Comparative efficiency of immobilized non-transition metal phthalocyanine photosensitizers for the visible light transformation of chlorophenols
- Agboola, Bolade, Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Agboola, Bolade , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286043 , vital:56233 , xlink:href="https://doi.org/10.1016/j.molcata.2005.12.009"
- Description: Photolysis of aqueous solutions of chlorophenols (4-chlorophenol, 2,4-dichlorophenol, 2,4,5-trichlorophenol and pentachlorophenol) in the presence of immobilized non-transition metal phthalocyanine photosensitizers onto Amberlite® is presented. The photosensitizers studied are: Al (AlOCPc) and Zn (ZnOCPc) octacarboxyphthalocyanines; Al (AlPcS4) and Zn (ZnPcS4) tetrasulfophthalocyanines; sulfonated phthalocyanine complexes (containing mixtures of differently substituted derivatives) of Al (AlPcSmix), Zn (ZnPcSmix), Ge (GePcSmix), Si (SiPcSmix) and Sn (SnPcSmix). Photolysis of the chlorophenols resulted mainly in the formation of chlorobenzoquinone derivatives. The complexes showed order of activity towards the transformation of pentachlorophenol as follows: ZnOCPc > SiPcSmix > SnPcSmix > ZnPcSmix > GePcSmix > ZnPcS4 > AlPcSmix > AlOCPc > AlPcS4. The generation of singlet oxygen (1O2) by these immobilized MPc photosensitizers was found to play a major role in their photoactivities towards the transformation of these chlorophenols. Langmuir–Hinshelwood (L–H) kinetic model studies showed that the ZnOCPc, GePcSmix and ZnPcSmix photocatalysis occurred on the catalysts surface. © 2005 Elsevier B.V. All rights reserved.
- Full Text:
- Date Issued: 2006
- Authors: Agboola, Bolade , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286043 , vital:56233 , xlink:href="https://doi.org/10.1016/j.molcata.2005.12.009"
- Description: Photolysis of aqueous solutions of chlorophenols (4-chlorophenol, 2,4-dichlorophenol, 2,4,5-trichlorophenol and pentachlorophenol) in the presence of immobilized non-transition metal phthalocyanine photosensitizers onto Amberlite® is presented. The photosensitizers studied are: Al (AlOCPc) and Zn (ZnOCPc) octacarboxyphthalocyanines; Al (AlPcS4) and Zn (ZnPcS4) tetrasulfophthalocyanines; sulfonated phthalocyanine complexes (containing mixtures of differently substituted derivatives) of Al (AlPcSmix), Zn (ZnPcSmix), Ge (GePcSmix), Si (SiPcSmix) and Sn (SnPcSmix). Photolysis of the chlorophenols resulted mainly in the formation of chlorobenzoquinone derivatives. The complexes showed order of activity towards the transformation of pentachlorophenol as follows: ZnOCPc > SiPcSmix > SnPcSmix > ZnPcSmix > GePcSmix > ZnPcS4 > AlPcSmix > AlOCPc > AlPcS4. The generation of singlet oxygen (1O2) by these immobilized MPc photosensitizers was found to play a major role in their photoactivities towards the transformation of these chlorophenols. Langmuir–Hinshelwood (L–H) kinetic model studies showed that the ZnOCPc, GePcSmix and ZnPcSmix photocatalysis occurred on the catalysts surface. © 2005 Elsevier B.V. All rights reserved.
- Full Text:
- Date Issued: 2006
Comparative electrochemistry and electrocatalytic activities of cobalt, iron and manganese phthalocyanine complexes axially co-ordinated to mercaptopyridine self-assembled monolayer at gold electrodes
- Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286054 , vital:56234 , xlink:href="https://doi.org/10.1016/j.electacta.2005.08.007"
- Description: Comparative surface electrochemistry and electrocatalytic properties of solid ultrathin monolayer films of metallophthalocyanine (MPc) complexes of cobalt (CoPc), iron (FePc) and manganese (MnPc) self-immobilised, via axial ligation reaction, onto preformed 4-mercaptopyridine self-assembled monolayers (SAMs) on gold electrodes have been described. Surface electrochemical parameters of the modified electrodes showed that these MPc-SAMs are densely packed with flat orientations. The electrochemical, electrocatalytic and stability properties of these MPc complexes follow this order: FePc > MnPc > CoPc. This finding is remarkable as it suggests that the success of using this method of self-assembling of MPc onto gold electrode is largely dependent on the bond distance between the pyridine linker and the central metal of the MPc; the shorter the distance, the faster the co-ordination and the better the electrocatalytic properties towards L-cysteine and thiocyanate. Thus, the superiority of FePc-based SAM over those of the MnPc and CoPc, has been proposed to be the result of the more favorable axial co-ordination properties of FePc with pyridine (i.e. shorter Fe–N(pyridine) bond length.
- Full Text:
- Date Issued: 2006
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286054 , vital:56234 , xlink:href="https://doi.org/10.1016/j.electacta.2005.08.007"
- Description: Comparative surface electrochemistry and electrocatalytic properties of solid ultrathin monolayer films of metallophthalocyanine (MPc) complexes of cobalt (CoPc), iron (FePc) and manganese (MnPc) self-immobilised, via axial ligation reaction, onto preformed 4-mercaptopyridine self-assembled monolayers (SAMs) on gold electrodes have been described. Surface electrochemical parameters of the modified electrodes showed that these MPc-SAMs are densely packed with flat orientations. The electrochemical, electrocatalytic and stability properties of these MPc complexes follow this order: FePc > MnPc > CoPc. This finding is remarkable as it suggests that the success of using this method of self-assembling of MPc onto gold electrode is largely dependent on the bond distance between the pyridine linker and the central metal of the MPc; the shorter the distance, the faster the co-ordination and the better the electrocatalytic properties towards L-cysteine and thiocyanate. Thus, the superiority of FePc-based SAM over those of the MnPc and CoPc, has been proposed to be the result of the more favorable axial co-ordination properties of FePc with pyridine (i.e. shorter Fe–N(pyridine) bond length.
- Full Text:
- Date Issued: 2006
Comparison of satellite rainfall data with observations from gauging station networks
- Authors: Hughes, Denis A
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7079 , http://hdl.handle.net/10962/d1009748
- Description: Networks of ground-based hydro-meteorological observations are frequently sparse in developing countries and the situation is not improving. Part of the reason is the lack of resources available in countries which have more pressing economic and social issues. However, these are also the very countries where improved estimates of water resource availability are required. While hydrological models have the potential to provide the necessary information, without adequately accurate climate (rainfall, evaporation, etc.) input information, it is extremely difficult to establish models and generate representative water resource availability information. This paper reports on a preliminary analysis of the potential for using satellite derived rainfall data through a comparison with available gauge data for four basins in the southern Africa region. It is clear that the satellite data cannot be used directly in conjunction with historical gauge data. Specifically, the satellite data do not reflect the strong influences on precipitation of topography in some of the basins. However, the prospects of applying relatively straightforward adjustments are promising and further assessments appear to be justified.
- Full Text:
- Date Issued: 2006
- Authors: Hughes, Denis A
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7079 , http://hdl.handle.net/10962/d1009748
- Description: Networks of ground-based hydro-meteorological observations are frequently sparse in developing countries and the situation is not improving. Part of the reason is the lack of resources available in countries which have more pressing economic and social issues. However, these are also the very countries where improved estimates of water resource availability are required. While hydrological models have the potential to provide the necessary information, without adequately accurate climate (rainfall, evaporation, etc.) input information, it is extremely difficult to establish models and generate representative water resource availability information. This paper reports on a preliminary analysis of the potential for using satellite derived rainfall data through a comparison with available gauge data for four basins in the southern Africa region. It is clear that the satellite data cannot be used directly in conjunction with historical gauge data. Specifically, the satellite data do not reflect the strong influences on precipitation of topography in some of the basins. However, the prospects of applying relatively straightforward adjustments are promising and further assessments appear to be justified.
- Full Text:
- Date Issued: 2006
Comprehension and acceptability of a patient information leaflet (PIL) for antiretroviral therapy:
- Mwingira, Betty, Dowse, Roslind
- Authors: Mwingira, Betty , Dowse, Roslind
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156902 , vital:40065 , https://doi.org/10.4102/hsag.v11i3.236
- Description: The patient information leaflet (PIL) is recognised as playing a key role in informing patients about their medicines. The objectives of this research were to evaluate the readability and understanding of a PIL for the first-line ARV (antiretroviral) regimen available in the South African public health sector, and investigate its acceptability in the target Xhosa population. The study took place between August 2003 and July 2004. A PIL was designed for the antiretroviral regimen of stavudine, lamivudine and efavirenz, using established usability guidelines. South African legal requirements concerning PILs were incorporated and the PILs were available in both English and isiXhosa.
- Full Text:
- Date Issued: 2006
- Authors: Mwingira, Betty , Dowse, Roslind
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156902 , vital:40065 , https://doi.org/10.4102/hsag.v11i3.236
- Description: The patient information leaflet (PIL) is recognised as playing a key role in informing patients about their medicines. The objectives of this research were to evaluate the readability and understanding of a PIL for the first-line ARV (antiretroviral) regimen available in the South African public health sector, and investigate its acceptability in the target Xhosa population. The study took place between August 2003 and July 2004. A PIL was designed for the antiretroviral regimen of stavudine, lamivudine and efavirenz, using established usability guidelines. South African legal requirements concerning PILs were incorporated and the PILs were available in both English and isiXhosa.
- Full Text:
- Date Issued: 2006
Confession and public life in post‐apartheid South Africa: A Foucauldian reading of Antjie Krog's country of my skull
- Authors: Garman, Anthea
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159724 , vital:40337 , DOI: 10.1080/02564710608530406
- Description: Truth commissions around the world have given the technique of confession a new public currency and political power. Many works of literature thematising these commissions have also adopted the technique of confession for literary purposes. In this paper I bring Foucault's understanding of the technique of confession, and his discourse on the role of public intellectuals in modernity, to bear upon an examination of Antjie Krog's literary reflection of the work of the Truth and Reconciliation Commission (TRC), entitled Country of My Skull (1998). I look at how this text, and Krog's subsequent public intellectual status as a witness of the TRC, perpetuate the technique of confession without problematising it in ways that Foucault's work would suggest is necessary.
- Full Text:
- Date Issued: 2006
- Authors: Garman, Anthea
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159724 , vital:40337 , DOI: 10.1080/02564710608530406
- Description: Truth commissions around the world have given the technique of confession a new public currency and political power. Many works of literature thematising these commissions have also adopted the technique of confession for literary purposes. In this paper I bring Foucault's understanding of the technique of confession, and his discourse on the role of public intellectuals in modernity, to bear upon an examination of Antjie Krog's literary reflection of the work of the Truth and Reconciliation Commission (TRC), entitled Country of My Skull (1998). I look at how this text, and Krog's subsequent public intellectual status as a witness of the TRC, perpetuate the technique of confession without problematising it in ways that Foucault's work would suggest is necessary.
- Full Text:
- Date Issued: 2006
Creating a low cost VoiceXML Gateway to replace IVR systems for rapid deployment of voice applications
- King, Adam, Terzoli, Alfredo, Clayton, Peter, G
- Authors: King, Adam , Terzoli, Alfredo , Clayton, Peter, G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427576 , vital:72448 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=af502fadc7349b9153c37f252bafbe07e86cbfd8
- Description: VoiceXML gateway which can be used to replace traditional Interactive Voice Re-sponse (IVR) platforms. The gateway is created by integrating a VoiceXML inter-preter, OpenVXI and a PBX, Asterisk, producing a Linux based, open source, sys-tem which is both a PBX and a VoiceXML browser. Reasons for choosing the components for the gateway and then the integration of these components are dis-cussed. VoiceXML applications can be used to replace IVR systems, which are then rendered by the gateway.
- Full Text:
- Date Issued: 2006
- Authors: King, Adam , Terzoli, Alfredo , Clayton, Peter, G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427576 , vital:72448 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=af502fadc7349b9153c37f252bafbe07e86cbfd8
- Description: VoiceXML gateway which can be used to replace traditional Interactive Voice Re-sponse (IVR) platforms. The gateway is created by integrating a VoiceXML inter-preter, OpenVXI and a PBX, Asterisk, producing a Linux based, open source, sys-tem which is both a PBX and a VoiceXML browser. Reasons for choosing the components for the gateway and then the integration of these components are dis-cussed. VoiceXML applications can be used to replace IVR systems, which are then rendered by the gateway.
- Full Text:
- Date Issued: 2006
Critical media literacy: a design for the future
- Authors: Prinsloo, Jeanne
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6331 , http://hdl.handle.net/10962/d1008476
- Description: [From OPENSPACE Editor Alice Kanengoni's editorial]: Professor Jeanne Prinsloo notes in her article that "In fact, it has been argued that the significance of the media in people’s lives has increased to the extent that it has been described as their primary curriculum, thereby recasting formal education as the secondary curriculum." This therefore requires an incestment in media literacy; people's ability to to understand the world around them, as represented in the media. Thus, Professor Prinsloo argues for critical media literacy, citing the role that the media played in fuelling the genocide in Rwanda, as an illustrative case in point. She states that "While we can not attribute all blame in the Rwandan scenario to the radio use, it is clear that the media mattered." She indicates that "media representations and engagements play a significant role in the way we understand the world, its people and events, and ourselves therein." As such, societies should invest in building a critical citizenry that can read and deconstruct the various ideologies that are often carries in and through the media.
- Full Text:
- Date Issued: 2006
- Authors: Prinsloo, Jeanne
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6331 , http://hdl.handle.net/10962/d1008476
- Description: [From OPENSPACE Editor Alice Kanengoni's editorial]: Professor Jeanne Prinsloo notes in her article that "In fact, it has been argued that the significance of the media in people’s lives has increased to the extent that it has been described as their primary curriculum, thereby recasting formal education as the secondary curriculum." This therefore requires an incestment in media literacy; people's ability to to understand the world around them, as represented in the media. Thus, Professor Prinsloo argues for critical media literacy, citing the role that the media played in fuelling the genocide in Rwanda, as an illustrative case in point. She states that "While we can not attribute all blame in the Rwandan scenario to the radio use, it is clear that the media mattered." She indicates that "media representations and engagements play a significant role in the way we understand the world, its people and events, and ourselves therein." As such, societies should invest in building a critical citizenry that can read and deconstruct the various ideologies that are often carries in and through the media.
- Full Text:
- Date Issued: 2006
Cultural significance of biodiversity: the role of medicinal plants in urban African cultural practices in the Eastern Cape, South Africa
- Cocks, Michelle L, Dold, Anthony P
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141338 , vital:37963 , DOI: 10.2993/0278-0771(2006)26[60:CSOBTR]2.0.CO;2
- Description: Since the International Convention on Biodiversity in 1992 conservation biologists, ecologists and conservationists have devoted considerable attention to the conservation of biodiversity. With this has come the realization that solutions to biological problems often lie in the mechanisms of social, cultural, and economic systems. This shift has emphasized the relationship between biodiversity and human diversity, or what the Declaration of Belem (1988) calls an “inextricable link” between biological and cultural diversity. The term biocultural diversity was introduced by Posey to describe the concept denoting this link. To date this concept has been used only in reference to “indigenous people” who, as part of their traditional lifestyles, use biodiversity to sustain their cultural identity. Our research, however, demonstrates that Xhosa people (amaXhosa) living in an urban context in the Eastern Cape Province of South Africa continue to use wild plants for cultural purposes and often access these through commercial trade. We suggest that recognition of the cultural and spiritual values associated with wild plants would greatly enhance biodiversity conservation efforts. Recognition of the significant role that wild plants play in fulfilling cultural needs for urban Xhosa people would go a long way towards achieving this.
- Full Text:
- Date Issued: 2006
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141338 , vital:37963 , DOI: 10.2993/0278-0771(2006)26[60:CSOBTR]2.0.CO;2
- Description: Since the International Convention on Biodiversity in 1992 conservation biologists, ecologists and conservationists have devoted considerable attention to the conservation of biodiversity. With this has come the realization that solutions to biological problems often lie in the mechanisms of social, cultural, and economic systems. This shift has emphasized the relationship between biodiversity and human diversity, or what the Declaration of Belem (1988) calls an “inextricable link” between biological and cultural diversity. The term biocultural diversity was introduced by Posey to describe the concept denoting this link. To date this concept has been used only in reference to “indigenous people” who, as part of their traditional lifestyles, use biodiversity to sustain their cultural identity. Our research, however, demonstrates that Xhosa people (amaXhosa) living in an urban context in the Eastern Cape Province of South Africa continue to use wild plants for cultural purposes and often access these through commercial trade. We suggest that recognition of the cultural and spiritual values associated with wild plants would greatly enhance biodiversity conservation efforts. Recognition of the significant role that wild plants play in fulfilling cultural needs for urban Xhosa people would go a long way towards achieving this.
- Full Text:
- Date Issued: 2006
Deelname Aan Die Bestuur Van Waterhulpbronne In Suid-Afrika
- Burt, Jane C, du Toit, Derick, Neves, David, Pollard, Sharon, Berold, Robert, Stanford, Mindy
- Authors: Burt, Jane C , du Toit, Derick , Neves, David , Pollard, Sharon , Berold, Robert , Stanford, Mindy
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437569 , vital:73394 , ISBN 1-77005-501-0 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT288-06.pdf
- Description: Die Nasionale Waterwet (1998) maak dit moontlik vir gewone mense om deel te neem aan die bestuur van waterhulpbronne. Hierdie boek bespreek wat deelname in die praktyk beteken. Die navorsing vir hierdie boek is tussen 2003 en 2005 gedoen deur ‘n groep deskundiges in die bestuur van water as hulpbron. Die navorsers het tot twee belangrike gevolgtrekkings gekom, naamlik: 1. Hoe ons die konsep ‘deelname’ verstaan, het ‘n direkte invloed op hoe ons water as hulpbron bestuur. Daarom is dit nodig om ons kennis en ervaring van deelname in die bestuur van wa-terhulpbronne te verdiep. 2. Ons het praktiese riglyne nodig wanneer ons deelname in die bestuur van waterhulpbronne beplan, maar hierdie riglyne behoort buigbaar te wees sodat die aard van die deelname by elke situasie of konteks kan aanpas.
- Full Text:
- Date Issued: 2006
- Authors: Burt, Jane C , du Toit, Derick , Neves, David , Pollard, Sharon , Berold, Robert , Stanford, Mindy
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437569 , vital:73394 , ISBN 1-77005-501-0 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT288-06.pdf
- Description: Die Nasionale Waterwet (1998) maak dit moontlik vir gewone mense om deel te neem aan die bestuur van waterhulpbronne. Hierdie boek bespreek wat deelname in die praktyk beteken. Die navorsing vir hierdie boek is tussen 2003 en 2005 gedoen deur ‘n groep deskundiges in die bestuur van water as hulpbron. Die navorsers het tot twee belangrike gevolgtrekkings gekom, naamlik: 1. Hoe ons die konsep ‘deelname’ verstaan, het ‘n direkte invloed op hoe ons water as hulpbron bestuur. Daarom is dit nodig om ons kennis en ervaring van deelname in die bestuur van wa-terhulpbronne te verdiep. 2. Ons het praktiese riglyne nodig wanneer ons deelname in die bestuur van waterhulpbronne beplan, maar hierdie riglyne behoort buigbaar te wees sodat die aard van die deelname by elke situasie of konteks kan aanpas.
- Full Text:
- Date Issued: 2006
Design considerations for a reliable and secure wireless network
- Janse van Rensburg, Johanna, Irwin, Barry V W, Zhao, X G
- Authors: Janse van Rensburg, Johanna , Irwin, Barry V W , Zhao, X G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428199 , vital:72493 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622818_Design_considerations_for_a_reliable_and_secure_wireless_network/links/5b9a114792851c4ba81819fe/Design-considerations-for-a-reliable-and-secure-wireless-network.pdf
- Description: Wireless Networks have become widely accepted in enterprise net-works and can no longer be considered an experimental technology. However users often experience performance problems due to poor designs. These problems can be attributed to the physical nature of wireless networks, the electromagnetic wave. As a wave propagates through the air it is susceptible to interference, reflection or refraction, to name a few, that changes the wave and ultimately the received signal. However the effect of these can be mitigated with the proper design of a wireless network. In this paper these design consideration will be in-troduced through discussion of visualization packages that aid in the design process. Furthermore we will take a look at the security consid-erations of wireless networks; as, surprisingly even with the ratification of 802.11 i for almost two years now; security is still considered one of the biggest challenges against implementing a wireless local area net-work.
- Full Text:
- Date Issued: 2006
- Authors: Janse van Rensburg, Johanna , Irwin, Barry V W , Zhao, X G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428199 , vital:72493 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622818_Design_considerations_for_a_reliable_and_secure_wireless_network/links/5b9a114792851c4ba81819fe/Design-considerations-for-a-reliable-and-secure-wireless-network.pdf
- Description: Wireless Networks have become widely accepted in enterprise net-works and can no longer be considered an experimental technology. However users often experience performance problems due to poor designs. These problems can be attributed to the physical nature of wireless networks, the electromagnetic wave. As a wave propagates through the air it is susceptible to interference, reflection or refraction, to name a few, that changes the wave and ultimately the received signal. However the effect of these can be mitigated with the proper design of a wireless network. In this paper these design consideration will be in-troduced through discussion of visualization packages that aid in the design process. Furthermore we will take a look at the security consid-erations of wireless networks; as, surprisingly even with the ratification of 802.11 i for almost two years now; security is still considered one of the biggest challenges against implementing a wireless local area net-work.
- Full Text:
- Date Issued: 2006
Destined to come to blows?: race and constructions of “rational-intellectual” masculinity ten years after apartheid
- Authors: Vincent, Louise
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141619 , vital:37990 , DOI: 10.1177/1097184X05277694
- Description: In 1994, a democratic government came to power in South Africa for the first time in the country's history. But political transition is never a single event or moment. Rather, it is a continuous process that faces setbacks and contradictions. One of the questions we might ask about a society in transition is to what extent its gender order has changed or is changing. The present paper sets out to read the country's transformation drama through the lens of contested conceptions of South African masculinity. The article is focused on one particular version of masculinity which it terms “rational-intellectual man,” and the argument is that a legacy of racism and the persistence of racialized modes of reasoning continue to marginalise black men from this and other powerful, high-status forms of hegemonic masculinity.
- Full Text:
- Date Issued: 2006
- Authors: Vincent, Louise
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141619 , vital:37990 , DOI: 10.1177/1097184X05277694
- Description: In 1994, a democratic government came to power in South Africa for the first time in the country's history. But political transition is never a single event or moment. Rather, it is a continuous process that faces setbacks and contradictions. One of the questions we might ask about a society in transition is to what extent its gender order has changed or is changing. The present paper sets out to read the country's transformation drama through the lens of contested conceptions of South African masculinity. The article is focused on one particular version of masculinity which it terms “rational-intellectual man,” and the argument is that a legacy of racism and the persistence of racialized modes of reasoning continue to marginalise black men from this and other powerful, high-status forms of hegemonic masculinity.
- Full Text:
- Date Issued: 2006
Developing a test for economic duress in the South African law of contract: a comparative perspective
- Authors: Glover, Graham B
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70832 , vital:29748 , https://hdl.handle.net/10520/EJC53694
- Description: Until the recent Supreme Court of Appeal decision in Medscheme Holdings (Pty) Ltd v Bhamjee 2005 (5) SA 339 (SCA), the courts in South Africa consistently adopted the attitude that so-called 'economic duress' does not constitute a valid cause of action in our law of contract. In this sense, our law lags behind other jurisdictions, which have recognised for some time that threats of economic harm can be just as coercive as threats to person or property, especially in the modern commercial word. While the indication given in the Medscheme case that our law could develop to recognise cases of economic duress is a welcome one, the court's statement in this regard was merely obiter, and the court consequently undertook no analysis of the issue. In this article, an attempt is made to develop guidelines for dealing with such cases, in accordance with a more modern and coherent test for duress in contract generally. Much of the discussion involves comparative analyses of the authorities on economic duress in Anglo-American jurisdictions, since there is a dearth of authority on the point in South Africa.
- Full Text: false
- Date Issued: 2006
- Authors: Glover, Graham B
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70832 , vital:29748 , https://hdl.handle.net/10520/EJC53694
- Description: Until the recent Supreme Court of Appeal decision in Medscheme Holdings (Pty) Ltd v Bhamjee 2005 (5) SA 339 (SCA), the courts in South Africa consistently adopted the attitude that so-called 'economic duress' does not constitute a valid cause of action in our law of contract. In this sense, our law lags behind other jurisdictions, which have recognised for some time that threats of economic harm can be just as coercive as threats to person or property, especially in the modern commercial word. While the indication given in the Medscheme case that our law could develop to recognise cases of economic duress is a welcome one, the court's statement in this regard was merely obiter, and the court consequently undertook no analysis of the issue. In this article, an attempt is made to develop guidelines for dealing with such cases, in accordance with a more modern and coherent test for duress in contract generally. Much of the discussion involves comparative analyses of the authorities on economic duress in Anglo-American jurisdictions, since there is a dearth of authority on the point in South Africa.
- Full Text: false
- Date Issued: 2006
DRAPA-a flexible framework for evaluating the quality of VoIP components
- Clayton, Bradley, Terzoli, Alfredo, Irwin, Barry V W
- Authors: Clayton, Bradley , Terzoli, Alfredo , Irwin, Barry V W
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428213 , vital:72494 , https://d1wqtxts1xzle7.cloudfront.net/3456214/No_268_-_Clayton-libre.pdf?1390832682=andresponse-content-disposi-tion=inline%3B+filename%3DDRAPA_a_flexible_framework_for_evaluatin.pdfandExpires=1714742712andSignature=FTQ3UMH7w9KMXeuld-NbnboBP9kqza7jDnVI2AJMFrhV6fkW56bPgPZKVAY-bKJFqJP-jq4h4JwRhWVuCA-oIIA4ckbhKHA4OoL4X5DYtlujkhkombcp-B5fVR02AioXBazDtfnTGvZLE21wluH0BnkBL9OAQSen7YJDzDsYtNH2pFIn06Nmg9-kDaJoRmW9KWlQs8BwyaXml4-pG~FrpiGCRclANXBSpmsxYSdJyZAnHq2ZZNqx9pEHigaYHUUgllDq64dp8C8R84xAbbbRcvt-XNhuQ~fU2AkJILms4FUkJSjGI0E-TOKhh7vQiVIh5KzZX8MOiS~rEuBH6ekx8g__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: When adding to or altering a VoIP system, the overall performance and quality of the system is at risk. For example, adding confidentiality, in-tegrity and authentication (CIA) would incur an overhead for each addi-tional security method. A method of measuring the performance of a VoIP system after a change or addition is needed. This paper describes a framework and testbed (DRAPA) which provides a flexible base from which VoIP performance analysis systems can be built. DRAPA gener-ates and collects data from any part of a VoIP system within a real do-main. This paper also discusses the flexibility of DRAPA. While security is our primary focus, DRAPA allows the user to configure the testbed and change the type and nature of data to be collected.
- Full Text:
- Date Issued: 2006
- Authors: Clayton, Bradley , Terzoli, Alfredo , Irwin, Barry V W
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428213 , vital:72494 , https://d1wqtxts1xzle7.cloudfront.net/3456214/No_268_-_Clayton-libre.pdf?1390832682=andresponse-content-disposi-tion=inline%3B+filename%3DDRAPA_a_flexible_framework_for_evaluatin.pdfandExpires=1714742712andSignature=FTQ3UMH7w9KMXeuld-NbnboBP9kqza7jDnVI2AJMFrhV6fkW56bPgPZKVAY-bKJFqJP-jq4h4JwRhWVuCA-oIIA4ckbhKHA4OoL4X5DYtlujkhkombcp-B5fVR02AioXBazDtfnTGvZLE21wluH0BnkBL9OAQSen7YJDzDsYtNH2pFIn06Nmg9-kDaJoRmW9KWlQs8BwyaXml4-pG~FrpiGCRclANXBSpmsxYSdJyZAnHq2ZZNqx9pEHigaYHUUgllDq64dp8C8R84xAbbbRcvt-XNhuQ~fU2AkJILms4FUkJSjGI0E-TOKhh7vQiVIh5KzZX8MOiS~rEuBH6ekx8g__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: When adding to or altering a VoIP system, the overall performance and quality of the system is at risk. For example, adding confidentiality, in-tegrity and authentication (CIA) would incur an overhead for each addi-tional security method. A method of measuring the performance of a VoIP system after a change or addition is needed. This paper describes a framework and testbed (DRAPA) which provides a flexible base from which VoIP performance analysis systems can be built. DRAPA gener-ates and collects data from any part of a VoIP system within a real do-main. This paper also discusses the flexibility of DRAPA. While security is our primary focus, DRAPA allows the user to configure the testbed and change the type and nature of data to be collected.
- Full Text:
- Date Issued: 2006
Duplicating road patterns in south african informal settlements using procedural techniques
- Glass, Kevin R, Morkel, Chantelle, Bangay, Shaun D
- Authors: Glass, Kevin R , Morkel, Chantelle , Bangay, Shaun D
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432875 , vital:72909 , https://doi.org/10.1145/1108590.1108616
- Description: The formation of informal settlements in and around urban complexes has largely been ignored in the context of procedural city modeling. However, many cities in South Africa and globally can attest to the presence of such settlements. This paper analyses the phenomenon of informal settlements from a procedural modeling perspective. Aerial photography from two South African urban complexes, namely Johannesburg and Cape Town is used as a basis for the extraction of various features that distinguish different types of settlements. In particular, the road patterns which have formed within such settlements are analysed, and various procedural techniques proposed (including Voronoi diagrams, subdivision and L-systems) to replicate the identified features. A qualitative assessment of the procedural techniques is provided, and the most suitable combination of techniques identified for unstructured and structured settlements. In particular it is found that a combination of Voronoi diagrams and subdivision provides the closest match to unstructured informal settlements. A combination of L-systems, Voronoi diagrams and subdivision is found to produce the closest pattern to a structured informal settlement.
- Full Text:
- Date Issued: 2006
- Authors: Glass, Kevin R , Morkel, Chantelle , Bangay, Shaun D
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432875 , vital:72909 , https://doi.org/10.1145/1108590.1108616
- Description: The formation of informal settlements in and around urban complexes has largely been ignored in the context of procedural city modeling. However, many cities in South Africa and globally can attest to the presence of such settlements. This paper analyses the phenomenon of informal settlements from a procedural modeling perspective. Aerial photography from two South African urban complexes, namely Johannesburg and Cape Town is used as a basis for the extraction of various features that distinguish different types of settlements. In particular, the road patterns which have formed within such settlements are analysed, and various procedural techniques proposed (including Voronoi diagrams, subdivision and L-systems) to replicate the identified features. A qualitative assessment of the procedural techniques is provided, and the most suitable combination of techniques identified for unstructured and structured settlements. In particular it is found that a combination of Voronoi diagrams and subdivision provides the closest match to unstructured informal settlements. A combination of L-systems, Voronoi diagrams and subdivision is found to produce the closest pattern to a structured informal settlement.
- Full Text:
- Date Issued: 2006
Dyke swarms and associated lava formations in the northern Lebombo monocline, Karoo Large Igneous Province, South Africa
- Klausen, Martin B, Marsh, Julian S, Watkeys, M K
- Authors: Klausen, Martin B , Marsh, Julian S , Watkeys, M K
- Date: 2006
- Language: English
- Type: text , Abstracts
- Identifier: http://hdl.handle.net/10962/132751 , vital:36880
- Description: As one of the early classical examples of plume-generated Large Igneous Provinces (LIPs), the Karoo is characterized by a bulls-eye distribution of High-Ti basalts, picrites, and earliest nephelinites onto a conspicuous triple rift junction (i.e., Okavango dyke swarm and the two Mwenezi and Lebombo monoclines), surrounded by Low-Ti basalts. It is noted that this regional distribution between high-and low-Ti basalts within the Jurassic Karoo LIP differs from that of the Permian Emeishan LIP; thereby undermining the use of this particular feature as evidence for mantle plume involvement.
- Full Text:
- Date Issued: 2006
- Authors: Klausen, Martin B , Marsh, Julian S , Watkeys, M K
- Date: 2006
- Language: English
- Type: text , Abstracts
- Identifier: http://hdl.handle.net/10962/132751 , vital:36880
- Description: As one of the early classical examples of plume-generated Large Igneous Provinces (LIPs), the Karoo is characterized by a bulls-eye distribution of High-Ti basalts, picrites, and earliest nephelinites onto a conspicuous triple rift junction (i.e., Okavango dyke swarm and the two Mwenezi and Lebombo monoclines), surrounded by Low-Ti basalts. It is noted that this regional distribution between high-and low-Ti basalts within the Jurassic Karoo LIP differs from that of the Permian Emeishan LIP; thereby undermining the use of this particular feature as evidence for mantle plume involvement.
- Full Text:
- Date Issued: 2006
Early effects of a community-based marine protected area on the food security of participating households
- Weiant, Pamela, Shankar, Aswani
- Authors: Weiant, Pamela , Shankar, Aswani
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439084 , vital:73543
- Description: There is general agreement among conservation practitioners that community-based marine protected areas (CB-MPAs) can improve food security in coastal communities. However, little attention has been given to how communities respond to CB-MPAs, particularly how households try to meet their livelihood needs following the establishment of a restrictive management regime. In this paper, we explore the early effects of a CB-MPA geared toward the management of marine resources harvested by women, as measured by perceived income and food availability. We strive to better understand (1) the contribution of women’s fishing activities to livelihood needs, particularly the harvest of blood cockles (Anadara granosa) and mud clams (Polymesoda spp.)(the species under management);(2) differences in how households respond to a CB-MPA; and (3) the relationship between food security and certain aspects of reef health. To illustrate our case, we draw upon our research experience with social and biological impact assessments and our experience in establishing marine protection in the Western Solomon Islands.
- Full Text:
- Date Issued: 2006
- Authors: Weiant, Pamela , Shankar, Aswani
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439084 , vital:73543
- Description: There is general agreement among conservation practitioners that community-based marine protected areas (CB-MPAs) can improve food security in coastal communities. However, little attention has been given to how communities respond to CB-MPAs, particularly how households try to meet their livelihood needs following the establishment of a restrictive management regime. In this paper, we explore the early effects of a CB-MPA geared toward the management of marine resources harvested by women, as measured by perceived income and food availability. We strive to better understand (1) the contribution of women’s fishing activities to livelihood needs, particularly the harvest of blood cockles (Anadara granosa) and mud clams (Polymesoda spp.)(the species under management);(2) differences in how households respond to a CB-MPA; and (3) the relationship between food security and certain aspects of reef health. To illustrate our case, we draw upon our research experience with social and biological impact assessments and our experience in establishing marine protection in the Western Solomon Islands.
- Full Text:
- Date Issued: 2006
Editorial: tracing actors, actants and relational dynamics in environmental education research
- Authors: Lotz-Sisitka, Heila
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67400 , vital:29084 , https://www.ajol.info/index.php/sajee/article/view/122719
- Description: publisher version , Introduction: This edition of the EEASA Journal provides insight into a range of relationships in the field of environmental education, and the complexities that exist around them, as reflected in the combination of papers. This Editorial picks up on the methodological ‘note’ (or is it a challenge?) provided by Godwell Nhamo in his paper in this edition of the journal. He provides a description of the possibilities that actor network theory provides for describing and explaining environmental policy processes, and recommends that environmental educators consider this methodology in their analyses. In particular, he refers environmental educators to applications of actor network theory for tracing relational dynamics between actors (i.e., environmental education practitioners) and actants which are non-human referents (e.g., the UN Decade of Education for Sustainable Development and UNESCO’s (2005) International Implementation Scheme). In response to his paper, I have chosen to ‘pick up’ on this methodological discussion in this Editorial, by considering aspects of this theoretical perspective in describing the ‘happenings’ that occur across the pages of this edition of the EEASA Journal. In doing so, I highlight (in part) the diversity of actors and actants that are influencing the field of environmental education, their subject matter and contexts, and I highlight the relational dynamics that become evident when one accepts a methodology that aims to trace such dynamics. In particular, this Editorial considers how ‘The language of actors, actants and actor/actant-networks brings to the fore the relationships and complexities that exist around them’ (Nhamo, this edition).
- Full Text:
- Date Issued: 2006
- Authors: Lotz-Sisitka, Heila
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67400 , vital:29084 , https://www.ajol.info/index.php/sajee/article/view/122719
- Description: publisher version , Introduction: This edition of the EEASA Journal provides insight into a range of relationships in the field of environmental education, and the complexities that exist around them, as reflected in the combination of papers. This Editorial picks up on the methodological ‘note’ (or is it a challenge?) provided by Godwell Nhamo in his paper in this edition of the journal. He provides a description of the possibilities that actor network theory provides for describing and explaining environmental policy processes, and recommends that environmental educators consider this methodology in their analyses. In particular, he refers environmental educators to applications of actor network theory for tracing relational dynamics between actors (i.e., environmental education practitioners) and actants which are non-human referents (e.g., the UN Decade of Education for Sustainable Development and UNESCO’s (2005) International Implementation Scheme). In response to his paper, I have chosen to ‘pick up’ on this methodological discussion in this Editorial, by considering aspects of this theoretical perspective in describing the ‘happenings’ that occur across the pages of this edition of the EEASA Journal. In doing so, I highlight (in part) the diversity of actors and actants that are influencing the field of environmental education, their subject matter and contexts, and I highlight the relational dynamics that become evident when one accepts a methodology that aims to trace such dynamics. In particular, this Editorial considers how ‘The language of actors, actants and actor/actant-networks brings to the fore the relationships and complexities that exist around them’ (Nhamo, this edition).
- Full Text:
- Date Issued: 2006
Effects of prophylactic progesterone in decomposing tissues on the development of Chrysomya chloropyga (Wiedeman)(Diptera Calliphoridae)
- da Silva, C, Villet, Martin H
- Authors: da Silva, C , Villet, Martin H
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442020 , vital:73950 , https://hdl.handle.net/10520/EJC32654
- Description: Medico-legal forensic entomology is often concerned with the estimation of postmortem intervals (PMI), the time elapsed since the death of a body, by estimating the age of maggots if they are found on a body. These estimates can be complicated by the presence of a variety of drugs that may be present in dead bodies, including steroids such as hydrocortisone (Musvasva et al. 2001).
- Full Text:
- Date Issued: 2006
- Authors: da Silva, C , Villet, Martin H
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442020 , vital:73950 , https://hdl.handle.net/10520/EJC32654
- Description: Medico-legal forensic entomology is often concerned with the estimation of postmortem intervals (PMI), the time elapsed since the death of a body, by estimating the age of maggots if they are found on a body. These estimates can be complicated by the presence of a variety of drugs that may be present in dead bodies, including steroids such as hydrocortisone (Musvasva et al. 2001).
- Full Text:
- Date Issued: 2006
Electrocatalytic oxidation of thiocyanate, L-cysteine and 2-mercaptoethanol by self-assembled monolayer of cobalt tetraethoxy thiophene phthalocyanine
- Sehlotho, Nthapo, Nyokong, Tebello
- Authors: Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283814 , vital:55993 , xlink:href="https://doi.org/10.1016/j.electacta.2005.12.024"
- Description: Catalytic activity of a self-assembled monolayer (SAM) of cobalt tetra ethoxythiophene phthalocyanine (CoTEThPc-SAM) complex towards oxidation of thiocyanate (SCN−), L-cysteine (CYS) and 2-mercaptoethanol (2-ME) is reported. The oxidation of thiocyanate occurs via a two electron transfer, whereas L-cysteine and 2-ME require 1 electron. The oxidation of thiocyanate is catalysed by ring based processes, while L-cysteine is catalysed by both CoIII/CoII process and by ring based processes. 2-ME is catalysed by CoIII/CoII process. The oxidation of thiocyanate on CoTEThPc was performed in acid media instead of basic media commonly employed. The reaction order was found to be unity for all the analytes, showing that only one molecule of analyte interacts with one molecule of the catalyst during the rate determining step.
- Full Text:
- Date Issued: 2006
- Authors: Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283814 , vital:55993 , xlink:href="https://doi.org/10.1016/j.electacta.2005.12.024"
- Description: Catalytic activity of a self-assembled monolayer (SAM) of cobalt tetra ethoxythiophene phthalocyanine (CoTEThPc-SAM) complex towards oxidation of thiocyanate (SCN−), L-cysteine (CYS) and 2-mercaptoethanol (2-ME) is reported. The oxidation of thiocyanate occurs via a two electron transfer, whereas L-cysteine and 2-ME require 1 electron. The oxidation of thiocyanate is catalysed by ring based processes, while L-cysteine is catalysed by both CoIII/CoII process and by ring based processes. 2-ME is catalysed by CoIII/CoII process. The oxidation of thiocyanate on CoTEThPc was performed in acid media instead of basic media commonly employed. The reaction order was found to be unity for all the analytes, showing that only one molecule of analyte interacts with one molecule of the catalyst during the rate determining step.
- Full Text:
- Date Issued: 2006
Electropolymerizable iron (III) and cobalt (II) dicyanophenoxy tetraphenylporphyrin complexes
- Ozoemena, Kenneth I, Zhao, Zhixin, Nyokong, Tebello
- Authors: Ozoemena, Kenneth I , Zhao, Zhixin , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286080 , vital:56236 , xlink:href="https://doi.org/10.1016/j.inoche.2005.11.024"
- Description: Solution and solid phase electrochemical features of 5-[4-(3,4-dicyanophenoxy)phenyl],10,15,20-triphenylporphyrin complexes of iron(III) (FeCNOTPP(Cl)) and cobalt(II) (CoCNOTPP) have been described. These novel asymmetric dicyanophenoxy-derivatised cobalt and iron porphyrin complexes were electropolymerised onto glassy carbon electrodes, which in aqueous solutions, gave surface concentrations (ca. 10−10 mol cm−2) typical of monolayer coverages. The films also exhibited excellent stability and electrocatalysis towards the direct detection of important analytes as nitrite, nitric oxide, and hydrogen peroxide in aqueous solutions.
- Full Text:
- Date Issued: 2006
- Authors: Ozoemena, Kenneth I , Zhao, Zhixin , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286080 , vital:56236 , xlink:href="https://doi.org/10.1016/j.inoche.2005.11.024"
- Description: Solution and solid phase electrochemical features of 5-[4-(3,4-dicyanophenoxy)phenyl],10,15,20-triphenylporphyrin complexes of iron(III) (FeCNOTPP(Cl)) and cobalt(II) (CoCNOTPP) have been described. These novel asymmetric dicyanophenoxy-derivatised cobalt and iron porphyrin complexes were electropolymerised onto glassy carbon electrodes, which in aqueous solutions, gave surface concentrations (ca. 10−10 mol cm−2) typical of monolayer coverages. The films also exhibited excellent stability and electrocatalysis towards the direct detection of important analytes as nitrite, nitric oxide, and hydrogen peroxide in aqueous solutions.
- Full Text:
- Date Issued: 2006