Number flux

This paper discusses preliminary results of a model which is designed to predict drift deposition drop size distributions and number flux. The influence of evaporation and the drop breakaway process are studied by using both a bulk breakaway criteria and a distributed partial breakaway criteria for each drop size. Comparisons are made at several downwind receptor sites for drop size distribution and number flux. 13 refs, cited. 

The flux of molecules to a surface, JN, determines either the rate at which it would be covered if each molecule stuck, or the rate of effusion through a hole in the surface. In studying the exposure, JNdt, of a surface to a gas, surface scientists find it useful to use the product of pressure and time as a measure of the exposure since this product is proportional to the number flux, JN, times the time JNt = (1/4)Cut = (u/4kT)pt, where C is the number density of molecules, u their average speed, k the Boltzmann constant and T the thermodynamic temperature. The unit langmuir (symbol L) corresponds to the exposure of a surface to a gas at 10" 6 torr for 1 second. 

In the case of localized losses we treat them as discontinuities of the energy, momentum and particle number fluxes at the shock front, which are characterized by three parameters e, 5, r/ equal to the fractions of corresponding fluxes lost at the shock front in the front comoving frame. We obtain the following expressions for the pressure p2, number density n2 and the Lorentz factor 72 immediately behind the shock front ... 

Metabolite/Co-metabolite with serial number Concentration (mM) Enzyme with serial number Flux (mM/s)... 

As regards change of composition, the situation is even more constrained and symmetrical than in Chapter 14. Not only is dC fdx the exact opposite of dC jdx, but also, because of the stoichiometry, the number of atoms of A that cross any plane of X atoms must be balanced by an equal number of atoms of B crossing the other way the number-fluxes must be equal and opposite, when measured in a frame attached to the substrate of X. Even if B is intrinsically more mobile than A, the stoichiometry hinders B and stimulates A until a single value for the number-flux describes both motions. 

FIGURE 11.2. The ratio of the number flux of droplets of kind j to its value at x = 0 as a function of the dimensionless distance Zj for various values of (tj +... 

J) as a function of the concentration gradient. For aerosols, it is common to use a number flux (i.e. the number of dispersed species per area per time unit) ... 

Mori H, Niimi T, Uenishi H, Hirako M (2005) Molecular number flux detection using oxygen sensitive luminophore. Phys Fluids 17 100610... 

Number flux quantifies flux in terms of the raw number of atoms or molecules of the species that is moving. It is related to the molar flux by Avogadro s number ... 

Volume flux is yet another way to quantify the flux of a species, using the volume rather than mass or moles of the species to describe the rate of transport. Volume flux is related to mass, molar, or number flux by the species density, molar volume, or atomic volume ... 

Since velocities through both internal and external coordinate spaces are defined, it is now possible to identify particle (number) fluxes, i.e., the number of particles flowing per unit time per unit area normal to the direction of the velocity. Thus / (x, r, t)R(x, r, Y, t) represents the particle flux through physical space and / (x, r, t)X x, r, Y, t) is the particle flux through internal coordinate space. Both fluxes are evaluated at time t and at the point (x, r) in particle state space. Indeed these fluxes are clearly important in the formulation of population balance equations. 

Incident particle number flux or intensity in kinetic theory (1/m s)... 

Faraday constant Electrostatic potential Avogadro s number Flux of species i Nernst potential Overpotential Ideal gas constant Charge transfer resistance Polarisation resistance... 

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