Tuning the physico-electrochemical properties of novel cobalt (II) octa[(3,5-biscarboxylate)-phenoxy] phthalocyanine complex using phenylamine-functionalised SWCNTs
- Agboola, Bolade Oyeyinka, Ozoemena, Kenneth I., Nyokong, Tebello, Fukuda, Takamitsu, Kobayashi, Nagao
- Authors: Agboola, Bolade Oyeyinka , Ozoemena, Kenneth I. , Nyokong, Tebello , Fukuda, Takamitsu , Kobayashi, Nagao
- Language: English
- Type: Article
- Identifier: vital:7238 , http://hdl.handle.net/10962/d1019689
- Description: The integration of phenylamine-functionalised SWCNTs (SWCNT-phenylamine) with a novel cobalt (II) octa[(3,5-biscarboxylate)-phenoxy] phthalocyanine (CoOBPPc) complex has been described. The physical and electrochemical properties of the CoOBPPc-SWCNT-phenylamine hybrid were evaluated using spectroscopy (IR and UV–vis), field emission scanning electron microscopy and electrochemistry (cyclic voltammetry and electrochemical impedance spectroscopy). Integration of SWCNT-phenylamine resulted in the physical transformation of the CoOBCPPc from the usually bluish colour of cobalt phthalocyanine complexes to a beautiful bright green colour. In addition, the heterogeneous electron transfer kinetics and electrocatalytic properties of the CoOBCPPc were greatly enhanced following the attachment of the SWCNT-phenylamine. The potential electrocatalytic application of the hybrid was tested using β-nicotinamide adenine dinucleotide (NADH) as a model biological analyte. Interestingly, the onset oxidation potential of this analyte was significantly reduced (300 mV) by this hybrid compared to the bare electrode. , Original publication is available at http://dx.doi.org/doi:10.1016/j.carbon.2009.10.023
- Full Text: false
- Authors: Agboola, Bolade Oyeyinka , Ozoemena, Kenneth I. , Nyokong, Tebello , Fukuda, Takamitsu , Kobayashi, Nagao
- Language: English
- Type: Article
- Identifier: vital:7238 , http://hdl.handle.net/10962/d1019689
- Description: The integration of phenylamine-functionalised SWCNTs (SWCNT-phenylamine) with a novel cobalt (II) octa[(3,5-biscarboxylate)-phenoxy] phthalocyanine (CoOBPPc) complex has been described. The physical and electrochemical properties of the CoOBPPc-SWCNT-phenylamine hybrid were evaluated using spectroscopy (IR and UV–vis), field emission scanning electron microscopy and electrochemistry (cyclic voltammetry and electrochemical impedance spectroscopy). Integration of SWCNT-phenylamine resulted in the physical transformation of the CoOBCPPc from the usually bluish colour of cobalt phthalocyanine complexes to a beautiful bright green colour. In addition, the heterogeneous electron transfer kinetics and electrocatalytic properties of the CoOBCPPc were greatly enhanced following the attachment of the SWCNT-phenylamine. The potential electrocatalytic application of the hybrid was tested using β-nicotinamide adenine dinucleotide (NADH) as a model biological analyte. Interestingly, the onset oxidation potential of this analyte was significantly reduced (300 mV) by this hybrid compared to the bare electrode. , Original publication is available at http://dx.doi.org/doi:10.1016/j.carbon.2009.10.023
- Full Text: false
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
Causes of decoupling between larval supply and settlement and consequences for understanding recruitment and population connectivity
- Pineda, Jesus, Porri, Francesca, Starczak, Victroria, Blythe, Jonathan
- Authors: Pineda, Jesus , Porri, Francesca , Starczak, Victroria , Blythe, Jonathan
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6869 , http://hdl.handle.net/10962/d1011501
- Description: Marine broadcast spawners have two-phase life cycles, with pelagic larvae and benthic adults. Larval supply and settlement link these two phases and are crucial for the persistence of marine populations. Mainly due to the complexity in sampling larval supply accurately, many researchers use settlement as a proxy for larval supply. Larval supply is a constraining variable for settlement because, without larval supply, there is no settlement. Larval supply and settlement may not be well correlated, however, and settlement may not consistently estimate larval supply. This paper explores the argument that larval supply (i.e., larval abundance near settlement sites) may not relate linearly to settlement. We review the relationship between larval supply and settlement, from estimates and biases in larval supply sampling, to non-behavioral and behavioral components, including small-scale hydrodynamics, competency, gregarious behavior, intensification of settlement, lunar periodicity, predation and cannibalism. Physical and structural processes coupled with behavior, such as small-scale hydrodynamics and intensification of settlement, sometimes result in under- or overestimation of larval supply, where it is predicted from a linear relationship with settlement. Although settlement is a function of larval supply, spatial and temporal processes interact with larval behavior to distort the relationship between larval supply and settlement, and when these distortions act consistently in time and space, they cause biased estimates of larval supply from settlement data. Most of the examples discussed here suggest that behavior is the main source of the decoupling between larval supply and settlement because larval behavior affects the vertical distribution of larvae, the response of larvae to hydrodynamics, intensification of settlement, gregariousness, predation and cannibalism. Thus, larval behavior seems to limit broad generalizations on the regulation of settlement by larval supply. Knowledge of the relationship is further hindered by the lack of a well founded theoretical relationship between the two variables. The larval supply–settlement transition may have strong general consequences for population connectivity, since larval supply is a result of larval transport, and settlement constrains recruitment. Thus, measuring larval supply and settlement effectively allows more accurate quantification and understanding of larval transport, recruitment and population connectivity.
- Full Text:
- Date Issued: 2010
- Authors: Pineda, Jesus , Porri, Francesca , Starczak, Victroria , Blythe, Jonathan
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6869 , http://hdl.handle.net/10962/d1011501
- Description: Marine broadcast spawners have two-phase life cycles, with pelagic larvae and benthic adults. Larval supply and settlement link these two phases and are crucial for the persistence of marine populations. Mainly due to the complexity in sampling larval supply accurately, many researchers use settlement as a proxy for larval supply. Larval supply is a constraining variable for settlement because, without larval supply, there is no settlement. Larval supply and settlement may not be well correlated, however, and settlement may not consistently estimate larval supply. This paper explores the argument that larval supply (i.e., larval abundance near settlement sites) may not relate linearly to settlement. We review the relationship between larval supply and settlement, from estimates and biases in larval supply sampling, to non-behavioral and behavioral components, including small-scale hydrodynamics, competency, gregarious behavior, intensification of settlement, lunar periodicity, predation and cannibalism. Physical and structural processes coupled with behavior, such as small-scale hydrodynamics and intensification of settlement, sometimes result in under- or overestimation of larval supply, where it is predicted from a linear relationship with settlement. Although settlement is a function of larval supply, spatial and temporal processes interact with larval behavior to distort the relationship between larval supply and settlement, and when these distortions act consistently in time and space, they cause biased estimates of larval supply from settlement data. Most of the examples discussed here suggest that behavior is the main source of the decoupling between larval supply and settlement because larval behavior affects the vertical distribution of larvae, the response of larvae to hydrodynamics, intensification of settlement, gregariousness, predation and cannibalism. Thus, larval behavior seems to limit broad generalizations on the regulation of settlement by larval supply. Knowledge of the relationship is further hindered by the lack of a well founded theoretical relationship between the two variables. The larval supply–settlement transition may have strong general consequences for population connectivity, since larval supply is a result of larval transport, and settlement constrains recruitment. Thus, measuring larval supply and settlement effectively allows more accurate quantification and understanding of larval transport, recruitment and population connectivity.
- Full Text:
- Date Issued: 2010
An in-service development programme for potential information services staff in the Rhodes Library
- Authors: Shepherd, Eileen
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6986 , http://hdl.handle.net/10962/d1011602
- Description: This paper discusses the need for continuing professional development for librarians in academic libraries in general and at Rhodes University Library, South Africa in particular. It describes the planning, design, implementation and evaluation of a staff-development and training pilot programme for professional librarians at Rhodes Library. A group of 15 librarians, drawn from the library staff complement, participated in an 8-session training course developed by Information Services librarians. The course, which covered basic information-finding skills using a variety of research databases and offered an introduction to concepts in 21st century academic librarianship, was presented using course management software in a face-to-face environment and required homework exercises and the completion of a 2-hour final test. The results of the project demonstrated the urgent need for such development programmes for professional library staff. 80% of the participants completed the course. The final test results indicated below average database search skills and an inability to think laterally. An unexpected finding was a lack of IT competencies. Important lessons were learned with regard to course-construction, content and timing.
- Full Text:
- Date Issued: 2010
- Authors: Shepherd, Eileen
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6986 , http://hdl.handle.net/10962/d1011602
- Description: This paper discusses the need for continuing professional development for librarians in academic libraries in general and at Rhodes University Library, South Africa in particular. It describes the planning, design, implementation and evaluation of a staff-development and training pilot programme for professional librarians at Rhodes Library. A group of 15 librarians, drawn from the library staff complement, participated in an 8-session training course developed by Information Services librarians. The course, which covered basic information-finding skills using a variety of research databases and offered an introduction to concepts in 21st century academic librarianship, was presented using course management software in a face-to-face environment and required homework exercises and the completion of a 2-hour final test. The results of the project demonstrated the urgent need for such development programmes for professional library staff. 80% of the participants completed the course. The final test results indicated below average database search skills and an inability to think laterally. An unexpected finding was a lack of IT competencies. Important lessons were learned with regard to course-construction, content and timing.
- Full Text:
- Date Issued: 2010
Change ringing in eastern Breconshire before the First World War, with especial reference to peal ringing at Glasbury
- Authors: Lewis, Colin A
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6191 , http://hdl.handle.net/10962/d1012397 , http://www.brecknocksociety.co.uk/society.htm
- Description: This paper discusses the development of change ringing in eastern Breconshire before the start of the First World War in 19 14, with special reference to peal ringing at Glasbury. Since the men who rang peals there, prior to that war, came from other towers as well as from Glasbury, brief mention is made of ringing at those towers and of members of those towers who rang peals at Glasbury. The towers discussed include Talgarth, Bronllys, Brecon, Llanelli (named Llanelly on Ordnance Survey maps) and Builth Wells, which were in the Diocese of St David's at that time, and centres in Herefordshire which were in the Diocese of Hereford. Attention is also paid to the role of the Hereford Diocesan Guild of Bellringers and of the peripatetic instructors employed by that Guild. An excellent introduction toringing is provided by R. J. Johnston's Bell-Ringing; the English Art of Change-Ringing (Viking, 1986), while the web-site of the Central Council of Church Bell Ringers (www.cccbr.org.uk) is also informative. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He was the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa for 20 years.
- Full Text:
- Date Issued: 2010
- Authors: Lewis, Colin A
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6191 , http://hdl.handle.net/10962/d1012397 , http://www.brecknocksociety.co.uk/society.htm
- Description: This paper discusses the development of change ringing in eastern Breconshire before the start of the First World War in 19 14, with special reference to peal ringing at Glasbury. Since the men who rang peals there, prior to that war, came from other towers as well as from Glasbury, brief mention is made of ringing at those towers and of members of those towers who rang peals at Glasbury. The towers discussed include Talgarth, Bronllys, Brecon, Llanelli (named Llanelly on Ordnance Survey maps) and Builth Wells, which were in the Diocese of St David's at that time, and centres in Herefordshire which were in the Diocese of Hereford. Attention is also paid to the role of the Hereford Diocesan Guild of Bellringers and of the peripatetic instructors employed by that Guild. An excellent introduction toringing is provided by R. J. Johnston's Bell-Ringing; the English Art of Change-Ringing (Viking, 1986), while the web-site of the Central Council of Church Bell Ringers (www.cccbr.org.uk) is also informative. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He was the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa for 20 years.
- Full Text:
- Date Issued: 2010
Multiple organ failure - death of consumer protection?
- Authors: Steinman, H A , Jobson, M R
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6436 , http://hdl.handle.net/10962/d1006613
- Description: The enormously profitable complementary medicines, dietary supplements and traditional medicines markets are largely unregulated internationally and South Africa. Attempts to ensure that consumers are not exposed to harmful or ineffective products have met with varying success around the world.
- Full Text:
- Date Issued: 2010
- Authors: Steinman, H A , Jobson, M R
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6436 , http://hdl.handle.net/10962/d1006613
- Description: The enormously profitable complementary medicines, dietary supplements and traditional medicines markets are largely unregulated internationally and South Africa. Attempts to ensure that consumers are not exposed to harmful or ineffective products have met with varying success around the world.
- Full Text:
- Date Issued: 2010
Control and integrability on SO (3)
- Authors: Remsing, C C
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6787 , http://hdl.handle.net/10962/d1006938
- Description: This paper considers control ane left- invariant systems evolving on matrix Lie groups. Such systems have signicant applications in a variety of elds. Any left-invariant optimal control problem (with quadratic cost) can be lifted, via the celebrated Maximum Principle, to a Hamiltonian system on the dual of the Lie algebra of the underlying state space G. The (minus) Lie-Poisson structure on the dual space g is used to describe the (normal) extremal curves. An interesting, and rather typical, single-input con- trol system on the rotation group SO (3) is investi- gated in some detail. The reduced Hamilton equa- tions associated with an extremal curve are derived in a simple and elegant manner. Finally, these equations are explicitly integrated by Jacobi elliptic functions.
- Full Text:
- Date Issued: 2010
- Authors: Remsing, C C
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6787 , http://hdl.handle.net/10962/d1006938
- Description: This paper considers control ane left- invariant systems evolving on matrix Lie groups. Such systems have signicant applications in a variety of elds. Any left-invariant optimal control problem (with quadratic cost) can be lifted, via the celebrated Maximum Principle, to a Hamiltonian system on the dual of the Lie algebra of the underlying state space G. The (minus) Lie-Poisson structure on the dual space g is used to describe the (normal) extremal curves. An interesting, and rather typical, single-input con- trol system on the rotation group SO (3) is investi- gated in some detail. The reduced Hamilton equa- tions associated with an extremal curve are derived in a simple and elegant manner. Finally, these equations are explicitly integrated by Jacobi elliptic functions.
- Full Text:
- Date Issued: 2010
Metallophthalocyanine-based molecular materials as catalysts for electrochemical reactions
- Zagal, José H, Griveau, Sophie J, Silva, Francisco, Nyokong, Tebello, Bedioui, Fethi
- Authors: Zagal, José H , Griveau, Sophie J , Silva, Francisco , Nyokong, Tebello , Bedioui, Fethi
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7239 , http://hdl.handle.net/10962/d1019718
- Description: Metallophthalocyanines confined on the surface of electrodes are active catalysts for a large variety of electrochemical reactions and electrode surfaces modified by these complexes can be obtained by simple adsorption on graphite and carbon. However, more stable electrodes can be achieved by coating their surfaces with electropolymerized layers of the complexes, that show similar activity than their monomer counterparts. In all cases, fundamental studies carried out with adsorbed layers of these complexes have shown that the redox potential is a very good reactivity index for predicting the catalytic activity of the complexes. Volcano-shaped correlations have been found between the electrocatalytic activity (as log I at constant E) versus the Co(II)/(I) formal potential (E°′) of Co-macrocyclics for the oxidation of several thiols, hydrazine and glucose. For the electroreduction of O2 only linear correlations between the electrocatalytic activity versus the M(III)/M(II) formal potential have been found using Cr, Mn, Fe and Co phthalocyanines but it is likely that these correlations are “incomplete volcano” correlations. The volcano correlations strongly suggest that E°′, the formal potential of the complex needs to be in a rather narrow potential window for achieving maximum activity, probably corresponding to surface coverages of an M-molecule adduct equal to 0.5 and to standard free energies of adsorption of the reacting molecule on the complex active site equal to zero. These results indicate that the catalytic activity of metallophthalocyanines for the oxidation of several molecules can be “tuned” by manipulating the E°′ formal potential, using proper groups on the macrocyclic ligand. This review emphasizes once more that metallophthalocyanines are extremely versatile materials with many applications in electrocatalysis, electroanalysis, just to mention a few, and they provide very good models for testing their catalytic activity for several reactions. Even though the earlier applications of these complexes were focused on providing active materials for electroreduction of O2, for making active cathodes for fuel cells, the main trend in the literature nowadays is to use these complexes for making active electrodes for electrochemical sensors. , Original publication is available at http://dx.doi.org/10.1016/j.ccr.2010.05.001
- Full Text: false
- Date Issued: 2010
- Authors: Zagal, José H , Griveau, Sophie J , Silva, Francisco , Nyokong, Tebello , Bedioui, Fethi
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7239 , http://hdl.handle.net/10962/d1019718
- Description: Metallophthalocyanines confined on the surface of electrodes are active catalysts for a large variety of electrochemical reactions and electrode surfaces modified by these complexes can be obtained by simple adsorption on graphite and carbon. However, more stable electrodes can be achieved by coating their surfaces with electropolymerized layers of the complexes, that show similar activity than their monomer counterparts. In all cases, fundamental studies carried out with adsorbed layers of these complexes have shown that the redox potential is a very good reactivity index for predicting the catalytic activity of the complexes. Volcano-shaped correlations have been found between the electrocatalytic activity (as log I at constant E) versus the Co(II)/(I) formal potential (E°′) of Co-macrocyclics for the oxidation of several thiols, hydrazine and glucose. For the electroreduction of O2 only linear correlations between the electrocatalytic activity versus the M(III)/M(II) formal potential have been found using Cr, Mn, Fe and Co phthalocyanines but it is likely that these correlations are “incomplete volcano” correlations. The volcano correlations strongly suggest that E°′, the formal potential of the complex needs to be in a rather narrow potential window for achieving maximum activity, probably corresponding to surface coverages of an M-molecule adduct equal to 0.5 and to standard free energies of adsorption of the reacting molecule on the complex active site equal to zero. These results indicate that the catalytic activity of metallophthalocyanines for the oxidation of several molecules can be “tuned” by manipulating the E°′ formal potential, using proper groups on the macrocyclic ligand. This review emphasizes once more that metallophthalocyanines are extremely versatile materials with many applications in electrocatalysis, electroanalysis, just to mention a few, and they provide very good models for testing their catalytic activity for several reactions. Even though the earlier applications of these complexes were focused on providing active materials for electroreduction of O2, for making active cathodes for fuel cells, the main trend in the literature nowadays is to use these complexes for making active electrodes for electrochemical sensors. , Original publication is available at http://dx.doi.org/10.1016/j.ccr.2010.05.001
- Full Text: false
- Date Issued: 2010
Synthesis and electrochemical properties of new cobalt and manganese phthalocyanine complexes tetra-substituted with 3,4-(methylendioxy)-phenoxy
- Erdoğmuş, Ali, Akinbulu, Isaac Adebayo, Nyokong, Tebello
- Authors: Erdoğmuş, Ali , Akinbulu, Isaac Adebayo , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7234 , http://hdl.handle.net/10962/d1019672
- Description: The synthesis and electrochemical properties of new cobalt and manganese phthalocyanine complexes, tetra-substituted with 3,4-(methylendioxy)-phenoxy at the peripheral (complexes 3 and 5) and non-peripheral (complexes 4 and 6) positions, are reported. Complexes 3 and 4 showed Q-band absorption, in DMF, at 668 and 686 nm, respectively while Q-band due to complexes 5 and 6 appeared at 732 and 760 nm, respectively in CHCl3. All the complexes showed well resolved redox processes attributed to both metal and ring based processes. Complexes 3 and 4 showed four redox processes, labeled I, II, III and IV. For complex 3, process I (CoIPc−2/CoIPc−3) was observed at −1.45 V, II (CoIIPc−2/CoIPc−2) at −0.38 V, III (CoIIIPc−2/CoIIPc−2) at +0.49 V and IV (CoIIIPc−1/CoIIIPc−2) at +0.97 V versus Ag|AgCl. Similar processes were observed for complex 4 at −1.36 V, −0.27 V, +0.56 V, +1.03 V versus Ag|AgCl, respectively. Complexes 5 and 6 showed two redox processes (I and II). For complex 5, these processes appeared at −0.79 V (MnIIPc−2/MnIIPc−3, I) and −0.07 V versus Ag|AgCl (MnIIIPc−2/MnIIPc−2, II), while for complex 6, they were observed at −0.86 V and −0.04 V versus Ag|AgCl. Spectroelectrochemistry was used to probe and confirm the origin of these processes. , Original publication is availabe at http://dx.doi.org/10.1016/j.poly.2010.05.012
- Full Text: false
- Authors: Erdoğmuş, Ali , Akinbulu, Isaac Adebayo , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7234 , http://hdl.handle.net/10962/d1019672
- Description: The synthesis and electrochemical properties of new cobalt and manganese phthalocyanine complexes, tetra-substituted with 3,4-(methylendioxy)-phenoxy at the peripheral (complexes 3 and 5) and non-peripheral (complexes 4 and 6) positions, are reported. Complexes 3 and 4 showed Q-band absorption, in DMF, at 668 and 686 nm, respectively while Q-band due to complexes 5 and 6 appeared at 732 and 760 nm, respectively in CHCl3. All the complexes showed well resolved redox processes attributed to both metal and ring based processes. Complexes 3 and 4 showed four redox processes, labeled I, II, III and IV. For complex 3, process I (CoIPc−2/CoIPc−3) was observed at −1.45 V, II (CoIIPc−2/CoIPc−2) at −0.38 V, III (CoIIIPc−2/CoIIPc−2) at +0.49 V and IV (CoIIIPc−1/CoIIIPc−2) at +0.97 V versus Ag|AgCl. Similar processes were observed for complex 4 at −1.36 V, −0.27 V, +0.56 V, +1.03 V versus Ag|AgCl, respectively. Complexes 5 and 6 showed two redox processes (I and II). For complex 5, these processes appeared at −0.79 V (MnIIPc−2/MnIIPc−3, I) and −0.07 V versus Ag|AgCl (MnIIIPc−2/MnIIPc−2, II), while for complex 6, they were observed at −0.86 V and −0.04 V versus Ag|AgCl. Spectroelectrochemistry was used to probe and confirm the origin of these processes. , Original publication is availabe at http://dx.doi.org/10.1016/j.poly.2010.05.012
- Full Text: false
Novel, soluble, FluXoro functional substituted zinc phthalocyanines; synthesis, characterization and photophysicochemical properties
- Erdoğmuş, Ali, Nyokong, Tebello
- Authors: Erdoğmuş, Ali , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7235 , http://hdl.handle.net/10962/d1019686
- Description: Three novel phthalonitriles and the respective, peripheral tetrakis zinc phthalocyanines were synthesized and characterized using elemental analysis, IR, 1H NMR, mass spectra and electronic spectroscopy. The phthalocyanines displayed good solubility in organic solvents such as CHCl3, DCM, DMSO, DMF, THF and toluene. The presence of a long chain fluorine substitituent was found to result in reduced aggregation. The singlet oxygen, photodegradation, fluorescence quantum yield, triplet quantum yield and triplet life time of the complexes in toluene were determined. The effect of fluoro-functional groups on the photophysical and photochemical parameters of the zinc(II) phthalocyanines are also reported. Fluorescence quantum yields for the complexes ranged from 0.021 to 0.041 , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2010.01.001
- Full Text: false
- Authors: Erdoğmuş, Ali , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7235 , http://hdl.handle.net/10962/d1019686
- Description: Three novel phthalonitriles and the respective, peripheral tetrakis zinc phthalocyanines were synthesized and characterized using elemental analysis, IR, 1H NMR, mass spectra and electronic spectroscopy. The phthalocyanines displayed good solubility in organic solvents such as CHCl3, DCM, DMSO, DMF, THF and toluene. The presence of a long chain fluorine substitituent was found to result in reduced aggregation. The singlet oxygen, photodegradation, fluorescence quantum yield, triplet quantum yield and triplet life time of the complexes in toluene were determined. The effect of fluoro-functional groups on the photophysical and photochemical parameters of the zinc(II) phthalocyanines are also reported. Fluorescence quantum yields for the complexes ranged from 0.021 to 0.041 , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2010.01.001
- Full Text: false
Synthesis of zinc phthalocyanine derivatives with improved photophysicochemical properties in aqueous media
- Erdoğmuş, Ali, Nyokong, Tebello
- Authors: Erdoğmuş, Ali , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7236 , http://hdl.handle.net/10962/d1019687
- Description: The synthesis, photophysical and photochemical properties of new peripherally (β) tetra-substituted thioquinoline Zn(II) (2) and quaternized thioquinoline Zn(II) phthalocyanines (3) and quaternized fluoro functional thiopyridine Zn(II) (5) are described for the first time. These complexes (2, 3 and 5) have been synthesized and characterized by elemental analysis, IR, 1H NMR spectroscopy and electronic spectroscopy. Complexes 2, 4 and 6have good solubility in organic solvents such as CHCl3, DCM, DMSO, DMF, THF and toluene and are not aggregated in all solvents (except for 2 in DMSO) within a wide concentration range. Complexes 3 and 5 showed very good solubility in water as well as DMSO and DMF. General trends are described for singlet oxygen, photodegradation, fluorescence quantum yields, triplet quantum yields and triplet life times of these complexes in DMSO (2, 4 and 6) and water (3 and 5). Complex 3 gave a very large triplet quantum yield in aqueous media (ΦT = 0.8 in water plus Triton X-100) and a reasonable triplet lifetime of 110 μs. Photophysical and photochemical properties of the phthalocyanines complexes 2–6 are very useful for PDT. , Original publication is available at http://dx.doi.org/10.1016/j.molstruc.2010.04.048
- Full Text: false
- Authors: Erdoğmuş, Ali , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7236 , http://hdl.handle.net/10962/d1019687
- Description: The synthesis, photophysical and photochemical properties of new peripherally (β) tetra-substituted thioquinoline Zn(II) (2) and quaternized thioquinoline Zn(II) phthalocyanines (3) and quaternized fluoro functional thiopyridine Zn(II) (5) are described for the first time. These complexes (2, 3 and 5) have been synthesized and characterized by elemental analysis, IR, 1H NMR spectroscopy and electronic spectroscopy. Complexes 2, 4 and 6have good solubility in organic solvents such as CHCl3, DCM, DMSO, DMF, THF and toluene and are not aggregated in all solvents (except for 2 in DMSO) within a wide concentration range. Complexes 3 and 5 showed very good solubility in water as well as DMSO and DMF. General trends are described for singlet oxygen, photodegradation, fluorescence quantum yields, triplet quantum yields and triplet life times of these complexes in DMSO (2, 4 and 6) and water (3 and 5). Complex 3 gave a very large triplet quantum yield in aqueous media (ΦT = 0.8 in water plus Triton X-100) and a reasonable triplet lifetime of 110 μs. Photophysical and photochemical properties of the phthalocyanines complexes 2–6 are very useful for PDT. , Original publication is available at http://dx.doi.org/10.1016/j.molstruc.2010.04.048
- Full Text: false
The genus Boccardia (Polychaeta: Spionidae) associated with mollusc shells on the south coast of South Africa
- Simon, Carol A, Worsfold, T M, Lange, Louise, Sterley, Jessica A
- Authors: Simon, Carol A , Worsfold, T M , Lange, Louise , Sterley, Jessica A
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6873 , http://hdl.handle.net/10962/d1011620 , http://dx.doi.org/10.1017/S0025315409990452
- Description: Three species of Boccardia (B. polybranchia, B. pseudonatrix and B. proboscidea) were associated with mollusc shells on the south and south-east coasts of South Africa. Boccardia polybranchia was widely distributed along the coast and falls within the known distribution range of this species. Comparisons with material from other, international, locations showed that some specimens have been misidentified. No characters could be found to characterize distinct species for different regions within the range of B. polybranchia, as currently recognized. Boccardia pseudonatrix was found only at the most eastern site, increasing its known distribution range. Boccardia proboscidea, a non-indigenous species, was found only on abalone farms and was most abundant in the west.
- Full Text:
- Date Issued: 2010
- Authors: Simon, Carol A , Worsfold, T M , Lange, Louise , Sterley, Jessica A
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6873 , http://hdl.handle.net/10962/d1011620 , http://dx.doi.org/10.1017/S0025315409990452
- Description: Three species of Boccardia (B. polybranchia, B. pseudonatrix and B. proboscidea) were associated with mollusc shells on the south and south-east coasts of South Africa. Boccardia polybranchia was widely distributed along the coast and falls within the known distribution range of this species. Comparisons with material from other, international, locations showed that some specimens have been misidentified. No characters could be found to characterize distinct species for different regions within the range of B. polybranchia, as currently recognized. Boccardia pseudonatrix was found only at the most eastern site, increasing its known distribution range. Boccardia proboscidea, a non-indigenous species, was found only on abalone farms and was most abundant in the west.
- Full Text:
- Date Issued: 2010
In-service training for academic librarians : a pilot programme for staff
- Authors: Shepherd, Eileen
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6992 , http://hdl.handle.net/10962/d1012418 , http://www.emeraldinsight.com/doi/full/10.1108/02640471011065346
- Description: This paper discusses the need for continuing professional development for librarians in academic libraries in general and at Rhodes University Library, South Africa in particular. It describes the planning, design, implementation and evaluation of a staff-development and training pilot programme for professional librarians at Rhodes Library. A group of 15 librarians, drawn from the library staff complement, participated in an 8-session training course developed by Information Services librarians. The course, which covered basic information-finding skills using a variety of research databases and offered an introduction to concepts in 21st century academic librarianship, was presented using course management software in a face-to-face environment and required homework exercises and the completion of a 2-hour final test. The results of the project demonstrated the urgent need for such development programmes for professional library staff. 80% of the participants completed the course. The final test results indicated below average database search skills and an inability to think laterally. An unexpected finding was a lack of IT competencies. Important lessons were learned with regard to course-construction, content and timing.
- Full Text:
- Date Issued: 2010
- Authors: Shepherd, Eileen
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6992 , http://hdl.handle.net/10962/d1012418 , http://www.emeraldinsight.com/doi/full/10.1108/02640471011065346
- Description: This paper discusses the need for continuing professional development for librarians in academic libraries in general and at Rhodes University Library, South Africa in particular. It describes the planning, design, implementation and evaluation of a staff-development and training pilot programme for professional librarians at Rhodes Library. A group of 15 librarians, drawn from the library staff complement, participated in an 8-session training course developed by Information Services librarians. The course, which covered basic information-finding skills using a variety of research databases and offered an introduction to concepts in 21st century academic librarianship, was presented using course management software in a face-to-face environment and required homework exercises and the completion of a 2-hour final test. The results of the project demonstrated the urgent need for such development programmes for professional library staff. 80% of the participants completed the course. The final test results indicated below average database search skills and an inability to think laterally. An unexpected finding was a lack of IT competencies. Important lessons were learned with regard to course-construction, content and timing.
- Full Text:
- Date Issued: 2010
2009/2010 CEO (Celebrating excellence in organisations) Most Influential Women in Business and Government (MIW) in the Education and Teaching Sector
- Authors: Rhodes University
- Subjects: Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7178 , http://hdl.handle.net/10962/d1006184 , Nyokong, Tebello
- Description: Professor Tebello Nyokong was awarded the 2009/2010 CEO (Celebrating excellence in organisations) Most Influential Women in Business and Government (MIW) in the Education and Teaching Sector and was named as a runner-up in the Quality of Life category of the Department of Science and Technology's (DST) 2009 Distinguished Woman Scientist Award. Holding a DST/NRF South African Research Chairs Initiative Chair in Medicinal Chemistry and Nanotechnology, she is also the Director of the DST/Mintek Nanotechnology Innovation Centre (NIC) for Sensors. Her pioneering research into photodynamic therapy to harness light for cancer therapy and the early detection of human diseases and environmental clean-up continues to draw attention for more reasons than are immediately apparent.
- Full Text:
- Authors: Rhodes University
- Subjects: Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7178 , http://hdl.handle.net/10962/d1006184 , Nyokong, Tebello
- Description: Professor Tebello Nyokong was awarded the 2009/2010 CEO (Celebrating excellence in organisations) Most Influential Women in Business and Government (MIW) in the Education and Teaching Sector and was named as a runner-up in the Quality of Life category of the Department of Science and Technology's (DST) 2009 Distinguished Woman Scientist Award. Holding a DST/NRF South African Research Chairs Initiative Chair in Medicinal Chemistry and Nanotechnology, she is also the Director of the DST/Mintek Nanotechnology Innovation Centre (NIC) for Sensors. Her pioneering research into photodynamic therapy to harness light for cancer therapy and the early detection of human diseases and environmental clean-up continues to draw attention for more reasons than are immediately apparent.
- Full Text:
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
- Language: English
- Type: Article
- Identifier: vital:7240 , http://hdl.handle.net/10962/d1019720
- Description: The different types of water-soluble phthalocyanines are presented and their synthesis is reviewed. , Original publication is available at http://dx.doi.org/10.1016/j.ccr.2010.05.002
- Full Text: false
- Authors: Dumoulin, Fabienne , Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7240 , http://hdl.handle.net/10962/d1019720
- Description: The different types of water-soluble phthalocyanines are presented and their synthesis is reviewed. , Original publication is available at http://dx.doi.org/10.1016/j.ccr.2010.05.002
- Full Text: false
Quest for space : Rhodes University Library odyssey 1904-2010
- Authors: Van der Riet, Sue
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6995 , http://hdl.handle.net/10962/d1012424
- Description: The completion in 2010 of the magnificent new and expanded Rhodes University Library, billed as Rhodes' most intelligent building, seems an appropriate time to trace its history and reflect on the events that led to this much-needed facility and the enormous amount of planning, canvassing, pleading, persuasion and fundraising that brought it to fruition. It is the nature of libraries to devour space. Collections grow exponentially, creating a voracious and insatiable appetite for more and more places in which to store them. In addition, as users’ needs change over time, there is an ongoing demand for working areas which are versatile, able to accommodate modern paradigms of teaching and learning which now necessitate group study areas with computer access, yet which remain inviting and attractive to a broad range of students and researchers who wish simply to find a congenial space to study. The ongoing shortage of space, and the need to accommodate evolving patterns of use, common to most academic libraries, fuelled the engine which drove the Rhodes Library on its circuitous journey from humble lodgings in a single room in the old Drostdy Building more than a hundred years ago, to its final destination in the imposing position it occupies today. A constant refrain was to be money – or more aptly, the lack of it.
- Full Text:
- Date Issued: 2010
- Authors: Van der Riet, Sue
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6995 , http://hdl.handle.net/10962/d1012424
- Description: The completion in 2010 of the magnificent new and expanded Rhodes University Library, billed as Rhodes' most intelligent building, seems an appropriate time to trace its history and reflect on the events that led to this much-needed facility and the enormous amount of planning, canvassing, pleading, persuasion and fundraising that brought it to fruition. It is the nature of libraries to devour space. Collections grow exponentially, creating a voracious and insatiable appetite for more and more places in which to store them. In addition, as users’ needs change over time, there is an ongoing demand for working areas which are versatile, able to accommodate modern paradigms of teaching and learning which now necessitate group study areas with computer access, yet which remain inviting and attractive to a broad range of students and researchers who wish simply to find a congenial space to study. The ongoing shortage of space, and the need to accommodate evolving patterns of use, common to most academic libraries, fuelled the engine which drove the Rhodes Library on its circuitous journey from humble lodgings in a single room in the old Drostdy Building more than a hundred years ago, to its final destination in the imposing position it occupies today. A constant refrain was to be money – or more aptly, the lack of it.
- Full Text:
- Date Issued: 2010
The synthesis and photophysical properties of water soluble tetrasulfonated, octacarboxylated and quaternised 2,(3)-tetra-(2 pyridiloxy) Ga phthalocyanines
- Masilela, Nkosiphile, Nyokong, Tebello
- Authors: Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6579 , http://hdl.handle.net/10962/d1004142
- Description: The photophysical behaviour of chlorogallium 2,(3)-tetra-(2 pyridiloxy) phthalocyanine (ClGaT-2-PyPc) and its quaternised derivative were compared with that of the water soluble anionic tetrasulfonated gallium phthalocyanine ((OH)GaTSPc) and hydoxy gallium octacarboxy phthalocyanine ((OH)GaOCPc). Although both the quaternised compound and the tetrasulfonated gallium phthalocyanine aggregated in aq. solution at pH 11, resulting in low fluorescence and triplet yields, the presence of the surfactant Cremophore EL improved yields. Triplet quantum yields ranged from 0.52 to 0.70 and fluorescence quantum yields ranged from <0.01 to 0.21. The nature of substituent (sulfonate, carboxy and pyridiloxy) did not influence photophysical properties. Chlorogallium 2,(3)-tetra-(2 pyridiloxy) phthalocyanine and its quaternised derivative displayed longer triplet lifetime than both the tetrasulfonated gallium phthalocyanine ((OH)GaTSPc) and hydroxy gallium octacarboxy phthalocyanine in DMSO and in aq. media in both the presence and absence of surfactant.
- Full Text:
- Date Issued: 2010
- Authors: Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6579 , http://hdl.handle.net/10962/d1004142
- Description: The photophysical behaviour of chlorogallium 2,(3)-tetra-(2 pyridiloxy) phthalocyanine (ClGaT-2-PyPc) and its quaternised derivative were compared with that of the water soluble anionic tetrasulfonated gallium phthalocyanine ((OH)GaTSPc) and hydoxy gallium octacarboxy phthalocyanine ((OH)GaOCPc). Although both the quaternised compound and the tetrasulfonated gallium phthalocyanine aggregated in aq. solution at pH 11, resulting in low fluorescence and triplet yields, the presence of the surfactant Cremophore EL improved yields. Triplet quantum yields ranged from 0.52 to 0.70 and fluorescence quantum yields ranged from <0.01 to 0.21. The nature of substituent (sulfonate, carboxy and pyridiloxy) did not influence photophysical properties. Chlorogallium 2,(3)-tetra-(2 pyridiloxy) phthalocyanine and its quaternised derivative displayed longer triplet lifetime than both the tetrasulfonated gallium phthalocyanine ((OH)GaTSPc) and hydroxy gallium octacarboxy phthalocyanine in DMSO and in aq. media in both the presence and absence of surfactant.
- Full Text:
- Date Issued: 2010
Compactification of lattice-valued convergence spaces
- Authors: Jäger, Gunter
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6828 , http://hdl.handle.net/10962/d1012339
- Description: We define compactness for stratified lattice-valued convergence spaces and show that a Tychonoff theorem is true. Further a generalization of the classical Richardson compactification is given. This compactification has a universal property.
- Full Text:
- Date Issued: 2010
- Authors: Jäger, Gunter
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6828 , http://hdl.handle.net/10962/d1012339
- Description: We define compactness for stratified lattice-valued convergence spaces and show that a Tychonoff theorem is true. Further a generalization of the classical Richardson compactification is given. This compactification has a universal property.
- Full Text:
- Date Issued: 2010
A South African response to ethics in legal education
- Authors: Kruuse, Helen
- Date: 2010
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54201 , vital:26403 , https://www.lehmanns.de/shop/recht-steuern/17056480-9780195985818-the-law-of-persons-in-south-africa?PHPSESSID=ogicv1k4dkbpi03lq53elurqh2
- Description: This book reflects the legislative change and consequent changes in common law that fundamentally affect the law of persons, in particular the Children's Act of 2007 and the application of the constitution.
- Full Text: false
- Date Issued: 2010
- Authors: Kruuse, Helen
- Date: 2010
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54201 , vital:26403 , https://www.lehmanns.de/shop/recht-steuern/17056480-9780195985818-the-law-of-persons-in-south-africa?PHPSESSID=ogicv1k4dkbpi03lq53elurqh2
- Description: This book reflects the legislative change and consequent changes in common law that fundamentally affect the law of persons, in particular the Children's Act of 2007 and the application of the constitution.
- Full Text: false
- Date Issued: 2010
Characterization of amine-functionalized single-walled carbon nanotube-low symmetry phthalocyanine conjugates
- Chidawanyika, Wadzanai J U, Nyokong, Tebello
- Authors: Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7237 , http://hdl.handle.net/10962/d1019688
- Description: Functionalization of single-walled carbon nanotubes (SWCNTs) with amine groups using a previously developed diazonium approach, followed by reaction with a carboxylic acid moiety allows direct attachment by an amide bond. We have developed a new SWCNT-low symmetry phthalocyanine conjugate using this approach, using dicyclohexylcarbodiimide as an activating agent to facilitate formation of an amide bond to give a covalently linked conjugate. A conjugate formed by non-covalent attachment has been used for a comparative investigation by FT-IR, Raman, and UV–Vis spectroscopies, and thermal gravimetric analysis. The fluorescence of the phthalocyanine is quenched in the conjugate. , Original publication is available at http://dx.doi.org/10.1016/j.carbon.2010.04.015
- Full Text: false
- Authors: Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7237 , http://hdl.handle.net/10962/d1019688
- Description: Functionalization of single-walled carbon nanotubes (SWCNTs) with amine groups using a previously developed diazonium approach, followed by reaction with a carboxylic acid moiety allows direct attachment by an amide bond. We have developed a new SWCNT-low symmetry phthalocyanine conjugate using this approach, using dicyclohexylcarbodiimide as an activating agent to facilitate formation of an amide bond to give a covalently linked conjugate. A conjugate formed by non-covalent attachment has been used for a comparative investigation by FT-IR, Raman, and UV–Vis spectroscopies, and thermal gravimetric analysis. The fluorescence of the phthalocyanine is quenched in the conjugate. , Original publication is available at http://dx.doi.org/10.1016/j.carbon.2010.04.015
- Full Text: false