Yield Extrinsic

FT rheometry is a powerful technique to document the nonlinear viscoelastic behavior of pure polymers as observed when performing large amplitude oscillatory strain (LAOS) experiments. When implemented on appropriate instmments, this test technique can readUy be applied on complex polymer systems, for instance, filled mbber compounds, in order to yield significant and reliable information. Any simple polymer can exhibit nonlinear viscoelastic properties when submitted to sufficiently large strain in such a case the observed behavior is so-called extrinsic... 

It is quite clear from these data that intrinsic resistance to dislocation motion in these metals does not determine their indentation hardnesses. Internal friction measurements have yielded similar results. Therefore, extrinsic factors need to be considered. 

The crystal structure of NiAl is the CsCl, or (B2) structure. This is bcc cubic with Ni, or A1 in the center of the unit cell and Al, or Ni at the eight comers. The lattice parameter is 2.88 A, and this is also the Burgers displacement. The unit cell volume is 23.9 A3 and the heat of formation is AHf = -71.6kJ/mole. When a kink on a dislocation line moves forward one-half burgers displacement, = b/2 = 1.44 A, the compound must dissociate locally, so AHf might be the barrier to motion. To overcome this barrier, the applied stress must do an amount of work equal to the barrier energy. If x is the applied stress, the work it does is approximately xb3 so x = 8.2 GPa. Then, if the conventional ratio of hardness to yield stress is used (i.e., 2x3 = 6) the hardness should be about 50 GPa. But according to Weaver, Stevenson and Bradt (2003) it is 2.2 GPa. Therefore, it is concluded that the hardness of NiAl is not intrinsic. Rather it is determined by an extrinsic factor namely, deformation hardening. 

Therefore, other factors that have not yet been studied and are not easily quantifiable, such as the absorption properties of the C.-T. adduct at the surface of the metal powder and the solubility of the formed species should be important in determining the oxidation properties of C.-T. adducts towards metal powders. Furthermore, some extrinsic factors inherent to the experimental conditions, such as reaction temperature, reagent concentration, and nature of the solvent have been reported to affect the overall yield or the course of the reaction, and led to separation of different products in some cases.55 59 In any case, it appears that the simultaneous presence of the donor molecule and the di-/inter-halogen lowers the oxidation potentials of the metals, allowing their oxidation, dissolution, and complexation. 

The fluorescence quantum yield of native DNA ( =4x 10 5)(,0>l,is much too small and its fluorescence lifetimes (ti 10 ps, t2 s 65 ps)(,2) are far too short to be useful for studying its rotational Brownian dynamics, so one must employ an extrinsic probe. Most commonly used is ethidium dye. Upon... 

Fluoroimmunoassays comprise a subclass of extrinsic labehng methods where various selective antigen (Ag)- antibody (Ab) immunoassay fluorescent labeling schemes yield a emission signal. One common scheme involves an enzyme-linked immunosorbent assay (ELISA) depicted in Figure 11.2 where the free Ab is tagged with a fluorophore. Numerous analytes can be detected via these types of selective lock-and-key methods. ... 

Extrinsic fluorescence is used whenever the natural fluorescence of a macromolecule is inadequate for accurate fluorescence measurement. In this case, one can attach a fluorescent reporter group by using the reactive isocyanate or isothiocyanate derivatives of fluorescein or rhodamine, two intensely fluorescent molecules. One can covalently also label a protein s a- and e-amino groups with dansyl chloride (/.e., A,A-dimethylaminonaphtha-lenesulfonyl chloride). Another useful reagent is 8-ani-lino-l-naphthalenesulfonic acid (abbreviated ANS). This compound is bound noncovalently by hydrophobic interactions in aqueous solutions, ANS is only very fluorescent, but upon binding within an apolar environment, the quantum yield of ANS becomes about 100 times greater. 

Analogously, the fluorescence quantum yield of an extrinsic fluorescent probe contained in a peptide can be measured by comparison with an appropriate standard. If the fluorescent peptide exists in a conformational equilibrium, the fluorophore may be located in a number of different environments and may have a distinct quantum yield (ip,) in each environment. In this case the determined fluorescence quantum yield represents a population-weighted average of the individual [Pg.700]

Also shown in Fig. 10(c)-(g) are the anion yield functions for submonolayer quantities of O2 deposited onto various multilayer atomic and molecular solids. The data represent part of a study [41] on the environmental factors involved in the DEA process. As can be seen, the yield of desorbed ions can vary greatly with substrate composition. Such variations can be attributed to the so-called extrinsic factors that modify the ESD process at times before attachment and after dissociation, for example, electron energy-loss processes in the substrate and postdissociation interactions (PDI) of ions with the surrounding medium [41]. These processes can be contrasted with intrinsic factors, which... 

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