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Life extension of systems for coal-fired power plants
Full text linkAbstract: Electricity is a crucial commodity for humankind. Population growth, industrial development, and urbanization are key factors steering the electricity demand globally. The power supply internationally is dominated by coal-fired power plants, although there is a gradual introduction of alternative energy systems, such as renewable energies, these are not meeting nor overcoming the need. Besides, renewable energy systems are more expensive compared to coal-fired systems. The coal-fired energy plants are required to run at full capacity to meet the electricity demand, resulting in the coal-fired infrastructure deteriorating, due to plant load variation and age. These concerns, therefore, necessitate optimum planning, strategies, and cost-effective resolutions to asset maintenance. There is a need for South Africa to follow this norm. This study investigates the life extension of systems for coal-fired power plants. This research aims to get a clear understanding of the contributing factors which influence a coal-fired boiler’s performance. Also, by examining the holistic reliability engineering and cost-effective maintenance philosophies for a coal-fired boiler. In finding answers for the mentioned themes, the study starts with the literature review to set a foundation, and the knowledge is used later to test the research findings. The three variables are used for this examination i.e., the boiler’s performance from two power plants, the contributing factors that influence the coal-fired boiler performance, and the reliability level of existing boilers from both organizations. The researcher uses secondary data from Company B and Company K. The research findings indicate a decline in boiler's performance over time. Moreover, the quantitative results from the Pareto chart analysis of both power stations demonstrate similar contributing factors that affect coal-fired boilers’ performance i.e., coal quality, soot blowing, tube leak, poor combustion failure, and forced drive fan failure. Lastly, the mean time between failure results of boilers reveals that both power plants have lower reliability levels.M.Phil. (Engineering Management
State of clinical social work in South Africa
Full text linkAbstract: Clinical social work has a long tradition in South Africa, with the first formal training program starting in 1977. More recently, clinical social work has been legislatively recognized as a specialization within social work, and clinical social workers will soon begin to register with this specialization. This article presents the only review of clinical social work in South Africa. It maps the history of the field, its current definition, training opportunities and registration (licensing) procedures. Drawing on a national survey of clinical social workers, the article describes the range of theories and practice modalities employed by clinical social workers, foregrounding the use of grief counselling, cognitive behavioral therapy, crisis intervention and psychodynamic therapy, and a predominance of individual work. Three case examples of clinical practice are advanced, related to a range of contemporary issues, including grief, violence, gender identity, sex work, migration and clinical work in macro contexts. The authors conclude with a reflection on the challenges and future directions for clinical social work, emphasizing clinical practice within a developmental social welfare approach and the need to address decoloniality and indigenous practice in the African context
Modular/Block teaching : practices and challenges at Higher Education Institutions of Ethiopia
Full text linkAbstract: The purpose of the study was to investigate the practices and challenges of modular/block teaching in higher education institutions of Ethiopia. A descriptive survey design was used with instructors and students. Questionnaires and semi-structured interviews were used to gather data and analysed quantitatively (descriptive and inferential statistics) and qualitatively (thematic analysis). The results showed variations in practice across different universities. It was found that modular/block teaching helps students to concentrate on one subject at a time but does not place emphasis on practical skills; this means that the theory and practice of the theory stay separate, which does not make learning credible. Additionally, it was found that due to the limited time given for one course, it was difficult to implement active learning. Generally, instructors and students faced challenges in the practice of modular/block teaching. Practically, the authors have made suggestions for the better implementation of modular/block teaching
Applications of advanced materials in bio-sensing in live cells : methods and applications
Full text linkAbstract: A wide variety of species, such as different ions, reactive oxygen species, and biomolecules play critical roles in many cell functions. These species are responsible for a range of cellular functions such as signaling, and disturbed levels could be involved in many diseases, such as diabetes, cancer, neurodegeneration etc. Thus, sensitive and specific detection methods for these biomarkers could be helpful for early disease detection and mechanistic investigations. New ultrasensitive sensors for detection of markers within living cells are a growing field of research. The present review provides updates in live cell-based biosensing, which have been published within the last decade. These sensors are mainly based on carbon, gold and other metals, and their physicochemical advantages and limitations are discussed. Advanced materials can be incorporated into probes for the detection of various analytes in living cells. The sensitivity is strongly influenced by the intrinsic properties of the nanomaterials as well their shape and size. The mechanisms of action and future challenges in the developments of new methods for live cell based biosensing are discussed
Transcranial photobiomodulation prevents PTSDlike comorbidities in rats experiencing underwater trauma
Full text linkAbstract: Maladaptive fear memory processing after a traumatic event is a major contributor to the development of the comorbidities related to posttraumatic stress disorder (PTSD). An intervention to normalize this process could be a first-line treatment to prevent PTSD development. However, little progress has been made in identifying interventions that can prevent trauma survivors from developing PTSD. A treatment that could help trauma survivors cope with traumatic memories and decrease the prevalence of PTSD is thus in high demand. This study was designed to investigate the potential beneficial effects of early photobiomodulation (PBM) interventions to prevent PTSD-like comorbidities in animals. PTSD-like comorbidities in rats were induced by an underwater trauma (UWT) procedure, followed by multiple swimming sessions on later days for memory recall. Immediately after UWT and swimming, rats were restrained with or without PBM treatment (808 nm, 25 mW/cm2, 3 J/day). PTSD-like commodities, such as anxietylike behavior, depression-like behavior, and cognitive dysfunction, were reproduced in UWT-rats. These comorbidities, however, could be prevented by early PBM interventions. By measuring the expression of immediate early genes (IEGs) as neuronal activity markers, we found that PBM treatment differentially regulated Arc and c-fos expression in the hippocampus and amygdala, two PTSD-related brain regions. Additionally, PBM boosted ATP production and regulated protein expression in the hippocampus following stress. Our results demonstrate that PBM can modulate brain activity in response to traumatic and stressful events and that early PBM intervention can prevent the occurrence of PTSD-like comorbidities in rats
Obstacles to Venture Capital Funding : the South African entrepreneurs’ perspective
Full text linkAbstract: The primary objective of this qualitative study was to explore the challenges faced by entrepreneurs in acquiring funding from venture capitalist companies in South Africa. A purposive snowball sampling technique was adopted to collect data from ten entrepreneurs and ten venture capitalist companies using semi-structured face-to-face interviews. Thematic analysis of the data revealed a number of prominent themes. Findings indicated that venture capitalist investors consider personal qualities of the entrepreneur as a key indicator of a viable business opportunity when making investment decisions. It was further revealed that the investment evaluation process is both lengthy and costly. In South Africa, the economic and political environments are unstable and risky. This plays an influential role to venture capitalist investors when making investment decisions. The study contributes to the existing body of knowledge and points to issues that can be further investigated. The study also has managerial implications in that it provides guidelines to entrepreneurs on how to approach venture capitalist investors for investment. The study has some limitations in that the use of a non-probability sampling techniques implies that findings cannot be generalised widely. Furthermore, the study was conducted only in South Africa and findings therefore cannot be generalised across other markets
Exploring the challenges in leadership roles experienced by nurse managers in a mining primary healthcare setting in South Africa
Full text linkAbstract: Background: The challenges in leadership roles hinder the rendering of quality primary healthcare service in the mines. Mining, the heart of the South African economy, requires good health to its personnel to carry out operations. However, nurse managers, the leaders in a mining primary healthcare setting experience difficulties in their leadership roles. Objectives: The aim of this study was to explore and describe the challenges in leadership roles experienced by nurse managers in a mining primary healthcare setting in South Africa. Method: The study was conducted in a mining primary healthcare setting in West Rand, Gauteng province, South Africa. A qualitative, exploratory, descriptive design that is contextual in nature, using a phenomenological approach, was adopted. Data from nurse managers in the mine were collected and data saturation was reached by the seventh participant. The study followed Giorgi’s four stages of the phenomenological descriptive data analysis. An expert independent coder in qualitative research coded the data, and consensus on the findings was reached with the researcher. Results: Three subthemes emerged from the study: mining management and unions interfere with nurse managers’ leadership roles, incongruent mining primary healthcare policies and communication gap between nurse managers and mining management. Conclusion: The triangulation of nurse managers, mining management and unions requires a collective fusion to directly tackle the challenges in leadership roles in mining primary healthcare
Performance characteristics of unsaturated polyester reinforced with high frequency microwave treated natural fibre
Full text linkAbstract: Using the most environmentally sustainable agro-waste fibers as reinforcement has opened up a new direction for polymer composite research. Research has recommended that altering of fibre surface by both chemical and physical means, increases the performance characteristic of natural fibre/polymer matrix. In this study, high-frequency microwave irradiation at a frequency of 2.45 GHZ and 550W power was used to treat natural fibre extracted from plantain (Musa paradisiacal) pseudo steam. Microwave modified and untreated plantain fibre was used to fabricate a biocomposite using polyester resin as polymer matrix, by means of hand lay-up and compression moulding technique. Results reveal an increase in mechanical strength of the modified fibre reinforced bio-composites at optimised conditions, thus creating opportunities and consistency to be use in technological and structural applications
Measurements of and production in the -bb decay channel in collisions at 13TeV with the ATLAS detector
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Measurement of hadronic event shapes in high- T multijet final states at √ = 13 TeV with the ATLAS detector
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