Reverse curl

One of the best known examples of reversibility in bond formation is the cross-linking of cysteine, a sulfur-containing amino acid, that affects tertiary structure in proteins and, ultimately, macroscale phenomena such as the degree of curl in hair. Other examples include the imine bond, formed by the reaction of an amine group with an aldehyde, and metal coordinate bonds to atoms such as nitrogen as found in many enzymes. 

The thermophysical events in a can in the retort (dissolution, hydration, dehydration, gelatinization decrystallization, defibrillation, curling, uncurling, etc.) obviously must be complex. Charge superimposes electrostatic and electrokinetic reactions on the thermophysical processes. Broken-curve profiles for some polysaccharide foodstuffs manifest a transition from conduction to convection heating, as a tenuous, reversible suprastructure reverts to a liquefied mass under the influence of + A//mix. 

Organic photoreceptors can be prepared in either a flexible web or drum format. Webs are usually prepared on polymer substrates, polyethylene tere-phthalate being the most common. The substrates are between 100 to 200 pm in thickness and coated with a conducting surface layer. The substrates often contain layers on the reverse side for reduced curl, static discharge prevention, and control of frictional characteristics. The web configuration is also widely used for laboratory studies. For drums, the substrate is a metal cylinder, usually Al. Recently, however, drums of a poly(phenylene sulfide) resin doped with conductive C black have been developed (Kawata and Hikima, 1996). Drums are widely used in low- and mid-volume applications. Drums, however, are not well suited for research purposes. Thus, the preparation and characterization of drum photoreceptors is usually related to a specific application. 

The influence of liquid properties is strong. There is clear evidence [Groothius and Zuiderweg, toe. cit. Chem. Eng. Sci., 12, 288 (I960)] that coalescence rates are enhanced by mass transfer from a drop to the surrounding continuum and retarded by transfer in the reverse direction. See also Howarth [Chem. Eng. Set., 19, 33 (1964)]. For a theoretical treatment of drop breakage and coalescence and their effects, see Valentas and Amundsen [Ind. Eng. Chem. Fundam., 5, 271, 533 (1966) 7, 66 (1968)], Gal-Or and Walatka [Am. Inst. Chem. Eng. J., 13,650 (1967)], and Curl [ibid., 9,175 (1963)]. 

Goolaup S, Singh N, Adeyeye AO, Ng V, Jalil MBA (2005) Transition from coherent rotation to curling mode reversal process in ferromagnetic nanowires. Eur Phys J B 44 259-264... 

Plesiopjc seres. The crystal structures of the members of these series are based on modules which have common features but may contain additional peculiar details. The family of serpentine-like structures (lizardite, chrysotile, antigorite, carlosturanite) is an example reported by Makovicky (1997). The members of this plesiotypic series are based on variously curled, reversed and/or interrupted TO (serpentine) layers. 

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