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Unformatted text preview: channel. We apply both a pressure and a mystifying body field force (MBFF - a force that is not physical in nature but one that will make the math easier for you to solve). This MBFF is a volumetric body force equal to e Bu , where e is the volumetric charge density, B is a magnetic field in Teslas, and u is a constant velocity in the y direction. What would the nanochannel velocity profile be (v x as a function of y)? Question 4: Two molecules with different mobilities and charges (mobility A = 4.3 x 10-13 , charge A = -2, and mobility B = 2.1 x 10-13 , charge B = -4) are traveling down a 200nm x 200nm square cross-sectional area (and 10mm long) nanochannel that has a nondimensional zeta potential =1 and 10 nm electric double layer thickness. a. What are the approximate time scales for diffusion, electromigration, and advection? b. What if the channel was 20um x 20um? c. Which molecule would travel faster in each case?...
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This note was uploaded on 08/06/2008 for the course ME 125 taught by Professor Pennathur during the Spring '08 term at UCSB.
- Spring '08