The use of mobile commerce to improve the services of life insurance post sale activities
- Authors: Afrifa, Rexford
- Date: 2008
- Subjects: Mobile commerce -- South Africa , Mobile computing -- South Africa , Mobile communication systems -- South Africa , Personal communication service systems -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8718 , http://hdl.handle.net/10948/913 , Mobile commerce -- South Africa , Mobile computing -- South Africa , Mobile communication systems -- South Africa , Personal communication service systems -- South Africa
- Description: Mobile commerce, due to its inherent characteristics of mobility and reachability in enhancing personalized services provides an excellent means for life insurers to exploit such avenue in their service offerings. The objective of this study was to determine whether mobile commerce can be used to improve the services of life insurance post-sale activities. This objective was achieved with the relevant literature and empirical study. To accomplish the objective of this treatise, a triangulated research approach was selected and a multiple-case study consisting of four cases was conducted. The four cases selected comprised of leading insurers with large market share in the life insurance market in South-Africa. The primary data were collected through questionnaire and face-to-face interviews with selected respondents. The main finding shows that the respondents had a positive view about mobile commerce and its application in their companies. This was demonstrated by 80 percent of respondents who agreed that mobile commerce was more of an opportunity rather than a challenge or even a threat for the life insurance market. The results also indicate that customer relationship management, mobile messaging services and field service automation functions were used by all the insurers; although minor discrepancies were observed due to the efficiency of each firms IT infrastructure. The Internet was found to assist in the collection of more precise data, to increase service performing abilities. Some of the major obstacles that were found to hinder the deployment of mobile commerce in the industry were security concerns, low and infrequent internet usage and performance by supporting industries. Cumbersome and inefficient legacy systems were declared as the greatest technological weakness particularly by respondents from case 1 and 2. Conversely, hardware and network infrastructure, lack of software packages, lack of technical expertise and the fear of disintermediation was rated low in hindering the deployment of mobile commerce. However, according to the findings the key benefits derived from engaging in increased mobile commerce activities include enhancing customer contact and service, more transparency and speed of claims management, increasing client retention and policy extension rates hence increasing overall company profit.
- Full Text:
- Date Issued: 2008
- Authors: Afrifa, Rexford
- Date: 2008
- Subjects: Mobile commerce -- South Africa , Mobile computing -- South Africa , Mobile communication systems -- South Africa , Personal communication service systems -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8718 , http://hdl.handle.net/10948/913 , Mobile commerce -- South Africa , Mobile computing -- South Africa , Mobile communication systems -- South Africa , Personal communication service systems -- South Africa
- Description: Mobile commerce, due to its inherent characteristics of mobility and reachability in enhancing personalized services provides an excellent means for life insurers to exploit such avenue in their service offerings. The objective of this study was to determine whether mobile commerce can be used to improve the services of life insurance post-sale activities. This objective was achieved with the relevant literature and empirical study. To accomplish the objective of this treatise, a triangulated research approach was selected and a multiple-case study consisting of four cases was conducted. The four cases selected comprised of leading insurers with large market share in the life insurance market in South-Africa. The primary data were collected through questionnaire and face-to-face interviews with selected respondents. The main finding shows that the respondents had a positive view about mobile commerce and its application in their companies. This was demonstrated by 80 percent of respondents who agreed that mobile commerce was more of an opportunity rather than a challenge or even a threat for the life insurance market. The results also indicate that customer relationship management, mobile messaging services and field service automation functions were used by all the insurers; although minor discrepancies were observed due to the efficiency of each firms IT infrastructure. The Internet was found to assist in the collection of more precise data, to increase service performing abilities. Some of the major obstacles that were found to hinder the deployment of mobile commerce in the industry were security concerns, low and infrequent internet usage and performance by supporting industries. Cumbersome and inefficient legacy systems were declared as the greatest technological weakness particularly by respondents from case 1 and 2. Conversely, hardware and network infrastructure, lack of software packages, lack of technical expertise and the fear of disintermediation was rated low in hindering the deployment of mobile commerce. However, according to the findings the key benefits derived from engaging in increased mobile commerce activities include enhancing customer contact and service, more transparency and speed of claims management, increasing client retention and policy extension rates hence increasing overall company profit.
- Full Text:
- Date Issued: 2008
The value of the middleman in the supply chain of South African tyre production
- Authors: Cornelius, André G
- Date: 2008
- Subjects: Tires -- Industrialists -- South Africa Tire Industry -- South Africa Commercial agents -- South Africa Business logistics -- Management -- South Africa Physical distribution of goods -- Management Commercial agents -- South Africa Marketing channels -- Management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:770 , http://hdl.handle.net/10962/d1003891
- Description: Only a few middlemen linking chemical intermediate product supply to world tyre productions have managed to survive new direct business models. In fact, the only region, where the practice of using a middleman in the supply chain of tyre production, for a certain primary manufacturer, is in South Africa. Tyre producers in other world regions, similar in market complexity to South Africa, have experienced the elimination of the middleman. Hence the question of this research, why is the middleman in the supply chain of tyre production in South Africa still a better option than that of direct business models? To begin with, the thesis stated that the middleman in the supply chain of South African tyre producers delivers better value than that of the direct business model. To prove/disprove this thesis, the principle that value is a trade-off between what you get for what you give was the basis of this research (Zeithaml, 1998). Further, a model was developed, from secondary literature, to conceptualise this trade-off to provide evidence to prove/disprove that the middleman provides greater value than value from the direct business model. From this point, the research approach was to collect data through interviews to find out the most important aspect of value created by the middleman. Data collected were analysed, using the structure of the model as a guide, to find evidence of the trade-off. This analysis provided evidence that the relationship between the middleman and the tyre producers in South Africa and between the middleman and primary product supplier is the value that the direct business model cannot replace.
- Full Text:
- Date Issued: 2008
- Authors: Cornelius, André G
- Date: 2008
- Subjects: Tires -- Industrialists -- South Africa Tire Industry -- South Africa Commercial agents -- South Africa Business logistics -- Management -- South Africa Physical distribution of goods -- Management Commercial agents -- South Africa Marketing channels -- Management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:770 , http://hdl.handle.net/10962/d1003891
- Description: Only a few middlemen linking chemical intermediate product supply to world tyre productions have managed to survive new direct business models. In fact, the only region, where the practice of using a middleman in the supply chain of tyre production, for a certain primary manufacturer, is in South Africa. Tyre producers in other world regions, similar in market complexity to South Africa, have experienced the elimination of the middleman. Hence the question of this research, why is the middleman in the supply chain of tyre production in South Africa still a better option than that of direct business models? To begin with, the thesis stated that the middleman in the supply chain of South African tyre producers delivers better value than that of the direct business model. To prove/disprove this thesis, the principle that value is a trade-off between what you get for what you give was the basis of this research (Zeithaml, 1998). Further, a model was developed, from secondary literature, to conceptualise this trade-off to provide evidence to prove/disprove that the middleman provides greater value than value from the direct business model. From this point, the research approach was to collect data through interviews to find out the most important aspect of value created by the middleman. Data collected were analysed, using the structure of the model as a guide, to find evidence of the trade-off. This analysis provided evidence that the relationship between the middleman and the tyre producers in South Africa and between the middleman and primary product supplier is the value that the direct business model cannot replace.
- Full Text:
- Date Issued: 2008
The variability and predictability of the IRI shape parameters over Grahamstown, South Africa
- Authors: Chimidza, Oyapo
- Date: 2008
- Subjects: Ionosphere -- Mathematical models -- South Africa , Atmosphere, Upper -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5496 , http://hdl.handle.net/10962/d1005282 , Ionosphere -- Mathematical models -- South Africa , Atmosphere, Upper -- South Africa
- Description: The International Reference Ionosphere (IRI) shape parameters B0, B1, and D1 provide a representation of the shape of the F2 layer, the thickness of the F2 layer and the shape of the F1 layer of the ionosphere respectively. The aim of this study was to examine the variability of these parameters using Grahamstown, South Africa (33.3±S, 26.5±E) ionosonde data and determine their predictability by the IRI-2001 model. A further aim of this study was to investigate developing an alternative model for predicting these parameters. These parameters can be determined from electron density profiles that are inverted from ionograms recorded with an ionosonde. Data representing the B0, B1 and D1 parameters, with half hourly or hourly intervals, were scaled and deduced from the digital pulse sounder (DPS) ionosonde for the period April 1996 to December 2006. An analysis of the diurnal, seasonal, and solar variations of the behaviour of these parameters was undertaken for the years 2000, 2004 and 2005 using monthly medians. Comparisons between the observational results and that of the IRI model (IRI 2001 version) indicate that the IRI-2001 model does not accurately represent the diurnal and seasonal variation of the parameters. A preliminary model was thus developed using the technique of Neural Networks (NNs). All available data from the Grahamstown ionosonde from 1996 to 2006 were used in the training of the NNs and the prediction of the variation of the shape parameters. Inputs to the model were the day number, the hour of day, the solar activity and the magnetic index. Comparisons between the preliminary NN model and the IRI-2001 model indicated that the preliminary model was more accurate at the prediction of the parameters than the IRI-2001 model. This analysis showed the need to improve the existing IRI model or develop a new model for the South African region. This thesis describes the results from this feasibility study which show the variability and predictability of the IRI shape parameters.
- Full Text:
- Date Issued: 2008
- Authors: Chimidza, Oyapo
- Date: 2008
- Subjects: Ionosphere -- Mathematical models -- South Africa , Atmosphere, Upper -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5496 , http://hdl.handle.net/10962/d1005282 , Ionosphere -- Mathematical models -- South Africa , Atmosphere, Upper -- South Africa
- Description: The International Reference Ionosphere (IRI) shape parameters B0, B1, and D1 provide a representation of the shape of the F2 layer, the thickness of the F2 layer and the shape of the F1 layer of the ionosphere respectively. The aim of this study was to examine the variability of these parameters using Grahamstown, South Africa (33.3±S, 26.5±E) ionosonde data and determine their predictability by the IRI-2001 model. A further aim of this study was to investigate developing an alternative model for predicting these parameters. These parameters can be determined from electron density profiles that are inverted from ionograms recorded with an ionosonde. Data representing the B0, B1 and D1 parameters, with half hourly or hourly intervals, were scaled and deduced from the digital pulse sounder (DPS) ionosonde for the period April 1996 to December 2006. An analysis of the diurnal, seasonal, and solar variations of the behaviour of these parameters was undertaken for the years 2000, 2004 and 2005 using monthly medians. Comparisons between the observational results and that of the IRI model (IRI 2001 version) indicate that the IRI-2001 model does not accurately represent the diurnal and seasonal variation of the parameters. A preliminary model was thus developed using the technique of Neural Networks (NNs). All available data from the Grahamstown ionosonde from 1996 to 2006 were used in the training of the NNs and the prediction of the variation of the shape parameters. Inputs to the model were the day number, the hour of day, the solar activity and the magnetic index. Comparisons between the preliminary NN model and the IRI-2001 model indicated that the preliminary model was more accurate at the prediction of the parameters than the IRI-2001 model. This analysis showed the need to improve the existing IRI model or develop a new model for the South African region. This thesis describes the results from this feasibility study which show the variability and predictability of the IRI shape parameters.
- Full Text:
- Date Issued: 2008
The very thorough lens Photojournalism: the professionals' approach, Kenneth Kobré: latest books
- Authors: Gess, Harold
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/455086 , vital:75401 , https://hdl.handle.net/10520/EJC140115
- Description: Each edition of Kenneth Kobré's book, Photojournalism: the profes-sionals' approach, has brought his enthusiastic and very thorough lens to bear on the changing terrain of photojournalism.
- Full Text:
- Date Issued: 2008
- Authors: Gess, Harold
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/455086 , vital:75401 , https://hdl.handle.net/10520/EJC140115
- Description: Each edition of Kenneth Kobré's book, Photojournalism: the profes-sionals' approach, has brought his enthusiastic and very thorough lens to bear on the changing terrain of photojournalism.
- Full Text:
- Date Issued: 2008
The WHO UNESCO FIP Pharmacy Education Taskforce: enabling concerted and collective global action
- Anderson, Claire, Bates, Ian, Beck, Diane, Brock, Tina, Futter, William T, Mercer, Hugo, Rouse, Mike, Wuliji, Tana, Yonemura, Akemi
- Authors: Anderson, Claire , Bates, Ian , Beck, Diane , Brock, Tina , Futter, William T , Mercer, Hugo , Rouse, Mike , Wuliji, Tana , Yonemura, Akemi
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6348 , http://hdl.handle.net/10962/d1006029 , http://dx.doi.org/10.1186/1478-4491-7-45
- Description: Pharmacy Education is a priority area for the International Pharmaceutical Federation (FIP), the global federation representing pharmacists and pharmaceutical scientists worldwide that is spearheading the Global Pharmacy Education Taskforce. This paper describes the work of the Taskforce that was established in March 2008, explores key issues in pharmacy education development, and describes the Global Pharmacy Action Plan 2008-2010. Given the significance of pharmacy education to the diverse practice of contemporary pharmacists and pharmacy support personnel, there is a need for pharmacy education to attain greater visibility on the global human resources for health agenda. From this perspective, FIP is steering the development of holistic and comprehensive pharmacy education and pharmacy workforce action to support and strengthen regional, national, and local efforts. The role of a global organization such as FIP is to facilitate, catalyze, and share efforts to maximize pharmacy education development and stimulate international research to develop guidance, tools, and better understanding of key issues. To achieve this goal, FIP has (1) established a formal collaborative partnership with the 2 United Nations agencies representing the education and health sectors, United Nations Educational, Scientific and Cultural Organization (UNESCO) and the World Health Organization (WHO); and (2) established the Global Pharmacy Education Taskforce to serve as the coordinating body of these efforts. The initial effort will serve to leverage strategic leadership and maximize the impact of collective actions at global, regional, and national levels. Three project teams have been convened to conduct research, consultations and develop guidance in the domains of vision for pharmacy education, competency, quality assurance, academic workforce, and institutional capacity.
- Full Text:
- Date Issued: 2008
- Authors: Anderson, Claire , Bates, Ian , Beck, Diane , Brock, Tina , Futter, William T , Mercer, Hugo , Rouse, Mike , Wuliji, Tana , Yonemura, Akemi
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6348 , http://hdl.handle.net/10962/d1006029 , http://dx.doi.org/10.1186/1478-4491-7-45
- Description: Pharmacy Education is a priority area for the International Pharmaceutical Federation (FIP), the global federation representing pharmacists and pharmaceutical scientists worldwide that is spearheading the Global Pharmacy Education Taskforce. This paper describes the work of the Taskforce that was established in March 2008, explores key issues in pharmacy education development, and describes the Global Pharmacy Action Plan 2008-2010. Given the significance of pharmacy education to the diverse practice of contemporary pharmacists and pharmacy support personnel, there is a need for pharmacy education to attain greater visibility on the global human resources for health agenda. From this perspective, FIP is steering the development of holistic and comprehensive pharmacy education and pharmacy workforce action to support and strengthen regional, national, and local efforts. The role of a global organization such as FIP is to facilitate, catalyze, and share efforts to maximize pharmacy education development and stimulate international research to develop guidance, tools, and better understanding of key issues. To achieve this goal, FIP has (1) established a formal collaborative partnership with the 2 United Nations agencies representing the education and health sectors, United Nations Educational, Scientific and Cultural Organization (UNESCO) and the World Health Organization (WHO); and (2) established the Global Pharmacy Education Taskforce to serve as the coordinating body of these efforts. The initial effort will serve to leverage strategic leadership and maximize the impact of collective actions at global, regional, and national levels. Three project teams have been convened to conduct research, consultations and develop guidance in the domains of vision for pharmacy education, competency, quality assurance, academic workforce, and institutional capacity.
- Full Text:
- Date Issued: 2008
The zonation of coastal dune plants in relation to sand burial, resource availability and physiological adaptation
- Authors: Gilbert, Matthew Edmund
- Date: 2008
- Subjects: Sand dune conservation -- South Africa -- Eastern Cape Coastal ecology -- South Africa -- Eastern Cape Botany -- South Africa -- Eastern Cape Coastal biology -- South Africa -- Eastern Cape Littoral plants -- South Africa -- Eastern Cape Littoral plants Sand dune plants -- Ecophysiology Sand dune plants -- Geographical distribution
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4195 , http://hdl.handle.net/10962/d1003764
- Description: When considering the large amount of work done on dune ecology, and that a number of the classical ecological theories originate from work on dunes, it is apparent that there remains a need for physiological and mechanistic explanations of dune plant phenomena. This thesis demonstrated that in the extreme coastal environment dune plants must survive both high rates of burial (disturbance), and low nutrient availability (stress). The ability of four species to respond to these two factors corresponded with their position in a vegetation gradient on the dunes. A low stem tissue density was shown to enhance the potential stem elongation rate of buried plants, but reduced the maximum height to which a plant could grow. Such a tradeoff implies that tall light-competitive plants are able to survive only in stable areas, while burial responsive mobile-dune plants are limited to areas of low vegetation height. This stem tissue density tradeoff was suggested as the mechanism determining the zonation that species show within the dune vegetation gradient present at various sites in South Africa. Finally, detailed investigations of dune plant ecophysiology found that: 1) The resources used in the response to burial derive from external sources of carbon and nitrogen, as well as simple physiological and physical mechanisms of resource allocation. 2) The leaves of dune plants were found to be operating at one extreme of the photosynthetic continuum; viz efficient use of leaf nitrogen at the expense of water loss. 3) Contrary to other ecosystems, the environmental characteristics of dunes may allow plants to occupy a high disturbance, high stress niche, through the maintenance of lowered competition. 4) At least two mobile-dune species form steep dunes, and are able to optimise growth, on steeper dunes, such that they have to grow less in response to burial than plants that form more shallow dunes. In this thesis, it was shown that the link between the carbon and nitrogen economies of dune plants was pivotal in determining species distributions and survival under extreme environmental conditions. As vast areas of the world’s surface are covered by sand dunes these observations are not just of passing interest.
- Full Text:
- Date Issued: 2008
- Authors: Gilbert, Matthew Edmund
- Date: 2008
- Subjects: Sand dune conservation -- South Africa -- Eastern Cape Coastal ecology -- South Africa -- Eastern Cape Botany -- South Africa -- Eastern Cape Coastal biology -- South Africa -- Eastern Cape Littoral plants -- South Africa -- Eastern Cape Littoral plants Sand dune plants -- Ecophysiology Sand dune plants -- Geographical distribution
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4195 , http://hdl.handle.net/10962/d1003764
- Description: When considering the large amount of work done on dune ecology, and that a number of the classical ecological theories originate from work on dunes, it is apparent that there remains a need for physiological and mechanistic explanations of dune plant phenomena. This thesis demonstrated that in the extreme coastal environment dune plants must survive both high rates of burial (disturbance), and low nutrient availability (stress). The ability of four species to respond to these two factors corresponded with their position in a vegetation gradient on the dunes. A low stem tissue density was shown to enhance the potential stem elongation rate of buried plants, but reduced the maximum height to which a plant could grow. Such a tradeoff implies that tall light-competitive plants are able to survive only in stable areas, while burial responsive mobile-dune plants are limited to areas of low vegetation height. This stem tissue density tradeoff was suggested as the mechanism determining the zonation that species show within the dune vegetation gradient present at various sites in South Africa. Finally, detailed investigations of dune plant ecophysiology found that: 1) The resources used in the response to burial derive from external sources of carbon and nitrogen, as well as simple physiological and physical mechanisms of resource allocation. 2) The leaves of dune plants were found to be operating at one extreme of the photosynthetic continuum; viz efficient use of leaf nitrogen at the expense of water loss. 3) Contrary to other ecosystems, the environmental characteristics of dunes may allow plants to occupy a high disturbance, high stress niche, through the maintenance of lowered competition. 4) At least two mobile-dune species form steep dunes, and are able to optimise growth, on steeper dunes, such that they have to grow less in response to burial than plants that form more shallow dunes. In this thesis, it was shown that the link between the carbon and nitrogen economies of dune plants was pivotal in determining species distributions and survival under extreme environmental conditions. As vast areas of the world’s surface are covered by sand dunes these observations are not just of passing interest.
- Full Text:
- Date Issued: 2008
Thermal, spectroscopic and x-ray diffraction studies of copper(II) 1,2,4,5-Benzenetetracarboxylates and copper(II) oxalate a study of metal-organic frameworks
- Authors: Lamprecht, Emmanuel
- Date: 2008
- Subjects: Organometallic compounds Copper Oxalates -- Thermal properties Organic compounds -- Synthesis Spectrum analysis X-rays -- Diffraction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4389 , http://hdl.handle.net/10962/d1005054
- Description: Novel and known metal organic frameworks with copper(II), sodium and 1,2,4,5-benzenetetracarboxylate were prepared by ambient precipitation, solvothermal and gel-synthesis methods, and characterized by single-crystal X-ray diffraction, X-ray powder diffraction, infrared spectroscopy, differential scanning calorimetry, and thermogravimetry with FTIR evolved-gas analysis. Some of these complexes were investigated for guest inclusion properties with water (the original guest species), methanol, ethanol and pyridine. The gel-synthesis products were the most interesting. The novel threedimensional metal-organic framework complex Cu₂ Na(OH)L·7H₂O (where L=1,2,4,5-benzenetetracarboxylate) -formed by gel-synthesis- is a covalent three-dimensional metal organic framework polymer with open channels containing both guest water molecules and water molecules coordinated to sodium. The structure collapsed on dehydration, but was essentially restored to the original structure on rehydration in moist air. On exposure of the dehydrated material to methanol and ethanol vapour, significant uptake of these solvents was observed, and the resolvated structures closely resembled that of the parent material. On heating in dry nitrogen, small amounts of methanol and ethanol remained until about 280 °C, when loss of the remaining guest triggered decomposition of the framework. The related complex, Cu₂¼(OH)½ L·7½H₂O (or possibly Cu₂⅓ (OH)⅔L·8H₂O) -formed by gel-synthesis- had a different physical appearance to Cu₂Na(OH)L·7H₂O above, but had nearly identical X-ray diffraction pattern, mid-infrared spectrum and thermal behaviour. The novel complex Cu₄Na₄L₃·14H₂O -formed by gel-synthesis- is a covalent three-dimensional metal-organic framework with small channels containing both guest water molecules and water coordinated to sodium and copper. Upon dehydration the structure collapsed, but on rehydration in moist air the original structure was partly restored. The dehydrated material did not absorb methanol. Known two-dimensional polymeric complexes [Cu₂L·6H₂O]·4H₂O and [Cu₂L·4H₂O]·2H₂O were also obtained by gel-synthesis, and were characterized and investigated for guest inclusion properties. The structures of these complexes collapsed on dehydration, and were only partly restored on rehydration in saturated water vapour. The dehydrated materials did not absorb methanol. The two-dimensional polymeric mixed-ligand complex Cu₂(pyridine)₄·6H₂O -formed very slowly by gel-synthesis- was characterized by TG-FTIR, and was shown to undergo a complicated decomposition involving the loss of water and pyridine, carbon dioxide and carbon monoxide in various stages. Solvothermal synthesis did not yield materials suitable for single-crystal X-ray diffraction studies or inclusion studies, producing only an anhydrous or hemihydrate complex with the formula Cu₂L·0.65H2O. Ambient precipitation syntheses did not yield materials suitable for singlecrystal diffraction studies, forming products approximately equivalent to the complexes [Cu₂L·6H₂O]·4H₂O and Cu₂¼(OH)½L·7 ½H₂O above. During the course of the above study it was discovered that, on changing the DSC purge from nitrogen to argon, the normally exothermic carboxylate decompositions appeared to become endothermic. The effects of the supposedly inert atmospheres of argon and nitrogen on the decomposition-mechanism of copper(II) oxalate -a well-studied copper carboxylate- were therefore studied by DSC, TG, TG-FTIR and XRPD. DSC experiments were performed in nitrogen and argon at different flow-rates, in various mixtures of nitrogen and argon, and at various heating rates. Regardless of the proportions of nitrogen and argon, the DSC residues consisted mainly of copper metal, a small amount of copper(I) oxide (cuprite) and, in some circumstances, traces of copper(II) oxide (tenorite). Also, regardless of whether TG-FTIR experiments were performed under argon or nitrogen, the gaseous decomposition products consisted mainly of carbon dioxide, with traces of carbon monoxide being detected over part of the decomposition period. Various explanations for the thermal behaviour are discussed, and it is possible that small amounts of O2 or monatomic oxygen were given off during the decomposition under argon. The design and implementation of a low-cost prototype X-ray proportional counter detector system, consisting of a hybrid analog-digital computer built using commonly available electronic components, is presented. This system was designed to replace ageing discrete-transistor designs still in use in earlier X-ray diffractometers. The prototype performs the functions of pulse-shaping, pulseheight discrimination, counting and scaling, and provides both digital and scaled analog outputs.
- Full Text:
- Date Issued: 2008
- Authors: Lamprecht, Emmanuel
- Date: 2008
- Subjects: Organometallic compounds Copper Oxalates -- Thermal properties Organic compounds -- Synthesis Spectrum analysis X-rays -- Diffraction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4389 , http://hdl.handle.net/10962/d1005054
- Description: Novel and known metal organic frameworks with copper(II), sodium and 1,2,4,5-benzenetetracarboxylate were prepared by ambient precipitation, solvothermal and gel-synthesis methods, and characterized by single-crystal X-ray diffraction, X-ray powder diffraction, infrared spectroscopy, differential scanning calorimetry, and thermogravimetry with FTIR evolved-gas analysis. Some of these complexes were investigated for guest inclusion properties with water (the original guest species), methanol, ethanol and pyridine. The gel-synthesis products were the most interesting. The novel threedimensional metal-organic framework complex Cu₂ Na(OH)L·7H₂O (where L=1,2,4,5-benzenetetracarboxylate) -formed by gel-synthesis- is a covalent three-dimensional metal organic framework polymer with open channels containing both guest water molecules and water molecules coordinated to sodium. The structure collapsed on dehydration, but was essentially restored to the original structure on rehydration in moist air. On exposure of the dehydrated material to methanol and ethanol vapour, significant uptake of these solvents was observed, and the resolvated structures closely resembled that of the parent material. On heating in dry nitrogen, small amounts of methanol and ethanol remained until about 280 °C, when loss of the remaining guest triggered decomposition of the framework. The related complex, Cu₂¼(OH)½ L·7½H₂O (or possibly Cu₂⅓ (OH)⅔L·8H₂O) -formed by gel-synthesis- had a different physical appearance to Cu₂Na(OH)L·7H₂O above, but had nearly identical X-ray diffraction pattern, mid-infrared spectrum and thermal behaviour. The novel complex Cu₄Na₄L₃·14H₂O -formed by gel-synthesis- is a covalent three-dimensional metal-organic framework with small channels containing both guest water molecules and water coordinated to sodium and copper. Upon dehydration the structure collapsed, but on rehydration in moist air the original structure was partly restored. The dehydrated material did not absorb methanol. Known two-dimensional polymeric complexes [Cu₂L·6H₂O]·4H₂O and [Cu₂L·4H₂O]·2H₂O were also obtained by gel-synthesis, and were characterized and investigated for guest inclusion properties. The structures of these complexes collapsed on dehydration, and were only partly restored on rehydration in saturated water vapour. The dehydrated materials did not absorb methanol. The two-dimensional polymeric mixed-ligand complex Cu₂(pyridine)₄·6H₂O -formed very slowly by gel-synthesis- was characterized by TG-FTIR, and was shown to undergo a complicated decomposition involving the loss of water and pyridine, carbon dioxide and carbon monoxide in various stages. Solvothermal synthesis did not yield materials suitable for single-crystal X-ray diffraction studies or inclusion studies, producing only an anhydrous or hemihydrate complex with the formula Cu₂L·0.65H2O. Ambient precipitation syntheses did not yield materials suitable for singlecrystal diffraction studies, forming products approximately equivalent to the complexes [Cu₂L·6H₂O]·4H₂O and Cu₂¼(OH)½L·7 ½H₂O above. During the course of the above study it was discovered that, on changing the DSC purge from nitrogen to argon, the normally exothermic carboxylate decompositions appeared to become endothermic. The effects of the supposedly inert atmospheres of argon and nitrogen on the decomposition-mechanism of copper(II) oxalate -a well-studied copper carboxylate- were therefore studied by DSC, TG, TG-FTIR and XRPD. DSC experiments were performed in nitrogen and argon at different flow-rates, in various mixtures of nitrogen and argon, and at various heating rates. Regardless of the proportions of nitrogen and argon, the DSC residues consisted mainly of copper metal, a small amount of copper(I) oxide (cuprite) and, in some circumstances, traces of copper(II) oxide (tenorite). Also, regardless of whether TG-FTIR experiments were performed under argon or nitrogen, the gaseous decomposition products consisted mainly of carbon dioxide, with traces of carbon monoxide being detected over part of the decomposition period. Various explanations for the thermal behaviour are discussed, and it is possible that small amounts of O2 or monatomic oxygen were given off during the decomposition under argon. The design and implementation of a low-cost prototype X-ray proportional counter detector system, consisting of a hybrid analog-digital computer built using commonly available electronic components, is presented. This system was designed to replace ageing discrete-transistor designs still in use in earlier X-ray diffractometers. The prototype performs the functions of pulse-shaping, pulseheight discrimination, counting and scaling, and provides both digital and scaled analog outputs.
- Full Text:
- Date Issued: 2008
Thomas Mofolo, Traveller to the East: Review
- Authors: Wylie, Dan
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458147 , vital:75719 , https://tinyurl.com/57nmnsmy
- Description: On the centenary of its first publication by the Morija Book Depot as Moeti oa bochabela, Mofolo's strange, muddled little parable, touted as the first novel ever written by a Mosotho, makes a welcome reappearance. Penguin Classics have reissued Harry Ashton's 1934 translation, with a couple of pages of illustrations and Mofolo's own autobiographical sketch, a letter to Mr Franz, as frontispieces.
- Full Text:
- Date Issued: 2008
- Authors: Wylie, Dan
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458147 , vital:75719 , https://tinyurl.com/57nmnsmy
- Description: On the centenary of its first publication by the Morija Book Depot as Moeti oa bochabela, Mofolo's strange, muddled little parable, touted as the first novel ever written by a Mosotho, makes a welcome reappearance. Penguin Classics have reissued Harry Ashton's 1934 translation, with a couple of pages of illustrations and Mofolo's own autobiographical sketch, a letter to Mr Franz, as frontispieces.
- Full Text:
- Date Issued: 2008
Tolerance in intergroup relations: cognitive representations reducing ingroup projection
- Authors: O'Sullivan, Clodagh M
- Date: 2008
- Subjects: Group identity , Social groups , Intergroup relations
- Language: English
- Type: Thesis , Masters , M Soc Sc (Psych)
- Identifier: vital:11604 , http://hdl.handle.net/10353/140 , Group identity , Social groups , Intergroup relations
- Description: This study assessed the personal, career and learning skills needs of 196 psychology students (M= 56, F= 103). The preferred means of counselling assistance, preferred experience of counselling and preferred counselling provider were also assessed. The most highly endorsed needs were time management skills (83.5 pecent, n=162), learning test-taking strategies (82 percent, n=159), job search strategies (73.6 percent, n=142), increasing self-confidence (70.3 percent, n=135), increasing motivation (72.4 percent, n=134), controlling anxiety and nervousness (68.7 percent, n=134), public speaking anxiety (68 percent, n=134), understanding career interests and abilities (67.5 percent, n=131), fear of failure (68.1 percent, n=130), and improving study skills (66.5 percent, n=129). Significant sex differences were found for the following, finding a greater purpose in life, controlling weight, job search strategies, concerns about career choice, understanding career interests and abilities in the selection of major subjects and improving study skills. Males highly endorsed the need for finding a greater purpose in life, job search strategies, and concern about career choice, understanding career interest and abilities, selection of major subjects and to improve study skills, whereas females endorsed the need for controlling weight. Respondents indicated individual counselling as being their preferred means of counselling assistance, but lectures were the most prevalent means of assistance previously received by respondents. Most respondents (78.1 percent) found the assistance they had received to be helpful.
- Full Text:
- Date Issued: 2008
- Authors: O'Sullivan, Clodagh M
- Date: 2008
- Subjects: Group identity , Social groups , Intergroup relations
- Language: English
- Type: Thesis , Masters , M Soc Sc (Psych)
- Identifier: vital:11604 , http://hdl.handle.net/10353/140 , Group identity , Social groups , Intergroup relations
- Description: This study assessed the personal, career and learning skills needs of 196 psychology students (M= 56, F= 103). The preferred means of counselling assistance, preferred experience of counselling and preferred counselling provider were also assessed. The most highly endorsed needs were time management skills (83.5 pecent, n=162), learning test-taking strategies (82 percent, n=159), job search strategies (73.6 percent, n=142), increasing self-confidence (70.3 percent, n=135), increasing motivation (72.4 percent, n=134), controlling anxiety and nervousness (68.7 percent, n=134), public speaking anxiety (68 percent, n=134), understanding career interests and abilities (67.5 percent, n=131), fear of failure (68.1 percent, n=130), and improving study skills (66.5 percent, n=129). Significant sex differences were found for the following, finding a greater purpose in life, controlling weight, job search strategies, concerns about career choice, understanding career interests and abilities in the selection of major subjects and improving study skills. Males highly endorsed the need for finding a greater purpose in life, job search strategies, and concern about career choice, understanding career interest and abilities, selection of major subjects and to improve study skills, whereas females endorsed the need for controlling weight. Respondents indicated individual counselling as being their preferred means of counselling assistance, but lectures were the most prevalent means of assistance previously received by respondents. Most respondents (78.1 percent) found the assistance they had received to be helpful.
- Full Text:
- Date Issued: 2008
Toward the development of a rearing protocol for juvenile dusky kob, Argyrosomus japonicus (Pisces: Sciaenidae)
- Authors: Collett, Paul David
- Date: 2008
- Subjects: Argyrosomus -- South Africa , Mariculture -- South Africa , Fishes -- Nutrition -- South Africa , Fishes -- Growth -- South Africa , Fish trade -- South Africa , Sciaenidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5325 , http://hdl.handle.net/10962/d1005171 , Argyrosomus -- South Africa , Mariculture -- South Africa , Fishes -- Nutrition -- South Africa , Fishes -- Growth -- South Africa , Fish trade -- South Africa , Sciaenidae
- Description: The South African mariculture industry is developing the rearing technology of indigenous fish species. Dusky kob (Argyrosomus japonicus) has high-quality flesh and a good market demand. Research is needed to determine the environmental requirements under which growth of dusky kob is optimised. This study assessed the effect of temperature, light intensity, feeding frequency and stocking density, respectively, on growth, feed conversion ratio (FCR) and survival of juvenile dusky kob within a weight range of 10-60 g fish⁻¹) in a series of four growth trials. The effect of temperature on growth and FCR was assessed at 14 temperatures from 17 to 28°C. The temperature for best growth was estimated to be 25.3 °C, while 21.4 °C was the temperature at which the best FCR was achieved. A growth trial testing the effect of light intensity on growth showed that light intensity did not affect growth in the range of 23 – 315 lx. Fish fed a restricted ration of 3.6% body weight per day (chapter 2) or 3.41% body weight per day (chapter 4) had a better FCR than fish fed to satiation. A trial to assess the effect of feeding frequency on growth and FCR showed that fish fed both two or three times daily grew better than those fed once daily. FCR was best in fish that were fed once or twice daily. Preliminary analysis of the results from a stocking density trial showed that stocking density in the range of 10 – 50 kg m⁻³ did not affect growth of juvenile dusky kob. It is recommended to culture dusky kob at a temperature of 25.3 - 21.4 °C at stocking densities up 50 kg m⁻³ to maximise growth. However, a study is needed to determine the environmental conditions needed to maximise profit under commercial conditions. The results allow the South African industry the opportunity to assess the culture potential of this species. In addition, the results will help develop protocols that can be used in other South African candidate aquaculture species such as silver kob, yellowtail, white-stumpnose and sole.
- Full Text:
- Date Issued: 2008
- Authors: Collett, Paul David
- Date: 2008
- Subjects: Argyrosomus -- South Africa , Mariculture -- South Africa , Fishes -- Nutrition -- South Africa , Fishes -- Growth -- South Africa , Fish trade -- South Africa , Sciaenidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5325 , http://hdl.handle.net/10962/d1005171 , Argyrosomus -- South Africa , Mariculture -- South Africa , Fishes -- Nutrition -- South Africa , Fishes -- Growth -- South Africa , Fish trade -- South Africa , Sciaenidae
- Description: The South African mariculture industry is developing the rearing technology of indigenous fish species. Dusky kob (Argyrosomus japonicus) has high-quality flesh and a good market demand. Research is needed to determine the environmental requirements under which growth of dusky kob is optimised. This study assessed the effect of temperature, light intensity, feeding frequency and stocking density, respectively, on growth, feed conversion ratio (FCR) and survival of juvenile dusky kob within a weight range of 10-60 g fish⁻¹) in a series of four growth trials. The effect of temperature on growth and FCR was assessed at 14 temperatures from 17 to 28°C. The temperature for best growth was estimated to be 25.3 °C, while 21.4 °C was the temperature at which the best FCR was achieved. A growth trial testing the effect of light intensity on growth showed that light intensity did not affect growth in the range of 23 – 315 lx. Fish fed a restricted ration of 3.6% body weight per day (chapter 2) or 3.41% body weight per day (chapter 4) had a better FCR than fish fed to satiation. A trial to assess the effect of feeding frequency on growth and FCR showed that fish fed both two or three times daily grew better than those fed once daily. FCR was best in fish that were fed once or twice daily. Preliminary analysis of the results from a stocking density trial showed that stocking density in the range of 10 – 50 kg m⁻³ did not affect growth of juvenile dusky kob. It is recommended to culture dusky kob at a temperature of 25.3 - 21.4 °C at stocking densities up 50 kg m⁻³ to maximise growth. However, a study is needed to determine the environmental conditions needed to maximise profit under commercial conditions. The results allow the South African industry the opportunity to assess the culture potential of this species. In addition, the results will help develop protocols that can be used in other South African candidate aquaculture species such as silver kob, yellowtail, white-stumpnose and sole.
- Full Text:
- Date Issued: 2008
Towards a corpus of Indian South African English (ISAE) : an investigation of lexical and syntactic features in a spoken corpus of contemporary ISAE
- Authors: Pienaar, Cheryl Leelavathie
- Date: 2008
- Subjects: English language -- South Africa Computational linguistics -- Methodology Discourse analysis -- Data processing English language -- Syntax -- South Africa English language -- Usage -- South Africa East Indians -- South Africa -- Language Lexicology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2357 , http://hdl.handle.net/10962/d1002640
- Description: There is consensus among scholars that there is not just one English language but a family of “World Englishes”. The umbrella-term “World Englishes” provides a conceptual framework to accommodate the different varieties of English that have evolved as a result of the linguistic cross-fertilization attendant upon colonization, migration, trade and transplantation of the original “strain” or variety. Various theoretical models have emerged in an attempt to understand and classify the extant and emerging varieties of this global language. The hierarchically based model of English, which classifies world English as “First Language”, “Second Language” and “Foreign Language”, has been challenged by more equitably-conceived models which refer to the emerging varieties as New Englishes. The situation in a country such as multi-lingual South Africa is a complex one: there are 11 official languages, one of which is English. However the English used in South Africa (or “South African English”), is not a homogeneous variety, since its speakers include those for whom it is a first language, those for whom it is an additional language and those for whom it is a replacement language. The Indian population in South Africa are amongst the latter group, as theirs is a case where English has ousted the traditional Indian languages and become a de facto first language, which has retained strong community resonances. This study was undertaken using the methodology of corpus linguistics to initiate the creation of a repository of linguistic evidence (or corpus), of Indian South African English, a sub-variety of South African English (Mesthrie 1992b, 1996, 2002). Although small (approximately 60 000 words), and representing a narrow age band of young adults, the resulting corpus of spoken data confirmed the existence of robust features identified in prior research into the sub-variety. These features include the use of ‘y’all’ as a second person plural pronoun, the use of but in a sentence-final position, and ‘lakker’ /'lVk@/ as a pronunciation variant of ‘lekker’ (meaning ‘good’, ‘nice’ or great’). An examination of lexical frequency lists revealed examples of general South African English such as the colloquially pervasive ‘ja’, ‘bladdy’ (for bloody) and jol(ling) (for partying or enjoying oneself) together with neologisms such as ‘eish’, the latter previously associated with speakers of Black South African English. The frequency lists facilitated cross-corpora comparisons with data from the British National Corpus and the Corpus of London Teenage Language and similarities and differences were noted and discussed. The study also used discourse analysis frameworks to investigate the role of high frequency lexical items such as ‘like’ in the data. In recent times ‘like’ has emerged globally as a lexicalized discourse marker, and its appearance in the corpus of Indian South African English confirms this trend. The corpus built as part of this study is intended as the first building block towards a full corpus of Indian South African English which could serve as a standard for referencing research into the sub-variety. Ultimately, it is argued that the establishment of similar corpora of other known sub-varieties of South African English could contribute towards the creation of a truly representative large corpus of South African English and a more nuanced understanding and definition of this important variety of World English.
- Full Text:
- Date Issued: 2008
- Authors: Pienaar, Cheryl Leelavathie
- Date: 2008
- Subjects: English language -- South Africa Computational linguistics -- Methodology Discourse analysis -- Data processing English language -- Syntax -- South Africa English language -- Usage -- South Africa East Indians -- South Africa -- Language Lexicology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2357 , http://hdl.handle.net/10962/d1002640
- Description: There is consensus among scholars that there is not just one English language but a family of “World Englishes”. The umbrella-term “World Englishes” provides a conceptual framework to accommodate the different varieties of English that have evolved as a result of the linguistic cross-fertilization attendant upon colonization, migration, trade and transplantation of the original “strain” or variety. Various theoretical models have emerged in an attempt to understand and classify the extant and emerging varieties of this global language. The hierarchically based model of English, which classifies world English as “First Language”, “Second Language” and “Foreign Language”, has been challenged by more equitably-conceived models which refer to the emerging varieties as New Englishes. The situation in a country such as multi-lingual South Africa is a complex one: there are 11 official languages, one of which is English. However the English used in South Africa (or “South African English”), is not a homogeneous variety, since its speakers include those for whom it is a first language, those for whom it is an additional language and those for whom it is a replacement language. The Indian population in South Africa are amongst the latter group, as theirs is a case where English has ousted the traditional Indian languages and become a de facto first language, which has retained strong community resonances. This study was undertaken using the methodology of corpus linguistics to initiate the creation of a repository of linguistic evidence (or corpus), of Indian South African English, a sub-variety of South African English (Mesthrie 1992b, 1996, 2002). Although small (approximately 60 000 words), and representing a narrow age band of young adults, the resulting corpus of spoken data confirmed the existence of robust features identified in prior research into the sub-variety. These features include the use of ‘y’all’ as a second person plural pronoun, the use of but in a sentence-final position, and ‘lakker’ /'lVk@/ as a pronunciation variant of ‘lekker’ (meaning ‘good’, ‘nice’ or great’). An examination of lexical frequency lists revealed examples of general South African English such as the colloquially pervasive ‘ja’, ‘bladdy’ (for bloody) and jol(ling) (for partying or enjoying oneself) together with neologisms such as ‘eish’, the latter previously associated with speakers of Black South African English. The frequency lists facilitated cross-corpora comparisons with data from the British National Corpus and the Corpus of London Teenage Language and similarities and differences were noted and discussed. The study also used discourse analysis frameworks to investigate the role of high frequency lexical items such as ‘like’ in the data. In recent times ‘like’ has emerged globally as a lexicalized discourse marker, and its appearance in the corpus of Indian South African English confirms this trend. The corpus built as part of this study is intended as the first building block towards a full corpus of Indian South African English which could serve as a standard for referencing research into the sub-variety. Ultimately, it is argued that the establishment of similar corpora of other known sub-varieties of South African English could contribute towards the creation of a truly representative large corpus of South African English and a more nuanced understanding and definition of this important variety of World English.
- Full Text:
- Date Issued: 2008
Towards a taxonomy of network scanning techniques
- Barnett, Richard J, Irwin, Barry V W
- Authors: Barnett, Richard J , Irwin, Barry V W
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430310 , vital:72682 , https://doi.org/10.1145/1456659.1456660
- Description: Network scanning is a common reconnaissance activity in network in-trusion. Despite this, it's classification remains vague and detection sys-tems in current Network Intrusion Detection Systems are incapable of detecting many forms of scanning traffic. This paper presents a classi-fication of network scanning and illustrates how complex and varied this activity is. The presented classification extends previous, well known, definitions of scanning traffic in a manner which reflects this complexity.
- Full Text:
- Date Issued: 2008
- Authors: Barnett, Richard J , Irwin, Barry V W
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430310 , vital:72682 , https://doi.org/10.1145/1456659.1456660
- Description: Network scanning is a common reconnaissance activity in network in-trusion. Despite this, it's classification remains vague and detection sys-tems in current Network Intrusion Detection Systems are incapable of detecting many forms of scanning traffic. This paper presents a classi-fication of network scanning and illustrates how complex and varied this activity is. The presented classification extends previous, well known, definitions of scanning traffic in a manner which reflects this complexity.
- Full Text:
- Date Issued: 2008
Towards a user centric model for identity and access management within the online environment
- Authors: Deas, Matthew Burns
- Date: 2008
- Subjects: Computers -- Access control , Computer networks -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9780 , http://hdl.handle.net/10948/775 , Computers -- Access control , Computer networks -- Security measures
- Description: Today, one is expected to remember multiple user names and passwords for different domains when one wants to access on the Internet. Identity management seeks to solve this problem through creating a digital identity that is exchangeable across organisational boundaries. Through the setup of collaboration agreements between multiple domains, users can easily switch across domains without being required to sign in again. However, use of this technology comes with risks of user identity and personal information being compromised. Criminals make use of spoofed websites and social engineering techniques to gain illegal access to user information. Due to this, the need for users to be protected from online threats has increased. Two processes are required to protect the user login information at the time of sign-on. Firstly, user’s information must be protected at the time of sign-on, and secondly, a simple method for the identification of the website is required by the user. This treatise looks at the process for identifying and verifying user information, and how the user can verify the system at sign-in. Three models for identity management are analysed, namely the Microsoft .NET Passport, Liberty Alliance Federated Identity for Single Sign-on and the Mozilla TrustBar for system authentication.
- Full Text:
- Date Issued: 2008
- Authors: Deas, Matthew Burns
- Date: 2008
- Subjects: Computers -- Access control , Computer networks -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9780 , http://hdl.handle.net/10948/775 , Computers -- Access control , Computer networks -- Security measures
- Description: Today, one is expected to remember multiple user names and passwords for different domains when one wants to access on the Internet. Identity management seeks to solve this problem through creating a digital identity that is exchangeable across organisational boundaries. Through the setup of collaboration agreements between multiple domains, users can easily switch across domains without being required to sign in again. However, use of this technology comes with risks of user identity and personal information being compromised. Criminals make use of spoofed websites and social engineering techniques to gain illegal access to user information. Due to this, the need for users to be protected from online threats has increased. Two processes are required to protect the user login information at the time of sign-on. Firstly, user’s information must be protected at the time of sign-on, and secondly, a simple method for the identification of the website is required by the user. This treatise looks at the process for identifying and verifying user information, and how the user can verify the system at sign-in. Three models for identity management are analysed, namely the Microsoft .NET Passport, Liberty Alliance Federated Identity for Single Sign-on and the Mozilla TrustBar for system authentication.
- Full Text:
- Date Issued: 2008
Towards revised physically based parameter estimation methods for the Pitman monthly rainfall-runoff model
- Kapangaziwiri, Evison, Hughes, Denis A
- Authors: Kapangaziwiri, Evison , Hughes, Denis A
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:7088 , http://hdl.handle.net/10962/d1012417
- Description: This paper presents a preliminary stage in the development of an alternative parameterisation procedure for the Pitman monthly rainfall runoff model which enjoys popular use in water resource assessment in Southern Africa. The estimation procedures are based on the premise that it is possible to use physical basin properties directly in the quantification of the soil moisture accounting, runoff, and recharge and infiltration parameters. The results for selected basins show that the revised parameters are at least as good as current regionalised sets or give satisfactory results in areas where no regionalised parameters exist.
- Full Text:
- Date Issued: 2008
- Authors: Kapangaziwiri, Evison , Hughes, Denis A
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:7088 , http://hdl.handle.net/10962/d1012417
- Description: This paper presents a preliminary stage in the development of an alternative parameterisation procedure for the Pitman monthly rainfall runoff model which enjoys popular use in water resource assessment in Southern Africa. The estimation procedures are based on the premise that it is possible to use physical basin properties directly in the quantification of the soil moisture accounting, runoff, and recharge and infiltration parameters. The results for selected basins show that the revised parameters are at least as good as current regionalised sets or give satisfactory results in areas where no regionalised parameters exist.
- Full Text:
- Date Issued: 2008
Towards the bioremediation of the hypertrophic Swartkops Solar Salt-works
- Authors: Difford, Mark
- Date: 2008
- Subjects: Salt industry and trade -- South Africa -- Port Elizabeth , Bioremediation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10606 , http://hdl.handle.net/10948/1506 , Salt industry and trade -- South Africa -- Port Elizabeth , Bioremediation
- Description: This thesis presents the results of three studies aimed at improving brine-quality at the Swartkops solar salt-works (Swartkops Sea Salt [Pty] Ltd) on the outskirts of Port Elizabeth, South Africa. This is a highly eutrophic salt-works, the management of which has become increasingly difficult in recent years. The fundamental problem is how best to operate the system at maximum capacity while limiting nutrient inputs from the nutrient-rich microtidal Swartkops Estuary. In the first study, brine-quality at several sites along the axis of the Swartkops Estuary, and the extent to which it is affected by a variety of factors, is compared. Sites were sampled on micro- and macrotidal time scales, and were selected by the management of the salt-works as possible locations for a new pump-house (for extracting brine from the estuary) for their salt-work operations at Swartkops and Missionvale. The study showed that there are incremental benefits to be had from moving the site of extraction downstream from its present position to a site closer to the mouth of the estuary, where the concentration of nutrients usually is lower and where salinity usually is higher. There is little to be gained from moving the site of extraction laterally, to the mouth of the Inlet from which brine currently is extracted, so that brine is extracted directly from the estuary itself. A set of models relating the concentrations of NH+ 4 , NO{u100000}3 , and PO34{u100000} to salinity is proposed. These take into account the influences of site and season and may be used to estimate the concentration of these nutrients from a measurement of salinity. The model for PO34{u100000} shows that it would be more damaging to the salt-works’ operations to pump “low”-salinity brine during the early months of summer than during autumn. Evidence is also presented to show that Wylde Bridge has no influence on nutrient concentrations in the estuary, with tidal flushing generally passing beyond the Wylde-Bridge break-point. The exceptionally heavy flooding of the estuary that occurred in September 2002 may, however, have biased this conclusion, because of its scouring effect. The second study concentrated on monitoring the effect of (1) decreasing pond depth and (2) increasing pond salinity—two readily available management tools—on brine quality at the salt-works. Pond depth throughout the salt-works was decreased by 40 cm, and the salinity of Pond 5, a pond in the middle of the system, was increased to 175 S. Both measures were kept in place for the duration of the study (Nov. 2002–Aug. 2004). The pond-depth experiment did not have the expected result, there being no evidence of the increase in microalgal growth in the water column that was predicted based on previous research. There was, however, a significant increase in benthic chlorophyll-a, and there was a general improvement in the condition of the sedimentary system of the salt-works. There was also a substantial decrease in particulate organic matter in the water column, with clear evidence that the remaining fraction was closely associated with living forms of particulate matter rather than with detritus. The pond-salinity experiment proves that there is a flourishing, and resilient, population of brine shrimp (Artemia salina L.) at the salt-works. Restocking the salina, or stocking it with a different strain of brine shrimp, is therefore not necessary. The results of this study show that the brine shrimp population at the salt-works needs salinities of greater than about 65–70 S to survive. As a living force they almost certainly need a protective salinity that is greater than about 120–140 S, perhaps even as great as 160 S. Brine shrimp thrived in the high salinity milieu of the experimental pond for the duration of the study, but dwindled from three other ponds of the system once their salinities fell to below 90 S, eventually to disappear from them, apparently completely, once salinity fell to below 65 S. The third and final study concentrated on establishing whether the products released by decomposing barley straw could be used in a solar salt-works to control macroalgal blooms without detrimentally affecting the benthic-mat. Previous research has shown that these products are effective inhibitors of macroalgal growth and that they remain effective under saline conditions. The results presented here show that the same products, or products released under similar conditions of decomposition, adversely effect both the structure and the function of the mat. Consequently, their use in a solar salt-works cannot be recommended.
- Full Text:
- Date Issued: 2008
- Authors: Difford, Mark
- Date: 2008
- Subjects: Salt industry and trade -- South Africa -- Port Elizabeth , Bioremediation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10606 , http://hdl.handle.net/10948/1506 , Salt industry and trade -- South Africa -- Port Elizabeth , Bioremediation
- Description: This thesis presents the results of three studies aimed at improving brine-quality at the Swartkops solar salt-works (Swartkops Sea Salt [Pty] Ltd) on the outskirts of Port Elizabeth, South Africa. This is a highly eutrophic salt-works, the management of which has become increasingly difficult in recent years. The fundamental problem is how best to operate the system at maximum capacity while limiting nutrient inputs from the nutrient-rich microtidal Swartkops Estuary. In the first study, brine-quality at several sites along the axis of the Swartkops Estuary, and the extent to which it is affected by a variety of factors, is compared. Sites were sampled on micro- and macrotidal time scales, and were selected by the management of the salt-works as possible locations for a new pump-house (for extracting brine from the estuary) for their salt-work operations at Swartkops and Missionvale. The study showed that there are incremental benefits to be had from moving the site of extraction downstream from its present position to a site closer to the mouth of the estuary, where the concentration of nutrients usually is lower and where salinity usually is higher. There is little to be gained from moving the site of extraction laterally, to the mouth of the Inlet from which brine currently is extracted, so that brine is extracted directly from the estuary itself. A set of models relating the concentrations of NH+ 4 , NO{u100000}3 , and PO34{u100000} to salinity is proposed. These take into account the influences of site and season and may be used to estimate the concentration of these nutrients from a measurement of salinity. The model for PO34{u100000} shows that it would be more damaging to the salt-works’ operations to pump “low”-salinity brine during the early months of summer than during autumn. Evidence is also presented to show that Wylde Bridge has no influence on nutrient concentrations in the estuary, with tidal flushing generally passing beyond the Wylde-Bridge break-point. The exceptionally heavy flooding of the estuary that occurred in September 2002 may, however, have biased this conclusion, because of its scouring effect. The second study concentrated on monitoring the effect of (1) decreasing pond depth and (2) increasing pond salinity—two readily available management tools—on brine quality at the salt-works. Pond depth throughout the salt-works was decreased by 40 cm, and the salinity of Pond 5, a pond in the middle of the system, was increased to 175 S. Both measures were kept in place for the duration of the study (Nov. 2002–Aug. 2004). The pond-depth experiment did not have the expected result, there being no evidence of the increase in microalgal growth in the water column that was predicted based on previous research. There was, however, a significant increase in benthic chlorophyll-a, and there was a general improvement in the condition of the sedimentary system of the salt-works. There was also a substantial decrease in particulate organic matter in the water column, with clear evidence that the remaining fraction was closely associated with living forms of particulate matter rather than with detritus. The pond-salinity experiment proves that there is a flourishing, and resilient, population of brine shrimp (Artemia salina L.) at the salt-works. Restocking the salina, or stocking it with a different strain of brine shrimp, is therefore not necessary. The results of this study show that the brine shrimp population at the salt-works needs salinities of greater than about 65–70 S to survive. As a living force they almost certainly need a protective salinity that is greater than about 120–140 S, perhaps even as great as 160 S. Brine shrimp thrived in the high salinity milieu of the experimental pond for the duration of the study, but dwindled from three other ponds of the system once their salinities fell to below 90 S, eventually to disappear from them, apparently completely, once salinity fell to below 65 S. The third and final study concentrated on establishing whether the products released by decomposing barley straw could be used in a solar salt-works to control macroalgal blooms without detrimentally affecting the benthic-mat. Previous research has shown that these products are effective inhibitors of macroalgal growth and that they remain effective under saline conditions. The results presented here show that the same products, or products released under similar conditions of decomposition, adversely effect both the structure and the function of the mat. Consequently, their use in a solar salt-works cannot be recommended.
- Full Text:
- Date Issued: 2008
Towards the development of InAs/GaInSb strained-layer superlattices for infrared detection
- Authors: Botha, Lindsay
- Date: 2008
- Subjects: Gallium arsenide semiconductors , Indium alloys , Compound semiconductors , Organometallic compounds , Infrared detectors , Infrared technology , Superlattices as materials
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10526 , http://hdl.handle.net/10948/713 , Gallium arsenide semiconductors , Indium alloys , Compound semiconductors , Organometallic compounds , Infrared detectors , Infrared technology , Superlattices as materials
- Description: This study focuses on the development of InAs/GaInSb strained-layer superlattice structures by metal organic chemical vapour deposition (MOCVD), and deals with two aspects of the development of InAs/GaInSb SLS’s by MOCVD viz. the deposition of nano-scale (~100 Å) GaInSb layers, and the electrical characterization of unstrained InAs. The first part of this work aims to study the MOCVD growth of GaInSb layers in terms of deposition rate and indium incorporation on the nano-scale. This task is approached by first optimizing the growth of relatively thick (~2 μm) epitaxial films, and then assuming similar growth parameters during nano-scale deposition. The GaInSb layers were grown as part of GaInSb/GaSb quantum well (QW) structures. By using this approach, the GaInSb QW’s (~100 Å) could be characterized with the use of photoluminescence spectroscopy, which, when used in conjunction with transmission electron microscopy and/or X-ray diffractomery, proves useful in the analysis of such small scale deposition. It is shown that the growth rate of GaInSb on the nano-scale approaches the nominal growth rates determined from thick (~2 μm) GaInSb calibration layers. The In incorporation efficiency in nano-layers, however, was markedly lower than what was predicted by the GaInSb calibration layers. This reduction in indium incorporation could be the result of the effects of strain on In incorporation. The choice of substrate orientation for QW deposition was also studied. QW structures were grown simultaneously on both (100) and 2°off (100) GaSb(Te) substrates, and it is shown that growth on non-vicinal substrates is more conducive to the deposition of high quality QW structures. The second part of this study focuses on the electrical characterization of unstrained InAs. It is long known that conventional Hall measurements cannot be used to accurately characterize InAs epitaxial layers, as a result of parallel conduction resulting from surface and/or interface effects. This study looks at extracting the surface and bulk electrical properties of n-type InAs thin films directly from variable magnetic field Hall measurements. For p-type InAs, the situation is complicated by the relatively large electron to hole mobility ratio of InAs which tends to conceal the p-type nature of InAs thin films from Hall measurements. Here, this effect is illustrated by way of theoretical simulation of Hall data.
- Full Text:
- Date Issued: 2008
- Authors: Botha, Lindsay
- Date: 2008
- Subjects: Gallium arsenide semiconductors , Indium alloys , Compound semiconductors , Organometallic compounds , Infrared detectors , Infrared technology , Superlattices as materials
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10526 , http://hdl.handle.net/10948/713 , Gallium arsenide semiconductors , Indium alloys , Compound semiconductors , Organometallic compounds , Infrared detectors , Infrared technology , Superlattices as materials
- Description: This study focuses on the development of InAs/GaInSb strained-layer superlattice structures by metal organic chemical vapour deposition (MOCVD), and deals with two aspects of the development of InAs/GaInSb SLS’s by MOCVD viz. the deposition of nano-scale (~100 Å) GaInSb layers, and the electrical characterization of unstrained InAs. The first part of this work aims to study the MOCVD growth of GaInSb layers in terms of deposition rate and indium incorporation on the nano-scale. This task is approached by first optimizing the growth of relatively thick (~2 μm) epitaxial films, and then assuming similar growth parameters during nano-scale deposition. The GaInSb layers were grown as part of GaInSb/GaSb quantum well (QW) structures. By using this approach, the GaInSb QW’s (~100 Å) could be characterized with the use of photoluminescence spectroscopy, which, when used in conjunction with transmission electron microscopy and/or X-ray diffractomery, proves useful in the analysis of such small scale deposition. It is shown that the growth rate of GaInSb on the nano-scale approaches the nominal growth rates determined from thick (~2 μm) GaInSb calibration layers. The In incorporation efficiency in nano-layers, however, was markedly lower than what was predicted by the GaInSb calibration layers. This reduction in indium incorporation could be the result of the effects of strain on In incorporation. The choice of substrate orientation for QW deposition was also studied. QW structures were grown simultaneously on both (100) and 2°off (100) GaSb(Te) substrates, and it is shown that growth on non-vicinal substrates is more conducive to the deposition of high quality QW structures. The second part of this study focuses on the electrical characterization of unstrained InAs. It is long known that conventional Hall measurements cannot be used to accurately characterize InAs epitaxial layers, as a result of parallel conduction resulting from surface and/or interface effects. This study looks at extracting the surface and bulk electrical properties of n-type InAs thin films directly from variable magnetic field Hall measurements. For p-type InAs, the situation is complicated by the relatively large electron to hole mobility ratio of InAs which tends to conceal the p-type nature of InAs thin films from Hall measurements. Here, this effect is illustrated by way of theoretical simulation of Hall data.
- Full Text:
- Date Issued: 2008
Towards understanding the mechanism of dimerisation of Saccharomyces cerevisiae eukaryotic translation initiation factor 5A
- Authors: Gentz, Petra Monika
- Date: 2008
- Subjects: Cytology Molecular biology Biochemistry Proteins -- Analysis Proteomics Polypeptides Amino acids -- Synthesis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3992 , http://hdl.handle.net/10962/d1004052
- Description: Eukaryotic translation initiation factor 5A (eIF5A) is the only known protein to contain hypusine, formed by post-translational modification of a highly conserved lysine residue. Hypusination is essential for eIF5A function, being required for binding of a specific subset of mRNAs necessary for progression of eukaryotic cells through the G1-S checkpoint. Little structural information is available for eIF5A other than that derived from archaeal homologues. The aim of this study was to conduct structure-function studies on Saccharomyces cerevisiae (yeast) eIF5A, encoded by TIF51A. Homology models of eIF5A were generated from the Methanococcus jannaschii archaeal homologue (aIF5A) and two Leishmania eIF5As. The models, along with secondary structure predictions identified an a-helix on the C-terminal domain, unique to eukaryote eIF5A. The Neurospora crassa structural analogue, HEX-1, which dimerises in three configurations, was used to generate similar dimeric model configurations of eIF5A. A biochemical and functional analysis was used to validate the homology models of eIF5A.Since the crystal structures of aIF5A and eIF5A were solved from unhypusinated protein produced in Escherichia coli, 6 x His-tagged eIF5A (His-eIF5A) was used for biochemical analysis. This analysis revealed that eIF5A existed as a dimer in solution, dependent on the presence of the highly conserved Cys 39 residue. A yeast TIF51A/TIF51B null yeast strain, with a chromosomal copy of TIF51A under control of PGAL1, was used to confirm that HiseIF5A and selected eIF5A mutants were functional in vivo. Biochemical analysis showed that hypusinated His-eIF5A also exists as a dimer, but neither the dimerisation, nor the function of eIF5A are dependent on the presence of Cys 39. Rather they depend on the presence of hypusine (Hpu) 51 and the presence of RNA leading to the conclusion that RNA and hypusine are required for dimerisation and hence function, of native eIF5A in vivo. In contrast, a Lys 51 to Arg 51 substitution or RNase treatment of His-eIF5A produced in E. coli did not destabilize the dimeric form, suggesting different folding/dimerisation mechanisms in E. coli and yeast cells. The information obtained from the initial homology models, together with the results of the biochemical analysis was used to propose a mechanism for dimerisation of yeast eIF5A involving both hypusine and RNA.
- Full Text:
- Date Issued: 2008
- Authors: Gentz, Petra Monika
- Date: 2008
- Subjects: Cytology Molecular biology Biochemistry Proteins -- Analysis Proteomics Polypeptides Amino acids -- Synthesis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3992 , http://hdl.handle.net/10962/d1004052
- Description: Eukaryotic translation initiation factor 5A (eIF5A) is the only known protein to contain hypusine, formed by post-translational modification of a highly conserved lysine residue. Hypusination is essential for eIF5A function, being required for binding of a specific subset of mRNAs necessary for progression of eukaryotic cells through the G1-S checkpoint. Little structural information is available for eIF5A other than that derived from archaeal homologues. The aim of this study was to conduct structure-function studies on Saccharomyces cerevisiae (yeast) eIF5A, encoded by TIF51A. Homology models of eIF5A were generated from the Methanococcus jannaschii archaeal homologue (aIF5A) and two Leishmania eIF5As. The models, along with secondary structure predictions identified an a-helix on the C-terminal domain, unique to eukaryote eIF5A. The Neurospora crassa structural analogue, HEX-1, which dimerises in three configurations, was used to generate similar dimeric model configurations of eIF5A. A biochemical and functional analysis was used to validate the homology models of eIF5A.Since the crystal structures of aIF5A and eIF5A were solved from unhypusinated protein produced in Escherichia coli, 6 x His-tagged eIF5A (His-eIF5A) was used for biochemical analysis. This analysis revealed that eIF5A existed as a dimer in solution, dependent on the presence of the highly conserved Cys 39 residue. A yeast TIF51A/TIF51B null yeast strain, with a chromosomal copy of TIF51A under control of PGAL1, was used to confirm that HiseIF5A and selected eIF5A mutants were functional in vivo. Biochemical analysis showed that hypusinated His-eIF5A also exists as a dimer, but neither the dimerisation, nor the function of eIF5A are dependent on the presence of Cys 39. Rather they depend on the presence of hypusine (Hpu) 51 and the presence of RNA leading to the conclusion that RNA and hypusine are required for dimerisation and hence function, of native eIF5A in vivo. In contrast, a Lys 51 to Arg 51 substitution or RNase treatment of His-eIF5A produced in E. coli did not destabilize the dimeric form, suggesting different folding/dimerisation mechanisms in E. coli and yeast cells. The information obtained from the initial homology models, together with the results of the biochemical analysis was used to propose a mechanism for dimerisation of yeast eIF5A involving both hypusine and RNA.
- Full Text:
- Date Issued: 2008
Tracing and erasure in Kathryn Smith's Psychogeographies: the washing away of wrongs
- Authors: de Jager, Maureen
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147413 , vital:38634 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31057
- Description: Kathryn Smith's Psychogeographies: The Washing Away of Wrongs is a series of twelve prints comprising photographs and handwritten text, wherein she records her 'pilgrimage' to the former homes of British serial killer Dennis Nilsen. As such, it utilises photographic and autographic traces to 'track' the elusive traces left by Nilsen. Given the lapse of two decades between Nilsen's arrest and Smith's visit, the traces of Nilsen's 'wrongs' seem all but erased by the banal façade of suburban living which has continued on, regardless. In taking this as a starting point, the following article considers the motif of absence that characterises Smith's work as intrinsic to traces per se.
- Full Text:
- Date Issued: 2008
- Authors: de Jager, Maureen
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147413 , vital:38634 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31057
- Description: Kathryn Smith's Psychogeographies: The Washing Away of Wrongs is a series of twelve prints comprising photographs and handwritten text, wherein she records her 'pilgrimage' to the former homes of British serial killer Dennis Nilsen. As such, it utilises photographic and autographic traces to 'track' the elusive traces left by Nilsen. Given the lapse of two decades between Nilsen's arrest and Smith's visit, the traces of Nilsen's 'wrongs' seem all but erased by the banal façade of suburban living which has continued on, regardless. In taking this as a starting point, the following article considers the motif of absence that characterises Smith's work as intrinsic to traces per se.
- Full Text:
- Date Issued: 2008
Transitions towards a knowledge society: Aspectual pre-evaluation of a culture-sensitive implementation framework
- Thinyane, Mamello, Terzoli, Alfredo, Clayton, Peter G
- Authors: Thinyane, Mamello , Terzoli, Alfredo , Clayton, Peter G
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431054 , vital:72741 , https://doi.org/10.1007/978-0-387-09729-9_41
- Description: Information and Communication Technology (ICT) is aiding the transi-tion of society into information society and ultimately knowledge society. Embedded within ICT are the cultural and philosophical undercurrents of the society in which the ICT solutions are developed, currently pre-dominantly the Western culture. The proliferation of ICT is therefore in-advertedly leading to more Westernization of the world. It is important, therefore, that ICT solutions are culture sensitive and flexible enough to be situated within different cultures. To that end, we utilize Herman Dooyeweerd’s Theory of Modal Aspects to analyze a framework we has developed for implementation of locally situated knowledge based systems, to determine its efficacy in addressing the different modal as-pects, which make up the total experience and cultural expressiveness of societies.
- Full Text:
- Date Issued: 2008
- Authors: Thinyane, Mamello , Terzoli, Alfredo , Clayton, Peter G
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431054 , vital:72741 , https://doi.org/10.1007/978-0-387-09729-9_41
- Description: Information and Communication Technology (ICT) is aiding the transi-tion of society into information society and ultimately knowledge society. Embedded within ICT are the cultural and philosophical undercurrents of the society in which the ICT solutions are developed, currently pre-dominantly the Western culture. The proliferation of ICT is therefore in-advertedly leading to more Westernization of the world. It is important, therefore, that ICT solutions are culture sensitive and flexible enough to be situated within different cultures. To that end, we utilize Herman Dooyeweerd’s Theory of Modal Aspects to analyze a framework we has developed for implementation of locally situated knowledge based systems, to determine its efficacy in addressing the different modal as-pects, which make up the total experience and cultural expressiveness of societies.
- Full Text:
- Date Issued: 2008
Treatment and care of children and adolescents diagnosed with Attention deficit/Hyperactivity disorder
- Authors: Snyman, Sanmari
- Date: 2008
- Subjects: Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10144 , http://hdl.handle.net/10948/871 , Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Description: Background: In recent years the incidence of Attention Deficit/Hyperactivity Disorder (ADHD) has increased. Objectives: The primary aim of the study was to determine the treatment of children and adolescents diagnosed with ADHD in South Africa and more specifically the Eastern Cape. Methods: The study consisted of two parts, a retrospective drug utilisation study and a questionnaire survey. The drug utilisation study was conducted on chronic medication records of a private sector medical scheme administrator and contained records from 1994 to 2006. A total of 42 250 records representing 8 274 patients and 4 001 families, were analysed. The questionnaire survey was conducted in the Eastern Cape. The questionnaires were distributed by responsible pharmacists to parents of children receiving medication for the treatment of ADHD from his/her pharmacy. Fifty one completed questionnaires were analysed. Results: The average age of patients in the drug utilisation study were 14.28 (SD = 5.50) years. Males represented 77.37 percent of patients. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product, followed by Ritalin® LA 20 mg. The two most frequently prescribed active ingredients apart from methylphenidate were fluticasone and budesonide. The two most common comorbid conditions were allergic rhinitis and asthma. The average age of patients in the questionnaire survey was 10.26 (SD = 2.51) years. Males represented 73.58 percent of patients. A third of patients had relatives previously diagnosed with ADHD. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product. Conclusion: ADHD is a complex life-long disorder. It does not only affect the child diagnosed with the disorder, but also has effects on the family, schooling system and peer relationship. Therefore, more studies regarding the incidence and treatment of ADHD need to be conducted in South Africa.
- Full Text:
- Date Issued: 2008
- Authors: Snyman, Sanmari
- Date: 2008
- Subjects: Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10144 , http://hdl.handle.net/10948/871 , Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Description: Background: In recent years the incidence of Attention Deficit/Hyperactivity Disorder (ADHD) has increased. Objectives: The primary aim of the study was to determine the treatment of children and adolescents diagnosed with ADHD in South Africa and more specifically the Eastern Cape. Methods: The study consisted of two parts, a retrospective drug utilisation study and a questionnaire survey. The drug utilisation study was conducted on chronic medication records of a private sector medical scheme administrator and contained records from 1994 to 2006. A total of 42 250 records representing 8 274 patients and 4 001 families, were analysed. The questionnaire survey was conducted in the Eastern Cape. The questionnaires were distributed by responsible pharmacists to parents of children receiving medication for the treatment of ADHD from his/her pharmacy. Fifty one completed questionnaires were analysed. Results: The average age of patients in the drug utilisation study were 14.28 (SD = 5.50) years. Males represented 77.37 percent of patients. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product, followed by Ritalin® LA 20 mg. The two most frequently prescribed active ingredients apart from methylphenidate were fluticasone and budesonide. The two most common comorbid conditions were allergic rhinitis and asthma. The average age of patients in the questionnaire survey was 10.26 (SD = 2.51) years. Males represented 73.58 percent of patients. A third of patients had relatives previously diagnosed with ADHD. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product. Conclusion: ADHD is a complex life-long disorder. It does not only affect the child diagnosed with the disorder, but also has effects on the family, schooling system and peer relationship. Therefore, more studies regarding the incidence and treatment of ADHD need to be conducted in South Africa.
- Full Text:
- Date Issued: 2008