Small-scale gold mining in southern Africa
- Authors: Joubert, Barend Daniel
- Date: 1992
- Subjects: Gold mines and mining -- South Africa , Abandoned mines , Abandoned mines -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5002 , http://hdl.handle.net/10962/d1005615 , Gold mines and mining -- South Africa , Abandoned mines , Abandoned mines -- South Africa
- Description: The general characteristics of gold deposits are reviewed, and a classification of gold deposits based on mineability is proposed. Evaluation, mlnlng and beneficiation methods are briefly discussed. It is concluded that the most viable targets for small-scale companies comprise deposits that require the least pre-production time and expense. Great potential exists for the small-scale reclamation of gold from tailings dumps and abandoned mines in Southern Africa. There is also potential for developing new smallscale gold mines in the Archaean greenstone terranes of the Zimbabwean and Kaapvaal cratons.
- Full Text:
- Date Issued: 1992
- Authors: Joubert, Barend Daniel
- Date: 1992
- Subjects: Gold mines and mining -- South Africa , Abandoned mines , Abandoned mines -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5002 , http://hdl.handle.net/10962/d1005615 , Gold mines and mining -- South Africa , Abandoned mines , Abandoned mines -- South Africa
- Description: The general characteristics of gold deposits are reviewed, and a classification of gold deposits based on mineability is proposed. Evaluation, mlnlng and beneficiation methods are briefly discussed. It is concluded that the most viable targets for small-scale companies comprise deposits that require the least pre-production time and expense. Great potential exists for the small-scale reclamation of gold from tailings dumps and abandoned mines in Southern Africa. There is also potential for developing new smallscale gold mines in the Archaean greenstone terranes of the Zimbabwean and Kaapvaal cratons.
- Full Text:
- Date Issued: 1992
Social development: theory, practice and evaluation
- Authors: Henderson, Thelma M
- Date: 1992
- Subjects: Social service -- South Africa -- Grahamstown , Social service -- Evaluation , Community development -- South Africa -- Grahamstown , Rhodes University. Centre for Social Development
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:697 , http://hdl.handle.net/10962/d1006418
- Description: Prior to 1976 few facilities and projects existed to serve the underprivileged communities in Grahamstown. Numerous attempts to establish development programmes had failed. From 1976 to 1981 informal attempts were initiated and a number of community based facilities were established. From 1981 to 1991 the Centre for Social Development assumed responsibility for this work and was able, with an enlarged staff, to inaugurate a wide range of projects and programmes. These cater to thousands of deprived people and enable them and their children to realise an improved quality of life. The dynamic processes and policies which have been employed are investigated. The value of this work is noteworthy because of the limited number of research papers on indigenous grassroots development projects in South Africa. The methods which have been utilised to enable unemployed people to play meaningful roles in their own communities are investigated. These include the establishment of much needed facilities and the in-service training of workers and committee teams to run and service them. Of particular importance is the role and structure of the Centre as an umbrella and resource organisation. The work of the Centre and its projects is described and evaluated. The qualitative, quantitative, exploratory and descriptive methods are used. The relationships between social welfare, community work and social planning are considered in relation to the theoretical base of the Centre. The situation in the Black and Coloured townships of Grahamstown, where most of the projects are located, is described with special reference to population, housing, basic services, crime and disease. Reasons for the high unemployment rates are enumerated. Various development models are described and their strengths and weaknesses assessed. Of particular significance are the origins of the Centre, the qualities brought to the project by the founding Director, its fundraising techniques, and procedures for training, supervision and project support. Aspects of development strategy not stressed in the literature, but of particular importance in the South African situation, are highlighted. These include the basic necessity for adequate financing, the provision of bursaries for tertiary study, the importance of nutritious food, the creation of job opportunities and the value of child centred projects as an access to the wider community. The necessity of financial control in the individual projects is also stressed. The primary aim of this work is to ascertain how projects have been established and maintained in a community where nothing on this scale has been attempted before. A secondary objective has been to find the theoretical base that best suits the work of the Centre. This is the social planning model in the social welfare field
- Full Text:
- Date Issued: 1992
- Authors: Henderson, Thelma M
- Date: 1992
- Subjects: Social service -- South Africa -- Grahamstown , Social service -- Evaluation , Community development -- South Africa -- Grahamstown , Rhodes University. Centre for Social Development
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:697 , http://hdl.handle.net/10962/d1006418
- Description: Prior to 1976 few facilities and projects existed to serve the underprivileged communities in Grahamstown. Numerous attempts to establish development programmes had failed. From 1976 to 1981 informal attempts were initiated and a number of community based facilities were established. From 1981 to 1991 the Centre for Social Development assumed responsibility for this work and was able, with an enlarged staff, to inaugurate a wide range of projects and programmes. These cater to thousands of deprived people and enable them and their children to realise an improved quality of life. The dynamic processes and policies which have been employed are investigated. The value of this work is noteworthy because of the limited number of research papers on indigenous grassroots development projects in South Africa. The methods which have been utilised to enable unemployed people to play meaningful roles in their own communities are investigated. These include the establishment of much needed facilities and the in-service training of workers and committee teams to run and service them. Of particular importance is the role and structure of the Centre as an umbrella and resource organisation. The work of the Centre and its projects is described and evaluated. The qualitative, quantitative, exploratory and descriptive methods are used. The relationships between social welfare, community work and social planning are considered in relation to the theoretical base of the Centre. The situation in the Black and Coloured townships of Grahamstown, where most of the projects are located, is described with special reference to population, housing, basic services, crime and disease. Reasons for the high unemployment rates are enumerated. Various development models are described and their strengths and weaknesses assessed. Of particular significance are the origins of the Centre, the qualities brought to the project by the founding Director, its fundraising techniques, and procedures for training, supervision and project support. Aspects of development strategy not stressed in the literature, but of particular importance in the South African situation, are highlighted. These include the basic necessity for adequate financing, the provision of bursaries for tertiary study, the importance of nutritious food, the creation of job opportunities and the value of child centred projects as an access to the wider community. The necessity of financial control in the individual projects is also stressed. The primary aim of this work is to ascertain how projects have been established and maintained in a community where nothing on this scale has been attempted before. A secondary objective has been to find the theoretical base that best suits the work of the Centre. This is the social planning model in the social welfare field
- Full Text:
- Date Issued: 1992
Southern African Journal of Gerontology, volume 1, number 1, October 1992
- Ferreira, Monica (editor), Moller, Valerie, HSRC/UCT Centre for Gerontology
- Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
- Date: 1992
- Subjects: Older people -- Care -- South Africa , Gerontology -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8065 , http://hdl.handle.net/10962/d1012658
- Description: Southern African Journal of Gerontology; Produced within the framework of the Co-operative Research Programme on Ageing , The broad social issue of generational competition versus generational interdependence is discussed. The way elders are housed offers an excellent example of how benefits putatively allocated to older people in fact more often than not subsume benefits to family members of all ages. Data on generationally shared households from a number of countries and the results of recent studies from the United States are discussed in this context. Separate housing of generations is often preferred where feasible. Where economic, environmental. health, or social needs of either elder or young generations make autonomous households dysfunctional, members of each generation show in their household-formative behaviour their willingness to assist the other generation .
- Full Text:
- Date Issued: 1992
- Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
- Date: 1992
- Subjects: Older people -- Care -- South Africa , Gerontology -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8065 , http://hdl.handle.net/10962/d1012658
- Description: Southern African Journal of Gerontology; Produced within the framework of the Co-operative Research Programme on Ageing , The broad social issue of generational competition versus generational interdependence is discussed. The way elders are housed offers an excellent example of how benefits putatively allocated to older people in fact more often than not subsume benefits to family members of all ages. Data on generationally shared households from a number of countries and the results of recent studies from the United States are discussed in this context. Separate housing of generations is often preferred where feasible. Where economic, environmental. health, or social needs of either elder or young generations make autonomous households dysfunctional, members of each generation show in their household-formative behaviour their willingness to assist the other generation .
- Full Text:
- Date Issued: 1992
Standardization of Raven's standard progressive matrices for secondary school African pupils in the Grahamstown region
- Authors: Vass, Vasili Arthur
- Date: 1992
- Subjects: Black people -- Education -- South Africa , Intelligence tests -- South Africa , Educational tests and measurements -- South Africa , Cognition and culture , Raven's Progressive Matrices
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3078 , http://hdl.handle.net/10962/d1002587 , Black people -- Education -- South Africa , Intelligence tests -- South Africa , Educational tests and measurements -- South Africa , Cognition and culture , Raven's Progressive Matrices
- Description: Arising out of a need, expressed by Clinical Psychologists in the Grahamstown region, for the fair assessment of secondary School African pupils, norms for the Raven's Standard Progressive Matrices (SPM) were established. Two methods of presentation were used, the first using the original instructions of John Raven translated into the students' first language of Xhosa, hence-forth referred to as the Alternate sample. The second method of presenting the instructions was adapted, to include the use of visual aids and active participation in the instruction phase of the test, hence-forth referred to as the Normative sample. In addition to the establishment of norms, the two methods of test presentation were investigated to see if the method of presentation had an effect on the results of the Raven's SPM. The population was drawn from the three African Secondary Schools in the Grahamstown municipality. The total population consisted of 3 232 students. Classes were randomly sampled across the three schools, with the average age of the Normative sample being 19.3 years. The sample consisted of 812 pupils, 711 in the Normative sample and 101 in the Alternate Sample. The following results and conclusions arose from the study: 1) Norms generated were considerably lower than previously established norms in similar studies. 2) t-Test results indicated that the method of test presentation on the Raven's SPM is important when assessing students that may be regarded as 'disadvantaged'. 3) Respondents scored significantly higher when the method of presenting the instructions ensured a greater understanding of the task demanded of the respondents. 4) The analyses of covariance indicate that male subjects score significantly higher than female subjects, and that there is a significant difference between the ages and educational standard, on the scores of the Raven's SPM. 5) The differences found contradict previous findings using the test, and question the cultural fairness of the test.
- Full Text:
- Date Issued: 1992
- Authors: Vass, Vasili Arthur
- Date: 1992
- Subjects: Black people -- Education -- South Africa , Intelligence tests -- South Africa , Educational tests and measurements -- South Africa , Cognition and culture , Raven's Progressive Matrices
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3078 , http://hdl.handle.net/10962/d1002587 , Black people -- Education -- South Africa , Intelligence tests -- South Africa , Educational tests and measurements -- South Africa , Cognition and culture , Raven's Progressive Matrices
- Description: Arising out of a need, expressed by Clinical Psychologists in the Grahamstown region, for the fair assessment of secondary School African pupils, norms for the Raven's Standard Progressive Matrices (SPM) were established. Two methods of presentation were used, the first using the original instructions of John Raven translated into the students' first language of Xhosa, hence-forth referred to as the Alternate sample. The second method of presenting the instructions was adapted, to include the use of visual aids and active participation in the instruction phase of the test, hence-forth referred to as the Normative sample. In addition to the establishment of norms, the two methods of test presentation were investigated to see if the method of presentation had an effect on the results of the Raven's SPM. The population was drawn from the three African Secondary Schools in the Grahamstown municipality. The total population consisted of 3 232 students. Classes were randomly sampled across the three schools, with the average age of the Normative sample being 19.3 years. The sample consisted of 812 pupils, 711 in the Normative sample and 101 in the Alternate Sample. The following results and conclusions arose from the study: 1) Norms generated were considerably lower than previously established norms in similar studies. 2) t-Test results indicated that the method of test presentation on the Raven's SPM is important when assessing students that may be regarded as 'disadvantaged'. 3) Respondents scored significantly higher when the method of presenting the instructions ensured a greater understanding of the task demanded of the respondents. 4) The analyses of covariance indicate that male subjects score significantly higher than female subjects, and that there is a significant difference between the ages and educational standard, on the scores of the Raven's SPM. 5) The differences found contradict previous findings using the test, and question the cultural fairness of the test.
- Full Text:
- Date Issued: 1992
Strike
- NUMSA
- Authors: NUMSA
- Date: Aug 1992
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/112756 , vital:33652
- Description: THE National Executive Committee (NEC) of NUMSA met on 27-28 June and agreed that strike action is necessary to achieve our demands in these industries: NICISEMI - Iron, Steel, Engineering, Metallurgical Industry, NICMI - Motor, NBF - Auto, TYRE AND RUBBER. The NEC has therefore decided to hold a STRIKE BALLOT for workers in NICISEMI, Auto and Tyre and Rubber from 6-17 July 1992. The workers in NICMI will ballot later because the Agreement only expires on 31 August 1992. The votes will be counted on the 18-19 July. The STRIKE COMMITTEE will meet on 20 July to consider the ballot result and decide on strike action.
- Full Text:
- Date Issued: Aug 1992
- Authors: NUMSA
- Date: Aug 1992
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/112756 , vital:33652
- Description: THE National Executive Committee (NEC) of NUMSA met on 27-28 June and agreed that strike action is necessary to achieve our demands in these industries: NICISEMI - Iron, Steel, Engineering, Metallurgical Industry, NICMI - Motor, NBF - Auto, TYRE AND RUBBER. The NEC has therefore decided to hold a STRIKE BALLOT for workers in NICISEMI, Auto and Tyre and Rubber from 6-17 July 1992. The workers in NICMI will ballot later because the Agreement only expires on 31 August 1992. The votes will be counted on the 18-19 July. The STRIKE COMMITTEE will meet on 20 July to consider the ballot result and decide on strike action.
- Full Text:
- Date Issued: Aug 1992
Structural analysis of some Escherichia coli capsular antigens
- Authors: Hackland, Peter Linton
- Date: 1992
- Subjects: Antigens , Enterobacteriaceae , Escherichia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3758 , http://hdl.handle.net/10962/d1003236 , Antigens , Enterobacteriaceae , Escherichia
- Description: The work presented in this thesis forms part of a collaborative effort to determine the chemical structures of the surface antigens of bacteria which belong to the Enterobacteriaceae. These antigens are largely polysaccharides and occur as lipopolysaccharides and capsular polysaccharides which give rise to the somatic or 0 antigens and the capsular or K antigens, respectively. In recent years interest has mostly been focused on the extracellular polysaccharide antigens expressed by the genus Escherichia coli because of the effect they exert on normal immunological processes and their structural relatedness to the surface antigens of other more pathogenic bacteria. Therefore the molecular structures of the capsular polysaccharides (Kantigens)produced by E. coli 09:K35(AI04a) and 09:K38(A262a) have been determined by novel enzymic, chemical and spectroscopic procedures. These investigations show that the structures of these polysaccharides can be determined by a combination of chemical and spectroscopic procedures , or almost entirely by n.m.r. spectroscopy alone. The in vitro bacteriophage mediated depolymerisation of the native E. coli K35 polysaccharide demonstrates the value of this method for the isolation of oligosaccharides representing the repeating- unit and multiples thereof. Finally E. coli K37 and K38 capsular polysaccharides were used as model compounds for the evaluation of partial and selective reductive cleavage as methods of generating oligosaccharide for further structural analysis. The products of these reactions were analysed largely by a combination of mass spectrometric procedures.
- Full Text:
- Date Issued: 1992
- Authors: Hackland, Peter Linton
- Date: 1992
- Subjects: Antigens , Enterobacteriaceae , Escherichia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3758 , http://hdl.handle.net/10962/d1003236 , Antigens , Enterobacteriaceae , Escherichia
- Description: The work presented in this thesis forms part of a collaborative effort to determine the chemical structures of the surface antigens of bacteria which belong to the Enterobacteriaceae. These antigens are largely polysaccharides and occur as lipopolysaccharides and capsular polysaccharides which give rise to the somatic or 0 antigens and the capsular or K antigens, respectively. In recent years interest has mostly been focused on the extracellular polysaccharide antigens expressed by the genus Escherichia coli because of the effect they exert on normal immunological processes and their structural relatedness to the surface antigens of other more pathogenic bacteria. Therefore the molecular structures of the capsular polysaccharides (Kantigens)produced by E. coli 09:K35(AI04a) and 09:K38(A262a) have been determined by novel enzymic, chemical and spectroscopic procedures. These investigations show that the structures of these polysaccharides can be determined by a combination of chemical and spectroscopic procedures , or almost entirely by n.m.r. spectroscopy alone. The in vitro bacteriophage mediated depolymerisation of the native E. coli K35 polysaccharide demonstrates the value of this method for the isolation of oligosaccharides representing the repeating- unit and multiples thereof. Finally E. coli K37 and K38 capsular polysaccharides were used as model compounds for the evaluation of partial and selective reductive cleavage as methods of generating oligosaccharide for further structural analysis. The products of these reactions were analysed largely by a combination of mass spectrometric procedures.
- Full Text:
- Date Issued: 1992
Sylvia Plath images of life in a poet of death
- Authors: Mather, Mary Lynn
- Date: 1992
- Subjects: Plath, Sylvia , Plath, Sylvia -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2245 , http://hdl.handle.net/10962/d1002288 , Plath, Sylvia , Plath, Sylvia -- Criticism and interpretation
- Description: On a creative and a personal level, Sylvia Plath seems to have been fascinated by the relationship between life and death. Her work reflects an ongoing preoccupation with duality and a sense of tension between two opposing forces suffuses virtually every poem she wrote in the period from 1956 to early 1963. Because her attitude to both life and death is deeply ambivalent, Plath's poetry rests on a strong awareness of conflict and her art is characterized by a continual pull between extremes. This thesis is an examination of how she uses images of life in poems that ostensibly deal with death.While Plath draws on the events of her own life for her poetic material, she also converts her personal experiences into a universal myth. She was familiar with Robert Graves's eclectic study of the pagan nature deity, The White Goddess, and she seems to have incorporated part of his symbolism into her own code of images. In particular, she adopts Graves's triple goddess of nature as one of the dominant figures in her created world, for the White Goddess is associated with life and death alike.Plath's dichotomy of life and death works on different planes. Firstly, she frequently envisages the self as divided and the opposition between life and death takes on the dimensions of an internal psychological war. Secondly, she extends the battle between life and death to the creative sphere. Thirdly, she explores the idea of life as a journey from birth to death. The White Goddess is linked with the three natural realms of earth, sky and underworld. And Plath relies largely on seasonal, lunar and chthonic images in her poetry. Furthermore, the three colours of the goddess - white , red and black - are the dominant hues of her poetry.
- Full Text:
- Date Issued: 1992
- Authors: Mather, Mary Lynn
- Date: 1992
- Subjects: Plath, Sylvia , Plath, Sylvia -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2245 , http://hdl.handle.net/10962/d1002288 , Plath, Sylvia , Plath, Sylvia -- Criticism and interpretation
- Description: On a creative and a personal level, Sylvia Plath seems to have been fascinated by the relationship between life and death. Her work reflects an ongoing preoccupation with duality and a sense of tension between two opposing forces suffuses virtually every poem she wrote in the period from 1956 to early 1963. Because her attitude to both life and death is deeply ambivalent, Plath's poetry rests on a strong awareness of conflict and her art is characterized by a continual pull between extremes. This thesis is an examination of how she uses images of life in poems that ostensibly deal with death.While Plath draws on the events of her own life for her poetic material, she also converts her personal experiences into a universal myth. She was familiar with Robert Graves's eclectic study of the pagan nature deity, The White Goddess, and she seems to have incorporated part of his symbolism into her own code of images. In particular, she adopts Graves's triple goddess of nature as one of the dominant figures in her created world, for the White Goddess is associated with life and death alike.Plath's dichotomy of life and death works on different planes. Firstly, she frequently envisages the self as divided and the opposition between life and death takes on the dimensions of an internal psychological war. Secondly, she extends the battle between life and death to the creative sphere. Thirdly, she explores the idea of life as a journey from birth to death. The White Goddess is linked with the three natural realms of earth, sky and underworld. And Plath relies largely on seasonal, lunar and chthonic images in her poetry. Furthermore, the three colours of the goddess - white , red and black - are the dominant hues of her poetry.
- Full Text:
- Date Issued: 1992
The "Big E": the English (first language) endorsement on the teacher's bilingualism certificate: an investigation into the background to and origin of this requirement, an evaluation of past and current examining practices and standards and criteria, a needs assessment, and suggestions and recommendations for sound practice
- Authors: Spingies, Conrad
- Date: 1992
- Subjects: Teachers -- Training of -- South Africa Teachers -- Selection and appointment Teachers -- Language Teachers -- Certification -- South Africa Bilingualism -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1427 , http://hdl.handle.net/10962/d1003308
- Description: South African education authorities demand of teachers a high degree of competency in both official languages. In the Cape Province in particular, teachers are not considered eligible for promotion posts unless they possess the so-called Higher Bilingualism Certificate, signifying their command of both official languages at "First Language" level. In view of the fact that the overwhelming majority of schools nowadays are single-medium institutions; this requirement may strike the objective observer as an anomaly. An attempt was made, therefore, first of all to investigate the historical background to this requirement. The "language question", a problematic feature of South African education since the beginning of the nineteenth.century, was not resolved when legislators chose "bilingualism and language equality" for the Union of South Africa in 1910. The available evidence suggests, however, that bilingualism was actively pursued as an educational ideal at least until the end of the 1940s, and for this reason education authorities placed a high premium on teachers who were "fully bilingual". Nowadays the typical (White) school is a single-medium institution where the second language is rarely if ever heard outside the classroom where it is taught as a subject. The present policy, to demand a high degree of proficiency in both official languages of teachers occupying promotion posts at such a school, may then be described not only as an anomaly, but as an anachronism. A further problem is the fact that the various educational institutions (specifically teachers' colleges and universities) that set examinations leading to the Higher Bilingualism Certificate rarely communicate with one another, and are therefore unable to agree on uniform standards and criteria, or to ensure that such standards are maintained. That this is indeed the case, was confirmed by examination of "Big E" test papers set at three teachers' colleges, two Colleges for Continued Training, and four universities in the Cape Province. In an attempt to establish what assistance and support might be needed by a "second language" user of English in order for him to improve to the point where he resembled a "first language" user of English in his "terminal language behaviour", a comparison (by means of error analysis) of the responses of two groups (an Ll and an L2 group) to the same test paper was undertaken. The available evidence suggests that L2 users may need to be helped to acquire a more extensive vocabulary, but, above all, that they need to improve their ability to handle two crucially important aspects of usage: idiom and grammar. The final chapter attempts to establish pedagogic and linguistic bases for a course intended for "Big E" candidates, and makes recommendations with regard to (i) the content and the form of the course, and (ii) sound examination practice. The concluding thoughts offer the view that such a course could remain useful even in a future South Africa where the emphasis may shift from a demand for teachers who are "fully bilingual" to teachers who have a good command of English.
- Full Text:
- Date Issued: 1992
- Authors: Spingies, Conrad
- Date: 1992
- Subjects: Teachers -- Training of -- South Africa Teachers -- Selection and appointment Teachers -- Language Teachers -- Certification -- South Africa Bilingualism -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1427 , http://hdl.handle.net/10962/d1003308
- Description: South African education authorities demand of teachers a high degree of competency in both official languages. In the Cape Province in particular, teachers are not considered eligible for promotion posts unless they possess the so-called Higher Bilingualism Certificate, signifying their command of both official languages at "First Language" level. In view of the fact that the overwhelming majority of schools nowadays are single-medium institutions; this requirement may strike the objective observer as an anomaly. An attempt was made, therefore, first of all to investigate the historical background to this requirement. The "language question", a problematic feature of South African education since the beginning of the nineteenth.century, was not resolved when legislators chose "bilingualism and language equality" for the Union of South Africa in 1910. The available evidence suggests, however, that bilingualism was actively pursued as an educational ideal at least until the end of the 1940s, and for this reason education authorities placed a high premium on teachers who were "fully bilingual". Nowadays the typical (White) school is a single-medium institution where the second language is rarely if ever heard outside the classroom where it is taught as a subject. The present policy, to demand a high degree of proficiency in both official languages of teachers occupying promotion posts at such a school, may then be described not only as an anomaly, but as an anachronism. A further problem is the fact that the various educational institutions (specifically teachers' colleges and universities) that set examinations leading to the Higher Bilingualism Certificate rarely communicate with one another, and are therefore unable to agree on uniform standards and criteria, or to ensure that such standards are maintained. That this is indeed the case, was confirmed by examination of "Big E" test papers set at three teachers' colleges, two Colleges for Continued Training, and four universities in the Cape Province. In an attempt to establish what assistance and support might be needed by a "second language" user of English in order for him to improve to the point where he resembled a "first language" user of English in his "terminal language behaviour", a comparison (by means of error analysis) of the responses of two groups (an Ll and an L2 group) to the same test paper was undertaken. The available evidence suggests that L2 users may need to be helped to acquire a more extensive vocabulary, but, above all, that they need to improve their ability to handle two crucially important aspects of usage: idiom and grammar. The final chapter attempts to establish pedagogic and linguistic bases for a course intended for "Big E" candidates, and makes recommendations with regard to (i) the content and the form of the course, and (ii) sound examination practice. The concluding thoughts offer the view that such a course could remain useful even in a future South Africa where the emphasis may shift from a demand for teachers who are "fully bilingual" to teachers who have a good command of English.
- Full Text:
- Date Issued: 1992
The administration and organisation of independent study topics with special reference to secondary school geography
- Authors: Van Harmelen, U
- Date: 1992
- Subjects: Geography -- Study and teaching (Secondary) , Project method in teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1419 , http://hdl.handle.net/10962/d1003300
- Description: Traditional school subjects are having to compete for a place in a curriculum which is increasingly judged according to its perceived utilitarian value. According to current educational theory, geography's role in the curriculum is to develop concepts, skills, values and attitudes that allow pupils to understand the human and environmental issues which face their communities and communities throughout the world. In order to achieve these aims, teachers need to adopt a learner-centred teaching approach, yet geography teachers are faced with the dilemma of having to develop participatory teaching strategies within an existing structure which is largely product oriented. This thesis attempts to illustrate how changes can be effected in the approach to the teaching of geography, while working within existing syllabus constraints and while continuing to meet the demands made by the current examination system. To this end, Independent Study Topics are analysed as a means to bring about the desired changes in geographical education. The concept, Independent Study Topics as a 'blanket term' (Diepeveen, 1986) for pupil-centred activities is relatively recent in terms of the South African geography syllabus. In order to obtain greater clarity about the concept and its implications for geography teaching, this study examines current geographical theory relating to learner-centred approaches and relates them to teachers' perceptions of the role of IST in the geography curriculum. The second aspect of the study is concerned with the implementation of Independent Study Topics in a classroom research setting. The organisation and administration of Independent Study Topics in a single school setting is analysed and evaluated as a process of change. This analysis provides guidelines for developing a learner-centred approach which is necessary to ensure that geography retains its position in the school curriculum of the 1990's and beyond.
- Full Text:
- Date Issued: 1992
- Authors: Van Harmelen, U
- Date: 1992
- Subjects: Geography -- Study and teaching (Secondary) , Project method in teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1419 , http://hdl.handle.net/10962/d1003300
- Description: Traditional school subjects are having to compete for a place in a curriculum which is increasingly judged according to its perceived utilitarian value. According to current educational theory, geography's role in the curriculum is to develop concepts, skills, values and attitudes that allow pupils to understand the human and environmental issues which face their communities and communities throughout the world. In order to achieve these aims, teachers need to adopt a learner-centred teaching approach, yet geography teachers are faced with the dilemma of having to develop participatory teaching strategies within an existing structure which is largely product oriented. This thesis attempts to illustrate how changes can be effected in the approach to the teaching of geography, while working within existing syllabus constraints and while continuing to meet the demands made by the current examination system. To this end, Independent Study Topics are analysed as a means to bring about the desired changes in geographical education. The concept, Independent Study Topics as a 'blanket term' (Diepeveen, 1986) for pupil-centred activities is relatively recent in terms of the South African geography syllabus. In order to obtain greater clarity about the concept and its implications for geography teaching, this study examines current geographical theory relating to learner-centred approaches and relates them to teachers' perceptions of the role of IST in the geography curriculum. The second aspect of the study is concerned with the implementation of Independent Study Topics in a classroom research setting. The organisation and administration of Independent Study Topics in a single school setting is analysed and evaluated as a process of change. This analysis provides guidelines for developing a learner-centred approach which is necessary to ensure that geography retains its position in the school curriculum of the 1990's and beyond.
- Full Text:
- Date Issued: 1992
The anatomy and ecophysiology of Mariscus congestus from three different habitats in the Albany and Bathurst districts of the Eastern Cape, investigated under field and laboratory conditions
- Authors: Sonnenberg, Bernd Jürgen
- Date: 1992
- Subjects: Cyperaceae -- South Africa , Plant anatomy , Plant physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4229 , http://hdl.handle.net/10962/d1003798 , Cyperaceae -- South Africa , Plant anatomy , Plant physiology
- Description: An investigation of the anatomy and gas exchange characteristics of Mariscus congestus in three different habitats was undertaken in order to establish whether M. congestus from the three different habitats displayed any ecotypic responses when placed in a new similar environment. It was hoped that the results of this investigation would yield evidence that would support the ecotype concept similar to the investigations of Milner and Hiesey (1964), Green (1969) and Slayter and Ferrar (1977). On the basis of the site leaf anatomy, M. congestus investigated at the coast (site 1) differed in many respects from the inland plants (sites 2 and 3). These differences suggest that the coastal plants may have undergone a slight ecotypic divergence from the inland plants. The anatomical investigation also suggested that the leaves of M. congestus from all three sites may either be C₄ NADP-ME or PCK and that all had typical Chlorocyperiod anatomy. The habitat microclimates at sites 1-3 had different light and water regimes. There were no significant differences between the 12 month temperature environments of the three sites. There was however, a minor difference between the coastal (high temperature) and the inland (lower temperature) sites. M. congestus at the three sites had significantly different CO₂ assimilation rates, transpiration and stomatal conductance in response to the differing habitat microclimates. The water use efficiency of the sites were however, similar. Site 1 attained the highest CO₂ assimilation rates, transpiration, stomatal conductance, and water use efficiency and site 3 the lowest. Under similar conditions the gas exchange data for the potted plants indicated that M. congestus from the different sites was typically C₄. The optimal photosynthetic temperatures of all the sites was above 30°C and they did not show significant inhibition of CO₂ assimilation by different oxygen concentrations. The results of the laboratory investigation of the potted plants suggested that the only site-specific (ecotypic) response of M. eongestus was the light intensity at which the plants from the different sites were light saturated. The light and temperature response of field plants under field conditions was not comparable to the light and temperature response of potted plants under laboratory conditions. This may have been due to the field results being obtained under differing water and soil nutrient regimes. The potted plants may also have had a reduced root mass compared to their field counterparts and the potted plants may have also have become root bound. Under field conditions the plants had differing light saturation points and optimal photosynthetic temperatures compared to the potted plants. This investigation thus did not support the hypothesis stated in this thesis. The data in this investigation thus may indicate that plants with as diverse habitats as Mariscus congestus that are removed from their natural habitats display rapid changes in gas exchange characteristics in response to their new microclimates, with few ecotypic physiological characteristics of the old habitat being retained.
- Full Text:
- Date Issued: 1992
- Authors: Sonnenberg, Bernd Jürgen
- Date: 1992
- Subjects: Cyperaceae -- South Africa , Plant anatomy , Plant physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4229 , http://hdl.handle.net/10962/d1003798 , Cyperaceae -- South Africa , Plant anatomy , Plant physiology
- Description: An investigation of the anatomy and gas exchange characteristics of Mariscus congestus in three different habitats was undertaken in order to establish whether M. congestus from the three different habitats displayed any ecotypic responses when placed in a new similar environment. It was hoped that the results of this investigation would yield evidence that would support the ecotype concept similar to the investigations of Milner and Hiesey (1964), Green (1969) and Slayter and Ferrar (1977). On the basis of the site leaf anatomy, M. congestus investigated at the coast (site 1) differed in many respects from the inland plants (sites 2 and 3). These differences suggest that the coastal plants may have undergone a slight ecotypic divergence from the inland plants. The anatomical investigation also suggested that the leaves of M. congestus from all three sites may either be C₄ NADP-ME or PCK and that all had typical Chlorocyperiod anatomy. The habitat microclimates at sites 1-3 had different light and water regimes. There were no significant differences between the 12 month temperature environments of the three sites. There was however, a minor difference between the coastal (high temperature) and the inland (lower temperature) sites. M. congestus at the three sites had significantly different CO₂ assimilation rates, transpiration and stomatal conductance in response to the differing habitat microclimates. The water use efficiency of the sites were however, similar. Site 1 attained the highest CO₂ assimilation rates, transpiration, stomatal conductance, and water use efficiency and site 3 the lowest. Under similar conditions the gas exchange data for the potted plants indicated that M. congestus from the different sites was typically C₄. The optimal photosynthetic temperatures of all the sites was above 30°C and they did not show significant inhibition of CO₂ assimilation by different oxygen concentrations. The results of the laboratory investigation of the potted plants suggested that the only site-specific (ecotypic) response of M. eongestus was the light intensity at which the plants from the different sites were light saturated. The light and temperature response of field plants under field conditions was not comparable to the light and temperature response of potted plants under laboratory conditions. This may have been due to the field results being obtained under differing water and soil nutrient regimes. The potted plants may also have had a reduced root mass compared to their field counterparts and the potted plants may have also have become root bound. Under field conditions the plants had differing light saturation points and optimal photosynthetic temperatures compared to the potted plants. This investigation thus did not support the hypothesis stated in this thesis. The data in this investigation thus may indicate that plants with as diverse habitats as Mariscus congestus that are removed from their natural habitats display rapid changes in gas exchange characteristics in response to their new microclimates, with few ecotypic physiological characteristics of the old habitat being retained.
- Full Text:
- Date Issued: 1992
The artificial recharge of urban stormwater runoff in the Atlantis coastal aquifer
- Authors: Wright, Alan
- Date: 1992
- Subjects: Atlantis water resource management scheme , Urban hydrology -- South Africa , Urban runoff -- South Africa , Storm sewers -- South Africa , Water resources development -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4817 , http://hdl.handle.net/10962/d1005491 , Atlantis water resource management scheme , Urban hydrology -- South Africa , Urban runoff -- South Africa , Storm sewers -- South Africa , Water resources development -- South Africa
- Description: The thesis covers the investigation of the storm water runoff and artificial recharge components of the Atlantis Water Resource Management Scheme in the Southwestern Cape. The objective of the study was to obtain an in-depth knowledge of the process of artificial recharge of urban storm water runoff, in order to identify the most efficient recharge management strategy for the Atlantis aquifer. To achieve the objective it was necessary to first study the existing knowledge on urban storm water hydrology and artificial recharge by spreading, and to create a conceptual model of what might be expected. The study area was then investigated to examine how closely the actual situation was reflected by the conceptual model, enabling recommendations to be made for the sound management of the system. The stormwater runoff component was found to differ from most urban hydrological studies as a result of its large baseflow component. The sandy nature of the catchment, small percentage area of effective impervious surface, and high groundwater table resulted in the baseflow constituting more than 40% of the total storm water runoff and accounting for over 60% of the pollution load. The "first flush" effect established as a major source of pollution in other studies, was found to be of minor significance in this study area. The overall stormwater quality (excluding the noxious industrial baseflow) was found acceptable for artificial recharge within the study area, although the baseflow from the industrial sub-catchments showed the potential for being a major source of pollution in the future. The treated wastewater used for artificial recharge prior to 1987 was found to be unacceptable for recharge purposes. The treated industrial effluent should under no circumstances be recharged up-gradient of the Witzand well field. The treated domestic effluent although of a poorer quality than the resident Witzand well field groundwater could be recharged in order to boost recharge volumes and form a buffer against further intrusion by the poor quality groundwater from the Brakkefontein area. This would however only be acceptable if strict water quality control is maintained and recharge does not take place west of the present basin. The recharge basin was found to be well situated with respect to influencing the Witzand wellfield and maintaining a groundwater buffer against poor quality groundwater flow from the northeast towards the central area of the wellfield. Unfortunately the surrounding low-lying topography and sandy retaining walls have resulted in return flow and raised groundwater-levels. The raised groundwater mound does not comply with the conceptual model and together with the sandy nature of the unsaturated zone resulted in less effective purification during infiltration. The practice of letting large portions of the basin floor dry-out during summer was shown to be beneficial and the periodic cleaning of the deeper portions of the basin essential. The artificially recharged water was found to have influenced the upper portion of the aquifer well beyond the West Coast Road. The study of groundwater quality being a good method for tracing artificially recharged water. The groundwater quality has improved as a result of artificial recharge since the removal of treated wastewater from the recharge basin. The groundwater was (ii) found to be very responsive to the slightest changes in recharge basin water quality or/and quantity. Management of the recharge basin therefore had to be very much of a compromise between qualitative and quantitative approaches. The present approach of recharging all the stormwater runoff throughout the year providing the most efficient compromise under the present conditions. The study revealed that the most efficient recharge management strategy would be the recharge of treated domestic sewage effluent in the present recharge basin and all residential storm water runoff plus industrial "storm flow" stormwater runoff in a new recharge basin located northwest of the present basin. Strict water quality control must be maintained on the water discharged into the basins and an annual wet/dry cycle implemented within the basins to boost infiltration. The entire system should continue being monitored to safe guard the groundwater resource from pollution and over exploitation.
- Full Text:
- Date Issued: 1992
- Authors: Wright, Alan
- Date: 1992
- Subjects: Atlantis water resource management scheme , Urban hydrology -- South Africa , Urban runoff -- South Africa , Storm sewers -- South Africa , Water resources development -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4817 , http://hdl.handle.net/10962/d1005491 , Atlantis water resource management scheme , Urban hydrology -- South Africa , Urban runoff -- South Africa , Storm sewers -- South Africa , Water resources development -- South Africa
- Description: The thesis covers the investigation of the storm water runoff and artificial recharge components of the Atlantis Water Resource Management Scheme in the Southwestern Cape. The objective of the study was to obtain an in-depth knowledge of the process of artificial recharge of urban storm water runoff, in order to identify the most efficient recharge management strategy for the Atlantis aquifer. To achieve the objective it was necessary to first study the existing knowledge on urban storm water hydrology and artificial recharge by spreading, and to create a conceptual model of what might be expected. The study area was then investigated to examine how closely the actual situation was reflected by the conceptual model, enabling recommendations to be made for the sound management of the system. The stormwater runoff component was found to differ from most urban hydrological studies as a result of its large baseflow component. The sandy nature of the catchment, small percentage area of effective impervious surface, and high groundwater table resulted in the baseflow constituting more than 40% of the total storm water runoff and accounting for over 60% of the pollution load. The "first flush" effect established as a major source of pollution in other studies, was found to be of minor significance in this study area. The overall stormwater quality (excluding the noxious industrial baseflow) was found acceptable for artificial recharge within the study area, although the baseflow from the industrial sub-catchments showed the potential for being a major source of pollution in the future. The treated wastewater used for artificial recharge prior to 1987 was found to be unacceptable for recharge purposes. The treated industrial effluent should under no circumstances be recharged up-gradient of the Witzand well field. The treated domestic effluent although of a poorer quality than the resident Witzand well field groundwater could be recharged in order to boost recharge volumes and form a buffer against further intrusion by the poor quality groundwater from the Brakkefontein area. This would however only be acceptable if strict water quality control is maintained and recharge does not take place west of the present basin. The recharge basin was found to be well situated with respect to influencing the Witzand wellfield and maintaining a groundwater buffer against poor quality groundwater flow from the northeast towards the central area of the wellfield. Unfortunately the surrounding low-lying topography and sandy retaining walls have resulted in return flow and raised groundwater-levels. The raised groundwater mound does not comply with the conceptual model and together with the sandy nature of the unsaturated zone resulted in less effective purification during infiltration. The practice of letting large portions of the basin floor dry-out during summer was shown to be beneficial and the periodic cleaning of the deeper portions of the basin essential. The artificially recharged water was found to have influenced the upper portion of the aquifer well beyond the West Coast Road. The study of groundwater quality being a good method for tracing artificially recharged water. The groundwater quality has improved as a result of artificial recharge since the removal of treated wastewater from the recharge basin. The groundwater was (ii) found to be very responsive to the slightest changes in recharge basin water quality or/and quantity. Management of the recharge basin therefore had to be very much of a compromise between qualitative and quantitative approaches. The present approach of recharging all the stormwater runoff throughout the year providing the most efficient compromise under the present conditions. The study revealed that the most efficient recharge management strategy would be the recharge of treated domestic sewage effluent in the present recharge basin and all residential storm water runoff plus industrial "storm flow" stormwater runoff in a new recharge basin located northwest of the present basin. Strict water quality control must be maintained on the water discharged into the basins and an annual wet/dry cycle implemented within the basins to boost infiltration. The entire system should continue being monitored to safe guard the groundwater resource from pollution and over exploitation.
- Full Text:
- Date Issued: 1992
The attitudes and perceptions of secondary school pupils in Transkei towards geography: a case study of the Butterworth district
- Authors: Sarpong, Emmanuel
- Date: 1992
- Subjects: Students, Black -- South Africa -- Attitudes Geography -- South Africa -- Transkei -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1425 , http://hdl.handle.net/10962/d1003306
- Description: Considerable attention has in recent times been given to the attitudes of secondary school pupils towards Geography among black schools in South Africa. Many reasons account for this. It is partly because of the poor results and falling numbers of pupils in the discipline. Concern has also been expressed on the relevance of the Geography syllabus to the black pupils. Evidence suggests that these problems are evident in Transkei. The need therefore exists to assess pupils' attitudes towards Geography in Transkei. Arising from this background, this study sets out to assess the attitudes of secondary school pupils in Transkei towards Geography. Two hundred and thirty four pupils from eight urban and rural secondary schools in the Butterworth District of the Republic of Transkei were used in the study. Attitudes were measured in terms of "interest in Geography", "desire to study the discipline", "commitment to Geography" and the perceived relevance of the discipline. Through the use of techniques such as percentages, chi-square and principal component analysis - among others - for the analysis of the data, the following information emerged from the study: (1) Geography is generally perceived as being worthy of study; (2) Differences in responses were noted to result from a complex of factors which were grouped into home environmental factors and school environmental ones. (3) The major factor influencing attitudes towards Geography was noted to be home environmental conditions.In general pupils from lower income families expressed more positive views about the worth of Geography than those from the upper income families. From the above findings, it has been proposed that teachers and educational planners need to be made aware of these findings as they are important for classroom practice. It has also been recommended that there is a need to improve certain school practices such as taking pupils on Geography excursions more often as factors such as this were shown to improve pupils' attitudes towards the discipline.
- Full Text:
- Date Issued: 1992
- Authors: Sarpong, Emmanuel
- Date: 1992
- Subjects: Students, Black -- South Africa -- Attitudes Geography -- South Africa -- Transkei -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1425 , http://hdl.handle.net/10962/d1003306
- Description: Considerable attention has in recent times been given to the attitudes of secondary school pupils towards Geography among black schools in South Africa. Many reasons account for this. It is partly because of the poor results and falling numbers of pupils in the discipline. Concern has also been expressed on the relevance of the Geography syllabus to the black pupils. Evidence suggests that these problems are evident in Transkei. The need therefore exists to assess pupils' attitudes towards Geography in Transkei. Arising from this background, this study sets out to assess the attitudes of secondary school pupils in Transkei towards Geography. Two hundred and thirty four pupils from eight urban and rural secondary schools in the Butterworth District of the Republic of Transkei were used in the study. Attitudes were measured in terms of "interest in Geography", "desire to study the discipline", "commitment to Geography" and the perceived relevance of the discipline. Through the use of techniques such as percentages, chi-square and principal component analysis - among others - for the analysis of the data, the following information emerged from the study: (1) Geography is generally perceived as being worthy of study; (2) Differences in responses were noted to result from a complex of factors which were grouped into home environmental factors and school environmental ones. (3) The major factor influencing attitudes towards Geography was noted to be home environmental conditions.In general pupils from lower income families expressed more positive views about the worth of Geography than those from the upper income families. From the above findings, it has been proposed that teachers and educational planners need to be made aware of these findings as they are important for classroom practice. It has also been recommended that there is a need to improve certain school practices such as taking pupils on Geography excursions more often as factors such as this were shown to improve pupils' attitudes towards the discipline.
- Full Text:
- Date Issued: 1992
The biology of four haplochromine species of Lake Kivu (Zaïre) with evolutionary implications
- Authors: Losseau-Hoebeke, Michèle
- Date: 1992
- Subjects: Cichlids -- Research -- Kivu, Lake (Congo and Rwanda) , Cichlids -- Ecology -- Research , Cichlids -- Breeding -- Research , Cichlids -- Evolution -- Research , Haplochromis -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5239 , http://hdl.handle.net/10962/d1005082 , Cichlids -- Research -- Kivu, Lake (Congo and Rwanda) , Cichlids -- Ecology -- Research , Cichlids -- Breeding -- Research , Cichlids -- Evolution -- Research , Haplochromis -- Research
- Description: Four species were selected within the littoral of Tshegera Island, and include H. astatodon, H. olivaceus, H. crebridens and H. paucidens. These species, identified on basis of the SMRS, express their individuality most strongly with respect to dentition, breeding colours, normal habitat and preferred breeding territory. All four species are maternal mouthbrooders. This reproductive strategy is characterized by complete division of labour and polygamy. Breeding males compete for optimal territories and ready to spawn females. They are characterized by fast growth, large size and overall low condition factor. Females invest in few but large yolked ova and go through a fasting period while incubating the eggs. Females are generally characterized by slower growth, smaller size and higher condition factor when compared to males. In females the energy turnover during gonadal development and subsequent mouthbrooding is high, but the energy expenditure low. Mean fecundity varies between 25 and 36 eggs per brood and mean egg size between 2.6 and 2.7 rnrn. The right ovary, although small, is functional. Breeding of variable intensity goes on throughout the year. The main dry season corresponds to synchronized breeding. During the other months of the year species breed asynchronously. Both types of breeding are related to food availability for adults and offspring. The major breeding peak which starts in July coincides to improved body condition in both sexes. In similarity with the East African flocks, the Lake Kivu haplochromines display subdivision within the major trophic groups and invasion of the major lacustrine habitats. They are nevertheless morphologically and ecologically generalized. They tend to be plesiomorphic with low diversification within each trophic group, have a lake wide distribution (eurytopic) and incline to be altricial within their specialized reproductive guild. The evolutionary status of the Lake Kivu haplochromines may be explained by survival of members of an ancestral fauna in an isolated bay during the Recent volcanic events which destroyed life in the Main Basin. The Lake Kivu flock, therefore, is a relict and is believed not to have evolved within the confines of the present-day lake.
- Full Text:
- Date Issued: 1992
- Authors: Losseau-Hoebeke, Michèle
- Date: 1992
- Subjects: Cichlids -- Research -- Kivu, Lake (Congo and Rwanda) , Cichlids -- Ecology -- Research , Cichlids -- Breeding -- Research , Cichlids -- Evolution -- Research , Haplochromis -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5239 , http://hdl.handle.net/10962/d1005082 , Cichlids -- Research -- Kivu, Lake (Congo and Rwanda) , Cichlids -- Ecology -- Research , Cichlids -- Breeding -- Research , Cichlids -- Evolution -- Research , Haplochromis -- Research
- Description: Four species were selected within the littoral of Tshegera Island, and include H. astatodon, H. olivaceus, H. crebridens and H. paucidens. These species, identified on basis of the SMRS, express their individuality most strongly with respect to dentition, breeding colours, normal habitat and preferred breeding territory. All four species are maternal mouthbrooders. This reproductive strategy is characterized by complete division of labour and polygamy. Breeding males compete for optimal territories and ready to spawn females. They are characterized by fast growth, large size and overall low condition factor. Females invest in few but large yolked ova and go through a fasting period while incubating the eggs. Females are generally characterized by slower growth, smaller size and higher condition factor when compared to males. In females the energy turnover during gonadal development and subsequent mouthbrooding is high, but the energy expenditure low. Mean fecundity varies between 25 and 36 eggs per brood and mean egg size between 2.6 and 2.7 rnrn. The right ovary, although small, is functional. Breeding of variable intensity goes on throughout the year. The main dry season corresponds to synchronized breeding. During the other months of the year species breed asynchronously. Both types of breeding are related to food availability for adults and offspring. The major breeding peak which starts in July coincides to improved body condition in both sexes. In similarity with the East African flocks, the Lake Kivu haplochromines display subdivision within the major trophic groups and invasion of the major lacustrine habitats. They are nevertheless morphologically and ecologically generalized. They tend to be plesiomorphic with low diversification within each trophic group, have a lake wide distribution (eurytopic) and incline to be altricial within their specialized reproductive guild. The evolutionary status of the Lake Kivu haplochromines may be explained by survival of members of an ancestral fauna in an isolated bay during the Recent volcanic events which destroyed life in the Main Basin. The Lake Kivu flock, therefore, is a relict and is believed not to have evolved within the confines of the present-day lake.
- Full Text:
- Date Issued: 1992
The chemistry of a new water-recirculation aquaculture system with emphasis on the influence of ozone on water quality
- Authors: Stobart, Michael David
- Date: 1992
- Subjects: Water quality -- Environmental aspects -- Testing , Ozone -- Physiological effect , Aquatic ecology , Aquaculture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5244 , http://hdl.handle.net/10962/d1005087 , Water quality -- Environmental aspects -- Testing , Ozone -- Physiological effect , Aquatic ecology , Aquaculture
- Description: Water quality changes that occur during establishment and maintenance of nitrification in two identical recirculating aquaculture systems containing rainbow trout are described. The time taken for the nitrification process to become established was 40-45 days. Mortality of fish attributed to elevated nitrite concentrations were recorded during the initial conditioning phase of the systems. Un-ionised ammonia concentrations did not attain lethal levels during this period. Nitrate concentrations accumulated slowly throughout the study, while the pH and alkalinity of the water decreased with progressive nitrification. Levels of carbon dioxide, calcium, dissolved and suspended solids remained relatively stable until the carrying capacity of the systems was increased, upon which they increased rapidly and general water quality deteriorated. Permanently elevated concentrations of ammonia and nitrite served as an indication that the carrying capacity of the systems had been exceeded. The use of ozone as a water enhancement treatment in aquaculture systems during one- and six-hour applications was also considered in this study. Ozonation significantly reduced nitrite levels at · low concentrations (0,1 - 0,15 mg/l), although they returned to pre-treatment levels within a few hours of cessation of the treatment. The formation of an unstable, intermediate product that reforms as nitrite in the absence of ozone, rather than the complete oxidation of nitrite to nitrate, is proposed. Ozonation also resulted in decreased dissolved solids, and improved the clarity and odour of the water. Ozone had no effect on ammonia concentrations (at pH > 7,0), or on nitrate or calcium levels, and did not conclusively increase the redox potential of the water. Residual ozone concentrations up to 0,04 mg/l in a sixhour treatment had no harmful effects on rainbow trout, and there were no signs of gas-bubble disease arising from supersaturation of the water with oxygen. Activated carbon filters were effective at removing residual ozone from the water after treatment. Treatment of the water with oxygen alone had no effect on nitrite concentrations.
- Full Text:
- Date Issued: 1992
- Authors: Stobart, Michael David
- Date: 1992
- Subjects: Water quality -- Environmental aspects -- Testing , Ozone -- Physiological effect , Aquatic ecology , Aquaculture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5244 , http://hdl.handle.net/10962/d1005087 , Water quality -- Environmental aspects -- Testing , Ozone -- Physiological effect , Aquatic ecology , Aquaculture
- Description: Water quality changes that occur during establishment and maintenance of nitrification in two identical recirculating aquaculture systems containing rainbow trout are described. The time taken for the nitrification process to become established was 40-45 days. Mortality of fish attributed to elevated nitrite concentrations were recorded during the initial conditioning phase of the systems. Un-ionised ammonia concentrations did not attain lethal levels during this period. Nitrate concentrations accumulated slowly throughout the study, while the pH and alkalinity of the water decreased with progressive nitrification. Levels of carbon dioxide, calcium, dissolved and suspended solids remained relatively stable until the carrying capacity of the systems was increased, upon which they increased rapidly and general water quality deteriorated. Permanently elevated concentrations of ammonia and nitrite served as an indication that the carrying capacity of the systems had been exceeded. The use of ozone as a water enhancement treatment in aquaculture systems during one- and six-hour applications was also considered in this study. Ozonation significantly reduced nitrite levels at · low concentrations (0,1 - 0,15 mg/l), although they returned to pre-treatment levels within a few hours of cessation of the treatment. The formation of an unstable, intermediate product that reforms as nitrite in the absence of ozone, rather than the complete oxidation of nitrite to nitrate, is proposed. Ozonation also resulted in decreased dissolved solids, and improved the clarity and odour of the water. Ozone had no effect on ammonia concentrations (at pH > 7,0), or on nitrate or calcium levels, and did not conclusively increase the redox potential of the water. Residual ozone concentrations up to 0,04 mg/l in a sixhour treatment had no harmful effects on rainbow trout, and there were no signs of gas-bubble disease arising from supersaturation of the water with oxygen. Activated carbon filters were effective at removing residual ozone from the water after treatment. Treatment of the water with oxygen alone had no effect on nitrite concentrations.
- Full Text:
- Date Issued: 1992
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.
- Full Text:
- Date Issued: 1992
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1992
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1992
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1992
- 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.
- Full Text:
- Date Issued: 1992