Strengths that contribute towards resilience in the early years of marriage
- Authors: Aboagye, Lauren Lee
- Date: 2012
- Subjects: Marriage -- Interpersonal relations , Marriage -- Religious aspects -- Christianity , Resilience (Personality trait) , Communication in marriage , Adjustment (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9983 , http://hdl.handle.net/10948/1667 , Marriage -- Interpersonal relations , Marriage -- Religious aspects -- Christianity , Resilience (Personality trait) , Communication in marriage , Adjustment (Psychology)
- Description: Divorce is a common phenomenon in South Africa, affecting many families across the country. On the other hand, there are many couples who choose to remain married, despite having endured significant stress. In a review of literature there have been studies conducted exploring enduring marriages (marriages that have lasted twenty years or more), but little on resilience in the early years of marriage. With many couples choosing to divorce within the first ten years of marriage, there is value in exploring the strengths of young marriages that contribute towards resilience. The following question then arises: what are the stressors that couples experience during the early years of marriage (under ten years) and how does the way they cope with these challenges enhance resilience in their marriages? This question has resulted in this qualitative study, employing an exploratory descriptive and contextual research design with the aim of exploring the strengths that contribute towards resilience in the early years of marriage. The study is based within the framework of positive psychology, as this facilitates the exploration of the factors that have contributed towards the resilience of the couples that were interviewed. A non-probability, purposive sampling technique was employed to obtain research participants. Data was collected through the use of individual semistructured interviews conducted with five couples (ten individuals) who have been married for ten years or less, have endured significant stress, have chosen to remain married, and experience their relationship as satisfying. The interviews were recorded, transcribed and analysed using thematic content analysis. The results of the study may be used to develop a strengths based-intervention programme for couples in the early years of marriage.
- Full Text:
- Date Issued: 2012
- Authors: Aboagye, Lauren Lee
- Date: 2012
- Subjects: Marriage -- Interpersonal relations , Marriage -- Religious aspects -- Christianity , Resilience (Personality trait) , Communication in marriage , Adjustment (Psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9983 , http://hdl.handle.net/10948/1667 , Marriage -- Interpersonal relations , Marriage -- Religious aspects -- Christianity , Resilience (Personality trait) , Communication in marriage , Adjustment (Psychology)
- Description: Divorce is a common phenomenon in South Africa, affecting many families across the country. On the other hand, there are many couples who choose to remain married, despite having endured significant stress. In a review of literature there have been studies conducted exploring enduring marriages (marriages that have lasted twenty years or more), but little on resilience in the early years of marriage. With many couples choosing to divorce within the first ten years of marriage, there is value in exploring the strengths of young marriages that contribute towards resilience. The following question then arises: what are the stressors that couples experience during the early years of marriage (under ten years) and how does the way they cope with these challenges enhance resilience in their marriages? This question has resulted in this qualitative study, employing an exploratory descriptive and contextual research design with the aim of exploring the strengths that contribute towards resilience in the early years of marriage. The study is based within the framework of positive psychology, as this facilitates the exploration of the factors that have contributed towards the resilience of the couples that were interviewed. A non-probability, purposive sampling technique was employed to obtain research participants. Data was collected through the use of individual semistructured interviews conducted with five couples (ten individuals) who have been married for ten years or less, have endured significant stress, have chosen to remain married, and experience their relationship as satisfying. The interviews were recorded, transcribed and analysed using thematic content analysis. The results of the study may be used to develop a strengths based-intervention programme for couples in the early years of marriage.
- Full Text:
- Date Issued: 2012
Budgeting, forecasting and financial planning as a strategic tool in the Eastern Cape's manufacturing industry
- Authors: Abrahams, Shaheed
- Date: 2012
- Subjects: Budget process -- South Africa -- Eastern Cape , Business forecasting -- South Africa -- Eastern Cape , Business planning -- South Africa -- Eastern Cape , Manufacturing industries -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8940 , http://hdl.handle.net/10948/d1008408 , Budget process -- South Africa -- Eastern Cape , Business forecasting -- South Africa -- Eastern Cape , Business planning -- South Africa -- Eastern Cape , Manufacturing industries -- South Africa -- Eastern Cape
- Description: The primary objective of the study is to assess whether organisations are using their budgeting, forecasting and financial planning information as a strategic tool in the decision-making process. The research aims to investigate the various factors that hinder the success of the finance department in delivering a quality financial plan, budget or forecast to top management and the rest of the organisation.
- Full Text:
- Date Issued: 2012
- Authors: Abrahams, Shaheed
- Date: 2012
- Subjects: Budget process -- South Africa -- Eastern Cape , Business forecasting -- South Africa -- Eastern Cape , Business planning -- South Africa -- Eastern Cape , Manufacturing industries -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8940 , http://hdl.handle.net/10948/d1008408 , Budget process -- South Africa -- Eastern Cape , Business forecasting -- South Africa -- Eastern Cape , Business planning -- South Africa -- Eastern Cape , Manufacturing industries -- South Africa -- Eastern Cape
- Description: The primary objective of the study is to assess whether organisations are using their budgeting, forecasting and financial planning information as a strategic tool in the decision-making process. The research aims to investigate the various factors that hinder the success of the finance department in delivering a quality financial plan, budget or forecast to top management and the rest of the organisation.
- Full Text:
- Date Issued: 2012
Investigating the devolution of decision-making in the Nelson Mandela Bay Municipality
- Authors: Adams, Sandiswa
- Date: 2012
- Subjects: Decentralization in government -- South Africa -- Port Elizabeth , Decision making -- South Africa -- Port Elizabeth , Local government --South Africa -- Port Elizabeth , Municipal services -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9053 , http://hdl.handle.net/10948/d1006783 , Decentralization in government -- South Africa -- Port Elizabeth , Decision making -- South Africa -- Port Elizabeth , Local government --South Africa -- Port Elizabeth , Municipal services -- South Africa -- Port Elizabeth
- Description: The research investigates the devolution of decision-making at the Nelson Mandela Bay Municipality (NMBM). The research sets out to investigate the extent to which the Municipality offers resources to its politically elected representatives and whether the support enables a devolution that includes local citizens in decision-making. The study was demarcated within the NMBM, using an empirical survey, a population group composed of councillors and officials who work very closely with politicians in mobilizing the community in public participation. The data collection tool of choice for the study was a selfadministered questionnaire, supplemented by document analysis, unstructured interviews and the researcher’s observations. The purpose of the study is to investigate reasons why devolution is not having the desired results at NMBM, Investigate and find alternatives to how devolved decision-making can be enhanced, using the viable local political process at the NMBM and similar municipalities. The study argues from a theoretical base of good governance and public participation. The findings made were inter alia: Politicians in public office are not using the resources at their disposal optimally; tussles amongst politicians and with officials do have a negative effect on devolved decision-making; and vandalism and closing down of ward council offices are not purely a reflection of a ward councillor’s failure to account to the constituency, and the ward committee system at NMBM has not since 2009. The recommendation is that deliberate efforts need to be made to establish democratically elected ward committees in all sixty wards of NMBM. The establishment of ward committees has to be a joint effort between political office bearers, the broader political landscape and officials as previous efforts have failed to produce legitimate structures. The politicians and officials need to work together to win over public opinion and community buy-in towards the establishment of ward committees that are representative and functional.
- Full Text:
- Date Issued: 2012
- Authors: Adams, Sandiswa
- Date: 2012
- Subjects: Decentralization in government -- South Africa -- Port Elizabeth , Decision making -- South Africa -- Port Elizabeth , Local government --South Africa -- Port Elizabeth , Municipal services -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9053 , http://hdl.handle.net/10948/d1006783 , Decentralization in government -- South Africa -- Port Elizabeth , Decision making -- South Africa -- Port Elizabeth , Local government --South Africa -- Port Elizabeth , Municipal services -- South Africa -- Port Elizabeth
- Description: The research investigates the devolution of decision-making at the Nelson Mandela Bay Municipality (NMBM). The research sets out to investigate the extent to which the Municipality offers resources to its politically elected representatives and whether the support enables a devolution that includes local citizens in decision-making. The study was demarcated within the NMBM, using an empirical survey, a population group composed of councillors and officials who work very closely with politicians in mobilizing the community in public participation. The data collection tool of choice for the study was a selfadministered questionnaire, supplemented by document analysis, unstructured interviews and the researcher’s observations. The purpose of the study is to investigate reasons why devolution is not having the desired results at NMBM, Investigate and find alternatives to how devolved decision-making can be enhanced, using the viable local political process at the NMBM and similar municipalities. The study argues from a theoretical base of good governance and public participation. The findings made were inter alia: Politicians in public office are not using the resources at their disposal optimally; tussles amongst politicians and with officials do have a negative effect on devolved decision-making; and vandalism and closing down of ward council offices are not purely a reflection of a ward councillor’s failure to account to the constituency, and the ward committee system at NMBM has not since 2009. The recommendation is that deliberate efforts need to be made to establish democratically elected ward committees in all sixty wards of NMBM. The establishment of ward committees has to be a joint effort between political office bearers, the broader political landscape and officials as previous efforts have failed to produce legitimate structures. The politicians and officials need to work together to win over public opinion and community buy-in towards the establishment of ward committees that are representative and functional.
- Full Text:
- Date Issued: 2012
The contribution of the trade in medicinal plants to urban livelihoods: a case study of the informal markets in Nelson Mandela Bay Municipality, Eastern Cape
- Ah Goo, Delia Felecia Stephanie
- Authors: Ah Goo, Delia Felecia Stephanie
- Date: 2012
- Subjects: Medicinal plants -- South Africa -- Port Elizabeth , Informal sector (Economics) -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Port Elizabeth -- Markets
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10654 , http://hdl.handle.net/10948/d1011601 , Medicinal plants -- South Africa -- Port Elizabeth , Informal sector (Economics) -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Port Elizabeth -- Markets
- Description: The commercialisation of natural resources such as medicinal plants is a strategy that is increasingly being employed by poor people in developing countries such as South Africa, as a means of generating an income. Increasing economic hardship and a lack of employment opportunities in the formal sector of the economy has led to many urban dwellers seeking alternative means of meeting their everyday livelihood needs. Although the contribution of natural resources to subsistence economies is widely recognised, there are few studies that have examined the significance of the trade in medicinal plants to the livelihoods of poor and marginalised people. Thirty informal street traders were interviewed to investigate the role of the medicinal plant trade in sustaining the livelihoods of the traders who operate in the informal sector of the Nelson Mandela Bay Municipality, South Africa. The findings of the research indicate that the sale and collection of medicinal plants is an activity which is exploited by people with limited resources, few skills, little or no education and often without any other source of household income. Middle-aged women from impoverished, single income households dominated the trade. Although income from the trade is modest, it contributed substantially to the total household cash income of the traders. Other benefits of the trade included independence and having a sense of purpose in life, as the traders felt that they were not only helping their families but also the wider community. However, without the income from the trade, many of the traders and their families would be destitute and thus the medicinal plant trade is vital to the wellbeing of these people.
- Full Text:
- Date Issued: 2012
- Authors: Ah Goo, Delia Felecia Stephanie
- Date: 2012
- Subjects: Medicinal plants -- South Africa -- Port Elizabeth , Informal sector (Economics) -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Port Elizabeth -- Markets
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10654 , http://hdl.handle.net/10948/d1011601 , Medicinal plants -- South Africa -- Port Elizabeth , Informal sector (Economics) -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Port Elizabeth -- Markets
- Description: The commercialisation of natural resources such as medicinal plants is a strategy that is increasingly being employed by poor people in developing countries such as South Africa, as a means of generating an income. Increasing economic hardship and a lack of employment opportunities in the formal sector of the economy has led to many urban dwellers seeking alternative means of meeting their everyday livelihood needs. Although the contribution of natural resources to subsistence economies is widely recognised, there are few studies that have examined the significance of the trade in medicinal plants to the livelihoods of poor and marginalised people. Thirty informal street traders were interviewed to investigate the role of the medicinal plant trade in sustaining the livelihoods of the traders who operate in the informal sector of the Nelson Mandela Bay Municipality, South Africa. The findings of the research indicate that the sale and collection of medicinal plants is an activity which is exploited by people with limited resources, few skills, little or no education and often without any other source of household income. Middle-aged women from impoverished, single income households dominated the trade. Although income from the trade is modest, it contributed substantially to the total household cash income of the traders. Other benefits of the trade included independence and having a sense of purpose in life, as the traders felt that they were not only helping their families but also the wider community. However, without the income from the trade, many of the traders and their families would be destitute and thus the medicinal plant trade is vital to the wellbeing of these people.
- Full Text:
- Date Issued: 2012
Large scale retrenchments: an overview of Section 189 A
- Authors: Ah Shene, Lee-Anne Dorothy
- Date: 2012
- Subjects: Employees -- Dismissal of -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa , Retrenchments
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10237 , http://hdl.handle.net/10948/d1012042 , Employees -- Dismissal of -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa , Retrenchments
- Description: This treatise sets out and evaluates recent developments in the area of large-scale retrenchments in South Africa. Dismissals are considered to be a source of great controversy, but more so large scale retrenchments. It was with this in mind that the various role players sought an amendment in 2002 so as to address the concerns by both employers and employees. The applicable legislation, namely section 189A of the Labour Relations Act 66 of 1995, was enacted to ensure the smooth operation of this genre of retrenchments. In this treatise, section 189A will be evaluated. Section 189A stipulates what procedure should be utilized, for dismissals necessitated by operational requirements. The inclusion of this provision was an attempt to address the concerns of both employers and employees. Chapter 1 provides us with an overview with regard to why change with regard to retrenchment legislation was necessary. In Chapter 2 the definition of operational requirements will be unpacked as well as what definition the courts have attached to the term "operational requirements‟, and more importantly the issue relating to substantive fairness. Chapter 3 examines when the applicable provision is triggered, whether or not an employer can stagger retrenchments, the facilitation process, and the regulations pertaining to facilitations. The facilitation process itself and the consultation aspect of the facilitation process are recounted. The meaning of „consultation‟ is evaluated, and it should be noted that section 189 and section 189A are interrelated when topics of consultation are considered. Chapter 4 addresses the instance when no facilitator is appointed and the mechanisms of section 189A(7) and (8); further discussions relating to subsection 13, and 19 will furthermore be evaluated with reference to case law. Chapter 5 sets out the various viewpoints on whether or not section 189A has been successful, and the chapter questions the effectiveness of the provision to provide a realistic view of large-scale retrenchments and whether the enactment thereof was an effective mechanism protecting the rights of employees faced with possible unemployment. The implementation of the training lay off system will be looked at and the statistics of the CCMA will be used as a measure to determine the effectiveness of section 189A. Chapter 6 concludes the thesis, by highlighting lessons learnt from case law for both employees and employers.
- Full Text:
- Date Issued: 2012
- Authors: Ah Shene, Lee-Anne Dorothy
- Date: 2012
- Subjects: Employees -- Dismissal of -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa , Retrenchments
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10237 , http://hdl.handle.net/10948/d1012042 , Employees -- Dismissal of -- Law and legislation -- South Africa , Labor laws and legislation -- South Africa , Retrenchments
- Description: This treatise sets out and evaluates recent developments in the area of large-scale retrenchments in South Africa. Dismissals are considered to be a source of great controversy, but more so large scale retrenchments. It was with this in mind that the various role players sought an amendment in 2002 so as to address the concerns by both employers and employees. The applicable legislation, namely section 189A of the Labour Relations Act 66 of 1995, was enacted to ensure the smooth operation of this genre of retrenchments. In this treatise, section 189A will be evaluated. Section 189A stipulates what procedure should be utilized, for dismissals necessitated by operational requirements. The inclusion of this provision was an attempt to address the concerns of both employers and employees. Chapter 1 provides us with an overview with regard to why change with regard to retrenchment legislation was necessary. In Chapter 2 the definition of operational requirements will be unpacked as well as what definition the courts have attached to the term "operational requirements‟, and more importantly the issue relating to substantive fairness. Chapter 3 examines when the applicable provision is triggered, whether or not an employer can stagger retrenchments, the facilitation process, and the regulations pertaining to facilitations. The facilitation process itself and the consultation aspect of the facilitation process are recounted. The meaning of „consultation‟ is evaluated, and it should be noted that section 189 and section 189A are interrelated when topics of consultation are considered. Chapter 4 addresses the instance when no facilitator is appointed and the mechanisms of section 189A(7) and (8); further discussions relating to subsection 13, and 19 will furthermore be evaluated with reference to case law. Chapter 5 sets out the various viewpoints on whether or not section 189A has been successful, and the chapter questions the effectiveness of the provision to provide a realistic view of large-scale retrenchments and whether the enactment thereof was an effective mechanism protecting the rights of employees faced with possible unemployment. The implementation of the training lay off system will be looked at and the statistics of the CCMA will be used as a measure to determine the effectiveness of section 189A. Chapter 6 concludes the thesis, by highlighting lessons learnt from case law for both employees and employers.
- Full Text:
- Date Issued: 2012
Community development through the ward committee structures in the Northern areas of the Nelson Mandela Bay Municipality
- Authors: Ah Shene, Walter T
- Date: 2012
- Subjects: Community development -- South Africa -- Nelson Mandela Bay Municipality , City council members -- South Africa -- Nelson Mandela Bay Municipality , Municipal government -- South Africa -- Nelson Mandela Bay Municipality , Citizens' advisory committees -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:8274 , http://hdl.handle.net/10948/d1016058
- Description: The purpose of this study was to investigate community development through the ward committee structures in the Northern Areas of the Nelson Mandela Bay Municipality. Community development through the ward committees is the key principle in the democratisation process, as well as the promotion of good governance. Community development is an opportunity for both local government and the community to strengthen the democracy that is being enjoyed; and simultaneously to promote accountability. In terms of the Local Government: Municipal Systems, 2000 (Act 32 of 2000), the role of local communities in the particular interests of their municipality must take place, among other things, by the ward councillor – as well as all other suitable procedures, mechanisms and processes set up by the municipality. Ward committees have the power to advise the ward councillor; and as municipal structures, they must ensure that there is always community participation in the sphere of local government. Community participation gives communities the opportunities to express their views, as well as giving them a sense of ownership. The objectives of the study were: - To determine the roles and responsibilities of the ward councillors in terms of the new developmental mandate (the need to encourage the involvement of communities and organisations in local government matters). - To investigate the relations between ward councillors and their ward committees, and between the offices of ward councillors and the general public. - To examine the extent to which ward councillors in the northern areas of the Nelson Mandela Bay Municipality understand the policy and administrative procedures and processes in the municipality, when addressing issues that affect the community. In order to achieve these objectives, it was necessary to review literature on community participation. An empirical search was conducted in wards 10 and 11 in the Northern Areas of Nelson Mandela Bay Municipality. Recommendations were provided which could assist the municipality to effectively make use of the ward committees and the ward councillors. If implemented, these recommendations could also enhance community development through the ward committee structures. Thus, the relationship between the ward committees and the ward councillor should be harmonious; and subsequently, they should also strengthen trust between them. Then the flow of communication will improve.
- Full Text:
- Date Issued: 2012
- Authors: Ah Shene, Walter T
- Date: 2012
- Subjects: Community development -- South Africa -- Nelson Mandela Bay Municipality , City council members -- South Africa -- Nelson Mandela Bay Municipality , Municipal government -- South Africa -- Nelson Mandela Bay Municipality , Citizens' advisory committees -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:8274 , http://hdl.handle.net/10948/d1016058
- Description: The purpose of this study was to investigate community development through the ward committee structures in the Northern Areas of the Nelson Mandela Bay Municipality. Community development through the ward committees is the key principle in the democratisation process, as well as the promotion of good governance. Community development is an opportunity for both local government and the community to strengthen the democracy that is being enjoyed; and simultaneously to promote accountability. In terms of the Local Government: Municipal Systems, 2000 (Act 32 of 2000), the role of local communities in the particular interests of their municipality must take place, among other things, by the ward councillor – as well as all other suitable procedures, mechanisms and processes set up by the municipality. Ward committees have the power to advise the ward councillor; and as municipal structures, they must ensure that there is always community participation in the sphere of local government. Community participation gives communities the opportunities to express their views, as well as giving them a sense of ownership. The objectives of the study were: - To determine the roles and responsibilities of the ward councillors in terms of the new developmental mandate (the need to encourage the involvement of communities and organisations in local government matters). - To investigate the relations between ward councillors and their ward committees, and between the offices of ward councillors and the general public. - To examine the extent to which ward councillors in the northern areas of the Nelson Mandela Bay Municipality understand the policy and administrative procedures and processes in the municipality, when addressing issues that affect the community. In order to achieve these objectives, it was necessary to review literature on community participation. An empirical search was conducted in wards 10 and 11 in the Northern Areas of Nelson Mandela Bay Municipality. Recommendations were provided which could assist the municipality to effectively make use of the ward committees and the ward councillors. If implemented, these recommendations could also enhance community development through the ward committee structures. Thus, the relationship between the ward committees and the ward councillor should be harmonious; and subsequently, they should also strengthen trust between them. Then the flow of communication will improve.
- Full Text:
- Date Issued: 2012
Creation of clay flameless burner for vaporizing an insect repellent containing pmd as an active ingredient
- Authors: Akwi, Faith Mary
- Date: 2012
- Subjects: Insect baits and repellents , Montmorillonite
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10383 , http://hdl.handle.net/10948/d1008406 , Insect baits and repellents , Montmorillonite
- Description: Insecticide treated mosquito bed nets, insecticide aerosol sprays, repellent lotions and creams, repellent candles, vaporizable repellent essential oils, mosquito mats and coils are some of the many malaria personal protection tools that are in use. The latter of these measures are the most accessible and affordable options for the rural population in sub-Saharan Africa. It is therefore important to determine how effective these personal protection measures are by determining their ability to efficiently disperse an active ingredient when the protection measure is in use. In this study, a copper II oxide montmorillonite clay burner (CuOMontmorillonite clay burner) was created to vaporize repellent formulations containing various concentrations of p-menthane-3,8-diol (PMD) as the active ingredient with the aim of determining the percentage of the active ingredient that is released into the air and the rate of release. The performance of the CuO-Montmorillonite clay burner was also compared to that of the Lampe Berger fragrance burner (LBFB). In addition to this, the percentage of PMD released from 6 percentage wt PMD candles of diameters 40mm, 69mm and 83mm was determined and compared to that released when the CuO-Montmorillonite clay burner and Lampe Berger Fragrance burner where used to vaporize PMD repellent formulations. It was found that the rate of vaporization of the various PMD repellent formulations vaporized using the Lampe Berger fragrance burner is affected by the mass of PMD present in the repellent formulations. The 6 percentage wt PMD repellent candles released the least percentage of PMD as compared to that released when the CuO-Montmorillonite clay burner and the Lampe Berger fragrance burner were used to vaporize the PMD repellent formulations.
- Full Text:
- Date Issued: 2012
- Authors: Akwi, Faith Mary
- Date: 2012
- Subjects: Insect baits and repellents , Montmorillonite
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10383 , http://hdl.handle.net/10948/d1008406 , Insect baits and repellents , Montmorillonite
- Description: Insecticide treated mosquito bed nets, insecticide aerosol sprays, repellent lotions and creams, repellent candles, vaporizable repellent essential oils, mosquito mats and coils are some of the many malaria personal protection tools that are in use. The latter of these measures are the most accessible and affordable options for the rural population in sub-Saharan Africa. It is therefore important to determine how effective these personal protection measures are by determining their ability to efficiently disperse an active ingredient when the protection measure is in use. In this study, a copper II oxide montmorillonite clay burner (CuOMontmorillonite clay burner) was created to vaporize repellent formulations containing various concentrations of p-menthane-3,8-diol (PMD) as the active ingredient with the aim of determining the percentage of the active ingredient that is released into the air and the rate of release. The performance of the CuO-Montmorillonite clay burner was also compared to that of the Lampe Berger fragrance burner (LBFB). In addition to this, the percentage of PMD released from 6 percentage wt PMD candles of diameters 40mm, 69mm and 83mm was determined and compared to that released when the CuO-Montmorillonite clay burner and Lampe Berger Fragrance burner where used to vaporize PMD repellent formulations. It was found that the rate of vaporization of the various PMD repellent formulations vaporized using the Lampe Berger fragrance burner is affected by the mass of PMD present in the repellent formulations. The 6 percentage wt PMD repellent candles released the least percentage of PMD as compared to that released when the CuO-Montmorillonite clay burner and the Lampe Berger fragrance burner were used to vaporize the PMD repellent formulations.
- Full Text:
- Date Issued: 2012
Investigation of the performance of photovoltaic systems
- Authors: Alistoun, Warren James
- Date: 2012
- Subjects: Photovoltaic power systems -- South Africa , Photovoltaic power generation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10517 , http://hdl.handle.net/10948/d1008396 , Photovoltaic power systems -- South Africa , Photovoltaic power generation -- South Africa
- Description: The main objective of this study was to investigate the performance of grid integrated PV systems. A data acquisition (DAQ) system was developed to monitor the performance of an existing grid integrated PV system with battery storage. This system is referred to as a grid assisted PV system. A data logger was used together with the inverters built in data logger to monitor environmental and electrical data on a grid tie PV system which was deployed during this study. To investigate the performance of these grid integrated PV systems PV and BOS device characterization was performed. This was achieved by using current voltage curve tracers and the DAQ system developed. Energy yield estimations were calculated referring to the literature review and a meteorological reference for comparison with measured energy yields from the grid tie PV system.
- Full Text:
- Date Issued: 2012
- Authors: Alistoun, Warren James
- Date: 2012
- Subjects: Photovoltaic power systems -- South Africa , Photovoltaic power generation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10517 , http://hdl.handle.net/10948/d1008396 , Photovoltaic power systems -- South Africa , Photovoltaic power generation -- South Africa
- Description: The main objective of this study was to investigate the performance of grid integrated PV systems. A data acquisition (DAQ) system was developed to monitor the performance of an existing grid integrated PV system with battery storage. This system is referred to as a grid assisted PV system. A data logger was used together with the inverters built in data logger to monitor environmental and electrical data on a grid tie PV system which was deployed during this study. To investigate the performance of these grid integrated PV systems PV and BOS device characterization was performed. This was achieved by using current voltage curve tracers and the DAQ system developed. Energy yield estimations were calculated referring to the literature review and a meteorological reference for comparison with measured energy yields from the grid tie PV system.
- Full Text:
- Date Issued: 2012
Trends and volatility in residential property prices in South Africa
- Authors: Anyikwa, Izunna Chima
- Date: 2012
- Subjects: Housing -- Prices -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9012 , http://hdl.handle.net/10948/d1018221
- Description: This study sought to empirically investigate trends and volatility in residential property prices in South Africa using quarterly data over the period 1980Q1 to 2011Q4. The empirical analysis uses a range of unit root and stationarity tests as well as a number of ARCH-family of models. The results from the trend analysis suggest that the behaviour of house prices in South Africa follows a random walk process. The randomness in the behaviour of house prices could be attributed to permanent effect of shock. Investigation into the dynamic behaviour of the house prices supports the existence of conditional volatility that is time-varying and highly persistent. Moreover, volatility is found to be asymmetric in news suggesting evidence of anti-leverage effects. These findings have important portfolio implications especially, considering the fact that large-scale losses are possible if house prices exhibit the type of persistent in behaviour as captured in this study. Also, the existence of asymmetric effects in volatility suggests that more caution needs to be placed on news arrival as they may have significant impacts on the house price behaviour. Accordingly, this study suggests the need for residential property market to be treated like other asset markets with regards to risk.
- Full Text:
- Date Issued: 2012
- Authors: Anyikwa, Izunna Chima
- Date: 2012
- Subjects: Housing -- Prices -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9012 , http://hdl.handle.net/10948/d1018221
- Description: This study sought to empirically investigate trends and volatility in residential property prices in South Africa using quarterly data over the period 1980Q1 to 2011Q4. The empirical analysis uses a range of unit root and stationarity tests as well as a number of ARCH-family of models. The results from the trend analysis suggest that the behaviour of house prices in South Africa follows a random walk process. The randomness in the behaviour of house prices could be attributed to permanent effect of shock. Investigation into the dynamic behaviour of the house prices supports the existence of conditional volatility that is time-varying and highly persistent. Moreover, volatility is found to be asymmetric in news suggesting evidence of anti-leverage effects. These findings have important portfolio implications especially, considering the fact that large-scale losses are possible if house prices exhibit the type of persistent in behaviour as captured in this study. Also, the existence of asymmetric effects in volatility suggests that more caution needs to be placed on news arrival as they may have significant impacts on the house price behaviour. Accordingly, this study suggests the need for residential property market to be treated like other asset markets with regards to risk.
- Full Text:
- Date Issued: 2012
A comparative study of the language, mathematics and science literacy knowledge and skills of grade 9 learners in secondary schools in Port Elizabeth
- Authors: Arnolds, Keith Victor
- Date: 2012
- Subjects: Educational tests and measurements -- South Africa -- Port Elizabeth , Comparative education , Language and languages -- Study and teaching -- South Africa -- Port Elizabeth , Mathematics -- Study and teaching -- South Africa -- Port Elizabeth , Science -- Study and teaching -- South Africa -- Port Elizabeth , Education, Secondary -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9566 , http://hdl.handle.net/10948/d1016062
- Description: In South Africa, on-going concerns surrounding the development of learners’ literacy, mathematics and science skills are evident and drive various research studies in this field. International studies and assessments, such as the Trends in International Mathematics and Science Study (TIMSS) and the Progress in International Reading Literacy Study (PIRLS) show major differences in the proficiency levels of learners in South Africa in comparison with their international counter parts. To date, however, the more comprehensive international standardised assessment called the Programme for International Student Assessment (PISA), has not been administered in South Africa. The main aim of this research study was to investigate and scientifically explore the real situation in terms of language, mathematics and science literacy knowledge and skills of Grade 9 learners in South Africa and to draw a comparison between Grade 9 learners from secondary schools in the Port Elizabeth district in South Africa and their international counterparts, using the PISA standardised international assessment. In addition, the aim of the study was to determine the actual language, mathematics and science literacy skills and knowledge acquired by participants in this study. Quantitative data collection was done by administering a modified version of the Program for International Student Assessment (PISA) to learners from eight schools in Port Elizabeth, supplemented with questionnaires completed by participating learners and school principals. Findings revealed that the South African learners sampled, ranked in the bottom percentile of participating countries in reading, mathematics and science. The study also exposed the glaring inequalities still prevalent in South African education today, 17 years into democracy. The implications point to a serious investigation into the societal and political factors responsible for the discrepancies in the South African educational system at present.
- Full Text:
- Date Issued: 2012
- Authors: Arnolds, Keith Victor
- Date: 2012
- Subjects: Educational tests and measurements -- South Africa -- Port Elizabeth , Comparative education , Language and languages -- Study and teaching -- South Africa -- Port Elizabeth , Mathematics -- Study and teaching -- South Africa -- Port Elizabeth , Science -- Study and teaching -- South Africa -- Port Elizabeth , Education, Secondary -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9566 , http://hdl.handle.net/10948/d1016062
- Description: In South Africa, on-going concerns surrounding the development of learners’ literacy, mathematics and science skills are evident and drive various research studies in this field. International studies and assessments, such as the Trends in International Mathematics and Science Study (TIMSS) and the Progress in International Reading Literacy Study (PIRLS) show major differences in the proficiency levels of learners in South Africa in comparison with their international counter parts. To date, however, the more comprehensive international standardised assessment called the Programme for International Student Assessment (PISA), has not been administered in South Africa. The main aim of this research study was to investigate and scientifically explore the real situation in terms of language, mathematics and science literacy knowledge and skills of Grade 9 learners in South Africa and to draw a comparison between Grade 9 learners from secondary schools in the Port Elizabeth district in South Africa and their international counterparts, using the PISA standardised international assessment. In addition, the aim of the study was to determine the actual language, mathematics and science literacy skills and knowledge acquired by participants in this study. Quantitative data collection was done by administering a modified version of the Program for International Student Assessment (PISA) to learners from eight schools in Port Elizabeth, supplemented with questionnaires completed by participating learners and school principals. Findings revealed that the South African learners sampled, ranked in the bottom percentile of participating countries in reading, mathematics and science. The study also exposed the glaring inequalities still prevalent in South African education today, 17 years into democracy. The implications point to a serious investigation into the societal and political factors responsible for the discrepancies in the South African educational system at present.
- Full Text:
- Date Issued: 2012
Effective and efficient performance management in local government, with reference to the Cacadu District Municipality
- Authors: Asmah-Andoh, Kwame
- Date: 2012
- Subjects: Performance -- Management , Performance standards -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Employees -- Rating of -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8161 , http://hdl.handle.net/10948/1633 , Performance -- Management , Performance standards -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Employees -- Rating of -- South Africa
- Description: This study examined the existing levels of effectiveness and efficiency in local government with the application of performance management systems in the provision of municipal services. The provision of district-wide water services in Cacadu District Municipality in the Province of the Eastern Cape, South Africa is used for particular reference. Local government reforms after 1994 led to the creation of the district municipality (which groups together a number of local municipalities) to drive district-wide services provision, the introduction of systematic services provision standards and performance management as part of management reforms in municipalities. The problem for the research deals with how the Cacadu District Council and the councils of the local municipalities within the district are collaborating in using performance management systems, what effects this could have on programmes and services provision and how communication of performance information would improve service provision. Conceptual and practical difficulties encountered in effective and efficient utilisation and some obstacles that contribute to impeding progress in the use of performance management systems in municipalities were analysed. The qualitative research included a review of documents from the public administration and management literature; discourse analysis of interviews with municipal councilors and appointed officials, community members and provincial managers. The document review included a review of municipal documents that incorporated performance management or described development and use of performance management systems. It also included the legal frameworks and statutory requirements for municipal government and administration. All the responding municipal councils within the Cacadu District Municipality reported using performance management over the past five years yet little empirical evidence explains usage for district-wide programmes and services provision. Research shows that a comprehensive performance management approach to programmes and services has a more effective and efficient impact on service improvement than utilisation of personnnel appraisal (Ammons and Rivenbark, 2005). Despite the expected benefits, personnel performance appraisal is often flawed and the need exists in the district municipal model to develop and utilise performance management systems that validly assess the work performance of personnel (Hindo, 2010). Performance management system utilisation in decision making management is more related to the long-term benefits of effectiveness and efficiency than personnel appraisal for performance rewards and reporting. To overcome and address a situation of managing performance without a performance management system the study proposes a programme performance measurement and management system which incorporates information on management inputs, programme-specific data and citizens' feedback for outcomes and impact of the service. The suggested design for district-wide and specific municipal services provision elicit and provide relevant and appropriate performance information for management, decision-making and accountability to community. The effectiveness of the proposed system is to provide information for decision-making, long-term planning, strategic management and accountability reporting. The proposal is built on the exisiting method and thus efficient in the utilisation of resources. This has implications both for the theory of Public Administration and Management and the practical application of performamce management in public institutions. The study explicity provides a Public Administration perspective on management in a multi-municipal district context with different authorities. The study contributes to the theory of administrative policy and management context of the municipality with special attention to functions for which different authorities are responsible and the role of a performance system for better insught into managing overlapping authority, gaps and duplications. A central purpose of public management research is to theorise and influence practice. The practical utilisation of the proposed method is intended to assist managers and politicians with better understanding of a sustainable performance management system.
- Full Text:
- Date Issued: 2012
- Authors: Asmah-Andoh, Kwame
- Date: 2012
- Subjects: Performance -- Management , Performance standards -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Employees -- Rating of -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8161 , http://hdl.handle.net/10948/1633 , Performance -- Management , Performance standards -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Employees -- Rating of -- South Africa
- Description: This study examined the existing levels of effectiveness and efficiency in local government with the application of performance management systems in the provision of municipal services. The provision of district-wide water services in Cacadu District Municipality in the Province of the Eastern Cape, South Africa is used for particular reference. Local government reforms after 1994 led to the creation of the district municipality (which groups together a number of local municipalities) to drive district-wide services provision, the introduction of systematic services provision standards and performance management as part of management reforms in municipalities. The problem for the research deals with how the Cacadu District Council and the councils of the local municipalities within the district are collaborating in using performance management systems, what effects this could have on programmes and services provision and how communication of performance information would improve service provision. Conceptual and practical difficulties encountered in effective and efficient utilisation and some obstacles that contribute to impeding progress in the use of performance management systems in municipalities were analysed. The qualitative research included a review of documents from the public administration and management literature; discourse analysis of interviews with municipal councilors and appointed officials, community members and provincial managers. The document review included a review of municipal documents that incorporated performance management or described development and use of performance management systems. It also included the legal frameworks and statutory requirements for municipal government and administration. All the responding municipal councils within the Cacadu District Municipality reported using performance management over the past five years yet little empirical evidence explains usage for district-wide programmes and services provision. Research shows that a comprehensive performance management approach to programmes and services has a more effective and efficient impact on service improvement than utilisation of personnnel appraisal (Ammons and Rivenbark, 2005). Despite the expected benefits, personnel performance appraisal is often flawed and the need exists in the district municipal model to develop and utilise performance management systems that validly assess the work performance of personnel (Hindo, 2010). Performance management system utilisation in decision making management is more related to the long-term benefits of effectiveness and efficiency than personnel appraisal for performance rewards and reporting. To overcome and address a situation of managing performance without a performance management system the study proposes a programme performance measurement and management system which incorporates information on management inputs, programme-specific data and citizens' feedback for outcomes and impact of the service. The suggested design for district-wide and specific municipal services provision elicit and provide relevant and appropriate performance information for management, decision-making and accountability to community. The effectiveness of the proposed system is to provide information for decision-making, long-term planning, strategic management and accountability reporting. The proposal is built on the exisiting method and thus efficient in the utilisation of resources. This has implications both for the theory of Public Administration and Management and the practical application of performamce management in public institutions. The study explicity provides a Public Administration perspective on management in a multi-municipal district context with different authorities. The study contributes to the theory of administrative policy and management context of the municipality with special attention to functions for which different authorities are responsible and the role of a performance system for better insught into managing overlapping authority, gaps and duplications. A central purpose of public management research is to theorise and influence practice. The practical utilisation of the proposed method is intended to assist managers and politicians with better understanding of a sustainable performance management system.
- Full Text:
- Date Issued: 2012
An investigation into the relationship between leadership and cognitive styles of supervisory employees in the automotive industry
- Authors: Attwell, Terry-Anne
- Date: 2012
- Subjects: Supervisors, Industrial , Cognitive styles , Leadership , Automobile industry and trade
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9403 , http://hdl.handle.net/10948/d1009320 , Supervisors, Industrial , Cognitive styles , Leadership , Automobile industry and trade
- Description: Human attributes that constitute a good leader in terms of leadership qualities and thinking styles are somewhat limited. The latter situation makes it difficult to employ the right person with the right leadership qualities in the continuously changing world of work (Lussier & Achua, 2000). The researcher investigated the relationship between cognitive styles and leadership styles of individuals who are employed in the automotive industry and in a supervisory position. A quantitative research methodology was employed for the study of (n= 115) using the Cognitive-Style Indicator (COSI) developed by Cools and van den Broeck (2007) and the Leadership-style questionnaire developed by Clark (2007). Leadership styles have been researched throughout the world, but a dearth of research specifically pertaining to cognitive styles was rather limiting in the context of the research that was undertaken. On the one hand, leadership focuses on three main dimensions, namely: Authoritarian, Participative and Delegative Leadership Styles. According to Clark (2007), the above three dimensions are the core styles that are used within the workplace. On the other hand, a three-dimensional cognitive style model, as proposed by Cools and Van den Broeck (2007) incorporates three dimensions with specific characteristics pertaining to each style. These three dimensions were labelled as: Knowing (K), Planning (P), and Creating (C) styles, which were utilised to find a significant relationship between the various leadership styles. Significant relationships were found between the Cognitive-Planning style and the Participative Leadership style, the Delegative Leadership style and the Knowing-Cognitive style, the Creative-Cognitive style and the Delegative Leadership style, and the Knowing-and-Planning Cognitive style. Similarities were also found between the Coloured and African groups, as the Delegative style is relevant to both the Coloured and African groups, while the participative style is more prominent in the White racial group. No significant correlations were produced for the Asian group, however. Organisations are rapidly changing and adapting to various types of change; and it is essential for all employees – and not only those within a leadership position – but it is imperative that leaders should not only understand and know their cognitive and leadership style, but also of those individuals who are reporting to them.
- Full Text:
- Date Issued: 2012
- Authors: Attwell, Terry-Anne
- Date: 2012
- Subjects: Supervisors, Industrial , Cognitive styles , Leadership , Automobile industry and trade
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9403 , http://hdl.handle.net/10948/d1009320 , Supervisors, Industrial , Cognitive styles , Leadership , Automobile industry and trade
- Description: Human attributes that constitute a good leader in terms of leadership qualities and thinking styles are somewhat limited. The latter situation makes it difficult to employ the right person with the right leadership qualities in the continuously changing world of work (Lussier & Achua, 2000). The researcher investigated the relationship between cognitive styles and leadership styles of individuals who are employed in the automotive industry and in a supervisory position. A quantitative research methodology was employed for the study of (n= 115) using the Cognitive-Style Indicator (COSI) developed by Cools and van den Broeck (2007) and the Leadership-style questionnaire developed by Clark (2007). Leadership styles have been researched throughout the world, but a dearth of research specifically pertaining to cognitive styles was rather limiting in the context of the research that was undertaken. On the one hand, leadership focuses on three main dimensions, namely: Authoritarian, Participative and Delegative Leadership Styles. According to Clark (2007), the above three dimensions are the core styles that are used within the workplace. On the other hand, a three-dimensional cognitive style model, as proposed by Cools and Van den Broeck (2007) incorporates three dimensions with specific characteristics pertaining to each style. These three dimensions were labelled as: Knowing (K), Planning (P), and Creating (C) styles, which were utilised to find a significant relationship between the various leadership styles. Significant relationships were found between the Cognitive-Planning style and the Participative Leadership style, the Delegative Leadership style and the Knowing-Cognitive style, the Creative-Cognitive style and the Delegative Leadership style, and the Knowing-and-Planning Cognitive style. Similarities were also found between the Coloured and African groups, as the Delegative style is relevant to both the Coloured and African groups, while the participative style is more prominent in the White racial group. No significant correlations were produced for the Asian group, however. Organisations are rapidly changing and adapting to various types of change; and it is essential for all employees – and not only those within a leadership position – but it is imperative that leaders should not only understand and know their cognitive and leadership style, but also of those individuals who are reporting to them.
- Full Text:
- Date Issued: 2012
Factors affecting the retention of employees in auditing firms
- Authors: Axon, Kerry
- Date: 2012
- Subjects: Employee retention -- South Africa -- Port Elizabeth , Labor turnover -- South Africa -- Port Elizabeth , Auditing -- South Africa , Job satisfaction -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9408 , http://hdl.handle.net/10948/d1015728
- Description: The twenty first century has identified knowledge, as opposed to labour, raw materials or capital, as the key resource required by firms. This has created a shift of ownership in relationships between employees and employers since employees own the tools of production through the knowledge they hold (Kinnear & Sutherland, 2000). The employment relationship is undergoing fundamental changes due to international competition, de-regularisation and globalisation which have major implications for attraction, motivation and retention of talented employees (De Vos & Meganck, 2009). Organisations face great challenges and intense competition with almost all strategies being easily replicable by competitors. This has led organisations to begin realising that people are in fact the only real differentiator that can gain the organisation competitive advantage (Munsamy & Bosch Venter, 2009). Turnover of employees costs South Africa millions of rands per annum through decreased productivity, increased accidents and quality problems. Specifically, loss of knowledge workers are identified through costs of hiring and training new employees, loss of institutional knowledge, lower office morale, loss of talent and customer dissatisfaction. It is therefore essential to understand the reasons why employees leave organisations in order to discover how to retain them (Mendes & Stander, 2011; Gaylard, Sutherland & Viedge, 2005). Employee turnover can have several negative consequences. It can be difficult to replace the departed employees and the cost of replacing employees can be exhaustive. Remaining employees can be left feeling demoralised from the loss of valued co-workers and work patterns can be disrupted until replacements are found (Newstrom and Davis, 1997). Bilal, Zia-ur-Rehman, and Raza, (2010) add to this list of negative consequences of turnover as turnover can increase recruitment and training costs, loss of productivity as projects lose continuity, interruption of key activities, increase in mistakes made, or even hiring the wrong person for the position.
- Full Text:
- Date Issued: 2012
- Authors: Axon, Kerry
- Date: 2012
- Subjects: Employee retention -- South Africa -- Port Elizabeth , Labor turnover -- South Africa -- Port Elizabeth , Auditing -- South Africa , Job satisfaction -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9408 , http://hdl.handle.net/10948/d1015728
- Description: The twenty first century has identified knowledge, as opposed to labour, raw materials or capital, as the key resource required by firms. This has created a shift of ownership in relationships between employees and employers since employees own the tools of production through the knowledge they hold (Kinnear & Sutherland, 2000). The employment relationship is undergoing fundamental changes due to international competition, de-regularisation and globalisation which have major implications for attraction, motivation and retention of talented employees (De Vos & Meganck, 2009). Organisations face great challenges and intense competition with almost all strategies being easily replicable by competitors. This has led organisations to begin realising that people are in fact the only real differentiator that can gain the organisation competitive advantage (Munsamy & Bosch Venter, 2009). Turnover of employees costs South Africa millions of rands per annum through decreased productivity, increased accidents and quality problems. Specifically, loss of knowledge workers are identified through costs of hiring and training new employees, loss of institutional knowledge, lower office morale, loss of talent and customer dissatisfaction. It is therefore essential to understand the reasons why employees leave organisations in order to discover how to retain them (Mendes & Stander, 2011; Gaylard, Sutherland & Viedge, 2005). Employee turnover can have several negative consequences. It can be difficult to replace the departed employees and the cost of replacing employees can be exhaustive. Remaining employees can be left feeling demoralised from the loss of valued co-workers and work patterns can be disrupted until replacements are found (Newstrom and Davis, 1997). Bilal, Zia-ur-Rehman, and Raza, (2010) add to this list of negative consequences of turnover as turnover can increase recruitment and training costs, loss of productivity as projects lose continuity, interruption of key activities, increase in mistakes made, or even hiring the wrong person for the position.
- Full Text:
- Date Issued: 2012
In vitro cytotoxic effects of selected Nigerian medicinal plant extracts on cancer cell lines
- Authors: Baatjies, Lucinda
- Date: 2012
- Subjects: Cancer -- Treatment , Cancer cells , Medicinal plants , Plant extracts , Traditional medicine , Public health
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10316 , http://hdl.handle.net/10948/d1008191 , Cancer -- Treatment , Cancer cells , Medicinal plants , Plant extracts , Traditional medicine , Public health
- Description: Cancer is a disease that imposes a heavy burden on public health and poses a challenge to science. The World Health Organization estimates that 80 percent of people in developing countries of the world rely on traditional medicine for their primary health needs, and about 85 percent of traditional medicine involves the use of plant extracts. This is particularly true in Africa where a large percentage of the population depends upon medicinal plants for health care. Therefore, detailed screening and evaluation of bioactive substances for chemotherapeutic purposes of African plants are urgently warranted. Furthermore, this will serve to validate the efficacy and safety of African traditional medicine. The current study investigated the in vitro cytotoxic effects of 17 ethanolic extracts of the following 16 plants used in traditional anticancer medicine in Nigeria: Sapium ellipticum leaves, Sapium ellipticum stembark, Combretum paniculatum, Celosia trigyna, Pupalia lappacea, Justica extensa, Hedranthera barteri leaves, Alternanthera sessilis, Ethulia conyzoides leaves, Lannea nigritana stembark, Combretum zenkeri root, Combretum molle leaves, Adenanthera parvoniana, Lannea acida, Cyathula achyranthoides, Drymaria cordata, Cyathula prostrata, against HeLa cancer cells. Five of the most promising extracts (Sapium ellipticum leaves, Combretum paniculatum, Celosia trigyna, Drymaria cordata, Cyathula prostrata) were selected for further screening against HT29 and MCF-7 cancer cells. Of the five, the first two were investigated further based on their activities in the screening phase. The S. ellipticum leaf extract yielded IC50 values of 88.60 ± 0.03 and 93.03 ± 0.03 μg/ml against HeLa and MCF-7, respectively. The toxicity was also evaluated on normal cells and an IC50 of 77.66 μg/ml was obtained for peripheral blood mononuclear cells (PBMCs). The IC50 values for proliferating and confluent Chang liver cells were both >125 μg/ml. These results suggest that the extract may be selective for specific cell types. Bio-assay guided fractionation of the S. ellipticum ethanolic extract yielded two active fractions; chloroform and ethyl acetate. Two compounds isolated from the chloroform extract were screened against the three cancer cell lines and found to be inactive. Three compounds were isolated from the ethyl acetate fraction and revealed IC50 values < 62.5 and < 31 μg/ml against MCF-7. Unfortunately these two compounds soon lost activity before any further work could be done on them and work was continued with the crude extract.
- Full Text:
- Date Issued: 2012
- Authors: Baatjies, Lucinda
- Date: 2012
- Subjects: Cancer -- Treatment , Cancer cells , Medicinal plants , Plant extracts , Traditional medicine , Public health
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10316 , http://hdl.handle.net/10948/d1008191 , Cancer -- Treatment , Cancer cells , Medicinal plants , Plant extracts , Traditional medicine , Public health
- Description: Cancer is a disease that imposes a heavy burden on public health and poses a challenge to science. The World Health Organization estimates that 80 percent of people in developing countries of the world rely on traditional medicine for their primary health needs, and about 85 percent of traditional medicine involves the use of plant extracts. This is particularly true in Africa where a large percentage of the population depends upon medicinal plants for health care. Therefore, detailed screening and evaluation of bioactive substances for chemotherapeutic purposes of African plants are urgently warranted. Furthermore, this will serve to validate the efficacy and safety of African traditional medicine. The current study investigated the in vitro cytotoxic effects of 17 ethanolic extracts of the following 16 plants used in traditional anticancer medicine in Nigeria: Sapium ellipticum leaves, Sapium ellipticum stembark, Combretum paniculatum, Celosia trigyna, Pupalia lappacea, Justica extensa, Hedranthera barteri leaves, Alternanthera sessilis, Ethulia conyzoides leaves, Lannea nigritana stembark, Combretum zenkeri root, Combretum molle leaves, Adenanthera parvoniana, Lannea acida, Cyathula achyranthoides, Drymaria cordata, Cyathula prostrata, against HeLa cancer cells. Five of the most promising extracts (Sapium ellipticum leaves, Combretum paniculatum, Celosia trigyna, Drymaria cordata, Cyathula prostrata) were selected for further screening against HT29 and MCF-7 cancer cells. Of the five, the first two were investigated further based on their activities in the screening phase. The S. ellipticum leaf extract yielded IC50 values of 88.60 ± 0.03 and 93.03 ± 0.03 μg/ml against HeLa and MCF-7, respectively. The toxicity was also evaluated on normal cells and an IC50 of 77.66 μg/ml was obtained for peripheral blood mononuclear cells (PBMCs). The IC50 values for proliferating and confluent Chang liver cells were both >125 μg/ml. These results suggest that the extract may be selective for specific cell types. Bio-assay guided fractionation of the S. ellipticum ethanolic extract yielded two active fractions; chloroform and ethyl acetate. Two compounds isolated from the chloroform extract were screened against the three cancer cell lines and found to be inactive. Three compounds were isolated from the ethyl acetate fraction and revealed IC50 values < 62.5 and < 31 μg/ml against MCF-7. Unfortunately these two compounds soon lost activity before any further work could be done on them and work was continued with the crude extract.
- Full Text:
- Date Issued: 2012
An evaluation of changes in capital investment by automotive companies in preparation for the Automotive Production and Development Programme (APDP)
- Authors: Bacela, Bandile Sakhekile
- Date: 2012
- Subjects: Automobile industry and trade -- South Africa , Capital investments -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8797 , http://hdl.handle.net/10948/d1016075
- Description: To thrive, developing countries depend on high levels of protection being given to key industries such as manufacturing; specifically the automotive and textile industries. South Africa, as a developing country and especially under the emergence of globalisation, has followed suit in terms of developing policies and structures to protect certain critical industries. During an era (1980 to 1989) of high political instability, South Africa experienced isolation from the rest of the world, which resulted in declines in industrial revenues as well as the country’s automotive industry undergoing a stage of perilous stagnation. It was through a protection regime that the automotive industry realised growth, a regime which started slowly in 1989 and accelerated in 1995 with the introduction of the Motor Industry Development Programme (MIDP) (Black, 2001). Through this regime the South African government sought to integrate the South African automotive industry into the global market by improving the competitiveness of this industry (The DTI, 2010). This led to the automotive industry becoming one of the most successful export sectors in South African manufacturing and a large net consumer of foreign currency, totalling R20 billion and R10 billion in imports and exports respectively by 1998 (Damoense and Simon, 2004). Reviews of the government legislation called the MIDP were held in year 1999 and 2002 and in 2008, a successor to the MIDP was named, the Automotive Production Development Programme (APDP) and is set to commence in year 2013 until 2020. Unlike its predecessor, the APDP policy promises to bring greater and more inclusive benefits to the automotive industry as a whole, provided organisations have prepared well to receive it. This study investigated whether organisations have prepared for the upcoming 2013 - 2020 APDP, with specific reference to capital investment in equipment. It determined whether automotive organisations have spent and are going to spend resources in securing equipment and technology in preparation for the introduction of the APDP.
- Full Text:
- Date Issued: 2012
- Authors: Bacela, Bandile Sakhekile
- Date: 2012
- Subjects: Automobile industry and trade -- South Africa , Capital investments -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8797 , http://hdl.handle.net/10948/d1016075
- Description: To thrive, developing countries depend on high levels of protection being given to key industries such as manufacturing; specifically the automotive and textile industries. South Africa, as a developing country and especially under the emergence of globalisation, has followed suit in terms of developing policies and structures to protect certain critical industries. During an era (1980 to 1989) of high political instability, South Africa experienced isolation from the rest of the world, which resulted in declines in industrial revenues as well as the country’s automotive industry undergoing a stage of perilous stagnation. It was through a protection regime that the automotive industry realised growth, a regime which started slowly in 1989 and accelerated in 1995 with the introduction of the Motor Industry Development Programme (MIDP) (Black, 2001). Through this regime the South African government sought to integrate the South African automotive industry into the global market by improving the competitiveness of this industry (The DTI, 2010). This led to the automotive industry becoming one of the most successful export sectors in South African manufacturing and a large net consumer of foreign currency, totalling R20 billion and R10 billion in imports and exports respectively by 1998 (Damoense and Simon, 2004). Reviews of the government legislation called the MIDP were held in year 1999 and 2002 and in 2008, a successor to the MIDP was named, the Automotive Production Development Programme (APDP) and is set to commence in year 2013 until 2020. Unlike its predecessor, the APDP policy promises to bring greater and more inclusive benefits to the automotive industry as a whole, provided organisations have prepared well to receive it. This study investigated whether organisations have prepared for the upcoming 2013 - 2020 APDP, with specific reference to capital investment in equipment. It determined whether automotive organisations have spent and are going to spend resources in securing equipment and technology in preparation for the introduction of the APDP.
- Full Text:
- Date Issued: 2012
The social and political identities of coloured women in the northern areas of Port Elizabeth
- Authors: Barker, Celeste Heloise
- Date: 2012
- Subjects: Women, Colored -- South Africa -- Port Elizabeth , Colored people (South Africa) -- Race identity , Ethnicity -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8261 , http://hdl.handle.net/10948/d1013081
- Description: This treatise explores the social and political identity of coloured women in the Nelson Mandela Bay Metro (NMBM) with the intention of understanding why some stereotypes of coloured women‟s identity have endured since colonialism in South Africa. Topic selection was stimulated by heated public response to a newspaper article (“Jou Ma se Kinders” (Your Mother‟s Children), (Roberts 2011: http://www.lifeissavage.com/) which negatively labeled and pigeon-holed coloured women‟s identity. With the notable exception of the Saartje Baartman story, most text selection in the Literature Review (Chapter 2) was informed by research in the Western Cape because studies have a patriarchal bias and there are scant records of coloured women‟s lives and identity in the East Cape, Port Elizabeth and the NMBM. The study includes select readings of literary theory and South African fiction from which examples were chosen to illustrate the longevity of stereotypes attached to coloured women‟s identity. Commemorative narrative highlights the role coloured women played and continue to play as their alternative histories or counter narratives embed alternative histories in group identity. A comparative historical analysis of racist and gendered policies and practices contextualises the social construction of coloured women‟s identity from the colonial period to the present time and a focus group discussion among ten female evictees from South End and Richmond ] Hill in Port Elizabeth (PE) generated rich details of coloured women‟s lives and experience in Port Elizabeth and the NMBM. Findings are captured in four themes: Living, Loving and Laughing; Religion and Resistance; Hardship and Trauma and Identity and Ambivalence. These themes highlight nostalgia, courage and humour; the special role played by religious affiliation and coloured people‟s successful resistance to the demolition and deconsecration of places of worship in PE together with pride and a sense of achievement which continues to influence coloured women‟s political identity in the NMBM. Police brutality, everyday racism and sexism, the impact of apartheid on matriculants and the influence of petty apartheid on coloured women‟s lives and identity, as well as participants‟ contradictory perceptions of their post-apartheid social and political identity which continue to be defined by a deficit discourse, are discussed and described in Chapter 4. Focus Group findings locate coloured women‟s identity in a milieu of racist and gendered laws, policies and practices. It is suggested that sexualised stereotypes of coloured women‟s commodification and second class status persist regardless of the South African transition to a constitutional democracy. Evidence is presented of coloured women as bounded storytellers who create a counter narrative to apartheid justification of forced removals.It is suggested that the counter narrative is a vehicle for group support, affirmation and the recovery of roots, identity and post apartheid heritage including records and memorabilia displayed in the South End Museum. As the field is under-researched it is recommended that further research should be conducted to include studies of the social and political identity of an expanded sample of coloured women representative of diverse ages and backgrounds in the rural and urban areas of South Africa.
- Full Text:
- Date Issued: 2012
- Authors: Barker, Celeste Heloise
- Date: 2012
- Subjects: Women, Colored -- South Africa -- Port Elizabeth , Colored people (South Africa) -- Race identity , Ethnicity -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8261 , http://hdl.handle.net/10948/d1013081
- Description: This treatise explores the social and political identity of coloured women in the Nelson Mandela Bay Metro (NMBM) with the intention of understanding why some stereotypes of coloured women‟s identity have endured since colonialism in South Africa. Topic selection was stimulated by heated public response to a newspaper article (“Jou Ma se Kinders” (Your Mother‟s Children), (Roberts 2011: http://www.lifeissavage.com/) which negatively labeled and pigeon-holed coloured women‟s identity. With the notable exception of the Saartje Baartman story, most text selection in the Literature Review (Chapter 2) was informed by research in the Western Cape because studies have a patriarchal bias and there are scant records of coloured women‟s lives and identity in the East Cape, Port Elizabeth and the NMBM. The study includes select readings of literary theory and South African fiction from which examples were chosen to illustrate the longevity of stereotypes attached to coloured women‟s identity. Commemorative narrative highlights the role coloured women played and continue to play as their alternative histories or counter narratives embed alternative histories in group identity. A comparative historical analysis of racist and gendered policies and practices contextualises the social construction of coloured women‟s identity from the colonial period to the present time and a focus group discussion among ten female evictees from South End and Richmond ] Hill in Port Elizabeth (PE) generated rich details of coloured women‟s lives and experience in Port Elizabeth and the NMBM. Findings are captured in four themes: Living, Loving and Laughing; Religion and Resistance; Hardship and Trauma and Identity and Ambivalence. These themes highlight nostalgia, courage and humour; the special role played by religious affiliation and coloured people‟s successful resistance to the demolition and deconsecration of places of worship in PE together with pride and a sense of achievement which continues to influence coloured women‟s political identity in the NMBM. Police brutality, everyday racism and sexism, the impact of apartheid on matriculants and the influence of petty apartheid on coloured women‟s lives and identity, as well as participants‟ contradictory perceptions of their post-apartheid social and political identity which continue to be defined by a deficit discourse, are discussed and described in Chapter 4. Focus Group findings locate coloured women‟s identity in a milieu of racist and gendered laws, policies and practices. It is suggested that sexualised stereotypes of coloured women‟s commodification and second class status persist regardless of the South African transition to a constitutional democracy. Evidence is presented of coloured women as bounded storytellers who create a counter narrative to apartheid justification of forced removals.It is suggested that the counter narrative is a vehicle for group support, affirmation and the recovery of roots, identity and post apartheid heritage including records and memorabilia displayed in the South End Museum. As the field is under-researched it is recommended that further research should be conducted to include studies of the social and political identity of an expanded sample of coloured women representative of diverse ages and backgrounds in the rural and urban areas of South Africa.
- Full Text:
- Date Issued: 2012
Using an intelligent self-service solution to support telecommunication service provisioning
- Authors: Barlow, Sherwin Riaan
- Date: 2012
- Subjects: Telecommunication systems -- Management , Electronic commerce -- Computer programs , Web applications
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10484 , http://hdl.handle.net/10948/d1013417
- Description: The increasing competition between telecommunication service providers (TSPs) and the large amounts of human resource costs incurred to provision telecommunication services to small, medium and micro enterprises (SMMEs), highlight the need for effective self-service provisioning methods to reduce costs. Existing service provisioning methods do not effectively support SMMEs in the service provisioning process. The current methods used are manual and Web-based. The manual service provisioning method is labour and time-intensive. TSPs are being forced to cut human resource costs as the profit margins for provisioning services are narrow due to competition. The current web-based systems do not allow SMMEs to effectively purchase services as they provide long textual lists to consult and limited information about services. The objective of this research was to develop an intelligent web-based self-service system to support SMMEs in telecommunication service provisioning, using a Design Science Research methodology. A constraint-based, knowledge-based recommender system was selected as the most appropriate intelligent system to support telecommunication service provisioning. A prototype called SelPro was developed as a solution to address the shortcomings of the current ineffective service provisioning methods available for SMMEs. SelPro incorporates an interactive wizard-style user interface with dynamic recommendations to support novice users as well as an expert interface which provides less user support. An expert review and a user study were conducted to determine if SelPro was usable, useful and effective. SelPro was perceived as being usable for SMMEs wishing to purchase telecommunication services. Expert participants were satisfied with the usability of SelPro and perceived it as being useful, easy to use and easy to learn. SelPro was considered effective because of the high task success ratings provided by the participants using the two interfaces. The research determined that intelligent web-based self-service provisioning can be used to effectively support SMMEs in telecommunication service provisioning. General design recommendations for similar systems were proposed and future work will involve using intelligent systems to support large enterprises in telecommunication service provisioning.
- Full Text:
- Date Issued: 2012
- Authors: Barlow, Sherwin Riaan
- Date: 2012
- Subjects: Telecommunication systems -- Management , Electronic commerce -- Computer programs , Web applications
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10484 , http://hdl.handle.net/10948/d1013417
- Description: The increasing competition between telecommunication service providers (TSPs) and the large amounts of human resource costs incurred to provision telecommunication services to small, medium and micro enterprises (SMMEs), highlight the need for effective self-service provisioning methods to reduce costs. Existing service provisioning methods do not effectively support SMMEs in the service provisioning process. The current methods used are manual and Web-based. The manual service provisioning method is labour and time-intensive. TSPs are being forced to cut human resource costs as the profit margins for provisioning services are narrow due to competition. The current web-based systems do not allow SMMEs to effectively purchase services as they provide long textual lists to consult and limited information about services. The objective of this research was to develop an intelligent web-based self-service system to support SMMEs in telecommunication service provisioning, using a Design Science Research methodology. A constraint-based, knowledge-based recommender system was selected as the most appropriate intelligent system to support telecommunication service provisioning. A prototype called SelPro was developed as a solution to address the shortcomings of the current ineffective service provisioning methods available for SMMEs. SelPro incorporates an interactive wizard-style user interface with dynamic recommendations to support novice users as well as an expert interface which provides less user support. An expert review and a user study were conducted to determine if SelPro was usable, useful and effective. SelPro was perceived as being usable for SMMEs wishing to purchase telecommunication services. Expert participants were satisfied with the usability of SelPro and perceived it as being useful, easy to use and easy to learn. SelPro was considered effective because of the high task success ratings provided by the participants using the two interfaces. The research determined that intelligent web-based self-service provisioning can be used to effectively support SMMEs in telecommunication service provisioning. General design recommendations for similar systems were proposed and future work will involve using intelligent systems to support large enterprises in telecommunication service provisioning.
- Full Text:
- Date Issued: 2012
An investigation into refuge trauma experiences in an ethnic Somali community in Port Elizabeth, South Africa
- Barnwell, Garret Christopher
- Authors: Barnwell, Garret Christopher
- Date: 2012
- Subjects: Refugees -- Legal status, laws, etc. -- South Africa -- Port Elizabeth , Somali diaspora , Forced migration -- South Africa -- Port Elizabeth , Refugees -- Abuse of -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8275 , http://hdl.handle.net/10948/d1016061
- Description: The study aimed to explore and describe the forced migration experiences of Somali refugees living in Port Elizabeth, South Africa and the impact of refugee-specific trauma on this population. A mixed method triangulation research design with a quantitative weighting was employed and purposive snowball, non-probability sampling was used to construct a sample of 30 adult Somali refugees from Port Elizabeth’s Korsten community. Participants were included in the study if they fulfilled the pre-defined inclusion criteria of having successfully applied for refugee status, having resided in South Africa for at least six months and being 18 years or older. A semi-structured interview questionnaire was developed by the researcher to operationalise the constructs being measured. The questionnaire comprised a biographical and antecedent event(s) questionnaires as well as sections of the Harvard Trauma Questionnaire Revised Version. Data was then analysed via exploratory descriptive statistics and correlation coefficients. The research found that the majority of Somali refugees cited conflict, insecurity and instability as the mainn reasons for leaving their country of origin, suggesting the basic need for safety and security was unmet. One third of the sample reported that the main reason for leaving was the same as their most traumatic life event. The average participant had experienced 16 traumatic events and experienced 23 trauma symptoms on average, demonstrating high levels of trauma among the study population. The study recommends that the link between the main reason for forced migration and refugee trauma be explored.
- Full Text:
- Date Issued: 2012
- Authors: Barnwell, Garret Christopher
- Date: 2012
- Subjects: Refugees -- Legal status, laws, etc. -- South Africa -- Port Elizabeth , Somali diaspora , Forced migration -- South Africa -- Port Elizabeth , Refugees -- Abuse of -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8275 , http://hdl.handle.net/10948/d1016061
- Description: The study aimed to explore and describe the forced migration experiences of Somali refugees living in Port Elizabeth, South Africa and the impact of refugee-specific trauma on this population. A mixed method triangulation research design with a quantitative weighting was employed and purposive snowball, non-probability sampling was used to construct a sample of 30 adult Somali refugees from Port Elizabeth’s Korsten community. Participants were included in the study if they fulfilled the pre-defined inclusion criteria of having successfully applied for refugee status, having resided in South Africa for at least six months and being 18 years or older. A semi-structured interview questionnaire was developed by the researcher to operationalise the constructs being measured. The questionnaire comprised a biographical and antecedent event(s) questionnaires as well as sections of the Harvard Trauma Questionnaire Revised Version. Data was then analysed via exploratory descriptive statistics and correlation coefficients. The research found that the majority of Somali refugees cited conflict, insecurity and instability as the mainn reasons for leaving their country of origin, suggesting the basic need for safety and security was unmet. One third of the sample reported that the main reason for leaving was the same as their most traumatic life event. The average participant had experienced 16 traumatic events and experienced 23 trauma symptoms on average, demonstrating high levels of trauma among the study population. The study recommends that the link between the main reason for forced migration and refugee trauma be explored.
- Full Text:
- Date Issued: 2012
Savings behaviour in selected poor townships of the Kouga municipal district
- Authors: Baxter, Chad
- Date: 2012
- Subjects: Saving and investment -- South Africa , South Africa -- Economic policy
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9009 , http://hdl.handle.net/10948/d1014540
- Description: This study considers the nature of savings behaviour amongst low income earners residing in the township areas of Kouga Municipal District. It reflects on the popularity and persistence of informal savings and credit associations, also known as stokvels, in these communities in the face of an increase in the availability of formal savings products. This study argues that despite financial deepening taking place within the South African economy, the popularity and widespread usage of stokvels can largely be attributed to the lack of appropraite formal products available for low income earners. This study does not conclude that the usage of informal savings products results in increased savings behaviours amongst this group, but it does conclude that they provide a suitable mechanism in which savings can take place.
- Full Text:
- Date Issued: 2012
- Authors: Baxter, Chad
- Date: 2012
- Subjects: Saving and investment -- South Africa , South Africa -- Economic policy
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9009 , http://hdl.handle.net/10948/d1014540
- Description: This study considers the nature of savings behaviour amongst low income earners residing in the township areas of Kouga Municipal District. It reflects on the popularity and persistence of informal savings and credit associations, also known as stokvels, in these communities in the face of an increase in the availability of formal savings products. This study argues that despite financial deepening taking place within the South African economy, the popularity and widespread usage of stokvels can largely be attributed to the lack of appropraite formal products available for low income earners. This study does not conclude that the usage of informal savings products results in increased savings behaviours amongst this group, but it does conclude that they provide a suitable mechanism in which savings can take place.
- Full Text:
- Date Issued: 2012
On the optical and electrical design of low concentrator photovoltaic modules
- Authors: Benecke, Mario Andrew
- Date: 2012
- Subjects: Photovoltaic cells -- Design and construction , Photovoltaic cells
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10543 , http://hdl.handle.net/10948/d1013102
- Description: The increasing interest in non-fossil fuel based electricity generation has caused a prominent boost for the renewable energy sector, especially the field of Photovoltaics (PV) with one of the main reasons being the decrease in cost of PV electricity generation. However, over the last few years a saturation in the efficiency of solar cells have been reached leading into a renewed search for other means to further reduce the cost of electricity generation from photovoltaic sources. One of the technologies that has attracted a lot of attention is low concentration photovoltaics (LCPV). LCPV investigates an alternative strategy to replace costly semiconductor material with relatively cheap optical materials by developing a Low Concentration Photovoltaic (LCPV) module. A LCPV module is divided into three subsystems, namely, the optical, electrical and thermal subsystem. This study focussed on the design, construction and characterisation of an optical subsystem accompanied by a thorough investigation into the design of an electrical subsystem. A facetted parabolic concentrator using a vertical receiver was modelled and a first prototype was constructed having a geometric concentration factor of 6.00 X. Upon electrical characterisation of this first vertical receiver LCPV prototype a concentration of only 4.53 X (receiver 1) and 4.71 X (receiver 2) was obtained. The first vertical receiver LCPV prototype did not reach the expected concentration factor due to optical losses and misalignment of optical elements. The illumination profile obtained from the reflector element was investigated and an undesirable non-uniform illumination profile was discovered. A second vertical receiver LCPV prototype was constructed in an attempt to improve on the first prototype, this second vertical receiver prototype had a geometrical concentration factor of 5.80 X. The results indicated a much improved illumination profile, yet still containing a number of non-uniformities. The second vertical receiver LCPV module yielded an operational concentration factor of 5.34 X. From the preliminary results obtained it was discovered that under concentrated illumination there was a limitation on the maximum power that could be obtained from the receiver. Upon further investigation it was discovered that this limitation was due to the higher current levels under concentrated illumination accompanied by a high series resistance of the receiver. This lead to the construction of new PV receivers, where this limitation could be minimised. 3 cell, 4 cell, 6 cell and 8 cell string configurations were constructed and used for the electrical characterisation of the prototypes. Due to non-uniformity of the illumination profile obtained from the second LCPV prototype a third vertical receiver LCPV prototype was constructed. This vertical receiver design illustrated more uniformity in the obtained illumination distribution and had a geometrical concentration factor of 4.61 X, although under operation only 4.26 X could be obtained. It is important to note that the geometric concentration factor does not account for reflective losses of the reflective material. One of the main reasons for the difficulty in obtaining a uniform illumination profile with the vertical receiver design is that the facetted reflector element is far away from the PV receiver. This enhances the effect of the slightest misalignment of any of the optical elements. This large distance also increases the effect of lensing from each facet. These factors lead to the consideration of a second design, which would counteract these factors. A horizontal receiver LCPV module design implementing a facetted parabolic reflector was considered to counteract these effects. From a mathematical model a horizontal receiver LCPV prototype was constructed having a geometrical concentration factor 5.3 X. The optical characterisation of the illumination profile showed a much improved illumination profile, which was much more uniform than the previous illumination profiles obtained from the other LCPV prototypes. The uniformity of the illumination profile could be seen in results obtained from the electrical characterisation where the concentrator reached operational concentration factor of 5.01 X. The reliability of the third vertical receiver LCPV prototype and the horizontal receiver LCPV prototype as well as the receivers were investigated by placing each receiver under stressed operational conditions for 60 sun hours. I-V characteristics were obtained after every five sun hours to investigate any signs of degradation. After 60 sun hours none of the receiver displayed any signs of degradation or reduction in electrical performance.
- Full Text:
- Date Issued: 2012
- Authors: Benecke, Mario Andrew
- Date: 2012
- Subjects: Photovoltaic cells -- Design and construction , Photovoltaic cells
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10543 , http://hdl.handle.net/10948/d1013102
- Description: The increasing interest in non-fossil fuel based electricity generation has caused a prominent boost for the renewable energy sector, especially the field of Photovoltaics (PV) with one of the main reasons being the decrease in cost of PV electricity generation. However, over the last few years a saturation in the efficiency of solar cells have been reached leading into a renewed search for other means to further reduce the cost of electricity generation from photovoltaic sources. One of the technologies that has attracted a lot of attention is low concentration photovoltaics (LCPV). LCPV investigates an alternative strategy to replace costly semiconductor material with relatively cheap optical materials by developing a Low Concentration Photovoltaic (LCPV) module. A LCPV module is divided into three subsystems, namely, the optical, electrical and thermal subsystem. This study focussed on the design, construction and characterisation of an optical subsystem accompanied by a thorough investigation into the design of an electrical subsystem. A facetted parabolic concentrator using a vertical receiver was modelled and a first prototype was constructed having a geometric concentration factor of 6.00 X. Upon electrical characterisation of this first vertical receiver LCPV prototype a concentration of only 4.53 X (receiver 1) and 4.71 X (receiver 2) was obtained. The first vertical receiver LCPV prototype did not reach the expected concentration factor due to optical losses and misalignment of optical elements. The illumination profile obtained from the reflector element was investigated and an undesirable non-uniform illumination profile was discovered. A second vertical receiver LCPV prototype was constructed in an attempt to improve on the first prototype, this second vertical receiver prototype had a geometrical concentration factor of 5.80 X. The results indicated a much improved illumination profile, yet still containing a number of non-uniformities. The second vertical receiver LCPV module yielded an operational concentration factor of 5.34 X. From the preliminary results obtained it was discovered that under concentrated illumination there was a limitation on the maximum power that could be obtained from the receiver. Upon further investigation it was discovered that this limitation was due to the higher current levels under concentrated illumination accompanied by a high series resistance of the receiver. This lead to the construction of new PV receivers, where this limitation could be minimised. 3 cell, 4 cell, 6 cell and 8 cell string configurations were constructed and used for the electrical characterisation of the prototypes. Due to non-uniformity of the illumination profile obtained from the second LCPV prototype a third vertical receiver LCPV prototype was constructed. This vertical receiver design illustrated more uniformity in the obtained illumination distribution and had a geometrical concentration factor of 4.61 X, although under operation only 4.26 X could be obtained. It is important to note that the geometric concentration factor does not account for reflective losses of the reflective material. One of the main reasons for the difficulty in obtaining a uniform illumination profile with the vertical receiver design is that the facetted reflector element is far away from the PV receiver. This enhances the effect of the slightest misalignment of any of the optical elements. This large distance also increases the effect of lensing from each facet. These factors lead to the consideration of a second design, which would counteract these factors. A horizontal receiver LCPV module design implementing a facetted parabolic reflector was considered to counteract these effects. From a mathematical model a horizontal receiver LCPV prototype was constructed having a geometrical concentration factor 5.3 X. The optical characterisation of the illumination profile showed a much improved illumination profile, which was much more uniform than the previous illumination profiles obtained from the other LCPV prototypes. The uniformity of the illumination profile could be seen in results obtained from the electrical characterisation where the concentrator reached operational concentration factor of 5.01 X. The reliability of the third vertical receiver LCPV prototype and the horizontal receiver LCPV prototype as well as the receivers were investigated by placing each receiver under stressed operational conditions for 60 sun hours. I-V characteristics were obtained after every five sun hours to investigate any signs of degradation. After 60 sun hours none of the receiver displayed any signs of degradation or reduction in electrical performance.
- Full Text:
- Date Issued: 2012