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Kinematics statistical

The important observation from this data, however, is that it tends to support the basic premise suggested in the previous section namely, geometric statistics appear to provide for the gross trend of the distribution data, without alluding to specific material or kinematic properties. More specific... [Pg.298]

This section furnishes a brief overview of the general formulation of the hydrodynamics of suspensions. Basic kinematical and dynamical microscale equations are presented, and their main attributes are described. Solutions of the many-body problem in low Reynolds-number flows are then briefly exposed. Finally, the microscale equations are embedded in a statistical framework, and relevant volume and surface averages are defined, which is a prerequisite to describing the macroscale properties of the suspension. [Pg.6]

For a gas mixture at rest, the velocity distribution function is given by the Maxwell-Boltzmann distribution function obtained from an equilibrium statistical mechanism. For nonequilibrium systems in the vicinity of equilibrium, the Maxwell-Boltzmann distribution function is multiplied by a correction factor, and the transport equations are represented as a linear function of forces, such as the concentration, velocity, and temperature gradients. Transport equations yield the flows representing the molecular transport of momentum, energy, and mass with the transport coefficients of the kinematic viscosity, v, the thermal diffirsivity, a, and Fick s diffusivity, Dip respectively. [Pg.55]

The unique features of our system enable us to use three different theoretical tools — a molecular dynamics simulation, models which focus on the repulsion between atoms and a statistical approach, based on an information theory analysis. What enables us to use a thermodynamic-like language under the seemingly extreme nonequilibrium conditions are the high density, very high energy density and the hard sphere character of the atom-atom collisions, that contribute to an unusually rapid thermalization. These conditions lead to short-range repulsive interactions and therefore enable us to use the kinematic point of view in a useful way. [Pg.28]

It is beyond the scope of this review to discuss in detail the statistical parameters of subduction zones, and Figure 10 is intended to demonstrate that conditions attained in subducting slabs are highly variable, even for similar convergence parameters, and that interplay between thermomechanical properties and reaction paths are responsible for a complex pattern of fluid release and magma genesis. Furthermore, any correlation of kinematic subduction parameters with volcano location tacitly assumes steady state, which is not necessarily the case. [Pg.1845]

The laws of statistical distribution for locally-isotropic turbulence are clearly determined by the kinematic viscosity v and the power per unit mass e = P/p -Dimensional analysis gives the following relationship for the linear dimension 2 of a turbulence element ... [Pg.21]

Statistical Mechanics of the Ising Model. A tremendously important model within statistical mechanics at large, and for materials in particular, is the Ising model. This model is built around the notion that the various sites on a lattice admit of two distinct states. The disposition of a given site is represented through a spin variable a which can take the values 1, with the two values corresponding to the two states. With these kinematic preliminaries settled, it is possible to write the energy (i.e. the Hamiltonian) as a function of the occupations of these spin variables as... [Pg.130]

Conventional kinematic notions are built around the idea that the system of interest can be characterized by a series of simple states without any reference to microscopic fluctuations or disorder. On the other hand, in the analysis of systems at finite temperature or in the presence of the effects of disorder, it is essential to build up measures that characterize the disposition of the system while at the same time acknowledging the possibility of an incomplete state of order within that system. Just as strain measures served as the primary kinematic engine used in our analysis of continua, the notion of a correlation function will serve to characterize the disposition of those systems that are better thought of statistically. Indeed, we will find that in problems ranging from the spins introduced earlier in conjunction... [Pg.137]

Pair Approximation. At the next level of approximation, we can insist that our probabilities P oi]) reproduce not only site occupancies with correct statistical weight, but also the distribution of AA, AB and BB bonds. We begin from a kinematic perspective by describing the relations between the number of A and B atoms Na and Nb), the number of AA, AB and BB bonds Naa, Nab and Nbb) and the total number of sites, N. Note that we have not distinguished AB and BA bonds. These ideas are depicted in fig. 6.21. What we note is that for our one-dimensional model, every A atom is associated with two bonds, the identity of which must be either AA or AB. Similar remarks can be made for the B atoms. [Pg.292]

We will later recognize this as the kernel for the continuum linear diffusion equation once we make the observation that the jump rate and the diffusion constant are related by Z) = Fa. For now we content ourselves by noting that the model of diffusion put forth here is invested with relatively little complexity. All we postulated was the uncorrelated hopping of the particles of interest. Despite the simplicity of the model, we have been led to relatively sophisticated predictions for what one might call the kinematics (which is statistical) of the diffusion field that results once the diffusive process has been set in motion. Indeed, the spreading... [Pg.321]

NES 00] NESTERETS Y.I., PUNEGOV V.I., The statistical kinematical theory of x-ray diffraction as applied to reciprocal-space mapping , Acta Cryst A, vol. 56, p. 540-548,2000. [Pg.336]

The phase-space model has been applied to triple collisions by F. T. Smith (1969) in a detailed study of termolecular reaction rates. He classified 3-body entry or exit channels into two classes, of pure and indirect triple collisions, and introduced kinematic variables appropriate to each class. These variables were then used to develop a statistical theory of break-up cross-sections. A recent contribution (Rebick and Levine, 1973) has dealt with collision induced dissociation (C1D) along similar lines. Two mechanisms were distinguished in the process A + BC->A + B + C. Direct CID, where the three particles are unbound in the final state, and indirect CID, where two of the particles emerge in a quasi-bound state. Furthermore, a distinction was made in indirect CID, depending on whether the quasi-bound pair is the initial BC or not. Enumeration of the product (three-body) states was made in terms of quantum numbers appropriate to three free bodies (see e.g. Delves and Phillips, 1969) the vibrational quantum number of a product... [Pg.41]

Quite another situation occurs when we consider collective properties of excitons. In this case, as shown above, the kinematic interaction can play an important role. However, the mutual scattering of elementary excitations, which causes this interaction, is quite different in three-, two- and one-dimensional crystals. In three-dimensional crystals at not very large concentration of excitations this scattering at least does not change the statistics. [Pg.434]

If we take into account not only the nearest, but also the farther neighbors, the additional so-called kinematic interaction between Fermi quasiparticles appears. For molecular chains the contribution of such additional resonance intermolecular interactions to one exciton energy is relatively small (36) even if a transition from the ground to an excited state is dipole allowed. However, its influence on the statistics of elementary excitations in these molecular structures has never... [Pg.435]


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See also in sourсe #XX -- [ Pg.137 , Pg.138 ]




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