The gap between what 'ought' to be and what students want
- Authors: Boshoff, Priscilla A
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70812 , vital:29747
- Description: There’s no curriculum! There’s no curriculum!” The young man in the focus group was so frustrated that he had to repeat himself, not just once, but several times. I had just asked the group what their feelings were about their second-year coursework. His sentiments were echoed by many of the students in the group, all of whom had passed the rigorous application process into second year at Rhodes University’s School of Journalism and Media Studies.
- Full Text:
- Date Issued: 2010
- Authors: Boshoff, Priscilla A
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70812 , vital:29747
- Description: There’s no curriculum! There’s no curriculum!” The young man in the focus group was so frustrated that he had to repeat himself, not just once, but several times. I had just asked the group what their feelings were about their second-year coursework. His sentiments were echoed by many of the students in the group, all of whom had passed the rigorous application process into second year at Rhodes University’s School of Journalism and Media Studies.
- Full Text:
- Date Issued: 2010
Maximization of power in randomized clinical trials using the minimization treatment allocation technique
- Authors: Marange, Chioneso Show
- Date: 2010
- Subjects: Clinical trials -- Statistical methods , Statistical hypothesis testing , Regression analysis , Logistic distribution , Estimation theory
- Language: English
- Type: Thesis , Masters , MSc (Biostatistics and Epidemiology)
- Identifier: vital:11777 , http://hdl.handle.net/10353/399 , Clinical trials -- Statistical methods , Statistical hypothesis testing , Regression analysis , Logistic distribution , Estimation theory
- Description: Generally the primary goal of randomized clinical trials (RCT) is to make comparisons among two or more treatments hence clinical investigators require the most appropriate treatment allocation procedure to yield reliable results regardless of whether the ultimate data suggest a clinically important difference between the treatments being studied. Although recommended by many researchers, the utilization of minimization has been seldom reported in randomized trials mainly because of the controversy surrounding the statistical efficiency in detecting treatment effect and its complexity in implementation. Methods: A SAS simulation code was designed for allocating patients into two different treatment groups. Categorical prognostic factors were used together with multi-level response variables and demonstration of how simulation of data can help to determine the power of the minimization technique was carried out using ordinal logistic regression models. Results: Several scenarios were simulated in this study. Within the selected scenarios, increasing the sample size significantly increased the power of detecting the treatment effect. This was contrary to the case when the probability of allocation was decreased. Power did not change when the probability of allocation given that the treatment groups are balanced was increased. The probability of allocation { } k P was seen to be the only one with a significant effect on treatment balance. Conclusion: Maximum power can be achieved with a sample of size 300 although a small sample of size 200 can be adequate to attain at least 80% power. In order to have maximum power, the probability of allocation should be fixed at 0.75 and set to 0.5 if the treatment groups are equally balanced.
- Full Text:
- Date Issued: 2010
- Authors: Marange, Chioneso Show
- Date: 2010
- Subjects: Clinical trials -- Statistical methods , Statistical hypothesis testing , Regression analysis , Logistic distribution , Estimation theory
- Language: English
- Type: Thesis , Masters , MSc (Biostatistics and Epidemiology)
- Identifier: vital:11777 , http://hdl.handle.net/10353/399 , Clinical trials -- Statistical methods , Statistical hypothesis testing , Regression analysis , Logistic distribution , Estimation theory
- Description: Generally the primary goal of randomized clinical trials (RCT) is to make comparisons among two or more treatments hence clinical investigators require the most appropriate treatment allocation procedure to yield reliable results regardless of whether the ultimate data suggest a clinically important difference between the treatments being studied. Although recommended by many researchers, the utilization of minimization has been seldom reported in randomized trials mainly because of the controversy surrounding the statistical efficiency in detecting treatment effect and its complexity in implementation. Methods: A SAS simulation code was designed for allocating patients into two different treatment groups. Categorical prognostic factors were used together with multi-level response variables and demonstration of how simulation of data can help to determine the power of the minimization technique was carried out using ordinal logistic regression models. Results: Several scenarios were simulated in this study. Within the selected scenarios, increasing the sample size significantly increased the power of detecting the treatment effect. This was contrary to the case when the probability of allocation was decreased. Power did not change when the probability of allocation given that the treatment groups are balanced was increased. The probability of allocation { } k P was seen to be the only one with a significant effect on treatment balance. Conclusion: Maximum power can be achieved with a sample of size 300 although a small sample of size 200 can be adequate to attain at least 80% power. In order to have maximum power, the probability of allocation should be fixed at 0.75 and set to 0.5 if the treatment groups are equally balanced.
- Full Text:
- Date Issued: 2010
Improving project implementation in firms
- Authors: Hassen, Ismail
- Date: 2010
- Subjects: Project management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8667 , http://hdl.handle.net/10948/1245 , Project management -- South Africa
- Description: Project implementation appears to be one the most difficult aspects of a manager’s job. The purpose of project management is to forecast or anticipate potential dangers and problems that may jeopardise the success of a project and then to plan, organise and control activities that will lead to the successful completion of projects in spite of all the envisaged risks. It is estimated that more than 80% of projects run late or over budget. Such failure often sinks small firms and erodes profits of larger organisations. Project implementation is therefore critical to the success of both small and big firms. The primary objective of this study is to improve project management in firms by investigating the variables that influence project implementation. More specifically, the study investigates the influence of organisational communication, leadership, business process management and resistance to change on project implementation. The sample consisted of 170 employees in a cross-section of industries. The sample was stratified to include senior managers, managers, supervisors and lower level employees. The empirical results show that organisational communication, participatory leadership, retention of the status quo and goal-oriented leadership increase project implementation, while resistance to change decreases project implementation.
- Full Text:
- Date Issued: 2010
- Authors: Hassen, Ismail
- Date: 2010
- Subjects: Project management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8667 , http://hdl.handle.net/10948/1245 , Project management -- South Africa
- Description: Project implementation appears to be one the most difficult aspects of a manager’s job. The purpose of project management is to forecast or anticipate potential dangers and problems that may jeopardise the success of a project and then to plan, organise and control activities that will lead to the successful completion of projects in spite of all the envisaged risks. It is estimated that more than 80% of projects run late or over budget. Such failure often sinks small firms and erodes profits of larger organisations. Project implementation is therefore critical to the success of both small and big firms. The primary objective of this study is to improve project management in firms by investigating the variables that influence project implementation. More specifically, the study investigates the influence of organisational communication, leadership, business process management and resistance to change on project implementation. The sample consisted of 170 employees in a cross-section of industries. The sample was stratified to include senior managers, managers, supervisors and lower level employees. The empirical results show that organisational communication, participatory leadership, retention of the status quo and goal-oriented leadership increase project implementation, while resistance to change decreases project implementation.
- Full Text:
- Date Issued: 2010
Evaluating the impact of public participation on the formulation and implementation of the Integrated Development Plan: the case of the Nelson Mandela Bay Municipality (2004-2008)
- Authors: Mqulwana, Nimrod Mbuyiseli
- Date: 2010
- Subjects: City planning -- South Africa -- Port Elizabeth , Civic improvement -- South Africa -- Port Elizabeth , Regional planning -- South Africa -- Port Elizabeth , Political participation -- South Africa -- Port Elizabeth , Local government -- South Africa -- Port Elizabeth , Community development -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:11638 , http://hdl.handle.net/10353/d1001247 , City planning -- South Africa -- Port Elizabeth , Civic improvement -- South Africa -- Port Elizabeth , Regional planning -- South Africa -- Port Elizabeth , Political participation -- South Africa -- Port Elizabeth , Local government -- South Africa -- Port Elizabeth , Community development -- South Africa -- Port Elizabeth
- Description: Local Government has a critical role to play in rebuilding local communities and environments as the basis for a democratic, integrated prosperous and truly non-racial society and this is enshrined in Chapter 7 of the Constitution of the Republic of South Africa Act 108 of 1996. The key focus area of this research study is the evaluation of the impact of Public Participation on the formulation and implementation of the Integrated Development Plan in the Nelson Mandela Bay Municipality for the period 2004 – 2008. This research study has two aims that are related to public participation in the Nelson Mandela Bay Municipality and they are: - To evaluate the impact of public participation in the Integrated Development Plan in the Nelson Mandela Bay Municipality and whether public participation is seen as a vehicle to enhance policy formulation and implementation or not especially with respect to community ownership of the Integrated Development Plan. To provide strategies/mechanisms to remedy the situation. The research study is people focused and the methodogical approach that is used in this investigation is qualitative and quantitative. The target groups for this research is the Community residing in the jurisdiction area of the Nelson Mandela Bay Municipality, Metro Councillors and Municipal Officials.
- Full Text:
- Date Issued: 2010
- Authors: Mqulwana, Nimrod Mbuyiseli
- Date: 2010
- Subjects: City planning -- South Africa -- Port Elizabeth , Civic improvement -- South Africa -- Port Elizabeth , Regional planning -- South Africa -- Port Elizabeth , Political participation -- South Africa -- Port Elizabeth , Local government -- South Africa -- Port Elizabeth , Community development -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:11638 , http://hdl.handle.net/10353/d1001247 , City planning -- South Africa -- Port Elizabeth , Civic improvement -- South Africa -- Port Elizabeth , Regional planning -- South Africa -- Port Elizabeth , Political participation -- South Africa -- Port Elizabeth , Local government -- South Africa -- Port Elizabeth , Community development -- South Africa -- Port Elizabeth
- Description: Local Government has a critical role to play in rebuilding local communities and environments as the basis for a democratic, integrated prosperous and truly non-racial society and this is enshrined in Chapter 7 of the Constitution of the Republic of South Africa Act 108 of 1996. The key focus area of this research study is the evaluation of the impact of Public Participation on the formulation and implementation of the Integrated Development Plan in the Nelson Mandela Bay Municipality for the period 2004 – 2008. This research study has two aims that are related to public participation in the Nelson Mandela Bay Municipality and they are: - To evaluate the impact of public participation in the Integrated Development Plan in the Nelson Mandela Bay Municipality and whether public participation is seen as a vehicle to enhance policy formulation and implementation or not especially with respect to community ownership of the Integrated Development Plan. To provide strategies/mechanisms to remedy the situation. The research study is people focused and the methodogical approach that is used in this investigation is qualitative and quantitative. The target groups for this research is the Community residing in the jurisdiction area of the Nelson Mandela Bay Municipality, Metro Councillors and Municipal Officials.
- Full Text:
- Date Issued: 2010
Synthesis and photophysical properties of 1, 1′-binaphthol substituted phthalocyanines
- Canlica, Meylude, Nyokong, Tebello
- Authors: Canlica, Meylude , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249148 , vital:51782 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.034"
- Description: We report on the synthesis, characterization and photophysical properties of a new symmetrically tetra substituted {at non-peripheral positions with tetra(1,1′-bi-binaphtoxy)} phthalocyanines containing H2, Mg(II), Al(III)Cl, Si(IV)Cl2 in the central cavity. The synthesized compounds were characterized by the elemental analyses, UV–Vis, FT-IR and 1H NMR spectroscopies. The fluorescence quantum yields, triplet quantum yields and lifetimes of the newly synthesized H2, Mg, Al, and Si phthalocyanines were explored. Triplet quantum yields ranged from 0.24 to 0.54. The triplet lifetime for the silicon phthalocyanine derivative was the highest ever reported for a phthalocyanine (∼3.5 ms).
- Full Text:
- Date Issued: 2010
- Authors: Canlica, Meylude , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249148 , vital:51782 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.034"
- Description: We report on the synthesis, characterization and photophysical properties of a new symmetrically tetra substituted {at non-peripheral positions with tetra(1,1′-bi-binaphtoxy)} phthalocyanines containing H2, Mg(II), Al(III)Cl, Si(IV)Cl2 in the central cavity. The synthesized compounds were characterized by the elemental analyses, UV–Vis, FT-IR and 1H NMR spectroscopies. The fluorescence quantum yields, triplet quantum yields and lifetimes of the newly synthesized H2, Mg, Al, and Si phthalocyanines were explored. Triplet quantum yields ranged from 0.24 to 0.54. The triplet lifetime for the silicon phthalocyanine derivative was the highest ever reported for a phthalocyanine (∼3.5 ms).
- Full Text:
- Date Issued: 2010
The in vitro biological activities of three Hypoxis species and their active compounds
- Authors: Boukes, Gerhardt Johannes
- Date: 2010
- Subjects: Potatoes -- Africa , Potatoes -- Therapeutic use , Medicinal plants
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10322 , http://hdl.handle.net/10948/1228 , Potatoes -- Africa , Potatoes -- Therapeutic use , Medicinal plants
- Description: The African potato is used as an African traditional medicine for its nutritional and medicinal properties. Most research has been carried out on H. hemerocallidea, with very little or nothing on other Hypoxis spp. The main aim of this project was to provide scientific data on the anticancer, anti-inflammatory and antioxidant properties of H. hemerocallidea, H. stellipilis and H. sobolifera chloroform extracts and their active compounds. The hypoxoside and phytosterol contents of the three Hypoxis spp. were determined using TLC, HPLC and GC. H. hemerocallidea and H. sobolifera chloroform extracts contained the highest amounts of hypoxoside and β-sitosterol, respectively. For the anticancer properties, cytotoxicity of the Hypoxis extracts and its purified compounds were determined against the HeLa, HT-29 and MCF-7 cancer cell lines (using MTT), and PBMCs (using CellTiter-Blue®). H. sobolifera had the best cytotoxicity against the three cancer cell lines, whereas H. stellipilis stimulated HeLa and HT-29 cancer cell growth. IC50 values of hypoxoside and rooperol were determined. DNA cell cycle arrest (using PI staining) occurred in the late G1/early S (confirmed by increased p21Waf1/Cip1 expression) and G2/M phases after 15 and 48 hrs, respectively, when treated with Hypoxis extracts and rooperol. H. sobolifera and rooperol activated caspase-3 and -7 (using fluorescently labelled antibodies) in HeLa and HT-29 cancer cells, and caspase-7 in MCF-7 cancer cells after 48 hrs. Annexin V binding to phosphatidylserines in rooperol treated U937 cells confirmed early apoptosis after 15 hrs. The TUNEL assay showed DNA fragmentation in the three cancer cell lines when treated with H. sobolifera and rooperol for 48 hrs. A shift pass the G2/M phase has led to the investigation of endoreduplication, which was confirmed by cell/nucleus size, and anti-apoptotic proteins (Akt, phospho-Akt, phospho-Bcl-2 and p21Waf1/Cip1). U937 cell differentiation to monocyte-macrophages was optimized using PMA and 1,25(OH)2D3, which was confirmed by morphological and biochemical changes. For the anti-inflammatory properties, Hypoxis extracts and rooperol significantly increased NO production in monocyte-macrophages (pre-loaded with DAF-2 DA) and phagocytosis of pHrodoTM E. coli BioParticles®. The treatments had no effect on COX-2 expression in monocyte-macrophages. The phytosterols significantly increased IL-1β and IL-6 secretion xv (using the FlowCytomix Multiplex human Th1/Th2 10plex Kit I) in the PBMCs of one donor. For the antioxidant properties, Hypoxis extracts and rooperol significantly increased ROS production in undifferentiated and differentiated U937 cells, which were pre-loaded with DCFH-DA. Hypoxis extracts and purified compounds had ferric reducing activities, but only rooperol had ferric reducing activities significantly greater than ascorbic acid. β-sitosterol, campesterol and cholesterol significantly increased SOD activity in Chang liver cells, while H. stellipilis, H. sobolifera and rooperol decreased SOD activity. Anticancer, anti-inflammatory and antioxidant properties of the Hypoxis extracts may be attributed to the β-sitosterol content, because Hypoxis chloroform extracts contained very little or no hypoxoside. Unidentified compounds, and synergistic and additive effects of the compounds may have contributed to the biological effects. This study confirms previous reports that rooperol is the active compound. Results provide scientific data on the medicinal properties of one of the most frequently used medicinal plants in South Africa.
- Full Text:
- Date Issued: 2010
- Authors: Boukes, Gerhardt Johannes
- Date: 2010
- Subjects: Potatoes -- Africa , Potatoes -- Therapeutic use , Medicinal plants
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10322 , http://hdl.handle.net/10948/1228 , Potatoes -- Africa , Potatoes -- Therapeutic use , Medicinal plants
- Description: The African potato is used as an African traditional medicine for its nutritional and medicinal properties. Most research has been carried out on H. hemerocallidea, with very little or nothing on other Hypoxis spp. The main aim of this project was to provide scientific data on the anticancer, anti-inflammatory and antioxidant properties of H. hemerocallidea, H. stellipilis and H. sobolifera chloroform extracts and their active compounds. The hypoxoside and phytosterol contents of the three Hypoxis spp. were determined using TLC, HPLC and GC. H. hemerocallidea and H. sobolifera chloroform extracts contained the highest amounts of hypoxoside and β-sitosterol, respectively. For the anticancer properties, cytotoxicity of the Hypoxis extracts and its purified compounds were determined against the HeLa, HT-29 and MCF-7 cancer cell lines (using MTT), and PBMCs (using CellTiter-Blue®). H. sobolifera had the best cytotoxicity against the three cancer cell lines, whereas H. stellipilis stimulated HeLa and HT-29 cancer cell growth. IC50 values of hypoxoside and rooperol were determined. DNA cell cycle arrest (using PI staining) occurred in the late G1/early S (confirmed by increased p21Waf1/Cip1 expression) and G2/M phases after 15 and 48 hrs, respectively, when treated with Hypoxis extracts and rooperol. H. sobolifera and rooperol activated caspase-3 and -7 (using fluorescently labelled antibodies) in HeLa and HT-29 cancer cells, and caspase-7 in MCF-7 cancer cells after 48 hrs. Annexin V binding to phosphatidylserines in rooperol treated U937 cells confirmed early apoptosis after 15 hrs. The TUNEL assay showed DNA fragmentation in the three cancer cell lines when treated with H. sobolifera and rooperol for 48 hrs. A shift pass the G2/M phase has led to the investigation of endoreduplication, which was confirmed by cell/nucleus size, and anti-apoptotic proteins (Akt, phospho-Akt, phospho-Bcl-2 and p21Waf1/Cip1). U937 cell differentiation to monocyte-macrophages was optimized using PMA and 1,25(OH)2D3, which was confirmed by morphological and biochemical changes. For the anti-inflammatory properties, Hypoxis extracts and rooperol significantly increased NO production in monocyte-macrophages (pre-loaded with DAF-2 DA) and phagocytosis of pHrodoTM E. coli BioParticles®. The treatments had no effect on COX-2 expression in monocyte-macrophages. The phytosterols significantly increased IL-1β and IL-6 secretion xv (using the FlowCytomix Multiplex human Th1/Th2 10plex Kit I) in the PBMCs of one donor. For the antioxidant properties, Hypoxis extracts and rooperol significantly increased ROS production in undifferentiated and differentiated U937 cells, which were pre-loaded with DCFH-DA. Hypoxis extracts and purified compounds had ferric reducing activities, but only rooperol had ferric reducing activities significantly greater than ascorbic acid. β-sitosterol, campesterol and cholesterol significantly increased SOD activity in Chang liver cells, while H. stellipilis, H. sobolifera and rooperol decreased SOD activity. Anticancer, anti-inflammatory and antioxidant properties of the Hypoxis extracts may be attributed to the β-sitosterol content, because Hypoxis chloroform extracts contained very little or no hypoxoside. Unidentified compounds, and synergistic and additive effects of the compounds may have contributed to the biological effects. This study confirms previous reports that rooperol is the active compound. Results provide scientific data on the medicinal properties of one of the most frequently used medicinal plants in South Africa.
- Full Text:
- Date Issued: 2010
Photoelectrochemical characterization of electrodeposited ZnO thin films sensitized by octacarboxymetallophthalocyanine derivatives
- Idowu, Mopelola, Loewenstein, Thomas, Hastall, Andreas, Nyokong, Tebello, Schlettwein, Derck
- Authors: Idowu, Mopelola , Loewenstein, Thomas , Hastall, Andreas , Nyokong, Tebello , Schlettwein, Derck
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262655 , vital:53541 , xlink:href="https://doi.org/10.1142/S1088424610001854"
- Description: Hybrid thin films of crystalline zinc oxide (ZnO) modified by different octacarboxymetallophthalocyanines (MOCPc) were prepared by the readsorption method. Homogeneously blue or green thin films were formed. The photoelectrochemical characteristics of the electrodes were studied by time-resolved photocurrent measurements. Zinc(II) 2,3,9,10,16,17,23,24-octacarboxyphthalocyanine (ZnOCPc) showed considerably large quantum efficiency in sensitization of ZnO, one of the highest quantum efficiencies obtained so far with phthalocyanine-type sensitizers on nanocrystalline ZnO films.
- Full Text:
- Date Issued: 2010
- Authors: Idowu, Mopelola , Loewenstein, Thomas , Hastall, Andreas , Nyokong, Tebello , Schlettwein, Derck
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262655 , vital:53541 , xlink:href="https://doi.org/10.1142/S1088424610001854"
- Description: Hybrid thin films of crystalline zinc oxide (ZnO) modified by different octacarboxymetallophthalocyanines (MOCPc) were prepared by the readsorption method. Homogeneously blue or green thin films were formed. The photoelectrochemical characteristics of the electrodes were studied by time-resolved photocurrent measurements. Zinc(II) 2,3,9,10,16,17,23,24-octacarboxyphthalocyanine (ZnOCPc) showed considerably large quantum efficiency in sensitization of ZnO, one of the highest quantum efficiencies obtained so far with phthalocyanine-type sensitizers on nanocrystalline ZnO films.
- Full Text:
- Date Issued: 2010
Synthetic pathways to water-soluble phthalocyanines and close analogs
- Dumoulin, Fabienne, Durmus, Mahmut, Ahsen, Vefa, Nyokong, Tebello
- Authors: Dumoulin, Fabienne , Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249082 , vital:51776 , xlink:href="https://doi.org/10.1016/j.ccr.2010.05.002"
- Description: The different types of water-soluble phthalocyanines are presented and their synthesis is reviewed.
- Full Text:
- Date Issued: 2010
- Authors: Dumoulin, Fabienne , Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249082 , vital:51776 , xlink:href="https://doi.org/10.1016/j.ccr.2010.05.002"
- Description: The different types of water-soluble phthalocyanines are presented and their synthesis is reviewed.
- Full Text:
- Date Issued: 2010
An in-line measuring technique with tool error detection in an automotive production line
- Authors: Viol, Florian
- Date: 2010
- Subjects: Automobile industry and trade -- Quality control
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: vital:9647 , http://hdl.handle.net/10948/1327 , Automobile industry and trade -- Quality control
- Description: The modern automobile industry faces an increasing demand on personalized high quality products. In order to stay competitive the automobile manufacturers have to ensure the customers high quality demands. With the increasing amount of applied parts and components manufacturing processes are becoming more complex. The recent quality assurance of the manufacturers considers only the product quality. Furthermore are with the recent quality assurance methods only punctual integrations of quality assurance tools in production chains possible. These limitations cause a large quality control loop. This leads in case of defective parts to an enormous time and money effort to track the cause for the defect. This project presents an innovative measurement strategy of quality assurance within the modern automobile production which will minimize the control loop and identify the tool causing the defect in the part. It highlights the possibility to integrate equipment for quality assurance directly into the production cell itself and analyse the geometrical conditions within the manufacturing processes. The result of this thesis is a fully automated prototype which is installed into the actual production of the Volkswagen Golf assembly. The prototype system consists on the one hand out of different on the market free available hardware and software components. On the other hand there are specifically for this prototype developed hardware components and software tools. For the first time it is possible to inspect the geometrical conditions of one tool continuously during production and identify, if occurring, deviations in the tool in position direction and size. The installation of similar systems in the production will minimize the control loops of the production. The chance of early recognition of errors will reduce the efforts and cost of error backtracking. In ideal conditions this instrument will identify defective tools before a product is manufactured. This innovative quality tool is the ideal addition to the current quality assurance and is the first link between the product quality and the geometrical conditions of the tools.
- Full Text:
- Date Issued: 2010
- Authors: Viol, Florian
- Date: 2010
- Subjects: Automobile industry and trade -- Quality control
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: vital:9647 , http://hdl.handle.net/10948/1327 , Automobile industry and trade -- Quality control
- Description: The modern automobile industry faces an increasing demand on personalized high quality products. In order to stay competitive the automobile manufacturers have to ensure the customers high quality demands. With the increasing amount of applied parts and components manufacturing processes are becoming more complex. The recent quality assurance of the manufacturers considers only the product quality. Furthermore are with the recent quality assurance methods only punctual integrations of quality assurance tools in production chains possible. These limitations cause a large quality control loop. This leads in case of defective parts to an enormous time and money effort to track the cause for the defect. This project presents an innovative measurement strategy of quality assurance within the modern automobile production which will minimize the control loop and identify the tool causing the defect in the part. It highlights the possibility to integrate equipment for quality assurance directly into the production cell itself and analyse the geometrical conditions within the manufacturing processes. The result of this thesis is a fully automated prototype which is installed into the actual production of the Volkswagen Golf assembly. The prototype system consists on the one hand out of different on the market free available hardware and software components. On the other hand there are specifically for this prototype developed hardware components and software tools. For the first time it is possible to inspect the geometrical conditions of one tool continuously during production and identify, if occurring, deviations in the tool in position direction and size. The installation of similar systems in the production will minimize the control loops of the production. The chance of early recognition of errors will reduce the efforts and cost of error backtracking. In ideal conditions this instrument will identify defective tools before a product is manufactured. This innovative quality tool is the ideal addition to the current quality assurance and is the first link between the product quality and the geometrical conditions of the tools.
- Full Text:
- Date Issued: 2010
Concussion in contact sport: investigating the neurocognitive profile of Afrikaans adolescent rugby players
- Authors: Horsman, Mark
- Date: 2010
- Subjects: Afrikaner students -- Intelligence testing Sports -- Psychological aspects Rugby football injuries Neural computers Neuropsychological tests Brain -- Concussion
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2994 , http://hdl.handle.net/10962/d1002503
- Description: A number of computerised tests have been especially developed to facilitate the medical management of the sports-related concussion. Probably the most widely used of these programmes is the ImPACT test that was developed in the USA and that is registered with the HPCSA for use in the South African context. A recent Afrikaans version of the test served as the basis of the present study with the following objectives: (i) to collect Afrikaans ImPACT normative data on a cohort of Afrikaans first language adolescent rugby players with Model C education for comparison with existing South African English first language adolescent rugby players with Private/Model C schooling, and (ii) to investigate the pre-versus postseason ImPACT neurocognitive test profiles of this cohort of Afrikaans first language adolescent rugby players versus equivalent noncontact sports controls. The results for Part 1 of the study generally demonstrate poorer performance in respect of the Afrikaans cohort, which is understood to be the result of poorer quality of education. The results for Part 2 demonstrated failure of the rugby group to benefit from practice on the ImPACT Visual Motor Speed composite score to the same extent as the control group. It is argued that this apparent cognitive vulnerability in the rugby group is due to lowered cognitive reserve capacity in association with long term exposure to concussive and sub-concussive injury.
- Full Text:
- Date Issued: 2010
- Authors: Horsman, Mark
- Date: 2010
- Subjects: Afrikaner students -- Intelligence testing Sports -- Psychological aspects Rugby football injuries Neural computers Neuropsychological tests Brain -- Concussion
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2994 , http://hdl.handle.net/10962/d1002503
- Description: A number of computerised tests have been especially developed to facilitate the medical management of the sports-related concussion. Probably the most widely used of these programmes is the ImPACT test that was developed in the USA and that is registered with the HPCSA for use in the South African context. A recent Afrikaans version of the test served as the basis of the present study with the following objectives: (i) to collect Afrikaans ImPACT normative data on a cohort of Afrikaans first language adolescent rugby players with Model C education for comparison with existing South African English first language adolescent rugby players with Private/Model C schooling, and (ii) to investigate the pre-versus postseason ImPACT neurocognitive test profiles of this cohort of Afrikaans first language adolescent rugby players versus equivalent noncontact sports controls. The results for Part 1 of the study generally demonstrate poorer performance in respect of the Afrikaans cohort, which is understood to be the result of poorer quality of education. The results for Part 2 demonstrated failure of the rugby group to benefit from practice on the ImPACT Visual Motor Speed composite score to the same extent as the control group. It is argued that this apparent cognitive vulnerability in the rugby group is due to lowered cognitive reserve capacity in association with long term exposure to concussive and sub-concussive injury.
- Full Text:
- Date Issued: 2010
"Fit for purpose": towards tracking the quality of university education of entry-level journalists
- Authors: Berger, Guy
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159835 , vital:40348 , DOI: 10.1080/02560054.2005.9653329
- Description: Debate about the extent to which university education should serve industry is an important consideration for institutions of higher learning in a transforming South Africa, and particularly for those teaching would-be journalists. This issue can also be profitably analysed with reference to the current framework of the South African education authorities who argue that the quality of higher education institutions should be measured in terms of their “fit for purpose” to missions aligned to stakeholder interests in the transformation of the country as a whole. This criterion for quality assessment tends to focus on the educative processes within a university, but it can be argued that it ought to extend into the examination of the output consequences of journalism teaching. This would amount to not just fitness for purpose, but also achievement of purpose – and the latter including a creative and critical impact.
- Full Text:
- Date Issued: 2010
- Authors: Berger, Guy
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159835 , vital:40348 , DOI: 10.1080/02560054.2005.9653329
- Description: Debate about the extent to which university education should serve industry is an important consideration for institutions of higher learning in a transforming South Africa, and particularly for those teaching would-be journalists. This issue can also be profitably analysed with reference to the current framework of the South African education authorities who argue that the quality of higher education institutions should be measured in terms of their “fit for purpose” to missions aligned to stakeholder interests in the transformation of the country as a whole. This criterion for quality assessment tends to focus on the educative processes within a university, but it can be argued that it ought to extend into the examination of the output consequences of journalism teaching. This would amount to not just fitness for purpose, but also achievement of purpose – and the latter including a creative and critical impact.
- Full Text:
- Date Issued: 2010
Contemporary left politics in South Africa: the case of the tri-partite alliance in the Eastern Cape
- Authors: Hesjedal, Siv Helen
- Date: 2010
- Subjects: Politics, Practical -- South Africa Social classes -- South Africa -- History Political parties -- South Africa African National Congress South African Communist Party Cosatu Eastern Cape (South Africa) -- Politics and government Politics, Practical -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3295 , http://hdl.handle.net/10962/d1003083
- Description: This thesis aims to make sense of Left politics in South Africa within the Tri-partite Alliance between the ANC, SACP and COSATU. The thesis focuses on developments in the Eastern Cape, between 2000 and 2008. The thesis describes the prevalent forms of Left politics in the Eastern Cape and the tendencies in the Alliance that organise this Left. The thesis also examines the historical, social and political conditions and that shape the form and content of Left politics in the province. Based on a survey of literature on what is considered the core manifestations of Left politics globally in the 20th Century Left politics is defined as the elements of the political spectrum that are concerned with the progressive resolution of involuntary disadvantage and with a goal of abolishing class society and capitalism. Although the Alliance as a whole should be seen to be on the Left on an international political spectrum, this thesis argues that the Left/Right dichotomy is useful for understanding the politics of the Alliance, as long as the second part of this definition is taken into consideration. The Alliance Left is understood as those leaders and activists within the Alliance that have the SACP and Cosatu as their operating base. It will be argued that this Left is, in its practice, largely concerned with what insiders refer to as politics of „influence‟, rather than with politics of „structural transformation‟. It is the ANC that is the leader of the Alliance and the party in government and thus it is on the terrain of ANC strategy, policy and positions that contestation in the Alliance plays itself out. Thus, for the Left, there is strength in the idea of the Alliance. However, there are significant theoretical and political weaknesses in the Left that undermine the possibility of making good use of various corporatist platforms to pursue the agenda of the Left in the Eastern Cape. There is also increased contestation within the Alliance Left itself about the continued usefulness of this strategy.
- Full Text:
- Date Issued: 2010
Contemporary left politics in South Africa: the case of the tri-partite alliance in the Eastern Cape
- Authors: Hesjedal, Siv Helen
- Date: 2010
- Subjects: Politics, Practical -- South Africa Social classes -- South Africa -- History Political parties -- South Africa African National Congress South African Communist Party Cosatu Eastern Cape (South Africa) -- Politics and government Politics, Practical -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3295 , http://hdl.handle.net/10962/d1003083
- Description: This thesis aims to make sense of Left politics in South Africa within the Tri-partite Alliance between the ANC, SACP and COSATU. The thesis focuses on developments in the Eastern Cape, between 2000 and 2008. The thesis describes the prevalent forms of Left politics in the Eastern Cape and the tendencies in the Alliance that organise this Left. The thesis also examines the historical, social and political conditions and that shape the form and content of Left politics in the province. Based on a survey of literature on what is considered the core manifestations of Left politics globally in the 20th Century Left politics is defined as the elements of the political spectrum that are concerned with the progressive resolution of involuntary disadvantage and with a goal of abolishing class society and capitalism. Although the Alliance as a whole should be seen to be on the Left on an international political spectrum, this thesis argues that the Left/Right dichotomy is useful for understanding the politics of the Alliance, as long as the second part of this definition is taken into consideration. The Alliance Left is understood as those leaders and activists within the Alliance that have the SACP and Cosatu as their operating base. It will be argued that this Left is, in its practice, largely concerned with what insiders refer to as politics of „influence‟, rather than with politics of „structural transformation‟. It is the ANC that is the leader of the Alliance and the party in government and thus it is on the terrain of ANC strategy, policy and positions that contestation in the Alliance plays itself out. Thus, for the Left, there is strength in the idea of the Alliance. However, there are significant theoretical and political weaknesses in the Left that undermine the possibility of making good use of various corporatist platforms to pursue the agenda of the Left in the Eastern Cape. There is also increased contestation within the Alliance Left itself about the continued usefulness of this strategy.
- Full Text:
- Date Issued: 2010
An evaluation into the implemation of the arts and culture learning area in Bizana schools of the Eastern Cape Province
- Authors: Mbeshu, Nonceba Cynthia
- Date: 2010
- Subjects: Arts -- Study and teaching -- South Africa , Culture -- Study and teaching -- South Africa , Teachers -- Training of -- South Africa -- Eastern Cape , Curriculum evaluation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:8508 , http://hdl.handle.net/10948/1189 , Arts -- Study and teaching -- South Africa , Culture -- Study and teaching -- South Africa , Teachers -- Training of -- South Africa -- Eastern Cape , Curriculum evaluation -- South Africa -- Eastern Cape
- Description: “Arts in education are arts that play a radical different role in the open classroom than traditional school. Arts are the real business of reading, writing, math or science” Siberman cited in Mark, (1995:160). This view by Siberman sharply contrasts with my observations in my school. During CASS moderation sessions, teachers bring learner portfolios with no learning activities, others prefer to teach learning areas they are qualified for rather than teaching Arts and Culture because they have no background knowledge in Arts and Culture. The question I wrestled with was: what could be the challenges faced by the Arts and Culture teachers given the fact that training has been conducted since the inclusion of the learning area in the curriculum from 1999 to date? In an implementation evaluation study that I conducted among four schools in the Bizana Area of the Eastern Cape Province, I found out through participant observation, questionnaires and interviews from four sampled senior phase teachers, that some of the participants have stopped teaching Arts and Culture in their schools because ‘they do not know what to teach’. Through the use of a thematic content analysis approach, I found out that many teachers complain about their lack of background knowledge of the art forms and that there is limited time provided in the timetable to teach this learning area. Seemingly, there are still challenges in the implementation of the learning area in this district. The results indicate a serious need for formal training of the Arts and Culture teachers with proper qualifications in more than one art form.
- Full Text:
- Date Issued: 2010
- Authors: Mbeshu, Nonceba Cynthia
- Date: 2010
- Subjects: Arts -- Study and teaching -- South Africa , Culture -- Study and teaching -- South Africa , Teachers -- Training of -- South Africa -- Eastern Cape , Curriculum evaluation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:8508 , http://hdl.handle.net/10948/1189 , Arts -- Study and teaching -- South Africa , Culture -- Study and teaching -- South Africa , Teachers -- Training of -- South Africa -- Eastern Cape , Curriculum evaluation -- South Africa -- Eastern Cape
- Description: “Arts in education are arts that play a radical different role in the open classroom than traditional school. Arts are the real business of reading, writing, math or science” Siberman cited in Mark, (1995:160). This view by Siberman sharply contrasts with my observations in my school. During CASS moderation sessions, teachers bring learner portfolios with no learning activities, others prefer to teach learning areas they are qualified for rather than teaching Arts and Culture because they have no background knowledge in Arts and Culture. The question I wrestled with was: what could be the challenges faced by the Arts and Culture teachers given the fact that training has been conducted since the inclusion of the learning area in the curriculum from 1999 to date? In an implementation evaluation study that I conducted among four schools in the Bizana Area of the Eastern Cape Province, I found out through participant observation, questionnaires and interviews from four sampled senior phase teachers, that some of the participants have stopped teaching Arts and Culture in their schools because ‘they do not know what to teach’. Through the use of a thematic content analysis approach, I found out that many teachers complain about their lack of background knowledge of the art forms and that there is limited time provided in the timetable to teach this learning area. Seemingly, there are still challenges in the implementation of the learning area in this district. The results indicate a serious need for formal training of the Arts and Culture teachers with proper qualifications in more than one art form.
- Full Text:
- Date Issued: 2010
Electrochemical, spectroscopic and microscopic studies of new manganese phthalocyanine complexes in solution and as self-assembled monolayers on gold
- Coates, Megan, Antunes, Edith M, Nyokong, Tebello
- Authors: Coates, Megan , Antunes, Edith M , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261144 , vital:53363 , xlink:href="https://doi.org/10.1142/S1088424610002471"
- Description: Four new manganese(III) phthalocyanines (3a–d), octasubstituted at the peripheral position with pentylthio, decylthio, benzylthio, and phenylthio groups, respectively, were synthesized. Their specific electrochemical, spectroscopic and microscopic properties in solution and as self-assembled monolayers on gold were characterized. The UV-vis spectra confirmed red-shifted Q bands for all the complexes, due to the effect of the central metal and the electron-donating substituents. Three redox couples were visible during cyclic voltammetry studies for the four complexes, and spectroelectrochemistry confirmed the couples as corresponding to MnIIIPc-2/MnIIPc-2 (II) (metal reduction), MnIIPc-2/MnIIPc-3 (III) (ring reduction) and MnIIIPc-1/MnIIIPc-2 (I) (ring oxidation). Electrochemistry was also used to determine the blocking characteristics of the MnPc self-assembled monolayers on gold, which proved to be highly dependent on the type of substituent. Other methods of characterization included Raman spectroscopy, atomic force and scanning electrochemical microscopy analyses of the SAMs.
- Full Text:
- Date Issued: 2010
- Authors: Coates, Megan , Antunes, Edith M , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261144 , vital:53363 , xlink:href="https://doi.org/10.1142/S1088424610002471"
- Description: Four new manganese(III) phthalocyanines (3a–d), octasubstituted at the peripheral position with pentylthio, decylthio, benzylthio, and phenylthio groups, respectively, were synthesized. Their specific electrochemical, spectroscopic and microscopic properties in solution and as self-assembled monolayers on gold were characterized. The UV-vis spectra confirmed red-shifted Q bands for all the complexes, due to the effect of the central metal and the electron-donating substituents. Three redox couples were visible during cyclic voltammetry studies for the four complexes, and spectroelectrochemistry confirmed the couples as corresponding to MnIIIPc-2/MnIIPc-2 (II) (metal reduction), MnIIPc-2/MnIIPc-3 (III) (ring reduction) and MnIIIPc-1/MnIIIPc-2 (I) (ring oxidation). Electrochemistry was also used to determine the blocking characteristics of the MnPc self-assembled monolayers on gold, which proved to be highly dependent on the type of substituent. Other methods of characterization included Raman spectroscopy, atomic force and scanning electrochemical microscopy analyses of the SAMs.
- Full Text:
- Date Issued: 2010
The pharmacotherapeutic treatment of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents
- Oettle, Judith Ann Elizabeth
- Authors: Oettle, Judith Ann Elizabeth
- Date: 2010
- Subjects: Attention-deficit hyperactivity disorder -- Treatment -- South Africa , Attention-deficit hyperactivity disorder -- Alternative treatment -- South Africa , Attention-deficit-disordered children -- Treatment -- South Africa , Attention-deficit disorder in adolescence -- Treatment -- South Africa , Drug utilization -- South Africa
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:10134 , http://hdl.handle.net/10948/1438 , Attention-deficit hyperactivity disorder -- Treatment -- South Africa , Attention-deficit hyperactivity disorder -- Alternative treatment -- South Africa , Attention-deficit-disordered children -- Treatment -- South Africa , Attention-deficit disorder in adolescence -- Treatment -- South Africa , Drug utilization -- South Africa
- Description: Background: The ideal treatment of Attention-Deficit/Hyperactivity Disorder is a highly debated issue. Opposition to pharmacological treatments has resulted in the popular use of non-pharmacological measures which are not necessarily efficacious for the management of ADHD. Objectives: The primary aim was to evaluate the treatment of children and adolescents diagnosed with ADHD in South Africa. Methods: The study consisted of two parts, a drug utilisation review (DUR) and questionnaire-based surveys. The DUR was conducted using a database containing central nervous system (CNS) drug prescriptions which were dispensed during 2008. A total of 21 650 prescriptions dispensed to 7 202 patients constituted the Primary study population which was analysed. The questionnaires were distributed to the parents/caregivers of children diagnosed with ADHD. A response rate of 20.81 percent was obtained. Results: The average age of patients in the DUR was 11.60 ±3.01 years. Male patients represented 74.09 percent (5 336: n = 7 202) of patients. Methylphenidate was the most commonly prescribed of the two drugs indicated for the treatment of ADHD (85.89 percent, 18 956: n = 21 650). A prescribing bias by practitioners in different parts of South Africa was identified. Drug holidays were identified during March and December of 2008. The average age of patients in the questionnaire was 10.67 ±2.83 years, with a male patient majority (86.11 percent, 31: n = 36). Methylphenidate was the most commonly used prescription treatment (93.75 percent, 30: n = 32). Drug holiday use was reported in 56.25 percent (18: n = 32) of patients. Most participants reported supplement use (83.33 percent, 30: n = 36), but 86.67 percent (26: n = 30) of these participants did not find them useful. Conclusion: ADHD is a poorly understood disorder which affects people in all spheres of life. Treatment of the disorder should be individualised and based on scientifically proven effectiveness. Further studies, both in South Africa and worldwide, need to be conducted on the treatment of ADHD
- Full Text:
- Date Issued: 2010
- Authors: Oettle, Judith Ann Elizabeth
- Date: 2010
- Subjects: Attention-deficit hyperactivity disorder -- Treatment -- South Africa , Attention-deficit hyperactivity disorder -- Alternative treatment -- South Africa , Attention-deficit-disordered children -- Treatment -- South Africa , Attention-deficit disorder in adolescence -- Treatment -- South Africa , Drug utilization -- South Africa
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:10134 , http://hdl.handle.net/10948/1438 , Attention-deficit hyperactivity disorder -- Treatment -- South Africa , Attention-deficit hyperactivity disorder -- Alternative treatment -- South Africa , Attention-deficit-disordered children -- Treatment -- South Africa , Attention-deficit disorder in adolescence -- Treatment -- South Africa , Drug utilization -- South Africa
- Description: Background: The ideal treatment of Attention-Deficit/Hyperactivity Disorder is a highly debated issue. Opposition to pharmacological treatments has resulted in the popular use of non-pharmacological measures which are not necessarily efficacious for the management of ADHD. Objectives: The primary aim was to evaluate the treatment of children and adolescents diagnosed with ADHD in South Africa. Methods: The study consisted of two parts, a drug utilisation review (DUR) and questionnaire-based surveys. The DUR was conducted using a database containing central nervous system (CNS) drug prescriptions which were dispensed during 2008. A total of 21 650 prescriptions dispensed to 7 202 patients constituted the Primary study population which was analysed. The questionnaires were distributed to the parents/caregivers of children diagnosed with ADHD. A response rate of 20.81 percent was obtained. Results: The average age of patients in the DUR was 11.60 ±3.01 years. Male patients represented 74.09 percent (5 336: n = 7 202) of patients. Methylphenidate was the most commonly prescribed of the two drugs indicated for the treatment of ADHD (85.89 percent, 18 956: n = 21 650). A prescribing bias by practitioners in different parts of South Africa was identified. Drug holidays were identified during March and December of 2008. The average age of patients in the questionnaire was 10.67 ±2.83 years, with a male patient majority (86.11 percent, 31: n = 36). Methylphenidate was the most commonly used prescription treatment (93.75 percent, 30: n = 32). Drug holiday use was reported in 56.25 percent (18: n = 32) of patients. Most participants reported supplement use (83.33 percent, 30: n = 36), but 86.67 percent (26: n = 30) of these participants did not find them useful. Conclusion: ADHD is a poorly understood disorder which affects people in all spheres of life. Treatment of the disorder should be individualised and based on scientifically proven effectiveness. Further studies, both in South Africa and worldwide, need to be conducted on the treatment of ADHD
- Full Text:
- Date Issued: 2010
Characterisation of dissimilar friction stir welds between 5754 Aluminium alloy and C11000 copper
- Authors: Akinlabi, Esther Titilayo
- Date: 2010
- Subjects: Friction stir welding , Aluminum alloys , Copper alloys
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:9629 , http://hdl.handle.net/10948/1536 , Friction stir welding , Aluminum alloys , Copper alloys
- Description: Friction Stir Welding (FSW) is a solid state welding process invented and patented by The Welding Institute (TWI) in 1991, for joining ferrous and non-ferrous materials1. The FSW of Aluminium and its alloys has been commercialised; and recent interest is focused on joining dissimilar materials. However, in order to commercialise the process, research studies are required to characterise and establish process windows. This research work through material characterisation of the welded joints establishes a process window for the Friction Stir welding of 5754 Aluminium Alloy and C11000 Copper. Furthermore, preliminary studies83,85 on the FSW of aluminium and copper have revealed the presence of intermetallic compounds which are detrimental to the weld qualities. This research work is also aimed at establishing process parameters that will result in limited or no intermetallic formation in the weld. The joint integrity of the resulting welds will also be correlated with the input process parameters. Based on the preliminary investigations conducted, a final weld matrix consisting of twenty seven welds was produced by varying the rotational speed between 600 and 1200 rpm, and the feed rate between 50 and 300 mm/min using three different shoulder diameter tools – 15, 18 and 25 mm to compare the heat input into the welds and to achieve the best results. The welds were characterised through microstructural evaluation, tensile testing, microhardness profiling, X-Ray Diffraction analysis, electrical resistivity and statistical analysis – in order to establish the interrelationship between the process parameters and the weld qualities. viii Microstructural evaluation of the weld samples revealed that the interfacial regions are characterised by mixture layers of aluminium and copper; while 33 percent of the tensile samples are within the acceptable range (> 75 percent joint efficiency). High Vickers microhardness values were measured at the joint interfaces, which corresponded with the intermetallic compounds. The Energy Dispersive Spectroscopy analysis revealed the presence of thin layers of intermetallics in nanoscale at the interfacial regions. The diffractograms of the X-Ray Diffraction analysis showed small peaks for intermetallics in some of the welds. Low electrical resistivities were measured at the joint interfaces. The statistical analysis showed that the downward vertical force, (Fz) can significantly influence the resulting weld qualities. An overall summary of the analysis of the weld qualities - with respect to the shoulder diameter tools employed showed that the 18 mm shoulder diameter tool is most appropriate among the three shoulder diameters considered, and a process window of medium spindle speed of 950 rpm and low-to-medium feed rate between 50 and 150 mm/min is established for FSW of Aluminium and Copper. Welds produced at 1200 rpm and 300 mm/min with low heat input did not have intermetallics formed at the joint interface.
- Full Text:
- Date Issued: 2010
- Authors: Akinlabi, Esther Titilayo
- Date: 2010
- Subjects: Friction stir welding , Aluminum alloys , Copper alloys
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:9629 , http://hdl.handle.net/10948/1536 , Friction stir welding , Aluminum alloys , Copper alloys
- Description: Friction Stir Welding (FSW) is a solid state welding process invented and patented by The Welding Institute (TWI) in 1991, for joining ferrous and non-ferrous materials1. The FSW of Aluminium and its alloys has been commercialised; and recent interest is focused on joining dissimilar materials. However, in order to commercialise the process, research studies are required to characterise and establish process windows. This research work through material characterisation of the welded joints establishes a process window for the Friction Stir welding of 5754 Aluminium Alloy and C11000 Copper. Furthermore, preliminary studies83,85 on the FSW of aluminium and copper have revealed the presence of intermetallic compounds which are detrimental to the weld qualities. This research work is also aimed at establishing process parameters that will result in limited or no intermetallic formation in the weld. The joint integrity of the resulting welds will also be correlated with the input process parameters. Based on the preliminary investigations conducted, a final weld matrix consisting of twenty seven welds was produced by varying the rotational speed between 600 and 1200 rpm, and the feed rate between 50 and 300 mm/min using three different shoulder diameter tools – 15, 18 and 25 mm to compare the heat input into the welds and to achieve the best results. The welds were characterised through microstructural evaluation, tensile testing, microhardness profiling, X-Ray Diffraction analysis, electrical resistivity and statistical analysis – in order to establish the interrelationship between the process parameters and the weld qualities. viii Microstructural evaluation of the weld samples revealed that the interfacial regions are characterised by mixture layers of aluminium and copper; while 33 percent of the tensile samples are within the acceptable range (> 75 percent joint efficiency). High Vickers microhardness values were measured at the joint interfaces, which corresponded with the intermetallic compounds. The Energy Dispersive Spectroscopy analysis revealed the presence of thin layers of intermetallics in nanoscale at the interfacial regions. The diffractograms of the X-Ray Diffraction analysis showed small peaks for intermetallics in some of the welds. Low electrical resistivities were measured at the joint interfaces. The statistical analysis showed that the downward vertical force, (Fz) can significantly influence the resulting weld qualities. An overall summary of the analysis of the weld qualities - with respect to the shoulder diameter tools employed showed that the 18 mm shoulder diameter tool is most appropriate among the three shoulder diameters considered, and a process window of medium spindle speed of 950 rpm and low-to-medium feed rate between 50 and 150 mm/min is established for FSW of Aluminium and Copper. Welds produced at 1200 rpm and 300 mm/min with low heat input did not have intermetallics formed at the joint interface.
- 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
The characteristics and role of informal leaders in work groups : a South African perspective
- Authors: Wienekus, Barend Willem
- Date: 2010
- Subjects: Supervisors, industrial -- South Africa Leadership -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:1166 , http://hdl.handle.net/10962/d1002782
- Description: It has been twenty years since F W De Klerk unbanned the African National Congress. This momentous occasion changed overnight the business landscape in South Africa and the way business were done for many decades. Before and after this crucial moment in South African history, leaders played a significant role in bringing change about as well as managing it. Whether hierarchical or non-hierarchical, leadership manifests itself through all spheres of civilisation. Within any collective, formal as well as informal leadership are always at work and within the environment there always seems to be an individual that appears to hold equal or more influence and sway over the collective. This research investigates the characteristics and role of this individual, the informal leader. In addition, against the melting pot of the diversity of culture, social structures, economics, and demographics in South Africa, the influence of culture on how leadership is being perceived and experienced is also researched. The research is grounded in a post-positivists approach and conducted within a constructivist-interpretative paradigm. A qualitative approach is followed with personal interviews as the method to collect the data from respondents. The interview protocol consists of a combination of questions containing questions of both a quantitative and qualitative nature. Questions of a qualitative nature were open-ended and of an in-depth nature. The research is two pronged. The focus of the research is an Original Equipment Manufacturer (OEM) in the South African Motor Industry and for the primary goal of the research data was collected from employees within work groups of the OEM. The primary research goal investigates the role and characteristics of informal leaders in work groups as seen and experienced by their fellow employees and if there is any congruence with that of the role and characteristics of formal leaders. The study found no fundamental differences between the characteristics and role of formal and informal leaders. The characteristics and role of leaders between different cultures also appear to be the same. For the secondary research goal – determining whether the role and characteristics of informal leaders in work groups could be underpinned in the principles of Ubuntu and if consideration should be given to any cultural differences between leaders and followers by organisational hierarchies – the literature was reviewed in order to reach a conclusion with regards this goal. The literature indicates that culture does affect leadership, especially on how the leadership is executed and experienced in a multicultural society and if ignored, will have a detrimental effect on effective leadership. In order to strive towards achieving maximum productivity, it is imperative that management in South African organisations be aware of the changed dynamic within their organisations as well as on the global stage. The research therefore ends with the practical implications of informal leaders for organisations in South Africa. It is recommended that the importance and contribution of informal leaders within work groups in a multi-culture organisation needs not only to be considered as an element of group leadership, but should be accommodated by the organisation. It is also recommended that organisations recognise the cultural differences between leaders and followers in organisations and the possible consequences if ignored. If the competitive pressures and requirements of globalisation are ignored against the background of Afrocentric expectations and motivational imperatives of the South African workforce, it will result in an ineffective workforce, which will in due course render these organisations uncompetitive and non-sustainable locally and globally.
- Full Text:
- Date Issued: 2010
- Authors: Wienekus, Barend Willem
- Date: 2010
- Subjects: Supervisors, industrial -- South Africa Leadership -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:1166 , http://hdl.handle.net/10962/d1002782
- Description: It has been twenty years since F W De Klerk unbanned the African National Congress. This momentous occasion changed overnight the business landscape in South Africa and the way business were done for many decades. Before and after this crucial moment in South African history, leaders played a significant role in bringing change about as well as managing it. Whether hierarchical or non-hierarchical, leadership manifests itself through all spheres of civilisation. Within any collective, formal as well as informal leadership are always at work and within the environment there always seems to be an individual that appears to hold equal or more influence and sway over the collective. This research investigates the characteristics and role of this individual, the informal leader. In addition, against the melting pot of the diversity of culture, social structures, economics, and demographics in South Africa, the influence of culture on how leadership is being perceived and experienced is also researched. The research is grounded in a post-positivists approach and conducted within a constructivist-interpretative paradigm. A qualitative approach is followed with personal interviews as the method to collect the data from respondents. The interview protocol consists of a combination of questions containing questions of both a quantitative and qualitative nature. Questions of a qualitative nature were open-ended and of an in-depth nature. The research is two pronged. The focus of the research is an Original Equipment Manufacturer (OEM) in the South African Motor Industry and for the primary goal of the research data was collected from employees within work groups of the OEM. The primary research goal investigates the role and characteristics of informal leaders in work groups as seen and experienced by their fellow employees and if there is any congruence with that of the role and characteristics of formal leaders. The study found no fundamental differences between the characteristics and role of formal and informal leaders. The characteristics and role of leaders between different cultures also appear to be the same. For the secondary research goal – determining whether the role and characteristics of informal leaders in work groups could be underpinned in the principles of Ubuntu and if consideration should be given to any cultural differences between leaders and followers by organisational hierarchies – the literature was reviewed in order to reach a conclusion with regards this goal. The literature indicates that culture does affect leadership, especially on how the leadership is executed and experienced in a multicultural society and if ignored, will have a detrimental effect on effective leadership. In order to strive towards achieving maximum productivity, it is imperative that management in South African organisations be aware of the changed dynamic within their organisations as well as on the global stage. The research therefore ends with the practical implications of informal leaders for organisations in South Africa. It is recommended that the importance and contribution of informal leaders within work groups in a multi-culture organisation needs not only to be considered as an element of group leadership, but should be accommodated by the organisation. It is also recommended that organisations recognise the cultural differences between leaders and followers in organisations and the possible consequences if ignored. If the competitive pressures and requirements of globalisation are ignored against the background of Afrocentric expectations and motivational imperatives of the South African workforce, it will result in an ineffective workforce, which will in due course render these organisations uncompetitive and non-sustainable locally and globally.
- Full Text:
- Date Issued: 2010
Language policy and practice at CM Vellem and PJ Olivier primary schools
- Authors: Fobe, Mila Pamella
- Date: 2010
- Subjects: C M Vellem School P J Olivier School Public schools -- South Africa -- Grahamstown Language policy -- South Africa Language and education -- South Africa -- Grahamstown Native language and education -- South Africa -- Grahamstown Afrikaans language -- Study and teaching (Primary) -- South Africa -- Grahamstown Xhosa language -- Study and teaching (Primary) -- South Africa -- Grahamstown English language -- Study and teaching (Primary) -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3586 , http://hdl.handle.net/10962/d1002161
- Description: This study looks at language policy and practice at two Eastern Cape schools. It further explores the link between language learning and teaching. Language implementation strategies were the main focus of this study. The Language-in-education policy of the Republic of South Africa (1997) promotes the use of all nine African languages, which have been afforded the status of official languages. This study looks at the language teaching practices at two Grahamstown primary schools, where isiXhosa and Afrikaans have been used as media of instruction. Qualitative methods were used, and the study took the form of interpretive case studies. , Thuto e, e ikaelela go tshegetsa patlisiso e e ka ga gore dipuo tsa Selegae tsa Seaforika mo Aforikaborwa di tshwanelwa ke go tsewa ka maemo le mokgwa o o lekanang go ya ka Molaotheo wa Aforikaborwa. Ka jalo, e tlaa utolola,e ribilole ditsela le go batla malepa a puso ya Aforikaborwa e ka fitlhelelang setšhaba se se kwa magaeng, se bokgoni jwa kitso ya Seesimane bo leng kwa tlase mo go bona. Bothata ke gore Aforikaborwa e laolwa bogolo ke tiriso e e kwa godimo ya Seesimane mme puso e tshwanelwa ke gore e tlose dikgoreletsi tse di leng teng ga jaana tsa puo. E bowe gape e thibele go se lekalekaneng ga botshelo ka kakaretso mo loagong go go tlholwang ke go sa lekalekaneng ga kitso ya dipuo mo setšhabeng ka kakaretso. Ditshwanelo mo puong fela jaaka ditshwanelo dingwe le dingwe tsa botho, di tshwanelwa ke go sireletswa, jaaka di akareditswe mo Molaotheo o mošwa wa temokerasi wa Aforikaborwa.
- Full Text:
- Date Issued: 2010
- Authors: Fobe, Mila Pamella
- Date: 2010
- Subjects: C M Vellem School P J Olivier School Public schools -- South Africa -- Grahamstown Language policy -- South Africa Language and education -- South Africa -- Grahamstown Native language and education -- South Africa -- Grahamstown Afrikaans language -- Study and teaching (Primary) -- South Africa -- Grahamstown Xhosa language -- Study and teaching (Primary) -- South Africa -- Grahamstown English language -- Study and teaching (Primary) -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3586 , http://hdl.handle.net/10962/d1002161
- Description: This study looks at language policy and practice at two Eastern Cape schools. It further explores the link between language learning and teaching. Language implementation strategies were the main focus of this study. The Language-in-education policy of the Republic of South Africa (1997) promotes the use of all nine African languages, which have been afforded the status of official languages. This study looks at the language teaching practices at two Grahamstown primary schools, where isiXhosa and Afrikaans have been used as media of instruction. Qualitative methods were used, and the study took the form of interpretive case studies. , Thuto e, e ikaelela go tshegetsa patlisiso e e ka ga gore dipuo tsa Selegae tsa Seaforika mo Aforikaborwa di tshwanelwa ke go tsewa ka maemo le mokgwa o o lekanang go ya ka Molaotheo wa Aforikaborwa. Ka jalo, e tlaa utolola,e ribilole ditsela le go batla malepa a puso ya Aforikaborwa e ka fitlhelelang setšhaba se se kwa magaeng, se bokgoni jwa kitso ya Seesimane bo leng kwa tlase mo go bona. Bothata ke gore Aforikaborwa e laolwa bogolo ke tiriso e e kwa godimo ya Seesimane mme puso e tshwanelwa ke gore e tlose dikgoreletsi tse di leng teng ga jaana tsa puo. E bowe gape e thibele go se lekalekaneng ga botshelo ka kakaretso mo loagong go go tlholwang ke go sa lekalekaneng ga kitso ya dipuo mo setšhabeng ka kakaretso. Ditshwanelo mo puong fela jaaka ditshwanelo dingwe le dingwe tsa botho, di tshwanelwa ke go sireletswa, jaaka di akareditswe mo Molaotheo o mošwa wa temokerasi wa Aforikaborwa.
- Full Text:
- Date Issued: 2010
Localisation of Theiler's murine encephalomyelitis virus protein 2C to the golgi apparatus using antibodies generated against a peptide region:
- Jauka, Tembisa, Mutsvunguma, Lorraine Z, Boshoff, Aileen, Edkins, Adrienne L, Knox, Caroline M
- Authors: Jauka, Tembisa , Mutsvunguma, Lorraine Z , Boshoff, Aileen , Edkins, Adrienne L , Knox, Caroline M
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165074 , vital:41206 , DOI: 10.1016/j.jviromet.2010.05.009
- Description: The picornavirus 2C protein is highly conserved and indispensible for virus replication. Polyclonal antibodies against Theiler's murine encephalomyelitis virus (TMEV) 2C protein were generated by immunisation of rabbits with a peptide comprising amino acids 31–210 of the protein. Antibodies were used to investigate the localisation of 2C in infected cells by indirect immunofluorescence and confocal microscopy. Analysis of infected cells revealed that the distribution of 2C changed during infection.
- Full Text:
- Date Issued: 2010
- Authors: Jauka, Tembisa , Mutsvunguma, Lorraine Z , Boshoff, Aileen , Edkins, Adrienne L , Knox, Caroline M
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165074 , vital:41206 , DOI: 10.1016/j.jviromet.2010.05.009
- Description: The picornavirus 2C protein is highly conserved and indispensible for virus replication. Polyclonal antibodies against Theiler's murine encephalomyelitis virus (TMEV) 2C protein were generated by immunisation of rabbits with a peptide comprising amino acids 31–210 of the protein. Antibodies were used to investigate the localisation of 2C in infected cells by indirect immunofluorescence and confocal microscopy. Analysis of infected cells revealed that the distribution of 2C changed during infection.
- Full Text:
- Date Issued: 2010