This paper presents mathematical models of potentiometric as well as amperometric biosensors, based on an electrode covered with an enzyme membrane. The models involve three regions: the enzyme layer where enzyme reaction as well as mass transport by diffusion takes place, a diffusion limiting region where only the diffusion takes place, and a convective region, where the analyte concentration ...

Gas diffusion layers are essential components of proton exchange membrane fuel cell since the reactants should pass through these layers. Mass transport in these layers is highly dependent on porosity. Many of simulations have assumed, for simplicity, the porosity of GDL is constant, but in practice, there is a considerable variation in porosity along gas diffusion layers. In the present study ...

The Bloch-Torrey Partial Differential Equation (PDE) can be used to model the diffusion Magnetic Resonance Imaging (dMRI) signal in biological tissue. In this paper, we derive an Anisotropic Diffusion Transmission Condition (ADTC) for the Bloch-Torrey PDE that accounts for anisotropic diffusion inside thin layers. Such diffusion occurs, for example, in the myelin sheath surrounding the axons of...

Arterial drug concentration distribution determines local toxicity. The safety issues dealt with Drug-Eluting Stents (DESs) reveal the needs for investigation about the effective factors contributing to fluctuations in arterial drug uptake. The current study focused on the importance of hypertension as an important and controversial risk factor among researchers on the efficacy of Heparin-Eluti...

In this work, adsorption kinetics were investigated in order to remove the acid blue 62 off the aqueous solutions using mesoporous silicate SBA-15 loaded with tannic acid (tannin-SBA-15). Nitrogen adsorption and desorption test (BET), X-ray diffraction (XRD) and Fourier transform infra-red spectroscopy (FT-IR) analysis characterize synthesized composite. The impacts of some parameters such as P...

The kinetics of the solid-state reactive diffusion between Sn­Ni alloys and pure Cu was experimentally observed to examine effects of addition of Ni into Sn on the growth behavior of compounds at the interconnection between the Sn-base solder and the multilayer Au/Ni/Cu conductor during energization heating. In this experiment, sandwich (Sn­Ni)/Cu/(Sn­Ni) diffusion couples with Ni concentration...

2014 The solution of the equation of one-dimensional diffusion with evaporation of the sample and exchange of the diffusant with the ambient at the surface has been applied to the cases of thick layer diffusion, diffusion from an implantation profile and isotope exchange diffusion. Revue Phys. Appl. 24 (1989) 11-16 JANVIER 1989, Classification Physics Abstracts 66.30

In this paper we construct numerical schemes to approximate linear transport equations with slab geometry by diffusion equations. We treat both the case of pure diffusive scaling and the case where kinetic and diffusive scalings coexist. The diffusion equations and their data are derived from asymptotic and layer analysis which allows general scattering kernels and general data. We apply the ha...

The metal-insulator-semiconductor (MIS) diode is the most useful device in the study of semiconductor surfaces. The current-voltage data of the metal-insulatorsemiconductor Schottky diode are simulated using thermionic emission diffusion equation taking into account the interfacial layer parameters. The calculated current–voltage data are fitted into ideal thermionic emission diffusion equation...

In this study, the physical and electrical characteristics of Al2O3/La2O3/Al2O3/Si stack structures affected by the thickness of an Al2O3 barrier layer between Si substrate and La2O3 layer are investigated after a rapid thermal annealing (RTA) treatment. Time of flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) tests indicate that an Al2O3 barrier laye...