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strontium

(Encyclopedia)strontium strŏnˈshēəm [key] [from Strontian, a Scottish town], a metallic chemical element; symbol Sr; at. no. 38; at. wt. 87.62; m.p. 769℃; b.p. 1,384℃; sp. gr. 2.6 at 20℃; valence +2. Stro...

neem tree

(Encyclopedia)neem tree or margosa tree, a fast-growing broad-leaved evergreen, Azadirachta indica, native to India and Myanmar. Its extracts have been used for centuries in Asia as pesticides, toothpaste, medicine...

Ramelli, Agostino

(Encyclopedia)Ramelli, Agostino ägōstēˈnō rämĕlˈlē [key], c.1531–c.1600, Italian engineer who served in the armies of the marquis de Marignan and of the duc d'Anjou (later Henry III of France). His book,...

canvas

(Encyclopedia)canvas, strong, coarse cloth of cotton, flax, hemp, or other fibers, early used as sailcloth. Left in its natural color, bleached, or dyed, it has a wide variety of uses, as for game, duffel, sport, m...

radio frequency

(Encyclopedia)radio frequency, range of electromagnetic waves with a frequency or wavelength suitable for communication uses. Some of these waves serve as carriers of the lower-frequency audio waves; others are mod...

tantalum

(Encyclopedia)tantalum tănˈtələm [key] [from Tantalus], metallic chemical element; symbol Ta; at. no. 73; at. wt. 180.94788; m.p. 2,996℃; b.p. 5,400±100℃; sp. gr. 16.65 at 20℃; valence +2, +3, +4, or +5....

Sannazaro, Jacopo

(Encyclopedia)Sannazaro, Jacopo yäˈkōpō sän-nätsäˈrō [key], 1456?–1530, Italian humanist. He lived briefly (1501–4) in France, a follower of the exiled Frederick III of Naples. On Frederick's death, he...

expert system

(Encyclopedia)expert system, a computer system or program that uses artificial intelligence techniques to solve problems that ordinarily require a knowledgeable human. The method used to construct such systems, kno...

fiberglass

(Encyclopedia)fiberglass, thread made from glass. It is made by forcing molten glass through a kind of sieve, thereby spinning it into threads. Fiberglass is strong, durable, and impervious to many caustics and to ...

balata

(Encyclopedia)balata bălˈətə [key], nonelastic natural rubber obtained as a latex from the South American tree Manikara bidentata and from related trees. Its properties are similar to those of gutta-percha, and...