# entropy

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Related to entropy: enthalpy

## 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 ?
Analysis of entropy generation during natural convection in porous right-angled triangular cavities with various thermal boundary conditions, International Journal of Heat and Mass Transfer, 55: 4521-4535.
It has been shown that for stationary ergodic processes, Hk converges to the entropy rate H(X) almost surely as n approaches infinity.
i] is found from the numerical entropy scheme (8) with [eta]([Q.
Notably, there are two modifications in the cross-fuzzy entropy (C-FuzzyEn) proposed by Xie et al.
When the observation point moves downstream, make [mathematical expression not reproducible] and according to the definition of information entropy, the information entropy of [x.
Always, is possible to measure exactly only the Effect State Value of a Cause State because an Effect State is always changing dynamics its Entropy NOW while the Cause changed its Entropy's dynamics in the past.
Factor- entropy analysis method is not a simple combination of these two methods.
Feature selection based on maximum entropy method would divide the cleaning RFID data blocks into rich feature set data and poor feature set data according to the features, then the sequential inflow into cleaning nodes is processed to find a suitable cleaning method, which could improve the cleaning efficiency and reduce error, and is particularly suitable for the cleaning of massive uncertainty RFID data streams.
Scientists next compared their statistical measures of relatively higher or lower entropy with participants' scores on two standard IQ tests: the Shipley-Hartford test, which gauges verbal skills, and the Wechsler test, which assesses problem-solving abilities.
Complete confidence in your security systems can only come from a consistent supply of true entropy across your entire application environment.
Is it possible to define a new cross entropy measure under interval-valued neutrosophic set environment that is free from asymmetrical phenomena?
The thermal energy (Eth), heat capacity (CV), entropy (S) and LUMO energy(Elumo) of 41 sulfonamides are taken from the quantum mechanics methodology with Hartree-Fock (HF) level using the ab initio 6-31G basis sets and the standard procedure in GUSSIAN 03.

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