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The conservation status of subtropical transitional thicket, and regeneration through seeding of shrubs in the Xeric succulent thicket of the Eastern Cape

  • Authors: La Cock, Graeme Dennis
  • Date: 1992
  • Subjects: Plant conservation -- South Africa -- Eastern Cape , Woody plants -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Western Cape
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4208 , http://hdl.handle.net/10962/d1003777 , Plant conservation -- South Africa -- Eastern Cape , Woody plants -- South Africa -- Eastern Cape , Shrubs -- South Africa -- Eastern Cape , Succulent plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Western Cape
  • Description: The historically poorly conserved subtropical transitional thicket (STT) of the Eastern Cape is overutilised by domestic stock and game in the more xeric areas, and has shown no signs of recovery from this grazing pressure. It has been postulated that no regeneration through seeding occurs. This project was undertaken to determine: 1) how much STT has disappeared between 1950 and present, and what the current conservation status is; and 2) whether regeneration of the xeric succulent thicket is taking place through seeding, and if so, where. The study was conducted at the Andries Vosloo Kudu Reserve near Grahamstown. Approximately one-third less STT was mapped in this study, based on 1981 Landsat images, than was mapped in 1950. Approximately 10 % of all remaining STT is conserved. The order Kaffrarian thicket is poorly conserved. Newly germinated seedlings of a wide range of shrub species occurred under the canopies of a wide range of shrubs which served as nurse plants, throughout a gradient of veld condition. Seedlings of Portulacaria afra, the dominant shrub in xeric succulent thicket, were most common. Similarly all saplings recorded in a survey of saplings were associated with bushclumps. One-third of all saplings have the potential to contribute to the spread of bushclumps. Regeneration of xeric succulent thicket through seeding probably does occur, contrary to current ideas. Ptareoxylon obliquum was the most common sapling, despite mature trees now being scarce following earlier heavier utilisation . P. obliquum was also the nurse plant which supported the highest density of newly germinated seedlings. The possible role of P. obliquum in the functioning of xeric succulent thicket is discussed. The confinement of seedlings and saplings to areas under the canopies of trees and shrubs implies that the xeric succulent thicket will not recover rapidly if allowed to rest. Active management techniques will be necessary if rapid recovery is required. Bare areas between bushclumps may no longer be suitable germination habitats because of high Al concentrations. There was no evidence to support the idea that germination and establishment of shrubs in clear areas is linked to episodic climatic events. Dung middens of recently reintroduced black rhinoceros may however aid in germination of seeds and establishment of seedlings under certain climatic conditions. Recommendations for further studies, based on the findings of this project, are made. Possible management techniques aimed at the rapid recovery of this veld are suggested, and management proposals for the Sam Knott Nature Reserve/Andries Vosloo Kudu Reserve complex are made.
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  • Date Issued: 1992

The culture of Dunaliella salina and the production of β-carotene in tannery effluents

  • Authors: Laubscher, Richard Keith
  • Date: 1992
  • Subjects: Dunaliella , Carotenes , Tanneries -- Waste disposal , Recycling (Waste, etc.)
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4055 , http://hdl.handle.net/10962/d1004116 , Dunaliella , Carotenes , Tanneries -- Waste disposal , Recycling (Waste, etc.)
  • Description: The problems of waste disposal in the tanning industry are unique in that the effluents are highly saline, have a high organic loading and contain heavy metals. Methods are available for the safe treatment and disposal of the latter two components, but the saline component requires the expensive outlay of evaporation ponds. This study has identified a possible use for the saline effluents, turning a problematic waste product into a potentially valuable by-product. A range of tannery effluents were identified and tested for their suitability for the mass cultivation of Dunaliella salina (bardawil strain). The bardawil strain was preferred over a local isolate because of its higher production of β-carotene. Ponded tannery effluents and combined processes effluent proved unsuitable for realistic propagation of the alga. Anaerobic digestion of combined processes effluent did not improve its suitability significantly. Anaerobic digestion of hide-soak effluent may remove persistent antimicrobial agents which influence algal growth, but its contribution to enhancing algal growth is equivocal. Undigested hide-soak effluent lacking in persistent antimicrobial agents was found to be an ideal culture medium, as no additional nutrients needed to be added. Significantly higher biomass was obtained in this effluent compared to chemically defined media. Induction of β-carotene was achieved in nitrogen-deficient defined media after culture in tannery effluent. This suggests that a two-stage system using hide-soak effluent for cell propagation and nitrogen deficient media for β-carotene induction, could be possible for the mass cultivation of D. salina for β-carotene production.
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  • Date Issued: 1992

The development and distribution of heavy mineral concentrations in alluvial systems

  • Authors: Lynn, Michael David
  • Date: 1992
  • Subjects: Heavy minerals -- Research , Alluvial plains -- Research , Geomorphology -- South Africa
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4937 , http://hdl.handle.net/10962/d1005549 , Heavy minerals -- Research , Alluvial plains -- Research , Geomorphology -- South Africa
  • Description: The objective of this review is to summarise the characteristics, significance and evolution of heavy minerals and their accumulations, and to identify the key controls on the development and distribution of heavy mineral concentrations in alluvial systems. These controls can be broadly classified as tectonic setting, geomorphic setting and grain-scale concentrating processes, each of which is discussed. Based on this review, exploration models are developed which are designed to indicate favourable localities for the accumulation of heavy minerals, and trends likely to be exhibited within these accumulations. The models are structured from the broadest scale of target selection, down to the local scale of sample site selection. The major conclusion of this work is that an understanding of process geomorphology is required to develop genetic models of placer development, including a detailed evaluation of climatic fluctuations throughout the Caenozoic. Palaeoplacers such as the Witwatersrand goldfield, are inferred to have formed under similar circumstances of tectonic setting as genetically comparable Caenozoic placers such as those of Otago, New Zealand. The means of preservation of such major basins is however poorly understood.
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  • Date Issued: 1992

The development and evaluation of an andragogic training programme for Ciskeian retailers

  • Authors: Kotzé, Clifford Jennings
  • Date: 1992
  • Subjects: Small business -- South Africa -- Ciskei Retail trade -- South Africa -- Ciskei
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:1184 , http://hdl.handle.net/10962/d1002801
  • Description: One of the greatest challenges facing South Africa and the "independent states" of Transkei, Bophuthatswana, Venda and Ciskei over the next decade will be job creation and the development of the skills of the people. This is particularly true of Ciskei with its rapid population growth, unemployment, shortage of skilled manpower and over abundance of unskilled labour. Small business and, in particular, retailing with its relatively low entry requirements, can play a significant role in the creation of jobs. Small business, and small business retailing in particular, suffers, however, from a high failure rate resulting in a waste of financial and human resources which a developing nation like Ciskei can ill afford. The training of people involved in small business retailing is, therefore, of great importance. There is no unanimity of opinion, however, as to what training models or approaches are most appropriate. The purpose of this study was, thus, to design a training model, develop an andragogic training programme for Ciskeian small retailers based upon the model and test it. In accordance with the model developed, the nature of the retailers performance problem was established, the job of the small retailer was analysed, the training needs of retailers were identified, performance standards were set, the course curriculum was developed, training strategies and styles were selected, the necessary training resources were obtained and the training programme was implemented. A pilot training programme was run in 1987 and then the amended programme was run for two years. The results of the training were measured in terms of: -the delegates reaction to the training programme -what the delegates learnt -changes in the business as perceived by regular customers -reaction of the delegates to the training programme one year later -case studies and survival rates Statistically significant positive results were obtained in all aspects evaluated. It can, therefore, be concluded that the andragogic training model for Ciskeian retailers resulted in a positive reaction of delegates to the training, an improvement in the retailer's knowledge of retailing, positive changes in the businesses as perceived by regular customer and improved survival rates of these small retail businesses.
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  • Date Issued: 1992

The distribution of the Wattled Starling in southern Africa

  • Authors: Craig, Adrian J F K
  • Date: 1992
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/447896 , vital:74682 , https://doi.org/10.1080/00306525.1992.9634180
  • Description: Dated distribution records of the Wattled Starling Creatophora cinerea have been assembled from the literature, museum specimens, atlas records, and other unpublished observations. The bulk of these records are from the period 1980–89. Breeding records are sparse, but breeding appears to be seasonal in the winter rainfall area. In summer rainfall areas nesting occurs from spring through to autumn, dependent on the presence of abundant insects. In most areas winter records (June to August) predominate, but in the eastern lowveld areas of South Africa Wattled Starlings are recorded most often in spring and summer. The species is correctly described as nomadic, and the pattern of occurrence does not suggest regular migration.
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  • Date Issued: 1992

The effect of pineapple cultivation on factors influencing soil erodibility in the Eastern Cape, South Africa

  • Authors: Boucher, Kim Gillian
  • Date: 1992
  • Subjects: Soil erosion -- South Africa Pineapple industry -- South Africa -- Eastern Cape Agriculture -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4827 , http://hdl.handle.net/10962/d1005502
  • Description: The study examines the effect of ridged pineapple cultivation on factors influencing the soil erodibility of Glenrosa and Oakleaf soil forms in the Bathurst district of South Africa. A number of physical and chemical variables influencing soil erodibility are investigated, namely soil moisture, bulk density, porosity, infiltration rate, aggregate stability, shear strength, soil texture, soil structure, penetrability, organic carbon, pH and cation exchange capacity. These soil characteristics are examined in undisturbed soils under natural vegetation and compared to those on adjacent traffic areas, pineapple ridges and pineapple furrows. The results of the analyses between the four sample sites indicate that ridged cultivation of pineapples has a negative effect on factors influencing soil erodibility on the areas studied. The results of the analysis within each of the sample sites do not illustrate any clear relationships and thus depict the complexity and multiplicity of the soil erodibility phenomenon. A further study, augmenting the soil erodibility data with actual soil loss data, is recommended
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  • Date Issued: 1992

The effect of temperature and photoperiod on the digestive physiology of the South African abalone Haliotis midae

  • Authors: Dixon, Mark Geoffrey
  • Date: 1992
  • Subjects: Abalone culture , Gastropoda -- Physiology , Gastropoda -- Food , Abalones -- South Africa
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5276 , http://hdl.handle.net/10962/d1005120 , Abalone culture , Gastropoda -- Physiology , Gastropoda -- Food , Abalones -- South Africa
  • Description: Inadequate information of the nutritive physiology and the dietary requirements of abalone are the principle factors that currently limit the development of a formulated feed for the commercial culture of Haliotis midae. The need to develop a method to determine apparent digestibility co-efficient's for abalone in order to facilitate further applied nutritional research was identified. Animals between 50 and 80 mm were collected from natural stocks along the east Cape coast of South Africa at Port Alfred and Great Fish point, and acclimated to laboratory conditions. Initial trials demonstrated that H. midae accepted and preferred a semi-purified diet to the seaweed Plocamium corallorhiza, one of the main components of it's natural diet. A technique of determining apparent digestibility co-efficient's (ADC) using the indirect method with chromic oxide as an inert marker was developed. Digestibility trials yielded higher dry matter (DMADC) and crude protein apparent digestibility co-efficient's (CPADC) for the semi-purified diet than for two species of algae, Gelidium amanzii and P. corallorhiza (83.7% and 95.6%, 70.7% and 80.0%, and 29.9% and 57.3% respectively). The ability of the animals to utilize terrestrial animal and plant ingredients efficiently makes it feasible to use conventional feed ingredients in formulated feeds for H. midae. Trials to determine the effect of different temperatures (15°C, 18°C and 22°C) on DMADC and CPADC of the semipurified diet showed that peak digestibility occurred at 18°C. There was also a positive relationship between temperature and consumption rate. Although no enzyme studies with H. midae have been conducted, the peak ADC's at 18°C is attributed to an increase in enzyme activity at this temperature. Transit time, an inverse function of temperature and consumption, is considered to be responsible for the decrease in the ADC' s at 22°C in conjunction with a possible decrease in enzyme activity at this temperature. A photoperiod trial to investigate the effect of darkness on DMADC and CPADC of the semi-purified diet revealed that digestive efficiency decreased with increasing hours of darkness. There was also a positive relationship between duration of darkness and the rate of consumption. The decrease in ADC's is attributed to decreased transit times as the duration of darkness increased . The contribution of this project to the understanding of abalone nutrition, the development of a formulated abalone feed and systems design for abalone farms is discussed.
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  • Date Issued: 1992

The effects of a 160 km run on selected anthropometric, physiological and psychological parameters

  • Authors: Oltmann, Carmen
  • Date: 1992
  • Subjects: Marathon running -- Psychological effects , Marathon running -- Physiological effects
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5148 , http://hdl.handle.net/10962/d1009706 , Marathon running -- Psychological effects , Marathon running -- Physiological effects
  • Description: Twenty-one male subjects volunteered to participate in this study of the effects of an ultramarathon run under competitive conditions. Selected anthropometric measurements were made before and after the race. Blood samples were taken before, and within 10 min. of completing the race. Haematocrit and cortisol concentrations were analysed from each sample. Three ratings of perceived exertion (RPE) - local, central and overall, were obtained at two-hourly intervals throughout the race. The shortened form of the Eysenck Personality Inventory (EPI) was administered before the race. The Profile of Mood States (POMS) test was completed both before and immediately after the race. The average running intensity was estimated to be about 32% VO₂max which would not have caused major lactate accumulation. Repetitive compressive forces as a result of heel-strike resulted in intervertebral disc fluid loss. This resulted in a significant (p<0.05) decrease in stature after the race. Mobilization of glycogen, trig1ycerides and protein for metabolism as well as fluid loss via sweat resulted in significantly decreased body mass after the race. Plasma volume and serum cortisol concentrations were significantly increased after the race compared to pre-race baseline levels. Local RPE responses were dominant throughout the entire race, followed by overall RPE. Running 160 km had an effect on mood state. "Depression", "fatigue" and "confusion" (profile of Mood states) were all significantly increased compared to pre-race scores. Sleep deprivation as a result of running through the night was probably an important contributing factor. The anthropometric profile of the ultramarathon runners in this sample was more like that of the general population than elite marathon runners from the literature. The ultramarathon runners were more extroverted than elite marathon runners, but exhibited a similar Profile of Mood state before the race. The stressor - running 160 km - resulted in a 'strain response'. This was evident in the decreased stature and mass, and increased serum cortisol, "depression", "confusion" and above all "fatigue".
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  • Date Issued: 1992

The evaluation of an individualised language programme in two multicultural Standard 9 classes : a pilot study

  • Authors: Hartman, Lorraine Mary
  • Date: 1992
  • Subjects: English language -- Study and teaching (Secondary) -- South Africa English language -- Study and teaching (Secondary) -- South Africa -- Foreign speakers Language and education -- South Africa
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1523 , http://hdl.handle.net/10962/d1003405
  • Description: Two multicultural, mixed-ability Standard Nine classes (17 year olds) were selected for this pilot study. As they were half way through the Senior Secondary phase they had completed most of their English Language syllabus. There was a wide range of achievement in English in addition to which, fifteen of the thirty-nine pupils were English second language speakers. The teacher had to decide how to cope adequately with these differences in the subject English in general and in particular, in the Language component. A Language programme was devised, based on the prescribed textbooks. The pupils could work through the programme at their own pace and order and could consult the researcher during or after class time. The programme only covered the prescribed Language Study component and only a quarter of the total English time during an eight-week period (one term) was given to its completion. A Pre-test was set, the Senior Certificate Language examination paper of 1986, and the results analysed. The two classes were combined into one group and then randomly placed in the experimental and control groups apart from eight boys whose timetable requirements restricted them to being in the same group. The experimental and control groups were not matched. Aspects of Action Research were included in the design; pupils kept individual records; diaries were written by three pupils from each group and an independent observation was made of each group. A Post-test was administered (the 1989 Human Sciences Research Council examination) and this was followed by a questionnaire. The hypothesis, stated in null form, was: Pupils taught by individualised methods will not achieve better results than those taught by traditional methods. This hypothesis proved to be true. The experimental group, who achieved a better result in the pre-test maintained their lead over the control group but did not increase it. Neither group fared well on the post-test but the experimental group achieved a result slightly higher than the provincial average. The affective results were more positive, most pupils enjoying their autonomy and experiencing a sense of achievement despite their results in the post-test. A few preferred whole and small-group teaching, showing that the teacher needs to present the subject in more than one style. This small-scale experiment dealt only with one aspect of English teaching, but there is potential for development particularly with regard to the use of individualised programmes both for remedial and enrichment purposes. The innovative teacher in the multicultural classroom could use individualised programmes profitably as part of his teaching repertoire.
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  • Date Issued: 1992

The evaluation of indomethacin and theophylline oral controlled/modified-release dosage forms in vitro-in vivo correlations

  • Authors: Tandt, Ludo Alfons Germaan Luc
  • Date: 1992
  • Subjects: Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3794 , http://hdl.handle.net/10962/d1003272 , Theophylline , Indomethacin , Drugs -- Controlled release , Drugs -- Dosage forms
  • Description: Over the past few decades many researchers have investigated the utility of in vitro - in vivo correlations for the assessment of dosage forms. These investigations are, however, dependent on reproducible dissolution data and well conducted biostudies in order to establish meaningful and robust correlations. Despite the fact that the establishment of such correlations is perhaps idealistic, considerable interest has still been shown in this area of research. Various Controlled/Modified Release Dosage Forms (CMRD's) of theophylline, a weakly basic drug, and indomethacin, a weakly acidic drug, were assessed in order to establish in vitro - in vivo correlations. Dissolution rate studies were carried out using either the USP basket or paddle apparatus. The dissolution rate studies were conducted in a range of dissolution media of varying pH. Bioavailability studies were conducted on the dosage forms used by the Biopharmaceutics Research Institute at Rhodes University. The results of these biostudies were kindly made available for use in this research project. Type A correlations were established using a mathematical simulation process whereby expected in vivo responses are simulated and compared to actual profiles obtained for the dosage forms. In order to perform the simulations the dissolution rate profiles were stripped and using linear regression and the methods of residuals the dissolution rate order and the relevant dissolution rates were obtained. The results of the s imulations indicated that the in vivo serum concentration-time curves could be accurately predicted for the theophylline dosage forms but to a lesser extent, for the indomethacin formulations. The dissolution rate studies indicated that the paddle method is a suitable method for dissolution rate studies of theophylline CMRD's, although it appeared that the optimum pH of the dissolution medium was formulation dependent. Dissolution rate studies conducted on indomethacin formulations indicated that the USP specified basket method for extended-release indomethacin formulations was not able to distinguish between two formulations which exhibited different in vivo profiles. The conversion to the paddle method was, however, able to highlight the differences between these formulations. The use of three dimensional topographs to depict dissolution rate profiles was demonstrated for formulations of both theophylline and indomethacin. The topographs enabled the successful differentiation between bioinequivalent formulations. The dissolution rate profiles were also fitted to the Wei bull equation and the parameters obtained from this were compared to the Weibull parameters obtained from the in vivo absorption plots obtained using the Wagner-Nelson method. The results indicated that the Weibull function was suitable to describe both the in vivo and in vitro data. The following recommendations for the preformulation dissolution studies of weakly acidic and weakly basic drugs are proposed. The dissolution rate studies of weakly acid drugs, such as indomethacin, should be carried out over a range of pH utilising the paddle apparatus. Three dimensional topographs based on the dissolution data should be constructed and used as a comparative tool for different formulations. Based on these comparisons the appropriate formulation can then be selected for a pilot scale in vivo bioavailability study. The dissolution rate studies of weakly basic drugs, such as theophylline, should be carried out over a range of pH utilising the paddle apparatus. The dissolution data should then be used to simulate the expected in vivo profile and on this basis the appropriate formulation selected for a pilot scale bioavailability study. The above approach to the preformulation studies of new CMRO's would allow for the more careful selection of new dosage forms and could thus eliminate costly and unnecessary bioavailability studies performed on inferior formulations.
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  • Date Issued: 1992

The exploitation of methane from landfill

  • Authors: Schütte, Renate
  • Date: 1992
  • Subjects: Methane , Waste products as fuel , Refuse as fuel , Sanitary landfills -- South Africa
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4530 , http://hdl.handle.net/10962/d1015949
  • Description: A review of literature on the subject of methane exploitation from landfill is presented in conjunction with the results of experiments concerning landfill gas extraction at the Grahamstown Landfill Site. A description of the LFG extraction system and the utilisation of LFG at the Grahamstown Landfill Site is included. Data concerning LFG enhancement parameters, LFG compositions and flow rates, refuse composition, LFG modelling, LFG pumping trials and the economics of LFG extraction and utilisation are presented. The indication is that LFG can be economically extracted and utilised as a heating fuel in South Africa.
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  • Date Issued: 1992

The exploration for and possible genesis of, some Archaean granite/gneiss-hosted gold deposits in the Pietersburg granite-greenstone terrane

  • Authors: Linklater, Michael Anthony Leonard Flanders
  • Date: 1992
  • Subjects: Gold ores -- Geology -- South Africa , Gneiss , Granite
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4945 , http://hdl.handle.net/10962/d1005557 , Gold ores -- Geology -- South Africa , Gneiss , Granite
  • Description: Abstract The gold mineralization event within Archaean granite-greenstone terranes occurred during the late Archaean, and followed the intrusion of syn- to late-tectonic granitic plutons into previously deformed greenstone belts. An Archaean granite/gneiss-hosted gold deposit, in terms of this project, is classified as having a gold-assay cutoff of 1g/metric ton over widths of at least several metres, or higher grades over narrower widths and/or verbal descriptions that indicate such values. Fluid inclusion studies and isotopic data identify two possible origins for the auriferous fluids; namely magmatic and metamorphic. The exploration target according to the magmatic model, is a late-Archaean, hydrothermally altered, mineralized and fractured granitic intrusion preferably with a granodioritic or quartz-dioritic composition. The exploration target according to the metamorphic replacement model is a granitic stock that has intruded a zone of crustal weakness such as a shear zone, active during the late Archaean. Alternatively, the granitic intrusion should be affected by regionally extensive late-Archaean shearing. It should be hydrothermally altered, deformed and mineralized. Five areas within the Pietersburg granite-greenstone terrane were selected for the 'Regional Area Selection' phase of exploration for Archaean granite/gneiss-hosted gold deposits; namely Roodepoort, Waterval, Ramagoep, Moletsie and Matlala. Roodepoort contains a known granodiorite-hosted gold deposit; the Knight's Pluton, and served as an orientation survey for this project. The use and interpretation of LANDSAT images formed an integral part of exploration techniques; to assess their usefulness in the exploration of Archaean granite/gneiss-hosted gold deposits. Area selection criteria for granite/gneiss-hosted gold mineralization at Roodepoort are the major ENE-trending shear zone, the NNW-trending lineament and hydrothermal alteration, shearing, quartz-stockworks and sulphide mineralization within the Knight's Pluton. The origin of the gold within the Knight's Pluton is uncertain; both magmatic and metamorphic models are possibilities. Ongoing exploration is in progress at Roodepoort. The only area selection criterion for granite/gneiss-hosted gold mineralization at Waterval is the sericitized, subcropping granites located within trenches. Gold mineralization is insignificant. No area selection criteria for Archaean granite/gneiss-hosted gold mineralization were located at Ramagoep, Matlala and Moletsie. No further exploration is recommended for all these areas. The MES image interpretations were successful in identifying lineaments, granitic outcrops, greenstones, vegetation and soil cover. The Clay-iron images adequately differentiated betweeen iron-rich and clay-bearing areas. However, not all clay-bearing areas were associated with hydrothermal alteratian; field checks were necessary to discriminate between weathered granites and hydrothermally altered granites. The Wallis images served to locally enhance the contrasts of the MES and Clay-iron images.
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  • Date Issued: 1992

The failure of the Coloured Persons' Representative Council and its constitutional repercussions, 1956-1985

  • Authors: Saks, David
  • Date: 1992
  • Subjects: South African Labour Party , Federal Coloured People's Party -- South Africa , South Africa. Parliament , South Africa -- Politics and government -- 20th century , South Africa -- Race relations , Coloured Persons Representative Council of South Africa , Colored people (South Africa) -- Politics and government , Political parties -- South Africa
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2624 , http://hdl.handle.net/10962/d1015907
  • Description: The thesis starts by providing a brief overview of South African ''Coloured" politics from the passing of Ordinance 50 in 1828 to the removal of the Cape Coloured people from the common voter's roll in 1956. It then goes on to discuss in detail the structures instituted by successive Nationalist Governments to serve as an alternative to parliamentary representation for the coloured people, the role of the various coloured political parties within such structures and the latter's gradual adaptation and development, culminating in the inauguration of the Tricameral Parliament in early 1985. The thesis is, on the one hand, a detailed record of coloured political activity following the loss of common roll voting rights in the Cape, focusing on specifically coloured political parties rather than on broader, non-ethnic resistance movements in which many coloured people took part during the same period. This covers the rise and rapid decline of a conservative grouping within the coloured community which sought to foster an exclusively coloured nationalism operating within the Government's policy of parallel development, and attempted to use the Coloured Persons' Representative Council as a means towards achieving the economic, social and political upliftment of the coloured people. It also deals with the important role of the Labour Party after 1966, showing how a moderate resistance movement carne to use the Council as a platform from which to confront the Government's apartheid policies and to render the institutions of parallel development unworkable through noncooperation and boycotting. The second important preoccupation of the thesis concerns the ambiguous and often contradictory attitudes towards the "coloured question" within the National Party itself. This ambivalence, it is argued, not only had much to do with the eventual failure of the Coloured Persons' Representative Council to become a viable substitute for Parliamentary representation acceptable to the majority of coloured people, but was also a primary cause of the National Party split in 1982. It shows too how the collapse of Grand Apartheid had its origins in the failure to incorporate the coloured population within its framework. The thesis is concerned primarily with coloured political developments. When relevant, however, the establishment and development of representative institutions for the Indian people is also dealt with, in so far as this overlaps with issues and events concerning the coloured Council. Finally, the five year period following the dissolution of the Coloured Persons' Representative Council in 1980 and the inauguration of the Tricameral Parliament in 1985 is briefly dealt with in a concluding chapter. This mainly concerns the gradual accommodation reached between the Government and the Labour Party when the latter eventually agreed, conditionally, to take part in the new constitution.
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  • Date Issued: 1992

The FITE for reading teaching : an examination of the initial training of senior primary teachers at a sample of institutions in England and South Africa

  • Authors: McKellar, David William
  • Date: 1992
  • Subjects: Reading (Elementary) -- South Africa Reading (Elementary) -- Great Britain Teachers -- Training of -- South Africa Teachers -- Training of -- Great Britain
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:1545 , http://hdl.handle.net/10962/d1003427
  • Description: Primary school teachers are expected to teach reading. Whether they are adequately prepared to fulfil this role, particularly for those preparing to teach in the senior primary phase, is the concern of this thesis. Reading teaching models are useful to reading teaching course developers for devising initial training syllabuses. Such models are described, followed by an example of such a syllabus developed at Rhodes University. The Rhodes University model, described early in the thesis, is used as a background for the further consideration of aspects of reading teaching at other institutions. This model is also used as an instrument for assessing the pre-service teaching experience of student teachers. The study focuses on English speaking teacher training institutions where the majority of the student teachers are preparing to teach in English speaking primary schools. Because of the considerable influence of developments in England on South African English speaking teacher training institutions, reading teaching developments in England from 1972 to 1990 are described. The pioneering work of Cook and Moyle provides a background against which subsequent developments in reading teaching are traced. Reports produced by the Department of Education and Science provide many insights into the state of reading teaching in schools in England as well as developments in teacher training. The reading teaching courses at six teacher training institutions are examined - three in England and three in South Africa. The differences are considerable, particularly the amount of time allocated to reading teaching during the four years of initial teacher education and training common to the six institutions. Two cohorts of student teachers review and assess the Rhodes University reading teaching course in terms of the extent of its interest and value for them as prospective teachers, and the amount of time allocated to the course. The most disturbing finding of this study is the nature of reading teaching observed in schools by student teachers. It is suggested that if reading teaching in senior primary schools is to be improved, the deadlocked cycle needs to be broken by education authorities, teachers and teacher trainers resolving the problem jointly.
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  • Date Issued: 1992

The geochemical evolution of three alkaline complexes in the Kuboos-Bremen igneous province, southern Namibia

  • Authors: Smithies, Robert Hugh
  • Date: 1992
  • Subjects: Alkalic igneous rocks -- Namibia Geochemistry -- Namibia
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4952 , http://hdl.handle.net/10962/d1005564
  • Description: The Kuboos-Bremen Igneous Province comprises a linear zone of alkaline complexes that intrude Proterozoic and Pan-African rocks and trends in a northeast direction from the northwest of the Cape Province in South Africa into southern Namibia. Of the three most southerly complexes in Namibia. two comprise silicate rocks ranging from nepheline syenite to alkali-granite and are called the Grootpenseiland and Marinkas Kwela Complexes (GPC and MKC). The Marinkas Kwela Carbonatite Complex is the third and most northerly of the complexes. Isotopic age determinations on a number of rock types from both the silicate complexes yield ages around 520Ma and are consistent with published Pan-African ages for the Province. Each silicate complex shows a migrating locus of intrusion from Siundersaturated rocks in the southwest to Si-oversaturated rocks in the northeast. The complexes overlap in outcrop. The rocks are moderately to highly felsiC and none reflects primary magma compositions. The Si-undersaturated rocks from both complexes include side-wall cumulates formed from magmas that fractionated alkali-feldspar, clinopyroxene and amphibole. Foyaites also occur in the MKC and have a compositional range reflecting alkali-feldspar fractionation and, probably, some interaction with dolomite country rocks. Major and trace element data suggest that critically saturated alkali syenites occurring in both complexes evolved via protracted feldspar fractionation, and that critically saturated alkali-feldspar syenite occurring only in the GPC is a cumulate. The two rock types cannot be related genetically. Of the SI-oversaturated rocks in both complexes, those in the compositional range monzonite to granite were intruded before alkali-granites. Compositional diversity amongst the former reflects fractionation of feldspar and of mafic phases, but that process cannot genetically link the rocks to the alkali-granites. Isotopic compositions of Sr and Nd indicate that the silicate magmas were derived from an upper mantle source region characterised by low time-integrated Rb/Sr ratios and high time-Integrated Sm/Nd ratios, However, the evidence of Sr and 0 isotopic data is that the Si-oversaturated melts possibly interacted with a crustal component. presumably the Proterowlc rocks of the Namaqua Metamorphic Province. This interaction may explain the occurrence of apparently co-genetic rock series that evolved on opposite sides of the feldspar join in Petrogeny's Residua System. The Marinkas Kwela Carbonatite Complex was emplaced before the final intrusive phases of the MKC and exhibits unusually pronounced late-stage enrichment in manganese. The earliest intrusive rocks in the complex were nepheline syenites which were fenitised by later intrusions of sôvites. Although the commonly occurring magmatic sequence of sôvite-beforsite-ferrocarbonatite is observed at Marinkas Kwela, sôvites do not appear to have been parental to beforsites. Removal of apatite and early crystallisation of magnetite distinguish magnetite-rich beforsite from co-genetic apatite-rich beforsite. Two further magmatic sequences. the first from apatite-rich beforsite through ferrocarbonatite to Mn-rich ferrocarbonatite (high Fe/Mn) and the second from magnetite-rich beforsite to Mn-rich ferrocarbonatite (low Fe/Mn). reflect fractionation of dolomite and of dolomite+magnetite respectively.
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  • Date Issued: 1992

The geology and evaluation of the "A"-reef at No.3 shaft, Western Holdings Mine, Welkom goldfield

  • Authors: Blamey, Nigel John Frederick
  • Date: 1992
  • Subjects: Gold mines and mining -- South Africa -- Free State , Gold ores -- Geology -- South Africa
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4957 , http://hdl.handle.net/10962/d1005569 , Gold mines and mining -- South Africa -- Free State , Gold ores -- Geology -- South Africa
  • Description: The "A" -Reef occurs within the Aandenk Formation of the Central Rand Group, Witwatersrand Supergroup, in the Welkom Goldfield. It comprises the Witpan and Uitsig Reefs which are both oligomictic conglomerates, and are exploited for their gold content by Anglo American Corporation. The main Witpan channel complex is orientated in a NW-SE direction and occurs close to No.3 Shaft of Western Holdings Mine where it is currently being mined. The Witpan Reef varies in thickness from 7-220cm, with lateral facies changes controlling the thickness. Within the reef, gold is associated with degradation surfaces, carbonaceous material, increase in pebble sphericity, and channel edges. Two channel edges have yielded the best gold values on No.3 Shaft although the potential for further payable gold lies in the recognition of sieve conditions. The potential also exists for extensions of the "carbon"-bearing Uitsig channel currently being mined on President Steyn Mine. The palaeo-environment proposed for formation of the Witpan Reef is a braidplain that was partly reworked by a brief transgression. Ore evaluation using geostatistics was considered a valid technique as the dataset is sufficiently well structured. Semi-variograms in the channel and across-channel directions differ markedly. It was found that variograms of gold in cmg/t lacked sufficient structure for modelling, however, log semi-variogram modelling followed by simple log-kriging and back-transformation, proved to be the most successful method. Owing to the morphology and distribution of gold within the reef, a geologically based geostatistical valuation method is proposed. The potential for further exploration of "A" -Reef depends on a substantially higher gold price. In this event, exploration of Uitsig Reef to the southwest of the current mining area is recommended as well as a new exploration strategy for Witpan Reef.
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  • Date Issued: 1992

The geology and geochemistry of the north-western portion of the Usushwana Complex, South-Eastern Transvaal

  • Authors: Riganti, Angela
  • Date: 1992
  • Subjects: Geology -- South Africa -- Transvaal , Geochemistry -- South Africa -- Transvaal
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4958 , http://hdl.handle.net/10962/d1005570 , Geology -- South Africa -- Transvaal , Geochemistry -- South Africa -- Transvaal
  • Description: The 2.9 Ga old Usushwana Complex in the Piet Retief-Amsterdam area (south-eastern Transvaal) represents an exposed segment of a layered intrusion. It has the form of a dyke-like body elongated in a northwesterly direction, and extends to an estimated depth of 3000 -5500 m. Lithologically, the Complex consists of a cumulate succession of mafic rocks capped by granitoids and has intruded along the contact between the basement and the supracrustal sequences of the Kaapvaal Craton. Differentiation of an already contaminated gabbroic magma resulted in an ordered stratigraphic sequence comprising progressively more evolved lithotypes, with at least two imperfect cyclic units developed over a stratigraphic thickness of about 700 metres (Hlelo River Section). Meso- to orthocumulate textured gabbros and quartz gabbros grade upwards into magnetite- and apatite-bearing quartz gabbros, interlayered with discontinuous magnetitite horizons. The gabbros in turn grade into hornblende-rich, granophyric granodiorites. The differentiation process is regarded as having been considerably enhanced by the assimilation of acidic material, derived by partial melting of the felsic country rocks at the roof of the magma chamber. Recrystallisation of these rocks gave rise to the microgranites that locally overlie the granodiorites. Mineralogical, textural and geochemical features indicate a relatively advanced fractionation stage, suggesting that the exposed sequence of the Usushwana Complex in the study area represents the upper portion of the intrusion. No significant mineralised occurrences were identified. However, on the basis of similarities between the Usushwana Complex and other mafic layered intrusions which host significant ore deposits, it is suggested that economic concentrations of base metal(Cu-Ni) sulphides, PGE and chromitites are likely to be developed at lower stratigraphic levels.
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  • Date Issued: 1992

The growth characteristics of sparid otoliths

  • Authors: Lang, Judy Brenda
  • Date: 1992
  • Subjects: Fishes -- Age determination , Otoliths , Sparidae
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5285 , http://hdl.handle.net/10962/d1005129 , Fishes -- Age determination , Otoliths , Sparidae
  • Description: The periodicity of formation of growth increments in the otoliths of South African sparids was validated by the oxytetracycline labelling technique. Intramuscular injections of oxytetracycline at a dosage of 250mg/kg marked the otoliths of laboratory held juvenile sparids, while a dosage range of 50 - 100mg/kg oxytetracycline, injected intramuscularly, marked adult sparids in the field. Laboratory held, larval sparid otoliths were marked by immersion for 24hrs a solution of 100-150mg/l alizarin complexone. Both daily (microstructural) and annual (macrostructural) growth increments were identified in the otoliths. The micro incremental pattern of deposition in the sparid otoliths conformed to the general pattern of otolith structure. Sparid otoliths consisted of a central opaque nucleus composed of multiple primordia. surrounding this nucleus were daily increments which decreased in width as the distance from the nucleus increased. Both check rings and subdaily increments were visible throughout the otolith. Minor environmental changes did not affect micro incremental deposition. Narrow opaque and wide hyaline annual growth zones were identified in sectioned sparid otoliths. Scanning electron microscope analysis of the annual growth zones revealed that microincrements within the opaque zone were narrowly spaced with prominent discontinuous phases. This resulted in the greater optical density and higher protein content of the zone. The hyaline zone was composed of widely spaced daily increments with prominent incremental phases accounting for the translucent nature of this zone. Opaque zone formation in the otoliths of many South African sparids was found to occur primarily during periods of reproductive activity and was shown to be indicative of slow otolith growth. The hyaline zone was formed after the spawning season, representative of fast otolith growth. The results of this study have resolved much of the controversy surrounding the rate of growth and time of formation of the opaque and hyaline growth zones in South African sparid otoliths.
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  • Date Issued: 1992

The in-service development of primary school teachers in the use of computers in education with special reference to computer assisted learning: a case study

  • Authors: Murray, John Charles
  • Date: 1992
  • Subjects: Education, Elementary -- South Africa -- Data processing Computer-assisted instruction Teachers -- In-service training -- South Africa
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1572 , http://hdl.handle.net/10962/d1003454
  • Description: Many white primary schools in South Africa have acquired computers which are being used in various ways. In my experience few members of staff are confident enough to use the computers in the school for educational purposes. Those who have been using them, generally have been doing computer literacy. The teachers in our school expressed the view that they would like to be able to use the computer, but that they lack the necessary skills and therefore would welcome some form of training. In my opinion computers should form an integral part of a child's learning environment. It has, for some time formed a part of his social environment, either in the home or in the workplace. For computers to be used effectively in the classroom, it follows that the teachers need to be trained to use them. In an attempt to overcome this problem, I designed and presented an in-service course, which used selected computer assisted learning (CAL) programs with teachers. These teachers then used these programs with the pupils in their class and evaluated the pupils' reactions to the innovation. As a result of the observations and the feedback provided by the sample of teachers, it is suggested that this might be a possible approach to in-service training for other schools. With adaptation it should be possible to follow this approach in any school which has a computer and someone on the staff who is willing to take the initiative to implement such an innovation.
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  • Date Issued: 1992

The influence of children on decision-makers in their homes : a case study in environmental education

  • Authors: Kruger, Jacqueline
  • Date: 1992
  • Subjects: Environmental education -- South Africa , Parent and child -- South Africa
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1574 , http://hdl.handle.net/10962/d1003456
  • Description: This study explores the possible influence of twenty children on their 'parents', with a view to better understanding the potential 'multiplier effect' of children regarding environmental responsibility. The criteria employed to study the potential influence included certain of the environmental activities learnt by the children during an Environmental Education programme. The programme was undertaken by the researcher with a Std 4 class from Ryneveld Primêreskool in Graaff-Reinet. An action research approach was adopted and results were analysed qualitatively. Due to the short duration and exploratory nature of the project, these results should be viewed as tentative. Proposals are made for increasing the impact of Environmental Education programmes in peri-urban township communities, and recommendations are put forward to help facilitate related studies in the future.
  • Full Text:
  • Date Issued: 1992
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