bottom-hole assembly
61Physical Sciences — ▪ 2009 Introduction Scientists discovered a new family of superconducting materials and obtained unique images of individual hydrogen atoms and of a multiple exoplanet system. Europe completed the Large Hadron Collider, and China and India took… …
62Door — For other uses, see Door (disambiguation). A door is a movable structure used to open and close off an entrance, typically consisting of a panel that swings on hinges or that slides or rotates inside of a space. When open, they admit ventilation… …
63Mir — This article is about the Soviet/Russian space station. For other uses, see Mir (disambiguation). Mir …
64Barbed wire — For other uses, see Barb wire (disambiguation). A close up view of a barbed wire barb …
65Hand grenade — M67 fragmentation grenade, a widely used modern hand grenade. A hand grenade is any small bomb that can be thrown by hand. Hand grenades are classified into three categories, explosive grenades, chemical and gas grenades.[1] Explosive grenades… …
66Completion (oil and gas wells) — This article is about the oil or gas well completion. For other uses of completion, see Completion (disambiguation) In petroleum production, completion is the process of making a well ready for production (or injection). This principally involves …
67Glock pistol — Infobox Weapon name=Glock caption=The Glock 17 (recent production model) origin=flag|Austria type=Semi automatic pistol is ranged=yes service=1980–present used by=See Users wars= designer=Gaston Glock design date=1980 manufacturer=Glock GmbH unit …
68Dye-sensitized solar cell — A selection of dye sensitized solar cells A dye sensitized solar cell (DSSC, DSC or DYSC[1]) is a low cost solar cell belonging to the group of thin film solar cells.[2] …
69India — /in dee euh/, n. 1. Hindi, Bharat. a republic in S Asia: a union comprising 25 states and 7 union territories; formerly a British colony; gained independence Aug. 15, 1947; became a republic within the Commonwealth of Nations Jan. 26, 1950.… …
70Arctic Regions — ▪ 2009 The Arctic regions may be defined in physical terms (astronomical [north of the Arctic Circle, latitude 66° 30′ N], climatic [above the 10 °C (50 °F) July isotherm], or vegetational [above the northern limit of the tree line]) or in human… …
