The layer-rotation phenomenon

The layer-rotation phenomenon is one of the unique behaviours of FLC and AFLC devices. It is caused by the presence of spontaneous polarization. 

This phenomenon can be explained by the surface electroclinic effect of the smectic A phase as shown in Fig. 6.1.20. Nakagawa et al. have suggested the existence of a local electric field at the boundary or surface field, which in turn is explained by the contact between the two materials, liquid crystal and aligning film. The induction of a molecular tilt by the electroclinic effect [39] can be expected under exposure to such a surface field. Since FLC molecules are aligned with the direction of rubbing, the layer is formed with a layer deviation angle 6. 

The direction of this surface field seems to depend on the materials at the boundary. In the case shown in Table 6.1.10, the relationship between the sign of 8 and the sign of Pg indicates that the direction of the surface field is from the liquid crystal layer to the surface. 

This layer-rotation phenomenon is clearly visible in FLC cells in which only one substrate has been rubbed and in which the FLC material has an lAC phase sequence. This layer rotation is also observed when FLC materials show the nematic phase and a single substrate is rubbed. This layer rotation is attributed to the helical structure of a material in the nematic phase [38]. When, on the other hand, the same aligning film is used under both substrates and the substrates 

Liquid crystal Layer rotation (5) Spontsmeous polmzation (Pg) 

5 2005 Kohki Takatoh, Masaki Hasegawa, Mitsuhiro Koden, Nobuyuki Itoh, Ray Hasegawa and Masanori Sakamoto 

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In the study of impedance plots, we may observe the depression of semicircles. This is the so-called semicircle rotation of the impedance. This phenomenon is associated with electrode/electrolyte interface double-layer properties. For example, the rough surface of the electrodes or porous electrodes can result in an uneven distribution of the double-layer electric field. This semicircle rotation can be explained using the equivalent circuit presented in Figure 3.10, where R is inversely proportional to the frequency CO (and b is a constant). 

In some foods, a thin layer of low-viscosity fluid forms at the solid-fluid interface that in turn contributes to lower viscosity values. The boundary condition that at the solid-fluid interface the fluid velocity is that of the wall is not satisfied. This phenomenon is known as slip effect. Mooney (1931) outlined the procedures for the quantitative determination of slip coefficients in capillary flow and in a Couette system. The development for the concentric cylinder system will be outlined here for the case of the bob rotating and details of the derivation can be found in Mooney (1931). 

If an external body is engulfed, it can enrich the star with the original interstellar medium abundances of 6Li, 7Li, 9Be and 10,11B (written here in increasing order of hardness to be destroyed by thermonuclear reactions). This mechanism is then supposed to produce stellar enrichment of these elements up to the maximum meteoritic value. Also, the engulfing star will suffer a rotational increase due to the gain of the planet momentum and a thermal expansion phenomenon due to the penetration of the body provoking mass loss phenomena (Siess Livio 1999). An extension to this scenario has been proposed by Denissenkov Weiss (2000) in order to explain supermeteoritic Li abundance values, via a combination of stellar rotation and activation of the 7Be mechanism at the base of the convective layer produced by the penetration of the external body. 

Musculoskeletal disorders are disorders of the muscles, nerves, tendons, ligaments, joints, cartilage and spinal discs not caused by slips, trips, falls, motor vehicle accidents or other similar accidents. Examples are carpal tunnel syndrome, rotator cuff syndrome, De Quervain s disease, trigger finger, tarsal tunnel syndrome, sciatica, epicondylitis, tendinitis, Raynaud s phenomenon, carpet layers knee, herniated spinal disc, and low back pain. 

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