- 行业: Mining
- Number of terms: 33118
- Number of blossaries: 0
- Company Profile:
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 ...
A precipitated deposit resulting directly or indirectly from vital activities of an organism, such as bacterial iron ore or coralline limestone.
Industry:Mining
A precise electronic measuring system for indicating distance from an airborne or shipborne station to each of two fixed ground stations simultaneously by recording (by means of cathode-ray screens) the time required for round-trip travel of radar signals or high-frequency radio waves and thereby determining the position of the mobile station. Its range is effectively limited to line-of-sight distances (or about 40 nmi or 74 km). Shoran is used in control of aerial photography, airborne geophysical prospecting, offshore hydrographic surveys, and geodetic surveying for measuring long distances. Compare: loran navigation.
Industry:Mining
A precise method of orienting underground workings in which plumblines are transferred down a deep shaft in stages of 400 to 600 ft (120 to 185 m). While shaft sinking is in progress, the lines can also be employed to orient the shaft itself and to keep it plumb.
Industry:Mining
A precision caliper gage that measures the overall dimensions of unmounted fashioned gems more accurately but less conveniently than dial gages.
Industry:Mining
A precision surveying instrument that is used for measuring angular distances in both vertical and horizontal planes.
Industry:Mining
A prefix denoting under, below, or less than. Containing only a relatively small proportion or less than the normal amount of (such) an element or radical; not used systematically.
Industry:Mining
