Design, implementation and evaluation of a directly water cooled photovoltaic- thermal system
- Authors: Mtunzi, Busiso
- Date: 2013
- Subjects: Sensitivity analysis -- Photovoltaic thermal system (PV/T) , Solar utilization -- Carbon emission
- Language: English
- Type: Thesis , Doctoral , PhD (Physics)
- Identifier: vital:11597 , http://hdl.handle.net/10353/d1016198 , Sensitivity analysis -- Photovoltaic thermal system (PV/T) , Solar utilization -- Carbon emission
- Description: This research project was based on the Design, Implementation and Evaluation of a Photovoltaic Water heating system in South Africa, Eastern Cape Province. The purpose of the study was to design and investigate the scientific and economic contribution of direct water cooling on the photovoltaic module. The method involved performance comparison of two photovoltaic modules, one naturally cooled (M1) and the other, direct water cooled module (M2). Module M2 was used to produce warm water and electricity, hence, a hybrid system. The study focused on comparing the modules’ efficiency, power output and their performance. The temperatures attained by water through cooling the module were monitored as well as the electrical energy generated. A data logger and a low cost I/V characteristic system were used for data collection for a full year. The data were then used for performance analysis of the modules. The results of the study revealed that the directly water cooled module could operate at a higher electrical efficiency for 87% of the day and initially produced 3.63% more electrical energy each day. This was found to be true for the first three months after installation. In the remaining months to the end of the year M2 was found to have more losses as compared to M1 as evidenced by the modules’ performance ratios. The directly water cooled module also showed an energy saving efficiency of 61%. A solar utilization of 47.93% was found for M2 while 8.77% was found for M1. Economically, the project was found to be viable and the payback period of the directly cooled module (M2) system was found to be 9.8 years. Energy economics showed that the system was more sensitive to the price changes and to the energy output as compared to other inputs such as operation and maintenance and years of operation. A generation cost of R0.84/kWh from the system was found and when compared to the potential revenue of R1.18 per kWh, the system was found to enable households to make a profit of 40.5 %. Use of such a system was also found to be able to contribute 9.55% towards carbon emission reduction each year. From these results, it was concluded that a directly cooled photovoltaic/thermal heating (PV/T) system is possible and that it can be of much help in terms of warm water and electricity provision.
- Full Text:
- Date Issued: 2013
- Authors: Mtunzi, Busiso
- Date: 2013
- Subjects: Sensitivity analysis -- Photovoltaic thermal system (PV/T) , Solar utilization -- Carbon emission
- Language: English
- Type: Thesis , Doctoral , PhD (Physics)
- Identifier: vital:11597 , http://hdl.handle.net/10353/d1016198 , Sensitivity analysis -- Photovoltaic thermal system (PV/T) , Solar utilization -- Carbon emission
- Description: This research project was based on the Design, Implementation and Evaluation of a Photovoltaic Water heating system in South Africa, Eastern Cape Province. The purpose of the study was to design and investigate the scientific and economic contribution of direct water cooling on the photovoltaic module. The method involved performance comparison of two photovoltaic modules, one naturally cooled (M1) and the other, direct water cooled module (M2). Module M2 was used to produce warm water and electricity, hence, a hybrid system. The study focused on comparing the modules’ efficiency, power output and their performance. The temperatures attained by water through cooling the module were monitored as well as the electrical energy generated. A data logger and a low cost I/V characteristic system were used for data collection for a full year. The data were then used for performance analysis of the modules. The results of the study revealed that the directly water cooled module could operate at a higher electrical efficiency for 87% of the day and initially produced 3.63% more electrical energy each day. This was found to be true for the first three months after installation. In the remaining months to the end of the year M2 was found to have more losses as compared to M1 as evidenced by the modules’ performance ratios. The directly water cooled module also showed an energy saving efficiency of 61%. A solar utilization of 47.93% was found for M2 while 8.77% was found for M1. Economically, the project was found to be viable and the payback period of the directly cooled module (M2) system was found to be 9.8 years. Energy economics showed that the system was more sensitive to the price changes and to the energy output as compared to other inputs such as operation and maintenance and years of operation. A generation cost of R0.84/kWh from the system was found and when compared to the potential revenue of R1.18 per kWh, the system was found to enable households to make a profit of 40.5 %. Use of such a system was also found to be able to contribute 9.55% towards carbon emission reduction each year. From these results, it was concluded that a directly cooled photovoltaic/thermal heating (PV/T) system is possible and that it can be of much help in terms of warm water and electricity provision.
- Full Text:
- Date Issued: 2013
Designing multi-touch tabletop interaction techniques to support co-located Group Information Management
- Authors: Ditta, Mohammed Ali
- Date: 2013
- Subjects: Groupware (Computer software) , Teams in the workplace -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10493 , http://hdl.handle.net/10948/d1020639
- Description: Co-located group information management (GIM) is a form of groupware with the aim of enabling users to collaboratively find, store, maintain, organise and share personal and/or group information in support of a group activity. Existing systems aimed at partially supporting GIM activities have been implemented on single user devices. These systems make use of asynchronous communication that may hinder collaboration by misinterpretation, information leaks, etc. Few systems exist, with limited functionality, that support co-located GIM. Multi-touch tabletop interaction has given rise to a new approach for supporting Computer Supported Cooperative Work (CSCW). Multi-touch tabletops allow multiple users to naturally interact with a computer device using a shared display and gesture interaction. The tabletop environment also enables users to sit in a natural environment and synchronously communicate without bulky desktops or laptops. Multi-touch tabletops provide the hardware necessary to support co-located GIM. Existing multi-touch interaction techniques were analysed and proved insufficient to support the advanced functional requirements of GIM. The goal of this research was therefore to support co-located GIM by designing new multi-touch tabletop interaction techniques. An architecture was proposed to support co-located GIM with new multi-touch interaction techniques. A software prototype was developed based on the proposed architecture to facilitate the main activities of GIM and to collaboratively compile documents. The prototype was named CollaGIM (Colla – collaborative, GIM – group information management). CollaGIM supports the main activities of GIM using natural gesture interaction on a multi-touch tabletop. An evaluation of the software was conducted by means of a user study where 15 teams of two people participated. High task success rates and user satisfaction results were achieved, which showed that CollaGIM was capable of supporting co-located GIM using the new multi-touch tabletop interaction techniques. CollaGIM also positively supported collaboration between users.
- Full Text:
- Date Issued: 2013
- Authors: Ditta, Mohammed Ali
- Date: 2013
- Subjects: Groupware (Computer software) , Teams in the workplace -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10493 , http://hdl.handle.net/10948/d1020639
- Description: Co-located group information management (GIM) is a form of groupware with the aim of enabling users to collaboratively find, store, maintain, organise and share personal and/or group information in support of a group activity. Existing systems aimed at partially supporting GIM activities have been implemented on single user devices. These systems make use of asynchronous communication that may hinder collaboration by misinterpretation, information leaks, etc. Few systems exist, with limited functionality, that support co-located GIM. Multi-touch tabletop interaction has given rise to a new approach for supporting Computer Supported Cooperative Work (CSCW). Multi-touch tabletops allow multiple users to naturally interact with a computer device using a shared display and gesture interaction. The tabletop environment also enables users to sit in a natural environment and synchronously communicate without bulky desktops or laptops. Multi-touch tabletops provide the hardware necessary to support co-located GIM. Existing multi-touch interaction techniques were analysed and proved insufficient to support the advanced functional requirements of GIM. The goal of this research was therefore to support co-located GIM by designing new multi-touch tabletop interaction techniques. An architecture was proposed to support co-located GIM with new multi-touch interaction techniques. A software prototype was developed based on the proposed architecture to facilitate the main activities of GIM and to collaboratively compile documents. The prototype was named CollaGIM (Colla – collaborative, GIM – group information management). CollaGIM supports the main activities of GIM using natural gesture interaction on a multi-touch tabletop. An evaluation of the software was conducted by means of a user study where 15 teams of two people participated. High task success rates and user satisfaction results were achieved, which showed that CollaGIM was capable of supporting co-located GIM using the new multi-touch tabletop interaction techniques. CollaGIM also positively supported collaboration between users.
- Full Text:
- Date Issued: 2013
Determinants of household savings in South Africa: an econometric approach
- Authors: Chipote, Precious
- Date: 2013
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11479 , http://hdl.handle.net/10353/d1015281
- Description: Savings play a crucial role in promoting economic growth through their effect on investments. In addition, savings cushion the economy against fluctuating international capital flows. In periods of low or fluctuating capital, domestic savings are essential to finance high levels of capital formation thereby leading to increased productivity and sustainable economic growth. In South Africa saving levels have been declining, particularly household savings. This has been a major cause of concern as low savings hinder economic growth. In light of this, the study explored the determinants of household savings in South Africa over the period 1990 to 2011 using quarterly data. Based on the review of the theoretical and empirical literature, particular attention was paid to the effects of age dependency ratio, the level of household income, inflation and real interest rate on household savings. Apart from informal graphical test, the study employed the Augmented Dickey-Fuller and Phillips Perron unit root tests to test for stationarity in the time series. To identify the long-run and short-run dynamics among the variables, the study used the Johansen co-integration and the Error Correction Mechanism. Results of the study indicated that age dependency ratio, inflation and real interest rate have a positive impact on household savings whilst income has a negative long run relationship with household savings. In addition, the findings revealed that income, inflation and real interest rate play a major role in determining household savings whereas age dependency ratio is insignificant. The study recommends that the government should employ a countercyclical fiscal policy to avoid the development of excessive current account deficits during periods of more rapid economic growth, rising investment and falling saving.
- Full Text:
- Date Issued: 2013
- Authors: Chipote, Precious
- Date: 2013
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11479 , http://hdl.handle.net/10353/d1015281
- Description: Savings play a crucial role in promoting economic growth through their effect on investments. In addition, savings cushion the economy against fluctuating international capital flows. In periods of low or fluctuating capital, domestic savings are essential to finance high levels of capital formation thereby leading to increased productivity and sustainable economic growth. In South Africa saving levels have been declining, particularly household savings. This has been a major cause of concern as low savings hinder economic growth. In light of this, the study explored the determinants of household savings in South Africa over the period 1990 to 2011 using quarterly data. Based on the review of the theoretical and empirical literature, particular attention was paid to the effects of age dependency ratio, the level of household income, inflation and real interest rate on household savings. Apart from informal graphical test, the study employed the Augmented Dickey-Fuller and Phillips Perron unit root tests to test for stationarity in the time series. To identify the long-run and short-run dynamics among the variables, the study used the Johansen co-integration and the Error Correction Mechanism. Results of the study indicated that age dependency ratio, inflation and real interest rate have a positive impact on household savings whilst income has a negative long run relationship with household savings. In addition, the findings revealed that income, inflation and real interest rate play a major role in determining household savings whereas age dependency ratio is insignificant. The study recommends that the government should employ a countercyclical fiscal policy to avoid the development of excessive current account deficits during periods of more rapid economic growth, rising investment and falling saving.
- Full Text:
- Date Issued: 2013
Determinants of life satisfaction among race groups in South Africa
- Ebrahim, Amina, Botha, Ferdi, Snowball, Jeanette D
- Authors: Ebrahim, Amina , Botha, Ferdi , Snowball, Jeanette D
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69311 , vital:29497 , https://doi.org/10.1080/0376835x.2013.797227
- Description: Economic indicators, like gross domestic product per capita, are commonly used as indicators of welfare. However, they have a very limited and narrow scope, excluding many potentially important welfare determinants, such as health, relative income and religion – not surprising since they were not designed to fill this role. As a result, there is growing acceptance, and use of, subjective measures of well-being (called ‘happiness’ or ‘life satisfaction’, often used interchangeably) both worldwide and in South Africa. Happiness economics does not propose to replace income-based measures of well-being, but rather attempts to complement them with broader measures, which can be important in making policy decisions that optimise societal welfare. This paper tests for differences in subjective well-being between race groups in South Africa, and investigates the determinants of self-rated life satisfaction for each group. Using the 2008 National Income Dynamics Study data, descriptive methods (analysis of variance) and an ordered probit model are applied. Results indicate that reported life satisfaction differs substantially among race groups, with black South Africans being the least satisfied group despite changes since the advent of democracy in 1994. Higher levels of educational attainment increased satisfaction for the whole sample, and women (particularly black women) are generally less satisfied than men. As found in many other studies, unemployed people have lower levels of life satisfaction than the employed, even when controlling for income and relative income. The determinants of life satisfaction are also different for each race group: white South Africans attach greater importance to physical health, whereas employment status and absolute income matter greatly for black people. For coloured people and black people, positional status (as measured by relative income) is an important determinant of well-being, with religious involvement contributing significantly to the well-being of Indian people.
- Full Text: false
- Date Issued: 2013
- Authors: Ebrahim, Amina , Botha, Ferdi , Snowball, Jeanette D
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69311 , vital:29497 , https://doi.org/10.1080/0376835x.2013.797227
- Description: Economic indicators, like gross domestic product per capita, are commonly used as indicators of welfare. However, they have a very limited and narrow scope, excluding many potentially important welfare determinants, such as health, relative income and religion – not surprising since they were not designed to fill this role. As a result, there is growing acceptance, and use of, subjective measures of well-being (called ‘happiness’ or ‘life satisfaction’, often used interchangeably) both worldwide and in South Africa. Happiness economics does not propose to replace income-based measures of well-being, but rather attempts to complement them with broader measures, which can be important in making policy decisions that optimise societal welfare. This paper tests for differences in subjective well-being between race groups in South Africa, and investigates the determinants of self-rated life satisfaction for each group. Using the 2008 National Income Dynamics Study data, descriptive methods (analysis of variance) and an ordered probit model are applied. Results indicate that reported life satisfaction differs substantially among race groups, with black South Africans being the least satisfied group despite changes since the advent of democracy in 1994. Higher levels of educational attainment increased satisfaction for the whole sample, and women (particularly black women) are generally less satisfied than men. As found in many other studies, unemployed people have lower levels of life satisfaction than the employed, even when controlling for income and relative income. The determinants of life satisfaction are also different for each race group: white South Africans attach greater importance to physical health, whereas employment status and absolute income matter greatly for black people. For coloured people and black people, positional status (as measured by relative income) is an important determinant of well-being, with religious involvement contributing significantly to the well-being of Indian people.
- Full Text: false
- Date Issued: 2013
Determinants of student satisfaction with campus residence life at a South African University
- Botha, Ferdi, Snowball, Jeanette D, De Klerk, Vivian A, Radloff, Sarah E
- Authors: Botha, Ferdi , Snowball, Jeanette D , De Klerk, Vivian A , Radloff, Sarah E
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68543 , vital:29281 , https://econrsa.org/publications/working-papers/determinants-student-satisfaction-campus-residence-life-south-african
- Description: Publisher version , Although there are a number of studies on the determinants of general quality of life among university students, these occur mainly in developed countries and do not focus specifically on campus-based residence life. It has long been accepted that factors outside the classroom (“the other curriculum”) can contribute to academic success, as well as the achievement of other important outcomes such as the appreciation of human diversity. Striving towards equality of residence life satisfaction across different racial and gender groups, for example, is thus important for academic outcomes and for the development of well-functioning citizens. This study is based on the 2011 Quality of Residence Life (QoRL) Survey, conducted at a South African university, comprising roughly 2 000 respondents. Based on descriptive analyses and ordered probit regressions, the study investigates the association between satisfaction with QoRL and (i) residence milieu and characteristics, (ii) direct and indirect discrimination, (iii) perceptions of drug and alcohol issues in residence, (iv) safety, and (v) individual student characteristics. One of the main findings is that there are no significant differences in satisfaction with QoRL across racial and gender groups; a finding that suggests significant progress in university transformation and equity goals. The general atmosphere and characteristics of residences are also important predictors of QoRL satisfaction. , Economic Research Southern Africa (ERSA) is a research programme funded by the National Treasury of South Africa.
- Full Text:
- Date Issued: 2013
- Authors: Botha, Ferdi , Snowball, Jeanette D , De Klerk, Vivian A , Radloff, Sarah E
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68543 , vital:29281 , https://econrsa.org/publications/working-papers/determinants-student-satisfaction-campus-residence-life-south-african
- Description: Publisher version , Although there are a number of studies on the determinants of general quality of life among university students, these occur mainly in developed countries and do not focus specifically on campus-based residence life. It has long been accepted that factors outside the classroom (“the other curriculum”) can contribute to academic success, as well as the achievement of other important outcomes such as the appreciation of human diversity. Striving towards equality of residence life satisfaction across different racial and gender groups, for example, is thus important for academic outcomes and for the development of well-functioning citizens. This study is based on the 2011 Quality of Residence Life (QoRL) Survey, conducted at a South African university, comprising roughly 2 000 respondents. Based on descriptive analyses and ordered probit regressions, the study investigates the association between satisfaction with QoRL and (i) residence milieu and characteristics, (ii) direct and indirect discrimination, (iii) perceptions of drug and alcohol issues in residence, (iv) safety, and (v) individual student characteristics. One of the main findings is that there are no significant differences in satisfaction with QoRL across racial and gender groups; a finding that suggests significant progress in university transformation and equity goals. The general atmosphere and characteristics of residences are also important predictors of QoRL satisfaction. , Economic Research Southern Africa (ERSA) is a research programme funded by the National Treasury of South Africa.
- Full Text:
- Date Issued: 2013
Determining the factors that influence customer service excellence in the South African retail sector
- Authors: Nzo, Yolisa Nomfundo
- Date: 2013
- Subjects: Retail trade -- Customer services -- South Africa -- Centurion , Relationship marketing -- South Africa -- Centurion , Employee empowerment -- South Africa -- Centurion , Consumer satisfaction -- South Africa -- Centurion , Employee morale -- South Africa -- Centurion
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8776 , http://hdl.handle.net/10948/d1012956
- Description: Customer service excellence (CSE) is the common thread that binds all businesses; as without customers no trade can take place. The South African retail sector is one of the drivers of the economy and it is important that CSE is continuously monitored to ensure that standards of excellence are maintained. What remains unknown and unmeasured is the impact of the employees and the organisation on CSE. The retail sector is dependent on its customer facing employees to be the face and character of the store. Investment in advertising and other media exposure must ultimately be tested when a consumer visits a store and experiences the CSE on the ground and in real time. The investment for the retailer becomes worthwhile if the real face of the company reflects the promises made in the media; and that is in the hands of the men and women who work in the stores. This study sought to find out the impact of employees and organisations in the Centurion mall based retail stores on CSE. Literature was reviewed and quantitative and qualitative research methods was undertaken by means of questionnaires that were distributed to the staff and management of national branded stores in the malls around Centurion. The results obtained were then discussed in terms of each variable tested. The study found that organisational commitment, employee education and employee training have a strong relationship to customer service excellence.
- Full Text:
- Date Issued: 2013
- Authors: Nzo, Yolisa Nomfundo
- Date: 2013
- Subjects: Retail trade -- Customer services -- South Africa -- Centurion , Relationship marketing -- South Africa -- Centurion , Employee empowerment -- South Africa -- Centurion , Consumer satisfaction -- South Africa -- Centurion , Employee morale -- South Africa -- Centurion
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8776 , http://hdl.handle.net/10948/d1012956
- Description: Customer service excellence (CSE) is the common thread that binds all businesses; as without customers no trade can take place. The South African retail sector is one of the drivers of the economy and it is important that CSE is continuously monitored to ensure that standards of excellence are maintained. What remains unknown and unmeasured is the impact of the employees and the organisation on CSE. The retail sector is dependent on its customer facing employees to be the face and character of the store. Investment in advertising and other media exposure must ultimately be tested when a consumer visits a store and experiences the CSE on the ground and in real time. The investment for the retailer becomes worthwhile if the real face of the company reflects the promises made in the media; and that is in the hands of the men and women who work in the stores. This study sought to find out the impact of employees and organisations in the Centurion mall based retail stores on CSE. Literature was reviewed and quantitative and qualitative research methods was undertaken by means of questionnaires that were distributed to the staff and management of national branded stores in the malls around Centurion. The results obtained were then discussed in terms of each variable tested. The study found that organisational commitment, employee education and employee training have a strong relationship to customer service excellence.
- Full Text:
- Date Issued: 2013
Determining the impact of leadership on the success of entrepreneurs
- Authors: Mtshibe, Nomaswazi
- Date: 2013
- Subjects: Leadership , Success in business , Entrepreneurship -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8920 , http://hdl.handle.net/10948/d1021108
- Description: The Eastern Cape Province has been cited as the second poorest province in South Africa. The impact of entrepreneurship on the economy, with respect to socio-economic development, has placed increased pressure on entrepreneurs to operate effectively. Moreover, entrepreneurs are required to adopt and adapt to leadership practices that lead to business success. Business success is largely dependent on the leader. The importance of this study may, thus, be attributed to the need for entrepreneurs to possess the necessary leadership attributes for the efficient running of a business. The primary objective of this study was to improve the success rate of entrepreneurs in the Eastern Cape Province. This was done by determining the impact of selected leadership attributes on the success of entrepreneurs. More specifically, this study investigated how the success of entrepreneurs is influenced by leadership attributes (the dependent variable), namely, leadership style, vision, networking, risk-taking and ethics (the independent variables). In order to achieve the research objectives, the researcher used the inferential statistical approach, specifically, hypothesis testing. The first step was to conduct a literature review on factors that influence entrepreneurs. This entailed the barriers to success, critical success factors, the impact of the SMME sector on the economy, as well as the selected leadership attributes. Secondly, the quantitative research method was used to assess the perceptions of entrepreneurs with regards to the influence of the leadership attributes on their businesses. This was done through an empirical survey, namely a self-administered questionnaire that was distributed to a sample of 100 entrepreneurs who are based in the Eastern Cape Province and have been operating for a minimum of three years. Out of the envisaged 100 respondents, 89 questionnaires were completed (89% response rate). The data obtained from the empirical survey was then analysed statistically and the descriptive statistics were presented by using graphs and tables. The results of the empirical survey revealed that although all the above-mentioned independent variables contribute towards increasing the success rate of entrepreneurs, networking and ethics exert the most significant influence. Based on the findings of the literature review and the results of the empirical survey, this study made recommendations on areas of improvement for entrepreneurs in order to increase their success rate. Suggestions were also made for possible future research.
- Full Text:
- Date Issued: 2013
- Authors: Mtshibe, Nomaswazi
- Date: 2013
- Subjects: Leadership , Success in business , Entrepreneurship -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8920 , http://hdl.handle.net/10948/d1021108
- Description: The Eastern Cape Province has been cited as the second poorest province in South Africa. The impact of entrepreneurship on the economy, with respect to socio-economic development, has placed increased pressure on entrepreneurs to operate effectively. Moreover, entrepreneurs are required to adopt and adapt to leadership practices that lead to business success. Business success is largely dependent on the leader. The importance of this study may, thus, be attributed to the need for entrepreneurs to possess the necessary leadership attributes for the efficient running of a business. The primary objective of this study was to improve the success rate of entrepreneurs in the Eastern Cape Province. This was done by determining the impact of selected leadership attributes on the success of entrepreneurs. More specifically, this study investigated how the success of entrepreneurs is influenced by leadership attributes (the dependent variable), namely, leadership style, vision, networking, risk-taking and ethics (the independent variables). In order to achieve the research objectives, the researcher used the inferential statistical approach, specifically, hypothesis testing. The first step was to conduct a literature review on factors that influence entrepreneurs. This entailed the barriers to success, critical success factors, the impact of the SMME sector on the economy, as well as the selected leadership attributes. Secondly, the quantitative research method was used to assess the perceptions of entrepreneurs with regards to the influence of the leadership attributes on their businesses. This was done through an empirical survey, namely a self-administered questionnaire that was distributed to a sample of 100 entrepreneurs who are based in the Eastern Cape Province and have been operating for a minimum of three years. Out of the envisaged 100 respondents, 89 questionnaires were completed (89% response rate). The data obtained from the empirical survey was then analysed statistically and the descriptive statistics were presented by using graphs and tables. The results of the empirical survey revealed that although all the above-mentioned independent variables contribute towards increasing the success rate of entrepreneurs, networking and ethics exert the most significant influence. Based on the findings of the literature review and the results of the empirical survey, this study made recommendations on areas of improvement for entrepreneurs in order to increase their success rate. Suggestions were also made for possible future research.
- Full Text:
- Date Issued: 2013
Determining the impact of leadership on the success of entrepreneurs
- Authors: Mtshibe, Nomaswazi
- Date: 2013
- Subjects: Leadership , Success in business
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8852 , http://hdl.handle.net/10948/d1020126
- Description: The Eastern Cape Province has been cited as the second poorest province in South Africa. The impact of entrepreneurship on the economy, with respect to socio-economic development, has placed increased pressure on entrepreneurs to operate effectively. Moreover, entrepreneurs are required to adopt and adapt to leadership practices that lead to business success. Business success is largely dependent on the leader. The importance of this study may, thus, be attributed to the need for entrepreneurs to possess the necessary leadership attributes for the efficient running of a business. The primary objective of this study was to improve the success rate of entrepreneurs in the Eastern Cape Province. This was done by determining the impact of selected leadership attributes on the success of entrepreneurs. More specifically, this study investigated how the success of entrepreneurs is influenced by leadership attributes (the dependent variable), namely, leadership style, vision, networking, risk-taking and ethics (the independent variables). In order to achieve the research objectives, the researcher used the inferential statistical approach, specifically, hypothesis testing. The first step was to conduct a literature review on factors that influence entrepreneurs. This entailed the barriers to success, critical success factors, the impact of the SMME sector on the economy, as well as the selected leadership attributes. Secondly, the quantitative research method was used to assess the perceptions of entrepreneurs with regards to the influence of the leadership attributes on their businesses. This was done through an empirical survey, namely a self-administered questionnaire that was distributed to a sample of 100 entrepreneurs who are based in the Eastern Cape Province and have been operating for a minimum of three years. Out of the envisaged 100 respondents, 89 questionnaires were completed (89% response rate). The data obtained from the empirical survey was then analysed statistically and the descriptive statistics were presented by using graphs and tables. The results of the empirical survey revealed that although all the above-mentioned independent variables contribute towards increasing the success rate of entrepreneurs, networking and ethics exert the most significant influence. Based on the findings of the literature review and the results of the empirical survey, this study made recommendations on areas of improvement for entrepreneurs in order to increase their success rate. Suggestions were also made for possible future research.
- Full Text:
- Date Issued: 2013
- Authors: Mtshibe, Nomaswazi
- Date: 2013
- Subjects: Leadership , Success in business
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8852 , http://hdl.handle.net/10948/d1020126
- Description: The Eastern Cape Province has been cited as the second poorest province in South Africa. The impact of entrepreneurship on the economy, with respect to socio-economic development, has placed increased pressure on entrepreneurs to operate effectively. Moreover, entrepreneurs are required to adopt and adapt to leadership practices that lead to business success. Business success is largely dependent on the leader. The importance of this study may, thus, be attributed to the need for entrepreneurs to possess the necessary leadership attributes for the efficient running of a business. The primary objective of this study was to improve the success rate of entrepreneurs in the Eastern Cape Province. This was done by determining the impact of selected leadership attributes on the success of entrepreneurs. More specifically, this study investigated how the success of entrepreneurs is influenced by leadership attributes (the dependent variable), namely, leadership style, vision, networking, risk-taking and ethics (the independent variables). In order to achieve the research objectives, the researcher used the inferential statistical approach, specifically, hypothesis testing. The first step was to conduct a literature review on factors that influence entrepreneurs. This entailed the barriers to success, critical success factors, the impact of the SMME sector on the economy, as well as the selected leadership attributes. Secondly, the quantitative research method was used to assess the perceptions of entrepreneurs with regards to the influence of the leadership attributes on their businesses. This was done through an empirical survey, namely a self-administered questionnaire that was distributed to a sample of 100 entrepreneurs who are based in the Eastern Cape Province and have been operating for a minimum of three years. Out of the envisaged 100 respondents, 89 questionnaires were completed (89% response rate). The data obtained from the empirical survey was then analysed statistically and the descriptive statistics were presented by using graphs and tables. The results of the empirical survey revealed that although all the above-mentioned independent variables contribute towards increasing the success rate of entrepreneurs, networking and ethics exert the most significant influence. Based on the findings of the literature review and the results of the empirical survey, this study made recommendations on areas of improvement for entrepreneurs in order to increase their success rate. Suggestions were also made for possible future research.
- Full Text:
- Date Issued: 2013
Developing a business model for growth in social enterprise : a case study of a hybrid organisation
- Authors: Olivier, Grant Jerome
- Date: 2013
- Subjects: Social entrepreneurship , Business planning , Free enterprise -- Social aspects , Small business -- Growth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8854 , http://hdl.handle.net/10948/d1020137
- Description: The Intshona Group of Companies operates in South Africa as a hybrid agribusiness combining entrepreneurial principles with a philosophy of social upliftment in Africa. This research views Intshona through the lens of social entrepreneurship theory, a hybrid research field with a dominant theme being the need for growth and scaling of impact, but which is seen as fragmented, containing ambiguities and lagging practice. In this research, a case study of Intshona is developed based on questionnaires and interviews with the organisation’s management, a concerned NGO, social beneficiaries as well as employees. The result is a two-way flow of knowledge integrating elements of existing social enterprise theory with Intshona’s business practices, building on a generic model of entrepreneurship and culminating in a business model for growth in a social enterprise. The research delivers strategic directives for Intshona for its future growth, presents a case study for addition to the body of knowledge on social entrepreneurship and concludes with suggestions for further research to continue developing theory.
- Full Text:
- Date Issued: 2013
- Authors: Olivier, Grant Jerome
- Date: 2013
- Subjects: Social entrepreneurship , Business planning , Free enterprise -- Social aspects , Small business -- Growth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8854 , http://hdl.handle.net/10948/d1020137
- Description: The Intshona Group of Companies operates in South Africa as a hybrid agribusiness combining entrepreneurial principles with a philosophy of social upliftment in Africa. This research views Intshona through the lens of social entrepreneurship theory, a hybrid research field with a dominant theme being the need for growth and scaling of impact, but which is seen as fragmented, containing ambiguities and lagging practice. In this research, a case study of Intshona is developed based on questionnaires and interviews with the organisation’s management, a concerned NGO, social beneficiaries as well as employees. The result is a two-way flow of knowledge integrating elements of existing social enterprise theory with Intshona’s business practices, building on a generic model of entrepreneurship and culminating in a business model for growth in a social enterprise. The research delivers strategic directives for Intshona for its future growth, presents a case study for addition to the body of knowledge on social entrepreneurship and concludes with suggestions for further research to continue developing theory.
- Full Text:
- Date Issued: 2013
Developing a virtualised testbed environment in preparation for testing of network based attacks
- Van Heerden, Renier, Pieterse, Heloise, Burke, Ivan, Irwin, Barry V W
- Authors: Van Heerden, Renier , Pieterse, Heloise , Burke, Ivan , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429648 , vital:72629 , 10.1109/ICASTech.2013.6707509
- Description: Computer network attacks are difficult to simulate due to the damage they may cause to live networks and the complexity required simulating a useful network. We constructed a virtualised network within a vSphereESXi environment which is able to simulate: thirty workstations, ten servers, three distinct network segments and the accompanying network traffic. The VSphere environment provided added benefits, such as the ability to pause, restart and snapshot virtual computers. These abilities enabled the authors to reset the simulation environment before each test and mitigated against the damage that an attack potentially inflicts on the test network. Without simulated network traffic, the virtualised network was too sterile. This resulted in any network event being a simple task to detect, making network traffic simulation a requirement for an event detection test bed. Five main kinds of traffic were simulated: Web browsing, File transfer, e-mail, version control and Intranet File traffic. The simulated traffic volumes were pseudo randomised to represent differing temporal patterns. By building a virtualised network with simulated traffic we were able to test IDS' and other network attack detection sensors in a much more realistic environment before moving it to a live network. The goal of this paper is to present a virtualised testbedenvironmentin which network attacks can safely be tested.
- Full Text:
- Date Issued: 2013
- Authors: Van Heerden, Renier , Pieterse, Heloise , Burke, Ivan , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429648 , vital:72629 , 10.1109/ICASTech.2013.6707509
- Description: Computer network attacks are difficult to simulate due to the damage they may cause to live networks and the complexity required simulating a useful network. We constructed a virtualised network within a vSphereESXi environment which is able to simulate: thirty workstations, ten servers, three distinct network segments and the accompanying network traffic. The VSphere environment provided added benefits, such as the ability to pause, restart and snapshot virtual computers. These abilities enabled the authors to reset the simulation environment before each test and mitigated against the damage that an attack potentially inflicts on the test network. Without simulated network traffic, the virtualised network was too sterile. This resulted in any network event being a simple task to detect, making network traffic simulation a requirement for an event detection test bed. Five main kinds of traffic were simulated: Web browsing, File transfer, e-mail, version control and Intranet File traffic. The simulated traffic volumes were pseudo randomised to represent differing temporal patterns. By building a virtualised network with simulated traffic we were able to test IDS' and other network attack detection sensors in a much more realistic environment before moving it to a live network. The goal of this paper is to present a virtualised testbedenvironmentin which network attacks can safely be tested.
- Full Text:
- Date Issued: 2013
Developing principles for research on young women and abortion
- Authors: Macleod, Catriona I
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434384 , vital:73053 , ISBN 9781919895581 , https://rowman.com/ISBN/9789280812275/Jacketed-Women-Qualitative-Research-Methodologies-on-Sexualities-and-Gender-in-Africa
- Description: Soon after the first democratic elections in South Africa in 1994, the Choice on Termination of Pregnancy (CTOP) Act of 1996, which legalised abortion for the first time, was passed. Women may now request abortions up to the twelfth week of pregnancy. After this, abortions may still be performed but under specified conditions, for instance, if continued pregnancy will significantly affect the woman’s social or economic circumstances. The Act also promotes the provision of non-mandatory counselling before and after abortions are performed. Minors are counselled to notify their parents or guardian but do not require consent for an abortion. Since the introduction of the CTOP, a number of studies have been conducted on abortion in South Africa. Many have taken a health-related focus, for example, studies on the quality of care provided by midwives (Dickson-Tetteh and Billings 2002); profiles of women seeking abortions (Ramonate, Hiemstra, De Coning and Nel 2001); attitudes, beliefs and experiences of health providers (Buga 2002; Da Costa and Donald 2003); the cost of termination of pregnancy services (Reproductive Rights Alliance 2000); prevalence of morbidity in termination of pregnancies (Jewkes, Brown, Dickson-Tetteh, Levin and Rees 2002); the proportion of pregnancies that end in termination of pregnancy (Buchmann, Mensah and Pillay 2002); and impediments in the provision of services (Engelbrecht, Pelser, Ngwena and Van Rensburg 2000).
- Full Text:
- Date Issued: 2013
- Authors: Macleod, Catriona I
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434384 , vital:73053 , ISBN 9781919895581 , https://rowman.com/ISBN/9789280812275/Jacketed-Women-Qualitative-Research-Methodologies-on-Sexualities-and-Gender-in-Africa
- Description: Soon after the first democratic elections in South Africa in 1994, the Choice on Termination of Pregnancy (CTOP) Act of 1996, which legalised abortion for the first time, was passed. Women may now request abortions up to the twelfth week of pregnancy. After this, abortions may still be performed but under specified conditions, for instance, if continued pregnancy will significantly affect the woman’s social or economic circumstances. The Act also promotes the provision of non-mandatory counselling before and after abortions are performed. Minors are counselled to notify their parents or guardian but do not require consent for an abortion. Since the introduction of the CTOP, a number of studies have been conducted on abortion in South Africa. Many have taken a health-related focus, for example, studies on the quality of care provided by midwives (Dickson-Tetteh and Billings 2002); profiles of women seeking abortions (Ramonate, Hiemstra, De Coning and Nel 2001); attitudes, beliefs and experiences of health providers (Buga 2002; Da Costa and Donald 2003); the cost of termination of pregnancy services (Reproductive Rights Alliance 2000); prevalence of morbidity in termination of pregnancies (Jewkes, Brown, Dickson-Tetteh, Levin and Rees 2002); the proportion of pregnancies that end in termination of pregnancy (Buchmann, Mensah and Pillay 2002); and impediments in the provision of services (Engelbrecht, Pelser, Ngwena and Van Rensburg 2000).
- Full Text:
- Date Issued: 2013
Developing teaching and learning skills at a Higher education institution: a collaborative action research study
- Authors: Mokhele, Paul Rampaola
- Date: 2013
- Subjects: Learning -- Study and teaching (Tertiary) -- South Africa
- Language: English
- Type: Thesis , Doctoral , D Ed
- Identifier: vital:18456 , http://hdl.handle.net/11260/d1007960
- Description: The thesis which was originally undertaken to improve my teaching skills and determine ways of allowing me space to live my academic values also turned out to become the enquiry to investigate students’ learning and study skills. Students and I collaborated in a year-long self-study action research where we were trying different teaching-learning strategies in order to improve our practice(s). Throughout the study I kept a reflective journal and students also reflected in a portfolio of learning their impressions about the new teaching-learning strategies. In addition to these data gathering methods data from students were gathered using chats, observation, and open-ended questionnaire. Data was analysed using a narrative method, reflexivity principle, and grounded theory. There are two major steps I followed in this study which are aimed at improving students’ basic study and learning skills, and my teaching skills. The first relates to action research into student learning at the school of Mathematics Science and Technology (MSTE) at a rural university. The study reveals that: Students have their own different and unique styles of learning, implementing various learning styles afford students an opportunity to find a style that matches their own. The second action step relates to my own self-study research trying different teaching methods based on my academic and personal values. Here, the study reveals that: The best teaching-learning practice is the one developed and agreed upon between the teacher educator and his or her students. These ‘action’ steps were not mutually exclusive – they were conducted in parallel. After the description of developing student learning skills at undergraduate level my reflections on the study followed in relation to theories and methods of teaching-learning and further revealed that what works with one group of students will not necessarily work with another group. The best teacher educator is constantly seeking ways of improving the learning experience of his or her students. The recommendations that teacher educators should become self reflective practitioners and improve their professions using self-study collaborative approach will benefit other teacher educators who are keen to study and improve their practice.
- Full Text:
- Date Issued: 2013
- Authors: Mokhele, Paul Rampaola
- Date: 2013
- Subjects: Learning -- Study and teaching (Tertiary) -- South Africa
- Language: English
- Type: Thesis , Doctoral , D Ed
- Identifier: vital:18456 , http://hdl.handle.net/11260/d1007960
- Description: The thesis which was originally undertaken to improve my teaching skills and determine ways of allowing me space to live my academic values also turned out to become the enquiry to investigate students’ learning and study skills. Students and I collaborated in a year-long self-study action research where we were trying different teaching-learning strategies in order to improve our practice(s). Throughout the study I kept a reflective journal and students also reflected in a portfolio of learning their impressions about the new teaching-learning strategies. In addition to these data gathering methods data from students were gathered using chats, observation, and open-ended questionnaire. Data was analysed using a narrative method, reflexivity principle, and grounded theory. There are two major steps I followed in this study which are aimed at improving students’ basic study and learning skills, and my teaching skills. The first relates to action research into student learning at the school of Mathematics Science and Technology (MSTE) at a rural university. The study reveals that: Students have their own different and unique styles of learning, implementing various learning styles afford students an opportunity to find a style that matches their own. The second action step relates to my own self-study research trying different teaching methods based on my academic and personal values. Here, the study reveals that: The best teaching-learning practice is the one developed and agreed upon between the teacher educator and his or her students. These ‘action’ steps were not mutually exclusive – they were conducted in parallel. After the description of developing student learning skills at undergraduate level my reflections on the study followed in relation to theories and methods of teaching-learning and further revealed that what works with one group of students will not necessarily work with another group. The best teacher educator is constantly seeking ways of improving the learning experience of his or her students. The recommendations that teacher educators should become self reflective practitioners and improve their professions using self-study collaborative approach will benefit other teacher educators who are keen to study and improve their practice.
- Full Text:
- Date Issued: 2013
Development and validation of in-process control test kits for biodiesel production
- Authors: Fibi, Pumza Oscarine
- Date: 2013
- Subjects: Biodiesel fuels -- South Africa , Biomass energy -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10416 , http://hdl.handle.net/10948/d1012645 , Biodiesel fuels -- South Africa , Biomass energy -- South Africa
- Description: The production of biodiesel from vegetable oils is not a new technology; it has been around since the 1950’s and both the research in terms of the different feedstock that can be used and the production of biodiesel has since been gaining momentum as there needs to be a new, sustainable and domestic alternative to petroleum fuels. These petroleum fuels pose enormous threats to the environment and therefore need to be replaced as they are mostly contributing to climate change and global warming not to mention the frequent price hikes which are crippling the South African economy. Biodiesel production using vegetable oils seems to be and is the future and a law has recently been passed which sanctions the production of biofuel locally.[1] South African fuel producers will instigate obligatory blending of fossil fuel with biofuel as the country moves to encourage investment in its biofuels sector. The production of biodiesel locally and the blending of biodiesel with other petroleum products will reduce the country’s dependence on imported fuel. The already established petrochemical companies like BP, Sasol and Engine are therefore mandated to purchase these biofuels if and when the biofuels meet the required South African National Standard (SANS) 1935 requirements. This is then where the challenge comes as most of these growing biofuel companies cannot afford to purchase testing equipment.The growing companiesthen discover upon completion of the biofuel manufacturing process that their product does not meet the required standard specification. The failure translates to a financial loss as the final product can possibly not be reworked. The aim of the project is then to assist these companies who are manufacturing biofuel, by providing them with in-house biofuel process methods which will allow for early detection, should there be a need to redo a step in the process and not wait until the completion of the production process. These in-house process-testing methods will range from pH determination, titration tests which will determine the soap content and the percentage free fatty acid content, water determination, density and visual testing. It is not cost-effective for these biodiesel manufacturers to send their samples for outsource testing as evidently the results obtained would be out of specification hence the need to provide these biodiesel manufacturers with in-house analytical testing techniques that will aid in monitoring of the biodiesel production.
- Full Text:
- Date Issued: 2013
- Authors: Fibi, Pumza Oscarine
- Date: 2013
- Subjects: Biodiesel fuels -- South Africa , Biomass energy -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10416 , http://hdl.handle.net/10948/d1012645 , Biodiesel fuels -- South Africa , Biomass energy -- South Africa
- Description: The production of biodiesel from vegetable oils is not a new technology; it has been around since the 1950’s and both the research in terms of the different feedstock that can be used and the production of biodiesel has since been gaining momentum as there needs to be a new, sustainable and domestic alternative to petroleum fuels. These petroleum fuels pose enormous threats to the environment and therefore need to be replaced as they are mostly contributing to climate change and global warming not to mention the frequent price hikes which are crippling the South African economy. Biodiesel production using vegetable oils seems to be and is the future and a law has recently been passed which sanctions the production of biofuel locally.[1] South African fuel producers will instigate obligatory blending of fossil fuel with biofuel as the country moves to encourage investment in its biofuels sector. The production of biodiesel locally and the blending of biodiesel with other petroleum products will reduce the country’s dependence on imported fuel. The already established petrochemical companies like BP, Sasol and Engine are therefore mandated to purchase these biofuels if and when the biofuels meet the required South African National Standard (SANS) 1935 requirements. This is then where the challenge comes as most of these growing biofuel companies cannot afford to purchase testing equipment.The growing companiesthen discover upon completion of the biofuel manufacturing process that their product does not meet the required standard specification. The failure translates to a financial loss as the final product can possibly not be reworked. The aim of the project is then to assist these companies who are manufacturing biofuel, by providing them with in-house biofuel process methods which will allow for early detection, should there be a need to redo a step in the process and not wait until the completion of the production process. These in-house process-testing methods will range from pH determination, titration tests which will determine the soap content and the percentage free fatty acid content, water determination, density and visual testing. It is not cost-effective for these biodiesel manufacturers to send their samples for outsource testing as evidently the results obtained would be out of specification hence the need to provide these biodiesel manufacturers with in-house analytical testing techniques that will aid in monitoring of the biodiesel production.
- Full Text:
- Date Issued: 2013
Development of a co-operative stakeholder framework for employment growth in the South African automotive sector
- Authors: Smith, Owen Christo
- Date: 2013
- Subjects: Cooperative societies -- South Africa , Job creation -- South Africa , Automobile industry and trade -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8884 , http://hdl.handle.net/10948/d1020799
- Description: Manufacturing has been identified by the Department of Trade and Industry as an important sector to drive economic growth in South Africa. The automotive manufacturing sector in particular has seen significant support from the DTI in the form of incentives to produce motor vehicles and components. South Africa is faced with a high unemployment rate and one of the strategies of the Government is to drive economic growth by supporting the automotive manufacturing sector. One of the spill-over targets is to increase employment creation in the industry. The automotive manufacturing sector consists of a diverse list of stakeholders representing motor vehicle manufacturers, component manufacturers, labour unions, government departments and industry associations. The Motor Industry Development Programme delivered significant progress in the number of vehicles produced in South Africa and the biggest growth was in the export of vehicles. Employment creation on the other hand did not see the same levels of growth as motor vehicle and component production. The purpose of this study was to identify and clarify what the variables are that influence employment creation and to develop a co-operation framework that would guide the automotive cluster stakeholders to work on employment creation initiatives as a collective. The survey questionnaire results representing the perception of managers showed that: - DTI Incentives schemes linked to employment creation; - Productivity, Technology and employment; - The role of competitiveness in the auto cluster; - Labour Union Collective bargaining; - Investment climate and infrastructure; - Education and skills development; does have an influence on employment creation in the automotive cluster.
- Full Text:
- Date Issued: 2013
- Authors: Smith, Owen Christo
- Date: 2013
- Subjects: Cooperative societies -- South Africa , Job creation -- South Africa , Automobile industry and trade -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8884 , http://hdl.handle.net/10948/d1020799
- Description: Manufacturing has been identified by the Department of Trade and Industry as an important sector to drive economic growth in South Africa. The automotive manufacturing sector in particular has seen significant support from the DTI in the form of incentives to produce motor vehicles and components. South Africa is faced with a high unemployment rate and one of the strategies of the Government is to drive economic growth by supporting the automotive manufacturing sector. One of the spill-over targets is to increase employment creation in the industry. The automotive manufacturing sector consists of a diverse list of stakeholders representing motor vehicle manufacturers, component manufacturers, labour unions, government departments and industry associations. The Motor Industry Development Programme delivered significant progress in the number of vehicles produced in South Africa and the biggest growth was in the export of vehicles. Employment creation on the other hand did not see the same levels of growth as motor vehicle and component production. The purpose of this study was to identify and clarify what the variables are that influence employment creation and to develop a co-operation framework that would guide the automotive cluster stakeholders to work on employment creation initiatives as a collective. The survey questionnaire results representing the perception of managers showed that: - DTI Incentives schemes linked to employment creation; - Productivity, Technology and employment; - The role of competitiveness in the auto cluster; - Labour Union Collective bargaining; - Investment climate and infrastructure; - Education and skills development; does have an influence on employment creation in the automotive cluster.
- Full Text:
- Date Issued: 2013
Development of a creep sample retrieval technique and friction weld site repair procedure
- Authors: Wedderburn, Ian Norman
- Date: 2013
- Subjects: Friction welding
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9635 , http://hdl.handle.net/10948/d1020116
- Description: The remnant life monitoring of creep loaded high temperature and pressure components in power stations is critical to ensuring their safe and cost effective operation as failures can have severe consequences. Effective creep life condition monitoring allows for optimising component life predictions and subsequent plant maintenance decisions. In South Africa many power generation stations have been in operation well beyond their 30 year design service life, as such knowledge of the remnant creep life of high temperature and pressure components, such as steam pipelines, becomes of utmost importance. Techniques for the remnant creep life assessments of critical high temperature and pressure components must therefore be as effective as possible. The common and well accepted in-situ inspection technique for assessing creep damage in steam pipes is by the metallographic replication technique. The technique is however limited to the outer surface of the pipe, without information on damage within the wall. This research will illustrate a means of obtaining a sample for creep life analysis with depth through the wall of a pipe, as wells as an alternative technique for the repair of the sample retrieval site. A sample retrieval technique was developed that would retrieve a small diameter cylindrical sample from a cored blind hole for creep analysis by visual creep void assessment or by the small punch creep test. The small punch creep test requires only a small diameter thin disc of material for testing for which its results are comparable with conventional uniaxial creep testing which requires a much larger sample of material. The smaller sample requirement of the small punch creep test therefore allows for a vastly reduced invasive sample retrieval operation and consequently smaller repair size area. Also the fact that the sample is retrieved from a blind hole is advantageous since the pipe wall is not penetrated which would require full plant shutdown. A friction welding technique was identified as an alternative to traditional arc fusion welding for the repair of the sample retrieval site, this technique being the Friction Hydro Pillar Processing technique. Friction Hydro Pillar Processing is a solid-state welding technique and as such has a number of inherent benefits over arc fusion welding as the weld is performed below the melting temperature of the material. From a process point of view Friction Hydro Pillar Processing is ideally suited for automation, has virtually no fumes generated, minimal distortion is experienced and no spatter has to be removed afterwards. The technique has yet to see industrial application and as such development of suitable process parameters was undertaken. Finally, to apply the sample retrieval and repair operations in-situ to a steam pipe in a power plant suitable equipment was developed. Existing friction welding equipment is generally bulky workshop based equipment and is unsuitable for on-site work due to its size and weight. Therefore development of dedicated equipment was required to enable Friction Hydro Pillar Processing to be applied to steam pipes within a power plant environment.
- Full Text:
- Date Issued: 2013
- Authors: Wedderburn, Ian Norman
- Date: 2013
- Subjects: Friction welding
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9635 , http://hdl.handle.net/10948/d1020116
- Description: The remnant life monitoring of creep loaded high temperature and pressure components in power stations is critical to ensuring their safe and cost effective operation as failures can have severe consequences. Effective creep life condition monitoring allows for optimising component life predictions and subsequent plant maintenance decisions. In South Africa many power generation stations have been in operation well beyond their 30 year design service life, as such knowledge of the remnant creep life of high temperature and pressure components, such as steam pipelines, becomes of utmost importance. Techniques for the remnant creep life assessments of critical high temperature and pressure components must therefore be as effective as possible. The common and well accepted in-situ inspection technique for assessing creep damage in steam pipes is by the metallographic replication technique. The technique is however limited to the outer surface of the pipe, without information on damage within the wall. This research will illustrate a means of obtaining a sample for creep life analysis with depth through the wall of a pipe, as wells as an alternative technique for the repair of the sample retrieval site. A sample retrieval technique was developed that would retrieve a small diameter cylindrical sample from a cored blind hole for creep analysis by visual creep void assessment or by the small punch creep test. The small punch creep test requires only a small diameter thin disc of material for testing for which its results are comparable with conventional uniaxial creep testing which requires a much larger sample of material. The smaller sample requirement of the small punch creep test therefore allows for a vastly reduced invasive sample retrieval operation and consequently smaller repair size area. Also the fact that the sample is retrieved from a blind hole is advantageous since the pipe wall is not penetrated which would require full plant shutdown. A friction welding technique was identified as an alternative to traditional arc fusion welding for the repair of the sample retrieval site, this technique being the Friction Hydro Pillar Processing technique. Friction Hydro Pillar Processing is a solid-state welding technique and as such has a number of inherent benefits over arc fusion welding as the weld is performed below the melting temperature of the material. From a process point of view Friction Hydro Pillar Processing is ideally suited for automation, has virtually no fumes generated, minimal distortion is experienced and no spatter has to be removed afterwards. The technique has yet to see industrial application and as such development of suitable process parameters was undertaken. Finally, to apply the sample retrieval and repair operations in-situ to a steam pipe in a power plant suitable equipment was developed. Existing friction welding equipment is generally bulky workshop based equipment and is unsuitable for on-site work due to its size and weight. Therefore development of dedicated equipment was required to enable Friction Hydro Pillar Processing to be applied to steam pipes within a power plant environment.
- Full Text:
- Date Issued: 2013
Development of a novel, quantitative assay for determining the rate of activity of antimalarial drugs
- Authors: Khan, Tasmiyah
- Date: 2013
- Subjects: Assay , ATP , Antimalarials -- Therapeutic use Malaria Malaria -- Drug therapy Adenosine triphosphate Luciferases Plasmodium falciparum
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3884 , http://hdl.handle.net/10962/d1001618
- Description: Malaria, caused by an intracellular Plasmodium parasite, remains a devastating disease, having claimed approximately 655 000 lives worldwide in 2010. The Medicines for Malaria Venture suggests a "single-dose radical cure" as the ideal malaria treatment since rapid clearance of blood-stage parasites and symptom relief improves patient compliance and limits drug resistance. Thus, novel antimalarials should be rapid-acting and assessing their rate of activity is critical to drug discovery. Traditional evaluation of this rate by morphological assessments is flawed by highly subjective, operator-specific interpretations, mainly due to heterogeneous parasite morphology under routine culture conditions. This study aimed to develop an alternative, quantitative assay. Energy is vital for the growth and maintenance of all living organisms. Commercially available kits allow rapid quantification of the cell's energy currency, ATP. Therefore, quantification of parasite ATP shows potential for diagnosing abnormal parasite metabolism and the kinetics of drug action. In this study, a rapid protocol for detecting ATP in Plasmodium falciparum parasites using a luminescence-based kit was developed and optimised. Furthermore, luciferase-expressing transgenic parasites, in which luciferase activity is detected using a similar kit, were acquired. The utility of both methods for evaluating the rate of drug-induced stress was explored using antimalarials with varying modes of action and, presumably, rates of activity. Results showed that parasite ATP remained unchanged, increased or decreased during drug exposure. Morphological examinations by light microscopy and a Recovery assay, aided interpretation of the drug-induced changes in parasite ATP. These investigations suggested that unchanged parasite ATP levels reflect poor drug action, increased ATP levels indicate a stress response and partially compromised viability, while significantly reduced ATP reflects severely compromised viability. Concerning the Luciferase assay, parasite luciferase activity decreased during drug exposure, even in the presence of proteasome inhibitors. Changes in parasite ATP and luciferase activity occurred at rates which suggested that chloroquine is slow-acting, mefloquine has a moderate rate of activity and artemisinin is rapid-acting. These findings are compatible with the expected rates of activity of these established antimalarials. Hence, measurement of parasite ATP and/or luciferase activity may support assessments of parasite health and the kinetics of antimalarial action during drug discovery
- Full Text:
- Date Issued: 2013
- Authors: Khan, Tasmiyah
- Date: 2013
- Subjects: Assay , ATP , Antimalarials -- Therapeutic use Malaria Malaria -- Drug therapy Adenosine triphosphate Luciferases Plasmodium falciparum
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3884 , http://hdl.handle.net/10962/d1001618
- Description: Malaria, caused by an intracellular Plasmodium parasite, remains a devastating disease, having claimed approximately 655 000 lives worldwide in 2010. The Medicines for Malaria Venture suggests a "single-dose radical cure" as the ideal malaria treatment since rapid clearance of blood-stage parasites and symptom relief improves patient compliance and limits drug resistance. Thus, novel antimalarials should be rapid-acting and assessing their rate of activity is critical to drug discovery. Traditional evaluation of this rate by morphological assessments is flawed by highly subjective, operator-specific interpretations, mainly due to heterogeneous parasite morphology under routine culture conditions. This study aimed to develop an alternative, quantitative assay. Energy is vital for the growth and maintenance of all living organisms. Commercially available kits allow rapid quantification of the cell's energy currency, ATP. Therefore, quantification of parasite ATP shows potential for diagnosing abnormal parasite metabolism and the kinetics of drug action. In this study, a rapid protocol for detecting ATP in Plasmodium falciparum parasites using a luminescence-based kit was developed and optimised. Furthermore, luciferase-expressing transgenic parasites, in which luciferase activity is detected using a similar kit, were acquired. The utility of both methods for evaluating the rate of drug-induced stress was explored using antimalarials with varying modes of action and, presumably, rates of activity. Results showed that parasite ATP remained unchanged, increased or decreased during drug exposure. Morphological examinations by light microscopy and a Recovery assay, aided interpretation of the drug-induced changes in parasite ATP. These investigations suggested that unchanged parasite ATP levels reflect poor drug action, increased ATP levels indicate a stress response and partially compromised viability, while significantly reduced ATP reflects severely compromised viability. Concerning the Luciferase assay, parasite luciferase activity decreased during drug exposure, even in the presence of proteasome inhibitors. Changes in parasite ATP and luciferase activity occurred at rates which suggested that chloroquine is slow-acting, mefloquine has a moderate rate of activity and artemisinin is rapid-acting. These findings are compatible with the expected rates of activity of these established antimalarials. Hence, measurement of parasite ATP and/or luciferase activity may support assessments of parasite health and the kinetics of antimalarial action during drug discovery
- Full Text:
- Date Issued: 2013
Development of thick section friction stir welding using a sliding tool shoulder
- Authors: Chetty, Shamalin
- Date: 2013
- Subjects: Friction welding
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9633 , http://hdl.handle.net/10948/d1015081
- Description: Sliding shoulder friction stir welding (SSFSW) is an alternative joining technique to the conventional friction stir welding process. The welding mechanism comprises of a rotating probe and a non-rotating shoulder. The shoulder therefore does not contribute to any heat generation or plastic deformation. When welding thicker section material, the contribution of heat generation from the shoulder becomes less significant and most of the heat and plastic deformation must be generated by the tool probe. For this reason it was decided to develop the process for thick section AA6082-T6. Due to the stationary (non-rotating) shoulder the weld track is smooth and there is no reduction in cross-sectional area. This research is based on the development of a sliding shoulder friction stir welding tool with the ability to create joints of up to 25mm thick on aluminium alloy 6082-T6 plate as well as the associated process development. The sliding shoulder friction stir welding tool was designed, manufactured and tested by initially performing partial penetration welds with various size tool probes and then finally by performing a sliding shoulder friction stir butt weld on 25mm thick plate. As welds were performed and more knowledge gained about the process, design modifications were made. These included varying the clearance between the tool probe and stationary shoulder; the profile of the shoulder which contributes to material flow during the process; and supporting the tool probe to prevent deflection when welding thicker sections at high forge forces. From the sliding shoulder friction stir welds performed, an understanding of material flow during the process was gained when analysing the macro-sections and exit holes of the welds. Typical process forces and torques associated with the process were measured to assist with future head unit and tool designs with regard to sliding shoulder friction stir welding.
- Full Text:
- Date Issued: 2013
- Authors: Chetty, Shamalin
- Date: 2013
- Subjects: Friction welding
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9633 , http://hdl.handle.net/10948/d1015081
- Description: Sliding shoulder friction stir welding (SSFSW) is an alternative joining technique to the conventional friction stir welding process. The welding mechanism comprises of a rotating probe and a non-rotating shoulder. The shoulder therefore does not contribute to any heat generation or plastic deformation. When welding thicker section material, the contribution of heat generation from the shoulder becomes less significant and most of the heat and plastic deformation must be generated by the tool probe. For this reason it was decided to develop the process for thick section AA6082-T6. Due to the stationary (non-rotating) shoulder the weld track is smooth and there is no reduction in cross-sectional area. This research is based on the development of a sliding shoulder friction stir welding tool with the ability to create joints of up to 25mm thick on aluminium alloy 6082-T6 plate as well as the associated process development. The sliding shoulder friction stir welding tool was designed, manufactured and tested by initially performing partial penetration welds with various size tool probes and then finally by performing a sliding shoulder friction stir butt weld on 25mm thick plate. As welds were performed and more knowledge gained about the process, design modifications were made. These included varying the clearance between the tool probe and stationary shoulder; the profile of the shoulder which contributes to material flow during the process; and supporting the tool probe to prevent deflection when welding thicker sections at high forge forces. From the sliding shoulder friction stir welds performed, an understanding of material flow during the process was gained when analysing the macro-sections and exit holes of the welds. Typical process forces and torques associated with the process were measured to assist with future head unit and tool designs with regard to sliding shoulder friction stir welding.
- Full Text:
- Date Issued: 2013
Diet and foraging distribution of gentoo penguins pygoscelis papua at Cow Bay, Falkland Islands
- Authors: Handley, Jonathan Murray
- Date: 2013
- Subjects: Gentoo penguin -- Food -- Falkland Islands
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10724 , http://hdl.handle.net/10948/d1020377
- Description: Knowledge of diet and distribution in marine top predators is critical in interpreting their ecological role. Furthermore, this information is required for effective management and conservation of these species. For gentoo penguins at the Falkland Islands a previous overlap in dietary items with commercial fisheries was recognised. Despite this the at-sea distribution has been poorly studied and only at a few localities. Therefore, this thesis looks to broaden the knowledge of foraging ecology for gentoo penguins at another site in the archipelago, Cow Bay. The aim was firstly, through stomach content analysis, to determine if diet changed over a large temporal scale (2002/03/04 – 2011/12/13), and between the chick guard and crèche periods of chick rearing. Secondly, through GPS loggers, to assess distribution at sea during the incubation and chick guard periods (2012/13). Additionally, foraging ecology between genders was investigated. Gentoo penguins at Cow Bay foraged primarily on fish (66-99 percent) throughout the entire study period. The principle prey item by mass was Patagonotothen spp., considered previously as discard by fisheries but now an important commercial resource, for all periods (47-78 percent) except that of the 2012/13 crèche period (19 percent). During this period Sprattus fugensis made up the bulk of the diet (52 percent). Cephalopods, particularly Loligo gahi (1-24 percent), were also prominent in the diet and crustaceans contributed negligibly. The diet indicated that gentoo penguins are capable of both a benthic and pelagic feeding strategy which likely reflects changes in local prey abundance. Birds typically conducted foraging activities during daylight hours with greater trip duration, path length, maximum distance and area utilised during the incubation period than the guard. All trips were confined to the continental shelf and within the boundaries of a marine management zone, the Falkland Islands Interim Conservation Zone (FICZ). Males and females fed on the same size and composition of prey items. Trip duration, path length and maximum distance from the colony were not significantly different, although males foraged in a slightly larger area than females marginally to the north. As at-sea distribution was confined within the FICZ this management area provides protection to food resources of gentoo penguins breeding at Cow Bay. At this site, the population is increasing, likely associated with increased prey availability as evidenced by record catches of Patagonotothen spp. in recent years at the Falkland Islands. Continued long term monitoring of gentoo penguin diet and fishery yields to allow detection of possible competition in the future is recommended. As marine sentinels, on-going monitoring of gentoo penguin populations at the Falkland Islands is likely to provide early warning signs of reduced prey availability.
- Full Text:
- Date Issued: 2013
- Authors: Handley, Jonathan Murray
- Date: 2013
- Subjects: Gentoo penguin -- Food -- Falkland Islands
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10724 , http://hdl.handle.net/10948/d1020377
- Description: Knowledge of diet and distribution in marine top predators is critical in interpreting their ecological role. Furthermore, this information is required for effective management and conservation of these species. For gentoo penguins at the Falkland Islands a previous overlap in dietary items with commercial fisheries was recognised. Despite this the at-sea distribution has been poorly studied and only at a few localities. Therefore, this thesis looks to broaden the knowledge of foraging ecology for gentoo penguins at another site in the archipelago, Cow Bay. The aim was firstly, through stomach content analysis, to determine if diet changed over a large temporal scale (2002/03/04 – 2011/12/13), and between the chick guard and crèche periods of chick rearing. Secondly, through GPS loggers, to assess distribution at sea during the incubation and chick guard periods (2012/13). Additionally, foraging ecology between genders was investigated. Gentoo penguins at Cow Bay foraged primarily on fish (66-99 percent) throughout the entire study period. The principle prey item by mass was Patagonotothen spp., considered previously as discard by fisheries but now an important commercial resource, for all periods (47-78 percent) except that of the 2012/13 crèche period (19 percent). During this period Sprattus fugensis made up the bulk of the diet (52 percent). Cephalopods, particularly Loligo gahi (1-24 percent), were also prominent in the diet and crustaceans contributed negligibly. The diet indicated that gentoo penguins are capable of both a benthic and pelagic feeding strategy which likely reflects changes in local prey abundance. Birds typically conducted foraging activities during daylight hours with greater trip duration, path length, maximum distance and area utilised during the incubation period than the guard. All trips were confined to the continental shelf and within the boundaries of a marine management zone, the Falkland Islands Interim Conservation Zone (FICZ). Males and females fed on the same size and composition of prey items. Trip duration, path length and maximum distance from the colony were not significantly different, although males foraged in a slightly larger area than females marginally to the north. As at-sea distribution was confined within the FICZ this management area provides protection to food resources of gentoo penguins breeding at Cow Bay. At this site, the population is increasing, likely associated with increased prey availability as evidenced by record catches of Patagonotothen spp. in recent years at the Falkland Islands. Continued long term monitoring of gentoo penguin diet and fishery yields to allow detection of possible competition in the future is recommended. As marine sentinels, on-going monitoring of gentoo penguin populations at the Falkland Islands is likely to provide early warning signs of reduced prey availability.
- Full Text:
- Date Issued: 2013
Digital multimedia network with latency control
- Gurdan, Robby, Foss, Richard
- Authors: Gurdan, Robby , Foss, Richard
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427043 , vital:72410 , https://patentimages.storage.googleapis.com/59/e3/43/6b49b528623ea3/US8477812.pdf
- Description: The present invention relates to a digital multimedia network 1 with latency control comprising apparatuses for processing of data streams, wherein a borderline input apparatus providing a data stream generates a latency time stamp (LTS) which contains an absolute time indicating a creation time of said data stream and an accumulated delay time which is updated by each apparatus processing said data stream, wherein said latency time stamp (LTS) of said data stream is evaluated by a borderline output apparatus of said network which synchronizes said data stream.
- Full Text:
- Date Issued: 2013
- Authors: Gurdan, Robby , Foss, Richard
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427043 , vital:72410 , https://patentimages.storage.googleapis.com/59/e3/43/6b49b528623ea3/US8477812.pdf
- Description: The present invention relates to a digital multimedia network 1 with latency control comprising apparatuses for processing of data streams, wherein a borderline input apparatus providing a data stream generates a latency time stamp (LTS) which contains an absolute time indicating a creation time of said data stream and an accumulated delay time which is updated by each apparatus processing said data stream, wherein said latency time stamp (LTS) of said data stream is evaluated by a borderline output apparatus of said network which synchronizes said data stream.
- Full Text:
- Date Issued: 2013
Disaster risk reduction in Namibia (flooding): responses and best practices
- Authors: Van der Ross, Nolan Lloyd
- Date: 2013
- Subjects: Flood damage prevention -- Risk assessment , delete
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9241 , http://hdl.handle.net/10948/d1021114
- Description: This study was undertaken in order to obtain an understanding of how Namibia in general, and the education sector in particular, deal with flood emergencies. The goal of the National Policy for Disaster Risk Management in Namibia (2009) is “to contribute to the attainment of sustainable development in line with Namibia’s Vision 2030 through strengthening national capacities to significantly reduce disaster risk and built community resilience to disasters” (Republic of Namibia, 2009). This goal was the starting point for determining the extent to which the Ministry of Education complies with these national standards, and for gauging, in the light of responses to flood emergencies so far, the Ministry’s preparedness and response capacities, in line with international frameworks that Namibia has ratified. This qualitative study is situated within the theory of resilience, and sustainable resilience particularly. To obtain some of the information sought, a non-probability sampling method was used to ‘hand-pick’ subjects within the Ministry of Education to be interviewed at their respective locations, nationally and regionally. Five education officials who were intimately involved in past responses to flood emergencies were interviewed – three in Oshana and Ohangwena Regions, and two at Head Office in Windhoek – by means of a semi-structured interview. In addition, a literature review was conducted. The conclusions drawn from both the literature review and the information obtained from the respondents accord with the research problem identified: the Ministry of Education does not appear to be adequately prepared for, and does not assign the necessary priority to deal with, flood emergencies in particular. Possible recommendations for uptake within the Ministry of Education include: mainstreaming Disaster Risk Reduction at all decentralized levels; sensitizing all education officials, school community members and relevant stakeholders to policy frameworks and accountability structures to strengthen resilience within school communities; deeming costed contingency planning a priority, and hence strengthening links between decentralized regional structures; and continuously monitoring implementation of designed interventions.
- Full Text:
- Date Issued: 2013
- Authors: Van der Ross, Nolan Lloyd
- Date: 2013
- Subjects: Flood damage prevention -- Risk assessment , delete
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9241 , http://hdl.handle.net/10948/d1021114
- Description: This study was undertaken in order to obtain an understanding of how Namibia in general, and the education sector in particular, deal with flood emergencies. The goal of the National Policy for Disaster Risk Management in Namibia (2009) is “to contribute to the attainment of sustainable development in line with Namibia’s Vision 2030 through strengthening national capacities to significantly reduce disaster risk and built community resilience to disasters” (Republic of Namibia, 2009). This goal was the starting point for determining the extent to which the Ministry of Education complies with these national standards, and for gauging, in the light of responses to flood emergencies so far, the Ministry’s preparedness and response capacities, in line with international frameworks that Namibia has ratified. This qualitative study is situated within the theory of resilience, and sustainable resilience particularly. To obtain some of the information sought, a non-probability sampling method was used to ‘hand-pick’ subjects within the Ministry of Education to be interviewed at their respective locations, nationally and regionally. Five education officials who were intimately involved in past responses to flood emergencies were interviewed – three in Oshana and Ohangwena Regions, and two at Head Office in Windhoek – by means of a semi-structured interview. In addition, a literature review was conducted. The conclusions drawn from both the literature review and the information obtained from the respondents accord with the research problem identified: the Ministry of Education does not appear to be adequately prepared for, and does not assign the necessary priority to deal with, flood emergencies in particular. Possible recommendations for uptake within the Ministry of Education include: mainstreaming Disaster Risk Reduction at all decentralized levels; sensitizing all education officials, school community members and relevant stakeholders to policy frameworks and accountability structures to strengthen resilience within school communities; deeming costed contingency planning a priority, and hence strengthening links between decentralized regional structures; and continuously monitoring implementation of designed interventions.
- Full Text:
- Date Issued: 2013