Investigation of the larval parasitoids of the false codling moth, Cryptophlebia Leucotreta (Meyrick) (Lepidoptera: Tortricidae), on citrus in South Africa
- Authors: Sishuba, Nomahlubi
- Date: 2004
- Subjects: Cryptophlebia leucotreta , Tortricidae , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Parasitoids , Citrus -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5918 , http://hdl.handle.net/10962/d1016267
- Description: The study examined the larval parasitoids of Cryptophlebia leucotreta (Meyrick) on citrus in South Africa and aimed to improve the existing rearing techniques of C. leucotreta with a view to mass rearing of biological control agents. The biological characteristics of Agathis bishopi Nixon (Hymenoptera: Braconidae) were studied, with an emphasis on parasitism rates in the field, host stage preference, developmental rate, life span and offspring sex ratios. Two larval parasitoids, A. bishopi and Apophua leucotretae (Wilkinson) (Hymenoptera: Ichneumonidae), and an egg parasitoid, Trichogrammatoidea cryptophlebiae Nagaraja (Hymenoptera: Trichogrammatidae), were recorded on C. leucotreta on citrus. A. bishopi was the more abundant of the larval parasitoids and exhibited density dependent parasitism. The highest parasitism rates were observed in December with up to 38% in Sundays River Valley and 34% in Gamtoos River Valley, at a time when the highest false codling moth infestations were observed. Agathis bishopi was recorded only in the Eastern Cape Province. The sex ratio of A. bishopi was biased towards females throughout the study (77% in Gamtoos River Valley and 72% in Sundays River Valley). Agathis bishopi is a solitary, koinobiont, larval-pupal endoparasitoid. The species showed a preference for 1st and 2"d instar hosts. Females regulate the sex of their progeny according to the size and larval stage of the host, ovipositing unfertilised eggs in younger, smaller larvae (1st instars) and fertilised eggs in older, larger larvae (2nd instars). The developmental rate of A. bishopi is in synchrony with that of the moth and adults emerge when adult moths that have escaped parasitism emerge. Agathis bishopi and T. cryptophlebiae compliment each other because they have different niches and strategies of attack. Integrating A. bishopi and T. cryptophlebiae into the management of citrus orchards has potential to suppress false codling moth. Larger rearing containers seemed ideal for large-scale rearing of false codling moth. A higher percentage of adults was obtained from larvae reared in larger containers than in smaller ones. The width of the sponges used as stoppers prevented escape of the larvae. Media prepared in larger containers are easier and simpler to prepare than in smaller ones, thus eliminating many precautions otherwise necessary to prevent contamination. Moth production was greatly reduced by the high concentration of Sporekill used for egg decontamination.
- Full Text:
- Date Issued: 2004
- Authors: Sishuba, Nomahlubi
- Date: 2004
- Subjects: Cryptophlebia leucotreta , Tortricidae , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Parasitoids , Citrus -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5918 , http://hdl.handle.net/10962/d1016267
- Description: The study examined the larval parasitoids of Cryptophlebia leucotreta (Meyrick) on citrus in South Africa and aimed to improve the existing rearing techniques of C. leucotreta with a view to mass rearing of biological control agents. The biological characteristics of Agathis bishopi Nixon (Hymenoptera: Braconidae) were studied, with an emphasis on parasitism rates in the field, host stage preference, developmental rate, life span and offspring sex ratios. Two larval parasitoids, A. bishopi and Apophua leucotretae (Wilkinson) (Hymenoptera: Ichneumonidae), and an egg parasitoid, Trichogrammatoidea cryptophlebiae Nagaraja (Hymenoptera: Trichogrammatidae), were recorded on C. leucotreta on citrus. A. bishopi was the more abundant of the larval parasitoids and exhibited density dependent parasitism. The highest parasitism rates were observed in December with up to 38% in Sundays River Valley and 34% in Gamtoos River Valley, at a time when the highest false codling moth infestations were observed. Agathis bishopi was recorded only in the Eastern Cape Province. The sex ratio of A. bishopi was biased towards females throughout the study (77% in Gamtoos River Valley and 72% in Sundays River Valley). Agathis bishopi is a solitary, koinobiont, larval-pupal endoparasitoid. The species showed a preference for 1st and 2"d instar hosts. Females regulate the sex of their progeny according to the size and larval stage of the host, ovipositing unfertilised eggs in younger, smaller larvae (1st instars) and fertilised eggs in older, larger larvae (2nd instars). The developmental rate of A. bishopi is in synchrony with that of the moth and adults emerge when adult moths that have escaped parasitism emerge. Agathis bishopi and T. cryptophlebiae compliment each other because they have different niches and strategies of attack. Integrating A. bishopi and T. cryptophlebiae into the management of citrus orchards has potential to suppress false codling moth. Larger rearing containers seemed ideal for large-scale rearing of false codling moth. A higher percentage of adults was obtained from larvae reared in larger containers than in smaller ones. The width of the sponges used as stoppers prevented escape of the larvae. Media prepared in larger containers are easier and simpler to prepare than in smaller ones, thus eliminating many precautions otherwise necessary to prevent contamination. Moth production was greatly reduced by the high concentration of Sporekill used for egg decontamination.
- Full Text:
- Date Issued: 2004
Investigations into the nutritional requirements of juvenile dusky kob, Argyrosomus japonicus (Pisces sciaendae), under ambient culture conditions
- Authors: Daniel, Simon James
- Date: 2004
- Subjects: Argyrosomus -- Nutrition -- Requirements , Sciaenidae -- Nutrition -- Requirements , Fishes -- Food , Fishes -- Growth , Fish culture , Fishes -- Nutrition -- Requirements
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5197 , http://hdl.handle.net/10962/d1002602 , Argyrosomus -- Nutrition -- Requirements , Sciaenidae -- Nutrition -- Requirements , Fishes -- Food , Fishes -- Growth , Fish culture , Fishes -- Nutrition -- Requirements
- Description: The effect of dietary protein, protein and energy ratios, fish meal replacement by Soya bean meal and feeding frequency was investigated on the growth, feed efficiency and body composition, of juvenile dusky kob, Argyrosomus japonicus. The effect of dietary protein levels was investigated by comparing isocaloric diets containing 35, 40, 45 and 55% protein. Dietary protein inclusion level significantly affected specific growth rates, feed efficiency and body composition (in terms of fat deposition) and results show that a minimum of 45% and maximum of 52.3% dietary protein is optimal. The protein and energy requirements were investigated by comparing three protein levels (35,40 and 45%) with three lipid levels (6, 9 and 12%) in a 3x3 factorial design. A diet 45% protein and 9% lipid, with a P: E ratio of29 mglkJ and DE of 15.5 kJ/g resulted in an optimal specific growth rate (1.6± 0.2), feed efficiency (FCR= 1.7±0.44; PER= 1.36) and body composition for A. japonicus. To investigate the effect of partial fish meal replacement by Soya bean meal (SBM) in the diet, 20-50% of the protein from fish meal was substituted by protein from SBM, and were compared with a control diet containing only fish meal. No significant differences in the specific growth rates, feed efficiencies and the body composition were recorded for the fish fed the control diet and for fish fed the 20 and 30% SBM treatments. Results show that up to 30% of the protein from fish meal can be replaced with protein from SBM in the diet of this species. The effect of feeding frequency and gut evacuation time was investigated by comparing four feeding frequencies. Fish were fed to satiation either once, twice, three or four times a day. Feed intake was significantly affected by feeding frequency and fish fed 2, 3 and 4 meals a day ate significantly more food (p< 0.05) than the fish fed one meal a day. No significant differences (p> 0.05) in the specific growth rates, feed efficiencies and body composition were recorded for fish fed 2, 3 and 4 times a day. Feed intake was used to calculate an optimal daily ration and feeding two meals a day resulted in an optimal daily ration of 4% BW/day. A gut evacuation time of 7.25 hours indicates that fish fed twice a day probably had sufficient time to digest their food and evacuate their guts, resulting in the same daily feed intake as fish given 3 and 4 meals a day. Results conclude that under the present experimental conditions, a minimum daily ration of 4% BW/day, fed twice a day (in the morning and evening) is required for optimal growth (SGR= 1.33± 0.1), feed efficiency (FCR= 1.96± 0.4; PER= 1.44± 0.2) and body composition in juvenile dusky kob.
- Full Text:
- Date Issued: 2004
- Authors: Daniel, Simon James
- Date: 2004
- Subjects: Argyrosomus -- Nutrition -- Requirements , Sciaenidae -- Nutrition -- Requirements , Fishes -- Food , Fishes -- Growth , Fish culture , Fishes -- Nutrition -- Requirements
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5197 , http://hdl.handle.net/10962/d1002602 , Argyrosomus -- Nutrition -- Requirements , Sciaenidae -- Nutrition -- Requirements , Fishes -- Food , Fishes -- Growth , Fish culture , Fishes -- Nutrition -- Requirements
- Description: The effect of dietary protein, protein and energy ratios, fish meal replacement by Soya bean meal and feeding frequency was investigated on the growth, feed efficiency and body composition, of juvenile dusky kob, Argyrosomus japonicus. The effect of dietary protein levels was investigated by comparing isocaloric diets containing 35, 40, 45 and 55% protein. Dietary protein inclusion level significantly affected specific growth rates, feed efficiency and body composition (in terms of fat deposition) and results show that a minimum of 45% and maximum of 52.3% dietary protein is optimal. The protein and energy requirements were investigated by comparing three protein levels (35,40 and 45%) with three lipid levels (6, 9 and 12%) in a 3x3 factorial design. A diet 45% protein and 9% lipid, with a P: E ratio of29 mglkJ and DE of 15.5 kJ/g resulted in an optimal specific growth rate (1.6± 0.2), feed efficiency (FCR= 1.7±0.44; PER= 1.36) and body composition for A. japonicus. To investigate the effect of partial fish meal replacement by Soya bean meal (SBM) in the diet, 20-50% of the protein from fish meal was substituted by protein from SBM, and were compared with a control diet containing only fish meal. No significant differences in the specific growth rates, feed efficiencies and the body composition were recorded for the fish fed the control diet and for fish fed the 20 and 30% SBM treatments. Results show that up to 30% of the protein from fish meal can be replaced with protein from SBM in the diet of this species. The effect of feeding frequency and gut evacuation time was investigated by comparing four feeding frequencies. Fish were fed to satiation either once, twice, three or four times a day. Feed intake was significantly affected by feeding frequency and fish fed 2, 3 and 4 meals a day ate significantly more food (p< 0.05) than the fish fed one meal a day. No significant differences (p> 0.05) in the specific growth rates, feed efficiencies and body composition were recorded for fish fed 2, 3 and 4 times a day. Feed intake was used to calculate an optimal daily ration and feeding two meals a day resulted in an optimal daily ration of 4% BW/day. A gut evacuation time of 7.25 hours indicates that fish fed twice a day probably had sufficient time to digest their food and evacuate their guts, resulting in the same daily feed intake as fish given 3 and 4 meals a day. Results conclude that under the present experimental conditions, a minimum daily ration of 4% BW/day, fed twice a day (in the morning and evening) is required for optimal growth (SGR= 1.33± 0.1), feed efficiency (FCR= 1.96± 0.4; PER= 1.44± 0.2) and body composition in juvenile dusky kob.
- Full Text:
- Date Issued: 2004
Is it feasable to increase the medium density fibreboard manufacturing capability in South Africa?
- Authors: Van Rooyen, Petrus Mynhardt
- Date: 2004
- Subjects: Fiberboard industry -- South Africa , Fiberboard , Particle board
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10938 , http://hdl.handle.net/10948/255 , Fiberboard industry -- South Africa , Fiberboard , Particle board
- Description: Medium density fibre (MDF) board is used in various applications in the building-, furniture- and casket industry. The market is shared by solid wood and other flat panels, such as particle board and plywood. The market in South Africa forms part of the global market. Therefore it is possible to import MDF. The demand for MDF is driven by the building industry, the Consumer Price Index (CPI) and the exchange rate. The CPI is an indication of the consumer’s willingness to purchase furniture or to invest in property with subsequent growth in the building industry. The 2002 market in SA is 500 000m3 for particle board and 110 000m3 for MDF. The imported boards during this same period were particle board 10 000m3 and 22 194m3 for MDF. The extrapolated expected imports for 2003 would be 12 362m3 and 35 045m3 for particle board and MDF respectively. According to the empirical study the market increase for particle board and MDF, for 2003, will be 18%. That means that the particle board market will increase to 590 000m3 and the MDF market to 130 000m3. The 2002 production capacity was 648 000m3 (particle board) and 155 000m3 for MDF. The Sonae factory in White River can produce either particle board or MDF and this influences the production capacities. According to various International databases the requirements for SA in 2020 will be 984 000m3 for particle board and 569 000m3 for MDF. Quick calculation show a shortfall of 414 000m3 for MDF in 2020 when compared to 2002 production capacity. First mover advantage will give the mover the major market share in SA. The demand will be there. All the above calculations have been done without taking the 2010 World Football event in SA into consideration. The question is – all the current players are almost on par to make it happen. The company with the burning desire to make it work will find the finance and will have the controlling market share.
- Full Text:
- Date Issued: 2004
- Authors: Van Rooyen, Petrus Mynhardt
- Date: 2004
- Subjects: Fiberboard industry -- South Africa , Fiberboard , Particle board
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10938 , http://hdl.handle.net/10948/255 , Fiberboard industry -- South Africa , Fiberboard , Particle board
- Description: Medium density fibre (MDF) board is used in various applications in the building-, furniture- and casket industry. The market is shared by solid wood and other flat panels, such as particle board and plywood. The market in South Africa forms part of the global market. Therefore it is possible to import MDF. The demand for MDF is driven by the building industry, the Consumer Price Index (CPI) and the exchange rate. The CPI is an indication of the consumer’s willingness to purchase furniture or to invest in property with subsequent growth in the building industry. The 2002 market in SA is 500 000m3 for particle board and 110 000m3 for MDF. The imported boards during this same period were particle board 10 000m3 and 22 194m3 for MDF. The extrapolated expected imports for 2003 would be 12 362m3 and 35 045m3 for particle board and MDF respectively. According to the empirical study the market increase for particle board and MDF, for 2003, will be 18%. That means that the particle board market will increase to 590 000m3 and the MDF market to 130 000m3. The 2002 production capacity was 648 000m3 (particle board) and 155 000m3 for MDF. The Sonae factory in White River can produce either particle board or MDF and this influences the production capacities. According to various International databases the requirements for SA in 2020 will be 984 000m3 for particle board and 569 000m3 for MDF. Quick calculation show a shortfall of 414 000m3 for MDF in 2020 when compared to 2002 production capacity. First mover advantage will give the mover the major market share in SA. The demand will be there. All the above calculations have been done without taking the 2010 World Football event in SA into consideration. The question is – all the current players are almost on par to make it happen. The company with the burning desire to make it work will find the finance and will have the controlling market share.
- Full Text:
- Date Issued: 2004
Jah children the experience of Rastafari children in South Africa as members of a minority group with particular reference to communities in the former Cape Province
- Authors: Bain, Pauline
- Date: 2004
- Subjects: Rastafari movement -- South Africa -- Eastern Cape , Rastafari movement -- South Africa -- Western Cape , Rastafari movement -- South Africa -- Northern Cape , Reggae music -- South Africa -- History and criticism , Rastafarian ethics -- South Africa , Rastafari movement -- Doctrines , Children of minorities -- South Africa -- Education , Socialization -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2087 , http://hdl.handle.net/10962/d1002650 , Rastafari movement -- South Africa -- Eastern Cape , Rastafari movement -- South Africa -- Western Cape , Rastafari movement -- South Africa -- Northern Cape , Reggae music -- South Africa -- History and criticism , Rastafarian ethics -- South Africa , Rastafari movement -- Doctrines , Children of minorities -- South Africa -- Education , Socialization -- South Africa
- Description: This thesis is an ethnography of Rastafari childhood in the former Cape Province, South Africa, through the eyes of both parents and children. If children are a ‘muted group’, then what are the identity formation implications for “double-muted” groups, the children of ethnic minorities whose voices are not heard? Rasta parents’ experience of the struggle, ie. the opposition to apartheid, has shaped the Rastafari chant of ‘equal rights’ and ‘justice’ into a distinctly South African form of protest and resistance. Their childhood experiences have resulted in a desire to provide a better life for their children, using Rastafari as a vehicle. This is expressed in a continuation of the struggle that was started during apartheid, in the Rasta ideology children grow up learning. The Rasta child has become a contested body in this struggle. The South African Government, through policy, has a mandate to protect the child, and legislature exists to do so in accordance with international law. However, as child-raising differs phenomenally from culture to culture, these goals on the part of the State start infringing upon the rights and freedoms of minorities to raise their children according to their own cultural goals. This study examines the tension between Rastafari and government with regards to child raising, specifically looking at the following main points of contestation: public health, public schools and policy/legislation; in order to examine how Rasta children negotiate their identity in the face of these conflicting messages and struggles. Their identity can be influenced by three main groups, the Rasta family they grow up in; school; and multi-media. What these children choose to accept or reject in their worldview is moderated by their own agency. This study shows that this tension results in a new generation of Rastafari children, who are strongly grounded in an identity as Rastafari and take pride in this identity. It also illustrates how Rastafari are impacting on and changing government policy through resistance. Their successes in challenging the state on the grounds of multiculturalism and religious freedom, has helped in the attainment of a sense of dignity.
- Full Text:
- Date Issued: 2004
- Authors: Bain, Pauline
- Date: 2004
- Subjects: Rastafari movement -- South Africa -- Eastern Cape , Rastafari movement -- South Africa -- Western Cape , Rastafari movement -- South Africa -- Northern Cape , Reggae music -- South Africa -- History and criticism , Rastafarian ethics -- South Africa , Rastafari movement -- Doctrines , Children of minorities -- South Africa -- Education , Socialization -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2087 , http://hdl.handle.net/10962/d1002650 , Rastafari movement -- South Africa -- Eastern Cape , Rastafari movement -- South Africa -- Western Cape , Rastafari movement -- South Africa -- Northern Cape , Reggae music -- South Africa -- History and criticism , Rastafarian ethics -- South Africa , Rastafari movement -- Doctrines , Children of minorities -- South Africa -- Education , Socialization -- South Africa
- Description: This thesis is an ethnography of Rastafari childhood in the former Cape Province, South Africa, through the eyes of both parents and children. If children are a ‘muted group’, then what are the identity formation implications for “double-muted” groups, the children of ethnic minorities whose voices are not heard? Rasta parents’ experience of the struggle, ie. the opposition to apartheid, has shaped the Rastafari chant of ‘equal rights’ and ‘justice’ into a distinctly South African form of protest and resistance. Their childhood experiences have resulted in a desire to provide a better life for their children, using Rastafari as a vehicle. This is expressed in a continuation of the struggle that was started during apartheid, in the Rasta ideology children grow up learning. The Rasta child has become a contested body in this struggle. The South African Government, through policy, has a mandate to protect the child, and legislature exists to do so in accordance with international law. However, as child-raising differs phenomenally from culture to culture, these goals on the part of the State start infringing upon the rights and freedoms of minorities to raise their children according to their own cultural goals. This study examines the tension between Rastafari and government with regards to child raising, specifically looking at the following main points of contestation: public health, public schools and policy/legislation; in order to examine how Rasta children negotiate their identity in the face of these conflicting messages and struggles. Their identity can be influenced by three main groups, the Rasta family they grow up in; school; and multi-media. What these children choose to accept or reject in their worldview is moderated by their own agency. This study shows that this tension results in a new generation of Rastafari children, who are strongly grounded in an identity as Rastafari and take pride in this identity. It also illustrates how Rastafari are impacting on and changing government policy through resistance. Their successes in challenging the state on the grounds of multiculturalism and religious freedom, has helped in the attainment of a sense of dignity.
- Full Text:
- Date Issued: 2004
Journeys of the learning soul: Plato to Descartes
- Authors: Hugo, Wayne
- Date: 2004
- Subjects: Education -- Philosophy Education -- History Education, Ancient Education, Greek
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1884 , http://hdl.handle.net/10962/d1005917
- Description: This thesis aims to build up a picture of what it has meant for us within the western canon to educate a human being through the depths and heights of existence. It uses narrative accounts of educational journeys from ancient, medieval and early modern sources to develop an integral picture of the spectrum of education along with the techniques and fore-structures needed to guide a student through the various stages and encounters. Key metaphors, journeys and relationships - Diotirna's ladder of beauty, Plato's cave, Philo's Abraham and Sarah, Origen's bride and Bridegroom, Plotinus' journey of the alone to the Alone, Augustine's Confessions, the tragic love of Abelard and Heloise, Dante's encounters in the infernal, purgatorial and paradisical realms of human experience, Shakespeare's great playing within the same realm, and Descartes' doubting genius provide a rich ensemble, each resonating with the next, opening out intellectual, affective, volitional, and imaginative paths through the full terrain of human existence. This multidimensional approach points towards a flexible and insightful pedagogics that works with the enormous variety and capacity of human learning rather than heavy-handedly insisting on one path, or, even worse, not recognizing and dealing with specific areas of human living that occur in the upper and lower reaches of our educational endeavours. Phenomenological, Hermeneutic and Integral methods suggested by Heidegger and Wilber amongst others were used to inform the process of research. The results of this thesis are not contained in its reconunendations but in the effects of its reading. It is itself a tool that embodies and encourages the principles of an educational tradition that has existed within the history of western learning, not seeking a return to ancient or medieval ways but to provide a backlight that assists current initiatives working with the full range of human potential.
- Full Text:
- Date Issued: 2004
- Authors: Hugo, Wayne
- Date: 2004
- Subjects: Education -- Philosophy Education -- History Education, Ancient Education, Greek
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1884 , http://hdl.handle.net/10962/d1005917
- Description: This thesis aims to build up a picture of what it has meant for us within the western canon to educate a human being through the depths and heights of existence. It uses narrative accounts of educational journeys from ancient, medieval and early modern sources to develop an integral picture of the spectrum of education along with the techniques and fore-structures needed to guide a student through the various stages and encounters. Key metaphors, journeys and relationships - Diotirna's ladder of beauty, Plato's cave, Philo's Abraham and Sarah, Origen's bride and Bridegroom, Plotinus' journey of the alone to the Alone, Augustine's Confessions, the tragic love of Abelard and Heloise, Dante's encounters in the infernal, purgatorial and paradisical realms of human experience, Shakespeare's great playing within the same realm, and Descartes' doubting genius provide a rich ensemble, each resonating with the next, opening out intellectual, affective, volitional, and imaginative paths through the full terrain of human existence. This multidimensional approach points towards a flexible and insightful pedagogics that works with the enormous variety and capacity of human learning rather than heavy-handedly insisting on one path, or, even worse, not recognizing and dealing with specific areas of human living that occur in the upper and lower reaches of our educational endeavours. Phenomenological, Hermeneutic and Integral methods suggested by Heidegger and Wilber amongst others were used to inform the process of research. The results of this thesis are not contained in its reconunendations but in the effects of its reading. It is itself a tool that embodies and encourages the principles of an educational tradition that has existed within the history of western learning, not seeking a return to ancient or medieval ways but to provide a backlight that assists current initiatives working with the full range of human potential.
- Full Text:
- Date Issued: 2004
Justifiability as grounds for the review of labour arbitration proceedings
- Authors: Young, Kirsty Leigh
- Date: 2004
- Subjects: South Africa. Commission for Conciliation, Mediation and Arbitration Mediation and conciliation, Industrial -- South Africa Arbitration, Industrial -- South Africa Arbitration, Industrial -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3666 , http://hdl.handle.net/10962/d1003070
- Description: This thesis focuses on the review of labour arbitration awards given under the auspices of the following bodies: the Commission for Conciliation, Mediation and Arbitration ("CCMA"), bargaining councils, statutory councils, accredited private agencies and private arbitration tribunals. The general grounds of review applicable to the arbitration awards of each body are set out. Against this background, the case of Carephone (Pty) Ltd v Marcus NO & Others (1998) 19 ILJ 1425 (LAC) is analysed and the principles pertaining to the justifiability test are clarified. The judicial rationale for the application of the test to CCMA arbitration proceedings and criticisms of the test are then examined. Currently the justifiability test applies in the review of CCMA proceedings only, so the judicial reasoning for the rejection of justifiability as a ground for private arbitration review is examined. Three approaches are suggested for the application of the justifiability test in private arbitration review. First it is proposed that the Arbitration Act could be interpreted to include the justifiability test under the statutory review grounds. Failing the acceptance of this approach, the second submission is that arbitration agreements could be interpreted to include an implied term that the arbitrator is under a duty to give justifiable awards. A third suggestion is that the law should be developed by attaching an ex lege term to all arbitration agreements requiring arbitrators to give justifiable awards. In the final chapter, the requirement of justifiability in awards given under the auspices of collective bargaining agents and accredited private agencies highlights the incongruity in applying the justifiability test in CCMA arbitration review and in rejecting this test in private arbitration review.
- Full Text:
- Date Issued: 2004
- Authors: Young, Kirsty Leigh
- Date: 2004
- Subjects: South Africa. Commission for Conciliation, Mediation and Arbitration Mediation and conciliation, Industrial -- South Africa Arbitration, Industrial -- South Africa Arbitration, Industrial -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3666 , http://hdl.handle.net/10962/d1003070
- Description: This thesis focuses on the review of labour arbitration awards given under the auspices of the following bodies: the Commission for Conciliation, Mediation and Arbitration ("CCMA"), bargaining councils, statutory councils, accredited private agencies and private arbitration tribunals. The general grounds of review applicable to the arbitration awards of each body are set out. Against this background, the case of Carephone (Pty) Ltd v Marcus NO & Others (1998) 19 ILJ 1425 (LAC) is analysed and the principles pertaining to the justifiability test are clarified. The judicial rationale for the application of the test to CCMA arbitration proceedings and criticisms of the test are then examined. Currently the justifiability test applies in the review of CCMA proceedings only, so the judicial reasoning for the rejection of justifiability as a ground for private arbitration review is examined. Three approaches are suggested for the application of the justifiability test in private arbitration review. First it is proposed that the Arbitration Act could be interpreted to include the justifiability test under the statutory review grounds. Failing the acceptance of this approach, the second submission is that arbitration agreements could be interpreted to include an implied term that the arbitrator is under a duty to give justifiable awards. A third suggestion is that the law should be developed by attaching an ex lege term to all arbitration agreements requiring arbitrators to give justifiable awards. In the final chapter, the requirement of justifiability in awards given under the auspices of collective bargaining agents and accredited private agencies highlights the incongruity in applying the justifiability test in CCMA arbitration review and in rejecting this test in private arbitration review.
- Full Text:
- Date Issued: 2004
Knowing what we can't believe
- Authors: Viedge, Nikolai
- Date: 2004
- Subjects: Reason , Reasoning , Truth , Explanation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2724 , http://hdl.handle.net/10962/d1002854 , Reason , Reasoning , Truth , Explanation
- Description: The aim of this thesis is to examine what affect, if any, finding an argument both unanswerable yet unbelievable has on three purported first-person doxastic constraints. The three proposed constraints are the principle of truth, the principle of adequate reason and the principle of epistemic explanation. In Chapter 1, I lay out the claim of each of these constraints; differentiate them from one another, examine under what conditions they can be said to apply and provide what I take to be the strongest arguments for each of them. In Chapter 2, I explicate what I mean by finding an argument unanswerable yet unbelievable. In Chapters 3, 4 and 5, I detail how it is that finding an argument unanswerable yet unbelievable could constitute a threat to each of these constraints. I conclude that while the principle of adequate reason is undermined in the face of this threat, both the principle of truth and the principle of epistemic explanation fail to be undermined by this challenge.
- Full Text: false
- Date Issued: 2004
- Authors: Viedge, Nikolai
- Date: 2004
- Subjects: Reason , Reasoning , Truth , Explanation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2724 , http://hdl.handle.net/10962/d1002854 , Reason , Reasoning , Truth , Explanation
- Description: The aim of this thesis is to examine what affect, if any, finding an argument both unanswerable yet unbelievable has on three purported first-person doxastic constraints. The three proposed constraints are the principle of truth, the principle of adequate reason and the principle of epistemic explanation. In Chapter 1, I lay out the claim of each of these constraints; differentiate them from one another, examine under what conditions they can be said to apply and provide what I take to be the strongest arguments for each of them. In Chapter 2, I explicate what I mean by finding an argument unanswerable yet unbelievable. In Chapters 3, 4 and 5, I detail how it is that finding an argument unanswerable yet unbelievable could constitute a threat to each of these constraints. I conclude that while the principle of adequate reason is undermined in the face of this threat, both the principle of truth and the principle of epistemic explanation fail to be undermined by this challenge.
- Full Text: false
- Date Issued: 2004
Laboratory investigation of a simulated industrial task pre- and post-ergonomics intervention
- Authors: Renz, Miriam Christina
- Date: 2004
- Subjects: Human engineering , Musculoskeletal system -- Diseases , Occupational diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5162 , http://hdl.handle.net/10962/d1015806
- Description: The focus of the present study was on the investigation of the effects of an intervention strategy on an industrial task in situ and a simulation of the same task within a laboratory setting. The task of offloading crates from a truck at a local business was simulated in a laboratory setting for rigorous analysis. The effect of an ergonomically sound intervention on selected physical, physiological and perceptual variables was evaluated in a test - retest experimental set-up using 28 young, healthy male students. Each of the two experimental conditions lasted for 16 minutes. In the pre-intervention task subjects were required to transfer the crates from one point to another by sliding them along the floor. During the execution of the post-intervention task responses to reductions in the stacking height and modifications of the working method were evaluated. Results obtained for spinal kinematics during the simulated industrial task indicated a high biomechanical risk, due to large ranges of motion, high velocities and accelerations in the sagittal and transverse planes. The heavy workload of the task was also evident in elevated physiological responses (HR, RF, VT, VE, VO2, RQ, EE) and perceptual ratings (RPE, Body Discomfort). Assessment of the intervention strategy revealed that the high risk industrial task was reduced to moderate acceptable, with measurements of spinal kinematics, physiological and perceptual variables being significantly reduced. An in situ re-assessment of the workers responses to the intervention also elicited reductions in heart rates and perceptual ratings compared to the original task.
- Full Text:
- Date Issued: 2004
- Authors: Renz, Miriam Christina
- Date: 2004
- Subjects: Human engineering , Musculoskeletal system -- Diseases , Occupational diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5162 , http://hdl.handle.net/10962/d1015806
- Description: The focus of the present study was on the investigation of the effects of an intervention strategy on an industrial task in situ and a simulation of the same task within a laboratory setting. The task of offloading crates from a truck at a local business was simulated in a laboratory setting for rigorous analysis. The effect of an ergonomically sound intervention on selected physical, physiological and perceptual variables was evaluated in a test - retest experimental set-up using 28 young, healthy male students. Each of the two experimental conditions lasted for 16 minutes. In the pre-intervention task subjects were required to transfer the crates from one point to another by sliding them along the floor. During the execution of the post-intervention task responses to reductions in the stacking height and modifications of the working method were evaluated. Results obtained for spinal kinematics during the simulated industrial task indicated a high biomechanical risk, due to large ranges of motion, high velocities and accelerations in the sagittal and transverse planes. The heavy workload of the task was also evident in elevated physiological responses (HR, RF, VT, VE, VO2, RQ, EE) and perceptual ratings (RPE, Body Discomfort). Assessment of the intervention strategy revealed that the high risk industrial task was reduced to moderate acceptable, with measurements of spinal kinematics, physiological and perceptual variables being significantly reduced. An in situ re-assessment of the workers responses to the intervention also elicited reductions in heart rates and perceptual ratings compared to the original task.
- Full Text:
- Date Issued: 2004
Law and culture in the new constitutional dispensation with specific reference to the custom of circumcision as practiced in the Eastern Cape
- Authors: Momoti, Ndyebo Kingsworth
- Date: 2004
- Subjects: Xhosa (African people) -- Social life and customs Xhosa (African people) -- Rites and ceremonies Circumcision -- Law and legislation -- South Africa -- Eastern Cape Initiation rites -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3685 , http://hdl.handle.net/10962/d1003200
- Description: This study examines the custom of circumcision in the context of culture, law and the Constitution. In Chapter 1 the writer considers the pervasive role of culture in the context of the current debate in relation to equality versus culture. In Chapter 2 the writer considers the origin, development and the legal significance of the custom of circumcision in the Eastern Cape. In Chapter 3 the writer traces the circumstances leading to the enactment of the Provincial statute governing circumcision of children. In this chapter the writer also poses the question whether an aspect of morality can effectively be regulated by law. Chapter 4 looks at the question of cultural rights in terms of the Constitution and the possible effect of the promulgation of the Commission for the Promotion and Protection of the Rights of Cultural, Religious and Linguistic Communities Act 19 of 2000 on the approach of the courts in respect of constitutional challenges directed at some aspects of customary law. Chapter 5 looks at the custom of circumcision and the need for the protection of children. The writer raises the issue of the role of traditional leaders in the eradication of abuses associated with circumcision. The last Chapter comments on the reasons for the failure of the new Act governing circumcision in the Province.
- Full Text:
- Date Issued: 2004
- Authors: Momoti, Ndyebo Kingsworth
- Date: 2004
- Subjects: Xhosa (African people) -- Social life and customs Xhosa (African people) -- Rites and ceremonies Circumcision -- Law and legislation -- South Africa -- Eastern Cape Initiation rites -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3685 , http://hdl.handle.net/10962/d1003200
- Description: This study examines the custom of circumcision in the context of culture, law and the Constitution. In Chapter 1 the writer considers the pervasive role of culture in the context of the current debate in relation to equality versus culture. In Chapter 2 the writer considers the origin, development and the legal significance of the custom of circumcision in the Eastern Cape. In Chapter 3 the writer traces the circumstances leading to the enactment of the Provincial statute governing circumcision of children. In this chapter the writer also poses the question whether an aspect of morality can effectively be regulated by law. Chapter 4 looks at the question of cultural rights in terms of the Constitution and the possible effect of the promulgation of the Commission for the Promotion and Protection of the Rights of Cultural, Religious and Linguistic Communities Act 19 of 2000 on the approach of the courts in respect of constitutional challenges directed at some aspects of customary law. Chapter 5 looks at the custom of circumcision and the need for the protection of children. The writer raises the issue of the role of traditional leaders in the eradication of abuses associated with circumcision. The last Chapter comments on the reasons for the failure of the new Act governing circumcision in the Province.
- Full Text:
- Date Issued: 2004
Learners' perceptions of creating a collaborative hypermedia product: an exploratory case study at Mount Pleasant Primary School
- Authors: du Plessis, André
- Date: 2004
- Subjects: Computer-assisted instruction -- South Africa Computers -- Study and teaching -- South Africa Education, Elementary -- Activity programs Competency-based education -- South Africa Educational technology -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1663 , http://hdl.handle.net/10962/d1003546
- Description: The Ministry of Education (SICTE, 2002) states that the widespread introduction of computers in schools should support Curriculum 2005 and that computer technology is part and parcel of making schools the center of community life. The vision is to establish Smart Schools: schools that are reinvented in terms of teaching-learning practices to prepare learners for the information era (SICTE, 2002). Kafai (1996:71) has found that conventional school assignments rarely give learners the opportunity to spend a great deal of time on complex projects. As a result, many learners have little experience in design: planning, problem solving, researching, dealing with time constraints, modifying expectations and synthesizing everything in a project. Research by Carver, Lehrer, Connell and Erickson (1992); Lehrer, (1993); Lehrer, Erickson and Connell (1994); Kafai (1996); Liu and Hsiao (2002) and Liu (2002) indicates that the design of hypermedia artefacts can assist in providing experience in design. To date, no equivalent research has been conducted in South Africa to ascertain the perceptions of learners regarding the creation of a hypermedia artefact over an extended period of time and whether some of the critical outcomes specified in Curriculum 2005 can be addressed in such a learning-by-design hypermedia project. This study shows that design skills and aspects related to the critical outcomes of Curriculum 2005 can be achieved. Furthermore, it indicates that this kind of project encourages interest, motivation and collaboration. In addition, it suggests that learners experience the role of the teacher as different and prefer such a learning environment. In spite of the positive results, some aspects that need attention for future implementation are suggested.
- Full Text:
- Date Issued: 2004
- Authors: du Plessis, André
- Date: 2004
- Subjects: Computer-assisted instruction -- South Africa Computers -- Study and teaching -- South Africa Education, Elementary -- Activity programs Competency-based education -- South Africa Educational technology -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1663 , http://hdl.handle.net/10962/d1003546
- Description: The Ministry of Education (SICTE, 2002) states that the widespread introduction of computers in schools should support Curriculum 2005 and that computer technology is part and parcel of making schools the center of community life. The vision is to establish Smart Schools: schools that are reinvented in terms of teaching-learning practices to prepare learners for the information era (SICTE, 2002). Kafai (1996:71) has found that conventional school assignments rarely give learners the opportunity to spend a great deal of time on complex projects. As a result, many learners have little experience in design: planning, problem solving, researching, dealing with time constraints, modifying expectations and synthesizing everything in a project. Research by Carver, Lehrer, Connell and Erickson (1992); Lehrer, (1993); Lehrer, Erickson and Connell (1994); Kafai (1996); Liu and Hsiao (2002) and Liu (2002) indicates that the design of hypermedia artefacts can assist in providing experience in design. To date, no equivalent research has been conducted in South Africa to ascertain the perceptions of learners regarding the creation of a hypermedia artefact over an extended period of time and whether some of the critical outcomes specified in Curriculum 2005 can be addressed in such a learning-by-design hypermedia project. This study shows that design skills and aspects related to the critical outcomes of Curriculum 2005 can be achieved. Furthermore, it indicates that this kind of project encourages interest, motivation and collaboration. In addition, it suggests that learners experience the role of the teacher as different and prefer such a learning environment. In spite of the positive results, some aspects that need attention for future implementation are suggested.
- Full Text:
- Date Issued: 2004
Liberal aristocracy & the limits of democracy
- Authors: Wareham, Christopher
- Date: 2004
- Subjects: Plato , Aristocracy (Political science) , Liberalism , Democracy , Constitutional law , Civil rights -- Philosophy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2725 , http://hdl.handle.net/10962/d1002855 , Plato , Aristocracy (Political science) , Liberalism , Democracy , Constitutional law , Civil rights -- Philosophy
- Description: I define and defend a non-democratic authority with the power to annul the decisions of democratic branches of government when such decisions infringe upon citizens’ basic rights and liberties. I refer to this non-democratic authority as Liberal Aristocracy. The argument for Liberal Aristocracy has two parts: the first part demonstrates that Liberal Aristocracy will arrive at decisions that further the moral end of sustaining citizens’ rights; the second part holds that Liberal Aristocracy is a moral means to this end. First, I discuss two existing arguments for non-democratic authorities – Platonic Aristocracy and Constitutional Court Judges. I claim that Plato’s argument is unsuccessful because it relies on controversial metaethical premises that are unlikely to provide a basis for rights. Liberal justifications of the power of Constitutional Courts are argued to be incomplete because they do not designate an authority that is qualified to decide when citizens’ rights are infringed by democratic branches of government. Nor do they show that such an authority is in fact required if citizens’ rights are to be protected. In order to supplement the liberal argument for the power of Constitutional Courts I develop an account of Liberal Aristocracy, which rests on the idea that Constitutional Court Judges should possess moral expertise. I claim that (i) moral expertise qualifies Judges to decide when citizens’ rights are violated by democratic decisions. Furthermore, I argue that (ii) decisions taken democratically will sometimes encroach on citizens’ rights. Claims (i) and (ii) are shown to justify the non-democratic authority of Liberal Aristocracy. The second part of the argument for Liberal Aristocracy examines arguments to the effect that only democratic procedures can be morally legitimate, even if other decision procedures arrive at outcomes that provide greater support for citizens’ rights. Three claims are offered in support of this idea. First, democracy is claimed to be necessary to support deliberation. Second, democracy is seen as the only procedure that can uphold the value of autonomy by securing citizens’ consent. Third, it is argued that non-democratic procedures will not recognise the equal status of citizens. I hold that these three claims are false and that Liberal Aristocratic procedures can be morally legitimate.
- Full Text:
- Date Issued: 2004
- Authors: Wareham, Christopher
- Date: 2004
- Subjects: Plato , Aristocracy (Political science) , Liberalism , Democracy , Constitutional law , Civil rights -- Philosophy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2725 , http://hdl.handle.net/10962/d1002855 , Plato , Aristocracy (Political science) , Liberalism , Democracy , Constitutional law , Civil rights -- Philosophy
- Description: I define and defend a non-democratic authority with the power to annul the decisions of democratic branches of government when such decisions infringe upon citizens’ basic rights and liberties. I refer to this non-democratic authority as Liberal Aristocracy. The argument for Liberal Aristocracy has two parts: the first part demonstrates that Liberal Aristocracy will arrive at decisions that further the moral end of sustaining citizens’ rights; the second part holds that Liberal Aristocracy is a moral means to this end. First, I discuss two existing arguments for non-democratic authorities – Platonic Aristocracy and Constitutional Court Judges. I claim that Plato’s argument is unsuccessful because it relies on controversial metaethical premises that are unlikely to provide a basis for rights. Liberal justifications of the power of Constitutional Courts are argued to be incomplete because they do not designate an authority that is qualified to decide when citizens’ rights are infringed by democratic branches of government. Nor do they show that such an authority is in fact required if citizens’ rights are to be protected. In order to supplement the liberal argument for the power of Constitutional Courts I develop an account of Liberal Aristocracy, which rests on the idea that Constitutional Court Judges should possess moral expertise. I claim that (i) moral expertise qualifies Judges to decide when citizens’ rights are violated by democratic decisions. Furthermore, I argue that (ii) decisions taken democratically will sometimes encroach on citizens’ rights. Claims (i) and (ii) are shown to justify the non-democratic authority of Liberal Aristocracy. The second part of the argument for Liberal Aristocracy examines arguments to the effect that only democratic procedures can be morally legitimate, even if other decision procedures arrive at outcomes that provide greater support for citizens’ rights. Three claims are offered in support of this idea. First, democracy is claimed to be necessary to support deliberation. Second, democracy is seen as the only procedure that can uphold the value of autonomy by securing citizens’ consent. Third, it is argued that non-democratic procedures will not recognise the equal status of citizens. I hold that these three claims are false and that Liberal Aristocratic procedures can be morally legitimate.
- Full Text:
- Date Issued: 2004
Local development : a response to economic challenges in Noordhoek Valley, Cape Town
- Authors: Gibb, Matthew William
- Date: 2004
- Subjects: Deindustrialization -- South Africa -- Western Cape -- Economic aspects Community development -- South Africa -- Western Cape Community development, Urban -- South Africa -- Western Cape Economic development -- South Africa -- Western Cape Economic development projects -- South Africa -- Western Cape Labor supply -- South Africa -- Western Cape Local government -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:4869 , http://hdl.handle.net/10962/d1007848
- Description: De-industrialisation and rising unemployment amongst the world's developed countries' manual labourers as well as continued economic stagnation in developing countries has resulted in many localities experiencing mounting economic hardships and uncertain futures. As a direct result, the time has come that localities are being called upon to take charge of their own futures using local resources for local solutions. Local development has appeared in various guises in different countries. Many agents in the developed North favour pro-business interventions that emphasise enterprise development, responsible local government, and investment in skills training. Stakeholders in developing nations however tend to favour bottom-up approaches focusing on participation in self-reliant activities, providing basic needs, and facilitating micro-enterprises. In addition to the actual nature of applied interventions, qualities such as commitment, innovation, co-operation, social capital and entrepreneurship are equally essential for over-all success. South Africa has recently devolved more autonomy to its localities to enable them to conduct local development as a way of coping with local socio-economic difficulties and is applying both pro-growth and pro-poor approaches. The Noordhoek Valley in the City of Cape Town is a locality where a community driven project seeks to promote both economic growth and poverty alleviation. The establishment of a skills training institution has equipped local residents with the skills to find jobs and become entrepreneurs. To date, over 1000 residents have received training and have earned over R5 million for the community. Although locality-based development is relatively new in South Africa, the activities and results achieved in the Noordhoek Valley indicate that with the appropriate approach and mentality local development and skills development are indeed possible.
- Full Text:
- Date Issued: 2004
- Authors: Gibb, Matthew William
- Date: 2004
- Subjects: Deindustrialization -- South Africa -- Western Cape -- Economic aspects Community development -- South Africa -- Western Cape Community development, Urban -- South Africa -- Western Cape Economic development -- South Africa -- Western Cape Economic development projects -- South Africa -- Western Cape Labor supply -- South Africa -- Western Cape Local government -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:4869 , http://hdl.handle.net/10962/d1007848
- Description: De-industrialisation and rising unemployment amongst the world's developed countries' manual labourers as well as continued economic stagnation in developing countries has resulted in many localities experiencing mounting economic hardships and uncertain futures. As a direct result, the time has come that localities are being called upon to take charge of their own futures using local resources for local solutions. Local development has appeared in various guises in different countries. Many agents in the developed North favour pro-business interventions that emphasise enterprise development, responsible local government, and investment in skills training. Stakeholders in developing nations however tend to favour bottom-up approaches focusing on participation in self-reliant activities, providing basic needs, and facilitating micro-enterprises. In addition to the actual nature of applied interventions, qualities such as commitment, innovation, co-operation, social capital and entrepreneurship are equally essential for over-all success. South Africa has recently devolved more autonomy to its localities to enable them to conduct local development as a way of coping with local socio-economic difficulties and is applying both pro-growth and pro-poor approaches. The Noordhoek Valley in the City of Cape Town is a locality where a community driven project seeks to promote both economic growth and poverty alleviation. The establishment of a skills training institution has equipped local residents with the skills to find jobs and become entrepreneurs. To date, over 1000 residents have received training and have earned over R5 million for the community. Although locality-based development is relatively new in South Africa, the activities and results achieved in the Noordhoek Valley indicate that with the appropriate approach and mentality local development and skills development are indeed possible.
- Full Text:
- Date Issued: 2004
Mapping the Radio KC community : a case study assessing the impact of participatory research methods in assisting community radio producers to identify programming content
- Authors: Davidson, Brett Russell
- Date: 2004
- Subjects: Radio broadcasting -- South Africa -- Paarl , Radio stations -- South Africa -- Paarl , Radio journalism -- South Africa -- Paarl , Radio broadcasters -- Research -- South Africa -- Paarl , Mass media -- Political aspects -- South Africa , Mass media -- Social aspects -- South Africa , Radio in community development
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3497 , http://hdl.handle.net/10962/d1003716 , Radio broadcasting -- South Africa -- Paarl , Radio stations -- South Africa -- Paarl , Radio journalism -- South Africa -- Paarl , Radio broadcasters -- Research -- South Africa -- Paarl , Mass media -- Political aspects -- South Africa , Mass media -- Social aspects -- South Africa , Radio in community development
- Description: This thesis deals with the introduction of participatory research methods to programming staff working at Radio KC, a South African community radio station based in Paarl, in the Western Cape province. The focus is on a series of workshops conducted at the station, dealing with research tools developed to enable station workers to undertake research of their community. The aim was to determine, by means ofa case study, whether the introduction of participatory research methods could improve the ability of community broadcasters to facilitate democratic participation among the communities in which they operate. More particularly, the thesis assesses whether the application of such methods has improved the ability of the programming staff that were involved in this case study to identify a wider range of stories and voices within their target community, for inclusion in programming content. The participatory research techniques that are applied at the radio station are based on ideas in 'civic mapping' developed by Harwood and McCrehan (1996) under the auspices of The Pew Center for Civic Journalism, and supplemented by insights from Friedland (2001) and Downs and Stea (1977) about the cognitive, normative and imagined dimensions of community. All of the ideas and techniques were adapted for the South African situation. The findings of the research project illustrate that for community stations, the key concepts of 'community' and 'participation' are highly complex ones and that stations need assistance to apply these concepts in their everyday practice. The account of the intervention at Radio KC shows that the process did indeed assist the individual research participants to better deal with the application of these concepts. It did not, however, make much impact on the station as a whole. Reasons for this are believed to lie in the organisational dynamics of the station, and the fact that the model as applied in this case did not provide a means for tackling the agendas, investments and power relations that define the activities of individuals at a given community radio station - what Hochheimer (1993) talks about as the entrenchment of power and personalities. In order to address these shortcomings, an attempt is made to develop a model for future application, which places the mapping process within the context of a broader strategic planning process, focussed on a station's programming schedule.
- Full Text:
- Date Issued: 2004
- Authors: Davidson, Brett Russell
- Date: 2004
- Subjects: Radio broadcasting -- South Africa -- Paarl , Radio stations -- South Africa -- Paarl , Radio journalism -- South Africa -- Paarl , Radio broadcasters -- Research -- South Africa -- Paarl , Mass media -- Political aspects -- South Africa , Mass media -- Social aspects -- South Africa , Radio in community development
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3497 , http://hdl.handle.net/10962/d1003716 , Radio broadcasting -- South Africa -- Paarl , Radio stations -- South Africa -- Paarl , Radio journalism -- South Africa -- Paarl , Radio broadcasters -- Research -- South Africa -- Paarl , Mass media -- Political aspects -- South Africa , Mass media -- Social aspects -- South Africa , Radio in community development
- Description: This thesis deals with the introduction of participatory research methods to programming staff working at Radio KC, a South African community radio station based in Paarl, in the Western Cape province. The focus is on a series of workshops conducted at the station, dealing with research tools developed to enable station workers to undertake research of their community. The aim was to determine, by means ofa case study, whether the introduction of participatory research methods could improve the ability of community broadcasters to facilitate democratic participation among the communities in which they operate. More particularly, the thesis assesses whether the application of such methods has improved the ability of the programming staff that were involved in this case study to identify a wider range of stories and voices within their target community, for inclusion in programming content. The participatory research techniques that are applied at the radio station are based on ideas in 'civic mapping' developed by Harwood and McCrehan (1996) under the auspices of The Pew Center for Civic Journalism, and supplemented by insights from Friedland (2001) and Downs and Stea (1977) about the cognitive, normative and imagined dimensions of community. All of the ideas and techniques were adapted for the South African situation. The findings of the research project illustrate that for community stations, the key concepts of 'community' and 'participation' are highly complex ones and that stations need assistance to apply these concepts in their everyday practice. The account of the intervention at Radio KC shows that the process did indeed assist the individual research participants to better deal with the application of these concepts. It did not, however, make much impact on the station as a whole. Reasons for this are believed to lie in the organisational dynamics of the station, and the fact that the model as applied in this case did not provide a means for tackling the agendas, investments and power relations that define the activities of individuals at a given community radio station - what Hochheimer (1993) talks about as the entrenchment of power and personalities. In order to address these shortcomings, an attempt is made to develop a model for future application, which places the mapping process within the context of a broader strategic planning process, focussed on a station's programming schedule.
- Full Text:
- Date Issued: 2004
Miscarriage : an exploration of women's experience : a qualitative study
- Watson, Julia Margretha Garland
- Authors: Watson, Julia Margretha Garland
- Date: 2004
- Subjects: Miscarriage -- Psychological aspects , Loss (Psychology) , Bereavement -- Psychological aspects , Infants -- Death -- Psychological aspects , Fetal death -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:688 , http://hdl.handle.net/10962/d1003735 , Miscarriage -- Psychological aspects , Loss (Psychology) , Bereavement -- Psychological aspects , Infants -- Death -- Psychological aspects , Fetal death -- Psychological aspects
- Description: Miscarriage can result in significant psychological distress to women. However, many women experience a cultural norm which attributes minimal meaning to the loss. This is reflected in the lack of support experienced from interaction with both medical professionals and those within the individual's social context. This qualitative study reports on the unique experiences of six South African women; their experience of other's reactions to their miscarriage; and their recommendations for better coping with the experience. Data was gathered using one semi-structured interview. Data reduction and analysis followed using a four-stage model of thematic outlines, coding, and comparisons (Marshall and Rossman 1998:152; Marck and Field 1994:9). The objective of the analysis sought to compare the themes generated by the actual data collected with those described in other studies. In this way the findings of the study are generalisable to a larger population and allows for a greater sense of representivity (Silverman 1994:160). Comparisons were made between the women's experiences, as told by them, and Bowles' identification of the Four Domains of Miscarriage Distress Symptoms (2000). The women viewed psychological support as essential in the process of coping; and acknowledgement of their loss as being the loss of a child, as a strong determinant of coming to terms with the loss. A strong need to have support from other women who had shared the experience was voiced. Recommendations for improved intervention are made. In short the core recommendations are: the provision of patient follow-up; the provision of written material; and, specialist training for those working in the area of pregnancy loss.
- Full Text:
- Date Issued: 2004
- Authors: Watson, Julia Margretha Garland
- Date: 2004
- Subjects: Miscarriage -- Psychological aspects , Loss (Psychology) , Bereavement -- Psychological aspects , Infants -- Death -- Psychological aspects , Fetal death -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:688 , http://hdl.handle.net/10962/d1003735 , Miscarriage -- Psychological aspects , Loss (Psychology) , Bereavement -- Psychological aspects , Infants -- Death -- Psychological aspects , Fetal death -- Psychological aspects
- Description: Miscarriage can result in significant psychological distress to women. However, many women experience a cultural norm which attributes minimal meaning to the loss. This is reflected in the lack of support experienced from interaction with both medical professionals and those within the individual's social context. This qualitative study reports on the unique experiences of six South African women; their experience of other's reactions to their miscarriage; and their recommendations for better coping with the experience. Data was gathered using one semi-structured interview. Data reduction and analysis followed using a four-stage model of thematic outlines, coding, and comparisons (Marshall and Rossman 1998:152; Marck and Field 1994:9). The objective of the analysis sought to compare the themes generated by the actual data collected with those described in other studies. In this way the findings of the study are generalisable to a larger population and allows for a greater sense of representivity (Silverman 1994:160). Comparisons were made between the women's experiences, as told by them, and Bowles' identification of the Four Domains of Miscarriage Distress Symptoms (2000). The women viewed psychological support as essential in the process of coping; and acknowledgement of their loss as being the loss of a child, as a strong determinant of coming to terms with the loss. A strong need to have support from other women who had shared the experience was voiced. Recommendations for improved intervention are made. In short the core recommendations are: the provision of patient follow-up; the provision of written material; and, specialist training for those working in the area of pregnancy loss.
- Full Text:
- Date Issued: 2004
Moral reform and the desiderata of responses to wrongdoing: the production of a "morally autonomous person freely attached to the good"
- Authors: Waller, Heath Frederick
- Date: 2004 , 2013-06-14
- Subjects: Victims of crimes -- Attitudes , Criminals -- Rehabilitation , Punishment -- Psychological aspects , Social ethics , Punishment
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2730 , http://hdl.handle.net/10962/d1003805 , Victims of crimes -- Attitudes , Criminals -- Rehabilitation , Punishment -- Psychological aspects , Social ethics , Punishment
- Description: Moral reform is a neglected response to wrongdoing that has been incorrectly portrayed as a practice involving illegitimate treatment of wrongdoers and as totally unsatisfying to those theorists advocating backward-looking practices such as retributive punishment. A clear explanation of the ethical legitimacy and practical necessity of the reformative techniques moral reform involves has been missed, and this paper details the design of moral reform proper in order to fill this gap in punishment theory. The moral reform of an offender is identified as a desideratum of responses to wrongdoing and it is explained what moral reform ought to entail. The claim that moral reform qualifies as the overriding aim of responses to wrongdoing is argued for on the grounds that this practice is capable of achieving all the established ends of responses to wrongdoing. The legitimate desiderata of our practices are identified as those usually selected as the ends of punishment practices, and moral reform must accomplish these if it is to be accepted. Moral reform is shown to realise the goals of punishments as the fortunate effects of what is done to achieve an offender's moral improvement and of what reformees do in taking responsibility for their actions. The suffering involved in moral reform receives particular emphasis since the practice will never satisfy unless it accommodates the widely-held intuition that the offender must suffer sufficiently as a consequence of his wrongdoing. Moral reform is further portrayed as the most meaningful practice for its ability to satisfy the appropriate needs and desires victims have in response to their victimization. A central claim of the thesis is that moral reform best serves the victim, since it most effectively relieves the victim's emotional responses to wrongdoing and is as adept as punishment at the expression of these same emotions. Reformers advocate a constructive response to wrongdoing that benefits all affected parties. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2004
- Authors: Waller, Heath Frederick
- Date: 2004 , 2013-06-14
- Subjects: Victims of crimes -- Attitudes , Criminals -- Rehabilitation , Punishment -- Psychological aspects , Social ethics , Punishment
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2730 , http://hdl.handle.net/10962/d1003805 , Victims of crimes -- Attitudes , Criminals -- Rehabilitation , Punishment -- Psychological aspects , Social ethics , Punishment
- Description: Moral reform is a neglected response to wrongdoing that has been incorrectly portrayed as a practice involving illegitimate treatment of wrongdoers and as totally unsatisfying to those theorists advocating backward-looking practices such as retributive punishment. A clear explanation of the ethical legitimacy and practical necessity of the reformative techniques moral reform involves has been missed, and this paper details the design of moral reform proper in order to fill this gap in punishment theory. The moral reform of an offender is identified as a desideratum of responses to wrongdoing and it is explained what moral reform ought to entail. The claim that moral reform qualifies as the overriding aim of responses to wrongdoing is argued for on the grounds that this practice is capable of achieving all the established ends of responses to wrongdoing. The legitimate desiderata of our practices are identified as those usually selected as the ends of punishment practices, and moral reform must accomplish these if it is to be accepted. Moral reform is shown to realise the goals of punishments as the fortunate effects of what is done to achieve an offender's moral improvement and of what reformees do in taking responsibility for their actions. The suffering involved in moral reform receives particular emphasis since the practice will never satisfy unless it accommodates the widely-held intuition that the offender must suffer sufficiently as a consequence of his wrongdoing. Moral reform is further portrayed as the most meaningful practice for its ability to satisfy the appropriate needs and desires victims have in response to their victimization. A central claim of the thesis is that moral reform best serves the victim, since it most effectively relieves the victim's emotional responses to wrongdoing and is as adept as punishment at the expression of these same emotions. Reformers advocate a constructive response to wrongdoing that benefits all affected parties. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2004
Multiprotocol control of networked home entertainment devices
- Authors: Siebörger, David Robert
- Date: 2004
- Subjects: Home entertainment systems , Home video systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4642 , http://hdl.handle.net/10962/d1006585 , Home entertainment systems , Home video systems
- Description: Networks will soon connect a wide range of computing devices within the home. Amongst those devices will be home entertainment devices. Remote control over the network will be a key application for networked entertainment devices, and requires a protocol for communication understood by both controller and controlled device. Devices capable of communication using multiple control protocols will be compatible with a wider range of controllers than those which implement only one control protocol. This work examines home networks and a number of control protocols. The implementations of the UPnP and AV/C protocols for an AV receiver are described. The issues involved in the concurrent use of multiple control protocols to control a device are considered, possible methods of concurrent control discussed, and a solution which simulates virtual copies of the device is implemented and tested.
- Full Text:
- Date Issued: 2004
- Authors: Siebörger, David Robert
- Date: 2004
- Subjects: Home entertainment systems , Home video systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4642 , http://hdl.handle.net/10962/d1006585 , Home entertainment systems , Home video systems
- Description: Networks will soon connect a wide range of computing devices within the home. Amongst those devices will be home entertainment devices. Remote control over the network will be a key application for networked entertainment devices, and requires a protocol for communication understood by both controller and controlled device. Devices capable of communication using multiple control protocols will be compatible with a wider range of controllers than those which implement only one control protocol. This work examines home networks and a number of control protocols. The implementations of the UPnP and AV/C protocols for an AV receiver are described. The issues involved in the concurrent use of multiple control protocols to control a device are considered, possible methods of concurrent control discussed, and a solution which simulates virtual copies of the device is implemented and tested.
- Full Text:
- Date Issued: 2004
Music and (post)colonialism : the dialectics of choral culture on a South African frontier
- Authors: Olwage, Grant
- Date: 2004
- Subjects: Choral music -- South Africa -- History Black people -- South Africa -- Music -- History and criticism Bokwe, John Knox, 1855-1922
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2679 , http://hdl.handle.net/10962/d1007717
- Description: This thesis explores the genesis of black choralism in late-nineteenth-century colonial South Africa, attending specifically to its dialectic with metropolitan Victorian choralism. In two introductory historiographic chapters I outline the political-narrative strategies by which both Victorian and black South African choralism have been elided from music histories. Part 1 gives an account of the "structures" within and through which choralism functioned as a practice of colonisation, as "internal colonialism" in Britain and evangelical colonialism in the eastern Cape Colony. In chapter 1 I suggest that the religious contexts within which choralism operated, including the music theoretical construction of the tonic sol-fa notation and method as "natural", and the "scientific" musicalisation of race, constituted conditions for the foreign mission's embrace of choralism. The second chapter explores further such affinities, tracing sol-fa choralism's institutional affiliations with nineteenth-century "reform" movements, and suggesting that sol-fa's practices worked in fulfilment of core reformist concerns such as "industry" and literacy. Throughout, the thesis explores how the categories of class and race functioned interchangeably in the colonial imagination. Chapter 3 charts this relationship in the terrain of music education; notations, for instance, which were classed in Britain, became racialised in colonial South Africa. In particular I show that black music education operated within colonial racial discourses. Chapter 4 is a reading of Victorian choralism as a "discipline", interpreting choral performance practice and choral music itself as disciplinary acts which complemented the political contexts in which choralism operated. Part 1, in short, explores how popular choralism operated within and as dominant politicking. In part 2 I turn to the black reception of Victorian choralism in composition and performance. The fifth chapter examines the compositional discourse of early black choral music, focussing on the work of John Knox Bokwe (1855-1922). Through a detailed account of several of Bokwe's works and their metropolitan sources, particularly late-nineteenth century gospel hymnody, I show that Bokwe's compositional practice enacted a politics that became anticolonial, and that early black choral music became "black" in its reception. I conclude that ethno/musicological claims that early black choral music contains "African" musical content conflate "race" and culture under a double imperative: in the names of a decolonising politics and a postcolonial epistemology in which hybridity as resistance is racialised. The final chapter explores how "the voice" was crucial to identity politics in the Victorian world, an object that was classed and racialised. Proceeding from the black reception of choral voice training, I attempt to outline the beginnings of a social history of the black choral voice, as well as analyse the sonic content of that voice through an approach I call a "phonetics of timbre".
- Full Text:
- Date Issued: 2004
- Authors: Olwage, Grant
- Date: 2004
- Subjects: Choral music -- South Africa -- History Black people -- South Africa -- Music -- History and criticism Bokwe, John Knox, 1855-1922
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2679 , http://hdl.handle.net/10962/d1007717
- Description: This thesis explores the genesis of black choralism in late-nineteenth-century colonial South Africa, attending specifically to its dialectic with metropolitan Victorian choralism. In two introductory historiographic chapters I outline the political-narrative strategies by which both Victorian and black South African choralism have been elided from music histories. Part 1 gives an account of the "structures" within and through which choralism functioned as a practice of colonisation, as "internal colonialism" in Britain and evangelical colonialism in the eastern Cape Colony. In chapter 1 I suggest that the religious contexts within which choralism operated, including the music theoretical construction of the tonic sol-fa notation and method as "natural", and the "scientific" musicalisation of race, constituted conditions for the foreign mission's embrace of choralism. The second chapter explores further such affinities, tracing sol-fa choralism's institutional affiliations with nineteenth-century "reform" movements, and suggesting that sol-fa's practices worked in fulfilment of core reformist concerns such as "industry" and literacy. Throughout, the thesis explores how the categories of class and race functioned interchangeably in the colonial imagination. Chapter 3 charts this relationship in the terrain of music education; notations, for instance, which were classed in Britain, became racialised in colonial South Africa. In particular I show that black music education operated within colonial racial discourses. Chapter 4 is a reading of Victorian choralism as a "discipline", interpreting choral performance practice and choral music itself as disciplinary acts which complemented the political contexts in which choralism operated. Part 1, in short, explores how popular choralism operated within and as dominant politicking. In part 2 I turn to the black reception of Victorian choralism in composition and performance. The fifth chapter examines the compositional discourse of early black choral music, focussing on the work of John Knox Bokwe (1855-1922). Through a detailed account of several of Bokwe's works and their metropolitan sources, particularly late-nineteenth century gospel hymnody, I show that Bokwe's compositional practice enacted a politics that became anticolonial, and that early black choral music became "black" in its reception. I conclude that ethno/musicological claims that early black choral music contains "African" musical content conflate "race" and culture under a double imperative: in the names of a decolonising politics and a postcolonial epistemology in which hybridity as resistance is racialised. The final chapter explores how "the voice" was crucial to identity politics in the Victorian world, an object that was classed and racialised. Proceeding from the black reception of choral voice training, I attempt to outline the beginnings of a social history of the black choral voice, as well as analyse the sonic content of that voice through an approach I call a "phonetics of timbre".
- Full Text:
- Date Issued: 2004
Occupational aspirations and gender stereotyping of Xhosa-speaking senior primary learners
- Authors: Els, Catherine
- Date: 2004
- Subjects: Vocational interests -- South Africa -- Research , Gender identity , School children -- South Africa -- Attitudes , Xhosa (African people) -- Attitudes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11020 , http://hdl.handle.net/10948/325 , Vocational interests -- South Africa -- Research , Gender identity , School children -- South Africa -- Attitudes , Xhosa (African people) -- Attitudes
- Description: International research highlights conflicting results regarding factors that could play a role in the development of occupational aspirations and occupational gender stereotyping of primary school children. Some of the variables that have been identified are age, gender, ethnicity, socioeconomic status and societal influences. There has been some research emphasis on the career development of South Africans. However, studies that have been conducted have focused mainly on adolescents and adults. Furthermore, the majority of this research has focused on programme intervention and not on acquiring baseline information. There has been no research to date on the career development of South African Xhosa-speaking senior primary school children. The lack of career research on South African Xhosa-speaking children indicates the need for the present research. This study aims to describe and compare the occupational aspirations and occupational gender stereotyping (in terms of Holland’s occupational and status level typology) of male and female Xhosa-speaking senior primary school learners. The study also describes the possible gender stereotypical perceptions preadolescent children hold regarding certain occupations. A non-probability sample of 274 Xhosa-speaking children between the ages of 10 and 14 years was drawn from two primary schools in townships in the Nelson Mandela Metropole. An exploratory and descriptive research framework was utilised, with descriptive statistical procedures employed to summarise and report the data in a meaningful manner. The major findings of the present study indicate that Xhosa-speaking senior primary school children’s favourite occupational aspirations fit into Holland’s Investigative typology and high status level. Some gender differences were evident, with slightly more boys aspiring to Investigative occupations than girls. Both boys and girls demonstrated gender stereotypical perceptions regarding xiii which occupations were suitable for both genders, with boys more willing to accept girls into traditional male occupations than girls willing to accept boys into traditional female occupations. The results of the present study emphasise the need for further exploration of the occupational aspirations and occupational ge nder stereotyping of Xhosa-speaking senior primary school children. Future research needs to include other cultural and age groups in order to explore how personal and situational variables may differentially influence children’s occupational aspirations and occupational gender stereotyping.
- Full Text:
- Date Issued: 2004
- Authors: Els, Catherine
- Date: 2004
- Subjects: Vocational interests -- South Africa -- Research , Gender identity , School children -- South Africa -- Attitudes , Xhosa (African people) -- Attitudes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11020 , http://hdl.handle.net/10948/325 , Vocational interests -- South Africa -- Research , Gender identity , School children -- South Africa -- Attitudes , Xhosa (African people) -- Attitudes
- Description: International research highlights conflicting results regarding factors that could play a role in the development of occupational aspirations and occupational gender stereotyping of primary school children. Some of the variables that have been identified are age, gender, ethnicity, socioeconomic status and societal influences. There has been some research emphasis on the career development of South Africans. However, studies that have been conducted have focused mainly on adolescents and adults. Furthermore, the majority of this research has focused on programme intervention and not on acquiring baseline information. There has been no research to date on the career development of South African Xhosa-speaking senior primary school children. The lack of career research on South African Xhosa-speaking children indicates the need for the present research. This study aims to describe and compare the occupational aspirations and occupational gender stereotyping (in terms of Holland’s occupational and status level typology) of male and female Xhosa-speaking senior primary school learners. The study also describes the possible gender stereotypical perceptions preadolescent children hold regarding certain occupations. A non-probability sample of 274 Xhosa-speaking children between the ages of 10 and 14 years was drawn from two primary schools in townships in the Nelson Mandela Metropole. An exploratory and descriptive research framework was utilised, with descriptive statistical procedures employed to summarise and report the data in a meaningful manner. The major findings of the present study indicate that Xhosa-speaking senior primary school children’s favourite occupational aspirations fit into Holland’s Investigative typology and high status level. Some gender differences were evident, with slightly more boys aspiring to Investigative occupations than girls. Both boys and girls demonstrated gender stereotypical perceptions regarding xiii which occupations were suitable for both genders, with boys more willing to accept girls into traditional male occupations than girls willing to accept boys into traditional female occupations. The results of the present study emphasise the need for further exploration of the occupational aspirations and occupational ge nder stereotyping of Xhosa-speaking senior primary school children. Future research needs to include other cultural and age groups in order to explore how personal and situational variables may differentially influence children’s occupational aspirations and occupational gender stereotyping.
- Full Text:
- Date Issued: 2004
On the mocvd growth of ZnO
- Authors: Pagni, Olivier Demeno
- Date: 2004
- Subjects: Zinc oxide thin films , Metal organic chemical vapor deposition
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11075 , http://hdl.handle.net/10948/382 , Zinc oxide thin films , Metal organic chemical vapor deposition
- Description: Zinc oxide (ZnO) is a II-VI semiconductor material that offers tremendous potential as a light emitter in the blue-to-UV range. It has a wurtzite structure, and a direct band gap that can be tuned from 3.0 to 4.0 eV by alloying with Cd or Mg, respectively. In this work, ZnO thin films were grown by metalorganic chemical vapor deposition (MOCVD) on n-Si 2 ° off (100), amorphous glass, n-GaAs (100), and c-plane sapphire substrates. Diethyl zinc (DEZn) and tert-butanol (TBOH) were chosen as precursors. For the first time, Second Harmonic Generation Imaging was applied to the mapping of ZnO epilayers. The images obtained highlighted the polycrystalline character of the thin films, and provided insight as to the growth mode of ZnO on Si. The influence of substrate temperature on the structural properties of the epilayers was investigated by X-ray diffraction and optical microscopy. Grain sizes as high as 54 nm were measured. The optimum temperature range for this system proved to be 450 – 500 °C. The influence of the VI:II ratio during growth on the optical properties of the epilayers was studied by UV-vis-near IR spectroscopy. The lowest Urbach tail E0 parameter was measured for material grown at a VI:II ratio of 18:1. The films’ free electron concentration was shown to decrease by over two orders of magnitude, from 1019 to 1017 cm-3, as the VI:II ratio increased from 10 to 60:1. This decrease in carrier concentration with rising VI:II ratio was paralleled to the surge at 12 K of a photoluminescence (PL) emission band characteristic of p-type ZnO. The band gap energies extracted from room temperature transmission spectra ranged between 3.35 and 3.38 eV, in agreement with the value of 3.35 eV measured by room temperature PL. Moreover, variable temperature PL spectra were recorded between 12 and 298 K on ZnO grown on Si. The 12 K spectrum was dominated by a donor-bound exciton (D°X) at 3.36 eV, while the 298 K scan displayed strong free exciton emission (FX) at 3.29 eV. The width of the D°X band proved to be as narrow as 7 meV. The intensity ratio between the room temperature near-band edge emission and the defect-related green band was as high as 28:1, highlighting the optical quality of the layers deposited in this work. The electrical properties of the thin films were studied by Hall measurements (van der Pauw configuration), and a maximum room temperature mobility of 11 cm2/Vs was recorded. Furthermore, a palladium (Pd) Schottky barrier diode on ZnO was fabricated. The barrier height and ideality factor were calculated from current–voltage measurements to be 0.83 eV and 1.6, respectively. The capacitance–voltage curve of the diode yielded a carrier concentration in the depletion region of 8·1017 cm-3. This study has shown that the optical and electrical properties of ZnO depend strongly on the growth conditions employed. A suitable choice of growth parameters can yield high quality ZnO that may be used for various devices. Keywords: Hall, MOCVD, optical spectroscopy, photoluminescence, Schottky barrier diode, SH Imaging, X-ray diffraction, ZnO.
- Full Text:
- Date Issued: 2004
- Authors: Pagni, Olivier Demeno
- Date: 2004
- Subjects: Zinc oxide thin films , Metal organic chemical vapor deposition
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11075 , http://hdl.handle.net/10948/382 , Zinc oxide thin films , Metal organic chemical vapor deposition
- Description: Zinc oxide (ZnO) is a II-VI semiconductor material that offers tremendous potential as a light emitter in the blue-to-UV range. It has a wurtzite structure, and a direct band gap that can be tuned from 3.0 to 4.0 eV by alloying with Cd or Mg, respectively. In this work, ZnO thin films were grown by metalorganic chemical vapor deposition (MOCVD) on n-Si 2 ° off (100), amorphous glass, n-GaAs (100), and c-plane sapphire substrates. Diethyl zinc (DEZn) and tert-butanol (TBOH) were chosen as precursors. For the first time, Second Harmonic Generation Imaging was applied to the mapping of ZnO epilayers. The images obtained highlighted the polycrystalline character of the thin films, and provided insight as to the growth mode of ZnO on Si. The influence of substrate temperature on the structural properties of the epilayers was investigated by X-ray diffraction and optical microscopy. Grain sizes as high as 54 nm were measured. The optimum temperature range for this system proved to be 450 – 500 °C. The influence of the VI:II ratio during growth on the optical properties of the epilayers was studied by UV-vis-near IR spectroscopy. The lowest Urbach tail E0 parameter was measured for material grown at a VI:II ratio of 18:1. The films’ free electron concentration was shown to decrease by over two orders of magnitude, from 1019 to 1017 cm-3, as the VI:II ratio increased from 10 to 60:1. This decrease in carrier concentration with rising VI:II ratio was paralleled to the surge at 12 K of a photoluminescence (PL) emission band characteristic of p-type ZnO. The band gap energies extracted from room temperature transmission spectra ranged between 3.35 and 3.38 eV, in agreement with the value of 3.35 eV measured by room temperature PL. Moreover, variable temperature PL spectra were recorded between 12 and 298 K on ZnO grown on Si. The 12 K spectrum was dominated by a donor-bound exciton (D°X) at 3.36 eV, while the 298 K scan displayed strong free exciton emission (FX) at 3.29 eV. The width of the D°X band proved to be as narrow as 7 meV. The intensity ratio between the room temperature near-band edge emission and the defect-related green band was as high as 28:1, highlighting the optical quality of the layers deposited in this work. The electrical properties of the thin films were studied by Hall measurements (van der Pauw configuration), and a maximum room temperature mobility of 11 cm2/Vs was recorded. Furthermore, a palladium (Pd) Schottky barrier diode on ZnO was fabricated. The barrier height and ideality factor were calculated from current–voltage measurements to be 0.83 eV and 1.6, respectively. The capacitance–voltage curve of the diode yielded a carrier concentration in the depletion region of 8·1017 cm-3. This study has shown that the optical and electrical properties of ZnO depend strongly on the growth conditions employed. A suitable choice of growth parameters can yield high quality ZnO that may be used for various devices. Keywords: Hall, MOCVD, optical spectroscopy, photoluminescence, Schottky barrier diode, SH Imaging, X-ray diffraction, ZnO.
- Full Text:
- Date Issued: 2004
Optimization of a manufacturing process for atrazine with a focus on waste minimization
- Authors: Mtyopo, Mteteleli Bethwell
- Date: 2004
- Subjects: Waste minimization , Atrazine -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10976 , http://hdl.handle.net/10948/259 , Waste minimization , Atrazine -- Environmental aspects
- Description: Chemical synthesis is not complete without waste treatment. There is no chemical process that does not produce waste. The untreated effluent discharged by chemical industries poses a major environmental concern. This dissertation describes the results of an investigation carried out on the formation of by-products (impurities) during the synthesis of atrazine by neutralization of the reaction mixture during the actual synthesis procedure, and prior to disposal using carbon dioxide or hydrochloric acid. The main objectives for the said investigation were: {u100083} To optimise the reaction parameters to obtain a higher yield and purity of atrazine. {u100083} To evaluate the use of carbon dioxide and hydrochloric acid to neutralise the reaction mixture. {u100083} To study the solids present in the effluent. Synthetic reactions were carried out in the presence of an organic solvent, methyl isobutyl ketone (MIBK). The synthesis of atrazine was optimised in terms of addition sequence and rates of amine reagents and base (proton acceptor) additions by means of bench scale reactions. It was found that addition of a neutralising step (hydrochloric acid or carbon dioxide) to neutralise the basic reaction mixture prior to and after addition of the secondary amine and the base minimizes the formation of by-products. Of particular importance in ensuring high yields and selectivity to the atrazine product was temperature control, pH control, reagent ratios, addition rates and mixing. The latter was important in view of the rapid reaction of amine/NaOH with cyanuric chloride, as well as the possible reaction of mono-i, the reaction intermediate, with IPA in cases of excesses of reagent. Under optimum conditions, an atrazine composition of >97% was achieved where the resultant product was well within stipulated product specifications.
- Full Text:
- Date Issued: 2004
- Authors: Mtyopo, Mteteleli Bethwell
- Date: 2004
- Subjects: Waste minimization , Atrazine -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10976 , http://hdl.handle.net/10948/259 , Waste minimization , Atrazine -- Environmental aspects
- Description: Chemical synthesis is not complete without waste treatment. There is no chemical process that does not produce waste. The untreated effluent discharged by chemical industries poses a major environmental concern. This dissertation describes the results of an investigation carried out on the formation of by-products (impurities) during the synthesis of atrazine by neutralization of the reaction mixture during the actual synthesis procedure, and prior to disposal using carbon dioxide or hydrochloric acid. The main objectives for the said investigation were: {u100083} To optimise the reaction parameters to obtain a higher yield and purity of atrazine. {u100083} To evaluate the use of carbon dioxide and hydrochloric acid to neutralise the reaction mixture. {u100083} To study the solids present in the effluent. Synthetic reactions were carried out in the presence of an organic solvent, methyl isobutyl ketone (MIBK). The synthesis of atrazine was optimised in terms of addition sequence and rates of amine reagents and base (proton acceptor) additions by means of bench scale reactions. It was found that addition of a neutralising step (hydrochloric acid or carbon dioxide) to neutralise the basic reaction mixture prior to and after addition of the secondary amine and the base minimizes the formation of by-products. Of particular importance in ensuring high yields and selectivity to the atrazine product was temperature control, pH control, reagent ratios, addition rates and mixing. The latter was important in view of the rapid reaction of amine/NaOH with cyanuric chloride, as well as the possible reaction of mono-i, the reaction intermediate, with IPA in cases of excesses of reagent. Under optimum conditions, an atrazine composition of >97% was achieved where the resultant product was well within stipulated product specifications.
- Full Text:
- Date Issued: 2004