Alignment transversal

For aligned transversely isotropic elements the self consistent method gives (Walpole58 ) the relations... 

I. Novel network polyurethane with azobenzene dye in the main frame, Macromolecules, 1995, 28, 6437 Nonlinear optical polymers. 2. Novel NLO linear polyurethane with dipole moments aligned transverse to the main backbone, Macromolecules, 1996, 29, 592. 

Materials. 4-[(2-Hydroxyethyl)amino]-2-(hydroxymethyl)-4 -nitroazobenzene (T-AZODIOL) (10) was used as the NLO chromophore whose dipole moment is aligned transverse to the main chain. T-AZODIOL was synthesized via two step reactions as shown in Schemes 1 and 2. As shown, 3-(2-hydroxylamino)-benzylalcohol (DIOL) prepared from w-aminobenzyl alcohol with 2-chloroethanol was coupled with diazotized / -nitroaniline to give rise to T-AZODIOL. The details of the synthetic procedures were previously reported (8). 4-[N-(2-Hydroxyethyl)-N-methylamino]-3 -(hydroxymethyl)-azobenzene (AZODIOL) dye was the NLO chromophore monomer for preparing the polymer with NLO chromophore incorporated in the main chain. Detailed synthetic procedures of AZODIOL were previously reported (5), Commercially available 2,4-tolylene diisocyanate (TDI) and 4,4 -diphenylmethane diisocyanate (PDI) were used without further purification. The chemical structures of these monomers are shown in Figure 1. 

In simplest terms, fibers tend to align in the flow direction when the flow is converging and align transverse to flow where the flow diverges (Fig. 7.58). With multiple injection points and complicated geometry, the final orientation distribution can be extremely complex. Simulation can assist here by first calculating the final orientation state and then using this information to derive the thermomechanical... 

Remark 5.7. For composites in accordance with Remark 5.2 consisting of aligned transversely isotropic fiber and matrix materials, the overall material behavior is expected to be at most orthotropic and, in the case of identical directional fiber fractions i/i and 1/2, to be transversely isotropic. 

The designs for several small-scale cw HF(DF) chemical lasers have been given in the literature. " These devices deliver power outputs of a few watts when operated with mixtures of H2(D2), SFe, and helium. Operation as an HCl chemical laser is also possible in this type of laser with either the Cl + HI > HCl + I or H + CI2 -> HCl + Cl reactions, albeit with somewhat lower power outputs than the HF(DF) lasers. Figure 3.8 illustrates one such device. An electrical discharge of about 1 kW(DC, RF, or micro-wave) is commonly used for dissociation of SFg to provide a source of F atoms. Hydrogen is injected by means of small orifices in a direction transverse to the primary flow of partially dissociated SFg in a helium diluent. The optical cavity is aligned transversely to the flow direction as shown in Figure 3.8. The output of such lasers usually consists of several P-branch transitions in the 1 ->0, 2-> 1, or 1 ->0, 2-> 1, and 3->2 bands for HF or DF, respectively. Operation as an HCl laser produces P-branch transitions in the... 

Oriented In-Plane Texture. In this kind of film the properties (H and in the various in-plane directions (texture and nontexture directions) are different. The texture of the film can be supported by the texture of the substrate and the crystal lattice can be smaller in the texture direction than in the transverse direction. This can be the source for strain-induced magnetic anisotropy (magnetostriction). It is also found that the crystal is aligned in the texture direction (92). 

Fine, short, cracklike pits run transversely across the apex of many corrugations on the stainless sheets (Figs. 2.24 and 2.25). The corrosion sites originate at the apex of the corrugations at small circular discolorations, spaced apart exactly the peak-to-peak distance between corrugations. All cracklike pits are aligned in the same direction, regardless of their locations on the plate. 

Pinhole perforations were discovered in the walls of chiller condenser tubes of an air-conditioning system. Close laboratory examination of the internal surfaces of affected tubes revealed distinct patches of small pits (Fig. 12.18) and pit sites aligned along longitudinal mandrel marks and fine scratches (Fig. 12.19). In some locations, transversely oriented pit sites that were aligned with the locations of the fins on the external surface branched off the primary longitudinal pit alignment (Fig. 12.20). 

El and E2 refer to the longitudinal and transverse moduli for aligned fibre composites of the type shown in (Fig. 3.29). These values can be determined experimentally or using specifically formulated empirical equations. However, if the fibres are relatively long then equation (3.5) and (3.13) may be used. These give results which are sufficiently accurate for most practical purposes. 

Pagano studied cylindrical bending of symmetric cross-ply laminated composite plates [6-21]. Each layer is orthotropic and has principal material directions aligned with the plate axes. The plate is infinitely long in the y-direction (see Figure 6-16). When subjected to a transverse load, p(x), that is, p is independent of y, the plate deforms into a cylinder ... 

The treatment of transverse shear stress effects in plates made of isotropic materials stems from the classical papers by Reissner [6-26] and Mindlin [6-27. Extension of Reissner s theory to plates made of orthotropic materials is due to Girkmann and Beer [6-28], Ambartsumyan [6-29] treated symmetrically laminated plates with orthotropic laminae having their principal material directions aligned with the plate axes. Whitney [6-30] extended Ambartsumyan s analysis to symmetrically laminated plates with orthotropic laminae of arbitrary orientation. 

The basic approaches as summarized by Ashton and Whitney [6-31] will now be discussed. First, a symmetric laminate with orthotropic laminae having principal material directions aligned with the plate axes will be treated. The transverse normal strain can be found from the orthotropic stress-strain relations, Equation (2.15), as... 

In polymers one will often particularly be interested in very slow dynamic processes. The solid echo technique just described is still limited by the transverse relaxation time T being of the order of a few ps at most. The ultimate limitation in every NMR experiment however, is not T but the longitudinal relaxation time T, which for 2H in solid polymers typically is much longer, being in the range 10 ms to 10 s. The spin alignment technique (20) circumvents transverse relaxation and is limited by Tx only, thus ultraslow motions become accessible of experiment. 

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