No description available.

This is an interdisciplinary, descriptive, empirical study and analysis of the use of opencast mining in a complex process of commercialisation of the coal industry, its impact upon the environment and communities. Much of the initial research was undertaken during a series of public inquiries into opencast mining which provided the wealth of material contained in the thesis. The thesis advanced here is that the State has regulated the supply of coal through positive discrimination for opencast coal in the operation of the planning system and by arbitrary financial regulation of British Coal operations. The argument presented is that despite contrasting approaches and political processes in Scotland and North East England, opencast coal production has been used as a common facilitator towards the commercialisation of the coal industry. Descriptive analysis is given of the changing strategic use of opencast mining across the decades, from its early commercial development and the policy of dual control to its intensive application to assist the coal industry meet government financial and operational directives. The expansion of opencast mining can be attributed to changes in the political economy of the 1970's, the application of the private sector ethos of input-output ratios and management control, the unprecedented (mis)use of secondary planning legislation and the continued use of narrow accountancy procedures. Despite the denials of British Coal, in the North East of England opencast coal output has supplanted deep mined capacity and has been maximised to the limits of the Power Generators* specifications for burning coal to maximise profit and provide a "bank' of assets to attract private investment. The strategy in Scotland shows opencast mining holding the markets during radical reconstruction of the industry, hibernating' investment to make the industry attractive for the private sector. Both strategies have been set within a general "sweetening' operation of the coal industry. The work assesses the changing policy process of environmental planning, planning law and the public inquiry process in relation to opencast coalmining. Two major attitude surveys in Scotland and North East England cover the social context of environmental planning policy, each confirm the marginalisation of the public to decisions made in opencast development. Certain themes define the scope of the thesis: The State’s approach to energy policy and planning policy. British Coal's economic "management' of coal production, as well as the attitudes of the public, public planning officials, British Coal and the National Union of Mineworkers in Scotland and North East England. Scrutiny of the market for coal and British Coal's claims for the need for opencast coal are given full coverage in light of the effects from the expansion of opencast mining on employment, the environment and people. Overall the thesis challenges accepted thinking on economic and planning policy aspects and technical requirements of opencast coal production in relation to deep mined coal.

Thesis (Ph.D.), University of the Witwatersrand, Faculty of Engineering (Chemical Engineering), 1983

The vertical guidance of longwall coal cutting machines (shearers), using a novel method of measuring machine position relative to the coal seam, is considered. Coal is a stratified sedimentary rock made up of horizontal layers of material with different physical properties, in particular hardness. A cutting pick mounted on the periphery of a rotating shearer drum will experience variations in cutting force as it passes through the various layers of the coal. The pattern of forces experienced as the drum rotates will be unique and if the drum is displaced in the vertical sense relative to the seam, then the force pattern will be similarly displaced. Therefore comparison of pick force patterns can form the basis for a drum position measurement system. An experimental trial was conducted to assess the viability of this concept. The results of the trial showed that it was possible to detect and measure changes in the vertical position of a shearer cutting drum, when cutting an artificial 'coal' face. On-line measurement of drum position was used to satisfactorily control a shearing machine. The effects of the pick force data signal to noise ratio, on the accuracy of the measurement system employed was considered by simulation, The minimum signal to noise ratio of data which could be used to give acceptably accurate results was determined. Simulation has been used to compare the operation of a proposed 'pick force' based control system with that of an existing guidance system. The results show the systems perform in a similar manner. The effect of time delay in the measurement of position by pick force analysis, on control was also studied to determine the maximum acceptable lag.

Thesis (M. Sc.)(Chemisty) -- University of Pretoria, 2009. / Summary in English.

Thesis (M.A.)--Guo li Taiwan da xue. / Includes bibliographical references (p. 110-113).

Thesis (Ph. D.)--University of Queensland, 2003. / Includes bibliographical references.

No description available.

No description available.

No description available.