Study into the synthesis, characterisation and applications of Vanadium-based metal organic frameworks, using 1, 2, 4, 5-benzenetetracarboxylic acid
- Authors: Feldmann, Wesley
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/55245 , vital:26680
- Description: This study focussed on the synthesis, characterisation and catalytic application of synthesised vanadium-based Metal-Organic Frameworks using 1,2,4,5-benzenetetracarboxylic acid as a ligand. A number of synthetic methods were tested in multiple attempts to synthesise a V-MOF, these included; ambient, gel, reflux and solvothermal methods of synthesis. Two products of interest were identified, an ambient synthesis produced a vanadium-based complex with the empirical formula: V2O2(Na2H2B4C).6H2O (RU-V2) and a solvothermal synthesis produced a MOF with the empirical formula: V2O2(H2O)2(B4C) (RU-V1). Both products were characterised using elemental analysis, infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry and X-ray powder diffraction. The catalytic activity of these products was tested, alongside the activity of the solid decavanadate ion, for the conversion of cyclohexene to cyclohexene oxide. The decavanadate ion was included to determine if the ion was catalytically active in the solid state, to potentially be used in the construction of a future MOF or V-complex. The reaction for the conversion of cyclohexene to cyclohexene oxide was chosen, as it has been previously conducted using a V-MOF and was found to be successful. The product of the reaction, the epoxide: cyclohexene oxide, is a very useful precursor for a number of reactions involved in the pharmaceutical industry, so developing catalysts which are able to convert cyclohexene to the epoxide with high yields and selectivities are well sought after in industry. The results of the catalytic reactions were varied, as the materials exhibited high yields and selectivities to the epoxide, but these results were only obtained when water was present in the reaction mixture. Water was able to bring about the cleavage of the bonds between the metal and ligand in a highly coordinated framework, at a faster rate than other solvents, such as decane. This ultimately leads to the structural decomposition of the entire complex or framework, depending upon the reaction time. The use of water was a double edged sword in that it was required to initiate the catalytic reaction, but was also the reason that the catalytic materials were noted to decompose over time. The solid decavanadate ion was only noted to exhibit homogeneous activity by dissolving into the small volume of water present in the reaction mixture. The study proved that using a multidentate ligand such as 1,2,4,5-benzenetetracarboxylic acid yielded products which were highly coordinated in nature and would therefore not have large open spaces associated with them, which is commonly observed with other MOFs. Instead the closed nature of the synthesised complexes and frameworks offered a different environment for catalytic reactions, where the small pores/channels had a controlling and inhibiting effect on the reaction. The conversion of cyclohexene to the epoxide is accompanied with a number of undesired side products, so when using the synthesised closed-natured MOF, it was found that there was a greater selectivity for the epoxide over other potential products. This indicates that close natured MOFs may find application in catalytic reactions which require high selectivities for a particular product.
- Full Text:
- Date Issued: 2016
- Authors: Feldmann, Wesley
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/55245 , vital:26680
- Description: This study focussed on the synthesis, characterisation and catalytic application of synthesised vanadium-based Metal-Organic Frameworks using 1,2,4,5-benzenetetracarboxylic acid as a ligand. A number of synthetic methods were tested in multiple attempts to synthesise a V-MOF, these included; ambient, gel, reflux and solvothermal methods of synthesis. Two products of interest were identified, an ambient synthesis produced a vanadium-based complex with the empirical formula: V2O2(Na2H2B4C).6H2O (RU-V2) and a solvothermal synthesis produced a MOF with the empirical formula: V2O2(H2O)2(B4C) (RU-V1). Both products were characterised using elemental analysis, infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry and X-ray powder diffraction. The catalytic activity of these products was tested, alongside the activity of the solid decavanadate ion, for the conversion of cyclohexene to cyclohexene oxide. The decavanadate ion was included to determine if the ion was catalytically active in the solid state, to potentially be used in the construction of a future MOF or V-complex. The reaction for the conversion of cyclohexene to cyclohexene oxide was chosen, as it has been previously conducted using a V-MOF and was found to be successful. The product of the reaction, the epoxide: cyclohexene oxide, is a very useful precursor for a number of reactions involved in the pharmaceutical industry, so developing catalysts which are able to convert cyclohexene to the epoxide with high yields and selectivities are well sought after in industry. The results of the catalytic reactions were varied, as the materials exhibited high yields and selectivities to the epoxide, but these results were only obtained when water was present in the reaction mixture. Water was able to bring about the cleavage of the bonds between the metal and ligand in a highly coordinated framework, at a faster rate than other solvents, such as decane. This ultimately leads to the structural decomposition of the entire complex or framework, depending upon the reaction time. The use of water was a double edged sword in that it was required to initiate the catalytic reaction, but was also the reason that the catalytic materials were noted to decompose over time. The solid decavanadate ion was only noted to exhibit homogeneous activity by dissolving into the small volume of water present in the reaction mixture. The study proved that using a multidentate ligand such as 1,2,4,5-benzenetetracarboxylic acid yielded products which were highly coordinated in nature and would therefore not have large open spaces associated with them, which is commonly observed with other MOFs. Instead the closed nature of the synthesised complexes and frameworks offered a different environment for catalytic reactions, where the small pores/channels had a controlling and inhibiting effect on the reaction. The conversion of cyclohexene to the epoxide is accompanied with a number of undesired side products, so when using the synthesised closed-natured MOF, it was found that there was a greater selectivity for the epoxide over other potential products. This indicates that close natured MOFs may find application in catalytic reactions which require high selectivities for a particular product.
- Full Text:
- Date Issued: 2016
Successes and challenges of women's income generating projects in Zimbabwe
- Authors: Hamunakwadi, Purity
- Date: 2016
- Subjects: Women in development -- Zimbabwe , Women -- Employment -- Zimbabwe , Economic development projects -- Zimbabwe , Women in rural development -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/6810 , vital:21145
- Description: Women’s income-generating projects are regarded as a critical area in promoting sustainable livelihoods in the lives of the poor. This study centres on a cattle project in Sadomba village in Nyanga District, Zimbabwe. The purpose of this study is to investigate the role and contributions of income-generating projects with regard to women; the necessary conditions for a successful cattle production project; the major challenges in women’s income-generating projects, and how income-generating projects can be strengthened, all in relation to this cattle project.The study is underpinned by the sustainable livelihood approach and literature on micro-financing of women’s projects in various countries. The study is based on qualitative methodology using a case study design and methods of data collection included semi-structured interviews, focus group discussions and participant observation. The data was analysed using thematic analysis and sub-themes that arose in the study and thereafter all the data was grouped by a process of coding. The results indicated that the Sadomba cattle project has benefited the project members in terms of income generation by the selling of cattle and milk, for agricultural purposes (draught power) and also income they obtained from hiring their cattle to other community members in rainy seasons. The income generated has assisted them to send their children to school and attain higher education.In addition, it promotes community engagement when they share paddocks and dip tanks. However, despite these benefits, they face a number of challenges such as long distances to the market, a lack of microcredit and the unavailability of exotic breeds. Therefore, there is need to integrate the conditions that are necessary for successful income generating projects to the Sadomba cattle project.
- Full Text:
- Date Issued: 2016
- Authors: Hamunakwadi, Purity
- Date: 2016
- Subjects: Women in development -- Zimbabwe , Women -- Employment -- Zimbabwe , Economic development projects -- Zimbabwe , Women in rural development -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/6810 , vital:21145
- Description: Women’s income-generating projects are regarded as a critical area in promoting sustainable livelihoods in the lives of the poor. This study centres on a cattle project in Sadomba village in Nyanga District, Zimbabwe. The purpose of this study is to investigate the role and contributions of income-generating projects with regard to women; the necessary conditions for a successful cattle production project; the major challenges in women’s income-generating projects, and how income-generating projects can be strengthened, all in relation to this cattle project.The study is underpinned by the sustainable livelihood approach and literature on micro-financing of women’s projects in various countries. The study is based on qualitative methodology using a case study design and methods of data collection included semi-structured interviews, focus group discussions and participant observation. The data was analysed using thematic analysis and sub-themes that arose in the study and thereafter all the data was grouped by a process of coding. The results indicated that the Sadomba cattle project has benefited the project members in terms of income generation by the selling of cattle and milk, for agricultural purposes (draught power) and also income they obtained from hiring their cattle to other community members in rainy seasons. The income generated has assisted them to send their children to school and attain higher education.In addition, it promotes community engagement when they share paddocks and dip tanks. However, despite these benefits, they face a number of challenges such as long distances to the market, a lack of microcredit and the unavailability of exotic breeds. Therefore, there is need to integrate the conditions that are necessary for successful income generating projects to the Sadomba cattle project.
- Full Text:
- Date Issued: 2016
Supra-maximal speed interval training effect on a 40m standing start sprint and timed 3000m running performance in moderately trained female runners: Alterg anti-gravity treadmill running
- Authors: Ellerbeck, Tim
- Date: 2016
- Subjects: Interval training , Women runners , Running -- Training
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/6772 , vital:21140
- Description: The purpose of this study was to explore what the supra-maximal speed interval training effect was on a 40m standing start sprint and timed 3000m running performance was for two separate study groups when using either the AlterG® anti-gravity treadmill, or downhill running as a training intervention, for moderately trained female runners. The level of delayed onset of muscle soreness (DOMS) after each supra-maximal speed interval session was also captured. Data from 20 women was collected during initial pre-intervention testing; involving the 40m standing start sprint and 3000m timed trial run. During a four week training intervention the level of DOMS experienced by participants at increments of 24 hours, 48 hours and 72 hours, in each respective training group was recorded. Post-intervention testing was performed to once again measure the participants 40m standing start sprint and 3000m timed trial run values, results were analysed and compared to pre-intervention data.
- Full Text:
- Date Issued: 2016
- Authors: Ellerbeck, Tim
- Date: 2016
- Subjects: Interval training , Women runners , Running -- Training
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/6772 , vital:21140
- Description: The purpose of this study was to explore what the supra-maximal speed interval training effect was on a 40m standing start sprint and timed 3000m running performance was for two separate study groups when using either the AlterG® anti-gravity treadmill, or downhill running as a training intervention, for moderately trained female runners. The level of delayed onset of muscle soreness (DOMS) after each supra-maximal speed interval session was also captured. Data from 20 women was collected during initial pre-intervention testing; involving the 40m standing start sprint and 3000m timed trial run. During a four week training intervention the level of DOMS experienced by participants at increments of 24 hours, 48 hours and 72 hours, in each respective training group was recorded. Post-intervention testing was performed to once again measure the participants 40m standing start sprint and 3000m timed trial run values, results were analysed and compared to pre-intervention data.
- Full Text:
- Date Issued: 2016
Surface characteristics of rock glaciers in the Jutulsessen, Dronning Maud Land, Antarctica
- Rudolph, Elizabeth Magdalena
- Authors: Rudolph, Elizabeth Magdalena
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2667 , vital:20314
- Description: Rock glaciers are landforms that present downslope movement of debris under the influence of ice and gravity. These landforms can be used as paleo-climate indicators as well as proxies for climate change. Rock glaciers have been investigated in a variety of climates and landscapes, however continental Antarctica, Dronning Maud Land specifically, remains understudied. This thesis aimed to investigate and classify five rock glaciers observed in the Jutulsessen, Dronning Maud Land. The surface characteristics and geomorphology were assessed and used as generic classifiers. Size, shape and landscape association was established by field surveying and GIS, whilst sediment and clast characteristics were determined from sampling. A surface temperature profile was created from short-term high frequency temperature measurements. All of the rock glaciers exhibit either undulating surfaces or patterned ground, or both, which suggests active-layer related processes. Sediment particle size analysis is inconclusive. The 137Cs-content and fabric analysis suggest movement regimes similar to other rock glaciers with higher activity at the head, and variable movement directions at the toe. Relative “activeness” is inferred from morphology: Grjotlia, Grjotøyra and Vassdalen were classified as lobate, spatulate and tongue-shaped respectively with Grjotlia the most stable. A new morphological classification of ‘crown-shaped’ is suggested for Brugdedalen and Jutuldalen, and they also appear most active. The control of local climate on rock glacier mechanics is emphasised by the findings, and thus climatic interpolation from a single weather stations is not useful. Increased spatial and temporal coverage of sediment profiles, surface topography and active-layer characteristics could be used to elucidate the processes and controls of these landforms in the Antarctic.
- Full Text:
- Date Issued: 2016
- Authors: Rudolph, Elizabeth Magdalena
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2667 , vital:20314
- Description: Rock glaciers are landforms that present downslope movement of debris under the influence of ice and gravity. These landforms can be used as paleo-climate indicators as well as proxies for climate change. Rock glaciers have been investigated in a variety of climates and landscapes, however continental Antarctica, Dronning Maud Land specifically, remains understudied. This thesis aimed to investigate and classify five rock glaciers observed in the Jutulsessen, Dronning Maud Land. The surface characteristics and geomorphology were assessed and used as generic classifiers. Size, shape and landscape association was established by field surveying and GIS, whilst sediment and clast characteristics were determined from sampling. A surface temperature profile was created from short-term high frequency temperature measurements. All of the rock glaciers exhibit either undulating surfaces or patterned ground, or both, which suggests active-layer related processes. Sediment particle size analysis is inconclusive. The 137Cs-content and fabric analysis suggest movement regimes similar to other rock glaciers with higher activity at the head, and variable movement directions at the toe. Relative “activeness” is inferred from morphology: Grjotlia, Grjotøyra and Vassdalen were classified as lobate, spatulate and tongue-shaped respectively with Grjotlia the most stable. A new morphological classification of ‘crown-shaped’ is suggested for Brugdedalen and Jutuldalen, and they also appear most active. The control of local climate on rock glacier mechanics is emphasised by the findings, and thus climatic interpolation from a single weather stations is not useful. Increased spatial and temporal coverage of sediment profiles, surface topography and active-layer characteristics could be used to elucidate the processes and controls of these landforms in the Antarctic.
- Full Text:
- Date Issued: 2016
Sustainble public bus transport services in the Nelson Mandela Bay
- Authors: Mntwini, Mkhonto
- Date: 2016
- Subjects: Urban transportation -- Economic aspects Urban transportation -- Research Transportation -- Customer services
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/11875 , vital:27000
- Description: Purpose - Transport is a common constant variable found in just about every aspect of our lives as well as commercial activities; this is so because transport enables accessibility to people, places and goods. The effective management of public passenger transport operations is a more complex and all-embracing concept than what it may appear at first glance. Wider dispersed work place locations and urban sprawl is on the rise driven by among other factors the increased rate of globalisation. A unique opportunity is then presented in a developing country like South Africa for effective planning and management of public passenger bus operations. In the main, the purpose of this case study research was to develop a more sustainable public passenger transport bus operation to better connect people, places and goods. The organisation that will be studied is Blunden Coach Tours a luxury and semi-lux coach Tour operator, operating from the Nelson Mandela Bay. Design / Methodology / Approach – This study employed the case study research approach which was based on the qualitative research paradigm as such allowed for in-depth description and analysis of the case as well as related phenomena in real world context. The researcher focused only on the public passenger bus transport operations in Nelson Mandela Bay thus assuming a single context focus with a single case namely the development of a more sustainable public passenger transport operations in Nelson Mandela Bay. An embedded multiple unit of analysis strategy was employed selecting a sample of key persons responsible for strategic operational areas at Blunden Coach tours, sub-contractors and suppliers. The case study employed an in-depth probing interview process in an effort to better comprehend occurrences within the actual context of the events observed. The secondary sources of information gathered were used to structure and backup the interview questions. Practical implications – The case study enabled thought provoking insight which by virtue of South Africa’s historical socio-economic landscape offered an unusual perspective of the South African bus transport scene with a particular focus on environmental, regulatory and socio-economic sustainability considerations. A limitation to the study – The lack of responses to the interview questions from some of the key role players in the bus industry who were contacted as well as some of the respondents interviewed. The lack of responses to some of the interview questions could be perceived as a limitation to validating the Summary drawn from the study.
- Full Text:
- Date Issued: 2016
- Authors: Mntwini, Mkhonto
- Date: 2016
- Subjects: Urban transportation -- Economic aspects Urban transportation -- Research Transportation -- Customer services
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/11875 , vital:27000
- Description: Purpose - Transport is a common constant variable found in just about every aspect of our lives as well as commercial activities; this is so because transport enables accessibility to people, places and goods. The effective management of public passenger transport operations is a more complex and all-embracing concept than what it may appear at first glance. Wider dispersed work place locations and urban sprawl is on the rise driven by among other factors the increased rate of globalisation. A unique opportunity is then presented in a developing country like South Africa for effective planning and management of public passenger bus operations. In the main, the purpose of this case study research was to develop a more sustainable public passenger transport bus operation to better connect people, places and goods. The organisation that will be studied is Blunden Coach Tours a luxury and semi-lux coach Tour operator, operating from the Nelson Mandela Bay. Design / Methodology / Approach – This study employed the case study research approach which was based on the qualitative research paradigm as such allowed for in-depth description and analysis of the case as well as related phenomena in real world context. The researcher focused only on the public passenger bus transport operations in Nelson Mandela Bay thus assuming a single context focus with a single case namely the development of a more sustainable public passenger transport operations in Nelson Mandela Bay. An embedded multiple unit of analysis strategy was employed selecting a sample of key persons responsible for strategic operational areas at Blunden Coach tours, sub-contractors and suppliers. The case study employed an in-depth probing interview process in an effort to better comprehend occurrences within the actual context of the events observed. The secondary sources of information gathered were used to structure and backup the interview questions. Practical implications – The case study enabled thought provoking insight which by virtue of South Africa’s historical socio-economic landscape offered an unusual perspective of the South African bus transport scene with a particular focus on environmental, regulatory and socio-economic sustainability considerations. A limitation to the study – The lack of responses to the interview questions from some of the key role players in the bus industry who were contacted as well as some of the respondents interviewed. The lack of responses to some of the interview questions could be perceived as a limitation to validating the Summary drawn from the study.
- Full Text:
- Date Issued: 2016
Synthesis and biological evaluation of novel thiazole-based compounds
- Authors: Olawode, Emmanual Oladayo
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62955 , vital:28325
- Description: Thesis embargoed for one-year period. Expected date of release: April 2019
- Full Text:
- Date Issued: 2016
- Authors: Olawode, Emmanual Oladayo
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62955 , vital:28325
- Description: Thesis embargoed for one-year period. Expected date of release: April 2019
- Full Text:
- Date Issued: 2016
Synthesis and characterisation of lanthanide complexes with nitrogen- and oxygen-donor ligands
- Authors: Madanhire, Tatenda
- Date: 2016
- Subjects: Rare earth metals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13127 , vital:27154
- Description: The reactions of Ln(NO3)3∙6H2O (Ln = Pr, Nd or Er) with the potentially tridentate O,N,O chelating ligand 2,6-pyridinedimethanol (H2pydm) were investigated, and complexes with the formula, [Ln(H2pydm)2(NO3)2](NO3) (Ln = Pr or Nd) and [Er(H2pydm)3](NO3)3 were isolated. The ten-coordinate Pr(III) and Nd(III) compounds crystallise in the triclinic space group P-1 while the nine-coordinate Er(III) complex crystallises in the monoclinic system (P21/n). The reaction of PrCl3∙6H2O with H2pydm yielded the compound, [Pr(H2pydm)3](Cl)3, that crystallises in the monoclinic system, space group P21/c with α = 90, β = 98.680(1) and γ = 90°. The nine-coordinate Pr(III) ion is bound to three H2pydm ligands, with bond distances Pr-O 2.455(2)-2.478(2) Å and Pr-N 2.6355(19)-2.64(2) Å. X-ray crystal structures of all the H2pydm complexes reveal that the ligand coordinates tridentately, via the pyridyl nitrogen atom and the two hydroxyl oxygen atoms. The electronic absorption spectra of complexes show 4f-4f transitions. Rare-earth complexes, [Ln(H2L1)2(NO3)3] [Ln = Gd, Ho or Nd], were also prepared from a Schiff base. The X-ray single-crystal diffraction studies and SHAPE analyses of the Gd(III) and Ho(III) complexes shows that the complexes are ten-coordinate and exhibit distorted tetradecahedron geometries. With proton migration occurring from the phenol group to the imine function, complexation of the lanthanides to the ligand gives the ligand a zwitterionic phenoxo-iminium form. A phenolate oxygen-bridged dinuclear complex, [Ce2(H2L1)(ovan)3(NO3)3], has been obtained by reacting Ce(NO3)3∙6H2O with an o-vanillin derived Schiff base ligand, 2-((E)-(1-hydroxy-2-methylpropan-2-ylimino)methyl)-6-methoxyphenol (H2L1). Hydrolysis of the Schiff base occurred to yield o-vanillin, which bridged two cerium atoms with the Ce∙∙∙Ce distance equal to 3.823 Å. The Ce(III) ions are both tencoordinate, but have different coordination environments, showing tetradecahedron and staggered dodecahedron geometries, respectively. The reaction of salicylaldehyde-N(4)-diethylthiosemicarbazone (H2L2) in the presence of hydrated Ln(III) nitrates led to the isolation of two novel compounds: (E)-2[(ortho-hydroxy)benzylidene]-2-(thiomethyl)-thionohydrazide (1) and bis[2,3-diaza4-(2-hydroxyphenyl)-1-thiomethyl-buta-1,3-diene]disulfide. The latter is a dimer of the former. For this asymmetric Schiff base, 1 and the symmetric disulfide, classical hydrogen bonds of the O–H∙∙∙N as well as N–H∙∙∙S (for 1) type are apparent next to C–H∙∙∙O contacts. 4-(4-Bromophenyl)-1-(propan-2-ylidene)thiosemicarbazide was also prepared upon reacting 4-(4-bromophenyl)-3-thiosemicarbazide with acetone in the presence of ethanol and La(NO3)3∙6H2O. The C=S bond length was found to be 1.6686(16) Å which is in good agreement with other thioketones whose metrical parameters have been deposited with the Cambridge Structural Database. Classical hydrogen bonds of the N–H∙∙∙N and the N–H∙∙∙Br type are observed next to C–H∙∙∙S contacts. All synthesised compounds were characterised by microanalyses, single-crystal X-ray diffraction (except for [Nd(H2L1)2(NO3)3]), 1H NMR and IR spectroscopy.
- Full Text:
- Date Issued: 2016
- Authors: Madanhire, Tatenda
- Date: 2016
- Subjects: Rare earth metals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13127 , vital:27154
- Description: The reactions of Ln(NO3)3∙6H2O (Ln = Pr, Nd or Er) with the potentially tridentate O,N,O chelating ligand 2,6-pyridinedimethanol (H2pydm) were investigated, and complexes with the formula, [Ln(H2pydm)2(NO3)2](NO3) (Ln = Pr or Nd) and [Er(H2pydm)3](NO3)3 were isolated. The ten-coordinate Pr(III) and Nd(III) compounds crystallise in the triclinic space group P-1 while the nine-coordinate Er(III) complex crystallises in the monoclinic system (P21/n). The reaction of PrCl3∙6H2O with H2pydm yielded the compound, [Pr(H2pydm)3](Cl)3, that crystallises in the monoclinic system, space group P21/c with α = 90, β = 98.680(1) and γ = 90°. The nine-coordinate Pr(III) ion is bound to three H2pydm ligands, with bond distances Pr-O 2.455(2)-2.478(2) Å and Pr-N 2.6355(19)-2.64(2) Å. X-ray crystal structures of all the H2pydm complexes reveal that the ligand coordinates tridentately, via the pyridyl nitrogen atom and the two hydroxyl oxygen atoms. The electronic absorption spectra of complexes show 4f-4f transitions. Rare-earth complexes, [Ln(H2L1)2(NO3)3] [Ln = Gd, Ho or Nd], were also prepared from a Schiff base. The X-ray single-crystal diffraction studies and SHAPE analyses of the Gd(III) and Ho(III) complexes shows that the complexes are ten-coordinate and exhibit distorted tetradecahedron geometries. With proton migration occurring from the phenol group to the imine function, complexation of the lanthanides to the ligand gives the ligand a zwitterionic phenoxo-iminium form. A phenolate oxygen-bridged dinuclear complex, [Ce2(H2L1)(ovan)3(NO3)3], has been obtained by reacting Ce(NO3)3∙6H2O with an o-vanillin derived Schiff base ligand, 2-((E)-(1-hydroxy-2-methylpropan-2-ylimino)methyl)-6-methoxyphenol (H2L1). Hydrolysis of the Schiff base occurred to yield o-vanillin, which bridged two cerium atoms with the Ce∙∙∙Ce distance equal to 3.823 Å. The Ce(III) ions are both tencoordinate, but have different coordination environments, showing tetradecahedron and staggered dodecahedron geometries, respectively. The reaction of salicylaldehyde-N(4)-diethylthiosemicarbazone (H2L2) in the presence of hydrated Ln(III) nitrates led to the isolation of two novel compounds: (E)-2[(ortho-hydroxy)benzylidene]-2-(thiomethyl)-thionohydrazide (1) and bis[2,3-diaza4-(2-hydroxyphenyl)-1-thiomethyl-buta-1,3-diene]disulfide. The latter is a dimer of the former. For this asymmetric Schiff base, 1 and the symmetric disulfide, classical hydrogen bonds of the O–H∙∙∙N as well as N–H∙∙∙S (for 1) type are apparent next to C–H∙∙∙O contacts. 4-(4-Bromophenyl)-1-(propan-2-ylidene)thiosemicarbazide was also prepared upon reacting 4-(4-bromophenyl)-3-thiosemicarbazide with acetone in the presence of ethanol and La(NO3)3∙6H2O. The C=S bond length was found to be 1.6686(16) Å which is in good agreement with other thioketones whose metrical parameters have been deposited with the Cambridge Structural Database. Classical hydrogen bonds of the N–H∙∙∙N and the N–H∙∙∙Br type are observed next to C–H∙∙∙S contacts. All synthesised compounds were characterised by microanalyses, single-crystal X-ray diffraction (except for [Nd(H2L1)2(NO3)3]), 1H NMR and IR spectroscopy.
- Full Text:
- Date Issued: 2016
Synthesis and characterization of group 12 dithiolate complexes as single source precursors for the preparation of hexadecylamine capped metal sulfide nanoparticles and polymer
- Authors: Osuntokun, Jejenija
- Date: 2016
- Subjects: Nanotechnology Nanoparticles Semiconductors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/14060 , vital:39801
- Description: A series of heteroleptic mixed ligand complexes of some alkyl substituted thiourea, tetramethyl thiuram disulfide and 1-cyano-1-carboethoxy-2,2 ditholate of Zn(II) Cd(II) and Hg(II) have been synthesized by stoichiometry reactions of the ligands with respective metal salts. They have been characterized with analytical and spectroscopic techniques. Seven out of the 19 complexes synthesized are pyridine 2, 2 bipyridine and 1, 10 phenanthroline adducts of dissopropyl parent adducts of Zn(II) and Cd(II) complexes. All the complexes are proposed as four coordinate except the pyridine adducts, 2, 2’ bipyridine and 1, 10 phenanhroline adducts that are proposed as five and six coordinate respectively. All the complexes are solid, air stable and moisture stable for a many months. They are not soluble in common organic solvents but partially soluble in coordinating solvents like DMF and DMSO and due to their insolubility problems all attempts to grow single crystal of the complexes proved abortive. The complexes gave respective metal sulfide on thermal decomposition in TGA and this makes them to be potentially useful single source precursor for the synthesis of metal sulfide. All the complexes were invariably thermolysed in HDA to synthesis a series of HDA-capped ZnS, CdS and HgS nanoparticles. The optical properties of the nanoparticles reveal that they are all blue-shifted from the absorbance edge and this confirms quantum confinement of the nanoparticles. The transmittance electron microscope showed that the nanoparticles are in nanodimension. ZnS nanoparticles from the pyridine adducts gave HDA-capped ZnS nanoparticles with a mixture of hexagonal and cubic phases while the HDA capped CdS from the 2, 2 bipyridine and 1,10 phenanthroline gave anisotropic nanoparticles. The sizes of the CdS from the 1,10 phenanthroline adducts were also found to be biggest while CdS nanoparticles from 2,2 bipyridine adduct were also revealed to be bigger than the particle sizes obtained from the parent complex, (1-cyano-1 carboethoxyethylene-2,2-dithiolato- κ,S’S)-bis(N, N’-diisopropylthiourea -κS)cadmium(II). ZnS and CdS polymer encapsulated nanocomposites were also synthesized using a solution casting method. The polymers employed were; Polymethyl metharcrylate (PMMA), Poly(vinly alcohol) (PVA), and poly vinyl pyrrolidone (PVP). The structural and thermal properties of the pure polymers and the respective nanocomposites were investigated. It was observed that the ZnS/PVA and CdS/PVA were the most thermally stable composites when the thermal stability of the pure polymers were compared relative to the nanocomposites using data obtained from thermal decomposition results of the TGA.
- Full Text:
- Date Issued: 2016
- Authors: Osuntokun, Jejenija
- Date: 2016
- Subjects: Nanotechnology Nanoparticles Semiconductors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/14060 , vital:39801
- Description: A series of heteroleptic mixed ligand complexes of some alkyl substituted thiourea, tetramethyl thiuram disulfide and 1-cyano-1-carboethoxy-2,2 ditholate of Zn(II) Cd(II) and Hg(II) have been synthesized by stoichiometry reactions of the ligands with respective metal salts. They have been characterized with analytical and spectroscopic techniques. Seven out of the 19 complexes synthesized are pyridine 2, 2 bipyridine and 1, 10 phenanthroline adducts of dissopropyl parent adducts of Zn(II) and Cd(II) complexes. All the complexes are proposed as four coordinate except the pyridine adducts, 2, 2’ bipyridine and 1, 10 phenanhroline adducts that are proposed as five and six coordinate respectively. All the complexes are solid, air stable and moisture stable for a many months. They are not soluble in common organic solvents but partially soluble in coordinating solvents like DMF and DMSO and due to their insolubility problems all attempts to grow single crystal of the complexes proved abortive. The complexes gave respective metal sulfide on thermal decomposition in TGA and this makes them to be potentially useful single source precursor for the synthesis of metal sulfide. All the complexes were invariably thermolysed in HDA to synthesis a series of HDA-capped ZnS, CdS and HgS nanoparticles. The optical properties of the nanoparticles reveal that they are all blue-shifted from the absorbance edge and this confirms quantum confinement of the nanoparticles. The transmittance electron microscope showed that the nanoparticles are in nanodimension. ZnS nanoparticles from the pyridine adducts gave HDA-capped ZnS nanoparticles with a mixture of hexagonal and cubic phases while the HDA capped CdS from the 2, 2 bipyridine and 1,10 phenanthroline gave anisotropic nanoparticles. The sizes of the CdS from the 1,10 phenanthroline adducts were also found to be biggest while CdS nanoparticles from 2,2 bipyridine adduct were also revealed to be bigger than the particle sizes obtained from the parent complex, (1-cyano-1 carboethoxyethylene-2,2-dithiolato- κ,S’S)-bis(N, N’-diisopropylthiourea -κS)cadmium(II). ZnS and CdS polymer encapsulated nanocomposites were also synthesized using a solution casting method. The polymers employed were; Polymethyl metharcrylate (PMMA), Poly(vinly alcohol) (PVA), and poly vinyl pyrrolidone (PVP). The structural and thermal properties of the pure polymers and the respective nanocomposites were investigated. It was observed that the ZnS/PVA and CdS/PVA were the most thermally stable composites when the thermal stability of the pure polymers were compared relative to the nanocomposites using data obtained from thermal decomposition results of the TGA.
- Full Text:
- Date Issued: 2016
Synthesis and exploration of resorcinol derivatives as Plasmodium falciparum Hsp90 inhibitors
- Authors: Umumararungu, Théoneste
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/717 , vital:19984
- Description: In this research project, we have synthesized a series of nine dimethyl ether resorcinol analogues of NMS-E973 (L-1) 38, a potent Hsp90 inhibitor. These analogues were chosen because they share the same pharmacophore with NMS-E973 (L-1) 38 and were thus expected to have a similar biological activity. Moreover, it is generally easier to synthesize the dimethyl ether resorcinol analogues of NMS-E973 (L-1) 38 as compared to their demethylated counterparts. Since other Hsp90 inhibitors such as geldanamycin 19 have demonstrated anti-plasmodial activity, we also expected our compounds to be Hsp90 inhibitors and to possess anti-plasmodial activity. However, our compounds were tested for growth inhibitory activity of Plasmodium falciparum and not for P. falciparum Hsp90 (PfHSP90) inhibitory activity. The synthesis involved a series of steps that led to the formation of the ester compound TU-011 (L-7) 43 that was then used as a precursor for different NMS-E973 (L-1) 38 analogues. The choice of analogues to be synthesized was dictated by binding affinity predictions obtained from molecular docking. The chosen synthetic analogues were active against chloroquine-sensitive Plasmodium falciparum (3D7 strain) in a Plasmodium lactate dehydrogenase assay and they were not generally cytotoxic to human cervical adenocarcinoma cell line HeLa. The most active of our compounds was TU-018 (L-103) 50 with an IC50 value of approximately 1.830 µM as compared to the standard, chloroquine, with an IC50 value of 0.01062 µM. Some of the compounds showed mild cytotoxicity towards HeLa cells with IC50 values higher than 25 µM as compared to the standard apoptosis inducer drug, emetine that had an IC50 value of 0.09948 µM. These results highlight the fact that the synthesized analogues are novel relatively non-toxic anti-plasmodial agents.
- Full Text:
- Date Issued: 2016
- Authors: Umumararungu, Théoneste
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/717 , vital:19984
- Description: In this research project, we have synthesized a series of nine dimethyl ether resorcinol analogues of NMS-E973 (L-1) 38, a potent Hsp90 inhibitor. These analogues were chosen because they share the same pharmacophore with NMS-E973 (L-1) 38 and were thus expected to have a similar biological activity. Moreover, it is generally easier to synthesize the dimethyl ether resorcinol analogues of NMS-E973 (L-1) 38 as compared to their demethylated counterparts. Since other Hsp90 inhibitors such as geldanamycin 19 have demonstrated anti-plasmodial activity, we also expected our compounds to be Hsp90 inhibitors and to possess anti-plasmodial activity. However, our compounds were tested for growth inhibitory activity of Plasmodium falciparum and not for P. falciparum Hsp90 (PfHSP90) inhibitory activity. The synthesis involved a series of steps that led to the formation of the ester compound TU-011 (L-7) 43 that was then used as a precursor for different NMS-E973 (L-1) 38 analogues. The choice of analogues to be synthesized was dictated by binding affinity predictions obtained from molecular docking. The chosen synthetic analogues were active against chloroquine-sensitive Plasmodium falciparum (3D7 strain) in a Plasmodium lactate dehydrogenase assay and they were not generally cytotoxic to human cervical adenocarcinoma cell line HeLa. The most active of our compounds was TU-018 (L-103) 50 with an IC50 value of approximately 1.830 µM as compared to the standard, chloroquine, with an IC50 value of 0.01062 µM. Some of the compounds showed mild cytotoxicity towards HeLa cells with IC50 values higher than 25 µM as compared to the standard apoptosis inducer drug, emetine that had an IC50 value of 0.09948 µM. These results highlight the fact that the synthesized analogues are novel relatively non-toxic anti-plasmodial agents.
- Full Text:
- Date Issued: 2016
Synthesis and structural studies of NiS and PdS nanoparticles/nanocomposites from dithiocarbamates single source precursors
- Authors: Nqombolo, Azile
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11359 , http://hdl.handle.net/10353/d1021326
- Description: The main aim of this research is to synthesize Ni(II) and Pd(II) dithiocarbamate complexes and use them as single source precursors for the synthesis of NiS and PdS nanoparticles and metal sulphides potato starch nanocomposites. Four dithiocarbamate ligands were synthesized and characterized using elemental analysis and spectroscopic techniques. The ligands were used to prepared homoleptic Ni(II) and Pd(II) complexes of the dithiocarbamate ligands. The metal complexes were characterized with elemental analysis, UV-Vis, FTIR and 1H-NMR spectroscopic techniques. Conductivity measurements indicate that all the complexes are non-electrolytes in solution and results from the electronic spectra studies confirmed the proposed 4-coordinate square planar geometry around the metal ions. The nickel complexes showed d-d transitions around 477 nm while in the palladium complexes, no d-d transitions were observed but the compounds showed strong metal to ligand charge transfer transitions. From the FTIR spectra studies, it can be confirmed that the complexes were successfully synthesised because all peaks of interest were observed at expected regions from the literature. The νC-N was observed around 1469-1495 cm-1, νC=S around 1101-1188 cm-1 and νC-S around 738-1060 cm-1 for both Ni(II) and Pd(II) complexes. νNi-S was observed around 375-543 cm-1 and νPd-S around 529-545 cm-1. The FTIR also confirmed that the dithiocarbamate ligands act as bidentate chelating ligands through the sulfur atoms. The complexes were used as single source precursors and thermolysed in hexadecylamine (HDA) at 220 °C to prepare four HDA-capped nickel sulfide nanoparticles and four palladium sulfide nanoparticles. The as-prepared nanoparticles were studied with optical absorption spectra, photoluminescence, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The optical studies results showed that NiS have large band gaps that are greater than that of the bulk, therefore they are found to be blue shifted relative to the bulk, which shows that they have small particle size and thus confirming their quantum confinement effect. PL spectra reveal that the emission peaks are red shifted compared to the absorption band edges of the nanoparticles. The XRD patterns confirmed the formation of cubic and rhombohedral phase for NiS nanoparticles and cubic phase for PdS nanoparticles. SEM images of both NiS and PdS show uniform surface morphology at low and high magnification with different shapes. EDS analyses confirmed the presence of Ni, S, and Pd in each of the spectrum indicating that the nanoparticles were successfully synthesized. TEM images showed that the synthesised nanoparticles have uniform and narrow size distribution with no agglomeration. The sizes of the NiS nanoparticles were found to be in the range of 12-38 nm for NiS1, 8-11 nm for NiS2, 9-16 nm for NiS3 and 4-9 nm for NiS4. The TEM images for the as-prepared PdS nanoparticles showed that the average crystallite sizes are 6.94-9.62 nm for PdS1, 8-11 nm for PdS2, 9-16 nm for PdS3 and 4-9 nm for PdS4 respectively. The nanoparticles were used to prepare potato starch nanocomposites and SEM images indicate that the surface morphology of starch polymer nanocomposites compose of potato starch and few particles in between the pores of the matrix, this is due to the small ratio of nanoparticles used.
- Full Text:
- Date Issued: 2016
- Authors: Nqombolo, Azile
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11359 , http://hdl.handle.net/10353/d1021326
- Description: The main aim of this research is to synthesize Ni(II) and Pd(II) dithiocarbamate complexes and use them as single source precursors for the synthesis of NiS and PdS nanoparticles and metal sulphides potato starch nanocomposites. Four dithiocarbamate ligands were synthesized and characterized using elemental analysis and spectroscopic techniques. The ligands were used to prepared homoleptic Ni(II) and Pd(II) complexes of the dithiocarbamate ligands. The metal complexes were characterized with elemental analysis, UV-Vis, FTIR and 1H-NMR spectroscopic techniques. Conductivity measurements indicate that all the complexes are non-electrolytes in solution and results from the electronic spectra studies confirmed the proposed 4-coordinate square planar geometry around the metal ions. The nickel complexes showed d-d transitions around 477 nm while in the palladium complexes, no d-d transitions were observed but the compounds showed strong metal to ligand charge transfer transitions. From the FTIR spectra studies, it can be confirmed that the complexes were successfully synthesised because all peaks of interest were observed at expected regions from the literature. The νC-N was observed around 1469-1495 cm-1, νC=S around 1101-1188 cm-1 and νC-S around 738-1060 cm-1 for both Ni(II) and Pd(II) complexes. νNi-S was observed around 375-543 cm-1 and νPd-S around 529-545 cm-1. The FTIR also confirmed that the dithiocarbamate ligands act as bidentate chelating ligands through the sulfur atoms. The complexes were used as single source precursors and thermolysed in hexadecylamine (HDA) at 220 °C to prepare four HDA-capped nickel sulfide nanoparticles and four palladium sulfide nanoparticles. The as-prepared nanoparticles were studied with optical absorption spectra, photoluminescence, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The optical studies results showed that NiS have large band gaps that are greater than that of the bulk, therefore they are found to be blue shifted relative to the bulk, which shows that they have small particle size and thus confirming their quantum confinement effect. PL spectra reveal that the emission peaks are red shifted compared to the absorption band edges of the nanoparticles. The XRD patterns confirmed the formation of cubic and rhombohedral phase for NiS nanoparticles and cubic phase for PdS nanoparticles. SEM images of both NiS and PdS show uniform surface morphology at low and high magnification with different shapes. EDS analyses confirmed the presence of Ni, S, and Pd in each of the spectrum indicating that the nanoparticles were successfully synthesized. TEM images showed that the synthesised nanoparticles have uniform and narrow size distribution with no agglomeration. The sizes of the NiS nanoparticles were found to be in the range of 12-38 nm for NiS1, 8-11 nm for NiS2, 9-16 nm for NiS3 and 4-9 nm for NiS4. The TEM images for the as-prepared PdS nanoparticles showed that the average crystallite sizes are 6.94-9.62 nm for PdS1, 8-11 nm for PdS2, 9-16 nm for PdS3 and 4-9 nm for PdS4 respectively. The nanoparticles were used to prepare potato starch nanocomposites and SEM images indicate that the surface morphology of starch polymer nanocomposites compose of potato starch and few particles in between the pores of the matrix, this is due to the small ratio of nanoparticles used.
- Full Text:
- Date Issued: 2016
Synthesis of chiral ketopinic acid-derived catalysts and their evaluation in asymmetric transformations
- Authors: Hassan, Yusuf
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/550 , vital:19969
- Description: Four new (+)-ketopinic acid-derived Mn(III) complexes, three of which possess pseudo C2- symmetry, were synthesised as chiral catalyst candidates. The ligands were prepared by refluxing (+)-ketopinic acid with ethane-1,2-diamine, the resolved (R,R)- and (S,S)-1,2-diaminocyclohexanes, and 1,2-diaminobenzene in chloroform. Treatment of the ligands with manganese(II) acetate tetrahydrate in refluxing ethanol afforded the respective complexes as brown amorphous powders. Characterisation of the ligands and the corresponding complexes was achieved using 1-D and 2-D NMR, IR spectroscopy, and elemental analysis. Various homogeneous asymmetric transformations, were investigated using these four complexes, viz., aldol, and Baylis-Hillman reactions, aza-Michael addition of piperidine to the Baylis-Hillman adducts, epoxidation, and ketone and imine reduction. Asymmetric aldol reactions of benzaldehyde with the aryl ketones, acetophenone, propiophenone, -tetralone, 4-nitroacetophenone, and 4-methoxyacetophenone, conducted in the presence of 10 mole % of the chiral catalysts, afforded enantioselectivities of up to 99% e.e. Asymmetric Baylis-Hillman reactions of methyl- and tert-butyl acrylates with pyridine-2- carbaldehyde, 6-methylpyridine-2-carbaldehyde, 5-chlorosalicylaldehyde, benzaldehyde, 4-chlorobenzaldehyde, and 2-nitrobenzaldehyde were conducted in the presence of catalyst 139 (10 mole %) to afford enantioselectivities of up to 44% e.e. Aza-Michael addition of piperidine to racemic Baylis- Hillman adducts in the presence of the catalyst 139 (10 mole %) was found to proceed with diastereoselectivities of up to 91% d.e. Asymmetric epoxidation of trans-methyl styrene, styrene, trans-stilbene, cis-stilbene, and indene, using a 5 mole % chiral catalyst loading and m-CPBA as the oxygen source, gave enantioselectivities of up to 32 % e.e. Asymmetric reductions of acetophenone, 3-chloropropiophenone, 4-hydroxyacetophenone, -tetralone, and 2-hydroxy-1-acetonapthone were investigated using NaBH4 as the reducing agent and a 10 mole % loading of the chiral catalysts. A stereoselectivity of 68% e.e. was obtained in the reduction of acetophenone, but attempts to reduce the selected imines to the corresponding chiral amines proved to be unsuccessful — even in the absence of the catalysts. It thus became apparent that the catalytic version of the reaction was not feasible.
- Full Text:
- Date Issued: 2016
- Authors: Hassan, Yusuf
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/550 , vital:19969
- Description: Four new (+)-ketopinic acid-derived Mn(III) complexes, three of which possess pseudo C2- symmetry, were synthesised as chiral catalyst candidates. The ligands were prepared by refluxing (+)-ketopinic acid with ethane-1,2-diamine, the resolved (R,R)- and (S,S)-1,2-diaminocyclohexanes, and 1,2-diaminobenzene in chloroform. Treatment of the ligands with manganese(II) acetate tetrahydrate in refluxing ethanol afforded the respective complexes as brown amorphous powders. Characterisation of the ligands and the corresponding complexes was achieved using 1-D and 2-D NMR, IR spectroscopy, and elemental analysis. Various homogeneous asymmetric transformations, were investigated using these four complexes, viz., aldol, and Baylis-Hillman reactions, aza-Michael addition of piperidine to the Baylis-Hillman adducts, epoxidation, and ketone and imine reduction. Asymmetric aldol reactions of benzaldehyde with the aryl ketones, acetophenone, propiophenone, -tetralone, 4-nitroacetophenone, and 4-methoxyacetophenone, conducted in the presence of 10 mole % of the chiral catalysts, afforded enantioselectivities of up to 99% e.e. Asymmetric Baylis-Hillman reactions of methyl- and tert-butyl acrylates with pyridine-2- carbaldehyde, 6-methylpyridine-2-carbaldehyde, 5-chlorosalicylaldehyde, benzaldehyde, 4-chlorobenzaldehyde, and 2-nitrobenzaldehyde were conducted in the presence of catalyst 139 (10 mole %) to afford enantioselectivities of up to 44% e.e. Aza-Michael addition of piperidine to racemic Baylis- Hillman adducts in the presence of the catalyst 139 (10 mole %) was found to proceed with diastereoselectivities of up to 91% d.e. Asymmetric epoxidation of trans-methyl styrene, styrene, trans-stilbene, cis-stilbene, and indene, using a 5 mole % chiral catalyst loading and m-CPBA as the oxygen source, gave enantioselectivities of up to 32 % e.e. Asymmetric reductions of acetophenone, 3-chloropropiophenone, 4-hydroxyacetophenone, -tetralone, and 2-hydroxy-1-acetonapthone were investigated using NaBH4 as the reducing agent and a 10 mole % loading of the chiral catalysts. A stereoselectivity of 68% e.e. was obtained in the reduction of acetophenone, but attempts to reduce the selected imines to the corresponding chiral amines proved to be unsuccessful — even in the absence of the catalysts. It thus became apparent that the catalytic version of the reaction was not feasible.
- Full Text:
- Date Issued: 2016
Synthesis, spectroscopic and nonlinear optical properties of metal-free and nickel β substituted binuclear phthalocyanines
- Authors: Kabwe, Kapambwe Peter
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3013 , vital:20352
- Description: In this project, nickel and metal-free 4β-(4-tert-butylphenoxy) phthalocyanine, biphenyl bridged binuclear 4-tert-butylphenoxy phthalocyanine and naphthalene bridged binuclear 4-tert-butylphenoxy phthalocyanine have been synthesised. The Z-scan technique has been employed to comparatively study their second order nonlinear optical (NLO) properties. This work, shows that the presence of H-aggregation in binuclear Pcs of metal-free and nickel 4β-(4-tertbutylphenoxy) phthalocyanines do not have an effect on the magnitude of second order nonlinear absorption coefficient (β) as compared to monomeric Pcs. Density functional (DFT) calculations of dipolar/octupolar contributions were performed, in order to explain experimentally determined β values. Spectroscopic and photophysical properties of the synthesised compounds have been determined using a range of different spectroscopic techniques, including magnetic circular dichroism (MCD), time correlated single photon counting spectroscopy (TCSPC), UV-visible absorption spectroscopy, mass spectroscopy and IR Spectroscopy.
- Full Text:
- Date Issued: 2016
- Authors: Kabwe, Kapambwe Peter
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3013 , vital:20352
- Description: In this project, nickel and metal-free 4β-(4-tert-butylphenoxy) phthalocyanine, biphenyl bridged binuclear 4-tert-butylphenoxy phthalocyanine and naphthalene bridged binuclear 4-tert-butylphenoxy phthalocyanine have been synthesised. The Z-scan technique has been employed to comparatively study their second order nonlinear optical (NLO) properties. This work, shows that the presence of H-aggregation in binuclear Pcs of metal-free and nickel 4β-(4-tertbutylphenoxy) phthalocyanines do not have an effect on the magnitude of second order nonlinear absorption coefficient (β) as compared to monomeric Pcs. Density functional (DFT) calculations of dipolar/octupolar contributions were performed, in order to explain experimentally determined β values. Spectroscopic and photophysical properties of the synthesised compounds have been determined using a range of different spectroscopic techniques, including magnetic circular dichroism (MCD), time correlated single photon counting spectroscopy (TCSPC), UV-visible absorption spectroscopy, mass spectroscopy and IR Spectroscopy.
- Full Text:
- Date Issued: 2016
Systemic influences on the career development of a sample of black South African adolescent females: adolescent and parental perspectives
- Stolarczyk, Elizabeth Maria, McMahon, Mary
- Authors: Stolarczyk, Elizabeth Maria , McMahon, Mary
- Date: 2016
- Subjects: Career development -- Women -- South Africa , Counseling -- Women -- South Africa , Vocational guidance -- Women -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/12865 , vital:27128
- Description: Career counselling in South Africa is yet fully support the transformation process taking place nationally. More specifically, the discipline of career psychology requires the emergence of a career development theory commensurate with its diverse population. historically, extensive use was made of western career theories which were not applicable to the majority of South Africa's culturally and ethically diverse population groups consisting predominantly of black individuals of low socioeconomic status. In addition, since 1994 a black middle class has emerged in South Africa that has become increasingly prominent. Familial and parental influence on the career development of adolescents is acknowledge as pivotal; however, little South Afriucan research exists on this topic. The aim of the present study is to investigate the systematic influence on adolescent career development from the perspectives of black South African middle class grade 11 females and their parents.
- Full Text:
- Date Issued: 2016
- Authors: Stolarczyk, Elizabeth Maria , McMahon, Mary
- Date: 2016
- Subjects: Career development -- Women -- South Africa , Counseling -- Women -- South Africa , Vocational guidance -- Women -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/12865 , vital:27128
- Description: Career counselling in South Africa is yet fully support the transformation process taking place nationally. More specifically, the discipline of career psychology requires the emergence of a career development theory commensurate with its diverse population. historically, extensive use was made of western career theories which were not applicable to the majority of South Africa's culturally and ethically diverse population groups consisting predominantly of black individuals of low socioeconomic status. In addition, since 1994 a black middle class has emerged in South Africa that has become increasingly prominent. Familial and parental influence on the career development of adolescents is acknowledge as pivotal; however, little South Afriucan research exists on this topic. The aim of the present study is to investigate the systematic influence on adolescent career development from the perspectives of black South African middle class grade 11 females and their parents.
- Full Text:
- Date Issued: 2016
Taking gendered harms seriously : the utility of rape trauma syndrome evidence in dispelling rape myths in criminal trials
- Authors: Nkala, Amanda Nothabo
- Date: 2016
- Subjects: Rape trauma syndrome Women -- Crimes against Rape -- Psychological aspects
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10353/13458 , vital:39668
- Description: Rape is a violent crime marked by underreporting and low conviction rates. Notwithstanding the fact that most rape laws have been made to be gender-neutral, the statistics of rape are still devastatingly high even on a global scale. The majority of the victims are still predominantly females especially in the context of acquaintance rape. It is an uncontestable fact that rape usually occurs in secret making it possible for one to falsely accuse another and effectively rendering it difficult to refute. In light of this, victims who have managed to reach the courts have come face to face with a myriad of stereotypical beliefs and rape myths about rape victims. These have dealt a blow to their cases once their credibility is doubted because they may have exhibited behaviour that does not match with the classic or real rape victim as expected by the society. However rape is an egregiously unique crime that presents with serious psychological issues for the victim. As such it is possible for a rape victim to exhibit counterintuitive behaviour that can only be sensibly explained by an expert who has delved in human behavioural sciences. The alleged victim will be questioned on things like lengthy delay in reporting, returning to the scene of the crime, asking for taxi money the morning after the rape or even failing to scream and fight off the alleged assailant. Unfortunately, the psychological effects of rape have more often than not been overlooked in our criminal justice system giving way for blame shifting in that the female victim is called upon to account for why the rape may have happened to her. These psychological reactions, responses and counterintuitive behaviour have been characterized as Rape Trauma Syndrome by specialists in psychology and psychiatry. In the context of this study, Rape Trauma Syndrome is a form of expert opinion evidence which is relevant, helpful and necessary because it can dispel rape myths and stereotypical beliefs about rape victims by educating the courts about the psychological reactions of rape victims. Against this backdrop, this research project investigates the utility of Rape Trauma Syndrome evidence in dispelling rape myths in rape trials, focusing especially on the admissibility and use of that syndrome as evidence in other jurisdictions at the level of comparative analysis in order to establish whether it can be utilised in the South African context.
- Full Text:
- Date Issued: 2016
- Authors: Nkala, Amanda Nothabo
- Date: 2016
- Subjects: Rape trauma syndrome Women -- Crimes against Rape -- Psychological aspects
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10353/13458 , vital:39668
- Description: Rape is a violent crime marked by underreporting and low conviction rates. Notwithstanding the fact that most rape laws have been made to be gender-neutral, the statistics of rape are still devastatingly high even on a global scale. The majority of the victims are still predominantly females especially in the context of acquaintance rape. It is an uncontestable fact that rape usually occurs in secret making it possible for one to falsely accuse another and effectively rendering it difficult to refute. In light of this, victims who have managed to reach the courts have come face to face with a myriad of stereotypical beliefs and rape myths about rape victims. These have dealt a blow to their cases once their credibility is doubted because they may have exhibited behaviour that does not match with the classic or real rape victim as expected by the society. However rape is an egregiously unique crime that presents with serious psychological issues for the victim. As such it is possible for a rape victim to exhibit counterintuitive behaviour that can only be sensibly explained by an expert who has delved in human behavioural sciences. The alleged victim will be questioned on things like lengthy delay in reporting, returning to the scene of the crime, asking for taxi money the morning after the rape or even failing to scream and fight off the alleged assailant. Unfortunately, the psychological effects of rape have more often than not been overlooked in our criminal justice system giving way for blame shifting in that the female victim is called upon to account for why the rape may have happened to her. These psychological reactions, responses and counterintuitive behaviour have been characterized as Rape Trauma Syndrome by specialists in psychology and psychiatry. In the context of this study, Rape Trauma Syndrome is a form of expert opinion evidence which is relevant, helpful and necessary because it can dispel rape myths and stereotypical beliefs about rape victims by educating the courts about the psychological reactions of rape victims. Against this backdrop, this research project investigates the utility of Rape Trauma Syndrome evidence in dispelling rape myths in rape trials, focusing especially on the admissibility and use of that syndrome as evidence in other jurisdictions at the level of comparative analysis in order to establish whether it can be utilised in the South African context.
- Full Text:
- Date Issued: 2016
Tanzania's development agenda and poverty reduction : a case of Mkukuta I1
- Authors: Mandalu, Martin Petro
- Date: 2016
- Subjects: Poverty--Tanzania Tanzania--Economic conditions
- Language: English
- Type: Thesis , Doctoral , Development Studies
- Identifier: http://hdl.handle.net/10353/15616 , vital:40487
- Description: Poverty reduction has always been part of Tanzania‘s development agenda since independence in 1961. Despite wealth of natural resources, peace and political stability, the country has continued to be poor for decades. A number of strategies have been employed to address the problem; however, they have not been so successful. Studies have explored the problem and came up with explanations that are insufficient. In recent years, more studies on poverty reduction increased, following the country‘s magnificent economic growth which, however, fails to alleviate poverty in the country. Recent literature on poverty reduction calls for improvement in the productive sectors such as agriculture and construction to increase their contribution in poverty reduction. However, most studies did not pay attention to the development model/s that led the economy since independence. Motivated by the unsatisfactory results of the previous poverty reduction strategies, and lacunas of the preceding studies, this research, through MKUKUTA I, examines factors affecting the development agenda in Tanzania and their influence on poverty reduction. It investigates, as well, the development models employed in the country since independence. The study is guided by the change of development theories: from socialism to neo-liberalism. Furthermore, the study proposes an alternative development model beyond dependency and neo-liberalism schools of thoughts that have been struggling to influence development in the country for over five decades. The study employs mainly secondary data and primary data as supplementary methods to analyse and explain the mismatch between economic growth and poverty reduction in the country. The study argues that the productive sectors fail to produce sufficiently and contribute to poverty reduction since they are not guided by any specific development model. Findings suggest that failure in poverty reduction despite remarkable economic growth is caused by failure of growth in the agriculture sector which employs the largest part of the workforce in the country. Economic transformation in the country, which contributed to economic growth, failed to generate more jobs in the productive sectors. Incorrect methodologies used for obtaining economic data are alleged as possible logical explanation for the mismatch between economic growth and failure in poverty reduction. Failure in poverty reduction had a negative impact on human development as the poor, especially in the rural areas, had limited access to quality services of education, health care, water and sanitation. Moreover, findings revealed that neoliberal policies in the country are not effective enough in guiding the development agenda and poverty reduction. Despite the rule of law, peace, political stability and favourable conditions for capitalism in the country, significant features of a neoliberal economy have not been effectively developed. The local private sector is still weak at the embryonic stage, and the market is weakened by corruption and poor infrastructure for doing business. Moreover, findings suggest that for about three decades, Tanzania has not had a clear and distinct development model to guide its development agenda in poverty alleviation. The constitution suggests that the country is guided by a socialist development philosophy whereas the official government website and practices indicate that the country is run by neoliberal policies. To resolve the matter and in view of attaining the TDV 2025 and poverty reduction, this study proposes that Tanzania becomes a democratic developmental state while governed by a dependency-neoliberal theory from the amalgamation of reviewed dependency and neo-liberal schools of thoughts as a guiding principle since all developmental states need guiding philosophies to lead them. Moreover, the study proposes pragmatic interventions to implement the development model.
- Full Text:
- Date Issued: 2016
- Authors: Mandalu, Martin Petro
- Date: 2016
- Subjects: Poverty--Tanzania Tanzania--Economic conditions
- Language: English
- Type: Thesis , Doctoral , Development Studies
- Identifier: http://hdl.handle.net/10353/15616 , vital:40487
- Description: Poverty reduction has always been part of Tanzania‘s development agenda since independence in 1961. Despite wealth of natural resources, peace and political stability, the country has continued to be poor for decades. A number of strategies have been employed to address the problem; however, they have not been so successful. Studies have explored the problem and came up with explanations that are insufficient. In recent years, more studies on poverty reduction increased, following the country‘s magnificent economic growth which, however, fails to alleviate poverty in the country. Recent literature on poverty reduction calls for improvement in the productive sectors such as agriculture and construction to increase their contribution in poverty reduction. However, most studies did not pay attention to the development model/s that led the economy since independence. Motivated by the unsatisfactory results of the previous poverty reduction strategies, and lacunas of the preceding studies, this research, through MKUKUTA I, examines factors affecting the development agenda in Tanzania and their influence on poverty reduction. It investigates, as well, the development models employed in the country since independence. The study is guided by the change of development theories: from socialism to neo-liberalism. Furthermore, the study proposes an alternative development model beyond dependency and neo-liberalism schools of thoughts that have been struggling to influence development in the country for over five decades. The study employs mainly secondary data and primary data as supplementary methods to analyse and explain the mismatch between economic growth and poverty reduction in the country. The study argues that the productive sectors fail to produce sufficiently and contribute to poverty reduction since they are not guided by any specific development model. Findings suggest that failure in poverty reduction despite remarkable economic growth is caused by failure of growth in the agriculture sector which employs the largest part of the workforce in the country. Economic transformation in the country, which contributed to economic growth, failed to generate more jobs in the productive sectors. Incorrect methodologies used for obtaining economic data are alleged as possible logical explanation for the mismatch between economic growth and failure in poverty reduction. Failure in poverty reduction had a negative impact on human development as the poor, especially in the rural areas, had limited access to quality services of education, health care, water and sanitation. Moreover, findings revealed that neoliberal policies in the country are not effective enough in guiding the development agenda and poverty reduction. Despite the rule of law, peace, political stability and favourable conditions for capitalism in the country, significant features of a neoliberal economy have not been effectively developed. The local private sector is still weak at the embryonic stage, and the market is weakened by corruption and poor infrastructure for doing business. Moreover, findings suggest that for about three decades, Tanzania has not had a clear and distinct development model to guide its development agenda in poverty alleviation. The constitution suggests that the country is guided by a socialist development philosophy whereas the official government website and practices indicate that the country is run by neoliberal policies. To resolve the matter and in view of attaining the TDV 2025 and poverty reduction, this study proposes that Tanzania becomes a democratic developmental state while governed by a dependency-neoliberal theory from the amalgamation of reviewed dependency and neo-liberal schools of thoughts as a guiding principle since all developmental states need guiding philosophies to lead them. Moreover, the study proposes pragmatic interventions to implement the development model.
- Full Text:
- Date Issued: 2016
Teacher's views on the implementation of HIV/AIDS policies in schools: a case study of four high schools in Fort Beaufort Education District
- Authors: Koza, Rebecca
- Date: 2016
- Subjects: HIV infections -- Government policy -- South Africa -- Eastern Cape AIDS (Disease) -- Government policy -- South Africa -- Eastern Cape HIV infections -- Study and teaching -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: http://hdl.handle.net/10353/2105 , vital:27610
- Description: HIV/AIDS is reducing the hard-won returns on investment in education in South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Koza, Rebecca
- Date: 2016
- Subjects: HIV infections -- Government policy -- South Africa -- Eastern Cape AIDS (Disease) -- Government policy -- South Africa -- Eastern Cape HIV infections -- Study and teaching -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: http://hdl.handle.net/10353/2105 , vital:27610
- Description: HIV/AIDS is reducing the hard-won returns on investment in education in South Africa.
- Full Text:
- Date Issued: 2016
Teachers' experiences of teacher-led professional development programs :an exploratory study of two clusters in the Mthatha district
- Authors: Zide, Lulama
- Date: 2016
- Subjects: Teachers -- In-service training -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: http://hdl.handle.net/10353/10394 , vital:35444
- Description: Professional growth of teachers is not new, but in recent years, the way in which it is structured and delivered has been reconceptualised. As part of the education reform process, many nations are investing in teacher education as a major engine for driving the changes in the classrooms to ensure learners’ academic success. South Africa is no exclusion to this trend of education reforms, hence, the founding of many professional growth initiatives. Most of these initiatives are aimed at Science and Maths teachers. This was mostly because the majority of Science and Maths teachers in South Africa are considered either under-qualified or not qualified to teach the subject. Yet, despite the efforts and enthusiasm, very little seems to have shifted in the teachers’ practices. Much of the literature still shows that even clusters are not effective in changing the situation completely. Using a qualitative case study design, the researcher explored teachers’ views on their clustering experience, and the benefits such participation and experience brings to their classroom instruction. The major findings of the study show that teachers find clustering as a tool that enriches their teaching, thus, both the content knowledge as well as their pedagogical strategies. The findings also show a consensus of teachers who need the cluster programs done continuously. The researcher concludes that teachers are still not happy with the professional development that is offered to them, and therefore recommends that such programs be offered according to teacher’s need.
- Full Text:
- Date Issued: 2016
- Authors: Zide, Lulama
- Date: 2016
- Subjects: Teachers -- In-service training -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: http://hdl.handle.net/10353/10394 , vital:35444
- Description: Professional growth of teachers is not new, but in recent years, the way in which it is structured and delivered has been reconceptualised. As part of the education reform process, many nations are investing in teacher education as a major engine for driving the changes in the classrooms to ensure learners’ academic success. South Africa is no exclusion to this trend of education reforms, hence, the founding of many professional growth initiatives. Most of these initiatives are aimed at Science and Maths teachers. This was mostly because the majority of Science and Maths teachers in South Africa are considered either under-qualified or not qualified to teach the subject. Yet, despite the efforts and enthusiasm, very little seems to have shifted in the teachers’ practices. Much of the literature still shows that even clusters are not effective in changing the situation completely. Using a qualitative case study design, the researcher explored teachers’ views on their clustering experience, and the benefits such participation and experience brings to their classroom instruction. The major findings of the study show that teachers find clustering as a tool that enriches their teaching, thus, both the content knowledge as well as their pedagogical strategies. The findings also show a consensus of teachers who need the cluster programs done continuously. The researcher concludes that teachers are still not happy with the professional development that is offered to them, and therefore recommends that such programs be offered according to teacher’s need.
- Full Text:
- Date Issued: 2016
Teachers' perceptions on the effects of frequent change in curriculum on effective teaching in junior secondary schools at Libode Education District, Eastern Cape
- Ngibe, Nondwe Cynthia Phelokazi
- Authors: Ngibe, Nondwe Cynthia Phelokazi
- Date: 2016
- Subjects: Curriculum change -- South Africa -- Eastern Cape Educational change Education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5587 , vital:29349
- Description: Worldwide educational change has been a topic of discussion. South Africa is among the countries having issues with the implementation of a new curriculum and its impact on effective teaching and learning in junior secondary schools. The country (South Africa) experienced frequent changes in education curriculum. The new curriculum was seen as the means to address poor state of education. It is common knowledge that teachers were and are presently still confused and stressed being unsure on how to apply some techniques to meet the requirements of the new curriculum. That led to underperformance of learners in their work at school. Hence, this study was conducted to explore the perceptions of teachers in South Africa regarding the effects that frequent changes in curriculum has on the effective teaching and learning in junior secondary schools. The change in curriculum is frequent in the sense that, from 1997 to 2016, the curriculum in South Africa was revised four times: Curriculum 2005 (C2005) in 1997, Revised National Curriculum Statement (RNCS) in 2002, National Curriculum Statement (NCS) in 2007 as well as Curriculum and Assessment Policy Statement (CAPS) in 2012. The study does not leave behind some literatures on concept of education, teaching and learning in junior secondary schools, curriculum in South Africa, an overview of curriculum policy in South Africa, curriculum changes to mention a few. Qualitative research methodology was used by the researcher so as interview participants (teachers) in their workplace. The case study was chosen as the design, whereby two junior secondary schools from the population of schools in Libode district were purposely sampled. Data was collected from teachers in these schools, that is, six teachers from each school. Four teachers from each phase were targeted, that is, (four from foundation phase, four from intermediate phase and four from senior phase). Semi-structured interviews were used as the instrument to collect information from the participants. From the study, the researcher found confusion and frustration due to the frequent changes in curriculum; negative influence on effective teaching and learning, by the fact that teachers ultimately do not know what to do to meet the requirements of the curriculum; and not much continuity or links between phases in as far as content and subjects are concerned. The study recommended the appointment of professional facilitators, revisiting of the language policy in GET band (with focus in LOLT in foundation phase), encouraging continuity across phases, actively involvement of teachers in formulating or drafting of any policy that will affect curriculum since they are the implementers of curriculum. The study established that frequent change in curriculum had negative effects on teaching and in junior secondary schools. This is the perception of the majority of participants. As far as literature regarding teachers is concerned, changing curriculum without changing teachers’ understanding and attitude has negative impact on learning especially in South Africa, with special focus on rural schools such as those of Libode district in the Eastern Cape Province.
- Full Text:
- Date Issued: 2016
- Authors: Ngibe, Nondwe Cynthia Phelokazi
- Date: 2016
- Subjects: Curriculum change -- South Africa -- Eastern Cape Educational change Education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5587 , vital:29349
- Description: Worldwide educational change has been a topic of discussion. South Africa is among the countries having issues with the implementation of a new curriculum and its impact on effective teaching and learning in junior secondary schools. The country (South Africa) experienced frequent changes in education curriculum. The new curriculum was seen as the means to address poor state of education. It is common knowledge that teachers were and are presently still confused and stressed being unsure on how to apply some techniques to meet the requirements of the new curriculum. That led to underperformance of learners in their work at school. Hence, this study was conducted to explore the perceptions of teachers in South Africa regarding the effects that frequent changes in curriculum has on the effective teaching and learning in junior secondary schools. The change in curriculum is frequent in the sense that, from 1997 to 2016, the curriculum in South Africa was revised four times: Curriculum 2005 (C2005) in 1997, Revised National Curriculum Statement (RNCS) in 2002, National Curriculum Statement (NCS) in 2007 as well as Curriculum and Assessment Policy Statement (CAPS) in 2012. The study does not leave behind some literatures on concept of education, teaching and learning in junior secondary schools, curriculum in South Africa, an overview of curriculum policy in South Africa, curriculum changes to mention a few. Qualitative research methodology was used by the researcher so as interview participants (teachers) in their workplace. The case study was chosen as the design, whereby two junior secondary schools from the population of schools in Libode district were purposely sampled. Data was collected from teachers in these schools, that is, six teachers from each school. Four teachers from each phase were targeted, that is, (four from foundation phase, four from intermediate phase and four from senior phase). Semi-structured interviews were used as the instrument to collect information from the participants. From the study, the researcher found confusion and frustration due to the frequent changes in curriculum; negative influence on effective teaching and learning, by the fact that teachers ultimately do not know what to do to meet the requirements of the curriculum; and not much continuity or links between phases in as far as content and subjects are concerned. The study recommended the appointment of professional facilitators, revisiting of the language policy in GET band (with focus in LOLT in foundation phase), encouraging continuity across phases, actively involvement of teachers in formulating or drafting of any policy that will affect curriculum since they are the implementers of curriculum. The study established that frequent change in curriculum had negative effects on teaching and in junior secondary schools. This is the perception of the majority of participants. As far as literature regarding teachers is concerned, changing curriculum without changing teachers’ understanding and attitude has negative impact on learning especially in South Africa, with special focus on rural schools such as those of Libode district in the Eastern Cape Province.
- Full Text:
- Date Issued: 2016
Teachers' perceptions whether school management teams contribute towards teacher leadership in primary schools
- Authors: Jacobs, Elfean Randall
- Date: 2016
- Subjects: School management teams , School management and organization -- South Africa , Educational leadership -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/6823 , vital:21149
- Description: Teachers in South African schools are one of the most valuable role players in the execution and implementation of curricular and co-curricular activities. They perform almost every formal and informal task in their daily work to ensure the effectiveness of our schools. Teacher leadership, a relatively new leadership in South African education, which is embedded in a distributed leadership theory, places the emphasis of leadership not only on the principal and the school management team (SMT) but can be located to a wide range of people who work effectively to improve the organisation. The purpose of this study was to determine Post Level (PL) 1 teachers' perceptions of whether the SMT contributes towards teacher leadership in the school. In this case study, through purposive sampling, the researcher made use of one school in a case where a total of 19 teachers participated in the study. The researcher used one instrument to collect data on the PL 1 teachers' perceptions. A set of questionnaires was distributed to elicit responses from PL 1 teachers and the result was analysed by means of themes. Evidence revealed that teachers are not aware of the existence of the new model of teacher leadership. However, findings also revealed that some teachers are ready to perform as leaders. These findings can influence leadership practices, collaboration, improvements in the school, motivation, and job satisfaction, as well as learner performance.
- Full Text: false
- Date Issued: 2016
- Authors: Jacobs, Elfean Randall
- Date: 2016
- Subjects: School management teams , School management and organization -- South Africa , Educational leadership -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/6823 , vital:21149
- Description: Teachers in South African schools are one of the most valuable role players in the execution and implementation of curricular and co-curricular activities. They perform almost every formal and informal task in their daily work to ensure the effectiveness of our schools. Teacher leadership, a relatively new leadership in South African education, which is embedded in a distributed leadership theory, places the emphasis of leadership not only on the principal and the school management team (SMT) but can be located to a wide range of people who work effectively to improve the organisation. The purpose of this study was to determine Post Level (PL) 1 teachers' perceptions of whether the SMT contributes towards teacher leadership in the school. In this case study, through purposive sampling, the researcher made use of one school in a case where a total of 19 teachers participated in the study. The researcher used one instrument to collect data on the PL 1 teachers' perceptions. A set of questionnaires was distributed to elicit responses from PL 1 teachers and the result was analysed by means of themes. Evidence revealed that teachers are not aware of the existence of the new model of teacher leadership. However, findings also revealed that some teachers are ready to perform as leaders. These findings can influence leadership practices, collaboration, improvements in the school, motivation, and job satisfaction, as well as learner performance.
- Full Text: false
- Date Issued: 2016
Teaching for criticality: an analysis of the current status at two teacher education colleges in Zimbabwe
- Authors: Manyumwa, Canisius
- Date: 2016
- Subjects: Critical pedagogy -- Zimbabwe , Teachers colleges -- Zimbabwe , Teachers -- Training of -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/8119 , vital:25016
- Description: The education system in Zimbabwe is an adoption and adaptation of former colonial education that ended in 1980 with the attainment of independence. However, much of the ethos and practices of colonial education appear to have defied the transition, resulting in a transmission-based education system that is averse to critical thinking and critical pedagogy. This research study sought to find out the level of criticality at selected Zimbabwe teacher education colleges and to suggest ways of improving the development of this criticality. The study was a critical social research, situated in the transformative paradigm of qualitative research. I adopted a multi-site case study approach where focus group discussion and document analysis techniques were used in data generation at two teacher education colleges. The sample for the study comprised six (6) and seven (7) members of the Theory of Education department teaching staff at the respective institutions who volunteered to take part in the focus group discussions. The study used Antonio Gramsci’s ‘cultural hegemony’ and Malewski and Jaramillo’s ‘epistemologies of ignorance’ as its theoretical framework. The main findings were that there were very low levels of criticality in the teacher education programme because critical thinking and critical pedagogy were generally viewed negatively in the institutions. The key operational documents in the programme, the syllabus and the examination question papers did not reflect any meaningful critical thinking or critical pedagogy concepts or demands. Research participants turned out to have a very inadequate understanding of critical thinking and critical pedagogy. In addition, they blamed the failure to teach critical thinking skills on shortage of time and the large numbers of students on the teacher education programme. From analysis, both of these reasons were not convincing. From the findings in the study, I recommended a nationwide campaign to raise teacher educators’ awareness of the nature and value of developing criticality. I also recommended some formal educational programmes for key players in the teacher education system that can help advance their understanding of critical thinking and critical pedagogy. Critical thinking and critical pedagogy should be substantively included on the teacher education syllabi and examinations. Teacher education, and all other sectors of education, should go beyond just teaching criticality skills to learners. Educators need to be able to use such skills themselves in their teaching and in their own lives. My suggested framework for the inclusion of criticality in education can be used as a way of ensuring that criticality is developed and catches appeal across the country.
- Full Text:
- Date Issued: 2016
- Authors: Manyumwa, Canisius
- Date: 2016
- Subjects: Critical pedagogy -- Zimbabwe , Teachers colleges -- Zimbabwe , Teachers -- Training of -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/8119 , vital:25016
- Description: The education system in Zimbabwe is an adoption and adaptation of former colonial education that ended in 1980 with the attainment of independence. However, much of the ethos and practices of colonial education appear to have defied the transition, resulting in a transmission-based education system that is averse to critical thinking and critical pedagogy. This research study sought to find out the level of criticality at selected Zimbabwe teacher education colleges and to suggest ways of improving the development of this criticality. The study was a critical social research, situated in the transformative paradigm of qualitative research. I adopted a multi-site case study approach where focus group discussion and document analysis techniques were used in data generation at two teacher education colleges. The sample for the study comprised six (6) and seven (7) members of the Theory of Education department teaching staff at the respective institutions who volunteered to take part in the focus group discussions. The study used Antonio Gramsci’s ‘cultural hegemony’ and Malewski and Jaramillo’s ‘epistemologies of ignorance’ as its theoretical framework. The main findings were that there were very low levels of criticality in the teacher education programme because critical thinking and critical pedagogy were generally viewed negatively in the institutions. The key operational documents in the programme, the syllabus and the examination question papers did not reflect any meaningful critical thinking or critical pedagogy concepts or demands. Research participants turned out to have a very inadequate understanding of critical thinking and critical pedagogy. In addition, they blamed the failure to teach critical thinking skills on shortage of time and the large numbers of students on the teacher education programme. From analysis, both of these reasons were not convincing. From the findings in the study, I recommended a nationwide campaign to raise teacher educators’ awareness of the nature and value of developing criticality. I also recommended some formal educational programmes for key players in the teacher education system that can help advance their understanding of critical thinking and critical pedagogy. Critical thinking and critical pedagogy should be substantively included on the teacher education syllabi and examinations. Teacher education, and all other sectors of education, should go beyond just teaching criticality skills to learners. Educators need to be able to use such skills themselves in their teaching and in their own lives. My suggested framework for the inclusion of criticality in education can be used as a way of ensuring that criticality is developed and catches appeal across the country.
- Full Text:
- Date Issued: 2016