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Specific rotation function

Another generalization uses referential (material) symmetric Piola-Kirchhoff stress and Green strain tensors in place of the stress and strain tensors used in the small deformation theory. These tensors have components relative to a fixed reference configuration, and the theory of Section 5.2 carries over intact when small deformation quantities are replaced by their referential counterparts. The referential formulation has the advantage that tensor components do not change with relative rotation between the coordinate frame and the material, and it is relatively easy to construct specific constitutive functions for specific materials, even when they are anisotropic. [Pg.119]

The referential formulation is translated into an equivalent current spatial description in terms of the Cauchy stress tensor and Almansi strain tensor, which have components relative to the current spatial configuration. The spatial constitutive equations take a form similar to the referential equations, but the moduli and elastic limit functions depend on the deformation, showing effects that have misleadingly been called strain-induced hardening and anisotropy. Since the components of spatial tensors change with relative rigid rotation between the coordinate frame and the material, it is relatively difficult to construct specific constitutive functions to represent particular materials. [Pg.119]

The energy within a hydraulic system is of no value until it is converted into work. Typically, this is accomplished by using an actuating device of some type. This actuating device may be a cylinder, which converts the hydraulic energy into linear mechanical force a hydraulic motor, that converts energy into rotational force or a variety of other actuators designed to provide specific work functions. [Pg.586]

Frequency is defined as the number of repetitions of a specific forcing function or vibration component over a specific unit of time. Take for example a four-spoke wheel with an accelerometer attached. Every time the shaft completes one rotation, each of the four spokes passes the accelerometer once, which is referred to as four cycles per revolution. Therefore, if the shaft rotates at 100 rpm, the frequency of the spokes passing the accelerometer is 400 cycles per minute (cpm). In addition to cpm, frequency is... [Pg.674]

Marvel, Dec, and Cooke [J. Am. Chem. Soc., 62 (3499), 1940] have used optical rotation measurements to study the kinetics of the polymerization of certain optically active vinyl esters. The change in rotation during the polymerization may be used to determine the reaction order and reaction rate constant. The specific rotation angle in dioxane solution is a linear combination of the contributions of the monomer and of the polymerized mer units. The optical rotation due to each mer unit in the polymer chain is independent of the chain length. The following values of the optical rotation were recorded as a function of time for the polymerization of d-s-butyl a-chloroacrylate... [Pg.74]

Aminoallenes constitute an important class of functionalized allenes with interesting chemical properties. They are known as attractive substrates for constructing three- to six-membered azacycles [78]. In 1999, Ohno and co-workers reported the stereoselective synthesis of chiral a-aminoallenes 179 and 181 by RCu(CN)M-medi-ated anti-SN2 substitution of chiral 2-ethynylaziridines 178 and 180 (Scheme 4.47) [79]. The X-ray data and specific rotations of the allenes were consistent with a net anti-S- 2 substitution reaction. [Pg.162]

In the simplest case, where (+)-AH and (-)AD are isotopically pure, a = [a]H[AH]0 and a2 = [a]D[AD]0 where a is the specific rotation of the AH and AD isotopomers, respectively, and [AH]0 and [AD]0 are the concentrations of the substrates in g ml-1 at time t = 0. When the substrate is neither isotopically nor enantiomerically pure, corrections must be made in calculating fli and a2 (Bergson et al., 1977). It is important to note that the pre-exponential factors, a and a2, which contain the information about the starting conditions, can be determined with high accuracy. The extreme, ae (the maximum or minimum value of the optical rotation in the optical rotation versus time plot) and the corresponding reaction time, te, are functions of the rate constant ratio (5 = kHlkD) (65) and the difference between the rate constants (66), respectively. [Pg.235]

Recently Isbell and coworkers have published the results of an extensive study of the behavior of solutions of sorbitol and D-mannitol in the presence of tetraborates. They found that sorbitol appears to form three complex borate compounds, whereas D-mannitol forms only two. Since the specific rotation in the tetraborate-D-mannitol system is a function of the ratio of the components and is independent of concentration at constant tetraborate-D-mannitol ratios, D-mannitol can be determined quantitatively by this method. However, sorbitol cannot be determined this way because the change in observed rotation at constant tetraborate concentration shows a reversal with increasing amounts of sorbitol. [Pg.225]

Fig. 11. (a) Far ultraviolet rotatory dispersion of ribonuclease. Corrected mean residue specific rotation vs. wavelength [to R = [aLAf/100 [3/(n2 + 2)l where a — specific rotation, M mean residue weight, and n = solvent refractive index. Bars give maximal deviation at peaks. Reproduced from Jirgensons (311). (b) Near ultraviolet rotatory dispersion of 0.48% pancreatic ribonuclease in a 1-mm cell, in (a) 0.15 M phosphate buffer at pH 62 (b) 0.15 M glycine-NaOH buffer at pH 11.5 (c) 0.1 N HC1 (d) 15% sodium dodecyl sulfate. Reproduced from Glazer and Simmons (313). (c) Far ultraviolet circular dichroic spectra of RNase-A, RNase-S, and S-protein at 25° and 3°. Reproduced from Pflumm and Beychok (313). (d) Near ultraviolet circular dichroic spectra of RNase-A as a function of pH. Reproduced from Pflumm and Beychok (313). [Pg.721]

Limits of detection for many amino acids were enhanced considerably by pre-column derivatization with the achiral reagent dansyl chloride whose function it was to increase their specific rotation [17]. Determinations of the enantiomeric purities for mixtures of D-and L-tryptophan [18] and of isomeric ratios for mixtures of pseudoephedrine and its diastereomer ephedrine [19], were effected using diode-laser polarimetry and using OR detection in series with UV absorbance detection respectively. [Pg.283]

From the WET, Eq. [166], it is obvious that the reduced matrix element (RME) depends on the specific wave functions and the operator, whereas it is independent of magnetic quantum numbers m. The 3/ symbol depends only on rotational symmetry properties. It is related to the corresponding vector... [Pg.148]

Fig. 8. Rotatory dispersion titration of transferrin with Fe3+. In the upper portion of the figure, specific rotation at 10, — [a] , is plotted against wavelength. In the presence of Fe3+, the rotatory dispersion of transferrin becomes anomalous due to a negative Cotton effect centered about the absorption maximum of the metal-protein complex at 470 mp. As with conalbumin (Fig. 1), the magnitude of the Cotton effect is a function of the amount of Fe3+ bound to transferrin and becomes maximal at 2 moles of Fe3+ per mole of protein (lower portion of figure). Conditions identical to those for conalbumin. (Biochem. Biophys. Res. Commun. 8, 331 [1962]). Fig. 8. Rotatory dispersion titration of transferrin with Fe3+. In the upper portion of the figure, specific rotation at 10, — [a] , is plotted against wavelength. In the presence of Fe3+, the rotatory dispersion of transferrin becomes anomalous due to a negative Cotton effect centered about the absorption maximum of the metal-protein complex at 470 mp. As with conalbumin (Fig. 1), the magnitude of the Cotton effect is a function of the amount of Fe3+ bound to transferrin and becomes maximal at 2 moles of Fe3+ per mole of protein (lower portion of figure). Conditions identical to those for conalbumin. (Biochem. Biophys. Res. Commun. 8, 331 [1962]).
T. Yet it must be remembered that the decision as to when a methyl group is in a frozen or a state of free rotation is made by the NMR experiment in such a way that the methyl group under consideration does or does not cross a specific rotational frequency. This deciding rotational frequency has been introduced in Equation 7 as the correlation frequency vc. According to Equation 7 vc is temperature dependent. Figure 5 shows the vc values calculated from Equation 7 as a function of the reciprocal temperature. [Pg.624]

There are different components that make up the extruder each with their specific important function. All components have to operate efficiently otherwise the extruder s operation is inefficient. A very important and essential parameter in the extruder is the plasticator s pumping process. It is the interaction between the rotating flights of the screw and the stationary barrel wall. For the plastic material to be conveyed, its friction must be low at the screw surface but high at the barrel wall. If this basic criterion is not met, the plastic will usually rotate with the screw and not move in the axial output direction. [Pg.231]

Kowalczyk et al. [121] have investigated the basis set dependence of calculated ORs at four different wavelengths, and of the lowest six states in the ECD spectrum, for (S)-2-chloropropionitrile optimized at the B3LYP/6-311++G(d,p) level of theory. The ORD was calculated at 633, 589, 436, and 355 nm. Six basis sets were selected to calculate the specific rotation with an origin-invariant GIAO approach aug-cc-pVDZ, aug-cc-pVTZ, aug-cc-pVQZ, d-aug-cc-pVDZ, d-aug-cc-pVTZ, and Sadlej-pVDZ (155, 326, 588, 207, 426, and 174 basis functions, respectively). All TDDFT calculations used the B3LYP functional. No solvation models were employed in the calculations. Experimental gas phase measurement... [Pg.21]

Fig. 8 The effect of basis set on the specific rotation of (S)-methyloxirane calculated with the B3LYP functional at 589 nm. The key labels the method of geometry optimization. Basis set numbers correspond to the following 1 = 6-31G(d), 2 = 6-31+-l-G(d,p), 3 = 6-31++G(2d,2p), 4 = cc-pVDZ, 5 = cc-pVTZ, 6 = aug-cc-pVDZ, 7 = d-aug-cc-pVDZ, 8 = mixed-cc-PVTZ (aug-cc-pVTZ(C,0) and aug-cc-pVDZ(H)), 9 = aug-cc-pVTZ, 10 = Sadlej-pVTZ. Data to prepare the plot were taken from [145]... Fig. 8 The effect of basis set on the specific rotation of (S)-methyloxirane calculated with the B3LYP functional at 589 nm. The key labels the method of geometry optimization. Basis set numbers correspond to the following 1 = 6-31G(d), 2 = 6-31+-l-G(d,p), 3 = 6-31++G(2d,2p), 4 = cc-pVDZ, 5 = cc-pVTZ, 6 = aug-cc-pVDZ, 7 = d-aug-cc-pVDZ, 8 = mixed-cc-PVTZ (aug-cc-pVTZ(C,0) and aug-cc-pVDZ(H)), 9 = aug-cc-pVTZ, 10 = Sadlej-pVTZ. Data to prepare the plot were taken from [145]...
Fig. 12 Specific rotation as a function of rotation of a substituent group. Left Rotation of the CH3 group in methyloxirane. Right Rotation of the CC1H2 group in epichlorohydrin. A 0° angle corresponds to a minimum-energy geometry. See [149]... Fig. 12 Specific rotation as a function of rotation of a substituent group. Left Rotation of the CH3 group in methyloxirane. Right Rotation of the CC1H2 group in epichlorohydrin. A 0° angle corresponds to a minimum-energy geometry. See [149]...

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