in a park in Europe
- Authors: Krueger, Anton
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229851 , vital:49717 , xlink:href="https://hdl.handle.net/10520/EJC47802"
- Full Text:
- Date Issued: 2008
- Authors: Krueger, Anton
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229851 , vital:49717 , xlink:href="https://hdl.handle.net/10520/EJC47802"
- Full Text:
- Date Issued: 2008
in the council chambers
- Authors: Krueger, Anton
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229862 , vital:49718 , xlink:href="https://hdl.handle.net/10520/EJC47802"
- Full Text:
- Date Issued: 2008
- Authors: Krueger, Anton
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229862 , vital:49718 , xlink:href="https://hdl.handle.net/10520/EJC47802"
- Full Text:
- Date Issued: 2008
Interaction of water-soluble thiol capped CdTe quantum dots and bovine serum albumin
- Idowu, Mopelola, Lamprecht, Emmanuel, Nyokong, Tebello
- Authors: Idowu, Mopelola , Lamprecht, Emmanuel , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265974 , vital:53906 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.02.008"
- Description: Luminescent water-soluble CdTe quantum dots (QDs) capped with different thiol carboxylic acids were synthesized in aqueous medium and then cross linked to bovine serum albumin (BSA) with 1-ethyl3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Enhancement of fluorescence emission intensity occurred for QDs in the presence of bovine serum albumin (BSA, mixed or linked) signifying inhibition of non-radiative recombination of the surface vacancies. Fluorescence studies reveal a positive deviation behaviour suggesting the occurrence of static and dynamic mechanisms of quenching together which was accounted for by the modified Stern–Volmer equation.
- Full Text:
- Date Issued: 2008
- Authors: Idowu, Mopelola , Lamprecht, Emmanuel , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265974 , vital:53906 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.02.008"
- Description: Luminescent water-soluble CdTe quantum dots (QDs) capped with different thiol carboxylic acids were synthesized in aqueous medium and then cross linked to bovine serum albumin (BSA) with 1-ethyl3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Enhancement of fluorescence emission intensity occurred for QDs in the presence of bovine serum albumin (BSA, mixed or linked) signifying inhibition of non-radiative recombination of the surface vacancies. Fluorescence studies reveal a positive deviation behaviour suggesting the occurrence of static and dynamic mechanisms of quenching together which was accounted for by the modified Stern–Volmer equation.
- Full Text:
- Date Issued: 2008
Introduction: Stimela: railway poems of South Africa
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7058 , http://hdl.handle.net/10962/d1007420
- Description: preprint , A collection of railway poems is an unusual undertaking. More than an exercise in nostalgia, this anthology captures a large slice of modern South African life, viewed from different perspectives. Many of South Africa’s best poets have written railway poems. This is unsurprising, for railways hold special meaning for a variety of people – people in all walks of life – who find them not only fascinating but emotionally sympatico. The place of railways in the South African economy is changing rapidly, and it will be interesting to see in the coming years whether the less personal, more streamlined business model that is taking shape will attract the same naïve fascination engendered by South African railways over the past two centuries.
- Full Text:
- Date Issued: 2008
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7058 , http://hdl.handle.net/10962/d1007420
- Description: preprint , A collection of railway poems is an unusual undertaking. More than an exercise in nostalgia, this anthology captures a large slice of modern South African life, viewed from different perspectives. Many of South Africa’s best poets have written railway poems. This is unsurprising, for railways hold special meaning for a variety of people – people in all walks of life – who find them not only fascinating but emotionally sympatico. The place of railways in the South African economy is changing rapidly, and it will be interesting to see in the coming years whether the less personal, more streamlined business model that is taking shape will attract the same naïve fascination engendered by South African railways over the past two centuries.
- Full Text:
- Date Issued: 2008
Inventing the Human: Brontosaurus Bloom and “the Shakespeare in us”
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7045 , http://hdl.handle.net/10962/d1007387 , https://www.taylorfrancis.com/books/e/9781351963534/chapters/10.4324%2F9781315264264-15
- Description: preprint , This essay was occasioned by the casual reading of a book called Harold Bloom’s Shakespeare (2002), a collection of responses, pro, ante and puzzled, to Bloom’s Shakespearean magnum opus. The more I browsed in the assembled essays, some of them originally reviews and conference papers, others specially commissioned responses, the more curious I became. On the whole, the contributors seemed not to understand Bloom, at least not to understand him adequately, which is a devastating handicap when the task in hand is to pass judgment. The problem seems to be that few academic commentators take Bloom seriously, accepting that he means what he says; more accurately, they find it hard to entertain with full seriousness matters Bloom intends should be taken entirely seriously. Shakespeareans, locked into their various ways of understanding the world and critical activity, generally try to find Shakespeare (or “Shakespeare”) through reading Bloom, whereas he wants us to find ourselves through reading Shakespeare: to uncover what Emerson called ‘the Shakespeare in us’ (‘Shakespeare, or The Poet’, 256). The difference is stupendous. We ought first to ask in regard to Bloom’s blockbuster the question Bloom tells us he learned from Kenneth Burke, ‘What is the author trying to do for himself or herself by writing this work?’ (Shakespeare, 412).
- Full Text:
- Date Issued: 2008
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7045 , http://hdl.handle.net/10962/d1007387 , https://www.taylorfrancis.com/books/e/9781351963534/chapters/10.4324%2F9781315264264-15
- Description: preprint , This essay was occasioned by the casual reading of a book called Harold Bloom’s Shakespeare (2002), a collection of responses, pro, ante and puzzled, to Bloom’s Shakespearean magnum opus. The more I browsed in the assembled essays, some of them originally reviews and conference papers, others specially commissioned responses, the more curious I became. On the whole, the contributors seemed not to understand Bloom, at least not to understand him adequately, which is a devastating handicap when the task in hand is to pass judgment. The problem seems to be that few academic commentators take Bloom seriously, accepting that he means what he says; more accurately, they find it hard to entertain with full seriousness matters Bloom intends should be taken entirely seriously. Shakespeareans, locked into their various ways of understanding the world and critical activity, generally try to find Shakespeare (or “Shakespeare”) through reading Bloom, whereas he wants us to find ourselves through reading Shakespeare: to uncover what Emerson called ‘the Shakespeare in us’ (‘Shakespeare, or The Poet’, 256). The difference is stupendous. We ought first to ask in regard to Bloom’s blockbuster the question Bloom tells us he learned from Kenneth Burke, ‘What is the author trying to do for himself or herself by writing this work?’ (Shakespeare, 412).
- Full Text:
- Date Issued: 2008
Jantjie v The Minister of Labour Unreported Eastern Cape Division Case No 2193/2006
- Authors: Glover, Graham B , Beard, M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186891 , vital:44545 , xlink:href="///C:/Users/User/Downloads/41DeJure648%20(1).pdf"
- Description: James Joyce once wrote that "mistakes ... are the portals of discovery" (Ulysses (1964) Ch 9). This aptly describes the legal significance of the judgment in Jantjie v Minister of Labour (unreported decision of the High Court, Eastern Cape Division, case no 3193/2006, decided on 2007-06- 14). In this case, Leach J had to deal with a matter of civil procedure that does not seem to have been dealt with in any reported judgment - the effect of an attorney of record mistakenly failing to sign a notice of motion where an application is brought before the High Court.
- Full Text:
- Date Issued: 2008
- Authors: Glover, Graham B , Beard, M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186891 , vital:44545 , xlink:href="///C:/Users/User/Downloads/41DeJure648%20(1).pdf"
- Description: James Joyce once wrote that "mistakes ... are the portals of discovery" (Ulysses (1964) Ch 9). This aptly describes the legal significance of the judgment in Jantjie v Minister of Labour (unreported decision of the High Court, Eastern Cape Division, case no 3193/2006, decided on 2007-06- 14). In this case, Leach J had to deal with a matter of civil procedure that does not seem to have been dealt with in any reported judgment - the effect of an attorney of record mistakenly failing to sign a notice of motion where an application is brought before the High Court.
- Full Text:
- Date Issued: 2008
Knowledge of plant resource use based on location, gender and generation
- Dovie, Delali B K, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181202 , vital:43707 , xlink:href="https://doi.org/10.1016/j.apgeog.2008.07.002"
- Description: The differences in knowledge of biological resource use between societal and demographic groups are often poorly understood; yet they are an important element of sustainability. Differences in gender and generational knowledge of locally useful woody plant species in South African savannas are examined. The results showed that young people and middle-aged females were highly knowledgeable. Over half of the total 267 woody plant species in nine use categories (i.e., medicinal, fruits–seeds, fuelwood, beverage, cultural, furniture, craft, fencing and housing poles) had multiple uses. Therefore, differences in knowledge of resource selection and use between social or demographic groups (for example based on gender and age) may appropriately inform conservation prioritisation, planning and monitoring.
- Full Text:
- Date Issued: 2008
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181202 , vital:43707 , xlink:href="https://doi.org/10.1016/j.apgeog.2008.07.002"
- Description: The differences in knowledge of biological resource use between societal and demographic groups are often poorly understood; yet they are an important element of sustainability. Differences in gender and generational knowledge of locally useful woody plant species in South African savannas are examined. The results showed that young people and middle-aged females were highly knowledgeable. Over half of the total 267 woody plant species in nine use categories (i.e., medicinal, fruits–seeds, fuelwood, beverage, cultural, furniture, craft, fencing and housing poles) had multiple uses. Therefore, differences in knowledge of resource selection and use between social or demographic groups (for example based on gender and age) may appropriately inform conservation prioritisation, planning and monitoring.
- Full Text:
- Date Issued: 2008
Links between the local trade in natural products, livelihoods and poverty alleviation in a semi-arid region of South Africa
- Shackleton, Sheona E, Campbell, Bruce, Lotz-Sisitka, Heila, Shackleton, Charlie M
- Authors: Shackleton, Sheona E , Campbell, Bruce , Lotz-Sisitka, Heila , Shackleton, Charlie M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181246 , vital:43712 , xlink:href="https://doi.org/10.1016/j.worlddev.2007.03.003"
- Description: Can the local commercialization of natural products contribute to reduced poverty and vulnerability? Commentary on this issue is mixed, with some observers being quite optimistic, while others hold a counterview. This paper explores the poverty alleviation potential of four products traded in Bushbuckridge, South Africa—traditional brooms, reed mats, woodcraft, and “marula” beer. While key in enhancing the livelihood security of the poorest households, these products were unlikely to provide a route out of poverty for most, although there were exceptions. Incomes often surpassed local wage rates, and some producers obtained returns equivalent to the minimum wage. Non-financial benefits such as the opportunity to work from home were highly rated, and the trade was found to represent a range of livelihood strategies both within and across products.
- Full Text:
- Date Issued: 2008
- Authors: Shackleton, Sheona E , Campbell, Bruce , Lotz-Sisitka, Heila , Shackleton, Charlie M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181246 , vital:43712 , xlink:href="https://doi.org/10.1016/j.worlddev.2007.03.003"
- Description: Can the local commercialization of natural products contribute to reduced poverty and vulnerability? Commentary on this issue is mixed, with some observers being quite optimistic, while others hold a counterview. This paper explores the poverty alleviation potential of four products traded in Bushbuckridge, South Africa—traditional brooms, reed mats, woodcraft, and “marula” beer. While key in enhancing the livelihood security of the poorest households, these products were unlikely to provide a route out of poverty for most, although there were exceptions. Incomes often surpassed local wage rates, and some producers obtained returns equivalent to the minimum wage. Non-financial benefits such as the opportunity to work from home were highly rated, and the trade was found to represent a range of livelihood strategies both within and across products.
- Full Text:
- Date Issued: 2008
Mussolini's moment: Roy Sargeant directs The Merchant of Venice at Maynardville, January, 2007
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7047 , http://hdl.handle.net/10962/d1007389 , http://hdl.handle.net/10520/EJC48107
- Description: preprint , What an inspired choice of play for this year’s Maynardville offering! With the national scene strewn with trials and rumours of trials, all of them vital to the quality of life citizens of this fair city beneath the beautiful mountain (‘Belmont’) may hope to enjoy in the future, Shakespeare’s cliff-hanger about the use and abuse of the law couldn’t be more apt.
- Full Text:
- Date Issued: 2008
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7047 , http://hdl.handle.net/10962/d1007389 , http://hdl.handle.net/10520/EJC48107
- Description: preprint , What an inspired choice of play for this year’s Maynardville offering! With the national scene strewn with trials and rumours of trials, all of them vital to the quality of life citizens of this fair city beneath the beautiful mountain (‘Belmont’) may hope to enjoy in the future, Shakespeare’s cliff-hanger about the use and abuse of the law couldn’t be more apt.
- Full Text:
- Date Issued: 2008
Opensource software and localisation in indigenous South African languages with Pootle
- Dalvit, Lorenzo, Terzoli, Alfredo, Wolff, F
- Authors: Dalvit, Lorenzo , Terzoli, Alfredo , Wolff, F
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428496 , vital:72515 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=912f3d0d94f0268467e1d790fd7780f14d9c4e44
- Description: The majority of the South African population is not fully proficient in Eng-lish. Besides access to the necessary infrastructure, many Africans lack epistemological access to the ICT world simply because of linguistic reasons. Limited availability of resources and lack of interest for the promotion of African languages in the ICT domain among their speakers are often blamed for this. The opensource community has been particu-larly responsive to the needs of this portion of the population, and a vari-ety of software is already available in African languages. Translate. org. za, an NGO committed to the development of opensource software in all 11 South African languages, has been particularly active with respect to this. On the one hand, they have developed a Webbased application to support collaborative translation online. On the other, they have part-nered with various institutions to organise translation efforts, mainly rely-ing on volunteers. In this paper we describe an experience showing how these two models can be used to address issues of lack of resources and support for the use of African languages in the ICT domain.
- Full Text:
- Date Issued: 2008
- Authors: Dalvit, Lorenzo , Terzoli, Alfredo , Wolff, F
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428496 , vital:72515 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=912f3d0d94f0268467e1d790fd7780f14d9c4e44
- Description: The majority of the South African population is not fully proficient in Eng-lish. Besides access to the necessary infrastructure, many Africans lack epistemological access to the ICT world simply because of linguistic reasons. Limited availability of resources and lack of interest for the promotion of African languages in the ICT domain among their speakers are often blamed for this. The opensource community has been particu-larly responsive to the needs of this portion of the population, and a vari-ety of software is already available in African languages. Translate. org. za, an NGO committed to the development of opensource software in all 11 South African languages, has been particularly active with respect to this. On the one hand, they have developed a Webbased application to support collaborative translation online. On the other, they have part-nered with various institutions to organise translation efforts, mainly rely-ing on volunteers. In this paper we describe an experience showing how these two models can be used to address issues of lack of resources and support for the use of African languages in the ICT domain.
- Full Text:
- Date Issued: 2008
Pan-African multilateralism: transformative or disconnected?
- Authors: Bischoff, Paul, 1954-
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161452 , vital:40628 , https://doi.org/10.1080/02589340802366968
- Description: Despite a multitude of international institutions on the African continent, worldwide Africa's multilateralism has generally received little attention. Yet, with the emergence of the African Union (AU) and its institutions, questions arise about its character. Will rhetoric and state symbolism take the place of substance or will the space opened up for democracy and civil society participation allow for greater democratically informed sustainability? With this in mind, the article addresses the issue to what extent the character of African multilateralism continues to display features of disconnectedness as opposed to those of transformation, where its institutions address issues of uneven development in concert with civil society concerns.
- Full Text:
- Date Issued: 2008
- Authors: Bischoff, Paul, 1954-
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161452 , vital:40628 , https://doi.org/10.1080/02589340802366968
- Description: Despite a multitude of international institutions on the African continent, worldwide Africa's multilateralism has generally received little attention. Yet, with the emergence of the African Union (AU) and its institutions, questions arise about its character. Will rhetoric and state symbolism take the place of substance or will the space opened up for democracy and civil society participation allow for greater democratically informed sustainability? With this in mind, the article addresses the issue to what extent the character of African multilateralism continues to display features of disconnectedness as opposed to those of transformation, where its institutions address issues of uneven development in concert with civil society concerns.
- Full Text:
- Date Issued: 2008
Phosphorescence of orthopaedic–grade ultra high molecular weight polyethylene
- Authors: Chithambo, Makaiko L
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125617 , vital:35801 , https://doi.10.1002/pssc.200776802
- Description: Isothermal luminescence decay curves have been measured from orthopaedic–standard ultra high molecular weight polyethylene between 35 and 70 ˚C on the rising edge of the main glow peak at 70 ˚C. Preparatory peak-shape analysis of the temperature-resolved glow peak at 70 ˚C measured at 1 ˚C s–1 gave a geometrical factor close to 0.5 suggestive of second order kinetics for both the isothermal and thermally stimulated luminescence. The results of analysis of the phosphorescence of transformed monotonic-to-peak isothermal decay curves are also second order, as is the conclusion from thermoluminescence glow-curve de-convolution. All methods of analysis give an activation energy of about 0.7 eV.
- Full Text:
- Date Issued: 2008
- Authors: Chithambo, Makaiko L
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125617 , vital:35801 , https://doi.10.1002/pssc.200776802
- Description: Isothermal luminescence decay curves have been measured from orthopaedic–standard ultra high molecular weight polyethylene between 35 and 70 ˚C on the rising edge of the main glow peak at 70 ˚C. Preparatory peak-shape analysis of the temperature-resolved glow peak at 70 ˚C measured at 1 ˚C s–1 gave a geometrical factor close to 0.5 suggestive of second order kinetics for both the isothermal and thermally stimulated luminescence. The results of analysis of the phosphorescence of transformed monotonic-to-peak isothermal decay curves are also second order, as is the conclusion from thermoluminescence glow-curve de-convolution. All methods of analysis give an activation energy of about 0.7 eV.
- Full Text:
- Date Issued: 2008
Photocatalytic oxidation of 1-hexene using GaPc and InPc octasubstituted derivatives
- Chauke, Vongani, Nyokong, Tebello
- Authors: Chauke, Vongani , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268611 , vital:54214 , xlink:href="https://doi.org/10.1016/j.molcata.2008.04.003"
- Description: Photocatalytic oxidation of 1-hexene by GaPc (1a–1c) and InPc (2a–2c) derivatives (Pc = phthalocyanine) is hereby presented. The derivatives studied are Pc octasubstituted with phenoxy (a), 4-tert-butylphenoxy (b) or benzyloxyphenoxy (c) at the peripheral positions. The photocatalytic oxidation products for 1-hexene were 1,2-epoxyhexane and 1-hexen-3-ol. The %conversion values of 1-hexene and %selectivity of 1,2-epoxyhexane were generally higher for InPc derivatives. Even though InPc derivatives showed better photocatalytic results than GaPc derivatives, the former were less stable relative to the latter. Both type I and type II mechanism were implicated in the photocatalysis mechanism.
- Full Text:
- Date Issued: 2008
- Authors: Chauke, Vongani , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268611 , vital:54214 , xlink:href="https://doi.org/10.1016/j.molcata.2008.04.003"
- Description: Photocatalytic oxidation of 1-hexene by GaPc (1a–1c) and InPc (2a–2c) derivatives (Pc = phthalocyanine) is hereby presented. The derivatives studied are Pc octasubstituted with phenoxy (a), 4-tert-butylphenoxy (b) or benzyloxyphenoxy (c) at the peripheral positions. The photocatalytic oxidation products for 1-hexene were 1,2-epoxyhexane and 1-hexen-3-ol. The %conversion values of 1-hexene and %selectivity of 1,2-epoxyhexane were generally higher for InPc derivatives. Even though InPc derivatives showed better photocatalytic results than GaPc derivatives, the former were less stable relative to the latter. Both type I and type II mechanism were implicated in the photocatalysis mechanism.
- Full Text:
- Date Issued: 2008
Photocatalytic transformation of 4-nitrophenol in aqueous media using suspended, water-insoluble metallophthalocyanine complexes
- Marais, Eloise, Antunes, Edith M, Nyokong, Tebello
- Authors: Marais, Eloise , Antunes, Edith M , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265986 , vital:53907 , xlink:href="https://doi.org/10.1080/00958970802146056"
- Description: Unsubstituted magnesium (MgPc), zinc (ZnPc) and chloroaluminium (ClAlPc) phthalocyanine complexes and the ring substituted zinc tetranitro (ZnPc(NO2)4), zinc tetraamino (ZnPc(NH2)4), zinc hexadecafluoro (ZnPcF16) and zinc hexadecachloro (ZnPcCl16), phthalocyanine complexes are employed as photocatalysts for the heterogeneous transformation of 4-nitrophenol (4-Np) to fumaric acid and 4-nitrocatechol. ClAlPc is the best catalyst, with 89 ± 8% degradation of 4-Np after 100 min. The least effective catalysts were ZnPcCl16 and MgPc.
- Full Text:
- Date Issued: 2008
- Authors: Marais, Eloise , Antunes, Edith M , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265986 , vital:53907 , xlink:href="https://doi.org/10.1080/00958970802146056"
- Description: Unsubstituted magnesium (MgPc), zinc (ZnPc) and chloroaluminium (ClAlPc) phthalocyanine complexes and the ring substituted zinc tetranitro (ZnPc(NO2)4), zinc tetraamino (ZnPc(NH2)4), zinc hexadecafluoro (ZnPcF16) and zinc hexadecachloro (ZnPcCl16), phthalocyanine complexes are employed as photocatalysts for the heterogeneous transformation of 4-nitrophenol (4-Np) to fumaric acid and 4-nitrocatechol. ClAlPc is the best catalyst, with 89 ± 8% degradation of 4-Np after 100 min. The least effective catalysts were ZnPcCl16 and MgPc.
- Full Text:
- Date Issued: 2008
Photoinduced energy transfer between water-soluble CdTe quantum dots and aluminium tetrasulfonated phthalocyanine
- Idowu, Mopelola, Chen, Ji-Yao, Nyokong, Tebello
- Authors: Idowu, Mopelola , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268564 , vital:54210 , xlink:href="https://doi.org/10.1039/B707808K"
- Description: Thiol stabilized CdTe quantum dots (QDs) synthesized in aqueous phase were used as energy donors to aluminium tetrasulfonated phthalocyanine (AlTSPc) through fluorescence resonance energy transfer (FRET). Energy transfer occurred from the QDs to AlTSPc upon photoexcitation of the QDs. An enhancement in efficiency of energy transfer with the nature of the carboxylic thiol stabilizers on the QDs was observed. The results showed that for enhanced FRET to occur, the donor–acceptor distance has to be lower than the critical distance. The quenching constant K as well as the binding constant kb values were calculated suggesting strong interaction of the QDs with the AlTSPc. Study of the photophysics of AlTSPc in the presence of the QDs revealed a high triplet state yield, hence the possibility of using QDs in combination with phthalocyanines as photosensitizers in photodynamic therapy. The triplet state lifetimes of AlTSPc in the presence of the QDs were calculated and the lifetime in the presence of CdTe capped with 3-mercaptopropionic acid (MPA) was found to be the longest. MPA capped QD in a mixture with AlTSPc resulted in long triplet lifetime and high triplet yield of the latter, and high energy transfer efficiency, hence was found to be most suitable as a potential candidate for photodynamic therapy of cancer studies.
- Full Text:
- Date Issued: 2008
- Authors: Idowu, Mopelola , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268564 , vital:54210 , xlink:href="https://doi.org/10.1039/B707808K"
- Description: Thiol stabilized CdTe quantum dots (QDs) synthesized in aqueous phase were used as energy donors to aluminium tetrasulfonated phthalocyanine (AlTSPc) through fluorescence resonance energy transfer (FRET). Energy transfer occurred from the QDs to AlTSPc upon photoexcitation of the QDs. An enhancement in efficiency of energy transfer with the nature of the carboxylic thiol stabilizers on the QDs was observed. The results showed that for enhanced FRET to occur, the donor–acceptor distance has to be lower than the critical distance. The quenching constant K as well as the binding constant kb values were calculated suggesting strong interaction of the QDs with the AlTSPc. Study of the photophysics of AlTSPc in the presence of the QDs revealed a high triplet state yield, hence the possibility of using QDs in combination with phthalocyanines as photosensitizers in photodynamic therapy. The triplet state lifetimes of AlTSPc in the presence of the QDs were calculated and the lifetime in the presence of CdTe capped with 3-mercaptopropionic acid (MPA) was found to be the longest. MPA capped QD in a mixture with AlTSPc resulted in long triplet lifetime and high triplet yield of the latter, and high energy transfer efficiency, hence was found to be most suitable as a potential candidate for photodynamic therapy of cancer studies.
- Full Text:
- Date Issued: 2008
Photophysical and photochemical properties of tetrasulfonated silicon and germanium phthalocyanine in aqueous and non-aqueous media
- Idowu, Mopolela, Nyokong, Tebello
- Authors: Idowu, Mopolela , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268624 , vital:54215 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.01.004"
- Description: The photophysical and photochemical properties of tetrasulfonated silicon and germanium phthalocyanine (SiPcS4 and GePcS4) in aqueous solution (phosphate-buffered saline (PBS) solution, pH 7.4) (in the presence and absence of cremophore EL (CEL)) and in dimethylsulphoxide (DMSO) were studied. The complexes have intense absorption in the visible/near-IR region though they highly aggregate in aqueous solution with a dimerization constant of ∼2 × 104 dm3 mol−1. The fluorescence excitation spectra however have only one band suggesting that only the monomer fluoresces. Both the quantum yields of the triplet state (ΦT) and the triplet lifetimes (τT) were found to be higher in DMSO compared to in aqueous solution. Aggregation is hindered by addition of cremophore EL in aqueous solution and this induced disaggregation caused an increased ΦT and τT probably due to the reduced interaction of the phthalocyanines with the aqueous medium in the presence of CEL.
- Full Text:
- Date Issued: 2008
- Authors: Idowu, Mopolela , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268624 , vital:54215 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.01.004"
- Description: The photophysical and photochemical properties of tetrasulfonated silicon and germanium phthalocyanine (SiPcS4 and GePcS4) in aqueous solution (phosphate-buffered saline (PBS) solution, pH 7.4) (in the presence and absence of cremophore EL (CEL)) and in dimethylsulphoxide (DMSO) were studied. The complexes have intense absorption in the visible/near-IR region though they highly aggregate in aqueous solution with a dimerization constant of ∼2 × 104 dm3 mol−1. The fluorescence excitation spectra however have only one band suggesting that only the monomer fluoresces. Both the quantum yields of the triplet state (ΦT) and the triplet lifetimes (τT) were found to be higher in DMSO compared to in aqueous solution. Aggregation is hindered by addition of cremophore EL in aqueous solution and this induced disaggregation caused an increased ΦT and τT probably due to the reduced interaction of the phthalocyanines with the aqueous medium in the presence of CEL.
- Full Text:
- Date Issued: 2008
Photosensitizing properties of octacarboxy metallophthalocyanines in aqueous medium and their interaction with bovine serum albumin
- Idowu, Mopelola, Nyokong, Tebello
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264552 , vital:53744 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.09.003"
- Description: Photosensitizing properties of aluminium, silicon, zinc and germanium octacarboxy phthalocyanines ((OH)AlOCPc, (OH)2SiOCPc, ZnOCPc and (OH)2GeOCPc) were studied in aqueous medium and in the presence of bovine serum albumin (BSA). Triplet quantum yields increased with increasing atomic number of the central metals of the metallophthalocyanine. The efficiency of singlet oxygen generation via energy transfer from the excited triplet state of the octacarboxy metallophthalocyanines (MOCPcs) to ground state oxygen increased markedly in the presence of BSA. The triplet state lifetimes of the MOCPc complexes in the presence of BSA were found to be longer than in the absence of BSA, ranging from 110 to 580 μs. These complexes bind readily to BSA. Stern–Volmer quenching constant KSV as well as the binding constant kb values were calculated. The probable mechanism of quenching of BSA fluorescence by the MOCPc complexes is by static quenching.
- Full Text:
- Date Issued: 2008
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264552 , vital:53744 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.09.003"
- Description: Photosensitizing properties of aluminium, silicon, zinc and germanium octacarboxy phthalocyanines ((OH)AlOCPc, (OH)2SiOCPc, ZnOCPc and (OH)2GeOCPc) were studied in aqueous medium and in the presence of bovine serum albumin (BSA). Triplet quantum yields increased with increasing atomic number of the central metals of the metallophthalocyanine. The efficiency of singlet oxygen generation via energy transfer from the excited triplet state of the octacarboxy metallophthalocyanines (MOCPcs) to ground state oxygen increased markedly in the presence of BSA. The triplet state lifetimes of the MOCPc complexes in the presence of BSA were found to be longer than in the absence of BSA, ranging from 110 to 580 μs. These complexes bind readily to BSA. Stern–Volmer quenching constant KSV as well as the binding constant kb values were calculated. The probable mechanism of quenching of BSA fluorescence by the MOCPc complexes is by static quenching.
- Full Text:
- Date Issued: 2008
Pragmatic research design
- Amos, Trevor L, Pearse, Noel J
- Authors: Amos, Trevor L , Pearse, Noel J
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270943 , vital:54494 , xlink:href="https://academic-publishing.org/index.php/ejbrm/article/view/1230/1193"
- Description: The creation of wealth is an important issue in any society, and entrepreneurship is regarded as an important catalyst in the creation of new wealth. This presents a challenge to develop entrepreneurship successfully. An important site for the development of entrepreneurship is higher education. The challenge however, is that there is a lack of a general understanding on how to educate students for entrepreneurship. In addition, current thought and practice on entrepreneurship education is historically biased, implying that graduates are essentially prepared for the past instead of for the future. From the perspective of higher education, the problem is how to develop current students to be entrepreneurial in the future. What is needed is to project into the future and then to develop an understanding of what should be taught as well as how it should be taught today. A versatile research technique that can assist in achieving this objective is the Delphi technique, as it is used to conduct futures research or research into areas where knowledge is incomplete. The Delphi method is a type of group interview, using the collective opinion of knowledgeable experts. The technique makes use of several rounds of data collection and feedback to create a consensus of opinion. Making use of the Delphi technique, research is being designed that will formulate expert‑based strategic guidelines on entrepreneurial education within the South African higher education sector. The aim of this paper is to illustrate the research design considerations that arise in the use of the Delphi technique for this purpose and how they are addressed. The main characteristics of the Delphi are presented and arguments for the use of the Delphi within a constructivist paradigm are discussed. Practical issues related to the design of the Delphi, panel‑member selection, and the formulation of panel questions, are examined. In illustrating these design considerations, the paper demonstrates a pragmatic approach to research design as well as the importance of creating coherence between the research question, the research paradigm, the research method and its use, encouraging research practitioners to adopt a more systematic, deliberate and philosophically‑based approach to research design.
- Full Text:
- Date Issued: 2008
- Authors: Amos, Trevor L , Pearse, Noel J
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270943 , vital:54494 , xlink:href="https://academic-publishing.org/index.php/ejbrm/article/view/1230/1193"
- Description: The creation of wealth is an important issue in any society, and entrepreneurship is regarded as an important catalyst in the creation of new wealth. This presents a challenge to develop entrepreneurship successfully. An important site for the development of entrepreneurship is higher education. The challenge however, is that there is a lack of a general understanding on how to educate students for entrepreneurship. In addition, current thought and practice on entrepreneurship education is historically biased, implying that graduates are essentially prepared for the past instead of for the future. From the perspective of higher education, the problem is how to develop current students to be entrepreneurial in the future. What is needed is to project into the future and then to develop an understanding of what should be taught as well as how it should be taught today. A versatile research technique that can assist in achieving this objective is the Delphi technique, as it is used to conduct futures research or research into areas where knowledge is incomplete. The Delphi method is a type of group interview, using the collective opinion of knowledgeable experts. The technique makes use of several rounds of data collection and feedback to create a consensus of opinion. Making use of the Delphi technique, research is being designed that will formulate expert‑based strategic guidelines on entrepreneurial education within the South African higher education sector. The aim of this paper is to illustrate the research design considerations that arise in the use of the Delphi technique for this purpose and how they are addressed. The main characteristics of the Delphi are presented and arguments for the use of the Delphi within a constructivist paradigm are discussed. Practical issues related to the design of the Delphi, panel‑member selection, and the formulation of panel questions, are examined. In illustrating these design considerations, the paper demonstrates a pragmatic approach to research design as well as the importance of creating coherence between the research question, the research paradigm, the research method and its use, encouraging research practitioners to adopt a more systematic, deliberate and philosophically‑based approach to research design.
- Full Text:
- Date Issued: 2008
Prototyping a p2p sip user agent with support for multiple overlays
- Tsietsi, Mosiuoa, Terzoli, Alfredo, Wells, George C
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430858 , vital:72722 , 10.1109/PERCOM.2008.102
- Description: This paper describes a systematic approach to provide support at the user agent level for peer-to-peer based multimedia communications us-ing SIP (session initiation protocol). In a society that is becoming in-creasingly mobile, the advantages of engaging in interactive sessions without relying on central servers or infrastructure are clear. Yet, cur-rently many user agents and devices have little support for peer-to-peer communications. In this paper, we motivate for the use of structured peer-to-peer protocols called DHTs, as a foundation for a peer-to-peer layer. We introduce the concept of "DHTplug-ins" which assist in ab-stracting the interface between the higher level application and the pro-prietary APIs exposed by the underlying DHTs, allowing us to manipu-late user agents with peer-to-peer logic. This embeddable-DHT concept allows these user agents to use different DHTs with one common inter-face and participate in multiple overlays. We show how an open source SIP user agent was thus modified and how realtime communications were supported.
- Full Text:
- Date Issued: 2008
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430858 , vital:72722 , 10.1109/PERCOM.2008.102
- Description: This paper describes a systematic approach to provide support at the user agent level for peer-to-peer based multimedia communications us-ing SIP (session initiation protocol). In a society that is becoming in-creasingly mobile, the advantages of engaging in interactive sessions without relying on central servers or infrastructure are clear. Yet, cur-rently many user agents and devices have little support for peer-to-peer communications. In this paper, we motivate for the use of structured peer-to-peer protocols called DHTs, as a foundation for a peer-to-peer layer. We introduce the concept of "DHTplug-ins" which assist in ab-stracting the interface between the higher level application and the pro-prietary APIs exposed by the underlying DHTs, allowing us to manipu-late user agents with peer-to-peer logic. This embeddable-DHT concept allows these user agents to use different DHTs with one common inter-face and participate in multiple overlays. We show how an open source SIP user agent was thus modified and how realtime communications were supported.
- Full Text:
- Date Issued: 2008
Reading Conference recommendations in a wider context of social change
- Authors: Lotz-Sisitka, Heila
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373792 , vital:66723 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122783"
- Description: This short Viewpoint paper considers the role and value of conference recommendations in shaping the field of environmental education. It explores the social politics, and often contested nature, of conference recommendations and their institutional histories, arguing that the act of producing conference recommendations forms part of the practices of new social movements. The paper recommends historicising conference recommendations and OEcross readings‚ to consider changing discourses and new developments in the field. Accompanying the short Viewpoint paper, are two sets of recently produced conference recommendations, one from the 4th International Environmental Education Conference held in Ahmedabad, India, and the other from the 1st International Conference on Mainstreaming Environment and Sustainability in African Universities held in Nairobi, Kenya.
- Full Text:
- Date Issued: 2008
- Authors: Lotz-Sisitka, Heila
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373792 , vital:66723 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122783"
- Description: This short Viewpoint paper considers the role and value of conference recommendations in shaping the field of environmental education. It explores the social politics, and often contested nature, of conference recommendations and their institutional histories, arguing that the act of producing conference recommendations forms part of the practices of new social movements. The paper recommends historicising conference recommendations and OEcross readings‚ to consider changing discourses and new developments in the field. Accompanying the short Viewpoint paper, are two sets of recently produced conference recommendations, one from the 4th International Environmental Education Conference held in Ahmedabad, India, and the other from the 1st International Conference on Mainstreaming Environment and Sustainability in African Universities held in Nairobi, Kenya.
- Full Text:
- Date Issued: 2008