Consider the scattering of an electromagnetic time-harmonic plane wave by an infinite cylinder having an open crack and a bounded domain in as cross section. We assume that the crack is divided into two parts. and one of the two parts is (possibly) coated on one side by a material with surface impedance . Different boundary conditions are given on and. https://www.spidertattooz.com/The-GelBottle-Inc-Gel-Polish-Cashmere-67oz-p20053/