نتایج جستجو برای: diffusion layer

تعداد نتایج: 436727  

Effect of clamping pressure on electrical resistance between Gas diffusion layer (GDL) and bipolar plate is a very important parameter in Proton exchange membrane (PEM) fuel cells. For investigation of this matter some researches have been done in these years. But there is not an experimental investigation of clamping pressure effect on PEM electrical resistance. In this paper, some experimenta...

Journal: :مهندسی سازه 0
کاظم بدو

one and two dimensional contaminant transport by pure diffusion through single layer of fine grained soil was investigated using one and two dimensional laboratory models. these models simulates a simple hydrogeologic situation underneath a solid waste landfill comprising a fine grained soil overlying a bed rock. sodium chloride solution was sued as a contaminant source above a compacted clayey...

Journal: :iranian journal of hydrogen & fuel cell 2015
hassan hassanzadeh seyed hadi golkar

in this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (gdl) of pem fuel cell is modeled. the governing equations including energy, mass and momentum conservation equations are solved by numerical methods. also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (gdl) thickness and inlet relative humidity are calculated...

2014
Pavlo Selyshchev

A theoretical approach to consider formation of chemical compound layer at the interface between initial substances A and B due to the interfacial interaction and diffusion is developed. It is considered situation when speed of interfacial interaction is large enough and diffusion of A-atoms through AB-layer is much more then diffusion of B-atoms. Atoms from A-layer diffuse toward B-atoms and f...

Journal: :Journal of the Optical Society of America. A, Optics, image science, and vision 2006
Lionel Simonot Mathieu Hébert Roger D Hersch

We propose a model for predicting the reflectance and transmittance of multiple stacked nonscattering coloring layers that have different refractive indices. The model relies on the modeling of the reflectance and transmittance of a bounded coloring layer, i.e., a coloring layer and its two interfaces with neighboring media of different refractive indices. This model is then applied to deduce t...

In this research, the diffusion bonding of the stabilized zirconia ceramic and Nimonic 105 superalloy using Ti/Nb/Ni multi-interlayer was carried out. Joint was performed using the plasma spark technique in a vacuum atmosphere and at different temperatures and times. The microstructure of the different joint zones was studied using optical and FESEM microscopes equipped with an EDS analyzer. Th...

ابوالحسن مبشری, , حسین ثقفی‌فر, , حمیدرضا فلاح, ,

  The design method and fabrication of mirrors with variable reflectivity are presented. To fabricate such a mirror a fixed mask with a circular aperture is used. The circular aperture is considered as an extended source with cosx(θ)as its diffusion distribution function and is the parameter for the distribution function of the particles through the aperture. The thickness profile of deposited ...

1997
Wei-Ming Ni

where ut = ∂u ∂t and ∆ =∑ni=1 ∂2 ∂xi is the usual Laplace operator, Ω is a bounded smooth domain in Rn, υ is the unit outer normal to ∂Ω, and u0 is a realvalued continuous function (not identically zero) representing the initial heat distribution. Here the boundary condition implies that (1) is an isolated system. It is well known that the solution u(x, t) of (1) becomes smooth as soon as t bec...

In this study, a time-dependent 2D axisymmetric model of a multilayer hollow fiber composite membrane for gas separation is proposed. In spite of the common multilayer membranes, which a dense layer coated on a porous support layer and subjected into the feed stream, here, the porous support is exposed to the feed gas. In this regard, the governing equations of species transport are developed f...

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