# entropy

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## entropy

[en´trŏ-pe]
1. in thermodynamics, a measure of the part of the internal energy of a system that is unavailable to do work. In any spontaneous process, such as the flow of heat from a hot region to a cold region, entropy always increases.
2. the tendency of a system to move toward randomness.
3. in information theory, the negative of information, a measure of the disorder or randomness in a physical system. The theory of statistical mechanics proves that this concept is equivalent to entropy as defined in thermodynamics.
4. diminished capacity for spontaneous change, as occurs in the psyche in aging.

## en·tro·py (S),

(en'trŏ-pē),
That fraction of heat (energy) content not available for the performance of work, usually because (in a chemical reaction) it has been used to increase the random motion of the atoms or molecules in the system; thus, entropy is a measure of randomness or disorder. Entropy occurs in the Gibbs free energy (G) equation: ΔG = ΔH - TΔSH, change in enthalpy or heat content; T, absolute temperature; ΔS, change in entropy; ΔG, change in Gibbs free energy).
[G. entropia, a turning toward]

## entropy

/en·tro·py/ (en´tro-pe)
1. the measure of that part of the heat or energy of a system not available to perform work; it increases in all natural (spontaneous and irreversible) processes. Symbol S.
2. the tendency of any system to move toward randomness or disorder.
3. diminished capacity for spontaneous change.

## entropy

[en′trəpē]
Etymology: Gk, en + tropos, a turning
the tendency of a system to change from a state of order to a state of disorder, expressed in physics as a measure of the part of the energy in a thermodynamic system that is not available to perform work. According to the principles of evolution, living organisms tend to go from a state of disorder to a state of order in their development and thus appear to reverse entropy. However, maintaining a living system requires the expenditure of energy, leaving less energy available for work, with the result that the entropy of the system and its surroundings increases.

## en·tro·py

(S) (en'trŏ-pē)
That fraction of heat (energy) content not available for the performance of work, usually because (in a chemical reaction) it has been used to increase the random motion of the atoms or molecules in the system; thus, a measure of randomness or disorder.
[G. entropia, a turning toward]

## entropy

the amount of disorder or the degree of randomness of a system. For example, when a protein is denatured by heat (see DENATURATION), the molecule (which has a definite shape) uncoils and takes up a random shape, producing a large change in entropy.

## entropy (enˑ·tr·pē),

n the propensity of matter and energy in a closed system to degrade into an equilibrium of uniform inertness and disorder. The apparent suspension of entropy in animate systems is used to support the philosophy of vitalism.

## entropy

1. in thermodynamics, a measure of the part of the internal energy of a system that is unavailable to do work. In any spontaneous process, such as the flow of heat from a hot region to a cold region, entropy always increases.
2. in information theory, the negative of information, a measure of the disorder or randomness in a physical system. The theory of statistical mechanics proves that this concept is equivalent to entropy as defined in thermodynamics.
References in periodicals archive ?
2003) found that by using high-purity starting components and a different heat treatment than was used in the previous work by Pecharsky and Gschneidner (1997a), the entropy change with magnetization and the adiabatic temperature change for G[d.
1]] has a Curie temperature of 287 K and experiences an entropy change of -28 J/kg.
eta]] is the portion of the stress due to the entropy change and [[sigma].
The entropy changes are based on the theory of rubber elasticity.
In this regard, the concept of political support can be a useful analytical foundation for looking into the entropy change within a political system.
However, in this paper, I will mainly focus on support to explain entropy change within political systems, because in such systems demand is not only closely related to support but also in the end is supposed to be reflected or converted into support through various channels.
The analysis of entropy change does not violate the second law nor change the basic relationship between entropy and energy.
To evaluate the entropy changes in relation to the mean entropy of the signal, the standard deviation of the WE was used as a measurable parameter, which can be defined as
Thermodynamic parameters of inclusion reaction (HSG) were all negativesuggesting that interaction process between AY-CD and QpE was spontaneous driven by enthalpy and entropy changes.
The similarity in the entropy changes upon orientation and upon crystallization (melting) permits an estimation of the maximum value of [[Lambda].

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