Abstract: A window composed of a frame having at least two, parallel disposed, spaced glass panes. At least one of the panes is composed of fire-resistant glass. The fire resistant pane can be a borosilicate or alumino silicate glass having a compressive prestress in the peripheral edge portion thereof, and for which the product of thermal expansion .alpha. and the elastic modulus E is 1-5 kp .times. cm.sup.-2 .times. .degree. C.sup.-1.

Abstract: A phototropic glass containing P.sub.2 O.sub.5 as the principal component and, as agents imparting phototropy, silver and halogen in non-crystalline form.

Abstract: A glass suitable for filters with steep absorption edges in the wavelength range of 455 to 850 nm, consisting essentially of:40 - 63 weight % SiO.sub.28 - 30 weight % alkali metal oxides14 - 30 weight % ZnO0.9 - 9 weight % TiO.sub.20 - 9 weight % B.sub.2 O.sub.30 - 2.5 weight % P.sub.2 O.sub.50 - 1.5 weight % Al.sub.2 O.sub.30 - 2 weight % F0 - 2 weight % CdO0 - 2.5 weight % CdTe0 - 1.65 weight % ZnS0 - 2.0 weight % CdS0 - 0.9 weight % S0 - 0.9 weight % Se0 - 0.8 weight % As.sub.2 S.sub.3 or As.sub.2 S.sub.4 or a mixture thereof0 - 0.5 weight % Sb.sub.2 S.sub.3 or Sb.sub.2 S.sub.5 or a mixture thereof0 - 6 weight % MgO0 - 15 weight % CaO0 - 8 weight % BaO0 - 12 weight % SrOwith the provision that the total of MgO, CaO, BaO, SrO, ZnO and CdO is not higher than 36% by weight, and that the minimum content of the colloidal coloring components consisting of one or more of CdO, CdTe, ZnS, CdS, S and Se or of any combination thereof is 0.5% by weight.

Abstract: A glass when in the form of an optical fiber having an optical loss of not more than 150 dB/km, high transparency, a high numerical aperture, and a high flexural strength, said glass being especially suitable for optical fibers and consisting essentially of:SiO.sub.2 : 65 - 75 mol-%; (38 - 46% by weight);R.sub.2 o: 4 - 17 mol-%; (4 - 13% by weight);PbO: 16 - 25 mol-%; (42 - 55% by weight); wherein R.sub.2 O is Na.sub.2 O, K.sub.2 O or Cs.sub.2 O or mixtures thereof, preferably not more than 3.0 mol % Na.sub.2 O, and with the provision that the molar ratio of SiO.sub.2 : PbO is 2.5 - 4.0.

Abstract: An optical glass with a path length independent of temperature comprises between 40 and 55% by weight P.sub.2 O.sub.5, between 40 and 54% by weight BaO and between 6 and 12% by weight Nb.sub.2 O.sub.5. Part of the BaO may be replaced by SrO or CaO. Minor amounts of SiO.sub.2 or B.sub.2 O.sub.3 may be included as may other metal oxides such as ZnO, Sb.sub.2 O.sub.3 and La.sub.2 O.sub.3.

Abstract: Optical, fluorine containing barium borosilicate glasses having an improved varying partial dispersion in the optical positional range of lanthanum crown and lanthanum flint glasses wherein the ratio of SiO.sub.2 with respect to SiO.sub.2 and B.sub.2 O.sub.3 is at least 0.62 and the content of fluorine in said glass is between 2 and 7 grams per 100 cc of said glass.

Abstract: Molding of hollow glass articles wherein a gob flows from a feeder into a mold and forms a hollow tube as it enters the mold, and a pressure differential is applied across the tube so that the tube is shaped in the mold to form the hollow article. During application of the pressure differential, deformation of the glass between the feeder and mold, is prevented by proximately positioning of the feeder and mold. This pressure differential is obtained by applying vacuum between the mold and molten tube.

Abstract: The invention provides a process for producing a transparent optical-glass body having a linear index of refraction gradient. Particles of optical glass which contain leachble ingredients are pressed to form a self-supporting porous optical glass body. Some of the leachable ingredient is leached from a part of the porous glass, and a different amount is leached from a second part of the porous glass, the index of refraction varying in proportion to the different amounts leached from the glass body. The porous optical glass body is heated to eliminate the pores. Various means for effecting the different amounts of leaching over the length of the glass body are shown.

Abstract: A glass-ceramic plate cooking surface comprises a glass-ceramic base layer which allows penetration of thermal radiation having a wave length of from 0.7 to 5 microns and a top covering layer smaller in thickness than the base layer which is tightly joined to the base layer and absorbs the radiation with wave lengths of 0.7 to 5 microns. The glass-ceramic plate cooking surface can have the heating areas indicated by design and can be provided with an additional layer to avoid asymmetric stress and strengthen the cooking surface.

Abstract: The invention consists of a device for lighting the light entering ends of a light guide consisting of at least two light guiding fibers, said lighting done by means of two light sources, by which, either singly or using both sources together, the receiving-ends of the light guides are illuminated.

Abstract: The invention relates to a process for producing a tubular glass membrane with wall thicknesses between 5 and 30 microns and reproducible pore sizes between 11 A and 50 A. Alkali borosilicate glass is drawn into discrete hollow tubes and immediately cooled. The tubes are thermally treated to effect a phase separation into a coherent silicon dioxide phase and a boron oxide phase rich in alkali borate. The boron oxide phase is leached out with mineral acid. The tubes can be subsequently treated to give enlarged or reduced pores, asymmetric pores and coated surfaces.

Abstract: For producing gradient refractive index optical components having substantially no internal stress, there is provided for the ion exchange step glass of the following composition______________________________________ SiO.sub.2 47 - 61 CaO 0 -5 Al.sub.2 O.sub.3 13 - 20 Li.sub.2 O 3 - 10 La.sub.2 O.sub.3 1 - 8 Na.sub.2 O 6 - 16 Ta.sub.2 O.sub.5 0 - 7.5 K.sub.2 O 0 - 6 ZrO.sub.2 0 - 4 PbO 0.5 - 15 WO.sub.3 0 - 3 TiO.sub.2 0 - 4 BaO 0 - 5 P.sub.2 O.sub.5 0 - 3 ZnO 0 - 5 B.sub.2 O.sub.3 0 - 5 MgO 0 - 5 Fining Agent.

Abstract: A neodymium-doped phosphate laser glass composition having a low threshold for stimulated emission, a negative temperature coefficient of refractive index, high acid resistence and homogeneity even in large structures comprises P.sub.2 O.sub.5, Na.sub.2 O or K.sub.2 O, Al.sub.2 O.sub.3, Nd.sub.2 O.sub.3, and optionally, F or RO, wherein R is Mg, Ba, Ca, Sr or Zn.

Abstract: A process for the treatment of glass to modify various properties thereof. The process comprises the steps of applying a coating of at least one metal, preferably by vapor deposition, onto the surface of a SiO.sub.2 containing glass. The coated glass is thereafter heated to a temperature sufficient to cause the metal to migrate from the surface of the glass into the glass without any residue or coating remaining on the surface of the glass.

Abstract: Transparent, colorless glass ceramic having a low coefficient of expansion, a high absorptivity for X-rays and which is useful in dental filling compositions, has the following ingredients, expressed as percent by weight of oxides: SiO.sub.2 40-55%, Al.sub.2 O.sub.3 15-25%, Li.sub.2 O 3-5%, P.sub.2 O.sub.5 3-10%, MgO 0-3%, ZnO 0-5%, ZrO.sub.2 2-7%, Ta.sub.2 O.sub.5 0-7% and La.sub.2 O.sub.3 10-20%.

Abstract: A process is disclosed to increase the resistance of glass products to alkaline cement liquors by coating the surface of the glass products with an effective amount of a water-soluble zinc compound. Cement compositions comprising a cementitious matrix and glass products produced in accordance with the process of this invention are also disclosed herein.

Abstract: Glass ceramic and the process for producing a dark red glass ceramic comprising the production of basic glass by melting at about 1620.degree. C a mixture of approximate percentages of sand 53.30%, hydrated alumina 27.15%, zirconium silicate 1.90%, titanium oxide 2.02%, lithium carbonate 7.49%, sodium carbonate 0.87%, potash 0.62%, dolomite 0.39%, barium carbonate 1.04%, barium nitrate 2.16%, zinc oxide 1.09%, manganese dioxide 0.56%, ferric oxide 0.21%, cobalt oxide 0.36%, nickel oxide 0.05% and antimony oxide 0.73%. After cooling to about 1480.degree. C, the glass is formed into articles, and the articles further cooled to at least 700.degree. C. The articles are then heat treated to 800.degree. C at about .ltoreq.10.degree. C/min., devitrifying the glass from 800.degree. C to 900.degree. C, at, for example, 0.5.degree. C/min and cooling the article from 890.degree. C to room temperature at, for example, 7.degree. C/min.

Abstract: Glasses suitable for use as long term reinforcing agents for a cementitious matrix, e.g., Portland cement, or concrete. The glasses are preferably in the form of continuous filaments, short fibers, hollow spheres, or foamed glasses and have a composition consisting essentially of:______________________________________ Weight Percent ______________________________________ SiO.sub.2 20-70 TiO.sub.2 3-12 ZnO 5-70 CuO 0-10 Fe.sub.2 O.sub.3 0-5 BaO 0-30 CaO 0-10 MgO 0-15 Al.sub.2 O.sub.

Abstract: A glass having a softening temperature (E.sub.W) between 596.degree. and 634.degree. C. and a working temperature (V.sub.A) between 792.degree. and 863.degree. C., said glass being produced from a melt having a composition expressed in percentages by weight as follows:______________________________________ SiO.sub.2 50.9 to 60.4, B.sub.2 O.sub.3 1.5 to 11.5, Al.sub.2 O.sub.3 2.5 to 5.3, Li.sub.2 O 0.75 to 3.0, Na.sub.2 O 6.0 to 15.0, K.sub.2 O 0 to 3.8, Li.sub.2 O + Na.sub.2 O 8.0 to 17.3, Li.sub.2 O + Na.sub.2 O + K.sub.2 O 11.0 to 19.7, CaO 0 to 1.5, BaO 0 to 12.9, ZnO 0 to 7.3, PbO 0 to 17.5, BaO + PbO 7.0 to 17.8, Fe.sub.3 O.sub.4 3.3 to 5.0, F.sub.2 0 to 0.7, Sb.sub.2 O.sub.3 0.05 to 0.1, Sugar 0.05 to 0.1.

Abstract: Optical glass with a path length independent of temperature includes SiO.sub.2, B.sub.2 O.sub.3, K.sub.2 O, BaO, ZrO.sub.2, TiO.sub.2, Nb.sub.2 O.sub.5, P.sub.2 O.sub.5 and F in specified percentages by weight, with the sum of the amounts of SiO.sub.2, B.sub.2 O.sub.3 and P.sub.2 O.sub.5 between 38 and 45% by weight and the sum of the amounts of ZrO.sub.2 and TiO.sub.2 between 12 and 27% by weight.