Cooperative association

Berufs-. professional, occupational, vocational, -genossenschaft, /. professional association cooperative association, -kleider, n.pi. working clothes. 

The polymer is capable of forming left-handed, double helices, and undergoes a sol-gel transition where a network is formed through cooperative association of the helices. Fig. 12 shows the c.d. spectra of agarose in aqueous solution at various temperatures. As the temperature is increased. 

Has a defined maximum effect that is determined by the cooperativity associated with its allosterism. 

T. K. Dam, R. Roy, D. Page, and C. F. Brewer, Negative cooperativity associated with binding of multivalent carbohydrates to lectins. Thermodynamic analysis of the multivalency effect Biochemistry, 41 (2002) 1351-1358. 

Somewhat unusual pressure dependence of the nature of the spin transition curve has been found for chain-like SCO systems containing substituted bridging triazole ligands [163, 164]. Although the transition is displaced to higher temperatures with increase in pressure, the shape of the transition curve, unusually, is effectively constant, i.e. there is no significant change in the hysteresis width and the transition remains virtually complete. This has been taken to indicate that the cooperativity associated with the transitions in these and related systems is confined within the iron(II) triazole chains. 

Mackay D (1982) US-EPA, the utility solid waste activities group. The Edison Electric Institute and The National Rural Electric Cooperative Association... 

IIS and 7S proteins dissociate into subunits at ionic strength below O.IM and 0.5M, respectively (11, 12). This is, therefore, a plausible explanation oT" tKe observed solubility behavior. The sharp minimum at O.IM salt concentration in the case of the NPI might correspond to the cooperative association reactions involving IIS subunits. Even though there has been no experimental demonstration, it would not be unreasonable to postulate that random association reactions also occur for denatured soy proteins. The broader minimum between 0.1 and 0.2M salt concentration might be indicative of less cooperative association reactions. 

This result clearly shows the intramolecular cooperativity associated with the carbonate motion. 

In order to investigate the intra- and intermolecular cooperativity associated with phenyl and carbonyl motions in glassy BPA-PC, it is interesting to perform dynamic molecular modelling in bulk. Two different modelling approaches have been used to yield information on the nature of cooperativity. 

Intermolecular cooperativity associated with the phenyl ring rotation, which concerns groups as far as 7 A from the moving phenyl ring, as well as a rearrangement of all the units within a volume of about 1 nm. ... 

It is an everyday experience that calcium soaps have a low aqueous solubility while many surfactants with monovalent counterions have an extremely high solubility. As for other compounds, the solubility is to a great extent given by conditions in the solid phase, but for surfactants the strongly cooperative association produces the peculiar temperature dependence of solubility schematized in Fig. 2.8. The so-... 

The term micelle, as normally understood and as used in this work, refers to a large aggregate formed in a strongly cooperative association of amphiphilic compounds. 

Fig. 2.23. Schematic picture of the aggregate size distribution well above the CMC for (a) a strongly cooperative association into micelles, (b) a weakly cooperative process, and (c) a noncooperative association...

National Rural Electric Cooperative Association (NRECA)... 

E-mail Address Patrick.lavigne nreca.coop Web Address www.nreca.coop The National Rural Electric Cooperative Association (NRECA) is the national service organization dedicated to representing the interests of consumer-owned cooperative electric utilities and the consumers they serve. 

Clearly, this proposed congestion at the critical branched state M, should exhibit (1) sterically-inhibited reaction rates, (2) sterically-induced stoichiometry, and, quite possibly, (3) a critical phase change due to surface cooperativity (association). These phenomena have been observed experimentally for the Starburst PAMAM dendrimers and may prove to be diagnostic probes for this critical branched state in other dendrimer families. 

When surface active agents are considered, a further complication may be encountered. Because of their surface active nature, the surfactants not only emich at the surfaces, but also form extended structures themselves. At low concentrations, the surfactants remain as dissolved monomers or asssociate to oligomers. However, when the critical micellization concentration (cmc) is surpassed, a cooperative association is activated to micelles (1 to 10 nm) consisting typically of some 50 to 100 monomers. At stiU higher concentrations, or in the presence of cosurfactants (alcohols, amines, fatty acids, etc.), liquid crystalline phases may separate. These phases have an infinite order on the x-ray scale, but may remain as powders on the NMR (nuclear magnetic resonance) scale. When the lamellar liquid crystalline phase is in equilibrium with the liquid micellar phase the conditions are optimal for emulsions to form. The interface of the emulsion droplets (1 to 100 pm) are stabilized by the lamellar liquid crystal. Both the micelles and the emulsions may be of the oil in water (o/w) or water in oil (w/o) type. Obviously, substances that otherwise are insoluble in the dispersion medium may be solubilized in the micelles or emulsified in the emulsions. For a more thorough analysis, the reader is directed to pertinent references in the literature. ... 

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