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Curvature three-dimensional

One can discover a special property of the functional (1) by analyzing the formula for the mean curvature (25) expressed in terms of the three dimensional field 4> y). From the form of Eq. (1) one can realize that for some local minima of (1) the average curvature given by... [Pg.699]

G. Dziuk. A boundary element method for curvature flow. Application to crystal growth. In J. E. Taylor, ed. Computational Crystal Growers Workshop, AMS Selected Lectures in Mathematics. Providence, Rhode Island American Mathematical Society, 1992, p. 34 A. Schmidt. Computation of three dimensional dendrites with finite elements. J Comput Phys 125 293, 1996. [Pg.917]

J. Holuigue, O. Bertrand, E. Arquis. Solutal convection in crystal growth effect of interface curvature on flow structuration in a three-dimensional cylindrical configuration. J Cryst Growth 180 591, 1997. [Pg.927]

Glossary 1079. Dogleg Severity (Hole Curvature) Calculations 1083. Deflection Tool Orientation 1085. Three-Dimensional Deflecting Model 1088. [Pg.498]

Total curvature Implies three-dimensional curvature. [Pg.1082]

It is proposed to use the terms world space and aether synonymously and to reserve space and vacuum for empty three-dimensional space. Curvature of world space may refer to any of its unknown number of dimensions. It... [Pg.127]

The three-dimensional APH display may be conveniently chosen to map onto a simple cylindrical surface (e.g., a coffee cup) by adding blank filling space to each helical turn in order to maintain a constant radius of curvature. Figure B.3 provides a simple planar template that one can cut and paste to form the APH cylindrical display. [Pg.718]

The first point to be made is that the structure of the bilayers changes due to an imposed curvature. These curvature effects are easily monitored in an SCF analysis. Unless one is willing to do a three-dimensional analysis, the method is restricted to homogeneously curved bilayers, i.e. cylindrical or spherically shaped vesicles. [Pg.78]

The Hessian matrix H(r) is defined as the symmetric matrix of the nine second derivatives 82p/8xt dxj. The eigenvectors of H(r), obtained by diagonalization of the matrix, are the principal axes of the curvature at r. The rank w of the curvature at a critical point is equal to the number of nonzero eigenvalues the signature o is the algebraic sum of the signs of the eigenvalues. The critical point is classified as (w, cr). There are four possible types of critical points in a three-dimensional scalar distribution ... [Pg.131]

Runnels and Eyman [41] report a tribological analysis of CMP in which a fluid-flow-induced stress distribution across the entire wafer surface is examined. Fundamentally, the model seeks to determine if hydroplaning of the wafer occurs by consideration of the fluid film between wafer and pad, in this case on a wafer scale. The thickness of the (slurry) fluid film is a key parameter, and depends on wafer curvature, slurry viscosity, and rotation speed. The traditional Preston equation R = KPV, where R is removal rate, P is pressure, and V is relative velocity, is modified to R = k ar, where a and T are the magnitudes of normal and shear stress, respectively. Fluid mechanic calculations are undertaken to determine contributions to these stresses based on how the slurry flows macroscopically, and how pressure is distributed across the entire wafer. Navier-Stokes equations for incompressible Newtonian flow (constant viscosity) are solved on a three-dimensional mesh ... [Pg.96]

A more complicated situation emerges in motion along nonintersecting surfaces with variable curvatures. If the distance between these surfaces remains finite everywhere, then the field lines do not expand infinitely in the directions normal to the surfaces. In the absence of dissipation this means that there is no unbounded growth of the normal field component. However, introduction of the finite conductivity yields an equation for the normal component which is not decoupled it contains the contribution of the Laplacian of the remaining components. At the same time, it is possible for all other components to increase exponentially with an increment which depends on the conductivity and vanishes for infinite conductivity. The authors called this mechanism of field amplification a slow dynamo, in contrast to the fast dynamo feasible in the three-dimensional case, i.e., the mechanism related only to infinite expansion of the field lines as, for example, in motion with magnetic field loop doubling. In a fast dynamo the characteristic time of the field increase must be of the same order as the characteristic period of the motion s fundamental scale. [Pg.105]

Significant new evidence is the self-similarity of sub-atomic, atomic, biological, planetary and galactic structures, all related to the golden section. The astronomical structures are assumed to trace out the shape of local space. The obvious conclusion is that all of space has a uniform non-zero characteristic curvature, conditioned by the universal constants tt and r. Space, in this sense, is to be interpreted as equivalent to the three-dimensional sub-space of the Robertson-Walker metric [104]. In standard cosmology this sub-space... [Pg.288]

Whether a function is a minimum or a maximum at an extremum is determined by the sign of its second derivative or curvature at this point in three-dimensional space for a given set of coordinates axis, the curvature is determined by the hessian matrix which elements are ... [Pg.294]

Three-dimensional chirality can likewise be resolved in four dimensions by transplantation in non-orientable projective space. This three-dimensional analog requires a four-dimensional twist that closes the three-dimensional universe onto itself and turns left-handed matter into right-handed antimatter. Considered as a single universe in three-dimensional space, chirality is preserved throughout. However, the interface created by the curvature separates regions of space with opposite chiralities. The interface cannot be crossed in three-dimensional motion, but allows interaction between entities near the interface to give rise to the quantum effects. [Pg.246]


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