Abstract: Reduced boron containing glass fibers are provided which have a refractive index similar to that of higher boron-containing glass fiber compositions. The glass fibers with a refractive index in the range of greater than 1.5495 to around 1.57 have in weight percent SiO.sub.2 - 55-56.5, CaO - 20-23, Al.sub.2 O.sub.3 14.5-15.5, B.sub.2 O.sub.3 - 5 to 5.8, R.sub.2 O - 1-1.5, wherein R is an alkali metal and F.sub.2 - 0.4 to 0.6. In addition, the glass fiber composition can have minor constituents such as TiO.sub.2 of up to around 0.6 weight percent and an MgO of up to around 0.3 weight percent and ferric oxide of up to around 0.3 weight percent. Basically, the glass fibers have a reduced content of both B.sub.2 O.sub.3 and CaO over standard glass fiber compositions such as E-glass and 621-glass and also has elevated amounts of alkali and of refractory constituents such as SiO.sub.2 and Al.sub.2 O.sub.3. The glass fibers are formed with an elevated temperature of 40.degree. to 50.degree. F. (22.degree.-28.degree.

Abstract: A fine powder of neodymium titanate or barium neodymium titanate, a process for its preparation and applications in ceramic compositions. A suspension of particles is formed by mixing a solution of neodymium nitrate or a solution of barium and neodymium nitrates with a sol of titania having a pH of from about 0.8 to 2.5 which contains elementary crystallites of TiO.sub.2 having a size of from about 10 to about 100 .ANG. in diameter which are agglomerated into submicron masses of from about 200 to about 1,000 .ANG. in diameter. The suspension obtained is dried, and the dried product is calcined at a temperature between 800.degree. C. and 1,300.degree. C., preferably for about 1 to 24 hours. If necessary, the powder obtained is milled. The fine powder obtained has a low fritting temperature and its density after heating for 2 hours at 1,300.degree. C. is greater than or equal to 95% of the theoretical density of the desired titanate powder.

Abstract: A dielectric ceramic composition consists essentially of a main component composed of a solid solution of a three component system Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 -Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 -PbTiO.sub.3, characterized in that said main component consists essentially of 68.05 to 69.60 wt % of Pb.sub.3 O.sub.4, 2.41 to 4.00 wt % of MgO, 0.08 to 3.15 wt % of ZnO, 24.01 to 26.66 wt % of Nb.sub.2 O.sub.5, and 0.13 to 2.59 wt % of TiO.sub.2, and has a set of compositional proportions of the three components falling within an area defined by a polygon ABCD encompassed by points A, B, C, and D in FIG. 1, and that a subsidiary component consisting essentially of MgO is incorporated into said main component in an amount of not more than 1.0 part by weight (except 0 part by weight) with respect to 100 part by weight of the main component. The composition may further contain, as a part of the subsidiary component, manganese and/or a compound represented by the general formula: A(Cu.sub.1/2 W.sub.1/2)O.sub.

Abstract: The present invention relates to a two-part gunning refractory composition wherein fine powders of a refractory aggregate and superfine refractory powders are previously made into the form of a slurry containing therein a deflocculant, thereby reducing the amount of aluminous cement and also reducing the amount of water to achieve a deposit applied by gunning having a quality comparable to one produced by casting.

Abstract: Disclosed is a sintered body of a composition comprising (i) 80 to 99% by weight of Si.sub.3 N.sub.4, (ii) 1 to 20% by weight of oxides, nitrides and the like of Sr, W and a rare earth element as the main additive and (iii) an oxide, a nitride or the like of Al, Ti, Cr, Si or Mo as the auxiliary additive in an amount of up to 5 parts by weight per 100 parts by weight of the components (i) and (ii). This sintered body is excellent in oxidation resistance and mechanical strength at high temperatures.

Abstract: A porous ceramic filter consisting of a planar porous support formed of a ceramic material, and a filtering layer formed of a fired mass of a ceramic powder integrally deposited on an upper surface of the porous ceramic support. A particle size of the ceramic powder, and a size of macro pores formed in the fired mass of said ceramic powder, decrease substantially continuously in a direction from the upper surface of the ceramic support toward an exposed surface of the filtering layer.

Abstract: A process for treating a halide, e.g. fluoride, glass composition, characterized by contacting a melt of the composition with dry oxygen. Oxygen, simply on contact with a fluoride glass melt, converts transition metals, e.g. from Fe(II) to Fe(III), from one stable state to another and thereby reduces loss at transmission wavelengths in optical fiber, e.g. the loss at 2.7 .mu.m attributable to Fe(II).

Abstract: A low-temperature sinterable ceramic composition comprising 1 to 20% by weight of Al.sub.2 O.sub.3, 15 to 50% by weight of SiO.sub.2, 0 to 5% by weight of MgO, 3 to 18% by weight of CaO, 0 to 5% by weight of TiO.sub.2, 1 to 8% by weight of B.sub.2 O.sub.3, 0 to 2% by weight of Li.sub.2 O, 20 to 80% by weight of at least one of zircon, mullite and spinnel, and 1 to 12% by weight of a fluoride selected from CaF.sub.2, MgF.sub.2, LiF, AlF.sub.3, MnF.sub.2, BaF.sub.2 and SrF.sub.2.

Abstract: Improved copper conductor inks useful in fabricating multilevel circuits are provided. The inks comprise copper powder, a novel zinc-aluminum-lead-borosilicate glass frit, bismuth oxide and a suitable organic vehicle. The inks are advantageous in that the films formed therefrom are oxidation resistant and have a reduced tendency for flux components to leach into adjacent dielectric films.

Abstract: Alumina fibers whose surface is coated with zirconia to retain their identity in an alumina matrix when the mixture is sintered at temperatures needed to form a fully dense ceramic. The resulting fully dense ceramic composite shows the beneficial effects of such reinforcing fibers by having increased crack toughness.

Abstract: Cordierite series dense and low expansion ceramics have excellent thermal shock resistance property, being airtight, heat resistant and having high dimensional stability at high temperatures can be achieved by incorporating 2-10% by weight of P.sub.2 O.sub.5 in the cordierite ceramic and acid treating the fired or sintered body to selectively remove P.sub.2 O.sub.5 to primarily result in an amount of 0.1% by weight of P.sub.2 O.sub.5 remaining in the sintered body.

Abstract: The present invention disclosed a magnesia clinker excellent in corrosion resistance, which is useful for a magnesia carbon refractory and also for a refractory for steel manufacturing furnace, and the magnesia clinker is characterized by:(a) having a purity of MgO of 97 wt. % or higher;(b) containing 2.0 wt. % or less of CaO;(c) containing 0.01 wt. % or more of B.sub.2 O.sub.3 ;(d) containing 0.3 wt. % or less of SiO.sub.2 ;(e) containing impurities other than MgO, CaO, B.sub.2 O.sub.3 and SiO.sub.2 of 2 wt. % or less;(f) having a bulk density of 3.35 (g/cc) or higher and an apparent porosity of 3.0 (vol. %) or less; and(g) having a mean crystal size of magnesia of 100 .mu.m or larger.

Abstract: A sintered alumina porcelain composition is described consisting of a ternary composition consisting of from 96 to 99 mol % of Al.sub.2 O.sub.3 and the remainder consisting of CaO and TiO.sub.2 present in a CaO/TiO.sub.2 molar ratio of from 0.8/1 to 1.1/1 and SiO.sub.2, wherein based on 100 parts by weight of the ternary Al.sub.2 O.sub.3 --CaO--TiO.sub.2 composition, SiO.sub.2 is present in an amount within the range defined by the area within the straight lines connecting points A-B-C-D-E-F-A in the composition diagram set forth in the attached drawing for describing the relationship between the SiO.sub.2 content and the Al.sub.2 O.sub.3 molar ratio, provided that point A is excluded from the range of the SiO.sub.2 content, with said points having the following locations:______________________________________ SiO.sub.2 Al.sub.2 O.sub.3 (parts by weight) (mol %) ______________________________________ Point A 0 96 Point B 0.01 98 Point C 0.03 99 Point D 1.20 99 Point E 0.48 98 Point F 0.

Abstract: An overglaze ink comprising(a) 55 to 70 weight % of a glass composition, the glass composition comprising(1) 15 to 43 weight % of a main glass component selected from the group consisting of BaO, SrO and SrO+BaO,(2) a glass forming component comprising34 to 45 weight % B.sub.2 O.sub.3 and0 to 6 weight % SiO.sub.2(3) 0 to 2 weight % of a colorant selected from the group consisting of Cr.sub.2 O.sub.3, CoO and NiO,(4) 7 to 20 weight % of a thermal expansion modifier selected from the group consisting of ZnO, Al.sub.2 O.sub.3, TiO.sub.2 and mixtures thereof, and(5) 1 to 7 weight % of a dopant comprising one or more of the following:ZnF.sub.2 having a weight % of 0 to 5,Li.sub.2 O having a weight % of 0 to 2,Na.sub.2 O having a weight % of 0 to 2,K.sub.2 O having a weight % of 0 to 2,LiF having a weight % of 0 to 2,NaF having a weight % of 0 to 2,KF having a weight % of 0 to 2,BaF.sub.2 having a weight % of 0 to 2,Na.sub.2 SiF.sub.6 having a weight % of 0 to 2,PbO having a weight % of 0 to 3,V.sub.2 O.sub.

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: A piezoelectric ceramic composition consists essentially of a main component consisting of lanthanum modified lead titanate and lead stanate antimonate, and an auxiliary component consisting of manganese oxide. The content of the main component is 98 to 99.0 mole % when expressed by the general formula:yPb(Sn.sub.1/2 Sb.sub.1/2)O.sub.3 -(1-y)(Pb.sub.1-3x/2 La.sub.x)TiO.sub.3(where 0.01.ltoreq.x.ltoreq.0.06 and 0.01.ltoreq.y.ltoreq.0.06), and the content of the manganese oxide is 0.1 to 2 mole % when converted into an amount of MnO.sub.2.

Abstract: A mortar composition comprises a mortar and a carboxymethyl hydroxyethyl cellulose (CMHEC) having a degree of substitution (DS), by carboxymethyl group per a glucose unit, of 0.7 or less and a molar substitution (MS), by ethylene oxide per a glucose unit, of 1.2 to 7.0.

Abstract: A cement composition is suitable for underwater concreting and comprises 100 parts by weight of cement and 0.1 to 2.0 parts by weight of carboxymethyl hydroxyethyl cellulose.

Abstract: This invention relates to a high-strength molybdenum silicide-based ceramic material and a process for producing such ceramic material. A powder mixture obtained by adding to titanium carbonitride 0-100% by weight of a specific metal boride compound is added to powder of molybdenum silicide used as base component, and the obtained mixed powder composition is sintered. Both strength and density of molybdenum silicide are increased while maintaining its low-temperature sinterability.

Abstract: A dielectric ceramic composition for microwave applications comprises a mixture represented by the general formula:xBaO-yTiO.sub.2 -z{(Sm.sub.2 O.sub.3).sub.100-(w.sbsb.1.sub.+w.sbsb.2.sub.) (CeO.sub.2).sub.w.sbsb.1 (La.sub.2 O.sub.3).sub.w.sbsb.2 }wherein x, y, z, w.sub.1 and w.sub.2 are mole % of respective components, 6.ltoreq.x.ltoreq.22, 59.ltoreq.y.ltoreq.79.5, 2.ltoreq.z.ltoreq.34.5, x+y+z=100, and 0<(w.sub.1 +w.sub.2).ltoreq.95, and wherein both w.sub.1 and w.sub.2 are exclusive of zero.Further this composition may include MnO.sub.2 as another component of which the amount is 4 weight % and less on the basis of total weight of BaO, TiO.sub.2, Sm.sub.2 O.sub.3, CeO.sub.2 and La.sub.2 O.sub.3.Since this composition has a high specific dielectric constant .epsilon.r, a high no load value Q and a positive or negative temperature coefficient .eta.f of about zero, it can be used as a microwave dielectric resonator, a temperature compensating capacitor or the like.