Digital multimedia network with hierarchical parameter control protocol
- Gurdan, Robby, Foss, Richard
- Authors: Gurdan, Robby , Foss, Richard
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427083 , vital:72413 , https://patentimages.storage.googleapis.com/21/04/39/2266c533e05a46/US20100299421A1.pdf
- Description: The present invention relates to a digital multimedia network of apparatuses each comprising a control device, wherein a device parameter of an apparatus is controlled by sending a command message (CMD) to said control device of said apparatus containing a tree-structured hierarchical parameter address (HPA) which consists of parameter grouping identifiers each corresponding to a hierarchy level of a predetermined tree-structured parameter hierarchy used for addressing device parameters throughout said digital multimedia network.
- Full Text:
- Date Issued: 2010
- Authors: Gurdan, Robby , Foss, Richard
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427083 , vital:72413 , https://patentimages.storage.googleapis.com/21/04/39/2266c533e05a46/US20100299421A1.pdf
- Description: The present invention relates to a digital multimedia network of apparatuses each comprising a control device, wherein a device parameter of an apparatus is controlled by sending a command message (CMD) to said control device of said apparatus containing a tree-structured hierarchical parameter address (HPA) which consists of parameter grouping identifiers each corresponding to a hierarchy level of a predetermined tree-structured parameter hierarchy used for addressing device parameters throughout said digital multimedia network.
- Full Text:
- Date Issued: 2010
Does reservoir trophic status influence the feeding and growth of the sharptooth catfish, Clarias gariepinus (Teleostei: Clariidae)?
- Potts, Warren M, Hecht, Thomas, Andrew, Timothy G
- Authors: Potts, Warren M , Hecht, Thomas , Andrew, Timothy G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124309 , vital:35591 , https://doi.org/10.2989/A JAS.2008.33.2.6.503
- Description: The diet and growth of sharptooth catfish, Clarias gariepinus, in an oligotrophic system (Kat River Reservoir, Eastern Cape, South Africa) were compared to those in a eutrophic system (Laing Reservoir, Eastern Cape) to determine if the trophic status of a waterbody had an effect on the growth rate of the species. In order of importance, the diet of catfish in Kat River Reservoir consisted of fish, insects, zooplankton, plant material and other items, while the diet of catfish in Laing Reservoir consisted of fish, plant material, zooplankton, other vertebrates and insects. The diets of catfish in the two reservoirs had a similarity index of 68.1% and there was no significant difference in their nutritional value. Fish prey was the most important dietary component in both reservoirs. Temperature regime and zooplankton and zoobenthos density were similar in both systems. However, fish prey density was significantly higher in the eutrophic Laing Reservoir and catfish grew significantly faster in that system. The slower growth rate in Kat River Reservoir was attributed to the higher energy costs associated with the capture of fish prey, which was less abundant than in Laing Reservoir. Trophic status therefore had an indirect effect on catfish growth by influencing the availability of fish prey.
- Full Text:
- Date Issued: 2010
- Authors: Potts, Warren M , Hecht, Thomas , Andrew, Timothy G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124309 , vital:35591 , https://doi.org/10.2989/A JAS.2008.33.2.6.503
- Description: The diet and growth of sharptooth catfish, Clarias gariepinus, in an oligotrophic system (Kat River Reservoir, Eastern Cape, South Africa) were compared to those in a eutrophic system (Laing Reservoir, Eastern Cape) to determine if the trophic status of a waterbody had an effect on the growth rate of the species. In order of importance, the diet of catfish in Kat River Reservoir consisted of fish, insects, zooplankton, plant material and other items, while the diet of catfish in Laing Reservoir consisted of fish, plant material, zooplankton, other vertebrates and insects. The diets of catfish in the two reservoirs had a similarity index of 68.1% and there was no significant difference in their nutritional value. Fish prey was the most important dietary component in both reservoirs. Temperature regime and zooplankton and zoobenthos density were similar in both systems. However, fish prey density was significantly higher in the eutrophic Laing Reservoir and catfish grew significantly faster in that system. The slower growth rate in Kat River Reservoir was attributed to the higher energy costs associated with the capture of fish prey, which was less abundant than in Laing Reservoir. Trophic status therefore had an indirect effect on catfish growth by influencing the availability of fish prey.
- Full Text:
- Date Issued: 2010
Ecological impacts of small dams on South African rivers Part 2: Biotic response – abundance and composition of macroinvertebrate communities
- Mantel, Sukhmani K, Muller, N W J, Hughes, Denis A
- Authors: Mantel, Sukhmani K , Muller, N W J , Hughes, Denis A
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7095 , http://hdl.handle.net/10962/d1012437
- Description: This paper investigates the cumulative impacts of small dams on invertebrate communities in 2 regions of South Africa – the Western Cape and Mpumalanga. Previous research found reduced discharge, increased total dissolved salts, and a decrease in average score per taxon (ASPT; collected using SASS4 methods) at sites with high density of small dams in their catchment. These changes in ASPT are investigated using the invertebrate abundance data available in the River Health Programme. Multivariate analyses found differences in invertebrate communities in rivers with high densities of small dams in their catchment in foothill-gravel streams (in both Western Cape and Mpumalanga) and in foothill-cobble streams (in Western Cape only). Opportunistic taxa that are tolerant of pollution, and capable of exploiting various habitats, and those that prefer slower currents increased in numbers, while other taxa that are sensitive to pollution and disturbance declined in numbers. Some regional differences were noted possibly reflecting climatic differences between the regions. Since the results of this study are correlative, it highlights the need for a systematic (by sites and seasons) and detailed (at species level) collection of data to verify the results of cumulative effects of small dams. This can further the development of a framework for small-dam construction and management that will limit their impact on river catchments.
- Full Text:
- Date Issued: 2010
- Authors: Mantel, Sukhmani K , Muller, N W J , Hughes, Denis A
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7095 , http://hdl.handle.net/10962/d1012437
- Description: This paper investigates the cumulative impacts of small dams on invertebrate communities in 2 regions of South Africa – the Western Cape and Mpumalanga. Previous research found reduced discharge, increased total dissolved salts, and a decrease in average score per taxon (ASPT; collected using SASS4 methods) at sites with high density of small dams in their catchment. These changes in ASPT are investigated using the invertebrate abundance data available in the River Health Programme. Multivariate analyses found differences in invertebrate communities in rivers with high densities of small dams in their catchment in foothill-gravel streams (in both Western Cape and Mpumalanga) and in foothill-cobble streams (in Western Cape only). Opportunistic taxa that are tolerant of pollution, and capable of exploiting various habitats, and those that prefer slower currents increased in numbers, while other taxa that are sensitive to pollution and disturbance declined in numbers. Some regional differences were noted possibly reflecting climatic differences between the regions. Since the results of this study are correlative, it highlights the need for a systematic (by sites and seasons) and detailed (at species level) collection of data to verify the results of cumulative effects of small dams. This can further the development of a framework for small-dam construction and management that will limit their impact on river catchments.
- Full Text:
- Date Issued: 2010
Econometric determinants of liquidity of the South African bond market
- Mingiri, Kapingura Forget https://orcid.org/0000-0002-5808-5612
- Authors: Mingiri, Kapingura Forget https://orcid.org/0000-0002-5808-5612
- Date: 2010
- Subjects: Economic indicators , Economic forecasting -- Africa , Bond market
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/26346 , vital:65243
- Description: The importance of the bond market to the financial system and broader economy of a country cannot be underestimated. It is important to analyse factors which determine liquidity in this essential market. This study seeks to establish the determinants of liquidity in the South African bond market using monthly data covering the period 1995 to 2009. It begins by providing an updated overview of the South African bond market and an analysis of the relevant literature. Two models linking bond market liquidity to its theoretical determinants were specified. In contrast to the available literature, this study analyses liquidity at both macroeconomic and market microstructure level using two measures of liquidity, volume and the bid-ask spread, applying the VAR approach and two-stage least squares for robust check. All macroeconomic variables (except stock market) were identified to have an impact on bond market liquidity in the long-run. As far as market microstructure factors are concerned, both volume and volatility were established to be important determinants of liquidity in the South African bond market. The study recommended that, as for macroeconomic factors, authorities should keep inflation at low and stables levels as well as a stable currency. Also, offering bond investors certain facilities and the removal of restrictions on foreign investor activities are other important conditions to improve bond market liquidity. As far as market microstructure factors are concerned, we suggest that, ways to safe-guard against excessive volatility include the creation of a vibrant derivative market, development of a more active and well-functioning repurchase market./ , Thesis (MCom) -- Faculty of Management and Commerce, 2010
- Full Text:
- Date Issued: 2010
- Authors: Mingiri, Kapingura Forget https://orcid.org/0000-0002-5808-5612
- Date: 2010
- Subjects: Economic indicators , Economic forecasting -- Africa , Bond market
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/26346 , vital:65243
- Description: The importance of the bond market to the financial system and broader economy of a country cannot be underestimated. It is important to analyse factors which determine liquidity in this essential market. This study seeks to establish the determinants of liquidity in the South African bond market using monthly data covering the period 1995 to 2009. It begins by providing an updated overview of the South African bond market and an analysis of the relevant literature. Two models linking bond market liquidity to its theoretical determinants were specified. In contrast to the available literature, this study analyses liquidity at both macroeconomic and market microstructure level using two measures of liquidity, volume and the bid-ask spread, applying the VAR approach and two-stage least squares for robust check. All macroeconomic variables (except stock market) were identified to have an impact on bond market liquidity in the long-run. As far as market microstructure factors are concerned, both volume and volatility were established to be important determinants of liquidity in the South African bond market. The study recommended that, as for macroeconomic factors, authorities should keep inflation at low and stables levels as well as a stable currency. Also, offering bond investors certain facilities and the removal of restrictions on foreign investor activities are other important conditions to improve bond market liquidity. As far as market microstructure factors are concerned, we suggest that, ways to safe-guard against excessive volatility include the creation of a vibrant derivative market, development of a more active and well-functioning repurchase market./ , Thesis (MCom) -- Faculty of Management and Commerce, 2010
- Full Text:
- Date Issued: 2010
Education for Sustainable Development and retention: unravelling a research agenda
- Authors: Lotz-Sisitka, Heila
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127192 , vital:35975 , https://10.1007/s11159-010-9165-9
- Description: This paper considers the question of what education for sustainable development (ESD) research might signify when linked to the concept of “retention”, and how this relation (ESD and retention) might be researched. It considers two different perspectives on retention, as revealed through educational research trajectories, drawing on existing research and case studies. Firstly, it discusses an ESD research agenda that documents retention by focusing on the issue of keeping children in schools. This research agenda is typical of the existing discourses surrounding Education for All (EFA). It then discusses a related ESD research agenda that focuses more on the pedagogical and curricular aspects of retention, as this provides for a deeper understanding of how ESD can contribute to improving the quality of teaching and learning within a wider EFA retention agenda.
- Full Text:
- Date Issued: 2010
- Authors: Lotz-Sisitka, Heila
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127192 , vital:35975 , https://10.1007/s11159-010-9165-9
- Description: This paper considers the question of what education for sustainable development (ESD) research might signify when linked to the concept of “retention”, and how this relation (ESD and retention) might be researched. It considers two different perspectives on retention, as revealed through educational research trajectories, drawing on existing research and case studies. Firstly, it discusses an ESD research agenda that documents retention by focusing on the issue of keeping children in schools. This research agenda is typical of the existing discourses surrounding Education for All (EFA). It then discusses a related ESD research agenda that focuses more on the pedagogical and curricular aspects of retention, as this provides for a deeper understanding of how ESD can contribute to improving the quality of teaching and learning within a wider EFA retention agenda.
- Full Text:
- Date Issued: 2010
Effects of hyperinflation on stock market performance: case of Zimbabwe
- Authors: Mutandwa, Tsitsi Hope
- Date: 2010
- Subjects: Stocks--Zimbabwe , Stock exchanges--Zimbabwe , Inflation targeting--Zimbabwe
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24980 , vital:63768
- Description: In this study an analysis of the long-term equilibrium relationship between inflation, selected macroeconomic variables and the Zimbabwe stock market (represented by market capitalization) is explored. Using stock market capitalization as a proxy for stock market performance is important for an investigator since it can capture movements in the whole market. The link between stock market performance and macroeconomic variables in particular inflation is well-documented in the literature. However, a void in the literature relates to examining the cointegration between hyperinflation and stock market performance. Although hyperinflation is nothing more than inflation at high rates, clarity on this point is necessary because of the seemingly unclear nature of the relationship in the literature. Inflation has mostly been documented as negatively impacting on financial markets. This is not so clear when it comes to hyperinflation. The Zimbabwean stock market has performed well during the high inflation period. This then raises the question: Does hyperinflation stimulate the growth of the stock market? The analysis is undertaken by employing cointegration and vector error correction modeling approach using quarterly data for the period 1980-2007 Our results show among others, that hyperinflation has impacted negatively on the growth of the stock market in Zimbabwe. However, other driving factors such as foreign direct investment and relatively high bank lending rates may have fuelled the observed growth in the stock market during the period of study. , Thesis (MCom) -- Faculty of Management and Commerce, 2010
- Full Text:
- Date Issued: 2010
- Authors: Mutandwa, Tsitsi Hope
- Date: 2010
- Subjects: Stocks--Zimbabwe , Stock exchanges--Zimbabwe , Inflation targeting--Zimbabwe
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24980 , vital:63768
- Description: In this study an analysis of the long-term equilibrium relationship between inflation, selected macroeconomic variables and the Zimbabwe stock market (represented by market capitalization) is explored. Using stock market capitalization as a proxy for stock market performance is important for an investigator since it can capture movements in the whole market. The link between stock market performance and macroeconomic variables in particular inflation is well-documented in the literature. However, a void in the literature relates to examining the cointegration between hyperinflation and stock market performance. Although hyperinflation is nothing more than inflation at high rates, clarity on this point is necessary because of the seemingly unclear nature of the relationship in the literature. Inflation has mostly been documented as negatively impacting on financial markets. This is not so clear when it comes to hyperinflation. The Zimbabwean stock market has performed well during the high inflation period. This then raises the question: Does hyperinflation stimulate the growth of the stock market? The analysis is undertaken by employing cointegration and vector error correction modeling approach using quarterly data for the period 1980-2007 Our results show among others, that hyperinflation has impacted negatively on the growth of the stock market in Zimbabwe. However, other driving factors such as foreign direct investment and relatively high bank lending rates may have fuelled the observed growth in the stock market during the period of study. , Thesis (MCom) -- Faculty of Management and Commerce, 2010
- Full Text:
- Date Issued: 2010
Electrocatalytic oxidation of amitrole and diuron on iron (II) tetraaminophthalocyanine-single walled carbon nanotube dendrimer
- Mugadza, Tawanda, Nyokong, Tebello
- Authors: Mugadza, Tawanda , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262611 , vital:53536 , xlink:href="https://doi.org/10.1016/j.electacta.2009.12.051"
- Description: FeTAPc-single walled carbon nanotube (SWCNT) dendrimers are employed as glassy carbon electrode modifiers for the electrocatalytic oxidations of amitrole and diuron. The catalytic rate constants were 4.55 × 103 M−1 s−1 and 1.79 × 104 M−1 s−1 for amitrole and diuron, respectively using chronoamperometric studies. The diffusion constants were found to be 1.52 × 10−4 cm2 s−1 and 1.91 × 10−4 cm2 s−1 for diuron and amitrole, respectively. The linear concentration range for both were from 5.0 × 10−5 to 1.0 × 10−4 M and sensitivities of 0.6603 μA/μM and 0.6641 μA/μM for amitrole and diuron, with corresponding limits of detection of 2.15 × 10−7 and 2.6 × 10−7 M using the 3δ notation, respectively.
- Full Text:
- Date Issued: 2010
- Authors: Mugadza, Tawanda , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262611 , vital:53536 , xlink:href="https://doi.org/10.1016/j.electacta.2009.12.051"
- Description: FeTAPc-single walled carbon nanotube (SWCNT) dendrimers are employed as glassy carbon electrode modifiers for the electrocatalytic oxidations of amitrole and diuron. The catalytic rate constants were 4.55 × 103 M−1 s−1 and 1.79 × 104 M−1 s−1 for amitrole and diuron, respectively using chronoamperometric studies. The diffusion constants were found to be 1.52 × 10−4 cm2 s−1 and 1.91 × 10−4 cm2 s−1 for diuron and amitrole, respectively. The linear concentration range for both were from 5.0 × 10−5 to 1.0 × 10−4 M and sensitivities of 0.6603 μA/μM and 0.6641 μA/μM for amitrole and diuron, with corresponding limits of detection of 2.15 × 10−7 and 2.6 × 10−7 M using the 3δ notation, respectively.
- Full Text:
- Date Issued: 2010
Electrochemical, spectroscopic and microscopic studies of new manganese phthalocyanine complexes in solution and as self-assembled monolayers on gold
- Coates, Megan, Antunes, Edith M, Nyokong, Tebello
- Authors: Coates, Megan , Antunes, Edith M , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261144 , vital:53363 , xlink:href="https://doi.org/10.1142/S1088424610002471"
- Description: Four new manganese(III) phthalocyanines (3a–d), octasubstituted at the peripheral position with pentylthio, decylthio, benzylthio, and phenylthio groups, respectively, were synthesized. Their specific electrochemical, spectroscopic and microscopic properties in solution and as self-assembled monolayers on gold were characterized. The UV-vis spectra confirmed red-shifted Q bands for all the complexes, due to the effect of the central metal and the electron-donating substituents. Three redox couples were visible during cyclic voltammetry studies for the four complexes, and spectroelectrochemistry confirmed the couples as corresponding to MnIIIPc-2/MnIIPc-2 (II) (metal reduction), MnIIPc-2/MnIIPc-3 (III) (ring reduction) and MnIIIPc-1/MnIIIPc-2 (I) (ring oxidation). Electrochemistry was also used to determine the blocking characteristics of the MnPc self-assembled monolayers on gold, which proved to be highly dependent on the type of substituent. Other methods of characterization included Raman spectroscopy, atomic force and scanning electrochemical microscopy analyses of the SAMs.
- Full Text:
- Date Issued: 2010
- Authors: Coates, Megan , Antunes, Edith M , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261144 , vital:53363 , xlink:href="https://doi.org/10.1142/S1088424610002471"
- Description: Four new manganese(III) phthalocyanines (3a–d), octasubstituted at the peripheral position with pentylthio, decylthio, benzylthio, and phenylthio groups, respectively, were synthesized. Their specific electrochemical, spectroscopic and microscopic properties in solution and as self-assembled monolayers on gold were characterized. The UV-vis spectra confirmed red-shifted Q bands for all the complexes, due to the effect of the central metal and the electron-donating substituents. Three redox couples were visible during cyclic voltammetry studies for the four complexes, and spectroelectrochemistry confirmed the couples as corresponding to MnIIIPc-2/MnIIPc-2 (II) (metal reduction), MnIIPc-2/MnIIPc-3 (III) (ring reduction) and MnIIIPc-1/MnIIIPc-2 (I) (ring oxidation). Electrochemistry was also used to determine the blocking characteristics of the MnPc self-assembled monolayers on gold, which proved to be highly dependent on the type of substituent. Other methods of characterization included Raman spectroscopy, atomic force and scanning electrochemical microscopy analyses of the SAMs.
- Full Text:
- Date Issued: 2010
Empirically modelled Pc3 activity based on solar wind parameters
- Heilig, B, Lotz, S I, Verő, J, Sutcliffe, P, Reda, J, Pajunpää, G, Raita, T
- Authors: Heilig, B , Lotz, S I , Verő, J , Sutcliffe, P , Reda, J , Pajunpää, G , Raita, T
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6814 , http://hdl.handle.net/10962/d1004324
- Description: It is known that under certain solar wind (SW)/interplanetary magnetic field (IMF) conditions (e.g. high SW speed, low cone angle) the occurrence of ground-level Pc3–4 pulsations is more likely. In this paper we demonstrate that in the event of anomalously low SW particle density, Pc3 activity is extremely low regardless of otherwise favourable SW speed and cone angle. We re-investigate the SW control of Pc3 pulsation activity through a statistical analysis and two empirical models with emphasis on the influence of SW density on Pc3 activity. We utilise SW and IMF measurements from the OMNI project and ground-based magnetometer measurements from the MM100 array to relate SW and IMF measurements to the occurrence of Pc3 activity. Multiple linear regression and artificial neural network models are used in iterative processes in order to identify sets of SW-based input parameters, which optimally reproduce a set of Pc3 activity data. The inclusion of SW density in the parameter set significantly improves the models. Not only the density itself, but other density related parameters, such as the dynamic pressure of the SW, or the standoff distance of the magnetopause work equally well in the model. The disappearance of Pc3s during low-density events can have at least four reasons according to the existing upstream wave theory: 1. Pausing the ion-cyclotron resonance that generates the upstream ultra low frequency waves in the absence of protons, 2. Weakening of the bow shock that implies less efficient reflection, 3. The SW becomes sub-Alfvénic and hence it is not able to sweep back the waves propagating upstream with the Alfvén-speed, and 4. The increase of the standoff distance of the magnetopause (and of the bow shock). Although the models cannot account for the lack of Pc3s during intervals when the SW density is extremely low, the resulting sets of optimal model inputs support the generation of mid latitude Pc3 activity predominantly through upstream waves.
- Full Text:
- Date Issued: 2010
- Authors: Heilig, B , Lotz, S I , Verő, J , Sutcliffe, P , Reda, J , Pajunpää, G , Raita, T
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6814 , http://hdl.handle.net/10962/d1004324
- Description: It is known that under certain solar wind (SW)/interplanetary magnetic field (IMF) conditions (e.g. high SW speed, low cone angle) the occurrence of ground-level Pc3–4 pulsations is more likely. In this paper we demonstrate that in the event of anomalously low SW particle density, Pc3 activity is extremely low regardless of otherwise favourable SW speed and cone angle. We re-investigate the SW control of Pc3 pulsation activity through a statistical analysis and two empirical models with emphasis on the influence of SW density on Pc3 activity. We utilise SW and IMF measurements from the OMNI project and ground-based magnetometer measurements from the MM100 array to relate SW and IMF measurements to the occurrence of Pc3 activity. Multiple linear regression and artificial neural network models are used in iterative processes in order to identify sets of SW-based input parameters, which optimally reproduce a set of Pc3 activity data. The inclusion of SW density in the parameter set significantly improves the models. Not only the density itself, but other density related parameters, such as the dynamic pressure of the SW, or the standoff distance of the magnetopause work equally well in the model. The disappearance of Pc3s during low-density events can have at least four reasons according to the existing upstream wave theory: 1. Pausing the ion-cyclotron resonance that generates the upstream ultra low frequency waves in the absence of protons, 2. Weakening of the bow shock that implies less efficient reflection, 3. The SW becomes sub-Alfvénic and hence it is not able to sweep back the waves propagating upstream with the Alfvén-speed, and 4. The increase of the standoff distance of the magnetopause (and of the bow shock). Although the models cannot account for the lack of Pc3s during intervals when the SW density is extremely low, the resulting sets of optimal model inputs support the generation of mid latitude Pc3 activity predominantly through upstream waves.
- Full Text:
- Date Issued: 2010
Estuarine use by spotted grunter Pomadasys commersonnii in a South African estuary, as determined by acoustic telemetry
- Childs, Amber-Robyn, Cowley, Paul D, Næsje, T F, Booth, Anthony J, Potts, Warren M, Thorstad, Eva B, Økland, F
- Authors: Childs, Amber-Robyn , Cowley, Paul D , Næsje, T F , Booth, Anthony J , Potts, Warren M , Thorstad, Eva B , Økland, F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124428 , vital:35612 , https://doi.org/10.2989/A JMS.2008.30.1.12.462
- Description: Estuaries are important in the life history and the maintenance of the diversity of coastal fish species because of their function as nursery areas for juveniles as well as feeding grounds for adults (Cyrus 1991). The dependence of many fish species on estuaries is well documented (e.g. Wallace et al. 1984, Lenanton and Potter 1987, Blaber et al. 1989, Whitfield 1990, Hoss and Thayer 1993). Spotted grunter Pomadasys commersonnii (Haemulidae) (Lacepède 1801) is an estuarine-dependent species which spawns in the KwaZulu-Natal inshore coastal waters, between August and December (Wallace 1975b, Wallace and van der Elst 1975, Harris and Cyrus 1997, 1999). The eggs and larvae are transported southwards by the Agulhas Current, and juveniles between 20 mm and 50 mm TL recruit into the KwaZulu-Natal and south-eastern Cape estuaries (Wallace and van der Elst 1975, Whitfield 1990). Juvenile spotted grunter make use of the abundant food resources in estuaries, where they grow rapidly and remain for a period of 1–3 years (Wallace and Schleyer 1979, Day et al. 1981). Upon attaining sexual maturity (at between 300 mm and 400 mm TL), they return to the marine environment (Wallace 1975b). Some adults, however, return to estuaries to feed and to regain condition after spawning (Wallace 1975b, Whitfield 1994). The return of post-spawning fish coincides with increased catches by fishers in estuaries between July and January. These events are known as ‘grunter runs’ (Wallace 1975a, Marais and Baird 1980, Marais 1988, Pradervand and Baird 2002). It is suggested that adults spend up to several months in estuaries, before moving back to sea where they undergo gonadal development and ultimately spawn (Wallace 1975b, Wallace and van der Elst 1975). It is believed that adult fish also enter estuaries in a prespawning state to gain condition en route to their spawning grounds in KwaZulu-Natal (Webb 2002).
- Full Text:
- Date Issued: 2010
- Authors: Childs, Amber-Robyn , Cowley, Paul D , Næsje, T F , Booth, Anthony J , Potts, Warren M , Thorstad, Eva B , Økland, F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124428 , vital:35612 , https://doi.org/10.2989/A JMS.2008.30.1.12.462
- Description: Estuaries are important in the life history and the maintenance of the diversity of coastal fish species because of their function as nursery areas for juveniles as well as feeding grounds for adults (Cyrus 1991). The dependence of many fish species on estuaries is well documented (e.g. Wallace et al. 1984, Lenanton and Potter 1987, Blaber et al. 1989, Whitfield 1990, Hoss and Thayer 1993). Spotted grunter Pomadasys commersonnii (Haemulidae) (Lacepède 1801) is an estuarine-dependent species which spawns in the KwaZulu-Natal inshore coastal waters, between August and December (Wallace 1975b, Wallace and van der Elst 1975, Harris and Cyrus 1997, 1999). The eggs and larvae are transported southwards by the Agulhas Current, and juveniles between 20 mm and 50 mm TL recruit into the KwaZulu-Natal and south-eastern Cape estuaries (Wallace and van der Elst 1975, Whitfield 1990). Juvenile spotted grunter make use of the abundant food resources in estuaries, where they grow rapidly and remain for a period of 1–3 years (Wallace and Schleyer 1979, Day et al. 1981). Upon attaining sexual maturity (at between 300 mm and 400 mm TL), they return to the marine environment (Wallace 1975b). Some adults, however, return to estuaries to feed and to regain condition after spawning (Wallace 1975b, Whitfield 1994). The return of post-spawning fish coincides with increased catches by fishers in estuaries between July and January. These events are known as ‘grunter runs’ (Wallace 1975a, Marais and Baird 1980, Marais 1988, Pradervand and Baird 2002). It is suggested that adults spend up to several months in estuaries, before moving back to sea where they undergo gonadal development and ultimately spawn (Wallace 1975b, Wallace and van der Elst 1975). It is believed that adult fish also enter estuaries in a prespawning state to gain condition en route to their spawning grounds in KwaZulu-Natal (Webb 2002).
- Full Text:
- Date Issued: 2010
Ethics-oriented learning in environmental education workplaces: An activity theory approach
- Authors: Olvitt, Lausanne L
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370961 , vital:66398 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122874"
- Description: In the context of increasing national and global environmental challenges and their implications for the working world, new ethics and practices are being introduced into workplaces that take better account of socio-ecological relations. Little is understood, however, about the nature of ethics-oriented workplace learning. Drawing on Cultural Historical Activity Theory (CHAT), which enables historically and contextually situated relational perspectives to emerge, this paper explores contradictions in the activity systems of two young environmental education learner-practitioners struggling to engage with the ethical dimensions of their professional work and the professional development course they are studying. The study focuses in particular on the environmental values and ethics component of their course – a year-long Learnership in Environmental Education, Training and Development Practices (EETDP). The paper reflects how tensions and contradictions within and between the interacting activity systems of the workplace, the course, and its regulating qualifications authority influence the teaching and learning of the environmental ethics component of the course. Ethics-oriented teaching and learning processes are found to be strongly influenced by the ‘rules’ and ‘mediating tools’ of these interacting systems, but these are often at odds with the ethical perspectives, socio-cultural context and skills of the ‘subject’ and ‘community’. These systemic contradictions can be more fully understood when their cultural and historical origins are made explicit. The analytical process has led to a more nuanced understanding of ethics-oriented teaching and learning in a workplace-based course, and has revealed several areas needing more careful research (particularly the area of environmental discourses) and the explicit and implicit language of ethics.
- Full Text:
- Date Issued: 2010
- Authors: Olvitt, Lausanne L
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370961 , vital:66398 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122874"
- Description: In the context of increasing national and global environmental challenges and their implications for the working world, new ethics and practices are being introduced into workplaces that take better account of socio-ecological relations. Little is understood, however, about the nature of ethics-oriented workplace learning. Drawing on Cultural Historical Activity Theory (CHAT), which enables historically and contextually situated relational perspectives to emerge, this paper explores contradictions in the activity systems of two young environmental education learner-practitioners struggling to engage with the ethical dimensions of their professional work and the professional development course they are studying. The study focuses in particular on the environmental values and ethics component of their course – a year-long Learnership in Environmental Education, Training and Development Practices (EETDP). The paper reflects how tensions and contradictions within and between the interacting activity systems of the workplace, the course, and its regulating qualifications authority influence the teaching and learning of the environmental ethics component of the course. Ethics-oriented teaching and learning processes are found to be strongly influenced by the ‘rules’ and ‘mediating tools’ of these interacting systems, but these are often at odds with the ethical perspectives, socio-cultural context and skills of the ‘subject’ and ‘community’. These systemic contradictions can be more fully understood when their cultural and historical origins are made explicit. The analytical process has led to a more nuanced understanding of ethics-oriented teaching and learning in a workplace-based course, and has revealed several areas needing more careful research (particularly the area of environmental discourses) and the explicit and implicit language of ethics.
- Full Text:
- Date Issued: 2010
Evaluation of the impact of financial fraud and corruption on the sustainable development of selected municipalities in South Africa
- Okubena, Olumuyiwa Olamilekan
- Authors: Okubena, Olumuyiwa Olamilekan
- Date: 2010-12
- Subjects: Sustainable development -- South Africa , Fraud -- South Africa -- Eastern Cape , Municipal services -- South Africa -- Eastern Cape
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/25569 , vital:64335
- Description: This thesis explored the pernicious effects of financial fraud and corruption and the importance of the rule of law, transparency and accountability of public sector. These critical conditions serve as the foundation for the effective and efficient governance and the economic growth of a nation, especially through utilizing the opportunities provided by globalization through increased investment and trade. The thesis looks at the importance of upholding the rule of law and fostering transparency and accountability in the public sector in combating financial fraud and corruption, particularly as components of effective national strategies. The rule of law, transparency and accountability in the public sector serve not only as means to counter financial fraud and corruption but also as fundamental conditions of effective governance. It was discovered that financial fraud and corruption is a complex phenomenon, present in all countries. Its causes are engendered by conditions of underdevelopment. Hence, its effects hinder and impede the development process itself. It was also confirmed that financial fraud and corruption are co-determined by many other factors, including cultural and moral values. The motivation to remain honest may be weakened by low public official’s salaries, promotion of personnel unconnected to performance, dysfunctional government budgets, loss of organizational purpose, bad example by chief official’s and political leaders, or long established patron-client relationships, in which the sharing of bribes or the exchange of favors has become entrenched. Financial fraud and corruption can be highly concentrated at the top of a political system and associated with political power, or broadly based at lower levels in the system, associated with administrative processes and discretionary powers. Hence, bribes can be blatant or subtle and take many different forms, including cash payments, job offers, scholarships, foreign trips or political and other favors. Furthermore, the development of sustainable local authorities however is an ambitious issue that requires local authorities to focus on the improvement of the quality of life of present and future communities without depleting the natural resources at their disposal. For sustainable and equitable development, this study espouses on the far-reaching implications for local authorities through multiple regression analysis due to various economic, social and institutional challenges that have to be taken into consideration when a process to promote sustainable development is considered. To comprehensively actualize the implications of financial fraud and corruption on the sustainable development of local authorities, a multistage cluster sampling, a form of probability sampling technique was adopted. Semantically, to identify the research paradigms suitable for this study, a hybrid approach to research design was used (quantitative and qualitative). This however enables the impact of financial fraud and corruption on the sustainable development of selected local authorities in South Africa to be ascertained. Moreover, the study explores the circumstances and implications surrounding financial fraud and corruption in the local authorities in South-Africa. Financial fraud and corruption tends to emerge when an organization or a public official has monopoly power over a good or service that generates rent, has the discretionary power to decide who will receive it, and is not accountable. Financial fraud and corruption’s roots are grounded in a country’s social and cultural history, political and economic development, bureaucratic traditions and policies. This study also identifies that, direct and indirect factors promote financial fraud and corruption. Direct factors include regulations and authorizations, taxation, spending decisions, provision of goods and services at below market prices, and financing political parties. On the other hand, quality of bureaucracy, level of public sector wages, penalty systems, institutional controls, and transparency of rules, laws, and processes are the indirect factors that promote financial fraud and corruption. Financial fraud and corruption is a symptom of deep institutional weaknesses that leads to inefficient economic, social, and political outcomes. It reduces economic growth, retards long-term foreign and domestic investments, enhances inflation, depreciates national currency, reduces expenditures for education and health, increases military expenditures, misallocates talent to rent-seeking activities, pushes firms underground, distorts markets and the allocation of resources, increases income inequality and poverty, reduces tax revenue, increases child and infant mortality rates, distorts the fundamental role of the government (on enforcement of contracts and protection of property. Nonetheless, this study concludes that financial fraud and corruption impedes economic efficiency which could slow or shrink economic growth. This will adversely affect all income classes, especially the most vulnerable, the poor. The effect of financial fraud and corruption through investment expenditure on health and education critical to sustainable development was noted in this study. In practice, the distinction between governance and government and the resultant mechanisms directed at local sustainable development do not seem to be clear. Hence, lack of understanding of the meaning of sustainability and governance for local development is still lacking. Recommendations on the serious consequences of financial fraud and corruption on economic growth, capital formation, poverty and inequality to foster and address sustainable development are also provided in this study. , Thesis (PhD) -- Faculty of Management and Commerce, 2010
- Full Text:
- Date Issued: 2010-12
- Authors: Okubena, Olumuyiwa Olamilekan
- Date: 2010-12
- Subjects: Sustainable development -- South Africa , Fraud -- South Africa -- Eastern Cape , Municipal services -- South Africa -- Eastern Cape
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/25569 , vital:64335
- Description: This thesis explored the pernicious effects of financial fraud and corruption and the importance of the rule of law, transparency and accountability of public sector. These critical conditions serve as the foundation for the effective and efficient governance and the economic growth of a nation, especially through utilizing the opportunities provided by globalization through increased investment and trade. The thesis looks at the importance of upholding the rule of law and fostering transparency and accountability in the public sector in combating financial fraud and corruption, particularly as components of effective national strategies. The rule of law, transparency and accountability in the public sector serve not only as means to counter financial fraud and corruption but also as fundamental conditions of effective governance. It was discovered that financial fraud and corruption is a complex phenomenon, present in all countries. Its causes are engendered by conditions of underdevelopment. Hence, its effects hinder and impede the development process itself. It was also confirmed that financial fraud and corruption are co-determined by many other factors, including cultural and moral values. The motivation to remain honest may be weakened by low public official’s salaries, promotion of personnel unconnected to performance, dysfunctional government budgets, loss of organizational purpose, bad example by chief official’s and political leaders, or long established patron-client relationships, in which the sharing of bribes or the exchange of favors has become entrenched. Financial fraud and corruption can be highly concentrated at the top of a political system and associated with political power, or broadly based at lower levels in the system, associated with administrative processes and discretionary powers. Hence, bribes can be blatant or subtle and take many different forms, including cash payments, job offers, scholarships, foreign trips or political and other favors. Furthermore, the development of sustainable local authorities however is an ambitious issue that requires local authorities to focus on the improvement of the quality of life of present and future communities without depleting the natural resources at their disposal. For sustainable and equitable development, this study espouses on the far-reaching implications for local authorities through multiple regression analysis due to various economic, social and institutional challenges that have to be taken into consideration when a process to promote sustainable development is considered. To comprehensively actualize the implications of financial fraud and corruption on the sustainable development of local authorities, a multistage cluster sampling, a form of probability sampling technique was adopted. Semantically, to identify the research paradigms suitable for this study, a hybrid approach to research design was used (quantitative and qualitative). This however enables the impact of financial fraud and corruption on the sustainable development of selected local authorities in South Africa to be ascertained. Moreover, the study explores the circumstances and implications surrounding financial fraud and corruption in the local authorities in South-Africa. Financial fraud and corruption tends to emerge when an organization or a public official has monopoly power over a good or service that generates rent, has the discretionary power to decide who will receive it, and is not accountable. Financial fraud and corruption’s roots are grounded in a country’s social and cultural history, political and economic development, bureaucratic traditions and policies. This study also identifies that, direct and indirect factors promote financial fraud and corruption. Direct factors include regulations and authorizations, taxation, spending decisions, provision of goods and services at below market prices, and financing political parties. On the other hand, quality of bureaucracy, level of public sector wages, penalty systems, institutional controls, and transparency of rules, laws, and processes are the indirect factors that promote financial fraud and corruption. Financial fraud and corruption is a symptom of deep institutional weaknesses that leads to inefficient economic, social, and political outcomes. It reduces economic growth, retards long-term foreign and domestic investments, enhances inflation, depreciates national currency, reduces expenditures for education and health, increases military expenditures, misallocates talent to rent-seeking activities, pushes firms underground, distorts markets and the allocation of resources, increases income inequality and poverty, reduces tax revenue, increases child and infant mortality rates, distorts the fundamental role of the government (on enforcement of contracts and protection of property. Nonetheless, this study concludes that financial fraud and corruption impedes economic efficiency which could slow or shrink economic growth. This will adversely affect all income classes, especially the most vulnerable, the poor. The effect of financial fraud and corruption through investment expenditure on health and education critical to sustainable development was noted in this study. In practice, the distinction between governance and government and the resultant mechanisms directed at local sustainable development do not seem to be clear. Hence, lack of understanding of the meaning of sustainability and governance for local development is still lacking. Recommendations on the serious consequences of financial fraud and corruption on economic growth, capital formation, poverty and inequality to foster and address sustainable development are also provided in this study. , Thesis (PhD) -- Faculty of Management and Commerce, 2010
- Full Text:
- Date Issued: 2010-12
Extending Java’s communication mechanisms for multicore processors
- Authors: Wells, George C
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430526 , vital:72697 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfdoi=4068ed60c317e81dc70288cf36ff586dc057233f
- Description: With the current trend towards the increased use of multicore proces-sors, there is a growing need for simple, efficient parallel programming mechanisms. While Java has good support for multithreaded and dis-tributed application development, our research into tuple-space systems for multicore processors highlighted a gap in the concurrency facilities available in Java. This arises in the context of independent applications (running in separate virtual machines) that need to synchronise their ac-tivities or communicate with each other. There are several possible solu-tions to this problem, ranging from extensions to the language and/or runtime environment through to the use of distributed programming methods. Using the latter introduces considerable performance over-heads, and so we explored the use of the Java Native Interface in order to take advantage of the interprocess communication (IPC) facilities pro-vided by the underlying operating system. The analysis and comparison of the performance of the standard approaches and our prototype library suggest that there are real benefits to be gained by alternative ap-proaches to the provision of IPC mechanisms for independent Java programs executing on multicore systems. We hope that these findings will spur further investigation of this problem and other possible solu-tions.
- Full Text:
- Date Issued: 2010
- Authors: Wells, George C
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430526 , vital:72697 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfdoi=4068ed60c317e81dc70288cf36ff586dc057233f
- Description: With the current trend towards the increased use of multicore proces-sors, there is a growing need for simple, efficient parallel programming mechanisms. While Java has good support for multithreaded and dis-tributed application development, our research into tuple-space systems for multicore processors highlighted a gap in the concurrency facilities available in Java. This arises in the context of independent applications (running in separate virtual machines) that need to synchronise their ac-tivities or communicate with each other. There are several possible solu-tions to this problem, ranging from extensions to the language and/or runtime environment through to the use of distributed programming methods. Using the latter introduces considerable performance over-heads, and so we explored the use of the Java Native Interface in order to take advantage of the interprocess communication (IPC) facilities pro-vided by the underlying operating system. The analysis and comparison of the performance of the standard approaches and our prototype library suggest that there are real benefits to be gained by alternative ap-proaches to the provision of IPC mechanisms for independent Java programs executing on multicore systems. We hope that these findings will spur further investigation of this problem and other possible solu-tions.
- Full Text:
- Date Issued: 2010
Fabrication and characterization of single walled carbon nanotubes-iron phthalocyanine nano-composite
- Akinbulu, Isaac A, Nyokong, Tebello
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262622 , vital:53537 , xlink:href="https://doi.org/10.1039/C0NJ00395F"
- Description: Nano-composite of single walled carbon nanotubes (SWCNTs) and iron phthalocyanine, peripherally tetra-substituted with diethylaminoethanethiol (complex 2), was fabricated and characterized by infra red (IR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM technique gave a convincing image of the nano-composite. Self-assembled monolayer (SAM) film of the composite (SWCNT-2-SAM) was formed on gold electrode. Its surface properties were investigated, relative to that of 2-SAM film, by cyclic voltammetry and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry, using [Fe(CN)6]3− as redox probe, were used to investigate the dynamics of electron transport in the SWCNT-2-SAM film. Lower charge transfer resistance, RCT, of the SWCNT-2-SAM modified Au electrode, relative to that of the 2-SAM modified Au electrode, was an indication of enhanced electron transport in the presence of SWCNT. The SAM film of the nano-composite showed better electrocatalytic behaviour, relative to that of 2-SAM film, towards the oxidation of the insecticide, carbofuran. The electrode (SWCNT-2-SAM) showed good selectivity for carbofuran, in the presence of diazinon (a non-electroactive interferent) and at lower concentration of the electroactive interferents (chlorpyrifos and dichlorfos).
- Full Text:
- Date Issued: 2010
- Authors: Akinbulu, Isaac A , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262622 , vital:53537 , xlink:href="https://doi.org/10.1039/C0NJ00395F"
- Description: Nano-composite of single walled carbon nanotubes (SWCNTs) and iron phthalocyanine, peripherally tetra-substituted with diethylaminoethanethiol (complex 2), was fabricated and characterized by infra red (IR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM technique gave a convincing image of the nano-composite. Self-assembled monolayer (SAM) film of the composite (SWCNT-2-SAM) was formed on gold electrode. Its surface properties were investigated, relative to that of 2-SAM film, by cyclic voltammetry and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry, using [Fe(CN)6]3− as redox probe, were used to investigate the dynamics of electron transport in the SWCNT-2-SAM film. Lower charge transfer resistance, RCT, of the SWCNT-2-SAM modified Au electrode, relative to that of the 2-SAM modified Au electrode, was an indication of enhanced electron transport in the presence of SWCNT. The SAM film of the nano-composite showed better electrocatalytic behaviour, relative to that of 2-SAM film, towards the oxidation of the insecticide, carbofuran. The electrode (SWCNT-2-SAM) showed good selectivity for carbofuran, in the presence of diazinon (a non-electroactive interferent) and at lower concentration of the electroactive interferents (chlorpyrifos and dichlorfos).
- Full Text:
- Date Issued: 2010
Facile electrocatalytic oxidation of diuron on polymerized nickel hydroxo tetraamino-phthalocyanine modified glassy carbon electrodes
- Mugadza, Tawanda, Nyokong, Tebello
- Authors: Mugadza, Tawanda , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261269 , vital:53379 , xlink:href="https://doi.org/10.1016/j.talanta.2010.02.037"
- Description: The facile electro-oxidation of diuron occurred at a glassy carbon electrode (GCE) modified with polymerized nickel tetraamino-phthalocyanine (NiTAPc), containing O–Ni–O bridges represented as poly-Ni(OH)TAPc-GCE. The oxidation of diuron occurred at a potential which is 60 mV less than that of poly-NiTAPc (without O–Ni–O bridges) and was accompanied by enhanced catalytic currents. The catalytic rate constant and the diffusion constant were found to be 5.91 × 102 mol−1 L s−1 and 6.43 × 10−6 cm2 s−1, respectively. The linear concentration range of diuron was 3.0 × 10−5 to 3.5 × 10−4 mol L−1 with a limit of detection (LOD) of 3.3 × 10−7 mol L−1 (3δ notation) and a sensitivity of 12.9 A mol−1 L cm−2.
- Full Text:
- Date Issued: 2010
- Authors: Mugadza, Tawanda , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261269 , vital:53379 , xlink:href="https://doi.org/10.1016/j.talanta.2010.02.037"
- Description: The facile electro-oxidation of diuron occurred at a glassy carbon electrode (GCE) modified with polymerized nickel tetraamino-phthalocyanine (NiTAPc), containing O–Ni–O bridges represented as poly-Ni(OH)TAPc-GCE. The oxidation of diuron occurred at a potential which is 60 mV less than that of poly-NiTAPc (without O–Ni–O bridges) and was accompanied by enhanced catalytic currents. The catalytic rate constant and the diffusion constant were found to be 5.91 × 102 mol−1 L s−1 and 6.43 × 10−6 cm2 s−1, respectively. The linear concentration range of diuron was 3.0 × 10−5 to 3.5 × 10−4 mol L−1 with a limit of detection (LOD) of 3.3 × 10−7 mol L−1 (3δ notation) and a sensitivity of 12.9 A mol−1 L cm−2.
- Full Text:
- Date Issued: 2010
Factors affecting recapture rates of raggedtooth sharks Carcharias taurus tagged off the east coast of South Africa
- Dicken, Matthew L, Booth, Anthony J, Smale, Malcolm J
- Authors: Dicken, Matthew L , Booth, Anthony J , Smale, Malcolm J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124493 , vital:35618 , https://doi.10.2989/AJMS.2009.31.3.9.997
- Description: Understanding differences in the recapture rate between different tags (A-, B- and C-types), capture methods (rock-and-surf anglers, scientific divers and Natal Sharks Board protection nets) and life-history stages (juvenile and adult) is critical in evaluating the results obtained from cooperative tagging programmes (CTPs). A generalised linear modelling approach, using a log-linear model, was used to determine significant differences in the probability of recapture between these various factors using data from the Oceanographic Research Institute and Port Elizabeth Museum CTPs. Between 1984 and 2004, a total of 3 385 raggedtooth sharks Carcharias taurus was tagged by volunteers from both programmes along the east coast of South Africa. A likelihood ratio test indicated significant differences in the probability of recapture between A- and C-type and B- and C-type tags (p < 0.01), between different capture methods (p < 0.05) and between juvenile and adult sharks (p < 0.01). A comparison of recapture rates between members of the CTPs also indicated a marked variability in the performance of individual taggers. The study highlights important data-quality issues inherent in large CTPs.
- Full Text:
- Date Issued: 2010
- Authors: Dicken, Matthew L , Booth, Anthony J , Smale, Malcolm J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124493 , vital:35618 , https://doi.10.2989/AJMS.2009.31.3.9.997
- Description: Understanding differences in the recapture rate between different tags (A-, B- and C-types), capture methods (rock-and-surf anglers, scientific divers and Natal Sharks Board protection nets) and life-history stages (juvenile and adult) is critical in evaluating the results obtained from cooperative tagging programmes (CTPs). A generalised linear modelling approach, using a log-linear model, was used to determine significant differences in the probability of recapture between these various factors using data from the Oceanographic Research Institute and Port Elizabeth Museum CTPs. Between 1984 and 2004, a total of 3 385 raggedtooth sharks Carcharias taurus was tagged by volunteers from both programmes along the east coast of South Africa. A likelihood ratio test indicated significant differences in the probability of recapture between A- and C-type and B- and C-type tags (p < 0.01), between different capture methods (p < 0.05) and between juvenile and adult sharks (p < 0.01). A comparison of recapture rates between members of the CTPs also indicated a marked variability in the performance of individual taggers. The study highlights important data-quality issues inherent in large CTPs.
- Full Text:
- Date Issued: 2010
Fashionably ethnic
- Authors: Krueger, Anton
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229567 , vital:49688 , xlink:href="https://doi.org/10.1080/1013929X.2010.9678333"
- Description: This essay highlights a shift in South African literature towards ideals of individualism and explores some of the paradoxes inherent in the competing claims of individuality and heritage. The characters created by Greig Coetzee in Happy Natives are examined as examples of identities constructed in terms of tradition, function and indoctrination. The comic potential of these incongruent identity constructions is then elaborated by means of Henri Bergson’s description of the humour arising from an inability to adapt to changing fashions. Ultimately, appeals towards tradition and individuality begin to look like similar proposals.
- Full Text:
- Date Issued: 2010
- Authors: Krueger, Anton
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229567 , vital:49688 , xlink:href="https://doi.org/10.1080/1013929X.2010.9678333"
- Description: This essay highlights a shift in South African literature towards ideals of individualism and explores some of the paradoxes inherent in the competing claims of individuality and heritage. The characters created by Greig Coetzee in Happy Natives are examined as examples of identities constructed in terms of tradition, function and indoctrination. The comic potential of these incongruent identity constructions is then elaborated by means of Henri Bergson’s description of the humour arising from an inability to adapt to changing fashions. Ultimately, appeals towards tradition and individuality begin to look like similar proposals.
- Full Text:
- Date Issued: 2010
Fluorescence quenching and energy transfer in conjugates of quantum dots with zinc and indium tetraamino phthalocyanines
- Britton, Jonathan, Antunes, Edith M, Nyokong, Tebello
- Authors: Britton, Jonathan , Antunes, Edith M , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262638 , vital:53539 , xlink:href="https://doi.org/10.1016/j.jphotochem.2009.12.013"
- Description: CdTe QDs capped with mercapto propionic acid (MPA) and thioglycolic acid (TGA) were covalently linked to zinc and indium tetraaminophthalocyanines (TAPcs) using N-ethyl-N(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS) as the coupling agents. The results presented give evidence in favour of formation of an amide bond between the MTAPc and CdTe QDs. Both the linked ZnTAPc–QD complexes and the mixture of QDs and ZnTAPc (without chemical linking) showed Förster resonance energy transfer (FRET), whereas the QD interactions with InTAPc yielded no evidence of FRET. Both MTAPcs quenched the QDs emission, with quenching constants of the order of 103–104 M−1. High energy transfer efficiencies were obtained in some cases (as high as 93%), due to the low donor to acceptor distances.
- Full Text:
- Date Issued: 2010
- Authors: Britton, Jonathan , Antunes, Edith M , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262638 , vital:53539 , xlink:href="https://doi.org/10.1016/j.jphotochem.2009.12.013"
- Description: CdTe QDs capped with mercapto propionic acid (MPA) and thioglycolic acid (TGA) were covalently linked to zinc and indium tetraaminophthalocyanines (TAPcs) using N-ethyl-N(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS) as the coupling agents. The results presented give evidence in favour of formation of an amide bond between the MTAPc and CdTe QDs. Both the linked ZnTAPc–QD complexes and the mixture of QDs and ZnTAPc (without chemical linking) showed Förster resonance energy transfer (FRET), whereas the QD interactions with InTAPc yielded no evidence of FRET. Both MTAPcs quenched the QDs emission, with quenching constants of the order of 103–104 M−1. High energy transfer efficiencies were obtained in some cases (as high as 93%), due to the low donor to acceptor distances.
- Full Text:
- Date Issued: 2010
Framework for local government to implement integrated water resource management linked to water service delivery
- Haigh, Eliria H, Fox, Helen E, Davies-Coleman, H D
- Authors: Haigh, Eliria H , Fox, Helen E , Davies-Coleman, H D
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7097 , http://hdl.handle.net/10962/d1012440
- Description: The Water Services Act (No. 8 of 1997) of South Africa states that water service delivery is the responsibility of local government as Water Services Authorities. The principal legal responsibility is to complete a Water Services Development Plan (WSDP) every 5 years with annual review. The WSDP encapsulates all the responsibilities and tasks required in water service delivery. However, it does not spell out local government’s role in water resource protection or its responsibilities as far as integrated water resource management is concerned. It is well known in South Africa that there is a challenging level of inadequate capacity in technical and administrative skills in local government to adequately fulfil water service delivery. This paper highlights the consequences of this incapacity for municipalities and their difficulties in fulfilling their responsibilities as service providers. A framework is provided within which improvements can be brought about, with guidance on how to engage in the practice of integrated water resource management (IWRM) in the context of the legal framework for water services. The additional tasks and changes required to practise IWRM are set in the context of the WSDP. The framework provides a guide for a municipality to first accomplish an adequate WSDP, and then to gradually implement IWRM. A discussion on the skills needed to accomplish, firstly, a comprehensive WSDP, and secondly, IWRM, is included.
- Full Text:
- Date Issued: 2010
- Authors: Haigh, Eliria H , Fox, Helen E , Davies-Coleman, H D
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7097 , http://hdl.handle.net/10962/d1012440
- Description: The Water Services Act (No. 8 of 1997) of South Africa states that water service delivery is the responsibility of local government as Water Services Authorities. The principal legal responsibility is to complete a Water Services Development Plan (WSDP) every 5 years with annual review. The WSDP encapsulates all the responsibilities and tasks required in water service delivery. However, it does not spell out local government’s role in water resource protection or its responsibilities as far as integrated water resource management is concerned. It is well known in South Africa that there is a challenging level of inadequate capacity in technical and administrative skills in local government to adequately fulfil water service delivery. This paper highlights the consequences of this incapacity for municipalities and their difficulties in fulfilling their responsibilities as service providers. A framework is provided within which improvements can be brought about, with guidance on how to engage in the practice of integrated water resource management (IWRM) in the context of the legal framework for water services. The additional tasks and changes required to practise IWRM are set in the context of the WSDP. The framework provides a guide for a municipality to first accomplish an adequate WSDP, and then to gradually implement IWRM. A discussion on the skills needed to accomplish, firstly, a comprehensive WSDP, and secondly, IWRM, is included.
- Full Text:
- Date Issued: 2010
Gaming culture: what lessons for pedagogy in South Africa?
- Kaschula, Russell H, Mostert, Andre
- Authors: Kaschula, Russell H , Mostert, Andre
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175189 , vital:42551 , https://hdl.handle.net/10520/EJC30895
- Description: Gaming culture is becoming increasingly ubiquitous. Whereas before it was the reserve of those who were prepared to invest in the latest gaming hardware, increasingly powerful entry level machines coupled with more powerful mobile technologies are impacting on how young learners and students assimilate information. This evolving characteristic exhibited by the learners across South Africa must generate a serious reflection of education and training methodologies. Historically, education structures have been slow to embrace the changes that are imperative if the products of the process are to be adequately prepared for the future that faces them. One of the most telling realities of the modern era, or the planetary phase as it is now being tagged, is rapid change. The question that all educators need to ask is 'how is my pedagogic approach evolving'?.
- Full Text:
- Date Issued: 2010
- Authors: Kaschula, Russell H , Mostert, Andre
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175189 , vital:42551 , https://hdl.handle.net/10520/EJC30895
- Description: Gaming culture is becoming increasingly ubiquitous. Whereas before it was the reserve of those who were prepared to invest in the latest gaming hardware, increasingly powerful entry level machines coupled with more powerful mobile technologies are impacting on how young learners and students assimilate information. This evolving characteristic exhibited by the learners across South Africa must generate a serious reflection of education and training methodologies. Historically, education structures have been slow to embrace the changes that are imperative if the products of the process are to be adequately prepared for the future that faces them. One of the most telling realities of the modern era, or the planetary phase as it is now being tagged, is rapid change. The question that all educators need to ask is 'how is my pedagogic approach evolving'?.
- Full Text:
- Date Issued: 2010