Results 181 - 190 of 270

• Electromagnetic Surface Fields Due to a Magnetic Dipole Buried in a Three-Layered Earth
  10/1/1982 - Reports of Investigations
  The Bureau of Mines electromagnetic trapped miner location and communications system requires a thorough understanding of TTE electromagnetic wave propagation.
• Methodology for Determining Occluded Gas Contents in Domal Rock Salt
  9/1/1982 - Reports of Investigations
  The Bureau of Mines has developed two experimental designs for determining the volumes and relative proportions of the various gas species, particularly methane (CH4), occluded in rock salt. The two methods are ball- mill crushing and dissolution. Of th...
• Investigation of Methane Emissions From an Advancing Face in the Belle Isle Domal Salt Mine, Louisiana
  1/1/1982 - Reports of Investigations
  The Bureau of Mines measured methane emission rates from an advancing salt face ranging from 15 to 56 ft3/ton (0.5 to 1.8 M3/t). Small room size, use of a continuous miner, and a well-defined ventilation system made possible air velocity and methane con...
• Underground Gob Gas Drainage During Longwall Mining
  1/1/1982 - Reports of Investigations
  The Bureau of Mines is developing underground gob gas drainage as an alternate means of methane control for U.S. longwalls. Holes are drilled into the roof over the panel and on retreating longwalls, towards the working face from a location inby the fac...
• Performance Evaluation of Electromagnetic Techniques for the Location of Trapped Miners
  1/1/1982 - Reports of Investigations
  The Bureau of Mines (NIOSH Mining) has conducted field studies in coal mines throughout the United States to determine the effectiveness of electromagnetic techniques in locating miners trapped underground following a mine accident.
• Degasification of the Mary Lee Coalbed, Brookwood, Ala
  1/1/1982 - Reports of Investigations
  The Bureau of Mines has developed several techniques for draining methane from coalbeds in advance of mining. Drilling long horizontal holes from an underground location is one such technique, which was successfully demonstrated in the Pittsburgh and Su...
• Drilling a Horizontal Coalbed Methane Drainage System from a Directional Surface Borehole
  1/1/1982 - Reports of Investigations
  Three long horizontal holes were drilled from a directionally drilled surface hole at the Emerald Mine near Waynesburg, Pennsylvania. The purpose was to adapt the technique of directional drilling for use in draining methane from coalbeds.
• Probability of Encountering Coalbed Discontinuities During Vertical and Horizontal Borehole Drilling
  1/1/1982 - Reports of Investigations
  Probabilities of encountering coalbed discontinuities during vertical or horizontal drilling in a specific coalbed can be estimated based on analysis of mined-out areas of the coalbed where the size, shape, orientation, and distribution of discontinuiti...
• Degasification Study From an Air Shaft in the Beckley Coalbed
  1/1/1982 - Reports of Investigations
  The Bureau of Mines conducted research to degasify a virgin block of coal in the Beckley coalbed using long horizontal holes drilled in an array from the bottom of a ventilation air shaft. Eight horizontal holes and an in situ pressure hole were drilled...
• Evaluation of the Seismic System for Locating Trapped Miners
  11/1/1981 - Reports of Investigations
  This report discusses the configuration and system deployment for the postdisaster surface seismic system for detecting and locating trapped miners.