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11/1/1974 - Contract reportsEight coal mines were visited to determine their communications usage and requirements. Volume 1 summarizes the entire report and includes both a dissertation on the strengths and weaknesses of various available communication techniques and a set of re...
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11/1/1974 - Contract reportsEight coal mines were visited to determine their communications usage and requirements. Available equipment was surveyed and evaluated to determine its applicability to the needs of the mines. Volume 3 contains all information used in predicting the per...
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11/1/1974 - Contract reportsEight coal mines were visited to determine their communications usage and requirements. Volume 4 describes the propagation measurements made in selected mines during the project, along with findings resulting from these measurements.
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9/1/1974 - Contract reportsTwo different techniques were used to make measurements of the absolute value of electromagnetic noise in an operating coal mine, Itmann No. 3 Mine, located near Mullens, West Virginia. The electromagnetic environment created by 250-volt dc and 550- and...
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9/1/1974 - Contract reportsTwo different techniques were used to make measurements of the absolute value of electromagnetic noise in and above an operating coal mine, McElroy Mine, located near Moundsville, West Virginia. The electromagnetic environment created by 300-volt dc and...
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9/1/1974 - Contract reportsTwo different techniques were used to make measurements of the absolute value of electromagnetic noise in an operating coal mine, Robena No. 4, located near Waynesburg, Pennsylvania. One technique measures noise over the entire electromagnetic spectrum ...
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1/10/1974 - Contract reportsField studies of ambient electromagnetic noise and electrical transmission properties of coal mine overburdens in Colorado, Illinois, Pennsylvania, and West Virginia were conducted. Field tests of the transmission of low-frequency (20 hz to 20,000 hz) s...
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1/1/1974 - Reports of InvestigationsMethane concentration peaks were measured at coal mine working faces during entry development. The statistical distribution of peaks was found to be normal or log normal depending on how well the methane was being mixed into the ventilation airstream.
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1/1/1974 - Information CircularsThis Bureau of Mines survey of methane emissions indicates that total daily emissions have declined from 227 mm ft3 in 1971 to 214.7 mm ft3 in 1973. The highest average daily emissions in million cubic feet per day are detailed by state.
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1/1/1974 - Information CircularsThe Technology Transfer Seminar on Mine Communications held on March 21-22, 1973, at the Pittsburgh Mining and Safety Research Center, Bruceton, Pennsylvania, presented information about recently developed equipment, instruments, and techniques for use ...
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Content source: National Institute for Occupational Safety and Health, Mining Program