Results 261 to 270 of about 141,211 (301)

Effect of succinate on the translational diffusion coefficient of aspartate transcarbamylase

Biochemistry, 1975
Employing a differential optical mixing spectrometer, we have determined that the translational diffusion coefficient (DT) of aspartate transcarbamylase (AT-Case) decreases by (4.1 plus or minus 0.6)% in the presence of succinate and carbamyl phosphate.
S B, Dubin, D S, Cannell
openaire   +2 more sources

Ageing effect of chloride diffusion coefficient

ConcreteLife'06 - International RILEM-JCI Seminar on Concrete Durability and Service Life Planning: Curing, Crack Control, Performance in Harsh Environments, 2006
Most of the currently used models to predict chloride ingress a constant diffusion coefficient over time. However, a reduction of the diffusion coefficient over time, is ob-served at specimens that are exposed to chlorides. This reduction of the diffusion coefficient is expressed with the ageing coefficient.
openaire   +3 more sources

Time-dependent neutron diffusion coefficient for the effective diffusion equation

Progress in Nuclear Energy, 2019
Abstract The time-dependency of neutron diffusion coefficient as well as neutronic interfacial coefficients in nuclear reactors at short time-scale is investigated via the volume averaging method. The boundary-value problems of governing differential equation for spatial deviations around averages of local variables are developed in this work.
Carlos G. Aguilar-Madera, Gilberto Espinosa-Paredes, Lázaro Molina-Espinosa   +2 more
openaire   +1 more source

Effective Diffusion Coefficient in Void Regions

Nuclear Science and Engineering, 1962
The muitigroup diffusion theory for a virtually critical medium with homogeneous regions, when applied to a void region having one-dimensional cylindrical geometry, yields slightly erroneous results as a result of the fact that the theory ignores the neutron current traversing the gap.
openaire   +1 more source

Effect of geometry on the effective moisture transfer diffusion coefficient

Journal of Food Engineering, 1996
Abstract The effective moisture transfer diffusion coefficient ( D eff ) of ready-to-eat breakfast cereals (RTE) is determined either from an individual particle or a bulk of material in the literature. The D eff is assumed to be the same in both cases which can be dependent on the material thickness. In this study, the effect of bed depth of
M.Ahmet Tütüncü, T.P. Labuza
openaire   +1 more source

Spin waves and spin diffusion in Fermi liquids: Bounds on effective diffusion coefficients

Physical Review B, 1986
We investigate the accuracy of the usual relaxation-time approximations, involving the spin-diffusion lifetime tau/sub D/, which are generally made in analyses of spin waves and the Leggett-Rice effect in Fermi liquids. By employing the variational methods of Ah-Sam, Hojgaard-Jensen, and Smith and of Egilsson and Pethick, we are able to determine upper
, Bedell, , Meltzer
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Effective Diffusion Coefficient in Porous Media

Journal of Applied Physics, 1963
Recent calculations by Prager of upper bounds for the effective diffusion coefficient (or conductivity) in porous media, in terms of certain statistical parameters of the random geometry, are reformulated so as to apply specifically to a bed of spherical particles.
openaire   +1 more source

Calculations of the effective diffusion coefficient for inhomogeneous media

Journal of Physics and Chemistry of Solids, 2002
Abstract We suggest a modification of the well-known Maxwell-Garnett equation for the mobility (effective diffusion coefficient) in two-phase media (a matrix with inclusions) which permits the description of a wide range of experimental situations.
Kalnin, J., Kotomin, E., Maier, J.
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Consistent measurement of diffusion coefficients for effectiveness factors

Chemical Engineering Science, 1980
Abstract An examination has been made of how structural factors influence the measured values of effective diffusivity using the steady(Wicke-Kallenbach) and unsteady (chromatographic) state methods. For a solid with a typical bidisperse pore size distribution it is shown that the steady state method tends to give longer values.
C. McGreavy, M.A. Siddiqui
openaire   +1 more source

Effective diffusion coefficient for two-band systems

Applied Physics Letters, 2005
The effective longitudinal diffusion coefficient for two-band systems is determined. Emphasis is put on the nonlinear transport regime realized at high electric fields. Particular results are obtained for bipolar transport in two-band semiconductors and vertical transport in semiconductor superlattices.
P. Kleinert, V. V. Bryksin
openaire   +1 more source