Small bending

To understand drainage we have to discuss the pressure inside the liquid films. At the contact line between liquid films, a channel is formed. This is called the Plateau border. Due to the small bending radius (rP in Fig. 12.18), there is a significant Laplace pressure difference between the inside of the compartment and the liquid phase. The pressure inside the liquid is significantly smaller than in the gas phase. As a result, liquid is sucked from the planar films into the Plateau s border. This is an important effect for the drainage of foams because the Plateau borders act as channels. Hydrodynamic flow in the planar films is a slow process [574], It is for this reason that viscosity has a drastic influence on the evolution of a foam. Once the liquid has reached a Plateau border the flow becomes much more efficient. The liquid then flows downwards driven by gravitation. 

In addition to helix F, helices D and E also contain small bends in IFN-a2b and 1FN-/3. In each molecule, the bend in heUx E is centered on Tyr-122, which hydrogen bonds to Glu-146 on heUx F. Thus the bend in helix E occurs at the same place as helix F in the center of the conserved structural core. The bend in helix D occurs at the position of the buried polar residue Gln-91 in lFN-a2b which forms a hydrogen bond with Ser-14 on helix A. A similar interaction is observed in IFN-/3 between the structurally identical Gln-94 and Gln-10 on helix A. It is notable that Gln-91 is conserved in all type I IFNs. 

Superposition of IFN-o 2 and IFN-/3 highlight several differences between the subtypes as well as general features of the type 1 IFN fold (Fig. 7). First, helix A is seven residues longer in 1FN-/3 than IFN-o. Helix A in 1FN-/3 contains a small bend that occurs approximately where helix A ends in lFN-a2b. This allows the longer helix A of IFN-/3 to pack efficiently against the helical bundle. In contrast to the helical N-terminus of 1FN-/3, the N-terminus of IFN-a forms a flexible loop that is connected to the DE loop by disulfide bond. 

Minimization of the cross-sectional deformation and the thinning or thickening of the wall thickness, especially for small bending radii... 

According to (2.21), both planar and three-dimensional (helical) small bending perturbations increase with the same growth rate if the relative velocity of gas flow is... 

In (2.25) primes denote time differentiation. The above-mentioned nonlinear effect related to stretching of the jet axis by finite bending perturbations is given by the third (nonlinear in H) term oti the left-hand side in (2.25). The linearized version of (2.33) corresponds to small bending perturbations and readily admits the solution H = exp( yt)- The amazing fact is that the growth rate y thus obtained satisfies the exact (2.21). The nonUnear numerical solution of (2.25) is depicted in Fig. 2.3 together with the numerical solution of the quasi-mie-dimensional equations and the result of the linear theory. 

With a very small bend radius, almost all the fibers from the outside radius to the neutral centerline and from the inside bend radius to the... 

All the diagonal bars were subjected to tensile force and to a very small bending moment. 

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