Abstract: A sensor and method for measuring the concentration of alcohol in an alcohol-hydrocarbon mixture for use with flexible fuel vehicles. The sensor and method are characterized by a pair of detectors or sensing elements which detect absorbance of two different wavelength bands of energy transmitted through the fuel. The first wavelength band is absorbed by the alcohol and substantially unabsorbed by the hydrocarbons and other non-alcohols in the fuel mixture. The second or reference wavelength band is selected where the absorbance of alcohols and hydrocarbons is essentially the same and preferably essentially zero. The output of the two detectors or sensing elements is ratioed to provide a signal representative of the alcohol content of the fuel mixture. In a preferred embodiment, the sensing elements are included in a differential thermopile.

Abstract: Lightweight, compact apparatus for detecting sudden changes in the concentration of at least one selected gas provides a warning when said gas concentration increases suddenly. In one embodiment, a chemically sensitive field effect transistor provides a sensing signal two amplifiers having different overall gains and widely different time constants. Detection of sudden gas concentration changes causes the relative magnitudes of the amplifier output signals to be inverted triggering a warning. The apparatus may occupy less than 1.25 cubic inches and weigh less than 4 ounces so that it may be worn by an individual throughout his work place.

Abstract: The use of multiple field effect transistors, wherein only one transistor is sensitive to the presence of a particular element, is disclosed whereby similar responses to temperature and/or humidity fluctuations may be subtracted yielding a response to a particular element that is relatively insensitive to temperature and/or humidity variations.

Abstract: Improved electrical double layer capacitors having carbon electrodes include in the electrolyte a voltage regulating agent selected from the group of bromides, chlorides, fluorides and iodides.

Abstract: In double layer capacitors having carbon electrodes, the electrodes contain at least 1%, by weight, of an inert particulate material to reduce the leakage current of the capacitor. The inert particulate material is selected from the group comprising SiO.sub.2, Al.sub.2 O.sub.3, SiC and aluminum silicates.

Abstract: A method for making electrodes for use in double layer capacitors comprising adding to a carbon powder-electrolyte mix an excess of liquid to render the mix pumpable, moderately overfilling an electrode cavity with the mix and removing the excess liquid in an equilibration step so that the remaining mix substantially fills the electrode cavity.

Abstract: The electron-conducting, ion-insulating connector of this invention comprises a sandwich structure of two layers of a thin, flexible graphite sheet having interposed therebetween an electrically-conductive polymer. These connectors are particularly suitable for use in paste electrode capacitors wherein the electrodes are composed of either carbon or metal particles in admixture with a liquid electrolyte.

Abstract: The connector of this invention comprises a thin, flexible sheet of graphite in which the pores and voids of the graphite are filled with a polymer to render the graphite impervious to the electrolyte of the capacitor.