Abstract: A hot-pressed optical body which is free from absorption bands due to carbon dioxide, water, hydroxyl ion and acid fluorides in the ultraviolet, visible and near-infrared wavelength regions. Typically, the optical body is formed from a powder of an alkaline earth metal fluoride, alkali metal fluoride, or rare earth metal fluoride. One or more absorption bands due to a single impurity may be reduced or eliminated, or bands due to plural impurities may be reduced or eliminated sequentially, or simultaneously. The optical body is made by flowing a reactive, reducing gas, optionally, in combination with hydrogen fluoride gas, directly into the die cavity containing a pressable ionic fluoride powder, and either hot-pressing or extruding the powder.

Abstract: A relatively low temperature nitrogen gas generating composition is disclosed which consists essentially of (a) from about 10 to about 50 percent by weight of an oxidizer selected from the oxides of iron, nickel and cobalt, said oxidizer having a primary particle size in the range from about 0.1 micron to about 7 microns in diameter; and, (b) at least 50 percent by weight of an alkali metal azide. Optionally, less than about 10 percent by weight of an alkali metal perchlorate may be included as a booster. The nitrogen gas generating composition provides the nitrogen gas at a low enough temperature but at a sufficiently high speed, without generating a large quantity of finely divided solid residue particles. A major portion of the combustion residue is a coherent porous solid sinter or fused mass of residue particles which autogenously provides both self-filtration of ejected particles and sorption of any molten combustion product.

Abstract: A malleable or press-forgeable ingot of barium fluoride, for use as an optical body, may be grown from an ultra-pure precipitate of barium fluoride which contains less than 10 parts per million (ppm) of strontium or calcium. A process is disclosed for crystallizing barium nitrate crystals in the presence of nitric acid, reacting barium nitrate with ammonium carbonate to form barium carbonate, recovering barium carbonate crystals, suspending the barium carbonate crystals in water and precipitating barium fluoride with hydrofluoric acid. The barium fluoride crystals are recovered, dried and then calcined in the presence of ammonium fluoride or bifluoride. Barium fluoride (BaF.sub.2) crystals obtained by the process of this invention contain less than 10 ppm of each strontium and calcium.Crystals of an alkaline earth metal fluoride which have been calcined in the presence of a fluoride of ammonium are unexpectedly densified, and are particularly suited for melt-growth of an ingot in a known manner.

Abstract: This invention concerns a treatment which may be applied on practically all hair and which substantially improves the cosmetic properties thereof. More particularly, it contemplates a novel hair grooming aid to beautify hair, particularly living hair, which includes as a necessary ingredient a solid phase of finely divided fibrillatable polytetrafluoroethylene (hereinafter referred to as "PTFE") resin. The invention includes a process of grooming hair comprising applying the grooming aid to hair and brushing the hair at a temperature above the transition temperature at which PTFE fibriliates to form microscopic and submicroscopic fibers, in an amount sufficient to give the hair a natural appearance and to maintain its set for a long time.

Abstract: A process is disclosed for converting basic magnesium carbonate into pure hot-pressable magnesium fluoride such as is used for the hot-pressing of infra-red radiation transmitting optical bodies. The process includes contacting a slurry of basic magnesium carbonate with carbon dioxide to form enough magnesium bicarbonate or hydrates of magnesium carbonate, in situ, to alter the particles in the slurry. Carbonation of the slurry increases solubility of the solids by establishing an equilibrium relationship in solution between the unstable magnesium bicarbonate and hydrates of magnesium carbonate particles. When the carbonated slurry is contacted with a slight excess of hydrofluoric acid it precipitates solid particles of fine hydrous magnesium fluoride. Neutralization of excess hydrofluoric acid is effected with ammonium hydroxide. The solid particulate precipitate is dried and calcined to yield hot-pressable magnesium fluoride powder of exceptional purity and consistent quality.

Abstract: Scintillation phosphors, infrared and ultraviolet transmitting shaped articles of unrestricted length and arbitrary cross section are formed by multiple extrusion of a relatively small single crystal, melt-grown macrocrystal ingot, or, re-extrusion of a relatively small, fully dense polycrystalline parent mass at a temperature below its melting point and under sufficient pressure to form a fully dense, homogeneous polycrystalline mass. A re-extrudate of a first extrudate is wider in cross section than the parent single crystal, or the first extrudate, yet the scintillation, infrared and ultraviolet transmission properties of the polycrystalline re-extrudate are essentially the same or better than those of the parent single crystal or polycrystalline first extrudate.A polycrystalline re-extrudate is disclosed which is optically the same as, but structurally different from a single crystal or first extrudate. It is both optically and structurally different from a hot-pressed or extruded powder.

Abstract: A method is disclosed for the use of thulium doped calcium fluoride in the form of a thermoluminescent dosimeter to measure the amount of radiation to which the dosimeter has been exposed.A new thermoluminescent material for use in a dosimeter is also disclosed. The material consists essentially of crystalline calcium fluoride doped with less than 0.5 mole percent thulium. The material has several unique properties, and displays two well separated glow maxima which permit using a lower temperature (150.degree. C) peak as a thermometer to determine a mean ambient temperature for the dosimeter. The mean ambient temperature may then be used to correct thermoluminescent data for a high temperature (250.degree. C) peak.

Abstract: A hot-pressed optical body is disclosed which is free from absorption bands due to carbon dioxide, water, hydroxyl ion and acid fluorides in the ultraviolet, visible and near-infrared wavelength regions. Typically, the optical body is formed from a powder of an alkaline earth metal fluoride, alkali metal fluoride, or rare earth metal fluoride. One or more absorption bands due to a single impurity may be reduced or eliminated, or bands due to plural impurities may be reduced or eliminated sequentially, or simultaneously. The optical body is made by flowing a reactive, reducing gas, optionally, in combination with hydrogen fluoride gas, directly into the die cavity containing a pressable powder, and either hot-pressing or extruding the powder.

Abstract: A coherent, weak agglomerated dustless solid particulate mass is formed from a mixture of discrete particles in the size range from less than about 1 micron to about 2,000 microns, and fibrillatable polytetrafluoroethylene (hereinafter referred to as PTFE) in an amount from about 0.02, but less than 1 percent and preferably less than 0.75 percent by weight based on total solids, by working the mixture in a dry or relatively dry state with a working action in an unconfined zone at a temperature in excess of 20.degree. C., but below the sintering temperature of PTFE or a temperature deleterious to said particles, whichever is lower, without changing the primary particle size range of the material.

Abstract: A retainer clip is formed from elongated rod or wire as a continuous L-shaped member having a pair of arms substantially at right angles to one another. Each arm has a resilient loop formed by bending the end portion of the arm through at least one complete turn. Each arm of the L-shaped member extends along of two sideboards in end-adjacent relationship with each other, biasing flatly against end-adjacent inner walls of the ingot mold. The end portion of each arm abuts the next adjacent sideboard orthogonally, the arm biasing parallel oppositely disposed sideboards against inner walls of the ingot mold. Each retainer clip thus thrusts one pair of sideboards, in end-adjacent relationship with each other, against coextensive inner walls of the ingot mold, and at the same time, thrusts against portions of two diagonally oppositely disposed sideboards also in end-adjacent relationship with each other.

Abstract: A filter element for aerosols and finely divided solid particles suspended in a gas, is formed by depositing a septum of microscopic and submicroscopic unsintered fibers of fibrillatable polytetrafluoroethylene (hereinafter referred to as PTFE) as a random network on a supporting screen. The filter so formed is especially effective to remove liquid and solid particles of micron and submicron size suspended in a gaseous medium to be filtered.A process is described for separating contaminant solid and liquid particles less than about 5 .mu. (micron) in diameter from the gas in which the particles are suspended, comprising introducing primary particles of fibrillatable PTFE less than about 1 .mu.

Abstract: A composition of matter transparent to infrared rays and shock resistant which is a directionally grown, polycrystalline solidified melt of a eutectic composition comprising at least two components wherein the ratio of the index of refraction of one to the other is within the range of 1.2 to 1.0, the directionally oriented, polycrystalline mass is grown in a controlled manner by adding heat to the melt and removing the same from the solids during the solidification step, the amount of heat being added to the melt and conducted through the solidified melt being 10.sup.3 to 10.sup.5 times the latent heat of fusion of the eutectic mixture.

Abstract: Metal salts which are crystallizable from a saturated aqueous solution of the salt in the presence of a dispersion of polytetrafluoroethylene (hereinafter referred to as PTFE) resin are grown as geometrically better defined and larger crystals than those grown from an unseeded saturated solution.

Abstract: A method is disclosed for preventing segregation of particles within a finely divided powder having disparate particle size ranges, compositions or densities. The method includes working the powder with a minute amount, preferably less than about 1% by weight of the powder, of a finely divided fibrillatable polytetrafluoroethylene resin (hereinafter referred to as PTFE) to form a mixture with the powder. The PTFE resin may be added to the powder as a colloidal aqueous dispersion or as a fine powder obtained by coagulation of the colloidal dispersion. Whichever form is used, the PTFE is intimately mixed with the finely divided powder to form a dry mixture. Alternatively, the PTFE resin may be blended with the powder in a wet treatment to facilitate the homogenous dispersion of the resin. In any event, the mixture of resin and powder is worked either in the wet state, preferably as a paste, or as a dry blend, using a masticating or kneading action to fibrillate the PTFE.

Abstract: A catalyst is provided which is useful in the direct single-step conversion of sulfur oxides to element sulfur. The catalyst comprises cobalt sulfate as an essential catalytic ingredient supported on an attrition resistant and decrepitation-resistant catalyst support wherein cobalt is present in an amount less than ten parts cobalt per hundred part by weight of catalyst.

Abstract: A continuous solvent extraction-steam distillation process for the recovery of aromatic hydrocarbons having boiling points in the range of about 80.degree.C. to about 175.degree.C. from a feedstock containing aliphatic hydrocarbons and said aromatic hydrocarbons comprising the following steps:A. introducing the feedstock into an extraction zone at about the midpoint thereof;B. introducing a mixture of water and solvent into the extraction zone at about the top of said extraction zone, said solvent being a water-miscible organic liquid having a boiling point of at least about 200.degree.C.;c. introducing reflux hydrocarbons into the extraction zone at about the bottom thereof;D. contacting the feedstock in the extraction zone with the mixture of water and a solvent, the water phase of step (j), and the reflux hydrocarbons to provide an extract comprising aromatic hydrocarbons, reflux aliphatic hydrocarbons, solvent, and water and a raffinate comprising essentially aliphatic hydrocarbons;E.

Abstract: A supported methanation catalyst and a process for utilizing the catalyst are disclosed. The catalyst yields a product containing a major proportion of methane and some ethane. Methanation of a gaseous feed stream containing from about 10 to about 50 mole percent carbon monoxide, and from about 1.0 to about 3.0 times as much hydrogen as carbon monoxide, is effected at elevated temperature and high pressure continuously over a prolonged period of time, while a conversion of carbon monoxide in excess of 80 mole percent is maintained. Thermal stability at elevated temperature and pressure permits essentially continuous use of the catalyst for extended periods of time without time-consuming shutdowns. High conversion of gaseous feed and thermal stability of catalyst permits economical process design which utilizes a minimal recycle, if any.The supported catalyst consists essentially of a complex of oxides of nickel, copper and molybdenum which complex is reduced on the support prior to or during use.

Abstract: A longitudinally sectioned collet pad having plural pad segments of the detachable type, such as are conventionally used in an expansible collet, is provided with a freely interchangeable liner for each pad segment. Fastening means secure each liner against the inner surface of an outer member of the pad segment, and hold the liner against movement, either circumferentially, or radially inwardly.Liners for each pad segment are provided with a roughened inner surface, preferably with serrations, to grip a bar of stock by coaction of the pad segments. Interchangeability of liners obviates the need for integral pad segments, permits the use of liners for a wide range of stock diameters using the same outer members of the pad segments, and effects great economy in the manufacture and use of removable collet pads.

Abstract: A malleable or press-forgeable ingot of barium fluoride, for use as an optical body, may be grown from an ultra-pure precipitate of barium fluoride which contains less than 10 parts per million (ppm) of strontium or calcium. A process is disclosed for crystallizing barium nitrate crystals in the presence of nitric acid, reacting barium nitrate with ammonium carbonate to form barium carbonate, recovering barium carbonate crystals, suspending the barium carbonate crystals in water and precipitating barium fluoride with hydrofluoric acid. The barium fluoride crystals are recovered, dried and then calcined in the presence of ammonium fluoride or bifluoride. Barium fluoride (BaF.sub.2) crystals obtained by the process of this invention contain less than 10 ppm of each strontium and calcium.Crystals of an alkaline earth metal fluoride which have been calcined in the presence of a fluoride of ammonium are unexpectedly densified, and are particularly suited for melt-growth of an ingot in a known manner.

Abstract: A lightweight protective garment is provided for skaters, skiers, and the like, to reduce the injury from a fall. The garment is worn over the torso primarily to cover the area of the lower back, upper back and arms. The fabric of the garment by itself has no impact protective function but serves simply to provide a base on which protective cushioning members are attached in such a way as to absorb a portion of the impact of a fall. The cushioning members are preferably in the form of resilient foamed plastic cylinders disposed exteriorly of the garment over selected areas of the body which are generally impacted most frequently such as the lower back, the trochanter region, the shoulders and the rear surfaces of the arms. In a preferred embodiment of the invention the cushoining members are removably affixed to the garment and a cover is provided over the cushioning members so that the garment appears to be conventional.