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Aki, Keiiti

(Encyclopedia)Aki, Keiiti, 1930–2005, American seismologist, b. Yokohama, Japan, Ph.D. Univ. of Tokyo, 1958. Associated with the Univ. of Tokyo 's Earthquake Research Institute from 1963, Aki joined the faculty o...

hibernation

(Encyclopedia)hibernation hīˌbərnāˈshən [key] [Lat.,= wintering], practice, among certain animals, of spending part of the cold season in a more or less dormant state, apparently as protection from cold when ...

frost

(Encyclopedia)frost or hoarfrost, ice formed by the condensation of atmospheric water vapor on a surface when the temperature of the surface is below 32℉ (0℃). In the formation of frost, a gas (water vapor) is ...

glaucoma

(Encyclopedia)glaucoma glôkōˈmə [key], ocular disorder characterized by pressure within the eyeball caused by an excessive amount of aqueous humor (the fluid substance filling the eyeball). This causes pressure...

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...

hydraulic machine

(Encyclopedia)CE5 Hydraulic pressure: In any hydraulic device the pressure exerted by one piston is transmitted throughout the fluid. Since pressure equals force divided by area, a small force (F1) exerted on a ...

corona, in astronomy

(Encyclopedia)corona, luminous envelope surrounding the sun, outside the chromosphere. Its density is less than one billionth that of the earth's atmosphere. The corona is visible only at the time of totality durin...

Unicode

(Encyclopedia)Unicode yo͞oˈnĭkōdˌ [key], set of codes used to represent letters, numbers, control characters, and the like, designed for use internationally in computers. It has been expanded to include such i...

iron lung

(Encyclopedia)iron lung, device used to maintain artificial respiration over an extended period of time. Before the successful vaccination program against poliomyelitis, it was used mostly in treatment of that dise...

pneumothorax

(Encyclopedia)pneumothorax no͞omōthôrˈăks [key], collapse of a lung with escape of air into the pleural cavity between the lung and the chest wall. The cause may be traumatic (e.g., gunshot or stab wound), spo...