Columbia Encyclopedia

Search results

500 results found

shoring

(Encyclopedia)shoring, placing of props or braces, called shores, against or beneath a structure for support. Shoring is often used to stabilize a building when it is to undergo structural modification or repair. C...

conscience

(Encyclopedia)conscience, sense of moral awareness or of right and wrong. The concept has been variously explained by moralists and philosophers. In the history of ethics, the conscience has been looked upon as the...

Council for Mutual Economic Assistance

(Encyclopedia)Council for Mutual Economic Assistance (COMECON or MEA), international organization active between 1956 and 1991 for the coordination of economic policy among certain nations then under Communist domi...

chernozem

(Encyclopedia)chernozem chĕrˈnəzĕmˌ [key] or black earth, variety of soil rich in organic matter in the form of humus. It is generally a modified type of loess. True chernozem is black in color, but there are ...

chitin

(Encyclopedia)chitin kītˈən [key], main constituent of the shells of arthropods. Chitin, a polysaccharide (see carbohydrate) analogous in chemical structure to cellulose, consists of units of a glucose derivativ...

alanine

(Encyclopedia)CE5 alanine ălˈənēnˌ [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of proteins (see stereochemi...

chalcedony

(Encyclopedia)chalcedony kălsĕdˈənē [key] [from Chalcedon], form of quartz the crystals of which are so minute that its crystalline structure cannot be seen except with the aid of a microscope. Chalcedony has ...

Turing machine

(Encyclopedia)Turing machine, a mathematical model of a device that computes via a series of discrete steps and is not limited in use by a fixed maximum amount of data storage. Introduced by the British mathematici...

pronoun

(Encyclopedia)pronoun, in English, the part of speech used as a substitute for an antecedent noun that is clearly understood, and with which it agrees in person, number, and gender. In English the pronouns are clas...

Frank, Joachim

(Encyclopedia)Frank, Joachim, 1940–, German-American physicist and biochemist, b. Siegen, Germany, Ph.D., Technical Univ. of Munich 1970. He became a U.S. citizen in 1997. Following several postdoctoral appointme...