Biocomposites from polyfurfuryl alcohol reinforced with microfibres and nanocellulose from flax fibres and maize stalks
- Authors: Mtibe, Asanda , Linganiso, Linda
- Date: 2016
- Subjects: Textile chemistry Textile chemicals Cellulose -- Chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/12175 , vital:27041
- Description: This study is aimed at extracting cellulose and nanocelluloses (cellulose nanocrystals (CNCs) and cellulose nanofibres (CNFs)) from maize stalks and flax fibres. Both flax fibres and maize stalks are composed of cellulose, lignin, hemicellulose and extractives. The extraction of cellulose involves the removal of lignin, hemicellulose and extractives. The presence of these components in plant fibres hinders the extraction of cellulose and nanocelluloses. Prior to extraction of cellulose, the different concentrations (1 wt.%, 1.5 wt.% and 2 wt.%) of NaOH were optimised. However, chemical compositions and XRD results revealed that the treatment of flax fibres with 1.5 wt.% sodium hydroxide (NaOH) gives optimum results and this concentration was further selected for the extraction of cellulose. Cellulose was extracted by chemical treatments (sodium hydroxide (NaOH), sodium chlorite (NaClO2) and potassium hydroxide (KOH)) and a combination of chemical treatments and mechanical process (supermass colloider). The materials obtained after each treatment stage during the extraction process were characterised by different characterisation techniques such as Fourier transform infrared (FTIR) spectroscopy, environmental scanning electron microscopy (ESEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The results from the aforementioned characterisation techniques confirmed that cellulose was successfully extracted from flax fibres and maize stalks. Cellulose nanocrystals (CNCs) were extracted by sulphuric acid hydrolysis accompanied with ultra-sonication from cellulose obtained from flax fibres and maize stalks. The extracted CNCs were rod-like material with diameters and lengths in nanoscale and microscale, respectively. On the other hand, cellulose nanofibres (CNFs) were extracted by mechanical process (supermass colloider). The extracted CNFs were web-like material with diameters and lengths in nanoscale and microscale, respectively. The dimensions of nanocelluloses were measured by atomic force microscopy (AFM). Their dispersion was investigated by light polarised microscopy. The extracted nanocelluloses and cellulose were used to produce nanopapers and micropaper. Nanopapers mimic the traditional paper, the only difference of the nanopapers is that they are produced from high aspect ratio nanomaterials. Both nanopapers and micropapers were prepared by solvent evaporating method. Their thermal, optical and mechanical properties were investigated and compared. The mechanical and thermal properties of nanopapers produced from CNFs were better than those produced from CNCs and micropapers. On the other hand, nanopapers produced from CNCs were more transparent in comparison to nanopapers produced from CNFs and micropapers. Cellulosic fibres have attracted a considerable attention in composite materials due to their high tensile strength and tensile modulus. This study is focused on the development of biocomposites of polyfurfuryl alcohol (PFA) by in-situ polymerisation in the presence of acid catalyst (p-toluene sulphonic acid). Biocomposites were produced by reinforcing PFA with flax fibres (untreated and treated), nanoparticles and CNCs. The biocomposites reinforced with CNCs and flax fibres showed an improvement in mechanical, thermal and thermo-mechanical properties. On the other hand, biocomposites reinforced with nanoparticles obtained from treated maize stalks showed an improvement in mechanical and thermal properties while biocomposites reinforced with nanoparticles obtained from untreated maize stalks showed lower mechanical properties and decreased thermal stability.
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- Date Issued: 2016
Participation of Zimbabwean female students in physics: Subject perception and identity formation
- Authors: Gudyanga, Anna
- Date: 2016
- Subjects: Participation -- Women -- Zimbabwe Women -- Education -- Zimbabwe Science -- Study and teaching -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/11542 , vital:26936
- Description: The central focus of this study was to determine the extent to which identity formation influenced Zimbabwean A-level female students’ perceptions of and participation in physics. The themes from the sub-problems included the influence of contextual factors on identity formation in relation to physics as a subject at Advanced Level (A-level), facets of identity formation considered to be of significance by female students in relation to physics, the way in which female students’ perceptions of physics influenced their participation in the subject as well as the factors of identity formation considered as contributing to developing an orientation towards physics by female students. A qualitative approach grounded in an interpretivist paradigm was used. A tri-hybrid theoretical lens comprising of Wenger’s (1998) Social Learning Theory featuring CoP, the Feminist Stand point Theory and Sfard and Prusak’s (2005) notion of ‘telling’ identities or stories, enabled a rich understanding of the influences of identity formation on female students’ perceptions of and participation in physics. The data generating methods used were classroom observation, Draw-A-Scientist Test and semi-structured interviews conducted with nine participants. The data were collated to generate narratives. Key findings: The contextual factors that influenced the identity formation of female students and subsequently their participation in physics at A-level included: Parental and siblings influence; cultural perceptions; impact of the O-level experience; A-level physics teachers’ attitudes; classroom and laboratory experience; male peer influence and other factors such as an understanding of the relevance of physics in daily life. Facets of identity formation considered to be of significance by female students in relation to physics included: being confident, fearless, intelligent, and courageous, liking physics and being determined. These facets motivated them to develop an identity in favour of physics. The female participants studying only mathematics perceived themselves as very intelligent but with a fear of failing physics, lacking confidence and courage. Female students who held negative perceptions towards physics chose to do only mathematics at A-level while those with positive perceptions which influenced the formation of a positive physics identity displayed enthusiasm and commitment to achieve high levels of performance in the subject. Factors of identity formation considered as contributing positively to the development of an orientation towards physics by female students included the importance of v female physics teachers as role models, motivation from O-level science teachers, high self-confidence, high self-esteem, parental support and encouragement, and aspirations towards a physics related career. Gender insensitivity displayed by male teachers, male peer harassment and gender stereotyping are factors in identity formation considered as inhibiting the development of an orientation towards physics by female students. This study provides physics educators, physics planners and the government with detailed information on the role identity formation plays on the participation of Zimbabwean female adolescent students in A-level physics. The findings may be used by heads of schools to sensitise academic staff on the gender dimensions of teaching and learning as well as by counsellors and parents to encourage females to enrol for physics and mathematics as their subjects of choice. This study also contributes to the strengthening of educational research in Zimbabwe, especially research aimed at emancipation of female students in Zimbabwe.
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- Date Issued: 2016
Higher order modulation formats for high speed optical communication systems with digital signal processing aided receiver
- Authors: Chabata, Tichakunda Valentine
- Date: 2016
- Subjects: Optical communications , Modulation (Electronics) , Signal processing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/4775 , vital:20677
- Description: The drastic increase in the number of internet users and the general convergence of all other communication systems into an optical system have brought a sharp rise in demand for bandwidth and calls for high capacity transmission networks. Large unamplified transmission reach is another contributor in reducing deployment costs of an optical communication system. Spectrally efficient modulation formats are suggested as a solution to overcome the problems associated with limited channels and bandwidth of dense wavelength division multiplexing (DWDM) optical communication systems. Higher order modulation formats which are considered to be spectrally efficient and can increase the transmission capacity by transmitting more information in the amplitude, phase, polarization or a combination of all was studied. Different detection technologies are to be implemented to suit a particular higher order modulation format. In this research multilevel modulation formats, different detection technologies and a digital signal processing aided receiver were studied in a practical optical transmission system. The work in this thesis started with the implementation of the traditional amplitude shift keying (ASK) modulation and a differential phase shift keying (DPSK) modulation systems as they form the basic building block in the design of higher order modulation formats. Results obtained from using virtual photonics instruments (VPI)simulation software, receiver sensitivity for 10Gbpsnon-return-to-zero (NRZ), amplitude phase shift keying (ASK) and DPSK signals were measured to be -22.7 dBm and -22.0 dBm respectively. Performance comparison for the two modulation formats were done over different transmission distances. ASK also known as On-Off keying (OOK) performed better for shorter lengths whereas DPSK performed better for longer lengths of up to90km.Experimental results on a 10 Gbps NRZ- ASK signal gave a receiver sensitivity of -21.1 dBm from digital signal processing (DSP) aided receiver against -19.8 dBm from the commercial bit error ratio tester (BERT) yielding a small difference of 1.3 dB hence validating the reliability and accuracy of the digital signal processing (DSP) assisted receiver. Traditional direct detection scheme and coherent detection scheme performances were evaluated again on a 10 Gbps NRZ ASK signal. Coherent detection that can achieve a large unamplified transmission reach and has a higher passive optical splitting ratio was first evaluated using the VPI simulation software. Simulation results gave a receiver sensitivity of -30.4 dBm forcoherent detection and -18.3 dBm for direct detection, yielding a gain in receiver sensitivity of 12.1 dB. The complex coherently detected signal, from the experimental setup gave a receiver sensitivity of -20.6 dBm with a gain in receiver sensitivity of 3.5 dBm with respect to direct detection. A multilevel pulse amplitude modulation (4-PAM) that doubles the data rate per channel from10 Gbps to 20 Gbps by transmitting more information in the amplitude of the carrier signal was implemented. This was achieved by modulating the optical amplitude with an electrical four level amplitude shift keyed (ASK) signal. A receiver consisting of a single photodiode, three decision circuits and a decoding logic circuit was used to receive and extract the original transmitted data. A DSP aided receiver was used to evaluate the link performance. A receiver sensitivity of -12.8 dBm is attained with a dispersion penalty of about 7.2 dB after transmission through 25 km of G.652 fibre.
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- Date Issued: 2016
Mechanism and synchronicity of wheat (Triticum aestivum) resistance to leaf rust (Puccinia triticina) and Russian wheat aphid (Duiraphis noxia) SA1
- Authors: Njom, Henry Akum
- Date: 2016
- Subjects: Wheat -- Disease and pest resistance Bacterial diseases of plants Russian wheat aphid
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/2700 , vital:28056
- Description: Wheat (Triticum aestivum and T. Durum) is an extremely important agronomic crop produced worldwide. Wheat consumption has doubled in the last 30 years with approximately 600 million tons consumed per annum. According to the International Maize and Wheat Improvement Center, worldwide wheat demand will increase over 40 percent by 2020, while land as well as resources available for the production will decrease significantly if the current trend prevails. The wheat industry is challenged with abiotic and biotic stressors that lead to reduction in crop yields. Increase knowledge of wheat’s biochemical constitution and functional biology is of paramount importance to improve wheat so as to meet with this demand. Pesticides and fungicides are being used to control biotic stress imposed by insect pest and fungi pathogens but these chemicals pose a risk to the environment and human health. To this effect, there is re-evaluation of pesticides currently in use by the Environmental Protection Agency, via mandates of the 1996 Food Quality Protection Act and those with higher perceived risks are banned. Genetic resistance is now a more environmental friendly and effective method of controlling insect pest and rust diseases of wheat than the costly spraying with pesticides and fungicides. Although, resistant cultivars effectively prevent current prevailing pathotypes of leaf rust and biotypes of Russian wheat aphid from attacking wheat, new pathotypes and biotypes of the pathogen/pest may develop and infect resistant cultivars. Therefore, breeders are continually searching for new sources of resistance. Proteomic approaches can be utilised to ascertain target enzymes and proteins from resistant lines that could be utilised to augment the natural tolerance of agronomically favourable varieties of wheat. With this ultimate goal in mind, the aim of this study was to elucidate the mechanism and synchronicity of wheat resistance to leaf rust (Puccinia triticina) and Russian wheat aphid (Duiraphis noxia) SA1. To determine the resistance mechanism of the wheat cultivars to leaf rust infection and Russian wheat aphid infestation, a proteomics approach using two-dimensional gel electrophoresis was used in order to determine the effect of RWA SA1 on the wheat cultivars proteome. Differentially expressed proteins that were up or down regulated (appearing or disappearing) were identified using PDQuestTM Basic 2-DE Gel analysis software. Proteins bands of interest were in-gel trypsin digested as per the protocol described in Schevchenko et al. (2007) and analysed using a Dionex Ultimate 3000 RSLC system coupled to an AB Sciex 6600 TripleTOF mass spectrometer. Protein pilot v5 using Paragon search engine (AB Sciex) was used for comparison of the obtained MS/MS spectra with a custom database containing sequences of Puccinia triticina (Uniprot Swissprot), Triticum aestivum (Uniprot TrEMBL) and Russian wheat aphid (Uniprot TrEMBL) as well as a list of sequences from common contaminating proteins. Proteins with a threshold of ≥99.9 percent confidence were reported. A total of 72 proteins were putatively identified from the 37 protein spots excised originating from either leaf rust or Russian wheat aphid experiments. Sixty-three of these proteins were associated with wheat response to stress imposed by RWA SA1 feeding while 39 were associated with infection by Puccinia triticina. Several enzymes involved in the Calvin cycle, electron transport and ATP synthesis were observed to be differentially regulated suggesting greater metabolic requirements in the wheat plants following aphid infestation and leaf rust infection. Proteins directly associated with photosynthesis were also differentially regulated following RWA SA1 infestation and P.
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- Date Issued: 2016
Investigating the nature of the linguistic challenges of the Department of Basic Education (DBE) 2013 Grade 4 Mathematics ANAs and learners’ and teachers’ experience of them.
- Authors: Sibanda, Lucy
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2079 , http://hdl.handle.net/10962/d1021312
- Description: The underperformance of South African learners in literacy and numeracy is a source of grave concern, especially at the transition from Grade 3 to Grade 4. The challenge that complicates this shift is to some extent linguistic, since at Grade 4 in South Africa the majority of learners begin learning in English, which is an additional language for most. The study adopts a sociocultural view of language and learning. Vygotsky’s influential theoretical work on language and learning, in which language is considered central to learning and learning is a social process embedded in sociocultural settings, informs the study. The introduction of the Annual National Assessments (ANAs) across primary and secondary grades in South Africa in mathematics and literacy in 2011 provides the context for this research. It is against this background that the present study aimed, through a case study approach of three Grade 4 classes of English additional language (EAL) learners, to achieve four things, namely: to investigate the linguistic challenges of the 2013 Grade 4 mathematics ANAs; to analyse the learners’ written responses to the 2013 mathematics ANA items; to explore the 2013 Grade 4 learners’ difficulties and experiences of the 2013 mathematics ANAs, and to investigate the Grade 4 mathematics teachers’ perspectives of the language of the ANAs. In order to achieve these aims, the data was collected in four phases. The first phase of the study addressed the nature of the linguistic challenges of the Department of Basic Education Grade 4 mathematics ANAs. Data collection occurred in two parts: 1) Comparing Grade 4 ANAs to exemplars provided and 2) Analysing the language of the 2013 mathematics ANAs. This was done through content analysis and Shaftel et al.’s (2006) linguistic complexity checklist. Findings for part 1 of the study revealed that there were several inconsistencies in the questioning format and language used in the ANAs and in the exemplars. Findings of the content analysis done on the 2013 mathematics ANA test items using Shaftel et al.’s (2006) linguistic complexity checklist and Vale’s (2013) Linguistic Complexity Index formula point to many linguistic complexities in several test items, particularly in relation to recurrent use of: 7 or more letter words, homophones, prepositional phrases and specific mathematics vocabulary across the majority of questions. In phase 2, the analysis of 106 learners’ written responses for the 2013 mathematics ANA questions revealed that for many of the questions the language used was unfamiliar for Grade 4 learners using English as an additional language. This was aggravated by the inclusion in the ANAs of linguistic forms learners would not have encountered in their workbooks or exemplars intended to prepare the learners for the assessments. Therefore, linguistic complexity of items was a key contributing factor to learners’ poor performance in the test. In the third phase, the quantitative and qualitative analysis of the 26 learners’ interviews revealed that during the task-based interviews, learners experienced difficulties in the following skills: reading, comprehension, transformation, process and encoding. The greatest difficulties were experienced in comprehension and in reading, especially in the two classes where the learners were less proficient in the English language. The fourth phase, in which two Grade 4 mathematics teachers’ perceptions of the linguistic demands of the Grade 4 mathematics ANAs were presented and analysed, the teachers’ perceptions indicated that the mathematical language was mostly too difficult for the Grade 4 learners. Teachers also were of the opinion that learners’ reading skills were poor and they struggled to comprehend what they read. A dilemma regarding whether teachers should assist learners during the ANAs, satisfying the local needs for mediating the language or whether they should comply with the ANA policy which states that they may not assist learners was expressed by one of the teachers. A range of language challenges that teachers managed with various strategies were raised. These included one teacher’s use of code-switching during the teaching of mathematics. The study concludes with implications and recommendations. These include that test designers should minimise the language complexity of test items, especially in the early transition grades of learning in English. Research should be conducted on possibilities for allowing teachers to provide linguistic mediation to ANA questions in these transition years of learners learning in English.
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- Date Issued: 2016
A framework to evaluate user experience of end user application security features
- Authors: Shava, Fungai Bhunu
- Date: 2016
- Subjects: User interfaces (Computer systems) -- Design Web sites -- Design
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/12951 , vital:27137
- Description: The use of technology in society moved from satisfying the technical needs of users to giving a lasting user experience while interacting with the technology. The continuous technological advancements have led to a diversity of emerging security concerns. It is necessary to balance security issues with user interaction. As such, designers have adapted to this reality by practising user centred design during product development to cater for the experiential needs of user - product interaction. These User Centred Design best practices and standards ensure that security features are incorporated within End User Programs (EUP). The primary function of EUP is not security, and interaction with security features while performing a program related task does present the end user with an extra burden. Evaluation mechanisms exist to enumerate the performance of the EUP and the user’s experience of the product interaction. Security evaluation standards focus on the program code security as well as on security functionalities of programs designed for security. However, little attention has been paid to evaluating user experience of functionalities offered by embedded security features. A qualitative case study research using problem based and design science research approaches was used to address the lack of criteria to evaluate user experience with embedded security features. User study findings reflect poor user experience with EUP security features, mainly as a result of low awareness of their existence, their location and sometimes even of their importance. From the literature review of the information security and user experience domains and the user study survey findings, four components of the framework were identified, namely: end user characteristics, information security, user experience and end user program security features characteristics. This thesis focuses on developing a framework that can be used to evaluate the user experience of interacting with end user program security features. The framework was designed following the design science research method and was reviewed by peers and experts for its suitability to address the problem. Subject experts in the fields of information security and human computer interaction were engaged, as the research is multidisciplinary. This thesis contributes to the body of knowledge on information security and on user experience elements of human computer interaction security regarding how to evaluate user experience of embedded InfoSec features. The research adds uniquely to the literature in the area of Human Computer Interaction Security evaluation and measurement in general, and is specific to end user program security features. The proposed metrics for evaluating UX of interacting with EUP security features were used to propose intervention to influence UX in an academic setup. The framework, besides presenting UX evaluation strategies for EUP security features, also presents a platform for further academic research on human factors of information security. The impact can be evaluated by assessing security behaviour, and successful security breaches, as well as user experience of interaction with end user programs.
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- Date Issued: 2016
The ecology of hard substrate communities around Sardinia Bay in the warm-temperate Agulhas Bioregion
- Authors: Evans, Adrian G , Nel, Ronel
- Date: 2016
- Subjects: Aquatic biodiversity -- South Africa -- Nelson Mandela Bay Municipality , Marine ecology -- South Africa -- Nelson Mandela Bay Municipality , Seashore biology -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/6782 , vital:21141
- Description: Hard substrates in the marine environment are an important ecosystem of great scientific and economic value. Hard substrates provide suitable habitat for a diverse assemblage of benthic organisms. This thesis investigated the ecology of benthic hard substrate communities along a section of wave-exposed coastline, including the Sardinia Bay Marine Protected Area (MPA), in the warm-temperate Agulhas bioregion of South Africa. The effect of physical variables on benthic communities, including both the intertidal and shallow subtidal, was quantitatively assessed across (Chapter 3) and along (Chapter 4) the shore to provide a model of zonation for this bioregion and a baseline of community patters and biodiversity, as this information was lacking especially for the Sardinia Bay MPA. The zones described in Chapter 3 were in agreement with previous trends described for this bioregion with the addition of different biotopes in the upper Balanoid and deeper subtidal zones as well as the addition of an intermediate/transition zone in the subtidal between the algal dominated shallow subtidal and deeper subtidal, which has an increased abundance of sessile invertebrates. Disturbance is an important process in structuring benthic communities, and its role in structuring shallow benthic communities was investigated using a disturbance simulation experiment across a wave-exposure gradient (Chapter 5). Communities were found to change along the exposure gradient and monitoring the undisturbed communities showed that large waves caused disturbances across all the exposures. The recovery process was similar across all exposures mainly through lateral vegetative growth and regrowth from basal parts with communities in disturbed quadrats recovering to resemble the surrounding undisturbed community. Recruitment did not have a significant effect in the recovery process and community composition was therefore a result of the effects of the physical environment along the exposure gradient. Lastly this thesis investigated the indirect effects of protection in the small Sardinia Bay MPA (Chapter 6). Despite the small size of the MPA this study found differences in diversity and abundance between communities inside and outside the MPA. These differences in benthic biota infer indirect effects of protection that are probably due to the increase in abundance of exploited fish inside the MPA. Lower abundances of red algae, macroinvertebrates and diversity inside the MPA in the shallow depth category was attributed to the higher abundance of the generalist fish species that concentrate in the shallows. Significantly lower abundances of Chordata in the shallow and medium depth categories inside the MPA was attributed to predation by the benthic carnivorous species as ascidians are included in the diet of these species. This chapter also compared the effectiveness of destructive (scraped quadrats) and non-destructive (visually assessed quadrats) sampling methods. Scraped quadrats were found to be more effective in detecting changes across the MPA compared to visually assessed quadrats. Destructive methods sample the entire assemblage, to a higher taxonomic level, and measure abundance using biomass. It was concluded that biomass is a better metric when comparing communities across protection or other treatments as it provides better biological information of the community.
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- Date Issued: 2016
The effect of silica on the reduction of precipitated iron-based fischer-tropsch catalysts
- Authors: Coombes, Matthew
- Date: 2016
- Subjects: Fischer-Tropsch process Reduction (Chemistry) , Catalysts
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14873 , vital:27888
- Description: Iron Fischer-Tropsch (FT) catalysts are typically prepared as iron oxides which are reduced to FT-active iron metal and iron carbide prior to FT synthesis. The iron oxides contain a variety of different chemical and structural promoters to alter FT-activity. Silica is a common structural promoter which stabilises the formation of small crystallites and provides mechanical integrity to the catalyst. However, silica inhibits the reduction of the oxide precursor to the FT-active phases. This ultimately affects catalyst activity and product selectivity. It has been proposed that the silica interacts with the iron to form encapsulating shells of fayalite (Fe2SiO4), or fayalite rafts between the iron oxide and the silica support. In this study, six silica-promoted iron oxide samples were prepared using a simple co-precipitation technique. Samples contain varying amounts of silica, and the samples are named 100/x Fe/SiO2, where x is the weight of silica for 100 weight iron, with x taking on values of 0, 10, 25, 50, 100 and 200. The resulting iron oxides were characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRPD), M¨ossbauer spectroscopy (MS), magnetic susceptibility measurements (MM), Raman spectroscopy, thermal gravimetric analysis (TGA) and nitrogen physisorption. Their reduction in a hydrogen atmosphere was investigated using temperature programmed reduction (TPR), in situ XRPD and TEM. The reduction in hydrogen of 100/0 Fe/SiO2 and 100/10 Fe/SiO2 was also studied using in situ gas flow TEM cells. These cells allow the samples to be studied in the electron microscope at temperature and pressure conditions approaching those experienced in a real reactor environment. In the absence of a silica promoter (100/0 Fe/SiO2), hematite particles are formed with mean particle diameters of 39 ± 12 and 52.7 ± 0.2 nm determined using TEM and XRPD respectively. MM data reveals a magnetic transition (Morin transition) at≈230 K, consistent with a mean particle size of≈50 nm. In a hydrogen atmosphere, the hematite reduces to metallic iron via a two-step process viz. hematite → magnetite → iron. The final iron particles have an average crystallite size of 68.0 ± 0.2 nm. The presence of lower amounts of silica in the samples 100/10 Fe/SiO2, 100/25 Fe/SiO2 and 100/50 Fe/SiO2 results in the formation of silicasubstituted 2-line ferrihydrite particles. Bands in the Raman spectra of these samples shift on increasing silica content, which indicates an increasing number of Fe-O-Si bonds within the ferrihydrite framework. MM reveals typical superparamagnetic (SPM) behaviour above a blocking temperature in the range 39 - 68 K which gives mean particle sizes of 4.2, 3.6 and 3.5 nm for 100/10 Fe/SiO2, 100/25 Fe/SiO2 and 100/50 Fe/SiO2 respectively, in good agreement with particle sizes determined using TEM (3.1±0.4, 2.4±0.3 and 2.4±0.3 nm respectively). MS data at 300 K and 4.2 K were fitted with distributions of ∆EQ and Bhf respectively. The median values of Bhf decrease with increasing silica content, indicating greater degrees of distortion in the Fe3+ environments induced by increased silica substitution. The reduction to metallic iron occurs via a three-step process viz. hematite → magnetite → wu¨stite → iron, with the silica stabilising the wu¨stite phase. The increasing amount of Fe-O-Si bonds on increasing silica content shifts reduction to higher temperatures broadens each reduction step as a result of local Fe-O-Si concentration variations. Fractions of each sample are not completely reduced even at 1000°C, with the relative proportion increasing with increasing silica content. In situ gas flow TEM studies reveal that the mechanism of reduction involves the liberation of atomic iron atoms from the silica-substituted iron oxides which agglomerate and grow into final iron particles. This leaves a poorly crystalline Fe-O-Si bonded framework behind. STEM-EDS and STEM-EELS reveal low concentrations of silicon at the surface of the resulting iron particles, however they do not form encapsulating shells of fayalite as previously suggested. The majority of the silica remains in the Fe-O-Si material which may crystallise into separate fayalite particles at elevated temperature. The presence of silica in high proportions (100/100 Fe/SiO2 and 100/200 Fe/SiO2) results in the formation of a two-phase system consisting of silicasubstituted 2-line ferrihydrite particles which are encapsulated in an ironinfused amorphous silica network. As with the other silica-bearing samples, there is an increase in Fe-O-Si bonds and an increase in the degree of distortion at Fe3+ sites with increasing silica content. The large amount of silica suppresses the blocking temperature of the SPM crystallites. In a hydrogen atmosphere, the reduction to metallic iron follows the same three step process as the other silica-bearing samples. Reduction temperatures are further shifted to higher values and given reduction steps are considerably broader with increasing silica content. The fraction of iron not fully reduced also increases. Iron particle diameters are very small, since encapsulation by the silica matrix prevents growth of particles.
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- Date Issued: 2016
Community structure and trophic ecology of shallow and deep rocky reefs in a well-established marine protected area
- Authors: Heyns, Elodie R
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54438 , vital:26565
- Description: The now formally adopted ecosystem approach to fisheries (EAF) considers not only commercially important species, but the entire ecosystem and the processes that support these species. A key component of EAF management is the implementation of no-take Marine Protected Areas (MPAs). Shallow water fish stocks are depleted and fishing effort is moving deeper and further offshore to keep up with demands. This situation calls for a detailed investigation of deep nearshore reefs to provide critical information relevant to policy uptake and management decisions regarding existing and new MPAs in terms of zonation and use. To address this need, the aim of this thesis was to investigate reefs that lie between 45 and 75 m and compare them in terms of community structure and function to the relatively well-studied shallow reefs that lie within SCUBA diving depth (<25 m). Ecological collections were made in the centre of a large and well-established MPA, Tsitsikamma National Park, to ensure that data represented non-anthropogenically impacted communities. Data were collected from two study sites; Rheeders Reef, (shallow reef) and Middlebank, a deep reef complex situated near the Storms River Mouth. The first step to address the aim of this study was to obtain baseline data on the distribution patterns of both the macrobenthic invertebrates and fish assemblages. Baseline data were obtained by underwater video methods and included the use of a remotely operated vehicle, baited remote underwater stereo-video systems (stereo-BRUVs) and traditional underwater camera equipment operated by SCUBA divers. To establish functional differences between the two study sites, fatty acid (FA) and stable isotope (SI) analyses were employed. These biomarker techniques provided insight into the importance of different sources of primary production, nutritional condition and species packing. From 360 photoquadrats examined for macrobenthic invertebrate distribution patterns, 161 invertebrates were identified that demonstrated a clear changeover of species along the depth gradient. Species richness was highest on the shallow reef and decreased with an increase in depth. To understand how the measured environmental variables impacted the macrobenthic assemblage data a LINKTREE analysis was performed. LINKTREEs produce hierarchical cluster analysis based on the macrobenthic assemblage data and provide a threshold of environmental variables that correspond to each cluster. The outcome of the LINKTREE analysis indicated that the changeover of species resulted in four distinct clusters, each cluster associated with a particular set of environmental variables that fell within a depth range. On the shallowest sites, the high energy environment resulting from wave action and surge prevented the settlement of suspended particles. The high energy environment of the shallow reef selected for low-growing encrusting species. High light intensities supported great abundances of benthic algae, and as light was lost with increasing depth, algal cover gradually diminished until it was completely absent on the deep reef. The reduced impact of surface wave action on the deep reef caused increased levels of settled suspended particles. The high levels of settled particles likely caused clogging of feeding parts of the encrusting species. Consequently, upright growth forms were more common in the lower energy environment of the deep reef. A total of 48 fish species were identified from 51 stereo-BRUVs samples. Fish assemblages differed significantly between the shallow and deep reefs. The shallowest sites were characterised by many small and juvenile fish species that fed at lower trophic levels. The deep reef supported the majority of the large predatory fish that fed at higher trophic levels. Many species demonstrated depth-related ontogenetic shifts in habitat use, and as such the deep reef hosted the majority of the sexually mature individuals. The fish assemblages also demonstrated a strong association with the macrobenthic clusters identified as habitat types by the LINKTREE analysis. The results from 201 FA and 191 SI samples provided information on specific feeding interactions, but more importantly shed some light on different processes that supported the shallow and deep reef communities. The shallow reef community was characterised by greater diversity of food sources, a pattern that could be explained by the presence of benthic algae and terrestrial inputs. Greater diversity of carbon sources at the bottom of the food web meant that a larger variety of species could be supported. Higher species richness increased the number of distinct taxa that performed similar functions, rendering the shallow reef more redundant and consequently more resilient to disturbance. In contrast, the deep reef demonstrated a food web supported mainly by pelagic production, which was more variable both over space and time. The deep reef was less redundant when compared to the shallow reef, as fewer species demonstrated similar trophic niches. These factors, in addition to the increased presence of sensitive calcareous macrobenthic species on the deep study site, rendered the deep reef more vulnerable to disturbance when compared to the shallow reef. Although the data presented here were from a single study area, the limitations typically associated with these inaccessible and challenging sampling environments made the dataset a significant contribution to the knowledge of reef ecosystems. The study addressed priority research questions for South Africa as identified during the National Biodiversity Assessment. The observable differences in structure, function and vulnerability point to the need for continued protection of our shallow reefs and offshore expansion of our MPA networks. Future research should determine if the patterns identified here are common throughout the Agulhas Ecoregion to provide managers with robust evidence for the extension our MPAs offshore.
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- Date Issued: 2016
Synthesis and biological evaluation of novel thiazole-based compounds
- Authors: Olawode, Emmanual Oladayo
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62955 , vital:28325
- Description: Thesis embargoed for one-year period. Expected date of release: April 2019
- Full Text:
- Date Issued: 2016
The implementation of the inclusive education policy in sport: a case study of four secondary schools in Masvingo District, Zimbabwe
- Authors: Mudyahoto, Tapiwa
- Date: 2016
- Subjects: Inclusive education -- Zimbabwe Educational equalization -- Zimbabwe Physical education and training -- Study and teaching (Secondary) -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/2116 , vital:27611
- Description: The purpose of the present study was to explore the implementation of the inclusive education policy in sport in four secondary schools in Masvingo District, Zimbabwe. The case study research design was employed; interviews, focus groups, document analysis and observations were used to collect data. Four school Heads, 4 sports masters, 4 team trainers, 4 team captains, 2 learners with disabilities and a district education officer were purposively selected to take part in this study. Data were presented, analysed/discussed, starting with demographic data in the first section followed by emerging themes. It emerged from the study that all the participants were not knowledgeable about inclusive education and the aspect of including learners with disabilities in mainstream sport. The major barriers identified include inadequate policy dialogue, unavailability of sporting equipment and attitudes. Further findings revealed that there is dire need for knowledge and skills in inclusive sport among teachers in regular schools. Findings also confirmed unavailability of policy circulars in schools. Most teachers were not afforded opportunities to attend workshops and seminars. Findings also revealed that teachers faced major challenges such as funding to undertake courses in SNE and inclusive sport. Teachers were reeled in with a lot of pressure due to congested timetables and large classes. Participants believed that the challenges they faced could be resolved through some proposed intervention strategies. The researcher concluded that teachers in regular schools were not equipped to teach sport to learners with special education needs in the mainstream. The MoPSE was not doing much in preparing teachers to be effective in including learners with disabilities in regular school sport. The study recommended that the MoPSE should put in place provisions to meet the inclusive needs of both teachers and learners. It also recommended that school Heads should be taught about SNE and inclusive sport for them to be able to guide teachers properly. Besides the national policy, schools should design inclusive policies specifically for their respective schools in line with the national policy. The study also recommended that the MoPSE should come up with a comprehensive framework in sport to counter some of these challenges.
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- Date Issued: 2016
An investigation into the public policy making role of the judiciary :The case of South Africa
- Authors: Maluleke, Life Reuben
- Date: 2016
- Subjects: Policy sciences -- South Africa Political planning -- South Africa Public opinion -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9812 , vital:35005
- Full Text: false
- Date Issued: 2016
A Foucauldian analysis of discourses shaping perspectives, responses, and experiences on the accessibility, availability and distribution of condoms in some school communities in Kavango Region
- Authors: Ngalangi, Naftal Sakaria
- Date: 2016
- Subjects: Foucault, Michel, 1926-1984 -- Methodology , Condom use -- Namibia , Sex instruction for teenagers -- Namibia , HIV infections -- Prevention -- Namibia , AIDS (Disease) -- Prevention -- Namibia , Education, Secondary -- Namibia , Teenage pregnancy -- Namibia , Sexual abstinence -- Moral and ethical aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2061 , http://hdl.handle.net/10962/d1019990
- Description: Condom use is promoted as an effective method for prevention and contraception for people who practice or are at risk of practicing high-risk sexual behaviors. According to the UNAIDS (2009) report, condoms are the only resource available to prevent the sexual spread of the HI-Virus; and with regard to family planning, the same report proposes that condoms expand the choices, have no medical side effects, and thus provide dual protection against pregnancy and disease. However, in Africa as elsewhere in the world, condom use has been fiercely debated. The debates on the accessibility, availability and distribution of condoms in schools are not new nor are they uncontested. In Namibia, the HIV and AIDS policy in education does not explain how, when and by whom condoms should be made available to learners. This leaves it to schools to decide on how (and whether) to make condoms available to learners. As a result, individual school‘s choices not only vary, but are mediated by different factors that are not always in the best interest of learners who, as the foregoing discussion suggests, continue to participate in behaviour that, amongst other things, puts them at risk of HIV infection and falling pregnant. Relying on Foucault‘s theory of discourses, this study investigated the dominant discourses that shape learner, teacher, parent religious and traditional leader and traditional healer perspectives, responses, and experiences with regard to the accessibility, availability, and distribution of condoms in school. The study was conducted in nine schools in Kavango Region in Namibia using a mixed methods approach. The study used triangulation in the data collection process through the use of questionnaires where 792 learners participated in this component, and focus group discussions and individual interviews targeting four groups namely, learners, teachers, parents and religious leaders, traditional leaders and traditional healers. The quantitative data were analyzed using the Statistical Packages for Social Sciences (SPSS), and findings from the focus group discussions and individual interviews were analyzed identifying themes and patterns and then organizing them into coherent categories with sub-categories. The study revealed that the majority of adult participants opposed the idea of making condoms available in schools; advocating abstinence instead. This was despite evidence on the prevalence of sexual activity amongst youth in the community. Reasons had to do with various competing and hierarchized discourses operating to shape participant beliefs, perspectives, and responses in a highly regulated and surveilled social and cultural context. Put differently, the dominant discourses invoked a particular sexual subject; authorized and legitimated who invoked such a subject; who was and was not allowed to speak on sexual matters; as well as how sexual matters were brought into the public space of schools. Such authorization and legitimation regulated the discursive space in which discussions on sexual health, safe sex, and resources such as condoms were permitted; with negative consequences for the sexual well-being of youth in Kavango Region. The study also highlighted the tension between freedom, choice, and rights, showing how complex in fact is decision to make condoms available in school. On the one hand, teenagers positioned themselves as capable subjects who had the right to exercise choice over their sexual lives. Requesting parent consent was thus viewed as a violation of this right to choose. Such a position displayed authority and agency by learners that was pitted against views amongst adults in this study that positioned youth as having no agency. In their view, youth (a) were still children and thus innocent and pure, (b) ought to abstain, and (c) were difficult to control given the modern context. Adults believed that early sexual involvement by learners did not result from lack of vigilance and control on their part, but rather from exposure to modern social mores. The study concluded that (a) schools remain difficult spaces not only for mediating discussions of sex and sexuality, but also for providing resources to mitigate sexual risk amongst leaners, (b) in highly regulated societies, dominant religious discourses are produced and reproduced in and through existing institutions such as family, church, and schools; highlighting how these serve to normalize beliefs and perspectives, (c) the dominant discourses shaping communities in which schools find themselves remain inconsistent with school discourses that are shaped by modernist conceptions of childhood and youth, and (b) adult choices to sanction and obstruct schools from making condoms available (and in the case of teachers, not accessible and distributable) put the very children at risk that they propose to be protecting.
- Full Text:
- Date Issued: 2016
Phylogenetics of the keratin-feeding beetle family Trogidae (Coleoptera: Scarabaeoidea)
- Authors: Strümpher, Werner Petrus
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/1232 , vital:20037
- Description: Trogidae constitute a monophyletic and biologically unique family within the Scarabaeoidea, being the only keratinophagous group in its superfamily. Traditionally, the family has been divided into three distinctive genera, Omorgus Erichson, Polynoncus Burmeister, and Trox Fabricius. Although the taxonomy of the group is relatively well studied, recently changes to the existing classification have been proposed without the family as currently constituted being subjected to phylogenetic analyses. In this study I present the first molecular phylogeny for this cosmopolitan family, based on three partially sequenced gene regions: 16SrRNA, 18S rRNA and 28S rRNA domain 2. Analyses resolved relationships between and within genera and subgenera that are largely congruent with existing taxonomic hypotheses based on morphology. I recovered four well-supported radiations: Polynoncus, Omorgus, Holarctic Trox and Afrotropical Phoberus. One of the more surprising results was the monophyly of Phoberus. Based on the evidence, I propose reinstating the genus Phoberus to accommodate all Afrotropical (including Madagascan endemic) species. The results re-emphasise the validity of Scholtz’s (1986a) classification system for the genus Omorgusand its subgeneraand provide evidence of an African origin for Madagascan trogids. Divergence analysis was able to date the major events for the origin of extant lineages of Trogidae. The subsequent diversification of the major lineages is largely attributed to Pangaean and Gondwanan vicariance events in the Mid-Jurassic and early Late Cretaceous, respectively. The separation of the landmasses resulted in the evolution of four distinct groups: Omorgus, Polynoncus, Trox and Phoberus. The monophyletic subgenus Phoberus MacLeay is of particular interest; about one-third (14 of 40) of the species in the Afrotropical region have lost the ability to fly. To gain insights into the evolution of flightlessness in this clade, phylogenetic relationships among species were inferred using molecular sequence data. Four partial sequences of four genes (COI, 16S, 18S and 28S domain 2) were obtained for 27 species, covering all of the recognised species-groups. Estimated times of divergence were based on published mutation rates for COI. The results recovered eight monophyletic lineages, supporting the morphology-based subdivisions of the genus. Flightlessness evolved at least five times within the subgenus. There is no strong support for the re-acquisition of functional wings once they are lost. Diversification, and the present relictual distributions, in African Phoberus can be linked to climatic and geological events associated with the Miocene and Pliocene Climate Optimum in southern Africa. The evolution of flightlessness in Phoberus is consistent with the habitat stability hypothesis. All flightless species occupy refugial areas with relatively long-term environmental stability. Phoberus is a promising model group for studying evolutionary trends relating to flightlessness, speciation and biogeography. Flightlessness is a counterintuitive evolutionary development, given the many advantages of flight. To interpret the diversification in the flightless Phoberus capensis Scholtz, the phylogenetic relationships among several populations of P. capensis are investigated. Phylogenetic relationships among populations were inferred using molecular sequence data that suggested three distinct evolutionary lineages, which was also supported by morphological characters. Divergence time estimates suggest a Pliocene-Pleistocene diversification. Based on these results, it is suggested that P. capensis experienced climatically-driven allopatric speciation with sheltered Afrotemperate forests and high mountain peaks serving as important refugia in response to climatic exacerbations. The P. capensis complex thus represents a speciation process in which flight-restricted populations evolved in close allopatry, possibly as recently as the Pleistocene. Two of the three divergent and geographically distinct lineages are described as novel species. This study represents the most recent comprehensive work on the Trogidae. On the basis of this study, it is proposed that taxonomic changes to the generic classification of the family be made. Trogidae are formally divided into two subfamilies, Omorginae and Troginae. The subgenus Phoberus is restored to genus rank to include all the Afrotropical species, and Afromorgus is confirmed at subgeneric rank. The genus Madagatrox is synonymised with Phoberus.
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- Date Issued: 2016
Nascent Desires: Gendered Sexualities in Life Orientation Sexuality Education Programmes and Popular Music
- Authors: Moodley, Dale Dhersen
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3274 , http://hdl.handle.net/10962/d1021260
- Description: Formal school-based sexuality education is one medium, amongst others, that recognises young people’s sexuality, but usually as at-risk and/or risk taking subjects, or as innocent subjects. I analyse the gendered sexualities of young people as represented in: Grade 10 Life Orientation sexuality education programmes and popular music, as two mediums of sexual socialisation in Grade 10 learners’ lives, and as engaged with by Grade 10 learners and educators. I collected data from two schools in the Eastern Cape that included: (i) sections on sexuality from two Life Orientation manuals used by educators in classrooms: ‘Oxford Successful Life Orientation’ (2011), and ‘Shuters Top Class Life Orientation’ (2011); (ii) videos and lyrics of three songs voted most popular by learners which were ‘Climax’ by Usher, ‘Beez in the Trap’ by Nicki Minaj, and ‘Where Have You Been’ by Rihanna; (iii) observations of seven sexuality education classes; and, (iv) in-depth semistructured interviews conducted with eight learners and two educators. I draw on an integrated theoretical and methodological approach – Foucauldian, feminist poststructural and psychosocial psychoanalytic perspectives – to conceptualise and analyse gendered sexualities in terms of: (i) the dominant gendered discourses found in sexuality education manuals, and music videos and lyrics; (ii) the reflexive and interactive gendered subject positions taken up and/or resisted by learners and educators during classroom lessons and one-on-one interviews; and, (iii) learners’ and educators’ conscious and unconscious investments in particular gendered subject positions during one-on-one interviews. These three sets of analysis produced four major themes. The first theme centres on responsible sexuality; young women are expected to assume more sexual responsility than young men, thus curbing their sexual agency. The second theme outlines three types of pleasure – sexual, romantic and dating and/or relationship pleasure – that accord young men and women active and passive ways of exercising pleasure. The third theme highlights the heteronormative transitioning adolescent subject that constructs young women as reproductive subjects and young men as sexual subjects. The last theme focuses on gendered power relations and raunch culture, and maintains that young men are powerful and likely to commit acts of sexual violence against young women because they are powerless. The central argument developed when viewing all the themes is that dominant gendered discourse, gendered subject positions, and conscious and unconscious investments in these positions challenge the extent to which the gendered meanings that underpin adolescent learners’ sexuality are stable and fixed. The gendered discourses in the Life Orientation sexuality education programmes showed that gender is expressed rigidly, thus privileging masculine over feminine sexuality. However, the gendered discourses in the popular music contested rigid gender binaries and produced fluid and equitable masculine and feminine sexualities. The classroom practices depicted multiple and more equatable gendered sexualities, highlighting just how contested gender is. Finally, educator and learners’ personal biographies illustrated how conflicting masculine and feminine sexualities present a signficant source of emotional conflict for them. It may benefit policymakers and stakeholders to consider informal mediums of sexual socialisation for learners, such as music, when drafting the Life Orientation sexuality education curriculum, whilst also taking into account learners and educators personal lives.
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- Date Issued: 2016
The relationship between readiness to change and work engagement: a case study within an accounting firm undergoing change
- Authors: Matthysen, Megan
- Date: 2016
- Subjects: Organizational change -- South Africa Corporate culture -- South Africa Organization -- Research -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/11553 , vital:26937
- Description: Readiness to change is a critical element for the successful implementation of organisational change (Weiner, 2009). Work engagement is an important driver for organisational success (Lockwood, 2007) and it is important that organisations sustain work engagement during organisational changes. Readiness to change and work engagement are both important aspects of a successful organisation. The purpose of this study was to investigate the relationship between readiness to change and work engagement within a mid-tier accounting firm in South Africa. A combined questionnaire, incorporating two measuring instruments was utilised to gather the data for the purpose of this study. These instruments are the Organisational Change Questionnaire – Climate of Change, Process and Readiness (OCQ-C,P,R) as well as Utrecht’s Work Engagement Scale (UWES). The measuring instrument utilised demonstrated adequate reliability. By utilising the OCQ-C,P,R two additional constructs were incorporated into the study namely process of change and trust in leadership. The measuring instrument was sent electronically to all the staff members within the mid-tier accounting firm across South Africa. The researcher obtained a sample of n = 340. A model was constructed based on the measuring instrument to illustrate the hypothesised relationships between the constructs. Results from confirmatory factor analysis suggested that there was a good model fit with the data. Both descriptive and inferential statistics techniques were used for the data analysis. The relationships between the constructs were tested through structure equation modelling and Pearson’s product-moment correlation coefficients. The results of the study indicated that there is a practical and statistically significant relationship between readiness to change and work engagement. The results of the study implied that high levels of work engagement will generate high levels of readiness to change. Engaged employees are better able to cope with job demands during change processes which ultimately will impact whether change implementation is successful. Readiness to change and work engagement also indicated significant correlations with process of change and trust in leadership. Demographic groups had significant differences in the mean scores for work engagement, process of change and trust in leadership.
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- Date Issued: 2016
The effects of land use on the avifauna and its conservation in a Kenyan coastal forest ecosystem, and the significance of the Arabuko Sokoke Forest to the local community
- Authors: Chiawo, David O
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5950 , http://hdl.handle.net/10962/d1020946
- Description: This study examines the effects of land use on the bird community of Arabuko Sokoke Forest, the largest area of coastal forest remaining in East Africa and a major Important Bird Area in mainland Kenya. Bird species diversity in three land use types (primary forest, plantation and farm lands) was compared using multivariate analysis to determine the response of different feeding guilds to habitat characteristics. The effect of habitat characteristics on overall bird diversity and specific feeding guilds was tested using linear mixed models. A total of 2600 bird observations were recorded during point counts, representing 97 bird species including 25 fruit-eating birds, 17 nectar feeders; and 60 species belonging exclusively to other feeding guilds. Land use had a significant effect on overall bird diversity and abundance. The distribution of frugivorous birds was primarily influenced by the presence of fruiting trees rather than land use type, while nectarivores were significantly affected by vertical habitat heterogeneity and vegetation type. Although the distribution of insectivorous birds is influenced by many habitat factors, proximity to natural forest, habitat heterogeneity, and the presence of large trees and fruiting trees appear to be most important to this guild. The natural forest has the greatest avian diversity and a distinctive community compared to plantation and farmlands. Patterns of habitat use by birds in the area suggest that vertical vegetation heterogeneity and complexity is especially significant in sustaining diverse and abundant bird populations, if they are in close proximity to native forests. Improvement of conservation management for the plantation and farmlands is thus critical for connectivity with other remnant primary forest patches in the area. Socio-economic data was collected from 109 forest adjacent households to determine the value of the forest to the local community and their perception of conservation issues. Arabuko Sokoke Forest is important in supplementing the livelihood needs of the local community. However, the community lacks information on the forest management plan and many people have little knowledge of local birds, which could limit their capacity to participate in conservation projects. Drivers for local community participation in conservation projects are primarily a sustainable income and the fulfillment of basic household needs. Community conservation education is needed to promote local knowledge of forest biodiversity, as well as clear frameworks for the active involvement of the local community in forest management. Support of community based projects is vital to achieve both the conservation and livelihood objectives of the Arabuko Sokoke Forest management plan.
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- Date Issued: 2016
E-governance in the public sector : a case study of the central admission system in Tanzania
- Authors: Mahundu, Fabian G
- Date: 2016
- Subjects: Universities and colleges -- Tanzania -- Admission , Universities and colleges -- Tanzania -- Entrance requirements , Education, Higher -- Tanzania , Information technology -- Social aspects -- Tanzania.
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3409 , http://hdl.handle.net/10962/d1020845
- Description: This thesis sets out to answer the following central research question: what are the influences, challenges, benefits and costs of the Central Admission System (CAS) as an e-Governance initiative in improving undergraduates’ admissions service delivery and quality assurance in Tanzania’s higher education institutions?’ In answering this key question, three sub-questions were explored: (1) To what extent and in what ways does the implementation of the CAS influence the organisation of admissions work and workplace relations in higher education institutions? (2) What are the sociotechnical challenges of implementing the CAS? (3) What are the advantages of the CAS in improving admissions service delivery and quality assurance in higher education institutions? The sociotechnical theoretical framework is an ideal for exploring these issues as it accommodates the understanding of dual relationship between social and technological aspects of the CAS in line with the contextual issues in its implementation. The focus of the thesis is on Tanzania’s higher education institutions where the CAS is being implemented. The study is informed by data collected through interviews and documentary analysis. Data organization and analysis was done using NVivo 10 QSR software. The study demonstrates that, notwithstanding the fast development and uptake of Information and Communication Technologies (ICTs), the implementation of the CAS in Tanzania is hampered by the fact that most of the end-users of CAS (particularly applicants) have relatively low access to the ICT infrastructure. Several factors continue to have a significant effect on the implementation of CAS, which in turn lead to implications for the uptake of improved admissions service delivery and quality assurance. A digital divide, resistance to change by some higher education institutions (HEIs), poor ICT skills among applicants, the costs of internet services, unreliable electricity supply, and inadequate IT experts continue to frustrate the objective of improved admissions service delivery and quality assurance. As a technological innovation in the workplace, the CAS has led to a restructuring of admissions work tasks among admissions officers, a need to review job descriptions, introduced tighter controls over admission work processes, and has shaped admission workers’ professional identities and self-presentations.
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- Date Issued: 2016
An exploration of how consistently and precisely mathematics teachers code-switch in multilingual classrooms
- Authors: Chikiwa, Clemence
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2076 , http://hdl.handle.net/10962/d1021304
- Description: Many education research studies conducted in and outside South Africa encourage teachers to take advantage of the presence of multilingualism in their classrooms and to use it to the advancement of students’ conceptual learning. This study adopts the notion that code switching is a potential resource that teachers can use when teaching multilingual mathematics classes. The aim of this study is to determine how precisely and consistently selected teachers of multilingual mathematics classes code switched during teaching of trigonometry and geometry at secondary school. This study is informed by socio-cultural theory in general and Vygotsky’s work in particular. It focussed specifically on the critical role that language plays in the teaching and cognitive development of mathematics. My study situated within an interpretivist paradigm, used a case study research design and a mixed method research approach. Data were obtained through document collection, observing and interviewing three Grade 11 Mathematics teachers purposively selected from three secondary schools in Grahamstown and King Williamstown education districts of the Eastern Cape Province, South Africa. Data were quantitatively and qualitatively analysed. Findings from this study revealed that the frequency of code switching was not consistent across teachers, topics and lessons. Teachers taught predominantly in the public domain exposing students to compromised mathematical content through their code switching practices. Borrowing code switching was prevalently employed consistently across the participating teachers. Very little transparent code switching, from mainly those mathematical terms commonly used in the foundation and the intermediate phases, was evident in teacher language. No Grade 11 trigonometry and geometry terms in isiXhosa were transparently and consistently code switched. The data suggested that while precision was observed in some cases, it was not consistent. Inconsistencies were caused by lack of planning for code switching, lack of teaching materials in indigenous languages, selective code switching, and ‘safe mode’ code switching strategies which affected teachers’ pedagogical practices. Overall results in this study illustrate that the lack of planning for code switching and the lack of explicit policies and clear-cut official positions on code switching for teaching has contributed to inconsistent and imprecise code switching by the participating teachers. This study concludes that the development of supporting mechanisms, identifying and documenting best practices to encourage transparent, meaningful and beneficial code switching is urgently required to aid and promote conceptual understanding of strongly bounded sub-registers of secondary school mathematics such as trigonometry and geometry. It is anticipated that this study will contribute significantly to the ongoing debate on language use in education and to the institution of best practices for judicious, consistent and precise use of students’ home language during the teaching of mathematics in South Africa.
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- Date Issued: 2016
The relationship between leaders’ emotional intelligence and followers’ motivational behaviour and organisational commitment
- Authors: Chipumuro, Juliet
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/484 , vital:19963
- Description: Over the past few years, emotional intelligence (EI) has generated significant interest and a wealth of research as a possible area of insight into what determines outstanding performance in the workplace (Ashworth, 2013:8; Pillay, Viviers and Mayer, 2013:1). The internal environment of organisations in the labour-intense hospitality industry is complex and dynamic. Given the unpredictability of change, the researcher found the hospitality industry to be an intriguing milieu within which to ascertain the importance of EI in predicting leaders’ effectiveness as a measure of outstanding performance. As employees are the internal customers of any hotel organisation, representing many hotel organisations’ only true competitive advantage, the purpose of this quantitative investigation was to examine the relationship between leaders’ EI and followers’ motivational behaviour and organisational commitment. Despite the intuitive plausibility of the assumption that leaders who exhibit EI competencies contribute to outstanding performance, the issue of followers’ motivational behaviour and organisational commitment as leadership indices has received little empirical attention. This study sets out to integrate prior findings on EI, motivation and organisational commitment, to support these findings in literature, and to incorporate these findings into a comprehensive conceptual framework. Using critical realists’ post-positivistic philosophical assumptions, the researcher used the Emotional and Social Competencies Inventory (ESCI) to assess leaders’ EI. Furthermore, the Motivational Sources Inventory (MSI) was used to assess followers’ motivational behaviour, while Organisational Commitment Scales (OCS) were used to assess followers’ organisational commitment. The survey respondents consisted of 120 leaders and 435 followers from 13 hotels in four prominent hotel groups in South Africa. The quantitative data collected from the surveys was analysed quantitatively using SPSS to reach substantial results with inferences. The analysis of variance revealed an overall positive relationship between demographic variables and Leaders EI, followers’ motivational behaviour and followers’ organisational commitment. The correlational analysis revealed positive relationships between leaders’ EI and followers’ motivational behaviour and organisational commitment (R= 0.05-, p<0.01) except for instrumental motivation. The correlation between leaders’ emotional self-awareness and followers’ intrinsic process motivation was somewhat weak while the relationship between leaders’ emotional self-awareness and instrumental motivation was found to be sufficient, but statistically not significant. The researcher can conclude that generally the results of this study reveal that organisational leaders can positively influence the motivational behaviour and organisational commitment of their followers by enhancing their own EI competencies. The results add to the leadership literature by illuminating possible antecedents to leadership effectiveness. It is believed that this research will help the hospitality industry at large in clarifying the importance of EI competencies in leadership as a means of obtaining positive motivation behaviour and commitment from followers. Furthermore, the findings have both managerial and research implications for hospitality operations strategy formulation in order to gain competitive advantage and improve the financial position of the businesses.
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- Date Issued: 2016