Abstract: The instant invention is directed to optical glass compositions capable of being shaped under the combined action of temperature and pressure in a mold so as to obtain articles having surfaces exhibiting highly precise reproduction of the mold walls. The inventive glasses demonstrate softening points not exceeding 500.degree. C., refractive indices between about 1.65-1.82, Abbe number between about 27-39, and consist essentially, in weight percent, of______________________________________ SiO.sub.2 8-20 B.sub.2 O.sub.3 5-20 PbO 50-70 Al.sub.2 O.sub.

Abstract: A method of measuring the degree of partitioning of a labeled species between free and bound states which involves the use of an insoluble porous monolith having a means for binding a portion of the labeled species within the pores thereof, which monolith is capable of substantially attenuating the signal emitted by labeled species subsequently bound within the pores thereof.

Abstract: Cellular ceramic bodies are produced by frothing a crystal-containing, ion-exchanged gel and setting the gel. An aqueous gel is prepared from a water-swelling mica and is blended in conjunction with a large cation donor, e.g., a potassium salt or silicate glass, and a surfactant to effect frothing of the gel by a shearing action and exchange of large cations with lithium and/or sodium ions from the mica to produce an ion-exchanged gel that sets in controllable manner.

Abstract: A method is disclosed for producing low density, ceramic bodies in the nature of hollow or solid beads which may be used as such or bonded into a unitary mass. The bodies are composed of ion-exchanged, synthetic mica crystals wherein large cations, such as K.sup.+, have been exchanged for lithium and/or sodium ions from the mica. The method involves forming a gel by dissolution of a synthetic mica in a polar liquid, releasing droplets of the gel into a fluid to form shaped bodies, effecting the indicated ion exchange, and drying the beads thus formed.

Abstract: Apparatus and a method for analyzing the refractive index profile of a cylindrical, transparent optical waveguide preform, utilizing a scanning light beam to traverse a fixed preform and a refractor to direct light deflected by the preform onto a displacement sensor, is described.

Abstract: The present invention is concerned with the preparation of hydraulic cements, demonstrating high mechanical strength, long term resistance to attack by moisture, and virtual freedom from creep, from glass powders consisting essentially, expressed in terms of mole percent on the oxide basis, of about 60-76% SiO.sub.2, 15-30% K.sub.2 O, and 2-15% total of at least one metal oxide selected from the group of 0-10% Al.sub.2 O.sub.3, 0-5% V.sub.2 O.sub.5, 0-5% TiO.sub.2, 0-5% MoO.sub.3 and 0-5% WO.sub.3. The cements exhibit particular utility in forming strong cellular ceramic articles. The glass powders may contain a phosphate component in which case the composition ranges are limited to 68-76% SiO.sub.2, 18-24% K.sub.2 O, 2-4.5% P.sub.2 O.sub.5 with the molar ratio K.sub.2 O:P.sub.2 O.sub.5 ranging between 5 and 10, and 2-5% total of at least one metal oxide selected from the group of Al.sub.2 O.sub.3, MoO.sub.3, V.sub.2 O.sub.5 and WO.sub.3.

Abstract: A method for spray-decorating a low-expansion glass, glass-ceramic or ceramic article having an expansion coefficient in the range of about 0-35.times.10.sup.-7 /.degree.C. with a relatively high expansion fritted ceramic enameling composition having an expansion coefficient in the range of about 45-75.times.10.sup.-7 /.degree.C. wherein good surface coverage and color uniformity in combination with acceptable spall resistance in the applied enamel are provided by applying the enameling composition as a very thin film in the form of a non-aqueous oil-based spraying suspension.

Abstract: The present invention is directed to the production of spontaneous opal glasses exhibiting softening points in excess of 750.degree. C., a coefficient of thermal expansion between about 60-90.times.10.sup.-7 /.degree.C., a crystal liquidus temperature below 1350.degree. C., a liquidus viscosity of at least 200 poises, and excellent resistance to attack by alkalies. Spherically-shaped glassy droplets constitute the opal phase in the glasses which consist essentially, in weight percent, of______________________________________ SiO.sub.2 50-72 Na.sub.2 O 0-8 CaO 10-40 Al.sub.2 O.sub.

Abstract: This invention is directed to transparent, essentially colorless glass-ceramic articles containing .beta.-quartz solid solution as the predominant crystal phase consisting essentially, expressed in terms of weight percent on the oxide basis, ofSiO.sub.2 --65-75,Li.sub.2 O--1-4,Al.sub.2 O.sub.3 --15-25,ZnO--0.5-2,Na.sub.2 O and/or K.sub.2 O--0-2,TiO.sub.2 --2-6,ZrO.sub.2 --0-2,BaO--0--0-2.5,F--0-1.2,Fe.sub.2 O.sub.3 -->0.01-<0.1,Through ion exchange reactions the article can be made highly resistant to attack by the atmospheres in coal and wood burning stoves.

Abstract: This invention is concerned with the fabrication of thick film, RuO.sub.2 -based resistors. More specifically, this invention is directed to the formulation of glass frits for use in such resistors exhibiting temperature coefficient of resistance values of less than 100 ppm. Such glass frits consist essentially, expressed in terms of mole percent on the oxide basis, of about 32-39% PbO, 44-47% B.sub.2 O.sub.3, 14-17% SiO.sub.2, and an effective amount up to 5% of WO.sub.3 or MoO.sub.3.

Abstract: The present invention is directed to fluorophosphate glasses containing about 3-21.5% Nb.sub.2 O.sub.5 and exhibiting softening points below 500.degree. C. The inventive glasses contemplate two general composition areas in weight percent:______________________________________ P.sub.2 O.sub.5 35-46 P.sub.2 O.sub.5 20-35 Al.sub.2 O.sub.3 3.5-6.5 Li.sub.2 O 0.5-5 Li.sub.2 O 0.8-3.0 Na.sub.2 O 0-10 Na.sub.2 O 3-10 Li.sub.2 O + Na.sub.2 O 0.5-10 Li.sub.2 O + Na.sub.2 O 5-10.5 PbO 0-40 BaO 18-44 Sb.sub.2 O.sub.3 0-25 CaO 0-12 PbO + Sb.sub.2 O.sub.3 20-50 SrO 0-15 BaO 0-20 MgO 0-7 Al.sub.2 O.sub.3 0-5 BaO + CaO + SrO + MgO 28-47 Nb.sub.2 O.sub.5 13-21.5 CaO + SrO + MgO <15 F 1-12 Nb.sub.2 O.sub.5 3-8.5 F 4.

Abstract: Precision dental tools, models, appliances, prostheses, and attachments are produced by providing a glass body of selected conformation, and then heat treating the glass body to yield a glass-ceramic component of superior characteristics wherein tetrasilicic fluormica constitutes the predominant crystal phase.

Abstract: This invention is directed to the production of glasses within the Li.sub.2 O-K.sub.2 O-ZrO.sub.2 -F-P.sub.2 O.sub.5 system having batch compositions as generally depicted in terms of mole percent in FIG. 2.

Abstract: The instant invention is directed to the preparation of glass-ceramic bodies exhibiting high strengths and use temperatures up to 1200.degree. C. The bodies consist essentially, expressed in terms of weight percent on the oxide basis, of______________________________________ Li.sub.2 O 1.5-5 Al.sub.2 O.sub.3 15-25 SiO.sub.2 60-75 ZrO.sub.2 1-5 Nb.sub.2 O.sub.5 0-10 Ta.sub.2 O.sub.5 0-10 Nb.sub.2 O.sub.5 + Ta.sub.2 O.sub.5 1-10 MgO 0-10 ______________________________________where excellent resistance to oxidation up to temperatures of 1200.degree. C. is desired, 0.5-3% As.sub.2 O.sub.3 will be included in the composition.

Abstract: This invention is directed to the production of composite articles composed of a substrate consisting of a machinable glass-ceramic and an integral, electrically-conductive surface layer consisting of metallic copper and/or silver. The inventive articles are prepared by heat treating precursor glass bodies containing copper and/or silver ions to grow fluormica crystals therein, thereby producing glass-ceramics, and to cause migration of the copper and/or silver ions to the surface thereof which are reduced to metallic copper and/or silver via heat treating in a reducing atmosphere. Where desired, holes can be bored, drilled, or punched into the glass-ceramic prior to exposure to the reducing heat treatment such that, upon heat treatment in a reducing environment, the sides of the holes will become metal plated.

Abstract: This invention is directed to glasses especially suitable for use as envelopes in tungsten-halogen lamps, those glasses exhibiting liquidus temperatures no higher than 1125.degree. C., liquidus viscosities of at least 50,000 poises, coefficients of thermal expansion between about 42-46.times.10.sup.-7 /.degree.C., and consisting essentially, in weight percent on the oxide basis ofSiO.sub.2 --56-59Al.sub.2 O.sub.3 --16-17B.sub.2 O.sub.3 --4.5-5.25CaO--7.5-9.25MgO--5.5-6.

Abstract: The present invention is directed to the preparation of photochromic glasses exhibiting a darkened luminous transmittance at 40.degree. C. below 35% and a five-minute fading rate at 40.degree. C. of at least 40 units of transmittance and a darkened transmittance at 25.degree. C. below 25% and a five-minute fading rate at 25.degree. C. of at least 35 units of transmittance. The glasses consist essentially, by weight, of:______________________________________ SiO.sub.2 56-60 Al.sub.2 O.sub.3 6-9 B.sub.2 O.sub.3 18-21 Li.sub.2 O >2.5-3.5 Na.sub.2 O 0.5-2.5 K.sub.2 O 5-7 ZrO.sub.2 3.75-5 PbO 0.1-0.15 Ag >0.15-0.25 Cl 0.2-0.35 Br 0.075-0.15 CuO 0.004-0.02 CeO.sub.2 0-0.5 ______________________________________wherein the levels of Ag, Br, Cl, and CuO represent values as analyzed in the glass.

Abstract: Mercury thallium fluorophosphate glasses are disclosed that have very low transition temperatures, very high refractive indices and dielectric constants, and are resistant to moisture attack. The glasses are free of alkali metals and substitute thallium chloride in the glass batch as a modifier. The melted glass is largely oxide in nature, but the halogens appear to facilitate melting of these soft glasses.

Abstract: There is disclosed a composite photochromic glass article composed of a glass core and a thin surface layer substantially encasing that core, the core preferably containing a copper-cadmium halide photochromic crystal system and the substantially encasing glass layer preferably containing a copper-cadmium-silver halide photochromic crystal system. The article may be made by fusion laminating two separately formed glasses, or by introducing silver into a surface layer on a glass article by ion exchange.

Abstract: This invention relates to the production of glasses especially suitable for ophthalmic lenses, the glasses exhibiting refractive indices between about 1.695-1.705, dispersive indices between about 40.5-43.2, densities below about 3.2 g/cm.sup.3, weight losses as measured in the AO test of less than 0.15 mg/cm.sup.2, transmittances at 400 nm in 10 mm thickness of at least 75%, and consisting essentially, in weight percent of______________________________________ CaO 16-21.5 La.sub.2 O.sub.3 6-15 TiO.sub.2 3.5-<9 Al.sub.2 O.sub.3 5.5-12 Nb.sub.2 O.sub.5 3-11 ZrO.sub.2 2-10 B.sub.2 O.sub.3 20.5-25 SiO.sub.