drift of a bore-hole
1Drift pin — drift punch In metalworking, a drift pin, drift pin punch, or simply drift, is the name for a tool used for enlarging holes, or aligning holes prior to bolting or riveting metal parts together. A drift pin is not used as a punch in the… …
2Transmission electron microscopy — A TEM image of the polio virus. The polio virus is 30 nm in size.[1] Transmission electron microscopy (TEM) is a microscopy technique whereby a beam of electrons is transmitted through an ultra thin specimen, interacting with the specimen as it… …
3excavation — noun 1. the act of digging (Freq. 2) there s an interesting excavation going on near Princeton • Syn: ↑digging, ↑dig • Derivationally related forms: ↑dig (for: ↑dig), ↑ …
4Opuwo — aerial view of Opuwo …
5Mining — This article is about the extraction of geological materials from the Earth. For the municipality in Austria, see Mining, Austria. For the siege tactic, see Mining (military). For name of the Chinese emperor, see Daoguang Emperor. Simplified… …
6mining — noun 1. the act of extracting ores or coal etc from the earth (Freq. 3) • Syn: ↑excavation • Derivationally related forms: ↑excavate (for: ↑excavation), ↑mine …
7tunnels and underground excavations — ▪ engineering Introduction Great tunnels of the world Great tunnels of the worldhorizontal underground passageway produced by excavation or occasionally by nature s action in dissolving a soluble rock, such as limestone. A vertical opening …
8Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
9literature — /lit euhr euh cheuhr, choor , li treuh /, n. 1. writings in which expression and form, in connection with ideas of permanent and universal interest, are characteristic or essential features, as poetry, novels, history, biography, and essays. 2.… …
10Punch (tool) — For punches used in punch presses, see Punching. A punch is a hard metal rod with a shaped tip at one end and a blunt butt end at the other, which is usually struck by a hammer. Punches are used to drive objects, such as nails, or to form an… …
