(Encyclopedia) waveguide, device that controls the propagation of an electromagnetic wave so that the wave is forced to follow a path defined by the physical structure of the guide. Waveguides, which…
(Encyclopedia) biennial, plant requiring two years to complete its life cycle, as distinguished from an annual or a perennial. In the first year a biennial usually produces a rosette of leaves (e.g…
(Encyclopedia) blood substitute, substance that mimics the function of blood. Blood substitutes typically concentrate only on reproducing the function of hemoglobin, the molecule that carries oxygen…
(Encyclopedia) bluebird, common name for a North American migratory bird of the family Turdidae (thrush family). The eastern bluebird, Sialia sialis, is among the first spring arrivals in the North.…
(Encyclopedia) Vazov, IvanVazov, Ivanĭvänˈ väˈzôf [key], 1850–1921, Bulgarian poet, novelist, and playwright, the first professional man of letters in Bulgaria. His work was inspired by the political…
(Encyclopedia) tritiumtritiumtrĭtˈēəm [key], radioactive isotope of hydrogen with mass number 3. The tritium nucleus, called a triton, contains one proton and two neutrons. It has a half-life of 12.5…
(Encyclopedia) Schenck v. United States, case decided in 1919 by the U.S. Supreme Court. During World War I, Charles T. Schenck produced a pamphlet maintaining that the military draft was illegal,…
(Encyclopedia) Simon, Herbert Alexander, 1916–2001, American social scientist and economist, b. Milwaukee, grad. Univ. of Chicago (B.A., 1936, Ph.D., 1943). A professor of computer science and…
(Encyclopedia) phenylketonuriaphenylketonuriafĕnˌəlkētˌən&oobreve;rˈēə [key] (PKU), inherited metabolic disorder caused by a deficiency in a specific enzyme (phenylalanine hydroxylase). The…
