List of Titles

Fluorescence behaviour of supramolecular hybrids containing graphene quantum dots and pyrene-derivatized phthalocyanines and porphyrins

- Achadu, Ojodomo John, Managa, Muthumuni, Nyokong, Tebello

Authors: Achadu, Ojodomo John , Managa, Muthumuni , Nyokong, Tebello
Date: 2017
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/188953 , vital:44801 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.10.029"
Description: Novel pyrene-derivatized zinc and cobalt phthalocyanines (Pcs) and porphyrins (Ps) were immobilized on graphene quantum dots (GQDs) to form GQDs-Pcs and GQDs-Ps supramolecular hybrids via the π–π stacking interaction method. Spectroscopic evidence shows that the resultant hybrids were stable owing to the strong π–π stacking interaction between the GQDs and the respective Pcs and Ps, thus leading to the fabrication of interesting and functional supramolecular hybrids by taking advantage of the delocalized π electron systems of GQDs and the macrocycles. The conjugates showed increased fluorescence quantum yields for the Pcs/Ps, but decreased values for the GQDs in the conjugates. These novel hybrid materials could potentially be deployed for studies in both fundamental and applied perspectives due to the synergistic contributions resulting from the combination of their excellent electronic and optical properties.
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Forensic entomotoxicology revisited: towards professional standardisation of study designs

- da Silva, Erica I T, Wilhelmi, Brendan S, Villet, Martin H

Authors: da Silva, Erica I T , Wilhelmi, Brendan S , Villet, Martin H
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/140819 , vital:37921 , DOI: 10.1007/s00414-017-1603-9
Description: Forensic entomotoxicology is the use of insects as evidence of whether a toxicant is present in an environment such as a corpse, river or landscape. The earliest overtly forensic study was published in 1977, and since then, at least 63 papers have been published, most of them focused on the detection of toxicants in insects or on effects of toxicants on diverse insect indicator taxa. A comprehensive review of the published literature revealed various inconsistencies between studies that could be addressed by introducing standard protocols for such studies. These protocols could include selecting widespread and common model organisms (such as Lucilia sericata, Calliphora vicina, Chrysomya megacephala and Dermestes maculatus) and model toxicants (e.g. morphine and amitriptyline) to build up comparative databases; developing a standard matrix for use as a feeding substrate; setting guidelines for statistically adequate sample sizes; and deploying more sophisticated analytical methods from the general field of toxicology.
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Date Issued: 2017

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Forest degradation and invasive species synergistically impact Mimusops andongensis (Sapotaceae) in Lama Forest Reserve, Benin

- Sinasson, Gisèle K, Shackleton, Charlie M, Glèlè Kakaï, Romain L, Sinsin, Brice

Authors: Sinasson, Gisèle K , Shackleton, Charlie M , Glèlè Kakaï, Romain L , Sinsin, Brice
Date: 2017
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/182038 , vital:43792 , xlink:href="https://doi.org/10.1111/btp.12370"
Description: Harvesting of Non-Timber Forest Products (NTFPs) can threaten target species, especially those with limited distribution and density. Exploited species also face threats from habitat fragmentation, fire, and invasive species. We assessed the impact of human disturbances and invasive species on the population of a key multipurpose NTFP species, Mimusops andongensis, in Lama Forest reserve (Benin). The densities of adult trees and regenerative stems decreased with increasing degradation. Mimusops andongensis contributed less to total tree density with increasing human disturbance. There were significantly fewer M. andongensis recruits with increasing cover of invasive Chromolaena odorata. Smaller diameter individuals predominated in non-degraded and moderately degraded sites while in degraded sites, the structure showed a negative exponential trend with the density of small diameter individuals being less than two trees/ha. Larger individuals were also rare in degraded sites. The low density of both mature trees and seedlings in degraded sites may undermine the long-term viability of M. andongensis, despite existing protection against NTFP harvesting and other anthropogenic pressures. Management should emphasize facilitating recruitment subsidies and limiting the presence of C. odorata.
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Date Issued: 2017

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Forest resources income, poverty and income inequality: evidence from rural households in South-western Nigeria.

- Azeez, Fatai Abiola

Authors: Azeez, Fatai Abiola
Date: 2017
Subjects: Poverty--Nigeria http://id.loc.gov/authorities/subjects/sh2010107919 , Rural poor--Nigeria , Income distribution--Nigeria
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10353/19454 , vital:43119
Description: This thesis explores economic contributions of forest resources in relation to rural households’ welfare and inequality as well as forest resources management. The thesis consists of an introductory chapter, study locations, literature review on major concepts of the study and findings on different forest extraction activities impacts on rural households livelihood in South-western region Nigeria, which make up the rest of the thesis chapters. , Thesis (PhD) (Agric Econs) -- University of Fort Hare, 2017
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Date Issued: 2017

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Formulation development, manufacture and evaluation of hydralazine hydrochloride microspheres

- Kangausaru, Shakemore Tinashe

Authors: Kangausaru, Shakemore Tinashe
Date: 2017
Subjects: Hydralazine , Microspheres , Drugs Controlled release , Drugs Design , Drug development , Hypertension Chemotherapy
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/59220 , vital:27482
Description: Despite improvements in its detection and treatment since the 1970s, hypertension is the most common and important risk factor for cardiovascular diseases. Hypertension is a chronic condition often underdiagnosed and/or inadequately treated in Sub-Saharan Africa. Recent survey results illustrate that the condition continues to contribute significantly to mortality and morbidity in adults and that it is poorly controlled in clinical practice. Hydralazine (HYD) is used either alone or in combination for the management of chronic hypertension, chronic cardiac failure and hypertensive crises. Due to its short plasma half-life of between 2 to 4 hours, HYD is normally administered two to four times daily, therefore making it a potential candidate for inclusion in sustained release formulations. The formulation of sustained release microsphere dosage forms may be useful to improve patient adherence and to achieve predictable and optimised therapeutic plasma concentrations. A stability indicating reversed-phase high performance liquid chromatography (RP-HPLC) method for the quantitation of HYD in pharmaceutical dosage forms was developed and optimised using a Central Composite Design (CCD) approach. UV/Vis detection method was selected as HYD contains an ultraviolet light-absorbing chromophore. The method was validated with respect to linearity and range, limits of quantitation (LOQ) and detection (LOD), accuracy, precision, sensitivity, selectivity and specificity as per International Conference on Harmonisation (ICH) guidelines. The method was applied to commercially available HYD tablets. No interfering peaks were observed from excipients used in the commercially available tablets. Preformulation studies were conducted to ensure the manufacture of high quality, stable sustained release HYD microspheres. The results revealed that there was an interaction between HYD and Carbopol® 971P, therefore Carbopol® polymers were not included during formulation studies. HYD was found to be compatible with Methocel® K100LV, Eudragit® RS PO and Avicel® 101 and HYD formulations were developed and optimised using these excipients. An oil-in-oil (o/o) solvent evaporation technique was selected for the manufacture of HYD microspheres due to its simplicity and to avoid exposure of HYD to moisture that could have been encountered if a water-in-oil (w/o) manufacturing process was used. The selection of o/o solvent evaporation technique was also based on the hydrophilicity of HYD and the polymers selected. Different grades of Methocel® and Eudragit® were selected to evaluate their effect on encapsulation efficiency (EE), in vitro release and microparticle shape and morphology. The best combination of these polymers which resulted in the desired EE, in vitro release, microparticle shape and size were then selected for formulation optimisation. A numerical optimisation approach was used to predict a formulation composition that would produce minimal HYD release initially and maximum HYD release after 12 hours of dissolution testing. The release kinetics of HYD from the manufactured microspheres were established by fitting in vitro release data to several mathematical models. The in vitro release data for the optimised formulations was best described using Higuchi model. The short-term stability of the optimised formulations was established by undertaking stability studies at 4°C, 25 °C/60 % RH and 40 °C/75 % RH. The results revealed that there was no significant change in appearance and physicochemical properties of the microspheres over a period of one month. However, long-term stability studies would be required to determine the shelf-life of the formulations. In addition, a gas chromatographic (GC) method was selected for determining residual amounts of acetone and n-hexane in the optimised formulations. GC methods were developed and optimised by evaluation of process parameters. System suitability testing was performed with respect to resolution, theoretical number of plates and selectivity. Method validation was performed with respect to linearity, range, inter- and intra-day precision, retention time (Rt) precision, limit of quantitation (LOQ) and detection (LOD). A solvent extraction method was used to analyse residual solvents in the optimised formulations. The drying process was sufficient in evaporating acetone and n-hexane from the optimised formulations. Solvent evaporation technique has been successfully used in the manufacture of HYD microspheres. The microspheres have potential for further development, scale up formulation studies and long-term stability studies. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
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Framing of transitional pedagogic practices in the sciences: enabling access

- Ellery, Karen

Authors: Ellery, Karen
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/66381 , vital:28942 , https://doi.org/10.1080/13562517.2017.1319812
Description: publisher version , Educational literature shows that students from working-class backgrounds are significantly less likely to persist to completion in higher education than middle-class students. This paper draws theoretically and analytically on Bernstein’s ([1990. Class, Codes and Control, Volume IV: The Structuring of Pedagogic Discourse. London: Routledge; 2000. Pedagogy, Symbolic Control, and Identity: Theory, Research, Critique. Lanham: Rowman and Littlefield]) thesis that, through differential framing of pedagogic practices, the curriculum has capacity to accommodate all groups of students. Pedagogic practices in both a science foundation course and four first-year mainstream science courses in a higher education institution in the South African context are examined. Whilst the foundation course exhibits modalities that generally favour access, the mainstream courses have some modalities that appear to be constraining. It is argued from a social justice perspective that holistic curriculum transformations that better enable epistemic transitions are an urgent imperative, and that consideration of differential framing of pedagogic modalities offer a close-up empirical means of conceptualising such reforms.
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Date Issued: 2017

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From Baudelaire to Beardsley: some thoughts on Poe's beast as an indicator of the tastes and fears of nineteenth-century Europe

- Beard, Margot

Authors: Beard, Margot
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/147781 , vital:38672 , https://doi.org/10.1080/00043389.2001.11876980
Description: Charles Baudelaire (1821 1867) was one of the major influences on the French Decadent poets of the late nineteenth century whose aesthetic principles were shared, to a large extent, by a group of English poets and artists, among whom was Aubrey Beardsley (1872 1898). One of the major influences on Baude laire had been the American, Edgar Allan Poe (1809 1849), in whose short stories and poems Baudelaire had recognised a kindred spirit. Some intriguing aspects of changing nine teenth century attitudes emerge from a study of Baudelaire's 1856 translation of Poe's `The Murders in the Rue Morgue' and Beardsley's 1893 illustration to this story.
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Date Issued: 2017

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From contradictions to complementarities: a social realist analysis of the evolution of academic development within a department

- Case, Jennifer M, Heydenrych, Hilton, Kotta, Linda, Marshall, Delia, McKenna, Sioux, Willliams, Kevin

Authors: Case, Jennifer M , Heydenrych, Hilton , Kotta, Linda , Marshall, Delia , McKenna, Sioux , Willliams, Kevin
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/66752 , vital:28990 , ISSN 1470-1294 , https://doi.org/10.1080/03075079.2015.1045479
Description: Publisher version , Academic development is a recent project in the university, intended to enable the university to respond to the needs of a more diverse student body. In South Africa, such work arose during late apartheid, and has now moved to a more central institutional position advocating responsiveness in the light of the educational disparities that are the legacy of apartheid. The present study uses a social realist perspective to analyse the 25-year evolution of an academic development project within an engineering department at a South African university. The findings show that while academic development initially posed a contradictory logic to the department, the response was to reform the nature of this project into one that suited the other commitments of the department: a logic of complementarity. The department's relationships with industry were shown to have played a key role in fostering this form of change.
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Date Issued: 2017

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From Technauriture to Cultauriture: Developing a Coherent Digitisation Paradigm for Enhancing Cultural Impact

- Mostert, Andre, Lisney, Bob, Maroko, Geoffrey M, Kaschula, Russell H

Authors: Mostert, Andre , Lisney, Bob , Maroko, Geoffrey M , Kaschula, Russell H
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/124528 , vital:35625 , http://www.ijscl.net/article_26650.html
Description: Developing suitable frameworks and paradigms (theoretical and practical) is a challenge for all disciplines in the face of rapid technological changes. Technological advances are fundamentally changing discourse in many well-established areas of research; from advances in understanding the brain, questioning the informed wisdom of sectors of the brain, through to impacts of social networks on sociology, to digitisation of culture. Technology’s potential is a double-edged sword which calls for coherent and reflective practices, to avoid the many pitfalls which abound. Kaschula recognised this as far back as 2004 in terms of orality, oral societies, and developed Technauriture as a framing solution. Drawing from this experience, the authors aim to expand the concept to offer a framing paradigm for culture in the form of Cultauriture. In this article the concept of Cultauriture is introduced and expanded to create a base for further research and dialogue with and between cultural practitioners, artists and policy makers.
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Date Issued: 2017

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Fuelwood preferences, use and availability in the #Khomani San resettlement farms, southern Kalahari, South Africa

- Nott, Michelle, Thondhlana, Gladman

Authors: Nott, Michelle , Thondhlana, Gladman
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/67667 , vital:29127 , https://doi.org/10.1080/14728028.2017.1294507
Description: Publisher version , Local level assessments of fuelwood preferences, demand and supply are important for ensuring a balance between ecological functions and livelihood needs. This study reports on an examination of fuelwood preferences, use and abundance in the #Khomani San resettlement farms in southern Kalahari, South Africa. The results show that Acacia erioloba was the most preferred fuelwood species, while Acacia mellifera was abundant but avoided. Across the study area, there were approximately 64 trees ha−1 but riverine sites had significantly more trees (approximately 80 trees ha−1) than non-riverine sites (48 trees ha−1). Live trees showed evidence of damage (cutting or breaking) and this was more pronounced in the riverine sites (close to human settlement) than in the non-riverine sites. However, overall current woody stocks and productivity rates of harvestable fuelwood are well above current fuelwood demand, suggesting fuelwood use may be within sustainable limits, though there is evidence of localised fuelwood depletion. The implications of these results for fuelwood management interventions, including the importance of context, are discussed.
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Date Issued: 2017

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Generic gold standard or contextualised public good? Teaching excellence awards in post-colonial South Africa

- Behari-Leak, Kasturi, McKenna, Sioux

Authors: Behari-Leak, Kasturi , McKenna, Sioux
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/66774 , vital:28992 , ISSN 1470-1294 , https://doi.org/10.1080/13562517.2017.1301910
Description: Publisher version , Teaching Excellence Awards have raised the profile of teaching as a scholarly project. There are however a number of questions about what constitutes teaching excellence and how ‘excellence’ is understood in current higher education. In a post-colonial South Africa, where significant injustices permeate our society, we question whether excellence can be understood in a generic manner. Furthermore, we argue that as universities are a public good, teaching excellence needs to explicitly attend to the ways in which universities contribute to broad goals of transformation and inclusivity. We analysed data from the national Teaching Excellence Awards and 13 South African universities’ awards to interrogate the discourses that underpin ‘excellence’ in this context of social inequality. We found that while the awards have gone some way to enhancing the position of teaching in institutions, ‘excellence’ was largely articulated in fairly generic ways which failed to take into account the enablements and constraints of the discipline and the institution. Furthermore, the guidelines and criteria privilege a decontextualised notion of excellence that seeks a ‘gold standard’ and validates performativity, rather than a contextualised response to the needs of the students.
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Date Issued: 2017

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Genetic analysis of native and introduced populations of the aquatic weed Sagittaria platyphylla – implications for biological control in Australia and South Africa

- Kwong, Raelene M, Broadhurst, Linda M, Keener, Brian R, Coetzee, Julie A, Knerr, Nunzio, Martin, Grant D

Authors: Kwong, Raelene M , Broadhurst, Linda M , Keener, Brian R , Coetzee, Julie A , Knerr, Nunzio , Martin, Grant D
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/76991 , vital:30653 , https://doi.org/10.1016/j.biocontrol.2017.06.002
Description: Sagittaria platyphylla (Engelm.) J.G. Sm. (Alismataceae) is an emergent aquatic plant native to southern USA. Imported into Australia and South Africa as an ornamental and aquarium plant, the species is now a serious invader of shallow freshwater wetlands, slow-flowing rivers, irrigation channels, drains and along the margins of lakes and reservoirs. As a first step towards initiating a classical biological control program, a population genetic study was conducted to determine the prospects of finding compatible biological control agents and to refine the search for natural enemies to source populations with closest genetic match to Australian and South African genotypes. Using AFLP markers we surveyed genetic diversity and population genetic structure in 26 populations from the USA, 19 from Australia and 7 from South Africa. Interestingly, we have established that populations introduced into South Africa and to a lesser extent Australia have maintained substantial molecular genetic diversity comparable with that in the native range. Results from principal coordinates analysis, population graph theory and Bayesian-based clustering analysis all support the notion that introduced populations in Australia and South Africa were founded by multiple sources from the USA. Furthermore, the divergence of some Australian populations from the USA suggests that intraspecific hybridization between genetically distinct lineages from the native range may have occurred. The implications of these findings in relation to biological control are discussed.
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Date Issued: 2017

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Genetic matching of invasive populations of the African tulip tree, Spathodea campanulata Beauv.(Bignoniaceae), to their native distribution: Maximising the likelihood of selecting host-compatible biological control agents

- Sutton, Guy F, Paterson, Iain D, Paynter, Quentin

Authors: Sutton, Guy F , Paterson, Iain D , Paynter, Quentin
Date: 2017
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/405797 , vital:70207 , xlink:href="https://doi.org/10.1016/j.biocontrol.2017.08.015"
Description: Spathodea campanulata Beauv (Bignoniaceae) has become a highly damaging environmental and agricultural weed in the Pacific Islands. It has been targeted for biological control due to the costly and inefficient nature of physical and chemical control methods. Determining the origin of weed populations has been increasingly recognised as an important component of successful biological control programmes, and may be important for the biological control of S. campanulata due to the high degree of morphological variability within the species, as well as the broad native distribution. Genetic matching, using inter-simple sequence repeats (ISSR’s), and morphological data found support for invasive Pacific Island S. campanulata plants originating from West Africa. Pacific and West African plants were genetically most similar, and were differentiated from native plants from East/Central Africa by PCA and Bayesian-clustering (STRUCTURE) analyses. Genetic data was corroborated by morphological data which showed that West African and Pacific Islands plants had more sparsely pubescent leaves compared to plants from East/Central Africa. Populations in South Africa, where the plant is introduced but not problematic, originated from a different source population than those in the Pacific Islands, probably in East/Central Africa. A greater sampling effort is required before the origin of the South African populations can be determined with certainty. Herbivores and pathogens for the Pacific Islands should be collected from West Africa as they are more likely to be compatible with S. campanulata plants in this region.
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Date Issued: 2017

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Geological study and economic evaluation of the Paardeplaats Coal Exploration Project

- Gcayi, Gcobani

Authors: Gcayi, Gcobani
Date: 2017
Subjects: Coal Geology South Africa Mpumalanga , Coal Prospecting South Africa Mpumalanga , Coal mines and mining South Africa Mpumalanga , Geology, Economic South Africa , Coal reserves South Africa Mpumalanga
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10962/59183 , vital:27452
Description: For a coal mining company the coal resources are an important asset, and they are acquired in a number of different ways, such as obtaining a prospecting permit from government or an existing permit from another entity and or purchasing an operating colliery from another entity. The Paardeplaats Project is a brownfields project located approximately 7 km south west of the town of Belfast in Mpumalanga Province, South Africa, on the far eastern edge of the Witbank Coalfield. The project is located adjacent to an operating mine, Glisa Colliery, owned by Eyesizwe Coal. Eyesizwe Coal was awarded the prospecting permit in 2006 by the Department of Mineral Resources. Subsequent exploration activities, which included airborne magnetic survey and borehole drilling, were conducted between 2008 and 2010. The results of the drilling confirmed the presence of coal resources, which are classified in the Measured, Indicated and Inferred categories. Mining and beneficiation methods from the adjacent Glisa Colliery, which has similar geology to the project area, were assumed in order to generate a coal reserve statement. The Coal Reserve qualities are suitable to the domestic market, particularly Eskom. South Africa’s coal supply is demand driven, primarily from Eskom for electricity generation followed by the export market and thirdly by Sasol for synthetic fuel generation. The majority of Eskom’s existing coal-fired power stations are located in the Mpumalanga Province, which provides a viable market for coal projects in Mpumalanga when considering existing transport infrastructure and transportation costs. Eskom’s continued demand for coal in the Mpumalanga region, at least until 2040, provides a future market for advanced coal projects in the region. A valuation of the project using the Cash Flow Approach showed the project to be economically viable. , Thesis (MSc) -- Faculty of Faculty of Science, Geology, 2017
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Geomorphological connectivity and sensitivity examined in a recently degraded gravel-bed stream: implications for river-floodplain rehabilitation

- Powell, Rebecca

Authors: Powell, Rebecca
Date: 2017
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10962/53722 , vital:26313
Description: The study of river complexity and sensitivity to future human land-use activities and climate change is a fast growing field within the discipline of fluvial geomorphology. Associated with this is a need to improve river rehabilitation and catchment management approach, design and effectiveness. This study aimed to investigate drivers of the recent geomorphological sensitivity of the Baviaanskloof River-floodplain, an upland system in South Africa, by integrating the concepts of geomorphological connectivity and Panarchy. The understanding generated was used to evaluate the approach of the State agency, Working for Wetlands (WfWet), to river-floodplain rehabilitation in the catchment.The concepts of geomorphological connectivity and Panarchy provide useful frameworks for understanding interactions between geomorphological processes and structure across scales of space and time. Geomorphological connectivity explains the degree to which water and sediment is linked in a river landscape, determined by the distribution of erosional and depositional landforms (Brierley et al. 2006; Fryirs et al. 2007a; Fryirs et al. 2007b). Panarchy attempts to explain lagged response to disturbances, non-linear interactions, and sudden shifts in system state, and has been applied largely to ecological systems. Panarchy theory, when combined with the concept of geomorphological connectivity, provides a guiding framework for understanding river complexity in greater depth. The first results chapter of this study investigated river long-term and recent geomorphological history, towards understanding the nature and timing of river geomorphological cycling between erosion and deposition. Optically Stimulated Luminescence dating of alluvial fan and floodplain sedimentary units was conducted, for analysis of river-floodplain long-term history (100s to 1 000s of years). Interviews with 11 local landowners, combined with analysis of historic aerial imagery and river-floodplain topographic surveys, provided a means of describing recent (last few decades) geomorphological dynamics. The results indicated that the Baviaanskloof is naturally a cut- and-fill landscape over scales of several hundred to thousands of years, characterized by the alternation between phases of high fluvial energy and alluvial fan expansion, and low energy conditions associated with floodplain accretion. Recent and widespread river-floodplain degradation was compressed into a short period of approximately 30 years, suggesting that one or more drivers have pushed the system beyond a threshold, resulting in increased water and sediment connectivity. The second results chapter investigated the role of human land-use activities and flooding frequency and magnitude, as drivers of recent river-floodplain degradation. Human impacts were investigated by describing land-use activities for the preceding 80 years, and relating these activities to changes in river-floodplain form and behavior. Temporal trends in flood events of different frequency and magnitude were investigated by analyzing rainfall data, integrated with landowner reports of flood-inducing rainfall magnitudes. The findings indicated that human land-use activities have been an important driver of recent river- floodplain degradation, through the enhancement of water and sediment connectivity across spatial scales of the catchment. Episodic and high magnitude floods synergized with human driven increased connectivity, precipitating stream power and geomorphological threshold breaches, resulting in a shift in river behaviour. The third results chapter investigated the influence of tributary-junction streams and fans on the geomorphological form, behavior and sensitivity of the Baviaanskloof River. Local- scale topographic impacts of tributary fans and streams were described using topographic surveys and geomorphological mapping techniques. Tributary streams form a major control on the behaviour of the river, by influencing the degree of coarse sediment connectivity with the main channel. Although tributary fans buffer the river from disturbances occurring in the wider catchment, they initiate topographic variations along the floodplain, influencing local-scale patterns of deposition and erosion along the river. The main river responds to water and sediment inputs from tributary junction streams by locally adjusting longitudinal slope, maintaining an overall constant slope of 0.0066 m/m. The response of the Baviaanskloof River to tributary junction fans and streams is however variable, and is fashioned by complex interactions between geomorphological and anthropogenic factors. The final two chapters of the thesis evaluate the findings of the study within the context of river-floodplain rehabilitation approaches in South Africa, and within the theoretical, philosophical and methodological context of the research. The first of these two chapters evaluates the approach of the WfWet programme to river-floodplain rehabilitation in the Baviaanskloof. The chapter indicates that the present practice of WfWet is to reinstate a pre-degradation state, which is not suited to the Baviaanskloof River-floodplain, since the river-floodplain has passed a geomorphological threshold, resulting in a new set of interacting processes and landforms. The author presents a conceptual model illustrating the existence of geomorphological adaptive cycles interacting across spatial and temporal scales, thereby attempting to explain a river Panarchy specific to the Baviaanskloof. From this conceptual model, a hierarchical rehabilitation framework, targeting geomorphological processes and structure situated at different spatial and temporal scales of the landscape is suggested. The final chapter discusses the implications of integrating the concepts of geomorphological connectivity and river Panarchy theory in studies of river complexity and sensitivity to geomorphological change. The author suggests that there is scope for further investigation of the application of the two concepts within the discipline of fluvial geomorphology, particularly with regard to developing quantitative approaches to measuring and describing connectivity and Panarchy.
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Date Issued: 2017

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Germinating in the cracks: the identity of contemporary Zambian art

- Mulenga, Andrew

Authors: Mulenga, Andrew
Date: 2017
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/146734 , vital:38552 , http://www.nationalgallery.co.zw/icac/
Description: The theme of the 2017 conference is Mapping the Future. We hope to gather art and culture professionals, academics, writers, critics and others in order to map out the future of art, culture and heritage from Africa. It will provide various players with an opportunity to interrogate the future of art institutions in the face of the current socio-economic challenges. Today the situation has changed since the first ICAC and the challenges that were there in the sixties, seventies and eighties are not the same today. ICAC comes at a time when art institutions around the world need urgent attention from both the local authorities, corporations and their governments.
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Date Issued: 2017

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Graphene quantum dot-phthalocyanine polystyrene conjugate embedded in asymmetric polymer membranes for photocatalytic oxidation of 4-chlorophenol

- Mafukidze, Donovan M, Nyokong, Tebello

Authors: Mafukidze, Donovan M , Nyokong, Tebello
Date: 2017
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/189189 , vital:44825 , xlink:href="https://doi.org/10.1080/00958972.2017.1400664"
Description: The feasibility of using π–π stacking as a means of fixing unsubstituted Zn phthalocyanine (ZnPc) to a support prior to formation of photoactive polymer asymmetric membranes was explored. Stable ZnPc–graphene quantum dot-polystyrene conjugates (6.15 μmol/g ZnPc loading) were synthesized and embedded in polystyrene membranes which proved to be photoactive with a singlet oxygen quantum yield of 0.43 in ethanol and 0.37 in water. The membranes also proved to be active in the photocatalytic oxidation of 4-chlorophenol in water where the reaction followed second-order kinetics. At 3.24 × 10−4 mol L−1, the photo-oxidation of 4-chlorophenol was observed with a kobs of 35.9 L mol−1 min−1 and a half-life of 86 min.
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Date Issued: 2017

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Graphene quantum dots anchored onto mercaptopyridine-substituted zinc phthalocyanine-Au@ Ag nanoparticle hybrid: Application as fluorescence “off-on-off” sensor for Hg2+ and biothiols

- Achadu, Ojodomo John, Nyokong, Tebello

Authors: Achadu, Ojodomo John , Nyokong, Tebello
Date: 2017
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/188194 , vital:44731 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.06.002"
Description: Novel supramolecular hybrid containing polyethyleneimine-functionalized graphene quantum dots (PEI-GQDs) and mercaptopyridine-substituted zinc phthalocyanine (Pc)-Au@Ag nano-alloys is presented in this study. The designed hybrid was employed as a dual fluorescence nanoprobe for Hg2+ and biothiol detection in aqueous solution using PEI-GQDs as the fluorescence switching signal probe. The dual sensing platform for the analytes detection is firstly, based on the quenching (turn “OFF”) of the PEI-GQDs fluorescence upon π-π interaction or electrostatic attraction with Pc-Au@Ag conjugate. The quenched fluorescence can be switched back to the “ON” mode in the presence of Hg2+ and switched “OFF” again when biothiols are introduced to capture the Hg2+ ion via the formation of the strong metal-thiol bond (Hg-S). The “off-on-off” processes were modulated by different amounts of Hg2+ and biothiols. The nanoprobes were found to be highly stable and selective towards the target analytes in the presence of other amino acids and metal ions. Also, the probes were successfully deployed in the assay of the test analytes in spiked samples.
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Date Issued: 2017

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