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Results 221 - 230 of 270
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1/1/1977 - Reports of InvestigationsTwo degasification test boreholes were drilled to depths of 1,238 and 1,212 feet on Bureau of Mines property at Bruceton, Pennsylvania, as part of the Bureau of Mines long-range coal degasification program.
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1/1/1976 - Reports of InvestigationsThis report describes three coal mine ventilation studies by the Bureau of Mines in which sulfur hexafluoride (SF6) was used as a tracer gas.
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1/1/1976 - Reports of InvestigationsThe Bureau of Mines conducted research to determine the effectiveness of long holes drilled in solid virgin coal in degasifying an area of the Pittsburgh coalbed showing that horizontal holes drilled into a virgin coalbed from the bottom of any shaft wi...
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1/1/1976 - Reports of InvestigationsIt is estimated that more than 1 trillion cubic feet of methane is contained within the coals of the Mary Lee Group in Jefferson, eastern Tuscaloosa, and southern Walker Counties, Alabama. It is calculated that approximately 90 pct of the methane is at ...
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1/1/1976 - Reports of InvestigationsCoalbeds exhibit a directional permeability, with the maximum permeability oriented parallel to the face cleat. Thus, the most efficient pattern of vertical degasification holes for a coalbed is dependent upon cleat orientation. Analysis of surface joi...
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1/1/1976 - Reports of InvestigationsThe theory of electromagnetic fields indicates such fields could be used to detect and locate trapped miners. To be useful, the hardware of the system must meet a number of requirements, including small size, intrinsic safety, and rugged construction. S...
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1/1/1976 - Reports of InvestigationsThe methane emissions from an advancing coal mine section were continuously monitored for 120 days. During this time, the section advanced 2,000 feet into virgin Pittsburgh coalbed producing 54,565 tons of coal with a total methane emission of 91 millio...
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1/1/1976 - Reports of InvestigationsA seismic system which utilizes in-mine geophones to detect trapped miners has been developed. Tests at the Bureau of Mines safety research mine at Bruceton, Pennsylvania, and at two operating mines indicate such a system has a maximum detection range i...
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1/1/1976 - Reports of InvestigationsThis Bureau of Mines study reviews the geological factors that affect methane in the Beckley coalbed in southern West Virginia, including overburden, coalbed structure, type and changes in lithology above and below the Beckley coalbed.
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1/1/1976 - Reports of InvestigationsExamination of several coalbeds in Walker County, Alabama, Cambria, Greene, and Fayette Counties, Pennsylvania, and Caleigh and Wyoming Counties, West Virginia, indicates that cleat orientations are similar throughout a vertical sequence of strata. Stud...
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Content source: National Institute for Occupational Safety and Health, Mining Program