Abstract: An oxygen measuring probe for use with molten metal baths for the manufacture of glass which probe comprises a probe body (4) comprising an elongate tubular member (6) closed at one end by a separate tip part (8) formed of stabilised zirconia which constitutes a solid electrolyte through which oxygen ions can pass, said tubular member (6) being formed of a heat-resistant material different from said zirconia, a first electrode (16) connected to the inner surface of the zirconia tip part (8), earthing means adapted for connection to earth out of contact with the molten metal and voltage measuring means (24) connected between the first electrode (16) and said earthing means (26).

Abstract: The present invention provides a process for producing a metal substrate for a thin film magnetic data storage disc, the process including the steps of: (a) providing a metal substrate; (b) printing a masking pattern onto at least a portion of the surface of the substrate; and (c) etching the unmasked surface of the substrate thereby to texture the substrate surface. The present invention also provides a metal substrate for a thin film magnetic data storage disc, the substrate having a roughened surface produced by preferential area etching, the roughened surface being composed of a regular pattern of peaks separated by valleys.

Abstract: A method of producing mirrors comprising depositing onto a ribbon of hot glass during the production process a coating comprising at least one pyrolytic reflecting layer and at least one color modifying layer whereby the mirrors exhibit color in reflectance and have a visible light reflection of at least 35% and less than 70%. There is also provided a mirror having such a coating.

Abstract: A naphthopyran compound of general formula (I) ##STR1## wherein R.sub.1 represents an alkyl group or an aryl group; each of R.sub.4 and R.sub.5, which may be the same or different, independently represents an alkyl, alkenyl, carbocyclic or heterocyclic group, or R.sub.4 and R.sub.5 taken together with the carbon atom to which they are attached form a carbocyclic ring or a heterocyclic ring; andR.sub.6 represents a hydrogen atom or a substituent selected from alkyl, alkoxy, aryl, aryloxy, heteroaryl, halogen, amino, substituted amino, azo, imino, amide, carboxylate, ester, cyano, trifluromethyl or nitro, and in addition R.sub.6 may represent a carbocyciic or heterocyclic ring fused to ring A.The naphthopyran compounds of the invention are useful as photochromic materials in lenses, e.g. sunglasses, and photochromic transparencies for cars and aircraft.

Abstract: An optical filter for absorption of electromagnetic radiation of wavelength 532.times.10.sup.-9 m with excellent photostability properties is provided by a polymeric host material such as polycarbonate incorporating the absorbing compound 5, 10, 15, 20 tetrakis (4-methoxyphenyl)-21H,23H porphine palladium (II).

Abstract: The present invention relates to a process for producing a substrate for a thin film magnetic data storage disc, the process including the steps of:- (a) providing a substrate; (b) printing a masking pattern of ink dots onto at least a portion of the surface of the substrate by an offset printing process in which the ink to form the masking pattern is transferred from a printing plate to the substrate by an offset printing member and wherein on transfer from the printing plate to the offset member the ink fragments into the ink dots; and (c) etching the unmasked surface of the substrate thereby to texture the substrate surface. The present invention also relates to a substrate for a thin film magnetic data storage disc, the substrate having a roughened surface composed of peaks separated by valleys produced by preferential area etching, the peaks being grouped into a plurality of substantially circular sub-arrays with the sub-arrays forming a regular pattern.

Abstract: An oxygen measuring probe for use with molten metal baths for the manufacture of glass which probe comprises a probe body (4) comprising an elongate tubular member (6) closed at one end by a separate tip part (8) formed of stabilised zirconia which constitutes a solid electrolyte through which oxygen ions can pass, said tubular member (6) being formed of a heat-resistant material different from said zirconia, a first electrode (16) connected to the inner surface of the zirconia tip part (8), earthing means adapted for connection to earth out of contact with the molten metal and voltage measuring means (24) connected between the first electrode (16) and said earthing means (26).

Abstract: A laminar microstrip patch antenna includes a ground plane dement having opposing first and second faces, a first dielectric planar member adjacent a first face of the ground plane element, a patch radiator on a face of the first dielectric member remote from said ground element, a second dielectric planar member adjacent a second face of the ground plane element, and a transmission line circuit for feeding the antenna. The transmission line circuit is located on a face of the second dielectric member remote from said ground plane element, and the ground plane has an aperture to couple the transmission line circuit to the patch radiator. The aperture is formed as a cross made up of two intersecting linear slots. The transmission line circuit is formed by two linear conductors intersecting each other at a single electrically insulated point, the intersection point being aligned with a center of the intersection of the aperture cross with the linear conductors lying between the slots of the aperture.

Abstract: Photochromic materials which have a structure which includes a spiro-pyrrolidinebenzoxazine structure comprising a pyrrolidine part and a benzoxazine part and the benzoxazine part includes at least one mesomeric electron donating group chosen from amino and alkoxy moieties, the one or more mesomeric electron donating groups being linked to the 6' position via attachment to a conjugated system in which the unsaturated bonds forming the linkage are chosen from --C.dbd.C--, --C.tbd.C--, --C.dbd.N-- and --N.dbd.N--.

Abstract: A photo reactive material, such as a photochromic material, which has the following structure: ##STR1## where the variables, A, R, R', R", R*, R.sup.+, m, and n are defined in claim 1.

Abstract: Photochromic compounds having the following structure II ##STR1## in which R.sup.1 is a group selected from hydrogen, alkyl, alkoxy, amino, aryl or heteroaryl;each R.sup.2 is a group selected from C1 to C10 branched or linear alkyls, carbocylic or heterocyclic, the R.sup.2 groups can be independent or together from part of a carboxylic or heterocyclic ring;R.sup.3 is a group selected from hydrogen, alkyl, alkoxy, alkenyl, alkynyl, imino, azo, amino, carboxy ester, amide, cyano, halogen, trifluoromethyl, nitro, aryl or heteroaryl, R.sup.3 is a fused carbocyclic or heterocyclic moiety;Y is a six membered carbocyclic or heterocyclic ring.X links N as shown to the ring Y to form a fused heterocyclic ring.

Abstract: A glass melting tank provides heat in a melting chamber 11 from pairs of electrodes 26, 27 and 28. A three-phase electrical power supply 34 provides power to the electrode pairs and the voltage supplied for the different phase is independently controlled by a power control 33.

Abstract: An antenna design for use with mobile telephones improves antenna performance by:(i) making the antenna less sensitive to the effects of the car body when mounted on a car window, e.g. backlight or sixthlight, and (ii) improving the impedance matching between the antenna and the coaxial feed line. Principally two arms extend from a ground plane strip around a separate monopole radiating "T"-piece. The ground plane and "T"-piece are insulated from each other and a coaxial connection is made to the antenna with the central core connected to the "T"-piece and the shield to the ground plane.

Abstract: A reaction mixture for preparation of a fire resistant composition comprising an epoxy resin, a curing agent for said resin and a boron compound which is not a curing agent for the epoxy resin, the reaction mixture being translucent such that the reaction mixture cures to a translucent reaction product. The invention further provides a method of producing a fire resistant laminate in which the cured reaction product of a boron compound containing epoxy resin is used as an interlayer between two translucent panes and to a translucent fire resistant laminate.

Abstract: A glass laminate assembly comprises two glass sheets 11,12 with an interlayer of cured resin 17 formed by a cast-in-place process. An aperture 15 for an attachment device 13 is formed in at least one of the glass sheets and a resilient adhesive sealing tape 16 is formed between the faces of the glass sheets 11 and 12 surrounding the hole 15.

Abstract: A glass melting tank has a melting chamber, a shallow uniflow conditioning chamber, a shallow refining chamber and a riser chamber between the melting chamber and refining chamber. Heat is input to glass in the riser chamber by electrodes located centrally in the riser chamber near the base of the riser chamber. Temperature sensors sense the temperature entering the riser chamber through a throat and near the base of a downstream wall of the riser chamber and the heat input is controlled to produce torroidal flow in the riser chamber.

Abstract: A projection unit for a car head-up display comprises a display source, a curved mirror which provides the optical power of the projection unit and, in use, receives light from the display source, and a Fresnel mirror extending generally between the display source and the curved mirror and disposed to receive reflected light from the curved mirror and to reflect that light in a desired direction. The curved mirror and the Fresnel mirror may be disposed on a solid block of transparent material having one curved end coated to provide the curved mirror, the display source being located at an opposite end of the block, and the Fresnel mirror being formed in a block face extending from the opposite end of the block to the curved end of the block.

Abstract: A neutral, generally green-gray low transmittance (no more than 25 luminous transmittance) soda-lime-silica glass has reduced solar energy transmittance when provided with the following colorant constituents in percent by weight:______________________________________ Fe.sub.2 O.sub.3 (total iron) 1.3-2 NiO 0.01-0.05 CoO 0.02-0.04 Se 0.0002-0.003 ______________________________________The glass has a ferrous value in the range of 18 to 30.

Abstract: An apparatus for determining the surface characteristics of a flat transparent article which includes a light beam source, a scanner to deflect the light beam to produce a line scan, a lens to collimate the light beam of the line scan, a locator for the flat transparent article to enable the article to be exposed to the collimated light, a grating through which the portion of collimated light reflected by the surface of the located article passes, another lens to focus the collimated light passing through the grating onto a sample detector which generates an intensity indicative signal, and a base reference signal generator. The signals are processed by a microprocessor to indicate the surface characteristics.

Abstract: A car head-up display projection unit has a substantially spherical concave mirror providing the optical power and which receives light at near axial incidence from a display source and reflects that light to an adjustable substantially plane mirror. Light from the projection unit is reflected from the car windshield to the driver's eyes.