The role of values in educational leadership: an interpretive study
- Authors: Drake, Melanie Lee
- Date: 2008
- Subjects: Educational leadership -- South Africa Leadership -- South Africa Values -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1756 , http://hdl.handle.net/10962/d1003640
- Description: This study set out to investigate the role of values in educational leadership. The renewed interest in values in both educational and corporate environments in South Africa places new pressures on members in leadership positions especially in school life. Schools are described as the ‘nurseries’ of values. The understanding of the abstract nature of values, as well as instrumentalising and implementing values in vision statements and organisational life, poses challenges to present and future school leaders. This study, based in the interpretive paradigm, is an in-depth investigation into the role of values at a former model C primary school in the Eastern Cape. Through the use of observations, document analysis, focus groups and interviews as data collection tools, this research highlights the importance of values in school leadership and how this impacts the life of the school leader. This case-study research combines theoretical and contextual frameworks to question the nature of values in leadership and uses the real-life experiences of these school leaders to resonate with current understandings of values in leadership and organisational culture. The importance of understanding these complexities in the lives and experiences of these school leaders cannot be underestimated. My findings highlight the tensions between leading successful schools (task/person efficiency) and remaining congruent with the need for leadership for social justice in post-apartheid educational institutions. The uniqueness of the school environment (‘families’ and ‘communities’) is also featured and resonates with previous literature. Through the lens of emerging leadership trends, we discover these school leaders’ understandings of values in their daily lives: they do what they are and this is reflected in this school’s unique organisational culture, which could be said to ‘transcend’ present leaders’ influence. Finally I propose that further research is necessary in order to broaden our understanding of the unique role of values in educational leadership in South Africa.
- Full Text:
- Date Issued: 2008
- Authors: Drake, Melanie Lee
- Date: 2008
- Subjects: Educational leadership -- South Africa Leadership -- South Africa Values -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1756 , http://hdl.handle.net/10962/d1003640
- Description: This study set out to investigate the role of values in educational leadership. The renewed interest in values in both educational and corporate environments in South Africa places new pressures on members in leadership positions especially in school life. Schools are described as the ‘nurseries’ of values. The understanding of the abstract nature of values, as well as instrumentalising and implementing values in vision statements and organisational life, poses challenges to present and future school leaders. This study, based in the interpretive paradigm, is an in-depth investigation into the role of values at a former model C primary school in the Eastern Cape. Through the use of observations, document analysis, focus groups and interviews as data collection tools, this research highlights the importance of values in school leadership and how this impacts the life of the school leader. This case-study research combines theoretical and contextual frameworks to question the nature of values in leadership and uses the real-life experiences of these school leaders to resonate with current understandings of values in leadership and organisational culture. The importance of understanding these complexities in the lives and experiences of these school leaders cannot be underestimated. My findings highlight the tensions between leading successful schools (task/person efficiency) and remaining congruent with the need for leadership for social justice in post-apartheid educational institutions. The uniqueness of the school environment (‘families’ and ‘communities’) is also featured and resonates with previous literature. Through the lens of emerging leadership trends, we discover these school leaders’ understandings of values in their daily lives: they do what they are and this is reflected in this school’s unique organisational culture, which could be said to ‘transcend’ present leaders’ influence. Finally I propose that further research is necessary in order to broaden our understanding of the unique role of values in educational leadership in South Africa.
- Full Text:
- Date Issued: 2008
The Sacred Door and other Stories: Cameroon Folktales of the Beba (Makuchi)
- Authors: Kaschula, Russell H
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175177 , vital:42550 , https://doi.org/10.17159/2309-9070/tvl.v.45i2.4743
- Description: In The Sacred Door and Other Stories: Cameroon Folktales of the Beba, Makuchi has collected thirty-three folktales of the Beba people. These stories are presented in English only. The book contains a foreword by well-known oral literature scholar, Isidore Okpewho and a preface by the author. In the foreword, Okpewho states that:“Tales like these need to be retold again and again, because the lessons they yield belong not merely to a long-forgotten historical or so-called primitive past but very much to the present times in which we live”(xi). The book therefore represents a sense of continuity between past and present. Although the tales may no longer be told in the same way that they were many years ago, the messages contained in the tales remain as relevant today as they did in the past.
- Full Text:
- Date Issued: 2008
- Authors: Kaschula, Russell H
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175177 , vital:42550 , https://doi.org/10.17159/2309-9070/tvl.v.45i2.4743
- Description: In The Sacred Door and Other Stories: Cameroon Folktales of the Beba, Makuchi has collected thirty-three folktales of the Beba people. These stories are presented in English only. The book contains a foreword by well-known oral literature scholar, Isidore Okpewho and a preface by the author. In the foreword, Okpewho states that:“Tales like these need to be retold again and again, because the lessons they yield belong not merely to a long-forgotten historical or so-called primitive past but very much to the present times in which we live”(xi). The book therefore represents a sense of continuity between past and present. Although the tales may no longer be told in the same way that they were many years ago, the messages contained in the tales remain as relevant today as they did in the past.
- Full Text:
- Date Issued: 2008
The separation of platinum and gold from an industrial feed solution
- Authors: Louw, Talana
- Date: 2008
- Subjects: Platinum -- Separation , Gold , Separation -- Technology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10400 , http://hdl.handle.net/10948/731 , Platinum -- Separation , Gold , Separation -- Technology
- Description: In this thesis, the aim was to develop resins which are platinum and gold specific to be utilized for the early removal of these metals from the industrial feed. Efforts were therefore directed towards the synthesis of silica based resins with active centra which were designed for platinum and gold specificity respectively. The large chlorometallate ions in the feed stream were characterized in terms of physical parameters relevant to phase distribution namely distortability (RD), charge density, softness (σ) etc. Matching cations for each of the types were investigated. In order to attempt the design of platinum specific resins different structural amines were used to aminate the silicone precursor and subsequently to fix these onto the silica framework. Two different solvents i.e. alcohol and dmf were used for this process, resulting in two sets of resins with different properties. For gold specific resins, various polyethers were attached to a different type of silicone precursor, which was attached to the silica framework. The design was based on previous experience with these ions with reference to their behaviour towards different types of cations. The platinum species PtCl6 2- and PtCl4 2-, the gold species AuCl4 -, as well as the most important contaminants in the feed stream were typified bearing in mind size, charge, charge density and distortability. Different types of cationic centra having differences in charge density, stereochemical crowding and extent of hydrophobicity were synthesized and tested both as solvent extractants (where possible) and silica based resins. The results indicated that partly screened secondary ammonium cationic resin species, which could be regarded as “intermediate”, proved to be satisfactory both in their high percentage extraction for PtCl4 2- and rejection of contaminants like chlororhodates, chloroiridates(III) and FeCl4 -. It was, however, necessary to work at a redox potential where iridium(IV) in the form of IrCl6 2- is absent. Various 2-aminoalkane resins were prepared with variation in the length of alkane group and synthesized in the two different solvents. The latter resulted in two sets of resins with different compactness also having significantly different properties with reference to platinum specificity, HCl effect and stripping potential. The 2- aminobutane and 2-aminoheptane resins both proved to be very satisfactory platinum specific resins with respect to selectivity, platinum capacity and stripping potential. The various physical parameters could be utilized to accommodate the chemical behaviour. To obtain gold specific resins, experiments were performed with resins having oxygen-donor atoms which can readily be protonated to form onium type cations for example amides and ether oxygen atoms. In the case of the latter, various polyethers with a different number of ether groups (polyether groups linked by ethylene and propylene groups) and variations of hydrophobicity (by substitution) have also been studied. Linked to the polyether groups were alkane and aryl groups. Those having 8 to 10 ether groups and aromatic tail ends proved to be moderately successful in terms of gold capacity and sharp breakthrough curves of their columns, however, platinum could not be very effectively rejected.
- Full Text:
- Date Issued: 2008
- Authors: Louw, Talana
- Date: 2008
- Subjects: Platinum -- Separation , Gold , Separation -- Technology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10400 , http://hdl.handle.net/10948/731 , Platinum -- Separation , Gold , Separation -- Technology
- Description: In this thesis, the aim was to develop resins which are platinum and gold specific to be utilized for the early removal of these metals from the industrial feed. Efforts were therefore directed towards the synthesis of silica based resins with active centra which were designed for platinum and gold specificity respectively. The large chlorometallate ions in the feed stream were characterized in terms of physical parameters relevant to phase distribution namely distortability (RD), charge density, softness (σ) etc. Matching cations for each of the types were investigated. In order to attempt the design of platinum specific resins different structural amines were used to aminate the silicone precursor and subsequently to fix these onto the silica framework. Two different solvents i.e. alcohol and dmf were used for this process, resulting in two sets of resins with different properties. For gold specific resins, various polyethers were attached to a different type of silicone precursor, which was attached to the silica framework. The design was based on previous experience with these ions with reference to their behaviour towards different types of cations. The platinum species PtCl6 2- and PtCl4 2-, the gold species AuCl4 -, as well as the most important contaminants in the feed stream were typified bearing in mind size, charge, charge density and distortability. Different types of cationic centra having differences in charge density, stereochemical crowding and extent of hydrophobicity were synthesized and tested both as solvent extractants (where possible) and silica based resins. The results indicated that partly screened secondary ammonium cationic resin species, which could be regarded as “intermediate”, proved to be satisfactory both in their high percentage extraction for PtCl4 2- and rejection of contaminants like chlororhodates, chloroiridates(III) and FeCl4 -. It was, however, necessary to work at a redox potential where iridium(IV) in the form of IrCl6 2- is absent. Various 2-aminoalkane resins were prepared with variation in the length of alkane group and synthesized in the two different solvents. The latter resulted in two sets of resins with different compactness also having significantly different properties with reference to platinum specificity, HCl effect and stripping potential. The 2- aminobutane and 2-aminoheptane resins both proved to be very satisfactory platinum specific resins with respect to selectivity, platinum capacity and stripping potential. The various physical parameters could be utilized to accommodate the chemical behaviour. To obtain gold specific resins, experiments were performed with resins having oxygen-donor atoms which can readily be protonated to form onium type cations for example amides and ether oxygen atoms. In the case of the latter, various polyethers with a different number of ether groups (polyether groups linked by ethylene and propylene groups) and variations of hydrophobicity (by substitution) have also been studied. Linked to the polyether groups were alkane and aryl groups. Those having 8 to 10 ether groups and aromatic tail ends proved to be moderately successful in terms of gold capacity and sharp breakthrough curves of their columns, however, platinum could not be very effectively rejected.
- Full Text:
- Date Issued: 2008
The snake family Psammophiidae (Reptilia: Serpentes): phylogenetics and species delimitation in the African sand snakes (Psammophis Boie, 1825) and allied genera
- Kelly, Christopher M R, Barker, Nigel P, Villet, Martin H, Broadley, Donald G, Branch, William R
- Authors: Kelly, Christopher M R , Barker, Nigel P , Villet, Martin H , Broadley, Donald G , Branch, William R
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6522 , http://hdl.handle.net/10962/d1005953
- Description: This study constitutes the first evolutionary investigation of the snake family Psammophiidae—the most widespread, most clearly defined, yet perhaps the taxonomically most problematic of Africa's familylevel snake lineages. Little is known of psammophiid evolutionary relationships, and the type genus Psammophis is one of the largest and taxonomically most complex of the African snake genera. Our aims were to reconstruct psammophiid phylogenetic relationships and to improve characterisation of species boundaries in problematic Psammophis species complexes. We used approximately 2500 bases of DNA sequence from the mitochondrial and nuclear genomes, and 114 terminals covering all psammophiid genera and incorporating approximately 75% of recognised species and subspecies. Phylogenetic reconstructions were conducted primarily in a Bayesian framework and we used the Wiens/Penkrot protocol to aid species delimitation. Rhamphiophis is diphyletic, with Rhamphiophis acutus emerging sister to Psammophylax. Consequently we transfer the three subspecies of Rhamphiophis acutus to the genus Psammophylax. The monotypic genus Dipsina is sister to Psammophis. The two species of Dromophis occupy divergent positions deeply nested within Psammophis, and we therefore relegate Dromophis to the synonymy of Psammophis. Our results allow division of the taxonomically problematic Psammophis 'sibilans' species complex into two monophyletic entities, provisionally named the 'phillipsii' and 'subtaeniatus' complexes. Within these two clades we found support for the status of many existing species, but not for a distinction between P.p. phillipsii and P. mossambicus. Additionally, P. cf. phillipsii occidentalis deserves species status as the sister taxon of P. brevirostris.
- Full Text:
- Date Issued: 2008
- Authors: Kelly, Christopher M R , Barker, Nigel P , Villet, Martin H , Broadley, Donald G , Branch, William R
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6522 , http://hdl.handle.net/10962/d1005953
- Description: This study constitutes the first evolutionary investigation of the snake family Psammophiidae—the most widespread, most clearly defined, yet perhaps the taxonomically most problematic of Africa's familylevel snake lineages. Little is known of psammophiid evolutionary relationships, and the type genus Psammophis is one of the largest and taxonomically most complex of the African snake genera. Our aims were to reconstruct psammophiid phylogenetic relationships and to improve characterisation of species boundaries in problematic Psammophis species complexes. We used approximately 2500 bases of DNA sequence from the mitochondrial and nuclear genomes, and 114 terminals covering all psammophiid genera and incorporating approximately 75% of recognised species and subspecies. Phylogenetic reconstructions were conducted primarily in a Bayesian framework and we used the Wiens/Penkrot protocol to aid species delimitation. Rhamphiophis is diphyletic, with Rhamphiophis acutus emerging sister to Psammophylax. Consequently we transfer the three subspecies of Rhamphiophis acutus to the genus Psammophylax. The monotypic genus Dipsina is sister to Psammophis. The two species of Dromophis occupy divergent positions deeply nested within Psammophis, and we therefore relegate Dromophis to the synonymy of Psammophis. Our results allow division of the taxonomically problematic Psammophis 'sibilans' species complex into two monophyletic entities, provisionally named the 'phillipsii' and 'subtaeniatus' complexes. Within these two clades we found support for the status of many existing species, but not for a distinction between P.p. phillipsii and P. mossambicus. Additionally, P. cf. phillipsii occidentalis deserves species status as the sister taxon of P. brevirostris.
- Full Text:
- Date Issued: 2008
The solvent-free approach versus the use of ionic liquids in the synthesis of ferrocenes
- Authors: Elago, Elago R T
- Date: 2008
- Subjects: Ferrocene , Inorganic compounds -- Synthesis , Ionic solutions , Solvents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10396 , http://hdl.handle.net/10948/853 , Ferrocene , Inorganic compounds -- Synthesis , Ionic solutions , Solvents
- Description: The philosophy of green chemistry has seen much development in the past decade. The use of environmentally benign solvents is amongst the areas of green chemistry that have received the most attention. In this context, imidazolium ionic liquids have been widely reported to offer high product yields, fast reaction rates, excellent selectivity and generally mild working conditions, when used as reaction media. In addition, concerns about costs of solvents and the long-term environmental impact that can potentially result when solvents are discarded after their use have led to focused investigations into solvent-free procedures, as reported in recent literature. We have set out to explore the extent to which these advantages could be realized within our research. Non-volatile, non-flammable imidazolium ionic liquids [bmim][I], [bmim][BF4] and [bmim][PF6] were used as green solvents in ferrocene chemistry. Ferrocenoate esters were synthesised efficiently by the respective DCC/DMAP-promoted reactions of ferrocenecarboxylic acid and substituted benzoic acids or, alternatively, the DMAP-promoted reactions of ferrocenoyl fluoride with a range of substituted phenols in [bmim][BF4] and [bmim][PF6]. High yields and short reaction times were achieved. In addition, the ionic liquid was reused several times without a reduction in product yields. Under solvent-free conditions, DCC/DMAP-promoted reactions provided high yields within 3 min of reaction. The possible rearrangement of one of the intermediates in these reactions was modelled theoretically using density function theory (DFT) at the B3LYP/6-31G* level of approximation. Catalyst-free esterification was achieved by the application of microwave radiation to the reaction of ferrocenoyl fluoride and a range of substituted phenols. All the reactions were complete after 1 min of irradiation and products were isolated in high yield. DPAT, HfCl4, Sc(OTf)3 and Al(OTf)3 were screened as catalysts for esterification in [bmim][BF4] and under solvent-free conditions at various temperatures. All attempts at esterification of ferrocenecarboxylic acid with alcohols and phenols were unsuccessful. The Suzuki cross-coupling reaction was carried out in [bmim][BF4]. The isolated yields are, however, poor and suffer from poor reproducibility with different batches of [bmim][BF4] used.
- Full Text:
- Date Issued: 2008
- Authors: Elago, Elago R T
- Date: 2008
- Subjects: Ferrocene , Inorganic compounds -- Synthesis , Ionic solutions , Solvents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10396 , http://hdl.handle.net/10948/853 , Ferrocene , Inorganic compounds -- Synthesis , Ionic solutions , Solvents
- Description: The philosophy of green chemistry has seen much development in the past decade. The use of environmentally benign solvents is amongst the areas of green chemistry that have received the most attention. In this context, imidazolium ionic liquids have been widely reported to offer high product yields, fast reaction rates, excellent selectivity and generally mild working conditions, when used as reaction media. In addition, concerns about costs of solvents and the long-term environmental impact that can potentially result when solvents are discarded after their use have led to focused investigations into solvent-free procedures, as reported in recent literature. We have set out to explore the extent to which these advantages could be realized within our research. Non-volatile, non-flammable imidazolium ionic liquids [bmim][I], [bmim][BF4] and [bmim][PF6] were used as green solvents in ferrocene chemistry. Ferrocenoate esters were synthesised efficiently by the respective DCC/DMAP-promoted reactions of ferrocenecarboxylic acid and substituted benzoic acids or, alternatively, the DMAP-promoted reactions of ferrocenoyl fluoride with a range of substituted phenols in [bmim][BF4] and [bmim][PF6]. High yields and short reaction times were achieved. In addition, the ionic liquid was reused several times without a reduction in product yields. Under solvent-free conditions, DCC/DMAP-promoted reactions provided high yields within 3 min of reaction. The possible rearrangement of one of the intermediates in these reactions was modelled theoretically using density function theory (DFT) at the B3LYP/6-31G* level of approximation. Catalyst-free esterification was achieved by the application of microwave radiation to the reaction of ferrocenoyl fluoride and a range of substituted phenols. All the reactions were complete after 1 min of irradiation and products were isolated in high yield. DPAT, HfCl4, Sc(OTf)3 and Al(OTf)3 were screened as catalysts for esterification in [bmim][BF4] and under solvent-free conditions at various temperatures. All attempts at esterification of ferrocenecarboxylic acid with alcohols and phenols were unsuccessful. The Suzuki cross-coupling reaction was carried out in [bmim][BF4]. The isolated yields are, however, poor and suffer from poor reproducibility with different batches of [bmim][BF4] used.
- Full Text:
- Date Issued: 2008
The Southern African Development Community's attraction to foreign direct investment
- Authors: Botha, Richard Kruger
- Date: 2008
- Subjects: Southern African Development Community , Africa, Southern -- Foreign economic relations , Africa, Southern -- Economic integration , Africa, Southern -- Economic conditions
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8716 , http://hdl.handle.net/10948/926 , Southern African Development Community , Africa, Southern -- Foreign economic relations , Africa, Southern -- Economic integration , Africa, Southern -- Economic conditions
- Description: In order to assess the question as to whether the Southern African Development Community in principle attracts foreign direct investment, literature and data have been cited that compared the economic profiles and relative privatisation programs of member states of the Southern African Development Community with relative high inflows of foreign direct investment with the economic profiles and relative privatisation programs of member states with relative low inflows of foreign direct investment. Qualitative research has been conducted, and the author is of opinion that generally the member states with relative high foreign direct investment inflows had economic profiles and relative privatisation programs that encouraged foreign direct investment, and member states with relative low foreign direct investment inflows had economic profiles and relative privatisation programs that deterred foreign direct investment inflows. From the above the author has inferred that the Southern African Development Community in principle attracted foreign direct investment, but not to its full potential. The reason may be that although the member states’ economic profiles are favourable for foreign direct investment, their economic growths tend to fluctuate, and the future economic profiles are therefore unpredictable. With the above in mind this mini-treatise aims to address the question as to what steps the governments of the Southern African Development Community’s member states could follow in order to attract foreign direct investment. iii The author is of opinion that the member states should endeavour to maintain an annual average economic growth rate, and that the governments continue to engage into privatisation programs in order to encourage foreign direct investment.
- Full Text:
- Date Issued: 2008
- Authors: Botha, Richard Kruger
- Date: 2008
- Subjects: Southern African Development Community , Africa, Southern -- Foreign economic relations , Africa, Southern -- Economic integration , Africa, Southern -- Economic conditions
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8716 , http://hdl.handle.net/10948/926 , Southern African Development Community , Africa, Southern -- Foreign economic relations , Africa, Southern -- Economic integration , Africa, Southern -- Economic conditions
- Description: In order to assess the question as to whether the Southern African Development Community in principle attracts foreign direct investment, literature and data have been cited that compared the economic profiles and relative privatisation programs of member states of the Southern African Development Community with relative high inflows of foreign direct investment with the economic profiles and relative privatisation programs of member states with relative low inflows of foreign direct investment. Qualitative research has been conducted, and the author is of opinion that generally the member states with relative high foreign direct investment inflows had economic profiles and relative privatisation programs that encouraged foreign direct investment, and member states with relative low foreign direct investment inflows had economic profiles and relative privatisation programs that deterred foreign direct investment inflows. From the above the author has inferred that the Southern African Development Community in principle attracted foreign direct investment, but not to its full potential. The reason may be that although the member states’ economic profiles are favourable for foreign direct investment, their economic growths tend to fluctuate, and the future economic profiles are therefore unpredictable. With the above in mind this mini-treatise aims to address the question as to what steps the governments of the Southern African Development Community’s member states could follow in order to attract foreign direct investment. iii The author is of opinion that the member states should endeavour to maintain an annual average economic growth rate, and that the governments continue to engage into privatisation programs in order to encourage foreign direct investment.
- Full Text:
- Date Issued: 2008
The status and prognosis of the smoothhound shark (mustelus mustelus) fishery in the Southeastern and Southwestern Cape coasts, South Africa
- Authors: Da Silva, Charlene
- Date: 2008
- Subjects: Osteichthyes -- South Africa Mustelus -- South Africa Sharks -- South Africa Fishery management -- South Africa Fisheries -- South Africa Chondrichthyes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5200 , http://hdl.handle.net/10962/d1003287
- Description: Global trends in commercially valuable teleost fisheries point to substantial deterioration in population size, offering limited potential for increased harvests. Consequently a shift in focus towards alternative fisheries has increased fishing effort towards targeting chondrichthyans as a possible solution to meet global demands. The life-history traits of chondrichthyans make them poor candidates for resolving economic and nutritional security as these make them particularly vulnerable to anthromorphic influences. Current fisheries management approaches based on centralized government intervention have proved inadequate. This failure of current management approaches is often linked with poor co-operation by industry with government when collecting fishery-dependent data. As management decisions are based on quantitative estimates from fishery assessment modes data collected are often of poor quality. Co-management with its implied power-sharing arrangement between government and fishing communities has been proposed as a more realistic alternative. The motivation within industry to collect high quality data can only be created with a feeling of ownership. The decline in linefish species in South Africa has led to increased exploitation of demersal sharks such as Mustelus mustelus. Their status as one of the target and by-catch species of South Africa's shark fisheries necessitated resource assessment. Age, growth, maturity and mortality calculations for M mustelus were made from data collected from 1983-2006. The maximum observed age for M mustelus was 25 years. Estimated von Bertalanffy growth parameters from observed length-at-age for combined sexes, females and males were L∞ = 1946.16 mm TL, K = 0.08 year⁻' , to = -3.63 year⁻'; L∞ = 2202.21mm, K = 0.05 year⁻', to = 4.67 years; and L∞ = 1713.19 mm TL, K = 0.08 year⁻' and to = -4.36 years, respectively. Instantaneous total mortality (Z) was estimated at 0.16 y⁻', whilst natural mortality (M) for M mustelus was estimated at 0.05 y⁻'. The age and length at 50% maturity was determined for combined sexes, females and males at 1216 mm TL corresponding to an age of 9.93 years, 1234 mm (TL) and 10.75 years, and 1106 mm TL and 9.1 years respectively. The smoothhound shark resource off the south-eastern and south-western Cape coast was assessed by three dynamic pool models; yield per recruit, spawner biomass per recruit and an extended yield and spawner biomass per recruit. Due to the longevity of elasmobranches the per-recruit model was extended over a 20 year time-frame to simulate resource responses to management options. Fo.1 was estimated as 0.034 year⁻' and F MAX was estimated as 0.045 year⁻'. FsB50 was estimated as 0.031. The extended per-recruit model tested the outcome of different management scenarios, Size and effort control showed the least probability of pristine biomass falling below 20% of current levels in 20 years (where selectivity was set at 3 years). The replacement yield model showed that the average catches over the past decade are 2.5 times higher than the replacement yield is on the South Coast and 1.30 on the West Coast. A more realistic level optimising yield would be at 0.05 with a selection pattern at 3 years, where the probability of the biomass falling to below 20% of pristine pre-exploited levels in twenty years becomes negligible. A comparison of the models showed that current catches need to be halved for exploitation of smoothhound sharks to be sustainable. The results of this study indicate a need for a management intervention for M mustelus in South Africa with regards to potential overexploitation and collection of quality data for further assessments. A demersal identification key was developed as part of this study, which should aid monitoring officials in accurately identifying shark logs for collecting data. This study showed how adopting a management plan with the inclusion of comanagement concepts would improve the quality of data collected and increase monitoring of fishing activities. The inclusion of co-management is possible due to the unique bottle neck created by few demersal shark processing facilities actively exporting shark. A fishery management plan was compiled proposing several management options including size and effort controls.
- Full Text:
- Date Issued: 2008
- Authors: Da Silva, Charlene
- Date: 2008
- Subjects: Osteichthyes -- South Africa Mustelus -- South Africa Sharks -- South Africa Fishery management -- South Africa Fisheries -- South Africa Chondrichthyes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5200 , http://hdl.handle.net/10962/d1003287
- Description: Global trends in commercially valuable teleost fisheries point to substantial deterioration in population size, offering limited potential for increased harvests. Consequently a shift in focus towards alternative fisheries has increased fishing effort towards targeting chondrichthyans as a possible solution to meet global demands. The life-history traits of chondrichthyans make them poor candidates for resolving economic and nutritional security as these make them particularly vulnerable to anthromorphic influences. Current fisheries management approaches based on centralized government intervention have proved inadequate. This failure of current management approaches is often linked with poor co-operation by industry with government when collecting fishery-dependent data. As management decisions are based on quantitative estimates from fishery assessment modes data collected are often of poor quality. Co-management with its implied power-sharing arrangement between government and fishing communities has been proposed as a more realistic alternative. The motivation within industry to collect high quality data can only be created with a feeling of ownership. The decline in linefish species in South Africa has led to increased exploitation of demersal sharks such as Mustelus mustelus. Their status as one of the target and by-catch species of South Africa's shark fisheries necessitated resource assessment. Age, growth, maturity and mortality calculations for M mustelus were made from data collected from 1983-2006. The maximum observed age for M mustelus was 25 years. Estimated von Bertalanffy growth parameters from observed length-at-age for combined sexes, females and males were L∞ = 1946.16 mm TL, K = 0.08 year⁻' , to = -3.63 year⁻'; L∞ = 2202.21mm, K = 0.05 year⁻', to = 4.67 years; and L∞ = 1713.19 mm TL, K = 0.08 year⁻' and to = -4.36 years, respectively. Instantaneous total mortality (Z) was estimated at 0.16 y⁻', whilst natural mortality (M) for M mustelus was estimated at 0.05 y⁻'. The age and length at 50% maturity was determined for combined sexes, females and males at 1216 mm TL corresponding to an age of 9.93 years, 1234 mm (TL) and 10.75 years, and 1106 mm TL and 9.1 years respectively. The smoothhound shark resource off the south-eastern and south-western Cape coast was assessed by three dynamic pool models; yield per recruit, spawner biomass per recruit and an extended yield and spawner biomass per recruit. Due to the longevity of elasmobranches the per-recruit model was extended over a 20 year time-frame to simulate resource responses to management options. Fo.1 was estimated as 0.034 year⁻' and F MAX was estimated as 0.045 year⁻'. FsB50 was estimated as 0.031. The extended per-recruit model tested the outcome of different management scenarios, Size and effort control showed the least probability of pristine biomass falling below 20% of current levels in 20 years (where selectivity was set at 3 years). The replacement yield model showed that the average catches over the past decade are 2.5 times higher than the replacement yield is on the South Coast and 1.30 on the West Coast. A more realistic level optimising yield would be at 0.05 with a selection pattern at 3 years, where the probability of the biomass falling to below 20% of pristine pre-exploited levels in twenty years becomes negligible. A comparison of the models showed that current catches need to be halved for exploitation of smoothhound sharks to be sustainable. The results of this study indicate a need for a management intervention for M mustelus in South Africa with regards to potential overexploitation and collection of quality data for further assessments. A demersal identification key was developed as part of this study, which should aid monitoring officials in accurately identifying shark logs for collecting data. This study showed how adopting a management plan with the inclusion of comanagement concepts would improve the quality of data collected and increase monitoring of fishing activities. The inclusion of co-management is possible due to the unique bottle neck created by few demersal shark processing facilities actively exporting shark. A fishery management plan was compiled proposing several management options including size and effort controls.
- Full Text:
- Date Issued: 2008
The synthesis and electrochemical behaviour of water soluble manganese phthalocyanines: Anion radical versus Mn(I) species
- Sehlotho, Nthapo, Durmuş, Mahmut, Ahsen, N, Nyokong, Tebello
- Authors: Sehlotho, Nthapo , Durmuş, Mahmut , Ahsen, N , Nyokong, Tebello
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6596 , http://hdl.handle.net/10962/d1004345
- Description: The following MnPc derivatives were synthesized: 1,(4)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (5a), quaternized 1,(4)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (5b), 2,(3)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (6a) and quaternized 2,(3)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH)(6b). Spectro-electrochemistry shows that the reduction of Mn(II)Pc to Mn(I)Pc occurs only when the complexes are in their quaternized form (5b and 6b). The reduction (to Mn(I)Pc(−2)) of the quaternized form occurs at a lower potential than that (to Mn(II)Pc(−3)) of the unquaternized form. This observation suggests that metal reduction (to Mn(I)Pc(−2)) versus ligand reduction (to Mn(II)Pc(−3)) in Mn(II)Pc complexes depends on the nature of the ring substituents.
- Full Text:
- Date Issued: 2008
- Authors: Sehlotho, Nthapo , Durmuş, Mahmut , Ahsen, N , Nyokong, Tebello
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6596 , http://hdl.handle.net/10962/d1004345
- Description: The following MnPc derivatives were synthesized: 1,(4)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (5a), quaternized 1,(4)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (5b), 2,(3)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH) (6a) and quaternized 2,(3)-tetra-(2-mercaptopyridine) phthalocyaninato manganese(III)(OH)(6b). Spectro-electrochemistry shows that the reduction of Mn(II)Pc to Mn(I)Pc occurs only when the complexes are in their quaternized form (5b and 6b). The reduction (to Mn(I)Pc(−2)) of the quaternized form occurs at a lower potential than that (to Mn(II)Pc(−3)) of the unquaternized form. This observation suggests that metal reduction (to Mn(I)Pc(−2)) versus ligand reduction (to Mn(II)Pc(−3)) in Mn(II)Pc complexes depends on the nature of the ring substituents.
- Full Text:
- Date Issued: 2008
The tax implications of a private equity buy-out : a case study of the Brait-Shoprite buy-out
- Authors: Mawire, Patrick N
- Date: 2008
- Subjects: South African Revenue Service , Consolidation and merger of corporations -- Finance , Taxation -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8959 , http://hdl.handle.net/10948/803 , South African Revenue Service , Consolidation and merger of corporations -- Finance , Taxation -- Law and legislation -- South Africa
- Description: This treatise examines the history of private equity as a context in which to understand its role in the economy and specifically, the background for the high profile leveraged buy-outs that have been entered into in the past year. The treatise then focuses specifically on the Brait-Shoprite buy-out, examining its structure and the tax implications. The treatise then reviews the reaction of the South African Revenue Authority (“SARS”) to the buy-out and evaluates whether it was the best approach that could have been taken under the circumstances. As a result of the research, the following conclusions have been reached: Private equity transactions Private equity transactions have a role to play in the business world despite the apprehensions of tax authorities. The perception that these transactions are tax driven as part of an avoidance scheme is not justified. Structure of the Shoprite buy-out transaction: The Shoprite buy-out transaction was structured to obtain deduction for interest. The transaction was also structured to utilise the relief provisions of Part II of Chapter II (Special Provisions Relating to Companies) of the Income Tax Act no.58 of 1962, as amended (“the Act”). The relief was for capital gains tax (“CGT”) on disposal of the Shoprite assets. Finally, the transaction was designed to allow the existing shareholders to exit their investments free of Secondary Tax on Companies (“STC”). The reaction of SARS to the Shoprite buy-out transaction Whereas SARS may have been justified in questioning the structure and its impact on fiscal revenue, the response in the form of withdrawing STC relief from amalgamation transactions in section 44 was not in the best interest of a stable tax system and the majority of tax payers who are not misusing or abusing loopholes in the income tax legislation. It may have been possible for SARS to attack the structure based on the General Anti-Avoidance Rule (GAAR) in part IIA of the Chapter III of the Act.
- Full Text:
- Date Issued: 2008
- Authors: Mawire, Patrick N
- Date: 2008
- Subjects: South African Revenue Service , Consolidation and merger of corporations -- Finance , Taxation -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8959 , http://hdl.handle.net/10948/803 , South African Revenue Service , Consolidation and merger of corporations -- Finance , Taxation -- Law and legislation -- South Africa
- Description: This treatise examines the history of private equity as a context in which to understand its role in the economy and specifically, the background for the high profile leveraged buy-outs that have been entered into in the past year. The treatise then focuses specifically on the Brait-Shoprite buy-out, examining its structure and the tax implications. The treatise then reviews the reaction of the South African Revenue Authority (“SARS”) to the buy-out and evaluates whether it was the best approach that could have been taken under the circumstances. As a result of the research, the following conclusions have been reached: Private equity transactions Private equity transactions have a role to play in the business world despite the apprehensions of tax authorities. The perception that these transactions are tax driven as part of an avoidance scheme is not justified. Structure of the Shoprite buy-out transaction: The Shoprite buy-out transaction was structured to obtain deduction for interest. The transaction was also structured to utilise the relief provisions of Part II of Chapter II (Special Provisions Relating to Companies) of the Income Tax Act no.58 of 1962, as amended (“the Act”). The relief was for capital gains tax (“CGT”) on disposal of the Shoprite assets. Finally, the transaction was designed to allow the existing shareholders to exit their investments free of Secondary Tax on Companies (“STC”). The reaction of SARS to the Shoprite buy-out transaction Whereas SARS may have been justified in questioning the structure and its impact on fiscal revenue, the response in the form of withdrawing STC relief from amalgamation transactions in section 44 was not in the best interest of a stable tax system and the majority of tax payers who are not misusing or abusing loopholes in the income tax legislation. It may have been possible for SARS to attack the structure based on the General Anti-Avoidance Rule (GAAR) in part IIA of the Chapter III of the Act.
- Full Text:
- Date Issued: 2008
The tax implications of non-resident sportspersons performing and earning an income in South Africa
- Authors: Wessels, Jacques
- Date: 2008
- Subjects: South African Revenue Service , Sports -- Taxation -- Law and legislation -- South Africa , Taxation -- Law and legislation -- South Africa , Income tax -- Law and legislation -- South Africa , Income tax -- Foreign income , Income tax -- South Africa -- Foreign income , Withholding tax -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:893 , http://hdl.handle.net/10962/d1003719 , South African Revenue Service , Sports -- Taxation -- Law and legislation -- South Africa , Taxation -- Law and legislation -- South Africa , Income tax -- Law and legislation -- South Africa , Income tax -- Foreign income , Income tax -- South Africa -- Foreign income , Withholding tax -- Law and legislation -- South Africa
- Description: As the number of non-resident sports persons competing in South Africa increases so does the need to tax them more effectively. It was for this reason that the South African legislature decided to insert Part IlIA into the Income Tax Act which regulates the taxation of non-resident sports persons in South Africa. The new tax on foreign sports persons, which came into effect during August 2006, is a withholding tax placing the onus upon the organizer of the event to withhold the tax portion of the payment to the non-resident sportsperson and pay it over to the revenue services. The rate of taxation has been set at 15 percent on all amounts received by or accruing to a foreign sportsperson. The question which the research addressed is whether this new tax will prove to be an effective tax, both from the point of view of its equity and the administration of the tax. In order to determine the impact of the new tax, it was compared to similar taxes implemented in the United Kingdom and Australia and also to other withholding taxes levied in South Africa. The new tax was also measured against a theoretical model for effectiveness, compared to the pre-August 2006 situation and to the taxation of resident sportsmen and women, using hypothetical examples. The major shortcomings of the new withholding tax are the uncertainty with regard to the intention of the legislature on matters such as the taxation of capital income versus revenue income, the question whether payments to support staff are included in the ambit of the new tax, the taxation of the award of assets in lieu of cash payments and the definition of a resident. A further area of concern is that the rate of taxation of 15 percent appears to be too low and creates horizontal inequity between the taxation of resident and non-resident sports persons. The new tax on non-resident sports persons may have its shortcomings but, depending upon the administrative and support structures put in place to deal with it, will be an effective tax. The rate at which the tax is levied could result in a less tax being collected than before but, with the reduced administrative cost of tax collection, the effective/statutory ratio of the tax could well be much higher than it was. This is a new tax in South Africa and certain initial problems are inevitable and will undoubtedly be solved as the administrators gain experience and as the case law governing this tax develops. , KMBT_363
- Full Text:
- Date Issued: 2008
- Authors: Wessels, Jacques
- Date: 2008
- Subjects: South African Revenue Service , Sports -- Taxation -- Law and legislation -- South Africa , Taxation -- Law and legislation -- South Africa , Income tax -- Law and legislation -- South Africa , Income tax -- Foreign income , Income tax -- South Africa -- Foreign income , Withholding tax -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:893 , http://hdl.handle.net/10962/d1003719 , South African Revenue Service , Sports -- Taxation -- Law and legislation -- South Africa , Taxation -- Law and legislation -- South Africa , Income tax -- Law and legislation -- South Africa , Income tax -- Foreign income , Income tax -- South Africa -- Foreign income , Withholding tax -- Law and legislation -- South Africa
- Description: As the number of non-resident sports persons competing in South Africa increases so does the need to tax them more effectively. It was for this reason that the South African legislature decided to insert Part IlIA into the Income Tax Act which regulates the taxation of non-resident sports persons in South Africa. The new tax on foreign sports persons, which came into effect during August 2006, is a withholding tax placing the onus upon the organizer of the event to withhold the tax portion of the payment to the non-resident sportsperson and pay it over to the revenue services. The rate of taxation has been set at 15 percent on all amounts received by or accruing to a foreign sportsperson. The question which the research addressed is whether this new tax will prove to be an effective tax, both from the point of view of its equity and the administration of the tax. In order to determine the impact of the new tax, it was compared to similar taxes implemented in the United Kingdom and Australia and also to other withholding taxes levied in South Africa. The new tax was also measured against a theoretical model for effectiveness, compared to the pre-August 2006 situation and to the taxation of resident sportsmen and women, using hypothetical examples. The major shortcomings of the new withholding tax are the uncertainty with regard to the intention of the legislature on matters such as the taxation of capital income versus revenue income, the question whether payments to support staff are included in the ambit of the new tax, the taxation of the award of assets in lieu of cash payments and the definition of a resident. A further area of concern is that the rate of taxation of 15 percent appears to be too low and creates horizontal inequity between the taxation of resident and non-resident sports persons. The new tax on non-resident sports persons may have its shortcomings but, depending upon the administrative and support structures put in place to deal with it, will be an effective tax. The rate at which the tax is levied could result in a less tax being collected than before but, with the reduced administrative cost of tax collection, the effective/statutory ratio of the tax could well be much higher than it was. This is a new tax in South Africa and certain initial problems are inevitable and will undoubtedly be solved as the administrators gain experience and as the case law governing this tax develops. , KMBT_363
- Full Text:
- Date Issued: 2008
The trajectory, dynamics, determinants and nature of institutional change in post-1994 South African higher education
- Authors: Badat, Saleem
- Date: 2008
- Language: English
- Type: Conference paper , text
- Identifier: vital:7120 , http://hdl.handle.net/10962/d1006568
- Description: Introduction: The institutional change agenda in post-1994 South African higher education has been extensive in its objects, ambitious in its goals, and far-reaching in nature. Given its scope, it is not possible here to critically analyse change in all its dimensions or in all arenas. Instead, this paper confines itself to analysing the trajectory, dynamics, outcomes and determinants of institutional change in South African higher education since 1994, and concludes with observations on the nature of change. , Higher Education Close Up 4 : University of Cape Town, Breakwater Conference Centre, 26-28 June 2008
- Full Text:
- Date Issued: 2008
- Authors: Badat, Saleem
- Date: 2008
- Language: English
- Type: Conference paper , text
- Identifier: vital:7120 , http://hdl.handle.net/10962/d1006568
- Description: Introduction: The institutional change agenda in post-1994 South African higher education has been extensive in its objects, ambitious in its goals, and far-reaching in nature. Given its scope, it is not possible here to critically analyse change in all its dimensions or in all arenas. Instead, this paper confines itself to analysing the trajectory, dynamics, outcomes and determinants of institutional change in South African higher education since 1994, and concludes with observations on the nature of change. , Higher Education Close Up 4 : University of Cape Town, Breakwater Conference Centre, 26-28 June 2008
- Full Text:
- Date Issued: 2008
The tuba in solo and ensemble repertory : a critical perspective
- Authors: Bower, Danel
- Date: 2008
- Subjects: Tuba -- Performance , Tuba -- History and criticism
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:8515 , http://hdl.handle.net/10948/759 , http://hdl.handle.net/10948/d1012064 , Tuba -- Performance , Tuba -- History and criticism
- Description: The topic of this research is to explore various aspects pertaining to the tuba and its role in music. The role of the tuba in modern performance practice is greatly dependent on the history of the tuba and the different roles that were fulfilled in the various eras. The study begins with an investigation into the most important predecessors of the tuba – the most prominent thereof being the ophicleide. The next field of study includes the role of the tuba in orchestras in different countries as well as the role that the tuba fulfills in various ensembles. There is a wide variety of brass instruments that were manufactured in the past and are still being produced today. Various improvements and adaptations of the tuba are listed and studied. Next the tuba is considered in its capacity as a solo instrument and the fact that the tuba can exist as a solo instrument is motivated. Even though it might not be evident that there are a large number of composers for this instrument, some of the most respected and influential composers of tuba music of all time are sighted in this study. Several famous and celebrated tuba players are mentioned and their accomplishments listed. Finally the three practical music examination institutions in South Africa are studied. Lists are compiled to assess the quality of the different examination options between these institutions and provide a suggestion of a preferred option.
- Full Text:
- Date Issued: 2008
- Authors: Bower, Danel
- Date: 2008
- Subjects: Tuba -- Performance , Tuba -- History and criticism
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:8515 , http://hdl.handle.net/10948/759 , http://hdl.handle.net/10948/d1012064 , Tuba -- Performance , Tuba -- History and criticism
- Description: The topic of this research is to explore various aspects pertaining to the tuba and its role in music. The role of the tuba in modern performance practice is greatly dependent on the history of the tuba and the different roles that were fulfilled in the various eras. The study begins with an investigation into the most important predecessors of the tuba – the most prominent thereof being the ophicleide. The next field of study includes the role of the tuba in orchestras in different countries as well as the role that the tuba fulfills in various ensembles. There is a wide variety of brass instruments that were manufactured in the past and are still being produced today. Various improvements and adaptations of the tuba are listed and studied. Next the tuba is considered in its capacity as a solo instrument and the fact that the tuba can exist as a solo instrument is motivated. Even though it might not be evident that there are a large number of composers for this instrument, some of the most respected and influential composers of tuba music of all time are sighted in this study. Several famous and celebrated tuba players are mentioned and their accomplishments listed. Finally the three practical music examination institutions in South Africa are studied. Lists are compiled to assess the quality of the different examination options between these institutions and provide a suggestion of a preferred option.
- Full Text:
- Date Issued: 2008
The underreporting of sexual violence against women in the Camdeboo
- Authors: Luyt, Derek
- Date: 2008
- Subjects: Women -- Violence against -- South Africa -- Camdeboo, Plains of Abused women -- South Africa -- Camdeboo, Plains of Sexual abuse victims -- South Africa -- Camdeboo, Plains of Camdeboo, Plains of (South Africa)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2796 , http://hdl.handle.net/10962/d1003006
- Description: This thesis examines the underreporting of sexual violence against women in the Camdeboo. It is based on a survey of 971 women living in the Camdeboo aged fifteen and older. The thesis considers, with reference to relevant secondary literature, methodological issues pertinent to conducting survey research into violence against women. While many survey researchers into violence against women argue that behaviourally specific questions lead to higher rates of disclosure, the survey on which this thesis is based employed complex and open-ended questions to allow respondents to record their own definitions of physical and sexual abuse. 31,2 percent of the women surveyed disclosed having experienced sexual abuse, but 76,7 percent did not report this abuse to the police. The thesis explores the patterns of sexual abuse of women in the Camdeboo and the factors influencing the underreporting of such abuse. While it was possible to establish correlations between certain socio-demographic variables and the underreporting of sexual abuse, such correlations should be treated with caution. The survey found that women were far more likely to report (and disclose) sexual assaults by strangers than by people known to them, particularly intimate partners. Sexual abuse in intimate relations was found to be strongly associated with physical abuse, and women who had experienced sexual and physical abuse within intimate relationships were more likely to report their physical abuse to the police than their sexual abuse. However, the majority of women, particularly poor and economically dependent women, believed that reporting their intimate partner abuse to the police would not end it, and might even place them at greater risk. The evidence suggests that these perceptions are accurate. Under current circumstances, reporting sexual abuse to the police may not be the best help-seeking strategy available to many sexually abused women, and alternative sources of help may be more appropriate. Consideration should be given to directing more resources into such alternatives.
- Full Text:
- Date Issued: 2008
- Authors: Luyt, Derek
- Date: 2008
- Subjects: Women -- Violence against -- South Africa -- Camdeboo, Plains of Abused women -- South Africa -- Camdeboo, Plains of Sexual abuse victims -- South Africa -- Camdeboo, Plains of Camdeboo, Plains of (South Africa)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2796 , http://hdl.handle.net/10962/d1003006
- Description: This thesis examines the underreporting of sexual violence against women in the Camdeboo. It is based on a survey of 971 women living in the Camdeboo aged fifteen and older. The thesis considers, with reference to relevant secondary literature, methodological issues pertinent to conducting survey research into violence against women. While many survey researchers into violence against women argue that behaviourally specific questions lead to higher rates of disclosure, the survey on which this thesis is based employed complex and open-ended questions to allow respondents to record their own definitions of physical and sexual abuse. 31,2 percent of the women surveyed disclosed having experienced sexual abuse, but 76,7 percent did not report this abuse to the police. The thesis explores the patterns of sexual abuse of women in the Camdeboo and the factors influencing the underreporting of such abuse. While it was possible to establish correlations between certain socio-demographic variables and the underreporting of sexual abuse, such correlations should be treated with caution. The survey found that women were far more likely to report (and disclose) sexual assaults by strangers than by people known to them, particularly intimate partners. Sexual abuse in intimate relations was found to be strongly associated with physical abuse, and women who had experienced sexual and physical abuse within intimate relationships were more likely to report their physical abuse to the police than their sexual abuse. However, the majority of women, particularly poor and economically dependent women, believed that reporting their intimate partner abuse to the police would not end it, and might even place them at greater risk. The evidence suggests that these perceptions are accurate. Under current circumstances, reporting sexual abuse to the police may not be the best help-seeking strategy available to many sexually abused women, and alternative sources of help may be more appropriate. Consideration should be given to directing more resources into such alternatives.
- Full Text:
- Date Issued: 2008
The use of mobile commerce to improve the services of life insurance post sale activities
- Authors: Afrifa, Rexford
- Date: 2008
- Subjects: Mobile commerce -- South Africa , Mobile computing -- South Africa , Mobile communication systems -- South Africa , Personal communication service systems -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8718 , http://hdl.handle.net/10948/913 , Mobile commerce -- South Africa , Mobile computing -- South Africa , Mobile communication systems -- South Africa , Personal communication service systems -- South Africa
- Description: Mobile commerce, due to its inherent characteristics of mobility and reachability in enhancing personalized services provides an excellent means for life insurers to exploit such avenue in their service offerings. The objective of this study was to determine whether mobile commerce can be used to improve the services of life insurance post-sale activities. This objective was achieved with the relevant literature and empirical study. To accomplish the objective of this treatise, a triangulated research approach was selected and a multiple-case study consisting of four cases was conducted. The four cases selected comprised of leading insurers with large market share in the life insurance market in South-Africa. The primary data were collected through questionnaire and face-to-face interviews with selected respondents. The main finding shows that the respondents had a positive view about mobile commerce and its application in their companies. This was demonstrated by 80 percent of respondents who agreed that mobile commerce was more of an opportunity rather than a challenge or even a threat for the life insurance market. The results also indicate that customer relationship management, mobile messaging services and field service automation functions were used by all the insurers; although minor discrepancies were observed due to the efficiency of each firms IT infrastructure. The Internet was found to assist in the collection of more precise data, to increase service performing abilities. Some of the major obstacles that were found to hinder the deployment of mobile commerce in the industry were security concerns, low and infrequent internet usage and performance by supporting industries. Cumbersome and inefficient legacy systems were declared as the greatest technological weakness particularly by respondents from case 1 and 2. Conversely, hardware and network infrastructure, lack of software packages, lack of technical expertise and the fear of disintermediation was rated low in hindering the deployment of mobile commerce. However, according to the findings the key benefits derived from engaging in increased mobile commerce activities include enhancing customer contact and service, more transparency and speed of claims management, increasing client retention and policy extension rates hence increasing overall company profit.
- Full Text:
- Date Issued: 2008
- Authors: Afrifa, Rexford
- Date: 2008
- Subjects: Mobile commerce -- South Africa , Mobile computing -- South Africa , Mobile communication systems -- South Africa , Personal communication service systems -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8718 , http://hdl.handle.net/10948/913 , Mobile commerce -- South Africa , Mobile computing -- South Africa , Mobile communication systems -- South Africa , Personal communication service systems -- South Africa
- Description: Mobile commerce, due to its inherent characteristics of mobility and reachability in enhancing personalized services provides an excellent means for life insurers to exploit such avenue in their service offerings. The objective of this study was to determine whether mobile commerce can be used to improve the services of life insurance post-sale activities. This objective was achieved with the relevant literature and empirical study. To accomplish the objective of this treatise, a triangulated research approach was selected and a multiple-case study consisting of four cases was conducted. The four cases selected comprised of leading insurers with large market share in the life insurance market in South-Africa. The primary data were collected through questionnaire and face-to-face interviews with selected respondents. The main finding shows that the respondents had a positive view about mobile commerce and its application in their companies. This was demonstrated by 80 percent of respondents who agreed that mobile commerce was more of an opportunity rather than a challenge or even a threat for the life insurance market. The results also indicate that customer relationship management, mobile messaging services and field service automation functions were used by all the insurers; although minor discrepancies were observed due to the efficiency of each firms IT infrastructure. The Internet was found to assist in the collection of more precise data, to increase service performing abilities. Some of the major obstacles that were found to hinder the deployment of mobile commerce in the industry were security concerns, low and infrequent internet usage and performance by supporting industries. Cumbersome and inefficient legacy systems were declared as the greatest technological weakness particularly by respondents from case 1 and 2. Conversely, hardware and network infrastructure, lack of software packages, lack of technical expertise and the fear of disintermediation was rated low in hindering the deployment of mobile commerce. However, according to the findings the key benefits derived from engaging in increased mobile commerce activities include enhancing customer contact and service, more transparency and speed of claims management, increasing client retention and policy extension rates hence increasing overall company profit.
- Full Text:
- Date Issued: 2008
The value of the middleman in the supply chain of South African tyre production
- Authors: Cornelius, André G
- Date: 2008
- Subjects: Tires -- Industrialists -- South Africa Tire Industry -- South Africa Commercial agents -- South Africa Business logistics -- Management -- South Africa Physical distribution of goods -- Management Commercial agents -- South Africa Marketing channels -- Management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:770 , http://hdl.handle.net/10962/d1003891
- Description: Only a few middlemen linking chemical intermediate product supply to world tyre productions have managed to survive new direct business models. In fact, the only region, where the practice of using a middleman in the supply chain of tyre production, for a certain primary manufacturer, is in South Africa. Tyre producers in other world regions, similar in market complexity to South Africa, have experienced the elimination of the middleman. Hence the question of this research, why is the middleman in the supply chain of tyre production in South Africa still a better option than that of direct business models? To begin with, the thesis stated that the middleman in the supply chain of South African tyre producers delivers better value than that of the direct business model. To prove/disprove this thesis, the principle that value is a trade-off between what you get for what you give was the basis of this research (Zeithaml, 1998). Further, a model was developed, from secondary literature, to conceptualise this trade-off to provide evidence to prove/disprove that the middleman provides greater value than value from the direct business model. From this point, the research approach was to collect data through interviews to find out the most important aspect of value created by the middleman. Data collected were analysed, using the structure of the model as a guide, to find evidence of the trade-off. This analysis provided evidence that the relationship between the middleman and the tyre producers in South Africa and between the middleman and primary product supplier is the value that the direct business model cannot replace.
- Full Text:
- Date Issued: 2008
- Authors: Cornelius, André G
- Date: 2008
- Subjects: Tires -- Industrialists -- South Africa Tire Industry -- South Africa Commercial agents -- South Africa Business logistics -- Management -- South Africa Physical distribution of goods -- Management Commercial agents -- South Africa Marketing channels -- Management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:770 , http://hdl.handle.net/10962/d1003891
- Description: Only a few middlemen linking chemical intermediate product supply to world tyre productions have managed to survive new direct business models. In fact, the only region, where the practice of using a middleman in the supply chain of tyre production, for a certain primary manufacturer, is in South Africa. Tyre producers in other world regions, similar in market complexity to South Africa, have experienced the elimination of the middleman. Hence the question of this research, why is the middleman in the supply chain of tyre production in South Africa still a better option than that of direct business models? To begin with, the thesis stated that the middleman in the supply chain of South African tyre producers delivers better value than that of the direct business model. To prove/disprove this thesis, the principle that value is a trade-off between what you get for what you give was the basis of this research (Zeithaml, 1998). Further, a model was developed, from secondary literature, to conceptualise this trade-off to provide evidence to prove/disprove that the middleman provides greater value than value from the direct business model. From this point, the research approach was to collect data through interviews to find out the most important aspect of value created by the middleman. Data collected were analysed, using the structure of the model as a guide, to find evidence of the trade-off. This analysis provided evidence that the relationship between the middleman and the tyre producers in South Africa and between the middleman and primary product supplier is the value that the direct business model cannot replace.
- Full Text:
- Date Issued: 2008
The variability and predictability of the IRI shape parameters over Grahamstown, South Africa
- Authors: Chimidza, Oyapo
- Date: 2008
- Subjects: Ionosphere -- Mathematical models -- South Africa , Atmosphere, Upper -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5496 , http://hdl.handle.net/10962/d1005282 , Ionosphere -- Mathematical models -- South Africa , Atmosphere, Upper -- South Africa
- Description: The International Reference Ionosphere (IRI) shape parameters B0, B1, and D1 provide a representation of the shape of the F2 layer, the thickness of the F2 layer and the shape of the F1 layer of the ionosphere respectively. The aim of this study was to examine the variability of these parameters using Grahamstown, South Africa (33.3±S, 26.5±E) ionosonde data and determine their predictability by the IRI-2001 model. A further aim of this study was to investigate developing an alternative model for predicting these parameters. These parameters can be determined from electron density profiles that are inverted from ionograms recorded with an ionosonde. Data representing the B0, B1 and D1 parameters, with half hourly or hourly intervals, were scaled and deduced from the digital pulse sounder (DPS) ionosonde for the period April 1996 to December 2006. An analysis of the diurnal, seasonal, and solar variations of the behaviour of these parameters was undertaken for the years 2000, 2004 and 2005 using monthly medians. Comparisons between the observational results and that of the IRI model (IRI 2001 version) indicate that the IRI-2001 model does not accurately represent the diurnal and seasonal variation of the parameters. A preliminary model was thus developed using the technique of Neural Networks (NNs). All available data from the Grahamstown ionosonde from 1996 to 2006 were used in the training of the NNs and the prediction of the variation of the shape parameters. Inputs to the model were the day number, the hour of day, the solar activity and the magnetic index. Comparisons between the preliminary NN model and the IRI-2001 model indicated that the preliminary model was more accurate at the prediction of the parameters than the IRI-2001 model. This analysis showed the need to improve the existing IRI model or develop a new model for the South African region. This thesis describes the results from this feasibility study which show the variability and predictability of the IRI shape parameters.
- Full Text:
- Date Issued: 2008
- Authors: Chimidza, Oyapo
- Date: 2008
- Subjects: Ionosphere -- Mathematical models -- South Africa , Atmosphere, Upper -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5496 , http://hdl.handle.net/10962/d1005282 , Ionosphere -- Mathematical models -- South Africa , Atmosphere, Upper -- South Africa
- Description: The International Reference Ionosphere (IRI) shape parameters B0, B1, and D1 provide a representation of the shape of the F2 layer, the thickness of the F2 layer and the shape of the F1 layer of the ionosphere respectively. The aim of this study was to examine the variability of these parameters using Grahamstown, South Africa (33.3±S, 26.5±E) ionosonde data and determine their predictability by the IRI-2001 model. A further aim of this study was to investigate developing an alternative model for predicting these parameters. These parameters can be determined from electron density profiles that are inverted from ionograms recorded with an ionosonde. Data representing the B0, B1 and D1 parameters, with half hourly or hourly intervals, were scaled and deduced from the digital pulse sounder (DPS) ionosonde for the period April 1996 to December 2006. An analysis of the diurnal, seasonal, and solar variations of the behaviour of these parameters was undertaken for the years 2000, 2004 and 2005 using monthly medians. Comparisons between the observational results and that of the IRI model (IRI 2001 version) indicate that the IRI-2001 model does not accurately represent the diurnal and seasonal variation of the parameters. A preliminary model was thus developed using the technique of Neural Networks (NNs). All available data from the Grahamstown ionosonde from 1996 to 2006 were used in the training of the NNs and the prediction of the variation of the shape parameters. Inputs to the model were the day number, the hour of day, the solar activity and the magnetic index. Comparisons between the preliminary NN model and the IRI-2001 model indicated that the preliminary model was more accurate at the prediction of the parameters than the IRI-2001 model. This analysis showed the need to improve the existing IRI model or develop a new model for the South African region. This thesis describes the results from this feasibility study which show the variability and predictability of the IRI shape parameters.
- Full Text:
- Date Issued: 2008
The very thorough lens Photojournalism: the professionals' approach, Kenneth Kobré: latest books
- Authors: Gess, Harold
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/455086 , vital:75401 , https://hdl.handle.net/10520/EJC140115
- Description: Each edition of Kenneth Kobré's book, Photojournalism: the profes-sionals' approach, has brought his enthusiastic and very thorough lens to bear on the changing terrain of photojournalism.
- Full Text:
- Date Issued: 2008
- Authors: Gess, Harold
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/455086 , vital:75401 , https://hdl.handle.net/10520/EJC140115
- Description: Each edition of Kenneth Kobré's book, Photojournalism: the profes-sionals' approach, has brought his enthusiastic and very thorough lens to bear on the changing terrain of photojournalism.
- Full Text:
- Date Issued: 2008
The WHO UNESCO FIP Pharmacy Education Taskforce: enabling concerted and collective global action
- Anderson, Claire, Bates, Ian, Beck, Diane, Brock, Tina, Futter, William T, Mercer, Hugo, Rouse, Mike, Wuliji, Tana, Yonemura, Akemi
- Authors: Anderson, Claire , Bates, Ian , Beck, Diane , Brock, Tina , Futter, William T , Mercer, Hugo , Rouse, Mike , Wuliji, Tana , Yonemura, Akemi
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6348 , http://hdl.handle.net/10962/d1006029 , http://dx.doi.org/10.1186/1478-4491-7-45
- Description: Pharmacy Education is a priority area for the International Pharmaceutical Federation (FIP), the global federation representing pharmacists and pharmaceutical scientists worldwide that is spearheading the Global Pharmacy Education Taskforce. This paper describes the work of the Taskforce that was established in March 2008, explores key issues in pharmacy education development, and describes the Global Pharmacy Action Plan 2008-2010. Given the significance of pharmacy education to the diverse practice of contemporary pharmacists and pharmacy support personnel, there is a need for pharmacy education to attain greater visibility on the global human resources for health agenda. From this perspective, FIP is steering the development of holistic and comprehensive pharmacy education and pharmacy workforce action to support and strengthen regional, national, and local efforts. The role of a global organization such as FIP is to facilitate, catalyze, and share efforts to maximize pharmacy education development and stimulate international research to develop guidance, tools, and better understanding of key issues. To achieve this goal, FIP has (1) established a formal collaborative partnership with the 2 United Nations agencies representing the education and health sectors, United Nations Educational, Scientific and Cultural Organization (UNESCO) and the World Health Organization (WHO); and (2) established the Global Pharmacy Education Taskforce to serve as the coordinating body of these efforts. The initial effort will serve to leverage strategic leadership and maximize the impact of collective actions at global, regional, and national levels. Three project teams have been convened to conduct research, consultations and develop guidance in the domains of vision for pharmacy education, competency, quality assurance, academic workforce, and institutional capacity.
- Full Text:
- Date Issued: 2008
- Authors: Anderson, Claire , Bates, Ian , Beck, Diane , Brock, Tina , Futter, William T , Mercer, Hugo , Rouse, Mike , Wuliji, Tana , Yonemura, Akemi
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6348 , http://hdl.handle.net/10962/d1006029 , http://dx.doi.org/10.1186/1478-4491-7-45
- Description: Pharmacy Education is a priority area for the International Pharmaceutical Federation (FIP), the global federation representing pharmacists and pharmaceutical scientists worldwide that is spearheading the Global Pharmacy Education Taskforce. This paper describes the work of the Taskforce that was established in March 2008, explores key issues in pharmacy education development, and describes the Global Pharmacy Action Plan 2008-2010. Given the significance of pharmacy education to the diverse practice of contemporary pharmacists and pharmacy support personnel, there is a need for pharmacy education to attain greater visibility on the global human resources for health agenda. From this perspective, FIP is steering the development of holistic and comprehensive pharmacy education and pharmacy workforce action to support and strengthen regional, national, and local efforts. The role of a global organization such as FIP is to facilitate, catalyze, and share efforts to maximize pharmacy education development and stimulate international research to develop guidance, tools, and better understanding of key issues. To achieve this goal, FIP has (1) established a formal collaborative partnership with the 2 United Nations agencies representing the education and health sectors, United Nations Educational, Scientific and Cultural Organization (UNESCO) and the World Health Organization (WHO); and (2) established the Global Pharmacy Education Taskforce to serve as the coordinating body of these efforts. The initial effort will serve to leverage strategic leadership and maximize the impact of collective actions at global, regional, and national levels. Three project teams have been convened to conduct research, consultations and develop guidance in the domains of vision for pharmacy education, competency, quality assurance, academic workforce, and institutional capacity.
- Full Text:
- Date Issued: 2008
The zonation of coastal dune plants in relation to sand burial, resource availability and physiological adaptation
- Authors: Gilbert, Matthew Edmund
- Date: 2008
- Subjects: Sand dune conservation -- South Africa -- Eastern Cape Coastal ecology -- South Africa -- Eastern Cape Botany -- South Africa -- Eastern Cape Coastal biology -- South Africa -- Eastern Cape Littoral plants -- South Africa -- Eastern Cape Littoral plants Sand dune plants -- Ecophysiology Sand dune plants -- Geographical distribution
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4195 , http://hdl.handle.net/10962/d1003764
- Description: When considering the large amount of work done on dune ecology, and that a number of the classical ecological theories originate from work on dunes, it is apparent that there remains a need for physiological and mechanistic explanations of dune plant phenomena. This thesis demonstrated that in the extreme coastal environment dune plants must survive both high rates of burial (disturbance), and low nutrient availability (stress). The ability of four species to respond to these two factors corresponded with their position in a vegetation gradient on the dunes. A low stem tissue density was shown to enhance the potential stem elongation rate of buried plants, but reduced the maximum height to which a plant could grow. Such a tradeoff implies that tall light-competitive plants are able to survive only in stable areas, while burial responsive mobile-dune plants are limited to areas of low vegetation height. This stem tissue density tradeoff was suggested as the mechanism determining the zonation that species show within the dune vegetation gradient present at various sites in South Africa. Finally, detailed investigations of dune plant ecophysiology found that: 1) The resources used in the response to burial derive from external sources of carbon and nitrogen, as well as simple physiological and physical mechanisms of resource allocation. 2) The leaves of dune plants were found to be operating at one extreme of the photosynthetic continuum; viz efficient use of leaf nitrogen at the expense of water loss. 3) Contrary to other ecosystems, the environmental characteristics of dunes may allow plants to occupy a high disturbance, high stress niche, through the maintenance of lowered competition. 4) At least two mobile-dune species form steep dunes, and are able to optimise growth, on steeper dunes, such that they have to grow less in response to burial than plants that form more shallow dunes. In this thesis, it was shown that the link between the carbon and nitrogen economies of dune plants was pivotal in determining species distributions and survival under extreme environmental conditions. As vast areas of the world’s surface are covered by sand dunes these observations are not just of passing interest.
- Full Text:
- Date Issued: 2008
- Authors: Gilbert, Matthew Edmund
- Date: 2008
- Subjects: Sand dune conservation -- South Africa -- Eastern Cape Coastal ecology -- South Africa -- Eastern Cape Botany -- South Africa -- Eastern Cape Coastal biology -- South Africa -- Eastern Cape Littoral plants -- South Africa -- Eastern Cape Littoral plants Sand dune plants -- Ecophysiology Sand dune plants -- Geographical distribution
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4195 , http://hdl.handle.net/10962/d1003764
- Description: When considering the large amount of work done on dune ecology, and that a number of the classical ecological theories originate from work on dunes, it is apparent that there remains a need for physiological and mechanistic explanations of dune plant phenomena. This thesis demonstrated that in the extreme coastal environment dune plants must survive both high rates of burial (disturbance), and low nutrient availability (stress). The ability of four species to respond to these two factors corresponded with their position in a vegetation gradient on the dunes. A low stem tissue density was shown to enhance the potential stem elongation rate of buried plants, but reduced the maximum height to which a plant could grow. Such a tradeoff implies that tall light-competitive plants are able to survive only in stable areas, while burial responsive mobile-dune plants are limited to areas of low vegetation height. This stem tissue density tradeoff was suggested as the mechanism determining the zonation that species show within the dune vegetation gradient present at various sites in South Africa. Finally, detailed investigations of dune plant ecophysiology found that: 1) The resources used in the response to burial derive from external sources of carbon and nitrogen, as well as simple physiological and physical mechanisms of resource allocation. 2) The leaves of dune plants were found to be operating at one extreme of the photosynthetic continuum; viz efficient use of leaf nitrogen at the expense of water loss. 3) Contrary to other ecosystems, the environmental characteristics of dunes may allow plants to occupy a high disturbance, high stress niche, through the maintenance of lowered competition. 4) At least two mobile-dune species form steep dunes, and are able to optimise growth, on steeper dunes, such that they have to grow less in response to burial than plants that form more shallow dunes. In this thesis, it was shown that the link between the carbon and nitrogen economies of dune plants was pivotal in determining species distributions and survival under extreme environmental conditions. As vast areas of the world’s surface are covered by sand dunes these observations are not just of passing interest.
- Full Text:
- Date Issued: 2008
Thermal, spectroscopic and x-ray diffraction studies of copper(II) 1,2,4,5-Benzenetetracarboxylates and copper(II) oxalate a study of metal-organic frameworks
- Authors: Lamprecht, Emmanuel
- Date: 2008
- Subjects: Organometallic compounds Copper Oxalates -- Thermal properties Organic compounds -- Synthesis Spectrum analysis X-rays -- Diffraction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4389 , http://hdl.handle.net/10962/d1005054
- Description: Novel and known metal organic frameworks with copper(II), sodium and 1,2,4,5-benzenetetracarboxylate were prepared by ambient precipitation, solvothermal and gel-synthesis methods, and characterized by single-crystal X-ray diffraction, X-ray powder diffraction, infrared spectroscopy, differential scanning calorimetry, and thermogravimetry with FTIR evolved-gas analysis. Some of these complexes were investigated for guest inclusion properties with water (the original guest species), methanol, ethanol and pyridine. The gel-synthesis products were the most interesting. The novel threedimensional metal-organic framework complex Cu₂ Na(OH)L·7H₂O (where L=1,2,4,5-benzenetetracarboxylate) -formed by gel-synthesis- is a covalent three-dimensional metal organic framework polymer with open channels containing both guest water molecules and water molecules coordinated to sodium. The structure collapsed on dehydration, but was essentially restored to the original structure on rehydration in moist air. On exposure of the dehydrated material to methanol and ethanol vapour, significant uptake of these solvents was observed, and the resolvated structures closely resembled that of the parent material. On heating in dry nitrogen, small amounts of methanol and ethanol remained until about 280 °C, when loss of the remaining guest triggered decomposition of the framework. The related complex, Cu₂¼(OH)½ L·7½H₂O (or possibly Cu₂⅓ (OH)⅔L·8H₂O) -formed by gel-synthesis- had a different physical appearance to Cu₂Na(OH)L·7H₂O above, but had nearly identical X-ray diffraction pattern, mid-infrared spectrum and thermal behaviour. The novel complex Cu₄Na₄L₃·14H₂O -formed by gel-synthesis- is a covalent three-dimensional metal-organic framework with small channels containing both guest water molecules and water coordinated to sodium and copper. Upon dehydration the structure collapsed, but on rehydration in moist air the original structure was partly restored. The dehydrated material did not absorb methanol. Known two-dimensional polymeric complexes [Cu₂L·6H₂O]·4H₂O and [Cu₂L·4H₂O]·2H₂O were also obtained by gel-synthesis, and were characterized and investigated for guest inclusion properties. The structures of these complexes collapsed on dehydration, and were only partly restored on rehydration in saturated water vapour. The dehydrated materials did not absorb methanol. The two-dimensional polymeric mixed-ligand complex Cu₂(pyridine)₄·6H₂O -formed very slowly by gel-synthesis- was characterized by TG-FTIR, and was shown to undergo a complicated decomposition involving the loss of water and pyridine, carbon dioxide and carbon monoxide in various stages. Solvothermal synthesis did not yield materials suitable for single-crystal X-ray diffraction studies or inclusion studies, producing only an anhydrous or hemihydrate complex with the formula Cu₂L·0.65H2O. Ambient precipitation syntheses did not yield materials suitable for singlecrystal diffraction studies, forming products approximately equivalent to the complexes [Cu₂L·6H₂O]·4H₂O and Cu₂¼(OH)½L·7 ½H₂O above. During the course of the above study it was discovered that, on changing the DSC purge from nitrogen to argon, the normally exothermic carboxylate decompositions appeared to become endothermic. The effects of the supposedly inert atmospheres of argon and nitrogen on the decomposition-mechanism of copper(II) oxalate -a well-studied copper carboxylate- were therefore studied by DSC, TG, TG-FTIR and XRPD. DSC experiments were performed in nitrogen and argon at different flow-rates, in various mixtures of nitrogen and argon, and at various heating rates. Regardless of the proportions of nitrogen and argon, the DSC residues consisted mainly of copper metal, a small amount of copper(I) oxide (cuprite) and, in some circumstances, traces of copper(II) oxide (tenorite). Also, regardless of whether TG-FTIR experiments were performed under argon or nitrogen, the gaseous decomposition products consisted mainly of carbon dioxide, with traces of carbon monoxide being detected over part of the decomposition period. Various explanations for the thermal behaviour are discussed, and it is possible that small amounts of O2 or monatomic oxygen were given off during the decomposition under argon. The design and implementation of a low-cost prototype X-ray proportional counter detector system, consisting of a hybrid analog-digital computer built using commonly available electronic components, is presented. This system was designed to replace ageing discrete-transistor designs still in use in earlier X-ray diffractometers. The prototype performs the functions of pulse-shaping, pulseheight discrimination, counting and scaling, and provides both digital and scaled analog outputs.
- Full Text:
- Date Issued: 2008
- Authors: Lamprecht, Emmanuel
- Date: 2008
- Subjects: Organometallic compounds Copper Oxalates -- Thermal properties Organic compounds -- Synthesis Spectrum analysis X-rays -- Diffraction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4389 , http://hdl.handle.net/10962/d1005054
- Description: Novel and known metal organic frameworks with copper(II), sodium and 1,2,4,5-benzenetetracarboxylate were prepared by ambient precipitation, solvothermal and gel-synthesis methods, and characterized by single-crystal X-ray diffraction, X-ray powder diffraction, infrared spectroscopy, differential scanning calorimetry, and thermogravimetry with FTIR evolved-gas analysis. Some of these complexes were investigated for guest inclusion properties with water (the original guest species), methanol, ethanol and pyridine. The gel-synthesis products were the most interesting. The novel threedimensional metal-organic framework complex Cu₂ Na(OH)L·7H₂O (where L=1,2,4,5-benzenetetracarboxylate) -formed by gel-synthesis- is a covalent three-dimensional metal organic framework polymer with open channels containing both guest water molecules and water molecules coordinated to sodium. The structure collapsed on dehydration, but was essentially restored to the original structure on rehydration in moist air. On exposure of the dehydrated material to methanol and ethanol vapour, significant uptake of these solvents was observed, and the resolvated structures closely resembled that of the parent material. On heating in dry nitrogen, small amounts of methanol and ethanol remained until about 280 °C, when loss of the remaining guest triggered decomposition of the framework. The related complex, Cu₂¼(OH)½ L·7½H₂O (or possibly Cu₂⅓ (OH)⅔L·8H₂O) -formed by gel-synthesis- had a different physical appearance to Cu₂Na(OH)L·7H₂O above, but had nearly identical X-ray diffraction pattern, mid-infrared spectrum and thermal behaviour. The novel complex Cu₄Na₄L₃·14H₂O -formed by gel-synthesis- is a covalent three-dimensional metal-organic framework with small channels containing both guest water molecules and water coordinated to sodium and copper. Upon dehydration the structure collapsed, but on rehydration in moist air the original structure was partly restored. The dehydrated material did not absorb methanol. Known two-dimensional polymeric complexes [Cu₂L·6H₂O]·4H₂O and [Cu₂L·4H₂O]·2H₂O were also obtained by gel-synthesis, and were characterized and investigated for guest inclusion properties. The structures of these complexes collapsed on dehydration, and were only partly restored on rehydration in saturated water vapour. The dehydrated materials did not absorb methanol. The two-dimensional polymeric mixed-ligand complex Cu₂(pyridine)₄·6H₂O -formed very slowly by gel-synthesis- was characterized by TG-FTIR, and was shown to undergo a complicated decomposition involving the loss of water and pyridine, carbon dioxide and carbon monoxide in various stages. Solvothermal synthesis did not yield materials suitable for single-crystal X-ray diffraction studies or inclusion studies, producing only an anhydrous or hemihydrate complex with the formula Cu₂L·0.65H2O. Ambient precipitation syntheses did not yield materials suitable for singlecrystal diffraction studies, forming products approximately equivalent to the complexes [Cu₂L·6H₂O]·4H₂O and Cu₂¼(OH)½L·7 ½H₂O above. During the course of the above study it was discovered that, on changing the DSC purge from nitrogen to argon, the normally exothermic carboxylate decompositions appeared to become endothermic. The effects of the supposedly inert atmospheres of argon and nitrogen on the decomposition-mechanism of copper(II) oxalate -a well-studied copper carboxylate- were therefore studied by DSC, TG, TG-FTIR and XRPD. DSC experiments were performed in nitrogen and argon at different flow-rates, in various mixtures of nitrogen and argon, and at various heating rates. Regardless of the proportions of nitrogen and argon, the DSC residues consisted mainly of copper metal, a small amount of copper(I) oxide (cuprite) and, in some circumstances, traces of copper(II) oxide (tenorite). Also, regardless of whether TG-FTIR experiments were performed under argon or nitrogen, the gaseous decomposition products consisted mainly of carbon dioxide, with traces of carbon monoxide being detected over part of the decomposition period. Various explanations for the thermal behaviour are discussed, and it is possible that small amounts of O2 or monatomic oxygen were given off during the decomposition under argon. The design and implementation of a low-cost prototype X-ray proportional counter detector system, consisting of a hybrid analog-digital computer built using commonly available electronic components, is presented. This system was designed to replace ageing discrete-transistor designs still in use in earlier X-ray diffractometers. The prototype performs the functions of pulse-shaping, pulseheight discrimination, counting and scaling, and provides both digital and scaled analog outputs.
- Full Text:
- Date Issued: 2008