Abstract: A mandrel assembly supports an umbilical cord during the shaping and curing of the cord for use as a vascular graft. The mandrel assembly has a pair of mandrel members adapted to be releasably connected in end-to-end relation. Adjacent end sections of the mandrel members have reduced cross sectional shapes to provide the graft with a Venturi throat. Each mandrel member has a low friction outer surface to facilitate the insertion and withdrawal of the mandrel member from the lumen of the umbilical cord.

Abstract: A process is herein disclosed for producing a slow release composite comprising grinding and mixing mechanically in a frozen state one or more polypeptides, one or more proteins and one or more physiologically active substances shaping the blend into a desired form and compressing at a pressure of from 100 to 20,000 kg/cm.sup.2 to thereby produce a slow release composite having the physiologically active substances encapsulated therein.

Abstract: Cleaning agent for fire-arm barrels based on ammonia or amine compounds, in particular for the removal of abraded shot or bullet material. In order to achieve a simple and non-dangerous application and to improve storability, the ammonia or amine compound is contained in a high viscosity gel. An improved cleaning action can be achieved when the gel additionally contains a grinding and polishing agent with a mechanical effect, for example cerium oxide or very finely pulverized silicon dioxide.

Abstract: The pitch is extruded at a suitable temperature through cylindrical nozzles. At the exit from these nozzles the pitch is lowered into water, where a cutter divides it into granules which, deposited on a conveyer belt, remain immersed long enough to permit suitable cooling. Then they undergo drying by hot jets of air.

Abstract: A method of making inserts suitable for tool or drill bits which includes the step of fragmenting, e.g. by means of a laser beam, an abrasive compact in a plurality of discrete, non-segmental fragments. The inserts may have a variety of shapes, some of which are new, such as conical, truncated conical or truncated pyrimidal. The inserts are particularly useful for wire-drawing die blanks and core or oil-well drill bits.

Abstract: A novel method is disclosed for preparing a tungsten carbide grit. The method comprises blending tungsten carbide powder with a binder, forming agglomerates of the powder and sintering the agglomerates to form the tungsten carbide grit.

Abstract: Shaped articles in thin-walled form, such as threads, membranes, sheets and tubes and particularly material for encasing sausage, are produced from a shapable mass containing in aqueous dispersion at least one coagulable, amphoteric high molecular organic substance, such as collagen or other coagulable animal protein, by extruding the mass through a die into an aqueous bath in which coagulation of such substance in the extrudate is effected by changing the pH of the dispersion so that the isoelectric point of the substance is traversed, the dispersion being prepared with a sufficient content of polyvalent ions, such as calcium ions, to inhibit formation in the extrudate of a barrier to ion penetration. The dispersion desirably also contains an agent for cross-linking the coagulable substance in the extrudate. The mass fed to the extruding die preferably is a collagen paste containing glyoxal and calcium ions. The speed of the coagulation can be enhanced by subjecting the extrudate in the bath to a D.C.

Abstract: A process for the production of a porous ceramic mold is described, compsiging adding about 40 to 60 parts by weight of water to 100 parts by weight of a ceramic material, mixing the thus-formed ceramic slurry with about 20 to 40 parts by weight of a hydrophilic urethane prepolymer having a free isocyanate group content of from about 4% to 7% by weight, reacting and foaming the resulting mixture after the introduction thereof into a mold, drying the thus-formed foamed urethane molded article, and combusting very slowly and sintering the dried foamed urethane molded article to produce a porous ceramic molded article.

Abstract: In corundum abrasive grain which is ceramically coated with ground frit, a binder and fine grain highly abrasive material for the purpose of improving adhesion of the abrasive grain in its processing to resin-bonded abrasives and their use in wet grinding. The fine grain material forms from 1 to 5 weight percent of the untreated corundum grain and ranges in size from 10 to 50 microns, which corresponds to from 1 to 10 percent of the average diameter of the initial grain.

Abstract: Coated wear resistant composite ceramic cutting tools comprise a composite substrate body consisting essentially of a particulate material selected from the group consisting of the refractory metal carbides, nitrides, carbonitrides and combinations thereof uniformly distributed in a matrix, coated with at least one intermediate adherent coating layer of a refractory material and an outer adherent coating layer. The intermediate adherent coating layer has a different chemical composition than the outer adherent coating layer. The particulate material is of an average particle size ranging between about 0.5 microns to about 20 microns and comprises from about 5 to about 60 volume percent of the composite cutting tool. The matrix consists essentially of a modified silicon aluminum oxynitride having about 2 to about 25 volume percent of a modifier selected from the oxides of silicon, yttrium, magnesium, hafnium, zirconium, beryllium, the lanthanides and combinations thereof.

Abstract: A process improvement is disclosed for making compacts containing diamond which reduces crystal flaws within the diamond. This is accomplished by isolating the single diamond crystals in an compressible matrix before exposing the sample to sintering conditions. One method for doing this (described with reference to FIG. 1) is embedding the diamond 14 in a mixture 16 of graphite and diamond fines. This mixture is disposed between two graphite discs 18 and 19 and two cobalt discs 22 and 23. This sub-assembly is contained within zirconium cup 10 on top of which is placed zirconium disc 12 and exposed to high pressure-high temperature sintering conditions.

Abstract: A hot roll, for use in a xerographic, dry-release, hot roll fuser, is made by a method which adds iron-containing, magnetically permeable, particles to the elastomer as the elastomer is mixed. The particles may be pre-coated with a silane adhesive promoter. The mixed elastomer is then injected around a hollow, cylindrical aluminum core. As the elastomer sets up, in the mold, a magnetic field is applied such that the iron-containing particles migrate toward the metal core, and away from the exterior surface of the elastomer. This exterior surface will later be used to fuse xerographic toner. After the elastomer has set, its external surface is ground slightly, to produce a true circular-cylinder, but without exposing the underlying, more dense, layers of iron particle filler. As a result, the elastomer-to-core interface is mechanically strong, and yet the fusing property of the elastomer is not degraded by the presence of filler.

Abstract: A film heating apparatus includes a vertical tank vertically adjustably mounted on a base supported post, a hollow vertical roller extends between and is journaled to brackets projecting from opposite ends of the tank, an electric motor driven pump mounted on the tank circulates a heat transfer liquid through and between the roller and tank through a rotary coupling mounted on the roller, the liquid in the tank being heated by an immersion electric heater which is energized in response to a temperature sensing member responsive to the liquid temperature and a second idler roller is supported between the brackets and is transversely spaced from the first roller.

Abstract: A cutting insert having a cutting portion comprising a dispersion of diamond crystals in a matrix of .beta.-silicon carbide and silicon nitride is produced by forming a first dispersion of diamond crystals evenly coated with carbon black in a temporary binder, and forming a second dispersion of carbon fiber, carbon black and filler in a temporary binder. The first and second dispersions are compacted together to produce an intermediate composite which is heated in a vacuum furnace in order to remove the temporary binder and allow liquefied silicon to infiltrate the composite. The composite is then sintered and subjected to nitrogen, wherein elemental silicon at the surface of the composite reacts with the nitrogen to produce silicon nitride.

Abstract: The invention provides an abrasive body suitable for mounting in a tool for abrading operations, the body including an abrasive compact comprising a mass of abrasive particles, present in an amount of at least 70 percent by volume of the compact, bonded into a hard conglomerate and support means covering a part of the surface of the compact and bonded to the compact, characterized in that the support means covers more than 50 percent of the surface of the compact and the compact presents an arcuate formation, salient in relation to the support means, capable of abrading a workpiece.

Abstract: Abrasive properties of co-fused alumina zirconia are improved by the addition of from 0.1 to 2% of Y.sub.2 O.sub.3 to the fusion mix and quenching the fused product. Y.sub.2 O.sub.3 ores containing mostly Y.sub.2 O.sub.3 with lesser amounts of rare earth oxides can be substituted for high purity Y.sub.2 O.sub.3.

Abstract: An apparatus for the production of calcium silicate based stone blanks including at least one mold into which a crude mixture is poured, the mixture comprising granulated silicate-containing material, lime, water, a cement and foam. The mold has a cover, a bottom and side plate, with one of the plates being movable to open and close the mold. The crude mixture is heated in the mold essentially uniformly to a temperature between 45.degree. C. and 90.degree. C. until achieving the desired blank-strength by strength-forming reactions of the cement in the crude mixture. The heater used for this purpose is a high frequency voltage heater using two parts of the mold as condensor plates connectable with a high frequency voltage source. The formed stone blanks are thereafter removed from the mold and transferred to a transport station.

Abstract: The upper and lower ends of numbers of curved cooling pipes are rotatably supported in the variable-type bubble water cooling apparatus according to the present invention. The cooling water is supplied to the pipes. The diameter of enveloping circle formed by these curved cooling pipes at a determined horizontal position is varied by relatively rotating the upper and lower support members of pipes. Thus, as the diameter of bubble passing portion of the apparatus can freely be varied, bubbles of variety of sizes can be produced by a single apparatus. Also, the cooling effects and positions are constant and the produced bubble has no unevenness of its thickness.

Abstract: Sintered silicon carbide composites containing diamond crystals are made through a process wherein a first dispersion of diamond crystals and carbon black in paraffin is formed, along with a second dispersion of carbon fiber, carbon black and filler in paraffin. One of the dispersions is compacted to produce a physically stable intermediate compact which is then recompacted with the remaining dispersion to produce a binary compact. The latter is subjected to a vacuum for a period of time at a temperature sufficient to vaporize essentially all of the paraffin, after which the binary compact is infiltrated with liquid silicon and sintered to produce a .beta.-silicon carbide binder uniting the resulting composite.

Abstract: A method and apparatus for continuously cooling a thermoplastic shape having two open sides in which the thermoplastic shape, in its at least partially molten state, is extruded and/or drawn along an elongated form having a contour complimentary to the contour of one side of the two open sides and, simultaneously with moving the thermoplastic shape, at least partially cooling the thermoplastic shape by cooling the form with a liquid cooling medium and drawing a vacuum, on the previously mentioned one side of the two open sides of the thermoplastic shape, through the form.