Abstract: The invention relates to a conductive nonwoven fabric that is carbonized and/or graphitized and possesses a bending rigidity <8 taber, a density of 0.1 g/m3 to 0.5 g/m3, a thickness of 80 ?m to 500 ?m, and an electrical conductivity of 10 to 300 S/cm in the nonwoven fabric strip and 30 to 220 S/cm2 perpendicular to the nonwoven fabric strip.

Abstract: A gas diffusion layer, including at least two functional areas (2a, 2b) which are operationally linked to one another, the first area (2a) having a porous structure and the second area (2b) being designed as a stabilization zone, achieves the object of providing a system which implements problem-free operation of a fuel cell while optimizing its efficiency. A system which includes two gas diffusion layers and a method for manufacturing the gas diffusion layer achieve the further cited objects.

Abstract: The invention relates to a conductive nonwoven fabric that is carbonized and/or graphitized and possesses a bending rigidity <8 taber, a density of 0.1 g/m3 to 0.5 g/m3, a thickness of 80 ?m to 500 ?m, and an electrical conductivity of 10 to 300 S/cm in the nonwoven fabric strip and 30 to 220 S/cm2 perpendicular to the nonwoven fabric strip.

Abstract: The invention relates to a conductive nonwoven fabric that is carbonized and/or graphitized and possesses a bending rigidity <8 taber, a density of 0.1 g/m3 to 0.5 g/m3, a thickness of 80 &mgr;m to 500 &mgr;m, and an electrical conductivity of 10 to 300 S/cm in the nonwoven fabric strip and 30 to 220 S/cm2 perpendicular to the nonwoven fabric strip.

Abstract: In order to improve a method for determining the substance conversion during areal electrochemical reactions in at least one local surface area between a counterelectrode arrangement of an areal design and an electrode arrangement of an areal design, which has a contact element segment designed in accordance with the surface area and a contact element contacting the remaining surface areas and being electrically insulated in relation to the contact element segment, in such a manner that the substance conversion can be determined in as simple a manner as possible it is suggested that not only the contact element but also the contact element segment be connected to one current source or current drain provided for carrying out the electrochemical reaction, that a current flowing between the contact element segment and the current source or current drain via a conductor generate a magnetic field around the conductor and that the magnetic field be determined as a measure for the substance conversion in the local s