Splaying

Fig. XV-10. Illustration of a bilayer membrane and two of its deformation modes (a) twist (b) splay. (From Ref. 75.)...

Here and are elastic constants. The first, is associated with a splay defonnation, is associated with... 

Figure C2.2.11. (a) Splay, (b) twist and (c) bend defonnations in a nematic liquid crystal. The director is indicated by a dot, when nonnal to the page. The corresponding Frank elastic constants are indicated (equation(C2.2.9)).

Here Fq is tire free energy of the isotropic phase. As usual, tire z direction is nonnal to tire layers. Thus, two elastic constants, B (compression) and (splay), are necessary to describe tire elasticity of a smectic phase [20,19, 86]. 

A phase itself, the amplitude of the density modulation is constant and twist and splay distortions are forbidden, thus the expression for the free energy density simplifies to equation (C2.2.10). 

If we compare with figure C2.2.I I, we can see that this defonnation involves bend and splay of the director field. This field-induced transition in director orientation is called a Freedericksz transition [9, 106, 1071. We can also define Freedericksz transitions when the director and field are both parallel to the surface, but mutually orthogonal or when the director is nonnal to the surface and the field is parallel to it. It turns out there is a threshold voltage for attaining orientation in the middle of the liquid crystal cell, i.e. a deviation of the angle of the director [9, 107]. For all tliree possible geometries, the threshold voltage takes the fonn [9, 107]... 

Figure C2.2.12. A Freedericksz transition involving splay and bend. This is sometimes called a splay defonnation, but only becomes purely splay in the limit of infinitesimal displacements of the director from its initial position [106]. The other two Freedericksz geometries ( bend and twist ) are described in the text.

Unlike quantum mechanics, molecular mechanics does not treat electrons explicitly. Molecular mechanics calculations cannot describe bond formation, bond breaking, or systems in which electronic delocalization or molecular orbital interaction splay a major role in determining geometry or properties. 

Fig. 6. The three basic curvature deformations of a nematic Hquid crystal bend, twist, and splay. The force constants opposing each of these strains are...

Other routes to reachieving filament separation have been described and rely on mechanical or aerodynamic forces to affect separation. Figure 4 illustrates one method which utilizes a rotating deflector plane to force the filaments apart while depositing the opened filaments ia overlapping loops (25). After the splayed filaments fall to the deposition surface or forming screen, a suction from below the disposition surface holds the fiber mass in place. 

Processing is similar to other engineering plastic resins. Drying is necessary before extmsion or molding. Special drying precautions are required for PET products to prevent degradation and splay. 

Dipole Moment To di.splay the dipole moment of acetic acid, select Dipole Moment. The magnitude of the dipole moment (in debyes) is displayed at the bottom of the screen and the dipole moment vector i where + to refer to the positive and negative ends of the dipole moment, respectively, is attached to the model on screen. Click on Done. 

C. Atomic Charges To di.splay atomic charges for acetic acid, select Atomic Charges. Click on an atom. The charge on that atom is di.splayed at the bottom of the screen. A positive number indicates a deficiency of electrons and a negative number, an excess of electrons. Repeat the process as necessary for different atoms, and click on Done when finished. 

Low-pressure SF products can have characteristic surface splay patterns. However, the utilization of increased mold temperatures, increased injection rates, or grained mold surfaces will serve to minimize or hide this surface streaking. Finishing systems like... 

High-pressure structural foam products have generally been found to require little or no postfinishing. Although high-pressure foam products may exhibit visual splay, their surface smoothness is maintained and no sanding or filling is required. 

These are usually self-adhesive, precut, printed patterns on a substrate that are simply adhered to the surface of a product. Decals generally use a transparent plastic film while labels are usually on an opaque plastic, metallic and multilayer sandwich base. Labels of sufficient thickness are useful for hiding unavoidable appearance problems such as gate and sprue removal areas, sink marks, blushes, splays, and weld lines. 

Splay ( bending or curvature ) defined by a splay constant K, or by a curvature elastic modulus = K h [76],... 

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