Abstract: This invention relates to glasses especially suitable for optical and ophthalmic applications which exhibit densities less than about 2.65 g/cm.sup.3, refractive indices between about 1.595-1.607, and Abbe numbers between about 40-47, and which consist essentially, in weight percent on the oxide basis, of______________________________________ SiO.sub.2 45-55 MgO and/or BaO and/or B.sub.2 O.sub.3 5-13 SrO and/or La.sub.2 O.sub.3 0-6 Al.sub.2 O.sub.3 0-5 CaO 0-12 Li.sub.2 O 1-7.5 ZnO 0-8 Na.sub.2 O 1-9 ZrO.sub.2 0-7 K.sub.2 O >10-24 TiO.sub.2 9.5-17.5 As.sub.2 O.sub.3 and/or Sb.sub.2 O.sub.3 0-1 and 13.5 < TiO.sub.2 + ZrO.sub.2 + La.sub.2 O.sub.3 + MgO <23.

Abstract: A process for determining the location and/or the alignment of the axis or point of symmetry of an optical surface of a precision optical element, such as an aspheric lens. A fiducial surface is provided on the element, comprising a surface which has a predetermined location and alignment relative to the axis or point of symmetry of the optical surface of the element. Predetermined light waves are impinged against the fiducial surface. The nature of the fiducial surface is such that the light waves are transmitted or reflected in a manner that is a function of the location and/or the alignment of the fiducial surface. The characteristic transmission or reflection of light waves can be resolved by various conventional optical techniques such as by interferometry, thereby precisely indicating the location and/or alignment of the optical surface.

Abstract: This invention is directed to a method for modifying the coloration produced in a silver halide-containing photochromic glass when heat treating the glass at a temperature not exceeding 450.degree. C. under reducing conditions. The method comprises subjecting such a glass having a base composition which contains at least 1% by weight Li.sub.2 O, at least 2% by weight Na.sub.2 O, and at least 6% by weight Li.sub.2 O+Na.sub.2 O+K.sub.2 O to an ion exchange reaction, wherein lithium ions, and potassium ions, when the latter are present in the composition, in the glass surface are exchanged with sodium ions from an external source, prior to the reduction heat treatment.

Abstract: This invention is drawn to spontaneous opal glasses containing an apatite-type crystal opacifying phase and exhibiting a temperature interval between the emulsion and high temperature crystallization liquidi of at least 50.degree. C. which consist essentially, in weight percent on the oxide basis, of______________________________________ Na.sub.2 O 7.5-11 B.sub.2 O.sub.3 2-4.5 K.sub.2 O 0-5 SiO.sub.2 57-65 Na.sub.2 O + K.sub.2 O .ltoreq.13 P.sub.2 O.sub.5 2-5.5 BaO 0-9.5 F 1.5-4 CaO 0-3 SrO 0-5 ZnO 0.4-5 MgO 0-2.5 Al.sub.2 O.sub.3 8-13 SrO + MgO 0-5 ______________________________________CaO and/or SrO and/or BaO at least 2.5 mole %.

Abstract: This invention is directed to spontaneous opal glasses containing an apatite opacifying phase and exhibiting a softening point of at least 740.degree. C., excellent chemical durability, and a temperature interval between the high temperature crystallization liquidus and the emulsion liquidus greater than 50.degree. C. The glasses consist essentially, in weight percent on the oxide basis, of______________________________________ SiO.sub.2 50-63 Na.sub.2 O 5.5-10 Al.sub.2 O.sub.3 10-14 K.sub.2 O 0-10 P.sub.2 O.sub.5 3.5-7 BaO 0-10 PbO 2-12 CaO 0-2.5 B.sub.2 O.sub.3 1-4 SrO 0-8 F 1.

Abstract: This invention is related to the production of machinable glass-ceramic articles which are essentially free from crystals having a mica structure and consist essentially, in weight percent, ofSiO.sub.2 : 24-28Al.sub.2 O.sub.3 : 9-20MgO: 12-28SrO: 0-11BaO: 0-14CuO: 0-5Ag.sub.2 O: 0-3.5NiO: 0-1.5Cr.sub.2 O.sub.3 : 0.5-6.

Abstract: This invention is concerned with the preparation of thermally crystallizable enamels suitable for application to glass-ceramics, particularly glass-ceramics having coefficients of thermal expansion less than 15.times.10.sup.-7 /.degree.C. The enamels are capable of being fired to maturity simultaneously with the precursor glass body being crystallized to a glass-ceramic. The enamels consist essentially, expressed in weight percent on the oxide basis, of:SiO.sub.2 : 36-58Al.sub.2 O.sub.3 : 8.5-16CaO: 0.5-10PbO: 27-40K.sub.2 O: 0.

Abstract: This invention relates to the production of sodium fluoride opal glasses tinted in a shade lying in the range from "cream-like" to "beige" by an iron-sulfur system, the analyzed quantities of sulfur (S), sulfide ions (S.sup.-2), iron (Fe), and ferric ions (Fe.sup.+3) conforming to the following expressions:S.sup.-2 /S.gtoreq.0.1570.ltoreq.Fe.ltoreq.300 ppm0.05.ltoreq.Fe.sup.+3 /Fe.sup.+2 .ltoreq.1and 3.ltoreq.S.sup.-2 .ltoreq.160 ppm when the ZnO content is below 0.1%. The glasses are especially applicable for use in culinary ware.

Abstract: This invention is concerned with the production of catalyst-coated, ceramic honeycomb structures wherein the ceramic contains microcracks and wherein a washcoat is applied to the honeycomb structures prior to the application of the catalyst. The invention contemplates depositing an organic material in the microcracks and, preferably, carbonizing said organic material prior to application of the washcoat, and which is burned out after application of the washcoat.

Abstract: There is disclosed an improved, transparent, mullite glass-ceramic doped with Cr.sub.2 O.sub.3 to fluoresce in the 650-900 nm. region of the spectrum and having an absorption peak centered at about 600 nm. The improvement is inclusion in the composition of 2-15% by weight of ZnO and sufficient MgO, if necessary, to provide at least 5% ZnO+MgO. The ZnO or ZnO--MgO components selectively shift the absorption peak centered at 600 nm. toward the lower (blue) end of the spectrum.

Abstract: There is disclosed a metal-glass composite comprising a photosensitive glass body with opacifying crystallites developed in at least a portion of the body, and a metal deposit on and/or in that portion of the glass surface coincident with the crystallized portion of the glass body, the metal deposit exhibiting useful electrical conductivity. There is further disclosed a method of producing such composite by forming crystallites in at least a portion of a glass body, subjecting at least the surface coincident therewith to a cationic ion exchange to introduce metal ions and thereafter firing the ion-exchanged glass in a hydrogen atmosphere to cause the metal ions to be reduced and subsequently migrate surfaceward and form a metal deposit.

Abstract: The present invention is primarily concerned with the production of transparent glass-ceramic articles especially suitable for use as cooking utensils nucleated with up to 6% TiO.sub.2 and containing up to 0.25% Fe.sub.2 O.sub.3 and, perhaps, up to 0.1% MnO.sub.2, which exhibits a light brown tint that the human eye perceives essentially constant when the dominant wavelength is held between 577-581 nm, purity between 8-15%, and the transmission factor between about 65-80. The desired tint is obtained by including 0.0025-0.02% CoO+Cr.sub.2 O.sub.3, consisting of 0.001-0.01% CoO and 0.001-0.01% Cr.sub.2 O.sub.3, in the base composition of the glass-ceramic.

Abstract: This invention is concerned with the production of substantially transparent glass-ceramic articles containing mullite as the predominant crystal phase which can be prepared by crystallizing in situ precursor glasses capable of being melted at temperatures no higher than 1650.degree. C. The inventive articles consist essentially, in weight percent, of 10-70% SiO.sub.2, 7-40% B.sub.2 O.sub.3, 14-50% Al.sub.2 O.sub.3, 0-35% RO, wherein RO consists of at least one member of the group in the indicated proportions of 0-15% MgO, 0-20% CaO, 0-30% SrO, 0-30% BaO, and 0-30% PbO, and 0-30% R.sub.2 O, wherein R.sub.2 O consists of at least one member of the group in the indicated proportions of 0-10% Li.sub.2 O, 0-15% Na.sub.2 O, 0-25% K.sub.2 O, 0-25% Rb.sub.2 O, and 0-25% Cs.sub.2 O, the mole ratio Al.sub.2 O.sub.3 :RO+R.sub.2 O>1.3. Where 0.01-1% Cr.sub.2 O.sub.

Abstract: There is disclosed an improved optical device of the type disclosed in application Ser. No. 520,456 and embodying an array of lenses integral with and raised above a crystalline matrix. The improvement comprises an ion-exchanged surface on the lenses wherein the lithium ion from the lens glass is exchanged with a larger monovalent ion, preferably sodium or potassium from a bath, and the contents of such alkali metal ions in the lens are defined by both radial and axial concentration gradients. The device may be heated above the glass strain point to relieve stress and enhance lens power, either simultaneously with or subsequent to the ion exchange.

Abstract: An integral optical device is disclosed that is composed of a photosensitive glass having an optical pattern developed therein by a refractive index change due to formation of colloidal metal particles and/or crystalline microphases nucleated by such particles. In a specific embodiment the pattern is composed of at least one transparent lens system having a radial gradient refractive index distribution of prescribed nature.

Abstract: There is disclosed a fiber-reinforced composite having improved mechanical strength and being composed of metal-coated, carbon fibers embodied within a glass or glass-ceramic matrix.

Abstract: This invention is directed to the production of glass-ceramic materials designed for application as glazes to low expansion ceramic bodies. The inventive glass-ceramics exhibit average coefficients of thermal expansion (25.degree.-100.degree. C.) of less than -15.times.10.sup.-7 /.degree.C., demonstrate excellent resistance to attack by acids and bases, contain beta-quartz solid solution as the predominant crystal phase, and consist essentially, in weight percent, of______________________________________ SiO.sub.2 50-67 Al.sub.2 O.sub.3 22-32 Li.sub.2 O 4.5-7 TiO.sub.2 and/or ZrO.sub.2 4.

Abstract: An integral optical imaging device is disclosed in which two or more porous glass bodies, embodying arrays of cylindrical gradient index lens systems, are rigidly maintained in a stacked relationship such that the lens systems are in register. This enhances the accumulative lens power and effective thickness of the device.

Abstract: There is disclosed an improved integral optical device of the type produced by creating optical patterns in porous glass bodies, especially patterns involving gradient refractive index distributions. The optical strength of an element, such as a lens, in such an optical pattern is increased by treatment with a polymerizable, organo functional silicone fluid while the matrix glass is sealed.

Abstract: This invention is directed to the production of sintered ceramic articles wherein aluminum titanate and mullite constitute the predominant crystal phases and wherein the microstructure thereof evidences grain boundary and intracrystalline microcracking. The articles have base compositions encompassed within the area I, J, K, L, M, I of the drawing to which 0.5-5% Fe.sub.2 O.sub.3 and/or 0.5-5% rare earth metal oxide may be added.