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Peters, Vera

(Encyclopedia)Peters, Vera (Mildred Vera Peters), 1911–93, Canadian radiation oncologist and clinical investigator, b. Rexdale, Ont., M.D. Univ. of Toronto, 1934. Beginning in 1935, she studied the treatment of H...

radiology

(Encyclopedia)radiology, branch of medicine specializing in the use of X rays, gamma rays, radioactive isotopes, and other forms of radiation in the diagnosis and treatment of disease. X ray machines and fluoroscop...

Tamm, Igor Yevgenyevich

(Encyclopedia)Tamm, Igor Yevgenyevich, 1895–1971, Soviet physicist, Ph.D. Moscow State Univ., 1933. He was a researcher at the P. N. Lebedev Physical Institute in Moscow from 1934 until his death in 1971. Tamm an...

savanna

(Encyclopedia)savanna or savannah both: səvănˈə [key], tropical or subtropical grassland lying on the margin of the trade wind belts. The climate of a savanna is characterized by a rainy period during the summe...

hedge

(Encyclopedia)hedge, ornamental or protective barrier composed of shrubs or small trees growing in close rows. The plants may be allowed to grow naturally or may be trimmed to various heights and shapes (see topiar...

ionization chamber

(Encyclopedia)ionization chamber, device for the detection and measurement of ionizing radiation. It consists basically of a sealed chamber containing a gas and two electrodes between which a voltage is maintained ...

Wien, Wilhelm

(Encyclopedia)Wien, Wilhelm vĭlˈhĕlm vēn [key], 1864–1928, German physicist. He was professor at the universities of Giessen (1899), Würzburg (1900–1920), and Munich (from 1920). He received the 1911 Nobel...

Ithaca, city, United States

(Encyclopedia)Ithaca ĭthˈəkə [key], city (2020 pop. 32,108), seat of Tompkins co., S central N.Y., at t...

Wyeth, N. C.

(Encyclopedia)Wyeth, N. C. (Newell Convers Wyeth), 1882–1945, American painter and illustrator, b. Needham, Mass., studied with Howard Pyle. Among his many well-known murals are those in the Missouri state capito...

particle detector

(Encyclopedia)CE5 Particle detector—Bubble chamber: A. Pressure drops as piston is raised; B. Charged particles passing through chamber ionize atoms in liquid; C. Bubbles form around atoms and form visible tra...