Abstract: Fluorescent materials such as certain metal ores are detected under ambient light conditions by observing the material through a gated aperture which is opened at predetermined intervals for periods of predetermined duration while simultaneously exposing the material to periodic pulses of fluorescent stimulating light. The frequency of the light pulse is synchronized with the frequency of the opening of the gated aperture so that the aperture is open for at least a portion of the period during which fluorescence is produced by the stimulating light pulse. Electro-optic goggles are a preferred type of gated aperture.

Abstract: Folic acid derivatives, such as radiolabeled pteroyltyrosine, are conveniently synthesized from either pteroic acid or by the direct condensation of 6-formylpterin with p-aminobenzoyltyrosine methyl ester. The radioiodinated derivatives are particularly useful in competitive protein binding and radioimmuno-assays of folate compounds.

Abstract: In graphite electrode joints comprising two graphite electrode ends having axial tapered end sockets and a double ended tapered thread connecting pin screwed into both of said sockets, the strength of the joint is improved by increasing the angle of the taper from the conventional 9.46 degrees to from 15 to 35 degrees.

Abstract: A direct, quantitative method is provided for the determination of chloride in blood serum which is based on the reaction between the chloride and ferric ions. A novel reagent is employed in the method which contains no mercury but does contain a surfactant which prevents protein precipitation.

Abstract: The density of hot pressed sintered refractory composites of AlN, TiB.sub.2 and BN powder mixtures is improved by the addition of small amounts of nickel powder.

Abstract: Resistance-heated vaporization boats for the vacuum vaporization of metals, such as aluminum, chromium, copper or the like, are made by machining a boat cavity in at least one side of a graphite bar. The bar is totally encapsulated over its entire outer surface, including the boat cavity, with a continuous coating of pyrolytic boron nitride (PBN). The PBN coating is removed from areas at both ends of the bar to provide electrical contact zones for connecting the bar to a power source. The sides and ends of the boat cavity have smooth contours without sharp corners and the ends of the cavity have a hemispherical configuration to resist longitudinal expansion of the PBN coating thereby preventing separation of the PBN coating from the surface of the graphite bar. The PBN coating is deposited from a gas at a temperature of 1750.degree. C. to 2300.degree. C. and has a thickness of at least 0.010 inch.

Abstract: Hydrogen and chlorine are burned to form hydrogen chloride gas using an improved burner which generates a flame of a diameter not much greater than the burner cap diameter, thereby avoiding impingement on the walls of the combustion vessel.

Abstract: An aluminum coated carbon article or composite, and process therefor having aluminum chemically bonded to carbon via an interface of a metal monocarbide formed in situ when an intermetallic phase comprising aluminum and a metal capable of reacting with carbon to form a metal carbide is reduced by carbon to aluminum and a metal carbide, the metal selected from the group consisting of tantalum, titanium and hafnium.

Abstract: Porous abradable sintered metal structures suitable for use as abradable seals are rendered oxidation resistant and thus suitable for high temperature service by introducing into the porous structure an intermetallic compound of aluminum with one of chromium, titanium, cobalt and nickel, which compound is then thermally reacted with the porous metal structures to form an aluminum alloy in the structure.

Abstract: Metal/ceramic abradable seals of the type used in jet aircraft are improved by using a substrate which is able to deform during cooling from the brazing temperature and then rendering the substrate rigid after the cool down.

Abstract: A method for the addition of a reactive metal to a molten metal bath wherein the vapor pressure of the reactive metal at the bath temperature exceeds the total ambient pressure above the surface of the bath by establishing a gaseous atmosphere containing a nonreactive gas and a small quantity of SF.sub.6 above the surface of the bath so as to increase the recovery of the reactive metal addition in the bath.

Abstract: Metal/ceramic abradable seals of the type used in jet aircraft are improved by maintaining a temperature differential between the metal/ceramic composite and the cooler substrate during cooling from the brazing temperature.

Abstract: A reformable packing ring comprising compressed particles of flexible graphite. Such packing ring can be used to pack the stuffing box assembly of any pump, valve, or like structure. Because such packing ring undergoes considerable flow when subjected to pressure, it is capable of forming a better interference fit within the stuffing box than presently employed packing rings. As a result of this ability to flow and reform its dimensions under pressure, such packing ring need not be sized as precisely to the dimensions of a particular stuffing box as presently employed rings.

Abstract: A master alloy containing barium, strontium, silicon and aluminum for modification of the aluminum-silicon eutectic phase of eutectic and hypoeutectic aluminum-silicon casting alloys.

Abstract: A chrysotile asbestos base material having a precipitation deposited siliceous layer and an organo-silane coating bonded to and overlying said siliceous layer.

Abstract: A method for the addition of manganese to a molten magnesium bath by mixing the manganese to be dissolved in a finely divided form with magnesium in a finely divided form and adding the mixture to the molten magnesium.

Abstract: The thermal insulation in the bottom of an electrolytic cell for the production of metal by electrolysis of metal ore or ore derivatives is protected from attack by the corrosive elements in the electrolytic bath. The protection is provided by a layer of graphite sheet formed from expanded graphite which is placed on top of the insulation. Preferably the graphite rests on a thin steel sheet.

Abstract: An electrode joint having tapered threaded recesses in the mating electrode sections and a connecting threaded nipple, with a friable thread segment either in each threaded recess, or on each half of the threaded nipple, the friable thread being thickened along at least a portion of its long flank and being reduced in thickness along its short flank.

Abstract: Porous abradable sintered metal structures suitable for use as abradable seals are rendered oxidation resistant and thus suitable for high temperature service by introducing into the porous structure an intermetallic compound of aluminum with one of chromium, titanium, cobalt and nickel, which compound is then thermally reacted with the porous metal structures to form an aluminum alloy in the structure.

Abstract: A method of producing improved fused alumina or fused alumina-chromia refractory bodies wherein the binder added to the fused grain powder prior to forming a slurry for molding contains chromium metal and unfused alumina.