Abstract: Light-absorbing glass-ceramic articles comprising beta-spodumene and/or beta-quartz as the principal crystal phase and exhibiting blue-to-black coloration are provided by adding a glass reducing agent to a titanium-containing lithium aluminosilicate glass batch for the parent glass.

Abstract: The present invention is concerned with the production of glass-ceramic articles, wherein the predominant crystal phase consists of beta-spodumene solid solution or nepheline, but which have integral surface films containing alpha-iron. The method for producing such articles comprises two general steps. First, a glass article having a composition within a particularly-defined area within the Li.sub.2 O-FeO-Al.sub.2 O.sub.3 -SiO.sub.2 -TiO.sub.2 field or within the Na.sub.2 O-FeO-Al.sub.2 O.sub.3 -SiO.sub.2 -TiO.sub.2 field is heat treated under oxidizing conditions at temperatures of at least about 1000.degree. C. to cause crystallization in situ of the glass to a glass-ceramic article wherein beta-spodumene solid solution or nepheline crystals constitute the predominant crystal phase in the interior of the article and, at the same time, an integral surface layer containing hematite crystals is developed.

Abstract: An optical fiber junction device for permanently coupling a pair of optical fibers with a third optical fiber. The end portions of the pair of fibers are fused together in side-by-side relationship so that their endfaces are coplanar, the cross-sectional area of this structure decreasing toward the endfaces of the pair of fibers. The endface of the third fiber is fused to the endfaces of the pair of fibers.

Abstract: The instant invention relates to the production of glass-ceramic articles, wherein the predominant crystal phase is beta-quartz solid solution and/or beta-spodumene solid solution, but which have a thin, integral, tightly-bonded surface film containing crystals exhibiting the structure of magnetite. The preferred method of production for such articles requires three general steps. First, a glass article having a particular composition within the Li.sub.2 O--FeO--Al.sub.2 O.sub.3 --SiO.sub.2 field nucleated with TiO.sub.2 is heat treated in air or other oxidizing atmosphere to yield a glass-ceramic article through the crystallization in situ of beta-quartz solid solution and/or beta-spodumene solid solution crystals. Simultaneously during this heat treatment, a surface layer containing hematite is developed. Second, the glass-ceramic article is subjected to a hot acid bath. Third, the acid-washed article is heat treated in a H.sub.

Abstract: This invention relates to a low temperature method for making and forming silicate glass bodies from reaction mixtures of soluble silicates and/or colloidal silicates and organic compounds wherein the formed reacted body is fired at elevated temperatures below the deformation point of the particular glass composition for a sufficient length of time to convert it to a glass body having a structural configuration similar to that of the formed body.

Abstract: Gel-like composition useful for separating and partitioning whole blood into serum and clot portions. The composition has a specific gravity between that of the serum and clot portions such that, when centrifuged in the presence of whole blood, the composition forms a chemical and physical barrier between the serum and clot portions. The composition comprises, in combination, a silicone fluid, an inert siliceous filler dispersed therein, and a network former consisting of a polysiloxane-polyoxyalkyl copolymer which stabilizes the composition by minimizing and/or avoiding "wet out" of the siliceous filler with time. The composition has a viscosity within the range of about 200,000 to about 600,000 centistokes, preferably within the range of about 350,000 to about 450,000 centistokes.

Abstract: This invention relates to the manufacture of glass-ceramic articles having integral surface layers exhibiting ferrimagnetic behavior. More specifically, this invention is directed to glass bodies having compositions within the Li.sub.2 O-Al.sub.2 O.sub.3 -Fe.sub.2 O.sub.3 -SiO.sub.2 -TiO.sub.2 base system, and that additionally contain NiO and/or CoO, which, when heat treated under oxidizing conditions to effect crystallization in situ to glass-ceramic articles, spontaneously develop crystallites of NiFe.sub.2 O.sub.4 and/or CoFe.sub.2 O.sub.4 in the surfaces thereof. The ferrite surfaces can be magnetized in a strong magnetic field and demonstrate magnetic properties eminently suitable for the recording, storage, and erasing of information.

Abstract: A float unit having two float portions operates a switching unit to stop the supply of liquid at a selected high level and to reestablish the supply at a selected low level. The switching unit may be a precision snap-acting switch, and the float unit may be integrally formed from glass. In the preferred embodiment, the switch and an upper switch-engaging portion of the float are mounted in a housing which serves as a closure for a container.

Abstract: A porous layer is formed on a surface of a body of phase separable glass by heat treating the glass to cause it to become separated into at least two distinct phases of different solubility. A surface of the body is subjected to a leaching solution which preferentially leaches at least the most soluble phase, leaving a surface layer consisting of a skeletal structure that comprises the least soluble phase disposed on a substrate of phase separated glass. The glass body is then subjected to a second heat treatment at a sufficiently high temperature that the phase separated glass substrate is caused to become homogeneous, the porous surface layer remaining substantially unchanged. The resultant homogeneous glass substrate is more chemically durable than it was in the phase separated state.

Abstract: The instant invention is directed to the production of foamed alkali metal silicate articles of low density, good chemical durability, and low thermal conductivity which can readily be made in essentially unlimited sizes and configurations. The process of the invention contemplates four general steps. First, an anhydrous glass consisting essentially of narrowly-defined compositions within the Na.sub.2 O and/or K.sub.2 O-Al.sub.2 O.sub.3 and/or B.sub.2 O.sub.3 and/or ZnO and/or Fe.sub.2 O.sub.3 -SiO.sub.2 field is hydrated. Second, particles of said hydrated glass not exceeding about 5 mm. in diameter are dehydrated in such a manner as to cause the formation of individual foamed bodies. Third, the individual foamed particles are collected together and rehydrated to a sufficient extent to bond said particles into an integral mass, but not so much to cause the foamed particles to collapse. Fourth, the integral mass is dehydrated to cause foaming thereof.

Abstract: This invention is concerned with spontaneous opal glasses wherein sodium fluoride (NaF) and strontium fluoride (SrF.sub.2) constitute the predominant opacifying phases. More specifically, the opal glasses of the instant invention have compositions within the Na.sub.2 O--SrO--Al.sub.2 O.sub.3 --SiO.sub.2 --F field and exhibit a dense white appearance, a softening point above 755.degree. C., a strain point in excess of 500.degree. C., a coefficient of thermal expansion (0.degree.-300.degree. C.) in excess of 65.degree. .times. 10.sup.-7 /.degree. C., and satisfactory resistance to weathering and dishwasher environments.

Abstract: Disclosed is a resistor comprising a nonconductive substrate on which is disposed a rectangularly-shaped coating of resistive material having a negative TCR. Oppositely disposed along the longer sides of the coating is a pair of elongated, parallel strips of resistive material having a positive TCR. Electrical connection is made to the opposed ends of the coating and to an end of each strip. The strips and electrical connections are so disposed that at low temperatures, current flow is predominantly across a relatively wide, short path in the coating between the strips, and at higher temperatures, current flow is predominantly along a longer, narrower path in the coating which is parallel to the strips.

Abstract: Copper, cadmium, silver and halogen-containing glass compositions suitable for the production of photochromic glass articles comprising these constituents in a separated, particulate photochromic phase are described. The glasses exhibit a characteristic copper-cadmium halide absorption inflection in the near ultraviolet, and are surface-darkenable on exposure to ultraviolet and short-wavelength visible light. However, they also exhibit optical bleaching characteristics and a variety of dark-state colors not previously obtained in surface darkening glasses.

Abstract: This invention is concerned with the production of glasses especially suitable for the encapsulation of semiconductor devices and, in particular, for the encapsulation of germanium and silicon diodes. The glasses have a low softening point, i.e., less than about 550.degree. C., are readily sealable to Dumet, and exhibit a viscosity at the liquidus of at least 20,000 poises. The glasses have compositions within the K.sub.2 O-PbO-B.sub.2 O.sub.3 -SiO.sub.2 system, are essentially free from Li.sub.2 O, Na.sub.2 O, Al.sub.2 O.sub.3, and TiO.sub.2, and demonstrate a mismatch in thermal expansion with Dumet at about 400.degree. C. of no more than about 200 PPM.

Abstract: Devices and processes are disclosed for the treatment of waste gases, particularly automotive exhaust gases, to remove the oxides of nitrogen therefrom. Mixed noble metal catalysts consisting essentially of platinum or palladium and at least one other noble metal selected from the group consisting of ruthenium, rhodium, and iridium are employed in combination with layered oxide support coatings to eliminate ammonia formation during the removal process.

Abstract: This invention relates to the strengthening of glass-ceramic articles wherein the crystal content thereof comprises the predominant portion and containing beta-spodumene solid solution as the principal crystal phase. The strengthening is effected by means of an ion exchange process taking place within the crystals in a surface layer of the article such that sodium ions from an external source are exchanged for lithium ions in the crystal phase thereby causing compressive stresses to be set up in the surface layer.

Abstract: This invention relates to the strengthening of glass-ceramic articles wherein the crystal content thereof comprises the predominant portion and containing beta-spodumene solid solution as the principal crystal phase. The strengthening effect is accomplished through an ion exchange process taking place within a surface layer of the article such that potassium ions from an external source are exchanged for lithium ions in the crystal phase thereby causing compressive stresses to be set up in the surface layer.

Abstract: A mask or face plate, having an orifice or opening formed therethrough of desired size and configuration, is positioned against the discharge face of an extrusion die. The mask restricts the flow of extrudable material through the die so that such material will conform to the size and configuration of the opening or orifice formed through the mask. A recess formed in the face of the mask adjacent the discharge face of the extrusion die, surrounds the orifice formed therethrough, and communicates with said orifice by means of a gap formed in the inlet face of the mask between said recess and said orifice.

Abstract: A colored glass article composed of a phase-separated borosilicate glass comprising a separated, glassy boron-rich phase having, in association therewith, a coloring metallic silver phase imparting a broad range of absorption colors thereto is provided by heat-treating a specified phase-separated borosilicate glass containing silver and a weak thermal reducing agent such as antimony at a temperature above the annealing point.

Abstract: A glass article having an optical quality surface smoothness can be formed by molding a "silanol" glass material against a die having a molding surface which is a mirror of that required for the glass article, thereby obviating glass grinding and polishing steps. The article is prepared by first forming an anhydrous base glass comprising, in mole percent on the oxide basis, about 72 to 82% SiO.sub.2, 10 to 17% Na.sub.2 O and/or K.sub.2 O, and 5 to 15% of an oxide or oxides selected from ZnO and PbO. The base glass may include up to 5% Al.sub.2 O.sub.3 and up to 3% of B.sub.2 O.sub.3, BaO and/or MgO. The anhydrous base glass is then hydrated to include a water content ranging from 0.5 to 10% by weight to form a "silanol" glass. That glass is then molded against the die surface at a temperature ranging from about 250.degree. C. to 500.degree. C.