Physical interaction, between

According to some remarks concerning the physical interaction between the incident ultrasonic wavelet and the defects [4-6], we consider that an Ascan signal, may be described as a weighted sum of few delayed and phase-shifted replicas of the ultrasonic incident wavelet j(r). We can express this mathematically as ... 

Real gases follow the ideal-gas equation (A2.1.17) only in the limit of zero pressure, so it is important to be able to handle the tliemiodynamics of real gases at non-zero pressures. There are many semi-empirical equations with parameters that purport to represent the physical interactions between gas molecules, the simplest of which is the van der Waals equation (A2.1.50). However, a completely general fonn for expressing gas non-ideality is the series expansion first suggested by Kamerlingh Onnes (1901) and known as the virial equation of state ... 

While this chapter is mainly concerned with the chemical interactions between ocean and atmosphere, a few words need to be said about the physical interactions, because of their general importance for climate. The main physical interaction between the ocean and atmosphere occurs through the exchange of heat, water and momentum, although the presence of sea-ice acts to reduce all of these exchanges to a greater or lesser extent. 

Adsorption on solids is a process in which molecules in a fluid phase are concentrated by molecular attraction at the interface with a solid. The attraction arises from van der Waals forces, which are physical interactions between the electronic fields of molecules, and which also lead to such behavior as condensation. Attraction to the surface is etihanced because the foreign molecules tend to satisfy an imbalance of forces on the atoms in the surface of a solid compared to atoms within the solid where they are surrounded by atoms of the... 

Barrier Coat a coating used to isolate a paint system from the surface to which it is applied in order to prevent chemical or physical interaction between them, e.g. to prevent the paint solvent attacking the underlying paint or to prevent bleeding from underlying paint or material. 

FIGURE 7.1 Enzyme ortho- and allosterism as presented by Koshland [2], Steric hindrance whereby the competing molecules physically interfered with each other as they bound to the substrate site was differentiated from a direct interaction where only portions of the competing molecules interfered with each other. If no direct physical interaction between the molecules occurred, then the effects were solely due to effects transmitted through the protein structure (allosteric). 

The basic requirement for cellulose dissolution is that the solvent is capable of interacting with the hydroxyl groups of the AGU, so as to eliminate, at least partially, the strong inter-molecular hydrogen-bonding between the polymer chains. There are two basic schemes for cellulose dissolution (i) Where it results from physical interactions between cellulose and the solvent (ii) where it is achieved via a chemical reaction, leading to covalent bond formation derivatizing solvents . Both routes are addressed in details below. 

Gamer, J., Bujard, H., Bukua, B. (1992). Physical interaction between heat shock proteins DnaK, DnaJ, CJtpE the bacterial heat shock transcription factor sigma 32. Cell 69, 833-842. 

The steric factor results from physical interactions between atoms. From this factor comes the basic chirality. For the cases of solid metal catalysts, chirality may come from the support, the arrangement of active sites on the metal surface (Ogston concept1), or from an adsorbed or attached chiral entity. 

The initial drying of currently applied alkyd paints is accomplished by evaporation of solvent (physical drying). Subsequently, the eventual curing of the alkyd paint is completed by the formation of a polymer network, which is mainly formed by chemical crosslinks (oxidative drying) but in some cases also physical interactions between the fatty acid side chains occur, such as crystallization or proton-bridge formation [129]. Efficient network formation is crucial in the formation of dry films with good mechanical properties. Due to the presence of unsaturated units in the investigated LOFA- and TOFA-PHA bin-... 

ACN vapor had the most pronounced permutation of the relatively rapid and relatively slow response and recovery kinetics. Such behavior could be due to the combination of physical and chemical adsorption. Physical adsorption effects are typically pronounced with rapid response and recovery kinetics because of the relatively low energies of physical interactions between vapors and the sensing surface. Chemical adsorption effects have much slower recovery kinetics because of the relatively high energies of chemical interactions between vapors and the sensing surface. The recovery from all tested vapors was reversible with the slowest recovery after the exposure to ACN on the order of several hours from the highest tested vapor concentration of 0.1 P/Po-... 

P. M. Physical interaction between specific E2 and Hect E3 enzymes determines functional cooperativity. J Biol Chem 1997, 272, 13548-54. 

Similarly, there is evidence for functional but not physical interaction of tricorn with the proteasome (Tamura et al. 1998) A physical interaction between these molecules by aligning their respective central pores would imply a symmetry mismatch. While such a physical interaction would be consistent with the geometric dimensions of both molecules, its existence needs to be experimentally confirmed and characterized. 

Pure isomers are often used as starting products for fine chemicals (e.g., different drugs). The separation of isomers entails great difficulties because they often have boiling points differing by only a fraction of a degree and they have closely similar solubilities in many solvents. Solvent extraction processes for the separation of isomers, therefore, have to rely more on chemical reactions than on nonspecific physical interactions between the solute and the solvent. 

The two systems analyzed were compared and contrasted on many accoimts. The infrared spectra of Figures 5 6 showed the unreacted materials on top and the reacted species below. The strong absorption band at 2200 cm-1 was attributed to the cyanate group and disappeared after reaction. The new absorption bands at 1370 cm-1 and 1570 cm-1 were due to the triazine ring. The percent conversion was monitored easily in this way. In both cases it was very high, almost 100J5 for I. Other important information extracted from the spectra was that no significant cross-reaction occurred. It was required that only physical interaction between the separate species should occiir if a true SIPN was to be obtained. 

As in the case of other receptor tyrosine kinases like erbB 1 and erbB2, efforts have been directed to identify and develop hiunanized antibodies that block the physical interaction between IGF-IR and its cognate ligands. Although obtained by applying different approaches, these antibodies have been shown in a variety of preclinical systems to specifically bind to the extracellular domain of IGF-IR, preventing downstream signahng. 

O Brien P, Pickett NL, et al (2002) Developments in CVD delivery systems, A chemist s perspective on the chemical and physical interactions between precursors. Chemical Vapor Deposition 8(6), 237-249... 

The chemical and physical interactions between small metal catalyst particles and the support are complex. They may introduce morphological changes in the particles and affect their reactivity. Studies of such modifications of supported... 

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