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Decisive factors

We have seen this situation before m the reaction of alcohols with hydrogen halides (8ection 4 11) m the acid catalyzed dehydration of alcohols (8ection 5 12) and m the conversion of alkyl halides to alkenes by the El mechanism (8ection 5 17) As m these other reactions an electronic effect specifically the stabilization of the carbocation intermediate by alkyl substituents is the decisive factor The more stable the carbo cation the faster it is formed... [Pg.342]

Particle Size Distribution. For many P/M processes, the average particle size is not necessarily a decisive factor, whereas the distribution of the particles of various sizes ia the powder mass is. The distribution curve can be irregular, show a rather regular distribution with one maximum, have more than one maximum, or be perfecdy uniform. [Pg.181]

In choosing a site for protection installations for steel-water structures, decisive factors are the location in the harbor area and the need to keep the lengths of cable to the protected object and anode as short as possible where very high protection currents are involved. [Pg.226]

Metrology and contamination analysis in particular have been decisive factors for profitable semiconductor production [4.47]. Semiconductor applications of TXRF go back to the late nineteen-eighties and were introduced by Eichinger et al. [4.48, 4.49]. Because of its high sensitivity, wide linear range, facile spectrum deconvolution, and... [Pg.189]

The significant differences in disturbance, when evaluated with regard to the average noise levels, shows that the noise level is a decisive factor with regard to disturbance. Measures to limit the disturbance reaction due to ventilation noise should, therefore, naturally be directed in the first instance at lowering the noise level. [Pg.351]

It is apparent from simple valence bond considerations as well as from calculations of rr-electron density, " that isoindoles should be most susceptible to electrophilic attack at carbon 1. This preference is most clearly evident when the intermediate cations (85-87) from electrophilic attack (by A+) at positions 1, 4, and 5 are considered. The benzenoid resonance of 85 is the decisive factor in favoring this intermediate over its competitors. [Pg.134]

Compounds of the type HC=C—CH=CHXR are not involved in a primary reaction with weak nucleophiles such as CH acids meanwhile, a final (secondary) cyclization with participation of active methylene groups happens to be feasible. Evidently, in most cases the energy gain in the heteroaromatic system realization is the decisive factor (81UK1252). [Pg.203]

Each coating method has its own particular advantages, which are really the decisive factors in determining which one is used for a given purpose. Consideration must be given to the complexity and size of the work, the corrosion resistance, and hence the coating thickness needed, and the quality of finish required. [Pg.490]

There are possible different forms of analytic representation of the t versus j dependence with an allowance made for non-Newtonian effects. To expose the decisive factors of this dependence an approach suggested in [19] deserves much attent-... [Pg.85]

If a monoarylacetylene (ArC = CH) is taken as a model for a transition state of an arenediazonium ion with a nucleophile Nu, two types of transition state can be visualized the first, 7.13, leads to the (Z)-azo compound 7.14, whereas the second, 7.15, results in the (E )-isomer 7.16 (Scheme 7-3). If the transition state is reactantlike (i.e., early on the reaction coordinate), repulsive interaction between the nucleophile and the aryl nucleus is small because the distance Nu-Np is still large. Therefore, the repulsion between the lone pair on Np and the aryl nucleus becomes the decisive factor. It favors an (E )-configuration of the Np lone pair with respect to the aryl nucleus (obviously it is energetically dominant compared with the repulsion between the lone pairs on Na and Np) therefore, transition state 7.13 is at a lower energy level, and Nu attacks NB in the (Z)-configuration. [Pg.156]

A decisive factor for the physical behaviour of a composite is the adhesion efficiency at the boundaries between phases. In all theoretical models this adhesion is considered as perfect, assuming that the interfaces ensure continuity of stresses and displacements between phases, which should be different because of the proper nature of the constituents of composites. However, such conditions are hardly fulfilled in reality, leading to imperfect bonding between phases and variable adhesion between them. The introduction of the mesophase layer has as function to reconcile in a smooth way the differences on both sides of interfaces. [Pg.159]

Besides quality of informahon, quanhty of data shll is a decisive factor in laboratory-scale development. [Pg.50]

It is very difficult in view of the vast amount of experimental data to draw general conclusions that would hold for different, let alone all electrocatalytic systems. The crystallographic orientation of the surface undoubtedly has some specific influence on adsorption processes and on the electrochemical reaction rates, but this influence is rather small. It can merely be asserted that the presence of a particular surface orientation is not the decisive factor for high catalytic activity of a given electrode surface. [Pg.532]

In our case the chemical composition and, consequently, the structure of the iron oxide is changed with time during reaction. Gold diffusion from film and nanoparticles underneath may occur but seem not to be the decisive factor in promoting the CO oxidation activity. [Pg.101]

Clearly the physicochemical properties of a drug are a decisive factor in its overall activity. Where possible, molecular structures should be optimized to obtain best clinical performance. Rarely does an oral drug have physicochemical features suitable for topical or transdermal therapy, and it can take a great deal of systematic research to identify where the best balance of activity and permeability lies. Experience with corticosteroids suggests that as much as a 100-fold improvement in clinical activity may be attainable through molecular design, for today s most potent topical corticosteroids are more active than hydrocortisone by a factor at least this large. [Pg.229]

On the other hand, since the angular derivative 19, whose constitution is characterized by two quasi-isolated hydroxynaphthalenecarboxylic acid subunits and whose structural analogy to a pair of scissors is removed for the most part, also yields an inclusion compound with dimethylformamide with strict stoichiometry of 1 237), and only and exclusively this one (Table 3), it is obvious that the free salicylic acid unit might be the decisive factor for the preferred binding of dimethylformamide of this class of compounds. [Pg.72]

The formation of crystal inclusion of 47 and 48 with cyclic ketones of suitable ring size (cyclopentanone, cyclohexanone) and with cyclohexene oxide are also important facts. Corresponding inclusion compounds with alcohols or amines could not be obtained. With reference to the heterocyclic guest molecules, the suitability of the ring size is likely to be the decisive factor for guest inclusion. [Pg.83]


See other pages where Decisive factors is mentioned: [Pg.691]    [Pg.185]    [Pg.67]    [Pg.1071]    [Pg.193]    [Pg.595]    [Pg.843]    [Pg.846]    [Pg.319]    [Pg.359]    [Pg.14]    [Pg.197]    [Pg.96]    [Pg.151]    [Pg.785]    [Pg.100]    [Pg.128]    [Pg.102]    [Pg.160]    [Pg.429]    [Pg.223]    [Pg.396]    [Pg.691]    [Pg.163]    [Pg.55]    [Pg.47]    [Pg.161]    [Pg.500]    [Pg.612]    [Pg.62]    [Pg.148]    [Pg.148]    [Pg.161]   
See also in sourсe #XX -- [ Pg.19 , Pg.22 ]




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