Determination of NiBi3 reaction-diffusion constants in Ni-Bi couples

1995 ◽  
Vol 14 (24) ◽  
pp. 1725-1727 ◽  
Author(s):  
O. V. Duchenko ◽  
V. I. Dybkov
Keyword(s):  
Reaction Diffusion ◽  
Diffusion Constants

scholarly journals A METHOD FOR THE DETERMINATION OF DIFFUSION CONSTANTS AND THE CALCULATION OF THE RADIUS AND WEIGHT OF THE HEMOGLOBIN MOLECULE

1929 ◽  
Vol 12 (4) ◽  
pp. 543-554 ◽  
Author(s):  
John H. Northrop ◽  
M. L. Anson
Keyword(s):  
Molecular Weight ◽  
Carbon Monoxide ◽  
Diffusion Coefficient ◽  
Porous Membrane ◽  
Diffusion Constants ◽  
Einstein's Equation ◽  
Hemoglobin Molecule

A method is described for determining the diffusion coefficient of solutes by determining the rate of passage of the solute through a thin porous membrane between two solutions of different concentration. The method has been used to determine the diffusion coefficient of carbon monoxide hemoglobin. This was found to be 0.0420 ± 0.0005 cm.2 per day at 5°C. The molecular weight of carbon monoxide hemoglobin calculated by means of Einstein's equation from this quantity is 68,600 ± 1,000.

Determination of oxygen profiles and diffusivity in encapsulated biomass k-carrageenan gel beads

1997 ◽  
Vol 36 (1) ◽  
pp. 271-277 ◽  
Author(s):  
Qin Zhou ◽  
Paul L. Bishop
Keyword(s):  
Gas Flow ◽  
Consumption Rate ◽  
Thin Liquid Film ◽  
Reaction Diffusion ◽  
Gel Beads ◽  
Reaction Diffusion Model ◽  
Volatile Organic ◽  
Oxygen Profiles ◽  
Gel Bead

Biofiltration is a popular method for removing volatile organic compounds (VOCs). One promising medium for biofilters is biomass encapsulated gel beads. Like any other biodegradation system, oxygen concentration is an important factor affecting microbial activities in gel beads and thus the VOC removal efficiency. This paper summarizes the studies on oxygen distribution and diffusivity in k-carrageenan gel beads using oxygen microelectrodes to measure oxygen profiles. By using a reaction-diffusion model and the concentration measurements obtained, a homogeneous diffusivity constant and an oxygen consumption rate constant in k-carrageenan gel beads were estimated. The estimated oxygen diffusivity in the gel bead is 46.3% of the value in water when the bead is immersed in water and 53.9% that of water when the bead is in air with a thin liquid film surrounding it. To provide more information for the design and operation of biofilters using biomass-loaded gel beads, we also investigated and report on effects of biomass immobilization time, TCE influent concentration and TCE gas flow rate on oxygen concentrations in the gel bead.

scholarly journals New Method for the Determination of Diffusion Constants from Partially Narrowed Nmr Lines

1980 ◽  
Vol 3 ◽  
Author(s):  
D. Wolf
Keyword(s):  
Relaxation Time ◽  
Free Induction Decay ◽  
Weighted Sum ◽  
Molecular Motions ◽  
Rigid Lattice ◽  
Background Contribution ◽  
Intermediate Temperature Range ◽  
Diffusion Constants ◽  
Free Induction

ABSTRACTThe effect of atomic and molecular motions on the NMR free-induction decay (FID) and lineshape is investigated theoretically in the intermediate temperature range in which the NMR line is only partially narrowed. It is shown that the FID may be decomposed into the weighted sum of a rigid-lattice (background) contribution and an exponentially decaying part containing all the information on the diffusive or reorientational motions in the crystal in terms of the spin-spin relaxation time T2.

A Simple Method for the Determination of Diffusion Constants

Science ◽  
1950 ◽  
Vol 112 (2921) ◽  
pp. 757-758 ◽  
Author(s):  
L. A. Walker
Keyword(s):  
Simple Method ◽  
Diffusion Constants
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