(piezoelectricity)
121electrostriction — electrostrictive, adj. /i lek treuh strik sheuhn/, n. Physics. elastic deformation produced by an electric field, independent of the polarity of the field. [ELECTRO + STRICTION] * * * ▪ physics property of all electrical nonconductors, or… …
122pyroelectricity — /puy roh i lek tris i tee, ee lek /, n. electrification or electrical polarity produced in certain crystals by temperature changes. [1825 35; PYRO + ELECTRICITY] * * * ▪ physics development of opposite electrical charges on different parts… …
123rock crystal — transparent quartz, esp. when colorless. [1660 70] * * * Transparent variety of the silica mineral quartz that is valued for its clarity and total lack of colour or flaws. Rock crystal formerly was used extensively as a gemstone, but it has been… …
124ultrasonics — /ul treuh son iks/, n. (used with a sing. v.) the branch of science that deals with the effects of sound waves above human perception. [1930 35; see ULTRASONIC, ICS] * * * Vibrational or stress waves in elastic media that have a frequency above… …
125wood — wood1 woodless, adj. /wood/, n. 1. the hard, fibrous substance composing most of the stem and branches of a tree or shrub, and lying beneath the bark; the xylem. 2. the trunks or main stems of trees as suitable for architectural and other… …
126Wood — /wood/, n. 1. Grant, 1892 1942, U.S. painter. 2. Leonard, 1860 1927, U.S. military doctor and political administrator. * * * I Hard, fibrous material formed by the accumulation of secondary xylem produced by the vascular cambium. It is the… …
127zirconium — zirconic /zerr kon ik/, adj. /zerr koh nee euhm/, n. Chem. a metallic element found combined in zircon, baddeleyite, etc., resembling titanium chemically: used in steel metallurgy, as a scavenger, as a refractory, and as an opacifier in vitreous… …
128Röntgen, Wilhelm Conrad — or Wilhelm Conrad Roentgen born March 27, 1845, Lennep, Prussia died Feb. 10, 1923, Munich, Ger. German physicist. He taught at the Universities of Giessen (1879–88), Würzburg (1888–1900), and Berlin (1900–20). In 1895 he discovered rays that did …
