The journal of the Reverend William Impey, 1838-1847 : a critical study of his work and theology
- Authors: Owen, David Rhys
- Date: 1993
- Subjects: Impey, William, 1818-1896 Methodist Church of Southern Africa -- Clergy -- Biography Methodist Church -- Missions Missionaries -- Biography
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1243 , http://hdl.handle.net/10962/d1009691
- Description: William Impey (1818-1896) came to South Africa as a Wesleyan Methodist Missionary in 1839. He held various missionary and colonial appointments until 1860 when he succeeded William Shaw as Chairman of the Albany and Kaffraria District and General Superintendent of Wesleyan Methodist Missions in South-East Africa. Impey's major contribution was in the provision of education for the indigenous peoples of this region, especially as President of Healdtown (1868-1878). This institution eventually became one of the most highly thought of mission education academies in South Africa. To date little has been known of the life and work of William Impey despite his senior position in South African Wesleyan Methodism. J Whiteside's History of the Wesleyan Methodist Church of South Africa, the last comprehensive history of South African Methodism, published in 1906, only devotes a few lines to Impey. He does however make further reference to Impey's work in his section on education. The Methodist Archive at Manchester University, which contains the personal records of all 19th century Wesleyan Methodist ministers, also has very little information about Impey. The reason for this relative lack of information is that he resigned from the Wesleyan Methodist Church in 1878 on doctrinal grounds. Impey came under the influence of 19th century liberal theology and eventually drew the conclusion that he could no longer accept the doctrine of 'eternal punishment'. He believed that the only honest thing for him to do was to resign from the Wesleyan Methodist Church, which he believed required its ministers to adhere to this doctrine. He was accepted for ordination by the Anglican Church and served as a deacon in 1878 and then as a priest until his death in 1896. Impey's journal affords the reader an opportunity to have a glimpse into what life was like for a 19th century missionary living and working in South Africa. Perhaps its particular value lies in the many detailed entries Impey made about his personal spiritual experiences. The aim of this thesis is to place the life's work of William Impey in its historical and theological context in the belief that this will enable us better to understand the 19th century missionaries. It is hoped that this study will make a further contribution to our understanding of both 19th century missionaries and the times in which they lived and worked.
- Full Text:
- Date Issued: 1993
- Authors: Owen, David Rhys
- Date: 1993
- Subjects: Impey, William, 1818-1896 Methodist Church of Southern Africa -- Clergy -- Biography Methodist Church -- Missions Missionaries -- Biography
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1243 , http://hdl.handle.net/10962/d1009691
- Description: William Impey (1818-1896) came to South Africa as a Wesleyan Methodist Missionary in 1839. He held various missionary and colonial appointments until 1860 when he succeeded William Shaw as Chairman of the Albany and Kaffraria District and General Superintendent of Wesleyan Methodist Missions in South-East Africa. Impey's major contribution was in the provision of education for the indigenous peoples of this region, especially as President of Healdtown (1868-1878). This institution eventually became one of the most highly thought of mission education academies in South Africa. To date little has been known of the life and work of William Impey despite his senior position in South African Wesleyan Methodism. J Whiteside's History of the Wesleyan Methodist Church of South Africa, the last comprehensive history of South African Methodism, published in 1906, only devotes a few lines to Impey. He does however make further reference to Impey's work in his section on education. The Methodist Archive at Manchester University, which contains the personal records of all 19th century Wesleyan Methodist ministers, also has very little information about Impey. The reason for this relative lack of information is that he resigned from the Wesleyan Methodist Church in 1878 on doctrinal grounds. Impey came under the influence of 19th century liberal theology and eventually drew the conclusion that he could no longer accept the doctrine of 'eternal punishment'. He believed that the only honest thing for him to do was to resign from the Wesleyan Methodist Church, which he believed required its ministers to adhere to this doctrine. He was accepted for ordination by the Anglican Church and served as a deacon in 1878 and then as a priest until his death in 1896. Impey's journal affords the reader an opportunity to have a glimpse into what life was like for a 19th century missionary living and working in South Africa. Perhaps its particular value lies in the many detailed entries Impey made about his personal spiritual experiences. The aim of this thesis is to place the life's work of William Impey in its historical and theological context in the belief that this will enable us better to understand the 19th century missionaries. It is hoped that this study will make a further contribution to our understanding of both 19th century missionaries and the times in which they lived and worked.
- Full Text:
- Date Issued: 1993
The Kinetic-Tree-House-Person drawing test as a diagnostic instrument in assessment of sexually abused children and monitoring the effects of group play therapy
- Authors: Donaldson, Marilyn Ann
- Date: 1993
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193140 , vital:45302
- Description: This research project was developed from the idea that children's drawings reflect both their internal emotional lives and their external lived worlds. The subjects of the project were sexually abused children referred to Fort England Hospital during the first half of 1992. The Kinetic-Tree-House-Person projective drawing test was used as an instrument of assessment in conjunction with the Maudsley Child Psychiatric interview technique. Indications of the effects of sexual abuse were sought in drawing tests administered before and after interventions of ten sessions of group play therapy. Drawing tests were also administered to a control group of children. The research project explored the effectiveness of group play therapy interventions through comparison of pre intervention and post intervention drawings. The rationale for this project was the high incidence of rape and sexual abuse of prepubescent black young women in the Eastern Cape particularly, and in South Africa generally. There is need for both assessments of screening instruments and validation of therapeutic interventions if this problem is to be addressed adequately. , Thesis (MA) -- Faculty of Humanities, Psychology, 1993
- Full Text:
- Date Issued: 1993
- Authors: Donaldson, Marilyn Ann
- Date: 1993
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193140 , vital:45302
- Description: This research project was developed from the idea that children's drawings reflect both their internal emotional lives and their external lived worlds. The subjects of the project were sexually abused children referred to Fort England Hospital during the first half of 1992. The Kinetic-Tree-House-Person projective drawing test was used as an instrument of assessment in conjunction with the Maudsley Child Psychiatric interview technique. Indications of the effects of sexual abuse were sought in drawing tests administered before and after interventions of ten sessions of group play therapy. Drawing tests were also administered to a control group of children. The research project explored the effectiveness of group play therapy interventions through comparison of pre intervention and post intervention drawings. The rationale for this project was the high incidence of rape and sexual abuse of prepubescent black young women in the Eastern Cape particularly, and in South Africa generally. There is need for both assessments of screening instruments and validation of therapeutic interventions if this problem is to be addressed adequately. , Thesis (MA) -- Faculty of Humanities, Psychology, 1993
- Full Text:
- Date Issued: 1993
The microbial production of polyphenol oxidase enzyme systems and their application in the treatment of phenolic wastewaters
- Authors: Goetsch, Patricia-Ann
- Date: 1993
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21060 , http://hdl.handle.net/10962/6190
- Description: Phenolic compounds are a group of organic chemicals present in the wastewaters of many synthetic industrial processes. Due to their extreme toxicity to man and animals, and deleterious impact on the environment, a range of techniques exist for the effective treatment and disposal of these pollutants. Biological degradation using microbial enzymes presents a valuable alternative to conventional wastewater treatment systems. This research was therefore initiated to investigate the polyphenol oxidase enzyme system and the feasibility of its application for effluent treatment and studies in organic solvents. The enzyme system is widely distributed in nature, with Agaricus bisporus (the common mushroom) being the best known producer. Biochemical investigations of the enzyme system were therefore carried out using this extract. A screening programme was initiated to identify microbial polyphenol oxidase producers which could be cultured in liquid media, thereby enabling the production of large quantities of enzyme in fermentation systems. Extensive growth optimization and enzyme induction and optimization studies were carried out on selected cultures. A number of good producers were isolated, namely a bacterial culture designated AECI culture no. 26, Streptomyces antibioticus, Streptomyces glaucescens and a manipulated strain, Streptomyces lividans (pIJ702). Enzyme production by Agaricus bisporus mycelia was optimized in deep-liquid culture; enzyme extracts showed high phenol removal efficiencies. Streptomyces antibioticus, Streptomyces glaucescens, Streptomyces lividans (pIJ702) and AECI culture no. 26 whole cells were also investigated for phenol-removing ability in simulated phenolic effluents. The use of whole cells reduces enzyme inactivation and instability due to the protection of the enzyme system within the cell. All cultures showed improved removal efficiencies in phenolic growth media. These results strongly suggest their use for phenol removal in continuous systems.
- Full Text:
- Date Issued: 1993
- Authors: Goetsch, Patricia-Ann
- Date: 1993
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21060 , http://hdl.handle.net/10962/6190
- Description: Phenolic compounds are a group of organic chemicals present in the wastewaters of many synthetic industrial processes. Due to their extreme toxicity to man and animals, and deleterious impact on the environment, a range of techniques exist for the effective treatment and disposal of these pollutants. Biological degradation using microbial enzymes presents a valuable alternative to conventional wastewater treatment systems. This research was therefore initiated to investigate the polyphenol oxidase enzyme system and the feasibility of its application for effluent treatment and studies in organic solvents. The enzyme system is widely distributed in nature, with Agaricus bisporus (the common mushroom) being the best known producer. Biochemical investigations of the enzyme system were therefore carried out using this extract. A screening programme was initiated to identify microbial polyphenol oxidase producers which could be cultured in liquid media, thereby enabling the production of large quantities of enzyme in fermentation systems. Extensive growth optimization and enzyme induction and optimization studies were carried out on selected cultures. A number of good producers were isolated, namely a bacterial culture designated AECI culture no. 26, Streptomyces antibioticus, Streptomyces glaucescens and a manipulated strain, Streptomyces lividans (pIJ702). Enzyme production by Agaricus bisporus mycelia was optimized in deep-liquid culture; enzyme extracts showed high phenol removal efficiencies. Streptomyces antibioticus, Streptomyces glaucescens, Streptomyces lividans (pIJ702) and AECI culture no. 26 whole cells were also investigated for phenol-removing ability in simulated phenolic effluents. The use of whole cells reduces enzyme inactivation and instability due to the protection of the enzyme system within the cell. All cultures showed improved removal efficiencies in phenolic growth media. These results strongly suggest their use for phenol removal in continuous systems.
- Full Text:
- Date Issued: 1993
The nature of olivine-rich cumulate rocks of the lower critical and lower zones of the northwestern Bushveld Complex
- Authors: Haikney, Susan Ann
- Date: 1993
- Subjects: Geochemistry -- South Africa , Igneous rocks -- South Africa , Olivine -- South Africa , Bushveld Complex (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4980 , http://hdl.handle.net/10962/d1005592 , Geochemistry -- South Africa , Igneous rocks -- South Africa , Olivine -- South Africa , Bushveld Complex (South Africa)
- Description: Boreholes NG1 and NG2 were drilled on the farm Nooitgedacht 406 KQ to intersect the lower Critical and lower Zones of the western Bushveld Complex. The aim of this study is to describe the textural features and chemical characteristics of the olivine-bearing rocks in the intersections, as determined by petrographic studies, XRF analysis and microprobe analysis. The olivine-bearing rocks are dunites, harzburgites and olivine pyroxenites. They comprise olivine and orthopyroxene, with minor chromite, clinopyroxene and plagioclase, and their textures vary between adcumulate, mesocumulate and poikilitic. The sequence intersected can be broadly correlated with that in the eastern Bushveld Complex. Of the whole-rock inter-element ratios, the MMF (MgO)/[MgO+FeO])ratio is the clearest indicator of cyclicity. The olivine-rich rocks are more primitive than the associated rocks, and seem to become more primitive with height in most intervals. The plagioclase in the olivine-bearing rocks is unusually sodic in corrposition, having a maximum Na₂0 content of 8.12%. A comparison of olivine and plagioclase compositions with those in other intrusions has revealed that the only other major intrusion with sodic plagioclase is the Kiglapait intrusion of Canada. In the Kiglapait intrusion the sodic plagioclase occurs in conjunction with fayalitic olivine as opposed to the forsteritic variety of this study. Chemical variations in the rocks sampled indicate that periodic replenishment of the magma from which the rocks crystallised must have occurred. In some of the olivine-bearing intervals where little fractionation is evident, replenishment seems to have been continuous. In other intervals fractionation appears to have continued uninterrupted for significant periods, prior to rejuvenation by fresh influxes of magma.
- Full Text:
- Date Issued: 1993
- Authors: Haikney, Susan Ann
- Date: 1993
- Subjects: Geochemistry -- South Africa , Igneous rocks -- South Africa , Olivine -- South Africa , Bushveld Complex (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4980 , http://hdl.handle.net/10962/d1005592 , Geochemistry -- South Africa , Igneous rocks -- South Africa , Olivine -- South Africa , Bushveld Complex (South Africa)
- Description: Boreholes NG1 and NG2 were drilled on the farm Nooitgedacht 406 KQ to intersect the lower Critical and lower Zones of the western Bushveld Complex. The aim of this study is to describe the textural features and chemical characteristics of the olivine-bearing rocks in the intersections, as determined by petrographic studies, XRF analysis and microprobe analysis. The olivine-bearing rocks are dunites, harzburgites and olivine pyroxenites. They comprise olivine and orthopyroxene, with minor chromite, clinopyroxene and plagioclase, and their textures vary between adcumulate, mesocumulate and poikilitic. The sequence intersected can be broadly correlated with that in the eastern Bushveld Complex. Of the whole-rock inter-element ratios, the MMF (MgO)/[MgO+FeO])ratio is the clearest indicator of cyclicity. The olivine-rich rocks are more primitive than the associated rocks, and seem to become more primitive with height in most intervals. The plagioclase in the olivine-bearing rocks is unusually sodic in corrposition, having a maximum Na₂0 content of 8.12%. A comparison of olivine and plagioclase compositions with those in other intrusions has revealed that the only other major intrusion with sodic plagioclase is the Kiglapait intrusion of Canada. In the Kiglapait intrusion the sodic plagioclase occurs in conjunction with fayalitic olivine as opposed to the forsteritic variety of this study. Chemical variations in the rocks sampled indicate that periodic replenishment of the magma from which the rocks crystallised must have occurred. In some of the olivine-bearing intervals where little fractionation is evident, replenishment seems to have been continuous. In other intervals fractionation appears to have continued uninterrupted for significant periods, prior to rejuvenation by fresh influxes of magma.
- Full Text:
- Date Issued: 1993
The nature of the oxidation products of dicyanoruthenium phthalocyanine in aqueous and non-aqueous solvents
- Authors: Nyokong, Tebello
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295543 , vital:57352 , xlink:href="https://doi.org/10.1016/S0277-5387(00)81741-6"
- Description: The cyclic voltammetry of [(CN)2RuIIPc]2− in acetonitrile or dichloromethane shows two oxidation couples at E12 = 0.31 and 0.85 V (vs S.C.E.) in CH2Cl2 and E12 = 0.45 and 1.15 V (vs S.C.E.) in acetonitrile. The spectroelectrochemistry of [(CN)2RuIIPc]2− in these solvents showed that oxidations occur at the phthalocyanine ligand. K2[(CN)2RuIIPc] dissolves in water at pHs greater than 5. The cyclic voltammetry of this complex showed oxidation couples at 0.32 and 0.29 V (vs S.C.E.) for aqueous solutions containing sodium sulphate (0.1M) and for buffered solutions (pH = 9), respectively. Both cyclic voltammetry and controlled potential coulometry gave evidence of electrocrystallization of the oxidation product. Chemical oxidations of [(CN)2RuIIPc]2− in water also showed phthalocyanine ligand oxidation.
- Full Text:
- Date Issued: 1993
- Authors: Nyokong, Tebello
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295543 , vital:57352 , xlink:href="https://doi.org/10.1016/S0277-5387(00)81741-6"
- Description: The cyclic voltammetry of [(CN)2RuIIPc]2− in acetonitrile or dichloromethane shows two oxidation couples at E12 = 0.31 and 0.85 V (vs S.C.E.) in CH2Cl2 and E12 = 0.45 and 1.15 V (vs S.C.E.) in acetonitrile. The spectroelectrochemistry of [(CN)2RuIIPc]2− in these solvents showed that oxidations occur at the phthalocyanine ligand. K2[(CN)2RuIIPc] dissolves in water at pHs greater than 5. The cyclic voltammetry of this complex showed oxidation couples at 0.32 and 0.29 V (vs S.C.E.) for aqueous solutions containing sodium sulphate (0.1M) and for buffered solutions (pH = 9), respectively. Both cyclic voltammetry and controlled potential coulometry gave evidence of electrocrystallization of the oxidation product. Chemical oxidations of [(CN)2RuIIPc]2− in water also showed phthalocyanine ligand oxidation.
- Full Text:
- Date Issued: 1993
The occurrence and development of' Siamese twins' and other abnormalities in Oreochromis mossambicus (Pisces, Cichlidae).
- Holden, Kathleen K, Bruton, Michael N
- Authors: Holden, Kathleen K , Bruton, Michael N
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447288 , vital:74602 , https://hdl.handle.net/10520/AJA00445096_605
- Description: Specimens from a clutch of Oreochromis mossambicus (Pisces, Cichlidae) exhibited a number of abnormalities such as enlarged pericardia, thin tube-like hearts, large depressions in the yolksac, spinal deformities and twinning. Descriptions of the differences in early ontogeny of two pairs of 'Siamese twins' over a period of at least eight days are given. The developmental pattern of the twins is similar to that of normal specimens but the developmental rate is slower in the twins. Possible explanations for these occurrences of polyembryony are given.
- Full Text:
- Date Issued: 1993
- Authors: Holden, Kathleen K , Bruton, Michael N
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447288 , vital:74602 , https://hdl.handle.net/10520/AJA00445096_605
- Description: Specimens from a clutch of Oreochromis mossambicus (Pisces, Cichlidae) exhibited a number of abnormalities such as enlarged pericardia, thin tube-like hearts, large depressions in the yolksac, spinal deformities and twinning. Descriptions of the differences in early ontogeny of two pairs of 'Siamese twins' over a period of at least eight days are given. The developmental pattern of the twins is similar to that of normal specimens but the developmental rate is slower in the twins. Possible explanations for these occurrences of polyembryony are given.
- Full Text:
- Date Issued: 1993
The political economy of educational provision in "white" commercial farming areas: findings from a case study conducted in the Ugie district in the north eastern Cape
- Authors: Stretton, Natasha Anne
- Date: 1993
- Subjects: Rural schools -- South Africa -- Northeastern Cape Province -- Ugie District , Education, Rural -- South Africa -- Ugie District , Black people -- Education -- South Africa Case studies , Education, Rural -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2833 , http://hdl.handle.net/10962/d1003043 , Rural schools -- South Africa -- Northeastern Cape Province -- Ugie District , Education, Rural -- South Africa -- Ugie District , Black people -- Education -- South Africa Case studies , Education, Rural -- South Africa -- Case studies
- Description: The under-provision of education for black South Africans has reached crisis proportions. While the education for black people in general is discriminatory and unequal, black rural people suffer further deprivations as there is a serious imbalance in the allocation of resources and the provision of education between urban and rural areas. Black education in the rural areas has been historically neglected for political and socio-economic reasons and, as a consequence, rural blacks have limited or no access to education. The purpose of this' study is to examine an aspect of rural education; viz: black farm schools in the 'white' commercial farming areas. It is argued that the provision of farm schools is intricately linked to the labour requirements of farmers and consequently farm schools cannot be understood independently from the social relations within commercial farming areas. The impact of local decision-making on the process of farm schooling is also significant and is an important aspect of this study. This thesis explores the political and socio-economic processes that have structured the provision of education within a small farming community, looking specifically at the effects of particular interest groups on the provision of black farm schools. The study operates on three levels. The first level provides a theoretical framework within which rural education can be better understood. It is argued that the bias towards urban areas is reflected in the current theoretical debates on the role and function of education ·in South Africa. As these theories are generally incapable of explaining rural education, an alternative model is proposed. As education cannot be understood in isolation from the rest of society, the second level of the study locates farm schooling within the broader political and socio-economic systems. This is done from two perspectives. The first perspective focuses on black education in general, tracing aspects of its development and highlighting the impact .of economic interests, white political control and black resistances to this development. The neglect of rural education is also contextualised historically and politically. The second perspective looks at rural education at a macro-level. The historical origins of the farm schools system and the effects of the relationship between agricultural capital and the state, and between farmers and farm workers on the process of farm schooling is examined. The final level of the study focuses on the micro-situation and provides an in-depth analysis of the political and socio-economic dynamics which have impacted upon the provision and process of farm schools within a specific farming community. In an attempt to understand the types of issues effecting farm schooling in this area, the attitudes of farmers, farm workers, farm- children and farm school teachers towards education are investigated. Four main issues were identified and are discussed in depth, viz: I) factors effecting the provision of black farm schools; 2) the relationship between education and the economic structure of the area; 3) the value of education; and 4) socio-economic factors effecting education in the area.
- Full Text:
- Date Issued: 1993
- Authors: Stretton, Natasha Anne
- Date: 1993
- Subjects: Rural schools -- South Africa -- Northeastern Cape Province -- Ugie District , Education, Rural -- South Africa -- Ugie District , Black people -- Education -- South Africa Case studies , Education, Rural -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2833 , http://hdl.handle.net/10962/d1003043 , Rural schools -- South Africa -- Northeastern Cape Province -- Ugie District , Education, Rural -- South Africa -- Ugie District , Black people -- Education -- South Africa Case studies , Education, Rural -- South Africa -- Case studies
- Description: The under-provision of education for black South Africans has reached crisis proportions. While the education for black people in general is discriminatory and unequal, black rural people suffer further deprivations as there is a serious imbalance in the allocation of resources and the provision of education between urban and rural areas. Black education in the rural areas has been historically neglected for political and socio-economic reasons and, as a consequence, rural blacks have limited or no access to education. The purpose of this' study is to examine an aspect of rural education; viz: black farm schools in the 'white' commercial farming areas. It is argued that the provision of farm schools is intricately linked to the labour requirements of farmers and consequently farm schools cannot be understood independently from the social relations within commercial farming areas. The impact of local decision-making on the process of farm schooling is also significant and is an important aspect of this study. This thesis explores the political and socio-economic processes that have structured the provision of education within a small farming community, looking specifically at the effects of particular interest groups on the provision of black farm schools. The study operates on three levels. The first level provides a theoretical framework within which rural education can be better understood. It is argued that the bias towards urban areas is reflected in the current theoretical debates on the role and function of education ·in South Africa. As these theories are generally incapable of explaining rural education, an alternative model is proposed. As education cannot be understood in isolation from the rest of society, the second level of the study locates farm schooling within the broader political and socio-economic systems. This is done from two perspectives. The first perspective focuses on black education in general, tracing aspects of its development and highlighting the impact .of economic interests, white political control and black resistances to this development. The neglect of rural education is also contextualised historically and politically. The second perspective looks at rural education at a macro-level. The historical origins of the farm schools system and the effects of the relationship between agricultural capital and the state, and between farmers and farm workers on the process of farm schooling is examined. The final level of the study focuses on the micro-situation and provides an in-depth analysis of the political and socio-economic dynamics which have impacted upon the provision and process of farm schools within a specific farming community. In an attempt to understand the types of issues effecting farm schooling in this area, the attitudes of farmers, farm workers, farm- children and farm school teachers towards education are investigated. Four main issues were identified and are discussed in depth, viz: I) factors effecting the provision of black farm schools; 2) the relationship between education and the economic structure of the area; 3) the value of education; and 4) socio-economic factors effecting education in the area.
- Full Text:
- Date Issued: 1993
The regulation of Serotonin N-acetyltransferase in the rat pineal gland
- Authors: Olivieri, Gianfranco
- Date: 1993
- Subjects: Serotonin -- Research Pineal gland Acetyltransferases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4051 , http://hdl.handle.net/10962/d1004112
- Description: The synthesis of the pineal hormone, melatonin, is finely regulated by the pineal enzyme serotonin N-acetyltransferase (NAT). In the absence of light, the activity of NAT is markedly enhanced by the release of nor-adrenaline from sympathetic nerve endings in the pineal. Exposure of animals to light during darkness causes a sudden and dramatic reduction in the activity of NAT. The present study investigated a possible mechanism for this sudden decline in NAT activity. These investigations included the determination of the effects of S-adenosylmethionine (SAM), adenosine nucleotides and calcium on NAT activity. In vitro experiments using SAM showed that pineals pre-incubated with SAM prior to adrenergic stimulation did not significantly alter NAT activity or pineal indoleamine metabolism. However, measurement of pineal cyclic AMP showed that SAM exposure reduced the adrenergic-induced rise in pineal cyclic AMP. Experiments using adenosine 5'-monophosphate (5'-AMP) showed that this nucleotide enhanced both dark- and isoproterenol-induced NAT activity. Adenosine 5'-triphosphate (A TP), on the other hand, reduced NAT activity with a concomitant reduction in pineal indoleamine metabolism. Exposure of isoproterenol-stimulated pineals in organ culture to propranolol resulted in a marked rise in ATP and adenosine 5'-diphosphate (ADP) synthesis accompanied by a decline in 5'-AMP levels as compared with pineals treated with isoproterenol alone. This then implies that exposure of animals to light could cause a change in pineal nucleotide levels. Since nucleotide levels are also controlled by calcium, experiments were carried out to determine the effect of calcium on pineal NAT activity. These experiments showed that ethyleneglycol-bis-N,N,N,N,-tetraacetic acid (EGTA) enhanced NAT activity whilst calcium reduced the activity in pineal homogenates, implying that calcium may act directly on NAT to regulate its activity. Exposure of pineal glands in organ culture to the calmodulin antagonist R24571 caused a rise in pineal cyclic AMP levels with a concomitant decrease in cAMP-phosphodiesterase activity. This was, however, accompanied by a decline in Nacetyl serotonin and melatonin synthesis. These findings implicate a number of factors in the regulation of pineal NAT activity. A mechanism for the regulation of pineal NAT is proposed.
- Full Text:
- Date Issued: 1993
- Authors: Olivieri, Gianfranco
- Date: 1993
- Subjects: Serotonin -- Research Pineal gland Acetyltransferases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4051 , http://hdl.handle.net/10962/d1004112
- Description: The synthesis of the pineal hormone, melatonin, is finely regulated by the pineal enzyme serotonin N-acetyltransferase (NAT). In the absence of light, the activity of NAT is markedly enhanced by the release of nor-adrenaline from sympathetic nerve endings in the pineal. Exposure of animals to light during darkness causes a sudden and dramatic reduction in the activity of NAT. The present study investigated a possible mechanism for this sudden decline in NAT activity. These investigations included the determination of the effects of S-adenosylmethionine (SAM), adenosine nucleotides and calcium on NAT activity. In vitro experiments using SAM showed that pineals pre-incubated with SAM prior to adrenergic stimulation did not significantly alter NAT activity or pineal indoleamine metabolism. However, measurement of pineal cyclic AMP showed that SAM exposure reduced the adrenergic-induced rise in pineal cyclic AMP. Experiments using adenosine 5'-monophosphate (5'-AMP) showed that this nucleotide enhanced both dark- and isoproterenol-induced NAT activity. Adenosine 5'-triphosphate (A TP), on the other hand, reduced NAT activity with a concomitant reduction in pineal indoleamine metabolism. Exposure of isoproterenol-stimulated pineals in organ culture to propranolol resulted in a marked rise in ATP and adenosine 5'-diphosphate (ADP) synthesis accompanied by a decline in 5'-AMP levels as compared with pineals treated with isoproterenol alone. This then implies that exposure of animals to light could cause a change in pineal nucleotide levels. Since nucleotide levels are also controlled by calcium, experiments were carried out to determine the effect of calcium on pineal NAT activity. These experiments showed that ethyleneglycol-bis-N,N,N,N,-tetraacetic acid (EGTA) enhanced NAT activity whilst calcium reduced the activity in pineal homogenates, implying that calcium may act directly on NAT to regulate its activity. Exposure of pineal glands in organ culture to the calmodulin antagonist R24571 caused a rise in pineal cyclic AMP levels with a concomitant decrease in cAMP-phosphodiesterase activity. This was, however, accompanied by a decline in Nacetyl serotonin and melatonin synthesis. These findings implicate a number of factors in the regulation of pineal NAT activity. A mechanism for the regulation of pineal NAT is proposed.
- Full Text:
- Date Issued: 1993
The remains of rock glaciers in Bottelnek, East Cape Drakensberg, South Africa
- Lewis, Colin A, Hanvey, Patricia M
- Authors: Lewis, Colin A , Hanvey, Patricia M
- Date: 1993
- Language: English
- Type: Article
- Identifier: vital:6698 , http://hdl.handle.net/10962/d1006734
- Description: Certain debris accumulations in Bottelnek are ascribed a rock glacier origin on the basis of morphological and sedimentological evidence. Radiocarbon dating indicates that rock glaciers were active at or subsequent to 21 000 BP and that cold, stadial conditions, existed on the region after 27 000 BP and before 13 000 BP, during the Bottelnek Stadial. At least sporadic permafrost existed in Bottelnek when the rock glaciers were active.
- Full Text: false
- Date Issued: 1993
- Authors: Lewis, Colin A , Hanvey, Patricia M
- Date: 1993
- Language: English
- Type: Article
- Identifier: vital:6698 , http://hdl.handle.net/10962/d1006734
- Description: Certain debris accumulations in Bottelnek are ascribed a rock glacier origin on the basis of morphological and sedimentological evidence. Radiocarbon dating indicates that rock glaciers were active at or subsequent to 21 000 BP and that cold, stadial conditions, existed on the region after 27 000 BP and before 13 000 BP, during the Bottelnek Stadial. At least sporadic permafrost existed in Bottelnek when the rock glaciers were active.
- Full Text: false
- Date Issued: 1993
The role of the industrial social worker in corporate community relations
- Authors: Harnett, Claire F
- Date: 1993
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:21091 , http://hdl.handle.net/10962/6342
- Description: This research study is a qualitative investigation of the role of the industrial social worker in corporate community relations. The research study was undertaken by means of mailed questionnaires. Two different populations were utilized, namely corporations known to practice corporate social responsibility and corporations employing industrial social workers. As a background to the research, relations is defined and its Furthermore, the contribution of relations in the realization of a corporate development community traced. corporate community government-business partnership to address community social problems, is discussed. Lastly, in an attempt to demonstrate that the social worker can indeed play a role in corporate community relations, the extent to which corporate community relations goals and approaches correspond with the community organization model of social work practice, is examined. The purpose of the empirical part of the research study was to determine what form community relations has taken in South Africa and the role that the industrial social worker assumes in this regard. From the findings it appears that there is a focus on philanthropic activities and less direct corporate involvement in creating new resources. Industrial social workers involvement in this function was limited. They primarily assumed the roles of consultant and expert. Although these social workers' have laid the ground work for expansion of the industrial social worker's role, it appears that development has been more serendipitous than rationally planned. It appears from the findings that the potential does exist for industrial social workers to assist the corporation to expand its social responsibility programme, and in so doing expand their practice to include macro level intervention strategies. Based on these assumptions, it is suggested that further in-depth research is carried out to establish what strategies are being employed by industrial social workers to expand their roles, it appears that there is a need to assist the industrial social worker to adopt a rationally planned approach in order to assume a greater role in the corporation's social responsibility activities internally and externally.
- Full Text:
- Date Issued: 1993
- Authors: Harnett, Claire F
- Date: 1993
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:21091 , http://hdl.handle.net/10962/6342
- Description: This research study is a qualitative investigation of the role of the industrial social worker in corporate community relations. The research study was undertaken by means of mailed questionnaires. Two different populations were utilized, namely corporations known to practice corporate social responsibility and corporations employing industrial social workers. As a background to the research, relations is defined and its Furthermore, the contribution of relations in the realization of a corporate development community traced. corporate community government-business partnership to address community social problems, is discussed. Lastly, in an attempt to demonstrate that the social worker can indeed play a role in corporate community relations, the extent to which corporate community relations goals and approaches correspond with the community organization model of social work practice, is examined. The purpose of the empirical part of the research study was to determine what form community relations has taken in South Africa and the role that the industrial social worker assumes in this regard. From the findings it appears that there is a focus on philanthropic activities and less direct corporate involvement in creating new resources. Industrial social workers involvement in this function was limited. They primarily assumed the roles of consultant and expert. Although these social workers' have laid the ground work for expansion of the industrial social worker's role, it appears that development has been more serendipitous than rationally planned. It appears from the findings that the potential does exist for industrial social workers to assist the corporation to expand its social responsibility programme, and in so doing expand their practice to include macro level intervention strategies. Based on these assumptions, it is suggested that further in-depth research is carried out to establish what strategies are being employed by industrial social workers to expand their roles, it appears that there is a need to assist the industrial social worker to adopt a rationally planned approach in order to assume a greater role in the corporation's social responsibility activities internally and externally.
- Full Text:
- Date Issued: 1993
The role of the international community in the South African transition: a critical review
- Authors: Dormehl, Andries Christian
- Date: 1993
- Subjects: Democracy -- South Africa , South Africa -- Politics and government -- 1989-1994 , South Africa -- Foreign relations -- 1989-1994
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2772 , http://hdl.handle.net/10962/d1002982 , Democracy -- South Africa , South Africa -- Politics and government -- 1989-1994 , South Africa -- Foreign relations -- 1989-1994
- Description: There is a dearth of position papers on international participation in the South African transition. Political parties and organisations in South Africa instead spend most of their time describing various forms of desirous IC intervention after the transition. This might explain why most articles and academic papers on 'the role of the international community' are suffixed - in the 'new South Africa' or 'post-apartheid South Africa' - few focus on the actual transition and then mostly from a systemic perspective, broadly outlining the constraints imposed by the 'new world order'. Perhaps the first serious attempt to address this gap in the debate over South Africa's future was D. Kempton and L. Mosia's 'The International Community in South Africa's Transition to non-racial Democracy' (1992). Before multiparty negotiations collapsed in June 1992, Kempton and Mosia examined the attitudes toward international intervention of most of the CODESA participants, as well as the major actors that had remained outside CODESA. This paper takes up the issue where Kempton and Mosia left off. It tries to explain transitional politics since the IC introduced an on-the-ground presence after the UN Security Council debates on South Africa in July 1992. It asks why, eight months after multiparty talks were suspended, the IC has been unable to revive multiparty negotiations, has apparently had little or no impact on the violence, and despite events like Boipatong and Bisho, still plays a minor peacekeeping role, confined to observer status. The research describes internal and external components of international intervention, examines the rationale behind the agreed forms of international participation, and assesses the viability of the internationally-supported conflict-resolution and transition-management structures that were formed to facilitate the transition. The evidence uncovered by the research leads the author to the conclusion that more of an international role is necessary, and sooner rather than later, but he concedes that this is not feasible, or likely, under the status quo.
- Full Text:
- Date Issued: 1993
- Authors: Dormehl, Andries Christian
- Date: 1993
- Subjects: Democracy -- South Africa , South Africa -- Politics and government -- 1989-1994 , South Africa -- Foreign relations -- 1989-1994
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2772 , http://hdl.handle.net/10962/d1002982 , Democracy -- South Africa , South Africa -- Politics and government -- 1989-1994 , South Africa -- Foreign relations -- 1989-1994
- Description: There is a dearth of position papers on international participation in the South African transition. Political parties and organisations in South Africa instead spend most of their time describing various forms of desirous IC intervention after the transition. This might explain why most articles and academic papers on 'the role of the international community' are suffixed - in the 'new South Africa' or 'post-apartheid South Africa' - few focus on the actual transition and then mostly from a systemic perspective, broadly outlining the constraints imposed by the 'new world order'. Perhaps the first serious attempt to address this gap in the debate over South Africa's future was D. Kempton and L. Mosia's 'The International Community in South Africa's Transition to non-racial Democracy' (1992). Before multiparty negotiations collapsed in June 1992, Kempton and Mosia examined the attitudes toward international intervention of most of the CODESA participants, as well as the major actors that had remained outside CODESA. This paper takes up the issue where Kempton and Mosia left off. It tries to explain transitional politics since the IC introduced an on-the-ground presence after the UN Security Council debates on South Africa in July 1992. It asks why, eight months after multiparty talks were suspended, the IC has been unable to revive multiparty negotiations, has apparently had little or no impact on the violence, and despite events like Boipatong and Bisho, still plays a minor peacekeeping role, confined to observer status. The research describes internal and external components of international intervention, examines the rationale behind the agreed forms of international participation, and assesses the viability of the internationally-supported conflict-resolution and transition-management structures that were formed to facilitate the transition. The evidence uncovered by the research leads the author to the conclusion that more of an international role is necessary, and sooner rather than later, but he concedes that this is not feasible, or likely, under the status quo.
- Full Text:
- Date Issued: 1993
The state of guidance in Mdantsane High Schools
- Nonyukela, Nontathu Elizabeth
- Authors: Nonyukela, Nontathu Elizabeth
- Date: 1993
- Subjects: Educational counseling -- South Africa -- Ciskei Black people -- Education -- South Africa -- Ciskei Counseling -- Vocational guidance -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1771 , http://hdl.handle.net/10962/d1003656
- Description: Guidance was introduced into Black Schools in 1981. Its aim was to help students so that they could understand themselves and the world they live in. At present it appears that very little Guidance is taking place in the Mdantsane High Schools. This was supported by these research findings. In the research five High Schools were investigated to discover the state of Guidance in these High Schools. The writer made use of an interview schedule which was presented to the principals of the five High Schools. Questionnaires were given to twenty seven Guidance teachers from the same High Schools and to two hundred and fifty student respondents. In each High School fifty student respondents were chosen, that is, ten from each standard. The research findings suggested that Guidance is not receiving its rightful place in these five High Schools since it is not effectively taught. The findings were generalised to other High Schools. Reasons for the ineffective teaching of Guidance were given by both the principal and teacher respondents. Recommendations are made as to how this state of Guidance can be remedied and improved.
- Full Text:
- Date Issued: 1993
- Authors: Nonyukela, Nontathu Elizabeth
- Date: 1993
- Subjects: Educational counseling -- South Africa -- Ciskei Black people -- Education -- South Africa -- Ciskei Counseling -- Vocational guidance -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1771 , http://hdl.handle.net/10962/d1003656
- Description: Guidance was introduced into Black Schools in 1981. Its aim was to help students so that they could understand themselves and the world they live in. At present it appears that very little Guidance is taking place in the Mdantsane High Schools. This was supported by these research findings. In the research five High Schools were investigated to discover the state of Guidance in these High Schools. The writer made use of an interview schedule which was presented to the principals of the five High Schools. Questionnaires were given to twenty seven Guidance teachers from the same High Schools and to two hundred and fifty student respondents. In each High School fifty student respondents were chosen, that is, ten from each standard. The research findings suggested that Guidance is not receiving its rightful place in these five High Schools since it is not effectively taught. The findings were generalised to other High Schools. Reasons for the ineffective teaching of Guidance were given by both the principal and teacher respondents. Recommendations are made as to how this state of Guidance can be remedied and improved.
- Full Text:
- Date Issued: 1993
The structure of an irrigation scheme
- Authors: Holbrook, Gregory Martin
- Date: 1993
- Subjects: Tyefu Irrigation Scheme -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Ciskei , Irrigation -- South Africa -- Ciskei , Xhosa (African people) -- Economic conditions , Xhosa (African people) -- Social life and customs
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2101 , http://hdl.handle.net/10962/d1002664 , Tyefu Irrigation Scheme -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Ciskei , Irrigation -- South Africa -- Ciskei , Xhosa (African people) -- Economic conditions , Xhosa (African people) -- Social life and customs
- Description: Faced with problems related to the sustainability and advisability of contemporary irrigation development in Africa, anthropologists have increasingly looked to economic and political explanations for the success or failure of those development schemes. Instead of seeking explanations in these isolated areas, this thesis has argued that irrigation development needs to be understood through relationships within and between politics, economics, social structure and culture. In order to uncover those interactions with regard to the Tyefu Irrigation Scheme in the southern African homeland of Ciskei, reference has been made, firstly, to the mechanisms underlying contemporary state expansion and secondly, to the interaction between external forces, structures and surface forms through time. Anthropological fieldwork techniques have been used to provide detailed descriptions of everyday communications within and between groups associated with the development. Ethnography allows implementation to be conceptualized in terms of the interaction between local level structures and structures associated with the planning and construction of irrigation development itself. When the effect of external forces on the interaction between structures and forms is then taken into account principles emerge that reflect local and historical transformations. These in turn suggest the form of contemporary state expansion in southern Africa, as well as its bearing on daily life on the rural periphery.
- Full Text:
- Date Issued: 1993
- Authors: Holbrook, Gregory Martin
- Date: 1993
- Subjects: Tyefu Irrigation Scheme -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Ciskei , Irrigation -- South Africa -- Ciskei , Xhosa (African people) -- Economic conditions , Xhosa (African people) -- Social life and customs
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2101 , http://hdl.handle.net/10962/d1002664 , Tyefu Irrigation Scheme -- South Africa -- Eastern Cape , Agricultural development projects -- South Africa -- Ciskei , Irrigation -- South Africa -- Ciskei , Xhosa (African people) -- Economic conditions , Xhosa (African people) -- Social life and customs
- Description: Faced with problems related to the sustainability and advisability of contemporary irrigation development in Africa, anthropologists have increasingly looked to economic and political explanations for the success or failure of those development schemes. Instead of seeking explanations in these isolated areas, this thesis has argued that irrigation development needs to be understood through relationships within and between politics, economics, social structure and culture. In order to uncover those interactions with regard to the Tyefu Irrigation Scheme in the southern African homeland of Ciskei, reference has been made, firstly, to the mechanisms underlying contemporary state expansion and secondly, to the interaction between external forces, structures and surface forms through time. Anthropological fieldwork techniques have been used to provide detailed descriptions of everyday communications within and between groups associated with the development. Ethnography allows implementation to be conceptualized in terms of the interaction between local level structures and structures associated with the planning and construction of irrigation development itself. When the effect of external forces on the interaction between structures and forms is then taken into account principles emerge that reflect local and historical transformations. These in turn suggest the form of contemporary state expansion in southern Africa, as well as its bearing on daily life on the rural periphery.
- Full Text:
- Date Issued: 1993
The systematics and phylogenetics of the Sycoecinae (Agaonidae, Chalcidoidea, Hymenoptera)
- Authors: Noort, Simon van
- Date: 1993
- Subjects: Agaonidae Chalcid wasps Fig wasp -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5784 , http://hdl.handle.net/10962/d1005472
- Description: The Sycoecinae are a distinct and well-defined subfamily of old world fig wasps (Agaonidae, Chalcidoidea 1 Hymenoptera) , exclusively associated with the figs of Ficus species (Moraceae). The most likely sister group of the Sycoecinae was determined to be the Sycoryctini (Sycoryctinae) based largely on synapomorphies of the underside of the head. 67 sycoecine species and 3 subspecies were recognised and included in a phylogenetic analysis of the subfamily. This analysis clearly delimited six genera (four African and two extra-African), although the phylogenetic relationships between the genera were not strongly supported and remain flexible. Comparisons of the phylogeny of the Sycoecinae with the classifications of the Agaoninae and their host fig trees (Ficus, Moraceae) suggest a degree of cospeciation sensu lato. Numerous homoplasies were detected within the Sycoecinae, some of which were shared with another group of fig wasps that also enter the fig to oviposit, the Agaoninae. The anatomy of the figs apparently provides strong selection pressures that have resulted in both parallelisms and convergences within and between the two subfamilies. Among the 67 species and 3 subspecies that were recognised, 43 species and 2 subspecies are described as new. The males of three previously recognised species are also described for the first time. One generic and two specific synonyms are established together with five new combinations. Keys are provided to the genera and species, for both sexes.
- Full Text:
- Date Issued: 1993
- Authors: Noort, Simon van
- Date: 1993
- Subjects: Agaonidae Chalcid wasps Fig wasp -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5784 , http://hdl.handle.net/10962/d1005472
- Description: The Sycoecinae are a distinct and well-defined subfamily of old world fig wasps (Agaonidae, Chalcidoidea 1 Hymenoptera) , exclusively associated with the figs of Ficus species (Moraceae). The most likely sister group of the Sycoecinae was determined to be the Sycoryctini (Sycoryctinae) based largely on synapomorphies of the underside of the head. 67 sycoecine species and 3 subspecies were recognised and included in a phylogenetic analysis of the subfamily. This analysis clearly delimited six genera (four African and two extra-African), although the phylogenetic relationships between the genera were not strongly supported and remain flexible. Comparisons of the phylogeny of the Sycoecinae with the classifications of the Agaoninae and their host fig trees (Ficus, Moraceae) suggest a degree of cospeciation sensu lato. Numerous homoplasies were detected within the Sycoecinae, some of which were shared with another group of fig wasps that also enter the fig to oviposit, the Agaoninae. The anatomy of the figs apparently provides strong selection pressures that have resulted in both parallelisms and convergences within and between the two subfamilies. Among the 67 species and 3 subspecies that were recognised, 43 species and 2 subspecies are described as new. The males of three previously recognised species are also described for the first time. One generic and two specific synonyms are established together with five new combinations. Keys are provided to the genera and species, for both sexes.
- Full Text:
- Date Issued: 1993
The taxonomie status of Apogon enigmaticus Smith, 1961 (Teleostei, Apogonidae)
- Authors: Gon, Ofer
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447304 , vital:74603 , https://www.ajol.info/index.php/az/article/view/154224
- Description: The validity of the cardinal fish species Apogon enigmaticus, described by Smith (1961) from a single specimen, is reassessed in view of a recent discovery of a second specimen of this species, collected by Smith, in the JLB Smith Institute of Ichthyology. Both fish were re-identified as specimens of A. apogonides (Bleeker, 1856) on the basis of dentition, pigmentation, and counts of pectoral-fin rays, gill rakers and predorsal scales. A. enigmaticas is therefore regarded as a junior synonym of A. apogonides.
- Full Text:
- Date Issued: 1993
- Authors: Gon, Ofer
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447304 , vital:74603 , https://www.ajol.info/index.php/az/article/view/154224
- Description: The validity of the cardinal fish species Apogon enigmaticus, described by Smith (1961) from a single specimen, is reassessed in view of a recent discovery of a second specimen of this species, collected by Smith, in the JLB Smith Institute of Ichthyology. Both fish were re-identified as specimens of A. apogonides (Bleeker, 1856) on the basis of dentition, pigmentation, and counts of pectoral-fin rays, gill rakers and predorsal scales. A. enigmaticas is therefore regarded as a junior synonym of A. apogonides.
- Full Text:
- Date Issued: 1993
The thermodynamics of solutions and binary liquid mixtures
- Authors: Mercer-Chalmers, June Dawn
- Date: 1993
- Subjects: Thermodynamics Liquids Solution (Chemistry)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4390 , http://hdl.handle.net/10962/d1005055
- Description: The thesis is presented in two parts. In part one, the excess thermodynamic properties have been determined for several binary liquid mixtures, with the aim of testing theories of liquid mixtures. The excess molar enthalpies, Hem, have been determined using an LKB flow microcalorimeter, and the excess molar volumes, Vem, have been determined using an Anton Paar densitometer. The HemS and VemS have been measured at 298.15 K for binary systems involving an alkanol (methanol, ethanol, I-propanol, 2-propanol) mixed with a hydrocarbon (l-hexene, I-heptene, l-octene, I-hexyne, I-heptyne, l-octyne, toluene, mesitylene, 0-, m-, or p-xylene, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane). The results show trends relating to the degree of unsaturation, or size, of component molecules as well as the position of the hydroxyl group on the alkanol. Measurements were also made on mixtures involving an (n-alkane + a pseudo-n-alkane) and ( a cYcloalkane + a pseudo-cycloalkane). Two theories of liquid mixtures were tested in this work. The first theory tested was the theory of Congruency. This theory was tested, by means of a null test, on a novel set of mixtures involving an n-alkane (hexane, heptane, octane, decane, dodecane) + a pseudo-nalkane,and mixtures of a cycloalkane (cyclopentane, cyclohexane, cycloheptane, cyclooctane)+ a pseudo-cycloalkane. Deviations from the theory was less than the experimental error for the (n-alkane + pseudo-n-alkane) mixtures. However, significant deviations were observed for the mixtures of (a cycloalkane + a pseudo-cycloalkane). The second theory tested was the Flory theory, which has been used to predict the excess molar enthalpies and excess molar volumes for the mixtures involving (a 1-alkene, or 1-alkyne, or methyl-substituted benzene) + an alkanol. The results show that the theory does not hold for hydrocarbon mixtures involving an alkanol. In the second part of this thesis, the partial molar volumes, at infinite dilution, of binary solution involving a solid solute (18-crown-6 ether, dibenzo-18-crown-6 ether, dicyclohexanov 18-crown-6 ether, 15-crown-5 ether, or cryptand-222) are determined in various solvents. The results were repeated with a view to determine the volume changes at infinite dilution upon complexation, ΔV∞ of the crown ether or cryptand with a metal halide salt, MX (NaCl, NaI, KCl, KI, CsCl, CsI). The ΔV∞ results were compared with results in the literature for cryptand-222 (c-222) and dibenzo-18-crown-6 ether (B₂CE6) complexed with MX, and the study was extended to include further MX complexes with c-222 and B₂CE6, as well as MX complexes with 15-crown-5 ether and dicyclohexano-18-crown-6 ether. ΔV∞ results were correlated with the Hepler prediction of the electrostriction solvent effect.
- Full Text:
- Date Issued: 1993
- Authors: Mercer-Chalmers, June Dawn
- Date: 1993
- Subjects: Thermodynamics Liquids Solution (Chemistry)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4390 , http://hdl.handle.net/10962/d1005055
- Description: The thesis is presented in two parts. In part one, the excess thermodynamic properties have been determined for several binary liquid mixtures, with the aim of testing theories of liquid mixtures. The excess molar enthalpies, Hem, have been determined using an LKB flow microcalorimeter, and the excess molar volumes, Vem, have been determined using an Anton Paar densitometer. The HemS and VemS have been measured at 298.15 K for binary systems involving an alkanol (methanol, ethanol, I-propanol, 2-propanol) mixed with a hydrocarbon (l-hexene, I-heptene, l-octene, I-hexyne, I-heptyne, l-octyne, toluene, mesitylene, 0-, m-, or p-xylene, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane). The results show trends relating to the degree of unsaturation, or size, of component molecules as well as the position of the hydroxyl group on the alkanol. Measurements were also made on mixtures involving an (n-alkane + a pseudo-n-alkane) and ( a cYcloalkane + a pseudo-cycloalkane). Two theories of liquid mixtures were tested in this work. The first theory tested was the theory of Congruency. This theory was tested, by means of a null test, on a novel set of mixtures involving an n-alkane (hexane, heptane, octane, decane, dodecane) + a pseudo-nalkane,and mixtures of a cycloalkane (cyclopentane, cyclohexane, cycloheptane, cyclooctane)+ a pseudo-cycloalkane. Deviations from the theory was less than the experimental error for the (n-alkane + pseudo-n-alkane) mixtures. However, significant deviations were observed for the mixtures of (a cycloalkane + a pseudo-cycloalkane). The second theory tested was the Flory theory, which has been used to predict the excess molar enthalpies and excess molar volumes for the mixtures involving (a 1-alkene, or 1-alkyne, or methyl-substituted benzene) + an alkanol. The results show that the theory does not hold for hydrocarbon mixtures involving an alkanol. In the second part of this thesis, the partial molar volumes, at infinite dilution, of binary solution involving a solid solute (18-crown-6 ether, dibenzo-18-crown-6 ether, dicyclohexanov 18-crown-6 ether, 15-crown-5 ether, or cryptand-222) are determined in various solvents. The results were repeated with a view to determine the volume changes at infinite dilution upon complexation, ΔV∞ of the crown ether or cryptand with a metal halide salt, MX (NaCl, NaI, KCl, KI, CsCl, CsI). The ΔV∞ results were compared with results in the literature for cryptand-222 (c-222) and dibenzo-18-crown-6 ether (B₂CE6) complexed with MX, and the study was extended to include further MX complexes with c-222 and B₂CE6, as well as MX complexes with 15-crown-5 ether and dicyclohexano-18-crown-6 ether. ΔV∞ results were correlated with the Hepler prediction of the electrostriction solvent effect.
- Full Text:
- Date Issued: 1993
The ultrastructure and computer-enhanced digital image analysis of plasmodesmata at the Kranz mesophyll-bundle sheath interface of Themeda triandra var. imberbis (Retz) A. Camus in conventionally-fixed leaf blades
- Botha, Christiaan E J, Hartley, B J, Cross, Robin H M
- Authors: Botha, Christiaan E J , Hartley, B J , Cross, Robin H M
- Date: 1993
- Language: English
- Type: Article
- Identifier: vital:6502 , http://hdl.handle.net/10962/d1005925
- Description: The ultrastructure of the plasmodesmata at the Kranz mesophyll-bundle sheath (KMS-BS) interface in Themeda triandra, and the substructures within the plasmodesmata were investigated, using conventionally fixed leaf-blade material, enhanced by the addition of 0.1% tannic acid to the primary fixative. Examination of high-resolution electronmicrographs, and computer-enhanced digital images suggests that these plasmodesmata are complex structures, comprised of helically-arranged particulate material. The electron-dense particles are between 2.5 and 3.0nm in diameter. These particles are specifically associated with the inner face of the inner plasmalemma membrane leaflet, and the outer region of the desmotubule wall. The electron-dense particles are presumably proteinaceous and embedded in a lipid matrix. In the constricted median portion of the KMS-BS plasmodesmata, the space between the desmotubule and the inner plasmalemma membrane leaflet and areas surrounding the proteinaceous particles thereof (the cytoplasmic sleeve) is about 3nm in cross-section, and constitutes what we believe to be the space through which intercellular transport takes place.
- Full Text: false
- Date Issued: 1993
- Authors: Botha, Christiaan E J , Hartley, B J , Cross, Robin H M
- Date: 1993
- Language: English
- Type: Article
- Identifier: vital:6502 , http://hdl.handle.net/10962/d1005925
- Description: The ultrastructure of the plasmodesmata at the Kranz mesophyll-bundle sheath (KMS-BS) interface in Themeda triandra, and the substructures within the plasmodesmata were investigated, using conventionally fixed leaf-blade material, enhanced by the addition of 0.1% tannic acid to the primary fixative. Examination of high-resolution electronmicrographs, and computer-enhanced digital images suggests that these plasmodesmata are complex structures, comprised of helically-arranged particulate material. The electron-dense particles are between 2.5 and 3.0nm in diameter. These particles are specifically associated with the inner face of the inner plasmalemma membrane leaflet, and the outer region of the desmotubule wall. The electron-dense particles are presumably proteinaceous and embedded in a lipid matrix. In the constricted median portion of the KMS-BS plasmodesmata, the space between the desmotubule and the inner plasmalemma membrane leaflet and areas surrounding the proteinaceous particles thereof (the cytoplasmic sleeve) is about 3nm in cross-section, and constitutes what we believe to be the space through which intercellular transport takes place.
- Full Text: false
- Date Issued: 1993
The use of the local environment for teaching geography : a case study in the Umtata administrative area
- Authors: Adonis, Agrinette Nolwandle
- Date: 1993
- Subjects: Geography -- Fieldwork -- Study and teaching Geography -- South Africa -- Study and teaching (Secondary) Black people -- Education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1816 , http://hdl.handle.net/10962/d1003702
- Description: Current theories in geographical education advocate the use of strategies that encourage the pupil to play an active role in learning, thereby making such learning more meaningful and effective. Fieldwork is perceived as one such method. Fieldwork helps pupils acquire and develop understanding of geographical concepts, skills, attitudes and values through their own efforts and involvement. Fieldwork approaches have tended to change with the changing paradigms resulting in the development of approaches that are more pupil and experience oriented. In the South African school geography curricula fieldwork has been explicit since 1985. However, research has shown that in most South African secondary schools fieldwork as a teaching strategy is only applied to a limited extent. Teachers have always used financial constraints and time limitations as explanations for their failure to use fieldwork in teaching geography. This study attempts to demonstrate how the local environment of any school can be used effectively for teaching and learning most aspects of the senior secondary school geography syllabus, thereby alleviating the problems of time and money perceived by teachers as the major constraints inhibiting their use of fieldwork. In order to illustrate the effectiveness of fieldwork in the local environment, this study incorporated an analysis of the current senior secondary school geography syllabus, the identification of potential fieldwork sites in the Umtata District and the development and implementation of three fieldwork units based on three of the sites identified. The analysis of the evaluations of the three fieldwork units by the researcher, the pupils and the non-participant observer revealed that fieldwork conducted in the local environment is highly effective, interesting and rewarding to pupils even when they have no prior experience of fieldwork.
- Full Text:
- Date Issued: 1993
- Authors: Adonis, Agrinette Nolwandle
- Date: 1993
- Subjects: Geography -- Fieldwork -- Study and teaching Geography -- South Africa -- Study and teaching (Secondary) Black people -- Education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1816 , http://hdl.handle.net/10962/d1003702
- Description: Current theories in geographical education advocate the use of strategies that encourage the pupil to play an active role in learning, thereby making such learning more meaningful and effective. Fieldwork is perceived as one such method. Fieldwork helps pupils acquire and develop understanding of geographical concepts, skills, attitudes and values through their own efforts and involvement. Fieldwork approaches have tended to change with the changing paradigms resulting in the development of approaches that are more pupil and experience oriented. In the South African school geography curricula fieldwork has been explicit since 1985. However, research has shown that in most South African secondary schools fieldwork as a teaching strategy is only applied to a limited extent. Teachers have always used financial constraints and time limitations as explanations for their failure to use fieldwork in teaching geography. This study attempts to demonstrate how the local environment of any school can be used effectively for teaching and learning most aspects of the senior secondary school geography syllabus, thereby alleviating the problems of time and money perceived by teachers as the major constraints inhibiting their use of fieldwork. In order to illustrate the effectiveness of fieldwork in the local environment, this study incorporated an analysis of the current senior secondary school geography syllabus, the identification of potential fieldwork sites in the Umtata District and the development and implementation of three fieldwork units based on three of the sites identified. The analysis of the evaluations of the three fieldwork units by the researcher, the pupils and the non-participant observer revealed that fieldwork conducted in the local environment is highly effective, interesting and rewarding to pupils even when they have no prior experience of fieldwork.
- Full Text:
- Date Issued: 1993
The work of the Reverend James Cameron of the Wesleyan Methodist Missionary Society from 1829 to 1835
- Authors: Van Heerden, Gary Paul
- Date: 1993
- Subjects: Cameron, James, 1800-1875 Wesleyan Methodist Missionary Society Methodist Church of Southern Africa -- History
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1245 , http://hdl.handle.net/10962/d1009726
- Description: The name James Cameron is not a familiar one. Despite being one of the missionary pioneers of Methodism in southern Africa, serving for more than forty-six years in various districts and being elected as chairman of two of these districts, very few people have ever heard of James Cameron. Barnabas Shaw says of Cameron that he "excelled in preaching the great truths of the gospel, and applying them to the heart of sinners".¹ Whiteside describes Cameron as a "remarkable man ... well read in most things".² W.B. Boyce pays Cameron an even greater tribute: In my day, as a preacher and as a theologian, he was unequalled in South Africa; and I do not think that he was second in these respects to any of his brethren in England.³ Notwithstanding the high esteem in which he was held by prominent peers, Cameron is mentioned only in passing in a few secondary sources, and to date has not been the subject of academic research. The reason for this is not clear. He was well educated, read and wrote extensively, and most of his correspondence has been preserved. Cameron's Journal is very well written, containing some beautiful poetic sections. It is a personal record of a missionary coping with peculiar and difficult circumstances, and a record of how determination, courage and faith enabled Cameron to overcome seemingly insurmountable difficulties. Cameron's recording of his struggles help fill out our understanding of missionaries and their tasks and problems in the nineteenth century. I believe that so important a figure in South African Methodism should be examined and deserves a definitive study. The aim of this thesis has been to provide a reference to his work in the western Cape, possibly to form a basis for closer historical scrutiny. ¹ Shaw 1840:232 ² Whiteside 1906:374 ³ Boyce 1874:179-80.
- Full Text:
- Date Issued: 1993
- Authors: Van Heerden, Gary Paul
- Date: 1993
- Subjects: Cameron, James, 1800-1875 Wesleyan Methodist Missionary Society Methodist Church of Southern Africa -- History
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1245 , http://hdl.handle.net/10962/d1009726
- Description: The name James Cameron is not a familiar one. Despite being one of the missionary pioneers of Methodism in southern Africa, serving for more than forty-six years in various districts and being elected as chairman of two of these districts, very few people have ever heard of James Cameron. Barnabas Shaw says of Cameron that he "excelled in preaching the great truths of the gospel, and applying them to the heart of sinners".¹ Whiteside describes Cameron as a "remarkable man ... well read in most things".² W.B. Boyce pays Cameron an even greater tribute: In my day, as a preacher and as a theologian, he was unequalled in South Africa; and I do not think that he was second in these respects to any of his brethren in England.³ Notwithstanding the high esteem in which he was held by prominent peers, Cameron is mentioned only in passing in a few secondary sources, and to date has not been the subject of academic research. The reason for this is not clear. He was well educated, read and wrote extensively, and most of his correspondence has been preserved. Cameron's Journal is very well written, containing some beautiful poetic sections. It is a personal record of a missionary coping with peculiar and difficult circumstances, and a record of how determination, courage and faith enabled Cameron to overcome seemingly insurmountable difficulties. Cameron's recording of his struggles help fill out our understanding of missionaries and their tasks and problems in the nineteenth century. I believe that so important a figure in South African Methodism should be examined and deserves a definitive study. The aim of this thesis has been to provide a reference to his work in the western Cape, possibly to form a basis for closer historical scrutiny. ¹ Shaw 1840:232 ² Whiteside 1906:374 ³ Boyce 1874:179-80.
- Full Text:
- Date Issued: 1993
Thermal decomposition of mixed metal oxalates
- Authors: Coetzee, Anita
- Date: 1993
- Subjects: Oxalates -- Research , Decomposition (Chemistry)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4388 , http://hdl.handle.net/10962/d1005053 , Oxalates -- Research , Decomposition (Chemistry)
- Description: The mixed metal oxalates, FeCu(ox)₂.3H₂0, CoCu(ox)₂.3H₂0, and NiCu(ox)₂.3.5H₂0, [ox = C₂0₄] have been prepared by coprecipitation from solution. The thermal behaviour of these compounds in nitrogen and in oxygen has been examined using thermogravimetry (TG), thermomagnetometry (TM), differential scanning calorimetry (DSC) and evolved gas analysis (EGA), and results are compared with results obtained for Cuox and Mox.yH₂0. The thermal behaviour of the mixed oxalates, MCU(OX)₂.xH₂0, differed from that of the individual metal oxalates, Cuox, Coox.2H₂0, Niox.2H₂0 and Feox.2H₂0. All three mixed oxalates on heating in N₂, first dehydrate and then decompose in at least two overlapping endothermic stages. Both CO and CO₂ were evolved in proportions which varied with the surrounding atmosphere, and from compound to compound, and with extent of reaction of a given compound. The mixed oxalates, MCU(OX)₂.xH₂0, do not show the exothermic behaviour characteristic of Cuox, and reasons for this are discussed. Thermochemical calculations were done and the enthalpies of formation of the hydrates and dehydrated oxalates were determined. It was found that the enthalpy of mixing was very small or within experimental error. X-ray powder diffraction patterns for the individual and mixed oxalates were compared. The pattern for Cuox differs from the patterns obtained for the other oxalates, confirming suggestions that Cuox has a structure different to most other transition metal oxalates. The kinetics of dehydration and decomposition of the mixed oxalates were investigated, using isothermal and programmed temperature TG and DSC experiments. The yield and composition of evolved gases during isothermal decomposition were measured and compared with the enthalpy changes. X-ray photoelectron spectroscopy studies provided some information on the electron environment of the metal atoms in the various oxalates.
- Full Text:
- Date Issued: 1993
- Authors: Coetzee, Anita
- Date: 1993
- Subjects: Oxalates -- Research , Decomposition (Chemistry)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4388 , http://hdl.handle.net/10962/d1005053 , Oxalates -- Research , Decomposition (Chemistry)
- Description: The mixed metal oxalates, FeCu(ox)₂.3H₂0, CoCu(ox)₂.3H₂0, and NiCu(ox)₂.3.5H₂0, [ox = C₂0₄] have been prepared by coprecipitation from solution. The thermal behaviour of these compounds in nitrogen and in oxygen has been examined using thermogravimetry (TG), thermomagnetometry (TM), differential scanning calorimetry (DSC) and evolved gas analysis (EGA), and results are compared with results obtained for Cuox and Mox.yH₂0. The thermal behaviour of the mixed oxalates, MCU(OX)₂.xH₂0, differed from that of the individual metal oxalates, Cuox, Coox.2H₂0, Niox.2H₂0 and Feox.2H₂0. All three mixed oxalates on heating in N₂, first dehydrate and then decompose in at least two overlapping endothermic stages. Both CO and CO₂ were evolved in proportions which varied with the surrounding atmosphere, and from compound to compound, and with extent of reaction of a given compound. The mixed oxalates, MCU(OX)₂.xH₂0, do not show the exothermic behaviour characteristic of Cuox, and reasons for this are discussed. Thermochemical calculations were done and the enthalpies of formation of the hydrates and dehydrated oxalates were determined. It was found that the enthalpy of mixing was very small or within experimental error. X-ray powder diffraction patterns for the individual and mixed oxalates were compared. The pattern for Cuox differs from the patterns obtained for the other oxalates, confirming suggestions that Cuox has a structure different to most other transition metal oxalates. The kinetics of dehydration and decomposition of the mixed oxalates were investigated, using isothermal and programmed temperature TG and DSC experiments. The yield and composition of evolved gases during isothermal decomposition were measured and compared with the enthalpy changes. X-ray photoelectron spectroscopy studies provided some information on the electron environment of the metal atoms in the various oxalates.
- Full Text:
- Date Issued: 1993