Abstract: A method and system for processing a photographic negative to obtain photographic prints exhibiting enhanced contrast therefrom are described. A sheet of darkened optically bleachable photochromic glass, positioned between the negative and a selected photographic printing medium, is selectively bleached by light passing through the negative to form an image of the negative in the glass. Light of a wavelength effective to activate the photographic printing medium is then passed through the photographic negative and selectively bleached photochromic glass and focused to provide an enhanced contrast image of the photographic negative on the printing medium. A photographic print of enhanced contrast is thus produced.

Abstract: There is disclosed a method of making composite glass tubing, and a molten glass feeding apparatus uniquely designed to carry out such method. The feeder apparatus comprises concentrically-arranged cylindrical containers, a blow tube located within the central container, and a plug member mounted on the base of the blow tube. The bottom portion of each cylindrical wall is downwardly and inwardly directed to provide restricted annular bottom openings. The bottom edges of the cylindrical walls and of the plug are positioned in such relation to each other that orifices are provided through which annular streams of molten glass may flow and contact adjacent streams in the fluid state, thereby forming composite glass tubing having at least three layers.

Abstract: Method of detecting and/or quantitating anti-virus antibodies comprising the steps of reacting serum containing an unknown amount of a given antibody, a known amount of the antibody (radioactively labelled), and a composite consisting of the antibodies coupled chemically through an intermediate silane coupling agent to a porous glass body, the composite having complexed thereto quantities of the virus; separating the composite from the reaction solution after a suitable reaction period; determining the radioactivity count of the separated composite or the remaining solution; and, relating the count to a standard curve.

Abstract: Gel-like compositions useful for separating and partitioning whole blood into serum and clot portions. The composition comprises a polybutene liquid polymer having an inert high surface area inorganic filler dispersed therein, the filler being present in an amount sufficient to impart to the composition a specific gravity ranging from about 1.030 to about 1.090 and a viscosity ranging from about 200,000 to about 850,000 centistokes. When centrifuged in the presence of whole blood, the composition forms a chemical and physical barrier between the serum and clot portions.

Abstract: A method for providing broad-band antireflective surface layers on a chemically durable borosilicate glass which comprises phase-separating the glass by heat treatment at 630.degree.-660.degree. C., removing a siliceous surface layer from the glass, and treating the glass in an aqueous solution containing both H.sup.+ ions and F.sup.- ions for a time sufficient to produce the antireflective surface layer, is described. Antireflective surface layers exhibiting reflectances as low as 0.5% throughout the wavelength range from about 0.4-2.0 microns have been produced.

Abstract: This invention is concerned with the production of highly-crystalline, transparent glass-ceramic articles, wherein the predominant crystal phase is a beta-quartz solid solution, and which exhibit transmittances of infra-red radiations in excess of 75%, and, frequently in excess of 85%, at a wave length of 2.5 microns in articles having cross sections of about 3 mm. The articles also demonstrate excellent resistance to attack by acids and detergents, and possess coefficients of thermal expansion over the range of room temperature (R.T.) to 600.degree. C. of less than 10 .times. 10.sup.-.sup.7 /.degree. C. Compositions operable in the invention are encompassed within a very narrow range of the Li.sub.2 O--MgO--ZnO--Al.sub.2 O.sub.3 --SiO.sub.2 quinary nucleated with a combination of TiO.sub.2 + ZrO.sub.2. Where desired, coloring agents conventional in the glass art can be added to yield colored, transparent, glass-ceramic articles.

Abstract: Mismatched expansions of monoclinic celsian and zirconia crystals and the refractoriness of both phases in a sintered ceramic body result in highly refractory, microcracked and thermal shock resistant products. Avoidance of the higher expansion hexagonal form of celsian is desirable to obtain the better thermal shock resistance.

Abstract: Small semiconductive devices such as diodes are encapsulated in glass sleeving composed of a PbO--K.sub.2 O--Al.sub.2 O.sub.3 --B.sub.2 O.sub.3 --SiO.sub.2 glass exhibiting good alkali durability and specified thermal expansion characteristics in combination with a reduced softening temperature.

Abstract: Chemically-strengthenable silver halide-containing lithium boroaluminosilicate glass compositions having physical and chemical characteristics required for sheet drawing processes and exhibiting excellent photochromic properties after heat treatment, and also strengthened photochromic drawn sheet glass articles provided therefrom, are described.

Abstract: An apparatus for severing the ends of a plurality of parallel optical fibers so that the endfaces thereof are relatively flat, are substantially perpendicular to the fiber axes and are relatively coplanar. The fibers are bent over an arcuate surface and are slidably clamped between the flat surfaces of two pieces of rubbery material. The clamp is urged by a spring in such a direction that the fibers are in tension. After one fiber is scored and breaks, the clamp automatically slides along the remaining fibers until the clamping force on those fibers is sufficient to prevent further sliding. The fibers are individually severed in this manner.

Abstract: The instant invention is directed to the production of opal glasses through the solid state vitrification of certain bentonite-type clays. The process involves five general steps: (1) the clay is ion exchanged at low temperatures in aqueous solutions; (2) the ion exchanged clay is thoroughly washed with water; (3) the ion exchanged clay is preferably heated at moderate temperatures to expedite removal of the water; (4) the dehydrated clay is shaped into a body of a desired configuration; and (5) the shaped body is fired to vitrification utilizing a defined sintering schedule. The resulting body is a white or off-white opal glass containing minor amounts of crystal phases. Uniformly colored glasses can be prepared employing such conventional glass coloring agents as chromium, cobalt, copper, nickel, vanadium, etc. The process possesses the practical advantages of inexpensive batch materials, the elimination of the need for glass melting facilities, and low energy consumption in forming glass articles.

Abstract: The instant invention relates to photosensitive glasses, i.e., glasses which, after an exposure to high energy or actinic radiations, can be heat treated in a certain manner to develop a colored transparent article, or which can be thermally opacified to produce a colored opal glass. More particularly, the instant invention is directed to alkali halide silver halide-containing photosensitive glasses which, through a unique sequence of shortwave radiation exposures and heat treatments, exhibit the total range of colors seen in the visible spectrum either in the transparent or in the opacified state and in three dimensions. The base glass composition can be varied widely, but the presence of silver, alkali oxide, fluorine, at least one of the group consisting of chlorine, bromine, and iodine, and, where ultra-violet radiations comprise the actinic radiations, cerium oxide is required. Multi-colored photographs and other unique decorative effects can be imparted into such glasses.

Abstract: Multifocal photochromic opthalmic lenses are produced by nucleating potentially photochromic major lens blanks through heat treatment, combining the nucleated blanks with compatible button or segment glasses, and fusing the combined glasses at temperatures suitable for achieving both fusion and the simultaneous development of full photochromic properties in the previously nucleated major lens blanks.

Abstract: A method of heat treating a plurality of geometrically congruent and flat lens blanks made from a phototropic glass, such heat treating being performed for development of the phototropic properties thereof. A plurality of lens blanks are formed into a stack by alternately positioning and clamping similar areas between the flat surfaces of two flat, annular, spacer members. The stack is then rotated about the longitudinal axis oriented in a substantially horizontal position while evenly heating the lens blanks to the phototropic development temperature of the glass. The stack of blanks is then vertically positioned while continuing the heating thereof and part of each of the blanks sags into the hollow of the spacer member therebelow to form such part of each blank into a curved configuration for an eyeglass lens.

Abstract: Method of reducing the firing shrinkage of the axial hub opening in a disc-type cellular or honeycomb, ceramic heat exchanger by substantially filling the hub opening with a plug which undergoes substantially the same firing shrinkage as the hub opening. The plug then shrinks with the heat exchanger and keeps the hub opening closed, thereby preventing accelerated heating of the cellular ceramic nearest the hub opening and corresponding local increase in the firing shrinkage due to the accelerated heating. A plug with a bulk density closely approximating that of the ceramic matrix is desirable and a plug fashioned from the same cellular ceramic material as the matrix is particularly convenient and effective.

Abstract: Sinterable powdered glasses comprising MgO, Al.sub.2 O.sub.3, SiO.sub.2 and at least one modifying oxide selected from the group consisting of BaO, PbO, SrO and CaO, which are thermally-crystallizable at sintering temperatures to yield highly crystalline, low expansion, thermally stable glass-ceramic coatings comprising crystals of a structure corresponding to hexagonal cordierite as the crystal phase, are described. The use of the glasses to provide crystallized electrical barrier layers on glass-ceramic articles is also described.

Abstract: Apparatus for controlling the temperature of an open liquid body when actual measurement of that temperature is not possible. A thermal analog of the liquid body, which is exposed to the same heating or cooling source as the liquid body, is incorporated into a sensor which provides controlling feedback to the heating or cooling source. The sensor, which is disposed in the atmosphere which surrounds or flows by the liquid body, includes a dry element and a wet wick, body of which are in thermal contact with a temperature sensing element. The dry element senses the temperature of the atmosphere and the wet wick has a cooling effect on the sensing element that is related to the rate of evaporation of liquid from the body. This sensor is advantageously employed in a system for regulating the temperature of a reagent film on a microscope slide.

Abstract: Useful products such as molecular hydrogen can be continuously produced by reacting a solution of a substrate in the presence of light with a photometabolically active microbe which has been stabilized on a support. In one embodiment, Rhodospirillium rubrum bacterial cells are mixed with agar gel and the mixture is spread over a plate which is placed in a transparent flow-through reactor. Then, an aqueous malate solution is passed through the reactor under essentially anaerobic conditions in the presence of light to yield molecular hydrogen. In another embodiment, Blue-Green algae are similarly stabilized for continuous biophotolysis of water by oxidizing the water and reducing NADP to NADPH. Other photosystems for producing useful products are disclosed.

Abstract: The instant invention relates to the production of composite glass articles involving the bringing together of two or more glasses, while in the molten state, into an integral unit. More particularly, the present invention is concerned with the manufacture of such articles wherein a reaction occurs at the interface between the laminae of molten glass such that an opal phase is spontaneously produced in situ thereat.