A framework to enhance the mobile user experience in an Mlearning interaction
- Authors: Botha, Adele
- Date: 2011
- Subjects: Educational technology , Information technology , Educational innovations , Teaching -- Aids and devices
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9753 , http://hdl.handle.net/10948/d1008163 , Educational technology , Information technology , Educational innovations , Teaching -- Aids and devices
- Description: The new millennium is witness to a telecommunications world that is vastly different from even the recent past with developments in the mobile sector having dramatically changed the Information and Communication Technology (ICT) landscape. Mobile cellular technology has proliferated faster than any previous technology and is now the most ubiquitous technology in the world. The focus of this thesis is the development of a framework to enhance the Mobile User Experience in an Mlearning interaction. This research is contextualised by the goal-oriented use of mobile cellular technologies in a formal educational environment. As such the study, although residing in the field of Human-Computer Interaction (HCI), acknowledges issues arising in the Education Domain as a specific field of application. The aim of the research was to investigate the components of a framework to enhance the Mobile User Experience in an Mlearning interaction. The development of the framework was facilitated by the exploration of: the Mobile User Experience factors and their impact, on the Mobile User Experience of learners participating in a goal-oriented Mlearning interaction. These critical factors were documented in terms of the Mobile User Experience components, and the relationships of these components to each other as well as the Mobile User Experience of an Mlearning interaction. The research, grounded in a phenomenological research philosophy, applied an inductive reasoning approach, and was operationalised through a single case study methodology. A qualitative research strategy was considered appropriate, as the phenomenon of User Experience is linked to the hedonistic attributes of the interaction. This study was conducted in four phases with focus on three embedded units of analysis. The three units of analysis were identified as: The learner as end user in an Mlearning interaction; The educator as designer of the Mlearning interaction; and The Mlearning interaction. The research revealed that the Mobile User Experience of an Mlearning interaction is affected by the mobile user, mobile use, mobile device, mobile business practices, mobile networks, mobile interaction and mobile context. Within the Mlearning interaction the significant components are the learners as mobile users, the enhance interactions, removal of barriers to the interaction, goal-oriented nature of the interaction and the ducational context. Identifying these components and their associated Mobile User Experience factors and impacts, present the main contribution of this thesis. In conclusion, the limitations of the study are documented and topics for future research are outlined.
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- Date Issued: 2011
An intervention for enhancing the mathematics teaching practices of grade four teachers in the Nelson Mandela Metropolitan area
- Authors: Botha, Adele
- Date: 2011
- Subjects: Mathematics -- Study and teaching , Mathematics , Mathematics -- Handbooks, manuals, etc , Mathematics teachers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9499 , http://hdl.handle.net/10948/d1008176 , Mathematics -- Study and teaching , Mathematics , Mathematics -- Handbooks, manuals, etc , Mathematics teachers
- Description: Mathematics is regarded as a driving force in economies worldwide. The performance of South African learners in mathematics over the past decade has highlighted that problems are being experienced across all grades. This situation needs to be addressed with urgency. The South African Department of Education stated that quality learning must be the objective for all grades. The implementation of good teaching practices plays a crucial role in improving the quality of education and in guiding learners towards quality learning. To achieve quality mathematics teaching and learning it is imperative to determine what good mathematics teaching practices are. The identification of good mathematic teaching practices will provide a yard stick to measure the mathematics teaching competency of teachers. This study identifies a set of good mathematics teaching practice indicators and evidences applicable to teachers in the Intermediate phase as a first contribution. These indicators and evidences frame the second research contribution: an assessment instrument entitled “A Classroom Observation Tool for Observing Mathematics Teaching Practices in Primary Schools”. As a third research contribution a generic profile of a Grade four mathematics teacher has been built. This generic profile has been built through an analysis of data gathered by means of self-assessment questionnaires completed by the research sample, as well as through applying the observation tool. The value of the generic profile lies in the identification of shared strengths and shared improvement opportunities in the mathematics teaching practice of the sample and as such, it forms the basis of a theory on Grade four mathematics teaching practice. The fourth research contribution is the design and application of an intervention that addresses the shared improvement opportunities. The research study concludes by comparing pre-intervention classroom observation data with post-intervention classroom observation data and reporting on the impact of the intervention.
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- Date Issued: 2011
Die outobiografiese kode in Antjie Krog se poëtiese oeuvre
- Authors: Botha, Maria Elizabeth
- Date: 2011
- Subjects: Krog, Antjie -- Criticism and interpretation , Autobiography -- History and criticism , Afrikaans poetry -- 20th century -- History and criticism
- Language: Afrikaans
- Type: Thesis , Doctoral , DLitt
- Identifier: vital:8444 , http://hdl.handle.net/10948/1534 , Krog, Antjie -- Criticism and interpretation , Autobiography -- History and criticism , Afrikaans poetry -- 20th century -- History and criticism
- Description: This study primarily investigates the autobiographical code in Antjie Krog's poetical oeuvre, spanning from 1970 to the present. Krog's poetry collections may be read as offering life writing through poetry, while the prose works mostly present the reader with a mixture of autobiographical fact plus creative reworkings of fact and fiction. Even though her 10 volumes of poetry follow her biological development from young girl to grandmother, uncertainty still exists about about where truth ends and fiction begins in this poet and autobiographer's interwoven tapestry of multiple and varied perspectives. Furthermore, autobiographical (as utilised and adapted in Krog's oeuvre, in combination with the conventioans from other genres), offers a variety of creatively innovative, experimental strategies and possibilities exploited adroitly by Krog. Reading her poetry with the focus on autobiographical markers leads to another, mostly untapped, dimension of interpretation. This literary approach is in stark contrast to the approach prescibed by N.P. van Wyk Louw in "Die 'mens' agter die boek" ["The 'Person' behind the Book] (1956), in which he states clearly that a text should be interpreted as not "about the human behind the text". To a large extent Krog as poet is inviting the reader to consciously break the taboo that Louw placed on the reader intent on "searching the actual person behind the text". My hypothesis is that in Krog's poetry there is a distinct interrelationship between the perceptions, experiences and sensual impressions of the lyrical "I" in the poems and that of the authobiographical "I" writing. It would be irresponsible to declare the poet and the speaker as one and the same, but in instances where the poet purposefully integrates autobiographical elements into her poems, she is implicitly requesting the reader to interpret her work in this way. This fictive and implicit request is referred to by Philippe Lejeune as the autobiographical poet. Krog's poetry can be divided into four categories: "direct autobiographical", "indirect autobiographical", "universal" and "general" poems. The first category involves criteria that are linked to the poet, such as the use of the names, initials and dates. Indirect autobiographical poems can be read against the background of knowledge (previously published information) about the poet. Poetry with no apparent autobiographical element, but with universal themes such as love, loss and transience, fall into the third category of "universal" poetry. If poems do not fit into the mentioned categories, they are deemed "general".
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- Date Issued: 2011
Maintenance of university facilities in developing countries
- Authors: Bowazi, Kenneth Mtunduwatha
- Date: 2011
- Subjects: College facilities -- Developing countries , Educational planning -- Developing countries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9723 , http://hdl.handle.net/10948/d1008472 , College facilities -- Developing countries , Educational planning -- Developing countries
- Description: Universities in developing countries are deteriorating physically due to lack of planned maintenance, lack of maintenance policies in the institutions, lack of up-to-date security system, and also lack of qualified personnel at decision-making level. Lack of planning leads to reactive maintenance. It also leads to unbudgeted expenditure and has an impact on the amount of money allocated to maintenance which results in unavailability of funds to carry out maintenance duties. Institutions which have no maintenance policy lack guidelines to follow when a maintenance problem arises. Most personnel in charge of maintenance are junior management or at supervisory level as a result they are not part of middle management that strategically directs the organisation. Most of the decisions made at supervisory scale are easily overruled at management level where the maintenance manager is not present during meetings to motivate maintenance cases. Lack of efficient security also allows vandalism to rise which contributes to the deterioration of facilities. Universities lack creativity and cost management skills to raise its own funds to supplement the maintenance budget, which is largely funded by the government. This study recommends employment of built environment professionals in decision-making positions. It also recommends that organizations should have a maintenance policy in place. Investment should be made in good security systems and management of the facilities should include income generating activities that could subsidise the maintenance budget.
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- Date Issued: 2011
Economic impact studies and methodological bias : the case of the National Arts Festival in South Africa
- Authors: Bragge, Brent Reuben
- Date: 2011
- Subjects: Standard Bank National Arts Festival Standard Bank National Arts Festival -- Economic aspects Performing arts festivals- Economic aspects -- South Africa Arts -- Economic aspects -- South Africa Economic impact analysis Edinburgh International Festival -- Economic aspects Klein Karoo Nasionale Kunstefees (Oudtshoorn, South Africa) -- Economic aspects Volksbladfees (Bloemfontein, South Africa) -- Economic aspects
- Language: English
- Type: Thesis , Masters , MEcon
- Identifier: vital:968 , http://hdl.handle.net/10962/d1002702
- Description: Over the course of the last three decades, it has become popular practice to evaluate tourism events like cultural festivals in financial terms, through the use of economic impact studies. This can be attributed at least in part to the notable growth in the number of festivals being held globally and, as such, a higher level of competition between festivals for the limited funding which is available. Economic impact studies, and the resultant findings, have thus become powerful tools for the lobbying of sponsorship, and it has become increasingly important that the impact calculations be as accurate as possible, so as to effectively allocate both government and private resources to projects which will be of the greatest benefit to the host region. The allocation of funding is especially vital in an area like the Eastern Cape Province of South Africa, which is faced with many financial difficulties. The allocation of public funds to an event like the National Arts Festival, which is hosted in a relatively wealthy part of the province, might be weighed against initiatives which directly benefit the poorer parts of the region. Although it is acknowledged that the benefits which are felt by the host community of a cultural event go beyond that of the financial, it is often on this basis that festivals are most easily compared. The primary goal of the thesis was to analyse the various forms of methodological bias which can exist in the economic impact analyses (EIA) associated with cultural events. Theoretical considerations were discussed, specifically regarding economic impact as a method of measuring value. Various forms of bias (including data collection, the calculation of visitor numbers, multipliers, defining the area of interest, inclusion of visitor spending, and accounting for benefits only, not costs) are put into a real-life context, through the investigation of economic impact studies conducted on three selected South African festivals (the Volksblad, the Klein Karoo Nasionale Kunstfees, and the National Arts Festival), and one international festival (the Edinburgh Festival). An in-depth comparison of two separate studies conducted at the National Arts Festival (NAF) in 2004 (by Antrobus and Snowball) and 2005 (by Saayman et al.) was made, focussing on the manner in which the economic impact was calculated. Having considered the common forms of bias, and assessing several possible reasons for the difference of approximately twenty million Rand in the advertised economic impacts, it was concluded that, most likely, the miscalculation of visitor numbers was the cause. This was confirmed when the Antrobus and Saayman methods were applied to the 2006 NAF data, and noting that the economic impact figures arrived at were strikingly similar. As such, it is advisable that extreme caution be taken when calculating visitor numbers, as they can significantly influence the outcome of an economic impact study. It is recommended that each study should also have transparent checks in place, regarding the key calculation figures, to ensure that less scrupulous researchers are not as easily able to succumb to the pressure event sponsors might impose to produce inflated impact values.
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- Date Issued: 2011
Nanomaterial modified electrodes : optimization of voltammetric sensors for pharmaceutical and industrial application
- Authors: Brimecombe, Rory Dennis
- Date: 2011
- Subjects: Voltammetry , Electrochemistry , Nanotubes , Nanostructured materials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4101 , http://hdl.handle.net/10962/d1009721
- Description: Nanomaterials, in particular carbon nanotubes have been shown to exhibit favourable properties for the enhancement of electrochemical detection of target analytes in complex matrices. There is however scope for improvement in terms of the optimization thereof in electrochemical sensors surface modification. The aim of this thesis was to examine methods that would result in increased current response, lowered passivation and application of such modified surfaces with application to pharmaceutically and industrially relevant analytes. Current methods for enhancing the performance of carbon nanotubes include acid functionalization which not only increases the hydrophilicity of the nanotubes, and consequently their ability to provide stable (aqueous) suspensions, but also introduces electrochemically active sites. This particular approach is however not normalized in the literature. Over-exposure to acid treatment results in loss of structural integrity of the carbon nanotubes, and as such a fine balance exists between achieving these dual outcomes. Guided by high resolution scanning electron microscopy, atomic force microscopy, voltammetric and impedance studies, this thesis examined the role of the length of time of the acid functionalization process as well as the impact of activation of carbon nanotubes and fullerenes on electrochemical sensor performance. Based on desired charge transfer resistances, rate transfer coefficients and sensitivity towards redox probes the optimal length of acid functionalization for multiwalled carbon nanotubes was 9 hours and 4 hours for single-walled carbon nanotubes. Further improvements in the desired outcomes were achieved through electrochemical activation of the modified electrode surface by cycling in the presence of catechol, in a novel approach. By employing electrochemical impedance spectroscopy it was observed that catechol activation resulted in lowered charge transfer resistance, before and after activation, with functionalized multi-walled carbon nanotubes (9 hours) exhibiting the greatest decrease of 90 % and functionalized single-walled carbon nanotubes (4 hours), a 50 % decrease. Corresponding increases in the heterologous rate transfer coefficient showed a 770 % increase for functionalized multi-walled carbon nanotubes (9 hours), following catechol activation. Comparative observations for fullerenes following partial reduction in potassium hydroxide yielded a 30 % decrease in charge transfer resistance, with an increased heterologous rate transfer coefficient at a fullerene modified surface The performance of the nanomaterial modified electrodes was applied to the detection of wortmannin with applications in bioprocess control and in the pharmaceutical sector as well as to the detection and monitoring of the industrial dye Reactive red. Of particular relevance to these analytes was the assessment of the nanomaterial modified electrodes for enhanced stability, reproducibility, sensitivity and decreased passivation effects. In this study the first known account of wortmannin detection through electrochemical methods is reported. Voltammetric characterization of wortmannin revealed an irreversible cathodic process with a total number of 4 electrons and a diffusion coefficient of 1.19 x 10-7 cm².s⁻¹. At a functionalized multiwalled carbon nanotubes modified glassy carbon electrode a limit of detection of 0.128 nmol.cm⁻³ was obtained, and with limited surface passivation the detection scheme afforded pertinent analyses in biological media representing a substantial improvement over chromatographic detection methods. This study also provided the first account of the voltammetric detection of reactive red, competing favourably with traditional spectroscopic methods for monitoring biodegradation of this compound in real time.
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- Date Issued: 2011
Optical limiting behavior of ring substituted zinc, indium and gallium phthalocyanines in the presence of quantum dots
- Authors: Britton, Jonathan , Litwinski, Christian , Durmus, Mahmut , Chauke, Vongani , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247122 , vital:51548 , xlink:href="https://doi.org/10.1142/S1088424611004142"
- Description: This paper presents the study of the effects of CdTe-TGA quantum dots (QDs) on optical limiting ability of different phthalocyanine (Pc) complexes (1–10) containing Zn, Ga, In central metals and substituted with benzyloxyphenoxy, phenoxy, tert-butylphenoxy and amino groups. The optical limiting parameters of Pcs were higher for tert-butylphenoxy when compared to benzyloxyphenoxy and phenoxy substituents, in DMSO. Non-peripheral substitution decreased the optical limiting parameters. Third-order susceptibility (Im[χ(3)]/α) values of Pcs in the absence and presence of CdTe QDs were in the 10-12 to 10-10 esu.cm range. Hyperpolarizabilities (γ) ranged from 10-31 to 10-29 esu L for Pc alone or in mixture with QDs. There is a general improvement in optical limiting ability of Pc complexes in the presence of CdTe TGA QDs. Due to these promising results, future work can be implemented for the creation of Pc:QD thin films, which would then be examined to ensure that their optical limiting ability is still acceptable.
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- Date Issued: 2011
Adventures with abalone : aquaculture, poaching, and fishery restoration
- Authors: Britz, Peter Jacobus, 1959-
- Date: 2011
- Language: English
- Type: Text
- Identifier: vital:583 , http://hdl.handle.net/10962/d1018943
- Description: [From the text] Tonight I am going to tell you about my research on a another mollusc, the humble abalone. - In contrast with the highly evolved squid, this marine snail belonging to the ancient archeogastrod lineage which has a much simpler anatomy and lifestyle. It doesn’t posses a proper brain mass, only having 4 ganglia or nerves knots at the front end. Its two simple eye spots which detect light and dark, a tough shell and a large and extremely powerful foot muscle to adhere to rocks. This simple configuration has served well for over 100 million years.
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- Date Issued: 2011
Studies in South African marine molluscan chemistry
- Authors: Bromley, Candice Leigh
- Date: 2011
- Subjects: Mollusks -- South Africa , Marine invertebrates -- South Africa , Marine metabolites -- South Africa , Chemical oceanography -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4356 , http://hdl.handle.net/10962/d1005021
- Description: This thesis investigates the variability occurring in the secondary metabolites produced by three South African marine molluscs. Chapter Two discusses the isolation and spectroscopic structure elucidation of the metabolites isolated from two Siphonaria species. The re-investigation of Siphonaria capensis yielded siphonarienfuranone (2.2) as the only common polypropionate isolated from both the 1998 and 2009 collections of S. capensis from the same areas suggesting possible seasonal or genetic variation in polypropionate production. The sterol cholest-7-en-3,5,7- triol (2.33) was also isolated form the 2009 collection of S. capensis and this is the first time this compound has been isolated from a Siphonaria species. The second species, Siphonaria oculus is closely related to S. capensis and the investigation into the former’s secondary metaboliteproduction revealed 2.2 as a major metabolite suggesting an inter-species overlap in polypropionate production. Three new polypropionate metabolites, 2.35, 2.36 and 2.37 were also isolated from S. oculus. An unsuccessful attempt was made to establish the absolute configuration of 2.37 using the modified Mosher’s method and the limited amount of 2.37 available prevented any further attempts at resolving the absolute configuration of this compound. The 1H NMR analysis of the defensive mucus collected directly from S. oculus revealed the presence of the acyclic polypropionate 2.37 as a minor metabolite. The absence of characteristic signals for the furanone containing compounds 2.2, 2.35 and 2.36, might suggest that these compounds cyclise from a hypothetical acyclic precursor (2.38) during standard work up of bulk acetone extracts of Siphonaria species. Chapter Three discusses the re-isolation and spectroscopic structure elucidation of the metabolites isolated from the nudibranch, Leminda millecra. Three known natural products, millecrone A (3.1), 8-hydroxycalamenene (3.6) and cubebenone (3.8) were re-isolated from our 2010 collection of L. millecra, as well as the new minor metabolite 8-acetoxycalamenene (3.16). The cytotoxic prenylated toluquinones and toluhydroquinones (3.9-3.15) initially isolated from the 1998 collection of L. millecra were not found in the 2010 collection supporting the hypothesis that these compounds may be of fungal origin. L. millecra clearly shows variability in the compounds sequestered by this species with millecrone A (3.1) being the only common metabolite in the three investigations of L. millecra to date. An unsuccessful attempt was made to establish the absolute configuration of 3.1, 3.6 and 3.8 through initial LAH reduction of the ketone moiety contained in 3.1 and 3.8 and esterification of the resultant diastereomeric alcohol mixtures and the phenol functionality in 3.6 with (1S)-camphanic chloride. Crystallisation of the (S)- camphanate esters of 3.6 and 3.8 for X-ray analysis were unsuccessful, while the unexpected conjugate addition of a hydride in 3.1 resulted in complex diastereomeric mixtures which could not be separated by HPLC.
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- Date Issued: 2011
Intimate masculinities in the work of Paul Emmanuel
- Authors: Bronner, Irene Enslé
- Date: 2011
- Subjects: Emmanuel, Paul, 1969- Masculinity in art Identity (Psychology) in art Gender identity in art Art, South African -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2397 , http://hdl.handle.net/10962/d1002193
- Description: Paul Emmanuel is a South African artist who produces incised drawings, outdoor installations and prints (particularly intaglio etchings and manière noire lithographs). These focus on the representation of male bodies and experience. Having begun his career as a collaborative printmaker, since 2002, his work has become more ambitious as well as critically acclaimed. In 2010, his most recent body of work, Transitions, was exhibited at the Smithsonian Museum of African Art in Washington D.C. I propose that Emmanuel represents the male body as a presence that either is not easily seen or that actively disappears or erases itself. Its subjectivity, and the viewer’s engagement with it, may be characterised as one of intimacy, exposure, loss and vulnerability. Emmanuel’s work may be said to question conventions and ideals of masculinity while, at the same time, refusing any prescriptive interpretation. To develop this proposition, I examine specifically Emmanuel’s incising drawing technique that ‘holds open’ transitions in male lives. In these liminal moments, Emmanuel represents men as ‘seen’ to change state or status, thereby exposing the ongoing process of building masculine identities. Equally elucidatory is Emmanuel’s imprinting of his own body, which, in his use of “traces” that reveal the vacillation between presence and absence, makes contingently ‘visible’ this gendering process, and has particular implications for the expression of subjectivity in a contemporary South African context.
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- Date Issued: 2011
Synthesis of bromochloromethane using phase transfer catalysis
- Authors: Brooks, Lancelot L
- Date: 2011
- Subjects: Chemistry, Analytic , Fire extinguishing agents , Chemical systems , Physical science
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10382 , http://hdl.handle.net/10948/d1008162 , Chemistry, Analytic , Fire extinguishing agents , Chemical systems , Physical science
- Description: The synthesis of bromochloromethane (BCM) in a batch reactor, using phase transfer catalysis, was investigated. During the synthetic procedure, sodium bromide (100.0g, 0.97mol) along with an excess amount of dichloromethane (265.0g, 3.12 mol) was charged to a reactor containing benzyl triethylammonium chloride (13 mmol), dissolved in 50 ml of water. The bench scale reactions were all carried out in a Parr 4520 bench top pressure reactor coupled to a Parr 4841 temperature controller. The method produced a 50.0 percent yield of the product BCM after a reaction time of 12 to 13 hours. The main objective for this investigation was to optimize the abovementioned reaction with respect to yield and reactor throughput. Quantitative analysis of BCM was performed on a Focus Gas Chromatograph, fitted with a flame ionization detector, and a BP20 column (30m × 0,32mm ID × 0,25 mm). Delta software, version 5.0, was applied for data collection and processing. The injector and detector port were set at 250°C and 280°C, respectively. The oven temperature was set and held at 40°C for a period of 2 minutes, then gradually increased at a rate of 10°C/min to 130°C, with the final hold time set for 1 minute. An analytical method for the quantitative analysis of BCM was developed, optimized and validated. Validation of the analytical method commenced over a period of three days, and focussed the following validation parameters: Accuracy, precision, and ruggedness. Statistical evaluation of the results obtained for precision showed that the error between individual injections is less than 2 percent for each component. However, ANOVA analysis showed a significant difference between the mean response factors obtained in the three day period (p-value < 0.05). Thus we could conclude that the response factors had to be determined on each day before quantitatively analyzing samples. The accuracy of the analytical method was assessed by using the percent recovery method. Results obtained showed that a mean percent recovery of 100.18 percent was obtained for BCM, with the absolute bias = 0.0004, and the percent bias = 0.18 percent. Hence the 95 confidence intervals for the percent recovery and percent bias are given by: (Lz, Uz) = (100.56 percent percent 102.15 percent), 13 (LPB, UPB) = (0.56 percent, 2.15 percent), respectively. Since the 95 percent confidence interval for the percent recovery contains 100, or equivalently, the 95 percent confidence interval for percent bias contains 0, the assay method is considered accurate and validated for BCM. In the same manner the accuracy and percent recovery for DCM and DBM was evaluated. The method was found to be accurate and validated for DBM, however, slightly biased in determining the recovered amount of DCM. With the analytical method validated, the batch production process could be evaluated. A total of six process variables, namely reaction time, water amount, temperature, volume of the two phases, stirring rate, and catalyst concentration, were selected for the study. The effects of the individual variables were determined in the classical manner, by varying only the one of interest while keeping all others constant. The experimental data generated was fit to a quadratic response surface model. The profile plots that were obtained from this model allowed a visual representation of the effect of the six variables. The experimental results obtained showed that the reaction follows pseudo zero-order kinetics and that the rate of the reaction is directly proportional to the concentration of the catalyst. The reaction obeys the Arrhenius equation, and the relatively high activation energy of 87kJ.mol -1 signifies that the rate constant is strongly dependent on the temperature of the reaction. The results also showed that the formation of BCM is favoured by an increase in the reaction temperature, catalyst concentration, and a high organic: aqueous phase ratio. Thus the synthesis of BCM using phase transfer catalyst could be optimised, to obtain a 100 percent yield BCM, by increasing both the reaction temperature to 105°C, and the concentration of the phase transfer catalyst -benzyl triethylammonium chloride - to 5.36 mol percent. The reaction time was also reduced to 6 hours.
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- Date Issued: 2011
The implementation of the arts and culture learning area in previously disadvantaged schools in the Nelsona Mandela Bay area : teacher experiences
- Authors: Browne, Elaine
- Date: 2011
- Subjects: Arts -- Study and teaching (Primary) , Culture -- Study and teaching , Teachers -- Training of -- Curricula
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9484 , http://hdl.handle.net/10948/1407 , Arts -- Study and teaching (Primary) , Culture -- Study and teaching , Teachers -- Training of -- Curricula
- Description: Inherent to post‐apartheid educational transformation was the design and subsequent implementation of a new national school curriculum. The current curriculum‐in‐use, namely the National Curriculum Statement (NCS) comprises eight compulsory learning areas. One of these learning areas, Arts and Culture, aims to equip learners with skills and knowledge with regard to four distinct arts disciplines, namely music, dance, drama and visual art. In the General Education and Training Band (GET) phase, general classroom teachers are expected to implement this highly specialised learning area. This research aimed to determine how teachers employed at Nelson Mandela Bay primary schools were disadvantaged during the apartheid era, experience the implementation of arts education. Focus group interviews were conducted at schools situated in the low socio‐economic areas. The results revealed that, despite their profound awareness of the unique advantages of arts education for the learners, several impediments hampered the successful attainment of its value. The obstacles highlighted by the teachers were the curriculum itself, teaching and learning environments that are not conducive for arts education, and unsatisfactory involvement of the Department of Education.
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- Date Issued: 2011
Unitarity constraints on the ratio of shear viscosity to entropy density in higher derivative gravity
- Authors: Brustein, R , Medved, A J M
- Date: 2011
- Language: English
- Type: text , Article
- Identifier: vital:6815 , http://hdl.handle.net/10962/d1004325
- Description: We discuss corrections to the ratio of shear viscosity to entropy density η/s in higher-derivative gravity theories. Generically, these theories contain ghost modes with Planck-scale masses. Motivated by general considerations about unitarity, we propose new boundary conditions for the equations of motion of the graviton perturbations that force the amplitude of the ghosts modes to vanish. We analyze explicitly four-derivative perturbative corrections to Einstein gravity which generically lead to four-derivative equations of motion, compare our choice of boundary conditions to previous proposals and show that, with our new prescription, the ratio η/s remains at the Einstein-gravity value of 1/4π to leading order in the corrections. It is argued that, when the new boundary conditions are imposed on six and higher-derivative equations of motion, η/s can only increase from the Einstein-gravity value. We also recall some general arguments that support the validity of our results to all orders in the strength of the corrections to Einstein gravity. We then discuss the particular case of Gauss-Bonnet gravity, for which the equations of motion are only of two-derivative order and the value of η/s can decrease below 1/4π when treated in a nonperturbative way. Our findings provide further evidence for the validity of the KSS bound for theories that can be viewed as perturbative corrections to Einstein gravity.
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- Date Issued: 2011
Evaluating the Wald entropy from two-derivative terms in quadratic actions
- Authors: Brustein, R , Gorbonos, D , Hadad, M , Medved, A J M
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6816 , http://hdl.handle.net/10962/d1004326
- Description: We evaluate the Wald Noether charge entropy for a black hole in generalized theories of gravity. Expanding the Lagrangian to second order in gravitational perturbations, we show that contributions to the entropy density originate only from the coefficients of two-derivative terms. The same considerations are extended to include matter fields and to show that arbitrary powers of matter fields and their symmetrized covariant derivatives cannot contribute to the entropy density. We also explain how to use the linearized gravitational field equation rather than quadratic actions to obtain the same results. Several explicit examples are presented that allow us to clarify subtle points in the derivation and application of our method.
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- Date Issued: 2011
Non-perturbative unitarity constraints on the ratio of shear viscosity to entropy density in ultraviolet-complete theories with a gravity dual
- Authors: Brustein, R , Medved, A J M
- Date: 2011
- Language: English
- Type: text , Article
- Identifier: vital:6817 , http://hdl.handle.net/10962/d1004327
- Description: We reconsider, from a novel perspective, how unitarity constrains the corrections to the ratio of shear viscosity η to entropy density s. We start with higher-derivative extensions of Einstein gravity in asymptotically anti-de Sitter spacetimes. It is assumed that these theories are derived from string theory and thus have a unitary UV completion that is dual to a unitary, UV-complete boundary gauge theory. We then propose that the gravitational perturbations about a solution of the UV-complete theory are described by an effective theory whose linearized equations of motion have at most two time derivatives. Our proposal leads to a concrete prescription for the calculation of η/s for theories of gravity with arbitrary higher-derivative corrections. The resulting ratio can take on values above or below 1/4π and is consistent with all the previous calculations, even though our reasoning is substantially different. For the purpose of calculating η/s, our proposal also leads to only two possible candidates for the effective two-derivative theory: Einstein and Gauss-Bonnet gravity. The distinction between the two is that Einstein gravity satisfies the equivalence principle, and so its graviton correlation functions are polarization-independent, whereas the Gauss-Bonnet theory has polarization-dependent correlation functions. We discuss the graviton three-point functions in this context and explain how these can provide additional information on the value of η/s.
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- Date Issued: 2011
Psychofortology of adults recovering from substance-use disorders
- Authors: Bubb, Tanielle Carmen
- Date: 2011
- Subjects: Substance-related disorders -- Therapy , Substance abuse -- Treatment , Substance abuse
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9870 , http://hdl.handle.net/10948/d1008117 , Substance-related disorders -- Therapy , Substance abuse -- Treatment , Substance abuse
- Description: Evaluating the psychofortology of adults recovering from a substance-use disorder has been identified as a research priority in South Africa. This is in line with calls from researchers in diverse fields of psychology for more attention to the resilience, strengths, resources and capacities of people. This study therefore aimed to explore and describe the coping resources, sense of coherence, happiness and satisfaction with life of adults recovering from a substance-use disorder within the Nelson Mandela Metropole. The sample consisted of 99 voluntary participants from various managed recovery centres within the Nelson Mandela Metropole. Participants were given a package of questionnaires to complete under the supervision of the researcher. The assessment consisted of a biographical questionnaire and four standardized paper and pencil measures namely; the Coping Resources Inventory (CRI), the Sense of Coherence Scale (SOC-29), the Affectometer 2 (AFM-2) and the Satisfaction with Life Scale (SWLS). A quantitative, non-experimental exploratory-descriptive research method was used. Data was analysed using descriptive statistics and the Pearson product-moment correlation coefficient. Key findings include the following: Results on the CRI revealed low average mean scores on both the Coping Resources Inventory and within all the five subscales. Results of the SOC-29 revealed a high average mean score for sense of coherence. Results of the AFM-2 revealed that more positive affect than negative affect is present, resulting in happiness. Results of the SWLS revealed an average level of satisfaction with life, with most participants’ reporting neutral levels of satisfaction with life. There were significant positive correlations between the coping resources, sense of coherence, happiness and satisfaction with life of the sample. This implies that these constructs can be categorized under the subdiscipline of psychofortology. Overall, these findings emphasized the need for more research into adults recovering from a substance-use disorder.
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- Date Issued: 2011
Fictional representations of trauma in Elias Canetti’s novel Auto-da-Fé
- Authors: Buczynski, Jennifer Ann
- Date: 2011
- Subjects: Violence in literature , Literature and society , Fictitious characters
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8447 , http://hdl.handle.net/10948/d1008062 , Violence in literature , Literature and society , Fictitious characters
- Description: This dissertation examines Elias Canetti‟s novel, Auto-da Fé, in an attempt to show how it depicts the manifestations of violence and the effects of traumaon the individual and on modernist society. This analysis of Auto-da Fé concentrates on the representation of trauma on a fictional level at a time when Europe was experiencing political, social and economic upheaval after the First World War. Auto-da Fé provides an intense emphasis on the psychological effects of trauma on the characters; thereby reflecting the turmoil of this period. An analysis of Canetti‟s novel, in the light of trauma, reveals an enigmatic testimony not only to the nature of violent events, but of the way trauma resists simple comprehension. I argue that this gives rise to complexities within the narration by tracing the insistently recurring words and symbols which point to an interpretation beyond the thematic content of the text, namely one which repetitively bears witness to hidden wounds within individual consciousness. The titles of the three parts of Auto-da-Fé reflect a condition of somatic and sychosomatic dislocation: “A Head without a World”, “Headless World”, and “The World in the Head”. My argument is that the fictional trauma in Canetti‟s novel contains several characters who suffer from a breach of the self and the inability to comprehend society. The inability to fit into society results in the protagonist creating an isolated refuge in order to protect himself from the outer world. However, his alienation exacerbates his physical and emotional dislocations and ultimately leads to his destruction.
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- Date Issued: 2011
A short composition portfolio
- Authors: Buitendag, Kingsley Alexander
- Date: 2011
- Subjects: Music -- South Africa Composition (Music)
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: vital:2632 , http://hdl.handle.net/10962/d1002297
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- Date Issued: 2011
Preparation and evaluation of Lignocellulose-Montmorillonite nanocomposites for the adsorption of some heavy metals and organic dyes from aqueous solution
- Authors: Bunhu, Tavengwa
- Date: 2011
- Subjects: Lignocellulose , Lignocellulose -- Biodegradation , Water -- Purification , Adsorption , Separation (Technology) , Dyes and dyeing , Montmorillonite
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11333 , http://hdl.handle.net/10353/535 , Lignocellulose , Lignocellulose -- Biodegradation , Water -- Purification , Adsorption , Separation (Technology) , Dyes and dyeing , Montmorillonite
- Description: The need to reduce the cost of adsorption technology has led scientists to explore the use of many low cost adsorbents especially those from renewable resources. Lignocellulose and montmorillonite clay have been identified as potentially low cost and efficient adsorbent materials for the removal of toxic heavy metals and organic substances from contaminated water. Montmorillonite clay has good adsorption properties and the potential for ion exchange. Lignocellulose possesses many hydroxyl, carbonyl and phenyl groups and therefore, both montmorillonite and lignocellulose are good candidates for the development of effective and low cost adsorbents in water treatment and purification. The aim of this study was to prepare composite materials based on lignocellulose and montmorillonite clay and subsequently evaluate their efficacy as adsorbents for heavy metal species and organic pollutants in aqueous solution. It was also important to assess the adsorption properties of the modified individual (uncombined) lignocellulose and montmorillonite. Lignocellulose and sodium-exchanged montmorillonite (NaMMT) clay were each separately modified with methyl methacrylate (MMA), methacrylic acid (MAA) and methacryloxypropyl trimethoxysilane (MPS) and used as adsorbents for the removal of heavy metals and dyes from aqueous solution. The lignocellulose and NaMMT were modified with MMA, MAA and MPS through free radical graft polymerisation and/or condensation reactions. NaMMT was also modified through Al-pillaring to give AlpMMT. The materials were characterised by fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and small angle X-ray scattering (SAXS) and characterisation results showed that the modification of the montmorillonite with MAA, MMA and MPS was successful. The modified lignocellulose and montmorillonite materials were evaluated for the adsorption of heavy metal ions (Cd2+ and Pb2+) from aqueous solution by the batch method. The adsorption isotherms and kinetics of both Cd2+ and Pb2+ onto the NaMMT clay, AlpMMT and lignocellulose materials are presented. The Langmuir isotherm was found to be the best fit for the adsorption of both heavy metals onto all the adsorbents. AlpMMT showed very poor uptake for heavy metals (both Cd2+ and Pb2+). PMMAgMMT, PMAAgMMT, PMAAgLig and PMPSgLig showed improved adsorption for both heavy metals. The mechanism of heavy metal adsorption onto the adsorbents was best represented by the pseudo second-order kinetic model. PMPSgLig, NaMMT and AlpMMT showed relatively high adsorption capacities for methyl orange, while the adsorption of neutral red was comparable for almost all the adsorbents. Neither the Langmuir model nor the Freundlich model was found to v adequately describe the adsorption process of dyes onto all the adsorbents. The pseudo second-order model was found to be the best fit to describe the adsorption mechanism of both dyes onto all the adsorbents. The modification of lignocellulose and montmorillonite with suitable organic groups can potentially produce highly effective and efficient adsorbents for the removal of both heavy metals and dyes from contaminated water. Novel adsorbent composite materials based on lignocellulose and montmorillonite clay (NaMMT) were also prepared and evaluated for the removal of pollutants (dyes and heavy metals) from aqueous solution. The lignocellulose-montmorillonite composites were prepared by in situ intercalative polymerisation, using methyl methacrylate, methacrylic acid and methacryloxypropyl trimethoxysilane (MPS) as coupling agents. The composite materials were characterised by FTIR, TGA, TEM and SAXS. SAXS diffractograms showed intercalated nanocomposites of PMMAgLig-NaMMT and PMAAgLig-NaMMT, whereas PMPSgLig-NaMMT showed a phase-separated composite and the same results were confirmed by TEM. The lignocellulose-montmorillonite composites were assessed for their adsorption properties for heavy metal ions (Cd2+ and Pb2+) and dyes (methyl orange and neutral red) from aqueous solution. Among these composite materials, only PMAAgLig-NaMMT showed a marked increase in the uptake of both Cd2+ and Pb2+ relative to lignocellulose and montmorillonite when used independently. The adsorption data were fitted to the Langmuir and Freundlich isotherms, as well as to the pseudo first-order and pseudo second-order kinetic models. The data were best described by the Langmuir isotherm and the pseudo second-order kinetic model. On the adsorption of dyes, only PMPSgLig-NaMMT showed enhanced adsorption of methyl orange (MetO) compared with lignocellulose and montmorillonite separately. The enhanced adsorption was attributed to the synergistic adsorption due to the presence of MPS, lignocellulose and NaMMT. Competitive adsorption studies were carried out from binary mixtures of MetO and Cd2+ or Pb2+ in aqueous solution. The adsorption process of MetO onto the composite material was found to follow the Freundlich adsorption model, while the mechanism of adsorption followed both the pseudo first-order and pseudo second-order models. This particular composite can be used for the simultaneous adsorption of both heavy metals and organic dyes from contaminated water. The adsorption of neutral red to the composite materials was comparable and the pseudo second-order kinetic model best described the adsorption mechanism.
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- Date Issued: 2011
Human figure drawings and the general mental development of South African children
- Authors: Burger, Reinhart
- Date: 2011
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9869 , http://hdl.handle.net/10948/d1008068
- Description: This quantitative exploratory-descriptive study investigated the value of human figure drawing (HFD) tests for developmental testing in the South African context. Due to their characteristics such tests may be particularly suitable to screen for developmental delays in the local South African context. The objectives of the research were to explore and describe the standardized HFD scores and Griffiths Mental Development Scales – Extended Revised (GMDS-ER) general quotients (GQ) of the sample; to investigate whether a relationship exists between the standardized HFD scores and GQs; and to investigate the strength and directionality of this relationship if it was found to exist in the sample. Relevant literature was discussed and an integration of key constructs was provided. The research sample consisted of 30 GMDS-ER protocols collected at a University Psychology Clinic in the Nelson Mandela metropol, Eastern Cape, South Africa. The HFDs of the Draw-a-person items of the GMDS-ER protocols were scored according to the scoring criteria of the Draw-a-Person Intellectual Ability Test for Children, Adolescents, and Adults (DAP: IQ). Key findings included the following: a statistically significant large positive correlation indicative of a marked relationship existed between standardized HFD scores and GQs. The DAP: IQ might provide a better indication of mental development than intellectual ability. A statistically significant medium positive correlation indicative of a small but definite relationship existed between chronological age and HFD raw scores. In conclusion, the findings suggest that HFDs follow a developmental progression and that HFD tests may be useful in developmental testing.
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- Date Issued: 2011