Strategy formulation, alignment and implementation to ensure that Behr is competitive internationally : a case study
- Authors: Samuels, Donald
- Date: 2006
- Subjects: Automobile industry and trade -- South Africa , Competition, International , Globalization , Strategic planning
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8761 , http://hdl.handle.net/10948/600 , http://hdl.handle.net/10948/d1011685 , Automobile industry and trade -- South Africa , Competition, International , Globalization , Strategic planning
- Description: South Africa’s transition to democracy in 1994 has heralded a re-entry into the global economy. This has meant that for the first time in more than 40 years of isolation because of “apartheid” policies, South African companies are facing global competition. The South African automotive industry has undergone major changes over the past few years. All the assemblers are now either wholly or partially owned by overseas parent companies. Under globalisation, foreign ownership of locally owned suppliers has also been escalating. The Behr strategy and values were examined to determine whether they are consistent with companies operating in the international environment. The literature study was conducted by using textbooks, periodicals and the internet. The empirical study was conducted by means of a questionnaire addressed to the Behr executives. The results of this empirical study were then directly correlated to the theoretical aspects. Distinctive competences, market growth and product development strategies were identified and comparisons made with theory.
- Full Text:
- Date Issued: 2006
- Authors: Samuels, Donald
- Date: 2006
- Subjects: Automobile industry and trade -- South Africa , Competition, International , Globalization , Strategic planning
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8761 , http://hdl.handle.net/10948/600 , http://hdl.handle.net/10948/d1011685 , Automobile industry and trade -- South Africa , Competition, International , Globalization , Strategic planning
- Description: South Africa’s transition to democracy in 1994 has heralded a re-entry into the global economy. This has meant that for the first time in more than 40 years of isolation because of “apartheid” policies, South African companies are facing global competition. The South African automotive industry has undergone major changes over the past few years. All the assemblers are now either wholly or partially owned by overseas parent companies. Under globalisation, foreign ownership of locally owned suppliers has also been escalating. The Behr strategy and values were examined to determine whether they are consistent with companies operating in the international environment. The literature study was conducted by using textbooks, periodicals and the internet. The empirical study was conducted by means of a questionnaire addressed to the Behr executives. The results of this empirical study were then directly correlated to the theoretical aspects. Distinctive competences, market growth and product development strategies were identified and comparisons made with theory.
- Full Text:
- Date Issued: 2006
Structure and distribution of the slope fish community in the vicinity of the sub-Antarctic Prince Edward Archipelago
- Pakhomov, E A, Bushula, T, Kaehler, Sven, Watkins, B P, Leslie, R W
- Authors: Pakhomov, E A , Bushula, T , Kaehler, Sven , Watkins, B P , Leslie, R W
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6958 , http://hdl.handle.net/10962/d1012000
- Description: Demersal fish community structure, distribution and trophic relationships on the slope (depth range 200–1500 m) of the sub-Antarctic Prince Edward Islands and surrounding sea rises were investigated during a pilot survey conducted in April 2001 onboard fishing vessel MV Iris. A total of 56 fish taxa were collected during the survey, of which 44 were identified to the species level, seven to the genus level and five to the family level. Among the identified taxa, 36 constituted new records for the area investigated. Total catch per unit effort (cpue) during the survey ranged from 1•1 to 241•2 individuals h 1. Both average fish diversity and total cpue positively correlated with trawling depth. Overall, mean sampling depth and near-bottom temperature explained 56% of total fish cpue. Hierarchal cluster analysis identified three distinct fish assemblages with pronounced dominant species. Major shifts in fish community composition occurred at 500–600 m and 800–900 m depth strata and could probably be a result of physical and biological vertical zonation. Analysis of the diet of selected fish species showed that they were generalist feeders, consuming predominantly pelagic, including epipelagic, meso- and benthopelagic, prey. Diets of six species and nitrogen stable isotope signatures of 22 species revealed that with a few exceptions most fishes occupied the fourth trophic level and were tertiary consumers. Wide variability in carbon isotopic signatures is discussed with respect to alternative, e.g. possible importance of high Antarctic and chemoautotrophic v. photoautotrophic sub-Antarctic primary production, organic matter sources at the base of deep-sea food webs.
- Full Text:
- Date Issued: 2006
- Authors: Pakhomov, E A , Bushula, T , Kaehler, Sven , Watkins, B P , Leslie, R W
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6958 , http://hdl.handle.net/10962/d1012000
- Description: Demersal fish community structure, distribution and trophic relationships on the slope (depth range 200–1500 m) of the sub-Antarctic Prince Edward Islands and surrounding sea rises were investigated during a pilot survey conducted in April 2001 onboard fishing vessel MV Iris. A total of 56 fish taxa were collected during the survey, of which 44 were identified to the species level, seven to the genus level and five to the family level. Among the identified taxa, 36 constituted new records for the area investigated. Total catch per unit effort (cpue) during the survey ranged from 1•1 to 241•2 individuals h 1. Both average fish diversity and total cpue positively correlated with trawling depth. Overall, mean sampling depth and near-bottom temperature explained 56% of total fish cpue. Hierarchal cluster analysis identified three distinct fish assemblages with pronounced dominant species. Major shifts in fish community composition occurred at 500–600 m and 800–900 m depth strata and could probably be a result of physical and biological vertical zonation. Analysis of the diet of selected fish species showed that they were generalist feeders, consuming predominantly pelagic, including epipelagic, meso- and benthopelagic, prey. Diets of six species and nitrogen stable isotope signatures of 22 species revealed that with a few exceptions most fishes occupied the fourth trophic level and were tertiary consumers. Wide variability in carbon isotopic signatures is discussed with respect to alternative, e.g. possible importance of high Antarctic and chemoautotrophic v. photoautotrophic sub-Antarctic primary production, organic matter sources at the base of deep-sea food webs.
- Full Text:
- Date Issued: 2006
Studies of equivalent fuzzy subgroups of finite abelian p-Groups of rank two and their subgroup lattices
- Authors: Ngcibi, Sakhile Leonard
- Date: 2006
- Subjects: Abelian groups Fuzzy sets Finite groups Group theory Polynomials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5416 , http://hdl.handle.net/10962/d1005230
- Description: We determine the number and nature of distinct equivalence classes of fuzzy subgroups of finite Abelian p-group G of rank two under a natural equivalence relation on fuzzy subgroups. Our discussions embrace the necessary theory from groups with special emphasis on finite p-groups as a step towards the classification of crisp subgroups as well as maximal chains of subgroups. Unique naming of subgroup generators as discussed in this work facilitates counting of subgroups and chains of subgroups from subgroup lattices of the groups. We cover aspects of fuzzy theory including fuzzy (homo-) isomorphism together with operations on fuzzy subgroups. The equivalence characterization as discussed here is finer than isomorphism. We introduce the theory of keychains with a view towards the enumeration of maximal chains as well as fuzzy subgroups under the equivalence relation mentioned above. We discuss a strategy to develop subgroup lattices of the groups used in the discussion, and give examples for specific cases of prime p and positive integers n,m. We derive formulas for both the number of maximal chains as well as the number of distinct equivalence classes of fuzzy subgroups. The results are in the form of polynomials in p (known in the literature as Hall polynomials) with combinatorial coefficients. Finally we give a brief investigation of the results from a graph-theoretic point of view. We view the subgroup lattices of these groups as simple, connected, symmetric graphs.
- Full Text:
- Date Issued: 2006
- Authors: Ngcibi, Sakhile Leonard
- Date: 2006
- Subjects: Abelian groups Fuzzy sets Finite groups Group theory Polynomials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5416 , http://hdl.handle.net/10962/d1005230
- Description: We determine the number and nature of distinct equivalence classes of fuzzy subgroups of finite Abelian p-group G of rank two under a natural equivalence relation on fuzzy subgroups. Our discussions embrace the necessary theory from groups with special emphasis on finite p-groups as a step towards the classification of crisp subgroups as well as maximal chains of subgroups. Unique naming of subgroup generators as discussed in this work facilitates counting of subgroups and chains of subgroups from subgroup lattices of the groups. We cover aspects of fuzzy theory including fuzzy (homo-) isomorphism together with operations on fuzzy subgroups. The equivalence characterization as discussed here is finer than isomorphism. We introduce the theory of keychains with a view towards the enumeration of maximal chains as well as fuzzy subgroups under the equivalence relation mentioned above. We discuss a strategy to develop subgroup lattices of the groups used in the discussion, and give examples for specific cases of prime p and positive integers n,m. We derive formulas for both the number of maximal chains as well as the number of distinct equivalence classes of fuzzy subgroups. The results are in the form of polynomials in p (known in the literature as Hall polynomials) with combinatorial coefficients. Finally we give a brief investigation of the results from a graph-theoretic point of view. We view the subgroup lattices of these groups as simple, connected, symmetric graphs.
- Full Text:
- Date Issued: 2006
Study South Africa
- International Education Association of South Africa (IEASA), Higher Education South Africa (Organization), Kishun, Roshen
- Authors: International Education Association of South Africa (IEASA) , Higher Education South Africa (Organization) , Kishun, Roshen
- Date: 2006
- 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/10962/65386 , vital:28754 , ISBN 0620367652
- Description: [Extract from message from Minister of Higher Education, Hon. Naledi Pandor]: It is a great pleasure for me to give a word of support to the sixth edition of Study South Africa: The Guide to South African Higher Education. I am particularly pleased with the effort and level of commitment shown by the International Education Association of South Africa (IEASA) in promoting South African higher education institutions internationally. The internationalisation of our higher education system is an acknowledgement that South African universities have a valuable contribution to make to the global higher education community, and in particular on the African continent. In this regard, I am pleased to note that of the 52,000 international students enrolled in our institutions, the majority come from the African continent. South Africa's higher education institutions offer unique benefits for international students, blending the experience of living in Africa with the opportunity to obtain internationally recognised qualifications at reasonably affordable costs. Also, high quality educational infrastructure, unique research opportunities, and a rich variety of cultures make South Africa one of the favourable study destinations for many international students. More than ever before our institutions are working hard to ensure that they provide high quality education, comparable to the best in the world. Our institutions continue to strive towards excellence and also to encourage international students, particularly those from Africa, upon completion of their studies to go back and make valuable contributions to the socio-economic development of their home countries. IEASA, Higher Education South Africa (HESA) and our universities have played a valuable role in reinforcing South Africa's international relations in academic and research exchange programmes. The Ministry would like to take this opportunity to commend IEASA and HESA for the dedicated efforts and targeted interventions made towards achieving our national priorities. , 6th Edition
- Full Text:
- Date Issued: 2006
- Authors: International Education Association of South Africa (IEASA) , Higher Education South Africa (Organization) , Kishun, Roshen
- Date: 2006
- 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/10962/65386 , vital:28754 , ISBN 0620367652
- Description: [Extract from message from Minister of Higher Education, Hon. Naledi Pandor]: It is a great pleasure for me to give a word of support to the sixth edition of Study South Africa: The Guide to South African Higher Education. I am particularly pleased with the effort and level of commitment shown by the International Education Association of South Africa (IEASA) in promoting South African higher education institutions internationally. The internationalisation of our higher education system is an acknowledgement that South African universities have a valuable contribution to make to the global higher education community, and in particular on the African continent. In this regard, I am pleased to note that of the 52,000 international students enrolled in our institutions, the majority come from the African continent. South Africa's higher education institutions offer unique benefits for international students, blending the experience of living in Africa with the opportunity to obtain internationally recognised qualifications at reasonably affordable costs. Also, high quality educational infrastructure, unique research opportunities, and a rich variety of cultures make South Africa one of the favourable study destinations for many international students. More than ever before our institutions are working hard to ensure that they provide high quality education, comparable to the best in the world. Our institutions continue to strive towards excellence and also to encourage international students, particularly those from Africa, upon completion of their studies to go back and make valuable contributions to the socio-economic development of their home countries. IEASA, Higher Education South Africa (HESA) and our universities have played a valuable role in reinforcing South Africa's international relations in academic and research exchange programmes. The Ministry would like to take this opportunity to commend IEASA and HESA for the dedicated efforts and targeted interventions made towards achieving our national priorities. , 6th Edition
- Full Text:
- Date Issued: 2006
Substituted phthalocyanines development and self-assembled monolayer sensor studies
- Authors: Matemadombo, Fungisai
- Date: 2006
- Subjects: Phthalocyanines , Monomolecular films , Electrochemistry , Spectrum analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4364 , http://hdl.handle.net/10962/d1005029 , Phthalocyanines , Monomolecular films , Electrochemistry , Spectrum analysis
- Description: Zinc, cobalt and iron phenylthio substituted phthalocyanines have been synthesized and characterized. Cyclic and square wave voltammetry in dimethylformamide containing tetrabutylammonium perchlorate revealed five and six redox processes respectively for the cobalt and iron phenylthio substituted phthalocyanines. These complexes are easier to reduce compared to the corresponding unsubstituted MPc and to butylthio substituted derivatives. Spectroelectrochemistry (in dimethylformamide containing tetrabutylammonium perchlorate) was employed to assign the cyclic voltammetry peaks, and gave spectra characteristic of Fe(I)Pc for reduction of iron phenylthio substituted phthalocyanine and Co(I)Pc for the reduction of cobalt phenylthio substituted phthalocyanine. The spectrum of the former is particularly of importance since such species have not received much attention in literature. Cobalt and iron phenylthio substituted phthalocyanines have been deposited on Au electrode surfaces through the self assembled monolayer (SAM) technique. The so formed layers were studied using voltammetric techniques. These SAMs blocked a number of Faradic processes and electrocatalyzed the oxidation of L-cysteine. Amine substituted cobalt phthalocyanine (CoTAPc) was deposited on gold surfaces by using an interconnecting SAM of mercaptopropionic acid or dithiobis(N-succinimidyl propionate) through the creation of an amide. Reductive and oxidative desorption of the SAMs limit the useful potential window. The SAM-CoTAPc layers show electrocatalytic activities towards oxygen reduction through the Co(I) central metal ion. Both SAMs were highly stable and hence will be interesting tools for further research in surface modification and sensor development.
- Full Text:
- Date Issued: 2006
- Authors: Matemadombo, Fungisai
- Date: 2006
- Subjects: Phthalocyanines , Monomolecular films , Electrochemistry , Spectrum analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4364 , http://hdl.handle.net/10962/d1005029 , Phthalocyanines , Monomolecular films , Electrochemistry , Spectrum analysis
- Description: Zinc, cobalt and iron phenylthio substituted phthalocyanines have been synthesized and characterized. Cyclic and square wave voltammetry in dimethylformamide containing tetrabutylammonium perchlorate revealed five and six redox processes respectively for the cobalt and iron phenylthio substituted phthalocyanines. These complexes are easier to reduce compared to the corresponding unsubstituted MPc and to butylthio substituted derivatives. Spectroelectrochemistry (in dimethylformamide containing tetrabutylammonium perchlorate) was employed to assign the cyclic voltammetry peaks, and gave spectra characteristic of Fe(I)Pc for reduction of iron phenylthio substituted phthalocyanine and Co(I)Pc for the reduction of cobalt phenylthio substituted phthalocyanine. The spectrum of the former is particularly of importance since such species have not received much attention in literature. Cobalt and iron phenylthio substituted phthalocyanines have been deposited on Au electrode surfaces through the self assembled monolayer (SAM) technique. The so formed layers were studied using voltammetric techniques. These SAMs blocked a number of Faradic processes and electrocatalyzed the oxidation of L-cysteine. Amine substituted cobalt phthalocyanine (CoTAPc) was deposited on gold surfaces by using an interconnecting SAM of mercaptopropionic acid or dithiobis(N-succinimidyl propionate) through the creation of an amide. Reductive and oxidative desorption of the SAMs limit the useful potential window. The SAM-CoTAPc layers show electrocatalytic activities towards oxygen reduction through the Co(I) central metal ion. Both SAMs were highly stable and hence will be interesting tools for further research in surface modification and sensor development.
- Full Text:
- Date Issued: 2006
Supplying lava eruptions in the Karoo Province, South Africa: a geochemical comparison of the volcanic sequence with intrusions in the main Karoo basin
- Marsh, Julian S, Mitha, Vindina R
- Authors: Marsh, Julian S , Mitha, Vindina R
- Date: 2006
- Language: English
- Type: text , abstract
- Identifier: http://hdl.handle.net/10962/132873 , vital:36901
- Description: Magma supply for lava eruptions remains a poorly understood facet of continental flood volcanism. In the Karoo Province a vast complex of dolerite sheets and dykes is exposed in the main Karoo sedimentary basin underlying the flood basalt remnant of Lesotho (Drakensberg Group) suggesting that lavas were erupted locally from a widely distributed network of fissures.
- Full Text:
- Date Issued: 2006
- Authors: Marsh, Julian S , Mitha, Vindina R
- Date: 2006
- Language: English
- Type: text , abstract
- Identifier: http://hdl.handle.net/10962/132873 , vital:36901
- Description: Magma supply for lava eruptions remains a poorly understood facet of continental flood volcanism. In the Karoo Province a vast complex of dolerite sheets and dykes is exposed in the main Karoo sedimentary basin underlying the flood basalt remnant of Lesotho (Drakensberg Group) suggesting that lavas were erupted locally from a widely distributed network of fissures.
- Full Text:
- Date Issued: 2006
Synthesis and electrochemical characterisation of benzylmercapto and dodecylmercapto tetra substituted cobalt, iron, and zinc phthalocyanines complexes
- Nyokong, Tebello, Ozoemena, Kenneth I, Agboola, Bolade O
- Authors: Nyokong, Tebello , Ozoemena, Kenneth I , Agboola, Bolade O
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6580 , http://hdl.handle.net/10962/d1004143
- Description: The work reports on cyclic voltammetry (CV), square wave voltammetry and spectroelectrochemistry of the following complexes: tetrakis (benzyl mercapto) phthalocyanine complexes of Zn(II) (ZnTBMPc, 4a ), Co(II) (CoTBMPc, 5a ), Fe(II) (FeTBMPc 6a ); and tetrakis (dodecylmercapto) phthalocyanine complexes of Zn(II) (ZnTDMPc, 4b), Co(II) (CoTDMPc, 5b) and Fe(II) (FeTDMPc, 6b). More reversible CV couples were observed for complexes 4a, 5a and 6a containing thiol phenyl ring substituents. Complexes 4b, 5b and 6b containing long chain thiol substituents showed less reversible couples. Complexes 6a and 6b showed a relatively large number of redox processes (5 for 6a and 6 for 6b) within the potential window employed in this work. The processes for FePc derivatives (6a) are assigned to FeIIIPc-1/FeIIIPc-2, FeIIIPc-2/FeIIPc-2, FeIIPc-2/FeIPc-2, FeIPc-2/FeIPc-3 and FeIPc-3/FeIPc-4 and for the CoPc derivative (5a) to CoIIIPc-1/CoIIIPc-2, CoIIIPc-2/CoIIPc-2, CoIIPc-2/CoIPc-2 and CoIPc-2/CoIPc-3.
- Full Text:
- Date Issued: 2006
- Authors: Nyokong, Tebello , Ozoemena, Kenneth I , Agboola, Bolade O
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6580 , http://hdl.handle.net/10962/d1004143
- Description: The work reports on cyclic voltammetry (CV), square wave voltammetry and spectroelectrochemistry of the following complexes: tetrakis (benzyl mercapto) phthalocyanine complexes of Zn(II) (ZnTBMPc, 4a ), Co(II) (CoTBMPc, 5a ), Fe(II) (FeTBMPc 6a ); and tetrakis (dodecylmercapto) phthalocyanine complexes of Zn(II) (ZnTDMPc, 4b), Co(II) (CoTDMPc, 5b) and Fe(II) (FeTDMPc, 6b). More reversible CV couples were observed for complexes 4a, 5a and 6a containing thiol phenyl ring substituents. Complexes 4b, 5b and 6b containing long chain thiol substituents showed less reversible couples. Complexes 6a and 6b showed a relatively large number of redox processes (5 for 6a and 6 for 6b) within the potential window employed in this work. The processes for FePc derivatives (6a) are assigned to FeIIIPc-1/FeIIIPc-2, FeIIIPc-2/FeIIPc-2, FeIIPc-2/FeIPc-2, FeIPc-2/FeIPc-3 and FeIPc-3/FeIPc-4 and for the CoPc derivative (5a) to CoIIIPc-1/CoIIIPc-2, CoIIIPc-2/CoIIPc-2, CoIIPc-2/CoIPc-2 and CoIPc-2/CoIPc-3.
- Full Text:
- Date Issued: 2006
Synthesis and electrochemical characterisation of α-and β-tetra-substituted oxo (phthalocyaninato) titanium (IV) complexes
- Tau, Prudence, Nyokong, Tebello
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283869 , vital:55998 , xlink:href="https://doi.org/10.1016/j.poly.2005.11.025"
- Description: The synthesis, spectroscopic and electrochemical characterisation of the following oxotitanium tetra-substituted phthalocyanines are reported: 1,(4)-(tetraphenoxyphthalocyaninato)titanium(IV) oxide (5a); 1,(4)-(tetra-tert-butylphenoxyphthalocyaninato)titanium(IV) oxide (5b); 2,(3)-(tetraphenoxyphthalocyaninato)titanium(IV) oxide (6a) and 2,(3)-(tetra-tert-butylphenoxyphthalocyaninato)titanium(IV) oxide (6b). Complexes 5a and 5b are substituted at the non-peripheral (α) positions, whereas complexes 6a and 6b are substituted at the peripheral (β) positions. Cyclic voltammograms of all four complexes are similar, with three reversible reduction couples and three quasi-reversible to irreversible oxidations. The first two reductions are two-electron processes, confirmed by spectroelectrochemistry to be due to TiIVPc−2/TiIIPc−3 and TiIIPc−2/TiIPc−3 redox processes. Spectroelectrochemistry showed that upon oxidation, the molecule decomposes. Oxidation is expected to occur at the ring. Chronocoulometry confirmed two electron transfer at the first and second reduction steps; and a one electron transfer at the third reduction.
- Full Text:
- Date Issued: 2006
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283869 , vital:55998 , xlink:href="https://doi.org/10.1016/j.poly.2005.11.025"
- Description: The synthesis, spectroscopic and electrochemical characterisation of the following oxotitanium tetra-substituted phthalocyanines are reported: 1,(4)-(tetraphenoxyphthalocyaninato)titanium(IV) oxide (5a); 1,(4)-(tetra-tert-butylphenoxyphthalocyaninato)titanium(IV) oxide (5b); 2,(3)-(tetraphenoxyphthalocyaninato)titanium(IV) oxide (6a) and 2,(3)-(tetra-tert-butylphenoxyphthalocyaninato)titanium(IV) oxide (6b). Complexes 5a and 5b are substituted at the non-peripheral (α) positions, whereas complexes 6a and 6b are substituted at the peripheral (β) positions. Cyclic voltammograms of all four complexes are similar, with three reversible reduction couples and three quasi-reversible to irreversible oxidations. The first two reductions are two-electron processes, confirmed by spectroelectrochemistry to be due to TiIVPc−2/TiIIPc−3 and TiIIPc−2/TiIPc−3 redox processes. Spectroelectrochemistry showed that upon oxidation, the molecule decomposes. Oxidation is expected to occur at the ring. Chronocoulometry confirmed two electron transfer at the first and second reduction steps; and a one electron transfer at the third reduction.
- Full Text:
- Date Issued: 2006
Synthesis and photophysical properties of octa-substituted phthalocyaninato oxotitanium (IV) derivatives
- Tau, Prudence, Nyokong, Tebello
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283881 , vital:55999 , xlink:href="https://doi.org/10.1142/S1088424606000399"
- Description: The synthesis, spectral and photophysical properties including fluorescence quenching of the following octa-substituted oxotitanium phthalocyanines are reported: 2,3,9,10,16,17,23,24-octaphenoxyphthalocyaninato titanium(IV) oxide, 2,3,9,10,16,17,23,24-[octakis(4-t-butylphenoxyphthalocyaninato)]titanium(IV) oxide, 2,3,9,10,16,17,23,24-{octakis[(4-benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide and 2,3,9,10,16,17,23,24-octaphenylthiophthalocyaninato titanium(IV) oxide. The complexes are characterized by 1H NMR, IR and UV-vis spectroscopies. Their photophysical properties are presented where moderate fluorescence quantum yields (0.14-0.19) and lifetimes were determined. Varied triplet quantum yields were obtained and the triplet lifetimes (40-100 μs) were short.
- Full Text:
- Date Issued: 2006
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283881 , vital:55999 , xlink:href="https://doi.org/10.1142/S1088424606000399"
- Description: The synthesis, spectral and photophysical properties including fluorescence quenching of the following octa-substituted oxotitanium phthalocyanines are reported: 2,3,9,10,16,17,23,24-octaphenoxyphthalocyaninato titanium(IV) oxide, 2,3,9,10,16,17,23,24-[octakis(4-t-butylphenoxyphthalocyaninato)]titanium(IV) oxide, 2,3,9,10,16,17,23,24-{octakis[(4-benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide and 2,3,9,10,16,17,23,24-octaphenylthiophthalocyaninato titanium(IV) oxide. The complexes are characterized by 1H NMR, IR and UV-vis spectroscopies. Their photophysical properties are presented where moderate fluorescence quantum yields (0.14-0.19) and lifetimes were determined. Varied triplet quantum yields were obtained and the triplet lifetimes (40-100 μs) were short.
- Full Text:
- Date Issued: 2006
Synthesis of triprenylated toluquinone and toluhydroquinone metabolites from a marine-derived Penicillium fungus
- Scheepers, Brent A, Klein, Rosalyn, Davies-Coleman, Michael T
- Authors: Scheepers, Brent A , Klein, Rosalyn , Davies-Coleman, Michael T
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6592 , http://hdl.handle.net/10962/d1004341
- Description: Two triprenylated toluquinone and toluhydroquinone marine fungal metabolites, 5-methyl-2-[(2′E,6′E)-3′,7′,11′-trimethyl-2′,6′,10′-dodecatrienyl]-2,5-cyclohexadiene-1,4-dione and 5-methyl-2-[(2′E,6′E)-3,7,11-trimethyl-2′,6′,10′-dodecatrienyl]-1,4-benzenediol, were synthesized in four and five steps, respectively, from 2-methyl-1,4-benzoquinone. The synthesis extends the applicability of the oxidative ether cleavage of hydroquinone dimethyl ethers with argentic oxide under acidic conditions to include the oxidative demethylation of polyprenylated-1,4-dimethoxy-toluhydroquinones with a quantitative survival of the oxidation- and acid-sensitive polyprenyl side chain. Graphical abstract: Marine fungal metabolites 1 and 2 were synthesized from 2-methyl-1,4-benzoquinone in four and five steps, respectively. [For graphic image see full-text version]
- Full Text:
- Date Issued: 2006
- Authors: Scheepers, Brent A , Klein, Rosalyn , Davies-Coleman, Michael T
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6592 , http://hdl.handle.net/10962/d1004341
- Description: Two triprenylated toluquinone and toluhydroquinone marine fungal metabolites, 5-methyl-2-[(2′E,6′E)-3′,7′,11′-trimethyl-2′,6′,10′-dodecatrienyl]-2,5-cyclohexadiene-1,4-dione and 5-methyl-2-[(2′E,6′E)-3,7,11-trimethyl-2′,6′,10′-dodecatrienyl]-1,4-benzenediol, were synthesized in four and five steps, respectively, from 2-methyl-1,4-benzoquinone. The synthesis extends the applicability of the oxidative ether cleavage of hydroquinone dimethyl ethers with argentic oxide under acidic conditions to include the oxidative demethylation of polyprenylated-1,4-dimethoxy-toluhydroquinones with a quantitative survival of the oxidation- and acid-sensitive polyprenyl side chain. Graphical abstract: Marine fungal metabolites 1 and 2 were synthesized from 2-methyl-1,4-benzoquinone in four and five steps, respectively. [For graphic image see full-text version]
- Full Text:
- Date Issued: 2006
Take Me to the River:
- Authors: Kaschula, Russell H
- Date: 2006
- Language: isiXhosa
- Type: text , book
- Identifier: http://hdl.handle.net/10962/175339 , vital:42566 , ISBN 9781869285852
- Full Text:
- Date Issued: 2006
- Authors: Kaschula, Russell H
- Date: 2006
- Language: isiXhosa
- Type: text , book
- Identifier: http://hdl.handle.net/10962/175339 , vital:42566 , ISBN 9781869285852
- Full Text:
- Date Issued: 2006
Teacher education for Mathematical Literacy: a modelling approach
- Brown, Bruce J L, Schäfer, Marc
- Authors: Brown, Bruce J L , Schäfer, Marc
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141040 , vital:37939 , DOI: 10.4102/pythagoras.v0i64.98
- Description: This paper reports on a study of the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil-and-paper exercises based on linear generalisation tasks set in both numeric and two-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was analysed and classified into one of seven categories. In addition, a meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The results of this study strongly support the notion that question design can play a critical role in influencing learners' choice of strategy and level of attainment when solving pattern generalisation tasks. An understanding of the importance of appropriate question design has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
- Date Issued: 2006
- Authors: Brown, Bruce J L , Schäfer, Marc
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141040 , vital:37939 , DOI: 10.4102/pythagoras.v0i64.98
- Description: This paper reports on a study of the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil-and-paper exercises based on linear generalisation tasks set in both numeric and two-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was analysed and classified into one of seven categories. In addition, a meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The results of this study strongly support the notion that question design can play a critical role in influencing learners' choice of strategy and level of attainment when solving pattern generalisation tasks. An understanding of the importance of appropriate question design has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
- Date Issued: 2006
Teacher's beliefs regarding the role of extensive reading in English language learning : a case study
- Authors: Kajinga, Gilford
- Date: 2006
- Subjects: Reading Children -- Books and reading Bilingualism in children Education, Bilingual English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1793 , http://hdl.handle.net/10962/d1003678
- Description: Research suggests numerous views to account for the influence on practice of teachers’ beliefs. One view states that teachers’ lived experiences shape their beliefs about practice. Another view attributes the influence to school experiences. This research sets out to gain insight into teachers’ beliefs on the role of extensive reading in second language learning. A case study of 9 teachers from 3 schools in Grahamstown, South Africa selected purposefully and conveniently was utilised. The teachers were viewed to be knowledgeable on this matter by virtue of their profession while the 3 schools were selected to represent a private school, a former Model C and former Department of Education and Training (DET) school. Data was mainly collected by means of semi-structured interviews, which utilised in-depth open-ended questions to yield teachers’ past experiences. The findings revealed the following: all the teachers appeared to believe that extensive reading was invaluable and enhanced language skills. However, white and black teachers differed in terms of their early experiences of reading. Whereas for white teachers early experiences with literacy were encountered in the home, for black teachers the school was where they had their first exposure to literacy. In addition formal training in the form of an ACE (Advanced Certificate in Education) seemed to have influenced black teachers’ beliefs about the subject at hand, whereas the role of teacher education/ training was not as significant for white teachers.
- Full Text:
- Date Issued: 2006
- Authors: Kajinga, Gilford
- Date: 2006
- Subjects: Reading Children -- Books and reading Bilingualism in children Education, Bilingual English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1793 , http://hdl.handle.net/10962/d1003678
- Description: Research suggests numerous views to account for the influence on practice of teachers’ beliefs. One view states that teachers’ lived experiences shape their beliefs about practice. Another view attributes the influence to school experiences. This research sets out to gain insight into teachers’ beliefs on the role of extensive reading in second language learning. A case study of 9 teachers from 3 schools in Grahamstown, South Africa selected purposefully and conveniently was utilised. The teachers were viewed to be knowledgeable on this matter by virtue of their profession while the 3 schools were selected to represent a private school, a former Model C and former Department of Education and Training (DET) school. Data was mainly collected by means of semi-structured interviews, which utilised in-depth open-ended questions to yield teachers’ past experiences. The findings revealed the following: all the teachers appeared to believe that extensive reading was invaluable and enhanced language skills. However, white and black teachers differed in terms of their early experiences of reading. Whereas for white teachers early experiences with literacy were encountered in the home, for black teachers the school was where they had their first exposure to literacy. In addition formal training in the form of an ACE (Advanced Certificate in Education) seemed to have influenced black teachers’ beliefs about the subject at hand, whereas the role of teacher education/ training was not as significant for white teachers.
- Full Text:
- Date Issued: 2006
Teacher-community cooperation to promote sustainability of wetlands in Kenya
- Authors: Ndaruga, Ayub M , Irwin, Pat
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373860 , vital:66728 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122727"
- Description: This study was undertaken with 83 teachers from 54 primary schools in Kenya. Its purpose was to establish how teachers relate with the local community and how they harness this interaction to promote sustainability of wetlands within their locality. Data were collected using questionnaires, interviews and observation. Results of the study indicated that teachers acknowledge the value of, and threats to, their local wetlands. Some teachers reported interacting and engaging in diverse activities with members of the community to conserve the local wetlands. Forums for interaction and action mentioned by the teachers included public baraza, women’s groups, church, youth groups, local community, parents’ meetings and environmental days. Use of these forums differed. The approaches used to involve the community in awareness and action ranged from theoretical arguments to visits to wetlands, use of wetland resources, ecomanagement and political action. The responses by teachers revealed lack of engagement with the real local wetland problems. This study demonstrated existence of a potential but under-utilised opportunity that can be harnessed by environmental education programmes to champion the sustainability of wetlands.
- Full Text:
- Date Issued: 2006
- Authors: Ndaruga, Ayub M , Irwin, Pat
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373860 , vital:66728 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122727"
- Description: This study was undertaken with 83 teachers from 54 primary schools in Kenya. Its purpose was to establish how teachers relate with the local community and how they harness this interaction to promote sustainability of wetlands within their locality. Data were collected using questionnaires, interviews and observation. Results of the study indicated that teachers acknowledge the value of, and threats to, their local wetlands. Some teachers reported interacting and engaging in diverse activities with members of the community to conserve the local wetlands. Forums for interaction and action mentioned by the teachers included public baraza, women’s groups, church, youth groups, local community, parents’ meetings and environmental days. Use of these forums differed. The approaches used to involve the community in awareness and action ranged from theoretical arguments to visits to wetlands, use of wetland resources, ecomanagement and political action. The responses by teachers revealed lack of engagement with the real local wetland problems. This study demonstrated existence of a potential but under-utilised opportunity that can be harnessed by environmental education programmes to champion the sustainability of wetlands.
- Full Text:
- Date Issued: 2006
Teachers as recontextualisers: a case study analysis of outcomes-based assessment policy implementation in two South African schools
- Authors: Wilmot, Pamela Dianne
- Date: 2006
- Subjects: Competency-based education -- South Africa Competency-based education -- South Africa -- Case studies Educational change -- South Africa Teacher participation in curriculum planning -- South Africa Teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1792 , http://hdl.handle.net/10962/d1003677
- Description: The research presented in this thesis is a case study analysis of outcomes-based assessment in Grade 9 Human and Social Sciences of Curriculum 2005 in two South African schools. The research consists of two parts: Phase One, 2002 to 2003, was a qualitative case study, interpretive in orientation and using ethnographic techniques, aimed at understanding teachers’ responses to curriculum policy and the role of a school-based intervention, located within critically reflexive practice, in supporting change. During this phase, I was a co-participant operating from an insider position. During Phase Two, 2004-2005, I withdrew from the schools and took up an outsider position in order to analyse and theorise the case study. The findings of the interpretive review revealed a fascinating process of change, with some unexpected results that I lacked the theoretical and methodological tools to process. With support from critical friends, I realised that a dynamic and social process of knowledge recontextualisation had taken place, and that the research had moved beyond its initial goals. Not wishing to compromise my integrity as a qualitative researcher, I changed direction and made use of Basil Bernstein’s theorising (1990, 1996) to arrive at a suitable vantage point for the analysis. The main contention of this thesis is that the new OBE curriculum framework offers exciting opportunities for teacher participation in curriculum processes. However, if teachers are to maximise these and become agents of change, they need to acquire the rules of recontextualisation and reposition themselves in the recontextualising field. This implies epistemological empowerment, which takes time and mediation but which can be achieved through an approach to teacher professional development located in critically reflexive practice.
- Full Text:
- Date Issued: 2006
- Authors: Wilmot, Pamela Dianne
- Date: 2006
- Subjects: Competency-based education -- South Africa Competency-based education -- South Africa -- Case studies Educational change -- South Africa Teacher participation in curriculum planning -- South Africa Teachers -- Training of -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1792 , http://hdl.handle.net/10962/d1003677
- Description: The research presented in this thesis is a case study analysis of outcomes-based assessment in Grade 9 Human and Social Sciences of Curriculum 2005 in two South African schools. The research consists of two parts: Phase One, 2002 to 2003, was a qualitative case study, interpretive in orientation and using ethnographic techniques, aimed at understanding teachers’ responses to curriculum policy and the role of a school-based intervention, located within critically reflexive practice, in supporting change. During this phase, I was a co-participant operating from an insider position. During Phase Two, 2004-2005, I withdrew from the schools and took up an outsider position in order to analyse and theorise the case study. The findings of the interpretive review revealed a fascinating process of change, with some unexpected results that I lacked the theoretical and methodological tools to process. With support from critical friends, I realised that a dynamic and social process of knowledge recontextualisation had taken place, and that the research had moved beyond its initial goals. Not wishing to compromise my integrity as a qualitative researcher, I changed direction and made use of Basil Bernstein’s theorising (1990, 1996) to arrive at a suitable vantage point for the analysis. The main contention of this thesis is that the new OBE curriculum framework offers exciting opportunities for teacher participation in curriculum processes. However, if teachers are to maximise these and become agents of change, they need to acquire the rules of recontextualisation and reposition themselves in the recontextualising field. This implies epistemological empowerment, which takes time and mediation but which can be achieved through an approach to teacher professional development located in critically reflexive practice.
- Full Text:
- Date Issued: 2006
Teachers' talk regarding inclusion: a comparative discursive study
- Authors: Bomela, Yolisa Faith
- Date: 2006
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3123 , http://hdl.handle.net/10962/d1006135
- Description: Much research on the educators' perceptions of and attitudes towards inclusive education has been conducted both in South Africa and abroad. What is absent in this literature is an acknowledgement of the socially constructed nature of teachers' responses to inclusive education and its recipients. In this study, the talk of educators involved in piloting inclusive education is compared to that of educators who are not involved, in order to determine the discourses from which educators draw in their construction of inclusive education. It is a comparative study premised on the social constructionist perspective in which discourse analysis was employed. The sample was drawn from schools piloting inclusive education in the East London District of the Eastern Cape Province in South Africa and was compared with schools not involved in the pilot, but in the same area. Semi- structured interviews were conducted with eight educators spread across two piloting and two non piloting schools. The analysis revealed significant similarities and quite minimal differences in the manner in which educators across the two settings construct their experiences of inclusive education. Even though the educators draw on the rights driven anti-discriminatory discourse, they still embrace the special needs/medical/expertise and charity discourses. These discourses construct disability around notions of disputed degrees of impairment, feared status and perceptions of disability as a personal issue rather than a public responsibility, and they undermine the status of people with a disability while supporting notions of dependency. In this article, I will argue that the historical legacy within which these discourses were originally constructed, will essentially continue unless there is a change in how diversity is viewed.
- Full Text:
- Date Issued: 2006
- Authors: Bomela, Yolisa Faith
- Date: 2006
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3123 , http://hdl.handle.net/10962/d1006135
- Description: Much research on the educators' perceptions of and attitudes towards inclusive education has been conducted both in South Africa and abroad. What is absent in this literature is an acknowledgement of the socially constructed nature of teachers' responses to inclusive education and its recipients. In this study, the talk of educators involved in piloting inclusive education is compared to that of educators who are not involved, in order to determine the discourses from which educators draw in their construction of inclusive education. It is a comparative study premised on the social constructionist perspective in which discourse analysis was employed. The sample was drawn from schools piloting inclusive education in the East London District of the Eastern Cape Province in South Africa and was compared with schools not involved in the pilot, but in the same area. Semi- structured interviews were conducted with eight educators spread across two piloting and two non piloting schools. The analysis revealed significant similarities and quite minimal differences in the manner in which educators across the two settings construct their experiences of inclusive education. Even though the educators draw on the rights driven anti-discriminatory discourse, they still embrace the special needs/medical/expertise and charity discourses. These discourses construct disability around notions of disputed degrees of impairment, feared status and perceptions of disability as a personal issue rather than a public responsibility, and they undermine the status of people with a disability while supporting notions of dependency. In this article, I will argue that the historical legacy within which these discourses were originally constructed, will essentially continue unless there is a change in how diversity is viewed.
- Full Text:
- Date Issued: 2006
Temporal scales of variation in settlement and recruitment of the mussel Perna perna (Linnaeus, 1758)
- Porri, Francesca, McQuaid, Christopher D, Radloff, Sarah E
- Authors: Porri, Francesca , McQuaid, Christopher D , Radloff, Sarah E
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6963 , http://hdl.handle.net/10962/d1012026 , http://dx.doi.org/10.1016/j.jembe.2005.11.008
- Description: Population dynamics of many intertidal organisms are strongly affected by the abundance and distribution of larvae arriving on the shore. In particular, not only absolute numbers of settlers but also the degree of synchronisation of settlement can have a strong influence on whether density-dependent or density-independent processes shape adult shape populations. Temporal variation in rates of settlement and recruitment of the mussel Perna perna on the south coast of South Africa was investigated using a nested spatial design at different temporal scales. Variability in settlement at spring tides was examined at two temporal scales: lunar (to investigate the effect of state of the moon on settlement) and tidal (to investigate the influence of state of the tide on mussel settlement). Recruitment over neap tides was examined at one temporal scale, fortnight (to investigate the effect of date on mussel recruitment). Strong temporal variation was evident for both settlement and recruitment, but not at all time scales. Distinct peaks of settler/recruit abundance were observed during the lunar and neap tide studies. Recruitment intensity differed over the course of the year, and pulsing of recruitment was generally synchronised among locations. However, the strength of pulsing differed dramatically among locations, giving a significant interaction between fortnight and location. The finest temporal scale, investigated in the tidal study, did not reveal a significant effect of the state of the tide on settlement. The state of the moon (new or full) was not significant as a main factor (p = 0.052), although generally more settlers arrived on the shore during new moon. Phase of the moon appeared to have an effect on settler abundances, but only when and where densities were high.
- Full Text:
- Date Issued: 2006
- Authors: Porri, Francesca , McQuaid, Christopher D , Radloff, Sarah E
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6963 , http://hdl.handle.net/10962/d1012026 , http://dx.doi.org/10.1016/j.jembe.2005.11.008
- Description: Population dynamics of many intertidal organisms are strongly affected by the abundance and distribution of larvae arriving on the shore. In particular, not only absolute numbers of settlers but also the degree of synchronisation of settlement can have a strong influence on whether density-dependent or density-independent processes shape adult shape populations. Temporal variation in rates of settlement and recruitment of the mussel Perna perna on the south coast of South Africa was investigated using a nested spatial design at different temporal scales. Variability in settlement at spring tides was examined at two temporal scales: lunar (to investigate the effect of state of the moon on settlement) and tidal (to investigate the influence of state of the tide on mussel settlement). Recruitment over neap tides was examined at one temporal scale, fortnight (to investigate the effect of date on mussel recruitment). Strong temporal variation was evident for both settlement and recruitment, but not at all time scales. Distinct peaks of settler/recruit abundance were observed during the lunar and neap tide studies. Recruitment intensity differed over the course of the year, and pulsing of recruitment was generally synchronised among locations. However, the strength of pulsing differed dramatically among locations, giving a significant interaction between fortnight and location. The finest temporal scale, investigated in the tidal study, did not reveal a significant effect of the state of the tide on settlement. The state of the moon (new or full) was not significant as a main factor (p = 0.052), although generally more settlers arrived on the shore during new moon. Phase of the moon appeared to have an effect on settler abundances, but only when and where densities were high.
- Full Text:
- Date Issued: 2006
Tetracarboxylic acid cobalt phthalocyanine SAM on gold: Potential applications as amperometric sensor for H2O2 and fabrication of glucose biosensor
- Mashazi, Philani N, Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Mashazi, Philani N , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6578 , http://hdl.handle.net/10962/d1004141
- Description: This report describes the applications of cobalt tetracarboxylic acid phthalocyanine (CoTCAPc) self-assembled monolayer (SAM) immobilized onto a preformed 2-mercaptoethanol (Au-ME) SAM on gold surface (Au-ME-CoTCAPc SAM) as a potential amperometric sensor for the detection of hydrogen peroxide (H[subscript 2]O[subscript 2]) at neutral pH conditions. The Au-ME-CoTCAPc SAM sensor showed a very fast amperometric response time of approximately 1 s, good linearity at the studied concentration range of up to 5 μM with a coefficient R² = 0.993 and a detection limit of 0.4 μM oxidatively. Also reductively, the sensor exhibited a very fast amperometric response time (~1 s), linearity up to 5 μM with a coefficient R² = 0.986 and a detection limit of 0.2 μM. The cobalt tetracarboxylic acid phthalocyanine self-assembled monolayer was then evaluated as a mediator for glucose oxidase (GOx)-based biosensor. The GOx (enzyme) was immobilized covalently onto Au-ME-CoTCAPc SAM using coupling agents: N-ethyl-N(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS), and the results demonstrated a good catalytic behavior. Kinetic parameters associated with the enzymatic and mediator reactions were estimated using electrochemical versions of Lineweaver–Burk and Hanes equation, and the stability of the sensor was tested. The biosensor (Au-ME-CoTCAPc-GOx SAM) electrode showed good sensitivity (7.5 nA/mM) with a good detection limit of 8.4 μM at 3σ, smaller Michaelis–Menten constant (4.8 mM from Hanes plot) and very fast response time of approximately 5 s.
- Full Text:
- Date Issued: 2006
- Authors: Mashazi, Philani N , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6578 , http://hdl.handle.net/10962/d1004141
- Description: This report describes the applications of cobalt tetracarboxylic acid phthalocyanine (CoTCAPc) self-assembled monolayer (SAM) immobilized onto a preformed 2-mercaptoethanol (Au-ME) SAM on gold surface (Au-ME-CoTCAPc SAM) as a potential amperometric sensor for the detection of hydrogen peroxide (H[subscript 2]O[subscript 2]) at neutral pH conditions. The Au-ME-CoTCAPc SAM sensor showed a very fast amperometric response time of approximately 1 s, good linearity at the studied concentration range of up to 5 μM with a coefficient R² = 0.993 and a detection limit of 0.4 μM oxidatively. Also reductively, the sensor exhibited a very fast amperometric response time (~1 s), linearity up to 5 μM with a coefficient R² = 0.986 and a detection limit of 0.2 μM. The cobalt tetracarboxylic acid phthalocyanine self-assembled monolayer was then evaluated as a mediator for glucose oxidase (GOx)-based biosensor. The GOx (enzyme) was immobilized covalently onto Au-ME-CoTCAPc SAM using coupling agents: N-ethyl-N(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS), and the results demonstrated a good catalytic behavior. Kinetic parameters associated with the enzymatic and mediator reactions were estimated using electrochemical versions of Lineweaver–Burk and Hanes equation, and the stability of the sensor was tested. The biosensor (Au-ME-CoTCAPc-GOx SAM) electrode showed good sensitivity (7.5 nA/mM) with a good detection limit of 8.4 μM at 3σ, smaller Michaelis–Menten constant (4.8 mM from Hanes plot) and very fast response time of approximately 5 s.
- Full Text:
- Date Issued: 2006
The application of integrated environmental management to improve storm water quality and reduce marine pollution at Jeffreys Bay (South Africa)
- Authors: Seebach, Rudi Dieter
- Date: 2006
- Subjects: Marine pollution -- South Africa -- Jeffreys Bay , Storm sewers -- South Africa -- Jeffreys Bay , Marine ecology -- South Africa -- Jeffreys Bay , Environmental management -- South Africa -- Jeffreys Bay , Environmental risk assessment -- South Africa -- Jeffreys Bay , Community development -- South Africa -- Jeffreys Bay , Sustainable development -- South Africa -- Jeffreys Bay , Sewage disposal -- South Africa -- Jeffreys Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4738 , http://hdl.handle.net/10962/d1005287 , Marine pollution -- South Africa -- Jeffreys Bay , Storm sewers -- South Africa -- Jeffreys Bay , Marine ecology -- South Africa -- Jeffreys Bay , Environmental management -- South Africa -- Jeffreys Bay , Environmental risk assessment -- South Africa -- Jeffreys Bay , Community development -- South Africa -- Jeffreys Bay , Sustainable development -- South Africa -- Jeffreys Bay , Sewage disposal -- South Africa -- Jeffreys Bay
- Description: It is projected that by 2025 three-quarters of the world’s population will live in the coastal zone. This is an alarming statistic, with a consequently significant impact on small coastal towns and the adjacent marine environments. Developing communities within the coastal zone of South Africa have proved to be a significant pollution source of storm water. Studies have shown that storm water that is deposited in the ocean will be trapped in the near shore marine environment causing poor seawater quality over a large distance. Furthermore, this can pose a significant threat to the health of recreational users and important marine ecosystems. In Jeffreys Bay storm water quality is thought to pose a threat to the maintenance of the international Blue Flag status for its beach. The aim of the current project was to investigate the main sources of storm water and subsequent marine pollution at Jeffreys Bay and to develop an appropriate management strategy using the integrated environmental management framework. In order to achieve this objective, it was also necessary to determine the current quality of water at various points within the catchment and near shore marine environment. Even though the storm water was found to be severely contaminated no evidence existed for a negative impact on the marine environment. None the less, a precautionary approach was adopted and a risk assessment employed in order to consider potential impacts on the marine and aquatic environment, human health and socio-economic welfare within the town. Significant sources of storm water contamination included grey water, domestic solid waste disposal and informal ablution. These significant aspects were investigated further and it was found that solid waste management in the catchment was poor with significant quantities of waste, primarily (76%) from domestic sources, being disposed of illegally. A study of sanitation management showed inadequacies where up to 58% of the residents from the informal settlements disposed of their grey water into open spaces. The ratio of residents to toilets in these areas was 28:1, therefore supporting the outcome of the risk assessment. Due to the fact that all the significant aspects were related to anthropogenic waste, an integrated waste management plan (IWMP) was developed that would not only facilitate the reduction of pollution of storm water, but would also allow for sustainable community-based development.
- Full Text:
- Date Issued: 2006
- Authors: Seebach, Rudi Dieter
- Date: 2006
- Subjects: Marine pollution -- South Africa -- Jeffreys Bay , Storm sewers -- South Africa -- Jeffreys Bay , Marine ecology -- South Africa -- Jeffreys Bay , Environmental management -- South Africa -- Jeffreys Bay , Environmental risk assessment -- South Africa -- Jeffreys Bay , Community development -- South Africa -- Jeffreys Bay , Sustainable development -- South Africa -- Jeffreys Bay , Sewage disposal -- South Africa -- Jeffreys Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4738 , http://hdl.handle.net/10962/d1005287 , Marine pollution -- South Africa -- Jeffreys Bay , Storm sewers -- South Africa -- Jeffreys Bay , Marine ecology -- South Africa -- Jeffreys Bay , Environmental management -- South Africa -- Jeffreys Bay , Environmental risk assessment -- South Africa -- Jeffreys Bay , Community development -- South Africa -- Jeffreys Bay , Sustainable development -- South Africa -- Jeffreys Bay , Sewage disposal -- South Africa -- Jeffreys Bay
- Description: It is projected that by 2025 three-quarters of the world’s population will live in the coastal zone. This is an alarming statistic, with a consequently significant impact on small coastal towns and the adjacent marine environments. Developing communities within the coastal zone of South Africa have proved to be a significant pollution source of storm water. Studies have shown that storm water that is deposited in the ocean will be trapped in the near shore marine environment causing poor seawater quality over a large distance. Furthermore, this can pose a significant threat to the health of recreational users and important marine ecosystems. In Jeffreys Bay storm water quality is thought to pose a threat to the maintenance of the international Blue Flag status for its beach. The aim of the current project was to investigate the main sources of storm water and subsequent marine pollution at Jeffreys Bay and to develop an appropriate management strategy using the integrated environmental management framework. In order to achieve this objective, it was also necessary to determine the current quality of water at various points within the catchment and near shore marine environment. Even though the storm water was found to be severely contaminated no evidence existed for a negative impact on the marine environment. None the less, a precautionary approach was adopted and a risk assessment employed in order to consider potential impacts on the marine and aquatic environment, human health and socio-economic welfare within the town. Significant sources of storm water contamination included grey water, domestic solid waste disposal and informal ablution. These significant aspects were investigated further and it was found that solid waste management in the catchment was poor with significant quantities of waste, primarily (76%) from domestic sources, being disposed of illegally. A study of sanitation management showed inadequacies where up to 58% of the residents from the informal settlements disposed of their grey water into open spaces. The ratio of residents to toilets in these areas was 28:1, therefore supporting the outcome of the risk assessment. Due to the fact that all the significant aspects were related to anthropogenic waste, an integrated waste management plan (IWMP) was developed that would not only facilitate the reduction of pollution of storm water, but would also allow for sustainable community-based development.
- Full Text:
- Date Issued: 2006
The appropriateness of Holland's interest code typology for South African field guides
- Authors: Allen, Lynda Jean
- Date: 2006
- Subjects: Personality and occupation -- South Africa , Vocational interests -- South Africa , Personality
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9846 , http://hdl.handle.net/10948/432 , Personality and occupation -- South Africa , Vocational interests -- South Africa , Personality
- Description: The foundational principles of Holland’s (1985b, 1992, 1997) vocational theory state that career choice is an expression of personality, in that individuals with specific personality types seek out work or learning environments that match their personality types. Furthermore, interest inventories such as the Self-Directed Search (Holland, Powell, & Fritzsche, 1994) can be regarded as personality inventories and used to ensure that individuals find themselves in a working environment that is best suited to their interests and personality type. In addition to instruments that measure interests, Holland also developed dictionaries of occupations coded according to the characteristics and interests of different occupations and working environments, such as the Dictionary of Holland occupational codes (Gottfredson & Holland, 1996). The level of congruence between personality types and occupational types is linked to career satisfaction, stability and achievement. This premise only holds true, however, if the codes for the occupational environment suggested by Holland (1985c) are, in fact, valid. In other words, do the codes suggested by Holland match the personality types of individuals entering or who are already employed in a particular work or learning environment? There have been many studies conducted with regard to the validity of Holland’s prescribed interest typology codes. Spokane, Meier and Catalano (2000) located a large number of empirical studies published since 1985 that relate directly to the validity of Holland’s codes, many of which have suggested that the existing codes may not be valid. There is a scarcity of such research in South Africa, especially with regard to vital and growing occupational fields, such as the ecotourism industry, that are so important to the economic well-being of the country. Consequently, the overall aim of the present study was to explore and describe the interest codes of male and female South African student and working field guides in order to discuss the appropriateness of the occupational codes prescribed by Holland for the field guiding profession. The quantitative design of the study was exploratory-descriptive in nature and made use of the Self-Directed Search Questionnaire (Holland, Fritzsche, & Powell, 1994). The total sample consisted of 100 participants (68 male and 32 female), constituting 40 working field guides and 60 field guide students. Descriptive analyses were conducted with the use of frequency tables, charts, means and standard ix deviations. In addition, Independent sample t-tests were computed in order to describe and compare the mean scores of the interests for males and females, and to compare the mean scores of the interests for student and working field guides. The results of this study suggest that the prescribed occupational code (SRI; Social, Realistic, Investigative) for South African field guides may not be appropriate and that an interest profile such as SREI AC may be more appropriate. These results, in combination with the findings of the research review, suggest the need for a more extensive, cross-cultural study to determine the appropriateness of Holland’s occupational codes for South African occupations, which may lead to a revision of the South African Dictionary of Occupations (Taljaard & von Mollendorf, 1987).
- Full Text:
- Date Issued: 2006
- Authors: Allen, Lynda Jean
- Date: 2006
- Subjects: Personality and occupation -- South Africa , Vocational interests -- South Africa , Personality
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9846 , http://hdl.handle.net/10948/432 , Personality and occupation -- South Africa , Vocational interests -- South Africa , Personality
- Description: The foundational principles of Holland’s (1985b, 1992, 1997) vocational theory state that career choice is an expression of personality, in that individuals with specific personality types seek out work or learning environments that match their personality types. Furthermore, interest inventories such as the Self-Directed Search (Holland, Powell, & Fritzsche, 1994) can be regarded as personality inventories and used to ensure that individuals find themselves in a working environment that is best suited to their interests and personality type. In addition to instruments that measure interests, Holland also developed dictionaries of occupations coded according to the characteristics and interests of different occupations and working environments, such as the Dictionary of Holland occupational codes (Gottfredson & Holland, 1996). The level of congruence between personality types and occupational types is linked to career satisfaction, stability and achievement. This premise only holds true, however, if the codes for the occupational environment suggested by Holland (1985c) are, in fact, valid. In other words, do the codes suggested by Holland match the personality types of individuals entering or who are already employed in a particular work or learning environment? There have been many studies conducted with regard to the validity of Holland’s prescribed interest typology codes. Spokane, Meier and Catalano (2000) located a large number of empirical studies published since 1985 that relate directly to the validity of Holland’s codes, many of which have suggested that the existing codes may not be valid. There is a scarcity of such research in South Africa, especially with regard to vital and growing occupational fields, such as the ecotourism industry, that are so important to the economic well-being of the country. Consequently, the overall aim of the present study was to explore and describe the interest codes of male and female South African student and working field guides in order to discuss the appropriateness of the occupational codes prescribed by Holland for the field guiding profession. The quantitative design of the study was exploratory-descriptive in nature and made use of the Self-Directed Search Questionnaire (Holland, Fritzsche, & Powell, 1994). The total sample consisted of 100 participants (68 male and 32 female), constituting 40 working field guides and 60 field guide students. Descriptive analyses were conducted with the use of frequency tables, charts, means and standard ix deviations. In addition, Independent sample t-tests were computed in order to describe and compare the mean scores of the interests for males and females, and to compare the mean scores of the interests for student and working field guides. The results of this study suggest that the prescribed occupational code (SRI; Social, Realistic, Investigative) for South African field guides may not be appropriate and that an interest profile such as SREI AC may be more appropriate. These results, in combination with the findings of the research review, suggest the need for a more extensive, cross-cultural study to determine the appropriateness of Holland’s occupational codes for South African occupations, which may lead to a revision of the South African Dictionary of Occupations (Taljaard & von Mollendorf, 1987).
- Full Text:
- Date Issued: 2006