Abstract: A new, simplified method of fabricating optically transparent fluoride glasses containing ZrF.sub.4 and/or HfF.sub.4 has been developed which relies on a high vacuum pretreatment for surface dehydration, melting in a rigorously inert argon atmosphere, and incorporation of a nonvolatile metallic oxidant in the melt such as InF.sub.3 or SnF.sub.4. Previous methods for making these glasses have relied on either addition of ammonium bifluoride into the batch materials, or melting in an oxidizing atmosphere (so-called reactive atmosphere processing or RAP); both of these latter techniques have significant drawbacks.

Abstract: A low reflectance glass surface is disclosed which includes a particular combination of surface structures which produce a low reflectance yet high clarity glass. The surface structure includes a plurality of randomly distributed surface scallops which have a diameter of about 100 to 2000 micrometers, with a plurality of islands at spaced-apart intervals distributed thereover, at a density of about 25 to 500 islands per square millimeter. The glass surface preferably also includes a microporous structure which is uniformly provided across the surface of both the scallops and the islands, with the micropores being about 0.2 to 1.0 micrometers in diameter. The glass further includes a skeletalized silica structure of 200 to 600 angstroms in diameter, uniformly distributed over the surface.

Abstract: A method is disclosed for producing coplanar metal/insulator films on a substrate according to a chem-mech polishing technique. In one example, a substrate having a patterned insulating layer of dielectric material thereon, is coated with a layer of metal. The substrate is then placed in a parallel polisher and the metal is removed elsewhere except in the holes where it is left intact. This is made possible through the use of an improved selective slurry which removes the metal much faster than the dielectric material. The insulating layer may then be used as an automatic etch stop barrier.In a second example a substrate having a patterned metallic layer is coated with an insulating layer and then subjected to chem-mech polishing. The structure is coplanarized by the chem-mech removal of the insulating material from the high points of the structure at a faster rate than from the lower points. Optional etch stop layers also may be used.

Abstract: A method of patterning a perforated screen printing screen (9) having a lacquer coating filling its perforations (10), using a laser engraving device, includes the steps of locating the position of the locus of aligned perforations (10), aligning an engraving head (7) of the laser engraving device with the locus of the perforations (10) and then selectively actuating the laser to remove the lacquer individually from those perforations (10) which it is required to unblock.

Abstract: An optical preform is prepared first by depositing soot about a glass subate rod (22) to form a boule. Then the soot boule is sintered to consolidate the material and provide a preform from which optical fiber is drawn. The boule is relatively large so that the resulting preform is capable of providing more optical fiber than those used in the past. In order to be able to sinter successfully the enlarged boule, microwave energy from a furnace (60) is coupled to the glass rod so that the sintering proceeds from the rod radially outwardly thereby allowing gases readily to escape and rendering the process highly efficient.

Abstract: Glass optical elements are molded by moving molds toward one another to press the glass and controlling the movement of the molds to balance the complete formation of the molded surfaces. A first mold is moved to a position short of contact with the glass and parked. A second mold is moved into contact with the glass to drive the glass into contact with the molding surface of the first mold. This changes the shape of the optical surface in contact with the second mold so that continued movement of the first and second molds results in balanced molding with the voids between the molding surfaces and the glass being equivalent for both surfaces.

Abstract: Disclosed is a glassware forming mold of three-layer construction including first and third bodies, one of which is to be in contact with a portion of molten glass fed, for controlling the heat transference in a glassware forming process. A second central body is located between said first and third bodies and is comprised of a metallic alloy which melts approximately at temperature between about 375.degree. C. and 550.degree. C. corresponding to a working temperature of the molten glass, provides a solid-liquid state, to control the heat transference from the molten glass to the first or third bodies and from these to the environment during the glass forming process, whereby the glass distribution within the mold is improved.

Abstract: After a semiconductor wafer is processed, a photoresist on the semiconductor wafer is removed by an irradiation of oxygen plasma while the wafer is cooled by a cooling device. The cooling device can be a susceptor or a stage on which the wafer is placed, and coolant flows through a pipe or duct installed thereto. Cooling of the wafer prevents the photoresist from being softened by the heat from the plasma. Thus, the inner side of the photoresist remains hard enough to support the affected surface portion of the photoresist, which is also difficult to remove, preventing the affected surface portion from sticking onto the surface of the wafer. Therefore, the affected portion can be more effectively irradiated by the plasma, and can be decomposed without leaving residue on the wafer. Reduced residue on the wafer surface contributes to improve production yield and quality of the products made from this wafer.

Abstract: A raw material supplying device having a gas tight tank for receiving a material to be gasified by heating; a heater for heating the raw material within the tank and a plurality of pipes for conveying a plurality of streams of gas in parallel to each other to a plurality of ports of a reaction apparatus, and a process for using the raw material supplying device. The raw material supplying device can be used in a system for manufacturing glass fibers in which the ends of the plurality of pipes are connected to the gas feed ports of at least one multi-layer burner.

Abstract: A food preservation composition comprising a combination of safe chemicals is effective in low concentrations and imparts no off-color taste to the foods with which it is used, yet effectively prevents the discoloration of vegetables such as potatoes. Citric acid and cysteine, combined in the ratio of about 1 part cysteine to about 25 to 30 parts citric acid, may effectively prevent the blackening of potatoes when applied in solutions of about 0.5 to 0.7 percent by weight in water. A water solution of cysteine and citric acid in which the citric acid does not exceed 1 percent by weight, and the cysteine does not exceed 0.05 percent by weight of the solution, effectively prevents such blackening. Citric acid/cysteine compositions are rendered even more effective in the presence of very low concentrations of ascorbic acid; for example, about 0.1 percent to about 0.3 percent by weight in the water solution.

Abstract: A large number of small superconducting solenoids are produced on a common substrate simultaneously. Two parallel slits (5) passing through a silicon wafer are dug in such manner that a core (10) is left between the slits and then a superconducting thin film of compound oxide is deposited around the core (10).

Abstract: A glass container forming mold, comprising an outer member formed of a metal, an inner member formed of a carbon material, and a flexible, compressible carbon sheet interposed between the outer member and the inner member, is provided.

Abstract: A fine pattern forming method capable of forming an accurate fine pattern without charge-up at the time of electron beam or focus ion beam exposure is provided by treating the bottom layer or intermediate layer or silicon containing resist of a multi-layer resist with ion shower irradiation or reducing solvent.

Abstract: Disclosed is a method of manufacturing a preform for an asymmetric optical fiber which comprises the steps of (a) fixing plural transparent glass rods involving at least one core-mother rod functioning as the core in said optical fiber in parallel relationship, (b) depositing glass soot around an assembly of said plural parallel fixed glass rods, thereby providing a single porous cladding bearing the predetermined shape, and (c) vitrifying the porous cladding by thermal fusion, thereby providing the entirely integral transparent preform. The above method does not involve any process of perforating a drilled-pore which is needed inevitably in conventional method. Therefore, it is possible to obtain a long preform with high dimensional precision, and to fabricate the optical fiber with low transmission loss.

Abstract: A method of manufacturing a thin film of an oxidic superconducting material in accordance with a pattern, in which a pattern is manufactured by means of etching using reactive ions and a mask of aluminium oxide or silicon oxide, said method enabling patterns having line widths smaller than 2 .mu.m to be manufactured with great accuracy without influencing the composition of the superconducting thin film in such a manner that the superconducting properties deteriorate.

Abstract: Grooves are etched in a glass substrate, using a metallic mask, after which the substrate is coated with a layer of glass having a refractive index which is higher than that of the substrate, the groove being filled completely. Excess glass is removed, the metallic mask being used as a stop layer and a protective layer being provided at the location of the filled grooves. Excess glass is removed at the location of the grooves by means of polishing so that a high accuracy as regards depth can be obtained.

Abstract: A method of making an economical fiber coupler comprises providing a glass tube having first and second end portions and a midregion, and a longitudinal aperture extending therethrough. Two suitably prepared glass optical fibers, each having a core and cladding, are disposed within the longitudinal aperture, the fibers extending beyond each end thereof. The fibers are held taut to effect a tension therein, and they are glued to each end portion. The midregion of the member is heated, collapsed about the fibers, and drawn to reduce the diameter thereof.

Abstract: The invention relates to a process for producing on a substrate conductor elements which are mutually spaced by a submicron dimension.This process comprises the stages of producing on substrate (1) spacers, whose dimensions and spacing are a function of the dimensions and spacing of the elements (11a) to be produced, anisotropic deposition on the substrate and perpendicular thereto of the material (11a) constituting the spacers and elimination of said spacers.The invention applies to the production of any random elements and particularly to the production of slightly mutually spaced electric conductors.

Abstract: Collector compositions for use in froth flotation processes for the beneficiation of gold, silver and platinum group values from base metal ores are disclosed. The collector compositions comprises at least one monothiophosphate compound selected from compounds of the formula: ##STR1## wherein each R is a C.sub.2 -C.sub.8 alkyl or a ##STR2## radical, R.sup.1 and R.sup.2 are, individually, hydrogen or C.sub.1 -C.sub.4 alkyl radicals, n is 0 or 1 and X is a cation. The use of the monothiophosphate collectors provides excellent selective recovery of gold, silver and platinum group metal values in froth flotation processes conducted under alkaline conditions.

Abstract: A process is disclosed for determining the dissolved zirconium content of a hydrofluoric acid-nitric acid etching bath for zirconium articles by determining the rise in temperature of a volume of the bath upon immersion therein of a known quantity of zirconium metal, immersing a known quantity of zirconium metal into a portion of the bath, measuring the rise in temperature over a predetermined period of time of said portion, determining the dissolved zirconium content of the bath as a function of the rise in temperature, and treating the bath dependent upon the dissolved zirconium content so determined to be in the bath.