isotropy


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to isotropy: Isotropy group

isotropy

(ÿ-sot -rŏ-pee) The property by which all directions appear indistinguishable to an observer expanding with the Universe. Isotropy about every point in space implies homogeneity but the reverse is not necessarily true. See cosmological principle.

Isotropy

 

identity of the physical properties of a medium in all directions (the opposite of anisotropy).

All gases, liquids, and solids are isotropic in the amorphous state in all physical properties. Most physical properties in crystals are anisotropic. However, the isotropy of the properties of a crystal increases with increasing symmetry. Thus, the elasticity, strength, and electro-optical properties are anisotropic in highly symmetrical crystals (diamond, germanium, and rock salt), but the index of refraction, electrical conductivity, and coefficient of thermal expansion are isotropic (in less symmetrical crystals, these properties are likewise anisotropic).

Homogeneous polycrystals are usually isotropic with respect to all properties, if their properties are studied in a volume that is considerably larger than the grain size.

M. P. SHASKOL’SKAIA

isotropy

[ī′sä·trə·pē]
(physics)
The quality of a property which does not depend on the direction along which it is measured, or of a medium or entity whose properties do not depend on the direction along which they are measured.
References in periodicals archive ?
Such high orientation factors for crystalline and amorphous phases, with high crystallinity, high amorphous isotropy, and unique fibrillar precursor lead to magnificently high tensile performance for the drawn hIB yarn.
Unfortunately most modeling software assumes isotropy which may result in over or underestimation of the heat removal.
Unless severely cold worked, grains in metallic materials are randomly oriented so that, on a statistical basis, the assumption of isotropy can be justified.
If we assume isotropy and isothermal moisture transfer, then the relation between the mass flux [q.
Marshall addresses Krivine's Positivstellensatz, the non-compact case, Archimedean T-modules, Schmudgen's Positivstellensatz, Putinar's question, the weak isotropy of quadratic forms, Scheiderer's local-global principle, and semidefinite programming and operation.
PR and hardpan characteristics were checked for isotropy and spatial variability by constructing semivariograms.
For instance, as Latour notes, interactions should not be viewed as isotropic or isochronic, as time and space are always folded, even if they may produce effects of isotropy or isochrony.
63) In a similar fashion, Jellison et al1 and Field et al (64) categorized fiber tracts using FA and MD measurements compared with the contralateral side in addition to FA color-map findings, in order to divide fiber tracts into 4 different patterns: 1) normal or nearly normal FA and ADC, with abnormal tract location or tensor directions attributable to bulk mass displacement; 2) moderately decreased FA and increased ADC with normal tract locations and tensor directions; 3) moderately decreased FA and increased ADC with abnormal tensor directions; and 4) near isotropy.
The casting structure is formed of an aggregate of grains or polyhedral crystallites which produce isotropy compensation, while in a solid metal they are anisotropic.
In order to do this, we have to bring on stage specific assumptions of isotropy and homogeneity: A body is assumed isotropic in the sense that it has normal and shear components of stress on any plane through a point of that solid, and homogeneous in the sense that this situation is valid for any point of the solid.
Assuming turbulence isotropy and normal distribution of fluctuating terms, one can sample the distribution (1000 elements in this case) to get a fluctuating terms population.
These orbits may exist in one or more of four families corresponding to one of the four isotropy subgroups of [Z.