An investigation into multimedia service creation using sip
- Hsieh, M, Okuthe, J, Terzoli, Alfredo, Wentworth, Peter N
- Authors: Hsieh, M , Okuthe, J , Terzoli, Alfredo , Wentworth, Peter N
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427533 , vital:72445 , https://www.researchgate.net/profile/Alfredo-Ter-zoli/publication/267852929_An_investigation_into_multimedia_service_creation_using_SIP/links/5523cb990cf2b351d9c338c9/An-investigation-into-multimedia-service-creation-using-SIP.pdf
- Description: This paper investigates two sip architectures and how services creation works in those two environments. The two architectures are SIPCOMM (www. sipcomm. com) and VOCAL (www. vovida. org). As a concrete example we look at how the voicemail service is implemented in both environments and then at how we could implement an alarm service.
- Full Text:
- Date Issued: 2002
- Authors: Hsieh, M , Okuthe, J , Terzoli, Alfredo , Wentworth, Peter N
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427533 , vital:72445 , https://www.researchgate.net/profile/Alfredo-Ter-zoli/publication/267852929_An_investigation_into_multimedia_service_creation_using_SIP/links/5523cb990cf2b351d9c338c9/An-investigation-into-multimedia-service-creation-using-SIP.pdf
- Description: This paper investigates two sip architectures and how services creation works in those two environments. The two architectures are SIPCOMM (www. sipcomm. com) and VOCAL (www. vovida. org). As a concrete example we look at how the voicemail service is implemented in both environments and then at how we could implement an alarm service.
- Full Text:
- Date Issued: 2002
An investigation into the conflict management styles used in organisations with special reference to some organisations in the northern region of the Eastern Cape Province
- Authors: Bwowe, Patrick W
- Date: 2002
- Subjects: Conflict management -- South Africa -- Eastern Provice
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10911 , http://hdl.handle.net/10948/103 , Conflict management -- South Africa -- Eastern Provice
- Description: common and in most cases unavoidable. Because of this, it has become critical for managers to start evaluating the styles they use in managing conflict and to assess the implications of these styles to the benefits and costs of conflict. In order to meet this challenge, managers must understand the nature, sources and the outcome of conflict. It is by reflecting on the above, that managers may become more informed about the right conflict management approach to apply. This research deals with an investigation into the conflict management styles used by managers in organisations. It seeks to identify the styles currently used and to establish whether there is any correlation between these styles and the conflict management styles identified in the literature survey. The study targeted six health institutions in the Northern Region of the Eastern Cape Province. Findings from the literature study revealed two main approaches to managing conflict. These were: the Resolution and the Stimulating approaches. Five conflict management styles were identified when the resolution technique is used. These included: Collaboration, Avoidance, Accommodating, Compromise and the Dominating styles. Five approaches for stimulating functional conflict in organisations were also identified.They included the following: use of programmed conflict, manipulation of communication channels, encouraging competition among employees, encouraging the use structured debates and changing the organisational structure and culture. A research questionnaire and personal interviews were used for collecting data. The Questionnaire sought to establish the conflict management styles currently used in organisations while the interview’s aim was to probe deeper and to establish the participants’ view of the factors which determine one’s preferred conflict handling style and also to assess to what extent managers understand contemporary approaches to managing conflict such as conflict stimulation. The study revealed that the conflict management styles used by managers are similar to those identified in the literature review. It also emerged that managers are not very knowledgeable about the view of managing conflict by stimulating it. This highlighted the importance for further research into managing conflict by means of the stimulation approach.
- Full Text:
- Date Issued: 2002
- Authors: Bwowe, Patrick W
- Date: 2002
- Subjects: Conflict management -- South Africa -- Eastern Provice
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10911 , http://hdl.handle.net/10948/103 , Conflict management -- South Africa -- Eastern Provice
- Description: common and in most cases unavoidable. Because of this, it has become critical for managers to start evaluating the styles they use in managing conflict and to assess the implications of these styles to the benefits and costs of conflict. In order to meet this challenge, managers must understand the nature, sources and the outcome of conflict. It is by reflecting on the above, that managers may become more informed about the right conflict management approach to apply. This research deals with an investigation into the conflict management styles used by managers in organisations. It seeks to identify the styles currently used and to establish whether there is any correlation between these styles and the conflict management styles identified in the literature survey. The study targeted six health institutions in the Northern Region of the Eastern Cape Province. Findings from the literature study revealed two main approaches to managing conflict. These were: the Resolution and the Stimulating approaches. Five conflict management styles were identified when the resolution technique is used. These included: Collaboration, Avoidance, Accommodating, Compromise and the Dominating styles. Five approaches for stimulating functional conflict in organisations were also identified.They included the following: use of programmed conflict, manipulation of communication channels, encouraging competition among employees, encouraging the use structured debates and changing the organisational structure and culture. A research questionnaire and personal interviews were used for collecting data. The Questionnaire sought to establish the conflict management styles currently used in organisations while the interview’s aim was to probe deeper and to establish the participants’ view of the factors which determine one’s preferred conflict handling style and also to assess to what extent managers understand contemporary approaches to managing conflict such as conflict stimulation. The study revealed that the conflict management styles used by managers are similar to those identified in the literature review. It also emerged that managers are not very knowledgeable about the view of managing conflict by stimulating it. This highlighted the importance for further research into managing conflict by means of the stimulation approach.
- Full Text:
- Date Issued: 2002
An investigation into the possible neuroprotective properties of phenytoin
- Authors: Naga, Nishal
- Date: 2002
- Subjects: Phenytoin -- Therapeutic use , Phenytoin -- Physiological effect , Nervous system -- Degeneration -- Prevention
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3780 , http://hdl.handle.net/10962/d1003258 , Phenytoin -- Therapeutic use , Phenytoin -- Physiological effect , Nervous system -- Degeneration -- Prevention
- Description: Cerebral ischaemia, traumatic injury to the brain, inflammatory neurological disorders and HIV infections are amongst the most prevalent causes of neurodegeneration. Neuroprotective strategies are usually to limit the progressive secondary injury that generally occurs, thus limiting overall tissue damage. Neuroprotective strategies are usually to limit the progressive secondary injury that generally occurs, thus limiting overall tissue damage. Sodium channel blockers have been often used for this matter as they prevent the cascade of events culminating in free radical generation and eventually neuronal apoptosis. Newer compounds, such as antiperoxidants and free radical scavengers, show encouraging experimental results, but their clinical use is still very limited. Phenytoin being a popular drug in the treatment of epilepsy has also been used as a neuroprotectant during certain neurological emergencies and in pharmacological prophylaxis of post-traumatic epilepsy. Furthermore this agent functions by prolonging inactivation of voltage gated sodium channels. In these sets of experiment the neuroprotective properties of phenytoin were examined. The histological study revealed that phenytoin confers protection to the CA1 and CA3 regions of the hippocampus under the insult of QUIN. Cells maintain their characteristic shape and minimal tissue necrosis occurs in the presence of this agent. The in vitro effect of this antiepileptic drug on free radicals generation shows that phenytoin does not reduce or prevent the formation of these reactive species. Lipid peroxidation was induced using QUIN and iron (II), two known neurotoxins. The study reveals that only lipid peroxidation induced using iron (II) is reduced by phenytoin. These experiments were carried out in whole rat brain homogenate. These studies show that phenytoin possesses poor free radical scavenging properties. However, the dose-related reduction of iron-induced lipid peroxidation allows for speculation that phenytoin interacts with iron in order to reduce neuronal damage. Metal binding studies were performed using UV, IR and electrochemical analysis to examine the interaction of phenytoin with iron (II) and iron (III). Phenytoin, when added to iron (II) in solution, first oxidises the latter to iron (III) and maintains it in that form. A shift in the peak was observed in the UV spectrum when iron was added to phenytoin. Moreover, electrochemical studies indicate that the interaction between the metal and the ligand is very weak. The IR analysis it shows that phenytoin may be coordinating with iron through the Nitrogen atom on the phenytoin molecule. These studies show that phenytoin maintains iron in its oxidised form, which is a good property to possess as a neuroprotectants. Pineal organ culture showed that phenytoin does not increase melatonin production but slightly and non-significantly reduces the levels of this pineal hormone. However there is a significant rise in precursor NAS levels. As melatonin is known to possess antioxidant and free radical scavenging properties, this could mean that this drug can cause the CNS to become more susceptible to attacks by reactive oxygen species.
- Full Text:
- Date Issued: 2002
- Authors: Naga, Nishal
- Date: 2002
- Subjects: Phenytoin -- Therapeutic use , Phenytoin -- Physiological effect , Nervous system -- Degeneration -- Prevention
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3780 , http://hdl.handle.net/10962/d1003258 , Phenytoin -- Therapeutic use , Phenytoin -- Physiological effect , Nervous system -- Degeneration -- Prevention
- Description: Cerebral ischaemia, traumatic injury to the brain, inflammatory neurological disorders and HIV infections are amongst the most prevalent causes of neurodegeneration. Neuroprotective strategies are usually to limit the progressive secondary injury that generally occurs, thus limiting overall tissue damage. Neuroprotective strategies are usually to limit the progressive secondary injury that generally occurs, thus limiting overall tissue damage. Sodium channel blockers have been often used for this matter as they prevent the cascade of events culminating in free radical generation and eventually neuronal apoptosis. Newer compounds, such as antiperoxidants and free radical scavengers, show encouraging experimental results, but their clinical use is still very limited. Phenytoin being a popular drug in the treatment of epilepsy has also been used as a neuroprotectant during certain neurological emergencies and in pharmacological prophylaxis of post-traumatic epilepsy. Furthermore this agent functions by prolonging inactivation of voltage gated sodium channels. In these sets of experiment the neuroprotective properties of phenytoin were examined. The histological study revealed that phenytoin confers protection to the CA1 and CA3 regions of the hippocampus under the insult of QUIN. Cells maintain their characteristic shape and minimal tissue necrosis occurs in the presence of this agent. The in vitro effect of this antiepileptic drug on free radicals generation shows that phenytoin does not reduce or prevent the formation of these reactive species. Lipid peroxidation was induced using QUIN and iron (II), two known neurotoxins. The study reveals that only lipid peroxidation induced using iron (II) is reduced by phenytoin. These experiments were carried out in whole rat brain homogenate. These studies show that phenytoin possesses poor free radical scavenging properties. However, the dose-related reduction of iron-induced lipid peroxidation allows for speculation that phenytoin interacts with iron in order to reduce neuronal damage. Metal binding studies were performed using UV, IR and electrochemical analysis to examine the interaction of phenytoin with iron (II) and iron (III). Phenytoin, when added to iron (II) in solution, first oxidises the latter to iron (III) and maintains it in that form. A shift in the peak was observed in the UV spectrum when iron was added to phenytoin. Moreover, electrochemical studies indicate that the interaction between the metal and the ligand is very weak. The IR analysis it shows that phenytoin may be coordinating with iron through the Nitrogen atom on the phenytoin molecule. These studies show that phenytoin maintains iron in its oxidised form, which is a good property to possess as a neuroprotectants. Pineal organ culture showed that phenytoin does not increase melatonin production but slightly and non-significantly reduces the levels of this pineal hormone. However there is a significant rise in precursor NAS levels. As melatonin is known to possess antioxidant and free radical scavenging properties, this could mean that this drug can cause the CNS to become more susceptible to attacks by reactive oxygen species.
- Full Text:
- Date Issued: 2002
An investigation into the possible neuroprotective role of antidepressant drugs
- Authors: Steiner, Claire
- Date: 2002
- Subjects: Antidepressants -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3792 , http://hdl.handle.net/10962/d1003270 , Antidepressants -- Research
- Description: Antidepressants are widely used in the treatment of depressive illnesses associated with neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease and Huntington’s disease. Neuroprotection in such disorders is of vital importance in order to delay the progression of the primary disorder. The pathology of neurodegeneration is not fully understood. It is however widely accepted that oxidative stress and excitotoxicity play a major role. Brain tissue is rich in phospholipids, which are especially prone to oxidation due to the high level of oxygen utilization in the brain. In addition, the brain lacks defence mechanisms to protect it against the wrath of free radicals. Presently, there is a wide variety of antidepressant drugs available. These range from the original tricyclic antidepressants to the newer selective serotonin reuptake inhibitors. It is not known whether antidepressant drugs, old or new, offer neuroprotection or how the existing state and/or the progression of neurodegeneration, is influenced by these agents. The present study was undertaken to determine how nortriptyline, trimipramine and fluoxetine affect neurodegeneration. Initial in vitro and in vivo studies show that all three of the antidepressants (0-1mM) studied provide neuroprotection from quinolinic acid induced lipid peroxidation. A histological investigation supported these findings by showing that a marginal degree of neuroprotection is apparent when treating animals with antidepressants (10mg/kg) before and following quinolinic acid intrastriatal injection. Further studies were undertaken in an attempt to determine the mode of neuroprotective action of the agents studied. An in vitro study of superoxide anion induced lipid peroxidation indicates that these agents do not act as antioxidants. The influence of the antidepressants on tryptophan 2,3-dioxygenase activity was assessed, based on the understanding that inhibition of this enzyme results in increased levels of the known antioxidant indoleamine, melatonin. Nortriptyline hydrochloride is seen to inhibit tryptophan 2,3-dioxygenase activity and as such it is possible that this antidepressant can indirectly provide neuroprotection by increasing available melatonin. Electrochemical and UV/visible studies show that trimipramine maleate interacts with free iron (II) and iron (III) ions. Free metal ions can catalyse the formation of damaging free radicals. Through interaction with trimipramine maleate, these ions will be unavailable to the system and thus cannot contribute to oxidative stress. The findings of this study indicate that antidepressants may be able to provide neuroprotection to neuronal cells. The mode of such neuroprotective actions need to be further examined so that patients suffering from depression coexisting with neurodegenerative diseases can be safely and effectively treated.
- Full Text:
- Date Issued: 2002
- Authors: Steiner, Claire
- Date: 2002
- Subjects: Antidepressants -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3792 , http://hdl.handle.net/10962/d1003270 , Antidepressants -- Research
- Description: Antidepressants are widely used in the treatment of depressive illnesses associated with neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease and Huntington’s disease. Neuroprotection in such disorders is of vital importance in order to delay the progression of the primary disorder. The pathology of neurodegeneration is not fully understood. It is however widely accepted that oxidative stress and excitotoxicity play a major role. Brain tissue is rich in phospholipids, which are especially prone to oxidation due to the high level of oxygen utilization in the brain. In addition, the brain lacks defence mechanisms to protect it against the wrath of free radicals. Presently, there is a wide variety of antidepressant drugs available. These range from the original tricyclic antidepressants to the newer selective serotonin reuptake inhibitors. It is not known whether antidepressant drugs, old or new, offer neuroprotection or how the existing state and/or the progression of neurodegeneration, is influenced by these agents. The present study was undertaken to determine how nortriptyline, trimipramine and fluoxetine affect neurodegeneration. Initial in vitro and in vivo studies show that all three of the antidepressants (0-1mM) studied provide neuroprotection from quinolinic acid induced lipid peroxidation. A histological investigation supported these findings by showing that a marginal degree of neuroprotection is apparent when treating animals with antidepressants (10mg/kg) before and following quinolinic acid intrastriatal injection. Further studies were undertaken in an attempt to determine the mode of neuroprotective action of the agents studied. An in vitro study of superoxide anion induced lipid peroxidation indicates that these agents do not act as antioxidants. The influence of the antidepressants on tryptophan 2,3-dioxygenase activity was assessed, based on the understanding that inhibition of this enzyme results in increased levels of the known antioxidant indoleamine, melatonin. Nortriptyline hydrochloride is seen to inhibit tryptophan 2,3-dioxygenase activity and as such it is possible that this antidepressant can indirectly provide neuroprotection by increasing available melatonin. Electrochemical and UV/visible studies show that trimipramine maleate interacts with free iron (II) and iron (III) ions. Free metal ions can catalyse the formation of damaging free radicals. Through interaction with trimipramine maleate, these ions will be unavailable to the system and thus cannot contribute to oxidative stress. The findings of this study indicate that antidepressants may be able to provide neuroprotection to neuronal cells. The mode of such neuroprotective actions need to be further examined so that patients suffering from depression coexisting with neurodegenerative diseases can be safely and effectively treated.
- Full Text:
- Date Issued: 2002
An investigation into the progress made towards achieving employment equity at Calsonic Kansei South Africa (PTY) Limited in terms of the Employment Equity Act no. 55 of 1998
- Authors: Ring, Grant
- Date: 2002
- Subjects: Affirmative action programs , Discrimination in employment -- South Africa , Affirmative action programs -- South Africa , Calsonic Kansei South Africa (Firm)
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10895 , http://hdl.handle.net/10948/104 , Affirmative action programs , Discrimination in employment -- South Africa , Affirmative action programs -- South Africa , Calsonic Kansei South Africa (Firm)
- Description: The key aspect to stimulating economic and individual growth in the workplace has been shown in numerous case studies to be the removal of discrimination. Affirmative Action looks at dealing with, and making amends for past injustices, as well as moving towards equal employment opportunities in a constructive manner. It is about recognizing that people are inherently different whilst trying to achieve a “colour – blind” society. The Employment Equity Act No. 55 of 1998 was put in place by Government to facilitate the implementation of fair workplace practices, which will correct the imbalances of the past as well as creating a workforce, which reflects the demographics of South Africa. The inequalities in employment patterns and practices with respect to access to employment, training, promotion and equitable remuneration especially for black people, women and people with disabilities are addressed in the said Act. The Employment Equity Act is quite specific about the minimum requirements of an organisation’s Employment Equity Plan, which make it easy to identify what progress is being made towards ending discrimination in the workplace. The minimum penalty for contravening the Employment Equity Act is R500 000 and the maximum is R900 000. The question arises as to whether South African organisations are merely implementing Employment Equity policies to adhere to the basic requirements and deadlines of the Act. Or, are these policies genuinely based on commitment to the principles of equality and equal opportunity for all in the workplace. Calsonic Kansei South Africa has put into place various training and succession plans, which will help to achieve the organizational goal of being more equitable in terms of the Employment Equity Act. Employment agency databases have also been analysed to determine the availability of suitably qualified Affirmative Action employees. In this paper the writer will investigate the progress that Calsonic Kansei South Africa has made towards achieving Employment Equity in relation to other organisations within the same industry.
- Full Text:
- Date Issued: 2002
- Authors: Ring, Grant
- Date: 2002
- Subjects: Affirmative action programs , Discrimination in employment -- South Africa , Affirmative action programs -- South Africa , Calsonic Kansei South Africa (Firm)
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10895 , http://hdl.handle.net/10948/104 , Affirmative action programs , Discrimination in employment -- South Africa , Affirmative action programs -- South Africa , Calsonic Kansei South Africa (Firm)
- Description: The key aspect to stimulating economic and individual growth in the workplace has been shown in numerous case studies to be the removal of discrimination. Affirmative Action looks at dealing with, and making amends for past injustices, as well as moving towards equal employment opportunities in a constructive manner. It is about recognizing that people are inherently different whilst trying to achieve a “colour – blind” society. The Employment Equity Act No. 55 of 1998 was put in place by Government to facilitate the implementation of fair workplace practices, which will correct the imbalances of the past as well as creating a workforce, which reflects the demographics of South Africa. The inequalities in employment patterns and practices with respect to access to employment, training, promotion and equitable remuneration especially for black people, women and people with disabilities are addressed in the said Act. The Employment Equity Act is quite specific about the minimum requirements of an organisation’s Employment Equity Plan, which make it easy to identify what progress is being made towards ending discrimination in the workplace. The minimum penalty for contravening the Employment Equity Act is R500 000 and the maximum is R900 000. The question arises as to whether South African organisations are merely implementing Employment Equity policies to adhere to the basic requirements and deadlines of the Act. Or, are these policies genuinely based on commitment to the principles of equality and equal opportunity for all in the workplace. Calsonic Kansei South Africa has put into place various training and succession plans, which will help to achieve the organizational goal of being more equitable in terms of the Employment Equity Act. Employment agency databases have also been analysed to determine the availability of suitably qualified Affirmative Action employees. In this paper the writer will investigate the progress that Calsonic Kansei South Africa has made towards achieving Employment Equity in relation to other organisations within the same industry.
- Full Text:
- Date Issued: 2002
An investigation into the viability of deploying thin client technology to support effective learning in a disadvantaged, rural high school setting
- Authors: Ndwe, Tembalethu Jama
- Date: 2002
- Subjects: Network computers , Education -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4627 , http://hdl.handle.net/10962/d1006500 , Network computers , Education -- Data processing
- Description: Computer Based Training offers many attractive learning opportunities for high school pupils. Its deployment in economically depressed and educationally marginalized rural schools is extremely uncommon due to the high technology skills and costs involved in its deployment and ongoing maintenance. This thesis puts forward thin client technology as a potential solution to the needs of education environments of this kind. A functional business case is developed and evaluated in this thesis, based upon a requirements analysis of media delivery in learning, and upon formal cost/performance models and a deployment field trial. Because of the economic constraints of the envisaged deployment area in rural education, an industrial field trial is used, and the aspects of this trial that can be carried over to the rural school situation have been used to assess performance and cost indicators. Our study finds that thin client technology could be deployed and maintained more cost effectively than conventional fat client solutions in rural schools, that it is capable of supporting the learning elements needed in this deployment area, and that it is able to deliver the predominantly text based applications currently being used in schools. However, we find that technological improvements are needed before future multimediaintensive applications can be adequately supported.
- Full Text:
- Date Issued: 2002
- Authors: Ndwe, Tembalethu Jama
- Date: 2002
- Subjects: Network computers , Education -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4627 , http://hdl.handle.net/10962/d1006500 , Network computers , Education -- Data processing
- Description: Computer Based Training offers many attractive learning opportunities for high school pupils. Its deployment in economically depressed and educationally marginalized rural schools is extremely uncommon due to the high technology skills and costs involved in its deployment and ongoing maintenance. This thesis puts forward thin client technology as a potential solution to the needs of education environments of this kind. A functional business case is developed and evaluated in this thesis, based upon a requirements analysis of media delivery in learning, and upon formal cost/performance models and a deployment field trial. Because of the economic constraints of the envisaged deployment area in rural education, an industrial field trial is used, and the aspects of this trial that can be carried over to the rural school situation have been used to assess performance and cost indicators. Our study finds that thin client technology could be deployed and maintained more cost effectively than conventional fat client solutions in rural schools, that it is capable of supporting the learning elements needed in this deployment area, and that it is able to deliver the predominantly text based applications currently being used in schools. However, we find that technological improvements are needed before future multimediaintensive applications can be adequately supported.
- Full Text:
- Date Issued: 2002
An investigation of the effect of time of pruning on the growth and fruiting of lemons [Citrus limon(L.) Burmann f.] cv. Eureka
- Authors: Pittaway, Timothy Michael
- Date: 2002
- Subjects: Lemon , Pruning , Fruit-culture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10974 , http://hdl.handle.net/10948/106 , Lemon , Pruning , Fruit-culture
- Description: Pruning has been used to reduce tree size, allow light penetration into trees, improve yield, improve fruit size and fruit quality, overcome alternate bearing, assist fruit harvest, and assist pest and disease control. The use of pruning has increased due to improving agricultural management techniques such as high planting densities, use of mechanical machinery in orchards and the need for effective pesticide and pathological chemical spray applications. The main objective of this study was to obtain a practical means of manipulating lemon trees at the right time. Pruning at the correct time to cultivate productive trees that produce quality fruit would have financial benefits. Lemon fruit quality is dependent on market demand and involves a number of features such as fruit shelf life, rind thickness, fruit size, rind colour, and juice content. The study was conducted on ’Eureka’ lemon trees budded on C. volkameriana rootstock, bearing the fifth and sixth commercial crops in 1999 and 2000 respectively. Twelve monthly pruning treatments per year were conducted on one row of trees starting in December 1997 (site 1) and repeated in the second year on the adjacent row of the same orchard starting in December 1998 (site 2). Selective pruning heading cuts were applied below the intercalation on the intercalary units. Potential branch bearing units were tagged and assessed during the harvest and flowering periods. Summer pruning between 16 to 19 months before the subsequent April/May harvest, resulted in the longest and most complex (intercalation sprouted per axil) vegetative response. The estimated crop value indicated that summer pruning treatments produced the highest income. This was ascribed not to differences in fruit size or quality, but to an increase in yield. The industry’s trend is to prune citrus from post-harvest to the pre-bloom stage. Results from this study have provided a beneficial cultural practice to prune during the summer months and provides a practice to optimise farm production and profit margins.
- Full Text:
- Date Issued: 2002
- Authors: Pittaway, Timothy Michael
- Date: 2002
- Subjects: Lemon , Pruning , Fruit-culture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10974 , http://hdl.handle.net/10948/106 , Lemon , Pruning , Fruit-culture
- Description: Pruning has been used to reduce tree size, allow light penetration into trees, improve yield, improve fruit size and fruit quality, overcome alternate bearing, assist fruit harvest, and assist pest and disease control. The use of pruning has increased due to improving agricultural management techniques such as high planting densities, use of mechanical machinery in orchards and the need for effective pesticide and pathological chemical spray applications. The main objective of this study was to obtain a practical means of manipulating lemon trees at the right time. Pruning at the correct time to cultivate productive trees that produce quality fruit would have financial benefits. Lemon fruit quality is dependent on market demand and involves a number of features such as fruit shelf life, rind thickness, fruit size, rind colour, and juice content. The study was conducted on ’Eureka’ lemon trees budded on C. volkameriana rootstock, bearing the fifth and sixth commercial crops in 1999 and 2000 respectively. Twelve monthly pruning treatments per year were conducted on one row of trees starting in December 1997 (site 1) and repeated in the second year on the adjacent row of the same orchard starting in December 1998 (site 2). Selective pruning heading cuts were applied below the intercalation on the intercalary units. Potential branch bearing units were tagged and assessed during the harvest and flowering periods. Summer pruning between 16 to 19 months before the subsequent April/May harvest, resulted in the longest and most complex (intercalation sprouted per axil) vegetative response. The estimated crop value indicated that summer pruning treatments produced the highest income. This was ascribed not to differences in fruit size or quality, but to an increase in yield. The industry’s trend is to prune citrus from post-harvest to the pre-bloom stage. Results from this study have provided a beneficial cultural practice to prune during the summer months and provides a practice to optimise farm production and profit margins.
- Full Text:
- Date Issued: 2002
An investigation of the effects of leadership training on junior managements' (sic) morale at three manufacturing organisations within the Buffalo City Area
- Authors: Naina, Ruweida Anastacia
- Date: 2002
- Subjects: Employee morale , Leadership
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10908 , http://hdl.handle.net/10948/105 , Employee morale , Leadership
- Description: The present study was undertaken to determine the effects that leadership training has on employees’ morale at work. The study was conducted on 15 students from three organisations within the Buffalo City area, studying towards a Diploma in Manufacturing Management at the Johnson & Johnson Leadership Development Institute, Rhodes University, East London Campus. The main aims of the study were: · to review the literature of the leadership training conducted at the Johnson & Johnson Leadership Development Institute (JJLDI), and to assess the effects it has on employees’ morale at work. · to provide industry with documented evidence that the leadership training conducted at the JJLDI has a positive influence on employees morale. · to provide the JJLDI with valuable information as to whether or not the course material and methods has a positive impact on meeting industry demands. A secondary objective of the study was to provide a medium in which students undergoing the leadership training were able to address their concerns with regard to course content and structure. Fieldwork comprised a 5-day, week (40 hours) of intensive lectures and group discussions at Rhodes University. Students were then assigned a 4-month workbased project with the lecturer acting as mentor to each student. The researcher used self- administered electronic questionnaires as the research tool. Results revealed the following: · that the students morale increased by more than 20 percent after having undergone leadership training; that the students communication skills has increased, and, · that the students interpersonal relations with co-workers has shown a significant increase Future implications are that students exposed to this type of leadership training will have a positive influence on their co-workers. This will spurn a new organisational culture that will cope with global demands. In some cases these future leaders will be the source of sustained competitive advantage over insurgents through increasing the organisation’s human, social and knowledge capital.
- Full Text:
- Date Issued: 2002
- Authors: Naina, Ruweida Anastacia
- Date: 2002
- Subjects: Employee morale , Leadership
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10908 , http://hdl.handle.net/10948/105 , Employee morale , Leadership
- Description: The present study was undertaken to determine the effects that leadership training has on employees’ morale at work. The study was conducted on 15 students from three organisations within the Buffalo City area, studying towards a Diploma in Manufacturing Management at the Johnson & Johnson Leadership Development Institute, Rhodes University, East London Campus. The main aims of the study were: · to review the literature of the leadership training conducted at the Johnson & Johnson Leadership Development Institute (JJLDI), and to assess the effects it has on employees’ morale at work. · to provide industry with documented evidence that the leadership training conducted at the JJLDI has a positive influence on employees morale. · to provide the JJLDI with valuable information as to whether or not the course material and methods has a positive impact on meeting industry demands. A secondary objective of the study was to provide a medium in which students undergoing the leadership training were able to address their concerns with regard to course content and structure. Fieldwork comprised a 5-day, week (40 hours) of intensive lectures and group discussions at Rhodes University. Students were then assigned a 4-month workbased project with the lecturer acting as mentor to each student. The researcher used self- administered electronic questionnaires as the research tool. Results revealed the following: · that the students morale increased by more than 20 percent after having undergone leadership training; that the students communication skills has increased, and, · that the students interpersonal relations with co-workers has shown a significant increase Future implications are that students exposed to this type of leadership training will have a positive influence on their co-workers. This will spurn a new organisational culture that will cope with global demands. In some cases these future leaders will be the source of sustained competitive advantage over insurgents through increasing the organisation’s human, social and knowledge capital.
- Full Text:
- Date Issued: 2002
An investigation of the management and leadership experiences of female school principals in the Ondangwa education regions
- Authors: Udjombala, Maria
- Date: 2002
- Subjects: Women school principals -- Namibia -- Ondangwa Educational leadership -- Namibia -- Ondangwa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1653 , http://hdl.handle.net/10962/d1003536
- Description: This study explores practical school leadership and management, as enacted by women. The study, conducted in an interpretive paradigm, attempts to gain an understanding of women’s subjective experiences of school leadership and management. Two women principals from Ondangwa West Educational Region were interviewed. The two were selected through consultations with one of the senior inspectors in the region. Both had been principals for more than ten years and were seen by those who are concerned with their school to be successful. The study found that these women prefer a participative style of leadership and management, characterised by consultations with others, teamwork, collaborative decision-making and the use of power to empower others. They also strive for good human relationships because they believe that it fosters mutual respect, trust, openness and a good working atmosphere. All these human centred approaches are directed towards creating a school atmosphere that is conducive to teaching and learning and therefore result in effective schooling and quality educational outcomes. They do not experience gender discrimination in their work places. They have the full support of their supervisors. Though both are married with children, these dual roles do not prevent them from being successful in their professional work. In fact they have reached a stage where they feel confident as leaders and feel that they are acting as role models for fellow women principals and those aspiring to this position. The study concludes that the styles of leadership and management displayed by women are similar to those that are universally accepted as characteristics needed for effective school management and leadership. Though these leadership styles are traditionally associated with women, these characteristics are not gender specific. Therefore it will be in the best interest of schools, if school principals, both men and women, could borrow from these qualities in order to change schools from authoritarian to more democratic institutions.
- Full Text:
- Date Issued: 2002
- Authors: Udjombala, Maria
- Date: 2002
- Subjects: Women school principals -- Namibia -- Ondangwa Educational leadership -- Namibia -- Ondangwa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1653 , http://hdl.handle.net/10962/d1003536
- Description: This study explores practical school leadership and management, as enacted by women. The study, conducted in an interpretive paradigm, attempts to gain an understanding of women’s subjective experiences of school leadership and management. Two women principals from Ondangwa West Educational Region were interviewed. The two were selected through consultations with one of the senior inspectors in the region. Both had been principals for more than ten years and were seen by those who are concerned with their school to be successful. The study found that these women prefer a participative style of leadership and management, characterised by consultations with others, teamwork, collaborative decision-making and the use of power to empower others. They also strive for good human relationships because they believe that it fosters mutual respect, trust, openness and a good working atmosphere. All these human centred approaches are directed towards creating a school atmosphere that is conducive to teaching and learning and therefore result in effective schooling and quality educational outcomes. They do not experience gender discrimination in their work places. They have the full support of their supervisors. Though both are married with children, these dual roles do not prevent them from being successful in their professional work. In fact they have reached a stage where they feel confident as leaders and feel that they are acting as role models for fellow women principals and those aspiring to this position. The study concludes that the styles of leadership and management displayed by women are similar to those that are universally accepted as characteristics needed for effective school management and leadership. Though these leadership styles are traditionally associated with women, these characteristics are not gender specific. Therefore it will be in the best interest of schools, if school principals, both men and women, could borrow from these qualities in order to change schools from authoritarian to more democratic institutions.
- Full Text:
- Date Issued: 2002
An investigation of the neuroprotective effects of estrogen in a model of quinolinic acid-induced neurodegeneration
- Authors: Heron, Paula Michelle
- Date: 2002
- Subjects: Estrogen , Quinolinic acid , Nervous system -- Degeneration
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3759 , http://hdl.handle.net/10962/d1003237 , Estrogen , Quinolinic acid , Nervous system -- Degeneration
- Description: The hippocampus, located in the medial temporal lobe, is an important region of the brain responsible for the formation of memory. Thus, any agent that induces stress in this area has detrimental effects and could lead to various types of dementia. Such agents include the neurotoxin, Quinolinic acid. Quinolinic acid (QUIN) is a neurotoxic metabolite of the tryptophan-kynurenine pathway and is an endogenous glutamate agonist that selectively injures and kills vulnerable neurons via the activation of the NMDA class of excitatory amino acid receptors. Estrogen is a female hormone that is responsible for reproduction. However, in the last decade estrogen has been shown to exhibit a wide range of actions on the brain, including neuroprotection. Estrogen has been shown to exhibit intrinsic antioxidant activity and protects cultured neurons against oxidative cell death. This is achieved by estrogen’s ability to scavenge free radicals, which is dependent on the presence of the hydroxyl group at the C3 position on the A ring of the steroid molecule. Numerous studies have shown that estrogen protects neurons against various toxic substances and may play a role in delaying the onset of neurodegenerative diseases, such as Alzheimer’s disease. Neuronal damage due to oxidative stress has been implicated in several neurodegenerative disorders. The detection and measurement of lipid peroxidation is the evidence most frequently cited to support the involvement of free radical reactions in toxicology and in human disease. The study aims to elucidate and further characterise the mechanism behind estrogen’s neuroprotection, using QUIN as a model of neurotoxicity. Initial studies confirm estrogen’s ability to scavenge potent free radicals. In addition, the results show that estrogen forms an interaction with iron (II) and also acts at the NMDA receptor as an agonist. Both mechanisms reduce the ability of QUIN to cause damage to neurons, since QUIN-induced toxicity is dependent on the activation of the NMDA receptor and the formation of a complex with iron (II) to induce lipid peroxidation. Heat shock proteins, especially Hsp 70 play a role in cytoprotection by capturing denatured proteins and facilitating the refolding of these proteins once the stress has been relieved. Estrogen has been shown to increase the level of expression of Hsp70, both inducible and cognate forms of the protein. This suggests that estrogen helps to protect against cellular protein damage induced by any form of stress the cell may encounter. The discovery of neuroprotective agents, such as estrogen, is becoming important as accumulating evidence indicates a protective role in vivo. Thus further research may favour the use of these agents in the treatment of several neurodegenerative disorders. Considering how devastating diseases, such as Alzheimer’s disease, are to a patient and the patient’s families, the discovery of new protective agents are a matter of urgency.
- Full Text:
- Date Issued: 2002
- Authors: Heron, Paula Michelle
- Date: 2002
- Subjects: Estrogen , Quinolinic acid , Nervous system -- Degeneration
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3759 , http://hdl.handle.net/10962/d1003237 , Estrogen , Quinolinic acid , Nervous system -- Degeneration
- Description: The hippocampus, located in the medial temporal lobe, is an important region of the brain responsible for the formation of memory. Thus, any agent that induces stress in this area has detrimental effects and could lead to various types of dementia. Such agents include the neurotoxin, Quinolinic acid. Quinolinic acid (QUIN) is a neurotoxic metabolite of the tryptophan-kynurenine pathway and is an endogenous glutamate agonist that selectively injures and kills vulnerable neurons via the activation of the NMDA class of excitatory amino acid receptors. Estrogen is a female hormone that is responsible for reproduction. However, in the last decade estrogen has been shown to exhibit a wide range of actions on the brain, including neuroprotection. Estrogen has been shown to exhibit intrinsic antioxidant activity and protects cultured neurons against oxidative cell death. This is achieved by estrogen’s ability to scavenge free radicals, which is dependent on the presence of the hydroxyl group at the C3 position on the A ring of the steroid molecule. Numerous studies have shown that estrogen protects neurons against various toxic substances and may play a role in delaying the onset of neurodegenerative diseases, such as Alzheimer’s disease. Neuronal damage due to oxidative stress has been implicated in several neurodegenerative disorders. The detection and measurement of lipid peroxidation is the evidence most frequently cited to support the involvement of free radical reactions in toxicology and in human disease. The study aims to elucidate and further characterise the mechanism behind estrogen’s neuroprotection, using QUIN as a model of neurotoxicity. Initial studies confirm estrogen’s ability to scavenge potent free radicals. In addition, the results show that estrogen forms an interaction with iron (II) and also acts at the NMDA receptor as an agonist. Both mechanisms reduce the ability of QUIN to cause damage to neurons, since QUIN-induced toxicity is dependent on the activation of the NMDA receptor and the formation of a complex with iron (II) to induce lipid peroxidation. Heat shock proteins, especially Hsp 70 play a role in cytoprotection by capturing denatured proteins and facilitating the refolding of these proteins once the stress has been relieved. Estrogen has been shown to increase the level of expression of Hsp70, both inducible and cognate forms of the protein. This suggests that estrogen helps to protect against cellular protein damage induced by any form of stress the cell may encounter. The discovery of neuroprotective agents, such as estrogen, is becoming important as accumulating evidence indicates a protective role in vivo. Thus further research may favour the use of these agents in the treatment of several neurodegenerative disorders. Considering how devastating diseases, such as Alzheimer’s disease, are to a patient and the patient’s families, the discovery of new protective agents are a matter of urgency.
- Full Text:
- Date Issued: 2002
An investigation to determine the readiness of management at selected manufacturing organisations in the Buffalo City area to manage the HIV/AIDS epidemic
- Authors: Meintjes, Samuel David
- Date: 2002
- Subjects: AIDS (Disease) -- Economic aspects -- South Africa , HIV infections -- Economic aspects -- South Africa , Labor productivity , Production management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10906 , http://hdl.handle.net/10948/108 , AIDS (Disease) -- Economic aspects -- South Africa , HIV infections -- Economic aspects -- South Africa , Labor productivity , Production management
- Description: The present study was conducted to determine the readiness of management at selected manufacturing organisation in the Buffalo City area to manage the HIV/AIDS epidemic. The study was conducted in the Buffalo City area on manufacturing organisations with a workforce greater than 250. The main aims of the present study were: · To provide an overview of relevant literature concerning theoretical key issues related to the management of HIV/AIDS in the workplace. · To assess the readiness of Buffalo City organisations in managing HIV/AIDS in the workplace, and to identify areas of improvement. · In the light of the findings, make further recommendations to manufacturing organisations to further improve their workplace policy, education and awareness programmes; and the accommodation of HIV-infected employees in the workplace. Another objective of the study was to provide additional research as a tool to assist organisations in managing HIV/AIDS in the workplace and to assist in fighting the HIV/AIDS epidemic in the Buffalo City area. The research process entailed: the selection of a test sample of manufacturing organisations in the Buffalo City area, and selecting an appropriate Human Resource manager or representative from these organisations to complete a structured questionnaire. The research tool used in the study was a questionnaire, which was used to extract relevant information on the demographics, policies, education and the accommodation of HIV/AIDS affected and infected employees in the workplace. The results revealed the following: · 73 percent of the selected manufacturing organisations in the Buffalo City have an HIV/AIDS policy in place; · 87 percent of the organisation indicated that their management are committed to the development and implementation of a HIV/AIDS policy; · management and supervisors in these organisations have not been adequately trained to manage the impact of HIV/AIDS in the workplace; · organisations in the Buffalo City area need to collaborate and share information; and · that very few organisations benchmark against best practices. Future research on HIV/AIDS policy can explore the effective implementation of HIV/AIDS policies in these organisations as well as the effective management of HIV/AIDS in the workplace.
- Full Text:
- Date Issued: 2002
- Authors: Meintjes, Samuel David
- Date: 2002
- Subjects: AIDS (Disease) -- Economic aspects -- South Africa , HIV infections -- Economic aspects -- South Africa , Labor productivity , Production management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10906 , http://hdl.handle.net/10948/108 , AIDS (Disease) -- Economic aspects -- South Africa , HIV infections -- Economic aspects -- South Africa , Labor productivity , Production management
- Description: The present study was conducted to determine the readiness of management at selected manufacturing organisation in the Buffalo City area to manage the HIV/AIDS epidemic. The study was conducted in the Buffalo City area on manufacturing organisations with a workforce greater than 250. The main aims of the present study were: · To provide an overview of relevant literature concerning theoretical key issues related to the management of HIV/AIDS in the workplace. · To assess the readiness of Buffalo City organisations in managing HIV/AIDS in the workplace, and to identify areas of improvement. · In the light of the findings, make further recommendations to manufacturing organisations to further improve their workplace policy, education and awareness programmes; and the accommodation of HIV-infected employees in the workplace. Another objective of the study was to provide additional research as a tool to assist organisations in managing HIV/AIDS in the workplace and to assist in fighting the HIV/AIDS epidemic in the Buffalo City area. The research process entailed: the selection of a test sample of manufacturing organisations in the Buffalo City area, and selecting an appropriate Human Resource manager or representative from these organisations to complete a structured questionnaire. The research tool used in the study was a questionnaire, which was used to extract relevant information on the demographics, policies, education and the accommodation of HIV/AIDS affected and infected employees in the workplace. The results revealed the following: · 73 percent of the selected manufacturing organisations in the Buffalo City have an HIV/AIDS policy in place; · 87 percent of the organisation indicated that their management are committed to the development and implementation of a HIV/AIDS policy; · management and supervisors in these organisations have not been adequately trained to manage the impact of HIV/AIDS in the workplace; · organisations in the Buffalo City area need to collaborate and share information; and · that very few organisations benchmark against best practices. Future research on HIV/AIDS policy can explore the effective implementation of HIV/AIDS policies in these organisations as well as the effective management of HIV/AIDS in the workplace.
- Full Text:
- Date Issued: 2002
Aphid (Sitobion yakini) investigation shows thin-walled sieve tubes in barley (Hordeum vulgare L) to be more functional than thick-walled sieve tubes
- Matsiliza, Balbalwa, Botha, Christiaan E J
- Authors: Matsiliza, Balbalwa , Botha, Christiaan E J
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6526 , http://hdl.handle.net/10962/d1005960
- Description: Barley, like most other grasses that have been studied, contains two kinds of sieve tube. The first formed are called thinwalled sieve tubes because of their thin wall compared to the late-formed, and are associated with companion cells. The late-formed are thick-walled sieve tubes, which differentiate next to the metaxylem vessels and lack companion cells. Aphid (Sitobion yakini (Eastop) feeding was studied using light microscopy to determine if they preferentially feed from thin- or thick-walled sieve tubes in the barley leaf. Penetration of the stylets through the leaf epidermis and mesophyll was largely intercellular, becoming partly intercellular and, partly, intracellular inside the vascular bundle. Sixteen of 19 pairs of stylets (84%), and 293 of 317 (92%) stylet tracks terminated at the thin-walled sieve tubes, suggesting that Sitobion yakini feeds preferentially on the thin-walled sieve tubes which seem to be more attractive to the aphid. These thin-walled sieve tubes are thus probably the most functional in terms of phloem loading and transport.
- Full Text:
- Date Issued: 2002
- Authors: Matsiliza, Balbalwa , Botha, Christiaan E J
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6526 , http://hdl.handle.net/10962/d1005960
- Description: Barley, like most other grasses that have been studied, contains two kinds of sieve tube. The first formed are called thinwalled sieve tubes because of their thin wall compared to the late-formed, and are associated with companion cells. The late-formed are thick-walled sieve tubes, which differentiate next to the metaxylem vessels and lack companion cells. Aphid (Sitobion yakini (Eastop) feeding was studied using light microscopy to determine if they preferentially feed from thin- or thick-walled sieve tubes in the barley leaf. Penetration of the stylets through the leaf epidermis and mesophyll was largely intercellular, becoming partly intercellular and, partly, intracellular inside the vascular bundle. Sixteen of 19 pairs of stylets (84%), and 293 of 317 (92%) stylet tracks terminated at the thin-walled sieve tubes, suggesting that Sitobion yakini feeds preferentially on the thin-walled sieve tubes which seem to be more attractive to the aphid. These thin-walled sieve tubes are thus probably the most functional in terms of phloem loading and transport.
- Full Text:
- Date Issued: 2002
Aspects pertinent to the provision of sustainable water supply projects in the Eastern Cape Province: a case study of Nomzamo Water Supply Project
- Authors: Mpendu, Daluhlanga Ayford
- Date: 2002
- Subjects: Water-supply -- South Africa -- Eastern Cape Nomzamo Water Supply Project Water-supply -- South Africa -- Social aspects
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:5952 , http://hdl.handle.net/10962/d1007450
- Description: This study explores views behind the failure of water supply projects to achieve sustainability, primarily from the 'users' perspective, and at a secondary level from the perspective of the government/funders. One completed water supply project was selected as a case study for the research project. The overriding principle behind the water infrastructure delivery programme is that the service must be provided in a sustainable manner, and that the community must actively participate and be involved in all the phases of the project. The provision of water is not simply as it might look. In reality it is a complex process, which involves a number of organisations with different, yet important roles and responsibilities. Ongoing collaboration is important among these organisations if the service is to be provided efficiently and in a sustainable manner. In particular, local government has a Constitutional obligation to provide services to all consumers in an efficient, affordable, economical and sustainable manner. The National and Provincial governments, however, have a number of responsibilities in the field of water services. Semi-structured interview method was used to collect data from respondents. Two sets of interview schedules were developed, one for the community/water project committee members, and the other for the government officials. The data collected was analysed both qualitatively and quantitatively. This analysis enabled the researcher to draw findings, make conclusions and propose recommendations. The findings and conclusions of the study point to lack of clarity on roles and responsibilities; gender and cultural constraints; and, poor training and capacity and building of the community as being some of the reasons for the failure of the project. The recommendations proposed entail, inter alia, massive community mobilisation and awareness creation programmes; improvement in levels of the service; adoption of a gender-sensitive approach to project development; and, implementation of a training and capacity building process in the community in order to 'revitalise' the project. The study has merely focussed on one water project and sets the scene for further exploration of the subject. It certainly highlights some critical issues around sustainability of water projects, and hopefully will contribute towards the ongoing debate in this area.
- Full Text:
- Date Issued: 2002
- Authors: Mpendu, Daluhlanga Ayford
- Date: 2002
- Subjects: Water-supply -- South Africa -- Eastern Cape Nomzamo Water Supply Project Water-supply -- South Africa -- Social aspects
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:5952 , http://hdl.handle.net/10962/d1007450
- Description: This study explores views behind the failure of water supply projects to achieve sustainability, primarily from the 'users' perspective, and at a secondary level from the perspective of the government/funders. One completed water supply project was selected as a case study for the research project. The overriding principle behind the water infrastructure delivery programme is that the service must be provided in a sustainable manner, and that the community must actively participate and be involved in all the phases of the project. The provision of water is not simply as it might look. In reality it is a complex process, which involves a number of organisations with different, yet important roles and responsibilities. Ongoing collaboration is important among these organisations if the service is to be provided efficiently and in a sustainable manner. In particular, local government has a Constitutional obligation to provide services to all consumers in an efficient, affordable, economical and sustainable manner. The National and Provincial governments, however, have a number of responsibilities in the field of water services. Semi-structured interview method was used to collect data from respondents. Two sets of interview schedules were developed, one for the community/water project committee members, and the other for the government officials. The data collected was analysed both qualitatively and quantitatively. This analysis enabled the researcher to draw findings, make conclusions and propose recommendations. The findings and conclusions of the study point to lack of clarity on roles and responsibilities; gender and cultural constraints; and, poor training and capacity and building of the community as being some of the reasons for the failure of the project. The recommendations proposed entail, inter alia, massive community mobilisation and awareness creation programmes; improvement in levels of the service; adoption of a gender-sensitive approach to project development; and, implementation of a training and capacity building process in the community in order to 'revitalise' the project. The study has merely focussed on one water project and sets the scene for further exploration of the subject. It certainly highlights some critical issues around sustainability of water projects, and hopefully will contribute towards the ongoing debate in this area.
- Full Text:
- Date Issued: 2002
Assessing the effectiveness of project management practices in the South African communications industry
- Authors: Smith, Michael
- Date: 2002
- Subjects: Telkom (Firm : South Africa) Management , Project management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10918 , http://hdl.handle.net/10948/77 , Telkom (Firm : South Africa) Management , Project management -- South Africa
- Description: In many organisations, project management is no longer a separately identified function, but is entrenched in the overall management of the business. The typical project management environment has become multi-project. Most of the project decisions require consideration of schedule, resource and cost concerns on other project work, necessitating the review and evaluation of multi-project data. Resource management is at least as important as schedule (time) management. Functional managers, supporting multiple projects with shared and limited resources, need to know the demands on their resources and the impact of new project loads and changing priorities. This means that the effectiveness of project management is not only influenced by the function itself, but it permeates throughout the entire organisation, for which the overriding goal is to survive and prosper in a competitive environment. The research problem of this study is to assess how effective project management practices in the South African communications’ industry are, by using Telkom SA as the selected target group. The research method employed was to first identify the best practices of project management, by focusing on generally accepted standards and practices, that is those which are particularly effective in helping an organisation to achieve its objectives. The Project Management Body of Knowledge (PMBOK®) which is considered to be the international standard for project management, was used as the framework for identifying the best practices. The identified best practices were used as an assessment tool to determine to what extent these practices are applied in Telkom SA.
- Full Text:
- Date Issued: 2002
- Authors: Smith, Michael
- Date: 2002
- Subjects: Telkom (Firm : South Africa) Management , Project management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10918 , http://hdl.handle.net/10948/77 , Telkom (Firm : South Africa) Management , Project management -- South Africa
- Description: In many organisations, project management is no longer a separately identified function, but is entrenched in the overall management of the business. The typical project management environment has become multi-project. Most of the project decisions require consideration of schedule, resource and cost concerns on other project work, necessitating the review and evaluation of multi-project data. Resource management is at least as important as schedule (time) management. Functional managers, supporting multiple projects with shared and limited resources, need to know the demands on their resources and the impact of new project loads and changing priorities. This means that the effectiveness of project management is not only influenced by the function itself, but it permeates throughout the entire organisation, for which the overriding goal is to survive and prosper in a competitive environment. The research problem of this study is to assess how effective project management practices in the South African communications’ industry are, by using Telkom SA as the selected target group. The research method employed was to first identify the best practices of project management, by focusing on generally accepted standards and practices, that is those which are particularly effective in helping an organisation to achieve its objectives. The Project Management Body of Knowledge (PMBOK®) which is considered to be the international standard for project management, was used as the framework for identifying the best practices. The identified best practices were used as an assessment tool to determine to what extent these practices are applied in Telkom SA.
- Full Text:
- Date Issued: 2002
Assessing the need for specific services for HIV/AIDS affected people using participatory needs assessment processes
- Authors: Moresby-White, Ann
- Date: 2002
- Subjects: AIDS (Disease) -- Patients -- Services for , HIV-positive persons -- Services for , AIDS (Disease) -- Research , AIDS (Disease) -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:713 , http://hdl.handle.net/10962/d1007692 , AIDS (Disease) -- Patients -- Services for , HIV-positive persons -- Services for , AIDS (Disease) -- Research , AIDS (Disease) -- South Africa
- Description: The purpose of the study undertaken is to develop knowledge to assist service providers in their planning and implementation of community -based programmes and projects. The thesis explores the most appropriate way of conducting a needs assessment, relating to HIV/AIDS services in a particular community; thereafter the needs assessment was carried out. This qualitative research study is conducted using participatory methods and techniques. The research reviews literature pertaining to HIV/AIDS, specifically in Africa, South Africa and the Eastern Cape and incorporates a discussion on the concept of community, community development and poverty. The design of the needs assessment tool, implementation and analysis is conducted through focus group discussions and individual semi-structured interviews. The theory on participatory approaches and community development are central to this study. The study found that HIV / AIDS as an issue is not perceived by the community under study to be an immediate need in light of basic needs being identified as priority. The use of participatory methods in this study highlighted the diversity within communities. Service providers who wish to initiate community - based projects need to take note of diversity and personal interests of individuals or groups who become involved in community- based projects. The study further highlighted the need for service providers to provide training, to their staff in participatory approaches and techniques, before embarking on community development projects. The study concludes that services relating to the HIV/AIDS epidemic cannot be carried out in isolation, but that an integrated approach is needed in the planning and implementation of services and programmes to address those affected by HIV/AIDS.
- Full Text:
- Date Issued: 2002
- Authors: Moresby-White, Ann
- Date: 2002
- Subjects: AIDS (Disease) -- Patients -- Services for , HIV-positive persons -- Services for , AIDS (Disease) -- Research , AIDS (Disease) -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:713 , http://hdl.handle.net/10962/d1007692 , AIDS (Disease) -- Patients -- Services for , HIV-positive persons -- Services for , AIDS (Disease) -- Research , AIDS (Disease) -- South Africa
- Description: The purpose of the study undertaken is to develop knowledge to assist service providers in their planning and implementation of community -based programmes and projects. The thesis explores the most appropriate way of conducting a needs assessment, relating to HIV/AIDS services in a particular community; thereafter the needs assessment was carried out. This qualitative research study is conducted using participatory methods and techniques. The research reviews literature pertaining to HIV/AIDS, specifically in Africa, South Africa and the Eastern Cape and incorporates a discussion on the concept of community, community development and poverty. The design of the needs assessment tool, implementation and analysis is conducted through focus group discussions and individual semi-structured interviews. The theory on participatory approaches and community development are central to this study. The study found that HIV / AIDS as an issue is not perceived by the community under study to be an immediate need in light of basic needs being identified as priority. The use of participatory methods in this study highlighted the diversity within communities. Service providers who wish to initiate community - based projects need to take note of diversity and personal interests of individuals or groups who become involved in community- based projects. The study further highlighted the need for service providers to provide training, to their staff in participatory approaches and techniques, before embarking on community development projects. The study concludes that services relating to the HIV/AIDS epidemic cannot be carried out in isolation, but that an integrated approach is needed in the planning and implementation of services and programmes to address those affected by HIV/AIDS.
- Full Text:
- Date Issued: 2002
Asthenospheric and lithospheric sources for Mesozoic dolerites from Liberia (Africa): trace element and isotopic evidence
- Dupuy, C, Marsh, Julian S, Dostal, J, Michard, A, Testa, S
- Authors: Dupuy, C , Marsh, Julian S , Dostal, J , Michard, A , Testa, S
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140422 , vital:37887 , https://doi.org/10.1016/0012-821X(88)90067-2
- Description: Combined elemental, and Sr and Nd isotopic data are presented for Mesozoic dolerite dikes of Liberia (Africa) which are related to the initial stage of opening of the Atlantic Ocean.
- Full Text: false
- Date Issued: 2002
- Authors: Dupuy, C , Marsh, Julian S , Dostal, J , Michard, A , Testa, S
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140422 , vital:37887 , https://doi.org/10.1016/0012-821X(88)90067-2
- Description: Combined elemental, and Sr and Nd isotopic data are presented for Mesozoic dolerite dikes of Liberia (Africa) which are related to the initial stage of opening of the Atlantic Ocean.
- Full Text: false
- Date Issued: 2002
Bad faith: the psychological life of a satanist who committed murder
- Authors: Du Toit, Jacobus Petrus
- Date: 2002
- Subjects: Murderers -- Psychology , Criminal psychology , Satanism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3152 , http://hdl.handle.net/10962/d1007483 , Murderers -- Psychology , Criminal psychology , Satanism
- Description: Traditional methods of psychological and forensic research fail to adequately provide an account of the psychological meaning that perpetrators of crime derive when appropriating their actions to Satanic involvement. In February 2001, a young man appeared in a South African High Court and testified that he had committed murder as a result of his involvement in Satanism. The aim of this study is to gain a phenomenological understanding of how this man appropriates the act of murder to involvement in Satanism. A review of literature elucidates Satanism as a context for meaning, provide a framework for defining murder as a criminal act, and situate this study in the broader field of phenomenological-existential, psychological research. An emergent design case-study approach was applied to data gathered from a single subject, by means of a three-interview series. An empirical phenomenological methodology was used during the interpretive phase to arrive at both a descriptive account of the subject's phenomenological experience and how the eidetic structure of the experience of Satanism as a context tor meaning emerged. A discussion of the subject's appropriation of murder with Satanism illustrates how the subject imposed a dichotomy of good and bad on his life-world in an attempt to derive meaning from his experience of inadequacy. Involvement with Satanism is meaningful, in that it affords its followers an increased sense of power, a safe environment to explore individuality, shared responsibility associated with exercising free choice, social situatedness and an affirmation of being through an increased awareness of finitude. The research subject experienced committing murder as an act of loyalty to the perceived gains he had been afforded as result of his involvement with Satanism.
- Full Text:
- Date Issued: 2002
- Authors: Du Toit, Jacobus Petrus
- Date: 2002
- Subjects: Murderers -- Psychology , Criminal psychology , Satanism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3152 , http://hdl.handle.net/10962/d1007483 , Murderers -- Psychology , Criminal psychology , Satanism
- Description: Traditional methods of psychological and forensic research fail to adequately provide an account of the psychological meaning that perpetrators of crime derive when appropriating their actions to Satanic involvement. In February 2001, a young man appeared in a South African High Court and testified that he had committed murder as a result of his involvement in Satanism. The aim of this study is to gain a phenomenological understanding of how this man appropriates the act of murder to involvement in Satanism. A review of literature elucidates Satanism as a context for meaning, provide a framework for defining murder as a criminal act, and situate this study in the broader field of phenomenological-existential, psychological research. An emergent design case-study approach was applied to data gathered from a single subject, by means of a three-interview series. An empirical phenomenological methodology was used during the interpretive phase to arrive at both a descriptive account of the subject's phenomenological experience and how the eidetic structure of the experience of Satanism as a context tor meaning emerged. A discussion of the subject's appropriation of murder with Satanism illustrates how the subject imposed a dichotomy of good and bad on his life-world in an attempt to derive meaning from his experience of inadequacy. Involvement with Satanism is meaningful, in that it affords its followers an increased sense of power, a safe environment to explore individuality, shared responsibility associated with exercising free choice, social situatedness and an affirmation of being through an increased awareness of finitude. The research subject experienced committing murder as an act of loyalty to the perceived gains he had been afforded as result of his involvement with Satanism.
- Full Text:
- Date Issued: 2002
Barkly East bells and the British Empire
- Authors: Lewis, Colin A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6178 , http://hdl.handle.net/10962/d1012371 , http://www.ringingworld.co.uk
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2002
- Authors: Lewis, Colin A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6178 , http://hdl.handle.net/10962/d1012371 , http://www.ringingworld.co.uk
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2002
Being Brave: Writing Environmental Education Research
- Lotz-Sisitka, Heila, Burt, Jane C
- Authors: Lotz-Sisitka, Heila , Burt, Jane C
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184734 , vital:44267 , xlink:href="https://eric.ed.gov/?id=EJ654591"
- Description: The heroine came back from her very important quest and sat down to write a thesis . . . While mythical journeys do not always end this way, the stories have to be told. The work of telling the story in the hero’s journey is often left untold. This paper explores some of the headwork that goes into textwork (Van Manen, 1995) in environmental education research. We argue that writing is an integral part of the research process, and should not be viewed as an “add on” or a silent, untold part of the adventure. We reflect on some of the institutional and epistemological issues associated with writing social science (in our case environmental education) research texts. Writing research is never an easy enterprise, it is bound by history and tradition, convention, institutional habit, and regulation. It is also constrained by the uncertainty of the process of writing itself, by problems of power relations in research, and the difficulty of writing to represent experience rigorously and authentically while recognizing that all writing is a constructed symbolic representation of experience. The paper reflexively reviews our attempts at “being brave” in the construction of our research texts.
- Full Text:
- Date Issued: 2002
- Authors: Lotz-Sisitka, Heila , Burt, Jane C
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184734 , vital:44267 , xlink:href="https://eric.ed.gov/?id=EJ654591"
- Description: The heroine came back from her very important quest and sat down to write a thesis . . . While mythical journeys do not always end this way, the stories have to be told. The work of telling the story in the hero’s journey is often left untold. This paper explores some of the headwork that goes into textwork (Van Manen, 1995) in environmental education research. We argue that writing is an integral part of the research process, and should not be viewed as an “add on” or a silent, untold part of the adventure. We reflect on some of the institutional and epistemological issues associated with writing social science (in our case environmental education) research texts. Writing research is never an easy enterprise, it is bound by history and tradition, convention, institutional habit, and regulation. It is also constrained by the uncertainty of the process of writing itself, by problems of power relations in research, and the difficulty of writing to represent experience rigorously and authentically while recognizing that all writing is a constructed symbolic representation of experience. The paper reflexively reviews our attempts at “being brave” in the construction of our research texts.
- Full Text:
- Date Issued: 2002
Biological generation of reactive alkaline species and their application in a sustainable bioprocess for the remediation of acid and metal contaminated wastewaters
- Authors: Van Hille, Robert Paul
- Date: 2002
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21049 , http://hdl.handle.net/10962/6129
- Description: This project focused on the development of an integrated biological system for the treatment of acidic and metal-laden effluents, based on the sustainable biological generation of reactive alkaline species. Initial studies concentrated on the binding and accumulation of heavy metals by biomass of the cyanobacteria, Spirulina sp. Metal binding was rapid, with saturation reached in 30 minutes, and followed an affinity series of Pb > Cu > Zn >>Fe. The binding capacity of the Spirulina for each of the metals was relatively low when compared to a range of other biosorbents. The toxicity thresholds of the algae was determined for copper and zinc. These were low (10umoles/g) and as such, the algae were not suitable for application in a treatment system in which they came into direct contact with the toxic metals. The algae were able to increase the pH of the surrounding medium. This occurred as a result of the accumulation of inorganic carbon, from bicarbonate, as a response to low concentrations of carbon dioxide in the medium. The resulting release of a hydroxide ion into solution led to the increase in pH. The increase in pH was shown to be due to a reduction in acidity, rather than an increase in alkalinity. The enzyme carbonic anhydrase was shown to be pivotal in this system. Attempts to determine the enzyme activity directly were unsuccessful, due to the inherent inaccuracy of the assay system. An indirect method of determining enzyme activity, by measuring changes in the carbonate species equilibrium, was developed. Under optimal conditions Spirulina was able to reduce the acidity by an amount equivalent to the addition of 3670umoles NaOH g·' h·'. Predictive modelling showed that this enhanced the potential of the medium to effect metal precipitation. For the algal system to be sustainable, a readily available source of bicarbonate was needed. This was achieved by the oxidation of organic carbon, under sulphidogenic conditions, by a bacterial consortium isolated from the anaerobic component of a facultative pond. The consortium was shown to consist of sulphate reducing (most likely Desulvovibrio and Desulfotomaculum)and acetogenic bacteria. Sulphate removal rates of 500mg 1·' day·' and 135mg 1·' day·' were achieved in a 21 agitated and 281 upflow reactor respectively. The bicarbonate generation rate in the 281 reactor was calculated as 4033umoles 1·' day·', which proved sufficient to act as a feed for the algal system. Sparging the anaerobic digester overflow with air and nitrogen resulted in a reduction in the aqueous sulphide concentration. Using nitrogen, a 70% recovery of sulphide, as H2S gas, was achieved in 60 minutes, while with air, this dropped to 40%, due to the oxidation of the aqueous sulphide. The stripping ofH2S resulted in an increase in pH. The H2S gas was used for the selective precipitation of copper and lead in the integrated system. The dynamics of metal precipitation was investigated. For simple reactions, between individual IV metal and base species, it was possible to generate an accurate predictive model and confirm the precipitating species using wavelength dispersive X-ray spectroscopy (WDS). In more complex systems, where precipitation of the artificial acid mine drainage was examined, the predictive modelling and WDS could not accurately describe the system. The addition of aqueous sulphide to copper and iron resulted in the formation of metastable, amorphous precipitates, which remained in suspension. Ageing of the copper precipitate resulted in the evolution of a stable crystalline structure (covellite) and the aggregation and settling of the precipitate. In the case of iron, the amorphous precipitate underwent oxidation before a stable iron sulphide could evolve and the settled precipitate was an iron oxide or oxyhydroxide. The artificial acid mine drainage was treated with sulphide, hydroxide, anaerobic digester overflow and algal overflow. The best metal removal was achieved with the sulphide and hydroxide, while the algal overflow outperformed the anaerobic digester overflow. The precipitate generated by the addition of sulphide was the most compact, followed by the algal overflow, the anaerobic digester overflow and the hydroxide. Efficient precipitation of all the heavy metals, except manganese, was achieved using the algal overflow at an acidity to alkalinity ratio of 1 :2. This ratio was selected for use in the pilot system. The Spirulina based pilot system was effectively used to treat an effluent from the Black Mountain base metal mine. The necessity to maintain the algae in suspension and avoid biomass washout were practical considerations which counted against this system. The replacement of the Spirulina by Oscillatoria, which adhered to a solid support, overcame these problems. The integrated biological system was able to effectively treat an artificial acid mine drainage for 90 days, reducing the concentration of all metals, except manganese, to below the acceptable environmental risk levels. The treatment of the final effluent in a second anaerobic digester reduced the manganese concentration to 4.5uM and proved that the sulphate reducing bacteria could be cultivated on enriched, partially treated acid mine drainage. The integrated biological treatment system performed well, effectively treating an effluent modelled closely on the quality of the water being discharged from the East Rand Basin. The cost of such a system would be considerably less than a "high tech" physico-chemical system. This, coupled with the potential long term sustainability of a biological system, would make it a potentially attractive option for the treatment of future acid mine drainage discharges.
- Full Text:
- Date Issued: 2002
- Authors: Van Hille, Robert Paul
- Date: 2002
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21049 , http://hdl.handle.net/10962/6129
- Description: This project focused on the development of an integrated biological system for the treatment of acidic and metal-laden effluents, based on the sustainable biological generation of reactive alkaline species. Initial studies concentrated on the binding and accumulation of heavy metals by biomass of the cyanobacteria, Spirulina sp. Metal binding was rapid, with saturation reached in 30 minutes, and followed an affinity series of Pb > Cu > Zn >>Fe. The binding capacity of the Spirulina for each of the metals was relatively low when compared to a range of other biosorbents. The toxicity thresholds of the algae was determined for copper and zinc. These were low (10umoles/g) and as such, the algae were not suitable for application in a treatment system in which they came into direct contact with the toxic metals. The algae were able to increase the pH of the surrounding medium. This occurred as a result of the accumulation of inorganic carbon, from bicarbonate, as a response to low concentrations of carbon dioxide in the medium. The resulting release of a hydroxide ion into solution led to the increase in pH. The increase in pH was shown to be due to a reduction in acidity, rather than an increase in alkalinity. The enzyme carbonic anhydrase was shown to be pivotal in this system. Attempts to determine the enzyme activity directly were unsuccessful, due to the inherent inaccuracy of the assay system. An indirect method of determining enzyme activity, by measuring changes in the carbonate species equilibrium, was developed. Under optimal conditions Spirulina was able to reduce the acidity by an amount equivalent to the addition of 3670umoles NaOH g·' h·'. Predictive modelling showed that this enhanced the potential of the medium to effect metal precipitation. For the algal system to be sustainable, a readily available source of bicarbonate was needed. This was achieved by the oxidation of organic carbon, under sulphidogenic conditions, by a bacterial consortium isolated from the anaerobic component of a facultative pond. The consortium was shown to consist of sulphate reducing (most likely Desulvovibrio and Desulfotomaculum)and acetogenic bacteria. Sulphate removal rates of 500mg 1·' day·' and 135mg 1·' day·' were achieved in a 21 agitated and 281 upflow reactor respectively. The bicarbonate generation rate in the 281 reactor was calculated as 4033umoles 1·' day·', which proved sufficient to act as a feed for the algal system. Sparging the anaerobic digester overflow with air and nitrogen resulted in a reduction in the aqueous sulphide concentration. Using nitrogen, a 70% recovery of sulphide, as H2S gas, was achieved in 60 minutes, while with air, this dropped to 40%, due to the oxidation of the aqueous sulphide. The stripping ofH2S resulted in an increase in pH. The H2S gas was used for the selective precipitation of copper and lead in the integrated system. The dynamics of metal precipitation was investigated. For simple reactions, between individual IV metal and base species, it was possible to generate an accurate predictive model and confirm the precipitating species using wavelength dispersive X-ray spectroscopy (WDS). In more complex systems, where precipitation of the artificial acid mine drainage was examined, the predictive modelling and WDS could not accurately describe the system. The addition of aqueous sulphide to copper and iron resulted in the formation of metastable, amorphous precipitates, which remained in suspension. Ageing of the copper precipitate resulted in the evolution of a stable crystalline structure (covellite) and the aggregation and settling of the precipitate. In the case of iron, the amorphous precipitate underwent oxidation before a stable iron sulphide could evolve and the settled precipitate was an iron oxide or oxyhydroxide. The artificial acid mine drainage was treated with sulphide, hydroxide, anaerobic digester overflow and algal overflow. The best metal removal was achieved with the sulphide and hydroxide, while the algal overflow outperformed the anaerobic digester overflow. The precipitate generated by the addition of sulphide was the most compact, followed by the algal overflow, the anaerobic digester overflow and the hydroxide. Efficient precipitation of all the heavy metals, except manganese, was achieved using the algal overflow at an acidity to alkalinity ratio of 1 :2. This ratio was selected for use in the pilot system. The Spirulina based pilot system was effectively used to treat an effluent from the Black Mountain base metal mine. The necessity to maintain the algae in suspension and avoid biomass washout were practical considerations which counted against this system. The replacement of the Spirulina by Oscillatoria, which adhered to a solid support, overcame these problems. The integrated biological system was able to effectively treat an artificial acid mine drainage for 90 days, reducing the concentration of all metals, except manganese, to below the acceptable environmental risk levels. The treatment of the final effluent in a second anaerobic digester reduced the manganese concentration to 4.5uM and proved that the sulphate reducing bacteria could be cultivated on enriched, partially treated acid mine drainage. The integrated biological treatment system performed well, effectively treating an effluent modelled closely on the quality of the water being discharged from the East Rand Basin. The cost of such a system would be considerably less than a "high tech" physico-chemical system. This, coupled with the potential long term sustainability of a biological system, would make it a potentially attractive option for the treatment of future acid mine drainage discharges.
- Full Text:
- Date Issued: 2002