Tilting process

Deviations from random orientation are observed by changes in relative intensities if the sample is tilted. The tilting process was per-... 

The principal parameter that distinguishes smectic-C from smectic-A is the tilt angle Oq. Because of the chiral character of the molecule, the tilt processes around the normal to the smectic layers, together with the transverse electric polarization P (cf Fig. 4.16). In the theories developed to describe the phase transition phenomena from the smectic-C phase to the smectic-A phase, the tilt angle is treated as a primary order parameter of the system, very much as the director axis n in the nematic or cholesteric phase, while P is regarded as a secondary one. 

The entire QSL process takes place in a single reactor as shown in Figure 6 (15). The reactor consists of an almost horizontal, refractory-lined cylinder, which can be tilted by 90° when operation is intermpted. Concentrates, fluxes, recirculated flue dust, and normally a small amount of coal, depending on the type of concentrate, are pelletized. The pelletizer ensures that the raw materials are mixed to the required degree of uniformity. 

For the butadiene-cyclobutene interconversion, the transition states for conrotatory and disrotatory interconversion are shown below. The array of orbitals represents the basis set orbitals, i.e., the total set of 2p orbitals involved in the reaction process, not the individual MOs. Each of the orbitals is tc in character, and the phase difference is represented by shading. The tilt at C-1 and C-4 as the butadiene system rotates toward the transition state is different for the disrotatory and conrotatory modes. The dashed line represents the a bond that is being broken (or formed). 

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