193 results about "Selective reaction" patented technology

Disclosed are implantable devices that include biocompatible polyurethane materials. In particular, the disclosed polyurethane materials can maintain desired elastomeric characteristics while exhibiting thermoset-like behavior and can exhibit improved characteristics so as to be suitable in load-bearing applications. For example, the disclosed polyurethane materials can be suitable for use in artificial joints, including total joint replacement applications. The disclosed polyurethane materials include biocompatible cross-linking agents as chain extenders, more particularly chain extenders comprising a terminal group capable of side reactions and further comprising an electron withdrawing group immediately adjacent the terminal group. In addition, the reaction materials and conditions can be selected to encourage intermediate levels of cross-linking without the use of traditional cross-linking trifunctional reagents. In addition, the chain extenders can also include substantially inflexible moieties so as to increase the rigidity of the product polyurethanes.

The invention provides shock initiation devices comprising multilayer structures with constituent layers that undergo an exothermic self-propagating reaction once initiated by shock. The multilayer structures may be used as components in shaped charges, EFP devices, warheads, munition casings, interceptors, missiles, bombs, and other systems. The reactive layer materials may be selected based on required structural properties, density and reaction temperature.

A system and process is provided to deplete or remove oxygen in the ullage of a fuel tank to reduce the oxygen/fuel vapor ratio below a lower explosion limit by exposing the ullage compounds to an oxygen removal catalyst active at a relatively low temperature. The oxygen removal catalyst may be a non-precious metal catalyst. A selective reaction of the oxygen by the catalyst forms primarily alcohols, aldehydes, and/or ketones and produces less than about 5% water by volume. The selective reaction, occurring at the relatively low temperature, reduces the risk of flammability of the fuel.

Proppants for hydraulic fracturing of oil and gas wells are coated with a polyurea-type coating. In a preferred embodiment, the polyurea-type coating is formed by contacting a polymeric isocyanate with an amount of water and a blowing catalyst at a rate and quantity sufficient to generate a reactive amine in situ on the outer surface of the proppant which thereby reacts with unconverted polymeric isocyanate to form a thin polyurea-type surface coating that is substantially solid and lacks foam or substantial porosity. Alternatively, the polyurea-type can be produced by selecting reactive amine compounds and isocyanates to develop the coated proppant. The coated proppants retain the discrete, free-flowing character of the original core solids but with the beneficial effects of the polyurea-type coating of the present invention.

A carbonylation process for producing acetic acid including: (a) carbonylating methanol or its reactive derivatives in the presence of a Group VIII metal catalyst and methyl iodide promoter to produce a liquid reaction mixture including acetic acid, water, methyl acetate and methyl iodide; (b) feeding the liquid reaction mixture at a feed temperature to a flash vessel which is maintained at a reduced pressure; (c) heating the flash vessel while concurrently flashing the reaction mixture to produce a crude product vapor stream, wherein the reaction mixture is selected and the flow rate of the reaction mixture fed to the flash vessel as well as the amount of heat supplied to the flash vessel is controlled such that the temperature of the crude product vapor stream is maintained at a temperature less than 90° F. cooler than the feed temperature of the liquid reaction mixture to the flasher and the concentration of acetic acid in the crude product vapor stream is greater than 70% by weight of the crude product vapor stream.

Method for producing hydrogen comprising contacting aluminum and one or more reaction materials selected from the group consisting of reaction promoters and reaction promoter precursors in the presence of an aqueous liquid under reaction conditions sufficient to yield hydrogen gas and an aqueous product, wherein the relative amounts of the reaction materials and the aqueous liquid are selected such that the pH of the aqueous product is less than about 12.

An improved optical sensor and methods for measuring the presence of various materials or constituents in a fluid sample uses reactive material(s) in a fluid environment. The reactive materials have optical properties that change in the presence of a target material that may be present in the environment. An optical emitter generates light that is directed to the reactive materials, and one or more optical detectors receive reflected light from one or more interfaces in the optical path between the emitter and the detector(s), one or more of the interfaces having a reactive material. The reactive material(s), emitter(s), and detector(s) are selected based on the desired target material to be sensed.

The subject invention provides a two-phase liquid-liquid extraction process that enables sorting and separation of single-walled carbon nanotubes based on (n, m) type and/or diameter. The two-phase liquid extraction method of the invention is based upon the selective reaction of certain types of nanotubes with electron withdrawing functional groups as well as the interaction between a phase transfer agent and ionic moieties on the functionalized nanotubes when combined in a two-phase liquid solution. Preferably, the subject invention enables efficient, bulk separation of metallic/semi-metallic nanotubes from semi-conducting nanotubes. More preferably, the subject invention enables efficient, bulk separation of specific (n, m) types of nanotubes.

The invention provides a preparation method of high-purity molybdenum powder, which comprises the steps: enabling molybdenum dioxide ore powder and chlorine gas to carry out a chlorination reaction; condensing to obtain MoO2C12 solid; then, enabling the MoO2C12 solid and ammonia water to carry out an ammonia leaching reaction to obtain ammonium paramolybdate and HCl gas; further roasting the ammonium paramolybdate to obtain MoO3; and finally, enabling MoO3 and reaction gas to carry out a reduction reaction to obtain high-purity molybdenum powder. Compared with a hydrometallurgical purification method of molybdenum ore sources in the prior art, the preparation method provided by the invention utilizes the molybdenum dioxide ore powder as a raw material to enable the chlorine gas and MoO2 to carry out a selective reaction. As the chlorine gas only reacts with metal Mo, other elements almost do not react; therefore, the content of product impurities is greatly reduced; a high-purity product is obtained; and the effects of the varieties and the contents of the impurities in the molybdenum ore sources of the raw material on the product purity are avoided.

The invention relates to a solid alkyl reaction regenerator, which comprises a liquid distributor, a lifter tube reactor, a fluid bed reactor, a circulate bed regenerator and a movable bed regenerator, wherein the liquid distributor is connected to the bottom of lifter tube reactor whose top is connected to the bottom of fluid bed reactor; the lower part of fluid bed reactor via valve tube is connected to the circulate bed regenerator and the movable bed regenerator; the lower part of circulate bed regenerator via the valve tube is connected to the top of movable bed; the lower part of circulate bed regenerator and the bottom of movable bed regenerator via valve tubes are connected to the liquid distributor, to form the cycle loop. The invention also provides a relative method, based on different catalysts, react liquids, and regenerate liquid, to select the reaction- regeneration loop, to meet the application of different solid acid catalyst particles.

Heparin is synthesized from a polysaccharide comprised of a 1-4 glycosidically linked alternating polymer of uronic acid and glucosamine residues, wherein the uronic acid is selected from iduronic and glucuronic acid, wherein the glucosamine is partially N-sulfated; by a series of selective reactions catalyzed by recombinant enzymes.

A method is provided for low temperature deposition of ceramic thin films of carbides, nitrides and mixed phases such as carbo-nitrides by atomic layer deposition (ALD), nano-layer deposition (NLD), and chemical vapor deposition (CVD). The deposition chemistries employ combinations of precursors to affect thin film processes at substantially lower temperatures than current deposition processes of thin films of boron (B) carbides, nitrogen (N), nitrides, carbonitrides of silicon (Si), carbon (C), germanium (Ge), phosphorus (P), arsenic (As), oxygen (O), sulfur (S), and selenium (S) on substrates. The inventive ALD and corresponding NLD and CVD process methods provide lower temperature deposition of various thin films comprising elements from the group B, C, Si, Ge, N, P, As and O, S and Se. The reactive precursor combinations are selected on the basis of reactivity towards one another as determined by the variation of Gibb's free energy (ΔG) with respect to deposition temperature.

The invention provides a method for quantitatively detecting six kinds of nitrobenzene compounds in fine atmospheric particles PM2.5. The method comprises the following steps: acquiring a sample, extracting the sample, concentrating and purifying the sample and quantitatively detecting by adopting chromatography-tandem mass spectrometry. By optimizing parameters of secondary mass spectrometry conditions, the method is better in selectivity and higher in sensitivity on target compounds in comparison with an existing detection method reported in literature. According to the method, the disadvantage that the selectivity and the sensitivity of a conventional detector in the process of detecting the trace quantity of nitrobenzene compounds in a complex background matrix cannot be ensured at the same time is overcome by virtue of a gas chromatography/tandem mass spectrometry selective reaction monitoring technology, and the qualitative operation is accurate and reliable, so that the method has very remarkable advantages in comparison with conventional GC/ECDs (gas chromatography/election capture detectors), GC/NPDs (gas chromatography/nitrogen-phosphorus detector), GC/LRMS (gas chromatography/low resolution mass spectrometry) detectors or GC/HRMS (gas chromatography/high resolution mass spectrometry) detectors.

The invention is directed to a method of selectively oligomerizing olefin monomers by controlling feedstock composition and reaction conditions. Reaction conditions are chosen to include at least one of: (a) dimer recycle; (b) staged injection of monomer; and (c) utilization of a two catalyst system.