Lamellar rotation

Polis DL et al (1999) Shear-induced lamellar rotation observed in a diblock copolymer by in situ small-angle X-ray scattering. Macromolecules 32(14) 4668—4676... 

Polls, D.L., Smith, S.D., Terrill, N.J., Ryan, A.J., Motsc, D.C., Winey, K.I. Shear-induced lamellar rotation observed in a diblock copolymer by in situ small-angle x-ray scattering. Macromolecules 32, 4668 (1999)... 

One production line of a paper mill consists according the size and the quality of the produced paper sometimes from more than 50 steam drums to dry and flatten the produced paper. These drums (cylinders with flat bottoms, see figure 1) will be used with a steam pressure up to 500 kPa (5 bar) and additionally with a rotation speed up 1200 m.min the material is mainly grey cast iron (with lamellar graphite). The diameters can reach up to 2.2 m and the cylindrical lengths up to 10 m. For the specific flattening drums the cyhndrical diameters can be up to 5 m and more. 

Resolution of helicenes has also been performed by the very laborious method of picking single crystals 4,5 29,79,80). After recrystallization of the partially resolved mixture the procedure can be repeated, until no more variation in optical rotation occurs. Because some helicenes crystallize into racemic crystals by lamellar intergrowth of pure P and pure M forms (see Sect. 6) the crystal picking method is not always applicable, however. A [7]-heterohelicene was partially resolved by crystallization from the chiral solvent54) (—>x-pinene. 

The model proposed above accounts for orientation produced at low extension. To account for the c-axis orientation observed at high extension, either c-axis slip, or breakup of the large lamellar crystallites accompanied by rigid rotation and formation of microfibrils must occur. Both mechanisms can occur as elongation progresses, and an example of the latter is shown in Figure... 

Crystals of most polar lipids can swell in the presence of water. The corresponding phases, gel-phases, with lamellarly packed lipid, and water layers, are sometimes thermodynamically stable (Larsson, 1994, p. 41). Also, the hydrocarbon chain packing of gel-phases usually show some axial rotational disorder. The alkyl chain cross-sectional area is close to 20 A2 in a plane perpendicular... 

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