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B = diffusion coefficient of the eluting particles in the longitudinal direction, resulting in dispersion [m 2 s −1] C = Resistance to mass transfer coefficient of the analyte between mobile and stationary phase [s] u = speed [m s −1] In open tubular capillaries, the A term will be zero as the lack of packing means channeling does not occur ...
Taylor dispersion or Taylor diffusion is an apparent or effective diffusion of some scalar field arising on the large scale due to the presence of a strong, confined, zero-mean shear flow on the small scale. Essentially, the shear acts to smear out the concentration distribution in the direction of the flow, enhancing the rate at which it ...
Given the dispersion relation, one can calculate the frequency-dependent phase velocity and group velocity of each sinusoidal component of a wave in the medium, as a function of frequency. In addition to the geometry-dependent and material-dependent dispersion relations, the overarching Kramers–Kronig relations describe the frequency ...
Thus axial dispersion coefficient D L can be estimated (L = packed height) [5] As mentioned before, there are also other boundary conditions that can be applied to the dispersion model giving different relationships for the dispersion number. [8] [9] [3] Advantages. From the safety technical point of view the PFR has the advantages that [10]
At low frequency, an SPP approaches a Sommerfeld-Zenneck wave, where the dispersion relation (relation between frequency and wavevector) is the same as in free space. At a higher frequency, the dispersion relation bends over and reaches an asymptotic limit called the " plasma frequency " [ 4 ] (see figure at right).
A. R. Forouhi and I. Bloomer deduced dispersion equations for the refractive index, n, and extinction coefficient, k, which were published in 1986 [1] and 1988. [2] The 1986 publication relates to amorphous materials, while the 1988 publication relates to crystalline.
Some of the contaminants will be "behind" or "ahead" the mean groundwater, giving rise to a longitudinal dispersivity (α L), and some will be "to the sides of" the pure advective groundwater flow, leading to a transverse dispersivity (α T). Dispersion in groundwater arises because each water "particle", passing beyond a soil particle, must ...
where n is the refractive index, λ is the wavelength, A, B, C, etc., are coefficients that can be determined for a material by fitting the equation to measured refractive indices at known wavelengths. The coefficients are usually quoted for λ as the vacuum wavelength in micrometres. Usually, it is sufficient to use a two-term form of the ...