Abstract: A sensor to detect gases and vapors, particularly carbon monoxide and water vapor, at relatively low concentrations includes a substrate having a layer on a face of the substrate. The layer comprises a semi conductor metallic oxide (such as stannic oxide), a catalyst (such as platinum black), and a rheological agent (such as kieselguhr or sepiolite). The rheological agent induces porosity into the surface of the layer. The rheological agent affects the mixing and processing of the layer, and aids binding, resulting in a sensor with greater sensitivity and faster response.

Abstract: An identification and information storage device, for attachment to an article to be identified, includes: a magneto-optical strip, formed on a substrate and attached to the article, which is adapted to store first information readable by the reflecting and modifying of the polarization state of a light beam directed thereon; and an optically detectable pattern portion including an optical bar code for storing second information relating to the identification of the article, wherein the magneto-optical strip is positioned in a known location relative to the optical bar code such that on visual identification of the bar code the location of the magneto-optical strip can be found.

Abstract: When a display incorporating electroluminescent (EL) device is switched on, the electrical resistance across electrodes and which indicates the moisture content of the EL layer is measured by electrical resistance measuring device. If the resistance is below a preset value corresponding to an unacceptable moisture content a current pulse source is activated to heat the EL layer and evaporate the moisture. The resistance is also measured periodically during continued use of the display.

Abstract: Electrophoresis of a colloidal suspension of a semiconducting sulphide, sulphoselenide, selenide or telluride in an aqueous medium produces a thin pin-hole-free film on a surface of a substrate. The film may be employed in solar cells.

Abstract: Application of heat preferentially to one surface of a film of a semiconducting sulphide, sulphoselenide, selenide or telluride to establish a temperature differential between the surfaces of the film improves the electrical and photochemical properties of the film. The film may be employed in solar cells. Preferably the film is prepared by electrophoresis of a colloidal suspension of the semiconductor in an aqueous medium.