THREE-DIMENSIONAL HYDRODYNAMIC AND OSMOTIC PORE ENTRANCE PHENOMENA (BIOLOGICAL MEMBRANE, INTERACTION).
Item
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Title
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THREE-DIMENSIONAL HYDRODYNAMIC AND OSMOTIC PORE ENTRANCE PHENOMENA (BIOLOGICAL MEMBRANE, INTERACTION).
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Identifier
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AAI8515677
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identifier
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8515677
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Creator
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YAN, ZONG-YI.
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Contributor
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Sheldon Weinbaum
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Date
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1985
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Language
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English
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Publisher
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City University of New York.
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Subject
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Applied Mechanics
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Abstract
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This thesis studies two important aspects of pore entrance/exit phenomena in biological and synthetic membranes--the three-dimensional osmotic fine structure and the hydrodynamic interaction near the pore entrance.;Chapter 2 presents a detailed quantitative model of osmotic fine structure for both permeable and semi-permeable membranes in dilute bathing solutions. By introducing an approximate description of the hydrodynamic interactions in the entrance/exit regions, the balance between the convective and diffusive fluxes is considered both inside and outside a membrane pore. For permeable membranes, the concentration variations in the entrance/exit regions may have an important influence on the osmotic flow rate, especially for relatively short pores, small solute particles and not very dilute solutions. It is shown for permeable membranes that the three-dimensional entrance region within two to three pore-radii from the pore opening forms a substructure of the much thicker unstirred layer described by Dainty (1963) and Pedley et al. (1978). When the porosity is low (such as in most biological membranes), the wall concentration in Pedley's solution is the far field concentration for the present entrance/exit solutions.;Chapter 3 proposes a combined multipole series representation and integral equation method for solving the problem of a finite sphere entering a zero-thickness orifice. This method combines the flexibility of the integral equation method for treating complicated geometries and the accuracy and computational efficiency of the multipole technique. Both axisymmetric and three-dimensional solutions are obtained. The present three-dimensional solutions for the force and torque correction factors are the first for a finite sphere and are valid for the difficult case where the sphere intersects the plane of the orifice opening. The behavior in the vicinity of the pore opening is important in many particle-pore entrance phenomena because of the rapid variations in the hydrodynamic force and torque coefficients in this region. The convergence of the present three-dimensional solution deteriorates beyond a few pore-radii from the pore axis or near the plane wall. The practical usefulness of the solution in these regions is limited by excessive computation cost.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Engineering
