Showing papers on "Silver oxide published in 1990"

A medicinal substance for topical application.

Abstract: A medicinal substance for topical application is disclosed. The substance comprises a water-soluble glass containing silver or a silver compound. Typically, the glass comprises phosphorus pentoxide and contains silver oxide. The substance may be used for the treatment of wounds, catheter and tubing entry points, stoma sites and body passage entrances where bacterial growth and migration are rife. The glass may be in the form of a powder, granules, woven into a dressing form, a sinter shaped in a particular way or used as filler in polymers for surface release.

Method for determination of neutral atomic oxygen flux

Abstract: A method for measuring atomic oxygen flux to a probe surface is presented which uses two probes. One is a glass probe enclosing a small ceramic resistor heater and a thermocouple for determining the ambient local temperature. Another probe has a silver tip and a thermocouple inside it. In an atomic oxygen environment, the silver probe will quickly develop a silver oxide coating which provides for atomic oxygen recombination. The use of the two probes allows a more accurate determination of the energy input into the catalytic silver oxide probe due to recombination.

Catalytic recombination of hydrogen in alkaline cells

Abstract: In rechargeable or primary electrochemical cells, hydrogen may evolve. The invention concerns the use of an auxiliary electrode material comprising manganese dioxide and a catalyst as the oxidant providing for the recombination of pressurized hydrogen, for example, the hydrogen being at pressures ranging from from substantially zero gauge pressure up to the relief pressure of the cell. The cell is a sealed cell having a manganese dioxide cathode, a zinc anode and aqueous electrolyte contacting both anode and cathode. The aqueous electrolyte may be alkaline or it may be ammonium chloride or zinc chloride, or mixtures thereof. The auxiliary electrode material, which may be mixed with the cathode material or be formed into a discrete auxiliary electrode, may optionally comprise a porous substrate, and in any event comprises MnO 2 and a catalyst for the recombination of pressurized hydrogen with the MnO 2 . The substrate may be carbon black or graphite; the catalyst may be a metal, metal salt or metal oxide of elements such as lead, nickel, titanium, lanthanum, chromium, vanadium, tantalum and catalytically active alloys thereof. Most particularly, the catalyst may be silver, platinum, silver oxide, or silver dioxide.

Synthesis of miltirone by an ultrasound-promoted cycloaddition

Abstract: The ultrasound-promoted cycloaddition of 3-isopropyl-o-benzoquinone, generated by the in situ silver oxide oxidation of the corresponding catechol, with 6,6-dimethyl-1-vinylcyclohexene has led to the synthesis of miltirone

Gradient-index silver alumina phosphate glasses by exchange of Na(+) for Ag(+).

Abstract: High index of refraction crown glasses containing silver oxide have been cast from a melt and used for ion exchange experiments. High quality axial and radial gradient-index profiles were fabricated and the interdiffusion coefficient calculated. Index changes up to 0.08 were achieved in a base glass with nd = 1.61 and Vd = 57.

Synthesis and characterization of rac‐1,2‐bis(palmitoyloxy)‐3‐propyl (2‐trimethylarsonioethyl)phosphonate, an arsenic‐containing phosphonolipid

Abstract: Arsenic analogs of lecithins (i.e. with replacement of nitrogen by arsenic in the choline group) are probably trace constituents of phospholipids in many organisms. Attempts to synthesize 1,2-bis(palmitoyloxy)-3-propyl 2-trimethylarsonioethyl phosphate (arsenolecithin) according to wellestablished procedures for the synthesis of the corresponding nitrogen compound failed. However, 1,2-bis(palmitoyloxy)-3-propyl 2-trimethylarsonioethylphosphonate, an arsenic-containing phosphonolipid, was obtained in 16% yield by reacting 1,2-bis(palmitoyloxy)-3-iodopropane with silver 2-trimethylarsonioethylphosphonate in isopropanol. The precursors to the arsenic-containing phosphonolipid were obtained by quaternization of trimethylarsine with diethyl 2-bromoethylphosphonate, hydrolysis of the resulting product with concentrated hydrochloric acid, and reaction of the phosphonic acid with silver oxide to give silver 2-trimethylarsonioethylphosphonate. Quaternization and hydrolysis proceeded almost quantitatively. The silver phosphonate was not isolated but was used in situ.

Silver oxide battery

Abstract: PURPOSE: To obtain a battery having excellent performance by containing chemically synthesized manganese dioxide having γ type crystal obtained by carrying out heat treatment on manganese oxide obtained by roasting manganese sulfate as its main ingredient and silver oxide (I), and using a positive electrode flux in which content of the former is a specific weight percentage. CONSTITUTION: Chemically synthesized manganese dioxide and flaky graphite are combined into silver oxide (I) so that volume of the chemically synthesized manganese dioxide becomes, for example, 5, 10 or 15% and volume of the flaky graphite becomes 5 % is in a positive electrode flux, and they are mixed together so that the uniform positive electrode flux 1 can be obtained. Furthermore, the positive electrode flux 1 is used so that a a silver oxide battery can be assembled. A positive electrode vessel 2 filled with the positive electrode flux 1, a separator 3, a zinc negative electrode 4 and an opening sealing plate 5 are provided, and a gasket is embedded in its vicinity, and the opening edge of the positive electrode vessel 2 is bent inward and pressurized so that it can be sealed up. Here, the positive electrode flux, which contains chemically synthesized manganese dioxide powder having γ type crystal obtained by carrying out acid treatment on manganese oxide obtained by roasting manganese sulfate as its main ingredient and silver oxide (I) powder, and in which content of the manganese dioxide is 5-15wt.% is used. COPYRIGHT: (C)1992,JPO&Japio

A New Method for the Quantitative Analysis of Silver Oxide Cathodes

Abstract: Une nouvelle methode basee sur la diffraction des RX, thermogravimetrie et la chromatographie en phase gazeuse est developpee pour l'analyse quantitative d'une electrode d'oxyde d'argent

Reduction of silver cations in silver zeolites by carbon monoxide

Abstract: At room temperature silver oxide and silver carbonate react with CO much faster than do Ag-A zeolites, the kinetics of the latter reaction showing a pronounced dependence on water content and a significant dependence on the exchange conditions; no reaction takes place in the absence of water, and immersion of the stable dry Ag+–CO zeolite complex in an alkaline aqueous environment results in immediate reduction of Ag+.

Formation of electronically excited silver oxide (AgxO) from the oxidation of small silver clusters

Abstract: The chemiluminescent reactions of silver clusters, M{sub n}, n {>=} 3, with ozone have been studied under multiple-collision conditions. As a function of variations in the silver flux, a minimum of five distinct electronic emissions associated with AgO, Ag{sub x}O (x {approximately} 2), and Ag{sub 2} are observed as well as features that are tentatively associated with the higher silver cluster oxides. The energetics of the observed spectral features combined with supplementary thermodynamic and kinetic information demonstrate that it is unlikely that electronically excited products with enough energy to account for the observed chemiluminescence can be produced through the reaction of either Ag or Ag{sub 2} with O{sub 3}. The smallest cluster whose reactions can readily yield the observed AgO emission features is the trimer. The formation of Ag{sub 2}O* can also be achieved through reaction of the trimer; however, it may better be accounted for via the reaction of higher clusters. The chemiluminescent spectrum between 500 and 700 nm has been found to contain two distinct emission band regions which have been assigned as the A-X and B-X band systems of Ag{sub 2}O. The observed frequencies are consistent with a nonlinear Ag-Ag-O structure, emission from the asymmetric cluster oxidesmore » characterizing these kinetically controlled oxidation experiments in contrast to the thermodynamically more stable symmetric species.« less

Method of producing antibacterial polymer and its use

Abstract: A polymer having an antibacterial activity and heat-treatability or thermoformability is produced by melt kneading a mixture of a heat-fusible thermoplastic copolymer having repeating units derived from an ethylenically unsaturated carboxylic acid or anhydride thereof with silver oxide. When applied to the inside of a packaging material, the polymer can exhibit an antibacterial effect upon the contents without detriment to the flavor retentivity thereof.

Method of producing YBa2 Cu3 O6+x superconductors with high transition temperatures

Abstract: A method for improving the superconducting transition temperature of the MBa2 Cu3 Ox where M is selected from the group consisting of Y, Er, Eu, Yb, Dy and Ho and where x is a value of from 6 to 7 ceramic by utilizing specific sequences of heat treating times and temperatures in conjunction with the use of silver oxide in making superconducting devices or wires for ultimate use in motors, generators and electrical circuits

Composition for vulcanizing fluororubber

Abstract: PURPOSE:To obtain the title composition which can give a vulcanized fluororubber improved in heat resistance and decreased in compression set by adding a silver compound to a composition for vulcanizing an iodinated or brominated fluororubber with an organic peroxide. CONSTITUTION:100 pts.wt. iodinated or brominated fluororubber based on an elastic copolymer of vinylidene fluoride with at least one fluorinated ethylenically unsaturated monomer, desirably containing 20-85mol% vinylidene fluoride and 0.01-5wt.% iodine or 0.05-1.5wt.% bromine is blended with desirably about 0.1-5 pts.wt. organic peroxide [e.g., 2,5-dimethyl-2,5-di(t-butylperoxy) hexane], desirably 0.1-10 pts.wt. polyfunctional compound (e.g., triallyl isocyanurate) desirably having reactivity with a peroxy radical and a polymer radical, and desirably 0.1-50 pts.wt. silver compound which is, for example, a silver oxide, a silver salt of formula I (wherein Z is a halogen, NO3 or the like) or an organosilver salt of formula II (wherein R is a 1-20C alkyl, a 6-20C aryl or an aralkyl).

Purification of high-concentration alcohol and absorbent for purification

Abstract: PURPOSE: To selectively absorb and remove only a sulfur compound by bringing an alcohol having high concentration and containing dimethyldisulfide and mercaptan as a sulfur compound into contact with an absorbent in which silver or silver oxide is carried on a porous support. CONSTITUTION: An alcohol having ≥60V% high concentration and containing ≥20ppm dimethyldisulfide, mercaptan, DMSO, etc., is brought into contact with an absorbent in which silver or silver oxide is carried on a porous support (e.g. alumina or zeolite) at a temperature not higher than the boiling point of the alcohol to reduce especially dimethyldisulfide to ≤10ppm content. The silver oxide is preferably used as an active ingredient of the absorbent, because regeneration treatment is readily carried out (at 400°C in air) in case of the silver oxide. According to the above-mentioned method, continuous operation is made possible by providing two absorbing towers and the treating cost is inexpensive, because the absorbent can repeatedly be used. COPYRIGHT: (C)1992,JPO&Japio

HTSC-thick films printed on different substrates

Abstract: Preparation and measurements of electrical and structural properties of HTSC thick films were carried out. Chemical reactions between different polycrystaline substrates and YBCO powder and thick films were studied as well. The influence of addition of silver oxide powder to the paste was investigated. The respective pastes were prepared and screen-printed on substrates then dried and subsequently fired. The best compatability with YBCO as to chemical reactivity and the coefficient of the thermal dilatation was observed for Y2BaCuO5 and MgO substrates, respectively. The best films were found to exhibit zero resistivity at 88 K when deposited on MgO. The addition of silver oxide powder to the pastes enhenced the critical temperature and the critical current density.

Method for producing high temperature superconductor wires with high critical current and their application for making superconducting devices

Abstract: Method for producing a ductile superconductor having high critical current in the form of a wire produced by hot isostatic pressing and mechanical working in which the superconducting phase, for example Y1BaA2Cu3O7-x is incorporated in a ductilising silver/silver oxide matrix which stabilises the oxygen partial pressure and is encased in a ductile metal sheath, characterised in that the temperature treatment necessary for working is also carried out under high gas pressures (HIP), as a result of which the superconductor core of the wire material is compact and defect-free and the microcrystallites are aligned in the direction of their highest critical current in the wire axis.

Comparison of aluminum silver oxide and lithium oxyhalide batteries performances for underwater weapons propulsion

Abstract: An important effort is discussed to offer electrical propulsion alternatives based on aluminum/silver oxide and lithium/oxyhalide electrochemistries. The differences between the application ranges of the lithium/oxyhalide and the aluminum/silver oxide technologies are: fast discharge, medium energy, high volumic density requirements for the Al/AgO technology application; and long discharge, high energy, high specific energy density for the lithium/oxyhalide technology application. Due to the small difference (approximately 10% for the specific energy) between the two technologies, considerations such as quietness, safety, shelf life or cost can impact on the final system selection. >

Cadmium negative electrode plate and alkaline secondary battery using its negative electrode plate

Abstract: PURPOSE:To facilitate the charge control and perform an extremely quick charge by providing a positive electrode plate using an active material mainly made of one of Ni hydroxide, Mn dioxide and silver oxide and a Cd negative electrode plate containing Ge oxide within the preset wt.% range with respect to the whole Cd quantity. CONSTITUTION:A positive electrode plate using an active material mainly made of one of Ni hydroxide, Mn dioxide and silver oxide and a Cd negative electrode plate containing Ge oxide 0.25wt.%-20wt.% with respect to the whole Cd quantity are provided to form an alkaline secondary battery. When Ge oxide is contained in the negative active material, the charging efficiency is increased. The negative electrode plate with excellent charging efficiency is used, the potential change until hydrogen is generated when the negative electrode plate is charged is detected as the change of the terminal voltage, then the charge control is facilitated, the current in the overcharge area is reduced if the fixed voltage is set at this time, thus the alkaline secondary battery which can be quickly charged and has no reduction of an electrolyte is formed.

Oxidation of 2,5-dimethylpyrazine with oxygen in the vapor phase on oxide catalysts and in the liquid phase in the presence of bases

Abstract: The vapor-phase oxidation of 2,5-dimethylpyrazine with oxygen on vanadium-molybdenum oxide catalysts modified with silver oxide gives 5-methyl-2-formylpyrazine and 2,5-diformylpyrazine in 37% and 35% yields, respectively. Pyrazine-2,5-dicarboxylic acid was obtained in 53% yield by the liquid-phase oxidation of 2,5-dimethylpyrazine with oxygen in the presence of a strong base and an interphase catalyst.

Adsorbent having both acidic and basic property

Abstract: PURPOSE:To obtain an adsorbent having both acidic and basic property by allowing an aq. dispersion of a water-insoluble or scarcely soluble phosphate to react with silver or an aq. soln. or dispersion of a water-insoluble or scarcely soluble silver compd. CONSTITUTION:Examples for the water-insoluble or scarcely soluble phosphate to be used are aluminum dihydrogen tripoly-phosphate, titanium phosphate, zirconium phosphate, cerium phosphate, or mixtures thereof. Examples for the silver compd. are silver nitrate, silver chloride, silver oxide, or mixtures thereof. A reaction product is obtd. by adding slowly an aq. soln. or dispersion of a silver compd. to an aq. dispersion of a phosphate while stirring the aq. dispersion, carrying out a reaction at room temp. or /H before the reaction is 0.25-1.0. Since these compds. are inorganic compds. and have high heat resistance, they can be mixed with a hot-melted resin, and can be formed ot a coating material, film, fiber, or foamed body.

Atomic oxygen effects on boron nitride and silicon nitride: A comparison of ground based and space flight data

Abstract: The effects of atomic oxygen on boron nitride (BN) and silicon nitride (Si3N4) were evaluated in a low Earth orbit (LEO) flight experiment and in a ground based simulation facility. In both the inflight and ground based experiments, these materials were coated on thin (approx. 250A) silver films, and the electrical resistance of the silver was measured in situ to detect any penetration of atomic oxygen through the BN and Si3N4 materials. In the presence of atomic oxygen, silver oxidizes to form silver oxide, which has a much higher electrical resistance than pure silver. Permeation of atomic oxygen through BN, as indicated by an increase in the electrical resistance of the silver underneath, was observed in both the inflight and ground based experiments. In contrast, no permeation of atomic oxygen through Si3N4 was observed in either the inflight or ground based experiments. The ground based results show good qualitative correlation with the LEO flight results, indicating that ground based facilities such as the one at Los Alamos National Lab can reproduce space flight data from LEO.

Method for cleaning apparatus for producing silver halide emulsion

Abstract: PURPOSE:To stably produce silver halide emulsion particles by the simple method by using an acid prior to a cleaning with pure water at the time of cleaning a line for adding an ammonia silver nitrate soln. CONSTITUTION:The acid is used at the time of cleaning the line for adding the ammonia silver nitrate soln. Acids which do not contain halogens are more preferable as the acid to be used and are exemplified by sulfuric acid, phosphoric acid, nitric acid, etc. among which the nitric acid is most preferable. The cleaning is executed by the method consisting of putting a silver nitrate soln. or sulfuric acid soln. to the line for adding the silver nitrate soln. after the execution of a charging by an ammonia method, then sealing and resting the liquid for >=40 minutes, more preferably >=60 minutes and thereafter, discharging the liquid and finally cleaning the line with the pure water. The silver oxide which cannot be removed by the pure water alone is removed in this way. The stable execution of the emulsification production thereafter is possible.

Flow Stream Detectors Based on the Electrocatalytic Oxidation of Polyhydroxy Compounds at Silver Oxide Electrodes

Abstract: Many simple carbohydrates and other polyhydroxy compounds can be oxidized at a silver oxide surface. The oxidation is via an electrocatalytic mechanism involving a Ag(I) oxide. This forms the basis of a flow stream detector operated in an amperometric mode which may be used for either flow injection or high performance liquid chromatography (HPLC) applications. The title electrode has been applied to the detection of simple carbohydrates, triglycerides and nucleic acid components.

Production of quinoline

Abstract: PURPOSE:To easily obtain quinoline in high selectivity by contacting an alkylquinoline and oxygen with a catalyst containing Ag and V oxide and/or Ag and Mo oxide or further K compound at a specific temperature, thereby effecting vapor-phase oxidative dealkylation of the raw material. CONSTITUTION:Quinoline useful as a raw material for nicotinic acid, agricultural chemicals, surfactants, etc., can be produced by contacting an alkylquinoline and oxygen with a catalyst containing Ag and V oxide and/or Ag and Mo oxide or further K compound at 250-400 deg.C. The above catalyst is produced by supporting oxide of V, Mo, etc., on a carrier such as alumina, silica or titanium oxide and adding silver oxide as an important component to the catalyst base prepared by the above process. The stability against deterioration van be improved by adding a K compound to the catalyst. The content of silver element in the formed catalyst is preferably 0.3-20%.

New Syntheses of Cyclopenta(cd)pyrene 3,4-Oxide and 4-Pyrenylacetic Acid.

Abstract: New syntheses of cyclopenta(cd)pyrene 3,4-oxide (CPPE) and 4-pyrenylacetic acid, a key intermediate in the synthesis of cyclopenta(cd)pyrene and CPPE, as described starting from 1,2,3,6,7,8-hexahydropyrene. 4-Pyrenylacetic acid is prepared from the corresponding alcohol, 2-(4-pyrenyl)ethanol, by applying two mild oxidation reactions. 4-Pyrenylacetaldehyde was obtained by N-chlorosuccinimide dimethyl sulfide oxidation, and this was converted smoothly to the desired 4-pyrenylacetic acid by silver oxide oxidation, an approach that has potential for a new route to arylacetic acids from arylethanols. The epoxide CPPE is prepared by cyclization of the 3,4-trans-dihydroxycyclopenta(cd)pyrene via its monotosylate, prepared in situ, with powdered sodium hydroxide.