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batholith

(Encyclopedia)batholith, enormous mass of intrusive igneous rock, that is, rock made of once-molten material that has solidified below the earth's surface (see rock). Batholiths usually are granitic (see granite) i...

compression

(Encyclopedia)compression, external stress applied to an object or substance, tending to cause a decrease in volume (see pressure). Gases can be compressed easily, solids and liquids to a very small degree if at al...

germination

(Encyclopedia)germination, in a seed, process by which the plant embryo within the seed resumes growth after a period of dormancy and the seedling emerges. The length of dormancy varies; the seed of some plants (e....

Mammoth Cave National Park

(Encyclopedia)Mammoth Cave National Park, 52,830 acres (21,396 hectares), central Kentucky, authorized 1926, est. 1941. Located in a hilly, forested region, it offers numerous outdoor activities. It is the site of ...

dissociation

(Encyclopedia)dissociation, in chemistry, separation of a substance into atoms or ions. Thermal dissociation occurs at high temperatures. For example, hydrogen molecules (H2) dissociate into atoms (H) at very high ...

porcelain

(Encyclopedia)porcelain [Ital. porcellana], white, hard, permanent, nonporous pottery having translucence which is resonant when struck. Porcelain was first made by the Chinese to withstand the great heat generated...

physical chemistry

(Encyclopedia)physical chemistry, branch of science that combines the principles and methods of physics and chemistry. It provides a fundamental theoretical and experimental basis for all of chemistry, including or...

Stirling engine

(Encyclopedia)Stirling engine, an external combustion reciprocating engine having an enclosed working fluid that is alternately compressed and expanded to operate a piston, thus converting heat from a variety of so...

harrow, in agriculture

(Encyclopedia)harrow, farm implement, consisting of a wooden or metal framework bearing metal disks, teeth, or sharp projecting points, called tines, which is dragged over plowed land to pulverize the clods of eart...

angelfish

(Encyclopedia)angelfish, common name for certain members of the Pomacanthidae, a family of brightly colored reef-dwelling tropical fishes with compressed bodies and small mouths and teeth. They were formerly classi...
 

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