Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Finite action

It was pointed out in Section XIII-4A that if the contact angle between a solid particle and two liquid phases is finite, a stable position for the particle is at the liquid-liquid interface. Coalescence is inhibited because it takes work to displace the particle from the interface. In addition, one can account for the type of emulsion that is formed, 0/W or W/O, simply in terms of the contact angle value. As illustrated in Fig. XIV-7, the bulk of the particle will lie in that liquid that most nearly wets it, and by what seems to be a correct application of the early oriented wedge" principle (see Ref. 48), this liquid should then constitute the outer phase. Furthermore, the action of surfactants should be predictable in terms of their effect on the contact angle. This was, indeed, found to be the case in a study by Schulman and Leja [49] on the stabilization of emulsions by barium sulfate. [Pg.510]

When the wave function is completely general and pennitted to vary in the entire Hilbert space the TDVP yields the time-dependent Schrodinger equation. However, when the possible wave function variations are in some way constrained, such as is the case for a wave function restricted to a particular functional form and represented in a finite basis, then the corresponding action generates a set of equations that approximate the time-dependent Schrodinger equation. [Pg.224]

This has also commonly heen termed direct interception and in conventional analysis would constitute a physical boundary condition path induced hy action of other forces. By itself it reflects deposition that might result with a hyj)othetical particle having finite size hut no fThis parameter is an alternative to N f, N i, or and is useful as a measure of the interactive effect of one of these on the other two. Schmidt numher. [Pg.1583]

This formula, however, tacitly supposes that the instanton period depends monotonically on its amplitude so that the zero-amplitude vibrations in the upside-down barrier possess the smallest possible period 2nla>. This is obvious for sufficiently nonpathological one-dimensional potentials, but in two dimensions this is not necessarily the case. Benderskii et al. [1993] have found that there are certain cases of strongly bent two-dimensional PES when the instanton period has a minimum at a finite amplitude. Therefore, the cross-over temperature, formally defined as the lowest temperature at which the instanton still exists, turns out to be higher than that predicted by (4.7). At 7 > Tc the trivial solution Q= Q Q is the saddle-point coordinate) emerges instead of instanton, the action equals S = pV (where F " is the barrier height at the saddle point) and the Arrhenius dependence k oc exp( — F ") holds. [Pg.61]

Thus for Hamiltonians of finite dimension the effective action functional can be found by immediately integrating a system of ordinary differential equations. The simplest yet very important case is a bath of two-level systems. [Pg.76]

In most designs, the reaetion of the turbine varies from hub to shroud. The impulse turbine is a reaetion turbine with a reaetion of zero (R = 0). The utilization factor for a fixed nozzle angle will increase as the reaction approaches 100%. For = 1, the utilization factor does not reach unity but reaches some maximum finite value. The 100% reaction turbine is not practical because of the high rotor speed necessary for a good utilization factor. For reaction less than zero, the rotor has a diffusing action. Diffusing action in the rotor is undesirable, since it leads to flow losses. [Pg.349]

When the surfaces are in contact due to the action of the attractive interfacial forces, a finite tensile load is required to separate the bodies from adhesive contact. This tensile load is called the pull-off force (P ). According to the JKR theory, the pull-off force is related to the thermodynamic work of adhesion (W) and the radius of curvature (/ ). [Pg.84]

This aspect of the model is illustrated in Figure 1.5. The error tendencies circle represents the intrinsic characteristics of people that predispose them to error. These tendencies include a finite capability to process information, a reliance on rules (which may not be appropriate) to handle commonly occurring situations, and variability in performing unfamiliar actions. These error tendencies are discussed in detail in Chapter 2. [Pg.13]

The LST is a finitely parameterized model of the action of a given CA rule, >, on probability measures on the space of configurations on an arbitrary lattice. In a very simple manner - which may be thought of as a generalization of the simple mean field theory (MFT) introduced in section 3.1.3. - the LST provides a sequence of approximations of the statistical features of evolving CA patterns. [Pg.247]

In passing from the consideration of a simple massive particle to finite masses, which may exert mutual actions, or in which... [Pg.24]

Exposure to other ideas, resources and opportunities broadens teachers awareness of possibilities for change and fosters a sense that alternatives are available. Teachers would make use, initially on a small scale, of classroom materials developed especially to meet the new approaches to models of the triplet relationship (see especially Tsaparlis, 2008 Tan et al., 2008 Meijer et al., 2008 Davidowitz Chittleborough, 2008 Justi et al., 2008 Treagust Chandra-segaran, 2008). This awareness of alternative resources implies either that such materials are prepared beforehand (Van Berkel, Pilot, finite, 2008) or that the teachers themselves prepare the materials by an action research approach (Ferk Savec et al., 2008). [Pg.342]

Often the actions of the radial parts of the kinetic energy (see Section IIIA) on a wave packet are accomplished with fast Fourier transforms (FFTs) in the case of evenly spaced grid representations [24] or with other types of discrete variable representations (DVRs) [26, 27]. Since four-atom and larger reaction dynamics problems are computationally challenging and can sometimes benefit from implementation within parallel computing environments, it is also worthwhile to consider simpler finite difference (FD) approaches [25, 28, 29], which are more amenable to parallelization. The FD approach we describe here is a relatively simple one developed by us [25]. We were motivated by earlier work by Mazziotti [28] and we note that later work by the same author provides alternative FD methods and a different, more general perspective [29]. [Pg.14]

Drug therapy is a dynamic process. When a drug product is administered, absorption usually proceeds over a finite time interval, and distribution, metabolism, and excretion (ADME) of the drug and its metabolites proceed continuously at various rates. The relative rates of these ADME processes determine the time course of the drug in the body, most importantly at the receptor sites that are responsible for the pharmacological action of the drug. [Pg.77]

In this section the symbols orthonormal basis functions of a Hilbert space L, which may be finite or infinite, and x stands for the variables on which the functions of L may depend. An operator defined on L has the action Tf(x) = g(x) where g L. The action of T on a basis function 4>n x) is described by... [Pg.68]

The role of finite temperature in quantum chaos is studied within the imaginary time formalism via quantum action approach (Caron et al 2001). [Pg.173]

Let X be a smooth projective variety over k with an action of a torus H which has only finitely many fixed points. A one-parameter subgroup Gm —> H of H which does not lie in a finite set of given hyperplanes in the lattice of one-parameter groups of H will have the same fixed points as H. In future we call such a one-parameter group general . Thus the induced action of a general one-parameter group Gm — G has only finitely many fixed points on P. ... [Pg.21]

We denote by the action of Gm on P induced by d>. As it has only finitely many fixed points, it gives a cell decomposition of P - Hilbn(P)re(i = Hilbn(A2,0) C P is the subvariety parametrizing subschemes Z of colength n with support supp(Z) = Po. If Z P has support Po, then... [Pg.21]


See other pages where Finite action is mentioned: [Pg.509]    [Pg.276]    [Pg.2511]    [Pg.134]    [Pg.83]    [Pg.438]    [Pg.377]    [Pg.227]    [Pg.248]    [Pg.252]    [Pg.291]    [Pg.681]    [Pg.57]    [Pg.614]    [Pg.252]    [Pg.325]    [Pg.358]    [Pg.12]    [Pg.41]    [Pg.173]    [Pg.66]    [Pg.155]    [Pg.122]    [Pg.301]    [Pg.303]    [Pg.163]    [Pg.194]    [Pg.107]    [Pg.277]    [Pg.21]    [Pg.26]    [Pg.80]    [Pg.190]   
See also in sourсe #XX -- [ Pg.21 ]




SEARCH



© 2024 chempedia.info