With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Treatments for peripheral artery disease include atherectomy to remove atherosclerosis from blood vessels within the body.
text_B: The Zenneck wave , Zenneck surface wave or Sommerfeld-Zenneck surface wave is an inhomogeneous or non-uniform electromagnetic plane wave incident at the complex Brewster angle onto a planar or spherical boundary interface between two homogeneous media having different dielectric constants .. The Zenneck wave propagates parallel to the interface and decays exponentially vertical to it , a property known as evanescence .. It exists under the condition that the permittivity of one of the materials forming the interface is negative , while the other one is positive , as for example the interface between air and a lossy conducting medium such as the terrestrial transmission line , below the plasma frequency .. permittivity. permittivity. plasma frequency. plasma frequency. Arising from original analysis by Arnold Sommerfeld and Jonathan Zenneck of the problem of wave propagation over a lossy earth , it exists as an exact solution to Maxwell 's equations .. Arnold Sommerfeld. Arnold Sommerfeld. Jonathan Zenneck. Jonathan Zenneck
not_related.