Results 291 - 300 of 341

• Adaptive-Noise-Cancellation Techniques for Through-the-Earth Electromagnetics: Volume III
  2/1/1984 - Contract reports
  An electromagnetic (EM) system for the location of trapped mine workers at coal-mine (300 m) depths has been developed.
• Electromagnetic Detection of Trapped Miners
  2/1/1984 - Peer reviewed journal articles
  The Bureau of Mines 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.
• Underground Mine Communications, Control and Monitoring
  1/1/1984 - Information Circulars
  Since 1969, the Bureau of Mines has sponsored numerous programs aimed at improving methods of underground communication. This manual brings together relevant data from all previous reports, studies, and other sources, and presents these data in such a w...
• A Short-Range Locator System for Detecting Trapped Miners
  1/1/1984 - Reports of Investigations
  A short-range locator system capable of locating trapped miners has been devised. The system consists of a light-weight, low-power radio transmitter incorporated into a miners cap lamp battery and a directional receiver carried by rescuers.
• Field Test of a Post-Disaster Communication System
  12/1/1983 - Contract reports, Open File Reports
  A new postdisaster communication and location system using through-the-earth electromagnetic wave propagation was tested at the Bureau of Mines Lake Lynn Experimental Mine. This describes the testing process and findings.
• Development of a Phase Difference of Arrival Technique for Location of Trapped Miners
  9/1/1983 - Open File Reports
  Current technologies for locating trapped miners from the surface are either simple direction finders or time difference pulse systems that have accuracy limitations. Developing technologies using full-vector field measurements at several receiving poin...
• Evaluation of Safety Assessment Methods for the Mining Industry. Volume II: User's Manual of Safety Assessment Methods for Mine Safety Officials
  5/1/1983 - Contract reports
  This study examines a cross section of formal safety analysis techniques developed for the nuclear and aerospace industries, recommending those methods suitable for application to the mining industry and including those methods in a user's manual.
• Above-the-Earth Field Contours for a Dipole Buried in a Homogeneous Half-Space
  1/1/1983 - Reports of Investigations
  An essential element of the USBM electromagnetic location and communication system for trapped miners is knowledge of the surface and above-surface electromagnetic fields created by an underground transmitter.
• A Medium Frequency Wireless Communication System For Underground Mines
  1/1/1983 - Contract reports
  An underground medium frequency radio communications system has been developed and demonstrated in both coal and metal/non metal mines. The principal advantage of the system are its low cost, ease of installation and the ability to provide radio communi...
• Theoretical Noise and Propagation Models for Through-the-earth Communication
  9/1/1982 - Contract reports
  A survey of the literature on extremely low-frequency and very low- frequency atmospheric noise was made.