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plastic

(Encyclopedia)plastic, any organic material with the ability to flow into a desired shape when heat and pressure are applied to it and to retain the shape when they are withdrawn. The first important plastic, cel...

liquid air

(Encyclopedia)liquid air, ordinary air that has been liquefied by compression and cooling to extremely low temperatures (see liquefaction). Its commercial preparation involves purification by washing to remove solu...

artesian well

(Encyclopedia)artesian well, deep drilled well through which water is forced upward under pressure. The water in an artesian well flows from an aquifer, which is a layer of very porous rock or sediment, usually san...

Tierra del Fuego

(Encyclopedia)Tierra del Fuego tyĕˈrä dĕl fwāˈgō [key], [Span.,=land of fire], archipelago, 28,476 sq mi (73,753 sq km), off S South America, separated from the mainland by the Strait of Magellan. It consist...

chiropractic

(Encyclopedia)chiropractic kīrəprăkˈtĭk [key] [Gr.,=doing by hand], medical practice based on the theory that all disease results from a disruption of the functions of the nerves. The principal source of inter...

Gobi

(Encyclopedia)Gobi gōˈbē [key], Mandarin Yintai shamo, great stony desert of N central Asia, c.500,000 sq mi (1,295,000 sq km), extending c.1,000 mi (1,610 km) from east to west across SE Mongolia and N China fr...

growing season

(Encyclopedia)growing season, period during which plant growth takes place. In temperate climates the growing season is limited by seasonal changes in temperature and is defined as the period between the last killi...

hail, in meteorology

(Encyclopedia)hail, precipitation in the form of pellets composed of ice or of ice and snow, occurring at any time of the year, usually during the passage of a cold front or during a thunderstorm. Small hailstones ...

silica

(Encyclopedia)silica or silicon dioxide, chemical compound, SiO2. It is insoluble in water, slightly soluble in alkalies, and soluble in dilute hydrofluoric acid. Pure silica is colorless to white. It occurs in sev...

smell

(Encyclopedia)smell, sense that enables an organism to perceive and distinguish the odors of various substances, also known as olfaction. In humans, the organ of smell is situated in the mucous membrane of the uppe...