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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/1232

Authors: Ashenafi, Feye
Advisors: Dr. Mulugeta Bekele,
Copyright: 2003
Date Added: 25-May-2008
Publisher: Addis Ababa university
Abstract: Abstract We present two mechanisms for segregating mixtures of Brownian particles. In the first model, we used a W-potential, which is piece-wise linear, with non-homogeneous temperature background to separate mixtures of two types of Brownian particles that differ in their diffusion constants. We found closed form expression for the dynamics of the separation as a function of the parameters characterizing the model. For a given set of model parameter, we explored how the separation evolves with time and found it to take a maximum value at a finite time. We are specifically interested in how the barrier height affects the process of segregation and found that the best separation between the particles occurs at infinite potentials which corresponds to waiting for infinite times. As such we optimized the segregation and found the barrier height that gives us the optimized separation. In the second model, we used a periodic sawtooth potential, created by a uniform gravitational field, to separate mixtures of two types of Brownian particles. With the application of a small load and a non-homogeneous temperature background, we have shown that it is possible to separate two types of Brownian particles that have different masses by making them move in opposite directions.
Description: A Thesis Submitted to the School of Graduate Studies Addis Ababa University In Partial Fulfillment of the Requirement for the Degree of Master of Science in Physics
URI: http://hdl.handle.net/123456789/1232
Appears in:Thesis - Physics

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