two-pole system
121Physical 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… …
122mechanics — /meuh kan iks/, n. 1. (used with a sing. v.) the branch of physics that deals with the action of forces on bodies and with motion, comprised of kinetics, statics, and kinematics. 2. (used with a sing. v.) the theoretical and practical application …
123Bow collector — A bow collector is one of the three main devices used on tramcars to transfer electric current from the wires above to the tram below. While once very common in continental Europe, it has now been largely replaced by the pantograph. OriginsWhen… …
124Light rail in North America — The term light rail was coined in 1972 by the U.S. Urban Mass Transit Association (UMTA) to describe new streetcar transformations which were taking place in Europe and the United States. The Germans used the term stadtbahn to describe the… …
125physical science — physical scientist. 1. any of the natural sciences dealing with inanimate matter or with energy, as physics, chemistry, and astronomy. 2. these sciences collectively. [1835 45] * * * Introduction the systematic study of the inorganic world …
126Colombian presidential election, 2010 — 2006 ← 30 May and 20 June 2010 → 2014 …
127United States — This article is about the United States of America. For other uses of terms redirecting here, see US (disambiguation), USA (disambiguation), and United States (disambiguation). United States of America …
128List of current systems for electric rail traction — This a list of the power supply systems that are, or have been, used for tramway and railway electrification systems. Note that the voltages are nominal and vary depending on load and distance from the substation. Many modern trams and trains use …
