Unstrained parameter value

Unstrained parameter value See ideal parameter value. 

Unstrained parameter value See Ideal parameter value. 

Strained set of lattice parameters and calculating the stress from the peak shifts, taking into account the angle of the detected sets of planes relative to the surface (see discussion above). If the assumed unstrained lattice parameters are incorrect not all peaks will give the same values. It should be borne in mind that, because of stoichiometry or impurity effects, modified surface films often have unstrained lattice parameters that are different from the same materials in the bulk form. In addition, thin film mechanical properties (Young s modulus and Poisson ratio) can differ from those of bulk materials. Where pronounced texture and stress are present simultaneously analysis can be particularly difficult. 

FIGURE 10.6. The ratio of the rate of heat release of a strained flame to that of an unstrained flame as a function of the reciprocal of the nondimensional strain rate for various values of the nonadiabaticity parameter H calculations were performed for a one-reactant, first-order reaction in an ideal gas with constant specific heat and Lewis number of unity, with thermal conductivity proportional to temperature and an adiabatic flame temperature four times the initial temperature [HO]. 

Here A and t are the extension ratio and tensile stress respectively, V is the volume of the strained specimen and a reference volume which may usually be taken as the unstrained volume. p,R,T, and A/<, are, respectively, density, gas constant, absolute temperature and repeat unit molecular weight. The parameter G, defined by Flory and Abe, provides a measure of the average correlation of local transition moment directions with respect to the chain end-to-end vector. Positive values of denote a tendency for the transition moments to orient in line with the end-to-end vector and negative G values are characteristic of... 

LDA band structure. To evaluate the internal strains by minimization of the energy, it was necessary to use for the unstrained crystal the calculated internal positions. Although these predictions are quite close to the measured values, the small differences do result in one noticeable difference in the band structure the band that just crosses the Fermi level from below and gives rise to the stick Fermi surface does not quite reach the Fermi level when the theoretical internal parameters are used for atomic positions. The apical oxygen 04 position is the critical one. However, it is only the trends (finite differences) in band structure that we will report, and these changes will be insensitive to the reference point. 

A rough estimate of the thickness ratio that results in = 0 can be obtained on the basis of the following reasoning. For the case considered by Suo and Hutchinson (1989), the elastic mismatch strain across the interface prior to delamination is zero, and the substrate is unstrained. Therefore, the conditions that the extensional strain of the film surface z = 0 after delamination must still be zero may correspond to a relatively small value of shear stress on the interface at the delamination front a nonsingular value of shear stress axz = 0 corresponds to the condition that ip = 0, provided that the normal stress azz is still singular and positive. The methods of Section 2.2 can be used to show that this condition on strain implies that / f// sl must have the value 2. While the estimate is crude, it may provide a useful indicator of behavior for arbitrary combinations of material parameters and film thicknesses in cases for which other indicators are not available. 

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