A Comparative Study of mLAN and CobraNet Technologies and their use in the Sound Installation Industry
- Klinkradt, Bradley, Foss, Richard
- Authors: Klinkradt, Bradley , Foss, Richard
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427331 , vital:72431 , https://www.aes.org/e-lib/browse.cfm?elib=12593
- Description: This paper highlights the two interconnection technologies of CobraNet and mLAN, and provides a comparative study of these technologies and their applicability to the sound installation industry, through a discussion of constraints inherent within such an installation. Issues such as the adherence to standards, costs, latency, speed, connection management, and the control and monitoring of devices are explored.
- Full Text:
- Date Issued: 2003
- Authors: Klinkradt, Bradley , Foss, Richard
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427331 , vital:72431 , https://www.aes.org/e-lib/browse.cfm?elib=12593
- Description: This paper highlights the two interconnection technologies of CobraNet and mLAN, and provides a comparative study of these technologies and their applicability to the sound installation industry, through a discussion of constraints inherent within such an installation. Issues such as the adherence to standards, costs, latency, speed, connection management, and the control and monitoring of devices are explored.
- Full Text:
- Date Issued: 2003
A new broom sweeps clean: the economic and cultural value of grass brooms in the Eastern Cape Province, South Africa
- Cocks, Michelle L, Dold, Anthony P
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141382 , vital:37967 , DOI: 10.1080/14728028.2004.9752477
- Description: In southern Africa over the last twenty years, much attention has been given to the importance of NTFPs for rural livelihoods through their household consumption and sale. They have been classified as having either subsistence consumption or commercial values. These values are mostly related to their utilitarian functions, but recent studies show that NTFPs also hold strong cultural functions. Such cultural functions can play a role in both rural and urban livelihoods; consequently the values of NTFPs may be related to both utilitarian and cultural functions. This paper demonstrates the cultural functions of grass brooms in urban areas in South Africa and the impact of their trade on income generation in rural areas, and discusses the concept of culture as a significant factor in the understanding of the role of NTFPs in livelihoods, and their values.
- Full Text:
- Date Issued: 2012
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141382 , vital:37967 , DOI: 10.1080/14728028.2004.9752477
- Description: In southern Africa over the last twenty years, much attention has been given to the importance of NTFPs for rural livelihoods through their household consumption and sale. They have been classified as having either subsistence consumption or commercial values. These values are mostly related to their utilitarian functions, but recent studies show that NTFPs also hold strong cultural functions. Such cultural functions can play a role in both rural and urban livelihoods; consequently the values of NTFPs may be related to both utilitarian and cultural functions. This paper demonstrates the cultural functions of grass brooms in urban areas in South Africa and the impact of their trade on income generation in rural areas, and discusses the concept of culture as a significant factor in the understanding of the role of NTFPs in livelihoods, and their values.
- Full Text:
- Date Issued: 2012
A New Connection Management Architecture for the Next Generation of mLAN
- Foss, Richard, Fujimori, J I
- Authors: Foss, Richard , Fujimori, J I
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427376 , vital:72434 , https://www.aes.org/e-lib/browse.cfm?elib=12539
- Description: mLAN is a networking technology based on the IEEE 1394 standard that allows for the transport of audio and music control data between audio devices. In the original implementation of mLAN, software within each mLAN node hosted by an audio device contained high level plug abstraction and connection management software. mLAN-B is the next generation mLAN architecture that splits the connection management function between workstation and device. The high level connection management and plug abstraction capability resides on the workstation, while a thin low level connection management capability is left on the device. This approach reduces cost and complexity on the device side and ensures that mLAN systems can be easily upgraded.
- Full Text:
- Date Issued: 2003
- Authors: Foss, Richard , Fujimori, J I
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427376 , vital:72434 , https://www.aes.org/e-lib/browse.cfm?elib=12539
- Description: mLAN is a networking technology based on the IEEE 1394 standard that allows for the transport of audio and music control data between audio devices. In the original implementation of mLAN, software within each mLAN node hosted by an audio device contained high level plug abstraction and connection management software. mLAN-B is the next generation mLAN architecture that splits the connection management function between workstation and device. The high level connection management and plug abstraction capability resides on the workstation, while a thin low level connection management capability is left on the device. This approach reduces cost and complexity on the device side and ensures that mLAN systems can be easily upgraded.
- Full Text:
- Date Issued: 2003
A new public sphere?: outstanding issues
- Wasserman, Herman, de Beer, Arrie
- Authors: Wasserman, Herman , de Beer, Arrie
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159142 , vital:40272 , https://hdl.handle.net/10520/EJC146261
- Description: It is widely accepted that a healthy public sphere is a necessity for democracy, and that the media can facilitate debate in this sphere. In the years since democratisation in South Africa, the media's freedom to fulfil this role has been jealously guarded.
- Full Text:
- Date Issued: 2003
- Authors: Wasserman, Herman , de Beer, Arrie
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159142 , vital:40272 , https://hdl.handle.net/10520/EJC146261
- Description: It is widely accepted that a healthy public sphere is a necessity for democracy, and that the media can facilitate debate in this sphere. In the years since democratisation in South Africa, the media's freedom to fulfil this role has been jealously guarded.
- Full Text:
- Date Issued: 2003
A Performance Comparison of Web Development Technologies to Distribute Multimedia across an Intranet
- Swales, D, Sewry, David, Terzoli, Alfredo
- Authors: Swales, D , Sewry, David , Terzoli, Alfredo
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427501 , vital:72443 , https://www.researchgate.net/profile/Alfredo-Ter-zoli/publication/237337386_A_Performance_Comparison_of_Web_Development_Technologies_to_Distribute_Multimedia_across_an_Intranet/links/0c9605298fdf33d7c0000000/A-Performance-Comparison-of-Web-Development-Technologies-to-Distribute-Multimedia-across-an-Intranet.pdf
- Description: In recent years the World Wide Web has transformed into a dynamic, interactive medium, exposing a proliferation of on-line services that dis-tribute large quantities of multimedia. This has increased awareness of the need to select an appropriate Web programming technology when creating Webbased services. This paper compares three dynamic Web programming technologies from the point of view of performance in multimedia distribution. In particular, this paper examines Sun Microsys-tem’s Java Server Pages (JSP), Microsoft’s Active Server Page’s (ASP) and the more recent ASP .NET. The comparison is based on testing applications that distribute multiple images from an Oracle 9i database to Web-enabled clients. Previous research conducted by Oracle indi-cates that JSP and the underlying Java platform outperform ASP. The results in this paper, however, do not agree with Oracle’s statement as JSP tends to be marginally slower than ASP.
- Full Text:
- Date Issued: 2003
A Performance Comparison of Web Development Technologies to Distribute Multimedia across an Intranet
- Authors: Swales, D , Sewry, David , Terzoli, Alfredo
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427501 , vital:72443 , https://www.researchgate.net/profile/Alfredo-Ter-zoli/publication/237337386_A_Performance_Comparison_of_Web_Development_Technologies_to_Distribute_Multimedia_across_an_Intranet/links/0c9605298fdf33d7c0000000/A-Performance-Comparison-of-Web-Development-Technologies-to-Distribute-Multimedia-across-an-Intranet.pdf
- Description: In recent years the World Wide Web has transformed into a dynamic, interactive medium, exposing a proliferation of on-line services that dis-tribute large quantities of multimedia. This has increased awareness of the need to select an appropriate Web programming technology when creating Webbased services. This paper compares three dynamic Web programming technologies from the point of view of performance in multimedia distribution. In particular, this paper examines Sun Microsys-tem’s Java Server Pages (JSP), Microsoft’s Active Server Page’s (ASP) and the more recent ASP .NET. The comparison is based on testing applications that distribute multiple images from an Oracle 9i database to Web-enabled clients. Previous research conducted by Oracle indi-cates that JSP and the underlying Java platform outperform ASP. The results in this paper, however, do not agree with Oracle’s statement as JSP tends to be marginally slower than ASP.
- Full Text:
- Date Issued: 2003
A solution community: ways that work
- Authors: du Toit, Peter
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159112 , vital:40268 , https://hdl.handle.net/10520/EJC146301
- Description: It begins in the Southern African country of Zambotswa in a place called Anytown. Population: 540 000. The owner-editor of the Anytown Farmers' Weekly (AFW) has died and the Big Media Company, with its substantial assets across the country, has bought out his struggling paper.
- Full Text:
- Date Issued: 2003
- Authors: du Toit, Peter
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159112 , vital:40268 , https://hdl.handle.net/10520/EJC146301
- Description: It begins in the Southern African country of Zambotswa in a place called Anytown. Population: 540 000. The owner-editor of the Anytown Farmers' Weekly (AFW) has died and the Big Media Company, with its substantial assets across the country, has bought out his struggling paper.
- Full Text:
- Date Issued: 2003
Africa: Media
- Authors: Garman, Anthea
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158752 , vital:40225 , https://hdl.handle.net/10520/EJC146281
- Description: Those are our twin concerns as we move into this new moment in human history which is being called the "Information Society" or the "Information Age".
- Full Text:
- Date Issued: 2003
- Authors: Garman, Anthea
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158752 , vital:40225 , https://hdl.handle.net/10520/EJC146281
- Description: Those are our twin concerns as we move into this new moment in human history which is being called the "Information Society" or the "Information Age".
- Full Text:
- Date Issued: 2003
An mLAN Connection Management Server for Web-Based, Multi-User, Audio Device Patching
- Foss, Richard, Fujimori, J I, Klinkradt, Bradley, Bangay, Shaun
- Authors: Foss, Richard , Fujimori, J I , Klinkradt, Bradley , Bangay, Shaun
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427404 , vital:72436 , https://www.aes.org/e-lib/browse.cfm?elib=12397
- Description: A connection management server has been developed that enables connections to be made between mLAN-compatible audio devices, via a client web browser on any web-enabled device, such as a laptop or PDA. The connections can also be made across IEEE1394 bridges, and will allow for the transport of audio and music data between mLAN devices on the same or separate IEEE 1394 buses. Multiple users will be able to make and break connections via the server.
- Full Text:
- Date Issued: 2003
- Authors: Foss, Richard , Fujimori, J I , Klinkradt, Bradley , Bangay, Shaun
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427404 , vital:72436 , https://www.aes.org/e-lib/browse.cfm?elib=12397
- Description: A connection management server has been developed that enables connections to be made between mLAN-compatible audio devices, via a client web browser on any web-enabled device, such as a laptop or PDA. The connections can also be made across IEEE1394 bridges, and will allow for the transport of audio and music data between mLAN devices on the same or separate IEEE 1394 buses. Multiple users will be able to make and break connections via the server.
- Full Text:
- Date Issued: 2003
Asterisk: A converged tdm and packet-based communications system
- Authors: Penton, J , Terzoli, Alfredo
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427547 , vital:72446 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=70080710a6f96bf1c071be14a8b21c17ff8cbc4d
- Description: Converged TDM and packet-based communications systems are a popular topic in computer science and telecommunications arenas. This paper discusses a system called Asterisk that is an open source hybrid TDM and packet voice platform. Asterisk is designed to interface any piece of telephony hardware or software with any telephony application. This makes Asterisk a powerful component that can be easily used in NGN softswitches, conferencing servers and Private Branch eXchanges (PBX). Asterisk has been deployed in the Rhodes University Computer Science Department’s VoIP environment and integrated with our existing H. 323 and SIP packet-based networks. This paper discusses the de-ployment of Asterisk, its interworking with our H. 323 and SIP networks and the functionality it offers in terms of a converged TDM and packet-based communications system.
- Full Text:
- Date Issued: 2003
- Authors: Penton, J , Terzoli, Alfredo
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427547 , vital:72446 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=70080710a6f96bf1c071be14a8b21c17ff8cbc4d
- Description: Converged TDM and packet-based communications systems are a popular topic in computer science and telecommunications arenas. This paper discusses a system called Asterisk that is an open source hybrid TDM and packet voice platform. Asterisk is designed to interface any piece of telephony hardware or software with any telephony application. This makes Asterisk a powerful component that can be easily used in NGN softswitches, conferencing servers and Private Branch eXchanges (PBX). Asterisk has been deployed in the Rhodes University Computer Science Department’s VoIP environment and integrated with our existing H. 323 and SIP packet-based networks. This paper discusses the de-ployment of Asterisk, its interworking with our H. 323 and SIP networks and the functionality it offers in terms of a converged TDM and packet-based communications system.
- Full Text:
- Date Issued: 2003
Basalt geochemistry and tectonic discrimination within continental flood basalt provinces
- Authors: Marsh, Julian S
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140412 , vital:37886 , https://doi.org/10.1016/0377-0273(87)90035-7
- Description: Continental flood basalts are usually regarded as a single tectonomagmatic entity but frequently quoted examples exhibit a variety of tectonic settings. In one well-studied, classic, flood basalt province, the Mesozoic Karoo province of southern Africa, magmatism occurred in the following tectonic settings: (a) continental rifting leading to ocean-floor spreading in the South Atlantic Ocean (Etendeka suite of Namibia); (b) stretched continental lithosphere and rifting not leading directly to ocean-floor formation (Lebombo suite of southeastern Africa); and (c) an a-tectonic, within-plate, continental setting characterized by an absence of faulting or warping (Lesotho highlands and Karoo dolerites of South Africa).
- Full Text: false
- Date Issued: 2003
- Authors: Marsh, Julian S
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140412 , vital:37886 , https://doi.org/10.1016/0377-0273(87)90035-7
- Description: Continental flood basalts are usually regarded as a single tectonomagmatic entity but frequently quoted examples exhibit a variety of tectonic settings. In one well-studied, classic, flood basalt province, the Mesozoic Karoo province of southern Africa, magmatism occurred in the following tectonic settings: (a) continental rifting leading to ocean-floor spreading in the South Atlantic Ocean (Etendeka suite of Namibia); (b) stretched continental lithosphere and rifting not leading directly to ocean-floor formation (Lebombo suite of southeastern Africa); and (c) an a-tectonic, within-plate, continental setting characterized by an absence of faulting or warping (Lesotho highlands and Karoo dolerites of South Africa).
- Full Text: false
- Date Issued: 2003
Capital E for events: ways that work: useful solutions
- Authors: Garman, Anthea
- Date: 2003
- Language: English
- Type: text , article
- Identifier: vital:38359 , http://hdl.handle.net/10520/EJC146297
- Description: You would think being located in a small town in one of the most impoverished provinces in South Africa would be a drawback for making media. But a small town is a reachable, convenient laboratory environment for student journalists - and never more so than when the National Arts Festival comes to Grahamstown during the winter vacation.
- Full Text:
- Date Issued: 2003
- Authors: Garman, Anthea
- Date: 2003
- Language: English
- Type: text , article
- Identifier: vital:38359 , http://hdl.handle.net/10520/EJC146297
- Description: You would think being located in a small town in one of the most impoverished provinces in South Africa would be a drawback for making media. But a small town is a reachable, convenient laboratory environment for student journalists - and never more so than when the National Arts Festival comes to Grahamstown during the winter vacation.
- Full Text:
- Date Issued: 2003
Direct-use value of smallholder crop production in a semi-arid rural South African village
- Dovie, Delali B K, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181595 , vital:43750 , xlink:href="https://doi.org/10.1016/S0308-521X(02)00124-5"
- Description: The monetary value of natural resources used by rural communities for subsistence is important when addressing issues affecting the livelihoods of impoverished rural households. There is therefore the need to attribute monetary values to non-marketed products from smallholder production systems in order to reliably account for resource availability and usage to further sound policy decisions. The objective of this paper is to present an empirical analysis of the direct-use and traded values of crop production by households, and to discuss the implications for policy development. The study was undertaken in combination with an evaluation of other livelihood sectors in Thorndale, a semi-arid rural village in the Limpopo province of South Africa. The net direct-use value of crops was estimated at $443.4 per household per annum across the village. Maize (Zea mays), watermelon (Citrullus, vulgaris), peanuts (Arachis hypogaea) and common beans (Phaseolus vulgaris) contributed over 90% to the total direct-use value of crops. Maize alone contributed 40% of this value per household at an estimated $652/ha. Marketing of resources was not a common practice, limited to only maize and peanuts. Farming was basically a rain-fed–mixed cropping system with low production inputs. Farmer support services, human capital development and tenure security were major areas identified for policy development.
- Full Text:
- Date Issued: 2003
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181595 , vital:43750 , xlink:href="https://doi.org/10.1016/S0308-521X(02)00124-5"
- Description: The monetary value of natural resources used by rural communities for subsistence is important when addressing issues affecting the livelihoods of impoverished rural households. There is therefore the need to attribute monetary values to non-marketed products from smallholder production systems in order to reliably account for resource availability and usage to further sound policy decisions. The objective of this paper is to present an empirical analysis of the direct-use and traded values of crop production by households, and to discuss the implications for policy development. The study was undertaken in combination with an evaluation of other livelihood sectors in Thorndale, a semi-arid rural village in the Limpopo province of South Africa. The net direct-use value of crops was estimated at $443.4 per household per annum across the village. Maize (Zea mays), watermelon (Citrullus, vulgaris), peanuts (Arachis hypogaea) and common beans (Phaseolus vulgaris) contributed over 90% to the total direct-use value of crops. Maize alone contributed 40% of this value per household at an estimated $652/ha. Marketing of resources was not a common practice, limited to only maize and peanuts. Farming was basically a rain-fed–mixed cropping system with low production inputs. Farmer support services, human capital development and tenure security were major areas identified for policy development.
- Full Text:
- Date Issued: 2003
Editorial: the policy-in-practice nexus
- Lotz-Sisitka, Heila, Obol, Charles, Nhamo, Godwell
- Authors: Lotz-Sisitka, Heila , Obol, Charles , Nhamo, Godwell
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67389 , vital:29083 , https://www.ajol.info/index.php/sajee/article/view/122661/112205
- Description: publisher version , Environmental policy development and implementation has become a ‘hot topic’ in southern Africa, following global imperatives for countries around the world to articulate their intentions to become more sustainable through public policy. Many policies in the region have been developed with the support of large scale donor funding. Much of the funding is often allocated to policy development processes rather than policy implementation processes, and many countries have experienced ‘gaps’ between policy intention and policy playing out in the field. Recently the Southern African Development Community’s Regional Environmental Education Programme (SADC REEP) appointed an environmental education policy advisor to influence regional policy (our Guest Editor, Charles Obol).This edition of the journal, funded by SADC REEP, aims to provide perspective on the policy-in-practice nexus in southern Africa.
- Full Text:
- Date Issued: 2003
- Authors: Lotz-Sisitka, Heila , Obol, Charles , Nhamo, Godwell
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67389 , vital:29083 , https://www.ajol.info/index.php/sajee/article/view/122661/112205
- Description: publisher version , Environmental policy development and implementation has become a ‘hot topic’ in southern Africa, following global imperatives for countries around the world to articulate their intentions to become more sustainable through public policy. Many policies in the region have been developed with the support of large scale donor funding. Much of the funding is often allocated to policy development processes rather than policy implementation processes, and many countries have experienced ‘gaps’ between policy intention and policy playing out in the field. Recently the Southern African Development Community’s Regional Environmental Education Programme (SADC REEP) appointed an environmental education policy advisor to influence regional policy (our Guest Editor, Charles Obol).This edition of the journal, funded by SADC REEP, aims to provide perspective on the policy-in-practice nexus in southern Africa.
- Full Text:
- Date Issued: 2003
Effect of pictograms on readability of patient information materials:
- Mansoor, Leila E, Dowse, Roslind
- Authors: Mansoor, Leila E , Dowse, Roslind
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157003 , vital:40078 , https://0-doi.org.wam.seals.ac.za/10.1345/aph.1C449
- Description: To design, develop, and evaluate a simple, understandable medicine label and patient information leaflet (PIL) for nystatin suspension, and to assess the effect of incorporating pictograms on understanding in low-literate participants.
- Full Text:
- Date Issued: 2003
- Authors: Mansoor, Leila E , Dowse, Roslind
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157003 , vital:40078 , https://0-doi.org.wam.seals.ac.za/10.1345/aph.1C449
- Description: To design, develop, and evaluate a simple, understandable medicine label and patient information leaflet (PIL) for nystatin suspension, and to assess the effect of incorporating pictograms on understanding in low-literate participants.
- Full Text:
- Date Issued: 2003
Electrochemical behavior and detection of dopamine and ascorbic acid at an iron (II) tetrasulfophthalocyanine modified carbon paste microelectrode
- Oni, Joshua, Westbroek, Philippe, Nyokong, Tebello
- Authors: Oni, Joshua , Westbroek, Philippe , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290279 , vital:56735 , xlink:href="https://doi.org/10.1002/elan.200390104"
- Description: In this article the electrocatalytic behavior of an iron(II)tetrasulfophthalocyanine modified carbon paste microelectrode for the oxidation of dopamine (DA) and ascorbic acid (AA) is described. Although the oxidation potential of ascorbic acid is shifted by over 100 mV to more positive potentials, no peak separation could be obtained. This can be explained by the immediate homogeneous reduction of the oxidation product of dopamine by ascorbic acid in solution. However, this reaction induces a shift of the half-wave potential as a function of ratio of concentration of dopamine to ascorbic acid (cDA/cAA). Therefore it was possible to determine the cAA and cDA from this potential shift and the experimental peak current. Detection limits of 4.5±0.2×10−7 and 7.5±0.5×10−7 mol L−1 were obtained respectively for dopamine and ascorbic acid for cDA/cAA>0.01.
- Full Text:
- Date Issued: 2003
- Authors: Oni, Joshua , Westbroek, Philippe , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290279 , vital:56735 , xlink:href="https://doi.org/10.1002/elan.200390104"
- Description: In this article the electrocatalytic behavior of an iron(II)tetrasulfophthalocyanine modified carbon paste microelectrode for the oxidation of dopamine (DA) and ascorbic acid (AA) is described. Although the oxidation potential of ascorbic acid is shifted by over 100 mV to more positive potentials, no peak separation could be obtained. This can be explained by the immediate homogeneous reduction of the oxidation product of dopamine by ascorbic acid in solution. However, this reaction induces a shift of the half-wave potential as a function of ratio of concentration of dopamine to ascorbic acid (cDA/cAA). Therefore it was possible to determine the cAA and cDA from this potential shift and the experimental peak current. Detection limits of 4.5±0.2×10−7 and 7.5±0.5×10−7 mol L−1 were obtained respectively for dopamine and ascorbic acid for cDA/cAA>0.01.
- Full Text:
- Date Issued: 2003
Electrochemical behaviour of thiol-derivatised zinc (II) phthalocyanine complexes and their self-immobilised films at gold electrodes
- Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290295 , vital:56737 , xlink:href="https://doi.org/10.1016/j.microc.2003.08.002"
- Description: Electrochemical properties of novel, peripherally substituted zinc phthalocyanine complex, octa(4-methylphenylthio-) phthalocyaninatozinc(II) [ZnPc(SC6H4CH3)8] (1a) in DMF solution are presented. This complex showed five quasi-reversible/reversible, diffusion-controlled redox couples. Solution voltammetry of 1a showed little contrast with that of its alkythiol-derivative, octabutylthiophthalocyaninatozinc(II) [ZnPc(SC4H9)8] (1b) in that both thiol-substituents tend to show electron-withdrawing influence on the phthalocyanine ligands; complex 1a showing easier reduction and more difficult to oxidation when compared to 1b and other alkyl derivatives. The voltammetric features of the solid ultrathin films of 1a and 1b, immobilized on gold electrodes via the self-assembling technique, are also presented. Interestingly, the self-assembled films are stable and reproducible and provide good suppression to the following Faradaic processes; gold surface oxidation, solution ion species and underpotential deposition (UPD) of copper.
- Full Text:
- Date Issued: 2003
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290295 , vital:56737 , xlink:href="https://doi.org/10.1016/j.microc.2003.08.002"
- Description: Electrochemical properties of novel, peripherally substituted zinc phthalocyanine complex, octa(4-methylphenylthio-) phthalocyaninatozinc(II) [ZnPc(SC6H4CH3)8] (1a) in DMF solution are presented. This complex showed five quasi-reversible/reversible, diffusion-controlled redox couples. Solution voltammetry of 1a showed little contrast with that of its alkythiol-derivative, octabutylthiophthalocyaninatozinc(II) [ZnPc(SC4H9)8] (1b) in that both thiol-substituents tend to show electron-withdrawing influence on the phthalocyanine ligands; complex 1a showing easier reduction and more difficult to oxidation when compared to 1b and other alkyl derivatives. The voltammetric features of the solid ultrathin films of 1a and 1b, immobilized on gold electrodes via the self-assembling technique, are also presented. Interestingly, the self-assembled films are stable and reproducible and provide good suppression to the following Faradaic processes; gold surface oxidation, solution ion species and underpotential deposition (UPD) of copper.
- Full Text:
- Date Issued: 2003
Evolution of a strongly differentiated suite of phonolites from the Klinghardt Mountains, Namibia
- Authors: Marsh, Julian S
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140400 , vital:37885 , https://doi.org/10.1016/0024-4937(87)90023-5
- Description: Phonolites of Tertiary age occur as eroded tholoids, lava flows, ignimbrites, and coulees in the Klinghardt Mountains of southern Namibia. Sixty samples have been analyzed for major and trace elements and fourteen of these for 87SR 86SR. The phonolites lie close to the low-pressure cotectics in Q-Ne-Ks, in keeping with their petrography which indicates that most samples have phenocrysts of both nepheline and sanidine. Na has been variably lost from the rocks during crystallization and devitrification/alteration of hypocrystalline specimens.
- Full Text: false
- Date Issued: 2003
- Authors: Marsh, Julian S
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140400 , vital:37885 , https://doi.org/10.1016/0024-4937(87)90023-5
- Description: Phonolites of Tertiary age occur as eroded tholoids, lava flows, ignimbrites, and coulees in the Klinghardt Mountains of southern Namibia. Sixty samples have been analyzed for major and trace elements and fourteen of these for 87SR 86SR. The phonolites lie close to the low-pressure cotectics in Q-Ne-Ks, in keeping with their petrography which indicates that most samples have phenocrysts of both nepheline and sanidine. Na has been variably lost from the rocks during crystallization and devitrification/alteration of hypocrystalline specimens.
- Full Text: false
- Date Issued: 2003
External and domestic sources of foreign policy ambiguity: South African foreign policy and the projection of pluralist middle power
- Authors: Bischoff, Paul, 1954-
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161442 , vital:40627 , https://doi.org/10.1080/0258934032000147291
- Description: As a pluralist middle power, post-apartheid South Africa seeks to generate successful foreign policy initiatives at bilateral, multilateral and regional levels in order to shape international outcomes. In this endeavour, it has three important political resources – a recognition of its geo-political position and importance as a democratic yardstick and reformer; its acceptance of a transnational, neo-liberal elite alliance and finally, recognition of its leadership role from forces wishing to challenge African political establishments. However, the international and domestic political environment which in the mid-1990s was favourable towards middle-power initiative and reform has narrowed.
- Full Text:
- Date Issued: 2003
- Authors: Bischoff, Paul, 1954-
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161442 , vital:40627 , https://doi.org/10.1080/0258934032000147291
- Description: As a pluralist middle power, post-apartheid South Africa seeks to generate successful foreign policy initiatives at bilateral, multilateral and regional levels in order to shape international outcomes. In this endeavour, it has three important political resources – a recognition of its geo-political position and importance as a democratic yardstick and reformer; its acceptance of a transnational, neo-liberal elite alliance and finally, recognition of its leadership role from forces wishing to challenge African political establishments. However, the international and domestic political environment which in the mid-1990s was favourable towards middle-power initiative and reform has narrowed.
- Full Text:
- Date Issued: 2003
Fuelwood availability and use in the Richtersveld National Park, South Africa
- Shackleton, Charlie M, Guthrie, G, Keirungi, J, Stewart, J
- Authors: Shackleton, Charlie M , Guthrie, G , Keirungi, J , Stewart, J
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181461 , vital:43736 , xlink:href=" https://doi.org/10.4102/koedoe.v46i2.66"
- Description: Concern has been voiced about the possible over-use of fuelwood from the riparian fringe by pastoralist herders in the Richtersveld National Park (RNP). This coincided with the current examination and modelling of the supply and use of ecosystem goods and services in the Gariep Basin as part of the Southern African Millennium Assessment (SAfMA). This paper reports on a study to index the current availability of deadwood within the riparian zone of RNP, its relationship with proximity to human habitation, and species preferences of the local herders. Deadwood availability was assessed per woody species and on the ground in 12 transects within the riparian fringe. Herders were interviewed regarding their species preferences, and the composition of woodpiles was examined. There was no relationship between the percentage of attached deadwood on the tree, or the percentage deadwood ground cover, and the distance from herder stockposts. Euclea pseudobenus and Tamarix usneoides were the dominant species in the riparian fringe. There was strong selection for Ziziphus mucronata as a fuelwood species and only marginal or random selection for E. pseudobenus. Tamarix usneoides and Prosopis sp. were abundant in the riparian zone, but were not used for fuelwood. There was a significant difference between species with respect to the mean proportion of the stem that was dead, the highest being Z. mucronata (± 28 % deadwood), followed by T. usneoides (± 12 %). Most of the Prosopis trees had no deadwood. Across all species, the mean percentage dead per tree was approximately 15 %. Additionally, detached deadwood covered just less than 9 % of ground area, averaged across all plots and transects. All the variables measured indicated that there seems to be little need for concern over the current fuelwood extraction activities of pastoralists within the RNP. There was no clear evidence of cutting of branches or deadwood. The abundance of both attached and detached deadwood was not depleted close to human habitation. There was still abundant deadwood, even on preferred species. The most preferred species (Ziziphus mucronata) had the greatest mean proportion of deadwood. The herders stated that they only used deadwood, and that there was plenty. They rarely used driftwood washed down the river, although there was an abundance of it. Thus, overall, there was no sign of depletion of the deadwood resource, even on favoured species, or degradation of the productive capacity for deadwood.
- Full Text:
- Date Issued: 2003
- Authors: Shackleton, Charlie M , Guthrie, G , Keirungi, J , Stewart, J
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181461 , vital:43736 , xlink:href=" https://doi.org/10.4102/koedoe.v46i2.66"
- Description: Concern has been voiced about the possible over-use of fuelwood from the riparian fringe by pastoralist herders in the Richtersveld National Park (RNP). This coincided with the current examination and modelling of the supply and use of ecosystem goods and services in the Gariep Basin as part of the Southern African Millennium Assessment (SAfMA). This paper reports on a study to index the current availability of deadwood within the riparian zone of RNP, its relationship with proximity to human habitation, and species preferences of the local herders. Deadwood availability was assessed per woody species and on the ground in 12 transects within the riparian fringe. Herders were interviewed regarding their species preferences, and the composition of woodpiles was examined. There was no relationship between the percentage of attached deadwood on the tree, or the percentage deadwood ground cover, and the distance from herder stockposts. Euclea pseudobenus and Tamarix usneoides were the dominant species in the riparian fringe. There was strong selection for Ziziphus mucronata as a fuelwood species and only marginal or random selection for E. pseudobenus. Tamarix usneoides and Prosopis sp. were abundant in the riparian zone, but were not used for fuelwood. There was a significant difference between species with respect to the mean proportion of the stem that was dead, the highest being Z. mucronata (± 28 % deadwood), followed by T. usneoides (± 12 %). Most of the Prosopis trees had no deadwood. Across all species, the mean percentage dead per tree was approximately 15 %. Additionally, detached deadwood covered just less than 9 % of ground area, averaged across all plots and transects. All the variables measured indicated that there seems to be little need for concern over the current fuelwood extraction activities of pastoralists within the RNP. There was no clear evidence of cutting of branches or deadwood. The abundance of both attached and detached deadwood was not depleted close to human habitation. There was still abundant deadwood, even on preferred species. The most preferred species (Ziziphus mucronata) had the greatest mean proportion of deadwood. The herders stated that they only used deadwood, and that there was plenty. They rarely used driftwood washed down the river, although there was an abundance of it. Thus, overall, there was no sign of depletion of the deadwood resource, even on favoured species, or degradation of the productive capacity for deadwood.
- Full Text:
- Date Issued: 2003
Government failure and state incapacity: the South African public sector in the 1990s
- Dollery, Brian, Snowball, Jeanette D
- Authors: Dollery, Brian , Snowball, Jeanette D
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71343 , vital:29835 , https://doi.org/10.1080/10113430309511164
- Description: In their editorial introduction to the 1994 Special Issue of the South African Journal of Economic History devoted to a sectoral analysis of the South African economy during the 1980s, Stuart Jones and Jon Inggs described this period as a "lost decade", with per capita incomes even lower in 1990 than they had been in 1980. Moreover, "no other Western country experienced a comparable decline in the 1980s and South Africa herself had never experienced anything like it since the formation of Union in 1910". Thus, from the perspective of economic growth, the decade of the 1990s could not have had a less auspicious beginning.
- Full Text: false
- Date Issued: 2010
- Authors: Dollery, Brian , Snowball, Jeanette D
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71343 , vital:29835 , https://doi.org/10.1080/10113430309511164
- Description: In their editorial introduction to the 1994 Special Issue of the South African Journal of Economic History devoted to a sectoral analysis of the South African economy during the 1980s, Stuart Jones and Jon Inggs described this period as a "lost decade", with per capita incomes even lower in 1990 than they had been in 1980. Moreover, "no other Western country experienced a comparable decline in the 1980s and South Africa herself had never experienced anything like it since the formation of Union in 1910". Thus, from the perspective of economic growth, the decade of the 1990s could not have had a less auspicious beginning.
- Full Text: false
- Date Issued: 2010