# expansion

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## expansion,

in physics, increase in volume resulting from an increase in temperature. Contraction is the reverse process. When heat is applied to a body, the rate of vibration and the distances between the molecules composing it are increased and, hence, the space occupied by the body, i.e., its volume, increases. This increase in volume is not constant for all substances for any given rise in temperature, but is a specific property of each kind of matter. For example, zinc and lead undergo greater expansion in a one-degree rise in temperature than do silver or brass. Since solidssolid,
one of the three commonly recognized states in which matter occurs, i.e., that state, as distinguished from liquid and gas, in which a substance has both a definite shape and a definite volume.
have a definite shape, each linear dimension of the solid increases by a proportional amount for a given temperature increase. The amount that a unit length along any direction of a substance increases for a temperature increase of one degree is called the coefficient of linear expansion of the substance. Most liquids also expand when heated. However, since liquids do not have a definite shape, it is the expansion of their volume as a whole that is relevant rather than the increase in a linear dimension. The amount of expansion that a unit volume (e.g., a cubic centimeter or a cubic foot) of any substance undergoes per one-degree rise in temperature is called its volume coefficient or coefficient of cubical expansion and is listed as a property of that substance. The coefficient of linear expansion can be calculated by dividing the coefficient of cubical expansion of the substance by three. When the amount of expansion of a given length of a substance has been determined experimentally, the linear coefficient is calculated by dividing the total amount of expansion by the product of the original number of length units and the number of degrees of rise in temperature. Gases also exhibit thermal expansion. The coefficient of expansion is about the same for all the common gases at ordinary temperatures; it is 1-273 of the volume at 0°C; per degree rise in temperature. The Kelvin, or absolute, scale is based upon this behavior (see Kelvin temperature scaleKelvin temperature scale,
a temperature scale having an absolute zero below which temperatures do not exist. Absolute zero, or 0°K;, is the temperature at which molecular energy is a minimum, and it corresponds to a temperature of −273.
). Charles's law concerning the expansion of gases states that the volume of a gas is directly proportional to its absolute temperature (see gas lawsgas laws,
physical laws describing the behavior of a gas under various conditions of pressure, volume, and temperature. Experimental results indicate that all real gases behave in approximately the same manner, having their volume reduced by about the same proportion of the
). Liquids differ from each other as do solids in their expansion coefficients. Water, unlike most substances, contracts rather than expands as its temperature is increased from 0°C; to 4°C;; above 4°C; it exhibits normal behavior, expanding as the temperature increases.

## expansion

[ik′span·shən]
(electronics)
A process in which the effective gain of an amplifier is varied as a function of signal magnitude, the effective gain being greater for large signals than for small signals; the result is greater volume range in an audio amplifier and greater contrast range in facsimile.
(mathematics)
The expression of a quantity as the sum of a finite or infinite series of terms, as a finite or infinite product of factors, or, in general, in any extended form.
(mechanical engineering)
Increase in volume of working material with accompanying drop in pressure of a gaseous or vapor fluid, as in an internal combustion engine or steam engine cylinder.
(physics)
Process in which the volume of a constant mass of a substance increases.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

## expansion

The increase in length or volume of a material, or a body, caused by temperature, moisture, or other environmental condition.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

## expansion

1. Maths
a. the form of an expression or function when it is written as the sum or product of its terms
b. the act or process of determining this expanded form
2. the part of an engine cycle in which the working fluid does useful work by increasing in volume
3. Physics the increase in the dimensions of a body or substance when subjected to an increase in temperature, internal pressure, etc.
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
The New York program is similar to the HIFA initiative because it uses savings from a more flexible package to help finance further coverage expansions.
Furthermore, she says water withdrawals, like ski area expansions themselves, are regulated by local, state, and federal authorities.
The majority of the more lucrative incentives offered are directly linked to the number of new jobs created and to the dollar amount of the capital investment associated with an expansion. More progressive programs have recently been established by which state and local officials have begun working with rail service carriers and utility companies to ensure access to quality transportation and favorable utility prices and services throughout an entire state.
Since skiing is just one of several possible uses for such land, some expansions, such as those proposed at Booth Creek Ski Holding's Loon Mountain Resort in New Hampshire, have led to forest-policy debates over how to balance those uses.
banks, making both supply and demand factors conducive to consumer credit expansion. On the demand side, rising levels of employment and income coupled with the dramatic increases in stock and bond prices, and thus aggregate household wealth, have led to both a greater ability and a greater willingness of consumers to spend.
Just recently, a 100-million-lb expansion was announced by Seadrift Polypropylene Co., Seadrift, Texas, which will add 50% to Unipol PP capacity there when it comes on stream in the second half of next year.
When a company faces the right opportunity to grow significantly through a large-scale expansion, management typically focuses on high returns, increased market share and improved margins -- and rightly so.
July was the heaviest month for business expansions, with eight accounting for \$71.5 million.
About 50,000 years later, geographically isolated human populations experienced dramatic growth and expansion fueled by the appearance of many cultural innovations.
The project includes the construction of a new 8,850-square-metre, three-storey terminal, an enlargement of the current apron for incoming and departing flights, the installation of service lines, an expansion of parking facilities and the construction of a hangar.
While that has certainly happened in Westchester over the past two years, the return of relocations and expansions to the county in the third quarter of this year is another strong indication of the trend toward recovery.
The capacity for custom mixed rubber in North America will continue to increase, as eight suppliers indicated expansion plans for 2000.

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