State, concept

In contrast to the solid state concepts presented above, Ioannidis et al. [90] describe the organic materials as amorphous molecules. This model is suitable to fit 1/V characteristics of LEDs based on Alq3 and PPVs with a low mobility (j.ik 1CT, h cm2 V 1 s l). Essentially, they found that the current flow through these materials can be attributed to the increase in the mobility (sec Eq. (9.18)) with the applied voltage, which has been observed for many conjugated polymers [91 ]. In the case that the mobility exponentially increases with the electric field, the current flow raids ... 

The effect of an applied pressure on the UCFT has been investigated for polymer particles that are sterically stabilized by polyisobutylene and dispersed in 2-methy1-butane. It was observed that the UCFT was shifted to a higher temperature as the hydrostatic pressure applied to the system increased. There was also a qualitative correlation between the UCFT as a function of applied pressure and the 6 conditions of PIB + 2-methylbutane in (P,T) space. These results can be rationalized by considering the effect of pressure on the free volume dissimilarity contribution to the free energy of close approach of interacting particles. Application of corresponding states concepts to the theory of steric stabilization enables a qualitative prediction of the observed stability behaviour as a function of temperature and pressure. 

By choosing the three metals, copper, nickel, and gold, two of them (Cu and Au) with low density of states close to the Fermi level E ) and one (Ni) with a high electron density of states close to E, the significance of the density of states concept could be explored 74). 

Readers might have noticed that the two chain reactions, (i) Reactions 2-121 and 2-122 and (ii) Reactions 2-116 and 2-117, are similar, but were treated differently. Reactions 2-116 and 2-117 were treated using the quasi-equilibrium assumption, but may also be treated using the steady-state concept. The result is a more complicated expression, which would reduce to the experimental reaction rate law if < ii6b- Readers can work this problem out as an exercise. Therefore, the... 

In the above chain reaction, the first step is the slow step and the second is the rapid step. The equilibrium constant for Reaction 2-8 is iCs = 0.00287, and the forward rate constant is lcgf = 0.043 s. The equilibrium constant for Reaction 2-132 is iCi32 = 10 and the rate constant is Ci32f = 10 s. Hence, the first step is the rate-determining step. Using the steady-state concept, the reaction rate law is (ignoring the backward reaction of Reaction 2-132) ... 

The transition state concept, once understood in static terms only, as the saddle point separating reactants and products, may be fruitfully expanded to encompass the transition region, a landscape in several significant dimensions, one providing space for a family of trajectories and for a significant transition state lifetime. The line between a traditional transition structure and a reactive intermediate thus is blurred The latter has an experimentally definable lifetime comparable to or longer than some of its vibrational periods. 

In essentially covalent compounds the oxidation state concept can be useful in their classification. The two main oxides of sulfur are S02 and SO3 and, if the oxidation state of oxygen is taken to be —2 by convention,... 

In terms of transition-state concepts we could also insert the preequilibrium... 

Koopmans s theorem is not valid for Xa calculations, but Slater s transition state concept applies. This approximation allows the interpretation of electronic transitions in terms of 1-electron orbitals and yet includes electronic relaxation effects (208). The virtual (unoccupied) orbitals of Xa theory have a physical significance and can be used to discuss excitations of the electronic system, because the same potential due to the iV - 1 other electrons affects both occupied and unoccupied... 

Atypical and Typical Antipsychotics in the Light of the Brain-Mind State Concept... 

The allowance for polarization in the DH model obviates the need for separation of long-range and short-range attractive forces and for inclusion of additional repulsive interactions. Belief in the necessity to include some kind of covolume term stems from the confused analysis of Onsager (13), and is compounded by a misunderstanding of the standard state concept. Reference to a solvated standard state in which there are no interionic effects can in principle be made at any arbitrary concentration, and the only repulsive or exclusion term required is that described by the DH theory which puts limits on the ionic atmosphere size and hence on the lowering of electrical free energy. The present work therefore supports the view of Stokes (34) that the covolume term should not be included in the comparison of statistical-mechanical results with experimental ones. 

Chapman has advanced a polar state concept to explain the observed behavior of unsaturated ketones.409 Usually the correct products are predicted to arise from the following type of charge-separated species ... 

Analogs Lacking One Double Bond. The polar state concept suggests that analogs of the photochemical rearrangements of cross-conju-... 

That surface interactions play such a role clearly demands that some sort of surface state concept be invoked. However, no simple techniques have yielded direct information about the nature of such states. To explain charge transfer, isoenergetic electron or hole processes are normally invoked with a subsequent thermalization of the electron or hole in the semiconductor. This unfortunately necessitates the existence of a surface state at the level of the redox potential. This may of necessity occur when strong chemisorption is present. However, in those cases,... 

The Michaelis-Menten equation, especially if derived with the steady-state concept as above, is a rigorous rate law which not only fits almost all one-substrate enzyme kinetics, except in the case of inhibition (see Section 5.3), but also allows identification of the kinetic constants with the elementary steps in Eq. (5.1). 

The model based on the concept of pure limiting film resistance involves the steady-state concept of the heat transfer process and omits the essential unsteady nature of the heat transfer phenomena observed in many gas-solid suspension systems. To take into account the unsteady heat transfer behavior and particle convection in fluidized beds, a surface renewal model can be used. The model accounts for the film resistance adjacent to the heat transfer... 

Liao, J. C. Iightfoot, E. N. Jr. Extending the quasi-steady state concept to analysis of metabolic networks. J Theor Biol 1987, 126 253-273. 

The Crumpled Globule State Concept for Estimation of Knot Formation Probability... 

Even this very incomplete list makes us realize how careless we have been in not applying the mental state concept to dreaming and the mental status approach to its analysis. 

Since the oxidation state concept is so important for osmium we shall make extensive use of it as a means of classification of material within ligand groups, covering the lowest oxidation states... 

The normal classification of material by oxidation state is inappropriate for nitrosyl complexes because the oxidation state concept is very much a formalism for them. Instead we shall use the generally accepted [M(NO)x] + classification in which x is the number of coordinated NO groups and n the number of metal d electrons, the latter being calculated on the basis that NO+ is the coordinated moiety. As will be apparent, osmium complexes within each such category do in fact show considerable similarities of structure and reactivity, and also with their ruthenium analogues. Osmium is unusual in forming an [M(NO)]5 type of complex. 

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