Edge Volterra process

The Volterra process for creating these disclinations is the same as for nematic disclinations. For the screw disclination the plane of cut is parallel to the cholesteric twist axis while for the edge disclination it is perpendicular to it. 

The equivalence just demonstrated for screw dislocations versus wedge x disclinations can be extended to edge dislocations (Figure 5.12) versus twist X disclinations and even further, to mixed dislocations and disclinations, for the simple reason that the two corresponding Volterra processes are the same. 

Figure 17. The Volterra process applied to cholesteric phases. The core structure is masked by a cylinder along the line L. (a, b) Edge and screw dislocation, (c-e) A section S limited by L, normal to the cholesteric axis, allows one to build either the edge dislocation (a) or a disclination (d), as in smectics (Fig. 16d and d"). (f, g) Construction of the opposite disclination. (Drawing made in collaboration with F. Livo-lant).

EDA complex formation, phase transitions 339 edge dislocation, Volterra process 419 effusity, phase transitions 320 Eglington-Glaser reaction, synthesis 99 eigenwaves, SLM 764 Einstein diffusivity-viscosity law 585... 

As for achiral disclinations, the Volterra process may be used to create screw or edge disclinations by cutting parallel or perpendicular, respectively, to the chiral nematic twist axis. 

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