of gold(III) has been shown to be dependent on the type of electrode employed, the electrolyte solution and the presence of interfering agents. The effect of copper(II) and silver(I) on the detection of the gold(III) in solution was investigated; whilst the silver(I) has shown no detrimental effects on gold (III) detection systems, copper(II) has indicated the possibility of forming an inter-metallic compound with the gold(III). However, mannan has shown to selectively and preferentially bind the gold(III) in the presence of a ten-fold excess of copper(II). Nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy, as well as computer modelling techniques were employed to further investIgate the mannan-gold(III) interaction and proposed complex formed. The NMR, IR and computer modelling data are in agreement with the electrochemical data on proposing a mannan-gold(III) complex. The co-ordination site was established to be in the vicinity of the H-I and H-2 protons and the gold(III) adopts a square-planar geometry upon co-ordination. The benefits of the research are useful from a biological perspective (i. e. as more is known about the binding sites, microbiologists/biochemists may work on the optimisation of parameters for these sites or work could be furthered into the enhanced expression of the sites) and an industrial one. In addition to the' two major benefits, an improved understanding of gold and its chemistry would be achieved, which is advantageous for other fields of research as well.
- Full Text:
- Date Issued: 1999
- Authors: Lack, Barbara Anne
- Date: 1999
- Subjects: Hydrometallurgy , Electrochemical analysis , Gold ores , Gold
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4311 , http://hdl.handle.net/10962/d1004969 , Hydrometallurgy , Electrochemical analysis , Gold ores , Gold
- Description: Gold, amongst other group 11 metals, was almost certainly one of the first three metals known to man. In addition to the economic importance of the metal, gold has a wide variety of applications in the medical, electrocatalytical and micro-electronics fields. However, the determination of gold ions in solution, with accuracy, precision, sensitivity and selectivity is still an interesting and much debated topic in analytical chemistry. A system whereby gold ions have been successfully detected employing an electrochemical technique, known as stripping voltammetry, has been developed. The electrochemical method was chosen over other available techniques for the sensitivity, particularly at low concentrations, and selectivity properties; notably in the presence of other metal ions. Under acidic conditions, the electrochemical technique was applied and the presence of gold(III), at a concentration of 2.53 x 10⁻⁵ mol dm⁻³ in a mine waste water sample, was detected. Biomass, in particular yeast and algal types, have been successfully employed in extracting low concentrations of gold ions from industrial effluents. The manipulation of the biological facility for mineral interaction, biohydrometallurgy, may yield numerous potential new technologies. South Africa in particular would benefit from this area of research, since the country is a major ore and metal refining country and if the output and the efficiency of the mines could be improved, even by a small percentage, the financial rewards would be vast. In this study, the application of adsorptive cathodic stripping voltammetry (AdCSV) of gold(III) in the presence of various Saccharomyces cerevisiae cell wall components, was investigated to determine which, if any, were involved specifically in the chemical binding of the gold ions. The chitin and mannan extracts showed the most promise with detection limits of 1.10 x 10⁻⁶ mol dm⁻³ and 9 x 10⁻⁹ mol dm⁻³, respectively; employing the AdCSV technique. A modification of the stripping voltammetry technique, Osteryoung square wave stripping voltammetry (OSWSV), provided the lowest detection limit, for gold(IIl) in the presence of mannan, of 1.70 x 10⁻¹¹ mol dm⁻³ ; utilising a modified carbon paste electrode. The detection of gold(III) has been shown to be dependent on the type of electrode employed, the electrolyte solution and the presence of interfering agents. The effect of copper(II) and silver(I) on the detection of the gold(III) in solution was investigated; whilst the silver(I) has shown no detrimental effects on gold (III) detection systems, copper(II) has indicated the possibility of forming an inter-metallic compound with the gold(III). However, mannan has shown to selectively and preferentially bind the gold(III) in the presence of a ten-fold excess of copper(II). Nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy, as well as computer modelling techniques were employed to further investIgate the mannan-gold(III) interaction and proposed complex formed. The NMR, IR and computer modelling data are in agreement with the electrochemical data on proposing a mannan-gold(III) complex. The co-ordination site was established to be in the vicinity of the H-I and H-2 protons and the gold(III) adopts a square-planar geometry upon co-ordination. The benefits of the research are useful from a biological perspective (i. e. as more is known about the binding sites, microbiologists/biochemists may work on the optimisation of parameters for these sites or work could be furthered into the enhanced expression of the sites) and an industrial one. In addition to the' two major benefits, an improved understanding of gold and its chemistry would be achieved, which is advantageous for other fields of research as well.
- Full Text:
- Date Issued: 1999
Electrochemical studies of metal-ligand interactions and of metal binding proteins
- Authors: Limson, Janice Leigh
- Date: 1999
- Subjects: Electrochemical analysis , Metals -- Analysis , Proteins -- Analysis , Electrochemistry -- Technique
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4551 , http://hdl.handle.net/10962/d1018239
- Description: Electrochemical methods were researched for the analysis of metals, proteins and the identification of metal binding proteins. Adsorptive cathodic stripping voltamrnetry for metal analysis combines the inherent sensitivity of electrochemical techniques with the specificity of ligands for the nonfaradaic preconcentration of analytes at the electrode. The utility of catechol, resorcinol, 4-methylcatechol and 4-t-butylcatechol as ligands was explored for the sensitive analysis of copper, bismuth, cadmium and lead on a mercury film glassy carbon electrode. Metal complexes of lead, copper and bismuth with resorcinol showed the largest increase in current with increase in metal concentration, whereas complexes of these metals with 4-t-butylcatechol showed the lowest current response. Cadmium showed the highest current responses with 4-methylcatechol. The four metals could be determined simultaneously in the presence of resorcinol, although considerable interference was observed between bismuth and copper. The electroanalysis of cysteine and cysteine containing proteins at carbon electrodes are impaired by slow electron transfer rates at carbon electrodes, exhibiting high overpotentials, greater than 1 V vs Ag! Agel. Metallophthalocyanines have been shown to promote the electrocatalysis of cysteine at lowered potentials. Chemical modification of electrodes with appropriate modifiers is a means of incorporating specificity into electroanalysis, with applications in electrocatalysis. A glassy carbon electrode was modified by electrodeposition of cobalt (II) tetrasulphophthalocyanine [Co(II)TSPct to produce a chemically modified glassy carbon electrode (CMGCE). The CoTSPc-CMGCE catalysed the oxidation of cysteine in the pH range 1 to 10. The significance of this electrode is an application for analysis of proteins at biological pH's. A biscyanoruthenium(II) phthalocyanine CMGCE catalysed the oxidation of cysteine at 0.43 V vs Ag/AgCl a significant lowering in the overpotential for the oxidation of cysteine. Metallothionein, a metal binding protein, is believed to be involved in metal homeostasis and detoxification in the peripheral organs of living systems. A method for the quantitative determination of this protein utilising its high cysteine content was presented. At pH 8.4 Tris-HCl buffer, and using a CoTSPc-CMGCE modified by electrodeposition of the modifier, the anodic peaks for the oxidation of metallothionein was observed at 0. 90 V vs Ag/ AgCI. Ferredoxin is a simple iron-sulphur protein. One tenth of its residues are cysteine. Ferredoxin is involved in simple electron transfer processes during photosynthesis and respiration. Electrochemical studies of spinach ferredoxin were conducted at a CoTSPc-CMGCE. Anodic currents for the oxidation of the cysteine fragment of ferredoxin was observed at 0.85 V vs Ag/AgCl in HEPES buffer at pH 7.4, representing a new method for analysis of this protein. Voltammetric studies of its ferric/ferrous transition have shown quasi-reversible waves atE~ -0.62 V vs Ag/AgCl only in the presence of promoters. At a CoTSPc-CMGCE, a cathodic wave attributed to the reduction of Fe(III)/Fe(II) was observed at Epc -0.34 V vs Ag/AgCl. This represents an alternative method for voltammetric studies of the ferric/ferrous transition at significantly lowered potentials. Melatonin, a pineal gland hormone functions m setting and entraining circadian rhythms and in neuroprotection as a free radical scavenger and general antioxidant. Using adsorptive cathodic stripping voltammetry, the binding affinities of melatonin, serotonin and tryptophan for metals, were measured. The results showed that the following metal complexes were formed: aluminium with melatonin, serotonin and tryptophan; cadmium with melatonin and tryptophan; copper with melatonin and serotonin; iron (III) with melatonin and serotonin; lead with melatonin, tryptophan and serotonin, zinc with melatonin and tryptophan and iron (II) with tryptophan. The studies suggest a further role for melatonin in the reduction of free radical generation and in metal detoxification and may explain the accumulation of aluminium in Alzheimer's disease.
- Full Text:
- Date Issued: 1999
- Authors: Limson, Janice Leigh
- Date: 1999
- Subjects: Electrochemical analysis , Metals -- Analysis , Proteins -- Analysis , Electrochemistry -- Technique
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4551 , http://hdl.handle.net/10962/d1018239
- Description: Electrochemical methods were researched for the analysis of metals, proteins and the identification of metal binding proteins. Adsorptive cathodic stripping voltamrnetry for metal analysis combines the inherent sensitivity of electrochemical techniques with the specificity of ligands for the nonfaradaic preconcentration of analytes at the electrode. The utility of catechol, resorcinol, 4-methylcatechol and 4-t-butylcatechol as ligands was explored for the sensitive analysis of copper, bismuth, cadmium and lead on a mercury film glassy carbon electrode. Metal complexes of lead, copper and bismuth with resorcinol showed the largest increase in current with increase in metal concentration, whereas complexes of these metals with 4-t-butylcatechol showed the lowest current response. Cadmium showed the highest current responses with 4-methylcatechol. The four metals could be determined simultaneously in the presence of resorcinol, although considerable interference was observed between bismuth and copper. The electroanalysis of cysteine and cysteine containing proteins at carbon electrodes are impaired by slow electron transfer rates at carbon electrodes, exhibiting high overpotentials, greater than 1 V vs Ag! Agel. Metallophthalocyanines have been shown to promote the electrocatalysis of cysteine at lowered potentials. Chemical modification of electrodes with appropriate modifiers is a means of incorporating specificity into electroanalysis, with applications in electrocatalysis. A glassy carbon electrode was modified by electrodeposition of cobalt (II) tetrasulphophthalocyanine [Co(II)TSPct to produce a chemically modified glassy carbon electrode (CMGCE). The CoTSPc-CMGCE catalysed the oxidation of cysteine in the pH range 1 to 10. The significance of this electrode is an application for analysis of proteins at biological pH's. A biscyanoruthenium(II) phthalocyanine CMGCE catalysed the oxidation of cysteine at 0.43 V vs Ag/AgCl a significant lowering in the overpotential for the oxidation of cysteine. Metallothionein, a metal binding protein, is believed to be involved in metal homeostasis and detoxification in the peripheral organs of living systems. A method for the quantitative determination of this protein utilising its high cysteine content was presented. At pH 8.4 Tris-HCl buffer, and using a CoTSPc-CMGCE modified by electrodeposition of the modifier, the anodic peaks for the oxidation of metallothionein was observed at 0. 90 V vs Ag/ AgCI. Ferredoxin is a simple iron-sulphur protein. One tenth of its residues are cysteine. Ferredoxin is involved in simple electron transfer processes during photosynthesis and respiration. Electrochemical studies of spinach ferredoxin were conducted at a CoTSPc-CMGCE. Anodic currents for the oxidation of the cysteine fragment of ferredoxin was observed at 0.85 V vs Ag/AgCl in HEPES buffer at pH 7.4, representing a new method for analysis of this protein. Voltammetric studies of its ferric/ferrous transition have shown quasi-reversible waves atE~ -0.62 V vs Ag/AgCl only in the presence of promoters. At a CoTSPc-CMGCE, a cathodic wave attributed to the reduction of Fe(III)/Fe(II) was observed at Epc -0.34 V vs Ag/AgCl. This represents an alternative method for voltammetric studies of the ferric/ferrous transition at significantly lowered potentials. Melatonin, a pineal gland hormone functions m setting and entraining circadian rhythms and in neuroprotection as a free radical scavenger and general antioxidant. Using adsorptive cathodic stripping voltammetry, the binding affinities of melatonin, serotonin and tryptophan for metals, were measured. The results showed that the following metal complexes were formed: aluminium with melatonin, serotonin and tryptophan; cadmium with melatonin and tryptophan; copper with melatonin and serotonin; iron (III) with melatonin and serotonin; lead with melatonin, tryptophan and serotonin, zinc with melatonin and tryptophan and iron (II) with tryptophan. The studies suggest a further role for melatonin in the reduction of free radical generation and in metal detoxification and may explain the accumulation of aluminium in Alzheimer's disease.
- Full Text:
- Date Issued: 1999
Employment Equity: An Introductory Workshop for Trade Unionists Organised by the COSATU Education Department
- COSATU
- Authors: COSATU
- Date: 1999
- Subjects: COSATU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/176014 , vital:42652
- Description: This workshop is designed to give you a reliable introduction the Employment Equity Act. It is based on hard information and on ACTIVITIES or discussion exercises that will help you to understand how the Act works, who it covers, and what the implications are for trade unionists. Each of the Activities is complemented with information that will help you to understand the Act in more detail. Sections have been added to help you find further information, and to understand the terms that are used in the Act itself In a two day programme, you are not going to be an 'expert' on the Employment Equity Act, but we hope that you will feel more confident about using the Act, especially in ensuring that it is used to address a wide range of discriminatory practices at the workplace. As with most legislation, the more that you begin to use it, the more its strengths and weaknesses will emerge. It is very important that any weaknesses in the practical application of the Act are reported through your Union to the Federation. This will help the Federation to campaign for improvements in the legislation, and to close any loopholes that allow employers to avoid their responsibilities. All Labour Legislation, including the new Employment Equity Act should serve as a 'base-line' or minimum standard. Employer and Union observance of the minimum standards as laid down in law should be our starting point. Through collective bargaining and improved Union organisation, we aim to improve upon the standards set by the law, and increase the protection of our members. This is a real challenge. It is especially important for us all to recognise that as we enter into a period where employers are demanding more 'flexibility', the introduction of a new law to correct the legacy of imbalances left by apartheid at the workplace deserves our special attention. We hope this workshop is the first in a series of educational events that will cover this vital new area. The main aim of this workshop is to help you to understand the basic workings of the law, and how best it can be implemented. We also hope this programme encourages you to find out more about Employment Equity issues, and contribute positively to the struggle for the eradication of inequality. This pack is designed for a series of two-day introductory workshops that are being sponsored by COSATU in each region. A workshop of COSATU Educators held in September 1999 helped to assemble the material, and to test its appropriateness. As a result there are a considerable number of educators who can advise, and facilitate this workshop and who can be contacted via COSATU Education Department. We would also be very interested to hear how the pack has been used, and in particular how it can be improved to meet the needs of trade unionists who want to tackle discrimination using the tool of the Employment Equity Act, as well as other organisational means. If you use this pack, feedback would be most welcome.
- Full Text:
- Date Issued: 1999
- Authors: COSATU
- Date: 1999
- Subjects: COSATU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/176014 , vital:42652
- Description: This workshop is designed to give you a reliable introduction the Employment Equity Act. It is based on hard information and on ACTIVITIES or discussion exercises that will help you to understand how the Act works, who it covers, and what the implications are for trade unionists. Each of the Activities is complemented with information that will help you to understand the Act in more detail. Sections have been added to help you find further information, and to understand the terms that are used in the Act itself In a two day programme, you are not going to be an 'expert' on the Employment Equity Act, but we hope that you will feel more confident about using the Act, especially in ensuring that it is used to address a wide range of discriminatory practices at the workplace. As with most legislation, the more that you begin to use it, the more its strengths and weaknesses will emerge. It is very important that any weaknesses in the practical application of the Act are reported through your Union to the Federation. This will help the Federation to campaign for improvements in the legislation, and to close any loopholes that allow employers to avoid their responsibilities. All Labour Legislation, including the new Employment Equity Act should serve as a 'base-line' or minimum standard. Employer and Union observance of the minimum standards as laid down in law should be our starting point. Through collective bargaining and improved Union organisation, we aim to improve upon the standards set by the law, and increase the protection of our members. This is a real challenge. It is especially important for us all to recognise that as we enter into a period where employers are demanding more 'flexibility', the introduction of a new law to correct the legacy of imbalances left by apartheid at the workplace deserves our special attention. We hope this workshop is the first in a series of educational events that will cover this vital new area. The main aim of this workshop is to help you to understand the basic workings of the law, and how best it can be implemented. We also hope this programme encourages you to find out more about Employment Equity issues, and contribute positively to the struggle for the eradication of inequality. This pack is designed for a series of two-day introductory workshops that are being sponsored by COSATU in each region. A workshop of COSATU Educators held in September 1999 helped to assemble the material, and to test its appropriateness. As a result there are a considerable number of educators who can advise, and facilitate this workshop and who can be contacted via COSATU Education Department. We would also be very interested to hear how the pack has been used, and in particular how it can be improved to meet the needs of trade unionists who want to tackle discrimination using the tool of the Employment Equity Act, as well as other organisational means. If you use this pack, feedback would be most welcome.
- Full Text:
- Date Issued: 1999
Evaluation of a 'defouling on demand' strategy for the ultrafiltration of brown water using activatable enzymes
- Authors: Buchanan, K
- Date: 1999
- Subjects: Water -- Purification , Ultrafiltration , Enzymes , Membranes (Technology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3904 , http://hdl.handle.net/10962/d1003963 , Water -- Purification , Ultrafiltration , Enzymes , Membranes (Technology)
- Description: New approaches to the application of membranes for the production of potable water are constantly being sought after in anticipation of future demands for increasingly rigorous water quality standards and reduced environmental impact. A major limitation, however, is membrane fouling, which manifests itself as a continual reduction in flux over time and thus restricts the practical implementation to restore flux. Mechanical and chemical methods have been implemented to restore flux to ultrafiltration systems, but these either result in a break in the process operation or lead to membrane damage or additional pollution problems. This project was aimed to develop a 'defouling on demand' stategy for cleaning membranes used during brown water ultrafiltration. The process involves the use of activatable peroxidase enzymes, which were immobilised onto flat sheet polysulphone membranes. Following flux decline which reaches a critical level with the build-up of the foulant layer, the immobilised enzyme layer was activated by the addition of a chemical activator solution, in this case hydrogen peroxidase and manganous sulphate. Manganese peroxidase was found to be the most effective enzyme at alleviating fouling by degrading the foulant layer formed on the membrane surface and hence restored flux to the ultrafiltration system. A 93% flux improvement was observed when manganese peroxidase was activated when 800uM manganous sulphate, 100mM hydrogen peroxide were added in the presence of a manganese chelator, lactate. The concept and the potential benefits this system holds will be discussed in further detail.
- Full Text:
- Date Issued: 1999
- Authors: Buchanan, K
- Date: 1999
- Subjects: Water -- Purification , Ultrafiltration , Enzymes , Membranes (Technology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3904 , http://hdl.handle.net/10962/d1003963 , Water -- Purification , Ultrafiltration , Enzymes , Membranes (Technology)
- Description: New approaches to the application of membranes for the production of potable water are constantly being sought after in anticipation of future demands for increasingly rigorous water quality standards and reduced environmental impact. A major limitation, however, is membrane fouling, which manifests itself as a continual reduction in flux over time and thus restricts the practical implementation to restore flux. Mechanical and chemical methods have been implemented to restore flux to ultrafiltration systems, but these either result in a break in the process operation or lead to membrane damage or additional pollution problems. This project was aimed to develop a 'defouling on demand' stategy for cleaning membranes used during brown water ultrafiltration. The process involves the use of activatable peroxidase enzymes, which were immobilised onto flat sheet polysulphone membranes. Following flux decline which reaches a critical level with the build-up of the foulant layer, the immobilised enzyme layer was activated by the addition of a chemical activator solution, in this case hydrogen peroxidase and manganous sulphate. Manganese peroxidase was found to be the most effective enzyme at alleviating fouling by degrading the foulant layer formed on the membrane surface and hence restored flux to the ultrafiltration system. A 93% flux improvement was observed when manganese peroxidase was activated when 800uM manganous sulphate, 100mM hydrogen peroxide were added in the presence of a manganese chelator, lactate. The concept and the potential benefits this system holds will be discussed in further detail.
- Full Text:
- Date Issued: 1999
Experiencing space and place in Grahamstown's informal settlements
- Coetzee, Jan K, Houssay-Holzschuch, Myriam, O'Reilly, Caroline
- Authors: Coetzee, Jan K , Houssay-Holzschuch, Myriam , O'Reilly, Caroline
- Date: 1999
- Subjects: Black people -- housing -- South Africa -- South Africa -- Grahamstown Squatter settlements -- South Africa -- Grahamstown Squatters -- South Africa -- Grahamstown -- interviews
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2623 , vital:20310 , ISBN 0868103616
- Description: In this research the relationship between people and the space they occupy will be looked at. In doing so, we shall see how people enter into a relationship with their environment in order to create out of material at their disposal, a shelter wherein they can live. By erecting a structure which serves as a house, the people involved in this project do essentially the same as other people in other parts of the world, who create a dwelling that provides protection against the climate and the elements in nature. A question to be raised, is extent their (i.e. the people involved in this project) entering into a relationship with their environment, was forced into a particular direction because of a set of political and economic factors. What are the political and economic factors which impact on the manner of building houses in the informal residential areas of Grahamstown? Traditional housing in France, for example, differs from region to region and has been shaped over long periods of time by the climate, family structures, the availability of land, modes of production, etc. One finds that large vine-growing families from the Mediterranean South of France live in fairly big villages; individual farmers of Brittany dwell in small, slate-roofed houses which are isolated among enclosed fields; pastoral communities in the Alps undertake seasonal moves up or down the slopes of the mountains and share their space during winter with their cattle. The way in which these families and/or communities have come to shape their lifeworlds, was not exposed to the same kind of determining factors as, for instance, in South Africa in general and in Grahamstown in particular. Notwithstanding political and economic determinants, it is clear that residents of informal houses in the Grahamstown area draw to a large extent from tradition with regards to the kind of shelters which they build (cf. the many mud-and-stick constructions). Similarly the settlement of people impacts on nature. Elements of the environment inform certain choices, but people interpret their natural environment and will erect shelters in terms of these interpretations. In addition there are the issues of how people orientate themselves in terms of important landmarks, what kind of representation they have of the future they are moving towards and which values do they draw from or attribute to their physical environment. The landscape surrounding people, contains and reflects cultural information. Important landmarks express aspects of life: the past, the present and the future. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1999
- Authors: Coetzee, Jan K , Houssay-Holzschuch, Myriam , O'Reilly, Caroline
- Date: 1999
- Subjects: Black people -- housing -- South Africa -- South Africa -- Grahamstown Squatter settlements -- South Africa -- Grahamstown Squatters -- South Africa -- Grahamstown -- interviews
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2623 , vital:20310 , ISBN 0868103616
- Description: In this research the relationship between people and the space they occupy will be looked at. In doing so, we shall see how people enter into a relationship with their environment in order to create out of material at their disposal, a shelter wherein they can live. By erecting a structure which serves as a house, the people involved in this project do essentially the same as other people in other parts of the world, who create a dwelling that provides protection against the climate and the elements in nature. A question to be raised, is extent their (i.e. the people involved in this project) entering into a relationship with their environment, was forced into a particular direction because of a set of political and economic factors. What are the political and economic factors which impact on the manner of building houses in the informal residential areas of Grahamstown? Traditional housing in France, for example, differs from region to region and has been shaped over long periods of time by the climate, family structures, the availability of land, modes of production, etc. One finds that large vine-growing families from the Mediterranean South of France live in fairly big villages; individual farmers of Brittany dwell in small, slate-roofed houses which are isolated among enclosed fields; pastoral communities in the Alps undertake seasonal moves up or down the slopes of the mountains and share their space during winter with their cattle. The way in which these families and/or communities have come to shape their lifeworlds, was not exposed to the same kind of determining factors as, for instance, in South Africa in general and in Grahamstown in particular. Notwithstanding political and economic determinants, it is clear that residents of informal houses in the Grahamstown area draw to a large extent from tradition with regards to the kind of shelters which they build (cf. the many mud-and-stick constructions). Similarly the settlement of people impacts on nature. Elements of the environment inform certain choices, but people interpret their natural environment and will erect shelters in terms of these interpretations. In addition there are the issues of how people orientate themselves in terms of important landmarks, what kind of representation they have of the future they are moving towards and which values do they draw from or attribute to their physical environment. The landscape surrounding people, contains and reflects cultural information. Important landmarks express aspects of life: the past, the present and the future. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1999