A study of the competencies and skills required by senior municipal managers in the O.R. Tambo District Municipality
- Authors: Kwinana, Jimmy Thozamile
- Date: 2010
- Subjects: Local government officials -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8181 , http://hdl.handle.net/10948/1470 , Local government officials -- South Africa -- Eastern Cape
- Description: This research document addresses the study of the competencies and skills required by executive municipal managers in the O.R. Tambo District Municipality. Dissertation focuses on questions such as “What is it that executive municipal managers, manage?” What generic management processes do these executive municipal managers, apply?” “What management technique and strategies do these managers employ to deliver services?”; “Under what circumstances do executive municipal managers manage?” In order for executive municipal managers to claim proficiency (competitiveness and skills), a clear discussion of the meaning and competency and skills is provided in this. Identifying and providing a meaningful narration of the characteristics of a competent and skilful executive municipal manager as being a person who has self-respect, high level of emotional intelligence, qualitative in nature, with reasonable adaptive ability by continuously learning and developing with high ethical and professional integrity. In all his/her attempts these executive municipal managers need to be innovative in nature, undertake constant networking and always be informative by character. Such a person is productive problem solver and continuously communicates vertically and horizontally within the hierarchy of the organization. All these discussions are denoted in the diagram indicate below. This research document has undertaken an empirical research to analyze the perception of executive municipal managers in terms of the diagram below and ultimately provide a narrative analysis of the developmental government such as the O.R. Tambo District Municipality.
- Full Text:
- Date Issued: 2010
- Authors: Kwinana, Jimmy Thozamile
- Date: 2010
- Subjects: Local government officials -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8181 , http://hdl.handle.net/10948/1470 , Local government officials -- South Africa -- Eastern Cape
- Description: This research document addresses the study of the competencies and skills required by executive municipal managers in the O.R. Tambo District Municipality. Dissertation focuses on questions such as “What is it that executive municipal managers, manage?” What generic management processes do these executive municipal managers, apply?” “What management technique and strategies do these managers employ to deliver services?”; “Under what circumstances do executive municipal managers manage?” In order for executive municipal managers to claim proficiency (competitiveness and skills), a clear discussion of the meaning and competency and skills is provided in this. Identifying and providing a meaningful narration of the characteristics of a competent and skilful executive municipal manager as being a person who has self-respect, high level of emotional intelligence, qualitative in nature, with reasonable adaptive ability by continuously learning and developing with high ethical and professional integrity. In all his/her attempts these executive municipal managers need to be innovative in nature, undertake constant networking and always be informative by character. Such a person is productive problem solver and continuously communicates vertically and horizontally within the hierarchy of the organization. All these discussions are denoted in the diagram indicate below. This research document has undertaken an empirical research to analyze the perception of executive municipal managers in terms of the diagram below and ultimately provide a narrative analysis of the developmental government such as the O.R. Tambo District Municipality.
- Full Text:
- Date Issued: 2010
Acacia Mearnsii debarking: comparing different debarking technologies in the KwaZulu-Natal and Mpumalanga forestry regions of South Africa
- Authors: Eggers, John Rolf
- Date: 2010
- Subjects: Acacia mearnsii -- South Africa -- KwaZulu-Natal , Acacia mearnsii -- South Africa -- Mpumalanga , Wattles (Plants) -- South Africa -- KwaZulu-Natal , Wattles (Plants) -- South Africa -- Mpumalanga
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10740 , http://hdl.handle.net/10948/1456 , Acacia mearnsii -- South Africa -- KwaZulu-Natal , Acacia mearnsii -- South Africa -- Mpumalanga , Wattles (Plants) -- South Africa -- KwaZulu-Natal , Wattles (Plants) -- South Africa -- Mpumalanga
- Description: Debarking of Acacia mearnsii in South Africa has been conducted using mainly manual systems. Labour shortages and reliability of these systems has caused interest in alternative systems that might be able to debark A. mearnsii. The aim of the research is to compare three mechanised debarking technologies used to debark A. mearnsii. Research trials were conducted on the Demuth, Hyena and Hypro debarkers that would form part of semi-mechanised harvesting systems. The debarking technologies were analysed and compared in terms of productivity per productive machine hour (PMH), debarking quality, system costs and the quality of the bark that was produced. Furthermore, the effect that tree volume, strippability and form have on each of the debarking technologies was determined. The debarking technologies were affected by each of the factors researched. Decreasing tree form had a negative effect on the productivity of each of the technologies. An increase in strippability class (strengthening wood-bark bond strength) caused a decrease in the productivity of each of the machines. An increasing tree volume had a positive effect on the productivity for the three debarking technologies. After the debarking had taken place, samples of bark were analysed at a laboratory to determine if it was acceptable for the processing facilities. Each of the debarking technologies produced bark of varying dimensions, but they were all found to be acceptable. The system costs of the three debarking technologies were compared to a manual system cost at tree volumes of 0.1m³, 0.15m³ and 0.2m³. The Demuth debarker had the best system cost for a tree size of 0.1m³, while the manual system was best for tree volumes 0.15m³ and 0.2m³. The Demuth, Hyena and manual system costs were very similar for each of the tree volumes, with the Hypro being a little higher.
- Full Text:
- Date Issued: 2010
- Authors: Eggers, John Rolf
- Date: 2010
- Subjects: Acacia mearnsii -- South Africa -- KwaZulu-Natal , Acacia mearnsii -- South Africa -- Mpumalanga , Wattles (Plants) -- South Africa -- KwaZulu-Natal , Wattles (Plants) -- South Africa -- Mpumalanga
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10740 , http://hdl.handle.net/10948/1456 , Acacia mearnsii -- South Africa -- KwaZulu-Natal , Acacia mearnsii -- South Africa -- Mpumalanga , Wattles (Plants) -- South Africa -- KwaZulu-Natal , Wattles (Plants) -- South Africa -- Mpumalanga
- Description: Debarking of Acacia mearnsii in South Africa has been conducted using mainly manual systems. Labour shortages and reliability of these systems has caused interest in alternative systems that might be able to debark A. mearnsii. The aim of the research is to compare three mechanised debarking technologies used to debark A. mearnsii. Research trials were conducted on the Demuth, Hyena and Hypro debarkers that would form part of semi-mechanised harvesting systems. The debarking technologies were analysed and compared in terms of productivity per productive machine hour (PMH), debarking quality, system costs and the quality of the bark that was produced. Furthermore, the effect that tree volume, strippability and form have on each of the debarking technologies was determined. The debarking technologies were affected by each of the factors researched. Decreasing tree form had a negative effect on the productivity of each of the technologies. An increase in strippability class (strengthening wood-bark bond strength) caused a decrease in the productivity of each of the machines. An increasing tree volume had a positive effect on the productivity for the three debarking technologies. After the debarking had taken place, samples of bark were analysed at a laboratory to determine if it was acceptable for the processing facilities. Each of the debarking technologies produced bark of varying dimensions, but they were all found to be acceptable. The system costs of the three debarking technologies were compared to a manual system cost at tree volumes of 0.1m³, 0.15m³ and 0.2m³. The Demuth debarker had the best system cost for a tree size of 0.1m³, while the manual system was best for tree volumes 0.15m³ and 0.2m³. The Demuth, Hyena and manual system costs were very similar for each of the tree volumes, with the Hypro being a little higher.
- Full Text:
- Date Issued: 2010
Advanced monitoring system for bolted connections in vehicle construction
- Authors: Buchmann, Macro
- Date: 2010
- Subjects: Automobiles -- Design and construction , Motor vehicles -- Design and construction , Bolted joints
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9617 , http://hdl.handle.net/10948/1417 , Automobiles -- Design and construction , Motor vehicles -- Design and construction , Bolted joints
- Description: Bolted connections where used from the beginning of vehicle construction for joining two or more parts. The reliability of bolted connections is still a major problem. The objective of this research thesis is focused on an advanced monitoring system for bolted connections in vehicle construction. A mechanical “vibrating test bench”, which was developed by the aeronautical engineer Mr. Junkers, is being adapted, to suite the requirements of the automotive industry. It is designed according to DIN 65151 standards. The bolted connection is tightened to a specific torque to achieve the required preload forces and then exposed to an oscillating elastic shear force. The preload force and their loss are measured in relation to the number of load cycles. The ideal locking mechanism would be, if no settling occurs. Realistic in practice is the remaining of a sufficient preload force which doesn’t decry with time. The aim of this thesis is, to gain knowledge that will assist in the future control of the bolt locking procedure. The test bench can be used to verify the clamping capability of a bolted connection. With the dynamic computer-aided test system it will also be possible to test critical bolted joints and their safety, which reduces the probability of costly product recalls, or even severe cases of failure.
- Full Text:
- Date Issued: 2010
- Authors: Buchmann, Macro
- Date: 2010
- Subjects: Automobiles -- Design and construction , Motor vehicles -- Design and construction , Bolted joints
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9617 , http://hdl.handle.net/10948/1417 , Automobiles -- Design and construction , Motor vehicles -- Design and construction , Bolted joints
- Description: Bolted connections where used from the beginning of vehicle construction for joining two or more parts. The reliability of bolted connections is still a major problem. The objective of this research thesis is focused on an advanced monitoring system for bolted connections in vehicle construction. A mechanical “vibrating test bench”, which was developed by the aeronautical engineer Mr. Junkers, is being adapted, to suite the requirements of the automotive industry. It is designed according to DIN 65151 standards. The bolted connection is tightened to a specific torque to achieve the required preload forces and then exposed to an oscillating elastic shear force. The preload force and their loss are measured in relation to the number of load cycles. The ideal locking mechanism would be, if no settling occurs. Realistic in practice is the remaining of a sufficient preload force which doesn’t decry with time. The aim of this thesis is, to gain knowledge that will assist in the future control of the bolt locking procedure. The test bench can be used to verify the clamping capability of a bolted connection. With the dynamic computer-aided test system it will also be possible to test critical bolted joints and their safety, which reduces the probability of costly product recalls, or even severe cases of failure.
- Full Text:
- Date Issued: 2010
An examination of international trophy hunters' South African hunting experiences
- Authors: Han, Xiliang
- Date: 2010
- Subjects: Hunting trophies -- South Africa , Big game hunting -- South Africa , Big game animals -- South Africa , Safaris -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9362 , http://hdl.handle.net/10948/1244 , Hunting trophies -- South Africa , Big game hunting -- South Africa , Big game animals -- South Africa , Safaris -- South Africa
- Description: The diversity of wildlife resources and the highly-developed trophy hunting and game ranching industry make South Africa a sought-after destination for travelling hunters. Significant economic, social and ecological benefits result from the annual visits of 16 000 hunters. These benefits, in turn, accelerate industry competition. To maintain or increase the clientele base, hunting providers should continue to manage and improve their clients’ safari experiences. This research investigated visiting hunters’ South African safari experiences by measuring their perceptions of service quality, satisfaction and behavioural intention. The results of the research could assist hunting providers in identifying areas where service expectations are not met and understanding the impact of service quality and satisfaction on clients’ loyalty. The literature study contextualised the South African trophy hunting industry within the tourism environment, the realms of wildlife tourism, and the characteristics of hunting tourism. An overview of tourism services, service quality, customer satisfaction, and behavioural intention was also provided. The resulting conceptual model hypothesised relationships among the safari experience variables (service quality, satisfaction and behavioural intention). ii The empirical data were collected by means of a mail survey, using a self-administered questionnaire distributed to 2 000 foreign hunters who had participated in a South African hunting safari at least once between 2003 and 2007. Two hundred and thirty six completed questionnaires were returned, giving a response rate of 13.2%. The majority of the hunters were male, aged between 40 and 60 years, and from the United States of America and Europe. Hunters perceived the level of service quality delivery by hunting providers to be relatively high and were generally satisfied with their South African safaris. As a result, they were willing to return for another hunting experience and were very likely to speak positively about their experiences. By performing exploratory and confirmatory factor analyses, a three-factor (augmented services, core services and supporting services) service quality construct was identified and confirmed. Multiple regression analyses found that core services was the strongest predictor of overall satisfaction; overall satisfaction was significantly related to revisit intention; and revisit intention significantly predicted word-of-mouth intention. An empirical model was accordingly constructed to replace the original conceptual model. iii It is recommended that South African hunting safari providers should: {u10007A} use the suggested measuring instrument to monitor their performance of service quality delivery on a regular basis; {u10007A} train their employees to ensure that they are knowledgeable and well prepared for field guidance and to promote ethical hunting practices; {u10007A} ensure an abundance of game and a wilderness atmosphere in the hunting area; {u10007A} conduct focus group studies to further understand the factors that shape clients’ perceptions of the safari experience; and {u10007A} invest in developing long-term relationships with existing clients.
- Full Text:
- Date Issued: 2010
- Authors: Han, Xiliang
- Date: 2010
- Subjects: Hunting trophies -- South Africa , Big game hunting -- South Africa , Big game animals -- South Africa , Safaris -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9362 , http://hdl.handle.net/10948/1244 , Hunting trophies -- South Africa , Big game hunting -- South Africa , Big game animals -- South Africa , Safaris -- South Africa
- Description: The diversity of wildlife resources and the highly-developed trophy hunting and game ranching industry make South Africa a sought-after destination for travelling hunters. Significant economic, social and ecological benefits result from the annual visits of 16 000 hunters. These benefits, in turn, accelerate industry competition. To maintain or increase the clientele base, hunting providers should continue to manage and improve their clients’ safari experiences. This research investigated visiting hunters’ South African safari experiences by measuring their perceptions of service quality, satisfaction and behavioural intention. The results of the research could assist hunting providers in identifying areas where service expectations are not met and understanding the impact of service quality and satisfaction on clients’ loyalty. The literature study contextualised the South African trophy hunting industry within the tourism environment, the realms of wildlife tourism, and the characteristics of hunting tourism. An overview of tourism services, service quality, customer satisfaction, and behavioural intention was also provided. The resulting conceptual model hypothesised relationships among the safari experience variables (service quality, satisfaction and behavioural intention). ii The empirical data were collected by means of a mail survey, using a self-administered questionnaire distributed to 2 000 foreign hunters who had participated in a South African hunting safari at least once between 2003 and 2007. Two hundred and thirty six completed questionnaires were returned, giving a response rate of 13.2%. The majority of the hunters were male, aged between 40 and 60 years, and from the United States of America and Europe. Hunters perceived the level of service quality delivery by hunting providers to be relatively high and were generally satisfied with their South African safaris. As a result, they were willing to return for another hunting experience and were very likely to speak positively about their experiences. By performing exploratory and confirmatory factor analyses, a three-factor (augmented services, core services and supporting services) service quality construct was identified and confirmed. Multiple regression analyses found that core services was the strongest predictor of overall satisfaction; overall satisfaction was significantly related to revisit intention; and revisit intention significantly predicted word-of-mouth intention. An empirical model was accordingly constructed to replace the original conceptual model. iii It is recommended that South African hunting safari providers should: {u10007A} use the suggested measuring instrument to monitor their performance of service quality delivery on a regular basis; {u10007A} train their employees to ensure that they are knowledgeable and well prepared for field guidance and to promote ethical hunting practices; {u10007A} ensure an abundance of game and a wilderness atmosphere in the hunting area; {u10007A} conduct focus group studies to further understand the factors that shape clients’ perceptions of the safari experience; and {u10007A} invest in developing long-term relationships with existing clients.
- Full Text:
- Date Issued: 2010
An exploration of the role of a strategic internal communication system in the merging Walter Sisulu University
- Authors: Soha, Sandi
- Date: 2010
- Subjects: Universities and colleges -- Communication systems -- Evaluation , Universities and colleges -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8485 , http://hdl.handle.net/10948/1458 , Universities and colleges -- Communication systems -- Evaluation , Universities and colleges -- South Africa -- Eastern Cape
- Description: The merger of institutions of higher learning in South Africa has demonstrated to the study an exploration of the role of strategic internal communication system – in the merging of the Walter Sisulu University. The purpose of the study is to determine to what extent employees of the Walter Sisulu University have perceived that the internal communication system of this university has contributed towards an effectively merged organisation. The study was conducted after three historically disadvantaged institutions of higher learning merged to form one comprehensive university. The three merged institutions are: the Border Technikon, the Eastern Cape Technikon and the University of Transkei. It was foreseeable during the process of the merger, that combining three institutions could possibly result in lower staff morale and uncertainty. The study has explored the theoretical framework for understanding the role of strategic internal communication systems in an organisation. The study was approached from a systems' perspective and that of a transformational model. A survey research design was utilised for the purpose of this study – in order to assess the validity and reliability of the data. A qualitative research design was used for the purpose of this study – in order to acquire the desired outcomes of the research. Questionnaires were used and the sample was drawn from a large population of the Walter Sisulu University – from, four campuses – with the aim of allowing one to make inferences about the population as a whole. The questionnaire was structured in four main sections namely: Biographical information, internal-communication systems, tools of internal communication, and line-management communication. The findings of the study aids the understanding behind the view of internal communication systems as having contributed – or not contributed – to a successfully merged university.
- Full Text:
- Date Issued: 2010
- Authors: Soha, Sandi
- Date: 2010
- Subjects: Universities and colleges -- Communication systems -- Evaluation , Universities and colleges -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8485 , http://hdl.handle.net/10948/1458 , Universities and colleges -- Communication systems -- Evaluation , Universities and colleges -- South Africa -- Eastern Cape
- Description: The merger of institutions of higher learning in South Africa has demonstrated to the study an exploration of the role of strategic internal communication system – in the merging of the Walter Sisulu University. The purpose of the study is to determine to what extent employees of the Walter Sisulu University have perceived that the internal communication system of this university has contributed towards an effectively merged organisation. The study was conducted after three historically disadvantaged institutions of higher learning merged to form one comprehensive university. The three merged institutions are: the Border Technikon, the Eastern Cape Technikon and the University of Transkei. It was foreseeable during the process of the merger, that combining three institutions could possibly result in lower staff morale and uncertainty. The study has explored the theoretical framework for understanding the role of strategic internal communication systems in an organisation. The study was approached from a systems' perspective and that of a transformational model. A survey research design was utilised for the purpose of this study – in order to assess the validity and reliability of the data. A qualitative research design was used for the purpose of this study – in order to acquire the desired outcomes of the research. Questionnaires were used and the sample was drawn from a large population of the Walter Sisulu University – from, four campuses – with the aim of allowing one to make inferences about the population as a whole. The questionnaire was structured in four main sections namely: Biographical information, internal-communication systems, tools of internal communication, and line-management communication. The findings of the study aids the understanding behind the view of internal communication systems as having contributed – or not contributed – to a successfully merged university.
- Full Text:
- Date Issued: 2010
Antimicrobial activity of selected Eastern Cape medical plants
- Authors: Mohlakoana, Keneuoe
- Date: 2010
- Subjects: Materia medica, Vegetable -- South Africa , Drug resistance in microorganisms -- South Africa , Anti-infective agents -- South Africa , Antibiotics
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10120 , http://hdl.handle.net/10948/1199 , Materia medica, Vegetable -- South Africa , Drug resistance in microorganisms -- South Africa , Anti-infective agents -- South Africa , Antibiotics
- Description: Bacterial resistance to antibiotics has been a great problem for many years. The degree of resistance and the speed with which resistance develops varies with different organisms and different drugs. Enzymes called β-lactamases are produced by bacteria and are one mechanism in which bacteria develop antimicrobial resistance. Gram-negative bacteria producing enzymes called ESBLs because of their wide substrate range are of a particular concern in nosocomial infections. In many countries people still use traditional medicine derived from plants as an alternative to the Western medicine due to increased cost of Western medicine and microbial resistance of antibiotic treatments. Biologically active compounds isolated from plants species are used in herbal medicine. Because of the high prevalence of the ESBLs and their increasing resistance to the antibiotics, this research study was done to test the antimicrobial activities of selected medicinal plants of the Eastern Cape; G. incanum, D. angustifolia and E. autumnalis which were traditionally used to treat various infections. The in vitro antimicrobial activity of three different extracts (acetone, methanol & distilled water) and the traditional preparations of the three plants were tested against the selected strains of ESBL-producing bacteria, non β-lactamase producers and the different fungal species. The extracts were screened against 26 Gram-positive bacterial strains, 53 Gram-negative bacterial strains and 15 fungal strains. The Gram-positive bacteria included strains from S. aureus, B. cereus and E. faecalis. The Gram-negative bacteria included strains from E. ii coli, E. cloacae, K. pneumoniae, P. aeruginosa and Acinetobacter spp. The fungal strains included 9 strains of Candida albicans and a single strain of each of the following opportunistic fungi, Mucor sp, Geotrichium sp, Penicillium sp, Fusarium sp and Rhizopus sp. The agar dilution assay was used for the antimicrobial screening of the plants extracts and for the determination of the MICs. The Ames test was performed for the determination of probable carcinogenicity of the extracts of G. incanum and D. angustifolia. The distilled water extracts followed by acetone extracts of the plants revealed the highest antimicrobial activity against the different microbial strains. The extracts of G. incanum followed by the extracts of D. angustifolia inhibited the highest number of microbial strains. The extracts of E. autumnalis did not show any antimicrobial activity against all the pathogens in this study. More of the Gram-positive bacteria were inhibited by the plant extracts. The lowest MIC was obtained with Gram-positive bacteria. The bacterial strains of E. faecalis and P. aeruginosa were not inhibited by any of the plants extracts in the agar dilution assay yet Acinetobacter species which are MDR were inhibited by the distilled water and methanol extracts of G. incanum. A single strain of Mucor sp was the only spore forming fungi that was inhibited by the distilled water extracts of G. incanum. None of the plants extracts showed any mutagenic effects on the TA100 S. typhimurium strains incorporated on the Ames test. Apart from revealing of new antimicrobial agents that may be used against resistant organisms, the proper use of antimicrobial agents should be recommended. The study has highlighted a need for further investigations on the properties of the medicinal plants used in this study.
- Full Text:
- Date Issued: 2010
- Authors: Mohlakoana, Keneuoe
- Date: 2010
- Subjects: Materia medica, Vegetable -- South Africa , Drug resistance in microorganisms -- South Africa , Anti-infective agents -- South Africa , Antibiotics
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10120 , http://hdl.handle.net/10948/1199 , Materia medica, Vegetable -- South Africa , Drug resistance in microorganisms -- South Africa , Anti-infective agents -- South Africa , Antibiotics
- Description: Bacterial resistance to antibiotics has been a great problem for many years. The degree of resistance and the speed with which resistance develops varies with different organisms and different drugs. Enzymes called β-lactamases are produced by bacteria and are one mechanism in which bacteria develop antimicrobial resistance. Gram-negative bacteria producing enzymes called ESBLs because of their wide substrate range are of a particular concern in nosocomial infections. In many countries people still use traditional medicine derived from plants as an alternative to the Western medicine due to increased cost of Western medicine and microbial resistance of antibiotic treatments. Biologically active compounds isolated from plants species are used in herbal medicine. Because of the high prevalence of the ESBLs and their increasing resistance to the antibiotics, this research study was done to test the antimicrobial activities of selected medicinal plants of the Eastern Cape; G. incanum, D. angustifolia and E. autumnalis which were traditionally used to treat various infections. The in vitro antimicrobial activity of three different extracts (acetone, methanol & distilled water) and the traditional preparations of the three plants were tested against the selected strains of ESBL-producing bacteria, non β-lactamase producers and the different fungal species. The extracts were screened against 26 Gram-positive bacterial strains, 53 Gram-negative bacterial strains and 15 fungal strains. The Gram-positive bacteria included strains from S. aureus, B. cereus and E. faecalis. The Gram-negative bacteria included strains from E. ii coli, E. cloacae, K. pneumoniae, P. aeruginosa and Acinetobacter spp. The fungal strains included 9 strains of Candida albicans and a single strain of each of the following opportunistic fungi, Mucor sp, Geotrichium sp, Penicillium sp, Fusarium sp and Rhizopus sp. The agar dilution assay was used for the antimicrobial screening of the plants extracts and for the determination of the MICs. The Ames test was performed for the determination of probable carcinogenicity of the extracts of G. incanum and D. angustifolia. The distilled water extracts followed by acetone extracts of the plants revealed the highest antimicrobial activity against the different microbial strains. The extracts of G. incanum followed by the extracts of D. angustifolia inhibited the highest number of microbial strains. The extracts of E. autumnalis did not show any antimicrobial activity against all the pathogens in this study. More of the Gram-positive bacteria were inhibited by the plant extracts. The lowest MIC was obtained with Gram-positive bacteria. The bacterial strains of E. faecalis and P. aeruginosa were not inhibited by any of the plants extracts in the agar dilution assay yet Acinetobacter species which are MDR were inhibited by the distilled water and methanol extracts of G. incanum. A single strain of Mucor sp was the only spore forming fungi that was inhibited by the distilled water extracts of G. incanum. None of the plants extracts showed any mutagenic effects on the TA100 S. typhimurium strains incorporated on the Ames test. Apart from revealing of new antimicrobial agents that may be used against resistant organisms, the proper use of antimicrobial agents should be recommended. The study has highlighted a need for further investigations on the properties of the medicinal plants used in this study.
- Full Text:
- Date Issued: 2010
Attitudes towards hunting amongst the economically active public in Port Elizabeth
- Coetzer, Wentzel Christoffel
- Authors: Coetzer, Wentzel Christoffel
- Date: 2010
- Subjects: Hunting -- South Africa -- Port Elizabeth , Wildlife management -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10746 , http://hdl.handle.net/10948/1507 , Hunting -- South Africa -- Port Elizabeth , Wildlife management -- South Africa -- Port Elizabeth
- Description: Wildlife ranching is recognized as one of the important agricultural industries in South Africa, with hunting being the primary segment of the game industry. Hunting is an essential part of wildlife management and it contributes significantly to the conservation of biodiversity and to the economy. Despite this, the social acceptability of hunting is often questioned and negative attitudes towards hunting within the larger society may become a potential threat to the hunting industry. This may jeopardize the effective management of game and have a negative impact on conservation and the economy. This study is an empirical investigation of the attitudes of the economically active public in Port Elizabeth towards hunting. The objectives of this study are to investigate the nature and extent of the public's attitudes towards hunting, as well as to identify factors influencing the public's attitudes towards hunting. The study commenced with the establishment of a theoretical framework, based on a literature study on the psychology of human perceptions and attitudes towards hunting. The theoretical framework was then used to develop the empirical component of the study. A survey was conducted amongst a statistically representative sample of the economically active public in Port Elizabeth during 2009. The data was collected by means of personal interviews and self-administered questionnaires were used as the survey instrument. The study found that the economically active public in Port Elizabeth generally holds favourable attitudes towards hunting, with only a small proportion of the population wanting to ban hunting. The belief that hunting endangers wildlife was the most prominent reason for opposing hunting. Negative attitudes towards hunting were largely based on incorrect beliefs regarding hunting. The extent of a person's knowledge of hunting and exposure to hunting, as well as a person's social ties had a significant influence on their attitudes towards hunting.
- Full Text:
- Date Issued: 2010
- Authors: Coetzer, Wentzel Christoffel
- Date: 2010
- Subjects: Hunting -- South Africa -- Port Elizabeth , Wildlife management -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10746 , http://hdl.handle.net/10948/1507 , Hunting -- South Africa -- Port Elizabeth , Wildlife management -- South Africa -- Port Elizabeth
- Description: Wildlife ranching is recognized as one of the important agricultural industries in South Africa, with hunting being the primary segment of the game industry. Hunting is an essential part of wildlife management and it contributes significantly to the conservation of biodiversity and to the economy. Despite this, the social acceptability of hunting is often questioned and negative attitudes towards hunting within the larger society may become a potential threat to the hunting industry. This may jeopardize the effective management of game and have a negative impact on conservation and the economy. This study is an empirical investigation of the attitudes of the economically active public in Port Elizabeth towards hunting. The objectives of this study are to investigate the nature and extent of the public's attitudes towards hunting, as well as to identify factors influencing the public's attitudes towards hunting. The study commenced with the establishment of a theoretical framework, based on a literature study on the psychology of human perceptions and attitudes towards hunting. The theoretical framework was then used to develop the empirical component of the study. A survey was conducted amongst a statistically representative sample of the economically active public in Port Elizabeth during 2009. The data was collected by means of personal interviews and self-administered questionnaires were used as the survey instrument. The study found that the economically active public in Port Elizabeth generally holds favourable attitudes towards hunting, with only a small proportion of the population wanting to ban hunting. The belief that hunting endangers wildlife was the most prominent reason for opposing hunting. Negative attitudes towards hunting were largely based on incorrect beliefs regarding hunting. The extent of a person's knowledge of hunting and exposure to hunting, as well as a person's social ties had a significant influence on their attitudes towards hunting.
- Full Text:
- Date Issued: 2010
C3TO : a scalable architecture for mobile chat based tutoring
- Authors: Butgereit, Laura Lee
- Date: 2010
- Subjects: Intelligent tutoring systems , Instructional systems -- Design
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9746 , http://hdl.handle.net/10948/1511 , Intelligent tutoring systems , Instructional systems -- Design
- Description: C³TO (Chatter Call Centre/Tutoring Online) is a scalable architecture to support mobile online tutoring using chat protocols over cell phones. It is the scalability of this architecture which is the primary focus of this dissertation. Much has been written lamenting the state of mathematics education in South Africa. It is not a pretty story. In order to help solve this mathematical crisis, the “Dr Math” research project was started in January, 2007. “Dr Math” strove to assist school pupils with their mathematics homework by providing access to tutors from a nearby university to help them. The school pupils used MXit on their cell phones and the tutors used normal computer workstations. The original “Dr Math” research project expected no more than twenty to thirty school pupils to participate. Unexpectedly thousands of school pupils started asking “Dr Math” to assist them with their mathematics homework. The original software could not scale. The original software could not cater for the thousands of pupils needing help. The scalability problems which existed in the original “Dr Math” project included: hardware scalability issues, software scalability problems, lack of physical office space for tutors, and tutor time being wasted by trivial questions. C³TO tackled these scalability concerns using an innovative three level approach by implementing a technological feature level, a tactical feature level, and a strategic feature level in the C³TO architecture. The technological level included specific components, utilities, and platforms which promoted scalability. The technological level provided the basic building blocks with which to construct a scalable architecture. The tactical level arranged the basic building blocks of the technological level into a scalable architecture. The tactical level provided short term solutions to scalability concerns by providing easy configurability and decision making. The strategic level attempted to answer the pupils questions before they actually arrived at the tutor thereby reducing the load on the human tutors. C³TO was extensively tested and evaluated. C³TO supported thousands of school pupils with their mathematics homework over a period of ten months. C³TO was used to support a small conference. C³TO was used to encourage people to volunteer their time in participation of Mandela Day. C³TO was used to support “Winter School” during the winter school holiday. In all these cases, C³TO proved itself to be scalable.
- Full Text:
- Date Issued: 2010
- Authors: Butgereit, Laura Lee
- Date: 2010
- Subjects: Intelligent tutoring systems , Instructional systems -- Design
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9746 , http://hdl.handle.net/10948/1511 , Intelligent tutoring systems , Instructional systems -- Design
- Description: C³TO (Chatter Call Centre/Tutoring Online) is a scalable architecture to support mobile online tutoring using chat protocols over cell phones. It is the scalability of this architecture which is the primary focus of this dissertation. Much has been written lamenting the state of mathematics education in South Africa. It is not a pretty story. In order to help solve this mathematical crisis, the “Dr Math” research project was started in January, 2007. “Dr Math” strove to assist school pupils with their mathematics homework by providing access to tutors from a nearby university to help them. The school pupils used MXit on their cell phones and the tutors used normal computer workstations. The original “Dr Math” research project expected no more than twenty to thirty school pupils to participate. Unexpectedly thousands of school pupils started asking “Dr Math” to assist them with their mathematics homework. The original software could not scale. The original software could not cater for the thousands of pupils needing help. The scalability problems which existed in the original “Dr Math” project included: hardware scalability issues, software scalability problems, lack of physical office space for tutors, and tutor time being wasted by trivial questions. C³TO tackled these scalability concerns using an innovative three level approach by implementing a technological feature level, a tactical feature level, and a strategic feature level in the C³TO architecture. The technological level included specific components, utilities, and platforms which promoted scalability. The technological level provided the basic building blocks with which to construct a scalable architecture. The tactical level arranged the basic building blocks of the technological level into a scalable architecture. The tactical level provided short term solutions to scalability concerns by providing easy configurability and decision making. The strategic level attempted to answer the pupils questions before they actually arrived at the tutor thereby reducing the load on the human tutors. C³TO was extensively tested and evaluated. C³TO supported thousands of school pupils with their mathematics homework over a period of ten months. C³TO was used to support a small conference. C³TO was used to encourage people to volunteer their time in participation of Mandela Day. C³TO was used to support “Winter School” during the winter school holiday. In all these cases, C³TO proved itself to be scalable.
- Full Text:
- Date Issued: 2010
Effect of exposure charts on reject rate of extremity radiographs
- Authors: Kalondo, Luzanne
- Date: 2010
- Subjects: Radiography, Medical -- Exposure , Radiography, Medical -- Image quality , Radiography, Medical -- South Africa , Diagnostic imaging -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10076 , http://hdl.handle.net/10948/1168 , Radiography, Medical -- Exposure , Radiography, Medical -- Image quality , Radiography, Medical -- South Africa , Diagnostic imaging -- South Africa
- Description: This study discusses reject film analyses (RFAs) before and after the implementation of a quality improvement intervention. RFAs were undertaken to investigate the effect of the introduction and use of exposure charts (ECs) on department and student reject rates of extremity radiographs. Methods: A quantitative comparative pre and post-treatment research design was used. Data was collected from the x-ray departments of two training hospitals in Windhoek, Namibia over a five month period. A retrospective RFA was conducted to determine the department and student reject rates for both departments before intervention. Emphasis was placed on exposure related reject films. ECs were compiled and introduced at Katutura State Hospital (venue B) by the researcher. The students were instructed to use these charts. At Windhoek Central Hospital (venue A) no ECs were used. A prospective RFA was conducted to establish department and student reject rates at both hospitals after the intervention at venue B. Results: During the retrospective phase the department reject rate for venue A was 21 percent while the student reject rate was 23 percent. At venue B 24 percent and 26 percent were scored respectively. Students at venue A produced rejected radiographs due to overexposure (49 percent) and underexposure (23 percent), whilst 37 percent was recorded for both causes at venue B. At venue A, 35 percent of films were rejected due to incorrect mAs selection, at venue B the figure was 42 percent. Undiagnostic radiographs due to inaccurate kV selection comprised 62 percent for venue A and 59 percent for venue B. During the prospective phase the department reject rate for venue A was 20 percent and that of the students was 19 percent. For venue B 12 percent and 11 percent were scored respectively. At venue A radiographs rejected due to over and underexposure were 43 percent and 33 percent respectively while those at venue B were 33 percent and 34 percent. Incorrect mAs selection caused 33 percent of discarded films at venue A and 38 percent at venue B. The figures for inaccurate kV selection were 68 percent and 62 percent for venues A and B. Conclusions: The introduction and use of ECs lowered the student reject rate at venue B in the prospective phase.
- Full Text:
- Date Issued: 2010
- Authors: Kalondo, Luzanne
- Date: 2010
- Subjects: Radiography, Medical -- Exposure , Radiography, Medical -- Image quality , Radiography, Medical -- South Africa , Diagnostic imaging -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10076 , http://hdl.handle.net/10948/1168 , Radiography, Medical -- Exposure , Radiography, Medical -- Image quality , Radiography, Medical -- South Africa , Diagnostic imaging -- South Africa
- Description: This study discusses reject film analyses (RFAs) before and after the implementation of a quality improvement intervention. RFAs were undertaken to investigate the effect of the introduction and use of exposure charts (ECs) on department and student reject rates of extremity radiographs. Methods: A quantitative comparative pre and post-treatment research design was used. Data was collected from the x-ray departments of two training hospitals in Windhoek, Namibia over a five month period. A retrospective RFA was conducted to determine the department and student reject rates for both departments before intervention. Emphasis was placed on exposure related reject films. ECs were compiled and introduced at Katutura State Hospital (venue B) by the researcher. The students were instructed to use these charts. At Windhoek Central Hospital (venue A) no ECs were used. A prospective RFA was conducted to establish department and student reject rates at both hospitals after the intervention at venue B. Results: During the retrospective phase the department reject rate for venue A was 21 percent while the student reject rate was 23 percent. At venue B 24 percent and 26 percent were scored respectively. Students at venue A produced rejected radiographs due to overexposure (49 percent) and underexposure (23 percent), whilst 37 percent was recorded for both causes at venue B. At venue A, 35 percent of films were rejected due to incorrect mAs selection, at venue B the figure was 42 percent. Undiagnostic radiographs due to inaccurate kV selection comprised 62 percent for venue A and 59 percent for venue B. During the prospective phase the department reject rate for venue A was 20 percent and that of the students was 19 percent. For venue B 12 percent and 11 percent were scored respectively. At venue A radiographs rejected due to over and underexposure were 43 percent and 33 percent respectively while those at venue B were 33 percent and 34 percent. Incorrect mAs selection caused 33 percent of discarded films at venue A and 38 percent at venue B. The figures for inaccurate kV selection were 68 percent and 62 percent for venues A and B. Conclusions: The introduction and use of ECs lowered the student reject rate at venue B in the prospective phase.
- Full Text:
- Date Issued: 2010
Implementing capital budgeting for the multinational corporation
- Authors: Wang, Xin
- Date: 2010
- Subjects: International business enterprises -- Accounting
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8939 , http://hdl.handle.net/10948/1304 , International business enterprises -- Accounting
- Description: There are many reasons to believe that budgeting lies at the heart of business management. Gray et al (2001:324) states that ―budgetary planning and control is the most visible use of accounting information in the management control process. By setting standards of performance and providing feedback by means of variance reports, the accountant supplies much of the fundamental information required for overall planning and control. However, Gray et al (2001:324) point out that capital budgeting decision is limited by the intricacies of the international business environment, which is characterized by economic, social, political, and cultural diversity. Therefore, decisions of capital investments and budgetary controls are more problematic (Gray et al., 2001:14). One of the defining characteristics of the globalization of the world economy in the past two decades has been the spread of multinational corporations' activities across countries, and, as a result, significant increases in global foreign direct investment (FDI) outflow in the 1990s (from R233 billion in 1990 to R1, 379 billion in 2000). For example, the total stock of Chinese direct investment abroad nearly tripled over the 1990s (from $2.2 trillion in 1990 to $6.3 trillion in 2000) as Chinese multinational corporations generated an increasingly large share of world GDP (6.8 percent in 1994 and 8.6 percent in 2000). Multinational corporations have become an important conduit in the global allocation of investment funds. However, the business environment in international markets has been considered volatile; there is no reliable and accurate method to aid 2 multinational corporations about decisions about the international environment. Thus, multinational corporations have encountered risk and challenge. Given the development and challenge of the international environment, this study have been considered to plan over a longer time horizon, develop formal mechanisms to set aside funds for preserving existing facilities, increase automation of the process, and link capital planning decisions to statewide performance goals and strategic plans. This research draws upon existing theoretical determinants of capital budgeting and empirically tests the hypotheses across a sample of multinational corporations in China. Although the sample is from China, the results have important implications for multinational corporations based in other countries. This paper is composed of four parts. The first part briefly gives both a theoretical and practical overview of multinational capital budgeting analysis. The second part discusses the data collection techniques and the questionnaire design used in this study. The third part provides some important findings of this research. The last section offers some conclusions from this study.
- Full Text:
- Date Issued: 2010
- Authors: Wang, Xin
- Date: 2010
- Subjects: International business enterprises -- Accounting
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:8939 , http://hdl.handle.net/10948/1304 , International business enterprises -- Accounting
- Description: There are many reasons to believe that budgeting lies at the heart of business management. Gray et al (2001:324) states that ―budgetary planning and control is the most visible use of accounting information in the management control process. By setting standards of performance and providing feedback by means of variance reports, the accountant supplies much of the fundamental information required for overall planning and control. However, Gray et al (2001:324) point out that capital budgeting decision is limited by the intricacies of the international business environment, which is characterized by economic, social, political, and cultural diversity. Therefore, decisions of capital investments and budgetary controls are more problematic (Gray et al., 2001:14). One of the defining characteristics of the globalization of the world economy in the past two decades has been the spread of multinational corporations' activities across countries, and, as a result, significant increases in global foreign direct investment (FDI) outflow in the 1990s (from R233 billion in 1990 to R1, 379 billion in 2000). For example, the total stock of Chinese direct investment abroad nearly tripled over the 1990s (from $2.2 trillion in 1990 to $6.3 trillion in 2000) as Chinese multinational corporations generated an increasingly large share of world GDP (6.8 percent in 1994 and 8.6 percent in 2000). Multinational corporations have become an important conduit in the global allocation of investment funds. However, the business environment in international markets has been considered volatile; there is no reliable and accurate method to aid 2 multinational corporations about decisions about the international environment. Thus, multinational corporations have encountered risk and challenge. Given the development and challenge of the international environment, this study have been considered to plan over a longer time horizon, develop formal mechanisms to set aside funds for preserving existing facilities, increase automation of the process, and link capital planning decisions to statewide performance goals and strategic plans. This research draws upon existing theoretical determinants of capital budgeting and empirically tests the hypotheses across a sample of multinational corporations in China. Although the sample is from China, the results have important implications for multinational corporations based in other countries. This paper is composed of four parts. The first part briefly gives both a theoretical and practical overview of multinational capital budgeting analysis. The second part discusses the data collection techniques and the questionnaire design used in this study. The third part provides some important findings of this research. The last section offers some conclusions from this study.
- Full Text:
- Date Issued: 2010
Laser surface hardening of AISI 1518 alloy steel
- Authors: Zhang, Tao
- Date: 2010
- Subjects: Lasers , Laser beams , Lasers in engineering , Nd-YAG lasers , Steel alloys , Surfaces -- Effect of radiation on
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9613 , http://hdl.handle.net/10948/723 , Lasers , Laser beams , Lasers in engineering , Nd-YAG lasers , Steel alloys , Surfaces -- Effect of radiation on
- Description: The laser surface hardening process will enhance the hardness profile of automotive components and ensure better process control and predictability of quality as compared to the conventional hardening processes. A 2KW Nd-YAG laser system was used to harden the surface of alloy steel with various process parameters (laser power, focal spot diameter and beam velocity). The results (microhardness, microstructure change and residual stress distribution) were measured and analyzed with Vickers microhardness tester, optical/electron microscope and hole-drilling residual stress equipment. Statistical analyses of the experimental data were used for explaining the relationships between process parameters, microhardness and microstructure. General thermal hardening was applied in the research to show the influence of heating temperature and cooling method on microstructure and mechanical properties. Also, the results were compared with laser surface hardening process from microhardness, microstructure and residual stress to show the advantage of laser surface hardening. Through analysis of the results of the laser surface hardening experiments, a suitable laser power density and interaction time for optimum hardening was obtained. The presented laser surface hardening process can also be applied to other alloy steel surface hardening process.
- Full Text:
- Date Issued: 2010
- Authors: Zhang, Tao
- Date: 2010
- Subjects: Lasers , Laser beams , Lasers in engineering , Nd-YAG lasers , Steel alloys , Surfaces -- Effect of radiation on
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9613 , http://hdl.handle.net/10948/723 , Lasers , Laser beams , Lasers in engineering , Nd-YAG lasers , Steel alloys , Surfaces -- Effect of radiation on
- Description: The laser surface hardening process will enhance the hardness profile of automotive components and ensure better process control and predictability of quality as compared to the conventional hardening processes. A 2KW Nd-YAG laser system was used to harden the surface of alloy steel with various process parameters (laser power, focal spot diameter and beam velocity). The results (microhardness, microstructure change and residual stress distribution) were measured and analyzed with Vickers microhardness tester, optical/electron microscope and hole-drilling residual stress equipment. Statistical analyses of the experimental data were used for explaining the relationships between process parameters, microhardness and microstructure. General thermal hardening was applied in the research to show the influence of heating temperature and cooling method on microstructure and mechanical properties. Also, the results were compared with laser surface hardening process from microhardness, microstructure and residual stress to show the advantage of laser surface hardening. Through analysis of the results of the laser surface hardening experiments, a suitable laser power density and interaction time for optimum hardening was obtained. The presented laser surface hardening process can also be applied to other alloy steel surface hardening process.
- Full Text:
- Date Issued: 2010
Modeling of arsenic removal from aqueous media using selected coagulants
- Authors: Majavu, Avela
- Date: 2010
- Subjects: Arsenic wastes , Water -- Purification -- Arsenic removal , Coagulation
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10426 , http://hdl.handle.net/10948/d1017100
- Description: The waste water from the industrial production of the herbicide monosodium methyl arsenate was treated using coagulation. The coagulation process as developed in this research proved to be suitable for arsenic removal in aqueous media using chromium (III), calcium (II), and combination of calcium (II) and chromium (III), and magnesium (II). The results obtained suggest that the coagulation process can be used for the treatment of the waste water from the monosodium methyl arsenate production. Response surface methodology was used to study the effects of the various parameters, namely pH, mole ratios (Cr:As, Ca:As, and Mg:As), concentration of flocculent and initial arsenic concentration. To optimize the process conditions for the maximum removal of arsenic. Central composite and factorial designs were used to study the effects of these variables and to predict the effect of each. ANOVA was used to identify those factors which had significant effects on model quality and performance. The initial arsenic concentration appeared to be the only significant factor. These models were statistically tested and verified by confirmation experiments.
- Full Text:
- Date Issued: 2010
- Authors: Majavu, Avela
- Date: 2010
- Subjects: Arsenic wastes , Water -- Purification -- Arsenic removal , Coagulation
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10426 , http://hdl.handle.net/10948/d1017100
- Description: The waste water from the industrial production of the herbicide monosodium methyl arsenate was treated using coagulation. The coagulation process as developed in this research proved to be suitable for arsenic removal in aqueous media using chromium (III), calcium (II), and combination of calcium (II) and chromium (III), and magnesium (II). The results obtained suggest that the coagulation process can be used for the treatment of the waste water from the monosodium methyl arsenate production. Response surface methodology was used to study the effects of the various parameters, namely pH, mole ratios (Cr:As, Ca:As, and Mg:As), concentration of flocculent and initial arsenic concentration. To optimize the process conditions for the maximum removal of arsenic. Central composite and factorial designs were used to study the effects of these variables and to predict the effect of each. ANOVA was used to identify those factors which had significant effects on model quality and performance. The initial arsenic concentration appeared to be the only significant factor. These models were statistically tested and verified by confirmation experiments.
- Full Text:
- Date Issued: 2010
Navigating between information security management documents : a modeling methodology
- Authors: Domingues, Steve
- Date: 2010
- Subjects: Computer security -- Management , Business -- Data processing -- Security measures , Information resources management -- Security measures , Business -- Standards
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9761 , http://hdl.handle.net/10948/1212 , Computer security -- Management , Business -- Data processing -- Security measures , Information resources management -- Security measures , Business -- Standards
- Description: Organizations no longer draft their own standards. Instead, organizations take advantage of the available international standards. One standard may not cover all the organization's needs, requiring organizations to implement more than one standard. The same aspect in an organization may be covered by two or more standards, creating an overlap. An awareness of such overlaps led to various institutions creating mapping documents illustrating how a control from one standard relates to a control from a different standard. The mapping documents are consulted by the end user, to identify how a control in one standard may relate to other standards. This allows the end user to navigate between the standards documents. These mapping documents are valuable to a person who wishes to grasp how different standards deal with a specific control. However, the navigation between standards is a cumbersome task. In order to navigate between the standards the end user is required to consult three or more documents, depending on the number of standards that are mapped to the control being investigated. The need for a tool that will provide fast and efficient navigation between standards was identified. The data tier of the tool is the focus of this dissertation. As a result, this research proposes a modeling methodology that will allow for the modeling of the standards and the information about the mapping between standards, thereby contributing to the creation of tools to aid in the navigation between standards. A comparison between the major data modeling paradigms identifies multi-dimensional modeling as the most appropriate technique to model standards. Adapting an existing modeling methodology to cater for the modeling standards, yield a five step standard modeling methodology. Once modeled, the standards can be physically implemented as a database. The database schema that results from the standard modeling methodology adheres to a specific pattern and can thus be expressed according to well-defined meta-model. This allows for the generation of SQL statements by a tool with limited knowledge of the standards in a way that allows the quick navigation between standards. To determine the usefulness of the standards modeling methodology the research presents iv a prototype that utilizes the well-defined meta-model to navigate between standards. It is shown that, as far as navigation is concerned, no code changes are necessary when adding a new standard or new mappings between standards. This research contributes to the creation of a tool that can easily navigate between standards by providing the ability to model the data tier in such a way that it is extensible, yet remains independent of the application and presentation tiers.
- Full Text:
- Date Issued: 2010
- Authors: Domingues, Steve
- Date: 2010
- Subjects: Computer security -- Management , Business -- Data processing -- Security measures , Information resources management -- Security measures , Business -- Standards
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9761 , http://hdl.handle.net/10948/1212 , Computer security -- Management , Business -- Data processing -- Security measures , Information resources management -- Security measures , Business -- Standards
- Description: Organizations no longer draft their own standards. Instead, organizations take advantage of the available international standards. One standard may not cover all the organization's needs, requiring organizations to implement more than one standard. The same aspect in an organization may be covered by two or more standards, creating an overlap. An awareness of such overlaps led to various institutions creating mapping documents illustrating how a control from one standard relates to a control from a different standard. The mapping documents are consulted by the end user, to identify how a control in one standard may relate to other standards. This allows the end user to navigate between the standards documents. These mapping documents are valuable to a person who wishes to grasp how different standards deal with a specific control. However, the navigation between standards is a cumbersome task. In order to navigate between the standards the end user is required to consult three or more documents, depending on the number of standards that are mapped to the control being investigated. The need for a tool that will provide fast and efficient navigation between standards was identified. The data tier of the tool is the focus of this dissertation. As a result, this research proposes a modeling methodology that will allow for the modeling of the standards and the information about the mapping between standards, thereby contributing to the creation of tools to aid in the navigation between standards. A comparison between the major data modeling paradigms identifies multi-dimensional modeling as the most appropriate technique to model standards. Adapting an existing modeling methodology to cater for the modeling standards, yield a five step standard modeling methodology. Once modeled, the standards can be physically implemented as a database. The database schema that results from the standard modeling methodology adheres to a specific pattern and can thus be expressed according to well-defined meta-model. This allows for the generation of SQL statements by a tool with limited knowledge of the standards in a way that allows the quick navigation between standards. To determine the usefulness of the standards modeling methodology the research presents iv a prototype that utilizes the well-defined meta-model to navigate between standards. It is shown that, as far as navigation is concerned, no code changes are necessary when adding a new standard or new mappings between standards. This research contributes to the creation of a tool that can easily navigate between standards by providing the ability to model the data tier in such a way that it is extensible, yet remains independent of the application and presentation tiers.
- Full Text:
- Date Issued: 2010
Process window for friction stir welding of 3 mm titanium (Ti-6AI-4V)
- Authors: Mashinini, Peter Madindwa
- Date: 2010
- Subjects: Friction stir welding , Titanium -- Welding , Welded joints
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9618 , http://hdl.handle.net/10948/1413 , Friction stir welding , Titanium -- Welding , Welded joints
- Description: Friction stir welding was used to join 3 mm Ti-6Al-4V alloy in a butt joint configuration. This research focused on optimization of a tool geometry and the interaction between process parameters and static performance of welded joints. The main parameters varied were tool travel speed and tool rotational speed. The results showed a relationship between heat input as a function of process parameters and static strength. Improved tensile properties correspond to high heat input. The hardness plots revealed an increase in hardness on both the stir zone and heat affected zone despite the small defects on the weld root. The weld microstructure was also evaluated, which showed a variation in microstructure on both the heat affected zone and stir zone in comparison to the parent material. It was also found that the use of MgO as a heat barrier on the backing plate was detrimental to the weld tensile properties of butt-welded plates compared to bead-on-plate welds of which MgO had no influence.
- Full Text:
- Date Issued: 2010
- Authors: Mashinini, Peter Madindwa
- Date: 2010
- Subjects: Friction stir welding , Titanium -- Welding , Welded joints
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9618 , http://hdl.handle.net/10948/1413 , Friction stir welding , Titanium -- Welding , Welded joints
- Description: Friction stir welding was used to join 3 mm Ti-6Al-4V alloy in a butt joint configuration. This research focused on optimization of a tool geometry and the interaction between process parameters and static performance of welded joints. The main parameters varied were tool travel speed and tool rotational speed. The results showed a relationship between heat input as a function of process parameters and static strength. Improved tensile properties correspond to high heat input. The hardness plots revealed an increase in hardness on both the stir zone and heat affected zone despite the small defects on the weld root. The weld microstructure was also evaluated, which showed a variation in microstructure on both the heat affected zone and stir zone in comparison to the parent material. It was also found that the use of MgO as a heat barrier on the backing plate was detrimental to the weld tensile properties of butt-welded plates compared to bead-on-plate welds of which MgO had no influence.
- Full Text:
- Date Issued: 2010
The fatigue life cycle prediction of a light aircraft undercarriage
- Authors: Erasmus, Daniel Jacobus
- Date: 2010
- Subjects: Metals--Fatigue
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9614 , http://hdl.handle.net/10948/1527 , Metals--Fatigue
- Description: The reliability of systems relies heavily on accurate fatigue life prediction of related components. Fatigue life prediction is a complicated process requiring the correct methodology to determine accurate and reliable predictions. The Palmgren – Miner damage accumulation hypothesis is widely used in determining the fatigue life of components exposed to variable loading conditions. Modifications have been made to this hypothesis trying to achieve a greater degree of accuracy, of these the Liu – Zenner modification has been the most successful. In this report the systematic process of fatigue life prediction using the Liu – Zenner modification to achieve reliable results is calculated. A representative stress time history measured in service on the component forms the basis for defining a flight cycle which is the chosen unit in which to express the fatigue life. Rainflow cycle counting performed on the stress time history allowed the formulation of a load spectrum to which the component is exposed in one cycle. Combining the load spectrum with the developed SN curve of the component and using the Liu – Zenner modification to the Palmgren – Miner rule a reliable fatigue life in cycles is predicted.
- Full Text:
- Date Issued: 2010
- Authors: Erasmus, Daniel Jacobus
- Date: 2010
- Subjects: Metals--Fatigue
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9614 , http://hdl.handle.net/10948/1527 , Metals--Fatigue
- Description: The reliability of systems relies heavily on accurate fatigue life prediction of related components. Fatigue life prediction is a complicated process requiring the correct methodology to determine accurate and reliable predictions. The Palmgren – Miner damage accumulation hypothesis is widely used in determining the fatigue life of components exposed to variable loading conditions. Modifications have been made to this hypothesis trying to achieve a greater degree of accuracy, of these the Liu – Zenner modification has been the most successful. In this report the systematic process of fatigue life prediction using the Liu – Zenner modification to achieve reliable results is calculated. A representative stress time history measured in service on the component forms the basis for defining a flight cycle which is the chosen unit in which to express the fatigue life. Rainflow cycle counting performed on the stress time history allowed the formulation of a load spectrum to which the component is exposed in one cycle. Combining the load spectrum with the developed SN curve of the component and using the Liu – Zenner modification to the Palmgren – Miner rule a reliable fatigue life in cycles is predicted.
- Full Text:
- Date Issued: 2010
The investigation of alternative processes for the oxidation of phenol
- Authors: Pongoma, Basanda
- Date: 2010
- Subjects: Phenol , Hydroquinone
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10381 , http://hdl.handle.net/10948/1479 , Phenol , Hydroquinone
- Description: The electrochemical oxidation of phenol can be considered as an important process for either producing value added products such as hydroquinone and catechol or for the removal of the phenol from waste water streams to form carbon dioxide. This process had been extensively studied with the main focus on type of anode material used. Even though the anode material could be made from a range of materials, this study focused on using PbO2 as anode material that was made by using Pb-acid battery principles in designing a microporous electrode. In this study, the focus was on using lead dioxide as an anode material that was made by using the formation principles used in the manufacturing of Pb-acid batteries. This allowed for the construction of an electrochemical flow-through micro-porous reactor that contained PbO2 as the anode and Pb as the cathode, allowing for a solution containing phenol to flow through the cell continuously. By applying a suitable potential across the cell, the almost complete oxidation of phenol would occur to form benzoquinone, which was followed by the sequential reduction to other products such as hydroquinone and catechol. The system was shown to be made up of tightly packed micro-porous material that had a very high surface area-to-volume ratio. The study showed that between 80 to 90 percent successful conversion of a 50 mM solution of phenol could be achieved by optimizing the continuous flow process of up to 500 minutes. The main reaction product from this process was hydroquinone, of up to 60 percent with a number of the minor products of which not all could be identified. In order to utilize the characteristics of this reactor system, its design and reaction conditions such as applied potential, phenol concentration, co-solvent concentration and support electrolyte concentration were investigated to optimize the convection of phenol and the yield of hydroquinone.
- Full Text:
- Date Issued: 2010
- Authors: Pongoma, Basanda
- Date: 2010
- Subjects: Phenol , Hydroquinone
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10381 , http://hdl.handle.net/10948/1479 , Phenol , Hydroquinone
- Description: The electrochemical oxidation of phenol can be considered as an important process for either producing value added products such as hydroquinone and catechol or for the removal of the phenol from waste water streams to form carbon dioxide. This process had been extensively studied with the main focus on type of anode material used. Even though the anode material could be made from a range of materials, this study focused on using PbO2 as anode material that was made by using Pb-acid battery principles in designing a microporous electrode. In this study, the focus was on using lead dioxide as an anode material that was made by using the formation principles used in the manufacturing of Pb-acid batteries. This allowed for the construction of an electrochemical flow-through micro-porous reactor that contained PbO2 as the anode and Pb as the cathode, allowing for a solution containing phenol to flow through the cell continuously. By applying a suitable potential across the cell, the almost complete oxidation of phenol would occur to form benzoquinone, which was followed by the sequential reduction to other products such as hydroquinone and catechol. The system was shown to be made up of tightly packed micro-porous material that had a very high surface area-to-volume ratio. The study showed that between 80 to 90 percent successful conversion of a 50 mM solution of phenol could be achieved by optimizing the continuous flow process of up to 500 minutes. The main reaction product from this process was hydroquinone, of up to 60 percent with a number of the minor products of which not all could be identified. In order to utilize the characteristics of this reactor system, its design and reaction conditions such as applied potential, phenol concentration, co-solvent concentration and support electrolyte concentration were investigated to optimize the convection of phenol and the yield of hydroquinone.
- Full Text:
- Date Issued: 2010
The management of extralimital giraffe (Giraffa Camelopardalis) in the mosaic thicket of Southern Cape, South Africa
- Authors: Cornelius, Andri Judith
- Date: 2010
- Subjects: Giraffe -- South Africa -- Eastern Cape , Giraffe -- Food -- South Africa -- Eastern Cape , Giraffe -- Ecology -- South Africa -- Eastern Cape , Animal behavior , Animal-plant relationships -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10749 , http://hdl.handle.net/10948/1345 , Giraffe -- South Africa -- Eastern Cape , Giraffe -- Food -- South Africa -- Eastern Cape , Giraffe -- Ecology -- South Africa -- Eastern Cape , Animal behavior , Animal-plant relationships -- South Africa -- Eastern Cape
- Description: The giraffe at Nyaru were found to be browsers who made little use of graze during the study period. They utilized a diversity of 20 browse species. Two species, Acacia karroo and Acacia cyclops, formed the bulk of the giraffe diet throughout the year. A definite seasonal dietary shift was evident. A. karroo was favoured in summer and autumn and formed the main food species in spring, summer and autumn. A. cyclops was favoured throughout the study, but its contribution to the diet increased during winter when less A. karroo was consumed. This seasonal shift is related to the deciduous nature of Acacia karroo. Although a seasonal shift in species contribution to giraffe diet has been observed in many other giraffe feeding studies, no studies on giraffe feeding have been done in the Mosaic Thicket of the southern Cape. The ecological browsing capacity for giraffe in thicket was estimated to be between 0.020 BU/ha and 0.095 BU/ha. The browsing capacity for giraffe at Nyaru, based on the available phytomass 2–5 m above the ground, was estimated using those species that formed the bulk of the giraffe diet, and amounted to 0.063 BU/ha. A maximum of three giraffe could thus be stocked on the 157 ha of suitable giraffe habitat on Nyaru. This stocking rate recommendation lies within the range commonly recommended by local consultants for giraffe introductions into the southern Cape. Their recommendations are, however, not based on quantitative assessments such as performed in this study. The recommendation of this study should not be applied as a fixed ecological capacity for giraffe in thicket, but should be seen as a starting point in the adaptive management cycle. Ongoing monitoring of parameters, such as herbaceous composition and phytomass; as well as the condition of key browse species, is strongly advocated. A. karroo was browsed significantly more and carried significantly fewer pods per tree at a heavily used site compared to a lightly used site. Heavy browsing thus appears to affect the reproductive success of A. karroo significantly. Fewer pods are likely to lead to lower regeneration and thus reduced density of A. karroo. Whether A. karroo will maintain its dominance within the thicket vii community in the long run will be related to how individual plants survive and reproduce and if some can escape from herbivory. Fewer G. occidentalis were clumped with other species at the heavily used site compared to the lightly used site. This could possibly be attributed to the fact that intense browsing pressure at the heavily used site caused protective clumps to be eaten away, thus exposing G. occidentalis to higher ungulate browsing. Previous studies have found that nurse shrubs protect G. occidentalis against ungulate browsing. G. occidentalis was browsed significantly more at the heavily used site compared to the lightly used site. There was a general trend of fewer fruits at the heavily used site compared to the lightly used site, while fruits were absent on G. occidentalis growing alone at the heavily used site. This suggests a negative effect of heavy browsing on plant reproductive success and emphasizes the importance of nurse plants for the successful recruitment and hence long term prevalence of G. occidentalis in Mosaic Thicket.
- Full Text:
- Date Issued: 2010
- Authors: Cornelius, Andri Judith
- Date: 2010
- Subjects: Giraffe -- South Africa -- Eastern Cape , Giraffe -- Food -- South Africa -- Eastern Cape , Giraffe -- Ecology -- South Africa -- Eastern Cape , Animal behavior , Animal-plant relationships -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10749 , http://hdl.handle.net/10948/1345 , Giraffe -- South Africa -- Eastern Cape , Giraffe -- Food -- South Africa -- Eastern Cape , Giraffe -- Ecology -- South Africa -- Eastern Cape , Animal behavior , Animal-plant relationships -- South Africa -- Eastern Cape
- Description: The giraffe at Nyaru were found to be browsers who made little use of graze during the study period. They utilized a diversity of 20 browse species. Two species, Acacia karroo and Acacia cyclops, formed the bulk of the giraffe diet throughout the year. A definite seasonal dietary shift was evident. A. karroo was favoured in summer and autumn and formed the main food species in spring, summer and autumn. A. cyclops was favoured throughout the study, but its contribution to the diet increased during winter when less A. karroo was consumed. This seasonal shift is related to the deciduous nature of Acacia karroo. Although a seasonal shift in species contribution to giraffe diet has been observed in many other giraffe feeding studies, no studies on giraffe feeding have been done in the Mosaic Thicket of the southern Cape. The ecological browsing capacity for giraffe in thicket was estimated to be between 0.020 BU/ha and 0.095 BU/ha. The browsing capacity for giraffe at Nyaru, based on the available phytomass 2–5 m above the ground, was estimated using those species that formed the bulk of the giraffe diet, and amounted to 0.063 BU/ha. A maximum of three giraffe could thus be stocked on the 157 ha of suitable giraffe habitat on Nyaru. This stocking rate recommendation lies within the range commonly recommended by local consultants for giraffe introductions into the southern Cape. Their recommendations are, however, not based on quantitative assessments such as performed in this study. The recommendation of this study should not be applied as a fixed ecological capacity for giraffe in thicket, but should be seen as a starting point in the adaptive management cycle. Ongoing monitoring of parameters, such as herbaceous composition and phytomass; as well as the condition of key browse species, is strongly advocated. A. karroo was browsed significantly more and carried significantly fewer pods per tree at a heavily used site compared to a lightly used site. Heavy browsing thus appears to affect the reproductive success of A. karroo significantly. Fewer pods are likely to lead to lower regeneration and thus reduced density of A. karroo. Whether A. karroo will maintain its dominance within the thicket vii community in the long run will be related to how individual plants survive and reproduce and if some can escape from herbivory. Fewer G. occidentalis were clumped with other species at the heavily used site compared to the lightly used site. This could possibly be attributed to the fact that intense browsing pressure at the heavily used site caused protective clumps to be eaten away, thus exposing G. occidentalis to higher ungulate browsing. Previous studies have found that nurse shrubs protect G. occidentalis against ungulate browsing. G. occidentalis was browsed significantly more at the heavily used site compared to the lightly used site. There was a general trend of fewer fruits at the heavily used site compared to the lightly used site, while fruits were absent on G. occidentalis growing alone at the heavily used site. This suggests a negative effect of heavy browsing on plant reproductive success and emphasizes the importance of nurse plants for the successful recruitment and hence long term prevalence of G. occidentalis in Mosaic Thicket.
- Full Text:
- Date Issued: 2010
The possibility of a flexible wireless 3-D measurement in the modern automobile production
- Authors: Frede, Stefan
- Date: 2010
- Subjects: Three-dimensional display systems , Automobile industry and trade , Automobile industry and trade -- South Africa -- Quality control
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9619 , http://hdl.handle.net/10948/1203 , Three-dimensional display systems , Automobile industry and trade , Automobile industry and trade -- South Africa -- Quality control
- Description: The quality control of geometrical coherences and relations in modern automobile production is done by different stationary and flexible measurement systems and strategies. Furthermore, there currently exists possibilities of inline measurements and offline measurements. This project presents the basic research concerning the possibility of a flexible wireless measurement system in modern automobile production, that is able to combine the advantages of both strategies. An investigation of existing measurement techniques was done in order to find a sensor technology, which enables the wireless measurement process. The research project introduces the current location systems and positioning systems. These techniques are compared by a value benefit analysis to expose a suited technology as basis for the measurement system. As result of the value benefit anlysis, the ultrasonic technique was selected for further investigations. The ultrasonic test setup is used to analyze the accuracy of modern sensors and to verify the possibility of a project related integration. The tests are done in different conditions, in order to compare the laboratory application and the industrial application. During the test measurements different physical influencing variables and disturbances occurred. From this research project, it can be concluded that the laboratory application of the system is possible. However, the industrial application is subject to restrictions.
- Full Text:
- Date Issued: 2010
- Authors: Frede, Stefan
- Date: 2010
- Subjects: Three-dimensional display systems , Automobile industry and trade , Automobile industry and trade -- South Africa -- Quality control
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9619 , http://hdl.handle.net/10948/1203 , Three-dimensional display systems , Automobile industry and trade , Automobile industry and trade -- South Africa -- Quality control
- Description: The quality control of geometrical coherences and relations in modern automobile production is done by different stationary and flexible measurement systems and strategies. Furthermore, there currently exists possibilities of inline measurements and offline measurements. This project presents the basic research concerning the possibility of a flexible wireless measurement system in modern automobile production, that is able to combine the advantages of both strategies. An investigation of existing measurement techniques was done in order to find a sensor technology, which enables the wireless measurement process. The research project introduces the current location systems and positioning systems. These techniques are compared by a value benefit analysis to expose a suited technology as basis for the measurement system. As result of the value benefit anlysis, the ultrasonic technique was selected for further investigations. The ultrasonic test setup is used to analyze the accuracy of modern sensors and to verify the possibility of a project related integration. The tests are done in different conditions, in order to compare the laboratory application and the industrial application. During the test measurements different physical influencing variables and disturbances occurred. From this research project, it can be concluded that the laboratory application of the system is possible. However, the industrial application is subject to restrictions.
- Full Text:
- Date Issued: 2010
Veldram performance testing of dorper rams in Namibia : performance testing, progency testing and factors influencing sale price of rams
- Grobler, Hermanus Johannes Fourie
- Authors: Grobler, Hermanus Johannes Fourie
- Date: 2010
- Subjects: Dorper sheep -- Breeding -- Namibia , Sheep -- Breeding -- Namibia , Dorper sheep , Sheep breeds
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10733 , http://hdl.handle.net/10948/1545 , Dorper sheep -- Breeding -- Namibia , Sheep -- Breeding -- Namibia , Dorper sheep , Sheep breeds
- Description: The study aims to determine the contribution made by available ram growth- and breed standard parameters on the sale price of auctioned rams in Namibia. These findings serve as an indication of the importance ram buyers place on individual parameters in selecting rams for breeding purposes. It furthermore tries to establish whether scientific measurement for the estimation of ram breeding values takes precedence over subjective appraisal. The analysis of the 100 day and 270 day growth performance of the progeny of selected Veldram tested rams were used to evaluate the accuracy of the estimation of ram breeding values and may serve to validate the proper execution of these Veldram tests.
- Full Text:
- Date Issued: 2010
- Authors: Grobler, Hermanus Johannes Fourie
- Date: 2010
- Subjects: Dorper sheep -- Breeding -- Namibia , Sheep -- Breeding -- Namibia , Dorper sheep , Sheep breeds
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10733 , http://hdl.handle.net/10948/1545 , Dorper sheep -- Breeding -- Namibia , Sheep -- Breeding -- Namibia , Dorper sheep , Sheep breeds
- Description: The study aims to determine the contribution made by available ram growth- and breed standard parameters on the sale price of auctioned rams in Namibia. These findings serve as an indication of the importance ram buyers place on individual parameters in selecting rams for breeding purposes. It furthermore tries to establish whether scientific measurement for the estimation of ram breeding values takes precedence over subjective appraisal. The analysis of the 100 day and 270 day growth performance of the progeny of selected Veldram tested rams were used to evaluate the accuracy of the estimation of ram breeding values and may serve to validate the proper execution of these Veldram tests.
- Full Text:
- Date Issued: 2010
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