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Fundamental most frequently used

An ability to form carbon-carbon bonds is fundamental to organic synthesis The addition of Grignard reagents to aldehydes and ketones is one of the most frequently used reactions m synthetic organic chemistry Not only does it permit the extension of carbon chains but because the product is an alcohol a wide variety of subsequent func tional group transformations is possible... [Pg.595]

XPS is among the most frequently used techniques in catalysis. It yields information on the elemental composition, the oxidation state of the elements and, in favorable cases, on the dispersion of one phase over another [ J.W. Niemantsverdriet, Spectroscopy in Catalysis, An Introduction (2000), Wiley-VCH, Weinheim G. Ertl and J. Kiippers, Low Energy Electrons and Surface Chemistry (1985), VCH, Weinheim L.C. Feldman and J.W. Mayer, Fundamentals of Surface and Thin Film Analysis (1986), North-Holland, Amsterdam]. [Pg.134]

Transition State Theory [1,4] is the most frequently used theory to calculate rate constants for reactions in the gas phase. The two most basic assumptions of this theory are the separation of the electronic and nuclear motions (stemming from the Bom-Oppenheimer approximation [5]), and that the reactant internal states are in thermal equilibrium with each other (that is, the reactant molecules are distributed among their states in accordance with the Maxwell-Boltzmann distribution). In addition, the fundamental hypothesis [6] of the Transition State Theory is that the net rate of forward reaction at equilibrium is given by the flux of trajectories across a suitable phase space surface (rather a hypersurface) in the product direction. This surface divides reactants from products and it is called the dividing surface. Wigner [6] showed long time ago that for reactants in thermal equilibrium, the Transition State expression gives the exact... [Pg.125]

A fundamental understanding of the mechanistic and stereochemical aspects of the Diels-Alder reaction was unfolded during the 1970s. Several theoretical approaches are available nowadays from which Fukui s Frontier Molecular Orbital theory (FMO theory) is most frequently used because of its simplicity49- 53. [Pg.339]

In zinc phosphating. a small amount of iron phosphate is formed initially, bul ihe bath contains primary zinc phosphate. ZnlHiP04)>, which crystallizes on Ihe metal surface as secondary and tertiary zinc phosphates, ZnHP04 and Znt(P04 j. respectively, when the pH rises at the mclal/solulion interlace. The most frequently used baths contain accelerators, preferably nitrates and nitrites, which oxidize the hydrogen lormcd hy the pickling reactions. The fundamental zinc phosphate reactions occur in three steps, all in the same hath ... [Pg.435]

There are four main procedures for measuring the texture of food empirical, imitative, fundamental, and ideal (Bourne, 1982). Of these procedures, empirical tests are the most frequently used in textural measurement however, they are poorly defined (Bourne, 1982). The protocols provided in this unit are all empirical tests. [Pg.1181]

The carbon-carbon bond forming step of the Prins reaction, the reaction of an alkene with a carbonyl group (1) - (2), is, in one sense, the most fundamental reaction of synthetic organic chemistry at one extreme it is the base-catalyzed aldol reaction, where the alkene component is an enolate ion and the carbonyl group is unprotonated, and at the other extreme it is the Friedel-Crafts reaction. It is a paradigm for a fast organic reaction both bonds involved in the key step are iT-bonds, which are simultaneously more reactive than o-bonds and more susceptible to modification in reactivity by the presence or absence of substituents on either or both components. It is no wonder that, in one form or another, it is the most frequently used of all carbon-carbon bond forming reactions. [Pg.563]

As pointed out in the preceding sections, the establishment of basin-wide or global balances of benthic material cycles always requires extrapolation procedures, because all available data sets are limited in size and usually consist of in-homogeneously distributed point data. Various conceptual approaches are available to approach this goal. In this section, fundamental aspects to the most frequently used methods will be briefly presented. [Pg.442]

The principles behind this membrane technology originate from solid-state electrochemistry. Conventional electrochemical halfceU reactions can be written for chemical processes occurring on each respective membrane surface. Since the general chemistry under discussion here is thermodynamically downhill, one might view these devices as short-circuited solid oxide fuel cells (SOFCs), although the ceramics used for oxygen transport are often quite different. SOFCs most frequently use fluorite-based solid electrolytes - often yttria stabUized zirco-nia (YSZ) and sometimes ceria. In comparison, dense ceramics for membrane applications most often possess a perovskite-related lattice. The key fundamental... [Pg.186]

In this chapter an overview is given on the possibilities for a quantitative characterization of adsorption layers at liquid/liquid interfaces. After a general introduction to the fundamental thermodynamic relationships and particular ideas on surfactant and protein adsorption, the process of adsorption-layer formation is discussed on the basis of the most frequently used methodology, the measurement of dynamic interfacial tensions. This will also include measurements of extremely low interfacial tensions and the effect of inter-facial transfer between the two liquid phases. [Pg.3]

One of the most frequent procedures in the formulation of adhesives is the addition of adhesion promoters. Of these, silanes are by far the most frequently used. The silanes form a multi-membered family of chemicals. Numerous publications have described aspects of silane chemistry and the applications of silanes [15-18]. Although many silanes are readily available, in many industrial formulations of adhesives the most frequently used of these are the primary amine and diamine versions because of their relatively low cost. However, these do not necessarily produce optimum benefits in adhesion for all applications. Guidelines for the selection of silanes best suited for specific applications would therefore be useful. These should be based on a fundamental understanding of the manner in which silane compounds affect the interface and interphase in adhesively bonded systems. The... [Pg.355]

PPy is one of the most frequently used ICPs in electroanalysis [29]. This is due both to the ease of electropolymerization (also possible in aqueous solutions and within a wide pH range) and to the relatively high stability of the p-doped polymer under ambient enviromnental conditions. Furthermore, many studies reveal that this material is biocompatible [30], which constitutes a fundamental feature when considering sensors for some clinical applications. [Pg.32]

After palladium, nickel is the most frequently used metal to catalyze cross-coupling reactions of C(sp )-organozincs. As in the case of palladium, the fundamentals of these reactions were disclosed more than 30 years ago [196]. Developments over... [Pg.311]

Table1.1-1 Brief list of the most frequently used fundamental constants... Table1.1-1 Brief list of the most frequently used fundamental constants...
The optimal damper distributions in buildings are found for various objective functions. The weighted sum of amplitudes of the transfer functions of interstorey drifts and the weighted sum of amplitudes of the transfer functions of displacements evaluated at the fundamental natural frequency of the frame with the dampers are most frequently used as the objective function. The optimization problem is solved using the sequential optimization method and the particle swarm optimization method. Several numerical solutions to the considered optimization problem are presented and discussed in detail. [Pg.75]


See other pages where Fundamental most frequently used is mentioned: [Pg.242]    [Pg.201]    [Pg.276]    [Pg.187]    [Pg.23]    [Pg.295]    [Pg.100]    [Pg.82]    [Pg.104]    [Pg.515]    [Pg.592]    [Pg.771]    [Pg.46]    [Pg.352]    [Pg.115]    [Pg.998]    [Pg.203]    [Pg.426]    [Pg.705]    [Pg.109]    [Pg.295]    [Pg.4]    [Pg.1123]    [Pg.171]    [Pg.387]   
See also in sourсe #XX -- [ Pg.4 ]

See also in sourсe #XX -- [ Pg.4 ]




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