- 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 glacier of considerable thickness and more than 50,000 km<sub>2</sub>in area, forming a continuous cover of ice and snow over a land surface, spreading outward in all directions and not confined by the underlying topography; a continental glacier. Ice sheets are now confined to polar regions (as on Greenland and Antarctica), but during the Pleistocene Epoch they covered large parts of North America and northern Europe.
Industry:Mining
A glass float on the end of a thin rod suspended in a liquid which is supported by two flat springs so that it is constrained to precise vertical motion. The float-rod assembly carries a coil similar to the voice-coil of a dynamic loudspeaker and a differential transformer core. Vertical movement of the float is detected by the electrical response of the differential transformer. The coil moves in a strong, radial, magnetic field, and when the float is buoyed up by the liquid, the reaction force between the coil and the field is used to pull it down. Thus, balance is achieved at a null position by adjusting the coil current while observing the null indicator.
Industry:Mining
A glass supersaturated with either iron, chromium, or copper oxide (or a combination of the oxides) that is melted and cooled under controlled conditions to cause the excessive oxides to crystallize, forming platelike crystals or spangles.
Industry:Mining
A glass tube employing mercury to establish electrical contact between circuits when the tube is tilted so that the mercury bridges the gap between contacts, and conversely.
Industry:Mining
A glass-membrane electrode used to measure pH or hydrogen-ion activity.
Industry:Mining
A glass-rich pyroclastic rock that has been indurated by the welding together of its glass shards under the combined action of the heat retained by particles, the weight of overlying material, and hot gases. It is generally composed of silicic pyroclasts and appears banded or streaky.
Industry:Mining
A glass-rich pyroclastic rock that has been indurated by the welding together of its glass shards under the combined action of the heat retained by particles, the weight of overlying material, and hot gases. It is generally composed of silicic pyroclasts and appears banded or streaky.
Industry:Mining
