Flux velocity

Fig. 11. HCCO product flux (velocity-angle) contour map from the 0(3P) + C2H2 reaction at Ec = 9.5kcalmol 1 (a). 3D perspective (b).

Fig. 16. Flux (velocity-angle) contour maps of the vinoxy (CH2CHO), acetyl (CH3CO), and ketene (CH2CO) products from the 0(3P) + C2H4 reaction at Ec = 12.9 kcal mol-1.

A phenomenogical expression for the hydrodynamic force F may be constructed by assuming that this force is linear in the flux velocities and in the strength of any applied flow field. We consider a system that is subjected to a macroscopic flow field v(r) characterized by a spatially homogeneous macroscopic velocity gradient Vv. We assume that Fa vanishes for all a = 1in the equilibrium state, where the flux velocities and the macroscopic... 

To relate this to the Cartesian flux velocity, we note that, in the infinitely stiff limit of interest, in which excursions from the constraint surface are negligible, the basis vectors 6R /92 may be accurately approximated by their values on the constraint surface, which are functions of the soft coordinates alone, and so may taken outside of the average average ( )f. By then using Eq. (2.107) to exclude contributions arising from the hard velocities, we identify... 

An equivalent dehnition of the drift velocity E" may be obtained by using the diffusion equation alone to calculate the average flux velocity in a statishcal ensemble characterized by a probability distribution... 

The change of flux velocity with transmembrane pressure can be explained by the concentration polarisation phenomenon. The physical processes at the membrane surface during the filtration procedure may be described by theo-... 

This brief discussion of the flow regime of an unconfined system emphasizes its three-dimensional nature and the large variety of water fluxes, velocities, and ages that prevail in each case study. The unconfined groundwater regime differs fundamentally from the one-dimensional tube of Darcy s experiment, with its particular properties (section 14.6). 

When a temperature gradient is imposed, the flux velocities in the forward and reverse direction will be, respectively. 

An alternative representation of the scattering data is the KI flux velocity-angle distribution shown in Fig. 5-10. In this figure the contours represent the relative amounts of product appearing at a given angle and recoil velocity in the center-of-mass coordinate system. Thus ten times more product is found at the contour labeled 10 than at the contour labeled 1. The zero of 6 is taken in the direction of the initial relative velocity component of K. All KI molecules with the same recoil velocity will lie in a circle centered at the center of mass and the dashed circle corresponds to the largest recoil... 

Fig. 5-10 Flux (velocity-angle) contour map for the KI product from the reaction K -f CH31 -KI + CH3. (Adapted from Rulis and Bernstein [33] and Levine and Bernstein [34].)...

In the two systems discussed thus far, the product scattering is very anisotropic. This indicates the lifetime of a molecular collision is very short relative to rotation of the complex formed between reactants (i.e., < --10" sec). If this were not the case, the scattering of product would be symmetric about the center of mass since all information about initial geometry of the collision would be lost after a few rotations. In fact, long-lived complexes have been observed in many cases. For example, the flux (velocity-angle) contour map for CsF formed in the reaction... 

Fig. 6-10 Flux velocity-angle contour map for DF obtained from the reaction F + D2 DF + D. The initial relative translational energy was 1.68 kcal/mole. The circles represent the largest possible value of the final velocity of DF consistent with the vibrational quantum number v. [Adapted from Y. T. Lee, in Physics of Electronic and Atomic Collisions, VII ICPEAC 1971, Fig. 4a. Reproduced by permission of copyright owner, North-Holland Publishing Co., Amsterdam.]...

LTHC means a selective surface attack in the form of corrosion pits that form under long-term operation cycles at lower temperatures (around 700°C-750 C). The research on engine operating conditions has proved that the higher the gas flux velocity, the slower the pit corrosion damage [18]. 

---