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stimulant

(Encyclopedia)stimulant, any substance that causes an increase in activity in various parts of the nervous system or directly increases muscle activity. Cerebral, or psychic, stimulants act on the central nervous s...

anatomy

(Encyclopedia)anatomy ənătˈəmē [key], branch of biology concerned with the study of body structure of various organisms, including humans. Comparative anatomy is concerned with the structural differences of pl...

rapid transit

(Encyclopedia)rapid transit, transportation system designed to allow passenger travel within or throughout an urban area, usually employing surface, elevated, or underground railway systems or some combination of t...

Strategic Defense Initiative

(Encyclopedia)Strategic Defense Initiative (SDI), former U.S. government program responsible for research and development of a space-based system to defend the nation from attack by strategic ballistic missiles (se...

Fourcroy, Antoine François, comte de

(Encyclopedia)Fourcroy, Antoine François, comte de äNtwänˈ fräNswäˈ kôNt də fo͞orkrwäˈ [key], 1755–1809, French chemist. He was a pioneer in animal and plant chemistry and collaborated with Lavoisier ...

Saimaa

(Encyclopedia)Saimaa sīˈmä [key], lake system c.1,850 sq mi (4,790 sq km), occupying the heavily glaciated plateau of S central Finland. It comprises more than 120 connecting lakes; the large southern basin of t...

free energy

(Encyclopedia)free energy or Gibbs free energy, quantity derived from the relationships between heat and work studied in thermodynamics and used as a measure of the relative stability of a physical or chemical syst...

Hitchcock, Frank Harris

(Encyclopedia)Hitchcock, Frank Harris, 1867–1935, U.S. Postmaster General (1909–13), b. Amherst, Ohio. After service in the Dept. of Agriculture (1897–1903), the Dept. of Commerce and Labor (1903–5), and as...

hysteresis

(Encyclopedia)hysteresis hĭsˌtərēˈsĭs [key], phenomenon in which the response of a physical system to an external influence depends not only on the present magnitude of that influence but also on the previous...

Amenhotep III

(Encyclopedia)Amenhotep III ăˌmĕnōˈfĭs [key], d. c.1372 b.c., king of ancient Egypt, of the XVIII dynasty. He succeeded his father, Thutmose IV, c.1411 b.c. His reign marks the culmination and the start of th...