upper grid plate
1Plate tectonics — The tectonic plates of the world were mapped in the second half of the 20th century …
2Control grid — The control grid is an electrode used in thermionic valves (vacuum tubes) used to modulate the flow of electrons in the cathode to anode or plate circuit. Contents 1 Operation 2 Construction 3 Effects of grid position …
3printing — /prin ting/, n. 1. the art, process, or business of producing books, newspapers, etc., by impression from movable types, plates, etc. 2. the act of a person or thing that prints. 3. words, symbols, etc., in printed form. 4. printed material. 5.… …
4India — /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.… …
5building construction — Techniques and industry involved in the assembly and erection of structures. Early humans built primarily for shelter, using simple methods. Building materials came from the land, and fabrication was dictated by the limits of the materials and… …
6Fly system — Fly loft of the Theater Bielefeld in Germany A fly system, flying system or theatrical rigging system, is a system of lines (e.g. ropes), blocks (pulleys), counterweights and related devices within a theatre that enable a stage crew to quickly,… …
7History of cartography — The Fra Mauro map, one of the greatest memorial of medieval cartography, was made around 1450 by the Venetian monk Fra Mauro. It is a circular world map drawn on parchment and set in a wooden frame, about two meters in diameter Cartography (from… …
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… …
9Polarizer — For the photographic filter, see Polarizing filter (Photography). A polarizing filter cuts down the reflections (top) and made it possible to see the photographer through the glass at roughly Brewster s angle although reflections off the back… …
10North America — North American. the northern continent of the Western Hemisphere, extending from Central America to the Arctic Ocean. Highest point, Mt. McKinley, 20,300 ft. (6187 m); lowest, Death Valley, 276 ft. (84 m) below sea level. 400,000,000 including… …
