Computer surface

Feldmann, RJ, Bing DH, Furie BC, Furie B. Interactive computer surface graphics approach to study of the active site of bovine trypsin. Proc Natl Acad Sci USA 1978 75 5409-12. 

Returning to Eq. (14 2), the next advance in dealing with the potential was to separate V(f) into electron-core and electron-electron components. The motivation for this was in part the desire to compute surface properties of semiconductors it also represented a step in the direction of developing potentials from first principles without experimental input. 

Charlock T.P. Rose F.G. Rutan D.A. Alberta T.L. Kratz D.P. Coleman L.H. Smith G.L. Manalo-Smith N. and Bess T.D. (1997). Compute Surface and Atmospheric Fluxes (System 5.0). CERES Algorithm Theoretical Basis Document, CERES Publ., Hampton, VA, 84 pp. 

A. He/H2 and Ha.—It is convenient to consider first these species. Tsapline and Kutzelnigg375 have applied the IEPA-PNO method, previously described, to the ground state of the He/Ha system. The van der Waals minimum was computed, using a gaussian lobe basis set with carefully optimized exponents. The collinear arrangement with a depth of 21 K was found for the van der Waals minimum, with a saddle point of 14 K for the Czv geometry. The computed surface was compared with experiment and with the R 6 term. The anisotropy of the potential is larger than that predicted asymptotically. 

Compute surface area based on solids loading rate. Because the solids concentration is between 0.5% and 1.5%, select a solids loading rate of 50 kg/m2 d from Table 16.4. Then... 

So far only one specific characteristic of computed surface potentials seems to have an important effect on experimental results. For thermionic emission of surfaces subject to an electric field, the Richardson equation must be modified in two ways. First the potential barrier is lowered by the electric field to give a new work function. In addition the reflection coefficient is altered. The relative current )/ 0 as a function of applied field E becomes... 

Table 2.1. Observed and computed surface tensions. Cahn-Hillicird model for regular solutions.

Table 7.1 Computed surface energy by density functional theory (DFT) for (1x1) rutile TiOj surfaces [91]...

Ma, Y.G., Gross, K.C., Hollingsworth, C.A., Seybold, P.G., Murray, J.S. Relationships between aqueous acidities and computed surface-electrostatic potentials and local ionization energies of substituted phenols and benzoic acids. J. Mol. Model. 2004,10(4), 235-9. 

Optical microscopic study of rock thin sections using dye tracers is a way to determine mineral-water contact (physical surface) areas if the water flows in rock matrix or fine fractures. The surface areas of particulate materials can be computed from particle size and geometry (cf. Sverdrup and Warfvinge 1993) or measured by BET gas adsorption methods. White and Peterson (1990) point out, however, that measured or computed surface areas of geological materials generally exceed their reactive surface areas. The reactive surface area (as de-hned by 5 ) is what we need to model sorption or reaction rates in porous media. 

Aleinov I, Puckett EG (1995) Computing Surface Tension with High-Order Kernels. In Oshima, K., (ed) Proceedings of the 6th International Symposium on Computational Fluid Dynamics, pp. 13-18, Lake Tahoe, CA, USA. 

Ellen B. Stechel is on temporary assignment from her position as manager of the Chemistry and Environmental Sciences Department of the Ford Motor Company She received her A.B. in mathematics and chemistry from Oberlin College (1974) and her M.S. in physical chemistry (1976) and Ph.D. in chemical physics (1978) from the University of Chicago. She joined Sandia National Laboratories in 1991, where she became manager of the Advanced Materials and Device Sciences Department in 1994. Her scientific interests are in computational, surface, and materials sciences. Dr. Stechel serves as a senior editor for the Journal of Physical... 

In this section, we introduce the computational method in the form used for the surfaces exhibited in Section IV, i.e., where the prescribed mean curvature of the computed surface is everywhere constant and the boundary conditions are determined by two dual periodic graphs. We also give generalizations of the method for the computation for a surface of prescribed—not necessarily constant—mean curvature, with prescribed contact angle against surface. Generalization to the computation of space curves of prescribed curvature or geodesic curvature is available (Anderson 1986). 

It is a simple matter to compute the area of each computed surface, as well as the volume fractions of the two labyrinths created by the partitioning surface ... 

As this review is intended to illustrate, the interplay between metal and oxygen leads to a richness of reactivity that is reflected in the surface structure of oxides. Much of this richness can be rationalised as varying proportions of ionic and covalent character in the metal-oxygen bonding, and is manifest in a variety of non-stoichiometric surfeces. We therefore focus on the prototypical transition metal oxide smface rutile Ti(>2 (1 1 0). This is contrasted with computational results for one of the most widely-studied p-block oxide surfaces - corundum Al2O3-(0 0 0 1) - and we refer also to computational surface studies on oxides of ruthenium, iron, vanadium, tin and silver, as well as ternary oxides. 

One possible explanation is that the surface models (both for the fitting of SXRD and for FP calculations) are too simple. The range of data for vacuum-annealed and (lx 3)-reconstructed TiOi (10 0) highlights the difficulties of fitting SXRD patterns to a limited set of over-simplified structural models [59]. However, an FP survey of over 60 stoichiometric surfaces of rutile (110) confirmed that the unreconstructed (1x1) bulk-termination is the most stable, with a computed surface energy of Ysuif=0-80 0.04 Jm [23]. 

As previously mentioned, hydrogen (as a elemental component of water) is the only heteroatom we consider in this review. The adorption and subsequent chemical behaviour of moecules on surfaces is certainly one of the most active areas of both experimental and computational surface science studies. For such a small and seemingly simple adorbate, the many types of possible interactions of water on oxide surfaces lead to richly complex chemistry. Water may be physisorbed intact, chemisorbed molecularly or dissociatively. In the last case, surface hydroxyls are formed, with the oxygen constituent of the hydroxyl originating either from the dissociated water molecule or the surface oxygen atoms. The H atom in the hydroxyls may be considered to be acidic (added to or abstracted from oxide anions as tf) or basic (as part of OIT added to or removed from metal cations). For all adsorbed species, molecular or dissociated, water or hydroxyl, there is the capability of strong hydrogen bond formation between other H, OH or O surface species. 

This equation may be applied directly to compute surface viscosity from experimental measurements of wc and w. ... 

The calculated convection surface usually will not correspond to an integral number of tube rows. In many cases, the computed surface is simply rounded up to an even number of tube rows, and the excess is considered a margin of safety. If a more exact rating is desired, it is necessary to assume a new overall efficiency and repeat the entire rating. The results can then be interpolated to the desired number of tubes. 

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