- Diseases and injuries
- Equipment, tools, and parts
- Geographic regions
- Hazard prevention and control
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- Mining types and methods
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Results 71 - 80 of 95
6/1/1980 - Contract reportsThe objective of this project was to develop technical data and evaluate performance and utility of leaky feeder communications systems currently used in U.S. underground mines.
10/1/1978 - Conference papersAn analysis is made of the trolley line as a communications line, and methods of improving its characteristics are discussed.
8/1/1978 - Conference papersMedium-frequency (MF) waves can propagate in a coal seam, bounded above and below by conducting rock, in an approximate transverse electro-magnetic (TEM) transmission-line mode with the electric field vertical and the magnetic field horizontal. The theo...
1/1/1978 - Peer reviewed journal articlesExtensive analysis of mine-communications systems has identified specific areas, in particular the excessive times required to locate key personnel underground, the inadequacy of existing phone systems in terms of capacity and privacy and the inability ...
1/1/1978 - Contract reportsThis report covers magnetic field strength measurements versus range and frequency in low to medium coal mines. Both quasi-conductor-free and conductor-proximity areas were investigated.
9/1/1977 - Contract reportsAn investigation was made of the feasibility of developing compact transmit antennas and/or other means to efficiently couple VLF to MF band radio energy between portable wireless communication units in coal mines. The completely wireless communication ...
1/1/1977 - Conference papersThis report is a comprehensive summary of the results of the propagation measurements program conducted for the Bureau of Mines.
1/1/1977 - Information CircularsThis Bureau of Mines report on underground mine communications addresses methods and equipment to meet the communication requirements of working sections and places of coal and metal-nonmetal mines. A review of the status of trapped miner detection is a...
1/1/1977 - Information CircularsThis Bureau of Mines report summarizes the research, development, and evaluation demonstrations conducted by the Bureau of Mines under the Coal Mine Health and Safety Act of 1969 to improve the means of notifying miners underground, who are away from th...
8/1/1976 - Conference papersA brief description is given of various Bureau of Mines research activities that have begun since July 1974 and are not being reported on by others at the Third West Virginia University (WW) Conference on Coal Mine Electrotechnology.