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mineral

(Encyclopedia)mineral, inorganic substance occurring in nature, having a characteristic and homogeneous chemical composition, definite physical properties, and, usually, a definite crystalline form. A few of the mi...

microelectronics

(Encyclopedia)microelectronics, branch of electronic technology devoted to the design and development of extremely small electronic devices that consume very little electric power. Although the term is sometimes us...

ophthalmology

(Encyclopedia)ophthalmology ŏfˌthălmŏlˈəjē [key], branch of medicine specializing in the anatomy, function and diseases of the eye. Ophthalmologists specialize in the medical and surgical treatment of eye di...

number theory

(Encyclopedia)number theory, branch of mathematics concerned with the properties of the integers (the numbers 0, 1, −1, 2, −2, 3, −3, …). An important area in number theory is the analysis of prime number...

Osage, indigenous people of North America

(Encyclopedia)Osage ōˈsāj, ōsājˈ [key], indigenous people of North America whose language belongs to the Siouan branch of the Hokan-Siouan linguistic stock (see Native American languages). In prehistoric time...

organic chemistry

(Encyclopedia)organic chemistry, branch of chemistry dealing with the compounds of carbon. While it is only the fourteenth most common element on earth, carbon forms by far the greatest number of different compound...

Potawatomi

(Encyclopedia)Potawatomi pŏtˌəwŏtˈəmē [key], Native North Americans whose language belongs to the Algonquian branch of the Algonquian-Wakashan linguistic stock (see Native American languages). They are close...

Wichita, indigenous people of North America

(Encyclopedia)Wichita wĭchˈĭtô [key], Native North Americans whose language belongs to the Caddoan branch of the Hokan-Siouan linguistic stock (see Native American languages). They formerly occupied central Kan...

Utrecht , city, Netherlands

(Encyclopedia)Utrecht, city (1994 pop. 234,106), capital of Utrecht prov., central Netherlands, on a branch of the Lower Rhine (Neder Rijn) River. It is a transportation, financial, and industrial center. Manufactu...

Rustin, Bayard

(Encyclopedia)Rustin, Bayard, 1910–87, African-American civil-rights leader, b. West Chester, Pa. He attended three colleges but did not obtain a degree. A Quaker, he was imprisoned as a conscientious objector fo...