Tight environment-dependent

Flaas FI, Wang C Z, Fahnie M, Elsasser C and Flo K M 1998 Environment-dependent tight-binding model for molybdenum Phys. Rev. B 57 1461... 

The optical activity of helical segments in proteins can vary considerably with helix length, conformation and nature of side chains. The Cotton effects at 198 and 207 mn are sensitive to hehx geometry, while the 233 nm Cotton effect is not, therefore [m]233 measurement gives better average helical contents than do measurements at other wavelengths. The ORD of perfect helices should be relatively independent of solvent because the tightly packed hehx structure provide the uniform local environment for the n tt transition, while distorted hehces will be more environment dependent. 

Environment-Dependent Tight-Binding Potential Models... 

Wang, C.Z. and Ho, K.M. (2005) Environment-dependent tight-binding potential models. Handbook of Materials Modeling, Part A. Methods, Springer, The Netherlands, 307-347. 

Field analogues should be based on reservoir rock type (e.g. tight sandstone, fractured carbonate), fluid type, and environment of deposition. This technique should not be overlooked, especially where little information is available, such as at the exploration stage. Summary charts such as the one shown in Figure 8.19 may be used in conjunction with estimates of macroscopic sweep efficiency (which will depend upon well density and positioning, reservoir homogeneity, offtake rate and fluid type) and microscopic displacement efficiency (which may be estimated if core measurements of residual oil saturation are available). 

The crevice shape markedly affects corrosion. Crevices so tight that water may not enter are entirely immune to attack. In misting environments or alternately wet-diy environments, the crevice holds water and may allow continued attack even when neeu by surfaces eire dry. In sea water, the severity of attack in stainless steel crevices depends on the ratio of the crevice area to the cathodic surface area outside the crevice. If the cathodic area is large relative to crevice eirea, corrosion is promoted. 

The heterogeneity of the reaction medium is also important in determining the molecular weight and in solution polymerization of maeromonomers. The magnitude of the effect varies according to the solvent quality. PS macromonomer chains in good solvents (e.g. toluene) have au extended conformation whereas in poor solvents (e.g. melhylcyclohexane) chains are tightly coiled.89 As a consequence, the radical center may see ail environment that is medium dependent (see also Sections 7.6.5 and 8.3.7). 

As mentioned previously, the cement contains both tightly bound and loosely bound water. The set cement can both lose and gain water depending on its environment. Under drying conditions (say 50 % relative humidity) it loses water and shrinks. When placed in water there is an... 

AP photophysics is determined by its environment, which makes 2AP a useful probe of RNA structure and dynamics but because its properties depend on its environment, the incorporation of 2AP into an RNA must be done cautiously, preferably with prior knowledge of the site—duplex or single strand, tight turn or floppy loop, etc. With that caveat in mind, 2AP has been used in several ways to provide unique information on the folding and dynamics of both small and large RJSIAs. 

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