Educational computing in secondary schools of the Cape Education Department: a research survey to assess computing facility acquisition and its utilization
- Authors: Bean, Pat
- Date: 1992
- Subjects: Education, Secondary -- South Africa -- Data processing Education, Secondary -- South Africa -- Computer network resources Computer-assisted instruction -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1505 , http://hdl.handle.net/10962/d1003387
- Description: Secondary schools under the jurisdiction of the Cape Education Department (CED) have, over the past 10 years, been acquiring computer equipment without a national policy on educational computing in South Africa, and within only broad parameters provided by their department. The aim of this study was to determine the present status of educational computing in these schools. A literature survey on educational computing was undertaken and a number of international and local 'computers-in-schools' initiatives were elucidated. A field survey, involving all CED secondary schools (239), was initiated by sending questionnaires to principals of these schools - a return rate of 89% was achieved. The results of the research revealed that most CED secondary schools have already acquired computer facilities. The role of pressure groups such as teachers, parents, business sector etc together with other factors that might have influenced schools in acquiring their computer facilities was also investigated. The investigation also revealed where and how these facilities are being utilised: most schools use their computers for administrative functions, with the computer-as-a-tool for teachers and pupils also fast gaining ground. Computer-assisted learning activities, where the computer is integrated with subject curricula, are however still limited. The extent of both teachers' formal training in educational computing and their familiarity with different software applications were also determined. Schools were also required to indicate the areas where they experience problems in getting teachers and pupils more involved in 'computers-in-education' activities. The present educational computing position in secondary schools of the CED will have to serve as a foundation for the department's CISR Project embarked upon in 1991.
- Full Text:
- Date Issued: 1992
- Authors: Bean, Pat
- Date: 1992
- Subjects: Education, Secondary -- South Africa -- Data processing Education, Secondary -- South Africa -- Computer network resources Computer-assisted instruction -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1505 , http://hdl.handle.net/10962/d1003387
- Description: Secondary schools under the jurisdiction of the Cape Education Department (CED) have, over the past 10 years, been acquiring computer equipment without a national policy on educational computing in South Africa, and within only broad parameters provided by their department. The aim of this study was to determine the present status of educational computing in these schools. A literature survey on educational computing was undertaken and a number of international and local 'computers-in-schools' initiatives were elucidated. A field survey, involving all CED secondary schools (239), was initiated by sending questionnaires to principals of these schools - a return rate of 89% was achieved. The results of the research revealed that most CED secondary schools have already acquired computer facilities. The role of pressure groups such as teachers, parents, business sector etc together with other factors that might have influenced schools in acquiring their computer facilities was also investigated. The investigation also revealed where and how these facilities are being utilised: most schools use their computers for administrative functions, with the computer-as-a-tool for teachers and pupils also fast gaining ground. Computer-assisted learning activities, where the computer is integrated with subject curricula, are however still limited. The extent of both teachers' formal training in educational computing and their familiarity with different software applications were also determined. Schools were also required to indicate the areas where they experience problems in getting teachers and pupils more involved in 'computers-in-education' activities. The present educational computing position in secondary schools of the CED will have to serve as a foundation for the department's CISR Project embarked upon in 1991.
- Full Text:
- Date Issued: 1992
Educational needs of adults in Mdantsane
- McAllister, Patrick A, Young, Michael, Manona, Cecil Wele, Hart, Jo
- Authors: McAllister, Patrick A , Young, Michael , Manona, Cecil Wele , Hart, Jo
- Date: 1992
- Subjects: Adult education -- South Africa -- Mdantsane (Ciskei) Adult education -- South Africa -- Mdantsane (Ciskei) -- Case studies
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2079 , vital:20253 , ISBN 0868102423
- Description: The purpose of the study was to collect some preliminary information in advance of the inauguration of a new educational project at Fort Hare University which, under the guidance of a new Vice-Chancellor, Dr. S.M.E. Bengu, is forging for itself a new course of development as a people's University. The new project arises out of a report prepared by the International Extension College for the University of Fort Hare. The hope is that a number of innovations can be introduced into adult education in the Eastern Cape which will prove of value in meeting the needs of people living in different kinds of localities. The planning will begin in the early winter, as soon as staff have assembled, and as soon as Dr. David Warr, the international consultant to the project, is in post. It seemed sensible to conduct, in advance, one of the surveys which will be needed to underpin plans. To do this at short notice and complete it in a short time (the work did not commence until February, 1992) the best course was to rely on an experienced team from a neighbouring University, Rhodes, which had already conducted surveys in different districts within the Eastern Cape, and to bring in further support from the University of Natal , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1992
- Authors: McAllister, Patrick A , Young, Michael , Manona, Cecil Wele , Hart, Jo
- Date: 1992
- Subjects: Adult education -- South Africa -- Mdantsane (Ciskei) Adult education -- South Africa -- Mdantsane (Ciskei) -- Case studies
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2079 , vital:20253 , ISBN 0868102423
- Description: The purpose of the study was to collect some preliminary information in advance of the inauguration of a new educational project at Fort Hare University which, under the guidance of a new Vice-Chancellor, Dr. S.M.E. Bengu, is forging for itself a new course of development as a people's University. The new project arises out of a report prepared by the International Extension College for the University of Fort Hare. The hope is that a number of innovations can be introduced into adult education in the Eastern Cape which will prove of value in meeting the needs of people living in different kinds of localities. The planning will begin in the early winter, as soon as staff have assembled, and as soon as Dr. David Warr, the international consultant to the project, is in post. It seemed sensible to conduct, in advance, one of the surveys which will be needed to underpin plans. To do this at short notice and complete it in a short time (the work did not commence until February, 1992) the best course was to rely on an experienced team from a neighbouring University, Rhodes, which had already conducted surveys in different districts within the Eastern Cape, and to bring in further support from the University of Natal , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1992
Environmental education in primary schools in Bophuthatswana : a case study in curriculum implementation
- Authors: Shongwe, Doctor Petrus
- Date: 1992
- Subjects: Environmental education -- South Africa -- Bophuthatswana , Primary school teaching -- Research -- South Africa -- Bophuthatswana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1514 , http://hdl.handle.net/10962/d1003396
- Description: This study examines the extent to which teachers in Senior Primary Schools who have obtained a professional qualification in Environmental Education, implement Environmental Education in their schools. It also explores factors which influence the implementation of Environmental Education at the Senior Primary School. Teachers who had qualified from Tlhabane and Hebron Colleges of Education were interviewed as were the principals of their schools and some of the lecturers who had taught them Environmental Education. The implementation of Environmental Education was addressed by means of comparing the teacher's responses with Primary Environmental Education Teacher Competencies as suggested by Glasgow and Robinson (1986) and Lahiry et al (1988). The information was deduced from the teachers responses from semi-structured interviews and were qualitatively analysed.
- Full Text:
- Date Issued: 1992
- Authors: Shongwe, Doctor Petrus
- Date: 1992
- Subjects: Environmental education -- South Africa -- Bophuthatswana , Primary school teaching -- Research -- South Africa -- Bophuthatswana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1514 , http://hdl.handle.net/10962/d1003396
- Description: This study examines the extent to which teachers in Senior Primary Schools who have obtained a professional qualification in Environmental Education, implement Environmental Education in their schools. It also explores factors which influence the implementation of Environmental Education at the Senior Primary School. Teachers who had qualified from Tlhabane and Hebron Colleges of Education were interviewed as were the principals of their schools and some of the lecturers who had taught them Environmental Education. The implementation of Environmental Education was addressed by means of comparing the teacher's responses with Primary Environmental Education Teacher Competencies as suggested by Glasgow and Robinson (1986) and Lahiry et al (1988). The information was deduced from the teachers responses from semi-structured interviews and were qualitatively analysed.
- Full Text:
- Date Issued: 1992
Environmental physiology of the intertidal limpets Patella (Prosobranchia) and Siphonaria (Pulmonata)
- Authors: Marshall, David John
- Date: 1992
- Subjects: Prosobranchia Pulmonata Patellidae Siphonaria Limpets
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5686 , http://hdl.handle.net/10962/d1005372
- Description: Physiological response to environmental change is examined in species of the intertidal limpets, Patella (Prosobranchia) and Siphonaria (Pulmonata). Characteristics of heart beat were determined using impedance pneumography and these are described. Heart rate of P. granularis is related to temperature and body size, and cardiac arrest in this limpet is apparently stress-related. Siphonaria oculus may exhibit a temperature-independent, extreme, and often prolonged bradycardia (<10 beats/min). When measured shortly after aerial exposure, heart rate and oxygen consumption of the above limpet species are closely correlated. The relationships of aerial oxygen consumption with body weight and ambient temperature were determined for the above high shore species of limpet. Both have low aerial rates of oxygen consumption relative to low shore limpet species, and their QlO values decrease with increasing temperature. Diel field recordings of heart rate of S. oculus, taken during summer and winter, suggest absence of temperature acclimation, and this was also shown for oxygen consumption at high aerial temperatures (30°C) in laboratory experiments. Oxygen consumption of P. granularis is partially temperature compensated temperature acclimation). In air, even though S. oculus loses water faster, it shows greater tolerance of water loss and survives longer than P. granularis. Prolonged aerial exposure of S. oculus leads to depression of heart rate and of V02 (down to 18% of the pre-exposure rate), responses interpreted as representing adaptive metabolic rate depression. In P. granularis aerial heart rate remains constant and V02 never falls below IX 38% of pre-exposure rate. This reduction in V02 in air is considered as being stress-related, resulting from impairment of oxygen uptake. In declining oxygen tension S. capensis shows a better capacity for oxyregulation than P. granularis. On exposure to hypoxia, sand-inundation and hyposalinity, S. capensis may show typical bradycardia ( <10 beats/min), suggesting depression of aerobic metabolism, and on return to pre-exposure conditions there is no overshoot of heart rate, suggesting absence of oxygen debt. The effect of hypoxia, sand-inundation and hyposalinity on heart rate of P. granularis is variable; this becomes depressed and is often interspersed with extended cardiac arrest. When conditions are normalized, this species exhibits a clear overshoot of heart rate. The significance of differences in physiological response between patellid and siphonariid limpets is discussed with regard to their habitat segregation, particularly in the upper-shore zone (open rock and tidal pools) and sand-inundated rock substrata, where only siphonariid limpets may be found. While not previously characterized in marine gastropods, metabolic rate depression by Siphonaria, through facilitating isolation and conserving food reserves, is suggested as a key factor determining their distribution in physico-chemically more extreme and variable intertidal habitats.
- Full Text:
- Date Issued: 1992
- Authors: Marshall, David John
- Date: 1992
- Subjects: Prosobranchia Pulmonata Patellidae Siphonaria Limpets
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5686 , http://hdl.handle.net/10962/d1005372
- Description: Physiological response to environmental change is examined in species of the intertidal limpets, Patella (Prosobranchia) and Siphonaria (Pulmonata). Characteristics of heart beat were determined using impedance pneumography and these are described. Heart rate of P. granularis is related to temperature and body size, and cardiac arrest in this limpet is apparently stress-related. Siphonaria oculus may exhibit a temperature-independent, extreme, and often prolonged bradycardia (<10 beats/min). When measured shortly after aerial exposure, heart rate and oxygen consumption of the above limpet species are closely correlated. The relationships of aerial oxygen consumption with body weight and ambient temperature were determined for the above high shore species of limpet. Both have low aerial rates of oxygen consumption relative to low shore limpet species, and their QlO values decrease with increasing temperature. Diel field recordings of heart rate of S. oculus, taken during summer and winter, suggest absence of temperature acclimation, and this was also shown for oxygen consumption at high aerial temperatures (30°C) in laboratory experiments. Oxygen consumption of P. granularis is partially temperature compensated temperature acclimation). In air, even though S. oculus loses water faster, it shows greater tolerance of water loss and survives longer than P. granularis. Prolonged aerial exposure of S. oculus leads to depression of heart rate and of V02 (down to 18% of the pre-exposure rate), responses interpreted as representing adaptive metabolic rate depression. In P. granularis aerial heart rate remains constant and V02 never falls below IX 38% of pre-exposure rate. This reduction in V02 in air is considered as being stress-related, resulting from impairment of oxygen uptake. In declining oxygen tension S. capensis shows a better capacity for oxyregulation than P. granularis. On exposure to hypoxia, sand-inundation and hyposalinity, S. capensis may show typical bradycardia ( <10 beats/min), suggesting depression of aerobic metabolism, and on return to pre-exposure conditions there is no overshoot of heart rate, suggesting absence of oxygen debt. The effect of hypoxia, sand-inundation and hyposalinity on heart rate of P. granularis is variable; this becomes depressed and is often interspersed with extended cardiac arrest. When conditions are normalized, this species exhibits a clear overshoot of heart rate. The significance of differences in physiological response between patellid and siphonariid limpets is discussed with regard to their habitat segregation, particularly in the upper-shore zone (open rock and tidal pools) and sand-inundated rock substrata, where only siphonariid limpets may be found. While not previously characterized in marine gastropods, metabolic rate depression by Siphonaria, through facilitating isolation and conserving food reserves, is suggested as a key factor determining their distribution in physico-chemically more extreme and variable intertidal habitats.
- Full Text:
- Date Issued: 1992
Environmentalism and its implications for education: a study of private schools in the Eastern Cape
- Authors: Slade, Wilfred John
- Date: 1992
- Subjects: Environmental education -- Study and teaching -- South Africa Environmental education -- Curricula -- South Africa Private schools -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1520 , http://hdl.handle.net/10962/d1003402
- Description: This study explores the extent to which the ethos and the basic approach to education taken by three Eastern Cape private schools influences the practice of environmental education within these schools. Their environmental education programmes are evaluated in terms of the guiding principles adopted by the international community in the 'Tbilisi Principles of Environmental Education'. An ethnographic approach was adopted for this research and findings are essentially descriptive and qualitative, with special regard to social structures and the attitudes of individuals within these structures.
- Full Text:
- Date Issued: 1992
- Authors: Slade, Wilfred John
- Date: 1992
- Subjects: Environmental education -- Study and teaching -- South Africa Environmental education -- Curricula -- South Africa Private schools -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1520 , http://hdl.handle.net/10962/d1003402
- Description: This study explores the extent to which the ethos and the basic approach to education taken by three Eastern Cape private schools influences the practice of environmental education within these schools. Their environmental education programmes are evaluated in terms of the guiding principles adopted by the international community in the 'Tbilisi Principles of Environmental Education'. An ethnographic approach was adopted for this research and findings are essentially descriptive and qualitative, with special regard to social structures and the attitudes of individuals within these structures.
- Full Text:
- Date Issued: 1992
Evaluation of three simple hydrosalinity models applied to citrus orchards in the Lower Coerney River irrigation area, Eastern Cape, South Africa
- Authors: Cobban, Dale Anne
- Date: 1992
- Subjects: Irrigation -- Management , Irrigation -- Research -- South Africa -- Eastern Cape , Water in agriculture , Citrus -- Irrigation -- South Africa , Soils, Salts in
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4829 , http://hdl.handle.net/10962/d1005504 , Irrigation -- Management , Irrigation -- Research -- South Africa -- Eastern Cape , Water in agriculture , Citrus -- Irrigation -- South Africa , Soils, Salts in
- Description: Three hydrosalinity models of different complexity were evaluated against data from selected citrus orchards in the Lower Coerney River irrigation area. These models were statistically compared with field data, and found to vary in accuracy of output predictions. The simplest model, the LEACHING REQUIREMENT (LR) model, has the lowest data input requirements and produces output predictions that correlate with up to 93% of the variance in measured data. SODICS, which is theoretically more detailed and requires a greater level of detail in input, produces predictions of an accuracy equivalent to the LR model. The PEAK model was assessed in two parts, the PEAKM module simulating soil moisture and soil moisture movement was able to predict variations in moisture up to 99% of the time. The PEAKD module, which predicts solute concentrations was less effective in replicating real world conditions
- Full Text:
- Date Issued: 1992
- Authors: Cobban, Dale Anne
- Date: 1992
- Subjects: Irrigation -- Management , Irrigation -- Research -- South Africa -- Eastern Cape , Water in agriculture , Citrus -- Irrigation -- South Africa , Soils, Salts in
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4829 , http://hdl.handle.net/10962/d1005504 , Irrigation -- Management , Irrigation -- Research -- South Africa -- Eastern Cape , Water in agriculture , Citrus -- Irrigation -- South Africa , Soils, Salts in
- Description: Three hydrosalinity models of different complexity were evaluated against data from selected citrus orchards in the Lower Coerney River irrigation area. These models were statistically compared with field data, and found to vary in accuracy of output predictions. The simplest model, the LEACHING REQUIREMENT (LR) model, has the lowest data input requirements and produces output predictions that correlate with up to 93% of the variance in measured data. SODICS, which is theoretically more detailed and requires a greater level of detail in input, produces predictions of an accuracy equivalent to the LR model. The PEAK model was assessed in two parts, the PEAKM module simulating soil moisture and soil moisture movement was able to predict variations in moisture up to 99% of the time. The PEAKD module, which predicts solute concentrations was less effective in replicating real world conditions
- Full Text:
- Date Issued: 1992
Exploration for stratabound copper, lead and zinc deposits in the Damara-Katanga orogen, central-southern Africa
- Authors: Latorre, J J
- Date: 1992
- Subjects: Mining geology -- Research -- Africa , Copper ores -- Africa , Lead ores -- Africa , Zinc ores -- Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4946 , http://hdl.handle.net/10962/d1005558
- Description: The Damara-Katanga orogen in central-southern Africa represents an area of 1.73xl0⁶ sq. km. The region is considered one of the wealthiest metallogenic provinces in the world. Successful exploration for stratabound base-metal deposits has taken place at this particular area since the introduction of more organised methodology in the early 1920s. The genesis, location and distribution of the ore deposits are related to their tectonic settings. Geodynamic evolution of the orogen, which initially formed part of a complex Pan-African rift system, comprises the following stages rifting; downwarping, including spreading on the western portion; syn-orogeny and late-orogeny. Two major tectonic events in the history of the region have been identified: the Katangan (900-750 Ma) and the Damaran episodes (750-500 Ma). Timing of mineralisation of ore deposits has been related to the evolutionary stages of the orogen. Genetic models of the most productive deposits are briefly discussed in this dissertation. The sedimentological, geochemical, paleogeographic and structural features can be employed as geological guidelines for integrated exploration programmes. Discoveries of major deposits and prospects in the orogen are also summarised, focussing on the exploration methods employed. The cost-effective use of the exploration techniques includes the classical copper-lead-zinc soil sampling for residual soils such as those in the Copperbelt area. Airborne magnetics and electromagnetics and follow-up ground geophysics have proved successful in areas where the cover is transported in the search for shallow ore deposits such as the Matchless massive sulphides. Remote sensing, geochemical and geophysical techniques have been tried in covered areas of western Botswana. The lack of geological control makes this interpretation difficult. A detailed geological mapping and the use of geochemical and geophysical techniques has been used to delineate carbonate-hosted base-metal deposits at the Otavi Land. The more expensive traditional methods necessary for the delineation of orebodies, such as pitting, trenching and drilling, are also discussed. Using a sequential approach, a possible exploration strategy is suggested, outlining the cost-effective use of remote sensing, geochemical and geophysical techniques. Standardisation in basic geological information is required for future successful explorations in the Damara-Katanga orogen, as well as attractive mining policies. In the event of their implementation, exploration perspectives are promising, specifically in terms of ore potential.
- Full Text:
- Date Issued: 1992
- Authors: Latorre, J J
- Date: 1992
- Subjects: Mining geology -- Research -- Africa , Copper ores -- Africa , Lead ores -- Africa , Zinc ores -- Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4946 , http://hdl.handle.net/10962/d1005558
- Description: The Damara-Katanga orogen in central-southern Africa represents an area of 1.73xl0⁶ sq. km. The region is considered one of the wealthiest metallogenic provinces in the world. Successful exploration for stratabound base-metal deposits has taken place at this particular area since the introduction of more organised methodology in the early 1920s. The genesis, location and distribution of the ore deposits are related to their tectonic settings. Geodynamic evolution of the orogen, which initially formed part of a complex Pan-African rift system, comprises the following stages rifting; downwarping, including spreading on the western portion; syn-orogeny and late-orogeny. Two major tectonic events in the history of the region have been identified: the Katangan (900-750 Ma) and the Damaran episodes (750-500 Ma). Timing of mineralisation of ore deposits has been related to the evolutionary stages of the orogen. Genetic models of the most productive deposits are briefly discussed in this dissertation. The sedimentological, geochemical, paleogeographic and structural features can be employed as geological guidelines for integrated exploration programmes. Discoveries of major deposits and prospects in the orogen are also summarised, focussing on the exploration methods employed. The cost-effective use of the exploration techniques includes the classical copper-lead-zinc soil sampling for residual soils such as those in the Copperbelt area. Airborne magnetics and electromagnetics and follow-up ground geophysics have proved successful in areas where the cover is transported in the search for shallow ore deposits such as the Matchless massive sulphides. Remote sensing, geochemical and geophysical techniques have been tried in covered areas of western Botswana. The lack of geological control makes this interpretation difficult. A detailed geological mapping and the use of geochemical and geophysical techniques has been used to delineate carbonate-hosted base-metal deposits at the Otavi Land. The more expensive traditional methods necessary for the delineation of orebodies, such as pitting, trenching and drilling, are also discussed. Using a sequential approach, a possible exploration strategy is suggested, outlining the cost-effective use of remote sensing, geochemical and geophysical techniques. Standardisation in basic geological information is required for future successful explorations in the Damara-Katanga orogen, as well as attractive mining policies. In the event of their implementation, exploration perspectives are promising, specifically in terms of ore potential.
- Full Text:
- Date Issued: 1992
Exploratory studies of novel ligand systems
- Authors: Taylor, Steven John
- Date: 1992
- Subjects: Ligands , Coordination compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4315 , http://hdl.handle.net/10962/d1004973 , Ligands , Coordination compounds
- Description: A range of novel ligand systems have been developed in three distinct phases and preliminary studies have been initiated to evaluate their complexation potential. Phase I incorporated the synthesis of single strand ligand systems, which were mainly based on amino acid residues. Techniques have been developed for the attachment of these ligand systems onto, firstly, a styrene monomer, and then later onto a pseudo-styrene linking group, viz. the p-toluoyl group. The linking reactions were based on the formation of amides or esters by the reaction of an acid chloride system with an amine or alcohol. Phase II involved the synthesis of bis-chain ligand systems and their attachment onto the p-toluoyl linking group. A further linking group was also developed at this stage, viz. the xylyl group. In the preparation of phase II ligand systems, use was made of malonic ester and iminodiacetic acid derivatives. Phase III has involved the synthesis of cyclic ligand systems, with skeletons based upon the structures used in phase I and phase II and two crown ether type systems have been prepared.
- Full Text:
- Date Issued: 1992
- Authors: Taylor, Steven John
- Date: 1992
- Subjects: Ligands , Coordination compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4315 , http://hdl.handle.net/10962/d1004973 , Ligands , Coordination compounds
- Description: A range of novel ligand systems have been developed in three distinct phases and preliminary studies have been initiated to evaluate their complexation potential. Phase I incorporated the synthesis of single strand ligand systems, which were mainly based on amino acid residues. Techniques have been developed for the attachment of these ligand systems onto, firstly, a styrene monomer, and then later onto a pseudo-styrene linking group, viz. the p-toluoyl group. The linking reactions were based on the formation of amides or esters by the reaction of an acid chloride system with an amine or alcohol. Phase II involved the synthesis of bis-chain ligand systems and their attachment onto the p-toluoyl linking group. A further linking group was also developed at this stage, viz. the xylyl group. In the preparation of phase II ligand systems, use was made of malonic ester and iminodiacetic acid derivatives. Phase III has involved the synthesis of cyclic ligand systems, with skeletons based upon the structures used in phase I and phase II and two crown ether type systems have been prepared.
- Full Text:
- Date Issued: 1992
Facies mapping of the Vaal Reef placer as an aid to remnant pillar extraction and stope width optimisation
- Authors: O'Donovan, Anthony Gareth
- Date: 1992
- Subjects: Facies (Geology) -- South Africa -- Vaal Reef placer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4947 , http://hdl.handle.net/10962/d1005559 , Facies (Geology) -- South Africa -- Vaal Reef placer
- Description: The Vaal Reef placer is situated on the unconformable junction of the Strathmore and Stilfontein formations of the Johannesburg Subgroup. Within the South Division of the Vaal Reefs Exploration and Mining company lease, the Vaal Reef Placer is shown to be composed of several different units. Each unit exhibits its own specific characteristics and trend direction which can be used to establish distinct "Reef packages". These packages can be mapped in such a way as to provide a preliminary lithofacies map for the Vaal Reef Placer. The delineation of such geologically homogenous zones, and the development of a suitable depositional model, can be utilised in several ways. The characteristics of a particular zone are shown to influence the control of stoping width, evaluation of remnant pillars and the geostatistical methodology of evaluating current and future ore reserve blocks.
- Full Text:
- Date Issued: 1992
- Authors: O'Donovan, Anthony Gareth
- Date: 1992
- Subjects: Facies (Geology) -- South Africa -- Vaal Reef placer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4947 , http://hdl.handle.net/10962/d1005559 , Facies (Geology) -- South Africa -- Vaal Reef placer
- Description: The Vaal Reef placer is situated on the unconformable junction of the Strathmore and Stilfontein formations of the Johannesburg Subgroup. Within the South Division of the Vaal Reefs Exploration and Mining company lease, the Vaal Reef Placer is shown to be composed of several different units. Each unit exhibits its own specific characteristics and trend direction which can be used to establish distinct "Reef packages". These packages can be mapped in such a way as to provide a preliminary lithofacies map for the Vaal Reef Placer. The delineation of such geologically homogenous zones, and the development of a suitable depositional model, can be utilised in several ways. The characteristics of a particular zone are shown to influence the control of stoping width, evaluation of remnant pillars and the geostatistical methodology of evaluating current and future ore reserve blocks.
- Full Text:
- Date Issued: 1992
Fieldwork as a compensatory teaching strategy for rural black senior secondary schools
- Authors: Boqwana, Eleanor Pindiwe
- Date: 1992
- Subjects: Black people -- Education -- South Africa , Geography -- Fieldwork -- Study and teaching , Geography -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1544 , http://hdl.handle.net/10962/d1003426 , Black people -- Education -- South Africa , Geography -- Fieldwork -- Study and teaching , Geography -- Study and teaching -- South Africa
- Description: The understanding of geographical concepts and the development of skills requires the use of appropriate teaching strategies. Modern school syllabuses emphasize the development of concepts and skills which are basic to the understanding of geography. Geography provides practical learning opportunities which directly involve the learner. Techniques which directly involve the learner are perceived to be the most valuable. Fieldwork, which embraces a wide range of innovative teaching strategies, is the one best suited to give first-hand experience to the pupils. This study investigates the potential of fieldwork to promote conceptual understanding in geography with special reference to pupils in rural schools. Extensive literature on fieldwork in geographical education was analysed. Surveys of geography teachers and pupils in senior secondary schools were conducted to assess their attitudes towards geography and the use of learner-centred approaches with special reference to fieldwork. The role of fieldwork to promote conceptual understanding was evaluated by exposing two groups of pupils to different field activities. This revealed that fieldwork promotes understanding, stimulates interest and builds up confidence even when first introduced at senior secondary level.
- Full Text:
- Date Issued: 1992
- Authors: Boqwana, Eleanor Pindiwe
- Date: 1992
- Subjects: Black people -- Education -- South Africa , Geography -- Fieldwork -- Study and teaching , Geography -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1544 , http://hdl.handle.net/10962/d1003426 , Black people -- Education -- South Africa , Geography -- Fieldwork -- Study and teaching , Geography -- Study and teaching -- South Africa
- Description: The understanding of geographical concepts and the development of skills requires the use of appropriate teaching strategies. Modern school syllabuses emphasize the development of concepts and skills which are basic to the understanding of geography. Geography provides practical learning opportunities which directly involve the learner. Techniques which directly involve the learner are perceived to be the most valuable. Fieldwork, which embraces a wide range of innovative teaching strategies, is the one best suited to give first-hand experience to the pupils. This study investigates the potential of fieldwork to promote conceptual understanding in geography with special reference to pupils in rural schools. Extensive literature on fieldwork in geographical education was analysed. Surveys of geography teachers and pupils in senior secondary schools were conducted to assess their attitudes towards geography and the use of learner-centred approaches with special reference to fieldwork. The role of fieldwork to promote conceptual understanding was evaluated by exposing two groups of pupils to different field activities. This revealed that fieldwork promotes understanding, stimulates interest and builds up confidence even when first introduced at senior secondary level.
- Full Text:
- Date Issued: 1992
Form and substance in R.M. Hare's utilitarianism
- Authors: Coetzee, Pieter Hendrik
- Date: 1992
- Subjects: Hare, R. M. (Richard Mervyn) -- Ethics , Utilitarianism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2706 , http://hdl.handle.net/10962/d1002836 , Hare, R. M. (Richard Mervyn) -- Ethics , Utilitarianism
- Description: Throughout his career as moral philosopher Hare has insisted that there is a rational way of arriving at substantive moral judgements. Hare develops this view - first presented in ' The language of morals' (1952) and ' Universalizability' (1955) - into the claim that rational agents are required to adopt utilitarian solutions to moral disputes. In ' Freedom and reason ' (1963) this claim is defended with reference to the view that the formal features of moral language (universalizability and prescriptivity)commit moral agents to a certain method of reasoning, and that this method of reasoning, when conjoined with facts about people's desires and preferences, leads us to accept substantive moral judgements consistent with those required by a form of utilitarianism. This view features throughout Hare's subsequent work, but the argument for it undergoes change. This means change in the defence of the claim that the meta-theory Universal Prescriptivism is consistent with a form of normative utilitarian theory, as this claim is argued for in 'Ethical theory and utilitarianism' (1976) and 'Moral Thinking' (1981). I shall endeavour to trace the chronological development of Hare's thinking, and will concentrate on developments in the argument for a theory of act-utilitarianism. I shall argue that the argument for utilitarianism gives rise to two major problems which arise from a specific feature of the argument, namely, the attempt to run the resolution of bi-lateral and multi-lateral cases of conflict along lines analogous to the resolution of conflict in the single-person case. Hare's argument requires that a decision-maker must identify the person with whom he reverses roles as himself, and that he must be prepared to concede that the things his recipient has good reasons for wanting are also reasons for him to want the same things. I argue that it is not possible to make coherent sense of the identity of the person in the reversed-role situation and that the motivational states a decision -maker is expected to deem 'his own' are not properly states of himself. If I am right, the 'identity'-question sits at the root of a motivational gap in Hare's theory.
- Full Text:
- Date Issued: 1992
- Authors: Coetzee, Pieter Hendrik
- Date: 1992
- Subjects: Hare, R. M. (Richard Mervyn) -- Ethics , Utilitarianism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2706 , http://hdl.handle.net/10962/d1002836 , Hare, R. M. (Richard Mervyn) -- Ethics , Utilitarianism
- Description: Throughout his career as moral philosopher Hare has insisted that there is a rational way of arriving at substantive moral judgements. Hare develops this view - first presented in ' The language of morals' (1952) and ' Universalizability' (1955) - into the claim that rational agents are required to adopt utilitarian solutions to moral disputes. In ' Freedom and reason ' (1963) this claim is defended with reference to the view that the formal features of moral language (universalizability and prescriptivity)commit moral agents to a certain method of reasoning, and that this method of reasoning, when conjoined with facts about people's desires and preferences, leads us to accept substantive moral judgements consistent with those required by a form of utilitarianism. This view features throughout Hare's subsequent work, but the argument for it undergoes change. This means change in the defence of the claim that the meta-theory Universal Prescriptivism is consistent with a form of normative utilitarian theory, as this claim is argued for in 'Ethical theory and utilitarianism' (1976) and 'Moral Thinking' (1981). I shall endeavour to trace the chronological development of Hare's thinking, and will concentrate on developments in the argument for a theory of act-utilitarianism. I shall argue that the argument for utilitarianism gives rise to two major problems which arise from a specific feature of the argument, namely, the attempt to run the resolution of bi-lateral and multi-lateral cases of conflict along lines analogous to the resolution of conflict in the single-person case. Hare's argument requires that a decision-maker must identify the person with whom he reverses roles as himself, and that he must be prepared to concede that the things his recipient has good reasons for wanting are also reasons for him to want the same things. I argue that it is not possible to make coherent sense of the identity of the person in the reversed-role situation and that the motivational states a decision -maker is expected to deem 'his own' are not properly states of himself. If I am right, the 'identity'-question sits at the root of a motivational gap in Hare's theory.
- Full Text:
- Date Issued: 1992
From FidoNet to internet: the evolution of a national network
- Jacot-Guillarmod, Francois F
- Authors: Jacot-Guillarmod, Francois F
- Date: 1992
- Language: English
- Type: Conference paper
- Identifier: vital:6974 , http://hdl.handle.net/10962/101
- Description: The South African academic research network, UNINET-ZA, evolved within two years from a FidoNet mail gateway that distributed email via interactive Kermit links, to a dialup uucp network, to wide area TCP/IP, and finally to full Internet connectivity. While the majority of UNINET-ZA sites are now TCP/IP connected, elements of the original gatewaying techniques are still fulfilling useful functions - for example a TCP/IP <=> FidoNet gateway, and links into non-Unix, non-TCP/IP based systems.
- Full Text:
- Date Issued: 1992
- Authors: Jacot-Guillarmod, Francois F
- Date: 1992
- Language: English
- Type: Conference paper
- Identifier: vital:6974 , http://hdl.handle.net/10962/101
- Description: The South African academic research network, UNINET-ZA, evolved within two years from a FidoNet mail gateway that distributed email via interactive Kermit links, to a dialup uucp network, to wide area TCP/IP, and finally to full Internet connectivity. While the majority of UNINET-ZA sites are now TCP/IP connected, elements of the original gatewaying techniques are still fulfilling useful functions - for example a TCP/IP <=> FidoNet gateway, and links into non-Unix, non-TCP/IP based systems.
- Full Text:
- Date Issued: 1992
Fuzzy uniform spaces
- Authors: Burton, Michael Howard
- Date: 1992
- Subjects: Fuzzy sets -- Research Uniform spaces -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5408 , http://hdl.handle.net/10962/d1005222
- Description: For a fuzzy uniform space, the notion of a Cauchy prefilter, a precompact fuzzy set, a complete fuzzy set and a bounded fuzzy set are defined in such a way that these notions are good extensions of the corresponding notions for a uniform space. A theory of fuzzy uniform spaces is developed which generalises the theory of uniform spaces.
- Full Text:
- Date Issued: 1992
- Authors: Burton, Michael Howard
- Date: 1992
- Subjects: Fuzzy sets -- Research Uniform spaces -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5408 , http://hdl.handle.net/10962/d1005222
- Description: For a fuzzy uniform space, the notion of a Cauchy prefilter, a precompact fuzzy set, a complete fuzzy set and a bounded fuzzy set are defined in such a way that these notions are good extensions of the corresponding notions for a uniform space. A theory of fuzzy uniform spaces is developed which generalises the theory of uniform spaces.
- Full Text:
- Date Issued: 1992
Genetic models for epithermal gold deposits and applications to exploration
- Authors: Veselinović, Milica
- Date: 1992
- Subjects: Gold ores -- Geology , Hydrothermal deposits
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4950 , http://hdl.handle.net/10962/d1005562 , Gold ores -- Geology , Hydrothermal deposits
- Description: Epithermal gold deposits are the product of large-scale hydrothermal systems in tectonically active regions. They form at shallow crustal levels where the physico-chemical conditions change abruptly. Two major groups of epithermal gold deposits can be distinguished based on their genetic connection with: A) Copper-molybdenum porphyry systems and B) Geothermal systems related to volcanic centres and calderas. Epithermal gold deposits connected with geothermal systems encompass three major types: adularia-sericite, acid-sulphate and disseminated replacement (the Carlin-type). Their essential ingredients are: high heat source which leads to convection of groundwater in the upper crust; source of hydrothermal fluid, metals and reduced sulphur; and high-permeability structures which allow fluid convection and metal deposition. Mixing of these ingredients leads to the formation of epithermal gold deposits throughout crustal history, without any restriction on age. The ores were deposited from near-neutral (adularia-sericite type and some of the Carlin-type) to acidic (acid-sulphate type and porphyry-related epithermal gold deposits), low-salinity, high C0₂ and high H₂S fluids, which were predominantly meteoritic in origin. The transport capability of deep fluids in epithermal hydrothermal systems may be shown to be dependent largely on their H₂S content and, through a series of fluid mineral equilibria, on temperature and on C0₂ content. The most common mechanisms of ore deposition are boiling (phase separation), mixing of fluids of different temperatures and salinities, reaction between them and wall rocks, dilution and cooling. An understanding of genetic models for epithermal gold deposits provides the basis for the selection of favourable areas for regional to prospect-scale exploration.
- Full Text:
- Date Issued: 1992
- Authors: Veselinović, Milica
- Date: 1992
- Subjects: Gold ores -- Geology , Hydrothermal deposits
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4950 , http://hdl.handle.net/10962/d1005562 , Gold ores -- Geology , Hydrothermal deposits
- Description: Epithermal gold deposits are the product of large-scale hydrothermal systems in tectonically active regions. They form at shallow crustal levels where the physico-chemical conditions change abruptly. Two major groups of epithermal gold deposits can be distinguished based on their genetic connection with: A) Copper-molybdenum porphyry systems and B) Geothermal systems related to volcanic centres and calderas. Epithermal gold deposits connected with geothermal systems encompass three major types: adularia-sericite, acid-sulphate and disseminated replacement (the Carlin-type). Their essential ingredients are: high heat source which leads to convection of groundwater in the upper crust; source of hydrothermal fluid, metals and reduced sulphur; and high-permeability structures which allow fluid convection and metal deposition. Mixing of these ingredients leads to the formation of epithermal gold deposits throughout crustal history, without any restriction on age. The ores were deposited from near-neutral (adularia-sericite type and some of the Carlin-type) to acidic (acid-sulphate type and porphyry-related epithermal gold deposits), low-salinity, high C0₂ and high H₂S fluids, which were predominantly meteoritic in origin. The transport capability of deep fluids in epithermal hydrothermal systems may be shown to be dependent largely on their H₂S content and, through a series of fluid mineral equilibria, on temperature and on C0₂ content. The most common mechanisms of ore deposition are boiling (phase separation), mixing of fluids of different temperatures and salinities, reaction between them and wall rocks, dilution and cooling. An understanding of genetic models for epithermal gold deposits provides the basis for the selection of favourable areas for regional to prospect-scale exploration.
- Full Text:
- Date Issued: 1992
Geochemical and petrological trends in the UG2-Merensky unit interval of the upper critical zone in the Western Bushveld Complex
- Authors: Maier, Wolfgang Derek
- Date: 1992
- Subjects: Petrology -- South Africa -- North-western Transvaal Geochemistry -- South Africa -- North-western Transvaal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4951 , http://hdl.handle.net/10962/d1005563
- Description: One of the most remarkable features of the layered sequence of the Bushveld Complex is its lateral consistency in lithology. This work has established a geochemical and lithological correlation along 170 km of strike of the interval between the UG2 chromitite and the Merensky Reef within the Upper Critical zone of the western limb of the Bushveld Complex. The correlation is based on geochemical investigations of 10 borehole intersections and lithological comparisons of more than 20 borehole intersections around the western lobe of the complex. The basic data presented include 123 whole-rock analyses for major and 12 trace elements, 97 analyses for ' 12 trace elements, and ca. 5500 microprobe analyses of all major phases. Patterns of cryptic variation are established. Some layers (the UG2 chromitite and pyroxenite) show considerable consistency with regard to geochemistry and lithology. Others can be traced along most of the investigated strike length, such as the Lone Chrome Seam, the Footwall Marker anorthosite and the immediate anorthosite footwall to the Merensky Unit. Most of the distinguishable members within the study section, however, show great variation along strike (i.e., the Lower and Upper Pseudoreef Markers, the central noritic sequence in the southern arm of the western limb and parts of the immediate Merensky Reef footwall succession). Several models have been evaluated to interpret the geochemical and lithological data. The author comes to the conclusion that the degree of lithological consistency depends on the variability of magmatic parameters within different parts of the chamber. The most important of these parameters are: (i) the size of fresh primitive influxes and consequently the heat flux, (ii) the composition of the residual liquid, and (iii) the frequency of the influxes. Fresh influxes of more or less similar composition thus spread out along the floor if the residual liquid was less dense than the fresh primitive liquid, but intruded the chamber as a plume where plagioclase had crystallized for some time and the residual liquid had become relatively dense. The size of the influx may be regarded as a measure of the amount of heat flux from the feeder into the chamber. A large influx created uniform physicochemical conditions in the chamber whereas a smaller influx created a strong lateral gradient of physicochemical parameters in the chamber, with subsequent differences in viscosity, density, convection currents, yield strength and thus different mixing behaviour of different liquids. Furthermore, a persistent heat flux from the feeder may have delayed crystallization of successive phases in those parts of the chamber proximal to the feeder . Therefore, new influxes would have been deposited on a footwall of varying thickness and lithology in response to different degrees of crystallization and accumulation along strike. The development of a normal cyclic unit (chromititeharzburgite-pyroxenite-norite (+anorthosite?)) may thus have been interrupted at various stages in different parts of the chamber. The ability to correlate anorthosites over great strike distances implies that their formation did not follow entirely random processes but was dependent on specific magmatic conditions which prevailed over laterally extensive portions of the chamber at certain stages during the evolution of the crystallizing liquid.
- Full Text:
- Date Issued: 1992
- Authors: Maier, Wolfgang Derek
- Date: 1992
- Subjects: Petrology -- South Africa -- North-western Transvaal Geochemistry -- South Africa -- North-western Transvaal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4951 , http://hdl.handle.net/10962/d1005563
- Description: One of the most remarkable features of the layered sequence of the Bushveld Complex is its lateral consistency in lithology. This work has established a geochemical and lithological correlation along 170 km of strike of the interval between the UG2 chromitite and the Merensky Reef within the Upper Critical zone of the western limb of the Bushveld Complex. The correlation is based on geochemical investigations of 10 borehole intersections and lithological comparisons of more than 20 borehole intersections around the western lobe of the complex. The basic data presented include 123 whole-rock analyses for major and 12 trace elements, 97 analyses for ' 12 trace elements, and ca. 5500 microprobe analyses of all major phases. Patterns of cryptic variation are established. Some layers (the UG2 chromitite and pyroxenite) show considerable consistency with regard to geochemistry and lithology. Others can be traced along most of the investigated strike length, such as the Lone Chrome Seam, the Footwall Marker anorthosite and the immediate anorthosite footwall to the Merensky Unit. Most of the distinguishable members within the study section, however, show great variation along strike (i.e., the Lower and Upper Pseudoreef Markers, the central noritic sequence in the southern arm of the western limb and parts of the immediate Merensky Reef footwall succession). Several models have been evaluated to interpret the geochemical and lithological data. The author comes to the conclusion that the degree of lithological consistency depends on the variability of magmatic parameters within different parts of the chamber. The most important of these parameters are: (i) the size of fresh primitive influxes and consequently the heat flux, (ii) the composition of the residual liquid, and (iii) the frequency of the influxes. Fresh influxes of more or less similar composition thus spread out along the floor if the residual liquid was less dense than the fresh primitive liquid, but intruded the chamber as a plume where plagioclase had crystallized for some time and the residual liquid had become relatively dense. The size of the influx may be regarded as a measure of the amount of heat flux from the feeder into the chamber. A large influx created uniform physicochemical conditions in the chamber whereas a smaller influx created a strong lateral gradient of physicochemical parameters in the chamber, with subsequent differences in viscosity, density, convection currents, yield strength and thus different mixing behaviour of different liquids. Furthermore, a persistent heat flux from the feeder may have delayed crystallization of successive phases in those parts of the chamber proximal to the feeder . Therefore, new influxes would have been deposited on a footwall of varying thickness and lithology in response to different degrees of crystallization and accumulation along strike. The development of a normal cyclic unit (chromititeharzburgite-pyroxenite-norite (+anorthosite?)) may thus have been interrupted at various stages in different parts of the chamber. The ability to correlate anorthosites over great strike distances implies that their formation did not follow entirely random processes but was dependent on specific magmatic conditions which prevailed over laterally extensive portions of the chamber at certain stages during the evolution of the crystallizing liquid.
- Full Text:
- Date Issued: 1992
Geological controls for coal exploration and mining
- Authors: Noppé , Mark Adrian
- Date: 1992
- Subjects: Coal -- Geology , Coal mines and mining
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4954 , http://hdl.handle.net/10962/d1005566 , Coal -- Geology , Coal mines and mining
- Description: The identification and interpretation of geological features is essential for the planning and ultimate success of any mining venture. Examples of geological features significant for mining are presented, and their identification during exploration discussed. In particular, the importance of coal qualities, seam thickness and seam elevation are emphasised in relation to longwall mining. Geostatistical analysis provides a powerful tool for improving the prediction and decision-making capabilities of both exploration and mine geologists. The availability of geostatistics, and the benefits resulting from its application, are demonstrated using actual data for calorific value, seam thickness and seam elevation. Contamination of run-of-mine coal is a common problem on highly-mechanised collieries. The problem generally arises from over-cutting of the designated mining horizon. A practical system for monitoring and controlling contamination on a mechanised bord-and-pillar and longwall colliery is presented. The results and benefits of applying such a system are cited for an actual longwall colliery. Numerical geological predictions are not always reported in terms of the reliability of such estimates. Many of these values can be reported in terms of confidence limits, particularly for routine grade control purposes. The methods and benefits of such reporting are described and illustrated by way of examples for calorific value and contamination levels.
- Full Text:
- Date Issued: 1992
- Authors: Noppé , Mark Adrian
- Date: 1992
- Subjects: Coal -- Geology , Coal mines and mining
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4954 , http://hdl.handle.net/10962/d1005566 , Coal -- Geology , Coal mines and mining
- Description: The identification and interpretation of geological features is essential for the planning and ultimate success of any mining venture. Examples of geological features significant for mining are presented, and their identification during exploration discussed. In particular, the importance of coal qualities, seam thickness and seam elevation are emphasised in relation to longwall mining. Geostatistical analysis provides a powerful tool for improving the prediction and decision-making capabilities of both exploration and mine geologists. The availability of geostatistics, and the benefits resulting from its application, are demonstrated using actual data for calorific value, seam thickness and seam elevation. Contamination of run-of-mine coal is a common problem on highly-mechanised collieries. The problem generally arises from over-cutting of the designated mining horizon. A practical system for monitoring and controlling contamination on a mechanised bord-and-pillar and longwall colliery is presented. The results and benefits of applying such a system are cited for an actual longwall colliery. Numerical geological predictions are not always reported in terms of the reliability of such estimates. Many of these values can be reported in terms of confidence limits, particularly for routine grade control purposes. The methods and benefits of such reporting are described and illustrated by way of examples for calorific value and contamination levels.
- Full Text:
- Date Issued: 1992
Guidelines to the evaluation of selectively mined, open pit gold deposits during the exploration stage of mine creation
- Pelly, Frederick Douglas Peter
- Authors: Pelly, Frederick Douglas Peter
- Date: 1992
- Subjects: Mining geology , Gold ores -- Geology , Gold mines and mining -- Economic aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4970 , http://hdl.handle.net/10962/d1005582 , Mining geology , Gold ores -- Geology , Gold mines and mining -- Economic aspects
- Description: This dissertation studies the evaluation of selectively mined, open pit gold deposits during the exploration stage of the mine's life. Since 1970 a large number of selectively mined, open pit gold mines have come into operation. The most common deposits include epithermal vein, mesothermal lode and laterite gold deposits. In general the deposits are characterized by small tonnages (1-20 million tonnes), relatively high grades (2-10 grams per tonne gold), submicroscopic to coarse gold, inexpensive mining, and both free milling and refractory ores.The key components that require evaluating during the exploration period are the deposit's geology, ore reserves, pit design, ore metallurgy and environmental impact. Feasibility studies are the main vehicle by which to report and guide the exploration programme. During the exploration period a company may undertake an initial (geological feasibility), second (preliminary mine feasibility) and third (final feasibility) delineation programme in order to gather sufficient data to justify a mine development decision. The responsibility of evaluating the mineral prospect lies primarily with the exploration geologist and mining engineer. Broad experience, a professional attitude, a thorough understanding of mining economics, and a high level of geological, engineering and technical skills are traits required by the evaluators. In order for mining companies to make sound investment decisions the geographical, geological, mining, metallurgical, environmental, marketing, political and financial aspects affecting the economic potential of the venture must be integrated so that the likely costs, risks and returns of the investment alternative are quantified. Ultimately, it is the economic analysis of these three items that determine whether the mineral prospect is developed into a mine I delineated further I retained until economic circumstances improve, or abandoned. To assess the costs, risks and returns, extensive use of the risk analysis is advocated throughout the exploration period . When combined with intelligent judgement of the intangible risk elements, the probabilistic distribution of discounted cash flows are invaluable in making sound investment decisions. However, the economic analysis is only as good as the information on which it is founded. Accurate and representative field data is the most important prerequisite to successfully evaluating and developing a new mine.
- Full Text:
- Date Issued: 1992
- Authors: Pelly, Frederick Douglas Peter
- Date: 1992
- Subjects: Mining geology , Gold ores -- Geology , Gold mines and mining -- Economic aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4970 , http://hdl.handle.net/10962/d1005582 , Mining geology , Gold ores -- Geology , Gold mines and mining -- Economic aspects
- Description: This dissertation studies the evaluation of selectively mined, open pit gold deposits during the exploration stage of the mine's life. Since 1970 a large number of selectively mined, open pit gold mines have come into operation. The most common deposits include epithermal vein, mesothermal lode and laterite gold deposits. In general the deposits are characterized by small tonnages (1-20 million tonnes), relatively high grades (2-10 grams per tonne gold), submicroscopic to coarse gold, inexpensive mining, and both free milling and refractory ores.The key components that require evaluating during the exploration period are the deposit's geology, ore reserves, pit design, ore metallurgy and environmental impact. Feasibility studies are the main vehicle by which to report and guide the exploration programme. During the exploration period a company may undertake an initial (geological feasibility), second (preliminary mine feasibility) and third (final feasibility) delineation programme in order to gather sufficient data to justify a mine development decision. The responsibility of evaluating the mineral prospect lies primarily with the exploration geologist and mining engineer. Broad experience, a professional attitude, a thorough understanding of mining economics, and a high level of geological, engineering and technical skills are traits required by the evaluators. In order for mining companies to make sound investment decisions the geographical, geological, mining, metallurgical, environmental, marketing, political and financial aspects affecting the economic potential of the venture must be integrated so that the likely costs, risks and returns of the investment alternative are quantified. Ultimately, it is the economic analysis of these three items that determine whether the mineral prospect is developed into a mine I delineated further I retained until economic circumstances improve, or abandoned. To assess the costs, risks and returns, extensive use of the risk analysis is advocated throughout the exploration period . When combined with intelligent judgement of the intangible risk elements, the probabilistic distribution of discounted cash flows are invaluable in making sound investment decisions. However, the economic analysis is only as good as the information on which it is founded. Accurate and representative field data is the most important prerequisite to successfully evaluating and developing a new mine.
- Full Text:
- Date Issued: 1992
How taboo are taboo words for girls?
- Authors: De Klerk, Vivian A
- Date: 1992
- Language: English
- Type: Article
- Identifier: vital:6143 , http://hdl.handle.net/10962/d1011596
- Description: In the past five years, there has been much interest in the question of whether women are really as concerned about politeness and status as they have been made out to be by such writers as Baroni and D'Urso (1984), Crosby and Nyquist (1977), Lakoff (1973), Spender (1980), and Trudgill (1972). Despite the commonly held perception that it is only males who bandy about derogatory and taboo words (Bailey 1985; Flexner 1975), Risch (1987) provided counterevidence based on data obtained in the United States. The results of the present study, based on data obtained in South Africa, strongly support her findings and challenge the assumption that women stick to standard speech, citing evidence that young females are familiar with, and use, a wide range of highly taboo/slang items themselves. In particular, attention is devoted to the question of pejorative words applicable to males and females, respectively, and the view that there are only a few pejorative terms commonly used to describe males (particularly by females) is challenged. (Women's language, politeness, linguistic taboo, stereotypes, slang, expletives, prestige forms).
- Full Text:
- Date Issued: 1992
- Authors: De Klerk, Vivian A
- Date: 1992
- Language: English
- Type: Article
- Identifier: vital:6143 , http://hdl.handle.net/10962/d1011596
- Description: In the past five years, there has been much interest in the question of whether women are really as concerned about politeness and status as they have been made out to be by such writers as Baroni and D'Urso (1984), Crosby and Nyquist (1977), Lakoff (1973), Spender (1980), and Trudgill (1972). Despite the commonly held perception that it is only males who bandy about derogatory and taboo words (Bailey 1985; Flexner 1975), Risch (1987) provided counterevidence based on data obtained in the United States. The results of the present study, based on data obtained in South Africa, strongly support her findings and challenge the assumption that women stick to standard speech, citing evidence that young females are familiar with, and use, a wide range of highly taboo/slang items themselves. In particular, attention is devoted to the question of pejorative words applicable to males and females, respectively, and the view that there are only a few pejorative terms commonly used to describe males (particularly by females) is challenged. (Women's language, politeness, linguistic taboo, stereotypes, slang, expletives, prestige forms).
- Full Text:
- Date Issued: 1992
Illness as intersubjectivity: a sociological perspective
- Authors: Pitfield, Doreen Jennie
- Date: 1992
- Subjects: Humanism , Medical care -- Sociological aspects , Intersubjectivity , Medical ethics -- Sociological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3329 , http://hdl.handle.net/10962/d1003117 , Humanism , Medical care -- Sociological aspects , Intersubjectivity , Medical ethics -- Sociological aspects
- Description: This thesis explores the historical roots of scientific medicine in an effort to highlight the lack of humanist intersubjectivity within the contemporary medical model. The study notes that contemporary medicine is overtly scientific and that its scientific framework is upheld and furthered by a medical model which draws legitimation from the irrefutability of what is referred to variously within this work, as its scientific "regime". It is shown that in terms of the humanist tradition people, not science, constitute the epicentre of meaningful experiential participation in the defining of human social reality. This, it is argued, implies a radically different ontology from other sociological perspectives on medicine. The thesis suggests that the contemporary medical model loses sight of the patient's ability to cognitively participate in the defining of illness, diagnosis and treatment in terms of his/her experience thereof , and argues that contemporary medicine, by advancing the idea that it alone has the correct and only answer to such problems, has led to a situation which promotes an overmedicalisation of society . The study gives an indication of the way in which this overmedicalisation has led to areas of human life becoming conceived of only in relation to medical expertise. In this respect it is noted that medicine has so successfully infiltrated the human consciousness (involving areas as diverse as childbirth, genetic engineering, transplant surgery and death), that decisions on health are invariably taken from a foundation of scientific legitimation which seems to exclude the patient as subject. It is argued that this way of making decisions reinforces the requirement for a scientific medical model which as it negates the human element insidiously amplifies its power over human life; thereby devaluing the very people it seeks to serve. The thesis suggests that in terms of a humanist reading of the Oath of Hippocrates, medical decisions can only be taken within a framework of experiential involvement which includes both medical expertise and lay understanding. It is indicated that when this happens, social reality functions in terms of a symbolic participation which fosters a commitment to equalise the conditions of human existence, and promotes a dialogical negotiatory process which is both intersubjectively and ongoingly produced.
- Full Text:
- Date Issued: 1992
- Authors: Pitfield, Doreen Jennie
- Date: 1992
- Subjects: Humanism , Medical care -- Sociological aspects , Intersubjectivity , Medical ethics -- Sociological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3329 , http://hdl.handle.net/10962/d1003117 , Humanism , Medical care -- Sociological aspects , Intersubjectivity , Medical ethics -- Sociological aspects
- Description: This thesis explores the historical roots of scientific medicine in an effort to highlight the lack of humanist intersubjectivity within the contemporary medical model. The study notes that contemporary medicine is overtly scientific and that its scientific framework is upheld and furthered by a medical model which draws legitimation from the irrefutability of what is referred to variously within this work, as its scientific "regime". It is shown that in terms of the humanist tradition people, not science, constitute the epicentre of meaningful experiential participation in the defining of human social reality. This, it is argued, implies a radically different ontology from other sociological perspectives on medicine. The thesis suggests that the contemporary medical model loses sight of the patient's ability to cognitively participate in the defining of illness, diagnosis and treatment in terms of his/her experience thereof , and argues that contemporary medicine, by advancing the idea that it alone has the correct and only answer to such problems, has led to a situation which promotes an overmedicalisation of society . The study gives an indication of the way in which this overmedicalisation has led to areas of human life becoming conceived of only in relation to medical expertise. In this respect it is noted that medicine has so successfully infiltrated the human consciousness (involving areas as diverse as childbirth, genetic engineering, transplant surgery and death), that decisions on health are invariably taken from a foundation of scientific legitimation which seems to exclude the patient as subject. It is argued that this way of making decisions reinforces the requirement for a scientific medical model which as it negates the human element insidiously amplifies its power over human life; thereby devaluing the very people it seeks to serve. The thesis suggests that in terms of a humanist reading of the Oath of Hippocrates, medical decisions can only be taken within a framework of experiential involvement which includes both medical expertise and lay understanding. It is indicated that when this happens, social reality functions in terms of a symbolic participation which fosters a commitment to equalise the conditions of human existence, and promotes a dialogical negotiatory process which is both intersubjectively and ongoingly produced.
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- Date Issued: 1992