Splitting, columnar phases

Another type of interpretation of the textures was proposed by Nas-tishin et al., who suggested that the By phase is a smectic and columnar phase at the same time. The geometry of the helical filaments (ribbons) is that one of the central region of a screw disclination with a giant Burgers vector split into two disclination lines of strength V2/ which boimd the ribbon. 

Figure 4-7. Experimental dipolar spectra of a methylene group with equal C-H dipolar couplings provided by the signal of the 3-carbon in static and oriented RufHSO sample in columnar phase at 85 °C. The smaller splittings in the SLF spectrum and the inner doublet in the PDLF spectrum are due to a weak coupling to the core proton H4. The frequency axes have been corrected for the scaUng factors...

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