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Directional review

If the end-user cannot directly review the level of quality embedded in a standard... [Pg.85]

Spindle microtubules generally lie parallel to one another and to the interpolar axis, but some microtubules crossing others at any angle are found, especially early in prometaphase (e.g., Bajer, 1968c Bajer and Mole-Bajer, 1969). The parallel arrangement of microtubules usually breaks down near the poles. This is especially evident in cells with centrioles, where the spindle microtubules terminate close to, but not at, the centrioles, amid a field of microtubules running in every direction (reviewed by de Harven, 1968 Robbins et al., 1968). Interestingly, intranuclear spindles of protozoa show parallel microtubules all the way to the pole (Jenkins, 1967 Tucker, 1967). [Pg.226]

Usher, E. L., Pajares, S. (2008). Sources of self-efficacy in school Critical review of the literature and future directions. Review of Educational Research, 78, 751-796. [Pg.214]

In a study conducted by Vos et al. (2003) the unfolded cube display method was compared to a conventional 3D (two-directional) review approach. Two blinded trained observers reviewed a selected population of 30 patients twice, with a median interval of more than 11 weeks between the reviews. The observers first used the unfolded cube display method for polyp detection, and then, in random order, the conventional 3D method. The viewing angle in the conventional review method was set to 120° to compromise between image distortion and surface visibility. Surface visibility, evaluation time per patient, as well as sensitivity and specificity, were compared between both approach. [Pg.273]

A) The thirtieth day after the date on which a decision or order of a commission administrative law judge has been docketed with the commission, unless a member of the commission has directed review or... [Pg.1327]

Can the directive review process survive an expansion of the EU in its current form Consensus between the 15 Member States is difficult to achieve in a reasonable time frame. I believe that we will need to seek out different ways of working when the expansion occurs. [Pg.220]

In this pattern, the client implicitly relieves Logica of any systems safety responsibility because the work is done imder their direction, review and control. [Pg.93]

Interesting pattern formations also occur in surfactants spreading on water due to a hydrodynamic instability [52]. The spreading velocity from a crystal may vary with direction, depending on the contour and crystal facet. There may be sufficient imbalance to cause the solid particle to move around rapidly, as does camphor when placed on a clean water surface. The many such effects have been reviewed by Stemling and Scriven [53]. [Pg.112]

As on previous occasions, the reader is reminded that no very extensive coverage of the literature is possible in a textbook such as this one and that the emphasis is primarily on principles and their illustration. Several monographs are available for more detailed information (see General References). Useful reviews are on future directions and anunonia synthesis [2], surface analysis [3], surface mechanisms [4], dynamics of surface reactions [5], single-crystal versus actual catalysts [6], oscillatory kinetics [7], fractals [8], surface electrochemistry [9], particle size effects [10], and supported metals [11, 12]. [Pg.686]

The direct dissociation of diatomic molecules is the most well studied process in gas-surface dynamics, the one for which the combination of surface science and molecular beam teclmiques allied to the computation of total energies and detailed and painstaking solution of the molecular dynamics has been most successful. The result is a substantial body of knowledge concerning the importance of the various degrees of freedom (e.g. molecular rotation) to the reaction dynamics, the details of which are contained in a number of review articles [2, 36, 37, 38, 39, 40 and 41]. [Pg.906]

A completely difierent approach to scattering involves writing down an expression that can be used to obtain S directly from the wavefunction, and which is stationary with respect to small errors in die waveftmction. In this case one can obtain the scattering matrix element by variational theory. A recent review of this topic has been given by Miller [32]. There are many different expressions that give S as a ftmctional of the wavefunction and, therefore, there are many different variational theories. This section describes the Kohn variational theory, which has proven particularly useftil in many applications in chemical reaction dynamics. To keep the derivation as simple as possible, we restrict our consideration to potentials of die type plotted in figure A3.11.1(c) where the waveftmcfton vanishes in the limit of v -oo, and where the Smatrix is a scalar property so we can drop the matrix notation. [Pg.968]

An important distinction among surfaces and interfaces is whether or not they exliibit mirror synnnetry about a plane nonnal to the surface. This synnnetry is particularly relevant for the case of isotropic surfaces (co-synnnetry), i.e. ones that are equivalent in every azunuthal direction. Those surfaces that fail to exliibit mirror synnnetry may be tenned chiral surfaces. They would be expected, for example, at the boundary of a liquid comprised of chiral molecules. Magnetized surfaces of isotropic media may also exliibit this synnnetry. (For a review of SFIG studies of chiral interfaces, the reader is referred to [68]. ... [Pg.1286]

Many of the fiindamental physical and chemical processes at surfaces and interfaces occur on extremely fast time scales. For example, atomic and molecular motions take place on time scales as short as 100 fs, while surface electronic states may have lifetimes as short as 10 fs. With the dramatic recent advances in laser tecluiology, however, such time scales have become increasingly accessible. Surface nonlinear optics provides an attractive approach to capture such events directly in the time domain. Some examples of application of the method include probing the dynamics of melting on the time scale of phonon vibrations [82], photoisomerization of molecules [88], molecular dynamics of adsorbates [89, 90], interfacial solvent dynamics [91], transient band-flattening in semiconductors [92] and laser-induced desorption [93]. A review article discussing such time-resolved studies in metals can be found in... [Pg.1296]

Another specialized application of EM image contrast is mass measurement. Using the elastic dark-field image in the STEM or the inelastic image in the EETEM, a direct measurement of the scattering mass can be performed. Eor reviews on this teclmique see [60.61]. [Pg.1645]

In this chapter, we look at the techniques known as direct, or on-the-fly, molecular dynamics and their application to non-adiabatic processes in photochemistry. In contrast to standard techniques that require a predefined potential energy surface (PES) over which the nuclei move, the PES is provided here by explicit evaluation of the electronic wave function for the states of interest. This makes the method very general and powerful, particularly for the study of polyatomic systems where the calculation of a multidimensional potential function is an impossible task. For a recent review of standard non-adiabatic dynamics methods using analytical PES functions see [1]. [Pg.251]

To add non-adiabatic effects to semiclassical methods, it is necessary to allow the trajectories to sample the different surfaces in a way that simulates the population transfer between electronic states. This sampling is most commonly done by using surface hopping techniques or Ehrenfest dynamics. Recent reviews of these methods are found in [30-32]. Gaussian wavepacket methods have also been extended to include non-adiabatic effects [33,34]. Of particular interest here is the spawning method of Martinez, Ben-Nun, and Levine [35,36], which has been used already in a number of direct dynamics studies. [Pg.253]

The Helgaker-Chen algorithm results in very large steps being possible, and despite the extra cost of the required second derivatives, this is the method of choice for direct dynamics calculations. A number of systems have been treated, and a review of the method as applied to chemical reactions is given in [2]. [Pg.267]

In this chapter, recent advances in the theory of conical intersections for molecules with an odd number of electrons are reviewed. Section II presents the mathematical basis for these developments, which exploits a degenerate perturbation theory previously used to describe conical intersections in nonrelativistic systems [11,12] and Mead s analysis of the noncrossing rule in molecules with an odd number of electrons [2], Section III presents numerical illustrations of the ideas developed in Section n. Section IV summarizes and discusses directions for future work. [Pg.452]


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See also in sourсe #XX -- [ Pg.153 ]




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