1973 | Mining Publications
In 1969, new coal mine health and safety legislation was enacted in the United States. As a result of this legislation, the Department of Interior, Bu...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 62-72 | National Institute for Occupational Safety and Health (NIOSH)
The use of radio signals for underground communications was considered as early as the mid-1920's [1] - [4] . However, early experiments did not produ...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 38-48 | National Institute for Occupational Safety and Health (NIOSH)
This paper is concerned with the theoretical study of UHF radio communication in coal mines, with particular reference to the rate of loss of signal s...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 20-33 | National Institute for Occupational Safety and Health (NIOSH)
One aspect of a program to improve the chances of survival following coal mine disasters is the development of a communications system which will allo...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 54-61 | National Institute for Occupational Safety and Health (NIOSH)
Radio propagation measurements were conducted in a coal mine at UHF (200 to 1000 MHz) and VLF (1 to 50 kHz) to characterize the transmission loss of i...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 15-19 | National Institute for Occupational Safety and Health (NIOSH)
Introduction The fields of an infinite line source in the presence of a conducting half-space have been examined by Wait and Spies (1971). In any real...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 73-80 | National Institute for Occupational Safety and Health (NIOSH)
An approximate solution to the electromagnetic boundary value problem consisting of a horizontal cylindrical conductor buried in a lossy half-space an...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 112-120 | National Institute for Occupational Safety and Health (NIOSH)
Considerable current interest is evident[l,2] in the use of transient electromagnetic methods for subsurface remote sensing. A transient method is dis...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 140-148 | National Institute for Occupational Safety and Health (NIOSH)
nvestigation into the expressions of the field produced by a loop over a conducting half space or in an infinite conducting half space are well docume...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 130-139 | National Institute for Occupational Safety and Health (NIOSH)
To realize a radiowave communication along mine galleries a few kilometers long without repeater, we show that it is possible to use a coaxial cable b...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 162-167 | National Institute for Occupational Safety and Health (NIOSH)
Explicit expressions are presented for the input admittance and effective height of several buried metal antennas, namely: (i) prolate spheroidal; (ii...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 169 | National Institute for Occupational Safety and Health (NIOSH)
The present status of the National Bureau of Standards program is that many magnetic tapes of analog data have been recorded in four major mines. Each...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 162-167 | National Institute for Occupational Safety and Health (NIOSH)
During the last week in March and the first week in April, 1973, the Naval Underwater Systems Center measured the 76 Hz magnetic field strength (in Wi...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 161 | National Institute for Occupational Safety and Health (NIOSH)
Noise processing experiments with ELF (3 to 300 Hz) atmospheric noise and signals in the 40 to 80 Hz range are described. The primary purpose of the e...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 168 | National Institute for Occupational Safety and Health (NIOSH)
An electromagnetic sounder developed for an archaeological application in Egypt has been successfully tested in a California dolomite mine. Chambers i...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 9-14 | National Institute for Occupational Safety and Health (NIOSH)
It is the purpose of this paper to review theoretical model concepts in through- the -earth transmission of electromagnetic waves. While the subject i...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 48-53 | National Institute for Occupational Safety and Health (NIOSH)
So far as the propagation of electromagnetic waves is concerned, an underground tunnel behaves like a pipe or hollowed waveguide. Waves propagate in t...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 34-37 | National Institute for Occupational Safety and Health (NIOSH)
The Coal Mine Health and Safety Act of 1969, passed by Congress in the wake of the disaster at Farmington, West Virginia, led to an extensive study by...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 92-94 | National Institute for Occupational Safety and Health (NIOSH)
Three -dimensional boundary value problems are difficult to solve. Indeed, while the separation of the scalar wave equation can be effected in 11 diff...
1973 | Proceedings of Thru-the-Earth Electromagnetics, August 15-17,1973, Colorado School of Mines, p. 95-97 | National Institute for Occupational Safety and Health (NIOSH)
I do not regard the criticism by Rankin of my work as valid or even meaningful. I strongly reject the assertion by Rankin that my results are invalid....
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