Spectroscopic behavior of cationic metallophthalocyanines in the presence of anionic quantum dots
- Idowu, Mopelola, Nyokong, Tebello
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262699 , vital:53545 , xlink:href="https://doi.org/10.1016/j.saa.2009.10.050"
- Description: The interactions and spectroscopic properties between cationic zinc phthalocyanine derivatives (peripherally and non-peripherally tetrasubstituted and peripherally octa substituted with 2-diethylmethylaminoethylsulfanyl (βTZnPc, αTZnPc and βOZnPc)) and CdTe core quantum dots (QDs) capped with mercaptopropionic acid or thioglycolic acid (represented as CdTe@MPA and CdTe@TGA, respectively) have been studied in methanol:water mixture. Strong coupling of MPcs was deduced from the interaction since the UV–vis spectroscopic studies of the ground state complex formed on mixing both components showed loss of the phthalocyanine monomeric band with the formation of a dimeric band (spectrum of aggregated species). The dimerization constants were of the order of 104 M−1.
- Full Text:
- Date Issued: 2010
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/262699 , vital:53545 , xlink:href="https://doi.org/10.1016/j.saa.2009.10.050"
- Description: The interactions and spectroscopic properties between cationic zinc phthalocyanine derivatives (peripherally and non-peripherally tetrasubstituted and peripherally octa substituted with 2-diethylmethylaminoethylsulfanyl (βTZnPc, αTZnPc and βOZnPc)) and CdTe core quantum dots (QDs) capped with mercaptopropionic acid or thioglycolic acid (represented as CdTe@MPA and CdTe@TGA, respectively) have been studied in methanol:water mixture. Strong coupling of MPcs was deduced from the interaction since the UV–vis spectroscopic studies of the ground state complex formed on mixing both components showed loss of the phthalocyanine monomeric band with the formation of a dimeric band (spectrum of aggregated species). The dimerization constants were of the order of 104 M−1.
- Full Text:
- Date Issued: 2010
Spectroscopic studies of nanostructures of negatively charged free base porphyrin and positively charged tin porphyrins
- George, Reama C, Egharevba, Gabriel O, Nyokong, Tebello
- Authors: George, Reama C , Egharevba, Gabriel O , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261661 , vital:53432 , xlink:href="https://doi.org/10.1016/j.poly.2010.01.028"
- Description: Spectroscopic studies were carried out on the homoaggregates of negatively charged free base meso-tetraphenylsulfonated porphyrin ([H2TPPS4]4−) and heteroaggregates of a mixture of protonated ([H4TPPS4]2−) and tin meso-tetra (N-methyl-4-pyridyl) porphyrin ([SnTMPyP]4+). The spectroscopic studies were done to determine the optimal conditions required for the fabrication of porphyrin nanorods by ionic self assembly of two oppositely charged porphyrins. In addition, the various spectral changes of [H4TPPS4]2− with concurrent change in pH and concentration are also investigated. In acid media at pH more than 3, and at concentrations less than 1 × 10−5 M, [H4TPPS4]2− molecules form J aggregates. A mixture of [H4TPPS4]2− and [SnTMPyP]4+ forms heteroaggregates of the J type in acid media. At pH’s 2 to 3, the optimum ratio for the formation of J aggregates is 3:1 and for pH 1, the optimum ratio is 2:1. Transmission electron microscope images of the nanostructures formed show that they are of cylindrical shape.
- Full Text:
- Date Issued: 2010
- Authors: George, Reama C , Egharevba, Gabriel O , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/261661 , vital:53432 , xlink:href="https://doi.org/10.1016/j.poly.2010.01.028"
- Description: Spectroscopic studies were carried out on the homoaggregates of negatively charged free base meso-tetraphenylsulfonated porphyrin ([H2TPPS4]4−) and heteroaggregates of a mixture of protonated ([H4TPPS4]2−) and tin meso-tetra (N-methyl-4-pyridyl) porphyrin ([SnTMPyP]4+). The spectroscopic studies were done to determine the optimal conditions required for the fabrication of porphyrin nanorods by ionic self assembly of two oppositely charged porphyrins. In addition, the various spectral changes of [H4TPPS4]2− with concurrent change in pH and concentration are also investigated. In acid media at pH more than 3, and at concentrations less than 1 × 10−5 M, [H4TPPS4]2− molecules form J aggregates. A mixture of [H4TPPS4]2− and [SnTMPyP]4+ forms heteroaggregates of the J type in acid media. At pH’s 2 to 3, the optimum ratio for the formation of J aggregates is 3:1 and for pH 1, the optimum ratio is 2:1. Transmission electron microscope images of the nanostructures formed show that they are of cylindrical shape.
- Full Text:
- Date Issued: 2010
Study South Africa
- International Education Association of South Africa (IEASA), Jooste, Nico
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2010
- Subjects: Education, Higher -- South Africa , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64963 , vital:28640 , ISBN 9780620482172
- Description: [Extract from message from Minister of Higher Education and Training, Hon. Dr BE Nzimande]: The 10th Edition focuses on the highly relevant issue of ‘Higher Education Internationalisation in the Development of Africa’. The internationalisation of higher education is of great importance for the continent, if Africa wants to be able to compete and participate in a global context. Currently, there are only three African institutions in the Top 500 of the Shanghai Academic Ranking of World Universities and all of these are in South Africa. Similarly, one South African institution appears in the Top 200 of the Times Higher Education World Ranking and no other African universities are represented. Despite being cautious about the methodology used to derive rankings, our aim in higher education should be to actively compete internationally and, more importantly, to serve the developmental challenges of Africa. It is imperative that Africa engages internationally and participates in the development of humanity’s knowledge. Research outputs and publications are particularly low on the continent, and African universities need to develop their research capabilities and direct resources to this important function. It is particularly important that research, which affects Africa and its development, is conducted on a large scale on the continent, supported by collaborative work and partnerships, rather than being carried out predominantly in other countries. The time has come for the tide to change and for our researchers and academics to focus on research opportunities presented on the continent. This is an important step for Africa to take if it is to deal effectively with the problems it faces and take its place in the international arena. One way to increase and develop knowledge outputs is through collaboration. An important opportunity for South African universities is the Erasmus Mundus Programme funded through the European Union (EU). This programme encourages collaboration between South African and European universities and provides resources for the exchange of staff and students within specific research programmes. It is also important for Africa to develop the research collaboration within the continent and with other developing and developed countries. In this regard, the Intra-ACP (Africa-Caribbean-Pacific) Scheme is of great importance. This initiative by the African Union (AU), working in collaboration with the EU, provides the opportunity for academic staff and student exchanges between universities in these regions. Intra-African exchanges are of particular importance in developing the continent’s capacity. Through such programmes African universities can work together to develop research and participate in the knowledge economy. We should also not ignore the challenges faced in improving the quality of teaching and learning in African universities, including many in South Africa. If sufficient attention and resources are not directed to improving these most basic activities of higher education, we will not only fail to meet the continent’s human resource development needs, but we will fail to establish the basis for future research advancement. Student mobility is very much a part of our fabric and provides the necessary intellectual stimulation, which is an essential part of student life. The number of African students from outside South Africa studying at South African institutions is growing annually, as is the number of non-African students. The networks established through such internationalisation are invaluable. There are also large numbers of our own students who, through universities’ reciprocal agreements, are studying abroad. The information provided in this publication provides a valuable opportunity to showcase our higher education sector and goes a long way to providing the necessary facts to encourage such student mobility. , 10th Edition
- Full Text:
- Date Issued: 2010
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2010
- Subjects: Education, Higher -- South Africa , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64963 , vital:28640 , ISBN 9780620482172
- Description: [Extract from message from Minister of Higher Education and Training, Hon. Dr BE Nzimande]: The 10th Edition focuses on the highly relevant issue of ‘Higher Education Internationalisation in the Development of Africa’. The internationalisation of higher education is of great importance for the continent, if Africa wants to be able to compete and participate in a global context. Currently, there are only three African institutions in the Top 500 of the Shanghai Academic Ranking of World Universities and all of these are in South Africa. Similarly, one South African institution appears in the Top 200 of the Times Higher Education World Ranking and no other African universities are represented. Despite being cautious about the methodology used to derive rankings, our aim in higher education should be to actively compete internationally and, more importantly, to serve the developmental challenges of Africa. It is imperative that Africa engages internationally and participates in the development of humanity’s knowledge. Research outputs and publications are particularly low on the continent, and African universities need to develop their research capabilities and direct resources to this important function. It is particularly important that research, which affects Africa and its development, is conducted on a large scale on the continent, supported by collaborative work and partnerships, rather than being carried out predominantly in other countries. The time has come for the tide to change and for our researchers and academics to focus on research opportunities presented on the continent. This is an important step for Africa to take if it is to deal effectively with the problems it faces and take its place in the international arena. One way to increase and develop knowledge outputs is through collaboration. An important opportunity for South African universities is the Erasmus Mundus Programme funded through the European Union (EU). This programme encourages collaboration between South African and European universities and provides resources for the exchange of staff and students within specific research programmes. It is also important for Africa to develop the research collaboration within the continent and with other developing and developed countries. In this regard, the Intra-ACP (Africa-Caribbean-Pacific) Scheme is of great importance. This initiative by the African Union (AU), working in collaboration with the EU, provides the opportunity for academic staff and student exchanges between universities in these regions. Intra-African exchanges are of particular importance in developing the continent’s capacity. Through such programmes African universities can work together to develop research and participate in the knowledge economy. We should also not ignore the challenges faced in improving the quality of teaching and learning in African universities, including many in South Africa. If sufficient attention and resources are not directed to improving these most basic activities of higher education, we will not only fail to meet the continent’s human resource development needs, but we will fail to establish the basis for future research advancement. Student mobility is very much a part of our fabric and provides the necessary intellectual stimulation, which is an essential part of student life. The number of African students from outside South Africa studying at South African institutions is growing annually, as is the number of non-African students. The networks established through such internationalisation are invaluable. There are also large numbers of our own students who, through universities’ reciprocal agreements, are studying abroad. The information provided in this publication provides a valuable opportunity to showcase our higher education sector and goes a long way to providing the necessary facts to encourage such student mobility. , 10th Edition
- Full Text:
- Date Issued: 2010
Sunday Times: Celebrating Women
- Authors: Sunday Times
- Date: 2010
- Subjects: Nyokong, Tebello
- Language: English
- Type: Article , text
- Identifier: vital:7187 , http://hdl.handle.net/10962/d1006279 , Nyokong, Tebello
- Description: A passion for light drove Professor Tebello Nyokong of Rhodes University into her photodynamic therapy research, harnessing light for cancer therapy and environmental clean-up using special dyes. And with this groundbreaking work she won the Africa-Arab State 2009 L'Oreal UNESCO Award for Women in Science.
- Full Text:
- Date Issued: 2010
- Authors: Sunday Times
- Date: 2010
- Subjects: Nyokong, Tebello
- Language: English
- Type: Article , text
- Identifier: vital:7187 , http://hdl.handle.net/10962/d1006279 , Nyokong, Tebello
- Description: A passion for light drove Professor Tebello Nyokong of Rhodes University into her photodynamic therapy research, harnessing light for cancer therapy and environmental clean-up using special dyes. And with this groundbreaking work she won the Africa-Arab State 2009 L'Oreal UNESCO Award for Women in Science.
- Full Text:
- Date Issued: 2010
Swelling, erosion and drug release characteristics of salbutamol sulfate from hydroxypropyl methylcellulose-based matrix tablets
- Chaibva, Faith A, Khamanga, Sandile M, Walker, Roderick B
- Authors: Chaibva, Faith A , Khamanga, Sandile M , Walker, Roderick B
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184139 , vital:44177 , xlink:href="https://doi.org/10.3109/03639045.2010.488648"
- Description: Background: Hydrophilic matrix formulations are important and simple technologies that are used to manufacture sustained release dosage forms. Method: Hydroxypropyl methylcellulose-based matrix tablets, with and without additives, were manufactured to investigate the rate of hydration, rate of erosion, and rate and mechanism of drug release. Scanning electron microscopy was used to assess changes in the microstructure of the tablets during drug release testing and whether these changes could be related to the rate of drug release from the formulations. Results: The results revealed that the rate of hydration and erosion was dependent on the polymer combination(s) used, which in turn affected the rate and mechanism of drug release from these formulations. It was also apparent that changes in the microstructure of matrix tablets could be related to the different rates of drug release that were observed from the test formulations. Conclusion: The use of scanning electron microscopy provides useful information to further understand drug release mechanisms from matrix tablets.
- Full Text:
- Date Issued: 2010
- Authors: Chaibva, Faith A , Khamanga, Sandile M , Walker, Roderick B
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184139 , vital:44177 , xlink:href="https://doi.org/10.3109/03639045.2010.488648"
- Description: Background: Hydrophilic matrix formulations are important and simple technologies that are used to manufacture sustained release dosage forms. Method: Hydroxypropyl methylcellulose-based matrix tablets, with and without additives, were manufactured to investigate the rate of hydration, rate of erosion, and rate and mechanism of drug release. Scanning electron microscopy was used to assess changes in the microstructure of the tablets during drug release testing and whether these changes could be related to the rate of drug release from the formulations. Results: The results revealed that the rate of hydration and erosion was dependent on the polymer combination(s) used, which in turn affected the rate and mechanism of drug release from these formulations. It was also apparent that changes in the microstructure of matrix tablets could be related to the different rates of drug release that were observed from the test formulations. Conclusion: The use of scanning electron microscopy provides useful information to further understand drug release mechanisms from matrix tablets.
- Full Text:
- Date Issued: 2010
Symmetrically and unsymmetrically substituted carboxy phthalocyanines as sensitizers for nanoporous ZnO films
- Masilela, Nkosiphile, Nombona, Nolwazi, Loewenstein, Thomas, Nyokong, Tebello, Schlettwein, Derck
- Authors: Masilela, Nkosiphile , Nombona, Nolwazi , Loewenstein, Thomas , Nyokong, Tebello , Schlettwein, Derck
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249126 , vital:51780 , xlink:href="https://doi.org/10.1142/S1088424610002793"
- Description: The photoelectroectrochemical studies of water soluble octacarboxylated oxotitanium (OTiOCPc), zinc (ZnOCPC), hydroxyaluminium ((OH)AlOCPc), dihydroxysilicon ((OH)2SiOCPc), hydroxygallium (OHGaOCPc) and low symmetry zinc monocarboxy (ZnMCPc) phthalocyanines were performed. The dyes were adsorbed to nanoporous ZnO electrodeposited in the presence of eosin Y as structure directing agent (SDA) on FTO substrates by refluxing or soaking the films in a solution containing the dye of interest such that a full surface coverage was achieved. High external (IPCE) and internal (APCE) quantum efficiencies of up to 50.6% and 96.7% were achieved for the OTiOCPc complex. There was a lower overall cell efficiency for cells sensitized with phthalocyanines containing hydroxyl as axial ligand ZnO/(OH)2SiOCPc, ZnO/(OH)GaOCPc and (OH)AlOCPc because of strong aggregation on the surface of the electrodes. To further suppress dye aggregation, the zinc complex of a new monocarboxylated phthalocyanine sensitizer with bulky naphtho side groups (ZnMCPc) was employed. Among the studied sensitizers, ZnMCPc gave the highest overall cell efficiency of phthalocyanine electrodeposited on ZnO of η = 0.48%.
- Full Text:
- Date Issued: 2010
- Authors: Masilela, Nkosiphile , Nombona, Nolwazi , Loewenstein, Thomas , Nyokong, Tebello , Schlettwein, Derck
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249126 , vital:51780 , xlink:href="https://doi.org/10.1142/S1088424610002793"
- Description: The photoelectroectrochemical studies of water soluble octacarboxylated oxotitanium (OTiOCPc), zinc (ZnOCPC), hydroxyaluminium ((OH)AlOCPc), dihydroxysilicon ((OH)2SiOCPc), hydroxygallium (OHGaOCPc) and low symmetry zinc monocarboxy (ZnMCPc) phthalocyanines were performed. The dyes were adsorbed to nanoporous ZnO electrodeposited in the presence of eosin Y as structure directing agent (SDA) on FTO substrates by refluxing or soaking the films in a solution containing the dye of interest such that a full surface coverage was achieved. High external (IPCE) and internal (APCE) quantum efficiencies of up to 50.6% and 96.7% were achieved for the OTiOCPc complex. There was a lower overall cell efficiency for cells sensitized with phthalocyanines containing hydroxyl as axial ligand ZnO/(OH)2SiOCPc, ZnO/(OH)GaOCPc and (OH)AlOCPc because of strong aggregation on the surface of the electrodes. To further suppress dye aggregation, the zinc complex of a new monocarboxylated phthalocyanine sensitizer with bulky naphtho side groups (ZnMCPc) was employed. Among the studied sensitizers, ZnMCPc gave the highest overall cell efficiency of phthalocyanine electrodeposited on ZnO of η = 0.48%.
- Full Text:
- Date Issued: 2010
Syntheses and investigation of the effects of position and nature of substituent on the spectral, electrochemical and spectroelectrochemical properties of new cobalt phthalocyanine complexes
- 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/10962/261677 , vital:53434 , xlink:href="https://doi.org/10.1016/j.poly.2010.01.004"
- Description: The syntheses of new cobalt phthalocyanine (CoPc) complexes, tetra-substituted with diethylaminoethanethio at the peripheral (complex 3a) and non-peripheral (complex 3b) positions, and with benzylmercapto at the non-peripheral position (complex 5), are reported. The effects of the nature and position of substituent on the spectral, electrochemical and spectroelectrochemical properties of these complexes are investigated. Solution electrochemistry of complex 3a showed three distinctly resolved redox processes attributed to CoIIIPc−2/CoIIPc−2 (E½ = +0.64 V versus Ag|AgCl), CoIIPc−2/CoIPc−2 (E½ = −0.24 V versus Ag|AgCl) and CoIPc−2/CoIPc−3 (E½ = −1.26 V versus Ag|AgCl) species. No ring oxidation was observed in complex 3a. Complex 3b showed both ring-based oxidation, attributed to CoIIIPc−1/CoIIIPc−2 species (Ep = +0.86 V versus Ag|AgCl), and ring-based reduction associated with CoIPc−2/CoIPc−3 species (E½ = −1.46 V versus Ag|AgCl), with the normal metal-based redox processes in CoPc complexes: CoIIIPc−2/CoIIPc−2 (Ep = +0.41 V versus Ag|AgCl) and CoIIPc−2/CoIPc−2 (E½ = −0.38 V versus Ag|AgCl). Solution electrochemistry of complex 5 showed the same type and number of species observed in complex 3a: CoIIIPc−2/CoIIPc−2 (Ep = +0.59 V versus Ag|AgCl), CoIIPc−2/CoIPc−2 (E½ = −0.26 V versus Ag|AgCl) and CoIPc−2/CoIPc−3 (E½ = −1.39 V versus Ag|AgCl) species. These processes were confirmed using spectroelectrochemistry.
- 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/10962/261677 , vital:53434 , xlink:href="https://doi.org/10.1016/j.poly.2010.01.004"
- Description: The syntheses of new cobalt phthalocyanine (CoPc) complexes, tetra-substituted with diethylaminoethanethio at the peripheral (complex 3a) and non-peripheral (complex 3b) positions, and with benzylmercapto at the non-peripheral position (complex 5), are reported. The effects of the nature and position of substituent on the spectral, electrochemical and spectroelectrochemical properties of these complexes are investigated. Solution electrochemistry of complex 3a showed three distinctly resolved redox processes attributed to CoIIIPc−2/CoIIPc−2 (E½ = +0.64 V versus Ag|AgCl), CoIIPc−2/CoIPc−2 (E½ = −0.24 V versus Ag|AgCl) and CoIPc−2/CoIPc−3 (E½ = −1.26 V versus Ag|AgCl) species. No ring oxidation was observed in complex 3a. Complex 3b showed both ring-based oxidation, attributed to CoIIIPc−1/CoIIIPc−2 species (Ep = +0.86 V versus Ag|AgCl), and ring-based reduction associated with CoIPc−2/CoIPc−3 species (E½ = −1.46 V versus Ag|AgCl), with the normal metal-based redox processes in CoPc complexes: CoIIIPc−2/CoIIPc−2 (Ep = +0.41 V versus Ag|AgCl) and CoIIPc−2/CoIPc−2 (E½ = −0.38 V versus Ag|AgCl). Solution electrochemistry of complex 5 showed the same type and number of species observed in complex 3a: CoIIIPc−2/CoIIPc−2 (Ep = +0.59 V versus Ag|AgCl), CoIIPc−2/CoIPc−2 (E½ = −0.26 V versus Ag|AgCl) and CoIPc−2/CoIPc−3 (E½ = −1.39 V versus Ag|AgCl) species. These processes were confirmed using spectroelectrochemistry.
- Full Text:
- Date Issued: 2010
Synthesis and electrochemical characterisation of new tantalum (V) alkythio phthalocyanines
- Chauke, Vongani, Nyokong, Tebello
- Authors: Chauke, Vongani , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249093 , vital:51777 , xlink:href="https://doi.org/10.1016/j.ica.2010.05.003"
- Description: The synthesis and electrochemical characterisation of octa-pentylthio (4a) and octa-octylthio (4b) – phthalocyaninato tantalum (III) hydroxide are hereby reported. These TaPc complexes absorb in the near infrared region (∼800 nm in dichloromethane). They show good solubility in most common solvents especially non-viscous solvents such as dichloromethane and chloroform. NMR, mass and infrared spectroscopy and elemental analysis confirmed the structures and purity of the synthesised complexes. The cyclic voltammograms (CVs) showed reversible reduction couples and irreversible oxidation peaks. The latter exhibited adsorption behavior. The reduction processes were observed at −0.74 and −1.13 V (versus Ag|AgCl) for 4a, and −0.67, −1.02 and −1.48 V (versus Ag|AgCl) for 4b. Spectroelectrochemistry confirmed one metal reduction, with the rest of the redox processes being centered on the phthalocyanine ring.
- Full Text:
- Date Issued: 2010
- Authors: Chauke, Vongani , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249093 , vital:51777 , xlink:href="https://doi.org/10.1016/j.ica.2010.05.003"
- Description: The synthesis and electrochemical characterisation of octa-pentylthio (4a) and octa-octylthio (4b) – phthalocyaninato tantalum (III) hydroxide are hereby reported. These TaPc complexes absorb in the near infrared region (∼800 nm in dichloromethane). They show good solubility in most common solvents especially non-viscous solvents such as dichloromethane and chloroform. NMR, mass and infrared spectroscopy and elemental analysis confirmed the structures and purity of the synthesised complexes. The cyclic voltammograms (CVs) showed reversible reduction couples and irreversible oxidation peaks. The latter exhibited adsorption behavior. The reduction processes were observed at −0.74 and −1.13 V (versus Ag|AgCl) for 4a, and −0.67, −1.02 and −1.48 V (versus Ag|AgCl) for 4b. Spectroelectrochemistry confirmed one metal reduction, with the rest of the redox processes being centered on the phthalocyanine ring.
- Full Text:
- Date Issued: 2010
Synthesis and photophysical properties of 1, 1′-binaphthol substituted phthalocyanines
- Canlica, Meylude, Nyokong, Tebello
- Authors: Canlica, Meylude , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249148 , vital:51782 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.034"
- Description: We report on the synthesis, characterization and photophysical properties of a new symmetrically tetra substituted {at non-peripheral positions with tetra(1,1′-bi-binaphtoxy)} phthalocyanines containing H2, Mg(II), Al(III)Cl, Si(IV)Cl2 in the central cavity. The synthesized compounds were characterized by the elemental analyses, UV–Vis, FT-IR and 1H NMR spectroscopies. The fluorescence quantum yields, triplet quantum yields and lifetimes of the newly synthesized H2, Mg, Al, and Si phthalocyanines were explored. Triplet quantum yields ranged from 0.24 to 0.54. The triplet lifetime for the silicon phthalocyanine derivative was the highest ever reported for a phthalocyanine (∼3.5 ms).
- Full Text:
- Date Issued: 2010
- Authors: Canlica, Meylude , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249148 , vital:51782 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.034"
- Description: We report on the synthesis, characterization and photophysical properties of a new symmetrically tetra substituted {at non-peripheral positions with tetra(1,1′-bi-binaphtoxy)} phthalocyanines containing H2, Mg(II), Al(III)Cl, Si(IV)Cl2 in the central cavity. The synthesized compounds were characterized by the elemental analyses, UV–Vis, FT-IR and 1H NMR spectroscopies. The fluorescence quantum yields, triplet quantum yields and lifetimes of the newly synthesized H2, Mg, Al, and Si phthalocyanines were explored. Triplet quantum yields ranged from 0.24 to 0.54. The triplet lifetime for the silicon phthalocyanine derivative was the highest ever reported for a phthalocyanine (∼3.5 ms).
- Full Text:
- Date Issued: 2010
Synthetic pathways to water-soluble phthalocyanines and close analogs
- Dumoulin, Fabienne, Durmus, Mahmut, Ahsen, Vefa, Nyokong, Tebello
- Authors: Dumoulin, Fabienne , Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249082 , vital:51776 , xlink:href="https://doi.org/10.1016/j.ccr.2010.05.002"
- Description: The different types of water-soluble phthalocyanines are presented and their synthesis is reviewed.
- Full Text:
- Date Issued: 2010
- Authors: Dumoulin, Fabienne , Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249082 , vital:51776 , xlink:href="https://doi.org/10.1016/j.ccr.2010.05.002"
- Description: The different types of water-soluble phthalocyanines are presented and their synthesis is reviewed.
- Full Text:
- Date Issued: 2010
Teaching conflict-sensitive journalism:
- Authors: du Toit, Peter
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159449 , vital:40298 , https://hdl.handle.net/10520/EJC139358
- Description: We expect court reporters to know something about the law, financial journalists to have a grounding in economics, and parliamentary correspondents to understand politics, but many journalists are ill-equipped handle social phenomenon that is ubiquitous to most beats - conflict.
- Full Text:
- Date Issued: 2010
- Authors: du Toit, Peter
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159449 , vital:40298 , https://hdl.handle.net/10520/EJC139358
- Description: We expect court reporters to know something about the law, financial journalists to have a grounding in economics, and parliamentary correspondents to understand politics, but many journalists are ill-equipped handle social phenomenon that is ubiquitous to most beats - conflict.
- Full Text:
- Date Issued: 2010
Teaching journalism to produce “interpretive communities" rather than just “professionals”:
- Authors: Garman, Anthea
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159846 , vital:40349 , DOI: 10.1080/02560054.2005.9653330
- Description: Debates about whether journalism is a “trade” and can only be learnt “on the job”, or whether journalism should even be taught at universities, are no longer fruitful or even interesting for teachers in tertiary environments. The far more important discussion around the teaching of journalism should be on the approach which focuses too exclusively on its nature as a “profession” and so ignores the critical function of journalists in the world as “interpretive communities”.
- Full Text:
- Date Issued: 2010
- Authors: Garman, Anthea
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159846 , vital:40349 , DOI: 10.1080/02560054.2005.9653330
- Description: Debates about whether journalism is a “trade” and can only be learnt “on the job”, or whether journalism should even be taught at universities, are no longer fruitful or even interesting for teachers in tertiary environments. The far more important discussion around the teaching of journalism should be on the approach which focuses too exclusively on its nature as a “profession” and so ignores the critical function of journalists in the world as “interpretive communities”.
- Full Text:
- Date Issued: 2010
Technology solutions to strengthen the integration of marginalized communities into the global knowledge society
- Hlungulu, Bulumko, Kunjuzwa, Dumani, Ndlovu, Nyankiso, Samalenge, Jimmy, Sikhumbuzo, Ngwenya, Thinyane, Mamello, Terzoli, Alfredo
- Authors: Hlungulu, Bulumko , Kunjuzwa, Dumani , Ndlovu, Nyankiso , Samalenge, Jimmy , Sikhumbuzo, Ngwenya , Thinyane, Mamello , Terzoli, Alfredo
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430769 , vital:72714 , https://ieeexplore.ieee.org/abstract/document/5753005
- Description: Information and Communication Technology (ICT) has made it possible to explore novel and innovative mechanisms to leap-frog socio-economic development in rural and marginalized communities. An ICT for development intervention called Siyakhula Living Lab (SLL) has been underway in Dwesa, a rural community in the Eastern Cape Prov-ince, for the past four years. The living lab methodology, which enables user-driven innovation within a multi-stakeholder relationship of aca-demia, user communities, government and private industry, has facili-tated greater integration of the Dwesa community into the digital ecolo-gy and subsequently the knowledge society. This paper introduces the SLL intervention, discusses the SLL's supporting technical infrastruc-ture and the interventions that are undertaken towards long-term sus-tainability of the project. The developed eServices are also discussed, with a view to highlighting the key characteristics that contribute to in-creased context-sensitivity, ownership, and buy-in from the community.
- Full Text:
- Date Issued: 2010
- Authors: Hlungulu, Bulumko , Kunjuzwa, Dumani , Ndlovu, Nyankiso , Samalenge, Jimmy , Sikhumbuzo, Ngwenya , Thinyane, Mamello , Terzoli, Alfredo
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430769 , vital:72714 , https://ieeexplore.ieee.org/abstract/document/5753005
- Description: Information and Communication Technology (ICT) has made it possible to explore novel and innovative mechanisms to leap-frog socio-economic development in rural and marginalized communities. An ICT for development intervention called Siyakhula Living Lab (SLL) has been underway in Dwesa, a rural community in the Eastern Cape Prov-ince, for the past four years. The living lab methodology, which enables user-driven innovation within a multi-stakeholder relationship of aca-demia, user communities, government and private industry, has facili-tated greater integration of the Dwesa community into the digital ecolo-gy and subsequently the knowledge society. This paper introduces the SLL intervention, discusses the SLL's supporting technical infrastruc-ture and the interventions that are undertaken towards long-term sus-tainability of the project. The developed eServices are also discussed, with a view to highlighting the key characteristics that contribute to in-creased context-sensitivity, ownership, and buy-in from the community.
- Full Text:
- Date Issued: 2010
The ambivalence of African elitehood:
- Authors: Matthews, Sally
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142442 , vital:38080 , DOI: 10.1177/0021909609357416
- Description: Recent discussions in South Africa about the role of the so-called patriotic bourgeoisie highlight the much debated question of what role elite Africans can and ought to play in the upliftment of the poor. Those supporting the notion of a patriotic bourgeoisie believe that national or racial solidarity is sufficient to allow privileged Africans to act in the interests of their poorer fellow citizens. However, a reconsideration of an older discussion of African elitehood, that of Amilcar Cabral, suggests that something more may be needed before elites can act in the interests of the poor. Cabral argues that elites need to renounce their privilege and to live and struggle alongside the poor if pro-poor societal transformation is to be achieved. While Cabral may be right that shared racial or national identity is insufficient for elite solidarity with the poor, he does not consider all the complexities that arise when elites actually try to work with and for the poor. A consideration of the experiences of a long-standing Senegalese NGO reveal some of these complexities and suggest that any attempt by African elites to engage meaningfully in the upliftment of the poor, will inevitably involve continuous and difficult negotiation between paternalism and naïve egalitarianism.
- Full Text:
- Date Issued: 2010
- Authors: Matthews, Sally
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142442 , vital:38080 , DOI: 10.1177/0021909609357416
- Description: Recent discussions in South Africa about the role of the so-called patriotic bourgeoisie highlight the much debated question of what role elite Africans can and ought to play in the upliftment of the poor. Those supporting the notion of a patriotic bourgeoisie believe that national or racial solidarity is sufficient to allow privileged Africans to act in the interests of their poorer fellow citizens. However, a reconsideration of an older discussion of African elitehood, that of Amilcar Cabral, suggests that something more may be needed before elites can act in the interests of the poor. Cabral argues that elites need to renounce their privilege and to live and struggle alongside the poor if pro-poor societal transformation is to be achieved. While Cabral may be right that shared racial or national identity is insufficient for elite solidarity with the poor, he does not consider all the complexities that arise when elites actually try to work with and for the poor. A consideration of the experiences of a long-standing Senegalese NGO reveal some of these complexities and suggest that any attempt by African elites to engage meaningfully in the upliftment of the poor, will inevitably involve continuous and difficult negotiation between paternalism and naïve egalitarianism.
- Full Text:
- Date Issued: 2010
The commercial agricultural economy of the East Cape: Die kommersiële landbou-ekonomie van die Oos-Kaap
- Authors: Antrobus, Geoffrey G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143079 , vital:38199 , DOI: 10.1080/03031853.1991.9524228
- Description: The East Cape, and in particular the Smaldeel area, is used to exemplify some of the characteristics and problems of commercial farming over a period of about three decades to serve as a backdrop for the broader theme of normalising South African agriculture. The regional economy is dominated by Port Elizabeth-Uitenhage and East London which account for most of the population and three-fourths of the Gross Geographic Product (GGP). Agriculture accounts for only 10% of GGP, but is one of the most labour intensive sectors in a region with 24% of its population unemployed. The agricultural economy of the region is very diversified, but livestock farming plays the most important part in all areas contributing 72% of gross income. The chief changes which have occured in East Cape farming, as elsewhere, have been the decline in the number of farms and increase in farm size, greater capital investment, increased specialisation and declining employment.
- Full Text:
- Date Issued: 2010
- Authors: Antrobus, Geoffrey G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143079 , vital:38199 , DOI: 10.1080/03031853.1991.9524228
- Description: The East Cape, and in particular the Smaldeel area, is used to exemplify some of the characteristics and problems of commercial farming over a period of about three decades to serve as a backdrop for the broader theme of normalising South African agriculture. The regional economy is dominated by Port Elizabeth-Uitenhage and East London which account for most of the population and three-fourths of the Gross Geographic Product (GGP). Agriculture accounts for only 10% of GGP, but is one of the most labour intensive sectors in a region with 24% of its population unemployed. The agricultural economy of the region is very diversified, but livestock farming plays the most important part in all areas contributing 72% of gross income. The chief changes which have occured in East Cape farming, as elsewhere, have been the decline in the number of farms and increase in farm size, greater capital investment, increased specialisation and declining employment.
- Full Text:
- Date Issued: 2010
The determination of acetaminophen using a carbon nanotube: graphite-based electrode
- Moghaddam, Abdolmajid B, Mohammadi, Ali, Mohammadi, Somaye, Rayeji, Danyal, Dinarvand, Rassoul, Baghi, Mansoureh, Walker, Roderick B
- Authors: Moghaddam, Abdolmajid B , Mohammadi, Ali , Mohammadi, Somaye , Rayeji, Danyal , Dinarvand, Rassoul , Baghi, Mansoureh , Walker, Roderick B
- Date: 2010
- Language: English
- Type: Article , text
- Identifier: vital:6414 , http://hdl.handle.net/10962/d1006509
- Description: The oxidation of acetaminophen was studied at a glassy carbon electrode modified with multi-walled carbon nanotubes and a graphite paste. Cyclic voltammety, differential pulse voltammetry and square wave voltammetry at various pH values, scan rates, and the effect of the ratio of nanotubes to graphite were investigated in order to optimize the parameters for the determination of acetaminophen. Square wave voltammetry is the most appropriate technique in giving a characteristic peak at 0.52 V at pH 5. The porous nanostructure of the electrode improves the surface area which results in an increase in the peak current. The voltammetric response is linear in the range between 75 and 2000 ng.mL−1, with standard deviations between 0.25 and 7.8%, and a limit of detection of 25 ng.mL−1. The method has been successfully applied to the analysis of acetaminophen in tablets and biological fluids.
- Full Text:
- Date Issued: 2010
- Authors: Moghaddam, Abdolmajid B , Mohammadi, Ali , Mohammadi, Somaye , Rayeji, Danyal , Dinarvand, Rassoul , Baghi, Mansoureh , Walker, Roderick B
- Date: 2010
- Language: English
- Type: Article , text
- Identifier: vital:6414 , http://hdl.handle.net/10962/d1006509
- Description: The oxidation of acetaminophen was studied at a glassy carbon electrode modified with multi-walled carbon nanotubes and a graphite paste. Cyclic voltammety, differential pulse voltammetry and square wave voltammetry at various pH values, scan rates, and the effect of the ratio of nanotubes to graphite were investigated in order to optimize the parameters for the determination of acetaminophen. Square wave voltammetry is the most appropriate technique in giving a characteristic peak at 0.52 V at pH 5. The porous nanostructure of the electrode improves the surface area which results in an increase in the peak current. The voltammetric response is linear in the range between 75 and 2000 ng.mL−1, with standard deviations between 0.25 and 7.8%, and a limit of detection of 25 ng.mL−1. The method has been successfully applied to the analysis of acetaminophen in tablets and biological fluids.
- Full Text:
- Date Issued: 2010
The effects of economic incentives in controlling pollution in the South African leather industry: die uitwerking van ekonomiese insentiewe op die beheer van besoedeling in die Suid-Afrikaanse leerbedryf
- Mowat, Shaun P, Antrobus, Geoffrey G, Fraser, Gavin C G
- Authors: Mowat, Shaun P , Antrobus, Geoffrey G , Fraser, Gavin C G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143057 , vital:38197 , DOI: 10.1080/03031853.1997.9523487
- Description: Pollution of the environment is becoming an increasingly serious problem. A large contributor to this is industry which generates effluent as a by-product of its production process. Two methods of controlling the pollution generated by industry are the so-called “command and control” techniques and economic incentives. In theory, economic incentives promise a more economically efficient and equitable means of pollution control. This paper sets out to ascertain whether this would hold in practice by applying environmental economic theory to the practical problem of controlling the effluent generated by one particular industry, viz the South African leather industry.
- Full Text:
- Date Issued: 2010
- Authors: Mowat, Shaun P , Antrobus, Geoffrey G , Fraser, Gavin C G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143057 , vital:38197 , DOI: 10.1080/03031853.1997.9523487
- Description: Pollution of the environment is becoming an increasingly serious problem. A large contributor to this is industry which generates effluent as a by-product of its production process. Two methods of controlling the pollution generated by industry are the so-called “command and control” techniques and economic incentives. In theory, economic incentives promise a more economically efficient and equitable means of pollution control. This paper sets out to ascertain whether this would hold in practice by applying environmental economic theory to the practical problem of controlling the effluent generated by one particular industry, viz the South African leather industry.
- Full Text:
- Date Issued: 2010
The effects of point of substitution on the electrochemical behavior of new manganese phthalocyanines, tetra-substituted with diethylaminoethanethiol
- Akinbulu, Isaac Adebayo, Nyokong, Tebello
- Authors: Akinbulu, Isaac Adebayo , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249137 , vital:51781 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.003"
- Description: The syntheses and comparative studies of the spectral, voltammetry and spectroelectrochemical properties of new manganese phthalocyanine complexes, tetra-substituted with diethylaminoethanethio at the peripheral (complex 3a) and non-peripheral positions (complex 3b) are reported. Solution electrochemistry of complex 3a showed quasi-reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.07 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.78 V vs. Ag|AgCl) reductions, but no ring-based oxidation. However, complex 3b showed weak irreversible ring-oxidation signal (Ep = +0.86 vs. Ag|AgCl). Reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.04 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.68 V vs. Ag|AgCl) reductions were also observed for complex 3b. Spectroelectrochemistry was used to confirm these processes. Reduction process involving the metal (MnIIIPc−2/MnIIPc−2) was associated with the formation of manganese μ-oxo complex in complex 3a.
- Full Text:
- Date Issued: 2010
- Authors: Akinbulu, Isaac Adebayo , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249137 , vital:51781 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.003"
- Description: The syntheses and comparative studies of the spectral, voltammetry and spectroelectrochemical properties of new manganese phthalocyanine complexes, tetra-substituted with diethylaminoethanethio at the peripheral (complex 3a) and non-peripheral positions (complex 3b) are reported. Solution electrochemistry of complex 3a showed quasi-reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.07 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.78 V vs. Ag|AgCl) reductions, but no ring-based oxidation. However, complex 3b showed weak irreversible ring-oxidation signal (Ep = +0.86 vs. Ag|AgCl). Reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.04 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.68 V vs. Ag|AgCl) reductions were also observed for complex 3b. Spectroelectrochemistry was used to confirm these processes. Reduction process involving the metal (MnIIIPc−2/MnIIPc−2) was associated with the formation of manganese μ-oxo complex in complex 3a.
- Full Text:
- Date Issued: 2010
The effects of point of substitution on the formation of manganese phthalocyanine-based molecular materials
- Akinbulu, Isaac Adebayo, Khene, Samson, Nyokong, Tebello
- Authors: Akinbulu, Isaac Adebayo , Khene, Samson , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249103 , vital:51778 , xlink:href="https://doi.org/10.1016/j.tsf.2010.08.145"
- Description: Molecular films of manganese phthalocyanine (MnPc) complexes, tetra-substituted with 2-diethylaminoethanethio at the peripheral (Mn(OAc)-β-TDEAETPc, 1) and non-peripheral (Mn(OAc)-α-TDEAETPc, 2) positions were formed on glassy carbon electrode by electropolymerization and electrodeposition respectively. Atomic force microscopy images confirmed the presence of the films and revealed significant morphological differences. The films exhibited an electrocatalytic activity towards the oxidation of the insecticide, bendiocarb. Hydrodynamic technique, using rotating disc electrode voltammetry, was used to investigate the kinetics of electro-oxidation of the insecticide. Morphological differences of the films significantly influenced kinetic parameters. Values of Tafel slopes, obtained from Tafel plots, suggested that catalysis of bendiocarb occurred via outer sphere mechanism.
- Full Text:
- Date Issued: 2010
- Authors: Akinbulu, Isaac Adebayo , Khene, Samson , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249103 , vital:51778 , xlink:href="https://doi.org/10.1016/j.tsf.2010.08.145"
- Description: Molecular films of manganese phthalocyanine (MnPc) complexes, tetra-substituted with 2-diethylaminoethanethio at the peripheral (Mn(OAc)-β-TDEAETPc, 1) and non-peripheral (Mn(OAc)-α-TDEAETPc, 2) positions were formed on glassy carbon electrode by electropolymerization and electrodeposition respectively. Atomic force microscopy images confirmed the presence of the films and revealed significant morphological differences. The films exhibited an electrocatalytic activity towards the oxidation of the insecticide, bendiocarb. Hydrodynamic technique, using rotating disc electrode voltammetry, was used to investigate the kinetics of electro-oxidation of the insecticide. Morphological differences of the films significantly influenced kinetic parameters. Values of Tafel slopes, obtained from Tafel plots, suggested that catalysis of bendiocarb occurred via outer sphere mechanism.
- Full Text:
- Date Issued: 2010
The Fishes of Zimbabwe and their Biology
- Authors: Marshall, Brian
- Date: 2010
- Subjects: Estuarine fishes -- Zimbabwe , Estuarine fishes -- Africa, Southern , Fishes -- Africa, Southern -- Identification , Estuaries -- Africa, Southern
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/167948 , vital:41524
- Description: The first comprehensive book on the fishes of Zimbabwe appeared in 1961 and was written by Rex Jubb. He followed it with a major treatise on the fishes of southern Africa published in 1967. These books were published at a time when interest in fishes – partly stimulated by the creation of Lake Kariba –was growing, and they were welcomed by anglers and scientists alike. Zimbabwean ichthyology progressed rapidly during the years following their publication and knowledge about our fishes grew steadily. New insights and understanding of their systematics led to numerous taxonomic revisions, bringing with them inevitable changes to their scientific names. At the same time increased collecting meant that new species were being added to the Zimbabwean list. By the early 1970s Jubb’s books had become outdated and there was a clear need for a new volume on the fishes of this country. The National Museums and Monuments met this need by publishing Graham Bell-Cross’ The Fishes of Rhodesia in 1976. This book was available at a remarkably low price and such was its popularity that it was soon out of print. It rapidly became outdated as well and was revised by John Minshull as the Fishes of Zimbabwe, published in 1988. This version had a number of new features such as the inclusion of exotic species and species discovered in the country since 1976, as well as name changes brought about by new developments in taxonomy. It, too, was available at a very low price and has proved to be very popular; the demand was so great that it was reprinted without alteration in the 1990s. By this time, however, it had also become outdated and there was a need for yet another revision, or for a completely new type of book. I have chosen the latter option in preparing this book, since there seemed little point in attempting to revise the earlier ones within their original format. I felt that it would not be desirable to produce another field guide type of book that would have to compete with Paul Skelton’s superb volume, A Complete Guide to the Freshwater Fishes of Southern Africa, first published in 1993, with a second edition eight years later. Instead, I decided that I should try to summarise the existing data about fishes in Zimbabwe. My dealings with students and inexperienced fish biologists has made it clear that many of them do not know what work has been done, or not done, on Zimbabwe’s fishes and they are not familiar with the literature. Much of it is, in any case, to be found in obscure publications that are not readily available in Zimbabwean libraries, which have declined in recent years and no longer subscribe to major international journals or even to local ones. This makes it very difficult to keep up with information or to track it down. I am aware, of course, that such a book will never be complete and may already be outdated at the time of its publication, but I hope that it will supply the basic background information for anyone interested in Zimbabwean fishes and provide a platform from which further studies can be launched. Wherever possible, I have used only data from Zimbabwe, although there may be an extensive literature from other countries for widespread or economically important species, such as Clarias gariepinus or Oreochromis mossambicus. This was a conscious decision because I wanted to summarise what is known about the fish in this country, so that other workers can assess what still needs to be done. Nevertheless, I have used some data from outside Zimbabwe, especially for fish from the upper Zambezi because of its relevance to our situation. As far as possible I have tried to use only published works as references, with the exception of university theses and some institutional reports, since most unpublished work is generally difficult to locate and ephemeral. The scientific names of fishes often change as systematic knowledge advances and the reader will note that there have been many changes since Bell-Cross & Minshull (1988) was published. Common names are a problem because of local variations and anglers in particular have various names (or nicknames) for popular angling species; I have used the standard names with these other names included in brackets where necessary.
- Full Text:
- Date Issued: 2010
- Authors: Marshall, Brian
- Date: 2010
- Subjects: Estuarine fishes -- Zimbabwe , Estuarine fishes -- Africa, Southern , Fishes -- Africa, Southern -- Identification , Estuaries -- Africa, Southern
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/167948 , vital:41524
- Description: The first comprehensive book on the fishes of Zimbabwe appeared in 1961 and was written by Rex Jubb. He followed it with a major treatise on the fishes of southern Africa published in 1967. These books were published at a time when interest in fishes – partly stimulated by the creation of Lake Kariba –was growing, and they were welcomed by anglers and scientists alike. Zimbabwean ichthyology progressed rapidly during the years following their publication and knowledge about our fishes grew steadily. New insights and understanding of their systematics led to numerous taxonomic revisions, bringing with them inevitable changes to their scientific names. At the same time increased collecting meant that new species were being added to the Zimbabwean list. By the early 1970s Jubb’s books had become outdated and there was a clear need for a new volume on the fishes of this country. The National Museums and Monuments met this need by publishing Graham Bell-Cross’ The Fishes of Rhodesia in 1976. This book was available at a remarkably low price and such was its popularity that it was soon out of print. It rapidly became outdated as well and was revised by John Minshull as the Fishes of Zimbabwe, published in 1988. This version had a number of new features such as the inclusion of exotic species and species discovered in the country since 1976, as well as name changes brought about by new developments in taxonomy. It, too, was available at a very low price and has proved to be very popular; the demand was so great that it was reprinted without alteration in the 1990s. By this time, however, it had also become outdated and there was a need for yet another revision, or for a completely new type of book. I have chosen the latter option in preparing this book, since there seemed little point in attempting to revise the earlier ones within their original format. I felt that it would not be desirable to produce another field guide type of book that would have to compete with Paul Skelton’s superb volume, A Complete Guide to the Freshwater Fishes of Southern Africa, first published in 1993, with a second edition eight years later. Instead, I decided that I should try to summarise the existing data about fishes in Zimbabwe. My dealings with students and inexperienced fish biologists has made it clear that many of them do not know what work has been done, or not done, on Zimbabwe’s fishes and they are not familiar with the literature. Much of it is, in any case, to be found in obscure publications that are not readily available in Zimbabwean libraries, which have declined in recent years and no longer subscribe to major international journals or even to local ones. This makes it very difficult to keep up with information or to track it down. I am aware, of course, that such a book will never be complete and may already be outdated at the time of its publication, but I hope that it will supply the basic background information for anyone interested in Zimbabwean fishes and provide a platform from which further studies can be launched. Wherever possible, I have used only data from Zimbabwe, although there may be an extensive literature from other countries for widespread or economically important species, such as Clarias gariepinus or Oreochromis mossambicus. This was a conscious decision because I wanted to summarise what is known about the fish in this country, so that other workers can assess what still needs to be done. Nevertheless, I have used some data from outside Zimbabwe, especially for fish from the upper Zambezi because of its relevance to our situation. As far as possible I have tried to use only published works as references, with the exception of university theses and some institutional reports, since most unpublished work is generally difficult to locate and ephemeral. The scientific names of fishes often change as systematic knowledge advances and the reader will note that there have been many changes since Bell-Cross & Minshull (1988) was published. Common names are a problem because of local variations and anglers in particular have various names (or nicknames) for popular angling species; I have used the standard names with these other names included in brackets where necessary.
- Full Text:
- Date Issued: 2010