Generalities, problems

The general problem is to determine at given conditions of temperature and pressure, the quantities and compositions of the two phases in equilibrium starting from an initial quantity of material of known composition and to resolve the system of the following equations ... 

General problems with synthetic organic reactions are discussed together with some practical solutions for specific examples. These problems include 9 regio- and stereoselectivity by exploitation of the substrates stereochemistry (e.g., p. 20ff.) and differentiated nucleophilicity (p. 24f, 44f, 56ff.)... 

We now turn from the general problems of peptide synthesis to specific problems connected with three currently important procedures, namely ... 

In 1972, the concept of pattern recognition as a general problem solving tool for a broad scope of chemical appHcations was introduced (9,10). 

Despite the considerable progress made in the few years in which anodic insertion/extraction films have been known, neither film compositions, film properties, nor electrochemical reactions are sufficientiy well characterized. There have been disagreements, as indicated for h-IrO and h-NiO in Table 2, as to whether is being extracted or OH inserted during coloration. The general problem is best illustrated by the important example of Pmssian blue. Early work (47—50) resulted in two different sets of equations for electrochromic reduction ... 

To solve the general problem using the backward Euler method, replace the nonlinear differential equation with the nonhuear algebraic equation for one step. 

The general problem is posed as finding the minimum number of variables necessary to define the relationship between n variables. Let (( i) represent a set of fundamental units, hke length, time, force, and so on. Let [Pj represent the dimensions of a physical quantity Pj there are n physical quantities. Then form the matrix Ot) ... 

Identification and quantitative estimation of common-cause failures are general problems in fault tree analysis. Boolean approaches are generally better smted to mathematically handle common-cause failures. 

General problems in electric motors and their remedy 10/239... 

Installation of bearings and pulleys Important checks at the time of commissioning Maintenance of electric motors and their checks Maintenance of bearings General problems in electric motors and their remedy Winding temperature measurement at site Analysis of insulation failures of an HT motor at a thermal power station... 

The main problem of elementary chemical reaction dynamics is to find the rate constant of the transition in the reaction complex interacting with its environment. This problem, in principle, is close to the general problem of statistical mechanics of irreversible processes (see, e.g., Blum [1981], Kubo et al. [1985]) about the relaxation of initially nonequilibrium state of a particle in the presence of a reservoir (heat bath). If the particle is coupled to the reservoir weakly enough, then the properties of the latter are fully determined by the spectral characteristics of its susceptibility coefficients. 

The most general problem should be that of a particle in a nonseparable potential, linearly coupled to an oscillator heat bath, when the dynamics of the particle in the classically accessible region is subject to friction forces due to the bath. However, this multidimensional quantum Kramers problem has not been explored as yet. 

As shown by Benderskii and Makarov [1992], one could consider an even more general problem with oscillator frequencies 03 dependent on Q. The result would be... 

Alcorn and Sullivan (1992) faced some specific and difficult problems in connection with coal slurry hydrogenation experiments. Solving these with the falling basket reactor, they also solved the general problem of batch reactors, that is, a good definition of initial conditions. The essence of their... 

The general problem of the mechanism of dehydrogenation in the yohimbine series has been discussed by Janot and Goutarel and by Julian, Magnani, Pikl and Karpel. ... 

General problem with quality of data Some risks cannot be quantified... 

Consider now the behaviour of the HF wave function 0 (eq. (4.18)) as the distance between the two nuclei is increased toward infinity. Since the HF wave function is an equal mixture of ionic and covalent terms, the dissociation limit is 50% H+H " and 50% H H. In the gas phase all bonds dissociate homolytically, and the ionic contribution should be 0%. The HF dissociation energy is therefore much too high. This is a general problem of RHF type wave functions, the constraint of doubly occupied MOs is inconsistent with breaking bonds to produce radicals. In order for an RHF wave function to dissociate correctly, an even-electron molecule must break into two even-electron fragments, each being in the lowest electronic state. Furthermore, the orbital symmetries must match. There are only a few covalently bonded systems which obey these requirements (the simplest example is HHe+). The wrong dissociation limit for RHF wave functions has several consequences. 

In spite of the potential complexity of the general problem, even when restricted to the reagent family of amines, the nucleophilicities of such series as meta- and pom-substituted pyridines and anilines appear to correlate very closely with the expected substituent effects and with the basicities. This has been verified in the following cases (i) The reaction of pyridines (R = H, m- andp-CHs) with 2-chloro-3-nitro-, 2-chloro-5-nitro-, and 4-chloro-3-nitro-pyridines. ... 

State Proton Transfer (Section VIII). The general problem of intramolecular proton transfers includes tunneling paths (91JPC10457). The most relevant results are reported in Table VI. 

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