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Passive sampling relies on the uptake of contaminants into appropriate sampling devices along a diffusion gradient without using pumps or bailers. Thus, for example, in groundwater sampling, changes to flow due to pumping can be avoided. If the diffusion g ...
Nuclear magnetic resonance is a powerful nonintrusive technique for measuring diffusion coefficients through the use of pulsed field gradients. The main limitation to the application range of this method is imposed by the relaxation time constants of the m ...
A transport equation is derived which describes the behavior of the nanostructured metal oxide films in a photoelectrochem. cell. A detailed anal. of the charge compensation mechanism necessarily leads to a transport equation with characteristics similar t ...
Electrochemical techniques were applied to a coulometric titration cell to study oxygen nonstoichiometry and transport in the perovskite-type oxide La0.4Ba0.6Fe0.8Co0.2O3-delta. Slow scan voltammetry (3mV/s) was used to obtain oxygen nonstoichiometry vs. t ...
The diffusivity of photogenerated electron-hole pairs in weakly disordered GaAs/AlGaAs V-groove quantum wires was measured using a photoluminescence (PL) time-of-flight technique. It is shown that the electron-hole pair diffusion is thermally activated abo ...
A theoretical modeling framework is proposed to follow shape and residual stress evolutions of layered flexible display structures with respect to deposition, ambient temperature and relative humidity conditions. This model couples the mechanical equilibri ...
In this study, we examine the parameters that govern the overall oxygen flux through a permeation membrane. The chemical diffusion (D) and the surface exchange (k) coefficients for oxygen in La0.6Sr0.4Fe0.8Co0.2O3-d were determined as a function of tempera ...
An atomic-scale description is provided for the long-range oxygen migration through the disordered SiO2 oxide during silicon oxidation. First-principles calculations, classical molecular dynamics, and Monte Carlo simulations are used in sequence to span th ...
Soils are known to support a great bacterial diversity down to the millimeter scale, but the mechanisms by which such a large diversity is sustained are largely unknown. A feature of unsaturated soils is that water usually forms thin, poorly-connected film ...
We investigate at the atomic scale the oxygen diffusion process occurring during silicon oxidation. First, we address the energetics of several oxygen species in the oxide using density-functional calculations. Our results support the interstitial O-2 mole ...