Ramm, Alexander G.Lu, Jane Wei-Zhen2011-06-162011-06-162010-05-21http://hdl.handle.net/2097/9255In this talk a method is described fof 8f;Jfr tg materials with a desired refraction coefficient. The method consists of embedding into a material with known refraction coefficient many small particles of size a. The number of particles per unit vo ume around any point is prescribed, the distance between neighboring particles is O(a ) as a -+ 0, 0 < K. < 1 is a fixed para1neter. The total number of the embedded particle is O(a ). The physical properties of the particles are described by the boundary impedance ( of the m - th particle, ( = O(a ) as a -+ 0. The refraction coefficient is the coefficientn (x) in the wave equation ['v + k n (x)]u = 0.This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).MesarteritisRefraction coefficientWave scatteringSmall particlesConference paper