Abstract: A flat heating element includes a thin resistance layer which contains an electro-conductive polymer and at least two flat electrodes arranged on One side of the resistance layer at a distance from each other, wherein the polymer has an intrinsic electric conductivity caused by a content of at least one metal or semimetal atom dopant.

Abstract: The invention provides an installation and method for generating an electrical field of a large area in soil having a vegetation zone between the ends of roots of plants in the soil and the surface of the soil, which comprises at least one cathode having a high conductivity and a low transition resistance arranged in the vegetation zone, each one of the cathodes being a flexible net comprised of threads defining meshes of a sufficient size to accommodate the plants therein, the threads of the net being comprised of at least one core material selected from the group consisting of polyamide, acrylic resin, polyester, and carbon and metal filaments embedded in an electrically conductive synthetic resin, an anode arranged in a deeper zone of the soil at a greater distance from the soil surface than each one of the cathodes, and an electrical conductor system connecting each one of the cathodes to the anode to enable an electric current to flow therebetween.

Abstract: A planar heating element having a positive temperature coefficient comprises a plurality of spaced electric current supply lines constituted by contact bands and a planar support therefor equally flexible in all directions. The contact bands are in operative connection with the support, and the support includes an ion-free, electrically conductive synthetic resin whose electrical resistance has a positive temperature coefficient.

Abstract: In a heating element comprising an electrical resistance layer disposed between two areal electrodes extending generally parallel to one another, the resistance layer is formed to be thermally insulating and is permeated with electrically conductive plastics material having a positive temperature coefficient of electrical resistance. The conductive plastics may comprise thermoplastics material incorporating a particulate filler of granular, spheroidal or bubble form, and the electrodes may be coated black to serve as black bodies. The element may be disposed within a thermally insulating member acting as a heat shield.

Abstract: Reinforcing or carrier elements for plaster are used as electrodes in electro-osmotic dehumidification installations. The elements comprise a carrier body constituted by a flexible net having a surface of synthetic resin in contact with the plaster and the net has filamentary carrier materials incorporated therein. The synthetic resin is a conductive, essentially ion-free thermosetting resin of macromolecular structure, preferably an at least partially cross-linked acrylate polymer having a high surface roughness and containing a small amount of a plasticizer, and forms either the matrix or a coating of the flexible net. The filamentary carrier materials may be carbon or metal filaments. In the use of the dehumidification installation, a voltage alternating between a positive and a negative potential is conducted between the cathode and the anode, the time interval of the positive potential exceeding that of the negative potential.

Abstract: A planar heating element having a positive temperature coefficient has a plurality of spaced electric current supply lines constituted by contact bands and a planar support, the electric current supply lines being operatively connected to the planar support, the contact bands and the support including an electrically conductive synthetic resin whose electrical resistance has a positive temperature coefficient.

Abstract: Reinforcing or carrier elements for plaster are used as electrodes in electro-osmotic dehumidification installations. The elements comprise a carrier body constituted by a flexible net having a surface of synthetic resin in contact with the plaster and the net has filamentary carrier materials incorporated therein. The synthetic resin is a conductive, essentially ion-free thermosetting resin of macromolecular structure, preferably an at least partially cross-linked acrylate polymer having a high surface roughness and containing a small amount of a plasticizer, and forms either the matrix or a coating of the flexible net. The filamentary carrier materials may be carbon or metal filaments. In the use of the dehumidification installation, a voltage alternating between a positive and a negative potential is conducted between the cathode and the anode, the time interval of the positive potential exceeding that of the negative potential.