Abstract: The present invention provides a porcelain enamel coating composition for use in forming a coating composition upon a metal substrate having an infrared reflectivity of at least 50% at 2.5 .mu.-microns measured with a Perkin Elmer Lambda 19 UV/VIS/NIR spectrometer with a labsphere RSA-PE 19 reflectance spectroscopy accessory. The coating composition comprises a glass component and a separate and distinct addition of cerium oxide. Preferably, the coating composition comprises from about 0.20% to about 3.0% by weight of the cerium oxide.

Abstract: Opal glass compositions for producing opal glass articles such as perfume bottles are disclosed. The compositions are borosilicate compositions and further include 0.5-3.0 wt % of CaO and 1.0-6.0 wt % of P.sub.2 O.sub.5, and the sum of alkaline oxides totals 9-18 wt %.

Abstract: A glass-ceramic substrate for a magnetic disk suitable for use as a contact recording type magnetic disk includes alpha-cristobalite (alpha-SiO.sub.2) and lithium disilicate (Li.sub.2.SiO.sub.2) as main crystal phases. The ratio of alpha-cristobalite/lithium disilicate is within a range from 0.25 to 0.35, a grain diameter of crystal grains is within a range from 0.1 .mu.m to 1.0 .mu.m, surface roughness (Ra) of the substrate after polishing is within a range from 2 .ANG. to 10 .ANG. and abrasion resistance index (Aa) of the substrate is within a range from 5 to 15.

Abstract: A bioactive ceramic composition including 47 to 51% SiO.sub.2, 23 to 25% CaO, 23 to 25% Na.sub.2 O and 0 to 6% P.sub.2 O.sub.5, the bioactive ceramic having a bioacitivity level such that the composition forms at least a thin layer of HCA within about 30 hours of implantation into a patient. The bioactive ceramic composition having a crystallinity of 34 to 60 volume percent and a crystalline phase of 1Na.sub.2 O.2CaO.3SiO.sub.2.

Abstract: A glass-ceramic substrate for a magnetic information storage medium such as a magnetic disk having a super flatness suited for a contact recording system includes a SiO.sub.2 --Al.sub.2 O.sub.3 --Li.sub.2 O system glass-ceramic and has either .beta.-quartz solid solution (.beta.-SiO.sub.2 solid solution) or a mixture of .beta.-quartz solid solution (.beta.-SiO.sub.2 solid solution) and .beta.-spodumene solid solution (.beta.-Li.sub.2 O.Al.sub.2 O.sub.3.4SiO.sub.2 solid solution) as its main crystal phase. The surface roughness (Ra) of the glass-ceramic substrate after polishing is within a range from 1 .ANG. to 5 .ANG..

Abstract: An optical glass has a large negative anomalous dispersion value and optical constants of refractive index (nd) within a range of 1.65-1.80 and Abbe number (.nu.d) within a range of 28-42. The optical glass includes, as its essential ingredients, in weight percent, 20-50% SiO.sub.2, 6-20% B.sub.2 O.sub.3 where SiO.sub.2 /B.sub.2 O.sub.3 .ltoreq.6, 0.5-15% ZrO.sub.2 and 31-50% Nb.sub.2 O.sub.5.

Abstract: The present invention relates to a process for forming glass-ceramic tiles. Fly ash containing organic material, metal contaminants, and glass forming materials is oxidized under conditions effective to combust the organic material and partially oxidize the metallic contaminants and the glass forming materials. The oxidized glass forming materials are vitrified to form a glass melt. This glass melt is then formed into tiles containing metallic contaminants.

Abstract: A method of preparing a membrane is disclosed, which includes the step of impregnating an inorganic proton-conductive material into matrices of porous ceramic membranes. The inorganic proton-conductive material may include an inorganic poly-acid, such as polyphosphates or poly-antimonic acids. The inorganic proton conducting material may include Zr (zirconium).The invention further provides a porous ceramic membrane, which includes an inorganic proton-conductive material impregnated into a porous ceramic membrane matrix.The ceramic membrane may be a tubular ceramic membrane, which includes pores with a diameter of at least 0.3 .mu.m, and depositions of electroconductive coatings onto its surface on which externally applied potential can be applied as a driving force for hydrogen separation.

Abstract: A ZrO.sub.2 -containing glass ceramic is described, the main crystalline phase of which is formed by ZrO.sub.2 and which has at least one further crystalline phase, and which can be used in particular in dentistry.

Abstract: A mold has a moling surface of a material containing silicon carbide and/or silicon nitride as a main component and a carbon thin film formed on the molding surface to prevent fusion sticking. A glass substance which has a sag point not higher than 565.degree. C. and a predetermined composition free from arsenic oxide is introduced into the mold. The glass substance is press-formed in a heated and softened condition into a glass optical element of high precision.

Abstract: A crystallized glass and a manufacturing method therefor are disclosed. The crystallized glass comprises .beta.-spodumene solid solution as the predominant crystal phase, and is produced by forming a melted raw glass, cooling and thereafter heat-treating it. The raw glass has a composition comprising, expressed in terms of weight percent: 52-65% SiO.sub.2 ; 8-15% Al.sub.2 O.sub.3 ; 0-4% P.sub.2 O.sub.5, 3-8% TiO.sub.2, and 0-4% ZrO.sub.2, wherein the following inequality is satisfied,0.1<(% of P.sub.2 O.sub.5 +% of ZrO.sub.2)/(% of TiO.sub.2)<0.8; 0-10% ZnO, 0-10% MgO, and 0-5% BaO, wherein the following inequality is satisfied,<(% of ZnO+% of MgO+% of BaO)<15; 3-12% Li.sub.2 O; 0-4% K.sub.2 O; and As.sub.2 O.sub.3 and Sb.sub.2 O.sub.3, wherein the following inequality is satisfied,0<% of As.sub.2 O.sub.3 +% of Sb.sub.2 O.sub.3 <2.

Abstract: A pharmaceutical preparation, including a glass phase which is bioactive silica containing glass in the form of a paste, suspension or solution mixed in a physiologically suitable liquid or bound to a physiologically suitable vehicle, and which preparation reduces the pulpal irritation or a tooth and/or strengthens the structure of a tooth. Bioactive silica containing glass may be a material which contains only Si-oxide or Si-hydroxide and which allows the formation and movement of Si--OH-groups. Preferably, the preparation also contains calcium and phosphate sources.

Abstract: Carriers comprising silica-based glass providing for the controlled release of biologically active molecules, their methods of preparation, and methods of use are disclosed. The carriers are prepared using a sol-gel-derived process. Biologically active molecules are incorporated within the matrix of the glass during production.

Abstract: A glass composition for magnetic disk substrates comprising as oxides: from 66 to 80% by weight of SiO.sub.2, from 5 to 15% by weight of Al.sub.2 O.sub.3, from 3 to 8.5% by weight of Li.sub.2 O, from 0 to 3% by weight of Na.sub.2 O, from 0 to 3% by weight of K.sub.2 O, from 0.5 to 8% by weight of TiO.sub.2, from 3.5 to 8% by weight of ZrO.sub.2, from 0.5 to 3% by weight of P.sub.2 O.sub.5, from 0 to 2% by weight of Sb.sub.2 O.sub.3, and from 0 to 2% by weight of As.sub.2 O.sub.3, and having a theoretical optical basicity of 0.548 or less; a magnetic disk substrate which is prepared by forming and polishing the above glass composition, followed by chemically strengthening the polished substrate by ion exchange or by forming, heat treating, and polishing the above composition and contains Li.sub.2 O.2SiO.sub.2 and/or spodumene as the main crystalline phase.

Abstract: Carriers comprising silica-based glass providing for the controlled release of biologically active molecules, their methods of preparation, and methods of use are disclosed. The carriers are prepared using a sol-gel-derived process. Biologically active molecules are incorporated within the matrix of the glass during production.

Abstract: A glass-ceramic substrate for a magnetic disk suitable for use as a contact recording type magnetic disk includes alpha-cristobalite (alpha-SiO.sub.2) and lithium disilicate (Li.sub.2 O . 2SiO.sub.2) as main crystal phases. The ratio of alpha-cristobalite/lithium disilicate is within a range from 0.25 to 0.35, a grain diameter of crystal grains is within a range from 0.1 .mu.m to 1.0 .mu.m, surface roughness (Ra) of the substrate after polishing is within a range from 2 .ANG. to 10 .ANG. and abrasion resistance index (Aa) of the substrate is within a range from 5 to 15.

Abstract: Carriers comprising silica-based glass providing for the controlled release of biologically active molecules, their methods of preparation, and methods of use are disclosed. The carriers are prepared using a sol-gel-derived process. Biologically active molecules are incorporated within the matrix of the glass during production.

Abstract: Glasses for use as substrates for flat panel displays, having a composition consisting essentially of, as calculated in weight percent on an oxide basis, 38-56 SiO.sub.2, 10-28 Al.sub.2 O.sub.3, 0-4 Li.sub.2 O, 0-6 Na.sub.2 O, 0-15 K.sub.2 O, 4-18 CaO, 0-5 MgO, more than 8 and less than or equal to about 24 SrO, 0-2 ZrO.sub.2, said glass further consisting essentially of Na.sub.2 O+K.sub.2 O in total between about 6 and 18 weight percent.

Abstract: Glasses for use as substrates for flat panel displays, having a composition consisting essentially of, as calculated in weight percent on an oxide basis, of 42-62 SiO.sub.2, 15-28 Al.sub.2 O.sub.3, 0-4 B.sub.2 O.sub.3, 3-10 Na.sub.2 O, 2-12 K.sub.2 O, 0-6 MgO, 9.5-24 CaO, 0-8 SrO, 0-16 BaO, 0-4 ZrO.sub.2 and 4-16 Li.sub.2 O+Na.sub.2 O+K.sub.2 O.

Abstract: A mineral fibre composition which is soluble in biological fluids contains substantially45-65% by weight of SiO.sub.215-40% by weight of CaO0-20% by weight of MgO0-6% by weight of Na.sub.2 O+K.sub.2 Oand in addition aluminium and/or iron oxides as well as phosphorus oxide in such amounts that the weight ratio of P.sub.2 O.sub.5 to the sum of Al.sub.2 O.sub.3 and iron oxide is circa 0.4 to 6.

Abstract: A bioceramic system for delivery of a bioactive compound, which comprises a combination of bioactive glass, bioactive glass ceramic or bioactive ceramic, hydroxyapatite, optionally one or more other calcium phosphate compound and optionally a matrix, and which may incorporate into the bioceramic system a bioactive compound. The timing of the release of the bioactive compound can be regulated as desired and depends on the conditions of the surrounding, the composition of the bioceramic system and its method preparation.

Abstract: A novel silica based bioactive glass composition that can be used in conjunction with a delivery agent such as a toothpaste, gel saliva, etc. having a particle size range <90 .mu.m which will form a rapid and continuous reaction with body fluids due to the immediate and long term ionic release of Ca and P from the core silica particles, to produce a stable crystalline hydroxy carbonate apatite layer deposited onto and into the dentin tubules for the immediate and long term reduction of dentin hypersensitivity.

Abstract: A glass-ceramic magnetic disk substrate which is prepared by forming, then heat treating, and then polishing a crystallizable glass composition comprising, expressed in terms of weight percent on the oxide basis: from 20 to 45% SiO.sub.2 ; from 25 to 45% Al.sub.2 O.sub.3 ; from 10 to 25% B.sub.2 O.sub.3 ; from 2 to 12% MgO; from 0.5 to 8% TiO.sub.2 ; from 0.5 to 5% P.sub.2 O.sub.5 ; from 0 to 2% Li.sub.2 O; from 0 to 2% Na.sub.2 O; from 0 to 3% K.sub.2 O; wherein, the total of the contents of Li.sub.2 O, Na.sub.2 O and K.sub.2 O is from 0 to 5%; and wherein the magnetic disk substrate comprises a main crystalline phase consisting of at least one member selected from the group consisting of mullite and aluminum borate crystals. The glass composition can easily be formed and the disk substrate can easily be polished, has excellent mechanical strength, surface flatness, surface smoothness, chemical durability, and heat resistance, and shows no deterioration of magnetic film characteristics by alkali migration.

Abstract: Composite materials formed from bone bioactive glass or ceramic fibers and structural fibers are disclosed. In preferred embodiments, a braid or mesh of interwoven bone bioactive glass or ceramic fibers and structural fibers is impregnated with a polymeric material to provide a composite of suitable biocompatibility and structural integrity. Most preferably, the mesh or braid is designed so that the bioactive fibers are concentrated at the surface of the implant to create a surface comprised of at least 30% bioactive material, thereby providing enhanced bone ingrowth. The interweaving between the bone bioactive glass or ceramic fibers and the core of structural fibers overcomes the problems found in prior composite systems where the bioactive material delaminates from the polymer. Preferred bioactive materials include calcium phosphate ceramics and preferred structural fibers include carbon fibers. Further preferred bioactive materials include aluminum oxide at greater than 0.2%, by mole.

Abstract: The present invention is concerned with a process for the formation of dental restorations from glass-ceramic materials and the resulting dental restorations. In this invention, a dental restoration is prepared by placing a glass-ceramic material in a heat-pressure deformable crucible. Heat is then applied to the crucible in order to bring the glass-ceramic material to a working range at temperatures above its liquidus temperature. The crucible in which the glass-ceramic material is placed has heat-pressure deformation properties which are matched to the working temperature of the glass-ceramic material being heated. The heat deformation properties of the crucible must be such that when the glass-ceramic material in the crucible is in the working range the crucible is heat-pressure deformable without rupturing.

Abstract: A ZrO.sub.2 -containing glass ceramic is described, the main crystalline phase of which is formed by ZrO.sub.2 and which has at least one further crystalline phase, and which can be used in particular in dentistry.

Abstract: In order to provide an enamel frit composition for a low-expansion crystallized glass, capable of producing an enamel coating excellent in abrasion resistance and acid resistance without occurrence of cracks by using glass powder which does not contain any harmful component such as PbO, and to provide an enamel-coated low-expansion crystallized glass plate using the enamel frit composition, the enamel frit composition for a low-expansion crystallized glass essentially consists 40-98 wt % glass powder, 1-55 wt % coloring pigment, and 0-54 wt % filler. The glass powder consists, by weight, of 55-72% SiO.sub.2, 4-8% Al.sub.2 O.sub.3, 14-22% B.sub.2 O.sub.3, 2-4% BaO, 5.1-15% Na.sub.2 O, 0-2% Li.sub.2 O, 0-2.8% K.sub.2 O, and 0-2% F.sub.2.

Abstract: A glass composition for magnetic disk substrates comprising as oxides: from 66 to 80% by weight of SiO.sub.2, from 5 to 15% by weight of Al.sub.2 O.sub.3, from 3 to 8.5% by weight of Li.sub.2 O, from 0 to 3% by weight of Na.sub.2 O, from 0 to 3% by weight of K.sub.2 O, from 0.5 to 8% by weight of TiO.sub.2, from 3.5 to 8% by weight of ZrO.sub.2, from 0.5 to 3% by weight of P.sub.2 O.sub.5, from 0 to 2% by weight of Sb.sub.2 O.sub.3, and from 0 to 2% by weight of As.sub.2 O.sub.3, and having a theoretical optical basicity of 0.548 or less; a magnetic disk substrate which is prepared by forming and polishing the above glass composition, followed by chemically strengthening the polished substrate by ion exchange or by forming, heat treating, and polishing the above composition and contains Li.sub.2 O.multidot.2SiO.sub.2 and/or spodumene as the main crystalline phase.

Abstract: Novel non-crystalline, porous bioactive glass and ceramic materials that permit the in vitro formation of bone tissue when exposed to a tissue culture medium and inoculated with cells are disclosed. The present invention also discloses methods of treating bioactive glass materials to control pH so that when the glass is exposed to a tissue culture medium and then inoculated with cells, bone tissue growth occurs in vitro. The glass material disclosed is preferably formed from SiO.sub.2, CaO, Na.sub.2 O and P.sub.2 O.sub.5 and the porous, non-crystalline structure is most preferably created by melting the constituents, cooling and pulverizing the resulting glass, and then forming and hot pressing the powder. The glass of the present invention may be formed to produce templates that are useful for various indications, as well as granules that may be formed into a paste.

Abstract: The present invention relates to a manufacturing method of a far infrared ray emitting material having a wavelength of predetermined frequency band and a far infrared ray emitting product using the same, the manufacturing method including steps of: having a mixing vessel containing a predetermined quantity of materials agitated for 0.5-1 hour by a stirrer having a rotative speed of 33 revolution per minute and mixied; and the materials being thrown into a glass dissolving furnace of 1,350-1,550 degrees celsius and fused for 19-21 hours, whereby the predetermined quantity of materials is constituted by silicon oxide of 45-65 weight %, felspar oxide of 7-9 weight %, borax of 10-20 weight %, boric acid of 4-6 weight %, potassium carbonate of 2-4 weight %, nite of 1.0-1.2 weight %, aluminum hydroxide of 3.3-6.8 weight %, limestone of 1.4-1.8 weight %, barium carbonate of 0.8-1.0 weight %, lithium of 0.7-0.8 weight %, zircon of 1.0-1.3 weight %, phosphoric acid of 0.2-0.4 weight %, carbon of 3.0-3.

Abstract: Disclosed is a barium-free glass of good x-ray absorption, which has a composition (in wt.-% on the oxide basis) of SiO.sub.2 50-75; ZrO.sub.2 5-30; Li.sub.2 O 0-5; Na.sub.2 O 0-25; K.sub.2 O 0-25; .SIGMA. alkali oxides 0-25. Preferred is a dental glass of the composition of SiO.sub.2 55-70; ZrO.sub.2 10-25; Li.sub.2 O 0-15; Na.sub.2 O 10-25; K.sub.2 O 0-15; .SIGMA. alkaloids 15-25. The glass can furthermore contain also up to 3 wt.-% of fluorine, up to 5 wt.-% of MgO, up to 5 wt.-% of TiO.sub.2, and in each case up to 10 wt.-% of the oxides Al.sub.2 O.sub.3, GeO.sub.2, P.sub.2 O.sub.5, La.sub.2 O.sub.3, Y.sub.2 O.sub.3, Ta.sub.2 O.sub.3, Gd.sub.2 O.sub.3, ZnO and Nb.sub.2 O.sub.5. The glass finds its use in powder form with an average particle size of .ltoreq.10 .mu.m as filler for dental composites for filling teeth.

Abstract: A photochromic glass having colorant incorporated in the glass composition to impart a permanent tint, and having its chromaticity point shifted from the blue-green side toward the red side of the white point in the CIE chromaticity coordinate system, and a method of producing such article by heating the article for a sufficient time, and at a sufficient temperature, in a dilute, hydrogen-containing atmosphere to so move the chromaticity point.

Abstract: Alkali-zinc-silicate glass ceramics and glasses are described which have a linear thermal expansion coefficient in the range from 8.0 to 18.7.times.10.sup.-6 K.sup.-1, an excellent chemical resistance and other advantageous optical properties and can be used in particular as dental material.

Abstract: The invention relates to a porcelain with a transparency and strength properties of a hard porcelain, characterized by a phosphate-containing glass phase as well as the predominance of unreacted quartz bodies [sic; grains] in the matrix. The invention relates to a porcelain batch composition as well as to a method for the manufacture of the porcelain.

Abstract: Carriers comprising silica-based glass providing for the controlled release of biologically active molecules, their methods of preparation, and methods of use are disclosed. The carriers are prepared using a sol-gel-derived process. Biologically active molecules are incorporated within the matrix of the glass during production.

Abstract: A low expansion glass-ceramic which has a coefficient of thermal expansion (.alpha..times.10.sup.-7 /.degree.C.) within the range of from -5 to +5 within a temperature range of from -60.degree. C. to +160.degree. C., has a remarkably reduced variation of 10 ppm or below in relative length of .DELTA.1/1, has an excellent optical homogeneity owing to reduced melting temperature in the base glass, and has an improved transparency is obtained by restricting the ratio in weight of P.sub.2 O.sub.5 to SiO.sub.2 within the range of from 0.08 to 0.20, and adding Li.sub.2 O, MgO, ZnO, CaO and BaO of specific content ranges as essential ingredients in a base glass of a SiO.sub.2 -P.sub.2 O.sub.5 -Al.sub.2 O.sub.3 -Li.sub.2 O system containing TiO.sub.2 and ZrO.sub.2 as nucleating agents, and As.sub.2 O.sub.3 as an optional ingredient.

Abstract: This invention is directed to the production of glasses essentially free of Nb.sub.2 O.sub.5, and having refractive index close to 1.7, an Abbe number of about 35 and a density close to 3.2. The glasses consist essentially in weight percent on the oxide basis, of______________________________________ SiO.sub.2 38-45 TiO.sub.2 15-<20 ZrO.sub.2 6-10 La.sub.2 O.sub.3 0.5-4 BaO 12-19 CaO 3-8 BaO + CaO + SrO 17-25 Na.sub.2 O 2-6 K.sub.2 O 4-8 Li.sub.2 O + Na.sub.2 O + K.sub.2 O 6-10.

Abstract: A Cu-doped/Fe-doped low expansion glass ceramic composition comprising:______________________________________ Wt. % ______________________________________ SiO.sub.2 50-65 Al.sub.2 O.sub.3 18-27 P.sub.2 O.sub.5 0-10 Li.sub.2 O 2-6 Na.sub.2 O 0-2 K.sub.2 O 0-2 B.sub.2 O.sub.3 0-1 MgO 0-4 ZnO 0-5 CaO 0-4 BaO 0-5 TiO.sub.2 1-3 ZrO.sub.2 1-3 As.sub.2 O.sub.3 0-1.5 Sb.sub.2 O.sub.3 0-1.5 CuO 0-3 Fe.sub.2 O.sub.3 0-1 ______________________________________wherein the total amount of SiO.sub.2, Al.sub.2 O.sub.3 and P.sub.2 O.sub.5 is 80-89 wt. %, and said glass ceramic contains as a dopant 0.1-3 wt. % CuO, 0.1-1 wt. % Fe.sub.2 O.sub.3 or a combined CuO+Fe.sub.2 O.sub.3 amount of 0.1-4 wt. %. The glass ceramic composition is suitable for use as a cladding material for solid laser energy storage mediums as well as for use in beam attenuators for measuring laser energy level and beam blocks or beam dumps used for absorbing excess or unused laser energy.

Abstract: An amorphous ceramic glass composition having a density greater than about 2.1 g/cm.sup.3 comprises: between about 35 and 55% by weight SiO.sub.2 ; between about 18 and 28% by weight Al.sub.2 O.sub.3 ; between about 1 and 5% by weight CaO; between about 7 and 14% by weight MgO; between about 0.5 and 5% by weight TiO.sub.2 ; between about 0.4 and 3% by weight B.sub.2 O.sub.3 ; and greater than 0 and up to about 1% by weight P.sub.2 O.sub.5. A convenient source of raw materials is a mixture of coal ash waste, borax (or boric acid) manufacturing plant waste, and titanium pigment waste. The ceramic glass is formed from an intermediate ceramic mixture which is subjected to a heat treatment. The intermediate ceramic mixture is formed by heating a mixture containing SiO.sub.2, Al.sub.2 O.sub.3, CaO, MgO, TiO.sub.2, B.sub.2 O.sub.3, and Na.sub.4 P.sub.2 O.sub.7 to a temperature between about 1400.degree. and 1600.degree. C.; cooling the mixture at a controlled rate between about 15.degree. C. and about 30.degree. C.

Abstract: An optical signal amplifier comprising an optical waveguide fiber integrated by thallium ion exchange in a boron-free silicate glass doped with up to 5 weight % erbium oxide, the glass having a base composition, as calculated in weight percent on an oxide basis, consisting essentially of______________________________________ SiO.sub.2 38-67 Al.sub.2 O.sub.3 1.5-4.5 Na.sub.2 O 0-20 ZnO 1.5-8 K.sub.2 O 0-25 Li.sub.2 O 0-1 Na.sub.2 O + K.sub.2 O 15-30 PbO 0-37 BaO 0-7 P.sub.2 O.sub.5 0-10 P.sub.2 O.sub.

Abstract: The invention relates to a porcelain with a transparency and strength properties of a hard porcelain, characterized by a phosphate-containing glass phase as well as the predominance of unreacted quartz grains in the matrix. The invention relates to a porcelain batch composition as well as to a method for the manufacture of the porcelain.

Abstract: A transparent or translucent inorganic material, especially a glass-ceramic and/or composite material, is provided with a low average thermal longitudinal expansion coefficient, .alpha., of from -1.times.10.sup.-6 K.sup.-1 to +2.times.10.sup.-6 K.sup.-1 in the temperature range of -50.degree.-700.degree. C., with the following composition (in weight percent):Li.sub.2 O, 2.5-6.0; Na.sub.2 O, 0-4.0; K.sub.2 O, 0-4.0; Na.sub.2 O+K.sub.2 O, 0.2-4.0; MgO, 0-3.0; ZnO, 0-3.0; BaO, 0-3.5; CaO, 0-1.0; SrO, 0-1.0; Al.sub.2 O.sub.3, 18-28; SiO.sub.2, 50-70; TiO.sub.2, 1.0-7.0; ZrO.sub.2, 0-3.5; TiO.sub.2 +ZrO.sub.2, 1.0-7.0; and P.sub.2 O.sub.5, 0-8.0,optionally with coloring components (in weight percent):V.sub.2 O.sub.5, 0-2.0; Cr.sub.2 O.sub.3, 0-2.0; MnO, 0-2.0; Fe.sub.2 O.sub.3, 0-2.0; CoO, 0-2.0; and NiO, 0-2.0,optionally, conventional refining agents, such as As.sub.2 O.sub.3, Sb.sub.2 O.sub.3, NaCl, and Ce.sub.2 O.sub.

Abstract: Lead- and barium-free crystal glass for the production of high-quality glasses and domestic articles, having high optical transmission, a refractive index n.sub.D of greater than 1.52, a density of at least 2.45 g/cm.sup.3, high hydrolytic resistance, good solarization resistance, and a K.sub.2 O+ZnO content of greater than 10% by weight, the glass system being based on an alkali-lime-silicate glass containing TiO.sub.2, ZrO.sub.2, Nb.sub.2 O.sub.3 and possibly Ta.sub.2 O.sub.5 and/or combinations thereof.

Abstract: An opalescent glass is described which is characterized by a continuous glass phase and a discontinuous glass phase dispersed therein, and which can be used as dental material or as a constituent of dental materials.

Abstract: A bone grafting material for use in medicine is glass wool which has the mean diameter of 100 .mu.m or less and whose composition is:SiO.sub.2 40-62% (w/w)Na.sub.2 O 10-32% (w/w)CaO 10-32% (w/w)P.sub.2 O.sub.5 0-12% (w/w)CaF.sub.2 0-12% (w/w)B.sub.2 O.sub.3 0-20% (w/w),When the grafting material is used for treatment of periodontal disease, the grafting material is completely replaced by newly formed bone, whereby dental ankylosis of the grafting material to a tooth root does not occur and the newly formed bone and the tooth root are bound with a tissue like a periodontal membrane.

Abstract: A glass-ceramic for a magnetic disk substrate in which the grain size can be controlled and the surface roughness after polishing is within the range from 15 .ANG. to 50 .ANG. is provided by heat treating a base glass including in weight percent:______________________________________ SiO.sub.2 65-83% Li.sub.2 O 8-13% K.sub.2 O 0-7% Mgo + ZnO + PbO 0.5-5.5% in which MgO 0.5-5.5% ZnO 0-5% PbO 0-5% P.sub.2 O.sub.5 1-4% Al.sub.2 O.sub.3 0-7% As.sub.2 O.sub.3 + Sb.sub.2 O.sub.3 0-2% ______________________________________The glass-ceramic contains lithium disilicate (Li.sub.2 O. 2SiO.sub.2) and alpha-quartz (SiO.sub.2) as the main crystal phases.

Abstract: A ceramic glass composition comprises: between about 35 and 55% by weight SiO.sub.2 ; between about 18 and 28% by weight Al.sub.2 O.sub.3 ; between about 1 and 5% by weight CaO; between about 7 and 14% by weight MgO; between about 0.5 and 5% by weight TiO.sub.2 ; between about 0.4 and 3% by weight B.sub.2 O.sub.3 ; and greater than 0 and up to about 1% by weight P.sub.2 O.sub.5. A convenient source of raw materials is a mixture of coal ash waste, borax (or boric acid) manufacturing plant waste, and titanium pigment waste. The ceramic glass is formed from an intermediate ceramic mixture which is subjected to a heat treatment. The intermediate ceramic mixture is formed by heating a mixture containing SiO.sub.2, Al.sub.2 O.sub.3, CaO, MgO, TiO.sub.2, B.sub.2 O.sub.3, and Na.sub.4 P.sub.2 O.sub.7 to a temperature between about 1400.degree. and 1600.degree. C.; cooling the mixture to solidify it; annealing the mixture at 600.degree. to 670.degree. C.

Abstract: A gradient index optical element for use in optical lens such as a camera or microscope is disclosed. The optical element comprises at least one of first metal dopants selected from La, Zr, Sn, In, Y, Ge, Zn, Ba, Ca, As, Sr, Ga and Gd distributed in solvent with a slope, and at least one of second metal dopants selected from Nb, Ta, Ti, Bi, Pb, Sb, Zr, Sn, In, Y and Tl, which is distributed equally in the solvent so as to satisfy following equation as absolute amount;.vertline..DELTA.C.sub.f /.DELTA.C.sub.g .vertline..multidot.100.ltoreq.5wherein .DELTA.C.sub.g is a difference between maximum value and minimum value of equivalent value of metal oxides of the first metal doping and .DELTA.C.sub.f is a difference between maximum value and minimum value of equivalent value of metal oxides of the second metal doping.

Abstract: Lead-free ceramic frits for producing glazes with intrinsic opacity, and methods of coationg ceramic substrates with the ceramic frits, wherein the ceramic frits have the following composition:______________________________________ SiO.sub.2 48-60 wt. % B.sub.2 O.sub.3 3-8 wt. % Al.sub.2 O.sub.3 4-8 wt. % Na.sub.2 O 0.2-2.0 wt. % K.sub.2 O 4-8 wt. % MgO 0-2 wt. % CaO 7.5-13 wt. % BaO 0-5 wt. % ZnO 7-12 wt. % ZrO.sub.2 0.3-2.5 wt. % TiO.sub.2 3.5-5.5 wt. % P.sub.2 O.sub.5 0-3 wt. % and Na.sub.2 O + K.sub.2 O 4.5-8.5 wt. %.

Abstract: The present invention relates to mineral fiber compositions useful for forming fibers which are readily degraded in a physiological medium such as that found within the human body. Advantageous compositions formed according to the present invention comprise the following components in the proportions by weight set forth below:______________________________________ SiO.sub.2 37 to 58 wt. %; Al.sub.2 O.sub.3 4 to 14 wt. %; CaO 7 to 40 wt. %; MgO 4 to 16 wt. %; P.sub.2 O.sub.5 1 to 10 wt. %; Fe.sub.2 O.sub.3 up to about to 15 wt. %: ______________________________________wherein the amount of CaO+MgO+Fe.sub.2 O.sub.3 is greater than 25% and the total amount of Na.sub.2 O+K.sub.2 O is less than 7%. The total iron contained within the composition is expressed in the form of ferric oxide (Fe.sub.2 O.sub.3).