Abstract: Preparation of electromagnetic radiation shielding composite exhibiting high conductivity and low resistance is shown by applying an electrical potential difference across a composite comprising an electrically conductive material dispersed within a foamed matrix material and applying at least one additional electrical potential difference being greater than the potential difference which precedes it.

Abstract: A specimen holder has flexible walls to provide good electrical contact between a material to be tested for its electrical properties and the conductors of a coaxial cable. The walls of the specimen holder are tubular in shape and coaxial and have a plurality of longitudinal slots spaced therearound to provide strips which are flexible in the radial direction. The walls are permanently distorted in a radial direction to urge them towards each other and into spring-like contact with an annular material specimen inserted between them. The specimen holder is particularly suited for measuring the electromagnetic shielding effectiveness of materials.

Abstract: The cutting edge of a scalpel blade is heated to a preselected constant temperature range by conduction of high frequency current through the blade of ferromagnetic material in a region thereof which is in close proximity to a conductor positioned along the cutting edge. Selective heating of regions of the cutting edge that are locally cooled by the tissue contact during surgical cutting is provided by constructing the blade of ferromagnetic materials that have a Curie point in the operating temperature range and that provide large increases in magnetic permeability for temperature decrements below the Curie point.