Electrochemical characterisation of tetra- and octa-substituted oxo(phthalocyaninato)titanium(IV) complexes
- Tau, Prudence Lerato, Nyokong, Tebello
- Authors: Tau, Prudence Lerato , Nyokong, Tebello
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6598 , http://hdl.handle.net/10962/d1004347
- Description: The synthesis and electrochemical characterisation of the following oxotitanium tetra-substituted phthalocyanines are reported: 1,(4)-(tetrabenzyloxyphthalocyaninato)titanium(IV) oxide (5a); 1,(4)- {tetrakis[4-(benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide (5b); 2,(3)- (tetrabenzyloxyphthalocyaninato)titanium(IV) oxide (6a) and 2,(3)-{tetrakis[4- (benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide (6b). The electrochemical characterisation of complexes octa-substituted with 4-(benzyloxy)phenoxy (9b), phenoxy (9c) and tert -butylphenoxy (9d) groups is also reported. The cyclic voltammograms of the complexes exhibit reversible couples I–III and couple IV is quasi-reversible for complexes 5a, 5b, 6a and 6b. The first two reductions are metal-based processes, confirmed by spectroelectrochemistry to be due to Ti IV Pc 2 − /Ti III Pc 2 − and Ti III Pc 2 − /Ti II Pc 2 − redox processes and the last two reductions are ring-based processes due to Ti II Pc 2 − /Ti II Pc 3 − and Ti II Pc 3 − /Ti II Pc 4 − . Chronocoulometry confirmed a one-electron transfer at each reduction step. The electrochemistry of the above complexes is also compared to the previously reported 5c, 5d, 6c and 6d.
- Full Text:
- Date Issued: 2007
- Authors: Tau, Prudence Lerato , Nyokong, Tebello
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6598 , http://hdl.handle.net/10962/d1004347
- Description: The synthesis and electrochemical characterisation of the following oxotitanium tetra-substituted phthalocyanines are reported: 1,(4)-(tetrabenzyloxyphthalocyaninato)titanium(IV) oxide (5a); 1,(4)- {tetrakis[4-(benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide (5b); 2,(3)- (tetrabenzyloxyphthalocyaninato)titanium(IV) oxide (6a) and 2,(3)-{tetrakis[4- (benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide (6b). The electrochemical characterisation of complexes octa-substituted with 4-(benzyloxy)phenoxy (9b), phenoxy (9c) and tert -butylphenoxy (9d) groups is also reported. The cyclic voltammograms of the complexes exhibit reversible couples I–III and couple IV is quasi-reversible for complexes 5a, 5b, 6a and 6b. The first two reductions are metal-based processes, confirmed by spectroelectrochemistry to be due to Ti IV Pc 2 − /Ti III Pc 2 − and Ti III Pc 2 − /Ti II Pc 2 − redox processes and the last two reductions are ring-based processes due to Ti II Pc 2 − /Ti II Pc 3 − and Ti II Pc 3 − /Ti II Pc 4 − . Chronocoulometry confirmed a one-electron transfer at each reduction step. The electrochemistry of the above complexes is also compared to the previously reported 5c, 5d, 6c and 6d.
- Full Text:
- Date Issued: 2007
Identity in the Siyagruva Series of novels: Toward an intercultural
- Authors: Kaschula, Russell H
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175159 , vital:42548 , DOI: 10.4314/tvl.v44i2.29792
- Description: This article explores the notion of changing South African youth identity and how it is depicted in the Siyagruva [We are Grooving] Series of novels for young adults. The article highlights the need for a broadening of literary theory in order to include an appropriate theoretical approach for new South African youth literature. This theory explores intercultural literary discourse by making use of, for example, the work of intercultural theorists such as Ting-Toomey (1999), Gudykunst (2003) and others. It is argued that this form of literary discourse is now appropriate as a theoretical paradigm within multilingual South Africa where intercultural communication is becoming a reality. There is also reference to intracultural communication where differences are beginning to appear between young people who are perceived to come from the same cultural group, for example, the character Brunette in the Siyagruva Series who is perceived as a “coconut” by her friends, and thus finds herself having to justify her belonging within a particular in-group or culture. The article concentrates on selected novels, though reference is made to many of the twenty three published novels in the Siyagruva Series, twenty in English, and three translated into isiXhosa.
- Full Text:
- Date Issued: 2007
- Authors: Kaschula, Russell H
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175159 , vital:42548 , DOI: 10.4314/tvl.v44i2.29792
- Description: This article explores the notion of changing South African youth identity and how it is depicted in the Siyagruva [We are Grooving] Series of novels for young adults. The article highlights the need for a broadening of literary theory in order to include an appropriate theoretical approach for new South African youth literature. This theory explores intercultural literary discourse by making use of, for example, the work of intercultural theorists such as Ting-Toomey (1999), Gudykunst (2003) and others. It is argued that this form of literary discourse is now appropriate as a theoretical paradigm within multilingual South Africa where intercultural communication is becoming a reality. There is also reference to intracultural communication where differences are beginning to appear between young people who are perceived to come from the same cultural group, for example, the character Brunette in the Siyagruva Series who is perceived as a “coconut” by her friends, and thus finds herself having to justify her belonging within a particular in-group or culture. The article concentrates on selected novels, though reference is made to many of the twenty three published novels in the Siyagruva Series, twenty in English, and three translated into isiXhosa.
- Full Text:
- Date Issued: 2007
Implementing innovative assessment methods in undergraduate Mathematics
- Authors: Matutu, Phethiwe P
- Date: 2007
- Language: English
- Type: Text
- Identifier: vital:6779 , http://hdl.handle.net/10962/d1006947
- Description: The following challenges associated with teaching undergraduate Mathematics will be discussed: Negative attitudes of students to Mathematics, Student’s reluctance to practise Mathematics, and surface learning. Some (or all) of the ways in which assessment can be used to address these challenges will be discussed. If used strategically assessment methods/tasks can enhance the teaching and learning of mathematics. Some of the unique challenges that we as lecturers face in teaching mathematics can be remedied by selecting appropriate assessment techniques/tasks. Using the tutorial time fruitfully is one of the challenging aspects in teaching mathematics. Not taking tutorials and other formative assessments seriously is not an uncommon student attitude in higher education contexts. Students who are pressured for time often do not see the immediate value of formative assessment or of discussion as a useful learning activity. A collection of case studies which clearly document what has been tried in different contexts is very useful in mathematics as this information is limited in the South African higher education sector. An innovative assessment method (peer-assessment) which was introduced for a Linear Algebra second year course at Rhodes University (South Africa) will be presented: The implementation method, purpose of introducing the assessment method, its advantages, and disadvantages will be examined. A reflection on the assessment method and concluding remarks will be provided.
- Full Text:
- Date Issued: 2007
- Authors: Matutu, Phethiwe P
- Date: 2007
- Language: English
- Type: Text
- Identifier: vital:6779 , http://hdl.handle.net/10962/d1006947
- Description: The following challenges associated with teaching undergraduate Mathematics will be discussed: Negative attitudes of students to Mathematics, Student’s reluctance to practise Mathematics, and surface learning. Some (or all) of the ways in which assessment can be used to address these challenges will be discussed. If used strategically assessment methods/tasks can enhance the teaching and learning of mathematics. Some of the unique challenges that we as lecturers face in teaching mathematics can be remedied by selecting appropriate assessment techniques/tasks. Using the tutorial time fruitfully is one of the challenging aspects in teaching mathematics. Not taking tutorials and other formative assessments seriously is not an uncommon student attitude in higher education contexts. Students who are pressured for time often do not see the immediate value of formative assessment or of discussion as a useful learning activity. A collection of case studies which clearly document what has been tried in different contexts is very useful in mathematics as this information is limited in the South African higher education sector. An innovative assessment method (peer-assessment) which was introduced for a Linear Algebra second year course at Rhodes University (South Africa) will be presented: The implementation method, purpose of introducing the assessment method, its advantages, and disadvantages will be examined. A reflection on the assessment method and concluding remarks will be provided.
- Full Text:
- Date Issued: 2007
Physical implications of prolonged sitting in a confined posture - a literature review
- Todd, Andrew I, Bennett, Anthea I, Christie, Candice J
- Authors: Todd, Andrew I , Bennett, Anthea I , Christie, Candice J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6756 , http://hdl.handle.net/10962/d1009458
- Description: The main purpose of this review article was to highlight some of the physical consequences of sitting for prolonged periods in a confined setting. More specifically, the review relates this research to call centre work and where applicable comments on the limited literature relating specifically to ergonomics research within call centre settings. In particular the article explores the biomechanical stresses placed on the musculoskeletal system during prolonged sitting at a workstation, and the physiological consequences thereof. The paper then provides possible solutions to reduce the physical strain placed on these workers by looking at workstation design and work organisation emphasizing worker education and the promotion of worker well being.
- Full Text:
- Date Issued: 2007
- Authors: Todd, Andrew I , Bennett, Anthea I , Christie, Candice J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6756 , http://hdl.handle.net/10962/d1009458
- Description: The main purpose of this review article was to highlight some of the physical consequences of sitting for prolonged periods in a confined setting. More specifically, the review relates this research to call centre work and where applicable comments on the limited literature relating specifically to ergonomics research within call centre settings. In particular the article explores the biomechanical stresses placed on the musculoskeletal system during prolonged sitting at a workstation, and the physiological consequences thereof. The paper then provides possible solutions to reduce the physical strain placed on these workers by looking at workstation design and work organisation emphasizing worker education and the promotion of worker well being.
- Full Text:
- Date Issued: 2007
The reintroduction of large carnivores to the Eastern Cape, South Africa: an assessment
- Hayward, M W, Kerley, Graham I H, Adendorff, John, Moolman, Lucius C, O'Brien, John, Sholto-Douglas, Angus, Bissett, Charlene, Bean, Peter, Fogarty, Alan, Howarth, Dale, Slater, Richard
- Authors: Hayward, M W , Kerley, Graham I H , Adendorff, John , Moolman, Lucius C , O'Brien, John , Sholto-Douglas, Angus , Bissett, Charlene , Bean, Peter , Fogarty, Alan , Howarth, Dale , Slater, Richard
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6900 , http://hdl.handle.net/10962/d1011662 , http://dx.doi.org/10.1017/S0030605307001767
- Description: Recently, conservation estate in South Africa's Eastern Cape Province has increased 10-fold resulting in large predators being increasingly reintroduced to restore ecological integrity and maximize tourism. We describe the reintroductions of large carnivores (>10 kg) that have occurred in the Eastern Cape and use various criteria to assess their success. Lion Panthera leo reintroduction has been highly successful with a population of 56 currently extant in the region and problems of overpopulation arising. The African wild dog Lycaon pictus population has increased to 24 from a founder population of 11. Preliminary results for spotted hyaenas Crocuta crocuta also indicate success. Wild populations of leopards Panthera pardus exist on several reserves and have been supplemented by translocated individuals, although deaths of known individuals have occurred and no estimate of reproduction is available. Cheetah Acinonyx jubatus reintroduction has also been less successful with 36 individuals reintroduced and 23 cubs being born but only 41 individuals surviving in 2005. Criteria for assessing the success of reintroductions of species that naturally occur in low densities, such as top predators, generally have limited value. Carrying capacity for large predators is unknown and continued monitoring and intensive management will be necessary in enclosed, and possibly all, conservation areas in the Eastern Cape to ensure conservation success.
- Full Text:
- Date Issued: 2007
- Authors: Hayward, M W , Kerley, Graham I H , Adendorff, John , Moolman, Lucius C , O'Brien, John , Sholto-Douglas, Angus , Bissett, Charlene , Bean, Peter , Fogarty, Alan , Howarth, Dale , Slater, Richard
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6900 , http://hdl.handle.net/10962/d1011662 , http://dx.doi.org/10.1017/S0030605307001767
- Description: Recently, conservation estate in South Africa's Eastern Cape Province has increased 10-fold resulting in large predators being increasingly reintroduced to restore ecological integrity and maximize tourism. We describe the reintroductions of large carnivores (>10 kg) that have occurred in the Eastern Cape and use various criteria to assess their success. Lion Panthera leo reintroduction has been highly successful with a population of 56 currently extant in the region and problems of overpopulation arising. The African wild dog Lycaon pictus population has increased to 24 from a founder population of 11. Preliminary results for spotted hyaenas Crocuta crocuta also indicate success. Wild populations of leopards Panthera pardus exist on several reserves and have been supplemented by translocated individuals, although deaths of known individuals have occurred and no estimate of reproduction is available. Cheetah Acinonyx jubatus reintroduction has also been less successful with 36 individuals reintroduced and 23 cubs being born but only 41 individuals surviving in 2005. Criteria for assessing the success of reintroductions of species that naturally occur in low densities, such as top predators, generally have limited value. Carrying capacity for large predators is unknown and continued monitoring and intensive management will be necessary in enclosed, and possibly all, conservation areas in the Eastern Cape to ensure conservation success.
- Full Text:
- Date Issued: 2007
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