منابع مشابه
Anomalous Knudsen Diffusion in Simple Pore Models
1. Introduction Gas diffusion in mesoporous media is often in the Knudsen regime, cross sections of the pores being considerably smaller than the intrinsic molecular mean free path. Coppens [1] predicted the effect of fractal wall roughness on Knudsen self-diffusivity K D in a channel. A " trapping " process was identified as the cause of reduction of
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Comparing the rates of molecular diffusion in porous materials under different regimes of measurement may provide valuable information about the underlying mechanisms. After quite generally explaining the benefit of such a procedure, we refer to a case which in the last few years has raised controversial discussion within the community, viz. the comparison of diffusion phenomena in pores of var...
متن کاملKnudsen Self- and Fickian Diffusion in Rough Nanoporous Media
The effect of pore surface roughness on Knudsen diffusion in nanoporous media is investigated by dynamic Monte-Carlo simulations and analytical calculations. A conceptual difference is found between the roughness dependence of the macroscopic, transport diffusivity and the microscopic, selfdiffusivity, which is reminiscent of diffusion in zeolites, where a similar difference arises due to adsor...
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هدف اصلی از این تحقیق به دست آوردن و مقایسه حق بیمه باورمندی در مدل های شمارشی گزارش نشده برای داده های طولی می باشد. در این تحقیق حق بیمه های پبش گویی بر اساس توابع ضرر مربع خطا و نمایی محاسبه شده و با هم مقایسه می شود. تمایل به گرفتن پاداش و جایزه یکی از دلایل مهم برای گزارش ندادن تصادفات می باشد و افراد برای استفاده از تخفیف اغلب از گزارش تصادفات با هزینه پائین خودداری می کنند، در این تحقیق ...
15 صفحه اولTransport diffusion coefficient for a Knudsen gas in a random tube
We consider transport diffusion in a stochastic billiard in a random tube which is elongated in the direction of the first coordinate (the tube axis). Inside the random tube, which is stationary and ergodic, non-interacting particles move straight with constant speed. Upon hitting the tube walls, they are reflected randomly, according to the cosine law: the density of the outgoing direction is ...
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ژورنال
عنوان ژورنال: Physics of Fluids
سال: 2007
ISSN: 1070-6631,1089-7666
DOI: 10.1063/1.2798748