two-wire pulsing
11Reel-to-reel audio tape recording — Reel to reel redirects here. For the music group, see Reel 2 Real. For other uses, see roll to roll processing. A reel to reel tape recorder (Sony TC 630), typical of those which were once common audiophile objects. Note the distinctive Scotch… …
12Panel switch — The panel switching system was an early type of automatic telephone exchange, first put into urban service by the Bell System in the 1920s and removed during the 1970s. The Panel and Rotary systems were developed in parallel by Bell Labs before… …
13Electric Line — The term wireline usually refers to a cabling technology used by operators of oil and gas wells to lower equipment or measurement devices into the well for the purposes of well intervention and reservoir evaluation. Braided line can contain an… …
14sound — sound1 soundable, adj. /sownd/, n. 1. the sensation produced by stimulation of the organs of hearing by vibrations transmitted through the air or other medium. 2. mechanical vibrations transmitted through an elastic medium, traveling in air at a… …
15Sound — /sownd/, n. The, a strait between SW Sweden and Zealand, connecting the Kattegat and the Baltic. 87 mi. (140 km) long; 3 30 mi. (5 48 km) wide. Swedish and Danish, Oresund. * * * I Mechanical disturbance that propagates as a longitudinal wave… …
16Drill — For other uses, see Drill (disambiguation). Drill scheme A drill or drill motor is a tool fitted with a cutting tool attachment or driving tool attachment, usually a drill bit or driver bit, used for drilling holes in various materials or… …
17microscope — /muy kreuh skohp /, n. 1. an optical instrument having a magnifying lens or a combination of lenses for inspecting objects too small to be seen or too small to be seen distinctly and in detail by the unaided eye. 2. (cap.) Astron. the… …
18Body piercing — For other uses, see Piercing (disambiguation). Nipple piercings, vertical labret piercing and stretched ears Body piercing, a form of body modification, is the practice of puncturing or cutting a part of the human body, creating an opening in… …
19Pittsburgh — This article is about the city in Pennsylvania. For the region, see Pittsburgh metropolitan area. For other uses, see Pittsburgh (disambiguation). City of Pittsburgh   City   …
20Electrical generator — In electricity generation, an electrical generator is a device that converts mechanical energy to electrical energy, generally using electromagnetic induction. The reverse conversion of electrical energy into mechanical energy is done by a motor …
