Factors that influence warranty costs at Volkswagen South Africa
- Authors: Blignaut, Bevan Hyron
- Date: 2013
- Subjects: Warranty , Automobile industry and trade -- South Africa , Total quality management , Quality assurance
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8944 , http://hdl.handle.net/10948/d1013088
- Description: Driving a vehicle while it is within the warranty period provide customers with assurance that should a failure occur on the vehicle, there would be no financial obligation for the customer to repair the vehicle. For the manufacturer, it is a huge financial obligation to repair or replace components that fail on the vehicle. The research conducted in this study explores and identifies the main reasons for high warranty costs as well as the reasons that do not influence high warranty costs at VWSA. The purpose of this research is to provide VWSA with a potential starting point to reduce warranty costs and increase profits. The study revealed that the main cause of high warranty costs at VWSA was related to the quality of vehicles. By improving the quality of vehicles produced, VWSA could reduce a significant portion of the warranty costs it spends each year. With reduced warranty costs, VWSA could increase the warranty period and thereby attract more customers to purchase VW products. In a cutthroat automotive industry, this would ensure a competitive advantage over rivals; maintain longevity, increase profits and continued success.
- Full Text:
- Date Issued: 2013
- Authors: Blignaut, Bevan Hyron
- Date: 2013
- Subjects: Warranty , Automobile industry and trade -- South Africa , Total quality management , Quality assurance
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8944 , http://hdl.handle.net/10948/d1013088
- Description: Driving a vehicle while it is within the warranty period provide customers with assurance that should a failure occur on the vehicle, there would be no financial obligation for the customer to repair the vehicle. For the manufacturer, it is a huge financial obligation to repair or replace components that fail on the vehicle. The research conducted in this study explores and identifies the main reasons for high warranty costs as well as the reasons that do not influence high warranty costs at VWSA. The purpose of this research is to provide VWSA with a potential starting point to reduce warranty costs and increase profits. The study revealed that the main cause of high warranty costs at VWSA was related to the quality of vehicles. By improving the quality of vehicles produced, VWSA could reduce a significant portion of the warranty costs it spends each year. With reduced warranty costs, VWSA could increase the warranty period and thereby attract more customers to purchase VW products. In a cutthroat automotive industry, this would ensure a competitive advantage over rivals; maintain longevity, increase profits and continued success.
- 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
Wireless mobile android technology in the monitoring and control of a safety integrated robotic cell
- Authors: Cumberlege, Aidan
- Date: 2013
- Subjects: Android (Electronic resource) , Application software -- Development , Computer software -- Development , Mobile computing
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/46284 , vital:39543
- Description: The constant strive for improving the efficiency of production processes has become a worldwide challenge. In high speed production facilities response time between man and machine is of utmost importance when financial implications are taken into account. This dissertation contributes to improving the response time by making use of wireless notification between the machine and the maintenance technician when process faults occur. The tool used to achieve this is based on Android. Research is carried out on the latest Android technology while taking the safety aspects of a production environment into consideration. Research in designing a rule based intelligent system is established by using a tablet as the user interface for automatic notification and corrective action recommendations. Quick response is achieved by setting up a wireless network. As a result of designing a wireless intelligent maintenance tool, production downtime is improved. Management can recall all activities logged by the system for graphical representation.
- Full Text:
- Date Issued: 2013
Wireless mobile android technology in the monitoring and control of a safety integrated robotic cell
- Authors: Cumberlege, Aidan
- Date: 2013
- Subjects: Android (Electronic resource) , Application software -- Development , Computer software -- Development , Mobile computing
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/46284 , vital:39543
- Description: The constant strive for improving the efficiency of production processes has become a worldwide challenge. In high speed production facilities response time between man and machine is of utmost importance when financial implications are taken into account. This dissertation contributes to improving the response time by making use of wireless notification between the machine and the maintenance technician when process faults occur. The tool used to achieve this is based on Android. Research is carried out on the latest Android technology while taking the safety aspects of a production environment into consideration. Research in designing a rule based intelligent system is established by using a tablet as the user interface for automatic notification and corrective action recommendations. Quick response is achieved by setting up a wireless network. As a result of designing a wireless intelligent maintenance tool, production downtime is improved. Management can recall all activities logged by the system for graphical representation.
- Full Text:
- Date Issued: 2013
The influence of student engagement on the academic success of first-year human resource management diploma students
- Authors: De Villiers, Bridget
- Date: 2013
- Subjects: Academic achievement -- South Africa , College freshmen -- South Africa -- Attitudes , Universities and colleges -- Curricula -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9391 , http://hdl.handle.net/10948/d1020792
- Description: Student success rates in South African higher education institutions are unacceptable. There are many contextual challenges facing these institutions, some as a result of the legacy of the apartheid educational system and some related to the challenges surrounding increased access to higher education. The impact in terms of the costs associated with re-educating students and the added pressure of readmitting failed students into continually growing classes, are substantial. In addition, there is a growing contention that the level of preparedness of students is declining. All of these challenges place immense pressure on academics to support students and ensure acceptable pass rates. There are numerous factors, both academic and non-academic, which have an influence on academic success including prior academic achievement, the academic experience, institutional expectations and commitment, finances, family support and university support services. Many factors are beyond the control of higher education. Student engagement, however, appears to be one factor over which educators have some control. Student engagement may be defined as student involvement in educationally purposive activities. For the purposes of this study two main factors contributing to student engagement were explored. Firstly, the amount of time and effort that the student spends on academic and other activities that lead to experiences and outcomes that constitute academic success. This factor was termed “student behaviours”. Secondly, the ways in which the institution allocates resources and organises learning opportunities and services in such a way as to induce the student to participate in and benefit from these activities. This factor was termed “institutional conditions”. The main research problem of this study was to determine the influence of student engagement on the academic success of first-year Human Resource Management (HRM) students at Nelson Mandela Metropolitan University. The main research problem had five sub-problems which were addressed through the following actions: A literature study was conducted, highlighting the challenges faced in higher education, building a case for student engagement and identifying the factors that contribute towards student engagement, more specifically the student behaviours and institutional conditions. Semi-structured interviews were also conducted with staff members lecturing first-year HRM diploma students at NMMU, with students registered as second- and third-year HRM diploma students, and with a staff member of the Centre for Teaching, Learning and Media (CTLM) at NMMU, to obtain their views on the nature of student engagement and its impact on academic success, as well as the student behaviours and institutional conditions that contribute towards student engagement. The insights gained from the literature survey and the interviews were incorporated into a survey questionnaire which was developed for use in the empirical study to identify the existence and levels of the student behaviours and perceived institutional conditions that contributed towards student engagement among HRM diploma students who were in their first year of study at NMMU in 2012. The final year marks achieved by these HRM diploma students in their first year of study were obtained and correlated with the levels of engagement identified as part of the empirical study. The results of the study revealed that the respondents demonstrated a fair range of the student behaviours which are conducive to promoting student engagement. Their perception of the existence of institutional conditions conducive to promoting student engagement was good. The results also revealed a significant positive correlation between the average final year mark and “student-staff interaction” for both student behaviours and institutional conditions. A significant relationship was revealed between student behaviours and institutional conditions related to “academic focus”, “student-staff interaction” and “social integration”. In exploring the relationship between selected demographic variables and academic success, living arrangements emerged as an important consideration in promoting academic success as all the respondents who failed, lived far from the university. First generation learners were found not to achieve the levels of success of their peers who have had exposure to family members and significant others with tertiary experience. Overall the importance of good relationships between students and staff in promoting engagement and ensuring academic success emerged as an important factor. The importance of improving student success rates should be of paramount importance to all educators. The factors contributing towards student success are numerous and vast. Educators who understand the nature of student engagement and are aware of the student behaviours and institutional conditions that can be promoted in the higher education setting to improve engagement could become more effective in improving student success rates. Their efforts could be further enhanced if students are made aware of how their behaviour, understanding and utilisation of the resources, learning opportunities and services provided by the institution, can positively influence their academic success.
- Full Text:
- Date Issued: 2013
- Authors: De Villiers, Bridget
- Date: 2013
- Subjects: Academic achievement -- South Africa , College freshmen -- South Africa -- Attitudes , Universities and colleges -- Curricula -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9391 , http://hdl.handle.net/10948/d1020792
- Description: Student success rates in South African higher education institutions are unacceptable. There are many contextual challenges facing these institutions, some as a result of the legacy of the apartheid educational system and some related to the challenges surrounding increased access to higher education. The impact in terms of the costs associated with re-educating students and the added pressure of readmitting failed students into continually growing classes, are substantial. In addition, there is a growing contention that the level of preparedness of students is declining. All of these challenges place immense pressure on academics to support students and ensure acceptable pass rates. There are numerous factors, both academic and non-academic, which have an influence on academic success including prior academic achievement, the academic experience, institutional expectations and commitment, finances, family support and university support services. Many factors are beyond the control of higher education. Student engagement, however, appears to be one factor over which educators have some control. Student engagement may be defined as student involvement in educationally purposive activities. For the purposes of this study two main factors contributing to student engagement were explored. Firstly, the amount of time and effort that the student spends on academic and other activities that lead to experiences and outcomes that constitute academic success. This factor was termed “student behaviours”. Secondly, the ways in which the institution allocates resources and organises learning opportunities and services in such a way as to induce the student to participate in and benefit from these activities. This factor was termed “institutional conditions”. The main research problem of this study was to determine the influence of student engagement on the academic success of first-year Human Resource Management (HRM) students at Nelson Mandela Metropolitan University. The main research problem had five sub-problems which were addressed through the following actions: A literature study was conducted, highlighting the challenges faced in higher education, building a case for student engagement and identifying the factors that contribute towards student engagement, more specifically the student behaviours and institutional conditions. Semi-structured interviews were also conducted with staff members lecturing first-year HRM diploma students at NMMU, with students registered as second- and third-year HRM diploma students, and with a staff member of the Centre for Teaching, Learning and Media (CTLM) at NMMU, to obtain their views on the nature of student engagement and its impact on academic success, as well as the student behaviours and institutional conditions that contribute towards student engagement. The insights gained from the literature survey and the interviews were incorporated into a survey questionnaire which was developed for use in the empirical study to identify the existence and levels of the student behaviours and perceived institutional conditions that contributed towards student engagement among HRM diploma students who were in their first year of study at NMMU in 2012. The final year marks achieved by these HRM diploma students in their first year of study were obtained and correlated with the levels of engagement identified as part of the empirical study. The results of the study revealed that the respondents demonstrated a fair range of the student behaviours which are conducive to promoting student engagement. Their perception of the existence of institutional conditions conducive to promoting student engagement was good. The results also revealed a significant positive correlation between the average final year mark and “student-staff interaction” for both student behaviours and institutional conditions. A significant relationship was revealed between student behaviours and institutional conditions related to “academic focus”, “student-staff interaction” and “social integration”. In exploring the relationship between selected demographic variables and academic success, living arrangements emerged as an important consideration in promoting academic success as all the respondents who failed, lived far from the university. First generation learners were found not to achieve the levels of success of their peers who have had exposure to family members and significant others with tertiary experience. Overall the importance of good relationships between students and staff in promoting engagement and ensuring academic success emerged as an important factor. The importance of improving student success rates should be of paramount importance to all educators. The factors contributing towards student success are numerous and vast. Educators who understand the nature of student engagement and are aware of the student behaviours and institutional conditions that can be promoted in the higher education setting to improve engagement could become more effective in improving student success rates. Their efforts could be further enhanced if students are made aware of how their behaviour, understanding and utilisation of the resources, learning opportunities and services provided by the institution, can positively influence their academic success.
- Full Text:
- Date Issued: 2013
Propagating some commonly-used South African medicinal plants with compost and vermitea
- Authors: Faulconbridge, Steven Craig
- Date: 2013
- Subjects: Medicinal plants -- Propagation -- South Africa , Compost -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10736 , http://hdl.handle.net/10948/d1020316
- Description: The use of many of South Africa’s medicinal plants has shown marked increase with over 27 million users in South Africa alone. Most plants are still being unsustainably wild-harvested, a major concern for biodiversity conservation. Commercial interest in certain more commonly-used species has increased, with potential to cultivate medicinal plants on a more sustainable basis. Focus has shifted from conventional use of synthetic fertilisers, pesticides and fungicides to more organic methods of plant propagation. Aqueous extract derived from earthworm composted food waste (vermitea) was used to study the germination and rooting success of selected species. Also survival and growth performance of selected plants grown in a medium amended with commercial NPK fertiliser was compared to those grown in the same medium amended with compost and to those grown in the same medium amended with compost with weekly applications of vermitea. No change in germination success was noted. Vermitea showed promising results on the rooting of cuttings. The application of NPK improved growth performance (biomass) significantly for all species tested. However, they had lower root:shoot ratios as well as lower survival rates compared to plants under the compost and compost/vermitea treatments. The improved survival of these plants highlights the potential of these organic treatments on the propagation of selected medicinal plants.
- Full Text:
- Date Issued: 2013
- Authors: Faulconbridge, Steven Craig
- Date: 2013
- Subjects: Medicinal plants -- Propagation -- South Africa , Compost -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10736 , http://hdl.handle.net/10948/d1020316
- Description: The use of many of South Africa’s medicinal plants has shown marked increase with over 27 million users in South Africa alone. Most plants are still being unsustainably wild-harvested, a major concern for biodiversity conservation. Commercial interest in certain more commonly-used species has increased, with potential to cultivate medicinal plants on a more sustainable basis. Focus has shifted from conventional use of synthetic fertilisers, pesticides and fungicides to more organic methods of plant propagation. Aqueous extract derived from earthworm composted food waste (vermitea) was used to study the germination and rooting success of selected species. Also survival and growth performance of selected plants grown in a medium amended with commercial NPK fertiliser was compared to those grown in the same medium amended with compost and to those grown in the same medium amended with compost with weekly applications of vermitea. No change in germination success was noted. Vermitea showed promising results on the rooting of cuttings. The application of NPK improved growth performance (biomass) significantly for all species tested. However, they had lower root:shoot ratios as well as lower survival rates compared to plants under the compost and compost/vermitea treatments. The improved survival of these plants highlights the potential of these organic treatments on the propagation of selected medicinal plants.
- 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
A framework to mitigate phishing threats
- Authors: Frauenstein, Edwin Donald
- Date: 2013
- Subjects: Computer networks -- Security measures , Mobile computing -- Security measures , Online social networks -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9832 , http://hdl.handle.net/10948/d1021208
- Description: We live today in the information age with users being able to access and share information freely by using both personal computers and their handheld devices. This, in turn, has been made possible by the Internet. However, this poses security risks as attempts are made to use this same environment in order to compromise the confidentiality, integrity and availability of information. Accordingly, there is an urgent need for users and organisations to protect their information resources from agents posing a security threat. Organisations typically spend large amounts of money as well as dedicating resources to improve their technological defences against general security threats. However, the agents posing these threats are adopting social engineering techniques in order to bypass the technical measures which organisations are putting in place. These social engineering techniques are often effective because they target human behaviour, something which the majority of researchers believe is a far easier alternative than hacking information systems. As such, phishing effectively makes use of a combination of social engineering techniques which involve crafty technical emails and website designs which gain the trust of their victims. Within an organisational context, there are a number of areas which phishers exploit. These areas include human factors, organisational aspects and technological controls. Ironically, these same areas serve simultaneously as security measures against phishing attacks. However, each of these three areas mentioned above are characterised by gaps which arise as a result of human involvement. As a result, the current approach to mitigating phishing threats comprises a single-layer defence model only. However, this study proposes a holistic model which integrates each of these three areas by strengthening the human element in each of these areas by means of a security awareness, training and education programme.
- Full Text:
- Date Issued: 2013
- Authors: Frauenstein, Edwin Donald
- Date: 2013
- Subjects: Computer networks -- Security measures , Mobile computing -- Security measures , Online social networks -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9832 , http://hdl.handle.net/10948/d1021208
- Description: We live today in the information age with users being able to access and share information freely by using both personal computers and their handheld devices. This, in turn, has been made possible by the Internet. However, this poses security risks as attempts are made to use this same environment in order to compromise the confidentiality, integrity and availability of information. Accordingly, there is an urgent need for users and organisations to protect their information resources from agents posing a security threat. Organisations typically spend large amounts of money as well as dedicating resources to improve their technological defences against general security threats. However, the agents posing these threats are adopting social engineering techniques in order to bypass the technical measures which organisations are putting in place. These social engineering techniques are often effective because they target human behaviour, something which the majority of researchers believe is a far easier alternative than hacking information systems. As such, phishing effectively makes use of a combination of social engineering techniques which involve crafty technical emails and website designs which gain the trust of their victims. Within an organisational context, there are a number of areas which phishers exploit. These areas include human factors, organisational aspects and technological controls. Ironically, these same areas serve simultaneously as security measures against phishing attacks. However, each of these three areas mentioned above are characterised by gaps which arise as a result of human involvement. As a result, the current approach to mitigating phishing threats comprises a single-layer defence model only. However, this study proposes a holistic model which integrates each of these three areas by strengthening the human element in each of these areas by means of a security awareness, training and education programme.
- Full Text:
- Date Issued: 2013
Online marketing of commercial and industrial properties and services in a small business
- Jansen van Rensburg, Charmaine
- Authors: Jansen van Rensburg, Charmaine
- Date: 2013
- Subjects: Internet marketing , Real estate management -- South Africa -- Marketing , Online information services -- Marketing , Business planning
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9328 , http://hdl.handle.net/10948/d1020988
- Description: In view of the factors influencing and the steps in the design of a Website, building a successful Website will vary from business to business. This study investigates what is required from a small commercial and industrial property and services business to take their business online and create an effective Website. The environment of the property market reflected the role that government plays in the property industry and also the role of the private sector. Marketing in the real estate context indicated that if real estate agents have access to the right type of information, not only can they add value to their own organizations, but they can also capitalize on the same information to create added value for their clients. The elements of the marketing management process include four steps, namely to gather information, to set marketing goals and plan strategy, to organize and implement marketing strategy and to control the marketing activities. Marketing in the online environment showed that the Marketing Mix includes personalisation, privacy, customer services, community, site, security and sales promotion. The principles of online marketing revealed the important role of the customer and customer relationships. An investigation into the difference between e-commerce and online marketing made it clear that online marketing is one component of e-commerce. This study critically analysed the available literature in order to suggest a proposed framework of what should be included in the Website of a small commercial and industrial property and services business. In order to successfully research online marketing of commercial and industrial properties and services in a small business, a basic but thorough understanding of online marketing principles and Website content are important. In this study a qualitative research approach was followed where secondary sources were critically evaluated to design the required framework. Thereafter three Websites of marketing of commercial and industrial properties and services were content analysed to see whether anything else should be added to the framework. This would assist in taking a small business in commercial and industrial properties and services online. The framework suggests that the Website homepage content should include: Business overview/information Products/services What’s new Search Employment opportunities Interactive feedback Customer service/ assistance Index/directory Financial facts Links to other sites Online business services/utilities Guest book Frequently Asked Questions Messages from CEO A purposeful sample of three Websites was then content analysed so as to provide the information necessary to reach the objectives of the study. The following Websites were included in the content analysis: Broll, which operates as a national agency with international associations. The firm renders services (Estate Agency) and does not own property. Bruce McWilliams Industries Pty Ltd is operative in Port Elizabeth, Uitenhage and surrounds. It is a family business that owns property, which it develops and markets itself. Seeff is a national agency. It renders services (estate agency) and does not own property. Lastly, a narrative of a small commercial and industrial property and services business was created by means of document analysis of a specific business. The researcher was allowed to study the documents and diaries of the business in order to provide a narrative for this business. This narrative can be used as part of the envisaged Website for the business.
- Full Text:
- Date Issued: 2013
- Authors: Jansen van Rensburg, Charmaine
- Date: 2013
- Subjects: Internet marketing , Real estate management -- South Africa -- Marketing , Online information services -- Marketing , Business planning
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9328 , http://hdl.handle.net/10948/d1020988
- Description: In view of the factors influencing and the steps in the design of a Website, building a successful Website will vary from business to business. This study investigates what is required from a small commercial and industrial property and services business to take their business online and create an effective Website. The environment of the property market reflected the role that government plays in the property industry and also the role of the private sector. Marketing in the real estate context indicated that if real estate agents have access to the right type of information, not only can they add value to their own organizations, but they can also capitalize on the same information to create added value for their clients. The elements of the marketing management process include four steps, namely to gather information, to set marketing goals and plan strategy, to organize and implement marketing strategy and to control the marketing activities. Marketing in the online environment showed that the Marketing Mix includes personalisation, privacy, customer services, community, site, security and sales promotion. The principles of online marketing revealed the important role of the customer and customer relationships. An investigation into the difference between e-commerce and online marketing made it clear that online marketing is one component of e-commerce. This study critically analysed the available literature in order to suggest a proposed framework of what should be included in the Website of a small commercial and industrial property and services business. In order to successfully research online marketing of commercial and industrial properties and services in a small business, a basic but thorough understanding of online marketing principles and Website content are important. In this study a qualitative research approach was followed where secondary sources were critically evaluated to design the required framework. Thereafter three Websites of marketing of commercial and industrial properties and services were content analysed to see whether anything else should be added to the framework. This would assist in taking a small business in commercial and industrial properties and services online. The framework suggests that the Website homepage content should include: Business overview/information Products/services What’s new Search Employment opportunities Interactive feedback Customer service/ assistance Index/directory Financial facts Links to other sites Online business services/utilities Guest book Frequently Asked Questions Messages from CEO A purposeful sample of three Websites was then content analysed so as to provide the information necessary to reach the objectives of the study. The following Websites were included in the content analysis: Broll, which operates as a national agency with international associations. The firm renders services (Estate Agency) and does not own property. Bruce McWilliams Industries Pty Ltd is operative in Port Elizabeth, Uitenhage and surrounds. It is a family business that owns property, which it develops and markets itself. Seeff is a national agency. It renders services (estate agency) and does not own property. Lastly, a narrative of a small commercial and industrial property and services business was created by means of document analysis of a specific business. The researcher was allowed to study the documents and diaries of the business in order to provide a narrative for this business. This narrative can be used as part of the envisaged Website for the business.
- Full Text:
- Date Issued: 2013
Biological activities of medical plants traditionally used in the Eastern Cape to treat pneumonia
- Kamanga, Melvin Chalochapasi
- Authors: Kamanga, Melvin Chalochapasi
- Date: 2013
- Subjects: Communicable diseases -- Eastern Cape , Medicinal plants -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10124 , http://hdl.handle.net/10948/d1020051
- Description: Infectious diseases such as pneumonia still pose a major global health concern. Currently, the world is facing widespread emergence of acquired bacterial resistance to antibiotics which constitute one of the chief causes of infectious diseases. The accumulation of different antibiotic resistance mechanisms within the same strains has induced the appearance of the so called “superbugs”, or “multiple-drug resistant bacteria”. Due to antibiotic resistance, attention is currently being drawn towards biologically active components isolated from plant species commonly used as herbal medicine, as they may offer a new source of antibacterial, antifungal and antiviral activities. This is the basis of this study. In this study four medicinal plants namely, Cassia abbreviata, Geranium incanum, Pelargonium hortorum and Tecoma capensis were investigated for their antimicrobial potential. In vitro antimicrobial activity using agar disc diffusion method, agar dilution method and broth microdilution plate determination of minimum inhibitory concentration (MIC), were carried out against ATCC (American Type Culture Collection) strains and clinical isolates known to cause pneumonia. Aqueous, methanol and acetone extracts from the selected plants were thus tested against strains of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli and Candida albicans. The plants exhibited pronounced antimicrobial activity and were more active against Gram-positive bacteria than Gram-negative bacteria. During agar disc diffusion method, the highest inhibition zone was demonstrated by the acetone extract of P. hortorum (IZ=22mm and AI=0.73) against the reference strain of S. pneumoniae (ATCC 49619). The range of zones of inhibition in diameter across strains of S. pneumoniae and H. influenzae was 7mm to 22mm with activity index range of 0.23 to 0.74. The lowest MIC produced by medicinal plants in the study during agar disc diffusion method against S. pneumoniae and H. influenzae strains, was 2.5mg/ml. In broth microdilution plate assay, the lowest MIC demonstrated by C. abbreviata, T. capensis and P. hortorum extracts on tested bacteria was 0.031mg/ml and that of G. incanum was 0.063mg/ml. Candida albicans strains were only inhibited at 20mg/ml by the study plants. The highest activity among the individual extracts was shown by P. hortorum methanol extract which inhibited 71% of the studied bacteria. T. capensis methanol extract was the least and inhibited only 17% of the tested bacteria. The strains of Klebsiella pneumoniae showed the highest resistance to medicinal plants employed in this study. Traditional preparation of selected medicinal plants did not show any significant antimicrobial activity. Bioactive analysis of compounds on study plants was carried out using standard methods which revealed the presence of anthraquinones, flavonoids, phytosterol, saponins, tannins and triterpenoids. Comparison of the inhibitory effect of the plant extracts against some broad spectrum antibiotics revealed that the tested medicinal plants showed greater antimicrobial activity than standard antibiotics. However, there was no correlation between the antibiotic susceptibility patterns of the bacteria and the effects of the plants, signifying that plants probably function through different mechanisms. Bioautographic findings on thin-layer chromatography plate, exhibited clear zones of inhibition of bacterial growth with the Rf value range of 0.09 to 0.94. Anti-mutagenic activity was assayed by the Ames mutagenicity test in the plate-incorporation method using histidine mutants of S. typhimurium strains TA 100. The selected plant extracts at 2.5mg/ml and 5mg/ml did not induce mutagenesis in the absence of liver-metabolizing enzymes. The study results indicated that the selected plants are capable of inhibiting the growth of the studied pathogenic microorganisms to a varied degree. The leaves of G. incanum, P. hortorum, T. capensis as well as the stem bark of C. abbreviata could be novel sources of antimicrobial agents that might have broad spectrum activity. The anti-mutagenic properties of the studied medicinal plants may also provide additional health supplemental value to the other claimed therapeutic properties of the plants.
- Full Text:
- Date Issued: 2013
- Authors: Kamanga, Melvin Chalochapasi
- Date: 2013
- Subjects: Communicable diseases -- Eastern Cape , Medicinal plants -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10124 , http://hdl.handle.net/10948/d1020051
- Description: Infectious diseases such as pneumonia still pose a major global health concern. Currently, the world is facing widespread emergence of acquired bacterial resistance to antibiotics which constitute one of the chief causes of infectious diseases. The accumulation of different antibiotic resistance mechanisms within the same strains has induced the appearance of the so called “superbugs”, or “multiple-drug resistant bacteria”. Due to antibiotic resistance, attention is currently being drawn towards biologically active components isolated from plant species commonly used as herbal medicine, as they may offer a new source of antibacterial, antifungal and antiviral activities. This is the basis of this study. In this study four medicinal plants namely, Cassia abbreviata, Geranium incanum, Pelargonium hortorum and Tecoma capensis were investigated for their antimicrobial potential. In vitro antimicrobial activity using agar disc diffusion method, agar dilution method and broth microdilution plate determination of minimum inhibitory concentration (MIC), were carried out against ATCC (American Type Culture Collection) strains and clinical isolates known to cause pneumonia. Aqueous, methanol and acetone extracts from the selected plants were thus tested against strains of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli and Candida albicans. The plants exhibited pronounced antimicrobial activity and were more active against Gram-positive bacteria than Gram-negative bacteria. During agar disc diffusion method, the highest inhibition zone was demonstrated by the acetone extract of P. hortorum (IZ=22mm and AI=0.73) against the reference strain of S. pneumoniae (ATCC 49619). The range of zones of inhibition in diameter across strains of S. pneumoniae and H. influenzae was 7mm to 22mm with activity index range of 0.23 to 0.74. The lowest MIC produced by medicinal plants in the study during agar disc diffusion method against S. pneumoniae and H. influenzae strains, was 2.5mg/ml. In broth microdilution plate assay, the lowest MIC demonstrated by C. abbreviata, T. capensis and P. hortorum extracts on tested bacteria was 0.031mg/ml and that of G. incanum was 0.063mg/ml. Candida albicans strains were only inhibited at 20mg/ml by the study plants. The highest activity among the individual extracts was shown by P. hortorum methanol extract which inhibited 71% of the studied bacteria. T. capensis methanol extract was the least and inhibited only 17% of the tested bacteria. The strains of Klebsiella pneumoniae showed the highest resistance to medicinal plants employed in this study. Traditional preparation of selected medicinal plants did not show any significant antimicrobial activity. Bioactive analysis of compounds on study plants was carried out using standard methods which revealed the presence of anthraquinones, flavonoids, phytosterol, saponins, tannins and triterpenoids. Comparison of the inhibitory effect of the plant extracts against some broad spectrum antibiotics revealed that the tested medicinal plants showed greater antimicrobial activity than standard antibiotics. However, there was no correlation between the antibiotic susceptibility patterns of the bacteria and the effects of the plants, signifying that plants probably function through different mechanisms. Bioautographic findings on thin-layer chromatography plate, exhibited clear zones of inhibition of bacterial growth with the Rf value range of 0.09 to 0.94. Anti-mutagenic activity was assayed by the Ames mutagenicity test in the plate-incorporation method using histidine mutants of S. typhimurium strains TA 100. The selected plant extracts at 2.5mg/ml and 5mg/ml did not induce mutagenesis in the absence of liver-metabolizing enzymes. The study results indicated that the selected plants are capable of inhibiting the growth of the studied pathogenic microorganisms to a varied degree. The leaves of G. incanum, P. hortorum, T. capensis as well as the stem bark of C. abbreviata could be novel sources of antimicrobial agents that might have broad spectrum activity. The anti-mutagenic properties of the studied medicinal plants may also provide additional health supplemental value to the other claimed therapeutic properties of the plants.
- Full Text:
- Date Issued: 2013
Guidelines for the effective use of telemedicine in public healthcare in resource constrained settings
- Authors: Kativu, Kevin
- Date: 2013
- Subjects: Telecommunication in medicine , Medical care- technology
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9820 , http://hdl.handle.net/10948/d1020061
- Description: On September 8 2000, world leaders gathered at the United Nations summit and resolved to help citizens in the world's poorest countries to achieve a better life by the year 2015. This resolve was outlined in the Millennium Development Goals that were subsequently published with goals 4, 5 and 6 specific to healthcare. The integration of ICT‘s in the remote delivery of services has opened new avenues from which centralised, scarce resources can be accessed remotely for the benefit of the general population. Telemedicine has made great strides in the developed world with remote populations benefiting from the improved access to healthcare. In the Eastern Cape Province of South Africa, the sub-field of teleradiology has shown promise for enabling the wider delivery of specialist services. However, in resource constrained settings such as developing countries, telemedicine has had limited success and as a result, the equitable access to healthcare for remote populations remains inconceivable. This is exacerbated by the migration of healthcare professionals both domestically and internationally. The public sector has suffered the most with acute staff shortages in the public healthcare institutions, more so in rural and remote areas. This study identifies the prevailing challenges posing as barriers to the effective use of telemedicine services in the Public health sector in resource constrained settings and provides recommendations and guidelines aimed at facilitating the adoption and effective use of telemedicine. Challenges are identified from literature and from the first person accounts of specific role-players who are directly involved with telemedicine in their respective institutions. Participants are drawn from institutions offering telemedicine services within the Eastern Cape Province of South Africa. Challenges identified from literature are collated with those identified from the participant interviews to provide a concise list of factors that is used as input to the recommendation and guideline development process. The results thus far point to an enthusiastic environment coupled with a semi-capable infrastructure but however hampered by staff shortages and a general lack of support structures and propulsion mechanisms to adequately encourage the wider use of telemedicine. The proposed guidelines aim to address the challenges at the different role-player levels.
- Full Text:
- Date Issued: 2013
- Authors: Kativu, Kevin
- Date: 2013
- Subjects: Telecommunication in medicine , Medical care- technology
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9820 , http://hdl.handle.net/10948/d1020061
- Description: On September 8 2000, world leaders gathered at the United Nations summit and resolved to help citizens in the world's poorest countries to achieve a better life by the year 2015. This resolve was outlined in the Millennium Development Goals that were subsequently published with goals 4, 5 and 6 specific to healthcare. The integration of ICT‘s in the remote delivery of services has opened new avenues from which centralised, scarce resources can be accessed remotely for the benefit of the general population. Telemedicine has made great strides in the developed world with remote populations benefiting from the improved access to healthcare. In the Eastern Cape Province of South Africa, the sub-field of teleradiology has shown promise for enabling the wider delivery of specialist services. However, in resource constrained settings such as developing countries, telemedicine has had limited success and as a result, the equitable access to healthcare for remote populations remains inconceivable. This is exacerbated by the migration of healthcare professionals both domestically and internationally. The public sector has suffered the most with acute staff shortages in the public healthcare institutions, more so in rural and remote areas. This study identifies the prevailing challenges posing as barriers to the effective use of telemedicine services in the Public health sector in resource constrained settings and provides recommendations and guidelines aimed at facilitating the adoption and effective use of telemedicine. Challenges are identified from literature and from the first person accounts of specific role-players who are directly involved with telemedicine in their respective institutions. Participants are drawn from institutions offering telemedicine services within the Eastern Cape Province of South Africa. Challenges identified from literature are collated with those identified from the participant interviews to provide a concise list of factors that is used as input to the recommendation and guideline development process. The results thus far point to an enthusiastic environment coupled with a semi-capable infrastructure but however hampered by staff shortages and a general lack of support structures and propulsion mechanisms to adequately encourage the wider use of telemedicine. The proposed guidelines aim to address the challenges at the different role-player levels.
- Full Text:
- Date Issued: 2013
Hydrothermal liquefaction of scenedesmus obliquus in a continuous reactor system
- Authors: Kaufmann, Gideon
- Date: 2013
- Subjects: Biomass chemicals Microalgae -- Biotechnology , Supercritical fluids
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/47878 , vital:40393
- Description: In 2009 InnoVenton, a research institute at the Nelson Mandela Metropolitan University (NMMU) set out to establish a technological concept of micro-algae to fuel, at which point an algae farm was established. The overall research strategy is envisaged to focus on a number of potential uses of algae biomass and related processes such as water treatment can take place, the binding of the biomass to coal fines to create briquettes are possible, and bio crude production from direct liquefaction. This project will focus on the latter. In 2010 a partnership between NMMU and the University of Cape Town’s (UCT) Department of Chemical Engineering was established to design, construct and commission a test unit that could convert the algae biomass into a pumpable bio crude by the liquefaction process. During the initial operation of this test unit, flow problems of the reaction product were observed. As such, the aim of this study is to investigate a number of process conditions and develop strategies to minimise or alleviate this problem. As part of this study, UCT will replicate the NMMU test unit in Cape Town in order to start focussing on finding relevant solutions to the problems which exist. Presently continuous reactor systems are not used for the liquefaction of micro-algae. According to Toor, et al(2011)¹ Other feedstocks have been placed in continuous reactor systems with good end results. They continue to write in their review that batch systems were used in most experiments. If micro-algae are to become a competitive alternative to crude oil then batch systems are not the way forward. From a commercial and efficiency standpoint, there are significant advantages to move from typical batch reactors to continuous reactors, specifically in terms of downtime and loading/unloading of vessels. From the evidence gathered in Port Elizabeth, the nature of the reaction product caused typical plugflow reactor systems to block. The aim of this study is to investigate possible solutions to the problem of the reactor system blockage and thus pave the way for the implementation of a continuous reactor system. There are many variables which can be manipulated to achieve success for example the use of catalysts, co-feeding of reactant gases like hydrogen, residence time, temperature or pressure. Manipulating these variable can help to change conversion and/or product spectrum. The results of this study will be compared to results obtained by typical batch experimentation conducted at NMMU. This research varied temperature only. This variation was effective enough to find solutions to the obstacles that were present. Once the algae feedstock was being diverted to the vent pot via the safety relief valve, it was understood that something was blocked. Once the reactor was cooled and removed, it was apparent that the reactor was not blocking up however the exit line to the product catch pot was. To solve this problem a new heated zone was created. This heated the exit line and the top of the product catch pot to around 50°C below the reaction temperature. This upgrade to the system made the oil liquor less vicous and flow easier. The exit line never blocked up again during the research. Energy values of the product were comparable to that of coal. Higher reaction temperatures favoured the production of paraffins and olefins while lower reaction temperatures favoured the production of oxygenates. An ampoule sampler was introduced to take samples of the gas exit line. The comprehensive gas chromatography analysis of the gas in the ampoules revealed that eventhough the concentration of the products present were low, there were significant quantities of paraffins present in the gas stream. More research and the variation of variables discussed previously need to be conducted. It is also apparent that the test unit needs to be upgraded to a bigger reactor and possibly to use materials of construction which do not corrode easily. A computer model could be developed in conjunction with the current test unit and then a bigger reactor might not be needed. The reducing of the oxygen content in the final bio crude also needs to be investigated. Overall the research is very promising in the fact that the final bio crude that was produced is comparable to coal. With further research it will be possible to create a product that is comparable to fossil crude oil and then could be used as a supplement to crude oil.
- Full Text:
- Date Issued: 2013
- Authors: Kaufmann, Gideon
- Date: 2013
- Subjects: Biomass chemicals Microalgae -- Biotechnology , Supercritical fluids
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/47878 , vital:40393
- Description: In 2009 InnoVenton, a research institute at the Nelson Mandela Metropolitan University (NMMU) set out to establish a technological concept of micro-algae to fuel, at which point an algae farm was established. The overall research strategy is envisaged to focus on a number of potential uses of algae biomass and related processes such as water treatment can take place, the binding of the biomass to coal fines to create briquettes are possible, and bio crude production from direct liquefaction. This project will focus on the latter. In 2010 a partnership between NMMU and the University of Cape Town’s (UCT) Department of Chemical Engineering was established to design, construct and commission a test unit that could convert the algae biomass into a pumpable bio crude by the liquefaction process. During the initial operation of this test unit, flow problems of the reaction product were observed. As such, the aim of this study is to investigate a number of process conditions and develop strategies to minimise or alleviate this problem. As part of this study, UCT will replicate the NMMU test unit in Cape Town in order to start focussing on finding relevant solutions to the problems which exist. Presently continuous reactor systems are not used for the liquefaction of micro-algae. According to Toor, et al(2011)¹ Other feedstocks have been placed in continuous reactor systems with good end results. They continue to write in their review that batch systems were used in most experiments. If micro-algae are to become a competitive alternative to crude oil then batch systems are not the way forward. From a commercial and efficiency standpoint, there are significant advantages to move from typical batch reactors to continuous reactors, specifically in terms of downtime and loading/unloading of vessels. From the evidence gathered in Port Elizabeth, the nature of the reaction product caused typical plugflow reactor systems to block. The aim of this study is to investigate possible solutions to the problem of the reactor system blockage and thus pave the way for the implementation of a continuous reactor system. There are many variables which can be manipulated to achieve success for example the use of catalysts, co-feeding of reactant gases like hydrogen, residence time, temperature or pressure. Manipulating these variable can help to change conversion and/or product spectrum. The results of this study will be compared to results obtained by typical batch experimentation conducted at NMMU. This research varied temperature only. This variation was effective enough to find solutions to the obstacles that were present. Once the algae feedstock was being diverted to the vent pot via the safety relief valve, it was understood that something was blocked. Once the reactor was cooled and removed, it was apparent that the reactor was not blocking up however the exit line to the product catch pot was. To solve this problem a new heated zone was created. This heated the exit line and the top of the product catch pot to around 50°C below the reaction temperature. This upgrade to the system made the oil liquor less vicous and flow easier. The exit line never blocked up again during the research. Energy values of the product were comparable to that of coal. Higher reaction temperatures favoured the production of paraffins and olefins while lower reaction temperatures favoured the production of oxygenates. An ampoule sampler was introduced to take samples of the gas exit line. The comprehensive gas chromatography analysis of the gas in the ampoules revealed that eventhough the concentration of the products present were low, there were significant quantities of paraffins present in the gas stream. More research and the variation of variables discussed previously need to be conducted. It is also apparent that the test unit needs to be upgraded to a bigger reactor and possibly to use materials of construction which do not corrode easily. A computer model could be developed in conjunction with the current test unit and then a bigger reactor might not be needed. The reducing of the oxygen content in the final bio crude also needs to be investigated. Overall the research is very promising in the fact that the final bio crude that was produced is comparable to coal. With further research it will be possible to create a product that is comparable to fossil crude oil and then could be used as a supplement to crude oil.
- Full Text:
- Date Issued: 2013
Commercialisation of emerging famers in the Eastern Cape province: identification of limiting factors that inhibit the progression from subsistence to commercial farming
- Authors: Khapayi, Musa
- Date: 2013
- Subjects: Farms, Small -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10593 , http://hdl.handle.net/10948/d1020067
- Description: The broad objective of the study was to investigate the limiting factors that prevent a breakthrough of emerging farmers to commercial agricultural farming industry. The research objectives were to describe the demographic characteristics such as age, education, farming skills and experience; determine the required support services needed; and inform the limiting factors that prevent breakthrough of emerging farmers to enter commercial agricultural industry. The study was conducted in King William’s Town area through structured questionnaires administered by the researcher. A sample of 50 emerging farmers was drawn in the area. The majority of households in the area depend on subsistence farming for household survival. Results indicated that emerging farmers are faced with poor physical infrastructure such as implements to better their production as well as low education levels which results as an inability to interpret market information to be used in production planning. It is also clear that the farmers face a lack of market infrastructure, poor roads, lack of market information, lack of transportation to markets and high transportation costs. The majority of the farmers were old and the youth was not engaged in agriculture. The findings showed that there is an insufficient role from government with regards to emerging farmer support and providing the required infrastructure to access markets or improving rural infrastructure. As a result the majority of the farmers are trapped in a cycle of poverty. The following policy recommendations are suggested: Financial services such as credit must be made available to emerging farmers at reasonable interest rates such as low interest rate subsidies to emerging farmers up until commercialisation. The requirements for emerging farmers to access loans, funding or credit should be restructured or adjusted to the ability of the farmer to repay the credit rather than the availability of title deeds or assets as collateral. Extension officers should regularly visit the localities were emerging farmers are farming have a better understanding of their farming areas, farming methods and improve their communication with the farmers. Lastly the land reform initiatives should be re-organised or developed if necessary to ensure efficient re-allocation of land. The policies should be developed to focus on both the individual farm plots and the collective rights.
- Full Text:
- Date Issued: 2013
- Authors: Khapayi, Musa
- Date: 2013
- Subjects: Farms, Small -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10593 , http://hdl.handle.net/10948/d1020067
- Description: The broad objective of the study was to investigate the limiting factors that prevent a breakthrough of emerging farmers to commercial agricultural farming industry. The research objectives were to describe the demographic characteristics such as age, education, farming skills and experience; determine the required support services needed; and inform the limiting factors that prevent breakthrough of emerging farmers to enter commercial agricultural industry. The study was conducted in King William’s Town area through structured questionnaires administered by the researcher. A sample of 50 emerging farmers was drawn in the area. The majority of households in the area depend on subsistence farming for household survival. Results indicated that emerging farmers are faced with poor physical infrastructure such as implements to better their production as well as low education levels which results as an inability to interpret market information to be used in production planning. It is also clear that the farmers face a lack of market infrastructure, poor roads, lack of market information, lack of transportation to markets and high transportation costs. The majority of the farmers were old and the youth was not engaged in agriculture. The findings showed that there is an insufficient role from government with regards to emerging farmer support and providing the required infrastructure to access markets or improving rural infrastructure. As a result the majority of the farmers are trapped in a cycle of poverty. The following policy recommendations are suggested: Financial services such as credit must be made available to emerging farmers at reasonable interest rates such as low interest rate subsidies to emerging farmers up until commercialisation. The requirements for emerging farmers to access loans, funding or credit should be restructured or adjusted to the ability of the farmer to repay the credit rather than the availability of title deeds or assets as collateral. Extension officers should regularly visit the localities were emerging farmers are farming have a better understanding of their farming areas, farming methods and improve their communication with the farmers. Lastly the land reform initiatives should be re-organised or developed if necessary to ensure efficient re-allocation of land. The policies should be developed to focus on both the individual farm plots and the collective rights.
- Full Text:
- Date Issued: 2013
A cyber security awareness and education framework for South Africa
- Authors: Kortjan, Noloxolo
- Date: 2013
- Subjects: Computer networks -- Security measures , Computer crimes -- Prevention , Computer security
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9811 , http://hdl.handle.net/10948/d1014829
- Description: The Internet is becoming increasingly interwoven in the daily life of many individuals, organisations and nations. It has, to a large extent, had a positive effect on the way people communicate. It has also introduced new avenues for business and has offered nations an opportunity to govern online. Nevertheless, although cyberspace offers an endless list of services and opportunities, it is also accompanied by many risks. One of these risks is cybercrime. The Internet has given criminals a platform on which to grow and proliferate. As a result of the abstract nature of the Internet, it is easy for these criminals to go unpunished. Moreover, many who use the Internet are not aware of such threats; therefore they may themselves be at risk, together with businesses and governmental assets and infrastructure. In view of this, there is a need for cyber security awareness and education initiatives that will promote users who are well versed in the risks associated with the Internet. In this context, it is the role of the government to empower all levels of society by providing the necessary knowledge and expertise to act securely online. However, there is currently a definite lack in South Africa (SA) in this regard, as there are currently no government-led cyber security awareness and education initiatives. The primary research objective of this study, therefore, is to propose a cyber security awareness and education framework for SA that will assist in creating a cyber secure culture in SA among all of its users of the Internet.
- Full Text:
- Date Issued: 2013
- Authors: Kortjan, Noloxolo
- Date: 2013
- Subjects: Computer networks -- Security measures , Computer crimes -- Prevention , Computer security
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9811 , http://hdl.handle.net/10948/d1014829
- Description: The Internet is becoming increasingly interwoven in the daily life of many individuals, organisations and nations. It has, to a large extent, had a positive effect on the way people communicate. It has also introduced new avenues for business and has offered nations an opportunity to govern online. Nevertheless, although cyberspace offers an endless list of services and opportunities, it is also accompanied by many risks. One of these risks is cybercrime. The Internet has given criminals a platform on which to grow and proliferate. As a result of the abstract nature of the Internet, it is easy for these criminals to go unpunished. Moreover, many who use the Internet are not aware of such threats; therefore they may themselves be at risk, together with businesses and governmental assets and infrastructure. In view of this, there is a need for cyber security awareness and education initiatives that will promote users who are well versed in the risks associated with the Internet. In this context, it is the role of the government to empower all levels of society by providing the necessary knowledge and expertise to act securely online. However, there is currently a definite lack in South Africa (SA) in this regard, as there are currently no government-led cyber security awareness and education initiatives. The primary research objective of this study, therefore, is to propose a cyber security awareness and education framework for SA that will assist in creating a cyber secure culture in SA among all of its users of the Internet.
- Full Text:
- Date Issued: 2013
Strategic adaptive management and the efficiency of invasive alien plant management in South African national parks
- Authors: Loftus, Wynand Johan
- Date: 2013
- Subjects: Biodiversity -- South Africa -- Management , Alien plants -- South Africa , Invasive plants -- South Africa , Ecosystem management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10755 , http://hdl.handle.net/10948/d1020089
- Description: It is well known that invasive alien plants (IAPs) pose a significant threat to natural biodiversity and human well-being. Through various pressures exerted on natural ecosystems, IAPs decrease and alter natural processes that provide important ecosystems services and livelihoods to human communities. These plants also displace and out-compete natural plant communities in the areas in which they invade. Management of IAPs is a complex issue with social, environmental and financial challenges. The long-term sustainable management of IAPs requires a management approach that monitors and measures the outcomes of current management practices, and considers the lessons learnt in future decision making. Adaptive management is such an approach and is characterised by monitoring, assessment, reflection and adaptation. In this dissertation I explore IAP management within the South African National Parks (SANParks) organisation. I focus on the quality of the available IAP clearing data for monitoring and environmental decision-making and explore how strategic adaptive management (SAM) is being applied to IAP management. Strategic adaptive management is a form of adaptive management that SANParks adopted to deal with the inherent unpredictability of the social ecological systems they manage, and is primarily a learning-by-doing approach. In chapter one I describe the various impacts that IAPs have on natural environments. I also discuss management of IAPs, the national Working for Water (WfW) programme and how SANParks control IAPs in partnership with WfW. Clearing of IAPs within the borders of SANParks is funded by the Department of Environmental Affairs‘ (DEA) Natural Resource Management programmes and carried out through the Working for Water programme, under SANParks‘ Biodiversity Social Projects programme and is done on a contract basis. Contract data are stored in the Working for Water Information Management System (WIMS) database. Although IAP clearing is well established, the efficiency of overall clearing operations within the parks, and quality and reliability of the data available in the WIMS, needs to be examined. In Chapter two, I (i) assess the status of IAP clearing and the direct clearing costs in each of the five national parks (costs are inflated to 2012 equivalents using the consumer price index), (ii) assess the accuracy of workload estimations for WfW IAP clearing, and (iii) discuss the utility of WIMS as a system to collate and store accurate data for monitoring purposes, focusing on the integrity and reliability of the data, the accuracy of density estimations and whether it can inform sound decision making. The planning of future clearing contracts lacks efficiency due to inaccuracies and unreliability of input data, specifically estimates of invasive alien plant density. The accuracy of density estimation and cost of clearing varies greatly between parks and does not appear to reflect the reality on the ground. In Chapter 3, through an interview process with IAP managers, I 1) unpack the steps in the SAM ‗cycle‘ and investigate the effectiveness of implementation of each step according to respondents; 2) assess the barriers that are currently keeping managers from implementing effective IAP management; 3) discuss whether learning and adaptation is taking place, and 4) discuss how the SAM process can be modified to promote its effectiveness.
- Full Text:
- Date Issued: 2013
- Authors: Loftus, Wynand Johan
- Date: 2013
- Subjects: Biodiversity -- South Africa -- Management , Alien plants -- South Africa , Invasive plants -- South Africa , Ecosystem management
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10755 , http://hdl.handle.net/10948/d1020089
- Description: It is well known that invasive alien plants (IAPs) pose a significant threat to natural biodiversity and human well-being. Through various pressures exerted on natural ecosystems, IAPs decrease and alter natural processes that provide important ecosystems services and livelihoods to human communities. These plants also displace and out-compete natural plant communities in the areas in which they invade. Management of IAPs is a complex issue with social, environmental and financial challenges. The long-term sustainable management of IAPs requires a management approach that monitors and measures the outcomes of current management practices, and considers the lessons learnt in future decision making. Adaptive management is such an approach and is characterised by monitoring, assessment, reflection and adaptation. In this dissertation I explore IAP management within the South African National Parks (SANParks) organisation. I focus on the quality of the available IAP clearing data for monitoring and environmental decision-making and explore how strategic adaptive management (SAM) is being applied to IAP management. Strategic adaptive management is a form of adaptive management that SANParks adopted to deal with the inherent unpredictability of the social ecological systems they manage, and is primarily a learning-by-doing approach. In chapter one I describe the various impacts that IAPs have on natural environments. I also discuss management of IAPs, the national Working for Water (WfW) programme and how SANParks control IAPs in partnership with WfW. Clearing of IAPs within the borders of SANParks is funded by the Department of Environmental Affairs‘ (DEA) Natural Resource Management programmes and carried out through the Working for Water programme, under SANParks‘ Biodiversity Social Projects programme and is done on a contract basis. Contract data are stored in the Working for Water Information Management System (WIMS) database. Although IAP clearing is well established, the efficiency of overall clearing operations within the parks, and quality and reliability of the data available in the WIMS, needs to be examined. In Chapter two, I (i) assess the status of IAP clearing and the direct clearing costs in each of the five national parks (costs are inflated to 2012 equivalents using the consumer price index), (ii) assess the accuracy of workload estimations for WfW IAP clearing, and (iii) discuss the utility of WIMS as a system to collate and store accurate data for monitoring purposes, focusing on the integrity and reliability of the data, the accuracy of density estimations and whether it can inform sound decision making. The planning of future clearing contracts lacks efficiency due to inaccuracies and unreliability of input data, specifically estimates of invasive alien plant density. The accuracy of density estimation and cost of clearing varies greatly between parks and does not appear to reflect the reality on the ground. In Chapter 3, through an interview process with IAP managers, I 1) unpack the steps in the SAM ‗cycle‘ and investigate the effectiveness of implementation of each step according to respondents; 2) assess the barriers that are currently keeping managers from implementing effective IAP management; 3) discuss whether learning and adaptation is taking place, and 4) discuss how the SAM process can be modified to promote its effectiveness.
- Full Text:
- Date Issued: 2013
Reactions towards the synthesis of the uncommon P57 cymarose moiety
- Authors: Mahanjana, Lungelwa
- Date: 2013
- Subjects: Chemistry, Organic , Organic compounds -- Synthesis
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/6711 , vital:21136
- Description: The work described in this study aims to investigate methods that will improve a lengthy synthetic pathway in the synthesis of the P57 cymarose moiety, and to examine the conformational structure of certain glycosides in order to shed light on the problematic stereochemical issues surrounding the formation of the cymarose glycosyl donor. The cymarose moiety forms part of the trisaccharide derivative present in P57, an appetite suppressant molecule. Modification of reaction steps in the conversion of the stereochemistry at C-3 of a previously reported synthesis of the P57 cymarose moiety was carried out. The first step was the selective oxidation of D-glucal using Pd/C in the presence of acetonitrile. These reaction conditions are more appropriate for the oxidation step to avoid decomposition of the formed molecules. Successive protection of the free OH groups was followed by NaBH4 reduction under stereo-controlled conditions, influenced by CeCl3•7H2O. However, the reduced product could not be isolated from the starting material and this led to ambiguous results when attempting to confirm whether the conversion of the stereochemistry at C-3 had occurred or not. The effect of reaction conditions, such as change in reaction temperature, during the preparation of the cymarose glycosyl donor was studied in order to find suitable reaction conditions to produce α,β-allo derivatives with high stereoselectivity. Compared to the reported synthetic method, this set-up gave improved yields with, unfortunately, similar or slightly lower selectivity to the formation of α-altro:α,β-allo derivative. Examination of the conformational structure of the allal derivative, in order to understand the mechanism at work during the placement of the directing group at C-2, was carried out using molecular modelling. The mechanistic implications of this very short study are discussed and it provides some insights into the likely pathway of the iodination reaction and its selectivity in particular, to the D-allose system.
- Full Text:
- Date Issued: 2013
- Authors: Mahanjana, Lungelwa
- Date: 2013
- Subjects: Chemistry, Organic , Organic compounds -- Synthesis
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/6711 , vital:21136
- Description: The work described in this study aims to investigate methods that will improve a lengthy synthetic pathway in the synthesis of the P57 cymarose moiety, and to examine the conformational structure of certain glycosides in order to shed light on the problematic stereochemical issues surrounding the formation of the cymarose glycosyl donor. The cymarose moiety forms part of the trisaccharide derivative present in P57, an appetite suppressant molecule. Modification of reaction steps in the conversion of the stereochemistry at C-3 of a previously reported synthesis of the P57 cymarose moiety was carried out. The first step was the selective oxidation of D-glucal using Pd/C in the presence of acetonitrile. These reaction conditions are more appropriate for the oxidation step to avoid decomposition of the formed molecules. Successive protection of the free OH groups was followed by NaBH4 reduction under stereo-controlled conditions, influenced by CeCl3•7H2O. However, the reduced product could not be isolated from the starting material and this led to ambiguous results when attempting to confirm whether the conversion of the stereochemistry at C-3 had occurred or not. The effect of reaction conditions, such as change in reaction temperature, during the preparation of the cymarose glycosyl donor was studied in order to find suitable reaction conditions to produce α,β-allo derivatives with high stereoselectivity. Compared to the reported synthetic method, this set-up gave improved yields with, unfortunately, similar or slightly lower selectivity to the formation of α-altro:α,β-allo derivative. Examination of the conformational structure of the allal derivative, in order to understand the mechanism at work during the placement of the directing group at C-2, was carried out using molecular modelling. The mechanistic implications of this very short study are discussed and it provides some insights into the likely pathway of the iodination reaction and its selectivity in particular, to the D-allose system.
- Full Text:
- Date Issued: 2013
Packed-bed rock thermal energy storage for concetrated solar power: enhancement of storage time and system efficiency
- Authors: Maidadi, Mohaman Bello
- Date: 2013
- Subjects: Solar thermal energy , Energy storage , Reliability (Engineering)
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9639 , http://hdl.handle.net/10948/d1020914
- Description: Solar thermal energy harvesting is a promising solution to offset the electricity demands of a growing population. The use of the technology is however still limited and this can most likely be attributed to the capital cost and also the intermittent nature of solar energy which requires incorporation of a storage system. To make the technology more attractive and effective, cheap means of harvesting solar energy and the development of efficient and inexpensive thermal energy storage devices will improve the performance of solar energy systems and the widespread use of solar energy. Heat storage in a packed-bed rock with air as the working fluid presents an attractive and simple solution for storing solar thermal energy and it is recommended for solar air heaters. A packed-bed rock storage system consists of rocks of good heat capacity packed in a storage tank. The working fluid (air) flows through the bed to transfer its energy. The major concern of the design for a packed-bed rock thermal storage system is to maximize the heat transfer and minimise the pressure drop across the storage tank and hence the pumping power. The time duration the stored energy can be preserved and the air flow wall effect through the bed are the common complications encountered in this system. This study presents an experimental and analytical analysis of a vacuum storage tank with the use of expanded perlite for high temperature thermal energy storage in a packed-bed of rocks. Dolerite rocks are used as the storage medium due to their high heat capacity and as they are locally available. To minimise the pressure drop across the tank, moderate rock sizes are used. The tank contains baffles, allowing an even spread of air to rock contact through the entire tank, therefore improving heat transfer. There is a good correlation between the predicted and the actual results (4 percent) which implies that the baffles incorporated inside the vacuum tank forces the air through the entire tank, thereby resulting in an even lateral temperature distribution across the tank. The investigation of heat loss showed that a vacuum with expanded perlite is a viable solution to high temperature heat storage for an extended period. The research also focuses on the investigation of a proposed low cost parabolic trough solar collector for an air heating system as shown in Figure (1.3). The use of a standard solar geyser evacuated tube (@R130 each) has cost benefits over the industry standard solar tubes normally used in concentrating solar power systems. A mathematical was developed to predict the thermal performance of proposed PTC and it was found that the measured results compared well with the predictions. The solar energy conversion efficiency of this collector is up to 70 percent. This research could impact positively on remote rural communities by providing a source of clean energy, especially for off-grid applications for schools, clinics and communication equipment. It could lead to a significant improvement in the cost performance, ease of installation and technical performance of storage systems for solar heating applications.
- Full Text:
- Date Issued: 2013
- Authors: Maidadi, Mohaman Bello
- Date: 2013
- Subjects: Solar thermal energy , Energy storage , Reliability (Engineering)
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9639 , http://hdl.handle.net/10948/d1020914
- Description: Solar thermal energy harvesting is a promising solution to offset the electricity demands of a growing population. The use of the technology is however still limited and this can most likely be attributed to the capital cost and also the intermittent nature of solar energy which requires incorporation of a storage system. To make the technology more attractive and effective, cheap means of harvesting solar energy and the development of efficient and inexpensive thermal energy storage devices will improve the performance of solar energy systems and the widespread use of solar energy. Heat storage in a packed-bed rock with air as the working fluid presents an attractive and simple solution for storing solar thermal energy and it is recommended for solar air heaters. A packed-bed rock storage system consists of rocks of good heat capacity packed in a storage tank. The working fluid (air) flows through the bed to transfer its energy. The major concern of the design for a packed-bed rock thermal storage system is to maximize the heat transfer and minimise the pressure drop across the storage tank and hence the pumping power. The time duration the stored energy can be preserved and the air flow wall effect through the bed are the common complications encountered in this system. This study presents an experimental and analytical analysis of a vacuum storage tank with the use of expanded perlite for high temperature thermal energy storage in a packed-bed of rocks. Dolerite rocks are used as the storage medium due to their high heat capacity and as they are locally available. To minimise the pressure drop across the tank, moderate rock sizes are used. The tank contains baffles, allowing an even spread of air to rock contact through the entire tank, therefore improving heat transfer. There is a good correlation between the predicted and the actual results (4 percent) which implies that the baffles incorporated inside the vacuum tank forces the air through the entire tank, thereby resulting in an even lateral temperature distribution across the tank. The investigation of heat loss showed that a vacuum with expanded perlite is a viable solution to high temperature heat storage for an extended period. The research also focuses on the investigation of a proposed low cost parabolic trough solar collector for an air heating system as shown in Figure (1.3). The use of a standard solar geyser evacuated tube (@R130 each) has cost benefits over the industry standard solar tubes normally used in concentrating solar power systems. A mathematical was developed to predict the thermal performance of proposed PTC and it was found that the measured results compared well with the predictions. The solar energy conversion efficiency of this collector is up to 70 percent. This research could impact positively on remote rural communities by providing a source of clean energy, especially for off-grid applications for schools, clinics and communication equipment. It could lead to a significant improvement in the cost performance, ease of installation and technical performance of storage systems for solar heating applications.
- Full Text:
- Date Issued: 2013
Guidelines for the use of the Indie approach in game development projects in the context of a capstone experience
- Authors: Marais, Craig
- Date: 2013
- Subjects: Computer games -- Design , Computer games -- Programming
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9824
- Description: This research addresses the challenges associated with the supervision of game development projects as part of a capstone experience. The context of this research is the capstone experience as undertaken by third year software development students who have chosen to develop a game for their project at the School of Information and Communication Technology (ICT) at the Nelson Mandela Metropolitan University (NMMU). This research begins by determining the curricular requirements with respect to the capstone experience for Information Technology (IT) qualifications. This is done by investigating the applicable documentation at the international, national and departmental levels. The position of game development as a sub-category of software development is established and the Indie paradigm is investigated as a further sub-category of game development. Furthermore, the Indie paradigm is investigated through in-depth analyses of the techniques used in the development of ten Indie games. This investigation serves to identify the commonly used techniques in the Indie paradigm. The research presents a case study of the game development projects at the School of ICT at the NMMU for the period from 2009 to 2013. This case study combined with the techniques identifed from the Indie paradigm forms the basis of the guidelines presented by this research. The guidelines are subject to a review by an industry expert. The review takes the form of an expert interview, which serves to verify the guidelines. This research concludes by demonstrating alignment with the objectives it set out to achieve and motivating the success of the research conducted.
- Full Text:
- Date Issued: 2013
- Authors: Marais, Craig
- Date: 2013
- Subjects: Computer games -- Design , Computer games -- Programming
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9824
- Description: This research addresses the challenges associated with the supervision of game development projects as part of a capstone experience. The context of this research is the capstone experience as undertaken by third year software development students who have chosen to develop a game for their project at the School of Information and Communication Technology (ICT) at the Nelson Mandela Metropolitan University (NMMU). This research begins by determining the curricular requirements with respect to the capstone experience for Information Technology (IT) qualifications. This is done by investigating the applicable documentation at the international, national and departmental levels. The position of game development as a sub-category of software development is established and the Indie paradigm is investigated as a further sub-category of game development. Furthermore, the Indie paradigm is investigated through in-depth analyses of the techniques used in the development of ten Indie games. This investigation serves to identify the commonly used techniques in the Indie paradigm. The research presents a case study of the game development projects at the School of ICT at the NMMU for the period from 2009 to 2013. This case study combined with the techniques identifed from the Indie paradigm forms the basis of the guidelines presented by this research. The guidelines are subject to a review by an industry expert. The review takes the form of an expert interview, which serves to verify the guidelines. This research concludes by demonstrating alignment with the objectives it set out to achieve and motivating the success of the research conducted.
- Full Text:
- Date Issued: 2013
Analysis of restricted earth fault relay application within a shunt capacitor bank design impacting on protection stability
- Authors: Minkley, Warick
- Date: 2013
- Subjects: Electric power systems -- Protection , Electric power transmission -- Equipment and supplies -- Protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9604 , http://hdl.handle.net/10948/d1021106
- Description: This research is aimed at analyzing the performance of the restricted earth fault relay used on a 400kV capacitor bank scheme used on the Eskom Transmission network. After the commissioning of two Capacitor Banks using the above mentioned scheme design the plant was energized. As a result of the energization the Shunt Capacitor Bank (SCB) then experienced spurious trips. The cause of the trips was found to be the operation of the restricted earth fault relay. In this research project, restricted earth fault protection on SCBs in the Eskom Transmission environment will be the area of interest. The proposed research will analyze the current SCB protection scheme in service specifically looking at the restricted earth fault circuit design and relay performance. An equivalent model of the SCB from primary plant perspective based on theory will be derived. Recording and analyzing of Comtrade transient waveforms respectively, when the bank is nergized, will be done in order to provide a reference base to work from. Manual alculations of various parameters from the derived model including transient inrush currents and fault currents will be performed to access applicable scheme parameters. Further calculations will include the voltage setting for the restricted earth fault relay. As a result of the analysis a recommendation will be made on a viable solution or a revised design will be put forward, based on the results, to improve the scheme’s performance. The protection scheme is used on the two 400kV 100MVAR capacitor banks 11 and 12 at Hydra Substation.
- Full Text:
- Date Issued: 2013
- Authors: Minkley, Warick
- Date: 2013
- Subjects: Electric power systems -- Protection , Electric power transmission -- Equipment and supplies -- Protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9604 , http://hdl.handle.net/10948/d1021106
- Description: This research is aimed at analyzing the performance of the restricted earth fault relay used on a 400kV capacitor bank scheme used on the Eskom Transmission network. After the commissioning of two Capacitor Banks using the above mentioned scheme design the plant was energized. As a result of the energization the Shunt Capacitor Bank (SCB) then experienced spurious trips. The cause of the trips was found to be the operation of the restricted earth fault relay. In this research project, restricted earth fault protection on SCBs in the Eskom Transmission environment will be the area of interest. The proposed research will analyze the current SCB protection scheme in service specifically looking at the restricted earth fault circuit design and relay performance. An equivalent model of the SCB from primary plant perspective based on theory will be derived. Recording and analyzing of Comtrade transient waveforms respectively, when the bank is nergized, will be done in order to provide a reference base to work from. Manual alculations of various parameters from the derived model including transient inrush currents and fault currents will be performed to access applicable scheme parameters. Further calculations will include the voltage setting for the restricted earth fault relay. As a result of the analysis a recommendation will be made on a viable solution or a revised design will be put forward, based on the results, to improve the scheme’s performance. The protection scheme is used on the two 400kV 100MVAR capacitor banks 11 and 12 at Hydra Substation.
- Full Text:
- Date Issued: 2013
Antimicrobial activities of three medicinal plants against selected diarrheagenic pathogens
- Authors: Nkosi, Themba Johan
- Date: 2013
- Subjects: Anti-infective agents , Drug resistance in microorganisms , Materia medica, Vegetable
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10126 , http://hdl.handle.net/10948/d1020759
- Description: Diarrhea is a global concern that the United Nations Children’s Fund (UNICEF) and the World Health Organization (WHO), have confirmed to be the second major cause of death in children under the age of five. Major bacterial pathogens that cause diarrhea include Escherichia coli, Salmonella species, Shigella species and Staphylococcus aureus. Antibiotic therapy is recommended depending on the severity and presentation of the disease; however, the appearance of antibiotic-resistant bacteria is an emerging global threat to the ability to treat these bacterial infections. This situation could be overcome by the discovery of new natural antibiotics. Plants have been a source of medicine for centuries and have been used to treat diseases including diarrhea. This makes plants a natural potential target to study for their antibiotic properties. The objective of this study was to determine the antibiotic properties of medicinal plants against known pathogens that cause bacterial diarrhea. Three medicinal plants, Cassia abbreviata, Kigelia africana, and Geranium incanum were investigated for their antimicrobial properties against these strains of microorganisms: American Type Culture Collection (ATTC) and Clinical Strains (CS). The plant materials were ground into powder, which was then dissolved in methanol, acetone and distilled water to extract the active compounds. The plant extracts were then used to (i) determine their antibiotic activity, (ii) determine the minimum inhibitory concentration (MICs), (iii) analyze the thin layer chromatography (TLC) fingerprints, and (iv) analyze the autobiography assay. The results obtained in this study met the aim and objectives of this study. The antimicrobial activities of the selected plants were obtained as discussed in Chapter 2 and 3. These results indicated that the traditional plants could be used as antimicrobials. In the screening assays, the test microorganisms were inhibited by the plant extracts, when they were subjected to plant extracts. This was performed on Mueller Hinton agar as sensitivity testing, which revealed clear zones of inhibition. The MIC values for each plant extract were established which ranged from 0.101 to 13.3 mg/dl. The TLC analysis revealed the spots which contained the active compounds which inhibited the bacterial growth. A bioautography assay was performed on the TLC plates, which exposed the exact spots containing the active compound inhibiting the bacteria. These results are clearly consistent with what former scientists have observed. Detailed explanations on the results are in Chapter 3 and 4 of this paper. It is important to note that all the procedures performed in this study were in vitro assays. Some effective in vitro assay activity may not always result in the same effective in vivo activity, because some active compounds may be metabolized and degraded into inactive metabolites. For this reason, the in vitro results obtained in this study, may not reflect the true effectiveness of the compounds in in vivo trials. It is therefore advised that future scientists should take a step further in analyzing the plant extracts through in vivo assays. Further testing and study on these plants at an advanced molecular level will be beneficial in the medical fields in the search for new antibiotics to treat infectious diseases. Purification and further analysis of their products can be helpful in the production of pure natural medicines. This will discover the active ingredients and compounds responsible for inhibition of the microorganisms. This will make the compounds potential candidates for a scientific validation and analysis for future scientists to bring a new dawn in the fight against infectious diseases.
- Full Text:
- Date Issued: 2013
- Authors: Nkosi, Themba Johan
- Date: 2013
- Subjects: Anti-infective agents , Drug resistance in microorganisms , Materia medica, Vegetable
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10126 , http://hdl.handle.net/10948/d1020759
- Description: Diarrhea is a global concern that the United Nations Children’s Fund (UNICEF) and the World Health Organization (WHO), have confirmed to be the second major cause of death in children under the age of five. Major bacterial pathogens that cause diarrhea include Escherichia coli, Salmonella species, Shigella species and Staphylococcus aureus. Antibiotic therapy is recommended depending on the severity and presentation of the disease; however, the appearance of antibiotic-resistant bacteria is an emerging global threat to the ability to treat these bacterial infections. This situation could be overcome by the discovery of new natural antibiotics. Plants have been a source of medicine for centuries and have been used to treat diseases including diarrhea. This makes plants a natural potential target to study for their antibiotic properties. The objective of this study was to determine the antibiotic properties of medicinal plants against known pathogens that cause bacterial diarrhea. Three medicinal plants, Cassia abbreviata, Kigelia africana, and Geranium incanum were investigated for their antimicrobial properties against these strains of microorganisms: American Type Culture Collection (ATTC) and Clinical Strains (CS). The plant materials were ground into powder, which was then dissolved in methanol, acetone and distilled water to extract the active compounds. The plant extracts were then used to (i) determine their antibiotic activity, (ii) determine the minimum inhibitory concentration (MICs), (iii) analyze the thin layer chromatography (TLC) fingerprints, and (iv) analyze the autobiography assay. The results obtained in this study met the aim and objectives of this study. The antimicrobial activities of the selected plants were obtained as discussed in Chapter 2 and 3. These results indicated that the traditional plants could be used as antimicrobials. In the screening assays, the test microorganisms were inhibited by the plant extracts, when they were subjected to plant extracts. This was performed on Mueller Hinton agar as sensitivity testing, which revealed clear zones of inhibition. The MIC values for each plant extract were established which ranged from 0.101 to 13.3 mg/dl. The TLC analysis revealed the spots which contained the active compounds which inhibited the bacterial growth. A bioautography assay was performed on the TLC plates, which exposed the exact spots containing the active compound inhibiting the bacteria. These results are clearly consistent with what former scientists have observed. Detailed explanations on the results are in Chapter 3 and 4 of this paper. It is important to note that all the procedures performed in this study were in vitro assays. Some effective in vitro assay activity may not always result in the same effective in vivo activity, because some active compounds may be metabolized and degraded into inactive metabolites. For this reason, the in vitro results obtained in this study, may not reflect the true effectiveness of the compounds in in vivo trials. It is therefore advised that future scientists should take a step further in analyzing the plant extracts through in vivo assays. Further testing and study on these plants at an advanced molecular level will be beneficial in the medical fields in the search for new antibiotics to treat infectious diseases. Purification and further analysis of their products can be helpful in the production of pure natural medicines. This will discover the active ingredients and compounds responsible for inhibition of the microorganisms. This will make the compounds potential candidates for a scientific validation and analysis for future scientists to bring a new dawn in the fight against infectious diseases.
- Full Text:
- Date Issued: 2013
Effects of crop rotation and tillage system on the control of ryegrass (lolium multiflorum X perenne) in wheat (triticum aestivum) in the Swartland production area of South Africa's Western Cape Province
- Authors: Nteyi, Sinovuyo Mava
- Date: 2013
- Subjects: Cropping systems , Conservation tillage -- South Africa -- Western Cape , Ryegrasses
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10738 , http://hdl.handle.net/10948/d1020990
- Description: A major challenge facing agriculture today is to sustain the productivity of agricultural systems with the reduction of weed invasion. The Swartland region in the Western Cape (South Africa) is intensively cropped, producing wheat (Triticum aestivum) as the major crop. As a result of the weedy ryegrass invasion the wheat yield is reduced. In addition, ryegrass has developed resistance to grass herbicides (graminicides). This situation has increased the need to use alternative practices for controlling the invasion of ryegrass in wheat fields. In this regard, crop rotation and tillage systems were proposed as techniques to suppress the ryegrass invasion. This could thus maintain a sustainable long-term wheat production system with less application of herbicides, decreased input costs and increased total grain yield. Against this background, the effects of crop rotation and tillage were determined on ryegrass seedling emergence in a field and shade netting experiment, while seed dormancy was determined in the laboratory. The objectives were to compare the wheat production of two crop rotations with mono-cropped wheat and assess the impact on the ryegrass population in no-till and minimum tillage systems. Analyses of variance on data sets of ryegrass seeds from 2009, 2010 and 2011 were used to determine germination and dormancy percentages in laboratory experiments. The performance of laboratory treatments was evaluated on the basis of germination percentage of seeds. In the field and shade netting experiments, analyses of variance for data from 2007, 2011 and 2012 were used to determine crop rotation x tillage system response. Field and shade netting performance were evaluated on the basis of ryegrass population inhibition and stimulation respectively. Ryegrass seeds from 2009 and 2010 showed higher germination percentages (80 per cent and 73 per cent) than 2011 (42 per cent). Primary dormancy prevented high germination of newly harvested seeds as dormancy release increase with age of the seed. Results of field and shade netting experiments showed stimulation of the ryegrass weed population in wheat monoculture under minimum tillage. However, when wheat was rotated with leguminous crops under both tillage systems (minimum-till and no-till) ryegrass was significantly inhibited. It was concluded that the critical period for weed competition is the first six weeks after planting. Results from this study provide a basis for producers of cereals to make good decisions with regards to timing weed control measures. It is essential to use competitive crop sequences which will inhibit weeds. The challenge is getting this practice adopted and implemented by producers as it will promote conservation agriculture within the region. This study promotes long-term sustainable wheat production systems with an efficient weed management programme that is environmentally friendly using less herbicides within the Swartland region.
- Full Text:
- Date Issued: 2013
- Authors: Nteyi, Sinovuyo Mava
- Date: 2013
- Subjects: Cropping systems , Conservation tillage -- South Africa -- Western Cape , Ryegrasses
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10738 , http://hdl.handle.net/10948/d1020990
- Description: A major challenge facing agriculture today is to sustain the productivity of agricultural systems with the reduction of weed invasion. The Swartland region in the Western Cape (South Africa) is intensively cropped, producing wheat (Triticum aestivum) as the major crop. As a result of the weedy ryegrass invasion the wheat yield is reduced. In addition, ryegrass has developed resistance to grass herbicides (graminicides). This situation has increased the need to use alternative practices for controlling the invasion of ryegrass in wheat fields. In this regard, crop rotation and tillage systems were proposed as techniques to suppress the ryegrass invasion. This could thus maintain a sustainable long-term wheat production system with less application of herbicides, decreased input costs and increased total grain yield. Against this background, the effects of crop rotation and tillage were determined on ryegrass seedling emergence in a field and shade netting experiment, while seed dormancy was determined in the laboratory. The objectives were to compare the wheat production of two crop rotations with mono-cropped wheat and assess the impact on the ryegrass population in no-till and minimum tillage systems. Analyses of variance on data sets of ryegrass seeds from 2009, 2010 and 2011 were used to determine germination and dormancy percentages in laboratory experiments. The performance of laboratory treatments was evaluated on the basis of germination percentage of seeds. In the field and shade netting experiments, analyses of variance for data from 2007, 2011 and 2012 were used to determine crop rotation x tillage system response. Field and shade netting performance were evaluated on the basis of ryegrass population inhibition and stimulation respectively. Ryegrass seeds from 2009 and 2010 showed higher germination percentages (80 per cent and 73 per cent) than 2011 (42 per cent). Primary dormancy prevented high germination of newly harvested seeds as dormancy release increase with age of the seed. Results of field and shade netting experiments showed stimulation of the ryegrass weed population in wheat monoculture under minimum tillage. However, when wheat was rotated with leguminous crops under both tillage systems (minimum-till and no-till) ryegrass was significantly inhibited. It was concluded that the critical period for weed competition is the first six weeks after planting. Results from this study provide a basis for producers of cereals to make good decisions with regards to timing weed control measures. It is essential to use competitive crop sequences which will inhibit weeds. The challenge is getting this practice adopted and implemented by producers as it will promote conservation agriculture within the region. This study promotes long-term sustainable wheat production systems with an efficient weed management programme that is environmentally friendly using less herbicides within the Swartland region.
- Full Text:
- Date Issued: 2013