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Determination of nonlinear optical properties of phthalocyanine regioisomers using computational models

Date: 2020
Subjects: Electrochemistry , Phthalocyanines , Nanoparticles , Nonlinear optics , Nonlinear optical spectroscopy , Refraction
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/166197 , vital:41337
Description: This work investigates the effects of the nonlinear optical properties of four different constitutional isomers (C4h, C2v, Cs, and D2h) of a series of tetrasubstituted phthalocyanines (free-base 3-4-tert-butylphenoxyether phthalocyanines, free-base 4-4-tertbutylphenoxyether phthalocyanines, SnCl2 tetra substituted 3-4-tert-butylphenoxyether phthalocyanine, and SnCl2 tetra substituted 4-4-tert-butylphenoxyether phthalocyanine). The properties investigated were the real and imaginary components of the 3rd order hyperpolarizability, as well as the excited state absorption and refraction cross sections. The investigations were performed with a z-scan over a range of laser beam intensities. This work determined the imaginary component of the 3rd order hyperpolarizability for the free-base and SnCl2 3-4-tert-butylphenoxyether phthalocyanines and 4-4-tert-butylphenoxyether phthalocyanines to be highly dependent on the excited state cross sections. The refraction caused due to the real component of the 3rd order hyperpolarizability of the phthalocyanines was also investigated, however, the values found were strongly dependent on the laser beam intensity and the cause of this was investigated. A Five-level model was developed and run on GPGPU computing devices in order to isolate the absorption and refractive cross sections. Theeffects of the regio substitution on the excited state cross sections were also investigated, and the 1st singlet excited state and 1st triplet state absorption cross sections were calculated for all constitutional isomers. It was found that the symmetry of the constitutional isomers have a disproportionately large effect on the excited state absorption when compared to the ground state absorption. The nonlinear refractive properties of all constitutional isomers were also investigated, and the values of the parametric susceptibility are reported herein. The nonlinear refraction was found to have less effect than was seen in the nonlinear absorption. The 1st singlet excited state and 1st triplet state refractive cross sections of all constitutional isomer was determined. The results indicated that if more than one excited state was present and contributing to the nonlinear refraction, then more data than was collected here would be required. However, the 1st singlet excited state cross section were successfully determined for the free-base constitutional isomers. This work concluded that the region substitution affected the excited states more than the ground state.
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Date Issued: 2020

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The chemistry of the wattle tannins

- Roux, David Gerhardus

Authors: Roux, David Gerhardus
Date: 1953
Subjects: Tannin plants , Tannins , Wattles (Plants)
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: vital:4492 , http://hdl.handle.net/10962/d1013098
Description: Four species of acacia of Auatralian origin are associated with the wattle industry in South Africa. Black wattle, Acacia mollissima willd., is the most important of these and is today almost exclusively cultivated. The tree grows successfully only in a limited area of rich soil and high rainfall and is easily affected by adverse conditions caused by insect pests, frost damage and drought. Expansion of the area under cultivation is therefore, not feasible, although the world demand for vegetable extracts far exceeds the available supply. The remaining species such as green (Acacia decurrrens willd.) and silver wattles (Acacia dealbata Link.) possess many desirable characteristics which resist such adverse factors. Their barks, however, give reddish extracts, which are considered unsuitable for tannery usage because of the red colour they impart to the leather. Hybridisation studies, involving the crossing of green and silver wattle with the black, and aimed at produc1ng progenies containing many of the desirable characterlstics of the parent plants, are thus a natural result and have been in progress for a considerable period. Summary, p. i.
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Date Issued: 1953

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Tomographic imaging of East African equatorial ionosphere and study of equatorial plasma bubbles

- Giday, Nigussie Mezgebe

Authors: Giday, Nigussie Mezgebe
Date: 2018
Subjects: Ionosphere -- Africa, Central , Tomography -- Africa, Central , Global Positioning System , Neural networks (Computer science) , Space environment , Multi-Instrument Data Analysis System (MIDAS) , Equatorial plasma bubbles
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/63980 , vital:28516
Description: In spite of the fact that the African ionospheric equatorial region has the largest ground footprint along the geomagnetic equator, it has not been well studied due to the absence of adequate ground-based instruments. This thesis presents research on both tomographic imaging of the African equatorial ionosphere and the study of the ionospheric irregularities/equatorial plasma bubbles (EPBs) under varying geomagnetic conditions. The Multi-Instrument Data Analysis System (MIDAS), an inversion algorithm, was investigated for its validity and ability as a tool to reconstruct multi-scaled ionospheric structures for different geomagnetic conditions. This was done for the narrow East African longitude sector with data from the available ground Global Positioning Sys-tem (GPS) receivers. The MIDAS results were compared to the results of two models, namely the IRI and GIM. MIDAS results compared more favourably with the observation vertical total electron content (VTEC), with a computed maximum correlation coefficient (r) of 0.99 and minimum root-mean-square error (RMSE) of 2.91 TECU, than did the results of the IRI-2012 and GIM models with maximum r of 0.93 and 0.99, and minimum RMSE of 13.03 TECU and 6.52 TECU, respectively, over all the test stations and validation days. The ability of MIDAS to reconstruct storm-time TEC was also compared with the results produced by the use of a Artificial Neural Net-work (ANN) for the African low- and mid-latitude regions. In terms of latitude, on average,MIDAS performed 13.44 % better than ANN in the African mid-latitudes, while MIDAS under performed in low-latitudes. This thesis also reports on the effects of moderate geomagnetic conditions on the evolution of EPBs and/or ionospheric irregularities during their season of occurrence using data from (or measurements by) space- and ground-based instruments for the east African equatorial sector. The study showed that the strength of daytime equatorial electrojet (EEJ), the steepness of the TEC peak-to-trough gradient and/or the meridional/transequatorial thermospheric winds sometimes have collective/interwoven effects, while at other times one mechanism dominates. In summary, this research offered tomographic results that outperform the results of the commonly used (“standard”) global models (i.e. IRI and GIM) for a longitude sector of importance to space weather, which has not been adequately studied due to a lack of sufficient instrumentation.
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Date Issued: 2018

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Shifting contexts, shifting identities: a realist exploration of transnational mobility, change and identity construction in South African Higher Education expatriates in Abu Dhabi, UAE.

- Reid, Gillian Janet

Authors: Reid, Gillian Janet
Date: 2019
Subjects: College teacher mobility , College teacher mobility -- Abū Ẓaby (United Arab Emirates) , College teachers, Foreign -- Abū Ẓaby (United Arab Emirates) , College teachers -- Psychology , Expatriation -- Psychological aspects
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/92898 , vital:30760
Description: Positioned in relation to the globalization of higher education, this realist study is approached from an interest in identity and focuses on nine South African academics professional contexts in South Africa and Abu Dhabi, UAE. As the context of identity formation and emergence is always local, the intention of this research was never to generalize. Rather, in using Bhaskar’s critical realism as its underpinning philosophy, and Archer’s social realism, theories on self, personal and the development and attainment of social identity - her concept of analytical dualism and her morphogenetic framework, this qualitative case study was designed to explore how global and national powers and mechanism effected change in this sub-group of academic’s respective higher education sectors and institutions in post- 1994 South Africa and in Abu Dhabi between 2008 and 2016. The study suggests that participants perceived their academic roles and role-incumbent professional identities to have been negatively impacted by the changes that were implemented in the South African higher education sector as a result the countries reintroduction to the global stage. Their response to become transnational educators in Abu Dhabi’s presented them with conditions that allied their professional experiences of the transformation of South African’s higher education sector. This led to a continued sense of loss of academic agency and powerlessness. This effecting the emergence, through the personal power of reflectivity, combined with discourse and affinity powers and mechanisms, in a social identity that supplanted their academic identities.
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Date Issued: 2019

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Code-switching as a pedagogical strategy in classroom settings: the case of township schools in a South African Metropolitan Municipality

- Marawu, Sithembele

Authors: Marawu, Sithembele
Date: 2018
Subjects: Code switching (Linguistics) , Multilingual education -- South Africa , Education, Bilingual -- South Africa , Language and languages -- Study and teaching -- Bilingual method , English language -- Social aspects -- South Africa , Language and education -- South Africa , Language and education -- Social aspects -- South Africa
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/62406 , vital:28173
Description: The purpose of this study was to explore the use of code-switching as a pedagogical strategy in bi/multilingual classroom settings. It was prompted by the widespread use of codeswitching (CS) in classrooms, particularly in South African rural and township schools. This study highlighted that learners from disadvantaged backgrounds struggle to learn through the medium of English but aspire to acquire it because of its association with socio-economic advancement. However, poor proficiency in English excludes them from being part of the country's economy. Research studies show that there is a shift from the old orthodoxy which perceived CS as undesirable in classrooms to a new orthodoxy that acknowledges its academic contribution in classrooms. Although more research on classroom CS has been done, this study identified the need for development of new strategies on how to use CS effectively in classrooms as a linguistic and pedagogical resource. In line with critical classroom ethnography, qualitative interpretation of data was used to understand the teachers' discourse behaviour. Additionally, non-probability sampling - specifically purposive sampling - was used to collect data. These methods and approaches assisted in the analysis of the discourse of the three teachers who served as units of analysis in this study. These teachers relied on CS to impart the content of their subjects to the learners. It transpired from data analysis that teachers use CS in classrooms to achieve various functions like social and pedagogical functions. Another finding is that the switches teachers make do not affect the syntactic structure of the matrix language. Moreover, CS enhances understanding of the subject matter. This study concludes by stating that as learners are emergent bilinguals, additive bilingualism would be more ideal in the South African situation than subtractive bilingualism which parents and learners seem to prefer. Lastly, there is a need to harness CS as a communicative and pedagogical resource in classrooms.
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Date Issued: 2018

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Movement of coastal fishery species in Southern Africa: research trends, characterisation of behaviours and a case study on fishery implications

- Maggs, Jade Quinton

Authors: Maggs, Jade Quinton
Date: 2018
Subjects: Fishery management -- Africa, Southern , Fisheries -- Africa, Southern , Fisheries -- Catch effort , Fisheries -- Environmental aspects , Fisheries --Monitoring , Biotelemetry , Sustainable fisheries -- Africa, Southern , Overfishing -- Africa, Southern
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/60574 , vital:27798
Description: Movement of fishes is an integral part of their daily life, but has significant implications for fishery management. As with nearly all coastal countries, South Africa relies on coastal fisheries as a renewable resource, but many stocks have been overexploited for decades. Although it has long been recognised that an understanding of fish movement is necessary for effective management, it is with some difficulty that the subject has been studied in the past. In recent years, however, improvements in technology have provided the means for more in-depth investigations into fish movement. This research has revealed a range of complex movement behaviours. Movement in fishes occurs on a variety of temporal and spatial scales leading to the characteristic patterns of distribution and abundance observed in marine ecosystems. Fishes move nearly constantly in search of food, shelter or reproductive opportunities. Observations of behaviours such as long-term site fidelity, longdistance migration and natal homing are enabling ecologists to understand patterns of distribution and abundance within a species' range. Fish movement around the South African coast has been studied on numerous occasions but this has largely been confined to studies on single species. Movement behaviour of multiple species has been studied, but this has been limited to spatially localised marine protected area research. There has been little attempt in southern Africa to synthesize interspecific movement behaviour over wide spatial scales.Unprecedented concern over the biological effects of overexploitation, together with rapid technological advances in biotelemetry, have provided the impetus for much research, on a global scale, into the movement of marine animals. I reviewed 101 marine and estuarine fish movement studies from southern Africa, published from 1928 to 2014, with the aim of synthesising research trends and findings. Trends showed an increasing emphasis on fish movement research in publications in the sub-tropical and warm-temperate biogeographic regions along the south and east coasts of southern Africa. Although 63% of publications featured only marine studies, research into fine-scale habitat use in estuaries has been on the increase, concomitant with increasing accessibility of biotelemetry. Overall, 26 fish families were identified in the surveyed literature with regionally endemic sparids featuring in 32% of the publications. Ten movement themes were identified in the surveyed literature, including broad-scale movement patterns, which featured in 68% of studies, followed by fine- scale habitat usage (33%) and protected areas (26%). The most prominent phenomenon, emerging from this research, is that of partial migration, which describes the occurrence of resident and migratory behaviour within a coexisting animal population. Substantial progress has also been made in unravelling the complexities of fine-scale movements in marine reserves and habitat usage in estuaries. While this knowledge has enabled more effective management of South Africa's multi-user, multi-species fisheries, focus should now be directed at improving our understanding of the commonalities in movement behaviour, the associated driving forces behind this behaviour and the extent of movement across reserve boundaries. Mark-recapture data, collected over the past 30 years by the Oceanographic Research Institute’s Cooperative Fish Tagging Project (ORICFTP), were used to investigate broad- scale movement patterns of 30 prominent coastal fishery species (Chapter 4). Fishes were tagged with plastic dart tags along the coastline of southern Africa from Angola to Mozambique. This exercise yielded more than 10000 recaptures. The 30 chosen species represented 14 families, although 12 species belonged to a single family (Sparidae). Overall, 67% of recaptures were reported from the original tagging locality and 73% were recorded within 5 km of the tagging locality. The remaining observations extended from 6-3000 km. Movements were assigned to four distance bins (0-5 km, 6-50km, 51-500km and >500 km) and modelled with an ordinal logistic regression. Species, life-stage (juvenile/adult) and time- at-liberty were included as predictor variables. Model coefficients were then included in a cluster analysis, which produced two primary groupings of species (Category I and II), with two sub-groupings (Category IIa and IIb). Category I species were characterised by wide-ranging movements, greatest median recapture length and highest trophic levels. Category II species were characterised by residency, lower median recapture length and lower trophic levels. These findings have implications for fisheries management. Exploitation of resident species may lead to localised depletion, but their diffuse spatial distribution may offer some resilience. In contrast, even localised targeting of migratory species may pose a population level risk if individuals are known to aggregate. Life-cycle diversity or intra-population variability describes the existence of alternative strategies or tactics among coexisting individuals within an animal population (Chapter 5). Partial migration is a specific case of life-cycle diversity where coexisting groups exhibit either resident or migratory (wide-ranging) behaviour within a single population. Mark- recapture data collected under the auspices of the ORICFTP were used to investigate the occurrence and nature of life-cycle diversity in the movement behaviour of five non- diadromous fish species around the coastline of southern Africa. Among the five species were three teleosts (Category I and IIa) and two elasmobranchs (Category I). A fish was considered to have remained resident if recaptured within 0-5 km after 365 days at liberty. A fish was considered to have undertaken a wide-ranging movement if recaptured more than 50 km away from the release site in 365 days or less. A total of 1848 individuals from the five study species were recaptured during the study, of which 73% of the observations were classified as being resident. Binomial logistic regression confirmed that species, life-stage (juvenile/adult) and ecoregion were significant (p < 0.001) predictors of the probability of wide-ranging behaviour. A Gaussian model confirmed that species and ecoregion were also significant (p < 0.001) predictors of direction and distance of wide-ranging movement. However, the direction and distance of wide-ranging movements in juveniles did not differ significantly (p > 0.05) to that of adults. The median growth rate was mostly greater in wide- ranging individuals; however, this was only statistically significant (p < 0.05) in two cases. These findings provide unequivocal evidence of life-cycle diversity in five fish species, with vastly different life-histories. This ecological phenomenon may provide species resilience at the population level and needs to be considered in fisheries management initiatives. The movement of fishes is a fundamental aspect to consider when designing fishery management regimes. Unfortunately, traditional management strategies have often disregarded movement behaviour to the detriment of fish populations (Chapter 6). As a case study, the management of Lichia amia (Category I: wide-ranging) was evaluated in the context of its movement behaviour. Long-term catch-per-unit-effort (CPUE) datasets were examined for three South African recreational fishery sectors. The CPUE was standardised using generalized linear models (delta-Gamma/hurdle approach) to reduce the effect of factors other than abundance. Factors that were available for this purpose were year, month and locality/zone. Year was included in every model as the primary objective was to detect trends in abundance over time. Although standardised CPUE for all sectors showed an overall long-term decline, there was considerable variability in trends between the different recreational sectors and between datasets. Contrasting trends between competitive shore angling and general shore angling datasets were ascribed to hyperstability in competitive CPUE data. Hyperstability in this case was mostly influenced by rapidly improving technology, techniques and communication networks amongst competitive anglers. Month and locality were significant factors explaining the probability of catching L. amia. This suggests that the predictable aggregatory behaviour of this species could further compound the observed CPUE hyperstability. Although the CPUE responded positively for six years after implementation of the first minimum size and bag limits, and for one year after the decommercialisation of the species, these regulations and their amendments failed to arrest a long-term decline in the CPUE despite the ample evidence for hyperstability. It is clear from this case study that the predictable nature of wide-ranging behaviour in L. amia has made the population vulnerable to exploitation. This has led to the demise in the population, which could have been worse if not for the occurrence of intra-population variability in its movement behaviour, which may provide some measure of resilience.
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Date Issued: 2018

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The current role of palm species Hyphaene Coriacea and Phoenix Reclanata in local livelihoods in the Zitundo area, southern Mozambique

- Martins, Angelina R O

Authors: Martins, Angelina R O
Date: 2020
Subjects: Ilala palm -- Economic aspects -- Mozambique , Palms -- Economic aspects -- Mozambique , Non-timber forest products industry -- Mozambique , Sustainable development -- Mozambique , Conservation of natural resources -- Mozambique
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/150613 , vital:38989
Description: The majority of rural households in developing countries are heavily dependent on non-timber forest products (NTFPs) to fulfill much of their basic daily needs. In Mozambique more than 64% of the population lives in rural areas and depends heavily in the extraction of NTFPs to complement agricultural production. One substantial source of NTFPs are palm species. Palms are sources of food, building materials, cloth, ornaments, medicines, and are also used for cultural purposes. In southern Mozambique two important palms species used as NTFPs are Hyphaene coriacea and Phoenix reclinata. These two species provide an array of subsistence and commercial products. The sap, leaves and stems of these two palms are harvested by local people as sources of traditional beverages, weaving, roofing, fencing and furniture material as well as other household utensils. The effects (if any) of harvesting of these palm products on palm distribution, population structure, dynamics and viability have never been examined, and thus the sustainability of the practices and benefits flows to local livelihoods are unknow-n. Any effects harvesting effects may also be exacerbated by predicted climate change for the area. The present study aims to investigate the role of the palm species Hyphaene coriacea and Phoenix reclinata in the livelihoods of households in the Zitundo area, Matutuine district, southern Mozambique and under future climate scenarios. Specifically, this study: i) evaluates the abundance, population structure and harvesting selection of these species; ii) characterizes the ethnobotanical knowledge and use of the two species; iii) examines the local production and trade of palm wine in the area; iv) examines the contribution of palm income to livelihoods and income diversification in area; v) describes the local management practices and perceptions on palm productivity and abundance; and vi) models the current and future distribution of the these palm species in the area. To evaluate the abundance, population structure and stability of these two palm species a population census was carried out, and the size class distribution, Simpson index of dominance, permutation index and the quotient between successive size classes were calculated. I further calculated the preference ratio for specific size classes. Additionally a questionnaire survey was conducted with 179 randomly selected households from the 16 villages in the study area to characterize the ethnobotanical knowledge and use of these two species, as well as to examine the contribution of palm income to livelihoods and diversification. Standard ethnobotanical indices were used as measures of each palm species use and knowledge while principal component analysis and cluster analysis were applied to highlight the livelihood patterns and the role of diversification and of palm income in local livelihoods. Structured interviews with 37 palm tappers were additionally used to examine the local production and trade of palm wine in the area, while both the household survey and palm tappers interviews, were employed to investigate the local management practices and perceptions on palms productivity and abundance. Maxent Software was used to model the current and future under climate change distribution of the two palm species. Hyphaene coriacea was more abundant than Phoenix reclinata. Both species exhibited steep negative slopes in the regression analyses of size class distribution, indicating the presence of more individuals in shorter size classes. Although there was a dominance of shorter over taller size classes, limited recruitment was observed through low stem densities of seedlings and juveniles compared to the 1-50 cm size class The Simpson index of dominance, the permutation index, and the fluctuating quotients between the consecutive size classes showed a level of instability in both populations. Hyphaene coriacea appeared to be more resilient to tapping than Phoenix reclinata as showed by the higher rate of stem survival after tapping. Hyphaene coriacea was favored for tapping compared to Phoenix reclinata. The most preferred size class to tap for both species was between 101cm and 150 cm. Currently the distribution of Hyphaene coriacea and Phoenix reclinata was mostly confined to the eastern side of the study area. Most of the area was predicted as unsuitable for both palm species, with less than six percent predicted to be suitable or higher. The occurrence of both species appeared to be influenced mostly by water related variables, such as precipitation, and distance to rivers and distance to water bodies. The habitat suitability for Hyphaene coriacea was predicted to increase under future climate conditions scenarios, while little variation was predicted for Phoenix reclinata distribution. The knowledge about the uses of these two palm species was widespread in the area, although only 32% of respondents were engaged in palm exploitation. Thirteen palm products were exploited, with palm wine production from the sap of both palms being the dominant activity, followed by broom production from Phoenix reclinata stems and basket production from Hyphaene coriacea leaves. The cultural importance of these species included the production of anklets and skirts used during traditional dances and the use of palm wine in the traditional ritual of libation. Palm tapping was practiced year round in five of the sixteen villages in the area. Palm tapping was an important livelihood activity, contributing over 80% of tappers’ total annual income, and tappers earned up to three times more than the national minimum wage for the agricultural and forestry sector. Palm wine was also a highly commercial commodity in Zitundo area, with an average commercialization index above 60%. The income from palm wine sales showed an important role in mitigating the level of poverty in the area. Palm income accounted for over 60% reduction on poverty incidence among palm tappers. Households in Zitundo further engaged in some level of livelihood diversification. The majority of households adopted a wage-based strategy, although this strategy was among the less remunerative in terms of per capita cash income. A palm-based livelihood strategy, although adopted only by 11% of households, was one of the most remunerative strategies. Palm income played a vital role in enhancing household livelihoods and mitigating poverty in the area as shown by the lower poverty incidences among households engaged in the palm-based livelihood strategy than alternatives strategies. The village of household residency, along with household demographic and socio-economic characteristics appeared to determine the knowledge and exploitation level of palms as well as a households’ choice of livelihood strategy, level of palm wine returns, commercialization index and palm income dependency. The importance of palms in local livelihoods and poverty alleviation needs greater acknowledgement by government and development agencies in the area. Palm wine, broom and basket production have a high potential for income generation, and therefore should be included in future local development policies and poverty reduction strategies. Although palms are an open access resource in Zitundo area, the perception is that they are abundant and that tapping does not have many detrimental effects. However, this study found some negative impacts of tapping on the recruitment of both palms species. The inclusion of palm products in future development programs and poverty reduction strategies will require the design of participatory conservation and management strategies that involve all palm users groups and others stakeholders and include long-term participatory monitoring of the effect of palm use on the populations.
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Date Issued: 2020

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Design and fabrication of components of dye sensitised solar cells

- Msane, Gugu

Authors: Msane, Gugu
Date: 2019
Subjects: Dye-sensitized solar cells
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/117106 , vital:34478
Description: In recent decades there has been increasing global concern about the sustainability of our use of fossil fuels, which has led to increased interest in carbon–free sustainable renewable sources such as solar energy. Dye sensitized solar cells (DSSCs) are a cheap and clean technology that harnesses solar energy efficiently and convert it to electrical energy. A DSSC consists of a transparent working electrode coated with a dye-sensitized mesoporous film of nanocrystalline particles of semiconductor e.g. TiO2, an electrolyte containing a suitable redox couple and a platinized counter electrode. All the components of the DSSCs play vital roles in controlling the performance of the cell. The synergy of these components of the cells also needs to be investigated to optimise their interaction and create efficient and stable DSSCs. The information gathered from this investigation can give insight on how to improve the efficiencies of DSSCs. In this research study the semiconductor, transparent conducting layer and sensitizer were designed, optimized one at a time and their effect on the overall efficiency of the DSSCs studied. In this way it was easy to observe the effect of the individual components on the efficiency of the DSSCs. The conventional DSSCs usually use TiO2 as a semiconductor. In this research TiO2 was doped with cerium (Ce) to enhance its optical properties by reducing the band gap. A series of Ce-doped TiO2 with Ce content ranging from 0.1 to 1 mol % were successfully synthesized by an acid catalyzed sol-gel method, and their performance as the photoanodes of dye-sensitized solar cells (DSSCs) was investigated. Ce doping resulted in a red shift in the absorption of the TiO2 indicating narrowing of the band gap. The band gap first narrowed with increase in concentration of dopant up until 0.9 % dopant concentration. After this optimum doping concentration the band gap widened again. DFT calculations showed that Ce doping introduces Ce4f impurity states located just below the conduction band resulting in band gap narrowing. Ce content (0.9%) doped TiO2 photoanodes improved the performance of DSSCs with a conversion efficiency of 2.11% compared to 0,21% for the one with a pure TiO2 under 1 sun, AM1.5. Graphitised/TiO2 nanocomposites were also used a semiconductor to slow down recombination of electrons and holes in the cells. Electrophoretic deposition (EPD) was used to deposit graphitised/TiO2 nanocomposites onto an FTO electrode for application as photoelectrode in dye-sensitized solar cells (DSSCs). An enhanced power conversion efficiency (PCE) of 2.25% was observed for the 0.5 wt% graphene oxide/TiO2 (GO/TiO2) based DSSC which was higher than that of the conversion efficiency of pure TiO2 nanoparticles (i.e. 0.52%). Graphene oxide led to high migration of photoinduced electrons to the conduction band of the collection electrode and inhibition of charge carriers recombination resulting in enhanced photoconversion efficiency. A GO content above 0.5 % resulted in a reduced transparency leading to a decrease in the PCE. 0.5 wt % GO/0.9 Ce–TiO2 Ce based DSSC showed a slightly enhanced efficiency of 2.45%. 0.5 rGO/TiO2 based DSSCs had a high efficiency than 0.5 rGO/TiO2 due to improved conductivity of rGO nanosheets and suppressed recombination of charge carriers. To cut down DSSC production costs a silver wire network transparent conducting polyethylene electrodes was fabricated and used as an indium tin oxide (ITO) alternative substrates in DSSCs. The transmittance of the AgNW network was 82 % which is comparable to ITO substrates. Titanium oxide (TiO2) films on the AgWN/PET substrates were obtained using the electrophoresis method. These substrates were sensitised and used to fabricate a dye sensitised solar cell. From the measured current–voltage or I-V characteristic under AM1.5 illumination of the formed DSSC using AgWN substrates, an open circuit voltage (VOC) of 0.377 V, a short circuit current (ISC) of 0.0067 mA and a fill factor (FF) 25.7 % with an efficiency of 0.00862 % were obtained from a cell of 0.075 cm2 working area. The stability of the cell improved when a room temperature ionic liquid electrolyte was used. Gold nanofiber transparent electrodes were also prepared by the electrospinning techniques and used as an alternative to indium tin oxides substrates. Transparent conducting gold nanofiber (AuNF) transparent conducting electrodes were fabricated by using a low–cost electrospinning process and used as photoelectrodes for DSSCs. TiO2 was deposited on these electrodes by using an electrospray method. DSSC using AuNF as transparent electrodes had a power efficiency of 0.52%, compared to devices made with FTO electrodes (1.48%). DSSCs. Versatile dyes with increased spectral response, stability and suppressed recombination of holes and electrons were synthesised and used as a sensitizers for DSSCs. The boron dipyrrin (BODIPY) chromophore was combined with a carboxy coumarin moiety to create donor–acceptor (dyad) system dyes. Regenerative dyad dyes were formed through covalently linking a porphyrin chromophore to a manganese(II) ion through bridging ligands. These chromophores and also porphyrin and BODIPY dyes were used as sensitisers for DSSCs. The regenerative dye based DSSCs showed a photoconversion efficiency of 4.09% which was higher than the efficiency of the parent porphyrin (2.57%). The enhanced efficiency was attributed to the manganese bypridine cluster in the ZnTPP–Mn bpy supramolecule which acted as an electron donor to the photo-oxidized porphyrin continuously regenerating the porphyrin and preventing its decay.
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Date Issued: 2019

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The characterization of DNAJC3: elucidating the function of the TPR domains

- Mutsvunguma, Lorraine Zvichapera

Authors: Mutsvunguma, Lorraine Zvichapera
Date: 2014
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/55874 , vital:26751
Description: DNAJC3 is a novel member of the DNAJ family with two domains linked to co-chaperone functions, namely the tetratricopeptide repeat (TPR) and J domain. Out of the two domains, the TPR domains are the least characterized. Therefore, the aim of this study was to characterize and elucidate additional functions of DNAJC3 TPR domains through in silico, in vitro and ex vivo approaches. Through multiple sequence and structural alignment as well as electrostatic potential analysis, DNAJC3 TPR domain were found to be most similar to TPR-containing proteins with Hsp90 or Hsp70 independent functions. In vitro pull down assays illustrated that DNAJC3 TPR domains did not interact with either cytosolic Hsp90 and Hsp70 or Grp78 and Grp94 directly, however a potential indirect interaction with Grp94 and Hsp90 was observed in mammalian lysates, via pull down assays; suggesting the formation of a complex between the proteins mediated by a specific substrate. DNAJC3 TPR domains were found to bind indiscriminately to both native and heat denatured substrates in a dose dependent manner. DNAJC3 TPR domains bound to β-galactosidase with greater affinity than malate dehydrogenase (MDH), suggesting that DNAJC3 TPR domains might exhibit substrate specificity that has not been reported before. Preliminary ex vivo analysis of DNAJC3 in mammalian cells showed that induced stress conditions did not alter the cytosolic or endoplasmic reticulum (ER) localization, or levels of DNAJC3 protein, suggesting that the protein is not stress inducible. However, protein levels of DNAJC3 were dramatically reduced by Hsp90 inhibitor novobiocin at 500 μM. Transient knockdown DNAJC3 did not change the protein levels of either Grp78 or Grp94, but decreased the protein levels of Hsp70/Hsp90 organizing protein HOP. On the other hand, protein levels of DNAJC3 were increased in HOP depleted cells. In conclusion, this study was the first to experimentally demonstrate that DNAJC3 TPR domains do not interact directly with Hsp90, Hsp70, Grp78 or Grp94, and therefore DNAJC3 is unlikely to participate in traditional co-chaperone interactions with those proteins via its TPR domain. However, the J domain is known to interact with Grp78. The discovery that DNAJC3 TPR domains resemble that of TPR-containing proteins with functions independent of Hsp90 or Hsp70 suggests that DNAJC3 might link the Hsp70/Grp78 chaperone machinery to non co-chaperone related functions, which requires further analysis.
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Date Issued: 2014

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Understanding a West African recreational fishery as a complex social-ecological system – a case study of the fishery for giant African threadfin Polydactylus quadrifilis (Cuvier, 1829) in the Kwanza Estuary, Angola

- Butler, Edward C

Authors: Butler, Edward C
Date: 2020
Subjects: Cuanza River (Angola) , Fishing -- Angola , Polynemidae , Fishes -- Angola -- Ecology
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/146688 , vital:38548
Description: Despite increasing global recognition of the importance of recreational fisheries, their management largely remains poor. This is because they exhibit unique human-nature relationships and are nested within complex social-ecological systems (SESs). Recreational fisheries in the developing world have large potential for socio-economic development, but are generally underappreciated, in terms of their value and their impact, and are poorly governed. This is particularly concerning as they are highly complex and often compete for resources with dependent artisanal and subsistence fisheries. Developing world recreational fishery SESs are not well understood and present an important research gap for improved governance. The general aim of this thesis was to explore the recreational fishery targeting Polydactylus quadrifilis on the Kwanza Estuary, Angola, and provide context for how managers should approach recreational fisheries in the developing world and in Africa. To do this, the recreational fishery SES was explored using a combination of methodologies including those characteristic of traditional fisheries science, and new methods involving biology, sociology, and economics. The thesis contains an introductory chapter, a chapter describing the background, study area and study species, five data chapters and a discussion chapter. Chapter 3 aimed to investigate the reproductive style of P. quadrifilis. Results identified the species as a protandrous hermaphrodite. Evidence to suggest this included degenerating testicular tissue and the presence of early developing ovarian tissues in transitional individuals. Early-stage oocytes were commonly found in the outer area of male regions and residual late-stage spermatids and spermatozoa were found in the luminal space of ovarian regions, suggesting a process of sex change from the outside inwards. Owing to the species’ reliance on large highly fecund females for reproduction, it is likely that P. quadrifilis will be sensitive to fisheries that target larger individuals, such as trophy recreational fisheries and line fisheries within other sectors. Chapter 4 aimed to investigate alternative methods for adequately describing the growth of P. quadrifilis individuals belonging to either one of two distinct hypothetical life-history pathways: pathway I (‘changers’) – initial maturation as a primary male followed by a sex change to female; pathway II (‘non-changers’) – initial maturation as a male fish with no subsequent sex change, using von Bertalanffy Growth Functions (VBGFs). Other specific objectives included determining the size- and age-at-maturity and size- and age-at-sex-change for P. quadrifilis. Otolith aging revealed rapid growth and early maturation (L50 = 399.2 mm FL, A50 = 1.50 years) and sex change occurred over a wide size (790–1125 mm FL) and age (3–8 years) range. There was strong evidence for partial protandry in P. quadrifilis with several extremely old male fish (up to 22 years) observed in the population. When compared to the conventional model produced for the entire population, there were significant differences in the models for the ‘non-changers’ (LRT, p < 0.01) and their parameters L∞ (full model = 130.8, ‘non-changers’ = 113.3, p < 0.01), k (0.32, 0.44, p < 0.01) and t0 (0.23, 0.43, p = 0.03) in the first approach and the models (LRT, p < 0.01) and their L∞ (‘changers’ = 113.7, p < 0.01) values in the second approach. This suggests that utilising conventional modelling techniques may be inappropriate for the stock assessment and management of P. quadrifilis and, potentially, other sequentially hermaphroditic fishery species. Chapter 5 aimed to assess the sensitivity of P. quadrifilis to recreational C&R within the foreign recreational fishery using a rapid assessment approach. To do this, a number of C&R variables including fight time, air exposure, hook placement, hooking injury, total time of the stress event, river depth and angling method were measured and related to two indicators of fish health and survival – the physiological stress indicators blood glucose and blood lactate concentration and reflex action mortality predictors (RAMPs). Air exposure was identified as a major contributor to motor impairment (Cumulative Link Model: p < 0.01) and fight time was an important contributor to motor impairment via its interaction with air exposure (Cumulative Link Model: p = 0.02). Handling practices appear to be particularly important for larger individuals as fish size was positively correlated with air exposure (Pearson’s r coefficient = 0.41, p < 0.01) and fight times (0.88, p < 0.01). The findings suggest that recreational C&R may result in mortalities directly, via C&R, and indirectly, via predation, and several recommendations were made for best practice. Chapter 6 aimed to assess the direct economic contribution of the recreational fishery for Polydactylus quadrifilis on the Kwanza Estuary. Results indicated that the recreational fishery for contributed significantly to the economy of an area that would otherwise likely receive little external input ($282 054 per four-month fishing season). However, high rates of economic leakage from the study area were identified (58.7%–92.9% of locally spent revenue) and were attributed to the sourcing of lodge supplies, services and staff outside of the local area and the repatriation of profit by foreign business owners. Capacity building within the local community is likely required to develop ‘linkages’ between the local community and the recreational fishery. Greater community involvement in the fishery is suggested to incentivise the protection of recreationally important fishery species and their associated ecosystems. Chapter 7 aimed to investigate the resource user groups involved within the SES. Results illustrated that artisanal and domestic recreational anglers are well-established and are characterised by long histories of participation. The artisanal fishery was highly valued as a source of livelihoods for the local community. Artisanal fishers were eager for involvement in the recreational sector, through the chartering of their vessels, due to the attractiveness of extra earnings. Both recreational and artisanal fishers reported recent decreases in P. quadrifilis catch and anticipated further declines. Domestic recreational anglers appeared to be highly consumptive in their use of the fishery and C&R angling was uncommon. User conflict may be problematic for future management as recreational anglers perceived the artisanal gill-net fishery to be a threat towards P. quadrifilis stocks. In conclusion, the open-access nature of the fishery was identified as the most pertinent threat to its sustainability and likely needs to be addressed. Potential solutions involve offering users the opportunity to purchase access rights (e.g. day permits), thus initiating the concept that users must pay for their use of public resources. Management should aim to protect large female fish due to their increased reproductive value and worth as trophy fish. Thus, C&R angling is likely to be an important interaction between users and the resource. However, angler behaviour will need to be manipulated to promote C&R and minimise C&R-related mortalities. Solutions include angler educational drives and interventions and the implementation of competitive C&R-only angling. Foreign recreational fisheries, although touted as potential ecotourism ventures, will only succeed in improving the lives of local people if they fully integrate the community into the operation of the fishery.
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Date Issued: 2020

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The further development, application and evaluation of a sediment yield model (WQSED) for catchment management in African catchments

- Gwapedza, David

Authors: Gwapedza, David
Date: 2021-04
Subjects: Sedimentation and deposition -- South Africa , Sedimentation and deposition -- Zimbabwe , Watersheds -- South Africa , Watersheds -- Zimbabwe , Watershed management -- Africa , Water quality -- South Africa , Water quality -- Zimbabwe , Modified Universal Soil Loss Equation (MUSLE) , Water Quality and Sediment Model (WQSED) , Soil and Water Assessment Tool (SWAT)
Language: English
Type: thesis , text , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/178376 , vital:42934 , 10.21504/10962/178376
Description: Erosion and sediment transport are natural catchment processes that play an essential role in ecosystem functioning by providing habitat for aquatic organisms and contributing to the health of wetlands. However, excessive erosion and sedimentation, mostly driven by anthropogenic activity, lead to ecosystem degradation, loss of agricultural land, water quality problems, reduced reservoir storage capacity and damage to physical infrastructure. It is reported that up to 25% of dams in South Africa have lost approximately 30% of their initial storage capacity to sedimentation. Therefore, excessive sedimentation transcends from an ecological problem to a health, livelihood and water security issue. Erosion and sedimentation occur at variable temporal and spatial scales; therefore, monitoring of these processes can be difficult and expensive. Regardless of all these prohibiting factors, information on erosion and sediment remains an urgent requirement for the sustainable management of catchments. Models have evolved as tools to replicate and simulate complex natural processes to understand and manage these systems. Several models have been developed globally to simulate erosion and sediment transport. However, these models are not always applicable in Africa because 1) the conditions under which they were developed are not as relevant for African catchments 2) they have high data requirements and cannot be applied with ease in our data-scarce African catchments 3) they are sometimes complicated, and there are little training available or potential users simply have no time to dedicate towards learning these models. To respond to the problems of erosion, sedimentation, water quality and unavailability of applicable models, the current research further develops, applies and evaluates an erosion and sediment transport model, the Water Quality and Sediment Model (WQSED), for integration within the existing water resources framework in South Africa and application for practical catchment management. The WQSED was developed to simulate daily suspended sediment loads that are vital for water quality and quantity assessments. The WQSED was developed based on the Modified Universal Soil Loss Equation (MUSLE), and the Pitman model is a primary hydrological model providing forcing data, although flow data from independent sources may be used to drive the WQSED model. The MUSLE was developed in the United States of America, and this research attempts to improve the applicability of the MUSLE by identifying key issues that may impede its performance. Assessments conducted within the current research can be divided into scale assessment and application and evaluation assessment. The scale assessment involved evaluating spatial and temporal scale issues associated with the MUSLE. Spatial scale assessments were conducted using analytical and mathematical assessments on a hypothetical catchment. Temporal scale issues were assessed in terms of the vegetation cover (C) factor within the Tsitsa River catchment in South Africa. Model application and evaluation involved applying and calibrating the model to simulate daily time-series sediment yield. The model was applied to calibrated and validated (split-sample validation) in two catchments in South Africa, two catchments in Zimbabwe and three catchments were selected from the USA and associated territories for further testing as continuous daily time-series observed sediment data could not be readily accessed for catchments in the Southern African region. The catchments where the model was calibrated and validated range in size from 50 km2 to 20 000 km2. Additionally, the model was applied to thirteen ‘ungauged’ catchments selected from across South Africa, where only long-term reservoir sedimentation rates were available to compare with long term model simulations converted to sediment yield rates. The additional thirteen catchments were selected from areas of different climatic, vegetation and soils conditions characterising South Africa and range in size from 30 km2 to 2 500 km2. The current research results are split into a) MUSLE scale dependency and b) WQSED testing and evaluation. Scale dependency testing showed that the MUSLE could be spatially scale-dependent, particularly when a lumped approach is used, resulting in simulations of up to 30% more sediment. Spatial scale dependence in the MUSLE was found to be related to the runoff and topographic factors used and how they are calculated. The current study resorted to adopting a reference grid in applying the MUSLE, followed by scaling up the outputs to the total catchment area. Using a reference grid resulted in a general avoidance of the problem of spatial scale. The adoption of a seasonal vegetation cover factor was shown to significantly account for temporal changes of vegetation cover within a year and reduce over-estimations in sediment output. The temporal scale evaluation demonstrated the uncertainties associated with using a fixed vegetation cover factor in a catchment with variable rainfall and runoff pattern. The WQSED model evaluation showed that the model could be calibrated and validated to provide consistent results. Satisfactory model evaluation statistics were obtained for most catchments to which the model was applied, based on general model evaluation guidelines (Nash Sutcliffe Efficiency and R2 > 0.5). The model also performed generally well compared to established models that had been previously applied in some of the study catchments. The highest sediment yields recorded per country were 153 t km-2 year-1 (Tsitsa River; South Africa), 90 t km-2 year-1 (Odzi River; Zimbabwe) and 340 t km-2 year-1 (Rio Tanama; Puerto Rico). The results also displayed consistent underestimations of peak sediment yield events, partly attributed to sediment emanating from gullies that are not explicitly accounted for in the WQSED model structure. Furthermore, the calibration process revealed that the WQSED storage model is generally challenging to calibrate. An alternative simpler version of the storage model was easier to calibrate, but the model may still be challenging to apply to catchments where calibration data are not available. The additional evaluation of the WQSED simulated sediment yield rates against observed reservoir sediment rates showed a broad range of differences between the simulated and observed sediment yield rates. Differences between WQSED simulated sediment and observed reservoir sediment ranges from a low of 30% to a high of > 40 times. The large differences were partly attributed to WQSED being limited to simulating suspended sediment from sheet and rill processes, whereas reservoir sediment is generated from more sources that include bedload, channel and gully processes. Nevertheless, the model simulations replicated some of the regional sediment yield patterns and are assumed to represent sheet and rill contributions to reservoir sediment in selected catchments. The outcome of this study is an improved WQSED model that has successfully undergone preliminary testing and evaluation. Therefore, the model is sufficiently complete to be used by independent researchers and water resources managers to simulate erosion and sediment transport. However, the model is best applicable to areas where some observed data or regional information are available to calibrate the storage components and constrain model outputs. The report on potential MUSLE scale dependencies is relevant globally to all studies applying the MUSLE model and, therefore, can improve MUSLE application in future studies. The WQSED model offers a relatively simple, effective and applicable tool that is set to provide information to enhance catchment, land and water resources management in catchments of Africa. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2021
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Date Issued: 2021-04

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Learning to learn: a critical realist exploration into the home established learning practices of a marginalised community in Port Elizabeth

- Armstrong, Meredith

Authors: Armstrong, Meredith
Date: 2019
Subjects: Minorities -- Education (Higher) -- South Africa , Readiness for school -- Social aspects -- South Africa , Inclusive education -- Social aspects -- South Africa , Marginality, Social -- South Africa , Critical realism
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/93778 , vital:30939
Description: This study was completed as part of a project exploring social inclusion and exclusion in South African higher education. In a globalised world, the achievement of a qualification from an institution of higher education is increasingly key to finding any sort of employment. This is particularly the case in South Africa where employment amongst black citizens is inordinately high. The aim of the research reported upon in this thesis was to better understand the construct of ‘epistemological access’ (Morrow, 1992), often used in relation to the needs of black working class students entering higher education, in relation to performance data (see for example, CHE, 2016) that repeatedly shows that black students fare less well than their white peers. Following what might be termed a ‘social’ approach to understanding access, this study begins long before most students have even heard of higher education and focuses on identifying the mechanisms that come into play at much earlier level of learning and literacy development. The study outlines the development of ‘ways of being’, or social practices, surrounding learning in a marginalised community in Port Elizabeth, in the Eastern Cape, South Africa. This was achieved by means of critical ethnography and it is therefore qualitatively based. The study shows how social structures enable or constrain a child’s school readiness and how they then go on to support or impede progress in school where the language and literacy needed for educational success are further developed. The study therefore aims to allow us to explain global data indicating that the single greatest indicator of a young person’s ability to access and succeed in higher education is the level of education of caregivers in their homes of origin. Examined from a critical perspective (i.e. with a concern for social justice), this study has made use of a framework using social, psychological and linguistic theory and more, particularly, the work of sociologist Margaret Archer (1995, 1996, 2003). The study makes particular use of Archer’s ‘morphogenetic framework’ which allows for an analysis of the way structure and culture impact on a child’s development over time. As I was concerned that my own social status might impact on the understandings I developed as a critical ethnographer, the study acknowledges my own experiences of learning and the way my own family sought to enhance them as enabling. In doing this, the study aims to better contribute to understandings of social justice in South Africa.
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Date Issued: 2019

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An investigation into the effect of an Extensive Reading Programme on bilingual Grade 3 learners’ reading attitudes in two primary schools in Grahamstown

- Nkomo, Sibhekinkosi Anna

Authors: Nkomo, Sibhekinkosi Anna
Date: 2017
Language: English
Type: Thesis , Doctoral , PhD , text
Identifier: http://hdl.handle.net/10962/7723 , vital:21289
Description: The focus of this study is to explore formative intervention of a bilingual Extensive Reading Programme (ERP) in two Grade 3 classes in Grahamstown, South Africa. ERP involves access to large quantities of reading materials for pleasure and to reading opportunities (Bamford & Day, 2002; Krashen 2004). The current focus on measurable reading achievement in clearly defined areas such as vocabulary, fluency and comprehension has resulted in reduced attention towards the affective component in relation to literacy development, and links attitudes to reading success. This study helps to fill this gap by examining the effect of an ERP on the reading attitudes of Grade 3 learners. The study draws on Cultural Historical Activity Theory (CHAT) to make sense of learning and social change through mediation, scaffolding, interaction and collaboration learning. The ERP is located within a broad framework of literacy and incorporates a balanced reading approach implemented in an informal reading setting so as to motivate, encourage and nurture reading for enjoyment. This formative intervention used expansive learning cycles to develop a responsive ERP that was implemented and evaluated to investigate its effects on learners’ reading attitude. There were three phases (pre-, during- and post- intervention) that were designed over 31 weeks where rich, qualitative data was collected from questionnaires, observations, learners’ drawings and interviews. To make sense of this data, concepts from CHAT such as contradictions, expansive learning, double stimulation, transformative agency and sustainability were used (Engestrom & Sannino, 2010; Haapasaari & Kerosuo, 2015; Saninno, 2015). In addition, Mathewson’s (1994) reading attitude model addressed the attitudinal aspects of the study whilst a multimodal social semiotic perspective (Kress & Van Leeuwen, 1996) was used to analyse learners’ drawings. The findings of this study demonstrate the effectiveness of combining top-down and bottom-up reading methodologies. In both research sites there was appreciable change in the number of books learners read. Learners also began to volunteer to read and participated in book talks. Through access to a variety of reading materials and reading opportunities, learners demonstrated agency, criticising some ERP practices and modelling new ways, thus claiming and sustaining the reading programme. Being provided with a safe, informal learning context where reading was presented as a social activity, learners gained confidence, engaged in meaningful discussions and improved their self- esteem. Finally, learners continue to access these resources even beyond the research programme.
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Date Issued: 2017

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I want them to be confident, to build an argument: an exploration of the structure of knowledge and knowers in Political Studies

- Hlatshwayo, Mlamuli Nkosingphile

Authors: Hlatshwayo, Mlamuli Nkosingphile
Date: 2019
Subjects: Political science -- Study and teaching (Higher) -- South Africa , Education, Higher -- Curricula -- South Africa , Rhodes University. Department of Political Studies
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/92392 , vital:30719
Description: The 2015-2016 student movements in South African higher education sharply critique what was perceived to be the slow pace of institutional transformation and decolonisation in institutions of higher learning (see Badat, 2016; Heleta, 2016b; Mbembe, 2016). One of the academic fields that has come under scrutiny is Political Studies, which has been accused of being un-transformed, irrelevant and not reflecting local, indigenous scholarship in curricula or pedagogy (see for example Matthews, 2018; Mngomezulu & Hadebe, 2018; Tselapedi, 2016). Although this literature critiques neo-colonial predominance of western thought within the field, and the need to re-centre non-Western modes of being, thinking and intellectualising, I argue that this literature actually considers epistemologies without necessarily making a razor sharp critique at the underlying mechanisms and processes of Political Studies knowledge, and the extent to which it can be decolonised and transformed. It is on this gap that I make a contribution to the field.This study is positioned in the field of higher education decolonisation, with a specific focus on exploring knowledge and knower structures in Political Studies. I explore the various ways in which knowledge is valued and legitimated in the field of Political Studies by asking the “how” question – that is, how is knowledge legitimated in Political Studies? This includes a consideration of how the Postgraduate Diploma in International Studies (PDIS) programme, designed to promote and enable an “expert in African International Studies”, legitimates a certain kind of knower in the field. I employ Basil Bernstein’s pedagogic device as a theoretical foundation for exploring 1) what the field of Political Studies knowledge production looks like, 2) how knowledge is recontextualised from the field of production and into the PDIS curriculum, and 3), how that knowledge is legitimated and evaluated through the programnme’s assessment documents, and what they revel as valued and legitimate curriculum knowledge in the field. Karl Maton’s Legitimation Code theory (LCT), specifically Specialisation, is called upon to offer sharp analytical tools for investigating the underlying mechanisms and processes of the knower and knowledge structures that the programme legitimates. It particularly sheds some insight on the kinds of gazes that are valued in the field of Political Studies in general, and in the PDIS programme in particular. The case study for this research is Rhodes University, a historically white university which offered insight and contested history into the kinds of being, knowledges and knowers that were historically legitimated and valued in the institution, as well as the current institutional landscape, and challenges that the institution is grappling with. The data generation included the formally planned curriculum as contained in the programme’s curriculum documents. These included course outlines, seminar critiques, presentations, class participation; class discussions; essay questions and exams/exam portfolio. The data generation also included semi-structured interviews with the lecturers who were regarded as the “recontextualising agents”, who taught in the programme and who offered key insights on some of the curriculum choices regarding selection, pacing, sequencing and evaluation of the curriculum knowledge in the PDIS programme.This study revealed that that the PDIS programmes values and legitimates curriculum knowledge by ensuring that students have a critical understanding of African political economy, war and conflict on the African continent, as well as the challenges of peacekeeping and peace building in new and fragile African states. This was also seen in how the attributes and dispositions of knowers were also valued in how students needed to have social and cultural gazes in order to access the curriculum and to successfully participate as knowers in the field. This suggested that access to both curriculum knowledge and to being a valued knower in the field, could be said to be relatively open and unrestrictive. In this study, I first argue that looking critically at how Political Studies knowledge is recontextualised from the field of production and into the PDIS curriculum can be seen as a decolonising process as it enables us to see the underlying mechanisms and processes of how Political studies knowledge and knowers are valued and legitimated in the field. This offers us an insightful space to see to what extent the fields of production, recontextualisation, as well as reproduction of Political Studies in general, and the PDIS programme in particular, could be said to have a colonising gaze. It also offers insight on how we can go about exploring, transforming and decolonising Political Studies and the PDIS programme. Secondly, exploring the knowledge and knower structures of the PDIS programme can help curriculum designers, lecturers and students identify the knowledge and knower codes of the curriculum, and to critically reflect on their curriculum codes and how to enable epistemological access to students. Furthermore, this study can help lecturers and curriculum designers construct their curriculum in ways that are inclusive, open, and socially just, by being critically aware of the kind of knowledge that they choose to legitimate, and those they choose to disregard in their knowledge recontextualisation and its evaluation. , Unyaka wezi 2015-2016 wombhikisho wabafundi eningizimu afrika zemfundo ephakeme umcwaningi nokungabikhona kakhulu ukuthi kube kancane awuhambi zesikhungo kanye decolonisation ezikhungweni of higher learning (bheka badat, nowezi-2016; Heleta, 2016b; Mbembe, nowezi-2016). Enye yenkambu yezemfundo ephakeme ethe yaba ngaphansi kokuhlolisiswa kabanzi izifundo zezombusazwe, ebhekene nezingqinamba zokungashinsthi, ukungabi lusizo endaweni, ukungabi yisithombe somphakathi, nokukungangeneleli isifundo somdabu kwezemfundo noma i-pedagogy (bheka isibonelo Matthews, 2018; Mngomezulu & Hadebe, 2018; Tselapedi, nowezi-2016). Nakuba lo mbhalo ugxeka ineo-kholoni ikakhulukazi imicabango yasentshonalanga, nokudinga ukubuyekezwa indlela yokucabanga nobuhlakani okungasibo baseNtshonalanga. Ngiyaphikisana nokuthi lo mbhalo ubuyekeza i-epistomology ngempela ngaphandle kokucwaninga kabanzi ukusetsenziswa kobuhlakani nolwazi lwezemfundo yombusazwe, kanye nokwandisa izinguquko noshintsho. Ngizophonsa esivivaneni kulolu gebe olulapho. Lolu cwaningo lusesimeni sokwenza izinguquko kwinkundlazwelo yemfundo ephakeme, ikakhulu ukuhlola ulwazi kanye nezakhiwo ze-knower kwezemfundo yombusazwe. Ngibheka izindlela ezahlukene ngolwazi kanye nokuba semthethweni kwinkundlazwelo yezemfundo zombusazwe ngokubuza umbuzo “kanjani”-ngokuthi, ulwazi lubekwa kanjani ngokomthethwo wezemfundo yombusazwe? Lokhu kubandakanya inkokhelo yombuzo wokuthi kwenzakala kanjani ukuthi ipostgraduate Diploma in International Studies (pdis), yenzelwe ukukhuthaza kanye nokuba wumpetha kwi African International studies”, ukwenza semthethweni eminye yenkundlazwelo yama-knower. Ngisebenzisa ithiyori ya Basil Bernstein ukuhlola 1) Ibukeka kanjani inkundla yokuhkiqiza yezemfundo zezombusazwe, 2) ngolwazi lobuhlakani enkundleni lapho nasesikhathini uhlelo lwezemfundo PDIS yenza umkhiqizo kanye 3), futhi ukwazi ukuthi khona lusemthethweni uhlelo nokuhlola, nokuthi yini abayiveza ukuthi isemthethweni kwizifundo zolwazi. Ithiyori ka Karl matonâ legitimation code theory (lct), ikakhulu Specialisation, yiyona enganikeza kafuphi izinsiza zokuphenya indlela kanye nenqubo ye-knower kanye nolwazi lwesakhiwo esisemthethweni. Iveza kabanzi izindlela zokubheka ezisemqoka nezisematheni kwinkundla yezemfundo zombusazwe kanye nohlelo lwe PDIS ikakhulukazi Indawo lapho ngizoqhuba khona lolu cwaningo iNyuvesi yaseRhodes, ngokomlando iNyuvesi yabamhlophe enikezana ukuqonda nokuncintana komlando kokungena kwezinhlobo, ubuhlakani kanye nama-knower omlando osemthethweni kanye nokhethekile kulesi sikhungo, kanjalo ne-Landscape yesikhungo samanje, kanye nezinselelo lesi sikhungo sikahulumeni esibheke nazo. Idatha equkethwe ifaka izifundo ezihleliwe ngokomthetho njengokuba zitholakala ezifundweni ezihleliwe kumbhalo. Lokhu, kubandakanya isifundo esinye, amasemina abuyekeziwe, izethulo, nokubamba iqhaza ekilasini; izingxoxo zekilasi; imibuzo yendaba kanye nezivivinyo / nokuhlolwa kwezivivinyo. Idatha yesizukulwane iphinde ibandakanye izingxoxo ezihleliwe kanye nabafundisi abathathwa njengabantu abayizingcithabuchopho, abafundisiwe kulo mkhakha kanye naba neso ekukhethweni kwamanye amakharikhulamu abhekelele ukuhlunga, i-pacing, ukulandelela kanye nokuhlolwa kwekharikhulamu kulwazi lohlelo i-PDIS Lolu cwaningo ludalule ukuthi izinhlelo ze-PDIS zikubeka emqoka kanye nokubeka emthethweni ubuhlakani bekhurikhulamu ngokucophelela ukuthi abafundi bakuqonda ukubaluleka okulunzulu ngezomnotho wombusazwe wase Afrika, yimpi nokungqubuzana ezwenikazi lase-Afrika, ukugcina ukuthula kanye nezinkinga ekwakheni uxolo kanye nobuthakathaka / nophukayo kwezwekazi i-Afrika. Lokhu futhi kubonakele ngendlela yokubambisana kanye nokuziqhathulula kwama-knower aabalulekile ekufundiseni abafundi ngokudinga kokuba nezenhlalo kanye nesiko ukuze bakwazi ukuthola ikhurikhulamu kanye nokubamba iqhaza ngempumelelo njengama-knower kule nkundla. Lokhu kuchaze ukuthi ukufinyelela kuhlelo lokufunda kanye nokuba yilunga lama-knower, kungaba ukuba babonisane ngendlela evulelekile kanye nengenamkhawulo. Kulolu cwaningo, ngaqala ngabheka kabanzi ngokubalulekile ukuthi izifundo zezombusazwe ngolwazi lobuhlakani kwinkundlazwelo yokukhiqiza kanye nePDIS kungabonwa njengenguquko eyenza ukuba sikwazi ukubona ezinye izindlela zokusebenza kwezemfundo zombusazwe kanye nokubeka phambili ama-knower. Lokhu kusenza sibone ukubaluleka komkhiqizo wale nkundla, ukubuyekezwa kwezobuhlakani, kanye nomkhiqizo wezemfundo zombusazwe, kanye nohlelo lwe PDIS ikakhulukazi, kungathiwa ingaba nokubanjwa kokubheka. Iphinde isambulele kabanzi ukuthi singahlola, sense izinguquko kanye noshintsho kwezemfundo zombusazwe kanye nohlelo lwe PDIS. Okwesibili, ukuhlola ulwazi kanye nezakhiwo ze-knower ze-PDIS kungasiza abaklami bekhurikhulamu, abafundisi kanye nabafunsi ukukwazi ukuhlonza ulwazi nekhurikhulamu yekhodi ye-knower, kanye nokwazi ukubuyekeza kabanzi amakhodi ekhurikhulami yabo kanye nokwazi ukwenza i-epistemology ukuba abafundi bafinyelele kuyo. Ngaphezu kwalokhu, lolu cwaningo lungasiza abafundisi kanye nabaklamu bekhurikhulamu ukuba bakwazi ukwakha ikhurikhulamu yabo ngendlela ekhethekile, evulelekile, ngokwenhlalo nje, okubalulekile ukuthi uhlobo lophi lolwazi abakhetha lube semthethweni, kanye nalabo abakhetha ukungayilandeli inqubomgomo yolwazi kanye nokuhlola.
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Date Issued: 2019

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A narrative study of students’ and staff’s experiences of living with HIV and AIDS at Rhodes University

- Tsope, Lindiwe

Authors: Tsope, Lindiwe
Date: 2021-04
Subjects: AIDS (Disease) South Africa Makhanda , HIV infections South Africa Makhanda , College students Health and hygiene South Africa Makhanda , Universities and colleges South Africa Makhanda Employees Health and hygiene , Stigma (Social psychology) , AIDS (Disease) Social aspects South Africa Makhanda , HIV infections Social aspects South Africa Makhanda , AIDS (Disease) Psychological aspects , HIV infections Psychological aspects , Health counseling South Africa Makhanda , Discourse analysis, Narrative
Language: English
Type: thesis , text , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/176894 , vital:42769 , 10.21504/10962/176894
Description: A narrative study of students’ and staff’s experiences of living with HIV and AIDS at Rhodes University Research on HIV and AIDS in university settings, especially research exploring the experience of living with the disease, has been minimal. As a response to the knowledge and research gaps, this thesis is a qualitative study involving students and staff living with HIV (LWH) and accessing treatment (ART) at the Rhodes University Health Care Centre. This study explored the personal and social symbolisms as well as meanings attached to living with HIV, through in-depth interviews with ten students and staff living with HIV, all purposively sampled and recruited through the Rhodes University Health Care Centre. Using social constructionism, symbolic interactionism and the theory of biographical disruption, the narratives revealed a positive and inspirational side of living with HIV and AIDS – especially emphasizing that PLWHA do not have to surrender to the deadly narrative of the disease. It became evident that stigma, both internal and external, largely influences illness narratives. Furthermore, the study revealed the social reconstruction of life narratives both in order to understand the illness in terms of past social experiences and to reaffirm the impression that life has a course and the self has a purpose. All participants found that accessing treatment from the Rhodes University Health Care Centre positively influenced their experiences of adherence and reconstruction of narratives. The study indicates that HIV-related interventions in place at the university need to pay more attention to the psychosocial needs of PLWH, involvement of PWLH, as well as keeping up with the continuously changing global HIV narrative. The study argues for more attention to in-depth experiences and personal narratives in HIV and AIDS, and PLWHA education at Rhodes University. , Thesis (PhD) -- Humanities, Department of Sociology, 2021
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Date Issued: 2021-04

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