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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Spatial variation of coke quality in the non-recovery beehive coke ovens

Segers, Magrieta. January 2004 (has links)
Thesis (M.Sc.)--University of Pretoria, 2004. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.
2

Bulk density and angle of repose of coal

Liu, Chang, Materials Science & Engineering, Faculty of Science, UNSW January 2007 (has links)
This thesis reports a study on the effects of size distribution, moisture content and oil addition on bulk density and angle of repose of coal. The experimental work includes four stages. The first stage is to develop reliable experimental techniques. The results confirm that ASTM cubic foot test is reliable for measurement of bulk density and angle of repose if properly operated, although the latter is better measured in a piling process. Stages 2 and 3 are to investigate the effects of size distribution by using -3.55mm% for stage 2 and mean size do.s for stage 3, water content and oil addition on bulk density and angle of repose of coal. For each of them, empirical equations are formulated to predict bulk density and angle of repose. The results indicate that the fraction -3.55mm cutting size in stage 2 does not affect bulk density significantly, while the increase of do.s decreases bulk density to a minimum and then increases. Particle size distribution does not affect angle of repose much. The increase of moisture content decreases bulk density and increases angle of repose significantly. The increase of oil addition increases bulk density while decreases angle of repose significantly. The correlation between bulk density and angle of repose can also be observed: the higher bulk density, the lower angle of repose. There are other variables affecting bulk density and angle of repose. They include oil type, absorption time discharging height and external loading. Their effects on bulk density and angle of repose are quantified in stage 4. The results suggest that, a higher discharging position or larger external loading increase bulk density significantly. Angle of repose decreases when increase the height of discharging position. Diesel oil performed better than waste oil addition in terms of bulk density enhancement. For most of the cases examined, bulk density and angle of repose become stable after ~24 hours oil absorption time.
3

Developing indicators for the assessment and proper management of the different levels of exposure to polycyclic aromatic hydrocarbons (PAH)s generally associated with coke-oven workers

Wang, Tianyuan January 2011 (has links)
Thesis (MTech(Environmental Health)--Cape Peninsula University of Technology, 2011 / Coke ovens may occur in the aluminium, steel, graphite, electrical, and construction industries. In the work area coke-oven workers may be exposed to various chemical compounds. Polycyclic aromatic hydrocarbons (PAHs), as human carcinogen, are primary compounds in coke oven emissions (COEs) generated in the coking process. Coke oven workers are often exposed to PAHs and can lead to a variety of human diseases.The primary routes of potential human exposure to coke oven emissions are inhalation and dermal contact. Occupational exposure may occur during the production of coke from coal, or while using coke to extract metals from their ores to synthesize calcium carbide, or to manufacture graphite and electrodes. Workers at coking plants and coal tar production plants, as well as the residents surrounding these plants, have a high risk of possible exposure to coke oven emissions.It is known that coke production could be carcinogenic to humans (Group-1) by IARC. There has been sufficient epidemiological evidence suggesting an etiological link between carcinogenic polycyclic aromatic hydrocarbon (PAHs) exposure and lung cancer risk among coke-oven workers. Lung cancer among coke-oven workers has been classified as one of the eight prescribed occupational cancers in China, and its incidence rate was about 10 times that of the general population. Therefore, lung cancer of coke-oven workers is still a critical issue in the field of prevention and control of occupational cancers in China.This thesis explores the various exposure levels of workers to PAHs at a steel plant in China. The measurement will focus on the exposure difference of personal sampling among workers in selected job classifications given the job descriptions and the coking process. The Benxi Steel Industry in Liaoning province of China (BXSI) was selected as the research location. Liaoning province is in the North of China and the location of various heavy industries in China. The measurements will be done two separate coke ovens in Benxi Steel Industry. One new coke oven was built in the 90's last century (coke oven N) and the other older coke oven was built in the 1940's in last century (coke oven O). In this research, the total number of employees that were selected in the sample for both coke ovens are 64 samples included 54 coke oven exposure workers and 10 non-exposure administrative workers working at the plants.
4

Landscapes of perception : reclaiming the Athabasca oil sands and the Sydney tar ponds

Dance, Anne T. January 2013 (has links)
This interdisciplinary project offers new insights into the reclamation history of two of the most controversial and contaminated sites in Canadian history: the Sydney tar ponds and coke ovens and the Athabasca oil sands. It argues that Canada’s natural resource-dependent economy, combined with jurisdictional uncertainty, created a hesitant, fragmentary site cleanup regime, one that left room for different ideas about landscapes to shape and even distort reclamation’s goals and processes. In the absence of substantive reclamation standards and legislation, researchers struggled to accommodate the unique challenges of the oil sands during the 1960s and 1970s. Ambitious goals for reclamation faltered, and even the most successful examples of oil sands reclamation differed significantly from the pre-extraction environment; reclamation was not restoration. Planners envisioned transforming northeastern Alberta into a managed wilderness and recreation nirvana, but few of these plans were realised. The Sydney tar ponds experience suggests that truly successful reclamation cannot exist unless past injustices are fully acknowledged, reparations made, and a more complete narrative of contamination and reclamation constructed through open deliberation. Reclamation, after all, does not repair history; nor can it erase the past. Effective oil sands reclamation, then, requires a reconsideration of the site’s past and an acknowledgement of the perpetuated vulnerabilities and injustices wrought by development and reclamation.

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