Abstract: There is disclosed a ceramic ferroelectric material consisting basically of lead magnesium niobate, lead nickel niobate lead titanate, having a stabilized perovskite crystal phase, having a high dielectric constant with a broad or diffuse ferroelectric to paraelectric phase transition, and adapted to being fired at temperatures up to 1200.degree. C. Numerous additives and their effects on dielectric properties are also disclosed.

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: The present invention is directed to a method for developing a bond having a shear strength in excess of 1200 psi between dental cements and dental appliances fashioned from glass-ceramic materials. The inventive method consists of contacting the fitting surface of the appliance with an etchant in flowable gel form at a temperature below about 150.degree. F., while protecting the exterior surface of the appliance. Subsequently, a silane solution followed by a dental cement is applied to the etched surface and cured in place.

Abstract: This invention relates to the production of transparent glass-ceramic bodies exhibiting properties especially suitable for use in ring laser gyros. The inventive products contain .beta.-quartz solid solution as essentially the sole crystal phase and consist essentially, expressed in terms of weight percent on the oxide basis, of______________________________________ SiO.sub.2 64-67 ZnO 0.7-4.2 Al.sub.2 O.sub.3 21-24 TiO.sub.2 2.0-3.25 Li.sub.2 O 2.6-3.7 ZrO.sub.2 1.25-2.5 MgO 0.8-1.5 TiO.sub.2 + ZrO.sub.2 4-5.

Abstract: A low loss fiber optic coupler is fabricated by forming a coupler preform having a plurality of spaced glass cores extending longitudinally through a matrix of glass having a refractive index lower than that of the cores. The coupler preform is heated and stretched by first pulling means to form a glass rod which is drawn by second pulling means past an intermittant source of localized heat. When the localized heat source is turned on, the second pulling means draws the rod downwardly at a rate faster than the first pulling means. Since the rod is softened by the localized heat source, a necked-down coupling region is formed. The rod is severed to form a plurality of coupler units. When an end of a unit is immersed in acid, the matrix glass dissolves, thereby leaving the unit cores and surrounding etch-resistant cladding glass protruding from the newly formed endface of the unit.

Abstract: A machine for grinding the cavity in a mold for optical lenses has a spherical grinding tool which is precisely positioned with respect to a predetermined reference by air slides which move the tool in orthogonal directions. The carriages of the air slides move relative to center rails. A film of air between the top plate of each air slide and the center rail is supplied from a first source at a pressure which supports the weight of the carriage. When precise alignment is obtained, the first air supply is cut off to lock the air slides in the position of alignment. A recess in end portions of the top plate has air holes communicating therewith which are supplied from air from a second source. The flow of air from this second source is continuous and is sufficient to prevent foreign material from entering the air slide.

Abstract: There is disclosed a composite body that is electrically insulating, and that is composed of metal particles dispersed in a continuous glassy matrix as a second phase. The metal particles are directionally anisotropic generally paralleling a predetermined plane through the body. This permits good thermal conductivity, while retaining the electrical insulating character of the glass, thus providing improved packaging for electronic components. A method of forming the composite body is also disclosed, as are methods of creating improved electronic packaging utilizing the composite material body.

Abstract: A multi-part mold assembly molds glass lenses. A cylindrical sleeve between the top and bottom molds has three cut-outs forming three alignment pads on both ends of the sleeve. These pads are preferably equally spaced around the circumference of the sleeve to constrain the top and bottom molds against rotation about X and Y axes which are orthogonal to the direction of closing of the mold. The alignment pads set the closed vertical positions of the molds. A torus on the bottom mold contacts a tapered opening in a removable sleeve insert to position a glass preform which is held by the insert. A torus on the top mold and a torus on the bottom mold bear against a cylindrical inner surface of the sleeve to precisely align the molds in the X and Y directions.

Abstract: This invention relates to glass compositions especially designed for use as envelopes for tungsten-halogen incandescent lamps wherein molybdenum metal lead wires are utilized. The glasses consist essentially, expressed in terms of weight percent on the oxide basis, of 8.5-14% BaO, 10.5-12.5% CaO, 14-15.5% Al.sub.2 O.sub.3, and 59.5-63% SiO.sub.2.

Abstract: A non-contact system for monitoring the tension in an optical waveguide fiber during drawing is provided. The system comprises: (a) means for sensing the motion of the fiber in a direction transverse to the direction in which the fiber is moving; (b) means for analyzing the sensed motion to determine at least one frequency component thereof; and (c) means for monitoring the frequency component so determined so as to monitor the tension in the fiber.

Abstract: This invention relates to the production of opal glasses having a creamy-white tint which are suitable for forming culinary articles. The opacity is obtained through precipitation of fluorides, preferably NaF. The creamy-white tint results from the association of Fe.sub.2 O.sub.3 with TiO.sub.2 and/or As.sub.2 O.sub.3 and/or CeO.sub.2, with the addition of nitrates. The preferred composition of the final glass consists essentially, in weight percent, of:______________________________________ SiO.sub.2 70-73 Fe.sub.2 O.sub.3 0.1-0.25 Na.sub.2 O 10.5-13 TiO.sub.2 0.1-0.7 Fluorine 4-5.5 As.sub.2 O.sub.3 0.05-0.4 Al.sub.2 O.sub.3 6-9 CeO.sub.2 0-0.2 CaO 0.2-1.7 B.sub.2 O.sub.3 0.5-3 BaO 1-3 ______________________________________The starting composition contains NaNO.sub.3 in a proportion of 0.2-2 by weight, counted as Na.sub.2 O with regard to the glass, or an equivalent quantity of another alkali metal or alkaline earth metal nitrate.

Abstract: This invention is concerned with the production of glass-ceramic articles wherein enstatite constitutes the predominant crystal phase. Compositions exhibiting a high modulus of rupture, a use temperature in excess of 1200.degree. C., and a high fracture toughness consist essentially, expressed in terms of weight percent on the oxide basis, of about 20-35% MgO, 2-12% Al.sub.2 O.sub.3, 40-70% SiO.sub.2, and at least one metal oxide in the indicated proportions selected from the group consisting of 0-2% Li.sub.2 O, 0-4% CaO, 0-12% SrO, and 0-17% BaO, at least 0.5% Li.sub.2 O being required when present alone and at least 1% SrO and/or BaO being required in the absence of Li.sub.2 O. Compositions exhibiting a use temperature of 1500.degree. C. consist essentially, expressed in terms of weight percent on the oxide basis, of about 30-35% MgO, 53-58% SiO.sub.2, and 10-14% ZrO.sub.2.

Abstract: A drilling rate and depth monitor is provided for determining the rate in which apertures are formed in a workpiece using an electro-chemical machining process. The drilling rate and depth monitor is particularly useful where the rate of aperture formation is extremely slow, i.e., less than one-thousandths of an inch per second. The drilling rate includes a position sensor coupled between a workholder and a movable member supporting a plurality of cathodic drilling tubes which yields a depth signal proportional to the distance between the drilling tubes and the surface of the workpiece. Differentiation means are responsive to the depth signal for producing a drilling rate signal and display means are provided for both the drilling rate and drilling depth.

Abstract: This invention relates to the production of highly transparent glass-ceramic articles containing about 30-50% by volume gahnite having dimensions finer than about 300 .ANG. as essentially the sole crystal phase. The articles have compositions essentially free of Li.sub.2 O, Na.sub.2 O, CaO, SrO, and BaO and consist essentially, by weight, of about 1.5-5% R.sub.2 O, consisting of 0-3% K.sub.2 O and/or 0-3% Rb.sub.2 O and/or 0-3% Cs.sub.2 O, 13-22% ZnO, 16-28% Al.sub.2 O.sub.3, 45-65% SiO.sub.2, and 1.5-8% TiO.sub.2.

Abstract: Methods are provided for reducing the water content of optical waveguide fibers produced from blanks having a centerline aperture and having compositions which prevent cooling of the blank to room temperature between consolidation and drawing. In accordance with certain aspects of the invention, the water content is reduced by storing the blanks at as low a temperature as possible, preferably below about 550.degree. C. In accordance with other aspects, the water content is reduced by filling the apertures of the blanks with an inert atmosphere during storage.

Abstract: A plurality of optical waveguide preforms are simultaneously formed by depositing on a plurality of starting members layers of glass soot to build up a coating on each starting member. The soot layers are deposited by traversing a series of burners along the starting members in such a manner that a given one of the burners traverses the first starting member from a first end thereof to a second end thereof to form a layer of soot thereon. The remaining burners of the series similarly traverses the first starting member, a plurality of burners traversing the first starting member at any given time. After the first burner has traversed the first starting member it similarly traverses the second starting member. After the last of the series of burners has begun its traverse along the first starting member, the first of the series of burners completes its traverse of the second starting member and again begins traversing the first starting member immediately following the last of the series of burners.

Abstract: Anamorphic lenses or lens arrays are formed in photosensitively crystallizable glass by selective exposure of the glass surface and thermal treatment to cause the crystallization of the glass surrounding the lenses. The lenses, which have elongated cross-sections in the plane of the exposed glass surface and raised curved surfaces resulting from the densification of the surround material, exhibit different surface curvatures over their major and minor transverse axes and thus anamorphic light-focusing properties.

Abstract: A composite body consisting of a glass or glass-ceramic substrate with a non-stick, heat resistant resin composition bonded to a surface thereof. Suitable substrates are those which contain one or more differentially etchable components. Particularly useful are glass compositions which undergo phase separation upon heat treatment. For example, some borosilicate glasses separate into a silica-rich phase and a borate-rich phase when heated to about 600.degree. C. and maintained at that temperature for about one hour. The substrate is etched to remove at least a portion of one component to provide a bonding surface containing extremely small pores of relatively uniform diameter for a non-stick heat resistant resin composition. The resin composition is uniformly applied to the etched substrate in liquid form and subsequently hardened, suitably by fusion, to form a solid, substantially continuous film over the etched surface.

Abstract: This invention is concerned with a method for preparing transparent laminated polarizing glass articles consisting of a support of an inorganic or organic glass, a coating exhibiting polarizing properties disposed on one of the surfaces of the support, and an optically transparent layer adhered to the coating which protects the coating from humidity. The vital feature of the method comprises a first treatment by a gamma-aminopropyltrialkoxysilane and a second treatment by an epoxyalkyltrialkoxysilane which is designed to improve the adherence of the optically transparent layer to the polarizing coating.The invention is especially useful in the fabrication of eyeglass lenses.

Abstract: A monolithic refractory honeycomb filter of zircon or zircon plus an oxide additive is useful to remove impurities from molten metal, particularly from molten steel. The filter has a frontal contact surface containing the openings of a plurality of through-and-through cells for passage of the molten metal. Impurities adhere to the frontal contact surface of the filter and to the cell walls themselves.