The development of catalytic oxovanadium (IV)-containing microspheres for the oxidation of various organosulfur compounds
- Ogunlaja, Adeniyi S, Khene, Samson M, Antunes, Edith M, Nyokong, Tebello, Torto, Nelson, Tshentu, Zenixole R
- Authors: Ogunlaja, Adeniyi S , Khene, Samson M , Antunes, Edith M , Nyokong, Tebello , Torto, Nelson , Tshentu, Zenixole R
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241783 , vital:50969 , xlink:href="https://doi.org/10.1016/j.apcata.2013.05.004"
- Description: The development of poly[allylSB-co-EGDMA] beads containing a tetradentate ligand was achieved via suspension polymerization. The catalyst poly[allylSB-co-EGDMA]-VO was synthesized by reacting VIVOSO4 with poly[allylSB-co-EGDMA]. XPS and EPR were used to confirm the presence of vanadium (V4+) on the beads. The synthesized catalyst (poly[allylSB-co-EGDMA]-VO) was found to have a BET surface area of 22 m2 g−1 and porosity of 135 Å, with the atomic force microscopy (AFM) showing more insight on the porous nature of the beads. Oxidation of thiophene (TH), benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) was carried out using tert-butyl hydroperoxide (t-BuOOH) as oxidant. An overall conversion of 60%, 82%, 98% and 87% was achieved for thiophene (TH), benzothiophene (BT), dibenzothiophene (DBT) and 4,6 dimethyldibenzothiophene (4,6-DMDBT) respectively at higher (t-BuOOH) to substrate ratio and at a temperature of 40 °C. The efficient oxidation of the various organosulfur compounds presents potential for the possible application of this catalyst in oxidative desulfurization (ODS) of crude oil.
- Full Text:
- Date Issued: 2013
- Authors: Ogunlaja, Adeniyi S , Khene, Samson M , Antunes, Edith M , Nyokong, Tebello , Torto, Nelson , Tshentu, Zenixole R
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241783 , vital:50969 , xlink:href="https://doi.org/10.1016/j.apcata.2013.05.004"
- Description: The development of poly[allylSB-co-EGDMA] beads containing a tetradentate ligand was achieved via suspension polymerization. The catalyst poly[allylSB-co-EGDMA]-VO was synthesized by reacting VIVOSO4 with poly[allylSB-co-EGDMA]. XPS and EPR were used to confirm the presence of vanadium (V4+) on the beads. The synthesized catalyst (poly[allylSB-co-EGDMA]-VO) was found to have a BET surface area of 22 m2 g−1 and porosity of 135 Å, with the atomic force microscopy (AFM) showing more insight on the porous nature of the beads. Oxidation of thiophene (TH), benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) was carried out using tert-butyl hydroperoxide (t-BuOOH) as oxidant. An overall conversion of 60%, 82%, 98% and 87% was achieved for thiophene (TH), benzothiophene (BT), dibenzothiophene (DBT) and 4,6 dimethyldibenzothiophene (4,6-DMDBT) respectively at higher (t-BuOOH) to substrate ratio and at a temperature of 40 °C. The efficient oxidation of the various organosulfur compounds presents potential for the possible application of this catalyst in oxidative desulfurization (ODS) of crude oil.
- Full Text:
- Date Issued: 2013
The development of novel nickel selective amine extractants
- Okewole, Adeleye I, Antunes, Edith M, Nyokong, Tebello, Tshentu, Zenixole R
- Authors: Okewole, Adeleye I , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241641 , vital:50957 , xlink:href="https://doi.org/10.1016/j.mineng.2013.04.019"
- Description: A chelating ion exchanger, prepared by functionalising Merrifield resin with 2,2′-pyridylimidazole, was utilized to selectively adsorb and separate nickel from other base metal ions in synthetic sulfate solutions. The sorbent material was characterized by scanning electron microscopy (SEM), microanalysis, infrared (IR), X-ray photoelectron spectroscopy (XPS) and BET surface area. The distribution ratio (D) and the sorption capacity of the microspheres toward Ni(II), Cu(II), Co(II) and Fe(II) ions was studied by using the batch and column methods, respectively. Ni(II) followed by Cu(II) showed the highest distribution ratio (D) and the highest sorption efficiency of nickel(II) ions around pH 2. The binary separation of nickel(II) from copper(II), cobalt(II) and iron(II) respectively, undertaken in a column study, through loading the metal ions at pH ≈ 2 followed by selective decomplexation, demonstrated the selectivity of the sorbent material for nickel(II). Thus, 2,2′-pyridylimidazole can be regarded as a nickel-specific extractant.
- Full Text:
- Date Issued: 2013
- Authors: Okewole, Adeleye I , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241641 , vital:50957 , xlink:href="https://doi.org/10.1016/j.mineng.2013.04.019"
- Description: A chelating ion exchanger, prepared by functionalising Merrifield resin with 2,2′-pyridylimidazole, was utilized to selectively adsorb and separate nickel from other base metal ions in synthetic sulfate solutions. The sorbent material was characterized by scanning electron microscopy (SEM), microanalysis, infrared (IR), X-ray photoelectron spectroscopy (XPS) and BET surface area. The distribution ratio (D) and the sorption capacity of the microspheres toward Ni(II), Cu(II), Co(II) and Fe(II) ions was studied by using the batch and column methods, respectively. Ni(II) followed by Cu(II) showed the highest distribution ratio (D) and the highest sorption efficiency of nickel(II) ions around pH 2. The binary separation of nickel(II) from copper(II), cobalt(II) and iron(II) respectively, undertaken in a column study, through loading the metal ions at pH ≈ 2 followed by selective decomplexation, demonstrated the selectivity of the sorbent material for nickel(II). Thus, 2,2′-pyridylimidazole can be regarded as a nickel-specific extractant.
- Full Text:
- Date Issued: 2013
The effect of herbivory by the mite Orthogalumna terebrantis on the growth and photosynthetic performance of water hyacinth (Eichhornia crassipes)
- Marlin, Danica, Hill, Martin P, Ripley, Brad, Strauss, Abram J, Byrne, Marcus J
- Authors: Marlin, Danica , Hill, Martin P , Ripley, Brad , Strauss, Abram J , Byrne, Marcus J
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419411 , vital:71642 , xlink:href="https://doi.org/10.1016/j.aquabot.2012.09.005"
- Description: Eutrophication of fresh water systems is one of the most important factors contributing to the invasion of fresh water bodies by water hyacinth, Eichhornia crassipes. The South American mite, Orthogalumna terebrantis, established on the weed in South Africa in the late 1980s, but the impact of mite herbivory on the weed has never been quantified. Water hyacinth was grown under low, medium and high nitrogen and phosphorus nutrient conditions and the effect of mite herbivory on the weed's growth was examined. Additionally, the impact of different mite herbivory intensities on the weed's photosynthetic performance was examined because herbivory may have more subtle effects on the plant than can be seen from changes in plant growth parameters. Water nutrient content had a great impact on plant growth, but growth was unaffected by mite herbivory in all levels of nutrients tested. Photosynthetic performance of water hyacinth leaves exposed to varying levels of mite herbivory was assessed by measuring net photosynthetic rate (A), leaf conductance (gl), transpiration rate (E) and intercellular CO2 concentration (Ci), and by measuring specific fluorescence parameters including maximal fluorescence (Fm), efficiency of photosystem II (Fv/Fm) and certain JIP-test parameters. Photosynthesis decreased as mite herbivory increased, but there was a positive correlation between gl, E and Ci, and the amount of leaf tissue damaged through mite feeding. The efficiency of photosystem II (PSII) decreased as mite herbivory increased, as seen in the altered fluorescence emission of mite-damaged plants, but this was not the consequence of decreased chlorophyll content. Feeding by O. terebrantis thus decreased water hyacinth photosynthetic rate and the light reaction performance, even at relatively low mite densities. These results show that the impact of a biological control agent on its host plant may not be obvious at a plant growth level, but may nonetheless affect the plant at a physiological level.
- Full Text:
- Date Issued: 2013
- Authors: Marlin, Danica , Hill, Martin P , Ripley, Brad , Strauss, Abram J , Byrne, Marcus J
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419411 , vital:71642 , xlink:href="https://doi.org/10.1016/j.aquabot.2012.09.005"
- Description: Eutrophication of fresh water systems is one of the most important factors contributing to the invasion of fresh water bodies by water hyacinth, Eichhornia crassipes. The South American mite, Orthogalumna terebrantis, established on the weed in South Africa in the late 1980s, but the impact of mite herbivory on the weed has never been quantified. Water hyacinth was grown under low, medium and high nitrogen and phosphorus nutrient conditions and the effect of mite herbivory on the weed's growth was examined. Additionally, the impact of different mite herbivory intensities on the weed's photosynthetic performance was examined because herbivory may have more subtle effects on the plant than can be seen from changes in plant growth parameters. Water nutrient content had a great impact on plant growth, but growth was unaffected by mite herbivory in all levels of nutrients tested. Photosynthetic performance of water hyacinth leaves exposed to varying levels of mite herbivory was assessed by measuring net photosynthetic rate (A), leaf conductance (gl), transpiration rate (E) and intercellular CO2 concentration (Ci), and by measuring specific fluorescence parameters including maximal fluorescence (Fm), efficiency of photosystem II (Fv/Fm) and certain JIP-test parameters. Photosynthesis decreased as mite herbivory increased, but there was a positive correlation between gl, E and Ci, and the amount of leaf tissue damaged through mite feeding. The efficiency of photosystem II (PSII) decreased as mite herbivory increased, as seen in the altered fluorescence emission of mite-damaged plants, but this was not the consequence of decreased chlorophyll content. Feeding by O. terebrantis thus decreased water hyacinth photosynthetic rate and the light reaction performance, even at relatively low mite densities. These results show that the impact of a biological control agent on its host plant may not be obvious at a plant growth level, but may nonetheless affect the plant at a physiological level.
- Full Text:
- Date Issued: 2013
The gold of one’s ring is not far more precious than the gold of one’s heart: Reported life satisfaction among married and cohabitating South African adults
- Botha, Ferdi, Booysen, Frikkie
- Authors: Botha, Ferdi , Booysen, Frikkie
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396181 , vital:69156 , xlink:href=" https://doi.org/10.1007/s10902-012-9337-3"
- Description: This paper tests for differences in reported life satisfaction between married and cohabiting persons, i.e. the cohabitation gap, and in particular whether selection factors can explain the cohabitation gap. The paper also explores whether age at marriage and at start of cohabitation as well as the duration of relationship type matters for subjective well-being. Based on statistical and regression analysis of the 2008 National Income Dynamics Survey, married and cohabiting persons exhibit some differences in their respective determinants of life satisfaction. While the age at relationship commencement has no relationship with well-being, there is evidence to suggest that married people become more satisfied at a later stage in marriage, while cohabitants are more satisfied initially. A significant cohabitation gap exists (0.251), but after controlling for various selection factors, the cohabitation gap virtually disappears (0.042) and becomes insignificant, which suggests that marriage and cohabitation are very similar in South Africa. Relative income, absolute income, and education explain the largest part of the cohabitation gap. Against the global backdrop of an increasing trend towards cohabitation and declining marriage rates, the overall results of this paper suggest that, since a cohabitation gap no longer exists after controlling for selection factors, South Africans may as well not go the “official route” of entering into marriage, as cohabitation provides similar benefits in terms of its contribution to individual satisfaction with life.
- Full Text:
- Date Issued: 2013
- Authors: Botha, Ferdi , Booysen, Frikkie
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396181 , vital:69156 , xlink:href=" https://doi.org/10.1007/s10902-012-9337-3"
- Description: This paper tests for differences in reported life satisfaction between married and cohabiting persons, i.e. the cohabitation gap, and in particular whether selection factors can explain the cohabitation gap. The paper also explores whether age at marriage and at start of cohabitation as well as the duration of relationship type matters for subjective well-being. Based on statistical and regression analysis of the 2008 National Income Dynamics Survey, married and cohabiting persons exhibit some differences in their respective determinants of life satisfaction. While the age at relationship commencement has no relationship with well-being, there is evidence to suggest that married people become more satisfied at a later stage in marriage, while cohabitants are more satisfied initially. A significant cohabitation gap exists (0.251), but after controlling for various selection factors, the cohabitation gap virtually disappears (0.042) and becomes insignificant, which suggests that marriage and cohabitation are very similar in South Africa. Relative income, absolute income, and education explain the largest part of the cohabitation gap. Against the global backdrop of an increasing trend towards cohabitation and declining marriage rates, the overall results of this paper suggest that, since a cohabitation gap no longer exists after controlling for selection factors, South Africans may as well not go the “official route” of entering into marriage, as cohabitation provides similar benefits in terms of its contribution to individual satisfaction with life.
- Full Text:
- Date Issued: 2013
The implementation of a service-learning component in an organic chemistry laboratory course
- Glover, Sarah R, Sewry, Joyce D, Bromley, Candice L, Davies-Coleman, Michael T, Hlengwa, Amanda I
- Authors: Glover, Sarah R , Sewry, Joyce D , Bromley, Candice L , Davies-Coleman, Michael T , Hlengwa, Amanda I
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70699 , vital:29690 , https://doi.org/10.1021/ed2008153
- Description: Education institutions globally are increasingly expected to explore avenues for the implementation of service-learning into their curricula. A second-year undergraduate organic chemistry laboratory experiment, in which the undergraduate students make azo dyes, can provide a vehicle for a service-learning module in which university undergraduate students then teach students from resource-limited secondary schools how to make azo dyes. Evidence is provided to show how the theory is reinforced for both sets of students through a shared practical experience. The practical application of chemistry is conveyed through the use of the synthetic azo dyes to dye tshirts. The results of this study show that the service-learning experience clearly assists undergraduate students to appreciate the role of chemists in the broader society while at the same time increasing awareness of the inequalities in school education systems.
- Full Text:
- Date Issued: 2013
- Authors: Glover, Sarah R , Sewry, Joyce D , Bromley, Candice L , Davies-Coleman, Michael T , Hlengwa, Amanda I
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70699 , vital:29690 , https://doi.org/10.1021/ed2008153
- Description: Education institutions globally are increasingly expected to explore avenues for the implementation of service-learning into their curricula. A second-year undergraduate organic chemistry laboratory experiment, in which the undergraduate students make azo dyes, can provide a vehicle for a service-learning module in which university undergraduate students then teach students from resource-limited secondary schools how to make azo dyes. Evidence is provided to show how the theory is reinforced for both sets of students through a shared practical experience. The practical application of chemistry is conveyed through the use of the synthetic azo dyes to dye tshirts. The results of this study show that the service-learning experience clearly assists undergraduate students to appreciate the role of chemists in the broader society while at the same time increasing awareness of the inequalities in school education systems.
- Full Text:
- Date Issued: 2013
The interaction of silver nanoparticles with low symmetry cysteinyl metallophthalocyanines and their antimicrobial effect
- Masilela, Nkosiphile, Nyokong, Tebello
- Authors: Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193735 , vital:45391 , xlink:href="https://doi.org/10.1016/j.jphotochem.2013.01.009"
- Description: This work reports on the synthesis of silver nanoparticles and their antimicrobial activity alone and in the presence of low symmetry phthalocyanines. The photochemical behaviour of various low symmetry phthalocyanines in the presence of AgNPs is investigated in DMF. A slight improvement in the photochemical behaviour and antimicrobial activity was achieved in the presence of AgNPs for all the complexes. The spherically shaped AgNPs gave the highest antimicrobial activity compared to the triangular and cubic structures. The (OH)2GeMCsPc complex gave the highest antimicrobial activity towards Staphylococcus aureas, both alone and in the presence of AgNPs under illumination with light.
- Full Text:
- Date Issued: 2013
- Authors: Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193735 , vital:45391 , xlink:href="https://doi.org/10.1016/j.jphotochem.2013.01.009"
- Description: This work reports on the synthesis of silver nanoparticles and their antimicrobial activity alone and in the presence of low symmetry phthalocyanines. The photochemical behaviour of various low symmetry phthalocyanines in the presence of AgNPs is investigated in DMF. A slight improvement in the photochemical behaviour and antimicrobial activity was achieved in the presence of AgNPs for all the complexes. The spherically shaped AgNPs gave the highest antimicrobial activity compared to the triangular and cubic structures. The (OH)2GeMCsPc complex gave the highest antimicrobial activity towards Staphylococcus aureas, both alone and in the presence of AgNPs under illumination with light.
- Full Text:
- Date Issued: 2013
The language of listening: the Marikana aftermath
- Authors: Wasserman, Herman
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158904 , vital:40239 , https://hdl.handle.net/10520/EJC141563
- Description: Unless you're, say, the National Press Club of South Africa, who decided that the South African rhino was the newsmaker of the year for 2012, there should be no doubt that the Marikana massacre was the biggest news event of last year. Some observers, like the University of Johannesburg sociologist, Professor Peter Alexander, even consider the massacre one of the turning points in South African history. How did the South African media respond to what was evidently a historic moment?
- Full Text:
- Date Issued: 2013
- Authors: Wasserman, Herman
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158904 , vital:40239 , https://hdl.handle.net/10520/EJC141563
- Description: Unless you're, say, the National Press Club of South Africa, who decided that the South African rhino was the newsmaker of the year for 2012, there should be no doubt that the Marikana massacre was the biggest news event of last year. Some observers, like the University of Johannesburg sociologist, Professor Peter Alexander, even consider the massacre one of the turning points in South African history. How did the South African media respond to what was evidently a historic moment?
- Full Text:
- Date Issued: 2013
The Monkey Cage
- Authors: Krueger, Anton
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229763 , vital:49708 , xlink:href="https://hdl.handle.net/10520/EJC149510"
- Full Text:
- Date Issued: 2013
- Authors: Krueger, Anton
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229763 , vital:49708 , xlink:href="https://hdl.handle.net/10520/EJC149510"
- Full Text:
- Date Issued: 2013
The nature of geometry instruction and observed learning-outcomes opportunities in Nigerian and South African high schools:
- Atebe, Humphrey U, Schäfer, Marc
- Authors: Atebe, Humphrey U , Schäfer, Marc
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140919 , vital:37929 , DOI: 10.1080/10288457.2011.10740712
- Description: The purpose of this qualitative case study involving six secondary school teachers was to obtain insight into how geometry is taught in selected Nigerian and South African high schools. It also aimed, by making use of the van Hiele model of geometry instruction, to elucidate what possible learning opportunities observed instructional methods could offer learners in the subject. The sample comprised three mathematics teachers from Nigeria and three mathematics teachers from South Africa, all of whom were selected using purposive sampling techniques. Instructional activities in six geometry classrooms were recorded on videotape. The van Hiele learning phases provided the framework for data analysis. The findings of this study indicate that observed teaching methods in geometry classrooms in the participating schools offer learners scant opportunity to learn geometry.
- Full Text:
- Date Issued: 2013
- Authors: Atebe, Humphrey U , Schäfer, Marc
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140919 , vital:37929 , DOI: 10.1080/10288457.2011.10740712
- Description: The purpose of this qualitative case study involving six secondary school teachers was to obtain insight into how geometry is taught in selected Nigerian and South African high schools. It also aimed, by making use of the van Hiele model of geometry instruction, to elucidate what possible learning opportunities observed instructional methods could offer learners in the subject. The sample comprised three mathematics teachers from Nigeria and three mathematics teachers from South Africa, all of whom were selected using purposive sampling techniques. Instructional activities in six geometry classrooms were recorded on videotape. The van Hiele learning phases provided the framework for data analysis. The findings of this study indicate that observed teaching methods in geometry classrooms in the participating schools offer learners scant opportunity to learn geometry.
- Full Text:
- Date Issued: 2013
The Personal Is the International
- Authors: Magadla, Siphokazi
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298674 , vital:57726 , xlink:href="https://doi.org/10.1080/02589346.2013.856568"
- Description: The article reflects on why I opted for Political Science as my career. It tells of a society where once black women could only imagine themselves either as maids, teachers or nurses—this was my mother's world. The narrative shows how a racialised and gendered history shapes both my hopes for a particular kind of international relations theory and practice, as it shapes my frustrations and anxieties about my own future in the discipline. I also locate my place in the discipline within broader global ‘disruptions’ that see previously marginalised actors moving to the centre of international life. I also attempt to demonstrate that international relations today is located in globalised peace but within localised extremes of poverty and privilege. I make the case that the challenge to International Relations (IR) theory today is to find a language, a new language, in which to articulate the contradictions of a globalised peace that exists within localised extremes of poverty and privilege.
- Full Text:
- Date Issued: 2013
- Authors: Magadla, Siphokazi
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298674 , vital:57726 , xlink:href="https://doi.org/10.1080/02589346.2013.856568"
- Description: The article reflects on why I opted for Political Science as my career. It tells of a society where once black women could only imagine themselves either as maids, teachers or nurses—this was my mother's world. The narrative shows how a racialised and gendered history shapes both my hopes for a particular kind of international relations theory and practice, as it shapes my frustrations and anxieties about my own future in the discipline. I also locate my place in the discipline within broader global ‘disruptions’ that see previously marginalised actors moving to the centre of international life. I also attempt to demonstrate that international relations today is located in globalised peace but within localised extremes of poverty and privilege. I make the case that the challenge to International Relations (IR) theory today is to find a language, a new language, in which to articulate the contradictions of a globalised peace that exists within localised extremes of poverty and privilege.
- Full Text:
- Date Issued: 2013
The photophysical and photochemical behaviour of coumarin-derivatized zinc phthalocyanine when conjugated with gold nanoparticles and electrospun into polymer fibers
- Tombe, Sekai, Antunes, Edith M, Nyokong, Tebello
- Authors: Tombe, Sekai , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232534 , vital:50000 , xlink:href="https://doi.org/10.1039/C2NJ40984D"
- Description: Polymer composite fibers doped with phthalocyanines and phthalocyanine-functionalized gold nanoparticles were developed. The phthalocyanine and phthalocyanine-functionalized gold nanoparticles have been characterized using UV/Vis, fluorescence and X-ray photoelectron spectroscopy (XPS), time correlated single photon counting (TCSPC), time-resolved emission spectra (TRES) and transmission electron microscopy (TEM). The changes in photophysical and photochemical behavior of the phthalocyanines induced by their interaction with gold nanoparticles and polystyrene were also investigated. In the presence of gold nanoparticles, the fluorescence lifetimes and quantum yields of the phthalocyanine decreased, whereas the singlet oxygen quantum yield increased. This work shows that polymer composite fibers could be used as functional fibers for a variety of applications such as gas sensing when using the advantageous properties of phthalocyanines and gold nanoparticles.
- Full Text:
- Date Issued: 2013
- Authors: Tombe, Sekai , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232534 , vital:50000 , xlink:href="https://doi.org/10.1039/C2NJ40984D"
- Description: Polymer composite fibers doped with phthalocyanines and phthalocyanine-functionalized gold nanoparticles were developed. The phthalocyanine and phthalocyanine-functionalized gold nanoparticles have been characterized using UV/Vis, fluorescence and X-ray photoelectron spectroscopy (XPS), time correlated single photon counting (TCSPC), time-resolved emission spectra (TRES) and transmission electron microscopy (TEM). The changes in photophysical and photochemical behavior of the phthalocyanines induced by their interaction with gold nanoparticles and polystyrene were also investigated. In the presence of gold nanoparticles, the fluorescence lifetimes and quantum yields of the phthalocyanine decreased, whereas the singlet oxygen quantum yield increased. This work shows that polymer composite fibers could be used as functional fibers for a variety of applications such as gas sensing when using the advantageous properties of phthalocyanines and gold nanoparticles.
- Full Text:
- Date Issued: 2013
The relationship between marital status and life satisfaction among South African adults
- Botha, Ferdi, Booysen, Frikkie
- Authors: Botha, Ferdi , Booysen, Frikkie
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396207 , vital:69158 , xlink:href="https://hdl.handle.net/10520/EJC138900"
- Description: This article examines the association between marital status and reported life satisfaction in South Africa. Using the 2008 National Income Dynamics Survey, the relationship between marital status and life satisfaction is heterogeneous. In the overall sample, life satisfaction is significantly higher for married compared to widowed individuals, while the former are more satisfied than those from all other marital statuses. In the overall and female samples, married people are more satisfied compared to those from all other marital status groups. Married men are not significantly more satisfied than men from other marital statuses as a whole. Marriage is positively associated with life satisfaction among women, but not among men.
- Full Text:
- Date Issued: 2013
- Authors: Botha, Ferdi , Booysen, Frikkie
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396207 , vital:69158 , xlink:href="https://hdl.handle.net/10520/EJC138900"
- Description: This article examines the association between marital status and reported life satisfaction in South Africa. Using the 2008 National Income Dynamics Survey, the relationship between marital status and life satisfaction is heterogeneous. In the overall sample, life satisfaction is significantly higher for married compared to widowed individuals, while the former are more satisfied than those from all other marital statuses. In the overall and female samples, married people are more satisfied compared to those from all other marital status groups. Married men are not significantly more satisfied than men from other marital statuses as a whole. Marriage is positively associated with life satisfaction among women, but not among men.
- Full Text:
- Date Issued: 2013
The South African Art Centre: a bygone ideology of Critical Selfhood?
- Authors: Lochner, Eben
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147615 , vital:38654 , https://0-doi.org.wam.seals.ac.za/10.1080/09528822.2013.795697
- Description: The political posters produced by art centres are their most celebrated contribution to the struggle to end Apartheid. However art centres made another valuable contribution by encouraging a form of critical selfhood. This type of internal struggle against inferiority was formulated by the Black Consciousness Movement and is an important element in transformation. However with the end of Apartheid this contribution seems to have been dismissed, alongside poster production, as irrelevant to the new nation. The author investigates how the art centre functioned as a vehicle for critical selfhood and argues for its contemporary relevance.
- Full Text:
- Date Issued: 2013
- Authors: Lochner, Eben
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147615 , vital:38654 , https://0-doi.org.wam.seals.ac.za/10.1080/09528822.2013.795697
- Description: The political posters produced by art centres are their most celebrated contribution to the struggle to end Apartheid. However art centres made another valuable contribution by encouraging a form of critical selfhood. This type of internal struggle against inferiority was formulated by the Black Consciousness Movement and is an important element in transformation. However with the end of Apartheid this contribution seems to have been dismissed, alongside poster production, as irrelevant to the new nation. The author investigates how the art centre functioned as a vehicle for critical selfhood and argues for its contemporary relevance.
- Full Text:
- Date Issued: 2013
The South African Defence Review (2012) and private military/security companies (PMSCs): heralding a shift from prohibition to regulation?
- Juma, Laurence, Tsabora, James
- Authors: Juma, Laurence , Tsabora, James
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126132 , vital:35852 , https://doi.org/10.17159/1727-3781/2013/v16i4a2415
- Description: This article discusses the possibility of South Africa enacting a new law regulating private military/security companies (PMSCs) beyond the Prohibition of Mercenary Activities and Regulation of Certain Activities in Country of Armed Conflict Act of 2006. It argues that such a possibility arises from the policy direction expressed in the Defence Review of 2012, and the recent developments at the international level, which indicate a shift towards accommodation of PMSCs as legitimate players in the security sector. The article surveys the current state of national and international law relating to PMSCs and illustrates how the emerging shift from prohibition to regulation has affirmed the need for legislative intervention in this field. It concludes that since the future is on the side of regulation and not prohibition, legislation that furthers the policy agenda envisioned by the Defence Review 2012 may be the best tool to unlock the inhibitions of the past and create a viable climate for reframing the debate on domestic law governing private militarism in South Africa.
- Full Text:
- Date Issued: 2013
- Authors: Juma, Laurence , Tsabora, James
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126132 , vital:35852 , https://doi.org/10.17159/1727-3781/2013/v16i4a2415
- Description: This article discusses the possibility of South Africa enacting a new law regulating private military/security companies (PMSCs) beyond the Prohibition of Mercenary Activities and Regulation of Certain Activities in Country of Armed Conflict Act of 2006. It argues that such a possibility arises from the policy direction expressed in the Defence Review of 2012, and the recent developments at the international level, which indicate a shift towards accommodation of PMSCs as legitimate players in the security sector. The article surveys the current state of national and international law relating to PMSCs and illustrates how the emerging shift from prohibition to regulation has affirmed the need for legislative intervention in this field. It concludes that since the future is on the side of regulation and not prohibition, legislation that furthers the policy agenda envisioned by the Defence Review 2012 may be the best tool to unlock the inhibitions of the past and create a viable climate for reframing the debate on domestic law governing private militarism in South Africa.
- Full Text:
- Date Issued: 2013
The supernatural detective: witchcraft crime narratives in the Daily Sun
- Authors: Boshoff, Priscilla A
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143447 , vital:38247 , DOI: 10.1080/1013929X.2013.833420
- Description: Reports of witchcraft crimes are a staple feature in the South African tabloid newspaper, the Daily Sun. Instead of dismissing these sensational and seemingly implausible narratives, this paper examines them as ‘fictions’ through the lens of theory developed for the analysis of detective fiction. It draws on Huhn's (1987) model of the readerly relationships established by the narrative forms of the classical detective story and the hard-boiled novel in order to show how the reportage, together with its expected reception, reveals subliminal tensions within working-class black culture. Ironically, such a reading illustrates how the brazen and emotive nature of the tabloid text, which signals for some its untrustworthiness, perhaps comes closer to telling a ‘truth’ about contemporary South African society than the most ‘objective’ reports.
- Full Text:
- Date Issued: 2013
- Authors: Boshoff, Priscilla A
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143447 , vital:38247 , DOI: 10.1080/1013929X.2013.833420
- Description: Reports of witchcraft crimes are a staple feature in the South African tabloid newspaper, the Daily Sun. Instead of dismissing these sensational and seemingly implausible narratives, this paper examines them as ‘fictions’ through the lens of theory developed for the analysis of detective fiction. It draws on Huhn's (1987) model of the readerly relationships established by the narrative forms of the classical detective story and the hard-boiled novel in order to show how the reportage, together with its expected reception, reveals subliminal tensions within working-class black culture. Ironically, such a reading illustrates how the brazen and emotive nature of the tabloid text, which signals for some its untrustworthiness, perhaps comes closer to telling a ‘truth’ about contemporary South African society than the most ‘objective’ reports.
- Full Text:
- Date Issued: 2013
The synthesis and characterisation of magnetic nanoparticles and their interaction with a zinc phthalocyanine
- Antunes, Edith M, Rapulenyane, Nomasonto, Ledwaba, Mpho, Litwinski, Christian, Chidawanyika, Wadzanai J U, Nyokong, Tebello
- Authors: Antunes, Edith M , Rapulenyane, Nomasonto , Ledwaba, Mpho , Litwinski, Christian , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242111 , vital:51002 , xlink:href="https://doi.org/10.1016/j.inoche.2012.12.010"
- Description: A variety of nanoparticles (NPs), including FePt nanoparticles with Fe as the shell (2) or Pt as the shell (3), Pt NPs (4), and FePd (5) were synthesised, characterised and their effect on a zinc phthalocyanine (1) tetra-substituted with a pyridyl-oxy substituent studied using UV/Vis and fluorescence spectroscopy (including time correlated single photon counting, TCSPC). The nanoparticles were characterised using a number of techniques including UV/Vis and inductively coupled plasma-optical emission (ICP-OES) spectroscopies, transmission electron microscopy (TEM), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) and electron paramagnetic resonance (EPR) spectroscopy. Nanocomposites (NCs, 6,7) where the ZnPc (1) was used as the stabiliser, instead of oleic acid and or oleylamine, were also synthesised and characterised.
- Full Text:
- Date Issued: 2013
- Authors: Antunes, Edith M , Rapulenyane, Nomasonto , Ledwaba, Mpho , Litwinski, Christian , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242111 , vital:51002 , xlink:href="https://doi.org/10.1016/j.inoche.2012.12.010"
- Description: A variety of nanoparticles (NPs), including FePt nanoparticles with Fe as the shell (2) or Pt as the shell (3), Pt NPs (4), and FePd (5) were synthesised, characterised and their effect on a zinc phthalocyanine (1) tetra-substituted with a pyridyl-oxy substituent studied using UV/Vis and fluorescence spectroscopy (including time correlated single photon counting, TCSPC). The nanoparticles were characterised using a number of techniques including UV/Vis and inductively coupled plasma-optical emission (ICP-OES) spectroscopies, transmission electron microscopy (TEM), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) and electron paramagnetic resonance (EPR) spectroscopy. Nanocomposites (NCs, 6,7) where the ZnPc (1) was used as the stabiliser, instead of oleic acid and or oleylamine, were also synthesised and characterised.
- Full Text:
- Date Issued: 2013
The triteness of knowing:
- Authors: Mkhize, Nomalanga
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158587 , vital:40209 , https://hdl.handle.net/10520/EJC141596
- Description: The de-commodification of English news and the online enclavism of opinion-making among South Africa's young educated elite.
- Full Text:
- Date Issued: 2013
- Authors: Mkhize, Nomalanga
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158587 , vital:40209 , https://hdl.handle.net/10520/EJC141596
- Description: The de-commodification of English news and the online enclavism of opinion-making among South Africa's young educated elite.
- Full Text:
- Date Issued: 2013
Think Piece : conceptions of quality and ‘Learning as Connection’: teaching for relevance
- Authors: Lotz-Sisitka, Heila
- Date: 2013
- Subjects: Teachers -- Quality -- South Africa , Quality assurance -- South Africa , Effective teaching , Relevance , SADC Regional Environmental Education Programme
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59635 , vital:27633 , https://www.ajol.info/index.php/sajee/article/view/122256
- Description: This think piece captures some of the thinking that emerged in and through the Southern African Development Community (SADC) Regional Environmental Education Programme research programme. This research programme emerged over a five-year period (2008–2012) and involved ten southern African teacher education institutions from eight countries (see ‘Acknowledgements’). The research programme sought to understand what contributions environment and sustainability education could make to debates on educational quality and relevance. Issues of educational quality are high on the national agendas of governments in southern Africa, as it is now well known that providing access to schooling is not a sufficient condition for achieving educational quality. Educational quality is intimately linked to the processes of teaching and learning, but the concept of educational quality is not unproblematic in and of itself. It is, as Noel Gough (2005) noted many years ago, an ‘order word’ that shapes the way people think and practise. Our enquiries during this research programme involved a number of case studies (that were reported on in the Southern African Journal of Environmental Education (SAJEE) in 2008, and are again reported on in this edition of the SAJEE), but the programme also involved theoretical engagement with the concept of educational quality and relevance. This think piece helps to make some of this thinking and theoretical deliberation visible. The author of this think piece was also the leader of the regional research programme and was tasked with synthesising the theoretical deliberations that emerged from the research design which were found to be useful for guiding interpretations and deliberation on more detailed case studies undertaken at country level.
- Full Text:
- Date Issued: 2013
- Authors: Lotz-Sisitka, Heila
- Date: 2013
- Subjects: Teachers -- Quality -- South Africa , Quality assurance -- South Africa , Effective teaching , Relevance , SADC Regional Environmental Education Programme
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59635 , vital:27633 , https://www.ajol.info/index.php/sajee/article/view/122256
- Description: This think piece captures some of the thinking that emerged in and through the Southern African Development Community (SADC) Regional Environmental Education Programme research programme. This research programme emerged over a five-year period (2008–2012) and involved ten southern African teacher education institutions from eight countries (see ‘Acknowledgements’). The research programme sought to understand what contributions environment and sustainability education could make to debates on educational quality and relevance. Issues of educational quality are high on the national agendas of governments in southern Africa, as it is now well known that providing access to schooling is not a sufficient condition for achieving educational quality. Educational quality is intimately linked to the processes of teaching and learning, but the concept of educational quality is not unproblematic in and of itself. It is, as Noel Gough (2005) noted many years ago, an ‘order word’ that shapes the way people think and practise. Our enquiries during this research programme involved a number of case studies (that were reported on in the Southern African Journal of Environmental Education (SAJEE) in 2008, and are again reported on in this edition of the SAJEE), but the programme also involved theoretical engagement with the concept of educational quality and relevance. This think piece helps to make some of this thinking and theoretical deliberation visible. The author of this think piece was also the leader of the regional research programme and was tasked with synthesising the theoretical deliberations that emerged from the research design which were found to be useful for guiding interpretations and deliberation on more detailed case studies undertaken at country level.
- Full Text:
- Date Issued: 2013
Think Piece, Naked Science-Avoiding Methodolatry in an Environmental Education Context
- Authors: Price, Leigh
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387264 , vital:68220 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122255"
- Description: Research methodology is significantly political and in this think piece I try to better understand the effect of this politicisation in the production of science. The main focus of the think piece is to identify the dominant methodological discourses and analyse them using techniques borrowed from post-structuralism. From this analysis, I suggest that methodological discourses are reproduced and normalised in much the same way as discourses of, for example, sexuality, and I give examples of this from my experience as a PhD student of environmental education. I also suggest that some transgressive methodologies, such as those associated with postmodernism or participatory research, despite purporting to empower, at times also disempower. Furthermore, all of the methodologies that I analyse are, in one way or another, ‘loaded’; they cloak their agendas. From this analysis, I move towards suggesting an alternative critical realist methodology for environmental education which is naked; its agendas are clearly stated, not least because this epistemology does not lend itself to deception. An important part of this critical realist conception of methodology is the idea of ‘meta-reflexivity’ in which truth is not vulgarly pragmatic or fideistic.
- Full Text:
- Date Issued: 2013
- Authors: Price, Leigh
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387264 , vital:68220 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122255"
- Description: Research methodology is significantly political and in this think piece I try to better understand the effect of this politicisation in the production of science. The main focus of the think piece is to identify the dominant methodological discourses and analyse them using techniques borrowed from post-structuralism. From this analysis, I suggest that methodological discourses are reproduced and normalised in much the same way as discourses of, for example, sexuality, and I give examples of this from my experience as a PhD student of environmental education. I also suggest that some transgressive methodologies, such as those associated with postmodernism or participatory research, despite purporting to empower, at times also disempower. Furthermore, all of the methodologies that I analyse are, in one way or another, ‘loaded’; they cloak their agendas. From this analysis, I move towards suggesting an alternative critical realist methodology for environmental education which is naked; its agendas are clearly stated, not least because this epistemology does not lend itself to deception. An important part of this critical realist conception of methodology is the idea of ‘meta-reflexivity’ in which truth is not vulgarly pragmatic or fideistic.
- Full Text:
- Date Issued: 2013
Third order nonlinear optical properties of phthalocyanines in the presence nanomaterials and in polymer thin films
- Britton, Jonathan, Durmus, Mahmut, Khene, Samson M, Chauke, Vongani, Nyokong, Tebello
- Authors: Britton, Jonathan , Durmus, Mahmut , Khene, Samson M , Chauke, Vongani , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241772 , vital:50968 , xlink:href="https://doi.org/10.1142/S108842461350003X"
- Description: Third order nonlinear optical properties were determined for phthalocyanine complexes 1–10 containing In, Ga and Zn central metals and tetra- or octa-substituted with benzyloxyphenoxy, phenoxy, tert-butylphenoxy and amino groups at peripheral or non-peripheral positions. The phthalocyanines were embedded in poly (methyl methacrylate) polymer in the presence of CdTe quantum dots. All complexes 1–10 were studied in the presence of CdTe quantum dots and embedded in poly (methyl methacrylate) to form thin films. Complex 3 tetrasubstituted with tert-butylphenoxy groups at non-peripheral positions was also studied in the presence of CdS, CdSe quantum dots, fullerenes, single walled carbon nanotubes. Third order nonlinear optical parameters generally increase for Pcs in the presence of CdTe quantum dots.
- Full Text:
- Date Issued: 2013
- Authors: Britton, Jonathan , Durmus, Mahmut , Khene, Samson M , Chauke, Vongani , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241772 , vital:50968 , xlink:href="https://doi.org/10.1142/S108842461350003X"
- Description: Third order nonlinear optical properties were determined for phthalocyanine complexes 1–10 containing In, Ga and Zn central metals and tetra- or octa-substituted with benzyloxyphenoxy, phenoxy, tert-butylphenoxy and amino groups at peripheral or non-peripheral positions. The phthalocyanines were embedded in poly (methyl methacrylate) polymer in the presence of CdTe quantum dots. All complexes 1–10 were studied in the presence of CdTe quantum dots and embedded in poly (methyl methacrylate) to form thin films. Complex 3 tetrasubstituted with tert-butylphenoxy groups at non-peripheral positions was also studied in the presence of CdS, CdSe quantum dots, fullerenes, single walled carbon nanotubes. Third order nonlinear optical parameters generally increase for Pcs in the presence of CdTe quantum dots.
- Full Text:
- Date Issued: 2013