RADGIS - an improved architecture for runtime-extensible, distributed GIS applications
- Authors: Preston, Richard Michael
- Date: 2002
- Subjects: Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4626 , http://hdl.handle.net/10962/d1006497
- Description: A number of GIS architectures and technologies have emerged recently to facilitate the visualisation and processing of geospatial data over the Web. The work presented in this dissertation builds on these efforts and undertakes to overcome some of the major problems with traditional GIS client architectures, including application bloat, lack of customisability, and lack of interoperability between GIS products. In this dissertation we describe how a new client-side GIS architecture was developed and implemented as a proof-of-concept application called RADGIS, which is based on open standards and emerging distributed component-based software paradigms. RADGIS reflects the current trend in development focus from Web browser-based applications to customised clients, based on open standards, that make use of distributed Web services. While much attention has been paid to exposing data on the Web, there is growing momentum towards providing “value-added” services. A good example of this is the tremendous industry interest in the provision of location-based services, which has been discussed as a special use-case of our RADGIS architecture. Thus, in the near future client applications will not simply be used to access data transparently, but will also become facilitators for the location-transparent invocation of local and remote services. This flexible architecture will ensure that data can be stored and processed independently of the location of the client that wishes to view or interact with it. Our RADGIS application enables content developers and end-users to create and/or customise GIS applications dynamically at runtime through the incorporation of GIS services. This ensures that the client application has the flexibility to withstand changing levels of expertise or user requirements. These GIS services are implemented as components that execute locally on the client machine, or as remote CORBA Objects or EJBs. Assembly and deployment of these components is achieved using a specialised XML descriptor. This XML descriptor is written using a markup language that we developed specifically for this purpose, called DGCML, which contains deployment information, as well as a GUI specification and links to an XML-based help system that can be merged with the RADGIS client application’s existing help system. Thus, no additional requirements are imposed on object developers by the RADGIS architecture, i.e. there is no need to rewrite existing objects since DGCML acts as a runtime-customisable wrapper, allowing existing objects to be utilised by RADGIS. While the focus of this thesis has been on overcoming the above-mentioned problems with traditional GIS applications, the work described here can also be applied in a much broader context, especially in the development of highly customisable client applications that are able to integrate Web services at runtime.
- Full Text:
- Date Issued: 2002
- Authors: Preston, Richard Michael
- Date: 2002
- Subjects: Geographic information systems
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4626 , http://hdl.handle.net/10962/d1006497
- Description: A number of GIS architectures and technologies have emerged recently to facilitate the visualisation and processing of geospatial data over the Web. The work presented in this dissertation builds on these efforts and undertakes to overcome some of the major problems with traditional GIS client architectures, including application bloat, lack of customisability, and lack of interoperability between GIS products. In this dissertation we describe how a new client-side GIS architecture was developed and implemented as a proof-of-concept application called RADGIS, which is based on open standards and emerging distributed component-based software paradigms. RADGIS reflects the current trend in development focus from Web browser-based applications to customised clients, based on open standards, that make use of distributed Web services. While much attention has been paid to exposing data on the Web, there is growing momentum towards providing “value-added” services. A good example of this is the tremendous industry interest in the provision of location-based services, which has been discussed as a special use-case of our RADGIS architecture. Thus, in the near future client applications will not simply be used to access data transparently, but will also become facilitators for the location-transparent invocation of local and remote services. This flexible architecture will ensure that data can be stored and processed independently of the location of the client that wishes to view or interact with it. Our RADGIS application enables content developers and end-users to create and/or customise GIS applications dynamically at runtime through the incorporation of GIS services. This ensures that the client application has the flexibility to withstand changing levels of expertise or user requirements. These GIS services are implemented as components that execute locally on the client machine, or as remote CORBA Objects or EJBs. Assembly and deployment of these components is achieved using a specialised XML descriptor. This XML descriptor is written using a markup language that we developed specifically for this purpose, called DGCML, which contains deployment information, as well as a GUI specification and links to an XML-based help system that can be merged with the RADGIS client application’s existing help system. Thus, no additional requirements are imposed on object developers by the RADGIS architecture, i.e. there is no need to rewrite existing objects since DGCML acts as a runtime-customisable wrapper, allowing existing objects to be utilised by RADGIS. While the focus of this thesis has been on overcoming the above-mentioned problems with traditional GIS applications, the work described here can also be applied in a much broader context, especially in the development of highly customisable client applications that are able to integrate Web services at runtime.
- Full Text:
- Date Issued: 2002
Radiocarbon dates and the Late Quaternary palaeogeography of the Province of the Eastern Cape, South Africa
- Authors: Lewis, Colin A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6693 , http://hdl.handle.net/10962/d1006728
- Description: A total of 193 dates are listed from the Eastern Cape. Middle Stone Age hunter-gatherers existed in the Drakensberg prior to the rigours of cold climatic conditions after ca. 22,000 BP. These uplands were reoccupied under more favourable climatic conditions after ca. 12,600 BP but were apparently abandoned between ca. 6000 BP and 3000 BP. Hunter-gatherer occupation throughout the Holocene is indicated at lower altitudes, with in-migration of pastoralists ca. 1800 BP in the Fish River area, and with Iron Age farmers entering coastal districts and adjacent river valleys from ca. 1400 BP. Sand dunes accumulated in the Holocene adjacent to the Indian Ocean. Flood plain development in the early Holocene was succeeded by incision of rivers in the later Holocene. Flood plain deposition began again in the Southern Drakensberg ca. 1000 BP. Palynological studies evidence marked climatic oscillations around the Late Glacial/Holocene boundary, with apparent stability at high altitude subsequent to 2700 BP.
- Full Text:
- Date Issued: 2002
- Authors: Lewis, Colin A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6693 , http://hdl.handle.net/10962/d1006728
- Description: A total of 193 dates are listed from the Eastern Cape. Middle Stone Age hunter-gatherers existed in the Drakensberg prior to the rigours of cold climatic conditions after ca. 22,000 BP. These uplands were reoccupied under more favourable climatic conditions after ca. 12,600 BP but were apparently abandoned between ca. 6000 BP and 3000 BP. Hunter-gatherer occupation throughout the Holocene is indicated at lower altitudes, with in-migration of pastoralists ca. 1800 BP in the Fish River area, and with Iron Age farmers entering coastal districts and adjacent river valleys from ca. 1400 BP. Sand dunes accumulated in the Holocene adjacent to the Indian Ocean. Flood plain development in the early Holocene was succeeded by incision of rivers in the later Holocene. Flood plain deposition began again in the Southern Drakensberg ca. 1000 BP. Palynological studies evidence marked climatic oscillations around the Late Glacial/Holocene boundary, with apparent stability at high altitude subsequent to 2700 BP.
- Full Text:
- Date Issued: 2002
Reading William Blake and T.S. Eliot: contrary poets, progressive vision
- Authors: Rayneard, Max James Anthony
- Date: 2002
- Subjects: Blake, William, 1757-1827 -- Criticism and interpretation , Eliot, T. S. (Thomas Stearns), 1888-1965 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2279 , http://hdl.handle.net/10962/d1007545 , Blake, William, 1757-1827 -- Criticism and interpretation , Eliot, T. S. (Thomas Stearns), 1888-1965 -- Criticism and interpretation
- Description: Many critics resort to explaining readers' experiences of poems like William Blake's Jerusalem and T.S. Eliot's Four Quartets in terms of "spirituality" or "religion". These experiences are broadly defined in this thesis as jouissance (after Roland Barthes' essay The Pleasure of the Text) or "experience qua experience". Critical attempts at the reduction of jouissance into abstract constructs serve merely as stopgap measures by which critics might avoid having to account for the limits of their own rational discourse. These poems, in particular, are deliberately structured to preserve the reader's experience of the poem from reduction to any particular meta-discursive construct, including "the spiritual". Through a broad application of Rezeption-Asthetik principles, this thesis demonstrates how the poems are structured to direct readers' faculties to engage with the hypothetical realm within which jouissance occurs, beyond the rationally abstractable. T.S. Eliot's poetic oeuvre appears to chart his growing confidence in non-rational, pre-critical faculties. Through "The Love Song of J. Alfred Prufrock", The Waste Land, and Four Quartets, Eliot's poetry becomes gradually less prescriptive of the terms to which the experience of his poetry might be reduced. In Four Quartets he finally entrusts readers with a great deal of responsibility for "co-creating" the poem's significance. Like T.S . Eliot, although more consistently throughout his oeuvre, William Blake is similarly concerned with the validation of the reader's subjective interpretative/creative faculties. Blake's Jerusalem is carefully structured on various intertwined levels to rouse and exercise in the reader what the poet calls the "All Glorious Imagination" (Keynes 1972: 679). The jouissance of Jerusalem or Four Quartets is located in the reader's efforts to co-create the significance of the poems. It is only during a direct engagement with this process, rather than in subsequent attempts to abstract it, that the "experience qua experience" may be understood.
- Full Text:
- Date Issued: 2002
- Authors: Rayneard, Max James Anthony
- Date: 2002
- Subjects: Blake, William, 1757-1827 -- Criticism and interpretation , Eliot, T. S. (Thomas Stearns), 1888-1965 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2279 , http://hdl.handle.net/10962/d1007545 , Blake, William, 1757-1827 -- Criticism and interpretation , Eliot, T. S. (Thomas Stearns), 1888-1965 -- Criticism and interpretation
- Description: Many critics resort to explaining readers' experiences of poems like William Blake's Jerusalem and T.S. Eliot's Four Quartets in terms of "spirituality" or "religion". These experiences are broadly defined in this thesis as jouissance (after Roland Barthes' essay The Pleasure of the Text) or "experience qua experience". Critical attempts at the reduction of jouissance into abstract constructs serve merely as stopgap measures by which critics might avoid having to account for the limits of their own rational discourse. These poems, in particular, are deliberately structured to preserve the reader's experience of the poem from reduction to any particular meta-discursive construct, including "the spiritual". Through a broad application of Rezeption-Asthetik principles, this thesis demonstrates how the poems are structured to direct readers' faculties to engage with the hypothetical realm within which jouissance occurs, beyond the rationally abstractable. T.S. Eliot's poetic oeuvre appears to chart his growing confidence in non-rational, pre-critical faculties. Through "The Love Song of J. Alfred Prufrock", The Waste Land, and Four Quartets, Eliot's poetry becomes gradually less prescriptive of the terms to which the experience of his poetry might be reduced. In Four Quartets he finally entrusts readers with a great deal of responsibility for "co-creating" the poem's significance. Like T.S . Eliot, although more consistently throughout his oeuvre, William Blake is similarly concerned with the validation of the reader's subjective interpretative/creative faculties. Blake's Jerusalem is carefully structured on various intertwined levels to rouse and exercise in the reader what the poet calls the "All Glorious Imagination" (Keynes 1972: 679). The jouissance of Jerusalem or Four Quartets is located in the reader's efforts to co-create the significance of the poems. It is only during a direct engagement with this process, rather than in subsequent attempts to abstract it, that the "experience qua experience" may be understood.
- Full Text:
- Date Issued: 2002
Reconciling Western and African philosophy : rationality, culture and communitarianism
- Authors: Vitsha, Xolisa
- Date: 2002
- Subjects: Philosophy, African , Africa -- Intellectual life , Philosophy, Comparative , Philosophy , Communitarianism , Self
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2838 , http://hdl.handle.net/10962/d1003807 , Philosophy, African , Africa -- Intellectual life , Philosophy, Comparative , Philosophy , Communitarianism , Self
- Description: This thesis attempts to reconcile Western and African philosophy with specific reference to the issues of rationality, culture and communitarianism. It also discusses the post-Enlightenment, Western philosophical concept of liberal "atomism" and the primacy of the individual and the emergence of a communitarian critique in response. This thesis intends exploring how Western notions of individuality and the communitarian response can be reconciled with contemporary African philosophy and African communitarian thought in particular. To do this, it is necessary to explore the problem of liberal individualism and how African communitarianism might reinforce the Western communitarian critique. African communitarianism has a processual understanding of personhood that underpins its conception of the Self. In contrast to this view, Western communitarianism has a relational conception of the individual Self. Thus, this thesis argues that African communitarianism has a more profound understanding of the constitution of the Self. To demonstrate these claims, this study discusses notions of rationality which inform each of the philosophical traditions. This will enable a comparative analysis of the above-mentioned philosophical traditions with the intention of uncovering the concepts that provide the platform for their reconciliation.
- Full Text:
- Date Issued: 2002
- Authors: Vitsha, Xolisa
- Date: 2002
- Subjects: Philosophy, African , Africa -- Intellectual life , Philosophy, Comparative , Philosophy , Communitarianism , Self
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2838 , http://hdl.handle.net/10962/d1003807 , Philosophy, African , Africa -- Intellectual life , Philosophy, Comparative , Philosophy , Communitarianism , Self
- Description: This thesis attempts to reconcile Western and African philosophy with specific reference to the issues of rationality, culture and communitarianism. It also discusses the post-Enlightenment, Western philosophical concept of liberal "atomism" and the primacy of the individual and the emergence of a communitarian critique in response. This thesis intends exploring how Western notions of individuality and the communitarian response can be reconciled with contemporary African philosophy and African communitarian thought in particular. To do this, it is necessary to explore the problem of liberal individualism and how African communitarianism might reinforce the Western communitarian critique. African communitarianism has a processual understanding of personhood that underpins its conception of the Self. In contrast to this view, Western communitarianism has a relational conception of the individual Self. Thus, this thesis argues that African communitarianism has a more profound understanding of the constitution of the Self. To demonstrate these claims, this study discusses notions of rationality which inform each of the philosophical traditions. This will enable a comparative analysis of the above-mentioned philosophical traditions with the intention of uncovering the concepts that provide the platform for their reconciliation.
- Full Text:
- Date Issued: 2002
Reengineering the business processes in small, medium and micro enterprises (SMME'S) in order to improve profitability
- Authors: Figg, Malcolm John
- Date: 2002
- Subjects: Reengineering (Management)
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10850 , http://hdl.handle.net/10948/112 , Reengineering (Management)
- Description: The research problem addressed in this study was to identify guidelines to improve business processes that will enhance the ability of Small, Medium, and Micro Enterprises (SMME’s) to be able to operate competitively in local and global markets. Reengineering of business processes (BPR) is necessary because of internal factors such as increasing global competition, increasing domestic competition, new technologies, industry overcapacity, shrinking markets and increasing pressure from suppliers. There are also various external factors that influence the necessity to reengineer business processes. These factors include increasing cost structure, declining profitability, declining sales, low productivity, inadequate employee skills and less efficiency in operations. In order to identify guidelines that will enhance SMME’s performance, questionnaires with relevant questions were used . The findings of the literature survey clearly highlights the specific areas where attention is required for improvements.
- Full Text:
- Date Issued: 2002
- Authors: Figg, Malcolm John
- Date: 2002
- Subjects: Reengineering (Management)
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10850 , http://hdl.handle.net/10948/112 , Reengineering (Management)
- Description: The research problem addressed in this study was to identify guidelines to improve business processes that will enhance the ability of Small, Medium, and Micro Enterprises (SMME’s) to be able to operate competitively in local and global markets. Reengineering of business processes (BPR) is necessary because of internal factors such as increasing global competition, increasing domestic competition, new technologies, industry overcapacity, shrinking markets and increasing pressure from suppliers. There are also various external factors that influence the necessity to reengineer business processes. These factors include increasing cost structure, declining profitability, declining sales, low productivity, inadequate employee skills and less efficiency in operations. In order to identify guidelines that will enhance SMME’s performance, questionnaires with relevant questions were used . The findings of the literature survey clearly highlights the specific areas where attention is required for improvements.
- Full Text:
- Date Issued: 2002
Relationship between temparament and linear body parameters of beef cattle under communal grazing system
- Authors: Nekhofhe, Avhasei Justice
- Date: 2002
- Subjects: Cattle , Grazing
- Language: English
- Type: Thesis , Masters , MTech (Agricultural Management)
- Identifier: vital:10965 , http://hdl.handle.net/10948/113 , Cattle , Grazing
- Description: Introduction : Indigenous cattle are mostly reared where the traditional farming is practiced including Northern Region of South Africa. The majority of farmers own Nguni type of cattle although other breeds are found in the region. They perform well under harsh conditions and they seem to produce better under intensive management. However, communal farmers are becoming aware and interested in indigenous breeds especially Nguni cattle type because of their adaptability. Beef cattle production and research require constant movement and handling of livestock (Erf et al., 1992 & Grandin, 1993). Dipping, castration, branding, ear-tagging and counting is commonly practiced as beef cattle management norms hence dehorning are partly practiced as some of the animals had horns which were disturbing them to pass through crushpens and as a result they increased bruising to other animals. At Matatani and Muledzhi areas animals including calves are packed in the crushpens, counted, weighed and temperament traits were also measured on the scale and this is done in order to document the information for this research and future use. Temperament is a behavioural response of animals as handled by man. It is important to be measured in beef cattle farmers under communal grazing conditions as it reduces farmer’s profit and it makes the stock man’s work unpleasant. Therefore, it is also needs to be improved for the improvement of beef cattle schemes. Management system of communal farmers was not conducive to better quality meat due to horns in some animals which ultimately cause bruising in other animals. However, exotic bulls were bought at random for the improvement of other breed types found in these two areas. The focus of this study is almost in Nguni cattle type managed under communal grazing system. Lastly, the purpose of this study is to determine behavioral response of beef cattle under communal management system at their dipping tanks.
- Full Text:
- Date Issued: 2002
- Authors: Nekhofhe, Avhasei Justice
- Date: 2002
- Subjects: Cattle , Grazing
- Language: English
- Type: Thesis , Masters , MTech (Agricultural Management)
- Identifier: vital:10965 , http://hdl.handle.net/10948/113 , Cattle , Grazing
- Description: Introduction : Indigenous cattle are mostly reared where the traditional farming is practiced including Northern Region of South Africa. The majority of farmers own Nguni type of cattle although other breeds are found in the region. They perform well under harsh conditions and they seem to produce better under intensive management. However, communal farmers are becoming aware and interested in indigenous breeds especially Nguni cattle type because of their adaptability. Beef cattle production and research require constant movement and handling of livestock (Erf et al., 1992 & Grandin, 1993). Dipping, castration, branding, ear-tagging and counting is commonly practiced as beef cattle management norms hence dehorning are partly practiced as some of the animals had horns which were disturbing them to pass through crushpens and as a result they increased bruising to other animals. At Matatani and Muledzhi areas animals including calves are packed in the crushpens, counted, weighed and temperament traits were also measured on the scale and this is done in order to document the information for this research and future use. Temperament is a behavioural response of animals as handled by man. It is important to be measured in beef cattle farmers under communal grazing conditions as it reduces farmer’s profit and it makes the stock man’s work unpleasant. Therefore, it is also needs to be improved for the improvement of beef cattle schemes. Management system of communal farmers was not conducive to better quality meat due to horns in some animals which ultimately cause bruising in other animals. However, exotic bulls were bought at random for the improvement of other breed types found in these two areas. The focus of this study is almost in Nguni cattle type managed under communal grazing system. Lastly, the purpose of this study is to determine behavioral response of beef cattle under communal management system at their dipping tanks.
- Full Text:
- Date Issued: 2002
Removal and recovery of gold and platinum from aqueous solutions utilising the non-viable biomass Asolla filiculoides
- Authors: Antunes, Ana Paula Martins
- Date: 2002
- Subjects: Azolla filiculoides Metal wastes -- Recycling Gold -- Recycling Platinum -- Recycling
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3894 , http://hdl.handle.net/10962/d1003726
- Description: Waste water from the mining industry is generally extremely complex and contains numerous species which influence the adsorption of the metals to any biomass. A variety of factors need to be addressed before treatment is considered viable. It is also beneficial to establish the binding characteristics of the metal of interest to maximise its interaction with the biomass to be utilised. Azalia filiculaides was investigated in the adsorption of gold(III), lead(II), iron(ID), copper(II) and platinum (IV). In batch studies, the optimum biomass and initial gold(III) concentrations were found to be 5 gIL and 8 mgIL respectively. The adsorption of gold(ID) is principally pH-dependent with optimal removal at pH 2. Lead(II), iron(III) and copper(II) did not compete with gold(III) adsorption under equimolar and simulated effluent conditions. Halides, with increasing affinity for gold (chloride < bromide < iodide), can affect gold uptake with the soft base, iodide, exhibiting the most inhibition (25%) and the hard base, chloride, O%. Mercaptoethanol (soft base) showed no interference in gold(III) adsorption while the presence of sulphate (hard base) and sulphite (borderline base) showed that concentrations in excess of 1 0 mM may adversely affect gold(ill) uptake, most likely due to competition for cationic sites on the biomass. Column studies, better suited to high volume treatment, indicated that a flow-rate of 5 mL/min and an initial gold(ill) concentration of 5 mgIL was optimal. Competitive effects between lead, iron, copper and gold again showed little or no interference. The halides, chloride, bromide and iodide, affect gold(ill) uptake similarly to the batch studies, while the bases mercaptoethanol and sulphate minimally affect gold(III) binding with sulphite severely hampering adsorption (70% inhibition). To optimise gold desorption, preliminary batch studies indicated that a ratio of 1:1 of adsorbentdesorbent was optimal, whilst gas purging of thiourea with oxygen, air and nitrogen decreased gold elution in proportion to decreased amounts of oxygen. A series of desorbents were utilised, in column studies, to optimise and determine the speciation of bound gold. The presence of an oxidant with thiourea enhanced desorption greater than 3 fold when compared with thiourea alone. Thiourea desorption studies, aided by the oxidant, suggest that gold is present in the + I and 0 oxidation states. Ultimately thiourea, perchloric acid and hydrochloric acid was found to be the most optimal elutant for gold (J 00% recovery). For selective metal recovery oflead and copper, pre-washing the plant material with water, utilising an acid (0.3 M nitric acid), pumping in an up-flow mode, and recycling the desorbent six times was found to be optimal elutant for gold (J 00% recovery). Cost analysis of utilising elutant versus incinerating the biomass for gold recovery indicated the latter as the most economical. Over a 5 cycle adsorption and desorption series, acid desorption before each adsorption cycle was found to result in greater than 92% desorption for lead and 96% for copper. Gold recovery was 97% with incineration. A preliminary study with gold effluent (Mine C) indicated that nickel and sulphate was removed in batch and column studies. Gold removal was found to be 100% and 4% in batch and column studies respectively. Adsorption of gold in the effluent study was accompanied by the release ofHt. Modifying the plant material with various reagents failed to identify the primary binding sites and the role of polysaccharides, proteins and lipids in gold(ill) uptake. The mode of gold binding is suggested as being initially ionic, this is very rapid, with the interaction of the anionic complex, [AuCI₄]". with the cationic biomass (PH 2). This eventually leads to the displacement of the chloride ligand(s) initiating covalent binding. Spectral studies of the chemical interaction between gold and the representative tannins indicated the protonated hydroxy groups to be responsible. All evidence suggests that the binding mechanisms of gold are not simple. Preliminary adsorption studies of platinum by Azalia filiculaides were conducted. Batch studies indicated that J gIL biomass concentration, initial platinum concentration of 20 mgIL and pH 2 are optimal, while the column studies indicated a flow-rate of! 0 rnL/min and initial platinum concentration of 20 mgIL as optimal. In the platinum effluent study, platinum showed a removal of 23 % and 2 J % for the batch and column studies respectively. Again adsorption was accompanied by //' release. Azalia filiculaides demonstrated its feasibility in the removal of gold and platinum from simulated as well as waste water solutions. Its potential viability as a biosorbent was demonstrated by the high recovery from synthetic solutions of greater than 99% for gold (2-10 mgIL), and greater than 89% for platinum (20 mgIL).
- Full Text:
- Date Issued: 2002
- Authors: Antunes, Ana Paula Martins
- Date: 2002
- Subjects: Azolla filiculoides Metal wastes -- Recycling Gold -- Recycling Platinum -- Recycling
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3894 , http://hdl.handle.net/10962/d1003726
- Description: Waste water from the mining industry is generally extremely complex and contains numerous species which influence the adsorption of the metals to any biomass. A variety of factors need to be addressed before treatment is considered viable. It is also beneficial to establish the binding characteristics of the metal of interest to maximise its interaction with the biomass to be utilised. Azalia filiculaides was investigated in the adsorption of gold(III), lead(II), iron(ID), copper(II) and platinum (IV). In batch studies, the optimum biomass and initial gold(III) concentrations were found to be 5 gIL and 8 mgIL respectively. The adsorption of gold(ID) is principally pH-dependent with optimal removal at pH 2. Lead(II), iron(III) and copper(II) did not compete with gold(III) adsorption under equimolar and simulated effluent conditions. Halides, with increasing affinity for gold (chloride < bromide < iodide), can affect gold uptake with the soft base, iodide, exhibiting the most inhibition (25%) and the hard base, chloride, O%. Mercaptoethanol (soft base) showed no interference in gold(III) adsorption while the presence of sulphate (hard base) and sulphite (borderline base) showed that concentrations in excess of 1 0 mM may adversely affect gold(ill) uptake, most likely due to competition for cationic sites on the biomass. Column studies, better suited to high volume treatment, indicated that a flow-rate of 5 mL/min and an initial gold(ill) concentration of 5 mgIL was optimal. Competitive effects between lead, iron, copper and gold again showed little or no interference. The halides, chloride, bromide and iodide, affect gold(ill) uptake similarly to the batch studies, while the bases mercaptoethanol and sulphate minimally affect gold(III) binding with sulphite severely hampering adsorption (70% inhibition). To optimise gold desorption, preliminary batch studies indicated that a ratio of 1:1 of adsorbentdesorbent was optimal, whilst gas purging of thiourea with oxygen, air and nitrogen decreased gold elution in proportion to decreased amounts of oxygen. A series of desorbents were utilised, in column studies, to optimise and determine the speciation of bound gold. The presence of an oxidant with thiourea enhanced desorption greater than 3 fold when compared with thiourea alone. Thiourea desorption studies, aided by the oxidant, suggest that gold is present in the + I and 0 oxidation states. Ultimately thiourea, perchloric acid and hydrochloric acid was found to be the most optimal elutant for gold (J 00% recovery). For selective metal recovery oflead and copper, pre-washing the plant material with water, utilising an acid (0.3 M nitric acid), pumping in an up-flow mode, and recycling the desorbent six times was found to be optimal elutant for gold (J 00% recovery). Cost analysis of utilising elutant versus incinerating the biomass for gold recovery indicated the latter as the most economical. Over a 5 cycle adsorption and desorption series, acid desorption before each adsorption cycle was found to result in greater than 92% desorption for lead and 96% for copper. Gold recovery was 97% with incineration. A preliminary study with gold effluent (Mine C) indicated that nickel and sulphate was removed in batch and column studies. Gold removal was found to be 100% and 4% in batch and column studies respectively. Adsorption of gold in the effluent study was accompanied by the release ofHt. Modifying the plant material with various reagents failed to identify the primary binding sites and the role of polysaccharides, proteins and lipids in gold(ill) uptake. The mode of gold binding is suggested as being initially ionic, this is very rapid, with the interaction of the anionic complex, [AuCI₄]". with the cationic biomass (PH 2). This eventually leads to the displacement of the chloride ligand(s) initiating covalent binding. Spectral studies of the chemical interaction between gold and the representative tannins indicated the protonated hydroxy groups to be responsible. All evidence suggests that the binding mechanisms of gold are not simple. Preliminary adsorption studies of platinum by Azalia filiculaides were conducted. Batch studies indicated that J gIL biomass concentration, initial platinum concentration of 20 mgIL and pH 2 are optimal, while the column studies indicated a flow-rate of! 0 rnL/min and initial platinum concentration of 20 mgIL as optimal. In the platinum effluent study, platinum showed a removal of 23 % and 2 J % for the batch and column studies respectively. Again adsorption was accompanied by //' release. Azalia filiculaides demonstrated its feasibility in the removal of gold and platinum from simulated as well as waste water solutions. Its potential viability as a biosorbent was demonstrated by the high recovery from synthetic solutions of greater than 99% for gold (2-10 mgIL), and greater than 89% for platinum (20 mgIL).
- Full Text:
- Date Issued: 2002
Reporting indigenous knowledge: the choices they deserve the local is the global
- Authors: Boshoff, Priscilla A
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71176 , vital:29804 , http://doi:10.1006/jmbi.1995.0238
- Description: A few days ago, an interesting article dealing with community development and education came close to being published in a national newspaper. But the editor tossed it back at the surprised journalist, and told him to write it again. Here are some excerpts: Researchers here have recently been facilitating local people to rediscover traditional practices that have been lost through the processes of colonisation and changes in lifestyles. “We are very excited about the ways in which things are being discovered,” said Samuel Mann, research facilitator at the project. “People are beginning to reclaim some of the ways of knowing that still have meaning and relevance to modern everyday life. People are rediscovering the importance of Indigenous Knowledge.” Mba Ngcobo, one of the participants in the project, showed how he and other members of his community had built a grain pit using old traditional knowledge. “It works really well,” he said, “it is amazing how these old ways really work. Our ancestors had marvellous ways of doing things. We can really appreciate the skills that are slowly being lost to us.” Mann explained how the traditional pit storage method produced carbon dioxide that keeps the grain fresh and insect-free for months. “Carbon dioxide storage is now the preferred way of many milling and storage companies to keep grain. It keeps grain fresh without having to resort to insecticides.”
- Full Text:
- Date Issued: 2002
- Authors: Boshoff, Priscilla A
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71176 , vital:29804 , http://doi:10.1006/jmbi.1995.0238
- Description: A few days ago, an interesting article dealing with community development and education came close to being published in a national newspaper. But the editor tossed it back at the surprised journalist, and told him to write it again. Here are some excerpts: Researchers here have recently been facilitating local people to rediscover traditional practices that have been lost through the processes of colonisation and changes in lifestyles. “We are very excited about the ways in which things are being discovered,” said Samuel Mann, research facilitator at the project. “People are beginning to reclaim some of the ways of knowing that still have meaning and relevance to modern everyday life. People are rediscovering the importance of Indigenous Knowledge.” Mba Ngcobo, one of the participants in the project, showed how he and other members of his community had built a grain pit using old traditional knowledge. “It works really well,” he said, “it is amazing how these old ways really work. Our ancestors had marvellous ways of doing things. We can really appreciate the skills that are slowly being lost to us.” Mann explained how the traditional pit storage method produced carbon dioxide that keeps the grain fresh and insect-free for months. “Carbon dioxide storage is now the preferred way of many milling and storage companies to keep grain. It keeps grain fresh without having to resort to insecticides.”
- Full Text:
- Date Issued: 2002
Representations of women in women's magazines
- Authors: Ndzamela, Viwe
- Date: 2002
- Subjects: Women in mass media , Women's periodicals, South African
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3475 , http://hdl.handle.net/10962/d1002930 , Women in mass media , Women's periodicals, South African
- Description: Women’s magazines as a popular form of entertainment are among the media products that have been criticised for misrepresenting women. These popular magazines are often condemned for their failure to represent women in a positive light although they claim to target women as their market. The objective of this research is to assess and analyse representations of women in selected women’s magazines. Because women’s magazines are part of popular culture, which is not only concerned with the production process but also takes into consideration the needs of the readers, the research seeks to find out whether these magazines meet the expectations of its readers. The study is a combination of qualitative analysis, which looks at the frequency and the manner in which women are represented, with a qualitative interpretation of women’s roles within those representations. The issue of representations of women in women’s magazines is a very complex one as magazines, like other cultural texts are open to multiple interpretations. Consequently, multiple conclusions have been reached and the outcome of the study is therefore a series of three conclusions based on feature articles, advertisements and at a theoretical level.
- Full Text:
- Date Issued: 2002
- Authors: Ndzamela, Viwe
- Date: 2002
- Subjects: Women in mass media , Women's periodicals, South African
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3475 , http://hdl.handle.net/10962/d1002930 , Women in mass media , Women's periodicals, South African
- Description: Women’s magazines as a popular form of entertainment are among the media products that have been criticised for misrepresenting women. These popular magazines are often condemned for their failure to represent women in a positive light although they claim to target women as their market. The objective of this research is to assess and analyse representations of women in selected women’s magazines. Because women’s magazines are part of popular culture, which is not only concerned with the production process but also takes into consideration the needs of the readers, the research seeks to find out whether these magazines meet the expectations of its readers. The study is a combination of qualitative analysis, which looks at the frequency and the manner in which women are represented, with a qualitative interpretation of women’s roles within those representations. The issue of representations of women in women’s magazines is a very complex one as magazines, like other cultural texts are open to multiple interpretations. Consequently, multiple conclusions have been reached and the outcome of the study is therefore a series of three conclusions based on feature articles, advertisements and at a theoretical level.
- Full Text:
- Date Issued: 2002
Reproductive conflicts in honeybee colonies
- Pirk, Christian Walter Werner
- Authors: Pirk, Christian Walter Werner
- Date: 2002
- Subjects: Honeybee -- Reproduction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5755 , http://hdl.handle.net/10962/d1005443
- Description: In advanced eusocial hymenopteran societies workers have ovaries and can lay eggs, but are unable to mate. Workers are more related to their own offspring than to every other member of the colony. So worker reproduction contains both worker-worker and worker-queen conflict. The queen- worker conflict is discussed elsewhere, but if the queen mates with more than two males, worker policing should be selected to lower potential conflicts. However in the Cape honeybee it was predicted that worker policing is absent or less expressed than in other honeybee subspecies, because workers produce female offspring thelytokously. So laying workers and their offspring are nearly genetically identical, which results in the fact that other workers are as related to workers derived from eggs laid by the queen as laid by a worker. However, worker reproduction may be costly and therefore worker policing could be an evolutionary adaptation in the Cape honeybee to lower the costs derived from laying worker activity. Indeed, Cape honeybee colonies show efficient egg removal behaviour, suggesting that other factors like colony efficiency could favour egg removal behaviour. Since egg removal behaviour is a colony phenomenon, factors that affect colony performance could also affect egg removal behaviour. Egg removal behaviour was considerably affected by environmental changes, indicating that other tasks have a higher priority than egg removal behaviour. Thousands of queenright colonies of the neighbouring subspecies (A. m. scutellata) were taken over by laying A. m. capensis workers, showing that A. m. capensis workers are facultative social parasites. These observations strongly indicate that laying workers of A. m. capensis are able to evade worker policing and the inhibitory effects of the queen pheromones, but what potential strategies could these laying workers use to increase the survival of their eggs and evade the queen? On the one hand, egg removal behaviour is variable. One behavioural strategy of laying workers to achieve successful reproduction could be that they lay during periods with low egg removal behaviour. On the other hand, the inhibitory effect of the queen’s pheromones diminishes with distance. Maybe the level of egg removal also depends, like the inhibitory effect of the queen pheromones, on the distance from the queen. Indeed, further away from the queen the effect of the queen pheromone and the level of egg removal is reduced, making successful worker reproduction possible. In both subspecies, A. m. capensis and A. m. scutellata, egg removal behaviour is reduced further away from the queen. In the case of A. m. scutellata egg removal is lacking further away from the queen. This explains why colonies of scutellata are so prone to takeovers by laying Cape honeybee workers. One question in the context of parasitic Cape honeybees is how they manage to get into the host colony. One way could be that they get into the colonies during a natural colony merger which is common in African bees. Two unrelated colonies merged and it took them only 24 hours to show effective integration. Because both colonies are unrelated, the potential reproductive conflict among workers should be more strongly expressed than in a normal colony, which is not the result of a merger. Therefore, the effect of nestmate recognition for eggs on the egg removal behaviour was investigated. The results suggest that workers recognise the origin of an egg and that the standard policing experiments overestimate the level of egg removal and only represent relative values. Moreover, the results show that colony specific components on the eggs are more important than a postulated queen egg marking pheromone. Finally, for the first time empirical evidence from a population of the parasitic laying Cape honeybee workers, invading thousands of colonies of A. m. scutellata in northern South Africa, for a short-sighted selection theory is presented.
- Full Text:
- Date Issued: 2002
- Authors: Pirk, Christian Walter Werner
- Date: 2002
- Subjects: Honeybee -- Reproduction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5755 , http://hdl.handle.net/10962/d1005443
- Description: In advanced eusocial hymenopteran societies workers have ovaries and can lay eggs, but are unable to mate. Workers are more related to their own offspring than to every other member of the colony. So worker reproduction contains both worker-worker and worker-queen conflict. The queen- worker conflict is discussed elsewhere, but if the queen mates with more than two males, worker policing should be selected to lower potential conflicts. However in the Cape honeybee it was predicted that worker policing is absent or less expressed than in other honeybee subspecies, because workers produce female offspring thelytokously. So laying workers and their offspring are nearly genetically identical, which results in the fact that other workers are as related to workers derived from eggs laid by the queen as laid by a worker. However, worker reproduction may be costly and therefore worker policing could be an evolutionary adaptation in the Cape honeybee to lower the costs derived from laying worker activity. Indeed, Cape honeybee colonies show efficient egg removal behaviour, suggesting that other factors like colony efficiency could favour egg removal behaviour. Since egg removal behaviour is a colony phenomenon, factors that affect colony performance could also affect egg removal behaviour. Egg removal behaviour was considerably affected by environmental changes, indicating that other tasks have a higher priority than egg removal behaviour. Thousands of queenright colonies of the neighbouring subspecies (A. m. scutellata) were taken over by laying A. m. capensis workers, showing that A. m. capensis workers are facultative social parasites. These observations strongly indicate that laying workers of A. m. capensis are able to evade worker policing and the inhibitory effects of the queen pheromones, but what potential strategies could these laying workers use to increase the survival of their eggs and evade the queen? On the one hand, egg removal behaviour is variable. One behavioural strategy of laying workers to achieve successful reproduction could be that they lay during periods with low egg removal behaviour. On the other hand, the inhibitory effect of the queen’s pheromones diminishes with distance. Maybe the level of egg removal also depends, like the inhibitory effect of the queen pheromones, on the distance from the queen. Indeed, further away from the queen the effect of the queen pheromone and the level of egg removal is reduced, making successful worker reproduction possible. In both subspecies, A. m. capensis and A. m. scutellata, egg removal behaviour is reduced further away from the queen. In the case of A. m. scutellata egg removal is lacking further away from the queen. This explains why colonies of scutellata are so prone to takeovers by laying Cape honeybee workers. One question in the context of parasitic Cape honeybees is how they manage to get into the host colony. One way could be that they get into the colonies during a natural colony merger which is common in African bees. Two unrelated colonies merged and it took them only 24 hours to show effective integration. Because both colonies are unrelated, the potential reproductive conflict among workers should be more strongly expressed than in a normal colony, which is not the result of a merger. Therefore, the effect of nestmate recognition for eggs on the egg removal behaviour was investigated. The results suggest that workers recognise the origin of an egg and that the standard policing experiments overestimate the level of egg removal and only represent relative values. Moreover, the results show that colony specific components on the eggs are more important than a postulated queen egg marking pheromone. Finally, for the first time empirical evidence from a population of the parasitic laying Cape honeybee workers, invading thousands of colonies of A. m. scutellata in northern South Africa, for a short-sighted selection theory is presented.
- Full Text:
- Date Issued: 2002
Research projects
- Authors: Thomas, Chacko
- Date: 2002
- Subjects: Mathematics -- Study and teaching -- South Africa Competency-based education -- South Africa Mathematics teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1856 , http://hdl.handle.net/10962/d1004531
- Description: The South African education is undergoing transformation. The introduction of Curriculum 2005 and Outcome Based Education (OBE) are important aspects of this transformation process. The implementation of the new curriculum however, has not been smooth. A lack of adequately qualified and trained teachers and effective learning support materials have been identified as some of the major problems facing the implementation of OBE at school level. Even though the colleges of education in the country were not brought on board in the planning and implementation levels of the new curriculum, they could have played an important role in training of educators and developing learning materials for the successful take off of the new curriculum. In the first research project I look into the preparedness of the Mathematics Department of a college of education in the Eastern Cape towards the implementation of Outcome Based Education. The first part of the research project consists of a literature review on Curriculum 2005, Outcome Based Education and the expectations of teachers in the new curriculum and the research methodologies used. The findings revealed that the department, as a whole, was not adequately prepared for the implementation of outcome-based education even though there were some indications that the department effected some modifications in its curriculum and practice teaching. As an OBE facilitator and a college lecturer, I developed some learning materials in Linear Programming. These activity-oriented materials were based on constructivist principles and were used by my first year Secondary Teachers Diploma students. In the second research project, I reflect on the results of using these learning materials by my students. In the first chapter of the project, the context and background of the research and the reasons for selecting Linear Programming as the topic for preparing the learning material are described. This is followed by a brief overview of constructivism together with a brief explanation of the reasons for considering the material to be constructivist. The research paradigm followed in the project, the research techniques employed in evaluating the learning material and the strengths and weaknesses of the evaluation techniques are given in the next chapter. In the following chapter, the findings from the various data gathering methods and the results of the implementation of the material are described. The concluding chapter presents a critical reflection on the whole process involved in the material development. The post 1994 government in South Africa seems to attach much importance to mathematics, science and technology education. The majority of the population who were previously denied access to these subjects is given more opportunities to learn them. The international Mathematics Union declared 2000 as the World Mathematical Year. One of the aims of the activities organized as part of the celebrations was improving the public image of mathematics to realize the vision of "Mathematics For All". The South African government shows keen interest to improve mathematics education in the country in an attempt to realize the vision of Mathematics For All. Even though the accessibility rate to mathematics has increased, the success rate has not yet increased as anticipated. In this context I, as a post-graduate student in Mathematics Education, thought of /reviewing the concept of Mathematics For All in the South African context. In the third research project, which is a literature review, initially an attempt is made to unpack the concept of Mathematics for ALL. In analyzing the concept, answers are sought for questions like: What is mathematics and why should it be taught? It is followed by a brief review of some goals of mathematics education. Then the current situation of mathematics education in South Africa and the efforts to improve it are also looked at. This is followed by an analysis pf the reasons for the general unpopularity of mathematics. In the concluding part some suggestions for improving mathematics education in the country are given.
- Full Text:
- Date Issued: 2002
- Authors: Thomas, Chacko
- Date: 2002
- Subjects: Mathematics -- Study and teaching -- South Africa Competency-based education -- South Africa Mathematics teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1856 , http://hdl.handle.net/10962/d1004531
- Description: The South African education is undergoing transformation. The introduction of Curriculum 2005 and Outcome Based Education (OBE) are important aspects of this transformation process. The implementation of the new curriculum however, has not been smooth. A lack of adequately qualified and trained teachers and effective learning support materials have been identified as some of the major problems facing the implementation of OBE at school level. Even though the colleges of education in the country were not brought on board in the planning and implementation levels of the new curriculum, they could have played an important role in training of educators and developing learning materials for the successful take off of the new curriculum. In the first research project I look into the preparedness of the Mathematics Department of a college of education in the Eastern Cape towards the implementation of Outcome Based Education. The first part of the research project consists of a literature review on Curriculum 2005, Outcome Based Education and the expectations of teachers in the new curriculum and the research methodologies used. The findings revealed that the department, as a whole, was not adequately prepared for the implementation of outcome-based education even though there were some indications that the department effected some modifications in its curriculum and practice teaching. As an OBE facilitator and a college lecturer, I developed some learning materials in Linear Programming. These activity-oriented materials were based on constructivist principles and were used by my first year Secondary Teachers Diploma students. In the second research project, I reflect on the results of using these learning materials by my students. In the first chapter of the project, the context and background of the research and the reasons for selecting Linear Programming as the topic for preparing the learning material are described. This is followed by a brief overview of constructivism together with a brief explanation of the reasons for considering the material to be constructivist. The research paradigm followed in the project, the research techniques employed in evaluating the learning material and the strengths and weaknesses of the evaluation techniques are given in the next chapter. In the following chapter, the findings from the various data gathering methods and the results of the implementation of the material are described. The concluding chapter presents a critical reflection on the whole process involved in the material development. The post 1994 government in South Africa seems to attach much importance to mathematics, science and technology education. The majority of the population who were previously denied access to these subjects is given more opportunities to learn them. The international Mathematics Union declared 2000 as the World Mathematical Year. One of the aims of the activities organized as part of the celebrations was improving the public image of mathematics to realize the vision of "Mathematics For All". The South African government shows keen interest to improve mathematics education in the country in an attempt to realize the vision of Mathematics For All. Even though the accessibility rate to mathematics has increased, the success rate has not yet increased as anticipated. In this context I, as a post-graduate student in Mathematics Education, thought of /reviewing the concept of Mathematics For All in the South African context. In the third research project, which is a literature review, initially an attempt is made to unpack the concept of Mathematics for ALL. In analyzing the concept, answers are sought for questions like: What is mathematics and why should it be taught? It is followed by a brief review of some goals of mathematics education. Then the current situation of mathematics education in South Africa and the efforts to improve it are also looked at. This is followed by an analysis pf the reasons for the general unpopularity of mathematics. In the concluding part some suggestions for improving mathematics education in the country are given.
- Full Text:
- Date Issued: 2002
Restoring democratic governance in Zimbabwe: a critical investigation of the internet as a possible means of creating new sites of struggle for positive democratic change by Zimbabwean media and activists in Zimbabwe
- Authors: Vennard, Francisca Caroline
- Date: 2002
- Subjects: Zimbabwe -- Politics and government -- 1980- , Internet in publicity , Press and politics -- Zimbabwe , Freedom of the press -- Zimbabwe , Digital media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2837 , http://hdl.handle.net/10962/d1003047 , Zimbabwe -- Politics and government -- 1980- , Internet in publicity , Press and politics -- Zimbabwe , Freedom of the press -- Zimbabwe , Digital media
- Description: This thesis is a reaction to the state of utter lawlessness and the abuse of human rights by those in power in Zimbabwe over the past two years and it investigates the possibility of restoring democratic governance in that country by increasing the freedom of expression and media freedom, which is considered to be one of the most valuable elements in advancing democratization. Its aim is to establish the Internet as the best means possible to increasing media freedom and creating new ‘sites of struggle’ for activists in a context where the substantive freedom of expression does not exist. This in turn is shown to advance levels of democracy. To this end, the value of the freedom of expression to media freedom and the value of the latter to increasing levels of democracy is developed and the lack of democracy in Zimbabwe at all levels of society is considered. The Internet is seen to increase the freedoms of speech and association in new and interesting ways and it is discussed in various examples in which it has already been instrumental in evading the censorship of the media and increasing the ability of activists to express themselves freely and to organize more efficiently. Finally, the resources that Internet technology makes available to African journalists and activists are considered along with lessons gleaned from international examples of successful Internet use and it is shown to already be of use to Zimbabwean journalists and activists as they create to new cyberspaces in which they can struggle for positive democratic change in Zimbabwe. The Internet is also shown to have tremendous potential for future use in that country.
- Full Text:
- Date Issued: 2002
- Authors: Vennard, Francisca Caroline
- Date: 2002
- Subjects: Zimbabwe -- Politics and government -- 1980- , Internet in publicity , Press and politics -- Zimbabwe , Freedom of the press -- Zimbabwe , Digital media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2837 , http://hdl.handle.net/10962/d1003047 , Zimbabwe -- Politics and government -- 1980- , Internet in publicity , Press and politics -- Zimbabwe , Freedom of the press -- Zimbabwe , Digital media
- Description: This thesis is a reaction to the state of utter lawlessness and the abuse of human rights by those in power in Zimbabwe over the past two years and it investigates the possibility of restoring democratic governance in that country by increasing the freedom of expression and media freedom, which is considered to be one of the most valuable elements in advancing democratization. Its aim is to establish the Internet as the best means possible to increasing media freedom and creating new ‘sites of struggle’ for activists in a context where the substantive freedom of expression does not exist. This in turn is shown to advance levels of democracy. To this end, the value of the freedom of expression to media freedom and the value of the latter to increasing levels of democracy is developed and the lack of democracy in Zimbabwe at all levels of society is considered. The Internet is seen to increase the freedoms of speech and association in new and interesting ways and it is discussed in various examples in which it has already been instrumental in evading the censorship of the media and increasing the ability of activists to express themselves freely and to organize more efficiently. Finally, the resources that Internet technology makes available to African journalists and activists are considered along with lessons gleaned from international examples of successful Internet use and it is shown to already be of use to Zimbabwean journalists and activists as they create to new cyberspaces in which they can struggle for positive democratic change in Zimbabwe. The Internet is also shown to have tremendous potential for future use in that country.
- Full Text:
- Date Issued: 2002
Rhodes University Graduation Ceremony 2002
- Authors: Rhodes University
- Date: 2002
- Language: English
- Type: text
- Identifier: vital:8145 , http://hdl.handle.net/10962/d1007267
- Description: Rhodes University Graduation Ceremonies 1820 Settlers National Monument Friday, 5 April 2002 at 10:30; 14:30 & 18:00 [and] Saturday, 6 April 2002 at 10:30 , Graduation Ceremony Christian Centre, Wyse Street, East London Friday, 10 May 2002 at 18:00
- Full Text:
- Date Issued: 2002
- Authors: Rhodes University
- Date: 2002
- Language: English
- Type: text
- Identifier: vital:8145 , http://hdl.handle.net/10962/d1007267
- Description: Rhodes University Graduation Ceremonies 1820 Settlers National Monument Friday, 5 April 2002 at 10:30; 14:30 & 18:00 [and] Saturday, 6 April 2002 at 10:30 , Graduation Ceremony Christian Centre, Wyse Street, East London Friday, 10 May 2002 at 18:00
- Full Text:
- Date Issued: 2002
Rhodes University Research Report 2002
- Authors: Rhodes University
- Date: 2002
- Language: English
- Type: Text
- Identifier: vital:557 , http://hdl.handle.net/10962/d1011943
- Description: [From Introduction] This is the first formal research report published by Rhodes University in this format. Each Department’s/Faculty’s highlights have been included as provided by the Head of Department as well as the research outputs produced. In addition, a table of provisional subsidy units earned by each Department/Faculty have been included as there is often a misconception that one journal article equates to one subsidy unit. This is the case if all the authors are from Rhodes University but where joint articles are written, a pro-rata share is calculated. Likewise due to the complex funding formula calculated by the Department of Education, the total research outputs produced do not equate directly to the subsidisable units. Please note that "in press" articles in 2001 but published in 2002 have already been claimed in 2001 and hence will not appear in the table but are recorded in the report. Articles that have been submitted for possible publication have not been included in the table nor the report as there is no way of proving that the articles have been accepted for publication by the time our submission to the Department of Education was audited. Also please note that subsidy units earned for book/chapter/patent/conference proceedings publications are not included in the subsidy unit tables since we receive no feedback from the Department of Education in terms of which books/chapters/patents/proceedings are finally accepted for subsidy purposes each year. Only a small fraction of such books, chapters, patents and proceedings which are submitted actually receive subsidy. I would like to stress the need to publish in subsidisable journals and submit accurate information so that the University can claim as many units as possible. The total audited (but not yet awarded) publication subsidy units for journal articles which have been submitted to the Department of Education for 2002 is 206.64 units. The average number of units awarded for the past three years (1999-2001) was 205.35 units. Based on past performance, the University can expect to earn an additional ±11.85 subsidy units for book, chapters, patents and proceedings publications in 2002. Publications in current non-subsidy earning journals in 2002 amounted to 16.00 units. These have been forwarded to the Department of Education for consideration for subsidy purposes. Finally, I would like to add my congratulations to that of the Vice-Chancellor to all staff and postgraduate students for their research efforts in 2002.
- Full Text:
- Date Issued: 2002
- Authors: Rhodes University
- Date: 2002
- Language: English
- Type: Text
- Identifier: vital:557 , http://hdl.handle.net/10962/d1011943
- Description: [From Introduction] This is the first formal research report published by Rhodes University in this format. Each Department’s/Faculty’s highlights have been included as provided by the Head of Department as well as the research outputs produced. In addition, a table of provisional subsidy units earned by each Department/Faculty have been included as there is often a misconception that one journal article equates to one subsidy unit. This is the case if all the authors are from Rhodes University but where joint articles are written, a pro-rata share is calculated. Likewise due to the complex funding formula calculated by the Department of Education, the total research outputs produced do not equate directly to the subsidisable units. Please note that "in press" articles in 2001 but published in 2002 have already been claimed in 2001 and hence will not appear in the table but are recorded in the report. Articles that have been submitted for possible publication have not been included in the table nor the report as there is no way of proving that the articles have been accepted for publication by the time our submission to the Department of Education was audited. Also please note that subsidy units earned for book/chapter/patent/conference proceedings publications are not included in the subsidy unit tables since we receive no feedback from the Department of Education in terms of which books/chapters/patents/proceedings are finally accepted for subsidy purposes each year. Only a small fraction of such books, chapters, patents and proceedings which are submitted actually receive subsidy. I would like to stress the need to publish in subsidisable journals and submit accurate information so that the University can claim as many units as possible. The total audited (but not yet awarded) publication subsidy units for journal articles which have been submitted to the Department of Education for 2002 is 206.64 units. The average number of units awarded for the past three years (1999-2001) was 205.35 units. Based on past performance, the University can expect to earn an additional ±11.85 subsidy units for book, chapters, patents and proceedings publications in 2002. Publications in current non-subsidy earning journals in 2002 amounted to 16.00 units. These have been forwarded to the Department of Education for consideration for subsidy purposes. Finally, I would like to add my congratulations to that of the Vice-Chancellor to all staff and postgraduate students for their research efforts in 2002.
- Full Text:
- Date Issued: 2002
Rumours of war : de-constructing media discourses of HIV/AIDS in South Africa
- Authors: Connelly, Mark
- Date: 2002
- Subjects: AIDS (Disease) -- South Africa AIDS (Disease) in mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3177 , http://hdl.handle.net/10962/d1007844
- Description: This paper explores discourses of HIV/AIDS evident in a South African daily newspaper from 1985 to 2000, and discusses the implications of these in terms of the way in which HIV/AIDS is constructed in society. In this paper I utilize a Foucauldian analysis of the relationship between power and knowledge. The discursive framework of the war against HIV/AIDS is used to show how different groups of subjects are positioned in relations of power. Within this the power of western science and medicine is influential and supports and informs other discourses of HIV/AIDS. I argue that the discursive framework constructing HIV/AIDS as a war does far more than provide a useful vehicle within which HIV/AIDS can be understood as it supports certain institutions and groups of people above others. The paper concludes by identifying the silenced voices of women and dissidents, and calling for greater reflection concerning the critical analysis of current issues surrounding HIV/AIDS.
- Full Text:
- Date Issued: 2002
- Authors: Connelly, Mark
- Date: 2002
- Subjects: AIDS (Disease) -- South Africa AIDS (Disease) in mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3177 , http://hdl.handle.net/10962/d1007844
- Description: This paper explores discourses of HIV/AIDS evident in a South African daily newspaper from 1985 to 2000, and discusses the implications of these in terms of the way in which HIV/AIDS is constructed in society. In this paper I utilize a Foucauldian analysis of the relationship between power and knowledge. The discursive framework of the war against HIV/AIDS is used to show how different groups of subjects are positioned in relations of power. Within this the power of western science and medicine is influential and supports and informs other discourses of HIV/AIDS. I argue that the discursive framework constructing HIV/AIDS as a war does far more than provide a useful vehicle within which HIV/AIDS can be understood as it supports certain institutions and groups of people above others. The paper concludes by identifying the silenced voices of women and dissidents, and calling for greater reflection concerning the critical analysis of current issues surrounding HIV/AIDS.
- Full Text:
- Date Issued: 2002
Science for all - myth or reality?: a research project
- Authors: Valiathazhel, James Daniel
- Date: 2002
- Subjects: Science -- Study and teaching -- South Africa Motion -- Study and teaching -- South Africa Physics -- Study and teaching -- South Africa Competency-based education -- South Africa Educational change -- South Africa Technical institutes -- South Africa Technical education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1847 , http://hdl.handle.net/10962/d1004391
- Description: Abstract: Transformation at a historically disadvantaged technikon in South Africa : a research project: South Africa is in the seventh year of democracy. During the first term of office, the ANC government proposed radical shift from the system(s) of education that was/were in existence in this country. A change in the education system in South Africa was inevitable. The ANC government have realised the need and proposed plans for a change in the education system in this country. We might be able to overcome the inequalities of the past and have an education system relevant for all South Africans that promote an equal opportunity for success as envisaged by Outcomes Based Education (OBE). This research project, using a qualitative case study methodology, reports on the readiness of Border Technikon in implementing Outcomes Based Education (OBE) as a teaching/lecturing strategy. Since 1998 Border Technikon organised a series of staff training workshops to empower the academic staff in Outcomes Based Education. A preliminary study on the topic was conducted during 1999, in which questionnaires (to 16 academic staff) and semi-structured interviews (with three academic staff) were used to collect data. During 2000, when the second and final round of this study was conducted semistructured interviews were employed with 4 staff members to gather data. Literature review and document analysis was also part of the research. The analysis of data indicated that the very nature of most of the Technikon Programmes demands an OBE approach in teaching/lecturing and hence OBE based teaching/lecturing is largely practised at Border Technikon. However a few areas of concerns were identified. Some of these concerns were: (i) Technikon employed academic staff (from industry, etc...) with no professional qualification in teaching and it was difficult to provide OBE training to such people and (ii) lack of sufficient support from the Technikon Management might be a cause for the poor attendance of academic staff during the training programme. Another aspect emerged from the data analysis was that all academic staff participated in this study expressed the need for further training in OBE and related topics. Abstract: Science for all - myth or reality?: Different educational projects around the world have made Scientific Literacy a world-wide concern. This study through a literature review shows that Scientific Literacy is a term that has many definitions and interpretations. This literature review reveals that, in the present system Science for All is a myth for various reasons. Governments around the world in general, and South Africa in particular, are in the process of introducing different projects such as the Year of Science and Technology (YEAST), science week and science exhibitions for the purpose of popularising science and technology. The Department of Education in Thailand has modified its education system to accommodate Science for All. In this literature review among other issues the status quo in South African science education and the Thailand model were examined. A few recommendations to achieve Science for All are also included in this project. Abstract: Developing and evaluating the use of learning material in science - a constructivist approach towards learning Newton's laws : a research project: The Government of National Unity in 1994 introduced a new educational policy for South Africa. This represented a shift in paradigm from a transmission mode of teaching and learning to a learner-centred education. The shift marks a transformation from a content-based curriculum to an Outcomes Based Education (OBE). Various authors found that different sections in the Physical Science syllabus in South Africa are often misunderstood by students for different reasons. One of the reasons was that students had their own ideas about laws of nature and these (mis)conceptions were resistant to change. From the literature and from the author's personal experience it was found that Bodies in Motion is a topic that is difficult to conceptualise by students of different age groups. The challenge facing educators is how to tackle this issue. In this research project a diagnostic test is developed and used to identify the topics where students have conceptual problems. To address these problem areas further, concept sheets/work sheets where developed and implemented. The different challenges and tasks given in the work sheets/learning material are organised in such a way as to make the students aware of their own ideas about Bodies in Motion in general and the key-concepts in particular and also to make them aware of the ideas of their peers (group members). It was also aimed at offering the learners the scientific alternative to their own beliefs. At the end, it was discovered that, even though the general understanding of the learners has improved in this topic (namely, Bodies in Motion), their original beliefs were largely unaffected. It is the hope of the researcher that the project would be the basis for further research on the development of learning material in science.
- Full Text:
- Date Issued: 2002
- Authors: Valiathazhel, James Daniel
- Date: 2002
- Subjects: Science -- Study and teaching -- South Africa Motion -- Study and teaching -- South Africa Physics -- Study and teaching -- South Africa Competency-based education -- South Africa Educational change -- South Africa Technical institutes -- South Africa Technical education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1847 , http://hdl.handle.net/10962/d1004391
- Description: Abstract: Transformation at a historically disadvantaged technikon in South Africa : a research project: South Africa is in the seventh year of democracy. During the first term of office, the ANC government proposed radical shift from the system(s) of education that was/were in existence in this country. A change in the education system in South Africa was inevitable. The ANC government have realised the need and proposed plans for a change in the education system in this country. We might be able to overcome the inequalities of the past and have an education system relevant for all South Africans that promote an equal opportunity for success as envisaged by Outcomes Based Education (OBE). This research project, using a qualitative case study methodology, reports on the readiness of Border Technikon in implementing Outcomes Based Education (OBE) as a teaching/lecturing strategy. Since 1998 Border Technikon organised a series of staff training workshops to empower the academic staff in Outcomes Based Education. A preliminary study on the topic was conducted during 1999, in which questionnaires (to 16 academic staff) and semi-structured interviews (with three academic staff) were used to collect data. During 2000, when the second and final round of this study was conducted semistructured interviews were employed with 4 staff members to gather data. Literature review and document analysis was also part of the research. The analysis of data indicated that the very nature of most of the Technikon Programmes demands an OBE approach in teaching/lecturing and hence OBE based teaching/lecturing is largely practised at Border Technikon. However a few areas of concerns were identified. Some of these concerns were: (i) Technikon employed academic staff (from industry, etc...) with no professional qualification in teaching and it was difficult to provide OBE training to such people and (ii) lack of sufficient support from the Technikon Management might be a cause for the poor attendance of academic staff during the training programme. Another aspect emerged from the data analysis was that all academic staff participated in this study expressed the need for further training in OBE and related topics. Abstract: Science for all - myth or reality?: Different educational projects around the world have made Scientific Literacy a world-wide concern. This study through a literature review shows that Scientific Literacy is a term that has many definitions and interpretations. This literature review reveals that, in the present system Science for All is a myth for various reasons. Governments around the world in general, and South Africa in particular, are in the process of introducing different projects such as the Year of Science and Technology (YEAST), science week and science exhibitions for the purpose of popularising science and technology. The Department of Education in Thailand has modified its education system to accommodate Science for All. In this literature review among other issues the status quo in South African science education and the Thailand model were examined. A few recommendations to achieve Science for All are also included in this project. Abstract: Developing and evaluating the use of learning material in science - a constructivist approach towards learning Newton's laws : a research project: The Government of National Unity in 1994 introduced a new educational policy for South Africa. This represented a shift in paradigm from a transmission mode of teaching and learning to a learner-centred education. The shift marks a transformation from a content-based curriculum to an Outcomes Based Education (OBE). Various authors found that different sections in the Physical Science syllabus in South Africa are often misunderstood by students for different reasons. One of the reasons was that students had their own ideas about laws of nature and these (mis)conceptions were resistant to change. From the literature and from the author's personal experience it was found that Bodies in Motion is a topic that is difficult to conceptualise by students of different age groups. The challenge facing educators is how to tackle this issue. In this research project a diagnostic test is developed and used to identify the topics where students have conceptual problems. To address these problem areas further, concept sheets/work sheets where developed and implemented. The different challenges and tasks given in the work sheets/learning material are organised in such a way as to make the students aware of their own ideas about Bodies in Motion in general and the key-concepts in particular and also to make them aware of the ideas of their peers (group members). It was also aimed at offering the learners the scientific alternative to their own beliefs. At the end, it was discovered that, even though the general understanding of the learners has improved in this topic (namely, Bodies in Motion), their original beliefs were largely unaffected. It is the hope of the researcher that the project would be the basis for further research on the development of learning material in science.
- Full Text:
- Date Issued: 2002
Secretariate report - Mobilise and invest for a sustainable cadre development
- NUM
- Authors: NUM
- Date: 2002
- Subjects: NUM
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/149517 , vital:38860
- Description: Three years ago this Province under the banner of the Western Cape National Union of Mineworkers gathered in this constitutional structure, the Regional conference under the slogan “Develop Leadership to Advance Socialism”. That conference then declared and adopted a comprehensive programme of action to take forward that Regional conference declaration. That the regional committee should and within the broad framework of the declaration ensure that the NUM in a regional context fight for better working conditions of our members. That the RC develops concrete programmes for the broader structures and membership to understand and ultimately be implemented at those levels. This conference has to deal with the assessment of the progress made during this period under review. Within the context of contestation forward mobility is ensured that seeks to help build the working class leadership which is ultimately or essentially political leadership. Worker control is one of the key founding principles of our union which will be better understood and implemented when we are to begin to find synergy between the worker leadership and the intellectual capacity within our organisation. This report will deal with the different chapters as identified. This report will also deal with our participation in COSATU structures as well as lack of cohesiveness between branch leaders and general membership and also the possible fear to engage. We will also try and attempt to discuss the lack of information flow from our structures to the broader membership. As we engage this report, let us try to use our organisational tools to resolve the problems facing our region and in particular the branches and as a result find suitable solutions to build and strengthen the organisation.
- Full Text:
- Date Issued: 2002
- Authors: NUM
- Date: 2002
- Subjects: NUM
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/149517 , vital:38860
- Description: Three years ago this Province under the banner of the Western Cape National Union of Mineworkers gathered in this constitutional structure, the Regional conference under the slogan “Develop Leadership to Advance Socialism”. That conference then declared and adopted a comprehensive programme of action to take forward that Regional conference declaration. That the regional committee should and within the broad framework of the declaration ensure that the NUM in a regional context fight for better working conditions of our members. That the RC develops concrete programmes for the broader structures and membership to understand and ultimately be implemented at those levels. This conference has to deal with the assessment of the progress made during this period under review. Within the context of contestation forward mobility is ensured that seeks to help build the working class leadership which is ultimately or essentially political leadership. Worker control is one of the key founding principles of our union which will be better understood and implemented when we are to begin to find synergy between the worker leadership and the intellectual capacity within our organisation. This report will deal with the different chapters as identified. This report will also deal with our participation in COSATU structures as well as lack of cohesiveness between branch leaders and general membership and also the possible fear to engage. We will also try and attempt to discuss the lack of information flow from our structures to the broader membership. As we engage this report, let us try to use our organisational tools to resolve the problems facing our region and in particular the branches and as a result find suitable solutions to build and strengthen the organisation.
- Full Text:
- Date Issued: 2002
Selecting an appropriate process for the formulating of an operations strategy for Bridgestone/Firestone, Port Elizabeth plant, in a changed market environment
- Authors: Jeena, Umesh
- Date: 2002
- Subjects: Tire industry -- South Africa -- Port Elizabeth -- Management , Bridgestone/Firestone (Firm)
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10945 , http://hdl.handle.net/10948/d1011325 , Tire industry -- South Africa -- Port Elizabeth -- Management , Bridgestone/Firestone (Firm)
- Description: The research problem addressed in this study was aimed in assisting the management of Bridgestone/Firestone, Port Elizabeth plant, in selecting an appropriate process for the formulation of an operations strategy. The author embarked on a literature survey to gain understanding of the challenges that are occurring in the market environment. The theories and techniques around operational strategies were extensively researched in an effort to effectively and efficiently assist the management of Firestone in achieving a competitive advantage over rival competitors. Other areas of focus include the content, development, principles and concepts in developing an operations strategy. The author details the process of the formulation of an operations strategy as well as the discussion of four models/procedures deployed in organisations that would enhance strategy formulation. It is evident from the findings of the empirical study that a high percentage of the respondents “agree” that the strategy deployed within Bridgestone/Firestone, Port Elizabeth plant is appropriate, yet an alarmingly high percentage believe it to be “ineffective.
- Full Text:
- Date Issued: 2002
- Authors: Jeena, Umesh
- Date: 2002
- Subjects: Tire industry -- South Africa -- Port Elizabeth -- Management , Bridgestone/Firestone (Firm)
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10945 , http://hdl.handle.net/10948/d1011325 , Tire industry -- South Africa -- Port Elizabeth -- Management , Bridgestone/Firestone (Firm)
- Description: The research problem addressed in this study was aimed in assisting the management of Bridgestone/Firestone, Port Elizabeth plant, in selecting an appropriate process for the formulation of an operations strategy. The author embarked on a literature survey to gain understanding of the challenges that are occurring in the market environment. The theories and techniques around operational strategies were extensively researched in an effort to effectively and efficiently assist the management of Firestone in achieving a competitive advantage over rival competitors. Other areas of focus include the content, development, principles and concepts in developing an operations strategy. The author details the process of the formulation of an operations strategy as well as the discussion of four models/procedures deployed in organisations that would enhance strategy formulation. It is evident from the findings of the empirical study that a high percentage of the respondents “agree” that the strategy deployed within Bridgestone/Firestone, Port Elizabeth plant is appropriate, yet an alarmingly high percentage believe it to be “ineffective.
- Full Text:
- Date Issued: 2002
Self-respecting practical reason: an analysis of self-respect and its implications for practical reason
- Authors: Roberts, Deborah Joan
- Date: 2002
- Subjects: Williams, Bernard Arthur Owen -- Ethics , Ethics, Modern -- 20th century , Self-esteem
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2719 , http://hdl.handle.net/10962/d1002849 , Williams, Bernard Arthur Owen -- Ethics , Ethics, Modern -- 20th century , Self-esteem
- Description: What should I do? As long as I am aware of the relevant facts of the situation and deliberating soundly, Bernard Williams argues that I should do what I want to do. It makes no sense to say that there are reasons that are fixed objects of concern, or values, that exist for an agent regardless of what she is in fact motivated to do. Reasons, for Williams, are hypothetical. I argue that he takes this view of practical reason because of a prior answer to the question “How should I live?”. A universal account of the good life would mean an account of values, or interests, that all human beings should have. Williams thinks it is not possible to give a universal account of the good life for human beings; any such account must be constructed out of the particular reasons of a community. But, he takes a constructivist view of the good life because he thinks that to be universal an account of the good life would have to be objective. Since objectivity cannot be achieved, he argues, neither can universality. Williams is only half right. That objectivity is not possible is inconsequential. A foundation for ethics has to be internal, but this does not preclude it being universal. I develop such a foundation based on the Aristotelian conception of human nature. A life cannot be wholly good if it is not self-respecting. Moreover, self-respect fits the framework for the specification of the good life that this foundation provides: I argue that self-respect can be shown to have a structure which provides an account of real interests - reasons that are objects of fixed concern. As such, reasons recognise rather than construct the good, making categorical reasons possible. A person can have a reason to change or act, even if reason itself cannot effect that change or action. Thus, I can be wrong about what I should do not only by being wrong about what would count as a satisfaction of my interests, but also by being wrong about what my interests are.
- Full Text:
- Date Issued: 2002
- Authors: Roberts, Deborah Joan
- Date: 2002
- Subjects: Williams, Bernard Arthur Owen -- Ethics , Ethics, Modern -- 20th century , Self-esteem
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2719 , http://hdl.handle.net/10962/d1002849 , Williams, Bernard Arthur Owen -- Ethics , Ethics, Modern -- 20th century , Self-esteem
- Description: What should I do? As long as I am aware of the relevant facts of the situation and deliberating soundly, Bernard Williams argues that I should do what I want to do. It makes no sense to say that there are reasons that are fixed objects of concern, or values, that exist for an agent regardless of what she is in fact motivated to do. Reasons, for Williams, are hypothetical. I argue that he takes this view of practical reason because of a prior answer to the question “How should I live?”. A universal account of the good life would mean an account of values, or interests, that all human beings should have. Williams thinks it is not possible to give a universal account of the good life for human beings; any such account must be constructed out of the particular reasons of a community. But, he takes a constructivist view of the good life because he thinks that to be universal an account of the good life would have to be objective. Since objectivity cannot be achieved, he argues, neither can universality. Williams is only half right. That objectivity is not possible is inconsequential. A foundation for ethics has to be internal, but this does not preclude it being universal. I develop such a foundation based on the Aristotelian conception of human nature. A life cannot be wholly good if it is not self-respecting. Moreover, self-respect fits the framework for the specification of the good life that this foundation provides: I argue that self-respect can be shown to have a structure which provides an account of real interests - reasons that are objects of fixed concern. As such, reasons recognise rather than construct the good, making categorical reasons possible. A person can have a reason to change or act, even if reason itself cannot effect that change or action. Thus, I can be wrong about what I should do not only by being wrong about what would count as a satisfaction of my interests, but also by being wrong about what my interests are.
- Full Text:
- Date Issued: 2002
Sensorless speed estimation in three phase induction motors
- Authors: Govindsamy, Matthew
- Date: 2002
- Subjects: Electric motors, induction , Electronic controllers
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10810 , http://hdl.handle.net/10948/139 , Electric motors, induction , Electronic controllers
- Description: This thesis proposes a technique to determine and improve the performance of a sensorless speed estimator for an induction motor based on Motor Current Signature Analysis (MCSA). The theoretical concepts underlying the parameter based observer are developed first and then the model of the observer is built using Simulink. The observer is developed based on Model Reference Adaptive System (MRAS). The dynamic performance of the observer and its behavior due to variation of machine parameters is studied. The error in speed estimated using this observer is shown and the ability of MCSA to retune the rotor speed from the stator current spectrum. The spectrum estimation technique has been implemented using a software routine in Matlab. Both the observer and MCSA techniques were implemented practically on an induction motor. The performance of the combined sensorless speed estimation system was tested and verified.
- Full Text:
- Date Issued: 2002
- Authors: Govindsamy, Matthew
- Date: 2002
- Subjects: Electric motors, induction , Electronic controllers
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10810 , http://hdl.handle.net/10948/139 , Electric motors, induction , Electronic controllers
- Description: This thesis proposes a technique to determine and improve the performance of a sensorless speed estimator for an induction motor based on Motor Current Signature Analysis (MCSA). The theoretical concepts underlying the parameter based observer are developed first and then the model of the observer is built using Simulink. The observer is developed based on Model Reference Adaptive System (MRAS). The dynamic performance of the observer and its behavior due to variation of machine parameters is studied. The error in speed estimated using this observer is shown and the ability of MCSA to retune the rotor speed from the stator current spectrum. The spectrum estimation technique has been implemented using a software routine in Matlab. Both the observer and MCSA techniques were implemented practically on an induction motor. The performance of the combined sensorless speed estimation system was tested and verified.
- Full Text:
- Date Issued: 2002