Argumentative and trustworthy scholars
- Authors: McKenna, Sioux , Boughey, Chrissie
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187216 , vital:44580 , xlink:href="https://doi.org/10.1080/13562517.2014.934351"
- Description: Research-intensive universities, such as the Russell Group in the UK, the Ivy League Colleges in the USA and the Sandstone Universities in Australia, enjoy particular status in the higher education landscape. They are, however, also often associated with social elitism and selectivity, and this has led to critique as higher education systems seek to widen access. This article looks at how academic staff are discursively constructed in five such institutions in South Africa through an analysis of documentation submitted as part of a national review. Three interrelated discourses are identified: a discourse of ‘staff as scholars’ whereby research is privileged over teaching, a discourse of ‘academic argumentation’ whereby a critical disposition is valued and is called upon by academics to resist development initiatives and a discourse of ‘trust’ whereby it is assumed that academics share a value system and should thus be trusted to undertake quality teaching without interference.
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- Date Issued: 2014
Assessing the genetic diversity of catface rockcod epinephelus andersoni in the subtropical Western Indian Ocean and modelling the effects of climate change on their distribution
- Authors: Coppinger, Christine Rose
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54499 , vital:26570
- Description: The catface rockcod Epinephelus andersoni is a range-restricted species that is endemic to the southeast coast of Africa from Quissico in Mozambique (subtropical) to Knysna in South Africa (warmtemperate). Its complex life-history, long-lived nature and high residency make E. andersoni potentially vulnerable to over-exploitation. Epinephelus andersoni is an important fishery species and has shown signs of depletion. Due to inadequate information necessary for management and conservation, further research is vital, particularly in the face of potentially significant climatic changes which could put further pressure on E. andersoni. The aim of the study was to provide information for the management of E. andersoni, with considerations for the possibly detrimental effects of future climate change. The objectives of this study were to describe the genetic structure and diversity of E. andersoni and to determine possible range shifts of E. andersoni with future changes in sea surface temperature. Genetic samples were collected throughout the distribution of E. andersoni. Standard DNA extraction and PCR using universal primers were conducted and nuclear (RPS7-1) and mitochondrial (cytochrome b) data were analysed to determine genetic diversity. A combination of nuclear and mitochondrial markers was used to ensure that the results were robust. RPS7-1 haplotype diversity was high (0.801) and an AMOVA on the RPS7-1 data showed significantly high among group variation (ΦCT = 0.204, p < 0.05) between five groups: 1. Quissico to Inhaca; 2. Cape Vidal to Port Edward; 3 Port St Johns to Coffee Bay; 4. Mbashe; 5. Port Alfred. This geographic structuring could be attributed to low gene flow across barriers such as the Port Alfred upwelling cell, the Mozambique Channel eddies and smaller more localised upwelling cells such as the Port St Johns cell. The cytochrome b results contrastingly indicate low haplotype diversity (0.309) and no differentiation (ΦCT = 0.265, p = 0.074) between groups and support the hypothesis of a historical population bottleneck. This may be due to an unusually slower mutation rate of the cytochrome b region than the RPS7-1 region, resulting in the RPS7-1 data showing a more recent picture of diversification. To complement the genetic results, niche modelling techniques were used to determine range shifts of E. andersoni with future temperature trends using species distribution and climatic data. The model illustrated a contraction of the E. andersoni distribution as well as future intensification of various upwelling cells along the south-east African coast including the Port Alfred upwelling cell. Due to the low gene flow across these barriers this intensification could decrease the resilience of E. andersoni, as its range becomes more limited with global change. The genetic data and modelling results combined provide useful information on which to base future fisheries management.
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- Date Issued: 2014
Assessment of the long-term response to rehabilitation of two wetlands in KwaZulu-Natal, South Africa:
- Authors: Cowden, Craig , Kotze, Donovan C , Ellery, William F N , Sieben, E J J
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144431 , vital:38345 , DOI: 10.2989/16085914.2014.954518
- Description: Assessing the ecological outcomes of wetland rehabilitation activities is an important need recognised by the ‘Working for Wetlands’ programme in South Africa. An assessment of ecological response was conducted in the Killarney and Kruisfontein wetlands, KwaZulu-Natal, in 2005 prior to rehabilitation in 2006, and again in 2011 and 2012, respectively, following rehabilitation. The assessment criteria included an evaluation of changes in ecological integrity, the supply of ecosystem services, and vegetation composition. Improvements in hydrological and geomorphic integrity were recorded in both wetlands, resulting in improved ecosystem delivery.
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- Date Issued: 2014
Bacterial degradation of waste coal
- Authors: Madikiza, Lwazikazi
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54576 , vital:26590
- Description: As an energy source coal has one of the largest agglomerations in the world. Consequently mining of coal creates large volumes of waste in the form of low ranks coals. The complex structure of coal makes it difficult for the microorganisms to degrade and relatively few bacteria and fungi have been shown to break down coal. This study aimed to investigate bacteria not previously known to degrade coal. In this study bacteria were isolated from hydrocarbon contaminated sites and inoculated in coal medium where coal served as the only carbon source. Three strains produced a yellow – brown supernatant after 14 d of incubation at 30 °C. Bacteria generating a yellow – brown coloured supernatant were presumed to possess coal degrading capabilities and the best performing of these bacterial species was identified using 16s rDNA as Bacillus flexus. Scanning electron microscopy showed that there was a close association between the bacterium and substrate coal. The close association of bacteria to substrate suggested that these organisms were able to maximize solubilisation. FT-IR spectroscopic analysis demonstrated the addition of single bonded compounds COOH, OH, CN and CH that were absent prior to bacterial interaction. The increase in oxygen rich regions indicated degradation of the coal substrate. Elemental analysis showed that there was a decrease in carbon content from 47 % to 24 % during the 14 day incubation period. Reduction in coal carbon content was assumed to be due to bacterial utilization for metabolism and growth particularly as untreated coal substrate showed minimal loss of carbon. Analysis of the residual culture medium revealed that there was a linear increase in humic-like substance concentration for 8 d, coincident with increased coal biosolubilisation and colour change. Laccase activity was insignificant, and at 13 d enzyme activity was only 5×10-3 U/L suggesting that B. flexus may use a different mechanism to degrade coal. Residual culture medium remaining after bacterial action on the coal substrate appeared to possess plant growth promoting activity. This soluble biodegradation product with characteristics similar to humic acid-like substances was shown to impact growth of radish cotyledons. Expansion of isolated radish cotyledons was enhanced by 140% when incubated in coal biodegradation product. In conclusion, this study has yielded B. flexus and two other unidentified bacteria, isolated from polyaromatic hydrocarbon contaminated soils, and demonstrated the ability of these microorganisms to degrade waste coal. Further studies to elucidate the mechanism of coal breakdown by B. flexus, synergies with other coal degrading microorganisms, and incorporation of bacterium into Fungcoal bioprocess technology is imminent.
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- Date Issued: 2014
Behavior of palladium nanoparticles in the absence or presence of cobalt tetraaminophthalocyanine for the electrooxidation of hydrazine
- Authors: Maringa, Audacity , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189796 , vital:44932 , xlink:href="https://doi.org/10.1002/elan.201400028"
- Description: We report on the electrodeposition of palladium nanoparticles (PdNPs) on a glassy carbon electrode (GCE) and onto a poly-CoTAPc-GCE (CoTAPc=cobalt tetraamino phthalocyanine) surface. The electrodes are denoted as PdNPs-GCE and PdNPs/poly-CoTAPc-GCE, respectively. PdNPs/poly-CoTAPc-GCE showed the best activity for the oxidation of hydrazine at the lowest potential of −0.28 V and with the highest currents. The results were further supported by electrochemical impedance spectroscopy (EIS) which showed that there was less resistance to charge transfer for PdNPs/poly-CoTAPc-GCE compared to PdNPs-GCE. The catalytic rate constant for hydrazine oxidation was 6.12×108 cm3 mol−1 s−1 using PdNPs/poly-CoTAPc-GCE.
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- Date Issued: 2014
Bells as memorials in South Africa to the Great (1914-18) War
- Authors: Lewis, Colin A , De Wet, Tertius , Teugels, Jet L , Van Deventer, Pieta J U
- Date: 2014
- Language: English
- Type: Article , text
- Identifier: vital:6192 , http://hdl.handle.net/10962/d1013418
- Description: The contribution of South Africa to the allied cause in the Great War, and the sacrifice of so many lives of the White and Coloured populations, is memorialised on bells of the Cape Town carillon, on ringing, and on clock and other bells. The contribution of the Black population awaits recognition. Restoration of the Cape Town carillon so that it can again be played effectively, would be a fitting memorial to those who lost their lives in the non-combative roles that were open to the majority population of South Africa. Completion of the ring at what is now Queenstown cathedral would also be a fitting tribute to the bravery and unstinting service of so many South Africans during the Great War. , 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 is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
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- Date Issued: 2014
Bioinformatics and data analysis in microbiology:
- Authors: Tastan Bishop, Özlem
- Date: 2014
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/148104 , vital:38710 , ISBN 9781908230737 , https://books.google.co.za/books?id=-G07DwAAQBAJanddq=Bioinformatics+and+data+analysis+in+microbiologyandsource=gbs_navlinks_s
- Description: The rapid advancement of sequencing techniques, coupled with the new methodologies of bioinformatics to handle large-scale data analysis, are providing exciting opportunities for us to understand microbial communities from a variety of environments beyond previous imagination. This book provides invaluable, up-to-date and detailed information on various aspects of bioinformatics data analysis with applications to microbiology. It describes a number of different useful bioinformatics tools, makes links to some wet-lab techniques, explains different approaches to tackle a problem, talks about current challenges and limitations, gives examples of applications of bioinformatics methods to microbiology, and discusses future trends. The chapters include topics such as genome sequencing techniques, assembly, SNP analysis, annotation, comparative genomics, microbial community profiling, metagenomics, phylogenetic microarrays, barcoding and more. Each chapter is written by scientists who are expert in the field, and is peer-reviewed. Bioinformatics and Data Analysis in Microbiology is an essential book for researchers, lecturers and students involved in microbiology, bioinformatics and genome analysis.
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- Date Issued: 2014
Bioinformatics education—perspectives and challenges out of Africa
- Authors: Tastan Bishop, Özlem , Adebiyi, Ezekiel F , Alzohairy, Ahmed M , Everett, Dean B , Ghedira, Kais , Ghouila, Amel , Kumuthini, Judit , Mulder, Nicola J , Panji, Sumir , Patterton, Hugh-G
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123244 , vital:35420 , https://doi.10.1093/bib/bbu022
- Description: The discipline of bioinformatics has developed rapidly since the complete sequencing of the first genomes in the 1990s.The development of many high-throughput techniques during the last decades has ensured that bioinformatics has grown into a discipline that overlaps with, and is required for, the modern practice of virtually every field in the life sciences. This has placed a scientific premium on the availability of skilled bioinformaticians, a qualification that is extremely scarce on the African continent. The reasons for this are numerous, although the absence of a skilled bioinformatician at academic institutions to initiate a training process and build sustained capacity seems to be a common African shortcoming.This dearth of bioinformatics expertise has had a knock-on effect on the establishment of many modern high-throughput projects at African institutes, including the comprehensive and systematic analysis of genomes from African populations, which are among the most genetically diverse anywhere on the planet. Recent funding initiatives from the National Institutes of Health and theWellcomeTrust are aimed at ameliorating this shortcoming. In this paper, we discuss the problems that have limited the establishment of the bioinformatics field in Africa, as well as propose specific actions that will help with the education and training of bioinformaticians on the continent. This is an absolute requirement in anticipation of a boom in high-throughput approaches to human health issues unique to data from African populations.
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- Date Issued: 2014
Book Review: Community of insecurity
- Authors: Magadla, Siphokazi
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298606 , vital:57720 , xlink:href="https://doi.org/10.1080/02589001.2014.936174"
- Description: Laurie Nathan's Community of Insecurity is a thoughtful engagement with the ‘establishment, evolution and effectiveness of the regional security arrangements of the Southern African Development Community (SADC)’ (1). He argues that it is of ‘great significance and irony that many of the major disputes among member states have been around the orientation and strategies of peacemaking and regional security’. Nathan's empirical claims about the SADC security architecture are drawn from his ‘insider perspective’ due to his involvement in official efforts to design a common security regime in Southern Africa, which include his service as regional security advisor to the SADC Secretariat from 1992 to 1996, to the Foreign Minister of Mozambique Pascoal Mocumbi from 1994 to 1995, to the South African Minister of Defence Joe Modise and the Deputy Minister of Defence Ronnie Kasrils between 1994 and 1999 and to the Foreign Minister of Swaziland Albert Shabangu when he oversaw the SADC Organ on Politics, Defence and Security Cooperation in 1999–2000 (12–13). This ‘insider’ view has allowed him to make a compelling challenge to current theoretical debates about SADC's status as a security community, that is, a community with an affinity amongst member states that is ‘so strong that they enjoy dependable expectations of peaceful change and thus regard the prospect of war among them as inconceivable’(129). While other commentators see SADC as either a ‘nascent’, ‘embryonic’ or ‘emerging’ security community, Nathan argues forcefully that ‘this perspective is mistaken’ as SADC continues to be demonstrative of a what he describes as a ‘community of insecurity’.
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- Date Issued: 2014
Breast cancer: current developments in molecular approaches to diagnosis and treatment
- Authors: de la Mare, Jo-Anne , Contu, Lara , Hunter, Morgan C , Moyo, Buhle , Sterrenberg, Jason N , Dhanani, Karim C H , Mutsvunguma, Lorraine Z , Edkins, Adrienne L
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164819 , vital:41175 , DOI: 10.2174/15748928113086660046
- Description: Due to the high heterogeneity of breast cancers, numerous recent patents describe improved methods of detection and classification which promise better patient prognosis and treatment. In particular, there has been a shift towards more effective genetic screening to identify specific mutations associated with breast tumours, which may lead to “personalised medicine” with improved outcomes. Two challenging areas of breast cancer research involve the development of treatments for the highly aggressive triple negative breast cancer subtype as well as the chemotherapy-resistant cancer stem cell subpopulation. In addition, despite numerous recent advances in breast cancer treatment in woman, male breast cancer remains poorly understood and there are limited therapies available which are developed specifically for men. This review serves to report on important developments in the treatment of breast malignancies patented in the past two years as well as to highlight the current gaps in the field of breast cancer therapeutics and areas which require further study.
- Full Text:
- Date Issued: 2014
Can δ15N and δ13C stable isotopes and fatty acid signatures indicate changes in phytobenthos composition on an artificial substrate?
- Authors: Dalu, Tatenda , Froneman, P William
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68086 , vital:29197 , https://doi.org/10.2989/16085914.2014.974018
- Description: Publisher version , Temporal changes in fatty acid composition and δ15N, δ13C stable isotope values of the phytobenthos growing on artificial clay substrates under natural conditions over a 28-day period at an upstream and a downstream site in the Kowie River near Grahamstown were investigated in 2012. High concentrations of diatom markers 16:1ω7 and 20:5ω3 fatty acids were recorded, especially at the downstream site, reflecting the importance of diatoms in contributing to the phytobenthos communities at that station. After day 7 at the downstream site the average δ15N value of the phytobenthos was lighter, gradually increasing by ∼2‰ and ∼5‰ overall to heavier values on day 28. At the upstream site there were no significant changes (<1‰ increase) in δ15N values of the phytobenthos over time. Stable nitrogen (δ15N) and carbon (δ13C) signatures in the phytobenthos communities were significantly different between sites (one-way ANOVA; p < 0.001). The stable isotope values and fatty acid concentrations of phytobenthos at the downstream site were different to those of the phytobenthos at the upstream site, and they changed concurrently with changes in the phytobenthos community structure. At the downstream site there was a strong correlation of the δ15N of phytobenthos with nitrates (R = 0.56) and time (weeks; R = 0.81). However, the fatty acids were not specific enough to characterise the composition of phytobenthos communities. Other biomarker methods, such as stable isotopes and microscopic examination of the communities, were found to be useful. The results from this relatively small-scale tile experiment indicate the complexity of changes in fatty acid composition and δ15N, δ13C stable isotope values of a phytobenthos community. Stable isotope and fatty acid composition can be successfully used to map changes in phytobenthos composition and carbon and nitrogen flow patterns along a river continuum.
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- Date Issued: 2014
Carbon nanotube-enhanced photoelectrochemical properties of metallo-octacarboxyphthalocyanines
- Authors: Mphahlele, Nonhlanhla E , Le Roux, Lukas , Jafta, Charl J , Cele, Leskev , Mathe, Mkhulu K , Nyokong, Tebello , Kobayashi, Nagao , Ozoemena, Kenneth I
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241595 , vital:50953 , xlink:href="https://doi.org/10.1007/s10853-013-7710-1"
- Description: The photoelectrochemistry of metallo-octacarboxyphthalocyanines (MOCPc, where M = Zn or Si(OH)2) integrated with MWCNTs for the development of dye-sensitized solar cells (DSSCs) is reported. The DSSC performance (obtained from the photo-chronoamperometric and photo-impedimetric data) decreased as ZnOCPc > (OH)2SiOCPc. The incorporation of the MWCNTs on the surface of the TiO2 film (MOCPc–MWCNT systems) gave higher photocurrent density than the bare MOCPc complexes. Also, from the EIS results, the MOCPc–MWCNT hybrids gave faster charge transport kinetics (approximately three times faster) compared to the bare MOCPc complexes. The electron lifetime was slightly longer (ca. 6 ms) at the ZnOCPc systems than at the (OH)2SiOCPc system (ca. 4 ms) meaning that the presence of the MWCNTs on the surface of the TiO2 film did not show any significant improvement on preventing charge recombination process.
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- Date Issued: 2014
Career success for women academics in higher education: choices and challenges
- Authors: Obers, Nöelle Marie Thérèse
- Date: 2014
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61346 , vital:28017 , http://0-journals.co.za.wam.seals.ac.za/content/high/28/3/EJC159132
- Description: The aim of the research reported on in this article was to contribute to an understanding of how women academics experience career success; how their choices and challenges impact on their career advancement; and how the playing fields in academia can be levelled. Understanding the constraints and identifying enabling aspects may help women academics to overcome obstacles in their career development and be more represented in academia and ultimately in society. This research was a case study undertaken at one higher education institution (HEI), Rhodes University (RU). The data was collected from institutional documents; questionnaire data from women academics at the HEI; and in-depth interviews with six women academics. The data indicate that mentoring is a strategy to enhance levels of self-esteem and research productivity and ultimately improve the representation of women in leadership and senior positions.
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- Date Issued: 2014
Challenges facing teachers in implementing alternative measures of discipline in schools: a case study of five secondary schools in the Umzimkhulu circuit of the Sisonke District in Kwazulu-Natal
- Authors: Zulu, Xolani Wycliff
- Date: 2014
- Subjects: School discipline , Secondary schools , Sisonke District -- Kwazulu-Natal, South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/11260/2393 , vital:41455
- Description: This dissertation is a report on a study that was conducted in rural schools of the Sisonke District in KwaZulu-Natal, a province of South Africa. The study covered the challenges experienced by teachers in implementing the alternative measures of discipline. The study was conducted because the researcher was the head of the disciplinary committee in the school where he was employed and he often dealt with disciplinary problems which usually occurred between the teachers, learners and SMTs. It was important to know from other schools, what problems they faced in implementing the alternative measures of discipline. The study used a qualitative research design in the form of a case study. Purposive sampling was used. The sample comprised 15 SMT members, and 20 post level 1 teachers, and the total number of participants was 35. Data was collected through observations which were followed by interviews. Qualitative methods were used to analyse data. This involved reduction and interpretation of data collected. The findings of the study highlighted the role that could be played by SMTs, teachers, parents, and the Department of Education in the smooth running of the school in dealing with the misunderstandings of alternative measures of discipline and so advance an effective work ethos. The study also illuminated the issue of negligence on the part of SMTs in enforcing the implementation of the alternative measures of discipline. There was a great need for school teachers to be well versed in the general legislation of the Department of Education so as to align themselves with the correct rules and regulations when they deal with disciplinary problems. , Thesis (MEd) -- Faculty of Humanities, Educational Management and Policy, 2014
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- Date Issued: 2014
Characterization and application of phthalocyanine-magnetic nanoparticle conjugates anchored to electrospun polyamide nanofibers
- Authors: Ledwaba, Mpho
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54610 , vital:26593
- Description: This work presents the syntheses, photophysical and photochemical characterization of zinc tetracarboxyphenoxy phthalocyanine (ZnTCPPc, 3) and its gadolinium oxide nanoparticle conjugate (4). By means of spectroscopic and microscopic characterization, the conjugation of the ZnTCPPc to the silica coated gadolinium oxide nanoparticles (Si-Gd2O3 NPs, 2) through an amide bond was confirmed. The thermal stability, morphology, nanoparticle sizes and their conjugates with the Pc were studied using ThermoGravimetric Analysis (TGA), Fourier Transform Infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and powder X-ray diffractometry (XRD). Conjugation of ZnTCPPc to the magnetic nanoparticles, proved to have a negligible effect on the photophysical parameters of the phthalocyanine, where a slight decrease in fluorescence and triplet quantum yields and lifetimes was observed. The singlet oxygen quantum yield, however, increased slightly upon conjugation, suggesting that the overall efficiency of the ZnTCPPc as a photosensitizer had improved. Physical mixing of the ZnTCPPc and the silica-coated gadolinium nanoparticles also showed an improvement in the singlet oxygen quantum yield and triplet lifetime, also showing an enhanced efficiency for the photosensitizer and therefore photocatalysis. ZnTCPPc (3) alone and the Pc-gadolinium oxide nanoparticle conjugate (4) were therefore electrospun into nanofibers to create a solid support. The fibers were characterized and their diameter sizes and composition was studied confirming the incorporation of the phthalocyanine and gadolinium oxide nanoparticle. Increased singlet oxygen generation resulted in increased Photodegradation of the environmental pollutant Orange G and the fibers were found to be more efficient as photocatalysts compared to the photosensitizer in solution. The nanomaterial may therefore be applied to the photodegradation of Orange G.
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- Date Issued: 2014
Characterization of electrodes modified by one pot or step by step electro-click reaction and axial ligation of iron tetracarboxyphthalocyanine
- Authors: Maringa, Audacity , Mashazi, Philani N , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193892 , vital:45403 , xlink:href="https://doi.org/10.1016/j.electacta.2014.09.011"
- Description: The modification of the glassy carbon electrode (GCE) was carried out using two methods. The first method is simultaneous electropolymerization and electro-click followed by immersion into a solution of dimethyl formamide (DMF) containing FeTCPc. The second method is step by step whereby electropolymerization is carried out first followed by electro-click and then immersion into a DMF solution containing FeTCPc. From the electrochemical characterization, it was observed that the second route (step by step method) was the best as indicated by the ferricyanide studies (cyclic voltammetry and scanning electrochemical microscopy). In the electrooxidation of hydrazine, we obtained a potential of 0.26 V. Of interest were the detection limit of 6.4 μM and the catalytic rate constant of 2.1 × 109 cm3 mol−1 s−1. This shows that the sensor can be used for the electrooxidation of hydrazine.
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- Date Issued: 2014
Climate Change and Environmental Challenges in Southern African Development Community (SADC): Responses in the Age of Globalisation
- Authors: Chikunda, Charles , Mandikonza, Caleb
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437249 , vital:73363 , ISBN 9789462098367 , https://brill.com/display/book/9789462098367/BP000009.xml
- Description: There is evidence that one of the greatest controversies facing Africa today is how to make sense of the two leading global intentions of the 21st century: sustainable development and globalisation. These two paradigms appear to have some op-posing tendencies within them, some of which are contestable. Globalisation advocates for liberalisation; reduction or elimina-tion of state regulations on the market, free reign, and a high degree of rights to the large corporations that dominate the market. Globalisation also entails the cross flow of knowledge and knowledge forms.
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- Date Issued: 2014
Collection of urban tree products by households in poorer residential areas of three South African towns
- Authors: Kaoma, Humphrey , Shackleton, Charlie M
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180980 , vital:43678 , xlink:href="https://doi.org/10.1016/j.ufug.2014.02.002"
- Description: The high rates of urban in-migration and poverty common in many developing country towns potentially increases the reliance of urban populations on the direct benefits provided by trees. Yet understanding of the extent of such use and the sources of these tree products is limited. Here we report on the extent of use of urban tree products by 450 households in the poorer areas of three towns along a rainfall gradient based on household questionnaires. We considered the proportion of households making use of each of several tree products and the collection or purchasing frequency which we disaggregated by source of the product, including trees in homesteads, urban spaces, edges of towns and via purchase from traders. Most households (91%) used firewood, which was most frequently collected from the urban fringe or purchased, although one-third at times also collected firewood from trees on their home plot. All households used fruits, most commonly sourced through purchase (98%), but nearly half of whom also supplemented by harvesting fruits from their home plot. Other products used included wood for building, fencing and utensils, herbal medicines, planting material and mulch. Collection of products from urban homestead trees was highest amongst households in the informal settlements and least in the more established townships. Residents of new low-cost housing areas made extensive use of urban tree products harvested in urban spaces because they had fewer homestead trees than residents of informal areas or townships. Overall, urban residents made use of a wide array of tangible products from trees which they sourced from a variety of places, including their homestead plot. This urges that planning agencies ensure that homestead plot sizes or other urban spaces that provide tree products are large enough to support the direct needs of poorer urban residents.
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- Date Issued: 2014
Colonisation and community structure of benthic diatoms on artificial substrates following a major flood event: a case of the Kowie River (Eastern Cape, South Africa)
- Authors: Dalu, Tatenda , Froneman, P William , Chari, Lenin D , Richoux, Nicole B
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143357 , vital:38239 , http://dx.doi.org/10.4314/wsa.v40i3.10
- Description: A major flooding event that occurred during October–November 2012 caused major changes in the Kowie River hydromorphology and aquatic communities. The aim of our study was to identify the environmental variables that structure riverine benthic diatom communities at upstream and downstream locations 25 km apart on the Kowie River, South Africa. This was undertaken using tiles as artificial substrates so that we could study how the communities developed after the flood disturbance. The diatom community structure was assessed over a 28-day period following a flood event in October 2012. The Mann Whitney test indicated that there was a statistically significant difference (p 0.05) in total dissolved solids, salinity, pH and oxygen reduction potential between the two sites. In total, 58 diatom species belonging to 30 genera were identified over the 28-day study.
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- Date Issued: 2014
Comparison between base metals and platinum group metals in nitrogen, M codoped TiO 2 (M= Fe, Cu, Pd, Os) for photocatalytic removal of an organic dye in water
- Authors: Kuvarega, Alex T , Mamba, Bhekie B , Krause, Rui W M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125129 , vital:35734 , https://doi.org/10.1155/2014/962102
- Description: The photocatalytic performance of a number of nonmetal and metal codoped TiO2 for the degradation of eosin yellow under simulated solar radiation was investigated. The synthesised materials were characterised by FTIR, Raman spectroscopy, XRD, DRUV-Vis, SEM, and TEM.The N, metal codoped TiO2 containing 0.5 wt.% of the metal consisted mainly of the anatase phase, with a particle size range of 15–28 nm. The particles were largely spherical and shifted the absorption edge well into the visible region. Band gap reduction was more pronounced for the N, PGM codoped TiO2 compared to N, base metal codoped samples. Codoping led to an enhancement in the photocatalytic activity of the materials for the degradation of eosin yellow. N, Pd codoped TiO2 was the most effective photocatalyst (99.9% dye removal) while N, Cu codoped TiO2 showed the least activity (25.5% removal). The mechanism for the photocatalytic enhancement was proposed on the basis of formation of an electron deficient Schottky barrier at the semiconductor-metal interface, which acts as an electron sink and thus retards electron-hole recombination. It was shown that the ability of the photocatalyst to degrade the dye depends on the nature and type of the metal dopant in the codoped TiO2 system.
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- Date Issued: 2014