Modify Selection
- Document types:
- Contract reports
Home Links
Results 41 - 50 of 74
-
9/1/1978 - Contract reportsThis report describes the feasibility test of an electromagnetic method for locating boreholes, with or without casing, that have been drilled in conjunction with mining operations but without precisely known locations with respect to the tunnel.
-
1/1/1978 - Contract reportsThis report presents system objectives and design criteria for an in-mine ultralow frequency radio paging system.
-
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 reports, Open File ReportsAn existing computer program for mine ventilation network is modified so that it can simulate ventilation conditions under the influence of mine fires. The resulting new program is designed for the practical ventilation engineer and should be applicable...
-
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 ...
-
9/1/1977 - Contract reportsThis report describes magnetic field measurements in the Helvetia Coal Co. Lucene No. 8 Mine for purposes of deriving a mapping of the magnetic field strength covering the major haulageways which contain conductors.
-
9/1/1976 - Contract reportsThis report describes an operational communications system which provides remote intra-terrestrial wireless transmission of environmental information.
-
This study addresses several engineering and economic facets of possible roll-over protective structure (ROPS) and falling object protection structure (FOPS) requirements in the metal-nonmetal mining industry.
-
7/1/1975 - Contract reportsThe applicability of voice bandwidth compression techniques to mine wireless communication systems is examined. Promise has been attached to such techniques because the lessened bandwidth gave hope for lessened received noise and hence increased operati...
-
4/1/1975 - Contract reportsThe pager phones used in many underground coal mines are battery-operated, party-line telephones with provisions for loudspeaker paging. The system is two-wire, non-polarized, and is operated by self-contained batteries. A description of the many teleph...
Home Links
Content source: National Institute for Occupational Safety and Health, Mining Program