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Hybrid Monte Carlo methods In machine learning: Stochastic volatility methods, shadow Hamiltonians, adaptive approaches and variance reduction techniques
Get PDFD.Phil. (Electrical and Electronic Engineering)Abstract: Please refer to full text to view abstract
Women as ‘Space Invaders’ in construction : examining stories of Women’s Agency in the construction sector
No full textAbstract: The purpose of this study was to explore how women use their agency to assert themselves in the construction industry. It was guided by four objectives, the first which was to examine women's experiences of working in the construction sector, the second which was to examine how women define their agency within the construction sector, and the third which was to examine how women use their agency to transform the working space into an inclusive one. Finally, how do women use their agency in the workplace to challenge male dominance? A purposeful sample of ten women working in male-dominated contexts, namely Kusile and Medupi Power Stations, was used. In-depth online interviews were conducted, and data was analysed thematically. The key findings illustrated that women are treated unfairly, are intimidated and made to feel as appendages to the company. Even though that this may be the case, these women appear to make headway in the construction of electricity-generating power plants at Kusile and Medupi, despite the antagonistic conditions they work under. Their agency serve as catalysts for them making strides in their work space. This includes asserting their rights, establishing names for themselves, working twice as hard to become an insider, and supporting one another. Notwithstanding these qualities, most of the participants singled out resilience as the necessary attribute to survive and thrive at work. They defined resilience as relying on one's own strength and capability. Resilience in this case means that these participants knew exactly what they sort to achieve and worked extra hard towards this end. According to the research, it was also critical to understand how the sector confines female workers in their working spaces. Key Words: Women’s Agency, Male Dominated industry, Construction, Kusile Power Station, Medupi Power Station, Male domination, Gender inequality.M.A. (Industrial Sociology
Production of bioethanol from Tarus Cape Kelp (TCK) and Spirulina Chlorella (SC) : a comparative study
Get PDFM.Tech. (Chemical Engineering)Abstract: Third-generation feedstock such as algae is a key raw material in the sustainable production of bioenergy. Previous studies on bioenergy production from algae have majorly been on biodiesel production. The high carbohydrate content in algae can also be used in the production of bioethanol. However, the bioethanol yields have been very low, and previous studies have established that the pretreatment of algae can improve the bioethanol yield. There has not been any report that compare the effect of pretreatment on the bioethanol yield from the two major types of algae namely microalgae and macroalgae. This study compares the bioethanol yield of Spirulina Chlorella (a microalgae) and the Tarus Cape Kelp (a macroalgae) under different pre-treatment conditions. Acid pretreatment was used as the pretreatment method and the acid used for the pretreatment was Sulphuric acid. The effect of pretreatment acid concentration, temperature and time on Spirulina Chlorella (SC) and the Tarus Cape Kelp (TCK) on the hydrolyzed carbohydrates was evaluated and the resulting bioethanol yields were compared. The acid concentration results showed that an increase in acid concentration from 0.5N to 3N increased the amount of hydrolyzed carbohydrates from both Spirulina Chlorella and Tarus Cape Kelp. The highest amounts were 52oplato and 60.61oplato from the SC and TCK respectively obtained at 3N concentration. However, a further increase in acid concentration from 3N to 5N resulted in a reduction of hydrolyzed carbohydrates obtained from the Tarus Cape Kelp but was almost constant in Spirulina Chlorella. Increasing the pretreatment temperature increased the amount of hydrolyzed carbohydrates until the temperature of 120oc; 58.06oplato and 70.45oplato were achieved for Spirulina Chlorella and the Tarus Cape Kelp respectively. A further increase in temperature to 140oc was slightly beneficial for Spirulina Chlorella but had a lesser effect on Tarus Cape Kelp. The pretreatment time indicated to be most effective parameter on cell disruption as it gave the highest amount of hydrolyzed carbohydrates from both the Spirulina Chlorella and the Tarus..
The antibacterial effect of multiple administrations of Hydrastis canadensis mother tincture on Escherichia coli in-vitro
Get PDFM.Tech. (Homoeopathy)Abstract: Escherichia coli (E. coli) is a Gram-negative bacterium that harmlessly colonises as normal flora in the gastrointestinal tract of mammals. While most strains have a beneficial relationship with the host, some are pathogenic and can result in severe bacterial infections. E. coli infections have been linked to higher hospitalisation and fatality rates compared to other enteric pathogens, and are a major cause of diarrhoeal diseases, peritonitis, colitis, bacteraemia, infant mortality, and urinary tract infections. Antibiotic resistance has become a major global health concern and as a result, alternative treatment options need to be investigated. Hydrastis canadensis L. (H. canadensis L.) is a medicinal plant belonging to the Ranunculaceae family; its antibacterial activity is thought to be as a result of its various active constituents, specifically the alkaloid berberine. H. canadensis L. has been shown to exhibit antibacterial activity against E. coli as both a herbal extract and a homeopathically prepared mother tincture, with the mother tincture used as a single dosage application. The effect of multiple doses of the mother tincture being administered has not been investigated. The aim of this study was to determine the antibacterial activity of multiple administrations of H. canadensis mother tincture on E. coli in-vitro, by means of sequential 96 well plate incubations. The results demonstrated positive antimicrobial effects of H. canadensis mother tincture against E. coli with the use of the microdilution method. This study proved that H. canadensis can inhibit the growth of E. coli regardless of its ethanol concentration; it demonstrated that ethanol alone does not have permanent inhibitory effects against E. coli as the bacteria were able to adapt and grow when the ethanol was removed. The results for the mother tincture however showed lasting effects on the inhibition of the bacteria even after the bacteria were removed from the tincture. This study has expanded our knowledge on the antimicrobial effects of H. canadensis on E. coli and furthered our knowledge on how the frequency of dose administration of a mother tincture influences its antimicrobial effects
Prevalence and risk factors of Lower Back Pain (LBP) among construction workers in upstream oil and gas facilities in Oman, Middle East
Get PDFM.A. (Public Health)Abstract: Background: Lower back pain (LBP) is the most commonly reported musculoskeletal and has become a worldwide public health problem among the working populations of different industries. While the Oil and Gas industry plays a significant role in the global economy and the sector is rapidly growing and providing job opportunities to many trades and professions, there is an increasing risk of work-related fatalities, injuries and diseases such as Musculoskeletal Disorders (MSDs), especially LBP. However, literature search on LBP in the Oil & Gas industry in Oman indicated no studies had ever been conducted. Objectives: The objectives of this study were to determine prevalence of LBP among Oil & Gas Construction workers and to assess the risk factors associated with LBP occurrence. Methods: This cross‑sectional study used a self‑administered questionnaire to collect data on risk factors and prevalence of LBP among Oil & Gas Construction workers (n = 400) in the past 12 months. Participants were selected using simple random selection. The study was carried out in Marmul, south of Oman, Middle East. Data management and analysis were done using Epi Info™ and SPSS Ver. 26.0. Multivariate logistic regression was performed to evaluate the association between LBP risk factors and LBP. Results: LBP prevalence was 57%. Risk factors significantly associated with LBP were cigarette smoking adjusted odds ratios (AOR) 1.78, 95% (CI 1.10 - 2.89); alcohol consumption odds ratios (OR) 1.71, 95% (CI 1.09 - 2.68); number of years in the same job, 11 – 28 years OR 1.72, 95% (CI 1.01 - 2.93); often bending AOR 3.75, 95% (CI 1.43 - 9.85); sometimes exposure to vibration AOR 2.64, 95% (CI 1.46 - 4.80); same posture for prolonged periods AOR 6.49, 95% (CI 2.61 - 16.14); and physical stress AOR 11.32, 95% (CI 4.39 - 29.21). Continuous and moderate LBP was negatively associated with age OR 0.62, 95% (CI 0.40 - 096) for continuous pain and OR 0.57, 95% (CI 0.36 - 0.90) for moderate pain. For other MSDs, age was significantly associated with right wrist pain AOR 1.66, 95% (CI 1.01- 2.72). Conclusion: LBP is prevalent among workers in the Oil & Gas construction projects in Oman. Working in the Oil & Gas industry in Oman is associated with an increased risk of LBP, in line with other studies done elsewhere. The study found that there are lifestyle and occupational factors that are significantly associated with LBP. Appropriate measures need to be taken in terms of policy, accompanied by improved lifestyle behaviours and the working environment in order to reduce the burden of LBP and other MSDs
Lived experiences of psychiatric nurses caring for mental healthcare users with a comorbid disorder at a psychiatric hospital in Limpopo Province
Get PDFAbstract: Caring for mental health care users (MHCUs) with comorbid disorders has always been a challenge and requires expert knowledge, skills, intuition, feelings and empathy. Comorbid disorders create significant challenges for the psychiatric nurses caring for these MHCUs. A comorbid disorder refers to the simultaneous manifestation of two or more disorders in a patient. In this study, it means a mental healthcare user is suffering from a physical and a mental disorder, such as schizophrenia and the Human Immunodeficiency Virus (HIV). As a result, the objectives of this study were to: • To explore and describe the lived experiences of psychiatric nurses caring for MHCUs with a comorbid disorder in a psychiatric hospital in Limpopo Province. • To develop specific recommendations to facilitate the mental health of psychiatric nurses caring for MHCUs with a comorbid disorder. A qualitative, exploratory, descriptive and contextual research design was used, and the research was carried out over two phases. Phase 1 focused on exploring and describing the lived experiences of psychiatric nurses caring for MHCU with a comorbid disorder in a psychiatric hospital in Limpopo Province. Phase 2 focused on specific recommendations to facilitate the mental health of these psychiatric nurses. Purposive sampling was employed in selecting participants for the study. The inclusion criteria were psychiatric nurses caring for MHCUs with a comorbid disorder in a psychiatric hospital in Limpopo Province. Participants could be male or female, and had to be able to communicate in English. Data were collected using in-depth phenomenological interviews, observational notes and field notes. The central question posed to the participants was, “What is it like to care for MHCUs with a comorbid disorder?” Eight participants were interviewed, and data saturation was reached...M.Cur. (Nursing Sciences
Young South African adults in the Johannesburg area and their experiences of coping with childhood trauma
Get PDFAbstract: This study explored the experiences of young South African adults’ coping with childhood trauma in the Johannesburg area. The purpose of the study was to investigate: their experiences and descriptions of childhood trauma; the coping mechanisms that they utilised to overcome the adverse effects of childhood trauma; and the support systems that were imperative in helping them to develop resilience and ultimately overcome their childhood trauma. A generic qualitative approach within the social constructivist paradigm was used for this study. There were five participants who were interviewed using a semistructured interview. The interviews were then transcribed and analysed using QDA Miner. A thematic analysis was used to generate categories of information. The focus areas that were identified after the thematic analysis were the experiences and effects of trauma, coping mechanisms, support systems, resilience and hopes with regard to this research. The findings confirmed what the research says about adverse effects as all participants struggled with adverse effects due to the childhood trauma. These adverse effects included depression and anxiety. The participants all started off by using maladaptive coping mechanisms to cope with their childhood trauma. However, they have since adopted more positive, healthy coping mechanisms. Teachers, therapists, family and significant others have all proven to be important support systems that helped participants to build resilience and overcome their childhood trauma.M.Ed. (Educational Psychology
A Comparative Study of Ensemble Models for Predicting Road Traffic Congestion
Get PDFAbstract: Please refer to full text to view abstrac
Assessing the water quality of selected public swimming pools within the Johannesburg area of the Gauteng province, South Africa
Get PDFAbstract: A number of contaminants in public swimming pools have been recognised globally, all of which are detrimental to the quality of such amenities as well as to human health. Thus, swimming pool water may serve as a medium for the transmission of waterborne pathogens amongst swimmers unless appropriate preventive measures are properly implemented. Moreover, at certain times various researchers have linked the poor quality of swimming pool waters to pathogenic outbreaks. Despite such negative health impacts, studies focusing on the water quality of swimming pools are limited in South Africa. Even so, the quality of drinking water in most African countries is alarming, let alone the quality of public swimming pool water. As a result, the present study was carried out to assess the water quality of selected public swimming pools within the CoJ Metropolitan Municipality, in the Gauteng province in South Africa. The swimming pool water’s pH, electrical conductivity, temperature, free available chlorine, total chlorine, alkalinity, water hardness, and cyanuric acid were measured on site while the collected water samples were analysed at the laboratory for the presence microbiological agents (i.e. E. coli and total faecal coliforms). The results showed different degrees of unsatisfactory and non-compliance across all selected public swimming pools. The findings also indicated the presence of waterborne pathogens largely due to inadequate disinfection. It has also been established that the existing recirculation-filtration systems are not always working optimally (due to electrical load shedding) and water chemical imbalances, thus resulting in water quality non-compliance. Unfortunately, surrounding communities use such facilities for recreation and leisure time, despite their health and hazard potential. Based on the results of this study, it is recommended that the swimming pool waters must be effectively treated to inactivate and kill microbes, therefore providing chemically balanced water. Furthermore, water quality testing kits and water quality sensors can be used to measure multiple physical and chemical water quality parameters simultaneously and to provide instant results.M.Sc. (Environmental Management
Detecting Learning Patterns in Tertiary Education Using K-Means Clustering
Get PDFAbstract: We are in the era where various processes need to be online. However, data from digital learning platforms are still underutilised in higher education, yet, they contain student learning pat- terns, whose awareness would contribute to educational development. Furthermore, the knowledge of student progress would inform educators whether they would mitigate teaching conditions for critically performing students. Less knowledge of performance patterns limits the development of adaptive teaching and learning mechanisms. In this paper, a model for data exploitation to dynamically study students progress is proposed. Variables to determine current students progress are defined and are used to group students into different clusters. A model for dynamic clustering is proposed and related cluster migration is analysed to isolate poorer or higher performing students. K-means clustering is performed on real data consisting of students from a South African tertiary institution. The proposed model for cluster migration analysis is applied and the corresponding learning patterns are revealed
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