Editorial
- Authors: Olvitt, Lausanne L
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391156 , vital:68625 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/121960"
- Description: This year marks the end of the United Nations Decade of Education for Sustainable Development which was first proposed at the World Summit on Sustainable Development in 2002 in Johannesburg. At the end of 2014 UNESCO hosted the World Conference on Education for Sustainable Development in Nagoya, Japan. To mark this occasion Professor Rob O’Donoghue produced a reflective Think Piece that traces the emergence of education for sustainable development (ESD) from its educational roots in the Modernist project, to the diversity of practices that currently frame ESD as a transgressive process of cultural change. O’Donoghue interrogates tensions around knowledge and participation in the ESD terrain and proposes that knowledge-led and ethics-led learning in relation to valued purposes might create educational possibilities for expansive, transgressive and reflexive learning processes towards a more sustainable future. This Think Piece opens the Journal; many of the strengths, tensions and generative opportunities in environment and sustainability education referred to by O’Donoghue are reflected in this edition of the journal.
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- Date Issued: 2014
Effect of bovine serum albumin and single walled carbon nanotube on the photophysical properties of zinc octacarboxy phthalocyanine
- Authors: Ogbodu, Racheal O , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189806 , vital:44933 , xlink:href="https://doi.org/10.1016/j.saa.2013.10.064"
- Description: This work reports on the photophysical parameters of the conjugate between zinc octacarboxy phthalocyanine (ZnOCPc) and bovine serum albumin (BSA) represented as ZnOCPc–BSA (1) which was further adsorbed onto single walled carbon nanotubes (SWCNT) represented as (ZnOCPc–BSA–SWCNT 2). ZnOCPc (without BSA) was also adsorbed on SWCNT represented as ZnOCPc–SWCNT (3). The presence of BSA resulted in the increase in singlet oxygen quantum yield (ΦΔ) for 1 (at ΦΔ = 0.44) and 2 (at ΦΔ = 0.41) compared to ΦΔ = 0.21 for ZnOCPc alone. For complex 3 which did not contain BSA singlet oxygen quantum yield decreased.
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- Date Issued: 2014
Effect of water trophic level on the impact of the water hyacinth moth Niphograpta albiguttalis on Eichhornia crassipes
- Authors: Canavan, Kim N , Coetzee, Julie A , Hill, Martin P , Paterson, Iain D
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423740 , vital:72090 , xlink:href="https://doi.org/10.2989/16085914.2014.893225"
- Description: Eutrophication contributes to the proliferation of alien invasive weed species such as water hyacinth Eichhornia crassipes. Although the South American moth Niphograpta albiguttalis was released in South Africa in 1990 as a biological control agent against water hyacinth, no post-release evaluations have yet been conducted here. The impact of N. albiguttalis on water hyacinth growth was quantified under low-, medium- and high-nutrient concentrations in a greenhouse experiment. Niphograpta albiguttalis was damaging to water hyacinth in all three nutrient treatments, but significant damage in most plant parameters was found only under high-nutrient treatments. However, E. crassipes plants grown in high-nutrient water were healthier, and presumably had higher fitness, than plants not exposed to herbivory at lower-nutrient levels. Niphograpta albiguttalis is likely to be most damaging to water hyacinth in eutrophic water systems, but the damage will not result in acceptable levels of control because of the plant's high productivity under these conditions. Niphograpta albiguttalis is a suitable agent for controlling water hyacinth infestations in eutrophic water systems, but should be used in combination with other biological control agents and included in an integrated management plan also involving herbicidal control and water quality management.
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- Date Issued: 2014
Effects of analytes on the fluorescence properties of CdTe@ ZnS quantum dots decorated with cobalt tetraamino-phthalocyanine
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189829 , vital:44935 , xlink:href="https://doi.org/10.1016/j.jlumin.2013.09.079"
- Description: In this work, we have carried out an investigation on the effects of different biologically active analytes on the fluorescence response of glutathione-capped CdTe@ZnS quantum dots (QDs)-colbalt tetraamino-phthalocyanine nanoconjugate system. Firstly, fluorescence quenching occurred. Experimental results showed that some analytes either “turned on”, others further quenched or showed no effect on the fluorescence emission of the nanoprobe.
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- Date Issued: 2014
Effects of number of ring substituents on the physicochemical properties of zinc aminophenoxy phthalocyanine-single walled carbon nanotube conjugate
- Authors: Ogbodu, Rachael O , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190356 , vital:44987 , xlink:href="https://doi.org/10.1016/j.jphotochem.2013.09.015"
- Description: This work reports on the linking of zinc monoaminophenoxy (ZnMAPPc) or zinc tetraaminophenoxy phthalocyanine (ZnTAPPc) complexes to single walled carbon nanotubes (SWCNTs) through either covalent or non-covalent (adsorption) bonding. The functionalized complexes showed better thermal stability when compared to the SWCNT-COOH, ZnMAPPc and ZnTAPPc alone as confirmed by thermogravimetric analyses. The covalently linked ZnMAPc-SWCNT showed higher electron transfer rate constant and photoinduced electron efficiency when compared to adsorbed complexes. ZnMAPPc-SWCNT complexes (linked and adsorbed) showed better photophysical and photochemical properties when compared to ZnTAPPc-SWCNT complexes. The triplet, singlet oxygen and florescence quantum yields of ZnMAPPc (or ZnTAPPc) decrease upon linking or adsorption onto SWCNTs.
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- Date Issued: 2014
Effects of pyrene on the photophysical and two-photon absorption-based nonlinear optical properties of indium (III) phthalocyanines
- Authors: Sanusi, Kayode , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189957 , vital:44951 , xlink:href="https://doi.org/10.1080/00958972.2014.959509"
- Description: Photophysical and two-photon-dependent nonlinear absorption properties of two chloroindium(III) phthalocyanines bearing pyrene units have been investigated. The tetra- (3) and the tri- (4) pyrene-substituted phthalocyanines exhibit strong triplet absorption with high triplet yields ( ) of 0.79 and 0.83, respectively. The measured nonlinear optical data, such as the two photon absorption cross-sections, the third- and second-order nonlinearities were found to be comparable with those of literature, thus, making the compounds promising candidates for a broad range of nonlinear optical applications.
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- Date Issued: 2014
Effects of redox mediators on the catalytic activity of iron porphyrins towards oxygen reduction in acidic media
- Authors: He, Qinggang , Wu, Gang , Liu, Ke , Khene, Samson M , Li, Qing , Mugadza, Tawanda , Deunf, Elise , Nyokong, Tebello , Chen, Shaowei W
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241472 , vital:50942 , xlink:href="https://doi.org/10.1002/celc.201402054"
- Description: The effects of different redox mediators on the oxygen reduction reaction (ORR) catalyzed by an iron porphyrin complex, iron(III) meso-tetra(N-methyl-4-pyridyl)porphine chloride [FeIIITMPyP], in 0.1 M triflic acid were investigated by cyclic voltammetry (CV) and spectroelectrochemistry in conjunction with density functional theory (DFT) calculations. The formal potentials of the FeIIITMPyP catalyst and the redox mediators, as well as the half-wave potentials for the ORR, were determined by CV in the absence and presence of oxygen in acidic solutions. UV/Vis spectroscopic and spectroelectrochemical studies confirmed that only the 2,2′-azino-bis(3-ethylbenzothiazioline-6-sulfonic acid)diammonium salt (C18H24N6O6S4) showed effective interactions with FeIIITMPyP during the ORR. DFT calculations suggested strong interaction between FeIIITMPyP and the C18H24N6O6S4 redox mediator. The redox mediator caused lengthening of the dioxygen iron bond, which thus suggested easier dioxygen reduction. Consistent results were observed in electrochemical impedance spectroscopic measurements for which the electron-transfer kinetics were also evaluated.
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- Date Issued: 2014
Electrocatalytic behahiour of cobalt tetraamino-phthalocyanine in the presence of a composite of reduced graphene nanosheets and of multi-walled carbon nanotubes
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189784 , vital:44931 , xlink:href="https://doi.org/10.1016/j.electacta.2014.05.093"
- Description: A composite of multi-walled carbon nanotubes (MWCNT) with reduced graphene nanosheets (rGNS-2) was developed in order to minimize the restacking of the latter. The composite was used to modify a glassy carbon electrode (GCE). GCE was further modified with cobalt tetraamino phthalocyanine (CoTAPc). The modified electrode is represented as rGNS-2-MWCNT-CoTAPc-GCE. X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electrochemical microscopy and Raman spectroscopy were used to explore into surface functionalities, morphology and topography of the nanocomposite. The rGNS-2-MWCNT-CoTAPc-GCE had a low limit of detection of 3.32 × 10−8 M towards the detection of paraguat as a test analyte. A mechanism for paraquat detection using an rGNS-2-MWCNT-CoTAPc-GCE is also proposed in this work.
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- Date Issued: 2014
Electrochemical behaviour of gold nanoparticles and Co tetraaminophthalocyanine on glassy carbon electrode
- Authors: Maringa, Audacity , Antunes, Edith M , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241573 , vital:50951 , xlink:href="https://doi.org/10.1016/j.electacta.2013.12.132"
- Description: We report on the electrodeposition of gold nanoparticles (AuNPs) onto the glassy carbon electrode (GCE) followed by polymerization of cobalt tetraamino phthalocyanine (CoPc(NH2)4) on top (represented as poly-CoPc(NH2)4-/AuNPs-GCE). The modified electrode where CoPc(NH2)4 is polymerized first followed by deposition of AuNPs is represented as AuNPs/poly-CoPc(NH2)4-GCE. In the absence of AuNPs, the electrode is represented as poly-CoPc(NH2)4-GCE or for AuNPs alone (AuNPs-GCE). The surface coverage was 1.5 × 10−9 mol cm−2 for AuNPs-GCE and 3.0 × 10−9 mol cm−2 for the rest of the modified electrodes. AuNPs/CoPc(NH2)4-GCE exhibited high electrocatalytic activity towards the oxidation of nitrite, with detection potential of 0.76 V. The catalytic rate constant of 3.96 × 107 cm3 mol−1 s−1 was obtained for nitrite oxidation.
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- Date Issued: 2014
Electrochemical inclusion of catechol into singlewalled carbon nanotubes: application for sensors
- Authors: Oni, Joshua , Limson, Janice L
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431090 , vital:72743 , xlink:href="10.1109/BioCAS.2014.6981727"
- Description: We report on the use of catechol for the electrochemical activation of acid-functionalised single-walled carbon nanotubes immobilised on glassy carbon electrodes. Following well-published methods for catechol activation of bare glassy carbon electrodes, these studies show the efficacy of extending the method to activation of carbon nanotubes. Voltammetric scans in catechol show an increase in current response of 37 μA for the catechol redox pair over a maximum of three cycles during the catechol activation step. An increase in the ease of electron flow is indicated by a larger value for K app , which corresponds to a decrease in R ct obtained during impedance measurements. Catechol activation enhanced electron transfer, potentially afforded by an ease of electron passage due to a decrease in the resistance of the layer.
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- Date Issued: 2014
Electropolymerized Fluorinated Aniline-Based Fiber for Headspace Solid-Phase Microextraction and Gas Chromatographic Determination of Benzaldehyde in Injectable Pharmaceutical Formulations
- Authors: Mohammadi, Ali , Mohammadi, Somayeh , Moghaddam, Bayandori A , Masoumi, Vahideh , Walker, Roderick B
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184120 , vital:44175 , xlink:href="https://doi.org/10.1093/chromsci/bmt152"
- Description: In this study, a simple method was developed and validated to detect trace levels of benzaldehyde in injectable pharmaceutical formulations by solid-phase microextraction coupled with gas chromatography–flame ionization detector. Polyaniline was electrodeposited on a platinum wire in trifluoroacetic acid solvent by cyclic voltammetry technique. This fiber shows high thermal and mechanical stability and high performance in extraction of benzaldehyde. Extraction and desorption time and temperature, salt effect and gas chromatography parameters were optimized as key parameters. At the optimum conditions, the fiber shows good linearity between peak area ratio of benzaldehyde/3-chlorobenzaldehyde and benzaldehyde concentration in the range of 50–800 ng/mL with percent relative standard deviation values ranging from 0.75 to 8.64% (n 5 3). The limits of quantitation and detection were 50 and 16 ng/mL, respectively. The method has the requisite selectivity, sensitivity, accuracy and precision to assay benzaldehyde in injectable pharmaceutical dosage forms.
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- Date Issued: 2014
Electro‐oxidation of acetaminophen on nickel/poly (o‐aminophenol)/multi‐walled carbon nanotube nanocomposite modified graphite electrode.
- Authors: Naeemy, Ali , Mohammadi, Ali , Bakhtiari, Hediech , Ashouri, Nasim , Walker, Roderick B
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184107 , vital:44173 , xlink:href="https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/mnl.2014.0197"
- Description: Poly(o-aminophenol) (POAP)/multi-walled carbon nanotube (MWCNT) nanocomposite and POAP in the absence of the MWCNT were fabricated by consecutive cyclic voltammetry (CV) on a graphite (G) electrode. The dispersion of nickel (II) ions was accomplished and incorporated into the polymeric electrodes (G/POAP and G/POAP-MWCNT) by immersing them into a 0.1 M nickel (II) solution. Following preparation of G/POAP/Ni and G/POAP-MWCNT/Ni, the electrochemical behaviour was examined using CV. Scanning electron microscopy was used for characterisation of the nanocomposite. The prepared electrodes showed enhanced electrocatalytic activity for the oxidation of acetaminophen and facilitated the detection of acetaminophen in a 0.1 M NaOH solution. Compared with the G/POAP/Ni electrode, the G/POAP-MWCNT/Ni electrode had a significant current response of acetaminophen oxidation because of the synergistic effects of POAP and the MWCNT. By CV, the calibration plot was linear in the range of 1–13 mM with standard deviation between 0.3 and 6.54% for acetaminophen. The G/POAP-MWCNT/Ni was successfully applied for acetaminophen determination in tablets and the results showed sufficient precision and achieved a mean recovery of 96.8% (R.S.D. = 4.9%).
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- Date Issued: 2014
Enhanced nonlinear optical properties of octa-substituted lead and cadmium phthalocyanines when embedded in poly (bisphenol A carbonate) as thin films
- Authors: Mkhize, Colin , Britton, Jonathan , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241459 , vital:50941 , xlink:href="https://doi.org/10.1016/j.poly.2014.07.025"
- Description: This work presents photophysical and nonlinear optical properties of a novel Cd 2,3-[octakis{4-tert-butylphenoxyphthalocyanine}] (CdOtBPPc) and compare them with those of Pb 2,3-[octakis{4-tert-butylphenoxyphthalocyanine}] (PbOtBPPc). For both the CdOtBPPc and PbOtBPPc, third order imaginary susceptibility and second order hyperpolarizability values were found to be within the limit set for good optical limiters. The Pcs were embedded in poly (methyl methacrylate) (PMMA) and poly(bisphenol A carbonate) (PBC) as thin films. The optical limiting values of the Pcs once embedded in film were found to be greatly improved and the limiting fluence of each film was well below the maximum threshold. Both PbOtBPPc and CdOtBPPc showed better optical limiting when embedded in PBC compared to PMMA. CdOtBPPc shows better nonlinear optical behavior than PbOtBPPc in solution and as thin films, even though the former is aggregated in solution.
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- Date Issued: 2014
Enhanced Optical Limiting Behavior of an Indium Phthalocyanine–Single-Walled Carbon Nanotube Composite
- Authors: Sanusi, Kayode , Amuhaya, Edith K , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193871 , vital:45401 , xlink:href="https://doi.org/10.1021/jp501469e "
- Description: The nonlinear optical behavior of 2(3),9(10),16(17),23(24)-tetrakis-(4-aminophenoxy) phthalocyaninato indium (III) chloride (2) and its carbon nanotube composite in dimethylsulfoxide (DMSO) and dimethylformamide (DMF) solutions is described. The nonlinear third-order susceptibility and second-order hyperpolarizability values are also reported. A large nonlinear absorption that increased on covalent linking with single-walled carbon nanotubes (SWCNTs) was observed for the compound in DMSO. The nanosecond nonlinear absorption and the optical limiting behavior of this complex are shown to be dominated by a strong excited state absorption from a two-photon pumped state. The optical limiter using the new nanocomposite material (SWCNT-2) in the appropriate solvent showed a much lower threshold for optical limiting together with a much lower transmission at high fluences than previously reported nanocomposite limiters. The optical properties of the phthalocyanine and its conjugate were found to show high sensitivity toward the change of solvent matrix.
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- Date Issued: 2014
Enhanced optical limiting performance in phthalocyanine-quantum dot nanocomposites by free-carrier absorption mechanism
- Authors: Sanusi, Kayode , Khene, Samson M , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193904 , vital:45404 , xlink:href="https://doi.org/10.1016/j.optmat.2014.07.024"
- Description: Enhanced nonlinear optical properties (in dimethyl sulphoxide) is observed for 2(3),9(10),16(17),23(24)-tetrakis-(4-aminophenoxy)phthalocyaninato indium(III) chloride (InPc) when covalently linked to CdSe/ZnS or CdSe quantum dots (QDs). The experimental nonlinear optical parameters were obtained from Z-Scan measurements. Contributions from two-photon absorption (2PA) due to the InPc, and free-carrier absorption (FCA) by QDS have been identified as the main factors responsible for the enhanced optical limiting. The effective nonlinear absorption coefficient for InPc-CdSe/ZnS was found to be 700.0 cm/GW. The FCA cross-sections for InPc-CdSe/ZnS and InPc-CdSe composites were found to be 1.52 × 10−19 and 6.00 × 10−20 cm2 respectively. A much lower limiting threshold of 92 mJ cm−2 was observed for InPc-CdSe/ZnS nanocomposite, hence, making it suitable for use as optical limiting material. Density Functional Theory (DFT) calculations on similar phthalocyanine-quantum dots system was modeled in order to explain the enhancement in the observed nonlinear optical properties of the Pc in the presence of the QDs. The experimentally determined nonlinear optical properties are well within the range of the DFT calculated properties.
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- Date Issued: 2014
Evidence of spatial and temporal changes in sources of organic matter in estuarine sediments
- Authors: Bergamino, Leandro , Dalu, Tatenda , Richoux, Nicole B
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457242 , vital:75619 , xlink:href="https://doi.org/10.1007/s10750-014-1853-1"
- Description: We investigated spatial and temporal changes in sources of organic matter in sediments within an estuarine environment in South Africa using fatty acids (FA) and stable isotopes (SI). Samples of sediments and sources of organic matter [i.e., particulate organic matter, microphytobenthos (MPB), macrophytes, salt marsh plants, and terrestrial leaves] were collected during spring and summer 2012, and autumn and winter 2013 from the upper, middle, and lower reaches. A Stable Isotope Analysis in R (SIAR) mixing model was used to identify the organic matter sources contributing to sediments in each estuarine reach and season. We found that diatom-associated fatty acids (20:5ω3; 16:1ω7) increased toward the upper reaches, while long-chained terrigenous fatty acids (24:0) tended to be more prevalent in lower reach sediments. In support of the FA results, the SI mixing model showed a substantial contribution from the marsh grass Spartina maritima in sediments of the lower estuary during periods of low-freshwater discharge (autumn and winter), while MPB was the main component in sediments from the upper and middle reaches during all seasons. Our results have implications for evaluating estuarine food webs since the spatial and seasonal variability in the organic matter deposited can influence estuarine community structure.
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- Date Issued: 2014
Exploring a knowledge-focused trajectory for researching environmental learning in the South African curriculum
- Authors: Schudel, Ingrid J
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/294375 , vital:57216 , xlink:href="https://www.researchgate.net/publication/305730521"
- Description: This paper explores the past twenty years of environmental learning in the South African curriculum in order to consider how one might best research a knowledge focus within the Fundisa for Change national teacher education programme. In exploring this knowledge focus, the paper draws on international literature. It also extensively, but not exclusively, draws on two key publications which informed the 2002 and the 2011 curriculum changes in South Africa. The paper draws on social realist curriculum theory, underpinned by critical realism. This theoretical perspective, which includes Bernstein’s pedagogic device and particularly recontextualisation of knowledge across the pedagogical landscape, provides a language of description for critically reviewing knowledge and environmental learning. In particular, the review develops five perspectives on environmental knowledge as it pertains to curriculum which include: Perspective #1) new environmental knowledge in the curriculum; Perspective #2) environmental knowledge in local and global contexts; Perspective # 3) dynamic knowledge for open-ended and futuristic thinking; Perspective #4) depth and complexity of environmental knowledge; and Perspective #5) combining discipline-specific core knowledge and skills with a systems perspective. The paper argues for a re-emphasis and review of new environmental knowledge and learning support materials. It suggests a consideration of context-rich but not context-bound explorations of local and global environmental issues and the need for adopting open-ended and futuristic thinking in the context of the dynamism of environmental knowledge. This involves exploring systems of meaning and structures of knowledge in dealing with the complexity of environmental knowledge and acknowledging the challenges of a transformative ideology within such a complex knowledge system. Additionally, the paper argues for creative ways of working across disciplines to develop better understanding of discipline-specific concepts and their potential to contribute to meaningful learning. The paper concludes by suggesting a research trajectory for future environmental education research in the context of the new South African Curriculum and Assessment Policy Statement (CAPS) extending the emphasis in this paper on the official recontextualising field, to fields across the entire pedagogic device.
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- Date Issued: 2014
Exploring Teacher Assessment Practices in The General Education and Training Level in Junior Secondary Schools in Mthatha Education District
- Authors: Xolile, Stwebile
- Date: 2014
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/2933 , vital:43116
- Description: This dissertation is a report of the study that was conducted in rural and urban periphery schools of Mthatha City within Mthatha Education District in the Eastern Cape, a province of South Africa. The study explored teacher-assessment practices in two selected junior secondary schools. The utmost purpose was to determine the nature of teacher-assessment practices in these junior secondary schools. This study involved mainly a quantitative research design and later supplemented by qualitative research design. The target population was made up of 63 teachers from both schools. Sampling entailed simple random sampling for quantitative approach and purposeful sampling for qualitative. Instrumentation involved questionnaires and focus group interviews to gather data for these two different research paradigms used. The data was analysed by means of SPSS for quantitative and thematically for qualitative. The results of this study from both instruments were crystallized, and indicated that teachers were grappling with difficulty in strategies and procedures of assessment due to an ever changing curriculum and overload of work. The main findings were: assessment based on content knowledge of learners, negative impact of teacher re-deployment on assessment, stress accumulated by various challenges such as overload of work and frequent curriculum changes as well as lack of data organisation and gathering. The recommendations were: workshops and training programmes on assessment to be provided to teachers; teachers should use various information sources for conducting assessment; more teachers need to be recruited for understaffing and overloading problems as well as pragmatic assessment strategies should be used for learners assessment. Teachers should be included in matters of curriculum changes and be exposed to in-service training. , Thesis (MMED) -- Faculty of Educational Sciences, 2014
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- Date Issued: 2014
Fabrication of phthalocyanine-magnetic nanoparticles hybrid nanofibers for degradation of Orange-G
- Authors: Modisha, Phillimon , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190394 , vital:44990 , xlink:href="https://doi.org/10.1016/j.molcata.2013.10.012"
- Description: Conjugates of zinc octacarboxy phthalocyanine (ZnOCPc) with magnetic nanoparticles (MNPs) were electrospun into fibers using polyamide-6 (PA-6) polymer. The ZnOCPc or ZnOCPc-MNPs conjugates on the fiber were employed for the photodegradation of an azo dye (Orange-G). The functionality of the ZnOCPc and ZnOCPc-MNPs was maintained within a solid fiber core. The singlet oxygen generation increases as we increase the fiber diameter by increasing the ZnOCPc concentration. The singlet oxygen quantum yield was higher for PA-6/ZnOCPc-MNPs nanofibers compared to PA-6/ZnOCPc. The rate of degradation of Orange-G increased with an increase in singlet oxygen quantum yield. Moreover, the kinetic analysis of the photodecomposition of Orange-G showed that its disappearance followed the Langmuir–Hinshelwood model.
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- Date Issued: 2014
Factors leading to the high failure rate of grade 12 learners in the Ngqeleni area: A case study of two schools in the Ngqeleni area of the Libode mega district, Eastern Cape.
- Authors: Maqokolo, Gideon Zitobile
- Date: 2014
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3444 , vital:43390
- Description: The study investigated the factors that lead to the high failure rate of grade 12 learners of the two high schools in the Ngqeleni area of Libode Mega District of the Eastern Cape, South Africa. The study was qualitative in nature; therefore interviews were used as the method of collecting data. Seven SMT members, four parents and four learners were, randomly selected from the two schools in the Ngqeleni area of Libode Mega District. The researcher randomly selected the participants then interviewed them. The researcher used a video recoder as an instrument to record the responses from the participants. To analyse data, the researcher transcribed the interview responses and interpreted them. The main findings of the study showed that the high failure rate was caused by the following factors: over-croweded classes, shortage of teaching and learnin~ materials, lack of parental involvement, teachers' low morale, poor learner discipline, teachers experiencing problems in implementing government policies, work-load and as such teaching becoming stressful. The researcher in his study therefore recommends that the Department of Education plans more workshops for schools to capacitate them. There should be provision for more classrooms and incentives for teachers. , Thesis (MMED) -- Faculty of Educational Sciences, 2019
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- Date Issued: 2014