title: Trapping of diffusing particles by striped cylindrical surfaces. Boundary homogenization approach.
abstract: We study trapping of diffusing particles by a cylindrical surface formed by rolling a flat surface, containing alternating absorbing and reflecting stripes, into a tube. For an arbitrary stripe orientation with respect to the tube axis, this problem is intractable analytically because it requires dealing with non-uniform boundary conditions. To bypass this difficulty, we use a boundary homogenization approach which replaces non-uniform boundary conditions on the tube wall by an effective uniform partially absorbing boundary condition with properly chosen effective trapping rate. We demonstrate that the exact solution for the effective trapping rate, known for a flat, striped surface, works very well when this surface is rolled into a cylindrical tube. This is shown for both internal and external problems, where the particles diffuse inside and outside the striped tube, at three orientations of the stripe direction with respect to the tube axis: (a) perpendicular to the axis, (b) parallel to the axis, and
authors.affiliation: Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, 09340 Mexico D.F., Mexico.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Dagdug
authors.affiliation: Mathematical and Statistical Computing Laboratory, Division for Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Berezhkovskii
authors.affiliation: Maritime Division, Defence Science and Technology Organisation, Fishermans Bend, VIC 3207, Australia.
authors.forename: Alexei T
authors.initials: AT
authors.lastname: Skvortsov
mesh_terms: D004058:Diffusion; D008956:Models, Chemical