speed reduction device
61railroad — /rayl rohd /, n. 1. a permanent road laid with rails, commonly in one or more pairs of continuous lines forming a track or tracks, on which locomotives and cars are run for the transportation of passengers, freight, and mail. 2. an entire system… …
62Europe, history of — Introduction history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …
63international relations — a branch of political science dealing with the relations between nations. [1970 75] * * * Study of the relations of states with each other and with international organizations and certain subnational entities (e.g., bureaucracies and political… …
64Railway air brake — Piping diagram from 1920 of a Westinghouse E T Air Brake system on a locomotive …
65Earth 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… …
66Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
67Radar — For other uses, see Radar (disambiguation). A long range radar antenna, known as ALTAIR, used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on Kwajalein Atoll …
68Flash memory — Computer memory types Volatile RAM DRAM (e.g., DDR SDRAM) SRAM In development T RAM Z RAM TTRAM Historical Delay line memory Selectron tube Williams tube Non volatile …
69turbine — /terr bin, buyn/, n. any of various machines having a rotor, usually with vanes or blades, driven by the pressure, momentum, or reactive thrust of a moving fluid, as steam, water, hot gases, or air, either occurring in the form of free jets or as …
70Digital photography — Nikon D700 a 12.1 megapixel full frame DSLR …