Orientation planar

Radiography is less effective for detecting arbitrarily oriented planar defects (such as tight cracks or lack of fusion) in thick metal sections unless the likely location and orientation of cracking is known in advance. 

Molecular orientation at the surface may also be important. A molecule orients planarly when deposited on a solid surface. Molecular strands prefer to be parallel to the surface their probability of being oriented normal to the surface is very low. Several mechanisms can cause this orientation (1) Surface-active sites may favor entire chain segments to interact with the surface. (2) The... 

Rainey JK, Sykes BD (2005) Optimizing oriented planar-supported lipid samples for solid-state protein NMR. Biophys J 89 2792-2805... 

The results illustrated so far show that polyreactions in oriented planar monolayers are possible and lead to highly ordered and very stable model membranes. This raises the question whether polymerization is also possible in bilayers (like vesicles and BLM) and whether these bilayers exhibit a higher stability than their unpolymerized counterparts. 

An active-site model has been proposed to explain the high asymmetric oxidation of sulfide to sulfoxides75 (Fig. 6). The model consists of three pockets, A, B, and C, where pocket B, defined by the two chlorine atoms and the phenylsulfonyl group, is responsible for the high enantioselectivity exhibited for the oxidation of sulfides Rl-S-Rs. The absolute stereochemistry of the final sulfoxides is predicted in terms of a simple steric model, which involves minimization of nonbonded interaction between the RL and Rs groups of the sulfides (RL-S-Rs) and the active site surface of the oxaziridine in an orientative planar transition state. 

In addition, the balance between the steric and electrostatic interactions, and not the van der Waals interactions, controls the conformation of linear siloxane. This finding means that the backbone conformation is neither helical nor hydrocarbonlike in nature (trans-trans). Rather, the backbone has a cis-trans conformation and forms randomly oriented planar segments 14),... 

Abstract A systematic overview of various electric-field induced pattern forming instabilities in nematic liquid crystals is given. Particular emphasis is laid on the characterization of the threshold voltage and the critical wavenumber of the resulting patterns. The standard hydrodynamic description of nematics predicts the occurrence of striped patterns (rolls) in five different wavenumber ranges, which depend on the anisotropies of the dielectric permittivity and of the electrical conductivity as well as on the initial director orientation (planar or homeotropic). Experiments have revealed two additional pattern types which are not captured by the standard model of electroconvection and which still need a theoretical explanation. 

Structural and mechanical property studies on stretched poly(amidoimides) have shown that heating causes crystallization and the formation of a highly oriented planar crystal structure. 

A frequent requirement for the growth of cells in tissue engineering is that the cells are not oriented randomly within the scaffold but are oriented planar or even uniaxial. Tissue engineering of bones or muscles is an example. 

Figure 4 Extinction coefficient for poly(di-n-hexylsilane), calculated from the reflectivity measurements shown in figure 2, along with the extinction coefficient for randomly oriented planar-zigzag poly(di-methylsilane), as calculated from the band structure theory of h tmire [14].

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