Thesis (DPhil(Communication Pathology))--University of Pretoria, 2004. / Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains x, 162 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 160-162).

M.Ing. / In the mining industry safety is a primary concern. Especially so when it comes to the large conveyances transporting people, equipment and ore up and down the shaft. Even though it has occurred seldomly, a so-called "slack rope event" - when the conveyance gets stuck in its guides - is extremely dangerous. If the conveyance should become freed it will fall freely until all the slack rope has been taken up and then whiplash. The immense strain could lead to complete failure of the rope or suspension mechanisms. The large deceleration rates experienced could in itself be sufficient to cause serious injury or even death to passengers. A strategy to alleviate this danger, originated by Greenway and Hymers (41), is to have passive energy absorber units in parallel to the suspension mechanism of the conveyance. In the event of an emergency the suspension mechanism will be detached and the absorbers will then be activated, safely absorbing the kinetic energy the conveyance has gained. The dynamic behaviour of the system with and without the energy absorbers in a free fall situation was studied and it was clear that the hazards associated with a slack rope event could be successfully alleviated using the energy absorbers. The question that now presented itself was, which energy absorbing mechanism should be used in this application. An encompassing set of qualifying criteria was subsequently set and after extensive research and evaluation the cyclic plastic bending energy absorber was deemed to be most suitable for this application, as also suggested by Greenway and Hymers (41). The device uses a metal element being bent and unbent while being pulled through a set of rollers. The kinetic energy is transformed to plastic metal deformation and dissipated as low grade heat. Further research was then done on this energy absorbtion device. It revealed a substantial amount of background information and two approximate equations for prediction of the resistive force delivered by the device. It was subsequently attempted to find an analytical solution from first principles, to predict the resistive force and characteristic behaviour of the device. Two solutions were obtained, using different approaches to the problem. A number of experiments were then conducted to study the actual characteristics and behaviour of the device. After manipulation of the results it was found that non-dimensional parameters could be formulated which would make it possible to predict the behaviour of full-scale prototypes using small-scale models. Upon comparing the experimental results with the analytical solutions it was found that the two analytical solutions provide an upper and lower bound to the experimental results. Finite element analysis was also utilized to characterize the behaviour of the device and to attempt to predict the resistive force the device delivers. The finite element models revealed some interesting characteristics of the device and mimicked the behaviour of the actual device. However, the resistive force values obtained, deviated slightly more from the experimental values than the scaling method or the analytical solutions. It is thus possible to predict the behaviour of the cyclicplastic- bending energy absorber by utilizing scaling techniques, analytical solutions or the finite element method. The cyclic-plastic-bending energy absorber has a wide spectrum of applications as it is a very versatile and reliable energy absorber.

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains iii, 240 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 221-232).

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xii, 130 p. : ill. (some col.), map (part col.). Includes abstract. Includes bibliographical references (p. 127-130).

Risk analysis using likelihood or probability and consequence (L x C) is prone to both methodological and application errors. This contributes to difficulties in achieving risk reduction. As an alternative to the L x C model, this study reviews risk and control effectiveness within the Australian extractive minerals industry. It draws on existing models, locally and internationally, and their application in other industry contexts. The study contends that control effectiveness is more useful and beneficial than L x C alone in determining ‘acceptable’ risk. This hypothesis is substantiated by the development of an alternative model, Major Accident Control Analysis (MACA), based around the prevention of fatalities by exploring and quantifying the following control parameters: 1) controls pre and/or post event, 2) the control type, and 3) the effectiveness of the specific control. By assigning these control parameters, discrete values, comparisons between individual ‘risk’ scenarios and established numerical acceptability risk criteria are possible. The theoretical proposition of this research was tested using detailed case studies to highlight the flaws of conventional risk analysis and, instead, accentuate control effectiveness as a superior method for prioritising risk and determine acceptability. The results of the research demonstrate that control effectiveness, utilised by the MACA method, is particularly valuable when limited data is available to permit quantification, data is too generalised for the operating conditions and where qualitative risk estimates are insufficient and inappropriate to prevent fatalities. MACA employs mathematically valid algorithms previously not envisaged nor developed by earlier methodologies. Importantly, these algorithms enable an interchangeable conversion of control effectiveness ‘values’ to risk ‘values’. Beyond the immediate findings of the research, the additional benefits of control effectiveness are multiple. The principles are suitable to the dynamic nature of the minerals industry, yet are highly adaptable and can be readily applied beyond the field of mining. The methodology could be applied to any circumstance where traditional risk analysis is typically undertaken, thus demonstrating broader application and significance. Furthermore, the methodology is compatible with, and complementary to, existing risk approaches. The intrinsic flexibility offered by this alternative method makes provision for international variations of risk criteria used to determine ‘acceptability’. It is thus determined that the application of control effectiveness estimation offers benefits over and beyond those currently employed.

Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains vi, 59 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 57-59).

No description available.

Since the MINER Act of 2006, the minimum static load of in-situ underground mine seals has been increased from 20-psi to either 50-psi if monitoring is conducted or 120-psi if left unmonitored. These minimum strength requirements in seals must be designed, built, and maintained throughout the lifetime of the seal. Due to this, it has become necessary to assess the effectiveness of non-destructive testing (NDT) technologies to determine seal integrity, which in this case, are explored using sonic waves and tracer gases. Through both small and large scale testing, two NDT methods were evaluated on their abilities to determine integrity of the seal. A sonic wave technique to observe a change in wave velocity to identify faults within the seal material. As a NDT method, tracer gases may be used as a potential indicator of a connection between both sides of the seal material through a series of faults and cracks within the material itself. This paper reviews the history of underground mine seals and discusses the overall assessment of sonic waves and tracer gases to serve as NDT methods for estimating the integrity of these seals. / Master of Science

M. Tech. (Cost and Management Accounting, Faculty of Management Sciences), Vaal University of Technology / Statistics in South Africa show that the fatality and injury rates within the mining industry have dropped since the end of the apartheid era. Regardless of the drop the fact remains that the mine workers, who are often the breadwinners, are still dying in the country’s mines leaving their families behind without any source of income. If they do not die they may suffer crippling injuries due to mine accidents making it impossible for them to perform their daily duties at work which results in the loss of income, loss of quality of life and this produces a humanitarian and a socio-economic problem. Mining companies incur enormous costs due to fatalities and injuries. Hence a target for zero fatalities was set in the mining industry for 2013. However, the industry has failed to reach this target that it set for itself and it is therefore of the utmost importance to encourage mining companies to invest more than they do currently in safety in order to prevent these fatal and crippling injuries due to mine accidents. The purpose of this study was to determine whether or not the requirements of safety legislation are observed and complied with by a single Colliery in South Africa that was selected for this study. The study also sought to investigate whether or not the employees of this mine observe the safety regulations to ensure safety and to maintain an accident free working environment. An analysis of organizational safety control mechanisms and production cost was conducted through the use of a structured questionnaire, completed by 151 participants. Descriptive statistics, frequency tables, exploratory factor analysis (EFA), one-way analysis of variance (ANOVA) and t-test were utilized to analyse the data. The results indicate that the Colliery was compliant with the safety legislations, a positive employee safety attitude had been cultivated and there was provision of adequate safety facilities through safety investments. Cost reduction due to the application of safety controls was also established, yet it was found necessary for the Colliery to enforce and encourage the application of safety measures to reduce the costs that are still incurred as it is evident that the application of safety controls results in reduced costs. Although the Colliery was considered compliant, with its employees showing a positive attitude towards safety controls, and with safety investments made and cost reduction achieved due to safety measures, ANOVA revealed different perceptions based on the departments in which the employees work, years of experience, English proficiency and qualifications. However, no differences were found in relation to gender and designation.