Coping with change: an investigation into language policy and practice in three Port Elizabeth primary schools
- Authors: Foli, Cordelia Nokuthula
- Date: 2004
- Subjects: Language policy -- South Africa -- Port Elizabeth , Education, Primary -- South Africa -- Port Elizabeth , Multicultural education -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10995 , http://hdl.handle.net/10948/327 , Language policy -- South Africa -- Port Elizabeth , Education, Primary -- South Africa -- Port Elizabeth , Multicultural education -- South Africa -- Port Elizabeth
- Description: This is a qualitative case study of three Primary, schools in Port Elizabeth District.They are an ex -White, ex-Coloured and ex-Indian schools. These schools have become desegregated and are multicultural and multilingual. The medium of instruction in the schools is English. The study aims to show: Adaptations that teachers are making to make the curriculum accessible to children from diverse linguistic and cultural backgrounds; coping strategies that learners have needed to adapt when learning in a language that is not their mother tongue; attitudes of parents, teachers and pupils to the use of English and to the level at which the other home languages are offered as subjects. Another aim of the study is to document strategies and adaptations that teachers and learners have had to make in teaching and learning in multicultural and multilingual environments. Data was gathered through questionnaires, classroom observation, discussions with teachers, interviews with principals, parents and learners. The study concludes that two of the schools that were investigated have attempted to change school language policy. They have done this by introducing isiXhosa as one of the subjects in the curriculum. Contrary to the language policy which encourages maintenance of primary language, these learning contexts encourage the development of English to the detriment of isiXhosa. The issue that still needs to be addressed is the level at which isiXhosa primary language speakers are offered the language at school. This study further concludes that isiXhosa and Afrikaans speaking parents and learners in the English environments, value their primary languages for communicative purposes only in informal situations. English is valued as a language of access and for use as a language of learning and teaching. Finally, it is teachers in the Foundation Phase who seem to have needed to make a lot of adaptations and adjustments to accommodate non- native speakers of English in the classrooms.
- Full Text:
- Date Issued: 2004
- Authors: Foli, Cordelia Nokuthula
- Date: 2004
- Subjects: Language policy -- South Africa -- Port Elizabeth , Education, Primary -- South Africa -- Port Elizabeth , Multicultural education -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10995 , http://hdl.handle.net/10948/327 , Language policy -- South Africa -- Port Elizabeth , Education, Primary -- South Africa -- Port Elizabeth , Multicultural education -- South Africa -- Port Elizabeth
- Description: This is a qualitative case study of three Primary, schools in Port Elizabeth District.They are an ex -White, ex-Coloured and ex-Indian schools. These schools have become desegregated and are multicultural and multilingual. The medium of instruction in the schools is English. The study aims to show: Adaptations that teachers are making to make the curriculum accessible to children from diverse linguistic and cultural backgrounds; coping strategies that learners have needed to adapt when learning in a language that is not their mother tongue; attitudes of parents, teachers and pupils to the use of English and to the level at which the other home languages are offered as subjects. Another aim of the study is to document strategies and adaptations that teachers and learners have had to make in teaching and learning in multicultural and multilingual environments. Data was gathered through questionnaires, classroom observation, discussions with teachers, interviews with principals, parents and learners. The study concludes that two of the schools that were investigated have attempted to change school language policy. They have done this by introducing isiXhosa as one of the subjects in the curriculum. Contrary to the language policy which encourages maintenance of primary language, these learning contexts encourage the development of English to the detriment of isiXhosa. The issue that still needs to be addressed is the level at which isiXhosa primary language speakers are offered the language at school. This study further concludes that isiXhosa and Afrikaans speaking parents and learners in the English environments, value their primary languages for communicative purposes only in informal situations. English is valued as a language of access and for use as a language of learning and teaching. Finally, it is teachers in the Foundation Phase who seem to have needed to make a lot of adaptations and adjustments to accommodate non- native speakers of English in the classrooms.
- Full Text:
- Date Issued: 2004
CREWS : a Component-driven, Run-time Extensible Web Service framework
- Authors: Parry, Dominic Charles
- Date: 2004
- Subjects: Component software -- Development , Computer software -- Reusability , Software reengineering , Web services
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4628 , http://hdl.handle.net/10962/d1006501 , Component software -- Development , Computer software -- Reusability , Software reengineering , Web services
- Description: There has been an increased focus in recent years on the development of re-usable software, in the form of objects and software components. This increase, together with pressures from enterprises conducting transactions on the Web to support all business interactions on all scales, has encouraged research towards the development of easily reconfigurable and highly adaptable Web services. This work investigates the ability of Component-Based Software Development (CBSD) to produce such systems, and proposes a more manageable use of CBSD methodologies. Component-Driven Software Development (CDSD) is introduced to enable better component manageability. Current Web service technologies are also examined to determine their ability to support extensible Web services, and a dynamic Web service architecture is proposed. The work also describes the development of two proof-of-concept systems, DREW Chat and Hamilton Bank. DREW Chat and Hamilton Bank are implementations of Web services that support extension dynamically and at run-time. DREW Chat is implemented on the client side, where the user is given the ability to change the client as required. Hamilton Bank is a server-side implementation, which is run-time customisable by both the user and the party offering the service. In each case, a generic architecture is produced to support dynamic Web services. These architectures are combined to produce CREWS, a Component-driven Runtime Extensible Web Service solution that enables Web services to support the ever changing needs of enterprises. A discussion of similar work is presented, identifying the strengths and weaknesses of our architecture when compared to other solutions.
- Full Text:
- Date Issued: 2004
- Authors: Parry, Dominic Charles
- Date: 2004
- Subjects: Component software -- Development , Computer software -- Reusability , Software reengineering , Web services
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4628 , http://hdl.handle.net/10962/d1006501 , Component software -- Development , Computer software -- Reusability , Software reengineering , Web services
- Description: There has been an increased focus in recent years on the development of re-usable software, in the form of objects and software components. This increase, together with pressures from enterprises conducting transactions on the Web to support all business interactions on all scales, has encouraged research towards the development of easily reconfigurable and highly adaptable Web services. This work investigates the ability of Component-Based Software Development (CBSD) to produce such systems, and proposes a more manageable use of CBSD methodologies. Component-Driven Software Development (CDSD) is introduced to enable better component manageability. Current Web service technologies are also examined to determine their ability to support extensible Web services, and a dynamic Web service architecture is proposed. The work also describes the development of two proof-of-concept systems, DREW Chat and Hamilton Bank. DREW Chat and Hamilton Bank are implementations of Web services that support extension dynamically and at run-time. DREW Chat is implemented on the client side, where the user is given the ability to change the client as required. Hamilton Bank is a server-side implementation, which is run-time customisable by both the user and the party offering the service. In each case, a generic architecture is produced to support dynamic Web services. These architectures are combined to produce CREWS, a Component-driven Runtime Extensible Web Service solution that enables Web services to support the ever changing needs of enterprises. A discussion of similar work is presented, identifying the strengths and weaknesses of our architecture when compared to other solutions.
- Full Text:
- Date Issued: 2004
Design and implementation of robotic control for industrial applications
- Authors: Will, Desmond Jeffrey
- Date: 2004
- Subjects: Robotics
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10819 , http://hdl.handle.net/10948/213 , Robotics
- Description: Background: With the pressing need for increased productivity and delivery of end products of uniform quality, industry is turning more and more to computer-based automation. At the present time, most of industrial automated manufacturing is carried out by specialpurpose machines, designed to perform specific functions in a manufacturing process. The inflexibility and generally high cost of these machines often referred to as hard automation systems, have led to a broad-based interest in the use of robots capable of performing a variety of manufacturing functions in a more flexible working environment and at lower production costs. A robot is a reprogrammable general-purpose manipulator with external sensors that can perform various assembly tasks. A robot may possess intelligence, which is normally due to computer algorithms associated with its controls and sensing systems. Industrial robots are general-purpose, computer-controlled manipulators consisting of several rigid links connected in series by revolute or prismatic joints. Most of today’s industrial robots, though controlled by mini and microcomputers are basically simple positional machines. They execute a given task by playing back a prerecorded or preprogrammed sequence of motion that has been previously guided or taught by the hand-held control teach box. Moreover, these robots are equipped with little or no external sensors for obtaining the information vital to its working environment. As a result robots are used mainly for relatively simple, repetitive tasks. More research effort has been directed in sensory feedback systems, which has resulted in improving the overall performance of the manipulator system. An example of a sensory feedback system would be: a vision Charge-Coupled Device (CCD) system. This can be utilized to manipulate the robot position dependant on the surrounding robot environment (various object profile sizes). This vision system can only be used within the robot movement envelope
- Full Text:
- Date Issued: 2004
- Authors: Will, Desmond Jeffrey
- Date: 2004
- Subjects: Robotics
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10819 , http://hdl.handle.net/10948/213 , Robotics
- Description: Background: With the pressing need for increased productivity and delivery of end products of uniform quality, industry is turning more and more to computer-based automation. At the present time, most of industrial automated manufacturing is carried out by specialpurpose machines, designed to perform specific functions in a manufacturing process. The inflexibility and generally high cost of these machines often referred to as hard automation systems, have led to a broad-based interest in the use of robots capable of performing a variety of manufacturing functions in a more flexible working environment and at lower production costs. A robot is a reprogrammable general-purpose manipulator with external sensors that can perform various assembly tasks. A robot may possess intelligence, which is normally due to computer algorithms associated with its controls and sensing systems. Industrial robots are general-purpose, computer-controlled manipulators consisting of several rigid links connected in series by revolute or prismatic joints. Most of today’s industrial robots, though controlled by mini and microcomputers are basically simple positional machines. They execute a given task by playing back a prerecorded or preprogrammed sequence of motion that has been previously guided or taught by the hand-held control teach box. Moreover, these robots are equipped with little or no external sensors for obtaining the information vital to its working environment. As a result robots are used mainly for relatively simple, repetitive tasks. More research effort has been directed in sensory feedback systems, which has resulted in improving the overall performance of the manipulator system. An example of a sensory feedback system would be: a vision Charge-Coupled Device (CCD) system. This can be utilized to manipulate the robot position dependant on the surrounding robot environment (various object profile sizes). This vision system can only be used within the robot movement envelope
- Full Text:
- Date Issued: 2004
Design of a performance evaluation tool for multimedia databases with special reference to Oracle
- Authors: Stakemire, Tonia
- Date: 2004
- Subjects: Oracle (Computer file) , Application software -- Evaluation , Database management -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4705 , http://hdl.handle.net/10962/d1015975
- Description: Increased production and use of multimedia data has led to the development of a more advanced Database Management System (DBMS), like an Object Relational Database Management System (ORDBMS). These advanced databases are necessitated by the complexity in structure and the functionality required by multimedia data. Unfortunately, no suitable benchmarks exist with which to test the performance of databases when handling multimedia data. This thesis describes the design of a benchmark to measure the performance of basic functionality found in multimedia databases. The benchmark, called MORD (Multimedia Object Relational Databases), targets Oracle, a well known commercial Object Relational Database Management System (ORDBMS) that can handle multimedia data. Although MORD targets Oracle, it can easily be applied to other Multimedia Database Management System (MMDBMS) as a result of a design that stressed its portability, and simplicity. MORD consists of a database schema, test data, and code to simulate representative queries on multimedia databases. A number of experiments are described that validate MORD and ensure its correct design and that its objectives are met. A by-product of these experiments is an initial understanding of the performance of multimedia databases. The experiments show that with multimedia data the buffer cache should be at least large enough to hold the largest dataset, a bigger block size improves the performance, and turning off logging and caching for bulk loading improves the performance. MORD can be used to compare different ORDBMS or to assist in the configuration of a specific database.
- Full Text:
- Date Issued: 2004
- Authors: Stakemire, Tonia
- Date: 2004
- Subjects: Oracle (Computer file) , Application software -- Evaluation , Database management -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4705 , http://hdl.handle.net/10962/d1015975
- Description: Increased production and use of multimedia data has led to the development of a more advanced Database Management System (DBMS), like an Object Relational Database Management System (ORDBMS). These advanced databases are necessitated by the complexity in structure and the functionality required by multimedia data. Unfortunately, no suitable benchmarks exist with which to test the performance of databases when handling multimedia data. This thesis describes the design of a benchmark to measure the performance of basic functionality found in multimedia databases. The benchmark, called MORD (Multimedia Object Relational Databases), targets Oracle, a well known commercial Object Relational Database Management System (ORDBMS) that can handle multimedia data. Although MORD targets Oracle, it can easily be applied to other Multimedia Database Management System (MMDBMS) as a result of a design that stressed its portability, and simplicity. MORD consists of a database schema, test data, and code to simulate representative queries on multimedia databases. A number of experiments are described that validate MORD and ensure its correct design and that its objectives are met. A by-product of these experiments is an initial understanding of the performance of multimedia databases. The experiments show that with multimedia data the buffer cache should be at least large enough to hold the largest dataset, a bigger block size improves the performance, and turning off logging and caching for bulk loading improves the performance. MORD can be used to compare different ORDBMS or to assist in the configuration of a specific database.
- Full Text:
- Date Issued: 2004
Designing an evaluation instrument for South African intermediate phase school textbooks
- Authors: Vosloo, Barend Jacobus
- Date: 2004
- Subjects: Textbooks -- South Africa -- Evaluation , Curriculum change -- South Africa -- Evaluation
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:11014 , http://hdl.handle.net/10948/324 , Textbooks -- South Africa -- Evaluation , Curriculum change -- South Africa -- Evaluation
- Description: No coherent theory about the practice of South African intermediate phase school textbook evaluation has been forthcoming since the advent of a new South African school curriculum in 1998. This deficiency has had an adverse effect on the quality of intermediate phase school textbooks, as well as on the capacity to assess their value. This research project, therefore, had two aims. The first was to articulate a theory about the practice of textbook evaluation. The second was to develop a procedure for evaluating South African intermediate phase school textbooks in terms of the theory. The research method was underpinned by the interpretive research paradigm in terms of which relevant data were analysed and interpreted. The data emanated from a literature review, an analysis of the national Department of Education’s Revised National Curriculum Statement and its draft policy for the evaluation of learning support material, and two surveys. The first survey comprised a sample of intermediate phase teachers and the second a sample of intermediate phase textbook authors. Sufficient evidence was found to conclude that the capabilities of the authoring team, the authors’ rationale and their observance of the process of learning and instruction, the accessibility of the textbook, the availability of teacher support, meeting the requirements of the Revised National Curriculum Statement, and certain key notions about textbook evaluation play a role in articulating a theory about textbook evaluation in order to guide the process of determining the effectiveness of South African intermediate phase school textbooks. Based on the above-mentioned theory, this study proposes a procedure to assist teachers and textbook evaluators to assess the worth of South African intermediate phase school textbooks in a brief, systematic, thorough, rigorous, and practical manner.
- Full Text:
- Date Issued: 2004
- Authors: Vosloo, Barend Jacobus
- Date: 2004
- Subjects: Textbooks -- South Africa -- Evaluation , Curriculum change -- South Africa -- Evaluation
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:11014 , http://hdl.handle.net/10948/324 , Textbooks -- South Africa -- Evaluation , Curriculum change -- South Africa -- Evaluation
- Description: No coherent theory about the practice of South African intermediate phase school textbook evaluation has been forthcoming since the advent of a new South African school curriculum in 1998. This deficiency has had an adverse effect on the quality of intermediate phase school textbooks, as well as on the capacity to assess their value. This research project, therefore, had two aims. The first was to articulate a theory about the practice of textbook evaluation. The second was to develop a procedure for evaluating South African intermediate phase school textbooks in terms of the theory. The research method was underpinned by the interpretive research paradigm in terms of which relevant data were analysed and interpreted. The data emanated from a literature review, an analysis of the national Department of Education’s Revised National Curriculum Statement and its draft policy for the evaluation of learning support material, and two surveys. The first survey comprised a sample of intermediate phase teachers and the second a sample of intermediate phase textbook authors. Sufficient evidence was found to conclude that the capabilities of the authoring team, the authors’ rationale and their observance of the process of learning and instruction, the accessibility of the textbook, the availability of teacher support, meeting the requirements of the Revised National Curriculum Statement, and certain key notions about textbook evaluation play a role in articulating a theory about textbook evaluation in order to guide the process of determining the effectiveness of South African intermediate phase school textbooks. Based on the above-mentioned theory, this study proposes a procedure to assist teachers and textbook evaluators to assess the worth of South African intermediate phase school textbooks in a brief, systematic, thorough, rigorous, and practical manner.
- Full Text:
- Date Issued: 2004
Determining the elements of the operations management transformation model for the monitoring and breaching of the Great Brak River Mouth system
- Authors: Kriel, J F
- Date: 2004
- Subjects: Rivers -- Management -- South Africa , Stream conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10935 , http://hdl.handle.net/10948/214 , Rivers -- Management -- South Africa , Stream conservation -- South Africa
- Description: The prime challenge to those responsible for the management of South Africa’s estuaries is to maintain their viability in the face of ever increasing pressures. It is important that we learn to appreciate the value of estuaries and that we act wisely to manage them for sustainable use. Any operation must have the adequate resources to perform the duties and the correct processes must be followed. The purpose of this research is to determine whether the current inputs and processes needed for the monitoring and breaching of the Great Brak River Mouth system are sufficient to adhere to the output objectives of a healthy estuary together with safeguarding of properties. The research methodology for this study comprised the following steps: Firstly, a literature study was performed to identify the key elements of the operation management transformation model. Operations management deals with the output of any business, in other words the conversion of inputs to create certain outputs and they do this by a process of transformation. Secondly, extensive literature study was performed in order to access material regarding effective estuary and river mouth management. Thirdly, the current situation at Great Brak was assessed to determine whether the current inputs and processes are in place and if additional or altered inputs and processes are needed.
- Full Text:
- Date Issued: 2004
- Authors: Kriel, J F
- Date: 2004
- Subjects: Rivers -- Management -- South Africa , Stream conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10935 , http://hdl.handle.net/10948/214 , Rivers -- Management -- South Africa , Stream conservation -- South Africa
- Description: The prime challenge to those responsible for the management of South Africa’s estuaries is to maintain their viability in the face of ever increasing pressures. It is important that we learn to appreciate the value of estuaries and that we act wisely to manage them for sustainable use. Any operation must have the adequate resources to perform the duties and the correct processes must be followed. The purpose of this research is to determine whether the current inputs and processes needed for the monitoring and breaching of the Great Brak River Mouth system are sufficient to adhere to the output objectives of a healthy estuary together with safeguarding of properties. The research methodology for this study comprised the following steps: Firstly, a literature study was performed to identify the key elements of the operation management transformation model. Operations management deals with the output of any business, in other words the conversion of inputs to create certain outputs and they do this by a process of transformation. Secondly, extensive literature study was performed in order to access material regarding effective estuary and river mouth management. Thirdly, the current situation at Great Brak was assessed to determine whether the current inputs and processes are in place and if additional or altered inputs and processes are needed.
- Full Text:
- Date Issued: 2004
Developing risk management strategies for stock market investment portfolio management
- Authors: Grant, Peter
- Date: 2004
- Subjects: Stocks , Risk management , Portfolio management , Investments , Securities
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10936 , http://hdl.handle.net/10948/215 , Stocks , Risk management , Portfolio management , Investments , Securities
- Description: This study was conducted to establish whether risk management strategies could be developed to enable stock market investment portfolio managers to reduce the risk involved in stock market trading. The awareness of stock market risk elevates the requirement for risk management strategies as discussed in Chapter 1. The research scope is identified, and an overview of the study gives further guidance as to what lies ahead. The theory behind macroeconomic forces and how they influence share prices is discussed in Chapter 2. It is established that market sectors and companies within those sectors react differently to macroeconomic forces. Technical analysis is discussed as a mechanism to identify buying and selling signals. In Chapter 3, risk management strategies are developed from the literature. The hypothesis of the study as described in Chapter 4 is that these risk management strategies are able to reduce the risk associated with trading in the stock market. The market simulation in Chapter 5 offers the opportunity to observe the risk management strategies at work in a simulated stock market investment portfolio. In Chapter 6, the outcome of the market simulation is compared to the criteria set in Chapter 4, and the conclusion that the risk management strategies were able to reduce the risk involved in stock market trading is drawn.
- Full Text:
- Date Issued: 2004
- Authors: Grant, Peter
- Date: 2004
- Subjects: Stocks , Risk management , Portfolio management , Investments , Securities
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10936 , http://hdl.handle.net/10948/215 , Stocks , Risk management , Portfolio management , Investments , Securities
- Description: This study was conducted to establish whether risk management strategies could be developed to enable stock market investment portfolio managers to reduce the risk involved in stock market trading. The awareness of stock market risk elevates the requirement for risk management strategies as discussed in Chapter 1. The research scope is identified, and an overview of the study gives further guidance as to what lies ahead. The theory behind macroeconomic forces and how they influence share prices is discussed in Chapter 2. It is established that market sectors and companies within those sectors react differently to macroeconomic forces. Technical analysis is discussed as a mechanism to identify buying and selling signals. In Chapter 3, risk management strategies are developed from the literature. The hypothesis of the study as described in Chapter 4 is that these risk management strategies are able to reduce the risk associated with trading in the stock market. The market simulation in Chapter 5 offers the opportunity to observe the risk management strategies at work in a simulated stock market investment portfolio. In Chapter 6, the outcome of the market simulation is compared to the criteria set in Chapter 4, and the conclusion that the risk management strategies were able to reduce the risk involved in stock market trading is drawn.
- Full Text:
- Date Issued: 2004
Development of a hydantoin-hydrolysing biocatalyst for the production of optically pure amino acids using Agrobacterium tumefaciens strain RU-ORPN1
- Authors: Foster, Ingrid Margaret
- Date: 2004
- Subjects: Agrobacterium tumefaciens Amino acids Hydantoin Hydrolysis Enzymes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3943 , http://hdl.handle.net/10962/d1004002
- Description: A calcium alginate bead-immobilised biocatalyst was developed utilising the D-hydantoinase and D-N-carbamoylase from a novel, mutant Agrobacterium tumefaciens strain RU-ORPN1. The growth conditions for the inducer-independent strain were optimised for production of hydantoinase and N-carbamoylase activities. Methods for the preparation of crude enzyme extracts were evaluated in terms of hydantoinase and N-carbamoylase activities produced. After comparison of the enzyme activities and stabilities in various extracts from fresh and frozen cells, sonication of frozen cells for 5 minutes was found to be the best method for the production of the enzyme extract. The optimal pH and temperature for the hydantoinase activity were pH 10 and 30°C, respectively, while pH 9 and 40°C were optimal for Ncarbamoylase activity. The hydantoinase activity was enhanced by the addition of Mg^(2+) ions to the enzyme extract and the N-carbamoylase was enhanced by the addition of Mg^(2+), Mn^(2+) or Zn^(2+) ions to the enzyme extract. The enzyme activities increased in the presence of ATP suggesting that the enzymes may be ATP-dependent. The addition of DTT and PMSF to the enzyme extract enhanced the hydantoinase activity but had no effect on the N-carbamoylase activity. The N-carbamoylase was unstable at 40°C and was almost completely inactivated after 24 hours incubation at this temperature. The hydantoinase and N-carbamoylase appeared to be insoluble. Various techniques were investigated for the solubilisation of the enzymes including various cell lysis methods, cell lysis at extremes of pH and ionic strength, addition of a reducing agent and protease inhibitors, and treatment with hydrolysing enzymes and detergents. Treatment with Triton X-100 was most effective for the solubilisation of the enzymes indicating that the enzymes were membrane-bound. Hydropathy and transmembrane prediction plots of the predicted amino acid sequences for two identified N-carbamoylase genes from A. tumefaciens RU-ORPN1 revealed possible transmembrane regions in the amino acid sequences, and thus supported the hypothesis that the enzymes were membrane-bound. Various methods were evaluated for the immobilisation of the enzymes in whole cells and enzyme extracts. Immobilisation of the enzyme extract in calcium alginate beads was found to be the best method in terms of enzyme activity retention and stability. The hydantoinase retained 55% activity while the N-carbamoylase exhibited a remarkable sevenfold increase in activity after immobilisation by this method. Furthermore, the hydantoinase activity increased after storage at 4°C for 21 days, while the N-carbamoylase retained 30% activity after this storage period. The calcium alginate bead-immobilised enzymes were further biochemically characterised and then applied in a bioreactor system for the production of D-hydroxyphenylglycine (D-HPG) from D,L-5-hydroxyphenylhydantoin (D,L-5-HPH). The pH and temperature optima for the immobilised hydantoinase were pH 7 and 50°C, respectively, while pH 8 and 40°C were optimal for the immobilised N-carbamoylase enzyme. The immobilised enzymes showed improved thermostability at 40°C in comparison to the free enzymes and retained high levels of activity after five repeated batch reactions. Low levels of conversion were obtained in a packed-bed bioreactor containing the A. tumefaciens RU-ORPN1 biocatalyst due to the low hydantoinase activity present in the strain, relative to N-carbamoylase. A novel, packed-bed bioreactor system was therefore developed for the production of D-HPG from D,L-5-HPH using the A. tumefaciens biocatalyst in combination with a Pseudomonas sp. biocatalyst having high hydantoinase activity. A conversion yield of 22 to 30% was achieved for the production of D-HPG from D,L-5-HPH over 5 days operation demonstrating that the hydantoin-hydrolysing enzymes from A. tumefaciens RU-ORPN1 could be stabilised by immobilisation and, in combination with a biocatalyst with high hydantoinase activity, could be applied to the fully enzymatic conversion of D,L-5-HPH to D-HPG.
- Full Text:
- Date Issued: 2004
- Authors: Foster, Ingrid Margaret
- Date: 2004
- Subjects: Agrobacterium tumefaciens Amino acids Hydantoin Hydrolysis Enzymes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3943 , http://hdl.handle.net/10962/d1004002
- Description: A calcium alginate bead-immobilised biocatalyst was developed utilising the D-hydantoinase and D-N-carbamoylase from a novel, mutant Agrobacterium tumefaciens strain RU-ORPN1. The growth conditions for the inducer-independent strain were optimised for production of hydantoinase and N-carbamoylase activities. Methods for the preparation of crude enzyme extracts were evaluated in terms of hydantoinase and N-carbamoylase activities produced. After comparison of the enzyme activities and stabilities in various extracts from fresh and frozen cells, sonication of frozen cells for 5 minutes was found to be the best method for the production of the enzyme extract. The optimal pH and temperature for the hydantoinase activity were pH 10 and 30°C, respectively, while pH 9 and 40°C were optimal for Ncarbamoylase activity. The hydantoinase activity was enhanced by the addition of Mg^(2+) ions to the enzyme extract and the N-carbamoylase was enhanced by the addition of Mg^(2+), Mn^(2+) or Zn^(2+) ions to the enzyme extract. The enzyme activities increased in the presence of ATP suggesting that the enzymes may be ATP-dependent. The addition of DTT and PMSF to the enzyme extract enhanced the hydantoinase activity but had no effect on the N-carbamoylase activity. The N-carbamoylase was unstable at 40°C and was almost completely inactivated after 24 hours incubation at this temperature. The hydantoinase and N-carbamoylase appeared to be insoluble. Various techniques were investigated for the solubilisation of the enzymes including various cell lysis methods, cell lysis at extremes of pH and ionic strength, addition of a reducing agent and protease inhibitors, and treatment with hydrolysing enzymes and detergents. Treatment with Triton X-100 was most effective for the solubilisation of the enzymes indicating that the enzymes were membrane-bound. Hydropathy and transmembrane prediction plots of the predicted amino acid sequences for two identified N-carbamoylase genes from A. tumefaciens RU-ORPN1 revealed possible transmembrane regions in the amino acid sequences, and thus supported the hypothesis that the enzymes were membrane-bound. Various methods were evaluated for the immobilisation of the enzymes in whole cells and enzyme extracts. Immobilisation of the enzyme extract in calcium alginate beads was found to be the best method in terms of enzyme activity retention and stability. The hydantoinase retained 55% activity while the N-carbamoylase exhibited a remarkable sevenfold increase in activity after immobilisation by this method. Furthermore, the hydantoinase activity increased after storage at 4°C for 21 days, while the N-carbamoylase retained 30% activity after this storage period. The calcium alginate bead-immobilised enzymes were further biochemically characterised and then applied in a bioreactor system for the production of D-hydroxyphenylglycine (D-HPG) from D,L-5-hydroxyphenylhydantoin (D,L-5-HPH). The pH and temperature optima for the immobilised hydantoinase were pH 7 and 50°C, respectively, while pH 8 and 40°C were optimal for the immobilised N-carbamoylase enzyme. The immobilised enzymes showed improved thermostability at 40°C in comparison to the free enzymes and retained high levels of activity after five repeated batch reactions. Low levels of conversion were obtained in a packed-bed bioreactor containing the A. tumefaciens RU-ORPN1 biocatalyst due to the low hydantoinase activity present in the strain, relative to N-carbamoylase. A novel, packed-bed bioreactor system was therefore developed for the production of D-HPG from D,L-5-HPH using the A. tumefaciens biocatalyst in combination with a Pseudomonas sp. biocatalyst having high hydantoinase activity. A conversion yield of 22 to 30% was achieved for the production of D-HPG from D,L-5-HPH over 5 days operation demonstrating that the hydantoin-hydrolysing enzymes from A. tumefaciens RU-ORPN1 could be stabilised by immobilisation and, in combination with a biocatalyst with high hydantoinase activity, could be applied to the fully enzymatic conversion of D,L-5-HPH to D-HPG.
- Full Text:
- Date Issued: 2004
Die bestuursrol van die skoolhoof in die implementering van 'n nuwe kurrikulum
- Authors: Mey, Hermanus Pieter
- Date: 2004
- Subjects: School principals -- South Africa , Educational leadership -- South Africa , Curriculum change -- South Africa
- Language: Afrikaans
- Type: Thesis , Masters , MPhil
- Identifier: vital:11010 , http://hdl.handle.net/10948/367 , School principals -- South Africa , Educational leadership -- South Africa , Curriculum change -- South Africa
- Description: The implementation of a new curriculum has become a very relevant issue in South Africa with the implementation of Curriculum 2005 (C 2005) since 1998. The school principal plays a very important role at school level in the implementation of change in general and a new curriculum in particular. The aim of this study was to have a closer look at this role. It is a qualitative study executed in six schools in the Port Elizabeth area. It investigates the problems school principals experienced with the implementation of C 2005 with the objective of identifying guidelines for the role of the principal in the implementation of a new curriculum The most important findings include the importance of equipping the principal to provide guidance with the implementation of a new curriculum. This equipping refers to the principal’s knowledge of the new curriculum, the ability to employ various leadership styles, as well as the maintenance of a certain balance between supporting and putting pressure on the staff. Other findings refer to the importance of well-trained and prepared facilitators of workshops, as well as the role the Department of Education needs to play in the training and preparation of these facilitators. The ongoing support of schools in the implementation process also needs to be emphasized. The principal should play a key role with respect to this last role of the Department. The study also emphasizes the principal’s responsibility to bind the educators together in building a shared vision, so that their focus will remain on the curriculum implementation.
- Full Text:
- Date Issued: 2004
- Authors: Mey, Hermanus Pieter
- Date: 2004
- Subjects: School principals -- South Africa , Educational leadership -- South Africa , Curriculum change -- South Africa
- Language: Afrikaans
- Type: Thesis , Masters , MPhil
- Identifier: vital:11010 , http://hdl.handle.net/10948/367 , School principals -- South Africa , Educational leadership -- South Africa , Curriculum change -- South Africa
- Description: The implementation of a new curriculum has become a very relevant issue in South Africa with the implementation of Curriculum 2005 (C 2005) since 1998. The school principal plays a very important role at school level in the implementation of change in general and a new curriculum in particular. The aim of this study was to have a closer look at this role. It is a qualitative study executed in six schools in the Port Elizabeth area. It investigates the problems school principals experienced with the implementation of C 2005 with the objective of identifying guidelines for the role of the principal in the implementation of a new curriculum The most important findings include the importance of equipping the principal to provide guidance with the implementation of a new curriculum. This equipping refers to the principal’s knowledge of the new curriculum, the ability to employ various leadership styles, as well as the maintenance of a certain balance between supporting and putting pressure on the staff. Other findings refer to the importance of well-trained and prepared facilitators of workshops, as well as the role the Department of Education needs to play in the training and preparation of these facilitators. The ongoing support of schools in the implementation process also needs to be emphasized. The principal should play a key role with respect to this last role of the Department. The study also emphasizes the principal’s responsibility to bind the educators together in building a shared vision, so that their focus will remain on the curriculum implementation.
- Full Text:
- Date Issued: 2004
Die toepassing van die proses van geïntegreerde ontwikkelingsbeplanning deur kategorie B plaaslike owerhede
- Authors: Els, Christoffel Gerhardus
- Date: 2004
- Subjects: Local government -- South Africa , Public administration -- South Africa
- Language: Afrikaans
- Type: Thesis , Masters , MTech (Public Management)
- Identifier: vital:10768 , http://hdl.handle.net/10948/266 , Local government -- South Africa , Public administration -- South Africa
- Description: Samevattende oorsig: In hierdie skripsie, is 'n studie onderneem ten opsigte van die Geïntegreerde Ontwikkelingsbeplanningsproses, wat die proses van beplanning en die toepassing van hierdie beplanningsresultate ten opsigte van twee klein B-munisipaliteite in die Wes-Kaap Provinsie insluit. Die skripsie bestaan uit sewe hoofstukke en is gebaseer op die veronderstelling dat die beplanningsproses van so 'n tegniese aard is dat kleiner owerhede nie in staat is om die proses na behore te kan bestuur nie. Dit gaan verder van die onderstelling uit dat die implementeeringskapasiteit by kleiner owerhede ontbreek om dievoorsiene uitkomste na behore te realiseer. Die primêre doelwitte van die navorsing sluit die volgende in: 'n basiese oorsig van openbare bestuur, die rolle en funksies van funksionarisse binne hierdie omgewing en die veranderende aard van openbare bestuur. Die proses van geïntegreerde ontwikkelingsbeplanning binne plaaslike regering word bestudeer met 'n volledige proses toeligting. Die noodsaaklikheid van beplanning en prestasiebestuur word bevestig tesame met die uitdagings en probleme wat die nuwe benadering bring aan klein plaaslike owerhede. 'n Finale waardebepaling rond die studie af. Die studie bestaan uit bronnavorsing om die veranderende aard van openbare bestuur toe te lig tesame met die werklike aard van die beplanningsproses soos vereis binne relevante wetgewing. Die impak van hierdie vereistes op klein plaaslike owerhede in die Wes-Kaap word ontleed aan die hand van twee geïntegreerde ontwikkelingsplanne soos deur die skrywer hiervan gefasiliteer by dié owerhede. Die gevolgtrekkings gemaak uit hierdie studie word dan ook aangedui met 'n aanbeveling oor die mees sinvolle inkrementele benadering ten opsigte van ontwikkeling as proses en die deelname van rolspelers daarbinne.
- Full Text:
- Date Issued: 2004
- Authors: Els, Christoffel Gerhardus
- Date: 2004
- Subjects: Local government -- South Africa , Public administration -- South Africa
- Language: Afrikaans
- Type: Thesis , Masters , MTech (Public Management)
- Identifier: vital:10768 , http://hdl.handle.net/10948/266 , Local government -- South Africa , Public administration -- South Africa
- Description: Samevattende oorsig: In hierdie skripsie, is 'n studie onderneem ten opsigte van die Geïntegreerde Ontwikkelingsbeplanningsproses, wat die proses van beplanning en die toepassing van hierdie beplanningsresultate ten opsigte van twee klein B-munisipaliteite in die Wes-Kaap Provinsie insluit. Die skripsie bestaan uit sewe hoofstukke en is gebaseer op die veronderstelling dat die beplanningsproses van so 'n tegniese aard is dat kleiner owerhede nie in staat is om die proses na behore te kan bestuur nie. Dit gaan verder van die onderstelling uit dat die implementeeringskapasiteit by kleiner owerhede ontbreek om dievoorsiene uitkomste na behore te realiseer. Die primêre doelwitte van die navorsing sluit die volgende in: 'n basiese oorsig van openbare bestuur, die rolle en funksies van funksionarisse binne hierdie omgewing en die veranderende aard van openbare bestuur. Die proses van geïntegreerde ontwikkelingsbeplanning binne plaaslike regering word bestudeer met 'n volledige proses toeligting. Die noodsaaklikheid van beplanning en prestasiebestuur word bevestig tesame met die uitdagings en probleme wat die nuwe benadering bring aan klein plaaslike owerhede. 'n Finale waardebepaling rond die studie af. Die studie bestaan uit bronnavorsing om die veranderende aard van openbare bestuur toe te lig tesame met die werklike aard van die beplanningsproses soos vereis binne relevante wetgewing. Die impak van hierdie vereistes op klein plaaslike owerhede in die Wes-Kaap word ontleed aan die hand van twee geïntegreerde ontwikkelingsplanne soos deur die skrywer hiervan gefasiliteer by dié owerhede. Die gevolgtrekkings gemaak uit hierdie studie word dan ook aangedui met 'n aanbeveling oor die mees sinvolle inkrementele benadering ten opsigte van ontwikkeling as proses en die deelname van rolspelers daarbinne.
- Full Text:
- Date Issued: 2004
Dismissal for medical incapacity
- Authors: Boy, Anthony Albert
- Date: 2004
- Subjects: Employees -- Dismissal of -- Law and legislation -- South Africa , Capacity and disability -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11047 , http://hdl.handle.net/10948/316 , Employees -- Dismissal of -- Law and legislation -- South Africa , Capacity and disability -- South Africa , Labor laws and legislation -- South Africa
- Description: Labour law in South Africa has evolved over the past century at an ever increasing pace. The establishment of a democratic government in 1995 has been the trigger for a large number of labour law statutes being promulgated, particularly with reference to the laws governing the employment relationship and dismissal. From very humble and employer biased dispute resolution application under the common law of contract, labour law in this country has evolved through the various acts culminating in a labour law system which is highly regulated and codified. Dismissal for medical incapacity in this treatise is reviewed with regard to the applicable statutes and the various codes of good practice as the law has evolved and developed from the period covered by the common law through that covered by the 1995 LRA up to and including the current period. Particular attention is paid to both substantive and procedural requirements as well as the remedies applicable under the different legal regimes and the pertinent tribunals and courts. Regard is also given to the duration and causes of incapacity and the effect this may have on the applicable remedy applied by these tribunals. It will become apparant that the medically incapacitated employee occupied a relatively weak and vulnerable position under the common law as opposed to the current position under the 1995 LRA. The influence of the remedies applied by the tribunals under the 1956 LRA are clearly evident in the current regulations and codes under the 1995 LRA which contain specific statutory provisions for employees not to be unfairly dismissed. Distinctions are drawn between permissible and impermissible dismissals, with medical incapacity falling under the former. v Furthermore, a distinction is drawn statutorily between permanent and temporary illhealth/ injury incapacity with detailed guidelines for substantive and procedural fairness requirements to be met by employers. The powers of the specialist tribunals (CCMA, Bargaining Councils and Labour Courts) are regulated by statutory provisions and deal with appropriate remedies (reinstatement and/or compensation) a wardable in appropriate circumstances. Certain specific areas nonetheless still remain problematic for these tribunals and hence questions that require clear direction from the drafters of our law are: 1. How to distinguish misconduct in alcohol and drug abuse cases? 2. What degree of intermittent absenteeism is required before dismissal would be warranted? In certain other areas the tribunals have been fairly consistent and prescriptive in their approach and remedies awarded. Included here would be permanent incapacity, HIV cases and misconduct. It will emerge, however, that under the 1995 LRA the position of employees and the protections afforded them have been greatly increased.
- Full Text:
- Date Issued: 2004
- Authors: Boy, Anthony Albert
- Date: 2004
- Subjects: Employees -- Dismissal of -- Law and legislation -- South Africa , Capacity and disability -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:11047 , http://hdl.handle.net/10948/316 , Employees -- Dismissal of -- Law and legislation -- South Africa , Capacity and disability -- South Africa , Labor laws and legislation -- South Africa
- Description: Labour law in South Africa has evolved over the past century at an ever increasing pace. The establishment of a democratic government in 1995 has been the trigger for a large number of labour law statutes being promulgated, particularly with reference to the laws governing the employment relationship and dismissal. From very humble and employer biased dispute resolution application under the common law of contract, labour law in this country has evolved through the various acts culminating in a labour law system which is highly regulated and codified. Dismissal for medical incapacity in this treatise is reviewed with regard to the applicable statutes and the various codes of good practice as the law has evolved and developed from the period covered by the common law through that covered by the 1995 LRA up to and including the current period. Particular attention is paid to both substantive and procedural requirements as well as the remedies applicable under the different legal regimes and the pertinent tribunals and courts. Regard is also given to the duration and causes of incapacity and the effect this may have on the applicable remedy applied by these tribunals. It will become apparant that the medically incapacitated employee occupied a relatively weak and vulnerable position under the common law as opposed to the current position under the 1995 LRA. The influence of the remedies applied by the tribunals under the 1956 LRA are clearly evident in the current regulations and codes under the 1995 LRA which contain specific statutory provisions for employees not to be unfairly dismissed. Distinctions are drawn between permissible and impermissible dismissals, with medical incapacity falling under the former. v Furthermore, a distinction is drawn statutorily between permanent and temporary illhealth/ injury incapacity with detailed guidelines for substantive and procedural fairness requirements to be met by employers. The powers of the specialist tribunals (CCMA, Bargaining Councils and Labour Courts) are regulated by statutory provisions and deal with appropriate remedies (reinstatement and/or compensation) a wardable in appropriate circumstances. Certain specific areas nonetheless still remain problematic for these tribunals and hence questions that require clear direction from the drafters of our law are: 1. How to distinguish misconduct in alcohol and drug abuse cases? 2. What degree of intermittent absenteeism is required before dismissal would be warranted? In certain other areas the tribunals have been fairly consistent and prescriptive in their approach and remedies awarded. Included here would be permanent incapacity, HIV cases and misconduct. It will emerge, however, that under the 1995 LRA the position of employees and the protections afforded them have been greatly increased.
- Full Text:
- Date Issued: 2004
Dismissal for medical incapacity
- Authors: Boy, Anthony Albert
- Date: 2004
- Subjects: Employees -- Dismissal of -- Law and legislation -- South Africa , Capacity and disability -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10242 , http://hdl.handle.net/10948/d1016262
- Description: Labour law in South Africa has evolved over the past century at an ever increasing pace. The establishment of a democratic government in 1995 has been the trigger for a large number of labour law statutes being promulgated, particularly with reference to the laws governing the employment relationship and dismissal. From very humble and employer biased dispute resolution application under the common law of contract, labour law in this country has evolved through the various acts culminating in a labour law system which is highly regulated and codified. Dismissal for medical incapacity in this treatise is reviewed with regard to the applicable statutes and the various codes of good practice as the law has evolved and developed from the period covered by the common law through that covered by the 1995 LRA up to and including the current period. Particular attention is paid to both substantive and procedural requirements as well as the remedies applicable under the different legal regimes and the pertinent tribunals and courts. Regard is also given to the duration and causes of incapacity and the effect this may have on the applicable remedy applied by these tribunals. It will become apparant that the medically incapacitated employee occupied a relatively weak and vulnerable position under the common law as opposed to the current position under the 1995 LRA. The influence of the remedies applied by the tribunals under the 1956 LRA are clearly evident in the current regulations and codes under the 1995 LRA which contain specific statutory provisions for employees not to be unfairly dismissed. Distinctions are drawn between permissible and impermissible dismissals, with medical incapacity falling under the former. Furthermore, a distinction is drawn statutorily between permanent and temporary illhealth/injury incapacity with detailed guidelines for substantive and procedural fairness requirements to be met by employers. The powers of the specialist tribunals (CCMA, Bargaining Councils and Labour Courts) are regulated by statutory provisions and deal with appropriate remedies (reinstatement and/or compensation) a wardable in appropriate circumstances. Certain specific areas nonetheless still remain problematic for these tribunals and hence questions that require clear direction from the drafters of our law are: How to distinguish misconduct in alcohol and drug abuse cases? What degree of intermittent absenteeism is required before dismissal would be warranted? In certain other areas the tribunals have been fairly consistent and prescriptive in their approach and remedies awarded. Included here would be permanent incapacity, HIV cases and misconduct. It will emerge, however, that under the 1995 LRA the position of employees and the protections afforded them have been greatly increased.
- Full Text:
- Date Issued: 2004
- Authors: Boy, Anthony Albert
- Date: 2004
- Subjects: Employees -- Dismissal of -- Law and legislation -- South Africa , Capacity and disability -- South Africa , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10242 , http://hdl.handle.net/10948/d1016262
- Description: Labour law in South Africa has evolved over the past century at an ever increasing pace. The establishment of a democratic government in 1995 has been the trigger for a large number of labour law statutes being promulgated, particularly with reference to the laws governing the employment relationship and dismissal. From very humble and employer biased dispute resolution application under the common law of contract, labour law in this country has evolved through the various acts culminating in a labour law system which is highly regulated and codified. Dismissal for medical incapacity in this treatise is reviewed with regard to the applicable statutes and the various codes of good practice as the law has evolved and developed from the period covered by the common law through that covered by the 1995 LRA up to and including the current period. Particular attention is paid to both substantive and procedural requirements as well as the remedies applicable under the different legal regimes and the pertinent tribunals and courts. Regard is also given to the duration and causes of incapacity and the effect this may have on the applicable remedy applied by these tribunals. It will become apparant that the medically incapacitated employee occupied a relatively weak and vulnerable position under the common law as opposed to the current position under the 1995 LRA. The influence of the remedies applied by the tribunals under the 1956 LRA are clearly evident in the current regulations and codes under the 1995 LRA which contain specific statutory provisions for employees not to be unfairly dismissed. Distinctions are drawn between permissible and impermissible dismissals, with medical incapacity falling under the former. Furthermore, a distinction is drawn statutorily between permanent and temporary illhealth/injury incapacity with detailed guidelines for substantive and procedural fairness requirements to be met by employers. The powers of the specialist tribunals (CCMA, Bargaining Councils and Labour Courts) are regulated by statutory provisions and deal with appropriate remedies (reinstatement and/or compensation) a wardable in appropriate circumstances. Certain specific areas nonetheless still remain problematic for these tribunals and hence questions that require clear direction from the drafters of our law are: How to distinguish misconduct in alcohol and drug abuse cases? What degree of intermittent absenteeism is required before dismissal would be warranted? In certain other areas the tribunals have been fairly consistent and prescriptive in their approach and remedies awarded. Included here would be permanent incapacity, HIV cases and misconduct. It will emerge, however, that under the 1995 LRA the position of employees and the protections afforded them have been greatly increased.
- Full Text:
- Date Issued: 2004
DRUBIS : a distributed face-identification experimentation framework - design, implementation and performance issues
- Authors: Ndlangisa, Mboneli
- Date: 2004
- Subjects: Principal components analysis , Human face recognition (Computer science) , Image processing , Biometric identification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4704 , http://hdl.handle.net/10962/d1015768
- Description: We report on the design, implementation and performance issues of the DRUBIS (Distributed Rhodes University Biometric Identification System) experimentation framework. The Principal Component Analysis (PCA) face-recognition approach is used as a case study. DRUBIS is a flexible experimentation framework, distributed over a number of modules that are easily pluggable and swappable, allowing for the easy construction of prototype systems. Web services are the logical means of distributing DRUBIS components and a number of prototype applications have been implemented from this framework. Different popular PCA face-recognition related experiments were used to evaluate our experimentation framework. We extract recognition performance measures from these experiments. In particular, we use the framework for a more indepth study of the suitability of the DFFS (Difference From Face Space) metric as a means for image classification in the area of race and gender determination.
- Full Text:
- Date Issued: 2004
- Authors: Ndlangisa, Mboneli
- Date: 2004
- Subjects: Principal components analysis , Human face recognition (Computer science) , Image processing , Biometric identification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4704 , http://hdl.handle.net/10962/d1015768
- Description: We report on the design, implementation and performance issues of the DRUBIS (Distributed Rhodes University Biometric Identification System) experimentation framework. The Principal Component Analysis (PCA) face-recognition approach is used as a case study. DRUBIS is a flexible experimentation framework, distributed over a number of modules that are easily pluggable and swappable, allowing for the easy construction of prototype systems. Web services are the logical means of distributing DRUBIS components and a number of prototype applications have been implemented from this framework. Different popular PCA face-recognition related experiments were used to evaluate our experimentation framework. We extract recognition performance measures from these experiments. In particular, we use the framework for a more indepth study of the suitability of the DFFS (Difference From Face Space) metric as a means for image classification in the area of race and gender determination.
- Full Text:
- Date Issued: 2004
Electrochemical investigation of valve regulated lead acid batteries
- Authors: Ferg, Ernst Eduard
- Date: 2004
- Subjects: Lead acid batteries -- South Africa , Storage batteries -- South Africa , Electrochemistry -- South Africa
- Language: English
- Type: Thesis , Doctoral , DTech (Chemistry)
- Identifier: vital:10979 , http://hdl.handle.net/10948/228 , Lead acid batteries -- South Africa , Storage batteries -- South Africa , Electrochemistry -- South Africa
- Description: One of the technical advances made by the lead-acid battery industry in the field of portable power supply was the development of the valve regulated lead-acid battery (VRLA). This battery reduced the necessity for periodic servicing in terms of having to replenish the cells with distilled water. Further, this new type of battery can now be installed near sensitive electronic equipment without the danger of acid spill or dangerous fumes being emitted. In addition, longer service performance is achieved in terms of life cycle capacity, when compared to the conventional flooded type batteries. However, the new type of battery requires the manufacturing of high precision electrodes and components with low tolerances for error. In order for the manufacturers to produce such a premium product, a thorough understanding of the electrochemistry of the inner components is necessary. None of the South African lead-acid battery manufacturers are currently making VRLA batteries to supply a very competitive global market, where a large range of sizes and capabilities are available. In order to introduce the VRLA battery into such a competing market in South Africa, a niche area for its application was identified in order to establish the viability of manufacturing such a battery locally. This is done by integrating the VRLA concept into an existing battery, such as the miners cap lamp (MCL) battery. Its application is specific with well-defined performance criteria in a relatively large consumable market in the South African mining industry. The study looked at various components within a local manufacturing environment that required a better understanding and modification of the processes to build VRLA MCL batteries. This included a detailed study of the manufacturing processes of the positive electrode. The study involved the investigation of the types of grid alloys used, the type of electrode design, such as tubular or flat plate, the addition of redlead to the paste mixing process and subjecting the batteries to accelerated life cycle testing. A better understanding of the oxygen recombination cycle was also performed in order to evaluate the correct use of certain design criteria in the manufacturing process. This included the study of the pressure release valve and the type of positive electrode used. The study also looked at developing an inexpensive analytical technique to evaluate the porosity of cured and formed electrodes using a glycerol displacement method. The monitoring of the state of health (SoH) of VRLA batteries on a continuous basis is an important parameter in unique applications such as remote power supply. A device was developed to monitor the SoH of VRLA batteries on a continuous basis. The working principle of the device was tested on a MCL VRLA battery. With the development of other types of VRLA batteries for specific applications such as in stand-by power supplies, the monitoring device would then be integrated in the battery design.
- Full Text:
- Date Issued: 2004
- Authors: Ferg, Ernst Eduard
- Date: 2004
- Subjects: Lead acid batteries -- South Africa , Storage batteries -- South Africa , Electrochemistry -- South Africa
- Language: English
- Type: Thesis , Doctoral , DTech (Chemistry)
- Identifier: vital:10979 , http://hdl.handle.net/10948/228 , Lead acid batteries -- South Africa , Storage batteries -- South Africa , Electrochemistry -- South Africa
- Description: One of the technical advances made by the lead-acid battery industry in the field of portable power supply was the development of the valve regulated lead-acid battery (VRLA). This battery reduced the necessity for periodic servicing in terms of having to replenish the cells with distilled water. Further, this new type of battery can now be installed near sensitive electronic equipment without the danger of acid spill or dangerous fumes being emitted. In addition, longer service performance is achieved in terms of life cycle capacity, when compared to the conventional flooded type batteries. However, the new type of battery requires the manufacturing of high precision electrodes and components with low tolerances for error. In order for the manufacturers to produce such a premium product, a thorough understanding of the electrochemistry of the inner components is necessary. None of the South African lead-acid battery manufacturers are currently making VRLA batteries to supply a very competitive global market, where a large range of sizes and capabilities are available. In order to introduce the VRLA battery into such a competing market in South Africa, a niche area for its application was identified in order to establish the viability of manufacturing such a battery locally. This is done by integrating the VRLA concept into an existing battery, such as the miners cap lamp (MCL) battery. Its application is specific with well-defined performance criteria in a relatively large consumable market in the South African mining industry. The study looked at various components within a local manufacturing environment that required a better understanding and modification of the processes to build VRLA MCL batteries. This included a detailed study of the manufacturing processes of the positive electrode. The study involved the investigation of the types of grid alloys used, the type of electrode design, such as tubular or flat plate, the addition of redlead to the paste mixing process and subjecting the batteries to accelerated life cycle testing. A better understanding of the oxygen recombination cycle was also performed in order to evaluate the correct use of certain design criteria in the manufacturing process. This included the study of the pressure release valve and the type of positive electrode used. The study also looked at developing an inexpensive analytical technique to evaluate the porosity of cured and formed electrodes using a glycerol displacement method. The monitoring of the state of health (SoH) of VRLA batteries on a continuous basis is an important parameter in unique applications such as remote power supply. A device was developed to monitor the SoH of VRLA batteries on a continuous basis. The working principle of the device was tested on a MCL VRLA battery. With the development of other types of VRLA batteries for specific applications such as in stand-by power supplies, the monitoring device would then be integrated in the battery design.
- Full Text:
- Date Issued: 2004
Emotions, social transformation and education
- Authors: Delport, Aletta Catherine
- Date: 2004
- Subjects: Educational sociology -- South Africa , Education -- Philosophy , Emotions (Philosophy)
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:11009 , http://hdl.handle.net/10948/318 , Educational sociology -- South Africa , Education -- Philosophy , Emotions (Philosophy)
- Description: This thesis addresses the topic of the education of the emotions in the context of a rapidly transforming South African society. It attempts to reconfigure the conceptual landscape in terms of which we think about rationality, social transformation and education, and contests the intellectual and instrumental prejudice in the currently dominant ways of thinking about education. It reclaims a sense of what it would be to think of education in terms of cultivating humanity, as a key to the profound transformation of the South African society. It argues that the emotions should be relocated in our conception of transformation and education, because without it, education will fail to assist South African society to transform into a society where most people are able to live improved quality lives. The thesis comprises three distinct parts. The first part consists of an account of a particular cognitive theory of the emotions, as developed by Martha Nussbaum in her book, Upheavals of thought. The Intelligence of Emotions (2001). This theory is then applied in Part 2 to examine the complexities of social transformation in South Africa at the more profound, personal level. This investigation is presented as a narrative and comprises the perspectives of the author, who is a white Afrikaner female, who grew up in South Africa in the heyday of Apartheid. In the final part, the concept of ‘education for transformation’ is discussed. It is argued that, in order for education to enhance the social transformation of South Africa, social transformation should be conceived according to a fundamental aspect of Rousseau’s political philosophy, namely that the ideal society comprises two reciprocally related spheres, the political and the personal sphere. Part 3 argues that ‘education for transformation’ should be conceived according to a conception of transformation, which acknowledges this double-layered texture. It further argues that ‘education for transformation’ should primarily be concerned with transformation at the personal level, since, according to Rousseau’s philosophy, this dimension is fundamental to ensuring the stability and legitimacy of the political order. However, built on the main insights of Part 2, this thesis also argues that personal transformation is only possible within a framework of rationality, which acknowledges the emotions as constitutive elements of rationality itself. Essentially, this thesis is about the conception of human being, which should be esteemed as the most fundamental and crucial element of successful social transformation.
- Full Text:
- Date Issued: 2004
- Authors: Delport, Aletta Catherine
- Date: 2004
- Subjects: Educational sociology -- South Africa , Education -- Philosophy , Emotions (Philosophy)
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:11009 , http://hdl.handle.net/10948/318 , Educational sociology -- South Africa , Education -- Philosophy , Emotions (Philosophy)
- Description: This thesis addresses the topic of the education of the emotions in the context of a rapidly transforming South African society. It attempts to reconfigure the conceptual landscape in terms of which we think about rationality, social transformation and education, and contests the intellectual and instrumental prejudice in the currently dominant ways of thinking about education. It reclaims a sense of what it would be to think of education in terms of cultivating humanity, as a key to the profound transformation of the South African society. It argues that the emotions should be relocated in our conception of transformation and education, because without it, education will fail to assist South African society to transform into a society where most people are able to live improved quality lives. The thesis comprises three distinct parts. The first part consists of an account of a particular cognitive theory of the emotions, as developed by Martha Nussbaum in her book, Upheavals of thought. The Intelligence of Emotions (2001). This theory is then applied in Part 2 to examine the complexities of social transformation in South Africa at the more profound, personal level. This investigation is presented as a narrative and comprises the perspectives of the author, who is a white Afrikaner female, who grew up in South Africa in the heyday of Apartheid. In the final part, the concept of ‘education for transformation’ is discussed. It is argued that, in order for education to enhance the social transformation of South Africa, social transformation should be conceived according to a fundamental aspect of Rousseau’s political philosophy, namely that the ideal society comprises two reciprocally related spheres, the political and the personal sphere. Part 3 argues that ‘education for transformation’ should be conceived according to a conception of transformation, which acknowledges this double-layered texture. It further argues that ‘education for transformation’ should primarily be concerned with transformation at the personal level, since, according to Rousseau’s philosophy, this dimension is fundamental to ensuring the stability and legitimacy of the political order. However, built on the main insights of Part 2, this thesis also argues that personal transformation is only possible within a framework of rationality, which acknowledges the emotions as constitutive elements of rationality itself. Essentially, this thesis is about the conception of human being, which should be esteemed as the most fundamental and crucial element of successful social transformation.
- Full Text:
- Date Issued: 2004
English language teaching and learning in the African preschool and educational achievement at grade 1: a case study
- Authors: Rendel, Philip Boudewijn
- Date: 2004
- Subjects: Education, Preschool -- South Africa -- Case studies , English language -- Study and teaching (Preschool) -- South Africa Case studies , English language -- Study and teaching (Elementary) -- South Africa -- Case studies , Children -- South Africa -- Language -- Case studies , Language acquisition -- Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2360 , http://hdl.handle.net/10962/d1002643 , Education, Preschool -- South Africa -- Case studies , English language -- Study and teaching (Preschool) -- South Africa Case studies , English language -- Study and teaching (Elementary) -- South Africa -- Case studies , Children -- South Africa -- Language -- Case studies , Language acquisition -- Case studies
- Description: In 1998, seventy per cent of children in South Africa failed and had to repeat the Grade 1 year. This is the result of a number of factors, among them academic and cultural readiness for school. Many primary schools in South Africa teach through English, a language that is not the home language of the majority of learners. Despite recent legislation aimed at improving preschool facilities and teacher capacity, there has been insufficient consideration of which languages are taught and how they should be taught to children before they arrive at Grade 1. This study sets out to explore whether there is a relational link between preschool English language teaching and learning and subsequent educational achievement at Grade 1. It also sketches out possible recommendations for improving the teaching and learning of English in the sample schools. The study does not attempt to enter the debate over choice of language of teaching and learning (LoLT). In this longitudinal case study, four children from two different preschools, (one mainly isiXhosa medium and one English medium), were observed in their classroom environments over a period of four months. The following year, the same children were observed in their respective Grade 1 classrooms, all of which were English medium either entirely or to a degree. The parents of all four children were interviewed in their home environment, as were their teachers. The study found that there is a significant communication gap between preschool teachers and Grade 1 teachers. This was combined with a self-confessed need amongst some teachers for increased training in teaching through English. Low motivation and limited professional experience in some cases contributed to a preschool language-learning environment that lacked many of the factors identified as being essential for a positive learning environment in early childhood There was in addition a clear bias in many sites towards universality of ECD prinCiples with little regard for the hegemony of Western pedagogy, particularly in the area of literacy acquisition. The study concludes by suggesting some ways in which this situation could be improved in order to enable preschool children to cope better with the demands of Grade 1.
- Full Text:
- Date Issued: 2004
- Authors: Rendel, Philip Boudewijn
- Date: 2004
- Subjects: Education, Preschool -- South Africa -- Case studies , English language -- Study and teaching (Preschool) -- South Africa Case studies , English language -- Study and teaching (Elementary) -- South Africa -- Case studies , Children -- South Africa -- Language -- Case studies , Language acquisition -- Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2360 , http://hdl.handle.net/10962/d1002643 , Education, Preschool -- South Africa -- Case studies , English language -- Study and teaching (Preschool) -- South Africa Case studies , English language -- Study and teaching (Elementary) -- South Africa -- Case studies , Children -- South Africa -- Language -- Case studies , Language acquisition -- Case studies
- Description: In 1998, seventy per cent of children in South Africa failed and had to repeat the Grade 1 year. This is the result of a number of factors, among them academic and cultural readiness for school. Many primary schools in South Africa teach through English, a language that is not the home language of the majority of learners. Despite recent legislation aimed at improving preschool facilities and teacher capacity, there has been insufficient consideration of which languages are taught and how they should be taught to children before they arrive at Grade 1. This study sets out to explore whether there is a relational link between preschool English language teaching and learning and subsequent educational achievement at Grade 1. It also sketches out possible recommendations for improving the teaching and learning of English in the sample schools. The study does not attempt to enter the debate over choice of language of teaching and learning (LoLT). In this longitudinal case study, four children from two different preschools, (one mainly isiXhosa medium and one English medium), were observed in their classroom environments over a period of four months. The following year, the same children were observed in their respective Grade 1 classrooms, all of which were English medium either entirely or to a degree. The parents of all four children were interviewed in their home environment, as were their teachers. The study found that there is a significant communication gap between preschool teachers and Grade 1 teachers. This was combined with a self-confessed need amongst some teachers for increased training in teaching through English. Low motivation and limited professional experience in some cases contributed to a preschool language-learning environment that lacked many of the factors identified as being essential for a positive learning environment in early childhood There was in addition a clear bias in many sites towards universality of ECD prinCiples with little regard for the hegemony of Western pedagogy, particularly in the area of literacy acquisition. The study concludes by suggesting some ways in which this situation could be improved in order to enable preschool children to cope better with the demands of Grade 1.
- Full Text:
- Date Issued: 2004
Equity in the South African legal system a critical ethnography
- Authors: Leiper, Jonathan
- Date: 2004
- Subjects: Court interpreting and translating -- South Africa , Language and languages -- Law and legislation -- South Africa , Translators -- Training of -- South Africa , Translators -- Legal status, laws, etc. -- South Africa , Law -- Translating -- South Africa , Law -- South Africa -- Language
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2355 , http://hdl.handle.net/10962/d1002637 , Court interpreting and translating -- South Africa , Language and languages -- Law and legislation -- South Africa , Translators -- Training of -- South Africa , Translators -- Legal status, laws, etc. -- South Africa , Law -- Translating -- South Africa , Law -- South Africa -- Language
- Description: This thesis focuses on the process of interpreting and the difficulties faced by interpreters in the Magistrates' Court in Grahamstown, South Africa. More particularly, the thesis seeks to establish whether the constitutional guarantee of language equity can be applied to the courts - given the numerous problems with interpreting. Respondents from different spheres of the legal profession were interviewed in order to ascertain their perspectives on the state of interpreting, problems that are encountered by interpreters and attitudes displayed by other members of the legal profession towards interpreters. The methodology used in the thesis is that of a critical ethnography. As such, the research also has a critical focus, seeking to determine the ideologies and interests of different ):articipants in the legal process. On the basis of the data collected, a number of conclusions are drawn. The first is that interpreting in South Africa is in trouble. The system of interpreting is beset by a number of different problems. This study describes four different types of problems that are faced by interpreters: linguistic problems, environmental problems, training and administrative issues, and poor status in the eyes of the other participants in the legal process. Together the cumulative effect of these problems is the undermining of the principle of equity in the justice system. Finally, the thesis provides various practical and achievable solutions to the problems outlined above, specifically those faced by interpreters. The researcher also critically evaluates the efforts and motives of the Department of Justice and Constitutional Development.
- Full Text:
- Date Issued: 2004
- Authors: Leiper, Jonathan
- Date: 2004
- Subjects: Court interpreting and translating -- South Africa , Language and languages -- Law and legislation -- South Africa , Translators -- Training of -- South Africa , Translators -- Legal status, laws, etc. -- South Africa , Law -- Translating -- South Africa , Law -- South Africa -- Language
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2355 , http://hdl.handle.net/10962/d1002637 , Court interpreting and translating -- South Africa , Language and languages -- Law and legislation -- South Africa , Translators -- Training of -- South Africa , Translators -- Legal status, laws, etc. -- South Africa , Law -- Translating -- South Africa , Law -- South Africa -- Language
- Description: This thesis focuses on the process of interpreting and the difficulties faced by interpreters in the Magistrates' Court in Grahamstown, South Africa. More particularly, the thesis seeks to establish whether the constitutional guarantee of language equity can be applied to the courts - given the numerous problems with interpreting. Respondents from different spheres of the legal profession were interviewed in order to ascertain their perspectives on the state of interpreting, problems that are encountered by interpreters and attitudes displayed by other members of the legal profession towards interpreters. The methodology used in the thesis is that of a critical ethnography. As such, the research also has a critical focus, seeking to determine the ideologies and interests of different ):articipants in the legal process. On the basis of the data collected, a number of conclusions are drawn. The first is that interpreting in South Africa is in trouble. The system of interpreting is beset by a number of different problems. This study describes four different types of problems that are faced by interpreters: linguistic problems, environmental problems, training and administrative issues, and poor status in the eyes of the other participants in the legal process. Together the cumulative effect of these problems is the undermining of the principle of equity in the justice system. Finally, the thesis provides various practical and achievable solutions to the problems outlined above, specifically those faced by interpreters. The researcher also critically evaluates the efforts and motives of the Department of Justice and Constitutional Development.
- Full Text:
- Date Issued: 2004
Evaluating the district office budgeting process of the Department of Education in terms of the Batho Pele principles
- Authors: Gorgonzola, Ernest
- Date: 2004
- Subjects: South Africa. Dept. of Education -- Appropriations and expenditures , Budget -- South Africa , Education -- South Africa -- Finance
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10926 , http://hdl.handle.net/10948/165 , South Africa. Dept. of Education -- Appropriations and expenditures , Budget -- South Africa , Education -- South Africa -- Finance
- Description: The objective of this research was to evaluate the district office budgeting process of the Department of Education, Port Elizabeth District, in terms of the Batho Pele principles. The aim of district offices is to satisfy the most basic education needs of people in their respective areas of jurisdiction. Improving service delivery is one of government’s eight priorities as set out in the White Paper on the transformation of the Public Service (South African Government, 1995: 4). The initiative to improve service delivery is called Batho Pele. The main research question to be addressed by this research is: Does the Department of Education experience any problems with its budgeting process to address service delivery? Through a literature survey and empirical study, various conclusions were reached and recommendations made. The bulk of education expenditure takes place within education districts but the controlling, forecasting and budgeting of expenditure takes place at the Provincial Head Office. Most high schools surveyed experience problems with the current funding policy of the Department of Education. The relative poverty of the community around the school impacts negatively on the parent’s ability to support the school. iv The budgeting process of the Department of Education should follow a bottom-up approach to budgeting. Therefore, the district office budget should be informed by the needs of the school and the provincial budget be informed by the district office budget. The management and administrative capacity at the district office need to be developed to ensure effective budgeting.
- Full Text:
- Date Issued: 2004
- Authors: Gorgonzola, Ernest
- Date: 2004
- Subjects: South Africa. Dept. of Education -- Appropriations and expenditures , Budget -- South Africa , Education -- South Africa -- Finance
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10926 , http://hdl.handle.net/10948/165 , South Africa. Dept. of Education -- Appropriations and expenditures , Budget -- South Africa , Education -- South Africa -- Finance
- Description: The objective of this research was to evaluate the district office budgeting process of the Department of Education, Port Elizabeth District, in terms of the Batho Pele principles. The aim of district offices is to satisfy the most basic education needs of people in their respective areas of jurisdiction. Improving service delivery is one of government’s eight priorities as set out in the White Paper on the transformation of the Public Service (South African Government, 1995: 4). The initiative to improve service delivery is called Batho Pele. The main research question to be addressed by this research is: Does the Department of Education experience any problems with its budgeting process to address service delivery? Through a literature survey and empirical study, various conclusions were reached and recommendations made. The bulk of education expenditure takes place within education districts but the controlling, forecasting and budgeting of expenditure takes place at the Provincial Head Office. Most high schools surveyed experience problems with the current funding policy of the Department of Education. The relative poverty of the community around the school impacts negatively on the parent’s ability to support the school. iv The budgeting process of the Department of Education should follow a bottom-up approach to budgeting. Therefore, the district office budget should be informed by the needs of the school and the provincial budget be informed by the district office budget. The management and administrative capacity at the district office need to be developed to ensure effective budgeting.
- Full Text:
- Date Issued: 2004
Evaluation and optimization of selected methods of arsenic removal from industrial effluent
- Authors: Rubidge, Gletwyn Robert
- Date: 2004
- Subjects: Arsenic wastes , Water -- Purification -- Arsenic removal , Sewage -- Purification
- Language: English
- Type: Thesis , Doctoral , DTech (Chemistry)
- Identifier: vital:10981 , http://hdl.handle.net/10948/230 , Arsenic wastes , Water -- Purification -- Arsenic removal , Sewage -- Purification
- Description: This research was directed at reducing arsenic levels in the effluents generated at the Canelands facility that manufactures monosodium methyl arsenate. Two effluent streams containing arsenic have to be considered, a raw water stream that is treated on site and a brine stream that is disposed of by sea outfall. Removal of arsenate from aqueous media by coagulation was investigated and models were developed describing selected variables that influence the removal of the arsenate. Three coagulant systems were investigated, namely aluminium(III) coagulation, iron(III) coagulation and binary mixtures of aluminium(III) and iron(III). Researchers have studied individual aluminium (III) sulphate and iron(III) chloride coagulation. No detailed research and modelling had, however, been carried out on the use of binary mixtures of aluminium (III) sulphate and iron (III) chloride coagulation of aqueous arsenate, nor had individual aluminium(III) sulphate and iron(III) chloride coagulation of arsenate been modelled at relatively high arsenate concentrations. The models that were generated were validated statistically and experimentally. The variables investigated in the aluminium(III) model included initial arsenate concentration, pH, polymeric flocculent concentration, aluminium(III) concentration and settling time. The variables modelled in the iron(III) coagulation were initial arsenate concentration, pH, polymeric flocculent concentration, and iron(III) to arsenic mole ratio. The modelling of the binary coagulant system included initial arsenate concentration, pH, iron (III) concentration, aluminium(III) concentration, and flocculent concentration as variables. The most efficient arsenic removal by coagulation was iron(III), followed by the binary mixture of aluminium(III) and iron(III) and the weakest coagulant was aluminium(III) sulphate. Scale-up coagulations performed on real raw water samples at a 50 litre volume showed that iron(III) was the most efficient coagulant (on a molar basis) followed closely by the binary mixture, while aluminium(III) coagulation was considerably weaker. The residual arsenic levels of the iron(III) and the binary coagulation systems met the effluent discharge criteria, but the aluminium coagulation system did not. Leaching tests showed that the iron(III) sludge was the most stable followed by the sludge of the binary mixture and the aluminium(III)-based sludge leached arsenic most readily. Settling rate studies showed that the flocs of the iron(III) coagulations settled the fastest, followed by binary mixture flocs and the aluminium flocs settled the slowest. The flocs of the binary mixture had the lowest volume, followed by the iron(III) flocs, while the aluminium(III) flocs were the most voluminous. Based on current operations of the raw water treatment plant the aluminium(III)-based coagulation is the most cost efficient. Given a relative costing of 1.00 for the aluminium(III) coagulation, the iron(III) chloride-based coagulation would be 2.67 times more expensive and the equimolar binary mixed aluminium(III)/iron(III) system would be 1.84 times the cost of aluminium(III) coagulation.
- Full Text:
- Date Issued: 2004
- Authors: Rubidge, Gletwyn Robert
- Date: 2004
- Subjects: Arsenic wastes , Water -- Purification -- Arsenic removal , Sewage -- Purification
- Language: English
- Type: Thesis , Doctoral , DTech (Chemistry)
- Identifier: vital:10981 , http://hdl.handle.net/10948/230 , Arsenic wastes , Water -- Purification -- Arsenic removal , Sewage -- Purification
- Description: This research was directed at reducing arsenic levels in the effluents generated at the Canelands facility that manufactures monosodium methyl arsenate. Two effluent streams containing arsenic have to be considered, a raw water stream that is treated on site and a brine stream that is disposed of by sea outfall. Removal of arsenate from aqueous media by coagulation was investigated and models were developed describing selected variables that influence the removal of the arsenate. Three coagulant systems were investigated, namely aluminium(III) coagulation, iron(III) coagulation and binary mixtures of aluminium(III) and iron(III). Researchers have studied individual aluminium (III) sulphate and iron(III) chloride coagulation. No detailed research and modelling had, however, been carried out on the use of binary mixtures of aluminium (III) sulphate and iron (III) chloride coagulation of aqueous arsenate, nor had individual aluminium(III) sulphate and iron(III) chloride coagulation of arsenate been modelled at relatively high arsenate concentrations. The models that were generated were validated statistically and experimentally. The variables investigated in the aluminium(III) model included initial arsenate concentration, pH, polymeric flocculent concentration, aluminium(III) concentration and settling time. The variables modelled in the iron(III) coagulation were initial arsenate concentration, pH, polymeric flocculent concentration, and iron(III) to arsenic mole ratio. The modelling of the binary coagulant system included initial arsenate concentration, pH, iron (III) concentration, aluminium(III) concentration, and flocculent concentration as variables. The most efficient arsenic removal by coagulation was iron(III), followed by the binary mixture of aluminium(III) and iron(III) and the weakest coagulant was aluminium(III) sulphate. Scale-up coagulations performed on real raw water samples at a 50 litre volume showed that iron(III) was the most efficient coagulant (on a molar basis) followed closely by the binary mixture, while aluminium(III) coagulation was considerably weaker. The residual arsenic levels of the iron(III) and the binary coagulation systems met the effluent discharge criteria, but the aluminium coagulation system did not. Leaching tests showed that the iron(III) sludge was the most stable followed by the sludge of the binary mixture and the aluminium(III)-based sludge leached arsenic most readily. Settling rate studies showed that the flocs of the iron(III) coagulations settled the fastest, followed by binary mixture flocs and the aluminium flocs settled the slowest. The flocs of the binary mixture had the lowest volume, followed by the iron(III) flocs, while the aluminium(III) flocs were the most voluminous. Based on current operations of the raw water treatment plant the aluminium(III)-based coagulation is the most cost efficient. Given a relative costing of 1.00 for the aluminium(III) coagulation, the iron(III) chloride-based coagulation would be 2.67 times more expensive and the equimolar binary mixed aluminium(III)/iron(III) system would be 1.84 times the cost of aluminium(III) coagulation.
- Full Text:
- Date Issued: 2004
Examining the feasibility of introducing environmental surcharges to finance local coastal management initiatives in South Africa : a case study in Plettenberg Bay
- Authors: Mollatt, David G R
- Date: 2004
- Subjects: Marine resources -- South Africa Marine resources conservation -- South Africa Coastal zone management -- South Africa Marine parks and reserves -- Management--South Africa Tourism--South Africa -- Taxation Tourism -- South Africa -- Economic aspects
- Language: English
- Type: Thesis , Masters , MEcon
- Identifier: vital:999 , http://hdl.handle.net/10962/d1002734
- Description: The management of coastal resources in South Africa has come under review as a result of the degradation of environmental resources along the coast. The challenge being faced by resource managers is to achieve economic growth while sustaining South Africa’s coastal resource base (Nobel, 2000). The South African government (RSA, 2000) has developed a coastal management strategy to meet this challenge: The strategy involves the inclusion of all stakeholders in the formation of policy regarding the management of coastal resources, in a more integrated approach to coastal management. To effectively achieve this stakeholder inclusion, it has become necessary to decentralize the political, administrative and fiscal authority to conduct coastal management functions. With regard to the need for fiscal decentralisation this thesis considers the possibility of implementing localised environmental surcharges to finance coastal management initiatives. The ability of the White Paper for Sustainable Coastal Development (RSA, 2000) to provide theformal institutional structure necessary for the introduction of environmental surcharges is firstconsidered. It is shown that the decentralised management strategy has the potential to create a management style that is transparent and accountability orientated. In addition to this the style is capable of adapting to dynamic local coastal conditions and is therefore an appropriate direction in which to steer coastal management in South Africa. The effectiveness of coastal co-management as an informal institutional arrangement is then examined. Provided that local Coastal Management Fora are created to include all relevant stakeholders and that a source of long term financing is secured co-management has the potential to create the conditions necessary for effective coastal management. With regard to a source of long term financing, local environmental surcharges to finance coastal management initiatives are considered. The public’s willingness to contribute to such a surcharge is analysed in the context of Plettenberg Bay by probing their willingness to pay (WTP) for a Bay Management Plan. A survey instrument is developed to measure the public’s WTP. The design of the instrument is based on the Contingent Valuation (CV) method that is used to analyse the nonmarket benefits that environmental resources (such as Plettenberg Bay) provide the public. It is found that the resident population is willing to pay R15 per month toward a Bay Management Plan whilst domestic and foreign tourists respectively are willing to pay R6 and R22 daily. The aggregation of these WTP estimates yields a total passive use value of between R15 397 900 – R20330 500 annually. This nuclear value of the Bay should be included in the formation of local coastal management policy and provides guidance for the introduction of a local environmental surcharge. A budget for a Bay Management Plan is proposed and a progressive surcharge based on municipal property value is set. To finance the local residents’ share of the budget, a monthly surcharge of R1 would be required of the average valued property. To calculate the domestic and foreign tourist contribution to the budget a schedule of accommodation offering property will be required. However, to finance the entire budget a residential surcharge of approximately R10 would be required of the average valued property. This figure is well below the average resident population WTP of R15, highlighting the fact that an environmental surcharge in Plettenberg Bay is indeed feasible. The difference in reported WTP and the contribution required to finance the Bay Management Plan also highlights that there is scope for experimentation in the introduction of such a surcharge.
- Full Text:
- Date Issued: 2004
- Authors: Mollatt, David G R
- Date: 2004
- Subjects: Marine resources -- South Africa Marine resources conservation -- South Africa Coastal zone management -- South Africa Marine parks and reserves -- Management--South Africa Tourism--South Africa -- Taxation Tourism -- South Africa -- Economic aspects
- Language: English
- Type: Thesis , Masters , MEcon
- Identifier: vital:999 , http://hdl.handle.net/10962/d1002734
- Description: The management of coastal resources in South Africa has come under review as a result of the degradation of environmental resources along the coast. The challenge being faced by resource managers is to achieve economic growth while sustaining South Africa’s coastal resource base (Nobel, 2000). The South African government (RSA, 2000) has developed a coastal management strategy to meet this challenge: The strategy involves the inclusion of all stakeholders in the formation of policy regarding the management of coastal resources, in a more integrated approach to coastal management. To effectively achieve this stakeholder inclusion, it has become necessary to decentralize the political, administrative and fiscal authority to conduct coastal management functions. With regard to the need for fiscal decentralisation this thesis considers the possibility of implementing localised environmental surcharges to finance coastal management initiatives. The ability of the White Paper for Sustainable Coastal Development (RSA, 2000) to provide theformal institutional structure necessary for the introduction of environmental surcharges is firstconsidered. It is shown that the decentralised management strategy has the potential to create a management style that is transparent and accountability orientated. In addition to this the style is capable of adapting to dynamic local coastal conditions and is therefore an appropriate direction in which to steer coastal management in South Africa. The effectiveness of coastal co-management as an informal institutional arrangement is then examined. Provided that local Coastal Management Fora are created to include all relevant stakeholders and that a source of long term financing is secured co-management has the potential to create the conditions necessary for effective coastal management. With regard to a source of long term financing, local environmental surcharges to finance coastal management initiatives are considered. The public’s willingness to contribute to such a surcharge is analysed in the context of Plettenberg Bay by probing their willingness to pay (WTP) for a Bay Management Plan. A survey instrument is developed to measure the public’s WTP. The design of the instrument is based on the Contingent Valuation (CV) method that is used to analyse the nonmarket benefits that environmental resources (such as Plettenberg Bay) provide the public. It is found that the resident population is willing to pay R15 per month toward a Bay Management Plan whilst domestic and foreign tourists respectively are willing to pay R6 and R22 daily. The aggregation of these WTP estimates yields a total passive use value of between R15 397 900 – R20330 500 annually. This nuclear value of the Bay should be included in the formation of local coastal management policy and provides guidance for the introduction of a local environmental surcharge. A budget for a Bay Management Plan is proposed and a progressive surcharge based on municipal property value is set. To finance the local residents’ share of the budget, a monthly surcharge of R1 would be required of the average valued property. To calculate the domestic and foreign tourist contribution to the budget a schedule of accommodation offering property will be required. However, to finance the entire budget a residential surcharge of approximately R10 would be required of the average valued property. This figure is well below the average resident population WTP of R15, highlighting the fact that an environmental surcharge in Plettenberg Bay is indeed feasible. The difference in reported WTP and the contribution required to finance the Bay Management Plan also highlights that there is scope for experimentation in the introduction of such a surcharge.
- Full Text:
- Date Issued: 2004