Columbia Encyclopedia

Search results

411 results found

pollution

(Encyclopedia)pollution, contamination of the environment as a result of human activities. The term pollution refers primarily to the fouling of air, water, and land by wastes (see air pollution; water pollution; s...

Cologne

(Encyclopedia)Cologne kəlōnˈ [key], Ger. Köln, city (2021 est. metro area pop. 1,129,000), North Rhine�...

Buffalo, city, United States

(Encyclopedia)Buffalo, city (2020 pop. 278,349), seat of Erie co., W N.Y., on Lake Erie and the Niagara and Buffalo rivers; inc. 1832. With more than 37 mi (60 km) of...

recycling

(Encyclopedia)recycling, the process of recovering and reusing waste products—from household use, manufacturing, agriculture, and business—and thereby reducing their burden on the environment. During World War ...

lubrication

(Encyclopedia)lubrication, introduction of a substance between the contact surfaces of moving parts to reduce friction and to dissipate heat. A lubricant may be oil, grease, graphite, or any substance—gas, liquid...

electrolysis

(Encyclopedia)CE5 Electrolysis: In a typical reaction electrodes are placed in a solution of hydrogen chloride, HCl, which contains both hydrogen and chlorine ions. The battery removes electrons from the anode, ...

rapid transit

(Encyclopedia)rapid transit, transportation system designed to allow passenger travel within or throughout an urban area, usually employing surface, elevated, or underground railway systems or some combination of t...

broadcasting

(Encyclopedia)broadcasting, transmission, usually using radio frequencies, of sound or images to a large number of radio or television receivers. In the United States the first regularly scheduled radio broadcasts ...

Monaco

(Encyclopedia)CE5 Monaco mŏnˈəkō, mōnäˈkō, Fr. mônäkōˈ [key], officially Principality of Monaco, independent principality (2015 est. pop. 38,000), c.370 acres (150 hectares), on the Mediterranean Sea...

Newark, cities, United States

(Encyclopedia)Newark. 1 City (1990 pop. 37,861), Alameda co., W Calif., on the east side of San Francisco Bay; inc. 1955. There is food processing and the manufacture of plastics, furniture, feeds, semiconductors, ...