Showing items 81 - 100 of 705

Your selections:

C3TO : a scalable architecture for mobile chat based tutoring

  • Authors: Butgereit, Laura Lee
  • Date: 2010
  • Subjects: Intelligent tutoring systems , Instructional systems -- Design
  • Language: English
  • Type: Thesis , Masters , MTech
  • Identifier: vital:9746 , http://hdl.handle.net/10948/1511 , Intelligent tutoring systems , Instructional systems -- Design
  • Description: C³TO (Chatter Call Centre/Tutoring Online) is a scalable architecture to support mobile online tutoring using chat protocols over cell phones. It is the scalability of this architecture which is the primary focus of this dissertation. Much has been written lamenting the state of mathematics education in South Africa. It is not a pretty story. In order to help solve this mathematical crisis, the “Dr Math” research project was started in January, 2007. “Dr Math” strove to assist school pupils with their mathematics homework by providing access to tutors from a nearby university to help them. The school pupils used MXit on their cell phones and the tutors used normal computer workstations. The original “Dr Math” research project expected no more than twenty to thirty school pupils to participate. Unexpectedly thousands of school pupils started asking “Dr Math” to assist them with their mathematics homework. The original software could not scale. The original software could not cater for the thousands of pupils needing help. The scalability problems which existed in the original “Dr Math” project included: hardware scalability issues, software scalability problems, lack of physical office space for tutors, and tutor time being wasted by trivial questions. C³TO tackled these scalability concerns using an innovative three level approach by implementing a technological feature level, a tactical feature level, and a strategic feature level in the C³TO architecture. The technological level included specific components, utilities, and platforms which promoted scalability. The technological level provided the basic building blocks with which to construct a scalable architecture. The tactical level arranged the basic building blocks of the technological level into a scalable architecture. The tactical level provided short term solutions to scalability concerns by providing easy configurability and decision making. The strategic level attempted to answer the pupils questions before they actually arrived at the tutor thereby reducing the load on the human tutors. C³TO was extensively tested and evaluated. C³TO supported thousands of school pupils with their mathematics homework over a period of ten months. C³TO was used to support a small conference. C³TO was used to encourage people to volunteer their time in participation of Mandela Day. C³TO was used to support “Winter School” during the winter school holiday. In all these cases, C³TO proved itself to be scalable.
  • Full Text:
  • Date Issued: 2010

Service quality perceptions in the Uganda mobile telephone branch of industry

  • Authors: Byarugaba, Jotham Mbiito
  • Date: 2010
  • Subjects: Cell phone services industry -- Uganda , Service industries -- Uganda -- Quality control , Cell phones -- Uganda -- Design , Consumer satisfaction -- Uganda
  • Language: English
  • Type: Thesis , Doctoral , DCom
  • Identifier: vital:9373 , http://hdl.handle.net/10948/1226
  • Description: Standard practice dictates that mobile telephone service providers remain accurately aligned with the dynamic expectations structure of the target mobile telephone service users they serve. To comply with this requirement, literature sources assert that service providers need to adopt a candid marketing research orientation to understand what the users expect and in-build it in their service designs. Theory further contends that if such a business stance is diligently applied, any service provider is bound to gain a competitive edge in the market place. Notwithstanding the aforementioned, service providers continue design services without sufficient understanding of what users expect. This mindset has led to disparities in both the designed and the recieved service. Despite the pioneering works of earlier reserachers on the Gaps model, evidence shows that no research had been carried out to measure users' and providers' service quality perceptions in the mobile telephone branch of industry in Uganda. Much remains unknown as regards users' perceptions of expected and actual service quality and any potential disparity thereof. In the same spirit, much remains unknown as regards providers' perceptions of users' expectations and users' real expectations and potential disparity thereof. In order to measure the aforementioned disparities, the Gaps model was used in which Gaps 1 and 5 were measured for providers and users of mobile telephone services in the branch industry in Uganda.
  • Full Text: false
  • Date Issued: 2010

A model for the alignment of ICT education with business ICT skills requirements

  • Authors: Calitz, André Paul
  • Date: 2010
  • Subjects: Educational technology -- South Africa , Education, Higher -- South Africa , Information technology -- Social aspects -- South Africa , Information technology -- Study and teaching
  • Language: English
  • Type: Thesis , Doctoral , DBA
  • Identifier: vital:8662 , http://hdl.handle.net/10948/1418 , Educational technology -- South Africa , Education, Higher -- South Africa , Information technology -- Social aspects -- South Africa , Information technology -- Study and teaching
  • Description: The Information and Communications Technology (ICT) skills shortage is of national and international concern. Modern business practices require the implementation of new technologies supported by a workforce with current and diversified ICT skill-sets. Acquiring suitable ICT skills has become a difficult task and employers are seeing government intervention at all levels. The school system in South Africa is under increased pressure and is faced with continuously declining matriculation pass rates, specifically in subjects such as science and mathematics. Schools are experiencing a decline in the number of scholars (learners) enrolling for the Information Technology (IT) school curriculum. The IT curriculum at school level is being criticised; under-prepared teachers are blamed and lack of suitable facilities highlighted. Surveys conducted amongst grade 9 and grade 12 scholars in the Eastern Cape have shown that scholars are not considering careers in ICT. Teachers, career/guidance counsellors and parents contribute to scholars' career decisions and are not encouraging scholars to pursue careers in ICT. Tertiary institutions in South Africa and internationally, are experiencing a decline in student enrolments and in pass and throughput rates. Industry is holding tertiary institutions responsible for not providing the “correct” ICT graduate skill-sets and passing an insufficient number of quality ICT graduates desperately required by industry. The accreditation of computing degree programs, such as Computer Science (CS), Information Systems (IS) and Information Technology (IT), collectively referred to as CIT, offered by tertiary institutions is becoming an international requirement. The ICT industry is constantly changing and new job requirements and new career opportunities are frequently introduced. Graduates entering the ICT industry should have acquired knowledge about ICT career tracks in order to specialise and choose a suitable career path. Tertiary CIT degree programs should further be linked to specific career tracks and provide a multi-disciplined education to graduates. ii ICT graduates working in industry utilise skills obtained in under-graduate and post-graduate CIT degree programs. The ICT graduates have also obtained valuable skills working in industry, including business skills and soft skills. ICT skill surveys have identified the graduate skills gap, indicating ICT skills industry requires from graduates completing tertiary level qualifications. ICT graduates working in industry, for example indicated that programming in some cases is over-emphasised at school and tertiary level and that soft skills are ignored by tertiary institutions. An ICT Graduate Skills Classifications Framework is developed to address the graduate ICT skills gap and highlight important business skills, soft skills, technical skills and programming skills required by industry. In this thesis, an Industry ICT Value Chain Model is further developed that suggests a holistic approach to the problems experienced at all levels of ICT skills development, including government, industry, tertiary education institutions and at school level. Results from a number of research surveys conducted along the proposed Industry ICT Skills Value Chain Model indicated that problems exist at all stages in the value chain and that the problems can only be addressed involving government, industry and tertiary institutions collectively. A number of interventions is required and the support from industry is essential in achieving overall success in addressing the ICT skills shortage in South Africa. A proposed Industry ICT Skills Value Chain Model that can be utilised to address the ICT skills shortage in South Africa is presented.
  • Full Text:
  • Date Issued: 2010

Investigating factors that negatively influence lean implementation in the Eastern Cape automotive industry

  • Authors: Camagu, Sibo
  • Date: 2010
  • Subjects: Lean manufacturing -- South Africa -- Eastern Cape , Production management -- South Africa -- Eastern Cape , Industrial efficiency , Automobile industry and trade
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: vital:8655 , http://hdl.handle.net/10948/1360 , Lean manufacturing -- South Africa -- Eastern Cape , Production management -- South Africa -- Eastern Cape , Industrial efficiency , Automobile industry and trade
  • Description: In this intensely competitive environment of the global economy, the survival of even the most established manufacturers depends on their ability to continuously improve quality whilst reducing costs. The resulting productivity of producing more with less is the only key to market leadership and sustainable competitive advantage. Changing production methods from mass-production to Lean Manufacturing has become the essential practise for successful manufacturers (Rogers and Sim, 2009). The purpose of this study is to investigate what factors negate the adoption and implementation of Lean Manufacturing as a means to gain competitive advantage. The focus was on companies that have participated in the AIDC Tirisano cluster programme. The study investigated what effect Organisational Culture, Leadership Behaviours, Employee Involvement and Strategy Integration have on Lean Manufacturing adoption and implementation. This study applied the mixed methodologies of qualitative and quantitative approaches using methodological triangulation. A cross sectional analytical survey approach in a descriptive case study was undertaken. The findings from the questions and the interviews from the respondents who participated in the survey indicated that the practices in some companies enable the successful adoption and implementation of Lean Manufacturing whilst in some others the practices will negatively affect the adoption and implementation. The study concludes by stating that South African automotive component manufacturers are under immense pressure to improve quality and reduce costs. Initiatives like Lean Manufacturing should be undertaken in order to bring about these improvements. But this improvement comes about by changing the current way of doing things. Companies need to undertake a total approach when implementing Lean as part of the business strategy and this must be driven by management as leaders and a team culture that involves all employees needs to be present.
  • Full Text:
  • Date Issued: 2010

Synthesis and photophysical properties of 1, 1′-binaphthol substituted phthalocyanines

  • Authors: Canlica, Meylude , Nyokong, Tebello
  • Date: 2010
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/249148 , vital:51782 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.034"
  • Description: We report on the synthesis, characterization and photophysical properties of a new symmetrically tetra substituted {at non-peripheral positions with tetra(1,1′-bi-binaphtoxy)} phthalocyanines containing H2, Mg(II), Al(III)Cl, Si(IV)Cl2 in the central cavity. The synthesized compounds were characterized by the elemental analyses, UV–Vis, FT-IR and 1H NMR spectroscopies. The fluorescence quantum yields, triplet quantum yields and lifetimes of the newly synthesized H2, Mg, Al, and Si phthalocyanines were explored. Triplet quantum yields ranged from 0.24 to 0.54. The triplet lifetime for the silicon phthalocyanine derivative was the highest ever reported for a phthalocyanine (∼3.5 ms).
  • Full Text:
  • Date Issued: 2010

Analytical methods for the quantitative determination of oxytocin

  • Authors: Chaibva, Faith A , Walker, Roderick B
  • Date: 2010
  • Language: English
  • Type: Article
  • Identifier: vital:6353 , http://hdl.handle.net/10962/d1006037
  • Description: Oxytocin is a clinically important nonapeptide that is used for the induction and/or augmentation of labor and is normally administered as a slow intravenous infusion diluted with normal saline or Ringer’s lactate solution. Oxytocin is also indicated for use in the prevention and treatment of post partum hemorrhage and may be administered via either the intramuscular or intravenous routes in order to increase uterine tone and/or reduce bleeding. The analysis of oxytocin in different media has evolved over the past 30 years with the result that more sophisticated, selective and sensitive techniques are used for the determination of the compound. A variety of techniques have been applied to the determination of oxytocin in different matrices ranging from simple paper chromatography to hyphenated liquid chromatographic such as liquid chromatography coupled with mass-spectrometry. Additionally enzyme linked immuno-sorbent assays (ELISA) and radio immuno-assays (RIA) are used for the determination of low concentrations of oxytocin in biological matrices. This manuscript provides a systematic survey of the analytical methods that have been reported for isolation and quantitation of oxytocin in different matrices.
  • Full Text:
  • Date Issued: 2010

Optimization of salbutamol sulfate dissolution from sustained release matrix formulations using an artificial neural network

  • Authors: Chaibva, Faith A , Burton, Michael , Walker, Roderick B
  • Date: 2010
  • Subjects: Neural networks (Computer science)
  • Language: English
  • Type: Article
  • Identifier: vital:6352 , http://hdl.handle.net/10962/d1006034
  • Description: An artificial neural network was used to optimize the release of salbutamol sulfate from hydrophilic matrix formulations. Model formulations to be used for training, testing and validating the neural network were manufactured with the aid of a central composite design with varying the levels of Methocel® K100M, xanthan gum, Carbopol® 974P and Surelease® as the input factors. In vitro dissolution time profiles at six different sampling times were used as target data in training the neural network for formulation optimization. A multi layer perceptron with one hidden layer was constructed using Matlab®, and the number of nodes in the hidden layer was optimized by trial and error to develop a model with the best predictive ability. The results revealed that a neural network with nine nodes was optimal for developing and optimizing formulations. Simulations undertaken with the training data revealed that the constructed model was useable. The optimized neural network was used for optimization of formulation with desirable release characteristics and the results indicated that there was agreement between the predicted formulation and the manufactured formulation. This work illustrates the possible utility of artificial neural networks for the optimization of pharmaceutical formulations with desirable performance characteristics.
  • Full Text:
  • Date Issued: 2010

Swelling, erosion and drug release characteristics of salbutamol sulfate from hydroxypropyl methylcellulose-based matrix tablets

  • Authors: Chaibva, Faith A , Khamanga, Sandile M , Walker, Roderick B
  • Date: 2010
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/184139 , vital:44177 , xlink:href="https://doi.org/10.3109/03639045.2010.488648"
  • Description: Background: Hydrophilic matrix formulations are important and simple technologies that are used to manufacture sustained release dosage forms. Method: Hydroxypropyl methylcellulose-based matrix tablets, with and without additives, were manufactured to investigate the rate of hydration, rate of erosion, and rate and mechanism of drug release. Scanning electron microscopy was used to assess changes in the microstructure of the tablets during drug release testing and whether these changes could be related to the rate of drug release from the formulations. Results: The results revealed that the rate of hydration and erosion was dependent on the polymer combination(s) used, which in turn affected the rate and mechanism of drug release from these formulations. It was also apparent that changes in the microstructure of matrix tablets could be related to the different rates of drug release that were observed from the test formulations. Conclusion: The use of scanning electron microscopy provides useful information to further understand drug release mechanisms from matrix tablets.
  • Full Text:
  • Date Issued: 2010

The use of response surface methodology and artificial neural networks for the establishment of a design space for a sustained release salbutamol sulphate formulation

  • Authors: Chaibva, Faith Anesu
  • Date: 2010
  • Subjects: Salbutamol sulphate Artificial intelligence -- Medical applications Neural networks (Computer science) Response surfaces (Statistics) Pharmaceutical biotechnology -- Quality contro Drugs -- Design Pharmacokinetics Drugs -- Dosage forms Drugs -- Controlled release
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3845 , http://hdl.handle.net/10962/d1010432
  • Description: Quality by Design (QbD) is a systematic approach that has been recommended as suitable for the development of quality pharmaceutical products. The QbD approach commences with the definition of a quality target drug profile and predetermined objectives that are then used to direct the formulation development process with an emphasis on understanding the pharmaceutical science and manufacturing principles that apply to a product. The design space is directly linked to the use of QbD for formulation development and is a multidimensional combination and interaction of input variables and process parameters that have been demonstrated to provide an assurance of quality. The objective of these studies was to apply the principles of QbD as a framework for the optimisation of a sustained release (SR) formulation of salbutamol sulphate (SBS), and for the establishment of a design space using Response Surface Methodology (RSM) and Artificial Neural Networks (ANN). SBS is a short-acting ♭₂ agonist that is used for the management of asthma and chronic obstructive pulmonary disease (COPD). The use of a SR formulation of SBS may provide clinical benefits in the management of these respiratory disorders. Ashtalin®8 ER (Cipla Ltd., Mumbai, Maharashtra, India) was selected as a reference formulation for use in these studies. An Ishikawa or Cause and Effect diagram was used to determine the impact of formulation and process factors that have the potential to affect product quality. Key areas of concern that must be monitored include the raw materials, the manufacturing equipment and processes, and the analytical and assessment methods employed. The conditions in the laboratory and manufacturing processes were carefully monitored and recorded for any deviation from protocol, and equipment for assessment of dosage form performance, including dissolution equipment, balances and hardness testers, underwent regular maintenance. Preliminary studies to assess the potential utility of Methocel® Kl OOM, alone and in combination with other matrix forming polymers, revealed that the combination of this polymer with xanthan gum and Carbopol® has the potential to modulate the release of SBS at a specific rate, for a period of 12 hr. A central composite design using Methocel® KlOOM, xanthan gum, Carbopol® 974P and Surelease® as the granulating fluid was constructed to fully evaluate the impact of these formulation variables on the rate and extent of SBS release from manufactured formulations. The results revealed that although Methocel® KlOOM and xanthan gum had the greatest retardant effect on drug release, interactions between the polymers used in the study were also important determinants of the measureable responses. An ANN model was trained for optimisation using the data generated from a central composite study. The efficiency of the network was optimised by assessing the impact of the number of nodes in the hidden layer using a three layer Multi Layer Perceptron (MLP). The results revealed that a network with nine nodes in the hidden layer had the best predictive ability, suitable for application to formulation optimisation studies. Pharmaceutical optimisation was conducted using both the RSM and the trained ANN models. The results from the two optimisation procedures yielded two different formulation compositions that were subjected to in vitro dissolution testing using USP Apparatus 3. The results revealed that, although the formulation compositions that were derived from the optimisation procedures were different, both solutions gave reproducible results for which the dissolution profiles were indeed similar to that of the reference formulation. RSM and ANN were further investigated as possible means of establishing a design space for formulation compositions that would result in dosage forms that have similar in vitro release test profiles comparable to the reference product. Constraint plots were used to determine the bounds of the formulation variables that would result in the manufacture of dosage forms with the desired release profile. ANN simulations with hypothetical formulations that were generated within a small region of the experimental domain were investigated as a means of understanding the impact of varying the composition of the formulation on resultant dissolution profiles. Although both methods were suitable for the establishment of a design space, the use of ANN may be better suited for this purpose because of the manner in which ANN handles data. As more information about the behaviour of a formulation and its processes is generated during the product Iifecycle, ANN may be used to evaluate the impact of formulation and process variables on measureable responses. It is recommended that ANN may be suitable for the optimisation of pharmaceutical formulations and establishment of a design space in line with ICH Pharmaceutical Development [1], Quality Risk Management [2] and Pharmaceutical Quality Systems [3]
  • Full Text:
  • Date Issued: 2010

The value of a Rhodes University degree and securing employment

An explanatory study into the rehabilitation of ex-freedom fighters in Gweru, Zimbabwe from 1990 to 1995

  • Authors: Charema, John
  • Date: 2010
  • Subjects: Guerrillas -- Zimbabwe -- Gweru , Political rehabilitation -- Zimbabwe -- Gweru , Nationalism -- Zimbabwe -- Gweru , Zimbabwe -- Politics and government -- 1990-1995 , Zimbabwe -- History -- 1990-1995
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:8202 , http://hdl.handle.net/10948/1223 , Guerrillas -- Zimbabwe -- Gweru , Political rehabilitation -- Zimbabwe -- Gweru , Nationalism -- Zimbabwe -- Gweru , Zimbabwe -- Politics and government -- 1990-1995 , Zimbabwe -- History -- 1990-1995
  • Description: The purpose of the study was to explore the rehabilitation of ex-combatants who fought the Zimbabwe liberation war, thus to find out if these ex-combatants received counseling and were resettled or reintegrated within the period 1990 to 1995. In order to maintain focus the aims of the study were set out as follows: • to focus on rehabilitation which encompasses taking care of the ex-combatants who were disabled and or injured during the war, as well as counseling, reintegrating and resettling them and • to explore whether the ex-combatants who were demobilized and those who opted for a civilian life were rehabilitated. • to explore if the ex-combatants were reintegrated. • to understand how the ex-combatants were coping with their lives and • to discover how they perceived their support from the government at the time of their demobilisation. The study concentrated on ex-combatants in Gweru, who were to be rehabilitated from 1990 to 1995. In-depth face-to-face interviews were conducted to achieve the objectives set out for the study. The results of the study indicate that there was no rehabilitation, counseling, resettlement and real integration. The findings clearly indicate that these ex-combatants still think of being resettled, allocated good land for farming. They went on to suggest being paid pension by the government and to have their children employed, educated and supported by the government.
  • Full Text:
  • Date Issued: 2010

Social relationships and identity online and offline: a study of the interplay between offline social relationships and facebook usage by Rhodes University students from socially disadvantaged backgrounds

  • Authors: Chatora, Arther Tichaona
  • Date: 2010
  • Subjects: Facebook (Electronic resource) Online social networks Information technology -- Social aspects Identity (Psychology) and mass media Rhodes University -- Students -- Social life and customs Rhodes University -- Students -- Social networks Rhodes University -- Students -- Social conditions
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3421 , http://hdl.handle.net/10962/d1002874
  • Description: Based on in-depth focus group and individual interviews, this thesis examines how Rhodes University students from socially disadvantaged backgrounds experience campus social life and how they subsequently use Facebook to perform, represent and negotiate their social identities. The study discusses utopian and dystopian positions and interrogates these theoretical perspectives in relation to the students‟ Facebook usage. The popularity and uptake of Facebook by students from disadvantaged backgrounds, such as those here at Rhodes University, is a growing phenomenon, provoking questions about the relationship between social experiences, social identity and social networks. Rhodes University‟s social space has been identified by previous studies as modern, liberal, “elite” and divided along race and class lines. The ways in which students experience this campus social space relates to their subject positions and identities. The study employs different perspectives of identity construction to interrogate the students‟ subject experiences in home and school contexts before coming to Rhodes University. The students‟ subjective positions are primarily embedded in tradition and their subject positions are sometimes in tension or come in conflict with the modern and liberal elements permitted by the Rhodes University context. The students also experience and adopt modern and liberal elements in their lifestyles which are permitted within the Rhodes University social space. The thesis found that Facebook offers a platform which facilitates a social connectivity that influences how students perform their identities in relation to their offline social identities and lived social experiences. This study concludes that the mediated symbolic materials for the construction and negotiation of identity provided by Facebook are sometimes in tension with the demands of traditional subjectivities experienced by these students at Rhodes University. Facebook allows the students to reinforce and affirm the validity of their traditional identities in this modern and liberal space. However, it also emerged that Facebook facilitates and allows students who experience and incorporate the modern and liberal elements permitted at Rhodes University to represent and negotiate their subjective positions online. The findings of the study indicate that participants primarily communicate with their friends, families, relatives and acquaintances - people they know personally offline, in line with the theoretical position which argues that online relationships are primarily shaped by offline relationships.
  • Full Text:
  • Date Issued: 2010

Remarkable sensitivity for detection of bisphenol A on a gold electrode modified with nickel tetraamino phthalocyanine containing Ni–O–Ni bridges

  • Authors: Chauke, Vongani , Matemadombo, Fungisai , Nyokong, Tebello
  • Date: 2010
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/261280 , vital:53380 , xlink:href="https://doi.org/10.1016/j.jhazmat.2010.01.061"
  • Description: This work reports the electrocatalysis of bisphenol A on Ni(II) tetraamino metallophthalocyanine (NiTAPc) polymer modified gold electrode containing Ni–O–Ni bridges (represented as Ni(OH)TAPc). The Ni(II)TAPc films were electro-transformed in 0.1 mol L−1 NaOH aqueous solution to form ‘O–Ni–O oxo bridges’, forming poly-n-Ni(OH)TAPc (where n is the number of polymerising scans). poly-30-Ni(OH)TAPc, poly-50-Ni(OH)TAPc, poly-70-Ni(OH)TAPc and poly-90-Ni(OH)TAPc films were investigated. The polymeric films were characterised by electrochemical impedance spectroscopy and the charge transfer resistance (RCT) values increased with film thickness. The best catalytic activity for the detection of bisphenol A was on poly-70-Ni(OH)TAPc. Electrode resistance to passivation improved with polymer thickness. The electrocatalytic behaviour of bisphenol A was compared to that of p-nitrophenol in terms of electrode passivation and regeneration. The latter was found to passivate the electrode less than the former. The poly-70-Ni(OH)TAPc modified electrode could reliably detect bisphenol A in a concentration range of 7 × 10−4 to 3 × 10−2 mol L−1 with a limit of detection of 3.68 × 10−9 mol L−1. The sensitivity was 3.26 × 10−4 A mol−1 L cm−2.
  • Full Text:
  • Date Issued: 2010

Synthesis and electrochemical characterisation of new tantalum (V) alkythio phthalocyanines

  • Authors: Chauke, Vongani , Nyokong, Tebello
  • Date: 2010
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/249093 , vital:51777 , xlink:href="https://doi.org/10.1016/j.ica.2010.05.003"
  • Description: The synthesis and electrochemical characterisation of octa-pentylthio (4a) and octa-octylthio (4b) – phthalocyaninato tantalum (III) hydroxide are hereby reported. These TaPc complexes absorb in the near infrared region (∼800 nm in dichloromethane). They show good solubility in most common solvents especially non-viscous solvents such as dichloromethane and chloroform. NMR, mass and infrared spectroscopy and elemental analysis confirmed the structures and purity of the synthesised complexes. The cyclic voltammograms (CVs) showed reversible reduction couples and irreversible oxidation peaks. The latter exhibited adsorption behavior. The reduction processes were observed at −0.74 and −1.13 V (versus Ag|AgCl) for 4a, and −0.67, −1.02 and −1.48 V (versus Ag|AgCl) for 4b. Spectroelectrochemistry confirmed one metal reduction, with the rest of the redox processes being centered on the phthalocyanine ring.
  • Full Text:
  • Date Issued: 2010

The feasibility of the Uitenhage provincial hospital private initiative

  • Authors: Cherry, Jacqueline Helen
  • Date: 2010
  • Subjects: Public health administration -- South Africa -- Uitenhage , Health care reform -- South Africa -- Uitenhage , Feasibility studies -- South Africa -- Uitenhage , Hospital care
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: vital:8619 , http://hdl.handle.net/10948/1508 , Public health administration -- South Africa -- Uitenhage , Health care reform -- South Africa -- Uitenhage , Feasibility studies -- South Africa -- Uitenhage , Hospital care
  • Description: The South African Health Care environment is in state of reform. Government strategy and change in legislation have been the catalyst for the development of new business models in South Africa. This report deals with the feasibility of a proposed model which is to be implemented by the Eastern Cape Department of Health at the Provincial Hospital in Uitenhage. The fundamental challenge in South Africa is the shortage of resources to support the health care industry from a public perspective. The point of departure for this research was to understand the complexity of this industry and investigate models that have evolved in South Africa and internationally. The literature research covers funding mechanisms from both a public and private perspective and takes into account the role the government plays in providing equitable health care for all. The literature provided the foundation to develop the model which is to be piloted at the hospital in Uitenhage. In terms of the research objective, a single case study methodology approach was conducted. Triangulation technique was used to gain insight from different perspectives and to test the model for validity. The core of this research focuses on the viability of the proposed model and the integration of this into the government health reform plan. The research revealed that in comparison to the existing PPP models in South Africa, this model is feasible. As a result of the analysis and the development of the proposed model, the research is concluded by offering suggestions for further research.
  • Full Text:
  • Date Issued: 2010

Photophysical study of a covalently linked quantum dot–low symmetry phthalocyanine conjugate

  • Authors: Chidawanyika, Wadzanai J U , Litwinski, Christian , Antunes, Edith M , Nyokong, Tebello
  • Date: 2010
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/261641 , vital:53430 , xlink:href="https://doi.org/10.1016/j.jphotochem.2010.03.008"
  • Description: The linkage of a low symmetry phthalocyanine, ZnttbIPc to mercaptopropionic acid (MPA) capped CdTe quantum dots has been achieved using a coupling agent, dicyclohexylcarbodiimide (DCC), to facilitate formation of an amide bond. UV–vis, Raman and IR spectroscopic studies on the linked (QD:ZnttbIPc-linked) conjugate suggest the reaction was a success. Förster resonance energy transfer (FRET) resulted in stimulated emission of ZnttbIPc in both the linked (QD:ZnttbIPc-linked) and mixed (QD:ZnttbIPc-mixed) conjugates. The linked complex (QD:ZnttbIPc-linked) gave the largest FRET efficiency hence showing the advantages of covalent linking. Photophysicochemical properties of the phthalocyanine were improved in the presence of the QDs i.e. for QD:ZnttbIPc-mixed. Fluorescence lifetimes of QDs were unchanged in QD:ZnttbIPc-mixed and decreased for QD:ZnttbIPc-linked.
  • Full Text:
  • Date Issued: 2010

Photophysiochemical studies of d¹⁰ metallophthalocyanines and their interaction with nanoparticles

  • Authors: Chidawanyika, Wadzanai Janet Upenyu
  • Date: 2010
  • Subjects: Nanoparticles Phthalocyanines Photochemistry Electrochemistry
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4335 , http://hdl.handle.net/10962/d1004996
  • Description: The syntheses, extensive spectroscopic characterization, photophysical and photochemical studies have been conducted for a variation of d10 metallophthaloycanines (MPcs). Comparisons have been made taking into consideration the nfluence of the central metal ion, solvent properties, substituent type and position. Coordination to heavy central metals i.e. Hg gives enhanced triplet state properties. Low symmetry metallophthalocyanine complexes were similarly haracterized and the influence of nteractions with nanoparticles on their photophysical and photochemical properties determined. The MPcs have been linked and adsorbed or mixed with nanoparticles i.e. hemically functionalized single-walled carbon nanotubes SWCNT) and mercaptocarboxylic acid capped CdTe quantum dots (QDs) and changes in the spectra accounted for with respect to the proposed conjugate structures. Distinct differences ccur for linked and adsorbed or mixed conjugates in the bsorption, infrared (IR) and Raman spectra and for thermal ravimetric decay profiles, suggesting successful formation f covalent bonds (linked) and point to structurally ifferent materials. SWCNT quench MPc fluorescence by a photoinduced electron transfer mediated process to give low fluorescence quantum yields. The QDs were used as energy transfer donors and facilitate energy transfer, through Förster resonance energy transfer (FRET) from the QDs to the MPcs. Improved FRET efficiencies were found for linked MPc-QD conjugates relative to the mixed species. Photophysicochemical properties of MPcs were, in general, improved as a result of interactions with nanoparticles.
  • Full Text:
  • Date Issued: 2010

Estuarine use by spotted grunter Pomadasys commersonnii in a South African estuary, as determined by acoustic telemetry

  • Authors: Childs, Amber-Robyn , Cowley, Paul D , Næsje, T F , Booth, Anthony J , Potts, Warren M , Thorstad, Eva B , Økland, F
  • Date: 2010
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/124428 , vital:35612 , https://doi.org/10.2989/A JMS.2008.30.1.12.462
  • Description: Estuaries are important in the life history and the maintenance of the diversity of coastal fish species because of their function as nursery areas for juveniles as well as feeding grounds for adults (Cyrus 1991). The dependence of many fish species on estuaries is well documented (e.g. Wallace et al. 1984, Lenanton and Potter 1987, Blaber et al. 1989, Whitfield 1990, Hoss and Thayer 1993). Spotted grunter Pomadasys commersonnii (Haemulidae) (Lacepède 1801) is an estuarine-dependent species which spawns in the KwaZulu-Natal inshore coastal waters, between August and December (Wallace 1975b, Wallace and van der Elst 1975, Harris and Cyrus 1997, 1999). The eggs and larvae are transported southwards by the Agulhas Current, and juveniles between 20 mm and 50 mm TL recruit into the KwaZulu-Natal and south-eastern Cape estuaries (Wallace and van der Elst 1975, Whitfield 1990). Juvenile spotted grunter make use of the abundant food resources in estuaries, where they grow rapidly and remain for a period of 1–3 years (Wallace and Schleyer 1979, Day et al. 1981). Upon attaining sexual maturity (at between 300 mm and 400 mm TL), they return to the marine environment (Wallace 1975b). Some adults, however, return to estuaries to feed and to regain condition after spawning (Wallace 1975b, Whitfield 1994). The return of post-spawning fish coincides with increased catches by fishers in estuaries between July and January. These events are known as ‘grunter runs’ (Wallace 1975a, Marais and Baird 1980, Marais 1988, Pradervand and Baird 2002). It is suggested that adults spend up to several months in estuaries, before moving back to sea where they undergo gonadal development and ultimately spawn (Wallace 1975b, Wallace and van der Elst 1975). It is believed that adult fish also enter estuaries in a prespawning state to gain condition en route to their spawning grounds in KwaZulu-Natal (Webb 2002).
  • Full Text:
  • Date Issued: 2010

Constraints and challenges faced by small, medium and micro enterprise contractors in Malawi

  • Authors: Chilipunde, Rodrick Lengama
  • Date: 2010
  • Subjects: Small business -- Malawi -- Management , Contractors' operations -- Malawi , Small business -- Malawi -- Finance
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:9686 , http://hdl.handle.net/10948/1220 , Small business -- Malawi -- Management , Contractors' operations -- Malawi , Small business -- Malawi -- Finance
  • Description: Small, medium and micro enterprises (SMMEs) are an important sector of any construction economy. The need for efficient SMMEs is well documented and cannot be over-emphasised. SMMEs are vital in their contribution to employment creation and value reorientation. However, their in process operations are not well understood and have rarely been addressed. The aim of this research was therefore to establish a base level of understanding of the operational core-face of SMMEs in Malawi. The methodology used included an extensive literature review and field survey conducted on 52 SMMEs. The field survey used the questionnaire instrument and random sampling. The critical findings from the literature were that there are binding constraints in the operations of SMMEs. The field survey confirmed the issues raised in the literature and posited the operational challenges as lack of finance, training and business skills; limited skills in Construction Information Technology (IT), and prevalence of unethical conduct amongst some of the stakeholders. The findings make an invaluable contribution to the search for solutions to the problems faced by construction SMMEs in Malawi and provide insight for further research in institutional weaknesses and policy issues regarding in this part of the world. The implications of the findings are that unless the limitations named above are resolved, SMMEs in Malawi will continue to experience poor growth and competitiveness. The recommendations include the developing of training programmes in business management, introduction of sector specific financing programmes and the provision of an appropriate regulatory and legislative framework. By establishing the core issues affecting the operations of SMMEs in the Malawian construction industry, the research has contributed to the enhancement of the understanding of this elusive subject.
  • Full Text:
  • Date Issued: 2010

Agricultural mechanization for sustainable agriculture and food security in Zimbabwe: a case of Bindura District in Mashonaland Central Province

  • Authors: Chisango, Future, T
  • Date: 2010
  • Subjects: Farm mechanization -- Zimbabwe , Agricultural machinery -- Zimbabwe , Agricultural productivity -- Zimbabwe , Sustainable agriculture -- Zimbabwe , Food supply -- Zimbabwe , Agriculture and state -- Zimbabwe
  • Language: English
  • Type: Thesis , Masters , MSc Agric (Agricultural Economics)
  • Identifier: vital:11156 , http://hdl.handle.net/10353/348 , Farm mechanization -- Zimbabwe , Agricultural machinery -- Zimbabwe , Agricultural productivity -- Zimbabwe , Sustainable agriculture -- Zimbabwe , Food supply -- Zimbabwe , Agriculture and state -- Zimbabwe
  • Description: A cardinal development goal of the Zimbabwean government is agricultural mechanization through the acquisition and use of tractors by arable crop farmers in communal and resettlement state land. This research project therefore aimed at investigating the impact of mechanization on agricultural productivity focusing on farmers in Bindura district of Zimbabwe who benefitted under the ongoing farm mechanization program. The existing land policy and the issue of technical efficiency in agricultural productivity are assumed to be the drivers of the program. It is likely that these key issues will constitute an important consideration in determining the sustainability of the mechanization policy. A multistage sampling technique was used to randomly select 90 farmers in the study area. The Cobb Douglas approach and Logistic regression were used to analyze data obtained from the respondents. Results revealed that tractor use was positively influenced by household size, access to extension services and crop output equivalent. Education, land area cultivated, stoniness negatively influenced the probability of adoption of mechanized farming. Furthermore, the technical efficiency estimate of adopter and nonadopters of mechanized farming showed no difference in their level of technical efficiency in agricultural productivity that was 64 percent on average. The level of observed inefficiency was increased by slope, stoniness and household size while age reduced technical inefficiency. It is recommended that government should consolidate the present gains arising from extension services. Also, environmental factors such as slope (topography) and stoniness, which constituted major disincentives in communal areas, could be overcome if government and farmers can identify and open up new areas of farmland for occupation by farmers.
  • Full Text:
  • Date Issued: 2010
  • Disclaimer
  • Privacy
  • Copyright
  • Contact