Abstract: An anti-interference filter for radio-shielding a feeder to a gradient coil in a nuclear magnetic resonance imaging apparatus is constructed as a band elimination (band rejection) filter for the operating frequency of the nuclear magnetic resonance imaging apparatus. The anti-interference filter can be in the form of a directionally symmetrical quadrupole having two input terminals and two output terminals. A first input terminal and a first output terminal are introducible into the feeder to the gradient coil, and a second input terminal and a second output terminal are connected to a conductor at reference potential. A number of blocking circuits are arranged in series between the first input terminal and the first output terminal. A number acceptor circuits are arranged between the input terminals, between the junctions of the blocking circuits and the reference potential conductor, and between the output terminals. The number of acceptor circuits is one more than the number of blocking circuits.

Abstract: A tomography apparatus utilizing nuclear magnetic resonance techniques for representing internal cross-sections of an examination subject has a surface coil for acquiring a signal corresponding to the displacement of the nuclear spins of the examination subject from a equilibrium position. The surface coil is annular and has its ends connected to ground through respective capacitances. A tape-shaped high-frequency shielding at least partially surrounds the surface coil.

Abstract: Soft or plasticized polyvinyl chloride compositions with good chemical, mechanical and electrical properties characterized by their fire-retardant and flame-resistant properties comprising polyvinyl chloride with a content of a triphosphate plasticizer, aluminum hydroxide and antimony trioxide compounds. The compositions are particularly suitable for use in electrical conductors as sheathings and/or insulation.

Abstract: A process for the production of a pulverulent, tricklable mixture of ethylene/vinyl acetate copolymer and polyvinylchloride comprising the steps of mixing a mixture consisting essentially of (a) an ethylene/vinyl acetate copolymer having an acetate content of from 15% to 75% by weight, (b) powdery polyvinylchloride, in a mixture ratio of (a) to (b) of 1:3 to 2:1, and (c) from 0 to 5% by weight of the mixture of additives customary for polymer processing, in a high-speed mixture at temperatures above the softening temperature of said polyvinylchloride and below 170.degree. C., for a time sufficient to effect homogenization, quenching said homogenized mixture with water and removing the water, grinding the quenched product with the addition of from 0.5 to 10 parts by weight of an inert powder having particles in the submicroscopic range, in a high speed mill under passage of an airstream which is heated by friction, and recovering said pulverulent, tricklable mixture; as well as the powdery mixture so produced.