Saturday, May 10, 2008

Know UR Facts



Thesaurus: evaporation
noun
The act or an example of passing out of sight: disappearance, evanescence, fade-out, vanishment.

Antonyms: evaporation
Definition: drying up; dissolutionAntonyms: dampening, soaking, wetting

Geography Dictionary: evaporation
The changing of a liquid into a vapour, or gas, at a temperature below the boiling point of that liquid.Evaporation occurs at the surface of a liquid, and energy is required to release the molecules from the liquid into the gas. The use of this energy, known as latent heat, causes the temperature of the liquid to fall.

Britannica Concise Encyclopedia: evaporation
Change of a liquid into the gaseous state; in particular, the process by which liquid water enters the atmosphere as water vapour. Evaporation, mostly from the sea and from vegetation, replenishes the humidity of the air. It is an important part of the exchange of energy in the Earth-atmosphere system that produces atmospheric motion, and therefore weather and climate. The rate of evaporation depends on the temperature difference between the evaporating surface and the air, the relative humidity, and wind.
For more information on evaporation, visit Britannica.com.

Sports Science and Medicine: evaporation
The conversion of liquid into vapour. Evaporation of sweat is the primary route for heat dissipation during exercise, accounting for up to 80% of heat lost from the body.

Columbia Encyclopedia: evaporation,
change of a liquid into vapor at any temperature below its boiling point. For example, water, when placed in a shallow open container exposed to air, gradually disappears, evaporating at a rate that depends on the amount of surface exposed, the humidity of the air, and the temperature. Evaporation occurs because among the molecules near the surface of the liquid there are always some with enough heat energy to overcome the cohesion of their neighbors and escape (see adhesion and cohesion; matter). At higher temperatures the number of energetic molecules is greater, and evaporation is more rapid. Evaporation is also increased by increasing the surface area of the liquid or by increasing the air circulation, thus carrying away the energetic molecules leaving the liquid before they can be slowed enough by collisions with air molecules to be reabsorbed into the liquid. If the air is humid some water molecules from the air will pass back into the liquid, thus reducing the rate of evaporation. An increase in atmospheric pressure also reduces evaporation. The process of evaporation is always accompanied by a cooling effect. For example, when a liquid evaporates from the skin, a cooling sensation results. The reason for this is that only the most energetic molecules of liquid are lost by evaporation, so that the average energy of the remaining molecules decreases; the surface temperature, which is a measure of this average energy, decreases also. Many refrigeration processes are based on this principle.

Science Dictionary: evaporation
The changing of a liquid into a gas, often under the influence of heat (as in the boiling of water). The evaporation of water from the oceans is a major component in the hydrologic cycle.

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