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The elucidation of nickel and zinc based Metal Organic Frameworks (MOFs) using a polycarboxylate-benzene ligand: a synthetic, spectroscopic, and thermoanalytical study
Get PDFThesis (MSc) -- Faculty of Science, Chemistry, 202
Comparison of a novel HPLC method and conventional protein assays for the quantitation of insulin aspart in Novorapid®
Get PDFThesis (MSc) -- Faculty of Pharmacy, Pharmacy, 202
The use of smartphones and visualisation processes for conceptual understanding of mensuration: a case study of the Mathcitymap Project in Namibia
Get PDFThe aim of this study was to investigate and analyse the potential use of smartphones as visualisation tools by learners to enhance conceptual understanding through mathematics trails developed using the MathCityMap (MCM) project. This research study is part of the VIPROmaths project which seeks to research the effective use of visualisation processes in mathematics classrooms in South Africa, Namibia, Zambia, Switzerland and Germany. This study adopted a case of twelve purposively selected Grade 9 learners from a school in the Eheke circuit of the Oshana region, Namibia. This study was framed within a social constructivist perspective and sought to investigate visualisation processes as well as conceptual understanding of learners as they conceptualised the MCM tasks in new, outdoor and collaborative learning situations. The MCM app was installed on selected learners’ smartphones to access and to walk the MCM trails located in various places in the schoolyard. Three MCM trails based on three key themes of mensuration (perimeter, area and volume) were created. Each consisted of four tasks that were sourced and developed in line with the Grade 9 Namibian mathematics syllabus. This study is oriented in an interpretive paradigm and employed video-recorded observations and focus group interviews as qualitative data collection methods. Data collected were analysed first using the themes developed from Ho’s (2010) work on visualisation processes and Kilpatrick, Swafford, and Findell’s (2001) conceptual understanding. During analysis, some themes emerged from the data and were considered. Findings from this study revealed that smartphones afforded learners ample opportunities to enhance the visualisation processes that they went through as they learned the concepts of measurement. In addition to this, some learners were initially pessimistic regarding the use of smartphones for learning purposes. This study recommends that resources such as MCM be effectively be used in formal school settings. The learning of measurement can be advanced in outdoor settings where learners have physical and spatial access to the learning content. Smartphone technology can be used as an additional tool to integrate Information and Communication Technology (ICT) in learning mathematics within the Namibian context.Thesis (MED) -- Faculty of Education, Education, 202
The systematic assembly of prostate specific antigen electrochemical sensors based on asymmetric Co(II) phthalocyanines, graphitic quantum dots and an aptamer
Get PDFThe need for low-cost, efficient and simple diagnostic tools has led to more research going into this subject, with the aim of making such medical devices more accessible where they are needed. This has led to more researchers developing point-of-care devices for this purpose worldwide, by sensor fabrication. This thesis focuses on electrochemical sensor development for the early diagnosis of prostate cancer. It is common knowledge that prostate cancer is one of the most prevalent carcinomas that have claimed lives due to late diagnosis where even the most invasive treatments have failed. For this reason, development of early detection devices that can even be used in the comfort of home is necessary and quite crucial. Electrochemical sensors have gained much attention due to their ease of fabrication, cost effectiveness, simplicity, ease of use and high efficiency. Using nanocomposites as modifiers has also become popular as they provide greater stability and improve detection limits when used together with biomolecules. With that said, the work reported herein has combined nanocomposites of graphenebased quantum dots, gold nanoparticles, phthalocyanines and an aptamer in order to fabricate aptasensors for the electrochemical detection of prostate cancer biomarker. The aptamer is specifically designed to bind to the biomarker, and the nanocomposites are expected to enhance current output thus lowering detection limits and increasing stability and efficiency. Reproducible results are also expected. Prior to the detection of the prostate cancer biomarker, the quantum dots-phthalocyanine nanohybrids were used to detect L-cysteine, which is an amino acid, in order to verify the synergistic effects as electrode modifiers that lead to the enhancement of current output. This increase in current output is then v exploited for the improvement of aptasensor functionality upon incorporation of the aptamer, for the detection of prostate specific antigen. The research in this thesis has been carried out with the intention of contributing to the world of medical research, more so because of the ever-increasing need for medical care to become accessible to all and not only to those who can afford expensive technologies and treatments.Thesis (PhD) -- Faculty of Science, Chemistry, 202
Rethinking the informal settlements upgrading programmes in the Free State Province, South Africa: a transformative and multi-faceted model
Get PDFThis thesis intended to reveal the factors that contributed to the formulation of the informal settlements upgrading programmes in the Free State, South Africa, from an institutional perspective; subsequently to conceptualise a transformative and multi faceted model for the development and management of human settlements. The mixed methods exploratory research design has been applied in this study. This research design has allowed for the implementation of research methods including the qualitative inductive content analysis method, the case study method, and the semi structured survey questionnaire method. The data collection methods used comprised both primary and secondary data. Primary data involved online surveys and field observations. Secondary data comprised of an inductive analysis of written sources. The main findings of the study were as follows. First, the policy design and implementation processes have been misaligned. Second, there has been inadequate stakeholder engagements. Third, the government has not prioritised the employment of specialists in the field of housing and human settlements. Fourth, corruption has caused the state to fail to provide adequate housing for all. Fifth, municipalities are unable to identify and define existing informal settlements. Lastly, illegal immigration is causing a rapid increase in the number of informal settlements. This thesis proffered key recommendations based on the conclusions drawn from these findings. First, there must be an implementation of an integrated model for the preparation of upgrading policy. Second, communication technology education for officials of the state must be enhanced. Third, the government must prioritise the employment of experts in upgrading work. Fourth, the upgrading policy must reflect the paradigm shift from housing to human settlements. Fifth, municipalities need to be systematically transformed and improved for their functions on upgrading. Finally, illegal immigration must be firmly monitored while legal immigration is discouraged. To this end, this thesis has presented a strong viewpoint that limits the influx of immigrants into unproclaimed urban land that leads to the growth of informal settlements. The study has also strongly advocated for the legal spatial placement of South African citizens and legal immigrants on strategically and socio-economically viable land, where it is suitably available and owned by the state. Housing in the thesis has been viewed as one of the essential instruments that must inevitably emerge as a prospect towards xiv effectively unlocking improved living conditions in informal settlements; rather than housing being perceived as human settlements.Thesis (PhD) -- Faculty of Engineering, the Built Environment and Information Technology, School of the Built Environment, 202
The role of a national system of innovation in facilitating development in South Africa from a comparative BRICS perspective
Get PDFThe aim of the dissertation was to investigate whether the adoption of a national system of innovation has helped facilitate development in South Africa from a comparative BRICS perspective. South Africa has an expanding focus on science and technology, as per the Science and Technology White Paper (1996). There appeared to be innovation that had left out much of the citizenry. There continued to be poverty, inequality, and joblessness. The study aimed to understand how the NSI approach could be used to foster inclusive and transformative development. The study used a mixed-methods approach. The qualitative aspect of the research focused on an innovation and public policy study which assessed the various policies and initiatives implemented in each of the BRICS countries to drive innovation and foster development. The qualitative aspect of the study found that the innovation paradigm required governments to adopt a more holistic approach to public policy design and analysis. The quantitative aspect of the research focused on a trend, correlation, and regression analysis. The trend analysis revealed that China and Brazil increased their allocation of resources towards R&D compared to the other countries. Brazil is regarded as a social investment state, while China is a developmental state: this means the state plays an extraordinarily strong coordinative and financing role in the NSI. On the other hand, the correlation matrix for South Africa revealed a statistically significant positive linear association between various NSI indicators and human development. This suggested that the innovation benefits are trickling down to the general citizenry. In essence the study articulated key elements of the understanding of current and potential impacts of technological change in productivity and growth, employment and inequality that can be used for policy making.Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 202
Development of a distributed optical fiber sensor for geological applications
Get PDFThe purpose of the study was to develop a distributed optical fiber acoustic sensor for monitoring ground subsidence before collapse sinkholes form causing costly damage on infrastructure. Costs in excess of R1.3 billion have been incurred while dealing with sinkhole related measures in South Africa. Monitoring sinkholes and the presence of an early warning alert system can drastically reduce the impact, risk and cost caused by sudden ground collapse. A related goal was to construct a reliable collapse alert early warning system to facilitate disaster preparedness and avoid further damage from accidents. This was achieved by developing a spectroscopic shift monitoring algorithm which analysed changes in the subsurface vibration modes using ambient noise signals. For the first time to our knowledge, an optic fiber sensor with an early warning alarm, using ambient noise vibrations to detect and monitor sinkholes was developed at NMU. A polarisation-based, interferometric optical fiber seismic sensor was developed and compared to a commercial geophone. The fiber sensor exhibited superior performance in sensitivity, bandwidth, signal response and recovery times. The sensitivity of the optical fiber sensor was 0.47 rad/Pa surpassing the geophone sensitivity by 9.32%, and the bandwidth of 3.349kHz was 20 times greater for the optical fiber sensor. The fiber sensor was used to measure millisecond events as the impact duration of a bouncing ball was successfully obtained. It was used to detect sinkhole formation in the simulator model, designed. Ground collapse precursors were identified, and early warning alert was achieved using the spectral analysis algorithm, developed. The collapse precursor condition was identified as a functional combination of variations in the peak frequency, bandwidth and peak intensity. A distributed acoustic sensor was built to detect ambient noise induced subsurface signals. Vibrations were located along the 28km length of optical fiber with a relative error of 9.6%. The sensor demonstrated a frequency response range of 212.25Hz, an event distance precision of 224m with time resolution of 1.12µs, and a spatial resolution of 1km. The position of disturbance was measured within 300m of its actual point of 3.21km along the optical fiber. The results showed that distributed optical fiber sensing allows real-time monitoring of the subsurface over extended distances, using ambient noise signals.Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 202
In vitro photoinactivation of S. aureus and photocatalytic degradation of tetracycline by novel phthalocyanine-graphene quantum dots nano-assemblies
Get PDFA novel asymmetrical zinc (II) phthalocyanine (Pc) 4 bearing three dimethoxy groups and one carboxyl group was linked to glutathione capped graphene quantum dots (GQDs) by the reaction of carboxylic acid substituent on Pc 4 with the amino group on the GQDs. On the other side, the symmetrical Pc analog 3 was linked to the same nanoparticles through π-π interactions. The as-formed nano-photosensitizers were fully characterized by spectroscopic methods and their photophysicochemical properties were investigated as well. Photodynamic antimicrobial chemotherapy was performed on the planktonic cells of S. aureus strain. And the results show that these nano assemblies were able to completely inhibit the metabolic activity of the resistant bacteria strain S. aureus with a 10.26 log reduction in the viable count. Again, asymmetrical Pc showed higher photocatalytic activity compared to the symmetrical complex with higher kobs and fast initial rates for the former. The photocatalysis obeyed the Langmuir-Hinshelwood kinetic model. The target conjugates showed all the advantages of two different groups existing on a single entity
Impedimetric aptasensor for HER2 biomarker using graphene quantum dots, polypyrrole and cobalt phthalocyanine modified electrodes
Get PDFA method is presented for the electrochemical detection of the breast cancer biomarker human epidermal growth factor receptor 2 (HER2). A glassy carbon electrode was modified using two techniques known as sequential adsorption and electro-polymerization, and the results are compared. The highly conductive polypyrrole (PPy) is used, in the presence of sulfur/nitrogen doped graphene quantum dots (SNGQDs) and a known cobalt phthalocyanine (CoPc). The different nanomaterials were used as an immobilization platform for the HER2 specific HB5 aptamer via amide linkage. The nanomaterials were arranged in various ways on the glassy carbon electrode, to investigate the effect of the electrode interface on the operational characteristics of a biosensor. The immobilized aptamer selectively recognizes HER2 on the electrode interface, and this leads to an increased charge transfer resistance (Rct) of the electrode when using ferricyanide as the electrochemical probe. The developed immunosensors showed high sensitivity with the best detection limit of 0.00141 ng/mL. The results showed that the method is simple and sensitive enough for the determination of HER2 in serum samples with good reproducibility and accuracy
Exploration of the factors influencing the upscaling of medical male circumcision targets in selected hospitals in eThekwini District, South Africa
Get PDFMedical male circumcision has been shown to reduce female to male HIV transmission. This study was designed to examine the underlying factors responsible for, or influencing, the inability of the health care system to achieve the MMC targets in selected hospitals in KZN. The objective of this study to was explore the challenges that lead to failure of the government to meet set targets, regarding the implementation of the MMC programme in the province of KZN, as perceived by the health care workers. Methodology A mixed quantitative and qualitative study where 150 questionnaires were used and in-depth open-ended interviews were conducted. Participants were from Clairwood and Wentworth hospitals in the district of eThekwini, KwaZulu-Natal. Eighteen healthcare workers (nurse managers, doctors, nurses and counsellors) were purposively selected from the two hospitals. Results Findings showed that poor marketing of MMC, in line with the cultural and religious inclination of the catchment populations, had an effect on the targets. The fear of pain by the male clients came out as the biggest factor followed by the fear of having an HIV test done. The six weeks healing period before indulgence in sexual intercourse had a part to play in the reluctance of clients to do MMC. Some clients feared losing the ability to have an erection post MMC and would therefore not come for MMC. Other contributory factors for failure to reach targets included shortage of staff, poor mobilisation by the staff due to lack of training on how to mobilise and how to market MMC, lack of availability of mobilisation and marketing resources, inadequate and inequitable allocated of resources. Other factors include, lack of incentives for staff to stay in the programme or even within the Department, lack of training, cultural and religious beliefs in the community. The staff also felt that the MMC targets were too high. Notwithstanding, the staff members were willing to learn how to market MMC and to mobilise clients. Clients and community education on the importance of MMC and the combination of this process with good sexual behaviour would improve MMC uptake and reduce HIV prevalence and the incidence. Conclusions The fear of pain, fear to do HIV test and the fear to loose erection were the most prominent reasons why the males would not come for MMC procedure.Thesis (MPH) -- Faculty of Health Sciences, Public Health, 202