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boiler

(Encyclopedia)boiler, device for generating steam. It consists of two principal parts: the furnace, which provides heat, usually by burning a fuel, and the boiler proper, a device in which the heat changes water in...

hysteresis

(Encyclopedia)hysteresis hĭsˌtərēˈsĭs [key], phenomenon in which the response of a physical system to an external influence depends not only on the present magnitude of that influence but also on the previous...

liquefaction

(Encyclopedia)liquefaction, change of a substance from the solid or the gaseous state to the liquid state. Since the different states of matter correspond to different amounts of energy of the molecules making up t...

cremation

(Encyclopedia)cremation, disposal of a corpse by fire. It is an ancient and widespread practice, second only to burial. It has been found among the tribes of the Pacific Northwest, among Northern Athapascan bands i...

spontaneous combustion

(Encyclopedia)spontaneous combustion, phenomenon in which a substance unexpectedly bursts into flame without apparent cause. In ordinary combustion, a substance is deliberately heated to its ignition point to make ...

entropy

(Encyclopedia)entropy ĕnˈtrəpē [key], quantity specifying the amount of disorder or randomness in a system bearing energy or information. Originally defined in thermodynamics in terms of heat and temperature, e...

seasons

(Encyclopedia)CE5 The seasons are caused by the tilt of the earth's axis to the plane of its orbit about the sun. The Northern Hemisphere is tilted toward the sun in the summer and receives more direct rays than...

Dewar flask

(Encyclopedia)Dewar flask [for Sir James Dewar], container after which the common thermos bottle is patterned. It consists of two flasks, one placed inside the other, with a vacuum between. The vacuum prevents the ...

shape memory

(Encyclopedia)shape memory, property possessed by certain alloys that allows them to return, when heated, to their original shape after having been deformed. This effect results because, as the alloy is deformed, i...

megapode

(Encyclopedia)megapode mĕgˈəpōdˌ [key], common name for large, stout-bodied, long-tailed, terrestrial, nonmigratory birds comprising six genera in the family Megapodiidae. Members of the family have large, str...