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astronomical coordinate systems

(Encyclopedia)astronomical coordinate systems. A coordinate system is a method of indicating positions. Each coordinate is a quantity measured from some starting point along some line or curve, called a coordinate ...

Atlas Mountains

(Encyclopedia)Atlas Mountains, system of ranges and plateaus in NW Africa, extending c.1,500 mi (2,410 km) from SW Morocco, through N Algeria, to N Tunisia; Jebel Toubkal (13,671 ft/4,167 m), in SW Morocco, is the ...

Lancaster, Joseph

(Encyclopedia)Lancaster, Joseph, 1778–1838, English educator. In 1801 he founded a free elementary school, using a type of monitorial system for which he acknowledged his debt to Andrew Bell. The Royal Lancasteri...

heart-lung machine

(Encyclopedia)heart-lung machine, device that maintains the circulation of the blood and the oxygen content of the body when connected with the arteriovenous system; it is also called the pump oxygenator. The machi...

Moore, Michael

(Encyclopedia)Moore, Michael, 1954–, American documentary filmmaker, author, and activist, b. Flint, Mich. A highly personal, populist, and frequently controversial and polarizing documentary filmmaker, he made h...

standard time

(Encyclopedia)standard time, civil time used within a given time zone. The earth is divided into 24 time zones, each of which is about 15° of longitude wide and corresponds to one hour of time. Within a zone all c...

Stirling engine

(Encyclopedia)Stirling engine, an external combustion reciprocating engine having an enclosed working fluid that is alternately compressed and expanded to operate a piston, thus converting heat from a variety of so...

corvée

(Encyclopedia)corvée kôrvāˈ [key], under the feudal system, compulsory, unpaid labor demanded by a lord or king and the system of such labor in general. There were national and local variations, but in broad te...

control systems

(Encyclopedia)control systems, combinations of components (electrical, mechanical, thermal, or hydraulic) that act together to maintain actual system performance close to a desired set of performance specifications...

standpipe

(Encyclopedia)standpipe, tank or pipe for holding water in an elevated position to create pressure in a water supply system. For a tall building, where the pressure from the mains at street level is insufficient to...