Abstract: Core sandwich structure comprised of a lightweight core material in the form of a low density thermosetting resin matrix composition containing glass microballoons, particularly an epoxy resin containing glass microballoons, sandwiched between high strength fiber-thermosetting resin matrix outer sheets, particularly woven graphite-epoxy sheets. Employing epoxy resin as the preferred thermosetting resin, the epoxy core material is B-staged, placed between sheets of pre-preg woven graphite-epoxy material, and the assembly co-cured under pressure to form the core sandwich structure.

Abstract: Direct contact heat transfer process and system for recovery of energy from geothermal brines or other hot aqueous solutions of a non-volatile solute, or for desalination, using staged evaporator-condenser units operating with a low boiling water-immiscible liquid hydrocarbon. Each stage comprises a closed vessel divided into two compartments, an evaporator and a condenser, by a bubble cap tray similar in construction to those used in distillation. In one embodiment, hot geothermal brine or other hot aqueous liquid is introduced into the liquid hydrocarbon contained in the lower compartment of each stage, causing boiling of the hydrocarbon. Hydrocarbon vapors pass from the evaporator compartment through the bubble caps to the upper condenser compartment where they are condensed in contact with a cooler water stream. The heated water stream under substantial pressure is fed to an expander or turbine to produce work.

Abstract: A novel class of chemical compounds useful as pesticides consists of alkylpolyoxysulfinyl and alkylpolythiosulfinyl derivatives of carbamate esters. The preparation of these compounds and their formulation to control insects are exemplified.

Abstract: A novel class of chemical compounds useful as pesticides consists of symmetrical and asymmetrical N,N'-sulfinyldicarbamate esters. The preparation of these compounds and their formulation to control insects are exemplified.

Abstract: Process for producing a resin-fiber composite which comprises applying a "B" stage resin film to a mold surface, placing a fiber reinforcement layer over the "B" stage film, applying a porous parting film over the fiber reinforcement layer, applying a bleeder layer over the fiber reinforcement layer and placing a non-porous material over the bleeder layer. A bag is placed over the materials and sealed to or around the mold. A vacuum is applied to the mold and then the assembly is heated to a temperature sufficient to cause the "B" stage resin to flow and to impregnate the reinforcement layer, and pass up through the porous parting film and to impregnate the bleeder layer. The volume of resin provided by the "B" stage resin film is calculated so that saturation of both the fiber reinforcement layer and the bleeder layer occur, assuring uniform impregnation of the fiber reinforcement layer.

Abstract: A process and system for obtaining fresh water from salt water such as sea water, by direct contact heat transfer using staged evaporator-condenser units operating with a low boiling water-immiscible liquid hydrocarbon. Each stage comprises a closed vessel divided into two compartments, an evaporator and a condenser, by a bubble cap tray similar in construction to those used in distillation. Relatively hot fresh water is introduced into the liquid hydrocarbon contained in the lower compartment of each stage, causing boiling of the hydrocarbon at a temperature differnce of 2.degree.-4.degree. F. Hydrocarbon vapors pass from the evaporator compartment through the bubble caps to the upper condenser compartment where they are condensed in contact with a colder saline stream, and the condensed hydrocarbon is returned to the lower compartment.

Abstract: The surfaces of organic polymeric coatings applied to detail parts or components are subject to contamination and ultraviolet degradation prior to final overcoating procedures. The sources of ultraviolet exposure are light transmission through windows, artificial lighting, or temporary exterior exposure of the detail part coated surface. The ultraviolet light altered surface layer is effectively removed by treatment with a mixture of a glycol ether, an alcohol, a ketone and deionized water, without removing the main body of the coating. This results in good adhesion of a subsequently applied touch-up coating or overcoating. The process can also be used for cleaning metals.

Abstract: Production of oxygen by compressing air to about 3 atmospheres, and passing the compressed air to a reversing heat exchanger in heat exchange relation with a nitrogen waste stream wherein a 3.degree. R temperature difference between the streams prevails at the cold end. Water vapor and CO.sub.2 are frozen out. Reversal of the flow stream causes sublimation or evaporation of the CO.sub.2 and water vapor. A portion of the air is withdrawn at an intermediate point in the exchanger and is further cooled in the lower portion of a non-adiabatic fractionating device wherein it is partly condensed by evaporating oxygen liquid product. The condensed air is then fed to the partial condensing zone of the fractionating device, whereby oxygen-rich liquid is condensed and overhead nitrogen is turbine expanded and passed in countercurrent heat exchange relation to the partial condensing zone.

Abstract: Highly fire resistant composites or laminates particularly applicable as structural components in aircraft, e.g. in the engine nacelle, as part of the acoustic panel-fire wall structure, and capable of withstanding a 2,000.degree. F. flame temperature, comprising incorporating an additive in the form of an ammonium salt, or an amine salt, of a phosphonic acid or a phosphinic acid, into a resin, e.g., a polyimide or an epoxy resin, such additive being soluble in the resin. The resulting resin containing the additive, e.g., the ammonium, or amine, salt of phenyl phosphonic or phenyl phosphinic acid, is then applied to or impregnated into a substrate such as glass fiber cloth or graphite fiber, to form a composite structure which is then cured. The resulting cured composite when subjected to high temperatures of the order of, e.g., a 2,000.degree. F.

Abstract: A novel class of chemical compounds useful as pesticides consists of N-alkylsulfonyl-, N-arylsulfonyl-, and N-aminosulfonylaminosulfinylcarbamate esters. The preparation of these compounds and their formulation to control insects are exemplified.

Abstract: A method for fabricating superplastically formed/diffusion bonded structures wherein metal blanks of a titanium alloy are joined at selected areas by diffusion bonding and expanded superplastically to form a desired sandwich or integrally stiffened structure. In such method, the metal blanks are treated in selected areas with a "stopoff" material to prevent bonding at those areas during diffusion bonding and to permit forming or shaping at the same areas during superplastic forming. An improved stopoff compound is provided for this purpose, in the form of yttria of relatively coarse particle size, coarser than 5 microns, in a suitable volatilizable vehicle. Such stopoff compound is inert to reactive metals such as titanium at the high diffusion bonding temperatures, and permits relatively low breakthrough pressure-time product during superplastic forming, thereby preventing excessive strain or rupture of the metal through non-superplastic deformation.

Abstract: Production of a device or filter for removal of ozone from air, e.g. in aircraft cabins, by depositing an oxide film containing manganese dioxide on a substrate, particularly a light weight thermally stable substrate, e.g. polybenzimidazole, by treatment with a permanganate solution containing a soluble ceric salt such as ceric ammonium nitrate, and preferably also a dichromate such as sodium dichromate, to form a dense strongly adherent film or coating of MnO.sub.2, ceric oxide and preferably also chromic oxide, on the substrate. A solution containing an oxidizable organic component such as abietic acid can be first applied to the substrate, followed by treatment with the above permanganate solution.

Abstract: A novel class of chemical compounds useful as pesticides consists of N-alkylthio- and N-arylthiosulfinylcarbamate esters. The preparation of these compounds and their formulation to control insects are exemplified.

Abstract: Production of nitrogen from air, by compressing air to relatively low pressure, e.g. to about 3 atmospheres, and passing the compressed feed air to alternate passages of a reversing heat exchanger in heat exchange relation with an oxygen-rich waste stream, whereby water vapor and CO.sub.2 in the feed air are frozen on the surface of the heat exchange passage. By reversing the flow streams the low pressure oxygen-rich waste stream now flows through the feed air passage. This causes sublimation or evaporation of the CO.sub.2 and water vapor. A portion of the feed air is withdrawn at an intermediate point in the exchanger and is expanded in a turbine. The cooled feed air withdrawn from the heat exchanger is fed to a non-adiabatic fractionating device, whereby oxygen-rich liquid is condensed and withdrawn, and nitrogen is removed as overhead.

Abstract: Method and apparatus for pyrolyzing agglomerative coals which comprises introducing a fluidized bed of hot char particles into a pyrolysis chamber or reactor, and injecting upwardly into the chamber a high velocity jet of agglomerative coal particles in a carrier gas, the fluidized hot char particles surrounding the high velocity coal jet and heating the coal particles to yield gaseous products and char. The hot char particles in the fluidized state and disposed around the coal jet are entrained in the upwardly expanding coal jet and mixed with the coal particles, so that by the time the coal particles contact the pyrolysis chamber wall, such coal particles being heated by the char have passed through the tacky state and are no longer tacky and do not adhere to the chamber wall. The gaseous product and char formed during pyrolysis are rapidly removed from the pyrolysis chamber, and such char can be separated, e.g.

Abstract: Process and system for recovery of energy from geothermal brines and other hot water sources by direct contact heat exchange between the brine or hot water, and a working fluid exiting the top of the heat transfer column is expanded through an expander to produce work. The discharge from the expander is cooled to condense working fluid which is separated in an accumulator from condensed water vapor present in the working fluid, and the condensed working fluid is pressurized and fed back to the heat transfer column. Uncondensible gas together with working fluid losses are vented from the accumulator. In order to decrease the amount of uncondensible vent gas from the accumulator, and the loss of working fluid therein, the hot water or brine feed to the heat transfer column is initially degassed as by flashing, the extent of degassing being controlled based on the concentration of uncondensibles in such hot water or brine feed.

Abstract: Carbon fiber reinforced tantalum carbide composites are produced by vacuum infiltration of omni-weave carbon, e.g. three dimensional graphite, yarn preforms with an aqueous saturated solution containing tantalum fluoride and sucrose. Anhydrous ammonia is added under pressure, forming ammonium fluoride, which is removed by vacuum sublimation by application of heat. The resulting preform containing tantalum pentoxide and partially pyrolyzed sucrose is heated at high temperature and reduced pressure to decompose the sucrose to yield active carbon which reacts with the tantalum pentoxide to yield tantalum carbide and carbon monoxide.

Abstract: Process and system for recovery of energy from geothermal brines and other hot water sources, by direct contact heat exchange between the brine or hot water, and an immiscible working fluid, e.g. a hydrocarbon such as isobutane, in a heat exchange column, the brine or hot water therein flowing countercurrent to the flow of the working fluid. The column can be operated at subcritical, critical or above the critical pressure of the working fluid. Preferably, the column is provided with a plurality of sieve plates, and the heat exchange process and column, e.g.

Abstract: A process and system for recovery of energy from geothermal brines or other hot aqueous solutions of a non-volatile solute, by direct contact heat transfer using staged evaporator-condenser units operating with a low boiling water-immiscible liquid hydrocarbon. Each stage comprises a closed vessel divided into two compartments, an evaporator and a condenser, by a bubble cap tray similar in construction to those used in distillation. Hot geothermal brine or other hot aqueous liuqid is introduced into the liquid hydrocarbon contained in the lower compartment of each stage, causing boiling of the hydrocarbon at a temperature difference of 2.degree.-4.degree. F. Hydrocarbon vapors pass from the evaporator compartment through the bubble caps to the upper condenser compartment where they are condensed in contact with a cooler water stream, and the condensed hydrocarbon is returned to the lower compartment.

Abstract: In the recovery of energy from geothermal brines and other water containing or hot water sources, such brine or hot water under pressure is introduced into direct heat exchange contact with a working fluid such as isobutane, the resulting hot isobutane is expanded in a turbine to produce work, the turbine discharge is condensed and returned to the heat exchanger and the cooled brine is withdrawn from the column. The present invention is directed to recovery of working fluid dissolved and/or entrained in the spent geothermal brine or water withdrawn from the direct contact heat exchanger, including the steps of settling the brine in a settling tank to recover some of the isobutane, flashing the remaining brine to flash off additional isobutane and steam stripping the spent brine to drive off further isobutane, the recovered isobutane in each of the steps being recycled to the direct contact heat exchanger.