A case study of stakeholders' perceptions of the management implications of the discipline provisions of the 1996 Schools Act in a rural Eastern Cape high school
- Authors: Luggya, Daniel
- Date: 2005
- Subjects: High school students -- Discipline -- South Africa -- Eastern Cape Discipline of children -- South Africa -- Eastern Cape School discipline -- South Africa -- Eastern Cape Corporal punishment -- South Africa -- Eastern Cape School management and organization -- South Africa -- Eastern Cape School discipline -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1897 , http://hdl.handle.net/10962/d1006156
- Description: South Africa's education management system has undergone a long history of transformation from the promulgation of the Bantu Education Act of 1953 to the realisation of democracy, and in this context, the South Mrican Schools Act (SASA) of l996. Apartheid legislation and the new democratic legislation have had a profound impact on the education leadership and management of schools, in which authoritarian management practices have been replaced by democratic management practices. However, democratic management practices have not yet had a significant effect in the leadership and management of schools, especially in the schools of previously disadvantaged areas. This thesis seeks to examine perceptions held by education stakeholders in the light of the rights of students as stipulated in the discipline provisions of the Schools Act of 1996, in one of the rural high schools in the Northern Region of the Eastern Cape Province. One of the most important discipline provisions is the ban on corporal punishment in schools. My intention in carrying out this research was not to generalise my findings but to understand the experiences and perceptions of the stakeholders in this school regarding the discipline provisions of the SASA. The data suggest that authoritarian education practices, especially corporal punishment, are still a factor in the maintenance of student discipline in this rural school. Stakeholders still believe in the use of corporal punishment as the only way of maintaining discipline and an orderly environment for teaching and learning. Such beliefs, assumptions and values concerning the use of corporal punishment are held by the principal, teachers, students and parents and have not changed since 1996. Beliefs, assumptions and values on the exclusive use of power by the principal on issues of suspension and expulsion are still being held by the above stakeholders in the school. The vision of the SASA that schools become autonomous institutions with democratic leadership and management practices does not seem to be practical because of the centralisation of power in the hands of the Provincial Head of the Education Department. This centralisation of power denies the principal and other stakeholders of the school the power to decide on crucial matters like the expulsion of misbehaving students, because it is the provincial Head who decides on the seriousness of offences committed by misbehaving students and subsequent expulsions. Apart from the location of power in the Provincial Head of the Education Department, the stakeholders of this school are also powerless on expulsion of students, or any other form of punishment because of the implication of the "right" to education in the Bill of Rights in the Constitution of the Republic of South Africa. The education department has to devise programmes that change the beliefs and assumptions of stakeholders on corporal punishment and decision-making on expulsions and suspensions. Unfortunately corporal punishment persists because parents use it in the home and support its use in school. Programmes on alternatives to corporal punishment are required for the smooth implementation of the SASA.
- Full Text:
- Date Issued: 2005
- Authors: Luggya, Daniel
- Date: 2005
- Subjects: High school students -- Discipline -- South Africa -- Eastern Cape Discipline of children -- South Africa -- Eastern Cape School discipline -- South Africa -- Eastern Cape Corporal punishment -- South Africa -- Eastern Cape School management and organization -- South Africa -- Eastern Cape School discipline -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1897 , http://hdl.handle.net/10962/d1006156
- Description: South Africa's education management system has undergone a long history of transformation from the promulgation of the Bantu Education Act of 1953 to the realisation of democracy, and in this context, the South Mrican Schools Act (SASA) of l996. Apartheid legislation and the new democratic legislation have had a profound impact on the education leadership and management of schools, in which authoritarian management practices have been replaced by democratic management practices. However, democratic management practices have not yet had a significant effect in the leadership and management of schools, especially in the schools of previously disadvantaged areas. This thesis seeks to examine perceptions held by education stakeholders in the light of the rights of students as stipulated in the discipline provisions of the Schools Act of 1996, in one of the rural high schools in the Northern Region of the Eastern Cape Province. One of the most important discipline provisions is the ban on corporal punishment in schools. My intention in carrying out this research was not to generalise my findings but to understand the experiences and perceptions of the stakeholders in this school regarding the discipline provisions of the SASA. The data suggest that authoritarian education practices, especially corporal punishment, are still a factor in the maintenance of student discipline in this rural school. Stakeholders still believe in the use of corporal punishment as the only way of maintaining discipline and an orderly environment for teaching and learning. Such beliefs, assumptions and values concerning the use of corporal punishment are held by the principal, teachers, students and parents and have not changed since 1996. Beliefs, assumptions and values on the exclusive use of power by the principal on issues of suspension and expulsion are still being held by the above stakeholders in the school. The vision of the SASA that schools become autonomous institutions with democratic leadership and management practices does not seem to be practical because of the centralisation of power in the hands of the Provincial Head of the Education Department. This centralisation of power denies the principal and other stakeholders of the school the power to decide on crucial matters like the expulsion of misbehaving students, because it is the provincial Head who decides on the seriousness of offences committed by misbehaving students and subsequent expulsions. Apart from the location of power in the Provincial Head of the Education Department, the stakeholders of this school are also powerless on expulsion of students, or any other form of punishment because of the implication of the "right" to education in the Bill of Rights in the Constitution of the Republic of South Africa. The education department has to devise programmes that change the beliefs and assumptions of stakeholders on corporal punishment and decision-making on expulsions and suspensions. Unfortunately corporal punishment persists because parents use it in the home and support its use in school. Programmes on alternatives to corporal punishment are required for the smooth implementation of the SASA.
- Full Text:
- Date Issued: 2005
A case study of strategy implementation at a major Eastern Cape component supplier company in the automotive industry
- Authors: Koyana, Gwyneth Puseletso
- Date: 2009
- Subjects: Automobile industry and trade -- South Africa -- Eastern Cape Automobile industry workers -- South Africa -- Eastern Cape Industrial organization -- South Africa -- Eastern Cape -- Case studies Strategic planning -- South Africa -- Eastern Cape -- Case studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:735 , http://hdl.handle.net/10962/d1003855
- Description: A review of the literature on strategy implementation reveals that there is limited knowledge on how strategies should be implemented. This thesis focuses on a case study of strategy implementation at a major Eastern Cape component supplier company in the automotive industry, for purposes of establishing how the company implemented its strategies to become one of the best cost leaders in the manufacture of automotive pressed metal body components in South Africa. Data collated from the company is analysed and discussed with a resultant description of how the research participants understood the process of strategy implementation within the research company during the period January 2006 to December 2007. Interviews were undertaken within the levels of top management, middle management and the operational employees. Interpretations were made of the constructs made by the research participants in their understanding of how the research company implemented its strategy to become one of the best cost leaders in the manufacture of automotive pressed metal body components. It transpired from the findings of the research that the research company manufactured 70% of its products for one major client. During the manufacture of its products, the research company had to conform to the quality standards required by the main client. The main client was therefore offered the desired service at the best price. The strategy of the research company was to strive to be one of the best cost leaders in the manufacture of its products. It sought to do this by producing high quality products. Analysis is made of the strategic content, strategic context, operational processes and outcomes for the research company after the implementation of its strategy. It emerges in the case study that the strategy implementation factors cannot be considered separately in linear models but holistically, since one implementation factor may influence the others, resulting in a context and process based approach.
- Full Text:
- Date Issued: 2009
- Authors: Koyana, Gwyneth Puseletso
- Date: 2009
- Subjects: Automobile industry and trade -- South Africa -- Eastern Cape Automobile industry workers -- South Africa -- Eastern Cape Industrial organization -- South Africa -- Eastern Cape -- Case studies Strategic planning -- South Africa -- Eastern Cape -- Case studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:735 , http://hdl.handle.net/10962/d1003855
- Description: A review of the literature on strategy implementation reveals that there is limited knowledge on how strategies should be implemented. This thesis focuses on a case study of strategy implementation at a major Eastern Cape component supplier company in the automotive industry, for purposes of establishing how the company implemented its strategies to become one of the best cost leaders in the manufacture of automotive pressed metal body components in South Africa. Data collated from the company is analysed and discussed with a resultant description of how the research participants understood the process of strategy implementation within the research company during the period January 2006 to December 2007. Interviews were undertaken within the levels of top management, middle management and the operational employees. Interpretations were made of the constructs made by the research participants in their understanding of how the research company implemented its strategy to become one of the best cost leaders in the manufacture of automotive pressed metal body components. It transpired from the findings of the research that the research company manufactured 70% of its products for one major client. During the manufacture of its products, the research company had to conform to the quality standards required by the main client. The main client was therefore offered the desired service at the best price. The strategy of the research company was to strive to be one of the best cost leaders in the manufacture of its products. It sought to do this by producing high quality products. Analysis is made of the strategic content, strategic context, operational processes and outcomes for the research company after the implementation of its strategy. It emerges in the case study that the strategy implementation factors cannot be considered separately in linear models but holistically, since one implementation factor may influence the others, resulting in a context and process based approach.
- Full Text:
- Date Issued: 2009
A critical assessment of the Eastern Cape Provincial Government intervention in dysfunctional municipalities : a case study of Sundays River Valley Local Municipality
- Authors: Njikelana, Vuyo Mxolisi
- Date: 2016
- Subjects: Intergovernmental cooperation -- South Africa -- Eastern Cape Local government -- South Africa -- Eastern Cape Municipal services -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10353/2403 , vital:27808
- Description: The research seeks to assess the effectiveness of the provincial intervention in accordance with section 139 of the Constitution, 1996 in dysfunctional municipalities in the Eastern Cape as a viable instrument vis-à-vis the implementation of the continuous support in terms of section 154 of the same Constitution. Both sections are legislative obligations on the part of the national and provincial spheres of government. The two sections are legal instruments of monitoring and support and their implementation in municipalities by the then Department of Local Government and Traditional Affairs (now known as Department of Cooperative Governance and Traditional Affairs) in the Eastern Cape is the focus of the study. However, the two instruments are not achieving their objectives as more municipalities continue remaining dysfunctional despite provincial interventions. The government set out a broad vision of developmental local government. This is essentially a vision that calls on municipalities to find means of confronting the legacy of underdevelopment and poverty in their local areas. Whereas section 154 seeks to ensure support and strengthen capacity of municipalities, section 139 presupposes intervention in areas where a municipality has failed to perform. The latter section is usually invoked when everything else has failed by way of the continuous support provided by section 154. The study examined critical aspects on the implementation of the two instruments by DLGTA, particularly at Sundays River Valley Local Municipality. It looked at the challenges that necessitate the provincial government to intervene in dysfunctional municipalities as well as at implementation challenges. It also looked at the impact of the provincial intervention and checked on the section that is likely to make an impact between the two. In so doing, the municipal functionaries; Mayor/Speaker, Section 56 Managers, departmental officials of DLGTA and stakeholders representing citizens of Sundays River Valley were interviewed. The results of the study reflect challenges in the implementation of the two instruments by the DLGTA and it would be advisable for the DLGTA to consider the findings and recommendations in an attempt to contribute in overcoming the section 139 challenges.
- Full Text:
- Date Issued: 2016
- Authors: Njikelana, Vuyo Mxolisi
- Date: 2016
- Subjects: Intergovernmental cooperation -- South Africa -- Eastern Cape Local government -- South Africa -- Eastern Cape Municipal services -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10353/2403 , vital:27808
- Description: The research seeks to assess the effectiveness of the provincial intervention in accordance with section 139 of the Constitution, 1996 in dysfunctional municipalities in the Eastern Cape as a viable instrument vis-à-vis the implementation of the continuous support in terms of section 154 of the same Constitution. Both sections are legislative obligations on the part of the national and provincial spheres of government. The two sections are legal instruments of monitoring and support and their implementation in municipalities by the then Department of Local Government and Traditional Affairs (now known as Department of Cooperative Governance and Traditional Affairs) in the Eastern Cape is the focus of the study. However, the two instruments are not achieving their objectives as more municipalities continue remaining dysfunctional despite provincial interventions. The government set out a broad vision of developmental local government. This is essentially a vision that calls on municipalities to find means of confronting the legacy of underdevelopment and poverty in their local areas. Whereas section 154 seeks to ensure support and strengthen capacity of municipalities, section 139 presupposes intervention in areas where a municipality has failed to perform. The latter section is usually invoked when everything else has failed by way of the continuous support provided by section 154. The study examined critical aspects on the implementation of the two instruments by DLGTA, particularly at Sundays River Valley Local Municipality. It looked at the challenges that necessitate the provincial government to intervene in dysfunctional municipalities as well as at implementation challenges. It also looked at the impact of the provincial intervention and checked on the section that is likely to make an impact between the two. In so doing, the municipal functionaries; Mayor/Speaker, Section 56 Managers, departmental officials of DLGTA and stakeholders representing citizens of Sundays River Valley were interviewed. The results of the study reflect challenges in the implementation of the two instruments by the DLGTA and it would be advisable for the DLGTA to consider the findings and recommendations in an attempt to contribute in overcoming the section 139 challenges.
- Full Text:
- Date Issued: 2016
A critical discourse analysis of the coverage of operation "Restore Order" (Operation Murambatsvina) by Zimbabwe's weekly newspapers, the state-owned The Sunday Mail and the privately owned The Standard, in the period 18 May to 30 June 2005
- Authors: Mukundu, Rashweat
- Date: 2010
- Subjects: Operation Murambatsvina, Zimbabwe, 2005- Political persecution -- Zimbabwe Mass media -- Political aspects -- Zimbabwe Press and politics -- Zimbabwe Freedom of the press -- Zimbabwe Newspapers -- Objectivity -- Zimbabwe Journalistic ethics -- Zimbabwe Critical discourse analysis Sunday Mail (Zimbabwe) The Standard (Zimbabwe)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3470 , http://hdl.handle.net/10962/d1002925
- Description: On May 16 2006 the government of Zimbabwe embarked on a clean-up programme of urban centres, destroying informal human settlements and informal businesses. This operation, which the government called operation "Restore Order", resulted in the displacement of nearly one million people and left thousands of families homeless. This study is a discussion and an analysis of the coverage of the clean-up operation by two of Zimbabwe's leading Sunday newspapers, The Sunday Mail and The Standard. The Sunday Mail is owned by the Zimbabwe government and The Standard is privately owned and perceived to be oppositional to the current Zimbabwe government. The two newspapers, therefore, covered the clean-up operation from different perspectives and often presented conflicting reports explaining why the clean-up operation was carried out and the extent of its impact on the lives of millions of Zimbabweans. The chosen research approach is the Critical Discourse Analysis (CDA) framework as developed by Fairclough (1995). Using CDA, this study seeks to find out and expose the underlying ideological struggles for hegemony between different social and political groups in Zimbabwe and how the newspapers became actors in this process. This process is made possible by looking at how news reporting is organised in the two newspapers, issues of language use, sourcing and external factors that influenced the coverage of the operation.
- Full Text:
- Date Issued: 2010
- Authors: Mukundu, Rashweat
- Date: 2010
- Subjects: Operation Murambatsvina, Zimbabwe, 2005- Political persecution -- Zimbabwe Mass media -- Political aspects -- Zimbabwe Press and politics -- Zimbabwe Freedom of the press -- Zimbabwe Newspapers -- Objectivity -- Zimbabwe Journalistic ethics -- Zimbabwe Critical discourse analysis Sunday Mail (Zimbabwe) The Standard (Zimbabwe)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3470 , http://hdl.handle.net/10962/d1002925
- Description: On May 16 2006 the government of Zimbabwe embarked on a clean-up programme of urban centres, destroying informal human settlements and informal businesses. This operation, which the government called operation "Restore Order", resulted in the displacement of nearly one million people and left thousands of families homeless. This study is a discussion and an analysis of the coverage of the clean-up operation by two of Zimbabwe's leading Sunday newspapers, The Sunday Mail and The Standard. The Sunday Mail is owned by the Zimbabwe government and The Standard is privately owned and perceived to be oppositional to the current Zimbabwe government. The two newspapers, therefore, covered the clean-up operation from different perspectives and often presented conflicting reports explaining why the clean-up operation was carried out and the extent of its impact on the lives of millions of Zimbabweans. The chosen research approach is the Critical Discourse Analysis (CDA) framework as developed by Fairclough (1995). Using CDA, this study seeks to find out and expose the underlying ideological struggles for hegemony between different social and political groups in Zimbabwe and how the newspapers became actors in this process. This process is made possible by looking at how news reporting is organised in the two newspapers, issues of language use, sourcing and external factors that influenced the coverage of the operation.
- Full Text:
- Date Issued: 2010
An investigation of students' role within the governing structures of educational institutions
- Authors: Ngaso, Khayalethu Edward
- Date: 1999
- Subjects: Student participation in administration -- South Africa School management and organization -- South Africa Student government -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1644 , http://hdl.handle.net/10962/d1003526
- Description: The question of the role of students in the governance of educational institutions has been an issue for decades in South Africa. It arose out of the desire and struggle by black students for a better sociopolitical environment in general and in education in particular. This demand gained momentum in the years 1976,1980 and 1985. The result was the establishment of Student Representative Councils, Parent-teacher-Student's Associations at schools, Broad Transformation Forums and Governing Councils at tertiary institutions. After 1994 the government of South Africa started the major task of reconstructing the country particularly education and its governance. Democratic governance was accepted as one of the fundamentals of education by the new department of education. The Schools' Act and the Higher Education Act were passed to give effect to this new spirit in 1996 and 1997 respectively. Students had a statutory right to be involved in all matters of governance in educational institutions. However, in the past two years i.e. 1997 and 1998 the issue of student participation has become controversial with tensions erupting amongst stakeholders particularly management and students. The bone of contention this time has not been whether students have to participate or not but how far should they be involved. The National Education Policy Investigation task team had recommended as early as 1992 for the systematic analysis of the roles of the various stakeholders within the governing structures to avoid the present situation to no avail. The aim of this study therefore was to investigate students' perceptions of their role within the governing structures and to assess the implications of such a role for the management of educational institutions. Central to this largely fact finding mission was an attempt to make a contribution engaging students in this debate and get to know them afresh, thereby understand their position, what their perception is about their role in the governance of their institutions. For this purpose the study used phenomenology as the method of research. The reason for that I wanted a methodology which will enable me to produce a report which would not be contaminated with my preconceived ideas about the phenomenon. The tool used for data-gathering was the interview. In-depth interviews were conducted with four student leaders. They were selected purposely due to the fact that they were involved in the governance of their various institutions. The study revealed the complexity of this phenomenon. It indicates that student involvement is crucial for harmonious relations to prevail and the creation of a climate of learning and teaching at educational institutions. Students saw their role as that of legitimising the process of decision-making. This is coupled with enforcing the management to be transparent, bringing back the rule of law, making sure that educational institutions are transformed, that students are empowered and capacitated and looking at the welfare of students. A recommendation that emerge from the study is that much investigation is needed on student participation. Areas which needed much attention are specified in the study.
- Full Text:
- Date Issued: 1999
- Authors: Ngaso, Khayalethu Edward
- Date: 1999
- Subjects: Student participation in administration -- South Africa School management and organization -- South Africa Student government -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1644 , http://hdl.handle.net/10962/d1003526
- Description: The question of the role of students in the governance of educational institutions has been an issue for decades in South Africa. It arose out of the desire and struggle by black students for a better sociopolitical environment in general and in education in particular. This demand gained momentum in the years 1976,1980 and 1985. The result was the establishment of Student Representative Councils, Parent-teacher-Student's Associations at schools, Broad Transformation Forums and Governing Councils at tertiary institutions. After 1994 the government of South Africa started the major task of reconstructing the country particularly education and its governance. Democratic governance was accepted as one of the fundamentals of education by the new department of education. The Schools' Act and the Higher Education Act were passed to give effect to this new spirit in 1996 and 1997 respectively. Students had a statutory right to be involved in all matters of governance in educational institutions. However, in the past two years i.e. 1997 and 1998 the issue of student participation has become controversial with tensions erupting amongst stakeholders particularly management and students. The bone of contention this time has not been whether students have to participate or not but how far should they be involved. The National Education Policy Investigation task team had recommended as early as 1992 for the systematic analysis of the roles of the various stakeholders within the governing structures to avoid the present situation to no avail. The aim of this study therefore was to investigate students' perceptions of their role within the governing structures and to assess the implications of such a role for the management of educational institutions. Central to this largely fact finding mission was an attempt to make a contribution engaging students in this debate and get to know them afresh, thereby understand their position, what their perception is about their role in the governance of their institutions. For this purpose the study used phenomenology as the method of research. The reason for that I wanted a methodology which will enable me to produce a report which would not be contaminated with my preconceived ideas about the phenomenon. The tool used for data-gathering was the interview. In-depth interviews were conducted with four student leaders. They were selected purposely due to the fact that they were involved in the governance of their various institutions. The study revealed the complexity of this phenomenon. It indicates that student involvement is crucial for harmonious relations to prevail and the creation of a climate of learning and teaching at educational institutions. Students saw their role as that of legitimising the process of decision-making. This is coupled with enforcing the management to be transparent, bringing back the rule of law, making sure that educational institutions are transformed, that students are empowered and capacitated and looking at the welfare of students. A recommendation that emerge from the study is that much investigation is needed on student participation. Areas which needed much attention are specified in the study.
- Full Text:
- Date Issued: 1999
Characterization of the distribution of platinum group elements in sulphide ores within the Merensky Reef at Modikwa and Two Rivers Platinum Mines, Eastern Bushveld Complex, South Africa
- Authors: Zilibokwe, Nosibulelo Julie
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7938 , vital:21326
- Description: The distribution of the platinum group element (PGE), in the Merensky Reef was characterized by, first determining the occurrence of the platinum group minerals (PGM), then by establishing the PGE concentration in the base metal sulphides (BMS) associated with the PGE mineralization in the Merensky Reef from selected borehole intersections, at the Two Rivers (TRP) and Modikwa Platinum Mines in the Eastern Bushveld Complex. A mineral liberation analyser (MLA) was then used to identify the PGM phases; their silicate and base metal associations; and their grain size distribution. Electron microprobe quantitative analysis and mapping were then used to determine the compositional variation of the PGM and the PGE elemental distribution in the BMS, respectively. The study showed that the BMS including pyrrhotite, pentlandite, and chalcopyrite were the principal sulphides, where pyrrhotite was most prominent with minor quantities of pyrite. Orthopyroxene, clinopyroxene and plagioclase were the most abundant primary silicate minerals identified, while secondary silicates identified included talc, serpentine and amphibole. Platinum group minerals showed three distinct groups with respect to the mineralogical association with the PGE; (i) BMS association; (ii) chromite association; and (iii) silicate association. Of the BMS, chalcopyrite showed the most dominant association with the PGMs. All samples from both mines exhibited a wide range of PGMs, including maslovite, braggite, cooperate, laurite and PGE alloys such as ferroplatinum as well as other unidentified platinum and palladium sulphides, arsenides and bismuthides, while gold was present as electrum. The PGMs ranged in size from less than a micron to about 125 microns with an average of 20 microns. The close association of PGM with BMS along the margins of sulphides indicates that the PGMs were derived from the sulphide melt. PGE distribution in the sulphides at Modikwa showed pentlandite contained the highest concentrations of palladium (up to 379 ppm) and chalcopyrite hosting the highest rhodium concentrations (up to 793 ppm). Samples from Two Rivers revealed pentlandite as the principal host to both palladium and rhodium, with concentrations reaching up to 695 and 930 ppm, respectively. Magnetite at both Modikwa and Two Rivers showed significant rhodium content, reaching up to 982 and 930 ppm, respectively. The pyrrhotite compared to other sulphides contained all the elements found in the platinum group (PPGE), namely, platinum, palladium and rhodium, with all the platinum identified found in the pyrrhotite. The concentrations for the iridium group (IPGE) namely, iridium, osmium, and ruthenium were below the detection limit. The PGE mineralization in the stratigraphy varied within each mine. The mineralization revealed top loading in the central sector (Modikwa) and bottom loading in the southern sector (Two Rivers). The sequence of the Merensky Reef at the two sectors of the Eastern Bushveld Complex showed a remarkable similarity in their mineralogy suggesting that these two sectors were formed from the same liquid or formed simultaneously within a single magma chamber; however the PGE distribution within the stratigraphy may have been controlled by the presence of cumulate sulphides.
- Full Text:
- Date Issued: 2017
- Authors: Zilibokwe, Nosibulelo Julie
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7938 , vital:21326
- Description: The distribution of the platinum group element (PGE), in the Merensky Reef was characterized by, first determining the occurrence of the platinum group minerals (PGM), then by establishing the PGE concentration in the base metal sulphides (BMS) associated with the PGE mineralization in the Merensky Reef from selected borehole intersections, at the Two Rivers (TRP) and Modikwa Platinum Mines in the Eastern Bushveld Complex. A mineral liberation analyser (MLA) was then used to identify the PGM phases; their silicate and base metal associations; and their grain size distribution. Electron microprobe quantitative analysis and mapping were then used to determine the compositional variation of the PGM and the PGE elemental distribution in the BMS, respectively. The study showed that the BMS including pyrrhotite, pentlandite, and chalcopyrite were the principal sulphides, where pyrrhotite was most prominent with minor quantities of pyrite. Orthopyroxene, clinopyroxene and plagioclase were the most abundant primary silicate minerals identified, while secondary silicates identified included talc, serpentine and amphibole. Platinum group minerals showed three distinct groups with respect to the mineralogical association with the PGE; (i) BMS association; (ii) chromite association; and (iii) silicate association. Of the BMS, chalcopyrite showed the most dominant association with the PGMs. All samples from both mines exhibited a wide range of PGMs, including maslovite, braggite, cooperate, laurite and PGE alloys such as ferroplatinum as well as other unidentified platinum and palladium sulphides, arsenides and bismuthides, while gold was present as electrum. The PGMs ranged in size from less than a micron to about 125 microns with an average of 20 microns. The close association of PGM with BMS along the margins of sulphides indicates that the PGMs were derived from the sulphide melt. PGE distribution in the sulphides at Modikwa showed pentlandite contained the highest concentrations of palladium (up to 379 ppm) and chalcopyrite hosting the highest rhodium concentrations (up to 793 ppm). Samples from Two Rivers revealed pentlandite as the principal host to both palladium and rhodium, with concentrations reaching up to 695 and 930 ppm, respectively. Magnetite at both Modikwa and Two Rivers showed significant rhodium content, reaching up to 982 and 930 ppm, respectively. The pyrrhotite compared to other sulphides contained all the elements found in the platinum group (PPGE), namely, platinum, palladium and rhodium, with all the platinum identified found in the pyrrhotite. The concentrations for the iridium group (IPGE) namely, iridium, osmium, and ruthenium were below the detection limit. The PGE mineralization in the stratigraphy varied within each mine. The mineralization revealed top loading in the central sector (Modikwa) and bottom loading in the southern sector (Two Rivers). The sequence of the Merensky Reef at the two sectors of the Eastern Bushveld Complex showed a remarkable similarity in their mineralogy suggesting that these two sectors were formed from the same liquid or formed simultaneously within a single magma chamber; however the PGE distribution within the stratigraphy may have been controlled by the presence of cumulate sulphides.
- Full Text:
- Date Issued: 2017
Computer-based remediation in Cape Senior Certificate standard grade mathematics
- Authors: Elgie, Brian James
- Date: 1991
- Subjects: Mathematics -- Computer-assisted instruction Mathematics -- Study and teaching -- Audio-visual aids Mathematics -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1458 , http://hdl.handle.net/10962/d1003339
- Description: This dissertation begins by reviewing the difficulties experienced in teaching mathematics to pupiis, weak in mathematics, in the Senior Secondary phase of Cape Education Department schools. The possible use of computer-aided instruction (CAl) in improving the examination performance of such pupils is considered. A suitable CAl software program, viz. the SERGO system, is identified and its operation is described in detail. The researcher investigates, both from a quantitative and a qualitative aspect, the change in mathematics examination performance of a number of weak in mathematics pupils, as a result of receiving an extended period of extra tuition on the SERGO system. It needs to be noted that these pupils are passing candidates in other subjects, and have above average intelligence. They are not slow learners. The researcher identifies three categories of pupils who are weak in mathematics. Different programmes of remediation are recommended for each category. The possible use of the SERGO system as a stand-alone instrument of remediation , for pupils working in pairs, and the possible use by H.G. pupils in combined H.G./S.G. classes are also investigated.
- Full Text:
- Date Issued: 1991
- Authors: Elgie, Brian James
- Date: 1991
- Subjects: Mathematics -- Computer-assisted instruction Mathematics -- Study and teaching -- Audio-visual aids Mathematics -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1458 , http://hdl.handle.net/10962/d1003339
- Description: This dissertation begins by reviewing the difficulties experienced in teaching mathematics to pupiis, weak in mathematics, in the Senior Secondary phase of Cape Education Department schools. The possible use of computer-aided instruction (CAl) in improving the examination performance of such pupils is considered. A suitable CAl software program, viz. the SERGO system, is identified and its operation is described in detail. The researcher investigates, both from a quantitative and a qualitative aspect, the change in mathematics examination performance of a number of weak in mathematics pupils, as a result of receiving an extended period of extra tuition on the SERGO system. It needs to be noted that these pupils are passing candidates in other subjects, and have above average intelligence. They are not slow learners. The researcher identifies three categories of pupils who are weak in mathematics. Different programmes of remediation are recommended for each category. The possible use of the SERGO system as a stand-alone instrument of remediation , for pupils working in pairs, and the possible use by H.G. pupils in combined H.G./S.G. classes are also investigated.
- Full Text:
- Date Issued: 1991
Engaging sense of place in an environment of change: youth, identity and place-based learning activities in environmental education
- Authors: Farrington, Katie
- Date: 2006
- Subjects: Environmental education -- South Africa -- Grahamstown Place-based education -- South Africa -- Grahamstown Educational change -- South Africa Youth -- South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1942 , http://hdl.handle.net/10962/d1007931
- Description: This case study investigates sense of place of youth amidst a background of change in postapartheid South Africa. As used in this study, sense of place refers to the attachments made to both physical and social places, and the social and cultural interactions and meanings associated with such places. The research was conducted with a group of 13 young adults at Mary Waters Senior Secondary School in Grahamstown. The literature suggests that the changes that occur in the lives of the participants at school-leaving age such as new opportunities to identify with global aspirations, tend to influence their sense of place in local contexts. Social change that occurs due to globalising forces such as access to new technologies and improved personal mobility, also influences sense of place in this context. Another integral factor is the structural influence of changing cultural and educational norms. These notions form part of the backdrop of this study. The research project was developed in response to calls for learning approaches that are situated more in local contexts and which include the youth as intrinsic participants informing environmental education approaches. This research draws attention to the significance of finding sustainable ways that enhance opportunities for agency on the part of the youth in future local and global environmental care-taking. The study took place over a period of 15 months in which time the participants undertook place-based activities in their communities around self-identified environmental concerns. The study was intentionally generative in approach as this allowed the voices of the participants and their environmental perspectives to be considered in developing methods and activities that were suitable to their particular contexts and interests. The study highlights the relevance of particular social contexts, through the perspectives of people and in this case learners, as key to environmental education enquiries. The combination of approaches that consider: a) knowledge about social context, b) the educational intervention (place-based activities) and, c) the situated social capital of the participants, all form the basis of meaningful pedagogical engagements and serve to address my research question: How is learners' sense of place developed and articulated through place-based activities, and what are the implications for environmental education amidst a contemporary landscape of change in South Africa?
- Full Text:
- Date Issued: 2006
- Authors: Farrington, Katie
- Date: 2006
- Subjects: Environmental education -- South Africa -- Grahamstown Place-based education -- South Africa -- Grahamstown Educational change -- South Africa Youth -- South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1942 , http://hdl.handle.net/10962/d1007931
- Description: This case study investigates sense of place of youth amidst a background of change in postapartheid South Africa. As used in this study, sense of place refers to the attachments made to both physical and social places, and the social and cultural interactions and meanings associated with such places. The research was conducted with a group of 13 young adults at Mary Waters Senior Secondary School in Grahamstown. The literature suggests that the changes that occur in the lives of the participants at school-leaving age such as new opportunities to identify with global aspirations, tend to influence their sense of place in local contexts. Social change that occurs due to globalising forces such as access to new technologies and improved personal mobility, also influences sense of place in this context. Another integral factor is the structural influence of changing cultural and educational norms. These notions form part of the backdrop of this study. The research project was developed in response to calls for learning approaches that are situated more in local contexts and which include the youth as intrinsic participants informing environmental education approaches. This research draws attention to the significance of finding sustainable ways that enhance opportunities for agency on the part of the youth in future local and global environmental care-taking. The study took place over a period of 15 months in which time the participants undertook place-based activities in their communities around self-identified environmental concerns. The study was intentionally generative in approach as this allowed the voices of the participants and their environmental perspectives to be considered in developing methods and activities that were suitable to their particular contexts and interests. The study highlights the relevance of particular social contexts, through the perspectives of people and in this case learners, as key to environmental education enquiries. The combination of approaches that consider: a) knowledge about social context, b) the educational intervention (place-based activities) and, c) the situated social capital of the participants, all form the basis of meaningful pedagogical engagements and serve to address my research question: How is learners' sense of place developed and articulated through place-based activities, and what are the implications for environmental education amidst a contemporary landscape of change in South Africa?
- Full Text:
- Date Issued: 2006
Evaluating the effect of microalgae biomass on the combustion of coal
- Authors: Ejesieme, Obialo Vitus
- Date: 2013
- Subjects: Co-combustion , Coal -- Combustion , Biomass -- Combustion
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10435 , http://hdl.handle.net/10948/d1020641
- Description: In this work the combustion characteristics of coal, charcoal, microalgae biomass and blends between these three components were evaluated by means of non-isothermal thermogravimetry. Blends between coal, charcoal and microalgae biomass were made according to the specifications of a D-optimal mixture design so as to be able to model interactions between the three components with maximum precision despite multiple constraints built into the design. These constraints specified that coal can have a minimum value of 70 mass percent in any blend, while microalgae can have a maximum value of 20 mass percent. While coal and charcoal were blended by mixing the two respective dry components, microalgae biomass was incorporated into the blends by first absorbing microalgae onto fine coal from concentrated slurry of the microalgae in water. The microalgae in these blends were therefore intimately associated with the coal. This approach differed substantially from the normal practice of preparing coal – biomass blends (which are usually dry-mixed as for coal – charcoal blends). Proximate analyses of the starting materials showed that the microalgae biomass has a significantly higher volatile matter: fixed carbon content than both coal and charcoal, which should improve the combustion of these materials by providing a more stable combustion flame. Analyses of the thermogravimetric data obtained showed that coal and charcoal have much simpler combustion profiles than microalgae biomass for which five different thermal events could be observed in the DTG combustion profile. Qualitative kinetic analyses showed that the combustion of coal and charcoal follows first-order kinetics, but for microalgae biomass combustion, the first two combustion stages appear to follow first-order kinetics. The TG and DTG profiles for coal, charcoal, microalgae and blends of these three components were used to derive values for the so-called comprehensive combustion property index (S-value), which provides a combined measure of the ease of ignition, rate of combustion, and burn-out temperature. The S-values so obtained were used as response variable for the construction of a response surface model in the experimental domain investigated. Following statistical validation of the response surface model, the model was used to predict an optimum S-value or a blend that would display optimum combustion behaviour. Two optimum blends were obtained from the optimisation process, one in which only charcoal is added to coal, and one in which only microalgae is added to coal. Adding both charcoal and microalgae produced an antagonistic effect compared to when only one of these are used. Qualitative kinetic analyses of the combustion data of blends indicate that blends of coal and charcoal combust in a manner similar to the individual components (hence following first-order kinetics), but blends of coal and microalgae follow more complex kinetics despite the fact that the combustion profile is visibly more simple compared to the combustion profile for microalgae alone.
- Full Text:
- Date Issued: 2013
- Authors: Ejesieme, Obialo Vitus
- Date: 2013
- Subjects: Co-combustion , Coal -- Combustion , Biomass -- Combustion
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10435 , http://hdl.handle.net/10948/d1020641
- Description: In this work the combustion characteristics of coal, charcoal, microalgae biomass and blends between these three components were evaluated by means of non-isothermal thermogravimetry. Blends between coal, charcoal and microalgae biomass were made according to the specifications of a D-optimal mixture design so as to be able to model interactions between the three components with maximum precision despite multiple constraints built into the design. These constraints specified that coal can have a minimum value of 70 mass percent in any blend, while microalgae can have a maximum value of 20 mass percent. While coal and charcoal were blended by mixing the two respective dry components, microalgae biomass was incorporated into the blends by first absorbing microalgae onto fine coal from concentrated slurry of the microalgae in water. The microalgae in these blends were therefore intimately associated with the coal. This approach differed substantially from the normal practice of preparing coal – biomass blends (which are usually dry-mixed as for coal – charcoal blends). Proximate analyses of the starting materials showed that the microalgae biomass has a significantly higher volatile matter: fixed carbon content than both coal and charcoal, which should improve the combustion of these materials by providing a more stable combustion flame. Analyses of the thermogravimetric data obtained showed that coal and charcoal have much simpler combustion profiles than microalgae biomass for which five different thermal events could be observed in the DTG combustion profile. Qualitative kinetic analyses showed that the combustion of coal and charcoal follows first-order kinetics, but for microalgae biomass combustion, the first two combustion stages appear to follow first-order kinetics. The TG and DTG profiles for coal, charcoal, microalgae and blends of these three components were used to derive values for the so-called comprehensive combustion property index (S-value), which provides a combined measure of the ease of ignition, rate of combustion, and burn-out temperature. The S-values so obtained were used as response variable for the construction of a response surface model in the experimental domain investigated. Following statistical validation of the response surface model, the model was used to predict an optimum S-value or a blend that would display optimum combustion behaviour. Two optimum blends were obtained from the optimisation process, one in which only charcoal is added to coal, and one in which only microalgae is added to coal. Adding both charcoal and microalgae produced an antagonistic effect compared to when only one of these are used. Qualitative kinetic analyses of the combustion data of blends indicate that blends of coal and charcoal combust in a manner similar to the individual components (hence following first-order kinetics), but blends of coal and microalgae follow more complex kinetics despite the fact that the combustion profile is visibly more simple compared to the combustion profile for microalgae alone.
- Full Text:
- Date Issued: 2013
Exploring employees' need for the development of an employee assistance programme at a welfare organisation
- Authors: Mncunzwa, Gcobisa
- Date: 2017
- Subjects: Employee assistance programs
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/5554 , vital:29325
- Description: The study was conducted in order to determine the employee needs for an employee assistance programme in a welfare organisation in East London, Eastern Cape. This study was born out of a need from the management of this welfare organisation in East London who identified a need for an employee assistance Programme (EAP) within their organisation. According to management, there was a decline in productivity, and high stress levels due to high caseloads and societal demands (Leeuw, May 15, 2015). The theoretical framework that guided this research was systems theory. The rationale for using systems theory is that this study deals with individuals within an organisation who must coexist on a daily basis. There is a general belief that people and their physical-social-cultural environment interact in processes of mutual reciprocity and complementary exchanges (Merton, 2009). A qualitative approach was used in this study. Eight (8) employees from various levels in a welfare organisation were purposively selected to participate in the study. Semi-structured interviews were conducted with the participants and the interviews took more than forty-five (45) minutes each and this enabled the acquisition of rich information which is described in the findings and is used as a basis for the recommendations in the study. After the examination of the needs of employees for an EAP from the observations of both the employer and the employee it was clear that there is a need for employee assistance programmes in welfare organisations. Employees in this organisation are experiencing stress, burnout and were highly concerned about high caseloads that makes them feel incompetent to render adequate and quality services to their employees. The study also revealed that both employees and management of this organisation have different needs, experience different types of problems and view the EAP in different contexts. Despite the differences in their outlook on the situation, the evidence indicates that both employer and employee perceive that there is a need for an EAP, especially clinical services. At the same time, the issue of funding such a programme is also a concern. Recommendations were made for the organisation to develop an EAP to address the needs identified by employees, and for a clear communication strategy be developed to make all levels of employees within the organisation aware of the existence of such a programme. Another recommendation was made for the organisation to identify specific days on which they will conduct preventative awareness and debriefing sessions for the employees. It was also recommended that the South African Council for Social Services Professionals must standardise, regulate and monitor caseloads for the social work profession.
- Full Text:
- Date Issued: 2017
- Authors: Mncunzwa, Gcobisa
- Date: 2017
- Subjects: Employee assistance programs
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/5554 , vital:29325
- Description: The study was conducted in order to determine the employee needs for an employee assistance programme in a welfare organisation in East London, Eastern Cape. This study was born out of a need from the management of this welfare organisation in East London who identified a need for an employee assistance Programme (EAP) within their organisation. According to management, there was a decline in productivity, and high stress levels due to high caseloads and societal demands (Leeuw, May 15, 2015). The theoretical framework that guided this research was systems theory. The rationale for using systems theory is that this study deals with individuals within an organisation who must coexist on a daily basis. There is a general belief that people and their physical-social-cultural environment interact in processes of mutual reciprocity and complementary exchanges (Merton, 2009). A qualitative approach was used in this study. Eight (8) employees from various levels in a welfare organisation were purposively selected to participate in the study. Semi-structured interviews were conducted with the participants and the interviews took more than forty-five (45) minutes each and this enabled the acquisition of rich information which is described in the findings and is used as a basis for the recommendations in the study. After the examination of the needs of employees for an EAP from the observations of both the employer and the employee it was clear that there is a need for employee assistance programmes in welfare organisations. Employees in this organisation are experiencing stress, burnout and were highly concerned about high caseloads that makes them feel incompetent to render adequate and quality services to their employees. The study also revealed that both employees and management of this organisation have different needs, experience different types of problems and view the EAP in different contexts. Despite the differences in their outlook on the situation, the evidence indicates that both employer and employee perceive that there is a need for an EAP, especially clinical services. At the same time, the issue of funding such a programme is also a concern. Recommendations were made for the organisation to develop an EAP to address the needs identified by employees, and for a clear communication strategy be developed to make all levels of employees within the organisation aware of the existence of such a programme. Another recommendation was made for the organisation to identify specific days on which they will conduct preventative awareness and debriefing sessions for the employees. It was also recommended that the South African Council for Social Services Professionals must standardise, regulate and monitor caseloads for the social work profession.
- Full Text:
- Date Issued: 2017
Exploring the experience of family members living with individuals who abuse alcohol and/or substances -(Study conducted in Khayelitsha, Western Cape)
- Authors: Modise, Badise
- Date: 2018
- Subjects: Alcoholism Substance abuse Family violence
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/13116 , vital:39466
- Description: The constant, excessive and frequently uncontrollable abuse of alcoholic beverages and drug related substances continues to have many devastating effects on family members of the abusers. The impact can be explored in various ways, but the findings are likely to be hand in glove regardless of the causes associated with this phenomenon. This study aimed to explore the experiences of family members living with individuals who abuse alcohol and/or substances through case studies conducted in Khayelitsha, in the Western Province of South Africa. The study was conducted to gain greater insight into the experiences of the family members in order to provide the appropriate assistance to help them deal with these issues. From the data that was captured and analysed, it was clear that alcohol and substance abuse inflicted profound suffering on family members. It contributes to high levels of interpersonal conflict, domestic violence, child abuse and neglect, financial problems as well as health issues for all parties involved - causing extreme emotional pain and suffering. Living with an alcohol or substance abuser inevitably results in financial burden, dysfunctional relationships and family life in addition to impacting on safety needs. Furthermore, the results have shown that family members of alcohol and substance dependents develop psychological and mental distress; anxiety, and insomnia. Likewise, the family members develop psychophysiological symptoms such as high-blood pressure and chronic headaches. With regards to rehabilitation, family members reported exclusion from rehabilitation programs and lost their belief in self-rehabilitation or detoxification.
- Full Text:
- Date Issued: 2018
- Authors: Modise, Badise
- Date: 2018
- Subjects: Alcoholism Substance abuse Family violence
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/13116 , vital:39466
- Description: The constant, excessive and frequently uncontrollable abuse of alcoholic beverages and drug related substances continues to have many devastating effects on family members of the abusers. The impact can be explored in various ways, but the findings are likely to be hand in glove regardless of the causes associated with this phenomenon. This study aimed to explore the experiences of family members living with individuals who abuse alcohol and/or substances through case studies conducted in Khayelitsha, in the Western Province of South Africa. The study was conducted to gain greater insight into the experiences of the family members in order to provide the appropriate assistance to help them deal with these issues. From the data that was captured and analysed, it was clear that alcohol and substance abuse inflicted profound suffering on family members. It contributes to high levels of interpersonal conflict, domestic violence, child abuse and neglect, financial problems as well as health issues for all parties involved - causing extreme emotional pain and suffering. Living with an alcohol or substance abuser inevitably results in financial burden, dysfunctional relationships and family life in addition to impacting on safety needs. Furthermore, the results have shown that family members of alcohol and substance dependents develop psychological and mental distress; anxiety, and insomnia. Likewise, the family members develop psychophysiological symptoms such as high-blood pressure and chronic headaches. With regards to rehabilitation, family members reported exclusion from rehabilitation programs and lost their belief in self-rehabilitation or detoxification.
- Full Text:
- Date Issued: 2018
Finite element modelling of magma convection and attendant groundwater flow
- Authors: Harrison, Keith
- Date: 1998
- Subjects: Groundwater flow , Magmas
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5467 , http://hdl.handle.net/10962/d1005252 , Groundwater flow , Magmas
- Description: This thesis describes preliminary two- and three-dimensional modelling of mass and heat transport of hot, molten magma in crustal intrusions and of the associated thermally induced flow of groundwater contained in the surrounding country rock. The aim of such modelling is to create a tool with which to predict the location of mineral deposits formed by the transport and subsequent precipitation of minerals dissolved in the convecting groundwater. The momentum equations (Navier-Stokes equations), continuity equation and energy equation are used in conjunction with specially constructed density and viscosity relationships to govern the mass and heat transport processes of magma and groundwater. Finite element methods are used to solve the equations numerically for some simple model geometries. These methods are implemented by a commercial computer software code which is manipulated with a control program constructed by the author for the purpose. The models are of simple two- or three-dimensional geometries which all have an enclosed magma chamber surrounded completely by a shell of country rock through which groundwater is free to move. Modelling begins immediately after the intrusive event when the magma (in most cases rhyolitic) is at its greatest temperature. Heat is allowed to flow from the magma into the country rock causing thermal convection of the groundwater contained therein. The effect of the country rock as a porous medium on the flow of groundwater is modelled by including a distributed resistance term in the momentum equation. The computer code that controls the modelling is such that adaptions made to the models to represent real physical intrusive systems are trivial. Results of the research at this stage allow approximate prediction of the location of mineral deposits. Enhanced predictions can be made by effecting improvements to the models such as a more detailed representation of chemical processes, adaption of the computer code to allow multiple injections of magma and the modelling of frozen magma as a porous medium which admits the flow of groundwater.
- Full Text:
- Date Issued: 1998
- Authors: Harrison, Keith
- Date: 1998
- Subjects: Groundwater flow , Magmas
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5467 , http://hdl.handle.net/10962/d1005252 , Groundwater flow , Magmas
- Description: This thesis describes preliminary two- and three-dimensional modelling of mass and heat transport of hot, molten magma in crustal intrusions and of the associated thermally induced flow of groundwater contained in the surrounding country rock. The aim of such modelling is to create a tool with which to predict the location of mineral deposits formed by the transport and subsequent precipitation of minerals dissolved in the convecting groundwater. The momentum equations (Navier-Stokes equations), continuity equation and energy equation are used in conjunction with specially constructed density and viscosity relationships to govern the mass and heat transport processes of magma and groundwater. Finite element methods are used to solve the equations numerically for some simple model geometries. These methods are implemented by a commercial computer software code which is manipulated with a control program constructed by the author for the purpose. The models are of simple two- or three-dimensional geometries which all have an enclosed magma chamber surrounded completely by a shell of country rock through which groundwater is free to move. Modelling begins immediately after the intrusive event when the magma (in most cases rhyolitic) is at its greatest temperature. Heat is allowed to flow from the magma into the country rock causing thermal convection of the groundwater contained therein. The effect of the country rock as a porous medium on the flow of groundwater is modelled by including a distributed resistance term in the momentum equation. The computer code that controls the modelling is such that adaptions made to the models to represent real physical intrusive systems are trivial. Results of the research at this stage allow approximate prediction of the location of mineral deposits. Enhanced predictions can be made by effecting improvements to the models such as a more detailed representation of chemical processes, adaption of the computer code to allow multiple injections of magma and the modelling of frozen magma as a porous medium which admits the flow of groundwater.
- Full Text:
- Date Issued: 1998
Gender equity in land tenure : an assessment of the challenges faced by women in the communal land tenure system in Keiskammahoek, South Africa
- Authors: Sonkosi, Abongile
- Date: 2018
- Subjects: Land tenure--South Africa--Eastern Cape Land use--South Africa--Eastern Cape Land tenure
- Language: English
- Type: Thesis , Masters , Rural Development
- Identifier: http://hdl.handle.net/10353/17138 , vital:40859
- Description: Despite the importance of land to women, women however are still deprived of security of tenure as a result of the gender biased laws which at their best only protect married women and at their worst fail to protect the rights of single, widowed and divorced women. An analysis of the land reform policies in South Africa as a whole on the issue of the advancement of women through land reform reveals a number of irregularities and false promises. Many of the new policy shifts are problematic as they tend to benefit the elite and continue to leave the majority of the rural poor people particularly women in communal areas with insecure land tenure. This research study examined: 1. the nature of land relations at work in Keiskammahoek and how they impact women’s rights to land. 2. How women in Keiskammahoek view their rights to land. 3. The challenges experienced and progress made by women in claiming their land rights in Keiskamahoek. Despite the importance of land to women, women however are still deprived of security of tenure as a result of the gender biased laws which at their best only protect married women and at their worst fail to protect the rights of single, widowed and divorced women. An analysis of the land reform policies in South Africa as a whole on the issue of the advancement of women through land reform reveals a number of irregularities and false promises. Many of the new policy shifts are problematic as they tend to benefit the elite and continue to leave the majority of the rural poor people particularly women in communal areas with insecure land tenure. This research study examined: 1. the nature of land relations at work in Keiskammahoek and how they impact women’s rights to land. 2. How women in Keiskammahoek view their rights to land. 3. The challenges experienced and progress made by women in claiming their land rights in Keiskamahoek. ownership in their communities. They expressed strong views against the suppression of their voice due to patriarchal structures that govern the way they live. They further observed that a woman’s voice in the rural communities generally does not get heard and that even if women get into positions of power they fail to stand up against women’s marginalization and gender inequalities. However, the most positive finding is that the wind of change is blowing in Keiskammahoek as different categories of women - married, single, divorced, widowed etc. begin to access residential and to some limited degree, agricultural plots. They appeal to the government to support them in accessing agricultural tools including tractors, irrigation systems, seeds etc. Although the progress made so far with regard to women’s access to land is acknowledged, a great deal of work still needs to be done in order to empower women through land reform. The study makes recommendations on the implementation of land tenure policy that addresses women’s challenges in land access and ownership.
- Full Text:
- Date Issued: 2018
- Authors: Sonkosi, Abongile
- Date: 2018
- Subjects: Land tenure--South Africa--Eastern Cape Land use--South Africa--Eastern Cape Land tenure
- Language: English
- Type: Thesis , Masters , Rural Development
- Identifier: http://hdl.handle.net/10353/17138 , vital:40859
- Description: Despite the importance of land to women, women however are still deprived of security of tenure as a result of the gender biased laws which at their best only protect married women and at their worst fail to protect the rights of single, widowed and divorced women. An analysis of the land reform policies in South Africa as a whole on the issue of the advancement of women through land reform reveals a number of irregularities and false promises. Many of the new policy shifts are problematic as they tend to benefit the elite and continue to leave the majority of the rural poor people particularly women in communal areas with insecure land tenure. This research study examined: 1. the nature of land relations at work in Keiskammahoek and how they impact women’s rights to land. 2. How women in Keiskammahoek view their rights to land. 3. The challenges experienced and progress made by women in claiming their land rights in Keiskamahoek. Despite the importance of land to women, women however are still deprived of security of tenure as a result of the gender biased laws which at their best only protect married women and at their worst fail to protect the rights of single, widowed and divorced women. An analysis of the land reform policies in South Africa as a whole on the issue of the advancement of women through land reform reveals a number of irregularities and false promises. Many of the new policy shifts are problematic as they tend to benefit the elite and continue to leave the majority of the rural poor people particularly women in communal areas with insecure land tenure. This research study examined: 1. the nature of land relations at work in Keiskammahoek and how they impact women’s rights to land. 2. How women in Keiskammahoek view their rights to land. 3. The challenges experienced and progress made by women in claiming their land rights in Keiskamahoek. ownership in their communities. They expressed strong views against the suppression of their voice due to patriarchal structures that govern the way they live. They further observed that a woman’s voice in the rural communities generally does not get heard and that even if women get into positions of power they fail to stand up against women’s marginalization and gender inequalities. However, the most positive finding is that the wind of change is blowing in Keiskammahoek as different categories of women - married, single, divorced, widowed etc. begin to access residential and to some limited degree, agricultural plots. They appeal to the government to support them in accessing agricultural tools including tractors, irrigation systems, seeds etc. Although the progress made so far with regard to women’s access to land is acknowledged, a great deal of work still needs to be done in order to empower women through land reform. The study makes recommendations on the implementation of land tenure policy that addresses women’s challenges in land access and ownership.
- Full Text:
- Date Issued: 2018
High-throughput modelling and structural investigation of cysteine protease complexes with protein inhibitors
- Authors: Kroon, Matthys Christoffel
- Date: 2013
- Subjects: Cysteine proteinases Cysteine proteinases -- Inhibitors Papain Cystatins Malaria -- Chemotherapy Homology (Biology) Protein-protein interactions
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3885 , http://hdl.handle.net/10962/d1001619
- Description: The papain-like cysteine protease family (C1 proteases) is highly important because of its involvement in research and industrial applications and its role in various human diseases. Protein inhibitors are an important aspect of C1 protease biology and are relevant to its clinical, industrial and research importance. To study the interaction between the proteases and the inhibitors it is very useful to have accurate structural models of the protease-inhibitor complexes. To this end, a high-throughput pipeline for modelling complexes of papain-like cysteine proteases and protein inhibitors was implemented and tested (Tastan Bishop & Kroon, 2011). The pipeline utilizes a novel technique for obtaining modelling templates by using superpositioning to combine coordinates from separate experimental structures. To test the pipeline, models of complexes with known structures (test set) were modelled using many different templates and the resultant models evaluated to compare the quality of the different templates. It was found that use of the new technique to obtain templates did not introduce significant errors, while allowing closer homologs to be used for modelling - leading to more accurate models. The test set models were also used to evaluate certain steps of the modelling protocol. The effect of Rosetta energy minimization on model accuracy and the use of Rosetta energy and DOPE Z-score values to identify accurate models were investigated. Several complexes were then modelled using the best available templates according to criteria informed by the previous results. A website was built that allows a user to download any of the metrics or models produced in the study. This website is accessible at http://rubi.ru.ac.za/cpmdb
- Full Text:
- Date Issued: 2013
- Authors: Kroon, Matthys Christoffel
- Date: 2013
- Subjects: Cysteine proteinases Cysteine proteinases -- Inhibitors Papain Cystatins Malaria -- Chemotherapy Homology (Biology) Protein-protein interactions
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3885 , http://hdl.handle.net/10962/d1001619
- Description: The papain-like cysteine protease family (C1 proteases) is highly important because of its involvement in research and industrial applications and its role in various human diseases. Protein inhibitors are an important aspect of C1 protease biology and are relevant to its clinical, industrial and research importance. To study the interaction between the proteases and the inhibitors it is very useful to have accurate structural models of the protease-inhibitor complexes. To this end, a high-throughput pipeline for modelling complexes of papain-like cysteine proteases and protein inhibitors was implemented and tested (Tastan Bishop & Kroon, 2011). The pipeline utilizes a novel technique for obtaining modelling templates by using superpositioning to combine coordinates from separate experimental structures. To test the pipeline, models of complexes with known structures (test set) were modelled using many different templates and the resultant models evaluated to compare the quality of the different templates. It was found that use of the new technique to obtain templates did not introduce significant errors, while allowing closer homologs to be used for modelling - leading to more accurate models. The test set models were also used to evaluate certain steps of the modelling protocol. The effect of Rosetta energy minimization on model accuracy and the use of Rosetta energy and DOPE Z-score values to identify accurate models were investigated. Several complexes were then modelled using the best available templates according to criteria informed by the previous results. A website was built that allows a user to download any of the metrics or models produced in the study. This website is accessible at http://rubi.ru.ac.za/cpmdb
- Full Text:
- Date Issued: 2013
Homeless men in East London : an exploration of significant life experiences to self-concepts
- Authors: Lobi, Thembelihle
- Date: 2017
- Subjects: Homeless persons Homelessness Homeless men
- Language: English
- Type: Thesis , Masters , Counselling Psychology
- Identifier: http://hdl.handle.net/10353/16069 , vital:40661
- Description: This dissertation investigated the life experiences of homeless persons and how they come to view their self-concepts as homeless men. The theoretical framework that underpinned this study was the self-concept theory and social identity theory. In this contextual descriptive study, four homeless men between ages of 28-50 participated in the study. Data was collected by means of disposable cameras and recorded interviews. Thematic analysis was employed to analyse data. The study found that when the participants first became homeless, they encountered stigmatisation and were not ready to accept the homeless identity as it conflicted with their past identity. However, with prolonged homelessness, they took on the new identity and the roles that come with it. The study found that homeless men view themselves as worthless due to their experiences on the street which include living under inhumane conditions, victimisation, and stigma associated with being homeless. The participants have internalised the negative utterances from housed people, which has negatively affected their self-image to a point where they view themselves as worthless,useless and forgetable. The study also found that homeless men use various methods to survive on the streets, which were both self-enhancing such as participating in the informal economy such as car guarding, car washing and collecting tins in exchange for money; and self-destructive such as using substances, risky sexual behaviour. The participants were found to have low self-concepts because of the tough experiences they encounter on the street.
- Full Text:
- Date Issued: 2017
- Authors: Lobi, Thembelihle
- Date: 2017
- Subjects: Homeless persons Homelessness Homeless men
- Language: English
- Type: Thesis , Masters , Counselling Psychology
- Identifier: http://hdl.handle.net/10353/16069 , vital:40661
- Description: This dissertation investigated the life experiences of homeless persons and how they come to view their self-concepts as homeless men. The theoretical framework that underpinned this study was the self-concept theory and social identity theory. In this contextual descriptive study, four homeless men between ages of 28-50 participated in the study. Data was collected by means of disposable cameras and recorded interviews. Thematic analysis was employed to analyse data. The study found that when the participants first became homeless, they encountered stigmatisation and were not ready to accept the homeless identity as it conflicted with their past identity. However, with prolonged homelessness, they took on the new identity and the roles that come with it. The study found that homeless men view themselves as worthless due to their experiences on the street which include living under inhumane conditions, victimisation, and stigma associated with being homeless. The participants have internalised the negative utterances from housed people, which has negatively affected their self-image to a point where they view themselves as worthless,useless and forgetable. The study also found that homeless men use various methods to survive on the streets, which were both self-enhancing such as participating in the informal economy such as car guarding, car washing and collecting tins in exchange for money; and self-destructive such as using substances, risky sexual behaviour. The participants were found to have low self-concepts because of the tough experiences they encounter on the street.
- Full Text:
- Date Issued: 2017
La femme dans l'oeuvre litteraire de Jean-Paul Sartre
- Authors: Seiler, Miriam Zimet
- Date: 1977
- Subjects: Sartre, Jean-Paul, 1905-1980 -- Criticism and interpretation
- Language: French
- Type: Thesis , Masters , MA
- Identifier: vital:3641 , http://hdl.handle.net/10962/d1014302
- Description: [From introduction]. Pourquoi examiner Ie rôle de la femme dans l' oeuvre de Sartre? Jean-Paul Sartre est l'un des philosophes les plus importants de ce siècle, un philosophe qui s'est consacré ấ un examen de l'homme et de ses rapports avec l'existence par la liberté conscienter; un penseur qui a montré son individualisme dans le domaine de la politique, n'acceptant que ce qu'il trouve défendable; un romancier et un dramaturge dont l'oeuvre a connu un succès mondial.
- Full Text:
- Date Issued: 1977
- Authors: Seiler, Miriam Zimet
- Date: 1977
- Subjects: Sartre, Jean-Paul, 1905-1980 -- Criticism and interpretation
- Language: French
- Type: Thesis , Masters , MA
- Identifier: vital:3641 , http://hdl.handle.net/10962/d1014302
- Description: [From introduction]. Pourquoi examiner Ie rôle de la femme dans l' oeuvre de Sartre? Jean-Paul Sartre est l'un des philosophes les plus importants de ce siècle, un philosophe qui s'est consacré ấ un examen de l'homme et de ses rapports avec l'existence par la liberté conscienter; un penseur qui a montré son individualisme dans le domaine de la politique, n'acceptant que ce qu'il trouve défendable; un romancier et un dramaturge dont l'oeuvre a connu un succès mondial.
- Full Text:
- Date Issued: 1977
Meat and its meanings: representations of meat-eating in selected works of South African literature
- Authors: Coetzer, Theo
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3860 , vital:20550
- Description: This thesis is situated within the burgeoning field of literary animal studies. Its aim is to analyse critically the way in which animals-as-meat are represented in South African literature. While meat pervades our lives and literature, there exists very little scholarship that considers literary depictions of meat. The thesis suggests that literary texts can offer useful reflections of the cultural environments in which they are immersed and, furthermore, can encourage what J. M. Coetzee calls the ‘sympathetic imagination’ in relation to animals. The dissertation offers close readings of three primary texts, while also drawing on a broader range of local fiction. Chapter 1 discusses Eben Venter’s Trencherman, with a specific focus on Venter’s use of the plaasroman and literary dystopia. Both genres are important to the novel’s ubiquitous depictions of meat, serving to illustrate some of the destructive, and irreversible, excesses associated with traditional Afrikaner culture in South Africa. Meat consumption is not only depicted as being among these harmful excesses, but also comes to represent them collectively. Chapter 2 offers a reading of Zakes Mda’s The Madonna of Excelsior, paying particular attention to its representation of the intersection between the objectification of women’s bodies and the transformation of animals into meat. In my approach to this text, I make use of Carol J. Adams’ notion of the ‘absent referent’. I suggest that while Mda ostensibly considers the subjugation of both women and animals, the novel does not ultimately demonstrate concern for animals in their own right. The final chapter considers the representation of suffering in Damon Galgut’s The Beautiful Screaming of Pigs. I argue that Galgut’s text is alone among the three primary texts in its attention to the animal suffering inextricably linked to meat production. The novel depicts this suffering as being comparable to human suffering, while simultaneously demonstrating humans’ indifference to their animal fellows. The dissertation concludes that while meat is infused with a range of meanings in South African literature, the most obvious and intrinsic one – the fact of animal death and animal suffering – is the one most often ignored.
- Full Text:
- Date Issued: 2016
- Authors: Coetzer, Theo
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3860 , vital:20550
- Description: This thesis is situated within the burgeoning field of literary animal studies. Its aim is to analyse critically the way in which animals-as-meat are represented in South African literature. While meat pervades our lives and literature, there exists very little scholarship that considers literary depictions of meat. The thesis suggests that literary texts can offer useful reflections of the cultural environments in which they are immersed and, furthermore, can encourage what J. M. Coetzee calls the ‘sympathetic imagination’ in relation to animals. The dissertation offers close readings of three primary texts, while also drawing on a broader range of local fiction. Chapter 1 discusses Eben Venter’s Trencherman, with a specific focus on Venter’s use of the plaasroman and literary dystopia. Both genres are important to the novel’s ubiquitous depictions of meat, serving to illustrate some of the destructive, and irreversible, excesses associated with traditional Afrikaner culture in South Africa. Meat consumption is not only depicted as being among these harmful excesses, but also comes to represent them collectively. Chapter 2 offers a reading of Zakes Mda’s The Madonna of Excelsior, paying particular attention to its representation of the intersection between the objectification of women’s bodies and the transformation of animals into meat. In my approach to this text, I make use of Carol J. Adams’ notion of the ‘absent referent’. I suggest that while Mda ostensibly considers the subjugation of both women and animals, the novel does not ultimately demonstrate concern for animals in their own right. The final chapter considers the representation of suffering in Damon Galgut’s The Beautiful Screaming of Pigs. I argue that Galgut’s text is alone among the three primary texts in its attention to the animal suffering inextricably linked to meat production. The novel depicts this suffering as being comparable to human suffering, while simultaneously demonstrating humans’ indifference to their animal fellows. The dissertation concludes that while meat is infused with a range of meanings in South African literature, the most obvious and intrinsic one – the fact of animal death and animal suffering – is the one most often ignored.
- Full Text:
- Date Issued: 2016
Medication errors in a private hospital closed intensive care unit: a retrospective analysis of process change
- Authors: Cruickshank, Deborah Claire
- Date: 2017
- Subjects: Medication errors
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10948/15501 , vital:28259
- Description: Healthcare professionals should be concerned about the safety of the patients in their care and the references to patient safety go back as far as the Hippocratic Oath. Study of literature however shows that medical errors are still of concern and the majority of medical errors are medication errors. The aim of the study was to determine whether process changes introduced reduced both the medication prescribing and medication administration errors in the intensive care unit, thereby contributing to an increase in overall patient safety in the intensive care unit. This study retrospectively analysed the effect of the process changes on medication prescribing and administration errors. The research objectives were to: Identify the number and type of prescribing medication errors prior to the implementation of process changes; Identify the number and type of administration medication errors prior to the implementation of process changes; Identify the process changes implemented; o Determine number and type of prescribing medication errors post the implementation of process changes; Determine number and type of administration medication errors post the implementation of process changes; Assess whether the process changes affected the number and type of prescribing medication errors; and o Assess whether the process changes affected the number and type of administration medication errors. In the Phase One (1 November 2013 to 31 January 2014) 534 patient prescription charts for 172 patients were examined. Medication error rates of 57.6% (n=99) of individual patients reviewed and 18.4% of total patient prescription charts reviewed were found. A total of 69 medication prescribing errors were found in Phase One. This equates to an error percentage of 12.9% per patient chart reviewed and 40.1% per patient reviewed. Thirty medication administration errors were identified in Phase One of the study representing 17.4% of patients reviewed and 5.6% of patient prescription charts reviewed. Medication administration errors included both errors of commission, incorrect doses administered, (n=19) and omission, dose missed, (n=11). Process changes were then introduced and the results of these changes analysed in Phase Two (1 April 2014 to 31 December 2014) show an overall reduction in total medication errors with relation to number of patients reviewed from 57.6% in Phase One to 40.5% in Phase Two. In relation to number of prescription charts reviewed the medication error rate in Phase One was 18.4% and in Phase Two 14.4%. Prescribing errors in relation to number of patients reviewed reduced from 40.1% in Phase One to 26.19% in Phase Two. Overall reductions in percentage of errors were seen in all categories of prescribing errors except duplication of therapy which showed a slight increase. Based on the number of patients reviewed a reduction of prescribing errors was seen in the following categories: transcription errors (13.3% to 7.6%), anticoagulant not prescribed when indicated (3.5% to 2.4%), medication safety (5.2% to 2.9%), dose errors (9.3% to 6.6%) and duration of therapy (6.3% to 3.6%). An increase in the duplication of therapy error rate was seen (2.3% to 3.1%). There was also a reduction in administration errors in relation to number of patients reviewed with a total number of errors of 17.4% in Phase One and 15.8% in Phase Two. The number of prescribing errors per medication chart in Phase Two showed a statistically significant reduction (p=.002). A statistically significant reduction was also seen when the number of errors per patient was reviewed (p=.008). The total number of medication administration errors per medication chart showed a significant reduction (p=.042) as did the number of administration errors per patient (p=.003). When combining the total number of medication errors (both prescriobing and administration) a significant reduction was seen for both the number of charts reviewed (p=.001) and the number of patients reviewed (p=.002). These results indicate that the desired goal of increasing patient safety with regard to medication errors has been achieved but ongoing study is required to ensure the sustainability of the process changes.
- Full Text:
- Date Issued: 2017
- Authors: Cruickshank, Deborah Claire
- Date: 2017
- Subjects: Medication errors
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10948/15501 , vital:28259
- Description: Healthcare professionals should be concerned about the safety of the patients in their care and the references to patient safety go back as far as the Hippocratic Oath. Study of literature however shows that medical errors are still of concern and the majority of medical errors are medication errors. The aim of the study was to determine whether process changes introduced reduced both the medication prescribing and medication administration errors in the intensive care unit, thereby contributing to an increase in overall patient safety in the intensive care unit. This study retrospectively analysed the effect of the process changes on medication prescribing and administration errors. The research objectives were to: Identify the number and type of prescribing medication errors prior to the implementation of process changes; Identify the number and type of administration medication errors prior to the implementation of process changes; Identify the process changes implemented; o Determine number and type of prescribing medication errors post the implementation of process changes; Determine number and type of administration medication errors post the implementation of process changes; Assess whether the process changes affected the number and type of prescribing medication errors; and o Assess whether the process changes affected the number and type of administration medication errors. In the Phase One (1 November 2013 to 31 January 2014) 534 patient prescription charts for 172 patients were examined. Medication error rates of 57.6% (n=99) of individual patients reviewed and 18.4% of total patient prescription charts reviewed were found. A total of 69 medication prescribing errors were found in Phase One. This equates to an error percentage of 12.9% per patient chart reviewed and 40.1% per patient reviewed. Thirty medication administration errors were identified in Phase One of the study representing 17.4% of patients reviewed and 5.6% of patient prescription charts reviewed. Medication administration errors included both errors of commission, incorrect doses administered, (n=19) and omission, dose missed, (n=11). Process changes were then introduced and the results of these changes analysed in Phase Two (1 April 2014 to 31 December 2014) show an overall reduction in total medication errors with relation to number of patients reviewed from 57.6% in Phase One to 40.5% in Phase Two. In relation to number of prescription charts reviewed the medication error rate in Phase One was 18.4% and in Phase Two 14.4%. Prescribing errors in relation to number of patients reviewed reduced from 40.1% in Phase One to 26.19% in Phase Two. Overall reductions in percentage of errors were seen in all categories of prescribing errors except duplication of therapy which showed a slight increase. Based on the number of patients reviewed a reduction of prescribing errors was seen in the following categories: transcription errors (13.3% to 7.6%), anticoagulant not prescribed when indicated (3.5% to 2.4%), medication safety (5.2% to 2.9%), dose errors (9.3% to 6.6%) and duration of therapy (6.3% to 3.6%). An increase in the duplication of therapy error rate was seen (2.3% to 3.1%). There was also a reduction in administration errors in relation to number of patients reviewed with a total number of errors of 17.4% in Phase One and 15.8% in Phase Two. The number of prescribing errors per medication chart in Phase Two showed a statistically significant reduction (p=.002). A statistically significant reduction was also seen when the number of errors per patient was reviewed (p=.008). The total number of medication administration errors per medication chart showed a significant reduction (p=.042) as did the number of administration errors per patient (p=.003). When combining the total number of medication errors (both prescriobing and administration) a significant reduction was seen for both the number of charts reviewed (p=.001) and the number of patients reviewed (p=.002). These results indicate that the desired goal of increasing patient safety with regard to medication errors has been achieved but ongoing study is required to ensure the sustainability of the process changes.
- Full Text:
- Date Issued: 2017
Missing values: a closer look
- Authors: Thorpe, Kerri
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/d1017827 , vital:20798
- Description: Problem: In today’s world, missing values are more present than ever. Due to the ever-changing and fast paced global society in which we live, most business and research data produced around the world contain missing data. This means that locating data which is meticulously precise can be a hard task in itself, but at times may prove essential as the consequences of making use of incomplete data could be disastrous. The reasons for missing data cropping up in almost all forms of work are numerous and shall be discussed in this dissertation. For example, those being interviewed or polled may choose to simply ignore questions which are posed to them, recording equipment may malfunction or be misplaced, or organisers may not be able to locate the respondent in order to rectify the missing data. Whatever the reasons for data being incomplete, it is necessary to avoid having to use inefficient and incomplete data as a result from the above problems. Therefore, various strategies or methods have been developed in order to handle these missing values. It is important, however, that these strategies or methods are utilised effectively as missing data treatment can introduce bias into the analysis. This dissertation shall look at these and other problems in more detail by using a data set which consists of records for 581 children who were interviewed in 1990 as part of the National Longitudinal Survey of Youth (NLSY). Approach: As mentioned above, many strategies or methods have been developed in order to deal with missing values. More specifically, traditional methods such as complete case analysis, available case analysis or single imputation are widely used by researchers and shall be discussed herein. Although these methods are simple and easy to implement, they require assumptions about the data that are not often satisfied in practice. Over the years, more up to date and relevant methods, such as multiple imputation and maximum likelihood have been developed. These methods rely on weaker assumptions and contain superior statistical properties when compared to the traditional techniques. In this dissertation, these traditional methods shall be reviewed and assessed in SAS and shall be compared to the more modern techniques. Results: The ad hoc techniques for handling missing data such as complete case and available case methods produce biased parameter estimates when the data is not missing completely at random (MCAR). Single imputation techniques likewise produce biased estimates as well as result in the underestimation of standard errors. Although the expectation maximisation (EM) algorithm yields unbiased parameter estimates, the lack of convenient standard errors suggests that using this algorithm for hypothesis testing is not a good idea. Multiple imputation, however, yields unbiased parameter estimates and correctly estimates standard errors. Conclusion: Ignoring missing data in any analysis produces biased parameter estimates. Using single imputation to handle missing values is not recommended, as using a single value to replace missing values does not account for the variation that would have been present if the variables were observed. As a result, the variance will be greatly underestimated. The more modern missing data methods such as the EM algorithm and multiple imputation are preferred over the traditional techniques as they require less stringent assumptions and they also mitigate the downsides of the older methods.
- Full Text:
- Date Issued: 2017
- Authors: Thorpe, Kerri
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/d1017827 , vital:20798
- Description: Problem: In today’s world, missing values are more present than ever. Due to the ever-changing and fast paced global society in which we live, most business and research data produced around the world contain missing data. This means that locating data which is meticulously precise can be a hard task in itself, but at times may prove essential as the consequences of making use of incomplete data could be disastrous. The reasons for missing data cropping up in almost all forms of work are numerous and shall be discussed in this dissertation. For example, those being interviewed or polled may choose to simply ignore questions which are posed to them, recording equipment may malfunction or be misplaced, or organisers may not be able to locate the respondent in order to rectify the missing data. Whatever the reasons for data being incomplete, it is necessary to avoid having to use inefficient and incomplete data as a result from the above problems. Therefore, various strategies or methods have been developed in order to handle these missing values. It is important, however, that these strategies or methods are utilised effectively as missing data treatment can introduce bias into the analysis. This dissertation shall look at these and other problems in more detail by using a data set which consists of records for 581 children who were interviewed in 1990 as part of the National Longitudinal Survey of Youth (NLSY). Approach: As mentioned above, many strategies or methods have been developed in order to deal with missing values. More specifically, traditional methods such as complete case analysis, available case analysis or single imputation are widely used by researchers and shall be discussed herein. Although these methods are simple and easy to implement, they require assumptions about the data that are not often satisfied in practice. Over the years, more up to date and relevant methods, such as multiple imputation and maximum likelihood have been developed. These methods rely on weaker assumptions and contain superior statistical properties when compared to the traditional techniques. In this dissertation, these traditional methods shall be reviewed and assessed in SAS and shall be compared to the more modern techniques. Results: The ad hoc techniques for handling missing data such as complete case and available case methods produce biased parameter estimates when the data is not missing completely at random (MCAR). Single imputation techniques likewise produce biased estimates as well as result in the underestimation of standard errors. Although the expectation maximisation (EM) algorithm yields unbiased parameter estimates, the lack of convenient standard errors suggests that using this algorithm for hypothesis testing is not a good idea. Multiple imputation, however, yields unbiased parameter estimates and correctly estimates standard errors. Conclusion: Ignoring missing data in any analysis produces biased parameter estimates. Using single imputation to handle missing values is not recommended, as using a single value to replace missing values does not account for the variation that would have been present if the variables were observed. As a result, the variance will be greatly underestimated. The more modern missing data methods such as the EM algorithm and multiple imputation are preferred over the traditional techniques as they require less stringent assumptions and they also mitigate the downsides of the older methods.
- Full Text:
- Date Issued: 2017
Movement patterns of Cape stumpnose, Rhabdosargus holubi (Sparidae), in the Kowie Estuary, South Africa
- Authors: Grant, Gareth Neil
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/982 , vital:20010
- Description: Rhabdosargus holubi is an ubiquitous estuary-dependent fishery species endemic to southern Africa. Although aspects of its recruitment dynamics from sea to estuary have received considerable research attention, little is known about its movement behaviour within estuarine systems. Fishery surveys have also revealed that R. holubi is a dominant species in catches within several temperate estuaries in South Africa. Therefore, investigating movement behaviour is fundamental to understanding the ecology of this species and providing a means for implementing effective fisheries management strategies. This study made use of passive acoustic telemetry to quantify the movement patterns of juvenile R. holubi in the Kowie Estuary, in the Eastern Cape Province of South Africa. Previous studies have revealed that surgically implanted transmitters may have adverse effects on the physiology and behaviour of tagged fish. Therefore, due to the small size of juvenile R. holubi, an a priori transmitter-effect experiment was undertaken. This experiment revealed that juvenile R. holubi (146-217 mm fork length) were not adversely affected by the surgical implantation of acoustic transmitters (7 mm Ø, 1.6 g out of water) and hence acoustic telemetry was well suited to monitoring the movements of this species. A 4-month telemetry study evaluated the movement patterns of 21 juveniles (140-190 mm fork length) tagged in three equal batches along the length of the estuary. Specific aspects of their movement included space use patterns, habitat connectivity, and the influences of geophysical cycles and environmental variables. Tagged fish exhibited high residency, which varied between each release site area. The mean length of estuary used was greater for the upper batch (15.65 ± 6.49 km) than the middle and lower batches (7.36 ± 3.68 and 2.67 ± 2 km, respectively). In terms of habitat connectivity, once the tagged fish left the estuary, they generally did not return. Tagged R. holubi spent the majority (83%) of their monitoring periods within the estuarine environment, with the sea (16%) and riverine (1%) environments being utilised to a lesser extent. Diel and tidal cycles influenced the movement patterns of juvenile R. holubi. However, the high levels of residency meant that fine-scale movements were difficult to detect due to the acoustic receiver deployment configuration (i.e. receivers moored one kilometer apart). The influence of environmental variables on the movement of individuals, modelled with general linear mixed models (GLMMs), revealed that the effects of river inflow and water temperature were greatest. Increased river inflow caused individuals to use larger portions of the estuary. Increased water temperature, particularly river temperature, caused individuals to shift their distributions downstream (towards the mouth of the estuary). This study highlighted the importance of estuarine nursery habitats to R. holubi, suggesting that a loss or reduction of healthy estuarine habitats may lead to significant declines in the abundance of this species. Furthermore, extreme resident behaviour suggests that no-take area closures (estuarine protected areas) would be an effective management strategy for this important fishery species.
- Full Text:
- Date Issued: 2016
- Authors: Grant, Gareth Neil
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/982 , vital:20010
- Description: Rhabdosargus holubi is an ubiquitous estuary-dependent fishery species endemic to southern Africa. Although aspects of its recruitment dynamics from sea to estuary have received considerable research attention, little is known about its movement behaviour within estuarine systems. Fishery surveys have also revealed that R. holubi is a dominant species in catches within several temperate estuaries in South Africa. Therefore, investigating movement behaviour is fundamental to understanding the ecology of this species and providing a means for implementing effective fisheries management strategies. This study made use of passive acoustic telemetry to quantify the movement patterns of juvenile R. holubi in the Kowie Estuary, in the Eastern Cape Province of South Africa. Previous studies have revealed that surgically implanted transmitters may have adverse effects on the physiology and behaviour of tagged fish. Therefore, due to the small size of juvenile R. holubi, an a priori transmitter-effect experiment was undertaken. This experiment revealed that juvenile R. holubi (146-217 mm fork length) were not adversely affected by the surgical implantation of acoustic transmitters (7 mm Ø, 1.6 g out of water) and hence acoustic telemetry was well suited to monitoring the movements of this species. A 4-month telemetry study evaluated the movement patterns of 21 juveniles (140-190 mm fork length) tagged in three equal batches along the length of the estuary. Specific aspects of their movement included space use patterns, habitat connectivity, and the influences of geophysical cycles and environmental variables. Tagged fish exhibited high residency, which varied between each release site area. The mean length of estuary used was greater for the upper batch (15.65 ± 6.49 km) than the middle and lower batches (7.36 ± 3.68 and 2.67 ± 2 km, respectively). In terms of habitat connectivity, once the tagged fish left the estuary, they generally did not return. Tagged R. holubi spent the majority (83%) of their monitoring periods within the estuarine environment, with the sea (16%) and riverine (1%) environments being utilised to a lesser extent. Diel and tidal cycles influenced the movement patterns of juvenile R. holubi. However, the high levels of residency meant that fine-scale movements were difficult to detect due to the acoustic receiver deployment configuration (i.e. receivers moored one kilometer apart). The influence of environmental variables on the movement of individuals, modelled with general linear mixed models (GLMMs), revealed that the effects of river inflow and water temperature were greatest. Increased river inflow caused individuals to use larger portions of the estuary. Increased water temperature, particularly river temperature, caused individuals to shift their distributions downstream (towards the mouth of the estuary). This study highlighted the importance of estuarine nursery habitats to R. holubi, suggesting that a loss or reduction of healthy estuarine habitats may lead to significant declines in the abundance of this species. Furthermore, extreme resident behaviour suggests that no-take area closures (estuarine protected areas) would be an effective management strategy for this important fishery species.
- Full Text:
- Date Issued: 2016