Nucleation sites secondary

It seems also meaningful to recall that, for both PVL and iPP, the metastable chiral modification is not obtained from solution. This fact is hard to rationalize if polymorphic discrimination occurs on the basis of the secondary nucleation site which should exist also in the presence of the solution it rather points to diffusion and to transport problems in the melt, or thermodynamic control in solution. 

Propagation Extend helix and sheet from the nucleation sites in both directions until the average probability of the end tetrapeptide falls below 1.0. End residues, which are breakers, are not to be included in the secondary structure. 

The rates and mechanisms of sorption reactions at the mineral/water interface are critical in determining the mobility, speciation, and bioavailability of metals in aqueous and terrestrial environments. This chapter discusses nonequilibrium aspects of metal sorption at the mineral/water interface, with emphasis on confirmation of slow sorption mechanisms using molecular approaches. It is shown that there is often a continuum between sorption processes, viz, diffusion, sites of varying energy states, and nucleation of secondary phases. For example, recent molecular level in-situ studies have shown that metal adsorption and surface precipitation can occur simultaneously. 

It is thought that portions of the chain, such as small stretches of secondary structure, might serve as nucleation sites around which the rest of the protein will fold so that folding may be cooperative. 

Criticism of the LH theory has grown steadily during the last ten years. It is difficult to present a comprehensive and short review of the critique. Dosiere, Colet and Point (1986) measured the persistence length (the average distance between adjacent secondary nucleation sites) by a decoration technique and obtained a maximum value of 200 nm. This led to much lower g values than those predicted by the LH theory. Point, Colet and Dosiere (1986) calculated the persistence length from growth-rate data of solution-crystallization of linear polyethylene within the framework of the LH theory. The I values obtained were clearly unrealistic. 

MWs the higher the MW of PET, the greater the rejection of chain sections in interlamellar regions. This rejection lead to larger secondary nucleation sites and supported the SC model, which involved the formation of an intermediate crystalline stmcture in-between two parent crystals. ... 

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