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pressure
pressure in mechanics, ratio of the force acting on a surface to the area of the surface; it is thus distinct from the total force acting on a surface. A force can be applied to and sustained by a single point on a solid. However, a force can only be sustained by the surface of an enclosed fluid,...
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wire
wire metal filament, strand, or solid rod usually having a round cross section. Metals and alloys used for wiremaking are chosen for high tensile strength and ductility or for their electrical conductivity, weight, melting point, or other properties, depending upon the use to which the wire is to b...
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blood pressure
blood pressure force exerted by the blood upon the walls of the arteries. The pressure in the arteries originates in the pumping action of the heart, and pressure waves can be felt at the wrist and at other points where arteries lie near the surface of the body (see pulse ). Since the heart can pu...
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Elephantine
Elephantine , island, SE Egypt, in the Nile below the First Cataract, near Aswan. In ancient times it was a military post guarding the southern frontier of Egypt. The Elephantine papyruses, which date from the 5th cent. BC and describe a colony of Jewish mercenaries, were found there. Surviving ruin...
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oxygen tent
oxygen tent device used to maintain a patient in an oxygen-rich environment. The oxygen tent is composed of a clear plastic sheet suspended over the bed and tucked beneath the mattress to provide an almost airtight compartment. The oxygen supply and temperature are controlled by means of gauges. Zi...
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steam engine
steam engine machine for converting heat energy into mechanical energy using steam as a medium, or working fluid. When water is converted into steam it expands, its volume increasing about 1,600 times. The force produced by the conversion is the basis of all steam engines. Steam engines operate by ...
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sea level
sea level the level of the sea, which serves as the datum used for measurement of land elevations and ocean depths. Theoretically, one would expect sea level to be a fixed and permanent horizontal surface on the face of the earth, and as a starting approximation, this is true. However, a number of ...
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voting
voting method of registering collective approval or disapproval of a person or a proposal. The term generally refers to the process by which citizens choose candidates for public office or decide political questions submitted to them. However, it may also describe the formal recording of opinion of...
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avionics
avionics , electronic instruments used in air or space flight; also the design and production of such instruments. Early planes had few instruments, but as aviation and aircraft became more complex, so did instrumentation. Most of the new technology was electronic; hence, the expression "aviation ...
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tsunami
tsunami , series of catastrophic ocean waves generated by submarine movements, which may be caused by earthquakes , volcanic eruptions, landslides beneath the ocean, or an asteroid striking the earth. Tsunamis are also called seismic sea waves or, popularly, tidal waves.
In the open ocean, tsu...
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