Strain corrections

E. Konofagou and J. Ophir, A new elastographic method for estimation and imaging of lateral displacements, lateral strains, corrected axial strains and Poisson s ratios in tissues, Ultrasound Med. Biol., 1998, 24, 1183-1199. 

Interestingly, the product is head-to-head , i.e. it has one new C—C and Sb—Sb bond, as opposed to two new C—Sb bonds. Assume we were convinced of the more or less invariance of the Sb—Sb bond enthalpy and that we had a reliable value for the —Sb bond enthalpy (say from a more trustworthy measurement of the enthalpy of formation of triphenylstibine ). With judicious use of Benson increments and strain corrections, one could thus estimate the enthalpy of formation of the dimer, and accordingly derive a trustworthy value for the monomer. We would then have a handle on the aromaticity of antimonin. The enthalpy of reaction of bismin, CjHjBi, to form the analogous dimer has likewise been derived to be — 50kJmoCL However, this does not particularly help us since elemental bismuth is metallic, i.e. it is illogical to consider that Bi (s) is held together by covalent Bi—Bi bonds. 

T°K Strained Corrected unstrained Corrected Strained unstrained ... 

After examination of Figure 2.17, what would you calculate as a proper group increment correction for the placement of two /-butyl groups cis in an alkene Assume no strain correction needed for the alkane you need to consider to answer the question. 

These formulas, like the corresponding ones in Chapter 5, imply small deformations and are approximations based on simplified representations of the states of strain. Corrections may be made for edge effects and bulging of the sides of shear sandwich samples of appreciable thickness, and for a more complete description of the state of strain in a twisted rod of rectangular cross-section. ... 

R engineering strain correction matrix rotational transform, matrix... 

For linear materials, the strain correction may be included for each arm, i.e. where ... 

Kinetics of the Q Qb QaQb reaction. The kinetics of electron transfer from to Qg following a single laser flash were determined in chromatophores by following the photoinduced electrochromic shift of the L-side bacteriopheophytin, observed at 760 nm [19]. Figure 2 shows these transients measured in chromatophores of the wild-type and revertant strains, corrected for the instantaneous rise and slow decay of P" " (Tiede and Hanson, this volume). The transients detected following formation of the initial P Qa state in the double mutant differed dramatically from those shown in Figure 2. TTie relatively slow rise and decay detected in the double mutant suggested forward and back rate constants of about 110 s and 50 s" respectively, for the Q Qb Qa b equilibrium. It is difficult to be certain that the transients measured in the double mutant are due to electron transfer between the quinones because the time scale of these transients is comparable to that for protein relaxation events associated with the P Q state (Tiede and Hanson, this volume), and the kinetics were not sensitive to inhibitors such as < -phenanthroline or atrazine. However, the loss of sensitivity to inhibitors may be a consequence of the amino acid replacements in the Qg site. A lower sensitivity to inhibitors was also seen for some of the revertant strains. In addition, the transient spectra associated with these kinetics were consistent with to Qg electron transfer. 

Putting the measured iAR/R) and iAR/R) into equations [5], the corrected pressure AP is obtained. However, using the presssure sensors of the straight-line type, equation [5] can not be applied for strain correction, because the ratio, a, of strain sensitivities depends on the direction. As shown in Table 2, a is 0.4 or 3 in x- or y- direction, respectively. On the other hand, the twin-arc type sensor has the uniqueness that a is the nearly independent of direction. As shown in Table 2, a is -0.55 and -0.56 in x- and y- direction, respectively. Therefore, the twin-arc type sensor enables the correction by equation [5]. 

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