Photophysical and photochemical properties of Ni (II), Pd (II) and Pt (II) aryloxo and alkylthio derivatised phthalocyanine
- Ogunbayo, Taofeek B, Nyokong, Tebello
- Authors: Ogunbayo, Taofeek B , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261511 , vital:53416 , xlink:href="https://doi.org/10.1016/j.molstruc.2010.03.047"
- Description: Several aryloxo (3a–6a and 3b–6b) and alkylthio (3d and 3e) derivatised phthalocyanines were synthesized, characterized and the photochemical and photophysical properties investigated along with those of the previously reported (3c–5c, 4d, 5d, 4e and 5e) complexes. The effects of open-shell metals (Ni(II), Pd(II) and Pt(II)) on the photophysical and photochemical properties of the phthalocyanine ligands were investigated. Palladium and platinum improved the triplet quantum yield and singlet oxygen generation capacities of the unmetalated phthalocyanines (3a–3e) making their complexes candidates for further investigation in photocatalysis. Ni(II)Pc analogues gave poor results compared with their Pd(II)Pc and Pt(II)Pc counterparts.
- Full Text:
- Date Issued: 2010
- Authors: Ogunbayo, Taofeek B , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261511 , vital:53416 , xlink:href="https://doi.org/10.1016/j.molstruc.2010.03.047"
- Description: Several aryloxo (3a–6a and 3b–6b) and alkylthio (3d and 3e) derivatised phthalocyanines were synthesized, characterized and the photochemical and photophysical properties investigated along with those of the previously reported (3c–5c, 4d, 5d, 4e and 5e) complexes. The effects of open-shell metals (Ni(II), Pd(II) and Pt(II)) on the photophysical and photochemical properties of the phthalocyanine ligands were investigated. Palladium and platinum improved the triplet quantum yield and singlet oxygen generation capacities of the unmetalated phthalocyanines (3a–3e) making their complexes candidates for further investigation in photocatalysis. Ni(II)Pc analogues gave poor results compared with their Pd(II)Pc and Pt(II)Pc counterparts.
- Full Text:
- Date Issued: 2010
Photophysical properties of newly synthesized fluorinated zinc phthalocyanines in the presence of CdTe quantum dots and the accompanying energy transfer processes
- Erdoğmuş, Ali, Moeno, Sharon, Litwinski, Christian, Nyokong, Tebello
- Authors: Erdoğmuş, Ali , Moeno, Sharon , Litwinski, Christian , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262671 , vital:53543 , xlink:href="https://doi.org/10.1016/j.jphotochem.2009.12.014"
- Description: The photophysical properties of two newly synthesized phthalocyanines (Pcs) were studied in the presence and the absence of 3-mercaptopropionic acid (MPA) capped quantum dots (QDs). Energy transfer processes resulting from the combination of QDs and the Pcs: 4-(tetrakis-5-(trifluoromethyl)-2-mercaptopyridinephthalocyaninato)zinc(II) (TtfmMPyZnPc, 3) and 4-(tetrakis-5-(trifluoromethyl)-2-pyridyloxyphthalocyaninato) zinc(II) (TtfmPyZnPc, 4) were also studied. The photophysical properties of the Pcs in the presence of QDs were enhanced and Förster resonance energy transfer (FRET) was observed with the phthalocyanines used. The efficiency of FRET between the QDs and TtfmMPyZnPc and TtfmPyZnPc was found to be 0.31% and 0.45% in DMSO and 0.24% and 0.32% in pyridine, respectively. The triplet state quantum yields for TtfmMPyZnPc and TtfmPyZnPc were found to be 0.86 and 0.74 in DMSO and 0.83 and 0.76 in pyridine.
- Full Text:
- Date Issued: 2010
- Authors: Erdoğmuş, Ali , Moeno, Sharon , Litwinski, Christian , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262671 , vital:53543 , xlink:href="https://doi.org/10.1016/j.jphotochem.2009.12.014"
- Description: The photophysical properties of two newly synthesized phthalocyanines (Pcs) were studied in the presence and the absence of 3-mercaptopropionic acid (MPA) capped quantum dots (QDs). Energy transfer processes resulting from the combination of QDs and the Pcs: 4-(tetrakis-5-(trifluoromethyl)-2-mercaptopyridinephthalocyaninato)zinc(II) (TtfmMPyZnPc, 3) and 4-(tetrakis-5-(trifluoromethyl)-2-pyridyloxyphthalocyaninato) zinc(II) (TtfmPyZnPc, 4) were also studied. The photophysical properties of the Pcs in the presence of QDs were enhanced and Förster resonance energy transfer (FRET) was observed with the phthalocyanines used. The efficiency of FRET between the QDs and TtfmMPyZnPc and TtfmPyZnPc was found to be 0.31% and 0.45% in DMSO and 0.24% and 0.32% in pyridine, respectively. The triplet state quantum yields for TtfmMPyZnPc and TtfmPyZnPc were found to be 0.86 and 0.74 in DMSO and 0.83 and 0.76 in pyridine.
- Full Text:
- Date Issued: 2010
Photophysical study of a covalently linked quantum dot–low symmetry phthalocyanine conjugate
- Chidawanyika, Wadzanai J U, Litwinski, Christian, Antunes, Edith M, Nyokong, Tebello
- Authors: Chidawanyika, Wadzanai J U , Litwinski, Christian , Antunes, Edith M , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261641 , vital:53430 , xlink:href="https://doi.org/10.1016/j.jphotochem.2010.03.008"
- Description: The linkage of a low symmetry phthalocyanine, ZnttbIPc to mercaptopropionic acid (MPA) capped CdTe quantum dots has been achieved using a coupling agent, dicyclohexylcarbodiimide (DCC), to facilitate formation of an amide bond. UV–vis, Raman and IR spectroscopic studies on the linked (QD:ZnttbIPc-linked) conjugate suggest the reaction was a success. Förster resonance energy transfer (FRET) resulted in stimulated emission of ZnttbIPc in both the linked (QD:ZnttbIPc-linked) and mixed (QD:ZnttbIPc-mixed) conjugates. The linked complex (QD:ZnttbIPc-linked) gave the largest FRET efficiency hence showing the advantages of covalent linking. Photophysicochemical properties of the phthalocyanine were improved in the presence of the QDs i.e. for QD:ZnttbIPc-mixed. Fluorescence lifetimes of QDs were unchanged in QD:ZnttbIPc-mixed and decreased for QD:ZnttbIPc-linked.
- Full Text:
- Date Issued: 2010
- Authors: Chidawanyika, Wadzanai J U , Litwinski, Christian , Antunes, Edith M , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261641 , vital:53430 , xlink:href="https://doi.org/10.1016/j.jphotochem.2010.03.008"
- Description: The linkage of a low symmetry phthalocyanine, ZnttbIPc to mercaptopropionic acid (MPA) capped CdTe quantum dots has been achieved using a coupling agent, dicyclohexylcarbodiimide (DCC), to facilitate formation of an amide bond. UV–vis, Raman and IR spectroscopic studies on the linked (QD:ZnttbIPc-linked) conjugate suggest the reaction was a success. Förster resonance energy transfer (FRET) resulted in stimulated emission of ZnttbIPc in both the linked (QD:ZnttbIPc-linked) and mixed (QD:ZnttbIPc-mixed) conjugates. The linked complex (QD:ZnttbIPc-linked) gave the largest FRET efficiency hence showing the advantages of covalent linking. Photophysicochemical properties of the phthalocyanine were improved in the presence of the QDs i.e. for QD:ZnttbIPc-mixed. Fluorescence lifetimes of QDs were unchanged in QD:ZnttbIPc-mixed and decreased for QD:ZnttbIPc-linked.
- Full Text:
- Date Issued: 2010
Population structure and growth of polydorid polychaetes that infest cultured abalone Haliotis midae
- Simon, Carol A, Booth, Anthony J
- Authors: Simon, Carol A , Booth, Anthony J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125731 , vital:35812 , https://doi.10.2989/AJMS.2007.29.3.16.346
- Description: Polydorid polychaetes can infest cultured abalone thereby reducing productivity. In order to effectively control these pests, their reproductive biology must be understood. The population dynamics and reproduction of polydorids infesting abalone Haliotis midae from two farms in South Africa is described using a length-based, age-structured model. Shells were infested mainly by introduced Boccardia proboscidea. Polydora hoplura and Dipolydora capensis were also present but in numbers too few to identify factors influencing infestation. At both farms, B. proboscidea lived for a minimum of 12 months. Growth rate, size at maturity, maximum size, infestation intensity, recruitment, percentage of the population brooding and mortality appear to be affected by abalone feeding regime and water temperature, and these factors need to be considered in controlling infestation. Brooders and recruits were present throughout the year, but increased significantly during mid- to late winter/early spring when water temperature and day length increased. Treatment measures should therefore be implemented throughout the year but with increased effort when water temperature increases.
- Full Text:
- Date Issued: 2010
Population structure and growth of polydorid polychaetes that infest cultured abalone Haliotis midae
- Authors: Simon, Carol A , Booth, Anthony J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125731 , vital:35812 , https://doi.10.2989/AJMS.2007.29.3.16.346
- Description: Polydorid polychaetes can infest cultured abalone thereby reducing productivity. In order to effectively control these pests, their reproductive biology must be understood. The population dynamics and reproduction of polydorids infesting abalone Haliotis midae from two farms in South Africa is described using a length-based, age-structured model. Shells were infested mainly by introduced Boccardia proboscidea. Polydora hoplura and Dipolydora capensis were also present but in numbers too few to identify factors influencing infestation. At both farms, B. proboscidea lived for a minimum of 12 months. Growth rate, size at maturity, maximum size, infestation intensity, recruitment, percentage of the population brooding and mortality appear to be affected by abalone feeding regime and water temperature, and these factors need to be considered in controlling infestation. Brooders and recruits were present throughout the year, but increased significantly during mid- to late winter/early spring when water temperature and day length increased. Treatment measures should therefore be implemented throughout the year but with increased effort when water temperature increases.
- Full Text:
- Date Issued: 2010
Probing electrochemical and electrocatalytic properties of cobalt (II) and manganese (III) octakis (hexylthio) phthalocyanine as self-assembled monolayers
- Mashazi, Philani N, Antunes, Edith M, Nyokong, Tebello
- Authors: Mashazi, Philani N , Antunes, Edith M , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249115 , vital:51779 , xlink:href="https://doi.org/10.1142/S108842461000277X"
- Description: New peripherally (β) and non-peripherally (α) substituted metal octakis(hexylthio)phthalocyanines (β- and α-MOcHexTPc) containing cobalt and manganese as metal centers were synthesized. Their characterization using electrochemical methods showed that these complexes exhibit several redox processes at E1/2 (mV vs. Ag∣AgCl) = 380 (212) (I), 1140 (864) (II), -450 (-460) (III) and -1170 (-1304) (IV) for β- (α-) CoOcHexTPc. These redox processes were assigned to CoIIIPc-2/CoIIPc-2 (I), CoIIIPc-1/CoIIIPc-2 (II), CoIIPc-2/CoIPc-2 (III) and CoIPc-2/CoIPc-3 (IV) using spectroelectrochemistry. For the β- (α-) MnOcHexTPc complex the redox processes were observed at E1/2 (mV vs. Ag∣AgCl) = -20 (5) (I), -530 (-640) (II) and -1270 (-1380) (III) and were assigned to MnIIIPc-2/MnIIPc-2 (I), MnIIPc-2/MnIIPc-3 (II) and MnIIPc-3/MnIIPc-4 (III). Electrochemical and microscopic characterization using AFM showed that the self-assembled monolayers (SAMs) are formed on the gold surface using these complexes. The electrochemical characterization showed the blocking of the Faradaic processes at SAMs modified electrodes and these reactions are well-known to easily occur at unmodified gold electrodes. The AFM characterization showed an increase in surface roughness upon modifying the gold surface with MOcHexTPc SAMs, further confirming the presence of the monolayers on the gold surface. The MOcHexTPc SAMs were investigated for their electrocatalytic application towards H2O2 detection. The MOcHexTPc SAMs modified gold electrodes gave excellent currents for H2O2 detection. The observed H2O2 electrocatalytic reduction peaks were close to where the metal redox processes from the MOcHexTPc occurred, showing the involvement of the metal redox processes in the electrocatalytic mediation reactions.
- Full Text:
- Date Issued: 2010
- Authors: Mashazi, Philani N , Antunes, Edith M , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249115 , vital:51779 , xlink:href="https://doi.org/10.1142/S108842461000277X"
- Description: New peripherally (β) and non-peripherally (α) substituted metal octakis(hexylthio)phthalocyanines (β- and α-MOcHexTPc) containing cobalt and manganese as metal centers were synthesized. Their characterization using electrochemical methods showed that these complexes exhibit several redox processes at E1/2 (mV vs. Ag∣AgCl) = 380 (212) (I), 1140 (864) (II), -450 (-460) (III) and -1170 (-1304) (IV) for β- (α-) CoOcHexTPc. These redox processes were assigned to CoIIIPc-2/CoIIPc-2 (I), CoIIIPc-1/CoIIIPc-2 (II), CoIIPc-2/CoIPc-2 (III) and CoIPc-2/CoIPc-3 (IV) using spectroelectrochemistry. For the β- (α-) MnOcHexTPc complex the redox processes were observed at E1/2 (mV vs. Ag∣AgCl) = -20 (5) (I), -530 (-640) (II) and -1270 (-1380) (III) and were assigned to MnIIIPc-2/MnIIPc-2 (I), MnIIPc-2/MnIIPc-3 (II) and MnIIPc-3/MnIIPc-4 (III). Electrochemical and microscopic characterization using AFM showed that the self-assembled monolayers (SAMs) are formed on the gold surface using these complexes. The electrochemical characterization showed the blocking of the Faradaic processes at SAMs modified electrodes and these reactions are well-known to easily occur at unmodified gold electrodes. The AFM characterization showed an increase in surface roughness upon modifying the gold surface with MOcHexTPc SAMs, further confirming the presence of the monolayers on the gold surface. The MOcHexTPc SAMs were investigated for their electrocatalytic application towards H2O2 detection. The MOcHexTPc SAMs modified gold electrodes gave excellent currents for H2O2 detection. The observed H2O2 electrocatalytic reduction peaks were close to where the metal redox processes from the MOcHexTPc occurred, showing the involvement of the metal redox processes in the electrocatalytic mediation reactions.
- Full Text:
- Date Issued: 2010
Production of and trade in African indigenous vegetables in the urban and peri-urban areas of Durban, South Africa
- Shackleton, Charlie M, Paumgartner, Fiona, Mthembu, Thami, Ernst, Lisa, Pasquini, Margaret W, Pichop, Germain
- Authors: Shackleton, Charlie M , Paumgartner, Fiona , Mthembu, Thami , Ernst, Lisa , Pasquini, Margaret W , Pichop, Germain
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181134 , vital:43701 , xlink:href="https://doi.org/10.1080/0376835X.2010.498937"
- Description: This paper reports on the farming and trade of lesser known crops, here termed African indigenous vegetables (AIVs), in the Durban metropole. Most households grow AIVs, and collect them from the wild, primarily for home consumption. Modal income from sale was approximately R30 per month per farmer, most of whom were middle-aged to elderly females, with limited education, who had been cultivating AIVs here for many years. The main constraints to greater sales were deemed to be low market demand and adverse climate. The commonest AIVs grown were pumpkin leaves, taro and amaranth. Although most farmers sold very little, there is a thriving retail trade in AIVs. Generally, retailers were females, but younger and more educated than the farmers. The majority viewed retailing as a full-time occupation. Modal income for retailers was R450 per month, but included non-AIV produce. Most of the traders thought there was insufficient market demand for AIVs.
- Full Text:
- Date Issued: 2010
- Authors: Shackleton, Charlie M , Paumgartner, Fiona , Mthembu, Thami , Ernst, Lisa , Pasquini, Margaret W , Pichop, Germain
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181134 , vital:43701 , xlink:href="https://doi.org/10.1080/0376835X.2010.498937"
- Description: This paper reports on the farming and trade of lesser known crops, here termed African indigenous vegetables (AIVs), in the Durban metropole. Most households grow AIVs, and collect them from the wild, primarily for home consumption. Modal income from sale was approximately R30 per month per farmer, most of whom were middle-aged to elderly females, with limited education, who had been cultivating AIVs here for many years. The main constraints to greater sales were deemed to be low market demand and adverse climate. The commonest AIVs grown were pumpkin leaves, taro and amaranth. Although most farmers sold very little, there is a thriving retail trade in AIVs. Generally, retailers were females, but younger and more educated than the farmers. The majority viewed retailing as a full-time occupation. Modal income for retailers was R450 per month, but included non-AIV produce. Most of the traders thought there was insufficient market demand for AIVs.
- Full Text:
- Date Issued: 2010
Promoting entrepreneurship in agriculture in the Eastern Cape:
- Antrobus, Geoffrey G, Fraser, Gavin C G
- Authors: Antrobus, Geoffrey G , Fraser, Gavin C G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143067 , vital:38198 , DOI: 10.1080/03031853.1994.9524779
- Description: Selected cases in developing entrepreneurship in small-scale subsistence and commercial agriculture in the Eastern Cape are examined, including the provision of marketing facilities, the training programme of the Africa Cooperative Action Trust (ACAT) in Ciskei, government sponsored irrigation projects and the farmer support programme. An attempt is made to draw general conclusions about the necessary ingredients for successful entrepreneurship and the formulation of proposals for further promoting entrepreneurship in agriculture in South Africa.
- Full Text:
- Date Issued: 2010
- Authors: Antrobus, Geoffrey G , Fraser, Gavin C G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143067 , vital:38198 , DOI: 10.1080/03031853.1994.9524779
- Description: Selected cases in developing entrepreneurship in small-scale subsistence and commercial agriculture in the Eastern Cape are examined, including the provision of marketing facilities, the training programme of the Africa Cooperative Action Trust (ACAT) in Ciskei, government sponsored irrigation projects and the farmer support programme. An attempt is made to draw general conclusions about the necessary ingredients for successful entrepreneurship and the formulation of proposals for further promoting entrepreneurship in agriculture in South Africa.
- Full Text:
- Date Issued: 2010
Quantifying commercial catch and effort of monkfish Lophius vomerinus and L. vaillanti off Namibia
- Maartens, Lima, Booth, Anthony J
- Authors: Maartens, Lima , Booth, Anthony J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125786 , vital:35817 , https://doi.10.2989/025776101784528999
- Description: Mark-recapture models do not distinguish how ‘‘deaths’’ accrue to marked animals in the population. If animals lose their tags, then recaptures will be fewer than expected and estimates of survival will be underestimated (Arnason and Mills, 1981; McDonald et al., 2003). Similarly, if the non-reporting rate is unknown and assumed to be negligible, as is the case in some tagging studies (e.g. Cliff et al., 1996, for white sharks Carcharodon carcharias), the probability of capture can be underestimated. The effects of both these problems, inherent in cooperative tagging programmes, lead to too few tagged fish being recovered, with a positive bias on the estimation of population size. These effects are most pronounced when capture probability is low and fewer tags are available for recapture (McDonald et al., 2003).
- Full Text:
- Date Issued: 2010
- Authors: Maartens, Lima , Booth, Anthony J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125786 , vital:35817 , https://doi.10.2989/025776101784528999
- Description: Mark-recapture models do not distinguish how ‘‘deaths’’ accrue to marked animals in the population. If animals lose their tags, then recaptures will be fewer than expected and estimates of survival will be underestimated (Arnason and Mills, 1981; McDonald et al., 2003). Similarly, if the non-reporting rate is unknown and assumed to be negligible, as is the case in some tagging studies (e.g. Cliff et al., 1996, for white sharks Carcharodon carcharias), the probability of capture can be underestimated. The effects of both these problems, inherent in cooperative tagging programmes, lead to too few tagged fish being recovered, with a positive bias on the estimation of population size. These effects are most pronounced when capture probability is low and fewer tags are available for recapture (McDonald et al., 2003).
- Full Text:
- Date Issued: 2010
Re-thinking rural development through agriculture
- Matunhu, Jephias (https://orcid.org/0000-0001-8415-5867)
- Authors: Matunhu, Jephias (https://orcid.org/0000-0001-8415-5867)
- Date: 2010
- Subjects: Rural development -- South Africa -- Eastern Cape , Agriculture -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24532 , vital:63067
- Description: This study addresses the problem of abject rural poverty in the post-apartheid South Africa with specific reference to the Amathole Rural District (ARD) in the Eastern Cape Province (the poorest province in the country). Abject poverty is conceptualized as inability to meet the basic human needs such as food, water, shelter and clothes. The study is premised in the revisionist trajectory of rural economic development, which regards agriculture as the ‘engine’ for rural development. The thesis addressed the following issues on rural poverty reduction in the ARD; the efficacy of rural agriculture in rural poverty reduction, value-adding to rural farm produce, support that is required and social factors that may affect the residents’ ability to fight poverty through agriculture? The thesis adopted the concurrent transformative mixed research methodology; and data were collected from a purposive sample of 138 respondents using unstructured interviews and semi-structured questionnaires. Data were collected with the help of research assistance. The study established that the ARD residents were keen to fight abject poverty through rural agriculture but were constrained by the lack of arable land, financial resources, technological support, corruption and HIV/AIDs. In view of the above findings, the thesis concluded that deep collaboration and participation of strategic partners such as government, the rural residents, NGOs and the business sector is essential in the implementation of pro-poor strategies in the ARD. The thesis also called for further research into the following areas that have a direct influence on the efficacy of rural agriculture on the ARD’s development; ICT and development, the rural residents’ attitude towards savings and on the political economy of cooperative ventures in rural agriculture. The thesis also encouraged further research to establish new linkages and roles of the following pertinent partners in ARD’s development; government, the rural residents, NGOs and the business sector. , Thesis (PhD) -- Faculty of Management and Commerce, 2010
- Full Text:
- Date Issued: 2010
- Authors: Matunhu, Jephias (https://orcid.org/0000-0001-8415-5867)
- Date: 2010
- Subjects: Rural development -- South Africa -- Eastern Cape , Agriculture -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24532 , vital:63067
- Description: This study addresses the problem of abject rural poverty in the post-apartheid South Africa with specific reference to the Amathole Rural District (ARD) in the Eastern Cape Province (the poorest province in the country). Abject poverty is conceptualized as inability to meet the basic human needs such as food, water, shelter and clothes. The study is premised in the revisionist trajectory of rural economic development, which regards agriculture as the ‘engine’ for rural development. The thesis addressed the following issues on rural poverty reduction in the ARD; the efficacy of rural agriculture in rural poverty reduction, value-adding to rural farm produce, support that is required and social factors that may affect the residents’ ability to fight poverty through agriculture? The thesis adopted the concurrent transformative mixed research methodology; and data were collected from a purposive sample of 138 respondents using unstructured interviews and semi-structured questionnaires. Data were collected with the help of research assistance. The study established that the ARD residents were keen to fight abject poverty through rural agriculture but were constrained by the lack of arable land, financial resources, technological support, corruption and HIV/AIDs. In view of the above findings, the thesis concluded that deep collaboration and participation of strategic partners such as government, the rural residents, NGOs and the business sector is essential in the implementation of pro-poor strategies in the ARD. The thesis also called for further research into the following areas that have a direct influence on the efficacy of rural agriculture on the ARD’s development; ICT and development, the rural residents’ attitude towards savings and on the political economy of cooperative ventures in rural agriculture. The thesis also encouraged further research to establish new linkages and roles of the following pertinent partners in ARD’s development; government, the rural residents, NGOs and the business sector. , Thesis (PhD) -- Faculty of Management and Commerce, 2010
- Full Text:
- Date Issued: 2010
Reflections of a Mathematician
- Authors: Mishra, S N
- Date: 2010
- Subjects: Mathematics
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/758 , vital:29750
- Description: In this lecture, an attempt is made to convey in a broad sense about mathematics and its applications and the impact it has made outside its own domain. While doing so, we try to dispel the belief (held in certain quarters) that there are two types of mathematics, namely useful mathematics and not so useful mathematics. An attempt is also made to reflect on the role of mathematics in industry along with the challenges of teaching of mathematics in the current environment.
- Full Text:
- Date Issued: 2010
- Authors: Mishra, S N
- Date: 2010
- Subjects: Mathematics
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/758 , vital:29750
- Description: In this lecture, an attempt is made to convey in a broad sense about mathematics and its applications and the impact it has made outside its own domain. While doing so, we try to dispel the belief (held in certain quarters) that there are two types of mathematics, namely useful mathematics and not so useful mathematics. An attempt is also made to reflect on the role of mathematics in industry along with the challenges of teaching of mathematics in the current environment.
- Full Text:
- Date Issued: 2010
Regional patterns in moult and sexual dimorphism of adult Southern Red Bishops Euplectes orix in southern Africa
- Craig, Adrian J F K, Bonnevie, Bo T, Oschadleus, Hans-Dieter
- Authors: Craig, Adrian J F K , Bonnevie, Bo T , Oschadleus, Hans-Dieter
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449503 , vital:74826 , https://doi.org/10.2989/00306525.2010.488357
- Description: Using the SAFRING database and the Underhill-Zucchini model of primary moult, we analysed the timing of wing moult in Southern Red Bishops Euplectes orix in relation to sex and geographical region. Birds from the winter rainfall region in the south-western sector of the Western Cape start the annual moult more than two months before any other population, but there were no significant differences in starting date within the summer rainfall region. There were striking differences in the estimates of moult duration (62–114 d), which did not follow a consistent pattern in relation to sex or geography; annual variation within a region may be an additional factor. Throughout southern Africa, both sexes showed a trend for longer-winged birds to take more time to complete their moult. We suggest that sex, geographical area and possible annual environmental variations may all influence the timing of moult in local populations. In this sexually dimorphic species, males are consistently longer-winged and heavier than females.
- Full Text:
- Date Issued: 2010
- Authors: Craig, Adrian J F K , Bonnevie, Bo T , Oschadleus, Hans-Dieter
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449503 , vital:74826 , https://doi.org/10.2989/00306525.2010.488357
- Description: Using the SAFRING database and the Underhill-Zucchini model of primary moult, we analysed the timing of wing moult in Southern Red Bishops Euplectes orix in relation to sex and geographical region. Birds from the winter rainfall region in the south-western sector of the Western Cape start the annual moult more than two months before any other population, but there were no significant differences in starting date within the summer rainfall region. There were striking differences in the estimates of moult duration (62–114 d), which did not follow a consistent pattern in relation to sex or geography; annual variation within a region may be an additional factor. Throughout southern Africa, both sexes showed a trend for longer-winged birds to take more time to complete their moult. We suggest that sex, geographical area and possible annual environmental variations may all influence the timing of moult in local populations. In this sexually dimorphic species, males are consistently longer-winged and heavier than females.
- Full Text:
- Date Issued: 2010
Relative feather mass indices: are feather masses needed to estimate the percentage of new feather mass grown for moult regression models?
- Authors: Bonnevie, Bo T
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448313 , vital:74721 , https://doi.org/10.2989/00306525.2010.455820
- Description: During the moult of primary wing feathers in birds it is likely that new feather material is being produced at an approximately constant rate if the energetic requirements of the birds are met. In moult regression analyses it is, therefore, desirable to transform moult measurements into a variable based on the amount of new feather material produced because of its linear properties. This can be achieved if the mass of each primary feather is known, and used as a weighting factor in a moult index. These primary feather masses would have to be known for every species being analysed. As an alternative, it is here tested if feather mass indices may be sufficient replacements for species-specific feather masses. Thirty-five species of birds with known primary feather masses were divided into four wing-shape groups, and a feather mass index was built for each group. Within each group, comparisons were made between estimates of moult parameters using the moult index with those using the known primary feather masses. Within groups there were no significant differences between any of the moult estimates.
- Full Text:
- Date Issued: 2010
- Authors: Bonnevie, Bo T
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448313 , vital:74721 , https://doi.org/10.2989/00306525.2010.455820
- Description: During the moult of primary wing feathers in birds it is likely that new feather material is being produced at an approximately constant rate if the energetic requirements of the birds are met. In moult regression analyses it is, therefore, desirable to transform moult measurements into a variable based on the amount of new feather material produced because of its linear properties. This can be achieved if the mass of each primary feather is known, and used as a weighting factor in a moult index. These primary feather masses would have to be known for every species being analysed. As an alternative, it is here tested if feather mass indices may be sufficient replacements for species-specific feather masses. Thirty-five species of birds with known primary feather masses were divided into four wing-shape groups, and a feather mass index was built for each group. Within each group, comparisons were made between estimates of moult parameters using the moult index with those using the known primary feather masses. Within groups there were no significant differences between any of the moult estimates.
- Full Text:
- Date Issued: 2010
Remarkable sensitivity for detection of bisphenol A on a gold electrode modified with nickel tetraamino phthalocyanine containing Ni–O–Ni bridges
- Chauke, Vongani, Matemadombo, Fungisai, Nyokong, Tebello
- Authors: Chauke, Vongani , Matemadombo, Fungisai , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261280 , vital:53380 , xlink:href="https://doi.org/10.1016/j.jhazmat.2010.01.061"
- Description: This work reports the electrocatalysis of bisphenol A on Ni(II) tetraamino metallophthalocyanine (NiTAPc) polymer modified gold electrode containing Ni–O–Ni bridges (represented as Ni(OH)TAPc). The Ni(II)TAPc films were electro-transformed in 0.1 mol L−1 NaOH aqueous solution to form ‘O–Ni–O oxo bridges’, forming poly-n-Ni(OH)TAPc (where n is the number of polymerising scans). poly-30-Ni(OH)TAPc, poly-50-Ni(OH)TAPc, poly-70-Ni(OH)TAPc and poly-90-Ni(OH)TAPc films were investigated. The polymeric films were characterised by electrochemical impedance spectroscopy and the charge transfer resistance (RCT) values increased with film thickness. The best catalytic activity for the detection of bisphenol A was on poly-70-Ni(OH)TAPc. Electrode resistance to passivation improved with polymer thickness. The electrocatalytic behaviour of bisphenol A was compared to that of p-nitrophenol in terms of electrode passivation and regeneration. The latter was found to passivate the electrode less than the former. The poly-70-Ni(OH)TAPc modified electrode could reliably detect bisphenol A in a concentration range of 7 × 10−4 to 3 × 10−2 mol L−1 with a limit of detection of 3.68 × 10−9 mol L−1. The sensitivity was 3.26 × 10−4 A mol−1 L cm−2.
- Full Text:
- Date Issued: 2010
- Authors: Chauke, Vongani , Matemadombo, Fungisai , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261280 , vital:53380 , xlink:href="https://doi.org/10.1016/j.jhazmat.2010.01.061"
- Description: This work reports the electrocatalysis of bisphenol A on Ni(II) tetraamino metallophthalocyanine (NiTAPc) polymer modified gold electrode containing Ni–O–Ni bridges (represented as Ni(OH)TAPc). The Ni(II)TAPc films were electro-transformed in 0.1 mol L−1 NaOH aqueous solution to form ‘O–Ni–O oxo bridges’, forming poly-n-Ni(OH)TAPc (where n is the number of polymerising scans). poly-30-Ni(OH)TAPc, poly-50-Ni(OH)TAPc, poly-70-Ni(OH)TAPc and poly-90-Ni(OH)TAPc films were investigated. The polymeric films were characterised by electrochemical impedance spectroscopy and the charge transfer resistance (RCT) values increased with film thickness. The best catalytic activity for the detection of bisphenol A was on poly-70-Ni(OH)TAPc. Electrode resistance to passivation improved with polymer thickness. The electrocatalytic behaviour of bisphenol A was compared to that of p-nitrophenol in terms of electrode passivation and regeneration. The latter was found to passivate the electrode less than the former. The poly-70-Ni(OH)TAPc modified electrode could reliably detect bisphenol A in a concentration range of 7 × 10−4 to 3 × 10−2 mol L−1 with a limit of detection of 3.68 × 10−9 mol L−1. The sensitivity was 3.26 × 10−4 A mol−1 L cm−2.
- Full Text:
- Date Issued: 2010
Reproductive biology of a riverine cyprinid, Labeo umbratus (Teleostei: Cyprinidae), in small South African reservoirs
- Potts, Warren M, Booth, Anthony J, Hecht, Thomas, Andrew, Timothy G
- Authors: Potts, Warren M , Booth, Anthony J , Hecht, Thomas , Andrew, Timothy G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125854 , vital:35826 , https://doi.10.2989/16085910509503849
- Description: The reproductive and recruitment characteristics of moggel, Labeo umbratus, populations were examined in four small South African reservoirs. Reproduction, characterised by an extended spawning season, high fecundity, short incubation time and rapid larval development, appears to be ideally suited to the highly variable environment of small reservoirs. Evidence suggested that L. umbratus spawns in the reservoirs. In two reservoirs where samples were conducted monthly, GSI (gonado-somatic index) was positively correlated with both water temperature and day length, whilst the CPUE (catch per unit effort) of juveniles was not related to any environmental variable. The success of moggel spawning appeared to increase when there was early spring and consistent summer rainfall.
- Full Text:
- Date Issued: 2010
- Authors: Potts, Warren M , Booth, Anthony J , Hecht, Thomas , Andrew, Timothy G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125854 , vital:35826 , https://doi.10.2989/16085910509503849
- Description: The reproductive and recruitment characteristics of moggel, Labeo umbratus, populations were examined in four small South African reservoirs. Reproduction, characterised by an extended spawning season, high fecundity, short incubation time and rapid larval development, appears to be ideally suited to the highly variable environment of small reservoirs. Evidence suggested that L. umbratus spawns in the reservoirs. In two reservoirs where samples were conducted monthly, GSI (gonado-somatic index) was positively correlated with both water temperature and day length, whilst the CPUE (catch per unit effort) of juveniles was not related to any environmental variable. The success of moggel spawning appeared to increase when there was early spring and consistent summer rainfall.
- Full Text:
- Date Issued: 2010
Reproductive seasonality of southern African inshore and estuarine invertebrates–a biogeographic review
- Authors: Hodgson, Alan N
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447415 , vital:74623 , https://doi.org/10.1080/15627020.2010.11657249
- Description: A literature review reveals that reproductive seasonality of less than 1% of South Africa’s inshore marine invertebrates has been studied. Approximately 95% of studies have been on large, long-lived, gonochoristic, iteroparous species, and nearly 50% on molluscs. There is only a weak relationship between biogeographic region and timing of reproduction. Nevertheless, a relatively large proportion of west coast species studied breed in winter, whereas south coast species tend to have breeding peaks in spring/summer, although many nearly always have mature gametes and probably reproduce year-round. East coast species are mainly continuous or summer breeders. The factors that control gametogenesis and trigger spawning are largely unresolved, although temperature and food are thought to be important in many species.
- Full Text:
- Date Issued: 2010
- Authors: Hodgson, Alan N
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447415 , vital:74623 , https://doi.org/10.1080/15627020.2010.11657249
- Description: A literature review reveals that reproductive seasonality of less than 1% of South Africa’s inshore marine invertebrates has been studied. Approximately 95% of studies have been on large, long-lived, gonochoristic, iteroparous species, and nearly 50% on molluscs. There is only a weak relationship between biogeographic region and timing of reproduction. Nevertheless, a relatively large proportion of west coast species studied breed in winter, whereas south coast species tend to have breeding peaks in spring/summer, although many nearly always have mature gametes and probably reproduce year-round. East coast species are mainly continuous or summer breeders. The factors that control gametogenesis and trigger spawning are largely unresolved, although temperature and food are thought to be important in many species.
- Full Text:
- Date Issued: 2010
Rethinking water service delivery system in Zimbabwe: a case study of Kwekwe Municipality
- Authors: Mupindu, Wisemen
- Date: 2010
- Subjects: Water-supply -- Zimbabwe
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24117 , vital:62379
- Description: This study examines the perceived scarcity of household water service delivery in the city of Kwekwe under the Midlands province of Zimbabwe. Kwekwe Municipality appears to be characterized by an erratic supply of clean water for household use. The city of Kwekwe has experienced an unreliable domestic water service delivery system since the beginning of this millennium. This study aims to investigate the causes of the problem, its extent, impact and what could be done to mitigate the problem. The study employs interviews, questionnaires, observations and document analyses to establish that population growth, ageing equipment, a lack of foreign currency and local funding, as well as a lack of expertise and of political will have contributed to the poor domestic water supply in the city of Kwekwe. The city of Kwekwe needs to commit itself to improving the current situation by involving the community, constructing more storage facilities, and by putting monitoring and evaluation mechanisms in place. The research design took the form of a case study of Kwekwe Municipality. A mixture of qualitative and quantitative research designs were used in this study. The qualitative/interpretivist approach was more dominant, allowing some overlapping with the quantitative/positivist paradigm whenever this was considered reasonable. The study sample consisted of a conveniently assembled sample of 120 respondents. The target population for the study comprised of 110 residents of Kwekwe urban and 10 Kwekwe City Municipality Water Authorities from the Works Department. This study focuses on the 4 residential areas of Kwekwe Municipality. The data collection instruments include questionnaires and focus group interviews. Electronically recorded, in-depth interviews were held with the water authorities and the consumers to establish their perceptions on the best practice of the water service delivery system in Zimbabwe. The data collection tools contained a preliminary section on the biological data of the respondents. All data was subjected to either qualitative or quantitative analysis techniques in order to strike a balance between the structured survey instruments and the anecdotes of the respondents. Quantitative data was analyzed using a Statistical Package for Social Sciences (SPSS), while qualitative data was subjected to document analysis which entailed classifying the data, extracting themes, identifying patterns, tallying and quantifying responses and making generalizations out of these patterns. This implies that the research methodology focused on the method, tools and techniques used to assist in achieving the objectives of the study and answering the research questions that the research seeks to address. The term research methodology is used, in this study, to refer to the philosophical assumptions, values, and theories which inform and underpin the way in which a particular research method is used. In this study, the case study research design was used as the operational framework for data gathering. The case study research method is essentially grounded in the interpretive research paradigm. To this end, the study sought the perceptions of both the consumers and the water authorities. The major finding of the study is that the ability of Kwekwe Municipality to provide household water service delivery to its consumers is slightly below average. However, there was a slight improvement in the household water service delivery but consumers are still remaining dissatisfied. Another finding, related to this one, was that the electricity deficiency cost the efficacy of Kwekwe Municipality in its provision of household water service delivery. The study proposes that more studies which seek to interrogate the domestic water service delivery system of the Zimbabwean Municipalities should be embarked upon by the state. The study also recommends that service delivery training programmes be implemented in order to enhance the competence of the water authorities. Furthermore, the study suggests that consumers be placed at the center of household water debates when policies, rules and regulations of the water service delivery system are formulated. Finally, the study implores that municipalities need to have their own reserves and generators for emergency cases during electricity power cuts. It is imperative that the water reservoirs constantly hold 4 days‟ worth of water capacity. The municipality of Kwekwe must refurbish the entire water reticulation system. Municipalities must carry out an audit of water meter readings and also confirm that all water meters are functional. Manpower to read the correct meter reading should be increased in number and must have reliable transport. , Thesis (PhD) -- Faculty of Management and Commerce, 2010
- Full Text:
- Date Issued: 2010
- Authors: Mupindu, Wisemen
- Date: 2010
- Subjects: Water-supply -- Zimbabwe
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24117 , vital:62379
- Description: This study examines the perceived scarcity of household water service delivery in the city of Kwekwe under the Midlands province of Zimbabwe. Kwekwe Municipality appears to be characterized by an erratic supply of clean water for household use. The city of Kwekwe has experienced an unreliable domestic water service delivery system since the beginning of this millennium. This study aims to investigate the causes of the problem, its extent, impact and what could be done to mitigate the problem. The study employs interviews, questionnaires, observations and document analyses to establish that population growth, ageing equipment, a lack of foreign currency and local funding, as well as a lack of expertise and of political will have contributed to the poor domestic water supply in the city of Kwekwe. The city of Kwekwe needs to commit itself to improving the current situation by involving the community, constructing more storage facilities, and by putting monitoring and evaluation mechanisms in place. The research design took the form of a case study of Kwekwe Municipality. A mixture of qualitative and quantitative research designs were used in this study. The qualitative/interpretivist approach was more dominant, allowing some overlapping with the quantitative/positivist paradigm whenever this was considered reasonable. The study sample consisted of a conveniently assembled sample of 120 respondents. The target population for the study comprised of 110 residents of Kwekwe urban and 10 Kwekwe City Municipality Water Authorities from the Works Department. This study focuses on the 4 residential areas of Kwekwe Municipality. The data collection instruments include questionnaires and focus group interviews. Electronically recorded, in-depth interviews were held with the water authorities and the consumers to establish their perceptions on the best practice of the water service delivery system in Zimbabwe. The data collection tools contained a preliminary section on the biological data of the respondents. All data was subjected to either qualitative or quantitative analysis techniques in order to strike a balance between the structured survey instruments and the anecdotes of the respondents. Quantitative data was analyzed using a Statistical Package for Social Sciences (SPSS), while qualitative data was subjected to document analysis which entailed classifying the data, extracting themes, identifying patterns, tallying and quantifying responses and making generalizations out of these patterns. This implies that the research methodology focused on the method, tools and techniques used to assist in achieving the objectives of the study and answering the research questions that the research seeks to address. The term research methodology is used, in this study, to refer to the philosophical assumptions, values, and theories which inform and underpin the way in which a particular research method is used. In this study, the case study research design was used as the operational framework for data gathering. The case study research method is essentially grounded in the interpretive research paradigm. To this end, the study sought the perceptions of both the consumers and the water authorities. The major finding of the study is that the ability of Kwekwe Municipality to provide household water service delivery to its consumers is slightly below average. However, there was a slight improvement in the household water service delivery but consumers are still remaining dissatisfied. Another finding, related to this one, was that the electricity deficiency cost the efficacy of Kwekwe Municipality in its provision of household water service delivery. The study proposes that more studies which seek to interrogate the domestic water service delivery system of the Zimbabwean Municipalities should be embarked upon by the state. The study also recommends that service delivery training programmes be implemented in order to enhance the competence of the water authorities. Furthermore, the study suggests that consumers be placed at the center of household water debates when policies, rules and regulations of the water service delivery system are formulated. Finally, the study implores that municipalities need to have their own reserves and generators for emergency cases during electricity power cuts. It is imperative that the water reservoirs constantly hold 4 days‟ worth of water capacity. The municipality of Kwekwe must refurbish the entire water reticulation system. Municipalities must carry out an audit of water meter readings and also confirm that all water meters are functional. Manpower to read the correct meter reading should be increased in number and must have reliable transport. , Thesis (PhD) -- Faculty of Management and Commerce, 2010
- Full Text:
- Date Issued: 2010
Revolutionary Overthrow of Constitutional Orders in Africa
- Authors: Anyangwe, Carlson
- Date: 2010
- Subjects: Constitutional law -- Africa Civil-military relations Coups’d’états Revolutions
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/823 , vital:29828
- Description: The title of my Professorial Inaugural Lecture is ‘Revolutionary Overthrow of Constitutional Orders in Africa’. It is a subject at the intersection of three disciplines: jurisprudence and legal philosophy, constitutional law and power politics, and civil-military relations, i.e. military security policy which is one aspect of national security policy.2 The subject is of interest in at least four aspects: (i) it problematises the inescapable question of governance in the African continent; (ii) it challenges the democratization agenda in Africa - how does one democratize not only political governance but also the instruments of violence in the state? (iii) it challenges African constitutional lawyers and policy makers to seek a constitutional model that addresses the enduring menace of the power of the gun in African affairs and the changing role of the military in African politics; and (iv) it underscores national security and sovereignty concerns.
- Full Text:
- Date Issued: 2010
- Authors: Anyangwe, Carlson
- Date: 2010
- Subjects: Constitutional law -- Africa Civil-military relations Coups’d’états Revolutions
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/823 , vital:29828
- Description: The title of my Professorial Inaugural Lecture is ‘Revolutionary Overthrow of Constitutional Orders in Africa’. It is a subject at the intersection of three disciplines: jurisprudence and legal philosophy, constitutional law and power politics, and civil-military relations, i.e. military security policy which is one aspect of national security policy.2 The subject is of interest in at least four aspects: (i) it problematises the inescapable question of governance in the African continent; (ii) it challenges the democratization agenda in Africa - how does one democratize not only political governance but also the instruments of violence in the state? (iii) it challenges African constitutional lawyers and policy makers to seek a constitutional model that addresses the enduring menace of the power of the gun in African affairs and the changing role of the military in African politics; and (iv) it underscores national security and sovereignty concerns.
- Full Text:
- Date Issued: 2010
Rhodes University 2010 Graduation Ceremonies Address
- Authors: Badat, Saleem
- Date: 2010
- Language: English
- Type: text
- Identifier: vital:7586 , http://hdl.handle.net/10962/d1006577
- Description: From introduction: Most of you who are graduating were born in the late 1980s, a period of great turbulence and social conflict. This was, however, also a time of great optimism for it was clear that apartheid tyranny could no longer continue and had to give way to a new social order. We must take immense pride in the imagination, creativity, ingenuity and courage that we displayed as a people to rid ourselves of tyranny and to fashion our democracy. You are a generation that has been, thankfully, largely spared the horrors, brutality and injustices of apartheid. You are the first generation with the opportunity of living in a society founded on a democratic Constitution that proclaims the commitment to human dignity, the achievement of equality, and the advancement of non-sexism and non-racialism and the human rights and freedoms that are contained in our Bill of Rights.
- Full Text:
- Date Issued: 2010
- Authors: Badat, Saleem
- Date: 2010
- Language: English
- Type: text
- Identifier: vital:7586 , http://hdl.handle.net/10962/d1006577
- Description: From introduction: Most of you who are graduating were born in the late 1980s, a period of great turbulence and social conflict. This was, however, also a time of great optimism for it was clear that apartheid tyranny could no longer continue and had to give way to a new social order. We must take immense pride in the imagination, creativity, ingenuity and courage that we displayed as a people to rid ourselves of tyranny and to fashion our democracy. You are a generation that has been, thankfully, largely spared the horrors, brutality and injustices of apartheid. You are the first generation with the opportunity of living in a society founded on a democratic Constitution that proclaims the commitment to human dignity, the achievement of equality, and the advancement of non-sexism and non-racialism and the human rights and freedoms that are contained in our Bill of Rights.
- Full Text:
- Date Issued: 2010
Rhodes University Graduation Ceremony 2010
- Authors: Rhodes University
- Date: 2010
- Language: English
- Type: text
- Identifier: vital:8137 , http://hdl.handle.net/10962/d1007247
- Description: Rhodes University Graduation Ceremonies [at] 1820 Settlers National Monument Thursday, 8 April at 18.00 [and] Friday, 9 April at 10:30; 14:30 & 18:00 [and] Saturday, 10 April at 10:30
- Full Text:
- Date Issued: 2010
- Authors: Rhodes University
- Date: 2010
- Language: English
- Type: text
- Identifier: vital:8137 , http://hdl.handle.net/10962/d1007247
- Description: Rhodes University Graduation Ceremonies [at] 1820 Settlers National Monument Thursday, 8 April at 18.00 [and] Friday, 9 April at 10:30; 14:30 & 18:00 [and] Saturday, 10 April at 10:30
- Full Text:
- Date Issued: 2010
Sedimentary facies and geomorphic evolution of a blocked‐valley lake: Lake Futululu, northern Kwazulu‐Natal, South Africa
- Grenfell, Suzanne E, Ellery, William F N, Grenfell, Michael C, Ramsay, Lisa F, Flügel, Tyrel J
- Authors: Grenfell, Suzanne E , Ellery, William F N , Grenfell, Michael C , Ramsay, Lisa F , Flügel, Tyrel J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126826 , vital:35928 , https://doi.10.1111/j.1365-3091.2009.01141.x
- Description: Blocked-valley lakes are formed when tributaries are impounded by the relatively rapid aggradation of a large river and its floodplain. These features are common in the landscape, and have been identified in the floodplains of the Solimo˜es-Amazon (Brazil) and Fly-Strickland Rivers (Papua New Guinea), for example, but their inaccessibility has resulted in studies being limited to remotely sensed image analysis. This paper documents the sedimentology and geomorphic evolution of a blocked-valley lake, Lake Futululu on the Mfolozi River floodplain margin, in South Africa, while also offering a context for the formation of lakes and wetlands at tributary junctions. The study combines aerial photography, elevation data from orthophotographs and field survey, and longitudinal sedimentology determined from a series of cores, which were sub-sampled for organic content and particle size analysis. Radiocarbon dating was used to gauge the rate and timing of peat accumulation. Results indicate that following the last glacial maximum, rising sea-levels caused aggradation of the Mfolozi River floodplain. By 3980 years bp, aggradation on the floodplain had impounded the Futululu drainage line, creating conditions suitable for peat formation, which has since occurred at a constant average rate of 0Æ13 cm year)1. Continued aggradation on the Mfolozi River floodplain has raised the base level of the Futululu drainage line, resulting in a series of backstepping sedimentary facies with fluvially derived sand and silt episodically prograding over lacustrine peat deposits. Blocked-valley lakes form where the trunk river has a much larger sediment load and catchment than the tributary stream. Similarly, when the relative difference in sediment loads is less, palustrine wetlands, rather than lakes, may be the result. In contrast, where tributaries drain a steep, well-connected catchment, they may impound much larger trunk rivers, creating lakes or wetlands upstream.
- Full Text:
- Date Issued: 2010
- Authors: Grenfell, Suzanne E , Ellery, William F N , Grenfell, Michael C , Ramsay, Lisa F , Flügel, Tyrel J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126826 , vital:35928 , https://doi.10.1111/j.1365-3091.2009.01141.x
- Description: Blocked-valley lakes are formed when tributaries are impounded by the relatively rapid aggradation of a large river and its floodplain. These features are common in the landscape, and have been identified in the floodplains of the Solimo˜es-Amazon (Brazil) and Fly-Strickland Rivers (Papua New Guinea), for example, but their inaccessibility has resulted in studies being limited to remotely sensed image analysis. This paper documents the sedimentology and geomorphic evolution of a blocked-valley lake, Lake Futululu on the Mfolozi River floodplain margin, in South Africa, while also offering a context for the formation of lakes and wetlands at tributary junctions. The study combines aerial photography, elevation data from orthophotographs and field survey, and longitudinal sedimentology determined from a series of cores, which were sub-sampled for organic content and particle size analysis. Radiocarbon dating was used to gauge the rate and timing of peat accumulation. Results indicate that following the last glacial maximum, rising sea-levels caused aggradation of the Mfolozi River floodplain. By 3980 years bp, aggradation on the floodplain had impounded the Futululu drainage line, creating conditions suitable for peat formation, which has since occurred at a constant average rate of 0Æ13 cm year)1. Continued aggradation on the Mfolozi River floodplain has raised the base level of the Futululu drainage line, resulting in a series of backstepping sedimentary facies with fluvially derived sand and silt episodically prograding over lacustrine peat deposits. Blocked-valley lakes form where the trunk river has a much larger sediment load and catchment than the tributary stream. Similarly, when the relative difference in sediment loads is less, palustrine wetlands, rather than lakes, may be the result. In contrast, where tributaries drain a steep, well-connected catchment, they may impound much larger trunk rivers, creating lakes or wetlands upstream.
- Full Text:
- Date Issued: 2010