Abstract: High tensile carbon fibers are provided with a high yield process in which, after oxidation of a precursor, the fibers are first precarbonized in an inert atmosphere to to about 600.degree. C. while imparting 5-10% stretch. In precarbonizing, the fibers are initially heated in a sweeping manner with substantial volumes of hot inert gas which is extracted along with products of decomposition before the fibers are cooled to a low, non-reactive exit temperature. The arrangement minimizes redeposition of tars on the fibers and stretches the fibers in a range in which substantial off-gassing occurs. Thereafter the fibers are finally carbonized at a higher temperature with a different tension being applied, to provide a more reliable less sensitive process that enables oxidation to be effected more rapidly.

Abstract: A medical gripping instrument for endoscopy. A sleeve has a passage with a distal opening. A periscope extends axially in this passage, along with at least three springy gripping arms, which also are axially movable. They leave a clear path between them so the periscope can see what they grasp. The arms and periscope are linked so that both move axially simultaneously so the region in the arms remains in the view of the periscope, and an object brought into the shaft by the arms will not harm the periscope.

Abstract: A hydraulic cement mix including hydraulic cement, aggregate, sufficient water to affect hydraulic setting of the cement, and an additive comprising an N-methylol amide, specifically, tri- or tetramethylolglycoluril alone or in combination with other accelerators of set. The additive is present in an amount sufficient to decrease the time necessary for the hardening of the concrete mix. Generally, the additive is present in a total amount of up to about 4.0% by weight based upon the weight of cement in the mix, usually in an amount of between about 0.01% and about 2.50% by weight of cement. The latter concentration is present when complex combinations of accelerators of set for hydraulic cement are employed.

Abstract: This invention relates to the preparation of hydraulic cements consisting essentially of glasses having compositions within area ABCDEA of FIG. 1 which, when contacted with water, hydrate to form strong, low porosity cements having crystals composed predominantly of hydrogarnet solid solution and/or hydrogehlenite.

Abstract: Sub-micron sized powders of the ceramic metal oxides such as zirconia, alumina, titania, etc. are produced by precipitation upon mixing aqueous or aqueous/organic solutions of salts of the corresponding metal(s) with substantially 95% solutions of ammonia donors such as hexamethylenetetramine which are capable of reacting with water to give ammonia. The precipitates are treated with an alkali metal hydroxide to remove adsorbed organic matter, neutralized after completion of this treatment with acid, then washed with ammoniated water to remove any residual soluble salt and/or organic matter, dried, and calcined. The powders thus produced are readily sintered to high density ceramic bodies after conventional pressing or casting into a desired shape.The process is especially suited to the production of zirconia powders, either pure or doped with conventional stabilizing oxides such as yttria, magnesia, or lime.

Abstract: A method of enhancing the brightness (beneficiating) of kaolin clays by removing titanium impurities is disclosed. The claimed method is a selective flocculation process wherein clay solids are blunged (dispersed) in water together with a dispersing agent and an ammonium salt conditioning agent. When a water-dispersible anionic polymer is added to the dispersed and conditioned clay suspension, titanium flocs are separated from the suspension yielding a whiter kaolin clay product. Unlike prior art selective flocculation processes, the use of highly-dilute dispersions and/or multiple washing steps is not required.

Abstract: The invention provides a novel inorganic fiber composed of the elements of silicon, carbon, boron and nitrogen of which the Si/B molar ratio is 2:1 to 200:1. The inorganic fiber is obtained by a method comprising the steps of: (a) preparing an organoborosilicon polymer by heating a mixture of an organopolysilane and an organoborazine compound, e.g. B-trimethyl-N-triphenyl borazine, to effect thermal decomposition and polycondensation reaction; (b) spinning the polymer into a fibrous form; (c) infusibilizing the fiber of the polymer by thermally oxidizing in an oxidizing atmosphere or by irradiating with ionizing radiations; and (d) calcining the infusibilized fiber at 900.degree. to 1800.degree. C. The inventive inorganic fiber is more stable at high temperatures than conventional silicon carbide fibers.

Abstract: A salt water hydraulic cement slurry and method of use in oil and gas well cement jobs involving a novel fluid loss additive comprising an admixture of sulfonated aromatic polymers. An effective amount of an admixture of water soluble salts of a sulfonated styrene/maleic anhydride copolymer, sulfonated polystyrene, sulfonated polyvinyltoluene and sulfonated polynaphthalene/formaldehyde condensate when added to a salt water/Portland cement slurry provides fluid loss control to the Portland cement slurry at bottomhole circulating temperature between 80.degree. and 210.degree. F. Further, addition of and/or the replacement of the sulfonated polystyrene by a water soluble lignosulfonate further enhances the high temperature properties of the salt water cement slurry.One exception to this appears in British Pat. No.

Abstract: Inorganic material comprises a mixture of water glass and metakaolin obtained by heat treating a kaolin group clay mineral at 600.degree. to 900.degree. C. This inorganic material, when solidified by drying, exhibits excellent water resistance, and when solidified by heating to a temperature of 80.degree. to 500.degree. C., exhibits excellent water and hot water resistances. The inorganic material may further contain a hydrous magnesium silicate type clay mineral. Such material, when solidified by drying, exhibits further excellent water resistance and when solidified by heating to a temperature of 80.degree. to 500.degree. C., exhibits excellent resistances to water, hot water and boiling water.

Abstract: A wound dressing and delivery means laminate composite is described comprising contiguously oriented and coplanary arranged discrete layers. A centrally-disposed wound dressing layer is in separable and releasable contiguous adhesive contact through an adhesive surface with an adjacent non-adhesive surface of a release liner layer. A non-adhesive surface of the wound dressing layer is further in separable and releasable contiguous heat lamination contact with an adjacent second non-adhesive surface of a delivery means layer. In using, the release liner layer is first peelably separated from the adhesive surface of the centrally disposed wound dressing layer with which it is in releasable adhesive contact. Next, the remaining adherent wound dressing layer and delivery means layer of the wound dressing composite are positioned over the wound application site and applied to said site by contact adhesion.

Abstract: A coating for a substrate includes a mix comprising sodium silicate, water and sialon powder. A defoaming agent is also added to the mix.

Abstract: A method for enhancing the activity of a synthetic crystalline zeolite, including a zeolite having a silica-to-alumina ratio greater than 500, is disclosed which involves compositing the zeolite with an alumina support matrix and reacting the composite with a concentrated aqueous solution of an ammonium halide preferably ammonium fluoride. The halide treated zeolite subsequently is contacted with an ammonium salt such as ammonium nitrate and subsequently is calcined.

Abstract: A method of manufacturing fine powder of BaZrO.sub.3 is described, in which a zirconium compound is first hydrolyzed. The hydrolyzed zirconium compound is then reacted with a water-soluble barium compound in a strongly alkaline solution having a pH not lower than 13.6.

Abstract: A burner skeleton made of a composition including calcium aluminate and a silica compound. The calcium aluminate contains 15 to 40 wt % of lime, 35 to 80 wt % of alumina and 0.3 to 20 wt % of iron oxide. The composition may include titanium oxide.

Abstract: Calcium carbide is prepared from a powdered lime material. The powdered lime material, possibly together with a reducing agent, is injected with the aid of a carrier gas into a plasma gas generated by a plasma generator. The heated lime material, together with any reducing agent used and the energy-rich plasma gas, is then introduced into a reaction chamber substantially surrounded on all sides by a solid reducing agent in piece form. When the lime material consists of quicklime, this is melted and reduced to liquid carbide and when the lime material consists of powdered limestone, it is burnt directly in the reaction zone to form liquid carbide.

Abstract: The invention provides carbon fibers having mechanical properties equival to or even better than those of the polyacrylonitrile-based carbon fibers from a bituminous material, e.g. coal tar pitch, as the starting material. The starting pitch is first partially hydrogenated in tetrahydroquinoline under specific conditions followed by a heat treatment to give a pitch composition suitable for spinning which can be characterized by several parameters including the proportions of the carbons and hydrogens having different chemical shifts in the NMR analysis. The pitch composition for spinning is then subjected to spinning under specific conditions including the temperature condition for controlling the viscosity behavior of the molten pitch composition determined by use of the Andrade's equation and the pitch filament is then infusibilized in an oxidative atmosphere and carbonized in an inert atmosphere into carbon fibers having a tensile strength of at least 200 kg/mm.sup.

Abstract: A process for the purification of silicon by the action of one or several acids, wherein silicon is established as a stationary phase and one or several acids are caused to form mobile phases for traversing the stationary phase under pressure and absorbing the impurities from the silicon during the passage, leaving behind the silicon with a higher degree of purity.

Abstract: The present invention relates to a composition intended for the preparation of facings by spraying by means of a hose a mixture based on rock wool (A), the composition having an almost instantaneous setting time and a formulation necessarily comprising a combination of (1) at least one powder product (B) containing at least 30% of sodium or potassium bicarbonate, the remainder comprising a compound of acid nature selected from the group comprising calcium chloride, sulfamic acid and sodium bicarbonate, in association with or without association with a solid silicate of sodium or potassium and (2) of at least an aqueous solution (C) of sodium or potassium silicate.

Abstract: High density magnesia clinker characterized by having a chemical composition, as oxides in weight %, ofMgO: 97.5% or moreCaO: 0.8-2.0%SiO.sub.2 : 0.12-1.0%Fe.sub.2 O.sub.3 : 0.3% or lessAl.sub.2 O.sub.3 : 0.15% or lessB.sub.2 O.sub.3 : 0.03% or lesswith a bulk density of at least 3.48 g/cm.sup.3. The said high density magnesia clinker can be produced by forming magnesium oxide by calcination of naturally occurring magnesite having a composition, based on ignition in weight %,MgO: 97.5% or moreCaO: 0.8-2.0%SiO.sub.2 : traces to 0.15%Fe.sub.2 O.sub.3 : 0.3% or lessAl.sub.2 O.sub.3 : 0.15% or lessB.sub.2 O.sub.3 : 0.1% or less,grinding the same after, or with, addition of amorphous silica, silica gel or a silicon compound capable of forming SiO.sub.2 by dead-burning in such a manner as to have the SiO.sub.2 content of 0.12-1.0% after dead-burning and dead-burning.

Abstract: A process for placing a cement composition having high strength is provided. The process comprises the steps of adding a viscosity increasing agent, vacuum de-bubbling under reduced pressure and allowing the de-bubbled cement composition to be hardened. At the vacuum de-bubbling step, relatively large foams present in the cement composition are removed and only fine bubbles are left in the composition. The strength of the cement composition is remarkably improved by the removal of large bubbles.