The assembly of p-aryl triazole foldamers into double and other super- helical structures
- Okerio, Jaspher Mosomi, Klumperman, Bert
- Authors: Okerio, Jaspher Mosomi , Klumperman, Bert
- Date: 2017
- Subjects: Supramolecular chemistry Chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20548 , vital:29319
- Description: The assembly of poly(para-aryltriazoles) (pPATs), synthesized via Cu(I)-catalysed azide-alkyne cycloaddition, into highly ordered structures is investigated. Firstly, the assembly of the pPATs into double helical structures, as a function of solvent quality and side chain chirality, was studied. The solvents employed (DMF and water) induced changes in van der Waals forces and surface free energy thus influencing the order of the pPATs’ random coils into double helical structures. The observed double helical structures, assembly that was analyzed using ultraviolet-visible (UV-Vis) specroscopy, circular dichroism (CD) spectroscopy, scanning transmission electron microscopy (STEM) and confocal fluorescence imaging microscopy upon addition of 0 – 80% water into the pPATs’ random coils, exhibit stable morphologies stabilized by π-π stacking and hydrogen bonding at 80% water content. The pPATs exist as random coils at 10% water in DMF. At 40% water in DMF, the pPATs’ strands were observed to exist in a side-by-side orientation. The adjacent strands, side by side, intertwine into double helices and eventually stack as the amount of water is increased to 80%. The obtained results present a facile strategy for the fabrication of polymeric double helical structures with stable morphologies. The average diameter of the resulting one-handed and opposite handed double helical structures is about 200 nm, a pitch of 170 nm and an overall length of several micrometres. The assembly of the pPATs into ordered structures in the presence of a neutral organic template and anions was also assessed. Hydrophobic poly(γ-benzyl-L-glutamate) (PBLG) template was introduced at various concentrations and transition region of the pPATs (10% water in DMF). At this stage the PBLG template is CD inactive. The template modified the assembly mechanism to afford structures, which cannot be achieved in its absence. It disallows the organization of the pPATs into double helical structures. The pPATs strands thread around the template and stack into long tubules of up to 10 microns and irregular diameter. The irregular diameter is attributed to uneven threading of pPATs strands around the template at some sections. The sensitivity and binding ability of the pPAT system to halide ions such as F-, Cl- and Br- , which involves re-organization of the aryl-triazole bonds, is explored using NMR and UV-Vis and CD spectroscopies. Br- which induces the highest shift of the triazole C-H proton signal in the NMR analysis also shows the highest dynamic quenching of the pPATs’ UV-Vis and CD spectra. The UV-Vis and CD signals are linearly dependent on the concentration of the anions. This confirms non-aggregation assembly in the presence of anions. Conclusively, the pPATs interact with the bromide anion in aqueous solution, which consequently prevents the aggregation of the foldamers. Finally, using PATs with different amounts of chiral side chains, co-operativity among side chains that leads to transfer, propagation and amplification of chirality is confirmed. A non-linear dependence of the CD signal on the amount of chiral side chains was observed. Chiral amplification was observed as low as 1% of the chiral side chains. However, approximately 20% of the chiral side chains are needed to obtain half the intensity of the cotton effect exhibited by the homochiral pPAT.
- Full Text:
- Date Issued: 2017
- Authors: Okerio, Jaspher Mosomi , Klumperman, Bert
- Date: 2017
- Subjects: Supramolecular chemistry Chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20548 , vital:29319
- Description: The assembly of poly(para-aryltriazoles) (pPATs), synthesized via Cu(I)-catalysed azide-alkyne cycloaddition, into highly ordered structures is investigated. Firstly, the assembly of the pPATs into double helical structures, as a function of solvent quality and side chain chirality, was studied. The solvents employed (DMF and water) induced changes in van der Waals forces and surface free energy thus influencing the order of the pPATs’ random coils into double helical structures. The observed double helical structures, assembly that was analyzed using ultraviolet-visible (UV-Vis) specroscopy, circular dichroism (CD) spectroscopy, scanning transmission electron microscopy (STEM) and confocal fluorescence imaging microscopy upon addition of 0 – 80% water into the pPATs’ random coils, exhibit stable morphologies stabilized by π-π stacking and hydrogen bonding at 80% water content. The pPATs exist as random coils at 10% water in DMF. At 40% water in DMF, the pPATs’ strands were observed to exist in a side-by-side orientation. The adjacent strands, side by side, intertwine into double helices and eventually stack as the amount of water is increased to 80%. The obtained results present a facile strategy for the fabrication of polymeric double helical structures with stable morphologies. The average diameter of the resulting one-handed and opposite handed double helical structures is about 200 nm, a pitch of 170 nm and an overall length of several micrometres. The assembly of the pPATs into ordered structures in the presence of a neutral organic template and anions was also assessed. Hydrophobic poly(γ-benzyl-L-glutamate) (PBLG) template was introduced at various concentrations and transition region of the pPATs (10% water in DMF). At this stage the PBLG template is CD inactive. The template modified the assembly mechanism to afford structures, which cannot be achieved in its absence. It disallows the organization of the pPATs into double helical structures. The pPATs strands thread around the template and stack into long tubules of up to 10 microns and irregular diameter. The irregular diameter is attributed to uneven threading of pPATs strands around the template at some sections. The sensitivity and binding ability of the pPAT system to halide ions such as F-, Cl- and Br- , which involves re-organization of the aryl-triazole bonds, is explored using NMR and UV-Vis and CD spectroscopies. Br- which induces the highest shift of the triazole C-H proton signal in the NMR analysis also shows the highest dynamic quenching of the pPATs’ UV-Vis and CD spectra. The UV-Vis and CD signals are linearly dependent on the concentration of the anions. This confirms non-aggregation assembly in the presence of anions. Conclusively, the pPATs interact with the bromide anion in aqueous solution, which consequently prevents the aggregation of the foldamers. Finally, using PATs with different amounts of chiral side chains, co-operativity among side chains that leads to transfer, propagation and amplification of chirality is confirmed. A non-linear dependence of the CD signal on the amount of chiral side chains was observed. Chiral amplification was observed as low as 1% of the chiral side chains. However, approximately 20% of the chiral side chains are needed to obtain half the intensity of the cotton effect exhibited by the homochiral pPAT.
- Full Text:
- Date Issued: 2017
Group membership and collective action among small-scale farmers in Nkonkobe Local Municipality, Eastern Cape Province, South Africa
- Authors: Arwari, Margaret Kwamboka
- Date: 2017
- Subjects: Farmers -- South Africa -- Eastern Cape Farms, Small -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8144 , vital:31535
- Description: In South Africa, the organisation of farmers into groups has been a basic tenet for numerous, small and dispersed small-scale farmers to make their voices heard, address challenges and access support services from the government and other development agencies. However, the literature shows that the South African government promotes inappropriate forms of farmer collective action, i.e. collective production. The government seems to lack knowledge on what forms of collective action to implement and support. It is also noted in the literature that in South Africa, the majority of farmers do not participate in farmer organisations. There is limited research on the determinants of membership in farmer organisations, especially in terms of the role of ‘human agency’. Human agency is a concept which is interrelated with the concept of ‘empowerme nt’, whereby a person with strong agency is someone who is an agent of positive change. Therefore, the study sought to address these gaps. The broad objective of this study was to explore the phenomenon of group membership and collective action among small-scale farmers in Nkonkobe Local Municipality, Eastern Cape Province, South Africa. The study used the mixed method approach where an exploratory design was employed. A mult istage sampling technique was used which employed random, purposive and convenience sampling techniques. Quantitative and qualitative data were collected from 245 farmers using semistructured questionnaires and detailed qualitative data were elicited from 16 farmer organisat ions using interview guides. For the quantitative research, a cross-sectional survey design was employed. After discarded unusable observations, data from 228 farmers were analysed using a combination of descriptive statistics, simple inferential statistics, and econometric analysis. For the qualitative data obtained, thematic analysis was used in line with the study objectives. The study findings show that farmers undertake collective action through farmer organisations. These farmer organisations were categorised into two types, i.e. farmer cooperatives and farmer associations. However, low membership in these farmer organisations is noted and this was attributed to the following: (1) low farmer awareness of the existence of farmer organisations, (2) challenges faced by the organisations that contribute to their ineffectiveness and thus low membership, (3) the prevalence of negative perceptions of farmer organisations due to confusion as to their role, (4) the government’s farmer support approach which compels or encourages farmers to form groups. The results also showed that the following are determinants of participation in farmer organisations: farmer’s age, level of education, human agency, whether a farmer has off-farm income sources, whether a farmer is involved in government supported projects, whether a farmer accesses extension information, the number of visits from extension officers received by a farmer, and the number of adults in a household contributing family labour. The study findings also show that the farmers in farmer organisations have higher human agency compared to those not in farmer organisations. According to the study results, farmer groups offer a number of benefits. For one, farmer organisations are avenues for farmers’ voices to be heard, they lobby government for better access to support services such as credit, input supply, information, and training. In addition, farmers who belong to organisations experience the benefits of collective marketing. Despite the aforementioned benefits of farmer organisations, group challenges are observed. For example, farmer organisations face declining membership, the free rider problem and conflicts between members, have a problem of ineffective, old members and lack of commitment of some group members. It was therefore recommended that there is a need for concerted effort by the government, development agencies, non-governmental organisations, farmers, and farmer organisations to ensure the success of farmer organisations in promoting small-scale agriculture.
- Full Text:
- Date Issued: 2017
- Authors: Arwari, Margaret Kwamboka
- Date: 2017
- Subjects: Farmers -- South Africa -- Eastern Cape Farms, Small -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8144 , vital:31535
- Description: In South Africa, the organisation of farmers into groups has been a basic tenet for numerous, small and dispersed small-scale farmers to make their voices heard, address challenges and access support services from the government and other development agencies. However, the literature shows that the South African government promotes inappropriate forms of farmer collective action, i.e. collective production. The government seems to lack knowledge on what forms of collective action to implement and support. It is also noted in the literature that in South Africa, the majority of farmers do not participate in farmer organisations. There is limited research on the determinants of membership in farmer organisations, especially in terms of the role of ‘human agency’. Human agency is a concept which is interrelated with the concept of ‘empowerme nt’, whereby a person with strong agency is someone who is an agent of positive change. Therefore, the study sought to address these gaps. The broad objective of this study was to explore the phenomenon of group membership and collective action among small-scale farmers in Nkonkobe Local Municipality, Eastern Cape Province, South Africa. The study used the mixed method approach where an exploratory design was employed. A mult istage sampling technique was used which employed random, purposive and convenience sampling techniques. Quantitative and qualitative data were collected from 245 farmers using semistructured questionnaires and detailed qualitative data were elicited from 16 farmer organisat ions using interview guides. For the quantitative research, a cross-sectional survey design was employed. After discarded unusable observations, data from 228 farmers were analysed using a combination of descriptive statistics, simple inferential statistics, and econometric analysis. For the qualitative data obtained, thematic analysis was used in line with the study objectives. The study findings show that farmers undertake collective action through farmer organisations. These farmer organisations were categorised into two types, i.e. farmer cooperatives and farmer associations. However, low membership in these farmer organisations is noted and this was attributed to the following: (1) low farmer awareness of the existence of farmer organisations, (2) challenges faced by the organisations that contribute to their ineffectiveness and thus low membership, (3) the prevalence of negative perceptions of farmer organisations due to confusion as to their role, (4) the government’s farmer support approach which compels or encourages farmers to form groups. The results also showed that the following are determinants of participation in farmer organisations: farmer’s age, level of education, human agency, whether a farmer has off-farm income sources, whether a farmer is involved in government supported projects, whether a farmer accesses extension information, the number of visits from extension officers received by a farmer, and the number of adults in a household contributing family labour. The study findings also show that the farmers in farmer organisations have higher human agency compared to those not in farmer organisations. According to the study results, farmer groups offer a number of benefits. For one, farmer organisations are avenues for farmers’ voices to be heard, they lobby government for better access to support services such as credit, input supply, information, and training. In addition, farmers who belong to organisations experience the benefits of collective marketing. Despite the aforementioned benefits of farmer organisations, group challenges are observed. For example, farmer organisations face declining membership, the free rider problem and conflicts between members, have a problem of ineffective, old members and lack of commitment of some group members. It was therefore recommended that there is a need for concerted effort by the government, development agencies, non-governmental organisations, farmers, and farmer organisations to ensure the success of farmer organisations in promoting small-scale agriculture.
- Full Text:
- Date Issued: 2017
Leadership style and organisational culture's effect on employee organisational commitment at Zimbabwe Electricity Supply Authority
- Authors: Garande, Bertha
- Date: 2017
- Subjects: Corporate culture Organizational commitment Employee motivation
- Language: English
- Type: Thesis , Masters , MAdmin
- Identifier: http://hdl.handle.net/10353/8429 , vital:32787
- Description: Orientation: “Any company can become a great place to work for”. This is an appealing statement but how are great places to work characterised? In an era characterised by turbulent changes in business environment due to elements like globalisation, organisations are trying their best to attain competitive advantage. Organisational commitment has been pointed by most researchers as a survival aspect for most organisations. However, internal organisational aspects such as leadership style and organisational culture needs to be closely looked at as they influence the level of commitment employees will have to an organisation. Research purpose: The objective of this study was to explore the effect of leadership style and organisational culture on employee organisational commitment. Motivation for the study: Employee organisational commitment is becoming a challenge for organisations regardless of the type or field of operation. Factors like leadership style and organisational culture needs to be closely scrutinised if organisations are to be successful as they are constantly affected by drastic changes facing organisations in today’s world. Research design, approach and method: A questionnaire was used as a method for data collection and it was administered to a sample of 250 respondents at Zimbabwe Electricity Supply Authority in Zimbabwe. Random sampling was used to select respondents. Main findings: Chi-square tests and multiple regression analysis were applied in testing the statistical significance of the relationship among variables. The results indicated that leadership style and organisational culture had a significant positive relationship on organisational commitment. Practical implications: The results of this study showed that managers should strategise or develop programmes that enhances employee retention so as to overcome labour turnover problems due to lack of employee commitment. The study also clearly indicated that better leadership style and organisational culture is fundamental in enhancing employee commitment in an organisation. Contribution: The findings of this study showed that leadership style and organisational culture have a positive significant effect on employee commitment.
- Full Text:
- Date Issued: 2017
- Authors: Garande, Bertha
- Date: 2017
- Subjects: Corporate culture Organizational commitment Employee motivation
- Language: English
- Type: Thesis , Masters , MAdmin
- Identifier: http://hdl.handle.net/10353/8429 , vital:32787
- Description: Orientation: “Any company can become a great place to work for”. This is an appealing statement but how are great places to work characterised? In an era characterised by turbulent changes in business environment due to elements like globalisation, organisations are trying their best to attain competitive advantage. Organisational commitment has been pointed by most researchers as a survival aspect for most organisations. However, internal organisational aspects such as leadership style and organisational culture needs to be closely looked at as they influence the level of commitment employees will have to an organisation. Research purpose: The objective of this study was to explore the effect of leadership style and organisational culture on employee organisational commitment. Motivation for the study: Employee organisational commitment is becoming a challenge for organisations regardless of the type or field of operation. Factors like leadership style and organisational culture needs to be closely scrutinised if organisations are to be successful as they are constantly affected by drastic changes facing organisations in today’s world. Research design, approach and method: A questionnaire was used as a method for data collection and it was administered to a sample of 250 respondents at Zimbabwe Electricity Supply Authority in Zimbabwe. Random sampling was used to select respondents. Main findings: Chi-square tests and multiple regression analysis were applied in testing the statistical significance of the relationship among variables. The results indicated that leadership style and organisational culture had a significant positive relationship on organisational commitment. Practical implications: The results of this study showed that managers should strategise or develop programmes that enhances employee retention so as to overcome labour turnover problems due to lack of employee commitment. The study also clearly indicated that better leadership style and organisational culture is fundamental in enhancing employee commitment in an organisation. Contribution: The findings of this study showed that leadership style and organisational culture have a positive significant effect on employee commitment.
- Full Text:
- Date Issued: 2017
South-South labour migration complexities and shifting visa policies in South Africa: a sociological analysis of Rhodes University academic labour migrants’ perceptions
- Authors: Domboka, Edward
- Date: 2017
- Subjects: Foreign workers -- South Africa , Foreign workers -- Government policy -- South Africa , College teachers, Foreign -- South Africa -- Attitudes , College teacher mobility -- Africa , Visas -- South Africa , Rhodes University -- Employees -- Attitudes
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/46242 , vital:25593
- Description: International migration is an old phenomenon caused by many factors divided into push and pull factors. However, there is no enough coverage on the perceptions of the labour migrants. Although there is a vast body of writing on migration, this study delves into the experiential perceptions of academic labour migrants at Rhodes University. These academic labour migrants include professors, lecturers, researchers and postdoctoral research fellows. The study took a qualitative approach to document the experiential perceptions of academic labour migrants at Rhodes University. In-depth interviews were conducted with twelve respondents, to analyse how academic labour migrants perceive South Africa’s changing visa policies in the context of regional integration and development, migration networks and choice, host-migrant relations. The study is underpinned by Probsting’s (2015) concept of "spatial fix" in the context of capitalism and migration, to locate the positionality of academic labour migrants within a capitalist society. The study established that the increase in skilled labour migration is relatively linked to the expansion of capitalism. Based on the perceptions of the respondents, the study concluded that migration is inherently vital in providing cheap labour for capitalists. It established that changing visa policies is not without problems. Historical dispositions of the apartheid system, conflicting domestic versus international imperatives, neo-liberal policies and the widely condemned results of capitalism as an imperialist system and other factors influence migration management in South Africa.
- Full Text:
- Date Issued: 2017
- Authors: Domboka, Edward
- Date: 2017
- Subjects: Foreign workers -- South Africa , Foreign workers -- Government policy -- South Africa , College teachers, Foreign -- South Africa -- Attitudes , College teacher mobility -- Africa , Visas -- South Africa , Rhodes University -- Employees -- Attitudes
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/46242 , vital:25593
- Description: International migration is an old phenomenon caused by many factors divided into push and pull factors. However, there is no enough coverage on the perceptions of the labour migrants. Although there is a vast body of writing on migration, this study delves into the experiential perceptions of academic labour migrants at Rhodes University. These academic labour migrants include professors, lecturers, researchers and postdoctoral research fellows. The study took a qualitative approach to document the experiential perceptions of academic labour migrants at Rhodes University. In-depth interviews were conducted with twelve respondents, to analyse how academic labour migrants perceive South Africa’s changing visa policies in the context of regional integration and development, migration networks and choice, host-migrant relations. The study is underpinned by Probsting’s (2015) concept of "spatial fix" in the context of capitalism and migration, to locate the positionality of academic labour migrants within a capitalist society. The study established that the increase in skilled labour migration is relatively linked to the expansion of capitalism. Based on the perceptions of the respondents, the study concluded that migration is inherently vital in providing cheap labour for capitalists. It established that changing visa policies is not without problems. Historical dispositions of the apartheid system, conflicting domestic versus international imperatives, neo-liberal policies and the widely condemned results of capitalism as an imperialist system and other factors influence migration management in South Africa.
- Full Text:
- Date Issued: 2017
Tetra 4-(propargyloxy)phenoxy phthalocyanines: synthesis, spectroscopic, nonlinear optical and electrocatalytic properties
- Authors: Mwanza, Daniel
- Date: 2017
- Subjects: Phthalocyanines , Nonlinear optics , Electrocatalysis , Spectrum analysis , Thermogravimetry , Phthalocyanines Spectra
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65144 , vital:28695
- Description: This study presents the synthesis, spectroscopic, photophysical and theoretical characterisation of metal-free (H2TPrOPhOPc), cobalt (CoTPrOPhOPc) and manganese (MnTPrOPhOPc) tetra 4-(4-propargyloxy) phenoxy phthalocyanines. Thermal analysis using thermogravimetric analysis (TGA) confirmed the excellent thermal stability of synthesized tetra 4-(4- propargyloxy) phenoxy phthalocyanines. The metal complexes, CoTPrOPhOPc and MnTPrOPhOPc, exhibited better thermal stability when compared to H2TPrOPhOPc. The residual percentage weight remaining was approximately 70% for CoTPrOPhOPc and MnTPrOPhOPc and 45% for H2TPrOPhOPc after 600°C, clearly confirming the stability of the metal complexes. The MTPrOPhOPcs (where M = H2, Co and Mn) complexes exhibited excellent nonlinear optical properties with strong reverse saturable absorption (RSA), especially when 560 nm excitation laser was used. Their nonlinear optical properties followed this trend: H2TPrOPhOPc > CoTPrOPhOPc > MnTPrOPhOPc. According to the trend observed, the H2TPrOPhOPc was an excellent nonlinear optical limiter when compared to the CoTPrOPhOPc and MnTPrOPhOPc. All the investigated complexes exhibited optical limiting properties comparable to the phthalocyanine complexes reported in the literature. The MTPrOPhOPc complexes were further studied for their electrocatalytic and electroanalytical properties towards the detection of hydrogen peroxide. For the electrocatalytic studies, the synthesized complexes were immobilized onto gold electrode surfaces pre-functionalized with phenylazide (Au-PAz) monolayer. Copper (I) catalyzed alkynyl-azide cycloaddition reaction was used to covalently immobilize the MTPrOPhOPcs onto the gold electrode surfaces to form Au-PAz-MTPrOPhOPc. The MTPrOPhOPcs modified gold surfaces (Au-PAz-MTPrOPhOPc) exhibited good reproducibility and stability in various electrolyte conditions. Electrochemical and surface characterisation of the functionalised gold electrode surfaces confirmed the presence of the MTPrOPhOPcs and their electroanalysis was excellent towards electrocatalytic reduction of H2O2, with the limit of detection (LoD) and limit of quantification (LoQ) in the ^M range. The electrocatalytic reduction peaks for H2O2 were observed at -0.37 V for Au-PAz-MnTPrOPhOPc and -0.31 V for Au-PAz-CoTPrOPhOPc when Ag|AgCl pseudo-reference electrode was used. The Au-PAz-MnTPrOPhOPc and Au- PAz-CoTPrOPhOPc gold electrode surfaces showed good sensitivity and reproducibility towards the electrocatalytic reduction of hydrogen peroxide in pH 7.4 phosphate buffer solution. , Thesis (MSc) -- Faculty of Science, Chemistry, 2017
- Full Text:
- Date Issued: 2017
- Authors: Mwanza, Daniel
- Date: 2017
- Subjects: Phthalocyanines , Nonlinear optics , Electrocatalysis , Spectrum analysis , Thermogravimetry , Phthalocyanines Spectra
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65144 , vital:28695
- Description: This study presents the synthesis, spectroscopic, photophysical and theoretical characterisation of metal-free (H2TPrOPhOPc), cobalt (CoTPrOPhOPc) and manganese (MnTPrOPhOPc) tetra 4-(4-propargyloxy) phenoxy phthalocyanines. Thermal analysis using thermogravimetric analysis (TGA) confirmed the excellent thermal stability of synthesized tetra 4-(4- propargyloxy) phenoxy phthalocyanines. The metal complexes, CoTPrOPhOPc and MnTPrOPhOPc, exhibited better thermal stability when compared to H2TPrOPhOPc. The residual percentage weight remaining was approximately 70% for CoTPrOPhOPc and MnTPrOPhOPc and 45% for H2TPrOPhOPc after 600°C, clearly confirming the stability of the metal complexes. The MTPrOPhOPcs (where M = H2, Co and Mn) complexes exhibited excellent nonlinear optical properties with strong reverse saturable absorption (RSA), especially when 560 nm excitation laser was used. Their nonlinear optical properties followed this trend: H2TPrOPhOPc > CoTPrOPhOPc > MnTPrOPhOPc. According to the trend observed, the H2TPrOPhOPc was an excellent nonlinear optical limiter when compared to the CoTPrOPhOPc and MnTPrOPhOPc. All the investigated complexes exhibited optical limiting properties comparable to the phthalocyanine complexes reported in the literature. The MTPrOPhOPc complexes were further studied for their electrocatalytic and electroanalytical properties towards the detection of hydrogen peroxide. For the electrocatalytic studies, the synthesized complexes were immobilized onto gold electrode surfaces pre-functionalized with phenylazide (Au-PAz) monolayer. Copper (I) catalyzed alkynyl-azide cycloaddition reaction was used to covalently immobilize the MTPrOPhOPcs onto the gold electrode surfaces to form Au-PAz-MTPrOPhOPc. The MTPrOPhOPcs modified gold surfaces (Au-PAz-MTPrOPhOPc) exhibited good reproducibility and stability in various electrolyte conditions. Electrochemical and surface characterisation of the functionalised gold electrode surfaces confirmed the presence of the MTPrOPhOPcs and their electroanalysis was excellent towards electrocatalytic reduction of H2O2, with the limit of detection (LoD) and limit of quantification (LoQ) in the ^M range. The electrocatalytic reduction peaks for H2O2 were observed at -0.37 V for Au-PAz-MnTPrOPhOPc and -0.31 V for Au-PAz-CoTPrOPhOPc when Ag|AgCl pseudo-reference electrode was used. The Au-PAz-MnTPrOPhOPc and Au- PAz-CoTPrOPhOPc gold electrode surfaces showed good sensitivity and reproducibility towards the electrocatalytic reduction of hydrogen peroxide in pH 7.4 phosphate buffer solution. , Thesis (MSc) -- Faculty of Science, Chemistry, 2017
- Full Text:
- Date Issued: 2017
Alex Baine's women's emancipation in Uganda: a visual archive of the history of a new generation of women in Uganda
- Authors: Tumusiime, Amanda
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145631 , vital:38453 , https://0-doi.org.wam.seals.ac.za/10.1162/AFAR_a_00344
- Description: Alex Baine is a contemporary Ugandan woman artist who graduated from the Margaret Trowell School of Industrial and Fine Art (or MTSIFA) in 1989. During her final year, she painted a large work, Women's Emancipation in Uganda (Fig. 1) (1989), in which she represented women in domestic and nondomestic (conventional and unconventional) economies, spaces, and histories. Baine has not produced any other painting since her graduation. It is evident that Baine's art career, like those of several other female graduates of the Art School, has been interrupted by many issues including family, business, further education, and diversion into other professions. However, in this article I acknowledge that she championed women's emancipation in Uganda's contemporary art in the 1980s, a debate that I trace in her work.
- Full Text:
- Date Issued: 2017
- Authors: Tumusiime, Amanda
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145631 , vital:38453 , https://0-doi.org.wam.seals.ac.za/10.1162/AFAR_a_00344
- Description: Alex Baine is a contemporary Ugandan woman artist who graduated from the Margaret Trowell School of Industrial and Fine Art (or MTSIFA) in 1989. During her final year, she painted a large work, Women's Emancipation in Uganda (Fig. 1) (1989), in which she represented women in domestic and nondomestic (conventional and unconventional) economies, spaces, and histories. Baine has not produced any other painting since her graduation. It is evident that Baine's art career, like those of several other female graduates of the Art School, has been interrupted by many issues including family, business, further education, and diversion into other professions. However, in this article I acknowledge that she championed women's emancipation in Uganda's contemporary art in the 1980s, a debate that I trace in her work.
- Full Text:
- Date Issued: 2017
Minimum dietary diversity scores for women indicate micronutrient adequacy and food insecurity status in South African towns
- Chakona, Gamuchirai, Shackleton, Charlie M
- Authors: Chakona, Gamuchirai , Shackleton, Charlie M
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60930 , vital:27892 , http://dx.doi.org/10.3390/nu9080812
- Description: The lack of dietary diversity is a severe problem experienced by most poor households globally. In particular; women of reproductive age (WRA) are at high risk of inadequate intake of micronutrients resulting from diets dominated by starchy staples. The present study considered the diets, dietary diversity, and food security of women aged 15-49 years along the rural-urban continuum in three South African towns situated along an agro-ecological gradient. A 48 h dietary recall was conducted across two seasons with 554 women from rural, peri-urban, and urban locations of Richards Bay, Dundee, and Harrismith. Minimum Dietary Diversity for WRA (MDD-W) were calculated and a dichotomous indicator based on a set of ten food groups was used to determine if women had consumed at least five food groups the previous 48 h to achieve minimum dietary intake for women. The mean (±sd) MDD-W for Richards Bay (3.78 ± 0.07) was significantly higher than at Dundee (3.21 ± 0.08) and Harrismith (3.36 ± 0.07). Food security and MDD-W were significantly higher in urban locations than in peri-urban or rural ones. There was lower dependence on food purchasing in Richards Bay compared to Dundee and Harrismith. The majority of women in Richards Bay practiced subsistence agriculture, produced a surplus for sale, and collected wild foods which improved dietary intake and food security. The peri-urban populations had limited dietary intake and were more food insecure because of high levels of poverty, unemployment, and lack of land. Peri-urban dwellers are therefore more sensitive to changes in incomes and food prices because they lack safety nets to absorb income or price shocks as they purchase more, rather than growing their own food. This compromises dietary diversity as they have limited access to diverse foods.
- Full Text:
- Date Issued: 2017
- Authors: Chakona, Gamuchirai , Shackleton, Charlie M
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60930 , vital:27892 , http://dx.doi.org/10.3390/nu9080812
- Description: The lack of dietary diversity is a severe problem experienced by most poor households globally. In particular; women of reproductive age (WRA) are at high risk of inadequate intake of micronutrients resulting from diets dominated by starchy staples. The present study considered the diets, dietary diversity, and food security of women aged 15-49 years along the rural-urban continuum in three South African towns situated along an agro-ecological gradient. A 48 h dietary recall was conducted across two seasons with 554 women from rural, peri-urban, and urban locations of Richards Bay, Dundee, and Harrismith. Minimum Dietary Diversity for WRA (MDD-W) were calculated and a dichotomous indicator based on a set of ten food groups was used to determine if women had consumed at least five food groups the previous 48 h to achieve minimum dietary intake for women. The mean (±sd) MDD-W for Richards Bay (3.78 ± 0.07) was significantly higher than at Dundee (3.21 ± 0.08) and Harrismith (3.36 ± 0.07). Food security and MDD-W were significantly higher in urban locations than in peri-urban or rural ones. There was lower dependence on food purchasing in Richards Bay compared to Dundee and Harrismith. The majority of women in Richards Bay practiced subsistence agriculture, produced a surplus for sale, and collected wild foods which improved dietary intake and food security. The peri-urban populations had limited dietary intake and were more food insecure because of high levels of poverty, unemployment, and lack of land. Peri-urban dwellers are therefore more sensitive to changes in incomes and food prices because they lack safety nets to absorb income or price shocks as they purchase more, rather than growing their own food. This compromises dietary diversity as they have limited access to diverse foods.
- Full Text:
- Date Issued: 2017
The influence of radiation-induced defects on thermoluminescence and optically stimulated luminescence of α-Al2O3: C
- Nyirenda, Angel N, Chithambo, Makaiko L
- Authors: Nyirenda, Angel N , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/119818 , vital:34786 , https://doi.org/10.1016/j.nimb.2017.02.077
- Description: It is known that when α-Al2O3:C is exposed to excessive amounts of ionising radiation, defects are induced within its matrix. We report the influence of radiation-induced defects on the thermoluminescence (TL) and optically stimulated luminescence (OSL) measured from α-Al2O3:C after irradiation to 1000 Gy. These radiation-induced defects are thermally unstable in the region 450–650 °C and result in TL peaks in this range when the TL is measured at 1 °C/s. Heating a sample to 700 °C obliterates the radiation-induced defects, that is, the TL peaks corresponding to the radiation induced defects are no longer observed in the subsequent TL measurements when moderate irradiation doses below 10 Gy are used. The charge traps associated with these radiation-induced defects are more stable than the dosimetric trap when the sample is exposed to either sunlight or 470-nm blue light from LEDs. TL glow curves measured following the defect-inducing irradiation produce a dosimetric peak that is broader and positioned at a higher temperature than observed in glow curves obtained before the heavy irradiation. In addition, sample sensitization/desensitization occurs due to the presence of these radiation-induced defects. Furthermore, both the activation energy and the kinetic order of the dosimetric peak evaluated when the radiation-induced defects are present in the sample are significantly lower in value than those obtained when these defects are absent. The radiation-induced defects also affect the shape and total light sum of the OSL signal as well as the position and width of the resultant residual phototransferred thermoluminescence main peak.
- Full Text: false
- Date Issued: 2017
- Authors: Nyirenda, Angel N , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/119818 , vital:34786 , https://doi.org/10.1016/j.nimb.2017.02.077
- Description: It is known that when α-Al2O3:C is exposed to excessive amounts of ionising radiation, defects are induced within its matrix. We report the influence of radiation-induced defects on the thermoluminescence (TL) and optically stimulated luminescence (OSL) measured from α-Al2O3:C after irradiation to 1000 Gy. These radiation-induced defects are thermally unstable in the region 450–650 °C and result in TL peaks in this range when the TL is measured at 1 °C/s. Heating a sample to 700 °C obliterates the radiation-induced defects, that is, the TL peaks corresponding to the radiation induced defects are no longer observed in the subsequent TL measurements when moderate irradiation doses below 10 Gy are used. The charge traps associated with these radiation-induced defects are more stable than the dosimetric trap when the sample is exposed to either sunlight or 470-nm blue light from LEDs. TL glow curves measured following the defect-inducing irradiation produce a dosimetric peak that is broader and positioned at a higher temperature than observed in glow curves obtained before the heavy irradiation. In addition, sample sensitization/desensitization occurs due to the presence of these radiation-induced defects. Furthermore, both the activation energy and the kinetic order of the dosimetric peak evaluated when the radiation-induced defects are present in the sample are significantly lower in value than those obtained when these defects are absent. The radiation-induced defects also affect the shape and total light sum of the OSL signal as well as the position and width of the resultant residual phototransferred thermoluminescence main peak.
- Full Text: false
- Date Issued: 2017
Mineralogy and geochemistry of structurally-controlled metasomatic alteration of carbonate-rich manganese ore at Mamatwan Mine, Kalahari Manganese Field
- Authors: Harawa, Esau Tonderai
- Date: 2017
- Subjects: Metasomatism (Mineralogy) , Manganese ores -- Geology -- South Africa , Geology -- South Africa , Mamatwan Mine (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4717 , vital:20715
- Description: The Kalahari Manganese Field (KMF) located in the Northern Cape Province about 700km south west of Johannesburg contains 80% of the world manganese ore reserves. Mamatwan Mine is hosted within the low grade Mamatwan type ore and is located in the southernmost tip of the KMF. This mine is an open pit mine which is divided into three benches namely the top cut, middle cut and bottom cut. These three benches are structurally controlled by faults which influence the overall grade of the manganese ore. This study is a follow up work to the previous two studies carried out at Wessels Mine and Mamatwan Mine by (Gutzmer and Beukes) in 1995 and 1996 respectively with regards to alteration processes around fault controlled systems in which they concluded that epithermal fluids caused local reduction and bleaching of ore followed by oxidation and carbonate leaching of manganese ore through ascending oxidized groundwater. Metasomatic activity around fault controlled systems is controlled by three main processes namely redistribution, enrichment and depletion. These processes are determined by mobility/immobility of elements from the fault which are introduced into the pre-existing braunite carbonate rich ore. Elements such as Ca, Mg, Si, Fe, C and Mn interact with pre-existing ore due to temperature, fluid pressure, physico-chemical property of fluid gradient. Structurally, faulting and folding contribute to the movement of elements as one end of the system gets depleted the other end of the system gets enriched and vice versa. To better understand this metasomatic activity, it is crucial to conduct mass balance studies of these elements. Grant (1986) introduced the isocon diagram which is a modification of Gresen’s equation (1967) to ascertain which elements are directly or indirectly related to alteration through enrichment and depletion of Ca, Mg, Si, Fe, C and Mn. As the section approaches from altered to less altered manganese ore the mineral chemistry gradually changes from a manganese rich matrix composed of manganomelane and todorokite to a carbonate rich matrix composed of braunite, dolomite, kutnohorite and Mn-rich calcites.
- Full Text:
- Date Issued: 2017
- Authors: Harawa, Esau Tonderai
- Date: 2017
- Subjects: Metasomatism (Mineralogy) , Manganese ores -- Geology -- South Africa , Geology -- South Africa , Mamatwan Mine (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4717 , vital:20715
- Description: The Kalahari Manganese Field (KMF) located in the Northern Cape Province about 700km south west of Johannesburg contains 80% of the world manganese ore reserves. Mamatwan Mine is hosted within the low grade Mamatwan type ore and is located in the southernmost tip of the KMF. This mine is an open pit mine which is divided into three benches namely the top cut, middle cut and bottom cut. These three benches are structurally controlled by faults which influence the overall grade of the manganese ore. This study is a follow up work to the previous two studies carried out at Wessels Mine and Mamatwan Mine by (Gutzmer and Beukes) in 1995 and 1996 respectively with regards to alteration processes around fault controlled systems in which they concluded that epithermal fluids caused local reduction and bleaching of ore followed by oxidation and carbonate leaching of manganese ore through ascending oxidized groundwater. Metasomatic activity around fault controlled systems is controlled by three main processes namely redistribution, enrichment and depletion. These processes are determined by mobility/immobility of elements from the fault which are introduced into the pre-existing braunite carbonate rich ore. Elements such as Ca, Mg, Si, Fe, C and Mn interact with pre-existing ore due to temperature, fluid pressure, physico-chemical property of fluid gradient. Structurally, faulting and folding contribute to the movement of elements as one end of the system gets depleted the other end of the system gets enriched and vice versa. To better understand this metasomatic activity, it is crucial to conduct mass balance studies of these elements. Grant (1986) introduced the isocon diagram which is a modification of Gresen’s equation (1967) to ascertain which elements are directly or indirectly related to alteration through enrichment and depletion of Ca, Mg, Si, Fe, C and Mn. As the section approaches from altered to less altered manganese ore the mineral chemistry gradually changes from a manganese rich matrix composed of manganomelane and todorokite to a carbonate rich matrix composed of braunite, dolomite, kutnohorite and Mn-rich calcites.
- Full Text:
- Date Issued: 2017
Strain behaviour of an eco-car wheel rim designed through topology and composite layup optimization
- Authors: Badenhorst, Martin Wessel
- Date: 2017
- Subjects: Wheels -- Design and construction Mechanical engineering
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/16066 , vital:28317
- Description: This research aimed to reduce the mass of a purpose built eco-car wheel through the sequential use of structural topology and composites optimization software packages while investigating the changes in mass and strain behaviour resulting from altering component geometry, lamina shape, and stacking sequence. The strain behaviour of a commercially available wheel constructed using pre-tensioned steel spokes was established through the comparison of measured physical and FEA strains resulting from applied pressure, radial, lateral, torsional, and combined loads. Structural topology optimization software was then utilized to produce 48 different wheel geometries corresponding to a combined loading scenario consisting of pressure, radial, and lateral loads. The variables controlled during this process included the objective optimization function, safety factor, target design volume, split-draw constraint, and degrees of cyclic symmetry. The optimum geometry was determined by means of evaluating specific stiffness and potential towards being manufactured as a composite component. Three composite wheel FEA base models, with uni-directional laminae stacked at different fibre orientation intervals, were created according to this geometry and lightened by means of composite free size optimization. Composite sizing and shuffling optimizations were then utilized to further enhance the mass and strain characteristics of the lightest of these three solutions Two composite wheels were manufactured according to the wheel geometry, lamina shapes, and stacking sequences determined by means of structural topology and composites ptimizations. The physical mass and strain behaviour of these wheels were measured and compared to those corresponding to the optimized FEA model, as well as the commercially available wheel. This comparison showed that structural topology and composites optimization software packages can be sequentially utilized to produce an adequately stiff composite wheel of lower mass than a commercially available wheel constructed using pre-tensioned steel spokes.
- Full Text:
- Date Issued: 2017
- Authors: Badenhorst, Martin Wessel
- Date: 2017
- Subjects: Wheels -- Design and construction Mechanical engineering
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/16066 , vital:28317
- Description: This research aimed to reduce the mass of a purpose built eco-car wheel through the sequential use of structural topology and composites optimization software packages while investigating the changes in mass and strain behaviour resulting from altering component geometry, lamina shape, and stacking sequence. The strain behaviour of a commercially available wheel constructed using pre-tensioned steel spokes was established through the comparison of measured physical and FEA strains resulting from applied pressure, radial, lateral, torsional, and combined loads. Structural topology optimization software was then utilized to produce 48 different wheel geometries corresponding to a combined loading scenario consisting of pressure, radial, and lateral loads. The variables controlled during this process included the objective optimization function, safety factor, target design volume, split-draw constraint, and degrees of cyclic symmetry. The optimum geometry was determined by means of evaluating specific stiffness and potential towards being manufactured as a composite component. Three composite wheel FEA base models, with uni-directional laminae stacked at different fibre orientation intervals, were created according to this geometry and lightened by means of composite free size optimization. Composite sizing and shuffling optimizations were then utilized to further enhance the mass and strain characteristics of the lightest of these three solutions Two composite wheels were manufactured according to the wheel geometry, lamina shapes, and stacking sequences determined by means of structural topology and composites ptimizations. The physical mass and strain behaviour of these wheels were measured and compared to those corresponding to the optimized FEA model, as well as the commercially available wheel. This comparison showed that structural topology and composites optimization software packages can be sequentially utilized to produce an adequately stiff composite wheel of lower mass than a commercially available wheel constructed using pre-tensioned steel spokes.
- Full Text:
- Date Issued: 2017
Enhancing productivity and market participation for poverty reduction and shared prosperity in South Africa
- Authors: Avuletey, Richard
- Date: 2017
- Subjects: Poverty -- South Africa Economic development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13978 , vital:39736
- Description: There have been several attempts by the South Africa government to improve the agricultural productivity on smallholder farms since the end of apartheid. In spite of the government support, agricultural productivity has stagnated for several years across the Eastern Cape rural communities including Mthatha and Qamata. The aim of this study was to understand the roles played by irrigation adoption and market participation in addressing poverty reduction and shared prosperity levels of smallholder farmers in Eastern Cape of South Africa. Data were collected using purposive and random sampling approach through the use of the snowball method. To collect data, a questionnaire was designed and administered through face-to-face interviews. Overall, 200 farmers were interviewed both at Mthatha and Qamata irrigation scheme to represent the farmers in the area. The collected data were analysed using both parametric and non-parametric methods. The non-parametric methods used include descriptive analysis, estimation of gross margins as a proxy for profitability. The Stochastic Frontier Analysis (SFA), Binomial Logistic Regression (BLR), Ordinary Least Squares (OLS), tobit censored regression and propensity score matching (PSM) were the parametric methods used in the study. Profit efficiency was measured using the normalized transcendent logarithmic profit frontier approach (Cobb-douglas). Stochastic Production Frontier (SPF) technique was used to determine the technical efficiency of individual farmers and to identify the major factors that influence technical efficiency. Binomial logistic regression was used to determine factors affecting irrigation adoption and market participation among smallholder farmers. OLS was used to estimate the impact of institutional characteristics, socio-economic and agronomic factors on smallholder farmers’ level of market participation for selected crop enterprises. Lastly, tobit regression and propensity score matching (PSM) analyses were used to estimate the impact of irrigation technology adoption on poverty reduction in the province. The results of the descriptive statistics of the overall sample revealed an average age of 61 years, and mean household size of 4.6 persons with majority of the household head having at least obtained some primary school education (59.5percent). Most of the household heads interviewed were men (68.5percent). Most farmers are single (65percent) with regard to their marital status. Farming is viewed as major source of livelihood for smallholders with an average income of R12523.37 for overall sample and income of R15559.80 and R5795.59 per crop season, respectively, for irrigators and non irrigators. Smallholder irrigators generated a higher gross margin of R7585.26, R21966.89 and R6266.07 from maize, cabbage and potato enterprises, respectively, compared to their non irrigator counterparts in maize (R131.39), cabbage (R10938.04) and potato (R3433.31) enterprises. The results of the frontier profit model revealed mean profit efficiency of 90percent, 99.99percent and 99.99percent, respectively, for maize, cabbage and potato.The binary logistic regression model for irrigation adoption indicated that years in school, cooperative membership, off-farm income, credit access and distance to market significantly explain smallholder farmers’ irrigation adoption decision. On the other hand, age of household head, market support, farm size, livestock income and distance to market were the key variables that accounted for smallholder farmers’ market participation adoption behaviour. The findings from the stochastic production frontier (SPF) indicate that smallholder farmers are technically efficient in maize and cabbage enterprises both at 99.99percent. Lastly, the findings from the Tobit regression and propensity score matching are consistent across the two methods, suggesting that being a member of irrigation adoption has a positive significant impact on income of smallholder farmers. Irrigation and market participation appear to have a significant and positive impact on smallholder poverty reduction (measured by crop income) for those farmers engaged in them. The findings from this study provide useful practical insights for policy makers, farm advisers and researchers in the design of effective and efficient policies, programmes and projects which can affect the adoption of irrigation technology and market participation.
- Full Text:
- Date Issued: 2017
- Authors: Avuletey, Richard
- Date: 2017
- Subjects: Poverty -- South Africa Economic development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13978 , vital:39736
- Description: There have been several attempts by the South Africa government to improve the agricultural productivity on smallholder farms since the end of apartheid. In spite of the government support, agricultural productivity has stagnated for several years across the Eastern Cape rural communities including Mthatha and Qamata. The aim of this study was to understand the roles played by irrigation adoption and market participation in addressing poverty reduction and shared prosperity levels of smallholder farmers in Eastern Cape of South Africa. Data were collected using purposive and random sampling approach through the use of the snowball method. To collect data, a questionnaire was designed and administered through face-to-face interviews. Overall, 200 farmers were interviewed both at Mthatha and Qamata irrigation scheme to represent the farmers in the area. The collected data were analysed using both parametric and non-parametric methods. The non-parametric methods used include descriptive analysis, estimation of gross margins as a proxy for profitability. The Stochastic Frontier Analysis (SFA), Binomial Logistic Regression (BLR), Ordinary Least Squares (OLS), tobit censored regression and propensity score matching (PSM) were the parametric methods used in the study. Profit efficiency was measured using the normalized transcendent logarithmic profit frontier approach (Cobb-douglas). Stochastic Production Frontier (SPF) technique was used to determine the technical efficiency of individual farmers and to identify the major factors that influence technical efficiency. Binomial logistic regression was used to determine factors affecting irrigation adoption and market participation among smallholder farmers. OLS was used to estimate the impact of institutional characteristics, socio-economic and agronomic factors on smallholder farmers’ level of market participation for selected crop enterprises. Lastly, tobit regression and propensity score matching (PSM) analyses were used to estimate the impact of irrigation technology adoption on poverty reduction in the province. The results of the descriptive statistics of the overall sample revealed an average age of 61 years, and mean household size of 4.6 persons with majority of the household head having at least obtained some primary school education (59.5percent). Most of the household heads interviewed were men (68.5percent). Most farmers are single (65percent) with regard to their marital status. Farming is viewed as major source of livelihood for smallholders with an average income of R12523.37 for overall sample and income of R15559.80 and R5795.59 per crop season, respectively, for irrigators and non irrigators. Smallholder irrigators generated a higher gross margin of R7585.26, R21966.89 and R6266.07 from maize, cabbage and potato enterprises, respectively, compared to their non irrigator counterparts in maize (R131.39), cabbage (R10938.04) and potato (R3433.31) enterprises. The results of the frontier profit model revealed mean profit efficiency of 90percent, 99.99percent and 99.99percent, respectively, for maize, cabbage and potato.The binary logistic regression model for irrigation adoption indicated that years in school, cooperative membership, off-farm income, credit access and distance to market significantly explain smallholder farmers’ irrigation adoption decision. On the other hand, age of household head, market support, farm size, livestock income and distance to market were the key variables that accounted for smallholder farmers’ market participation adoption behaviour. The findings from the stochastic production frontier (SPF) indicate that smallholder farmers are technically efficient in maize and cabbage enterprises both at 99.99percent. Lastly, the findings from the Tobit regression and propensity score matching are consistent across the two methods, suggesting that being a member of irrigation adoption has a positive significant impact on income of smallholder farmers. Irrigation and market participation appear to have a significant and positive impact on smallholder poverty reduction (measured by crop income) for those farmers engaged in them. The findings from this study provide useful practical insights for policy makers, farm advisers and researchers in the design of effective and efficient policies, programmes and projects which can affect the adoption of irrigation technology and market participation.
- Full Text:
- Date Issued: 2017
The impact of post-apartheid agricultural changes on citrus farmers in the Peddie area
- Authors: Peter, Bantu Desmond
- Date: 2017
- Subjects: Agriculture and state -- South Africa -- Eastern Cape Agriculture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/5380 , vital:29225
- Description: This study explores the impact of post-apartheid agricultural changes on citrus farmers in the Peddie area. The case study focused on the Craighead Citrus Farm at Kwatho as well as the Naudeshoek Citrus Farm, Ripplemead Citrus Farm and Siyamila Citrus Farm in the Balteni area. The study considered the effect of agricultural changes on citrus production, productivity of the farms in question, as well as the impact on poverty alleviation in Peddie District. In the study, the challenges encountered by both farmers and communities due to the agricultural changes in the new democratic dispensation were also considered. The study further considered the role played by the Department of Agriculture and Ngqushwa Local Municipality in assisting these farmers to increase citrus production in order to create employment opportunities. To achieve these objectives, a review of literature and collection of evidence in the form of interviews, and observations were conducted in the research areas. The research findings indicated that the Craighead Citrus Farms is state owned land, which belonged to Ulimocor, a parastatal under the former homeland government (Ciskei). This farm is no longer operational and is abandoned. During the period of this study the Naudeshoek Citrus Farm, Ripplemead Citrus Farm and Siyamila Citrus Farm were operational and progressing. Citrus farming in this area has potential to boost the economy, which would only be possible with the establishment of partnerships between the emerging farmers, government, commercial farmers and Ngqushwa Local Municipality.
- Full Text:
- Date Issued: 2017
- Authors: Peter, Bantu Desmond
- Date: 2017
- Subjects: Agriculture and state -- South Africa -- Eastern Cape Agriculture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/5380 , vital:29225
- Description: This study explores the impact of post-apartheid agricultural changes on citrus farmers in the Peddie area. The case study focused on the Craighead Citrus Farm at Kwatho as well as the Naudeshoek Citrus Farm, Ripplemead Citrus Farm and Siyamila Citrus Farm in the Balteni area. The study considered the effect of agricultural changes on citrus production, productivity of the farms in question, as well as the impact on poverty alleviation in Peddie District. In the study, the challenges encountered by both farmers and communities due to the agricultural changes in the new democratic dispensation were also considered. The study further considered the role played by the Department of Agriculture and Ngqushwa Local Municipality in assisting these farmers to increase citrus production in order to create employment opportunities. To achieve these objectives, a review of literature and collection of evidence in the form of interviews, and observations were conducted in the research areas. The research findings indicated that the Craighead Citrus Farms is state owned land, which belonged to Ulimocor, a parastatal under the former homeland government (Ciskei). This farm is no longer operational and is abandoned. During the period of this study the Naudeshoek Citrus Farm, Ripplemead Citrus Farm and Siyamila Citrus Farm were operational and progressing. Citrus farming in this area has potential to boost the economy, which would only be possible with the establishment of partnerships between the emerging farmers, government, commercial farmers and Ngqushwa Local Municipality.
- Full Text:
- Date Issued: 2017
Composition portfolio
- Boesack, Lenrick Jonathan Angus
- Authors: Boesack, Lenrick Jonathan Angus
- Date: 2017
- Subjects: Piano music , Prepared piano music , Saxophone music
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/56233 , vital:26786
- Description: This short composition portfolio comprises 40% of the requirements for the Master of Music Degree in performance and composition at Rhodes University. In addition to the music presented here, I played two public exam recitals of 70 minutes each. While I played piano as a child, my main instrument during my BMUS studies at the University of Cape Town (2004-2007) was the saxophone. In 2010 I was diagnosed with Polymyositis(an auto-immune desease) which particularly affected my breathing and therefore my ability to play the saxophone. For this reason I opted to play my recitals on the piano. The first recital focused on interpretations of Swing Era, Bebop and post-Bebop standards such as: Someday my prince will come, What is this thing called love, In your own sweet way, Eternal Triangle, Recordame, Peace, Dolphin Dance, Caravan and Some other blues. The second recital comprised of seven original compositions that were presented in trio, quartet and quintet settings.
- Full Text:
- Date Issued: 2017
- Authors: Boesack, Lenrick Jonathan Angus
- Date: 2017
- Subjects: Piano music , Prepared piano music , Saxophone music
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/56233 , vital:26786
- Description: This short composition portfolio comprises 40% of the requirements for the Master of Music Degree in performance and composition at Rhodes University. In addition to the music presented here, I played two public exam recitals of 70 minutes each. While I played piano as a child, my main instrument during my BMUS studies at the University of Cape Town (2004-2007) was the saxophone. In 2010 I was diagnosed with Polymyositis(an auto-immune desease) which particularly affected my breathing and therefore my ability to play the saxophone. For this reason I opted to play my recitals on the piano. The first recital focused on interpretations of Swing Era, Bebop and post-Bebop standards such as: Someday my prince will come, What is this thing called love, In your own sweet way, Eternal Triangle, Recordame, Peace, Dolphin Dance, Caravan and Some other blues. The second recital comprised of seven original compositions that were presented in trio, quartet and quintet settings.
- Full Text:
- Date Issued: 2017
Education in the Anthropocene: Ethico-moral dimensions and critical realist openings
- Authors: Olvitt, Lausanne L
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372753 , vital:66620 , xlink:href="https://doi.org/10.1080/03057240.2017.1342613"
- Description: Human-induced changes in planetary bio-geo-chemical processes have tipped earth into a newly-proposed geological epoch: the Anthropocene, which places moral and ethical demands on people regarding who should take responsibility for the well-being of people and planet, how, and why. Drawing generally on critical realist ontology, and more particularly on Roy Bhaskar’s concept of the person as a ‘four-planar social being’ living in the world as a laminated ontological whole, the article examines the dimensions of people’s ethico-moral engagement with the Anthropocene and considers what types of learning processes might enable people to understand, live in, and co-create this period known as ‘the Anthropocene’ in just, care-filled and—where necessary—transformative ways. The article points to the need for a radical re-orientation of education systems in the light of ethico-moral challenges that come to prominence in the Anthropocene, and argues for learning processes that nurture individual and collective moral agency through transformative, even transgressive, learning processes that are relational, humble, interdisciplinary, multi-perspectival, systemic, reality-congruent and contextually responsive.
- Full Text:
- Date Issued: 2017
- Authors: Olvitt, Lausanne L
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372753 , vital:66620 , xlink:href="https://doi.org/10.1080/03057240.2017.1342613"
- Description: Human-induced changes in planetary bio-geo-chemical processes have tipped earth into a newly-proposed geological epoch: the Anthropocene, which places moral and ethical demands on people regarding who should take responsibility for the well-being of people and planet, how, and why. Drawing generally on critical realist ontology, and more particularly on Roy Bhaskar’s concept of the person as a ‘four-planar social being’ living in the world as a laminated ontological whole, the article examines the dimensions of people’s ethico-moral engagement with the Anthropocene and considers what types of learning processes might enable people to understand, live in, and co-create this period known as ‘the Anthropocene’ in just, care-filled and—where necessary—transformative ways. The article points to the need for a radical re-orientation of education systems in the light of ethico-moral challenges that come to prominence in the Anthropocene, and argues for learning processes that nurture individual and collective moral agency through transformative, even transgressive, learning processes that are relational, humble, interdisciplinary, multi-perspectival, systemic, reality-congruent and contextually responsive.
- Full Text:
- Date Issued: 2017
Intergenerational learning and environmental care: a case of a fishing community next to Africa’s first marine protected area
- Authors: Cloete, Cindy-Lee
- Date: 2017
- Subjects: Tsitsikamma Marine Protected Area (South Africa) , Covie (South Africa) , Intergenerational relations -- South Africa -- Covie , Intergenerational communication -- South Africa -- Covie , Fishing villages -- South Africa -- Covie , Sustainable fisheries -- South Africa -- Covie , Environmental education -- South Africa -- Covie
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/7598 , vital:21277
- Description: This study explored the relationship between intergenerational learning and environmental care in the small fishing community of Covie, located next to the Tsitsikamma Marine Protected Area (TMPA) on the south-eastern coast of South Africa. Since Covie’s establishment as a woodcutter settlement in 1883, the community has depended on the marine and coastal environment such that their communal identity and basic means of subsistence are closely tied to their traditional fishing practices. Since its proclamation in 1964, the TMPA has undergone numerous policy changes, most notably the complete closure of the TMPA to fishing in 2001. Against this backdrop, the study sought to understand how intergenerational learning about fishing practices are mediated in Covie and the ways in which such learning processes constitute a sense of place and belonging for the Covie fishers, and to develop a sense of care for the natural environment. The study included 12 Covie community members of different generations and genders so as to be representative of the community (approximately 86 members). The research was informed by qualitative data generated through a focus group discussion with eight Covie community members, a mirror workshop with the same eight community members, eight semi-structured interviews, and five naturalistic observations of fishing practices. Data generation and analysis was informed by Etienne Wenger’s theory of Communities of Practice which was complemented by theoretical perspectives on intergenerational learning and attachment to place. This study found that the Covie fishers indeed operate as a community of practice who depend significantly on intergenerational learning processes to transfer knowledge, skills and values about fishing practices to younger generations. The 2001 policy changes that denied the Covie fishers access to their traditional fishing sites were shown to reduce the participation in fishing of a range of community members (in particular children and women), which in turn influenced forms of intergenerational learning about fishing. The youth’s reduced participation especially was linked to more protracted and fragmented processes of learning about fishing and Covie’s code of fishing conduct, including its underpinning sense of environmental care. Finally, this study argues that the affective and socio-material connections to their natural surroundings have shaped the Covie community’s sense of care and responsibility toward the environment.
- Full Text:
- Date Issued: 2017
- Authors: Cloete, Cindy-Lee
- Date: 2017
- Subjects: Tsitsikamma Marine Protected Area (South Africa) , Covie (South Africa) , Intergenerational relations -- South Africa -- Covie , Intergenerational communication -- South Africa -- Covie , Fishing villages -- South Africa -- Covie , Sustainable fisheries -- South Africa -- Covie , Environmental education -- South Africa -- Covie
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/7598 , vital:21277
- Description: This study explored the relationship between intergenerational learning and environmental care in the small fishing community of Covie, located next to the Tsitsikamma Marine Protected Area (TMPA) on the south-eastern coast of South Africa. Since Covie’s establishment as a woodcutter settlement in 1883, the community has depended on the marine and coastal environment such that their communal identity and basic means of subsistence are closely tied to their traditional fishing practices. Since its proclamation in 1964, the TMPA has undergone numerous policy changes, most notably the complete closure of the TMPA to fishing in 2001. Against this backdrop, the study sought to understand how intergenerational learning about fishing practices are mediated in Covie and the ways in which such learning processes constitute a sense of place and belonging for the Covie fishers, and to develop a sense of care for the natural environment. The study included 12 Covie community members of different generations and genders so as to be representative of the community (approximately 86 members). The research was informed by qualitative data generated through a focus group discussion with eight Covie community members, a mirror workshop with the same eight community members, eight semi-structured interviews, and five naturalistic observations of fishing practices. Data generation and analysis was informed by Etienne Wenger’s theory of Communities of Practice which was complemented by theoretical perspectives on intergenerational learning and attachment to place. This study found that the Covie fishers indeed operate as a community of practice who depend significantly on intergenerational learning processes to transfer knowledge, skills and values about fishing practices to younger generations. The 2001 policy changes that denied the Covie fishers access to their traditional fishing sites were shown to reduce the participation in fishing of a range of community members (in particular children and women), which in turn influenced forms of intergenerational learning about fishing. The youth’s reduced participation especially was linked to more protracted and fragmented processes of learning about fishing and Covie’s code of fishing conduct, including its underpinning sense of environmental care. Finally, this study argues that the affective and socio-material connections to their natural surroundings have shaped the Covie community’s sense of care and responsibility toward the environment.
- Full Text:
- Date Issued: 2017
An analysis on role of judges in interpreting tax legislation
- Authors: Chanhuwa, Mildred Kudzanai
- Date: 2017
- Subjects: Taxation -- Law and legislation -- South Africa , Law -- South Africa , Judicial discretion -- South Africa , Judicial opinion -- South Africa , Judges -- Attitudes -- South Africa , South Africa. Constitution of the Republic of South Africa, 1996
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/4289 , vital:20644
- Description: This thesis focusses on the role of judges as interpreters of tax legislation. It examines the role of judges by analysing how the perceptions of judges can impact on how they interpret legislation. It also analyses various other factors that play a role when judges interpret legislation, in an effort to answer the question to what extent do philosophical theories and interpretative approaches explain the role of judges as interpreters? Jurisprudential theories such as the natural law theory, positivist theories, and American realist theories are used to analyse how judges interpret and how theorists think judges should play their interpretational role. It is noted that in pre-constitutional South Africa the courts followed a positivist paradigm; as a result, the judges used a strict literal approach to interpretation. The new Constitution brought a change in the jurisprudential paradigm accepted in South Africa and has transformed how judges perceive and carry out their role as interpreters of legislation. Judges have now adopted the purposive value-laden approach as authoritative. As custodians of the Constitution, judges should interpret provisions against the values imposed by it. The purposive value-laden interpretational approach allows judges to take into account more considerations and to weigh a provision against the constitutional values. Other issues discussed pertain to how institutional guidelines such as the doctrine of precedent and separation of powers, to a lesser extent, play a role in how judges interpret the law. It is demonstrated that the doctrine of precedent does not limit the role of judges but rather contributes to maintaining certainty, predictability and coherence in the legal system. It is also noted that judicial discretion is the mechanism by which judges use extra-legal factors such as public policy and moral considerations to assist in interpreting legislation.
- Full Text:
- Date Issued: 2017
- Authors: Chanhuwa, Mildred Kudzanai
- Date: 2017
- Subjects: Taxation -- Law and legislation -- South Africa , Law -- South Africa , Judicial discretion -- South Africa , Judicial opinion -- South Africa , Judges -- Attitudes -- South Africa , South Africa. Constitution of the Republic of South Africa, 1996
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/4289 , vital:20644
- Description: This thesis focusses on the role of judges as interpreters of tax legislation. It examines the role of judges by analysing how the perceptions of judges can impact on how they interpret legislation. It also analyses various other factors that play a role when judges interpret legislation, in an effort to answer the question to what extent do philosophical theories and interpretative approaches explain the role of judges as interpreters? Jurisprudential theories such as the natural law theory, positivist theories, and American realist theories are used to analyse how judges interpret and how theorists think judges should play their interpretational role. It is noted that in pre-constitutional South Africa the courts followed a positivist paradigm; as a result, the judges used a strict literal approach to interpretation. The new Constitution brought a change in the jurisprudential paradigm accepted in South Africa and has transformed how judges perceive and carry out their role as interpreters of legislation. Judges have now adopted the purposive value-laden approach as authoritative. As custodians of the Constitution, judges should interpret provisions against the values imposed by it. The purposive value-laden interpretational approach allows judges to take into account more considerations and to weigh a provision against the constitutional values. Other issues discussed pertain to how institutional guidelines such as the doctrine of precedent and separation of powers, to a lesser extent, play a role in how judges interpret the law. It is demonstrated that the doctrine of precedent does not limit the role of judges but rather contributes to maintaining certainty, predictability and coherence in the legal system. It is also noted that judicial discretion is the mechanism by which judges use extra-legal factors such as public policy and moral considerations to assist in interpreting legislation.
- Full Text:
- Date Issued: 2017
The development of a good governed costing management model for Mandela Bay Development Agency projects within the Nelson Mandela Bay Municipal boundaries
- Authors: Martin, Monica
- Date: 2017
- Subjects: Economic development projects -- South Africa -- Port Elizabeth Activity-based costing -- South Africa -- Port Elizabeth , Cost accounting -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/18584 , vital:28684
- Description: The purpose of this single case study was to investigate the variables that determine the perceived success of the costing management of Mandela Bay Development Agency Projects (MBDA). Eleven propositions namely Strategic Planning, Stakeholders, Procurement Processes, Contracts, Design Management, Implementation Management, Internal Regulatory Structures, Outside Advice, Human Behaviour, Risk Management and Governance Structure, were identified that could influence costing management of MBDA projects. By using qualitative research methods, the MBDA was compared with three other agencies with similar mandates, by means of four semi-structured interviews, in order to identify similarities and differences between the organisations in terms of costing management. The results of nine in-depth interviews with MBDA project role players, with open ended questions about the participants’ views on the factors that influence costing management, were used to discover themes that were overlooked in the proposed model of perceived success of costing management of MBDA projects. Most of the propositions as per the proposed model for the perceived success of costing management of MBDA projects were confirmed to have a positive relationship to the costing management of MBDA projects. The model was revised after the results were presented to include two ante-ceding variables that were overlooked in the literature review, but emerged from the data namely Funding Model and Compliance to Legislation. The identification of the additional variables namely Team Dynamics (replacing Human Behaviour) and Planning Model are important aspects to be considered in relation to the costing management of MBDA projects. With the focus on good governance and the MBDA’s good record of clean and unqualified audits, it is to be noted that the performance of government projects is usually measured against progress and expenditure and not necessarily against the value for money and the quality of the completed project.
- Full Text:
- Date Issued: 2017
- Authors: Martin, Monica
- Date: 2017
- Subjects: Economic development projects -- South Africa -- Port Elizabeth Activity-based costing -- South Africa -- Port Elizabeth , Cost accounting -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/18584 , vital:28684
- Description: The purpose of this single case study was to investigate the variables that determine the perceived success of the costing management of Mandela Bay Development Agency Projects (MBDA). Eleven propositions namely Strategic Planning, Stakeholders, Procurement Processes, Contracts, Design Management, Implementation Management, Internal Regulatory Structures, Outside Advice, Human Behaviour, Risk Management and Governance Structure, were identified that could influence costing management of MBDA projects. By using qualitative research methods, the MBDA was compared with three other agencies with similar mandates, by means of four semi-structured interviews, in order to identify similarities and differences between the organisations in terms of costing management. The results of nine in-depth interviews with MBDA project role players, with open ended questions about the participants’ views on the factors that influence costing management, were used to discover themes that were overlooked in the proposed model of perceived success of costing management of MBDA projects. Most of the propositions as per the proposed model for the perceived success of costing management of MBDA projects were confirmed to have a positive relationship to the costing management of MBDA projects. The model was revised after the results were presented to include two ante-ceding variables that were overlooked in the literature review, but emerged from the data namely Funding Model and Compliance to Legislation. The identification of the additional variables namely Team Dynamics (replacing Human Behaviour) and Planning Model are important aspects to be considered in relation to the costing management of MBDA projects. With the focus on good governance and the MBDA’s good record of clean and unqualified audits, it is to be noted that the performance of government projects is usually measured against progress and expenditure and not necessarily against the value for money and the quality of the completed project.
- Full Text:
- Date Issued: 2017
The influence of extraction techniques on the chemical composition of essential oils from Pelargonium cv.rose in the Eastern Cape
- Authors: Ngcangatha-Maqhude, Bulelwa
- Date: 2017
- Subjects: Essences and essential oils Pelargoniums Rose geranium oil
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8111 , vital:31524
- Description: Rose geranium is a world known essential oil plant priced for its high grade essential oil mostly utilized in the perfumery industry. However, South Africa has just joined the geranium oil production industry and still battling with the variations in oil yield and composition. Volatile components from Rose geranium were respectively extracted by three methods including hydro-distillation, steam distillation and solvent free microwave. The composition was characterized by GC-FID and GC-MS .No significant differences were found in the oil constituents, colour of the oil was the same in hydro-distillation and steam distillation (light green) but in solvent free microwave extraction the oil was clear because in the receiving flask there was hexane and the quantity of the oil was not the same. The difference was the time taken to extract the oil: Hydro-distillation took 3 hours, steam distillation took 1 hour, 30 minutes and solvent free microwave took only 30 minutes. The main constituents of the essential oil of rose geranium (steam distillation) are Dohne: Citronellol (20.61percent), geraniol (14.79percent), linalool (1.98percent), citronellyl formate (14.25percent), geranyl formate (10.25percent) and guaiadiene 6, 9 (7.22percent). Kieskammahoek: Citronellol (20.36percent), geraniol (9.81percent), linalool (1.54percent), citronellyl formate (16.09percent), geranyl formate F (8.96percent) and guaiadiene 6, 9 (8. 22percent).University of FortHare: Citronellol (21.55percent), geraniol (9.41percent), linalool (1.40percent), citronellyl formate (16.37percent), geranyl formate (8.10percent) and guaiadiene 6, 9 7.92percent). For hydro-distillation, Dohne: Citronellol (24.68percent), geraniol (11.68percent), linalool (11.74percent), citronellyl formate (14.97percent), geranyl formate (5.95percent) and guaiadiene 6, 9 (4.63percent). Kieskammahoek: Citronellol (25.25percent), geraniol (13.44percent), linalool (3.35percent), citronellyl formate (15.62percent), geranyl formate (5.40percent) and guaiadiene 6, 9(4.96percent).University of FortHare: Citronellol (24.73percent), geraniol (8.35percent), linalool (9.76percent), citronellyl formate (16.54percent), geranyl formate (4.42percent) and guaiadiene 6, 9(9.76percent). The solvent free microwave extraction , Dohne: Citronellol (20.87), geraniol (17.85percent), linalool (1.21percent), citronellyl formate (13.44percent), geranyl formate (10.26percent) and guaiadiene 6, 9 (4.59percent).Kieskammahoek: Citronellol (20.13percent), geraniol (5.40percent), linalool (0.28percent), citronellyl formate (14.22percent), geranyl formate (6.04percent) and guaiadiene 6, 9(8.63percent).University of FortHare: Citronellol (21.15percent), geraniol (22.36percent), linalool (1.37percent), citronellyl formate (12.13percent), geranyl formate (8.91percent) and guaiadiene 6, 9 (5.82percent).The percentage of oil composition in hydro-distillation and Solvent Free Microwave Extraction was higher than steam distillation.
- Full Text:
- Date Issued: 2017
- Authors: Ngcangatha-Maqhude, Bulelwa
- Date: 2017
- Subjects: Essences and essential oils Pelargoniums Rose geranium oil
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8111 , vital:31524
- Description: Rose geranium is a world known essential oil plant priced for its high grade essential oil mostly utilized in the perfumery industry. However, South Africa has just joined the geranium oil production industry and still battling with the variations in oil yield and composition. Volatile components from Rose geranium were respectively extracted by three methods including hydro-distillation, steam distillation and solvent free microwave. The composition was characterized by GC-FID and GC-MS .No significant differences were found in the oil constituents, colour of the oil was the same in hydro-distillation and steam distillation (light green) but in solvent free microwave extraction the oil was clear because in the receiving flask there was hexane and the quantity of the oil was not the same. The difference was the time taken to extract the oil: Hydro-distillation took 3 hours, steam distillation took 1 hour, 30 minutes and solvent free microwave took only 30 minutes. The main constituents of the essential oil of rose geranium (steam distillation) are Dohne: Citronellol (20.61percent), geraniol (14.79percent), linalool (1.98percent), citronellyl formate (14.25percent), geranyl formate (10.25percent) and guaiadiene 6, 9 (7.22percent). Kieskammahoek: Citronellol (20.36percent), geraniol (9.81percent), linalool (1.54percent), citronellyl formate (16.09percent), geranyl formate F (8.96percent) and guaiadiene 6, 9 (8. 22percent).University of FortHare: Citronellol (21.55percent), geraniol (9.41percent), linalool (1.40percent), citronellyl formate (16.37percent), geranyl formate (8.10percent) and guaiadiene 6, 9 7.92percent). For hydro-distillation, Dohne: Citronellol (24.68percent), geraniol (11.68percent), linalool (11.74percent), citronellyl formate (14.97percent), geranyl formate (5.95percent) and guaiadiene 6, 9 (4.63percent). Kieskammahoek: Citronellol (25.25percent), geraniol (13.44percent), linalool (3.35percent), citronellyl formate (15.62percent), geranyl formate (5.40percent) and guaiadiene 6, 9(4.96percent).University of FortHare: Citronellol (24.73percent), geraniol (8.35percent), linalool (9.76percent), citronellyl formate (16.54percent), geranyl formate (4.42percent) and guaiadiene 6, 9(9.76percent). The solvent free microwave extraction , Dohne: Citronellol (20.87), geraniol (17.85percent), linalool (1.21percent), citronellyl formate (13.44percent), geranyl formate (10.26percent) and guaiadiene 6, 9 (4.59percent).Kieskammahoek: Citronellol (20.13percent), geraniol (5.40percent), linalool (0.28percent), citronellyl formate (14.22percent), geranyl formate (6.04percent) and guaiadiene 6, 9(8.63percent).University of FortHare: Citronellol (21.15percent), geraniol (22.36percent), linalool (1.37percent), citronellyl formate (12.13percent), geranyl formate (8.91percent) and guaiadiene 6, 9 (5.82percent).The percentage of oil composition in hydro-distillation and Solvent Free Microwave Extraction was higher than steam distillation.
- Full Text:
- Date Issued: 2017
The abundance of an invasive freshwater snail Tarebia granifera (Lamarck, 1822) in the Nseleni River, South Africa
- Jones, Roy W, Hill, Jaclyn M, Coetzee, Julie A, Hill, Martin P, Avery, T S, Weyl, Olaf L F
- Authors: Jones, Roy W , Hill, Jaclyn M , Coetzee, Julie A , Hill, Martin P , Avery, T S , Weyl, Olaf L F
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69077 , vital:29382 , https://doi.org/10.2989/16085914.2017.1298984
- Description: The invasive freshwater snail Tarebia granifera (Lamarck, 1822) was first reported in South Africa in 1999 and it has become widespread across the country, with some evidence to suggest that it reduces benthic macroinvertebrate biodiversity. The current study aimed to identify the primary abiotic drivers behind abundance patterns of T. granifera, by comparing the current abundance of the snail in three different regions, and at three depths, of the highly modified Nseleni River in KwaZulu-Natal, South Africa. Tarebia granifera was well established throughout the Nseleni River system, with an overall preference for shallow waters and seasonal temporal patterns of abundance. Although it is uncertain what the ecological impacts of the snail in this system are, its high abundances suggest that it should be controlled where possible and prevented from invading other systems in the region.
- Full Text: false
- Date Issued: 2017
- Authors: Jones, Roy W , Hill, Jaclyn M , Coetzee, Julie A , Hill, Martin P , Avery, T S , Weyl, Olaf L F
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69077 , vital:29382 , https://doi.org/10.2989/16085914.2017.1298984
- Description: The invasive freshwater snail Tarebia granifera (Lamarck, 1822) was first reported in South Africa in 1999 and it has become widespread across the country, with some evidence to suggest that it reduces benthic macroinvertebrate biodiversity. The current study aimed to identify the primary abiotic drivers behind abundance patterns of T. granifera, by comparing the current abundance of the snail in three different regions, and at three depths, of the highly modified Nseleni River in KwaZulu-Natal, South Africa. Tarebia granifera was well established throughout the Nseleni River system, with an overall preference for shallow waters and seasonal temporal patterns of abundance. Although it is uncertain what the ecological impacts of the snail in this system are, its high abundances suggest that it should be controlled where possible and prevented from invading other systems in the region.
- Full Text: false
- Date Issued: 2017
The risk of borrowed capital for commercial, industrial and residential property developments
- Authors: Loock, Morne
- Date: 2017
- Subjects: Commercial buildings -- Finance Industrial sites -- Finance , Real estate developers -- South Africa Financial institutions -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/18288 , vital:28615
- Description: Most property development firms who invest in property will need to raise some extra financial support. Unforeseen or unexpected expenses can arise at any point in time during the development process. Calculated decisions should be taken with regards to the financial circumstances for any property development project. Decisions should be taken not only for the present but for the future as well. It is therefore important to understand the market and the current economic conditions before applying for capital to fund a property development project. There several types of finance available to fund property development, these include long term borrowing, short term borrowing, construction loans property development investment trust, second mortgages. There is risk to all of the aforementioned finance available.
- Full Text:
- Date Issued: 2017
- Authors: Loock, Morne
- Date: 2017
- Subjects: Commercial buildings -- Finance Industrial sites -- Finance , Real estate developers -- South Africa Financial institutions -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/18288 , vital:28615
- Description: Most property development firms who invest in property will need to raise some extra financial support. Unforeseen or unexpected expenses can arise at any point in time during the development process. Calculated decisions should be taken with regards to the financial circumstances for any property development project. Decisions should be taken not only for the present but for the future as well. It is therefore important to understand the market and the current economic conditions before applying for capital to fund a property development project. There several types of finance available to fund property development, these include long term borrowing, short term borrowing, construction loans property development investment trust, second mortgages. There is risk to all of the aforementioned finance available.
- Full Text:
- Date Issued: 2017