- 行业: Mining
- Number of terms: 33118
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The U.S. Bureau of Mines (USBM) was the primary United States Government agency conducting scientific research and disseminating information on the extraction, processing, use, and conservation of mineral resources.
Founded on May 16, 1910, through the Organic Act (Public Law 179), USBM's missions ...
For many transducers, the three-dimensional directivity is such that it may be represented by the surface generated by rotating a two-dimensional directivity pattern about the axis corresponding to the reference bearing of the transducer. This axis may then be described as an axis of acoustic symmetry or as the acoustic axis.
Industry:Mining
For many years, the Greenburg-Smith impinger was the routine dust sampling instrument in this country. It is still relied upon as a standard, but because of its size and weight, is little used underground today.
Industry:Mining
For measuring entire internal capacity of a vessel: One register ton equals 100 ft<sub>3</sub>(1.8 m<sub>3</sub>); for measuring cargo; one U.S. shipping ton equals 40 ft<sub>3</sub>(1.1 m<sub>3</sub>) or 32.143 U.S. bushels.
Industry:Mining
For mine timbers that are exposed to severe conditions of damp, ventilation, and stress, any of several chemicals used to impregnate them to resist dry or wet rot. These include copper sulfate, creosote, salt, sodium fluoride and silicofluoride, and zinc as chloride or sulfate.
Industry:Mining
For normal measurement, 0 degrees C (regarding gas properties). For thermodynamics and physical properties, either 18 degrees C or 25 degrees C, as defined in each stated case.
Industry:Mining
For safety reasons, mines with only a single outlet (shaft) are subjected to restrictions in the numbers of mine workers employed at a time.
Industry:Mining
For weighing materials in transit, these include the track scale (carload lots) in which the load is checked by manual operation of weights; platform scales; automatic dump hoppers; conveying weighers that continuously record or register the weight of a portion of passing conveyor belt.
Industry:Mining
Force that produces a unit elongation of the spring used in geophysical instruments.
Industry:Mining
