1176 results about "Nitrogen dioxide" patented technology

Hemostatic agents and devices are made from oxidized cellulose fiber, the oxidized cellulose having a carboxylation content increased by the action of nitrogen dioxide on virgin cellulose fiber. A composition may be incorporated into the oxidized cellulose fiber to cause a pharmacological effect on a wound to which the hemostatic agents and devices are applied. When applied, the oxidized cellulose fiber causes blood emanating from the wound to clot. The oxidized cellulose fiber can either be resorbed into the wound or removed from the wound after healing. A hemostatic bandage includes a pad of unwoven oxidized cellulose fibers mounted on a substrate. Methods of arresting a flow of blood emanating from a wound using such devices are also disclosed. Methods of fabricating oxidized cellulose are also disclosed.

A photochemical sensing system enables the measurement of nitrogen oxides (nitrogen dioxide and nitric oxide) by photolyzing nitrogen dioxide to form oxygen atoms which combine with oxygen molecules to form ozone. Ozone reacts with nitric oxide to for nitrogen dioxide-decreasing ozone. Changes in ozone concentration are measured as a surrogate for the nitrogen dioxide and nitric oxide. Any species which photolyzes to yield oxygen atoms may be measured by this technique. Additional specificity for nitrogen oxides is conferred by allowing the nitric oxide to react with the ozone to recreate the nitrogen dioxide. By periodically photolyzing the nitrogen dioxide (to form ozone), and then allowing the resulting nitric oxide to react with the ozone (thereby reducing ozone), a pulsed signal is obtained whose amplitude is proportional to the total amount of nitrogen dioxide and nitric oxide present. Medical applications include measuring nitric oxide concentrations in expired air samples.

A combustion analyzer apparatus and method for combustion analysing a sample, the analyzer comprising a combustion chamber (82) for receiving a sample for combustion therein to form combustion products, and a fluid supply apparatus for supplying fluid(s) into the chamber. The fluid supply apparatus (130-140) comprises a nitrogen oxides (NO_x) generating apparatus (140,190,210,240) and is arranged to supply NO_x into the combustion chamber. A yield of sulphur dioxide in the combustion products may thereby be improved. The NO_x generating apparatus may be operated at a raised working temperature. The NO_x generating apparatus may be provided by an ozonator with a supply of nitrogen and oxygen. A Venturi tube arrangement (246) may draw the generated NO_x into a (carrier or oxygen) gas line to the combustion chamber. Ozone may be supplied to the combustion products to convert nitrogen monoxide therein to nitrogen dioxide. The NO_x and ozone may be supplied by a single device (210,240).

Various methods for decreasing the amount of nitrogen oxides released to the atmosphere as a component of combustion gas mixtures are provided. The methods specifically provide for the removal of nitric oxide and nitrogen dioxide (NOx) from gas mixtures emitted from stationary combustion systems. In particular, methods for improving efficiency of nitrogen oxide reduction from combustion systems include injecting metal-containing compounds into the main combustion zone and/or the reburning zone of a combustion system. The metal containing compounds react with active combustion species, and these reactions change radical concentrations and significantly improve NOx conversion to molecular nitrogen. The metal-containing additives can be injected with the main fuel, in the main combustion zone, with secondary or reburning fuel addition, or at several locations in the main combustion zone and reburning zone. Optionally, nitrogenous reducing agents and/or overfire air can be injected downstream to further increase NOx reduction.

A new method for the removal of environmental compounds from gaseous streams, in particular, flue gas streams. The new method involves first oxidizing some or all of the acid anhydrides contained in the gas stream such as sulfur dioxide (SO₂) and nitric oxide (NO) and nitrous oxide (N₂O) to sulfur trioxide (SO₃) and nitrogen dioxide (NO₂). The gas stream is subsequently treated with aqua ammonia or ammonium hydroxide which captures the compounds via chemical absorption through acid-base or neutralization reactions. The products of the reactions can be collected as slurries, dewatered, and dried for use as fertilizers, or once the slurries have been dewatered, used directly as fertilizers. The ammonium hydroxide can be regenerated and recycled for use via thermal decomposition of ammonium bicarbonate, one of the products formed. There are alternative embodiments which entail stoichiometric scrubbing of nitrogen oxides and sulfur oxides with subsequent separate scrubbing of carbon dioxide.

A gas sensing device (nanosensor) includes a substrate with at least a pair of conductive electrodes spaced apart by a gap, and an electrochemically functionalized semiconductive nanomaterial bridging the gap between the electrodes to form a nanostructure network. The nanomaterial may be single-walled carbon nanotubes (SWNTs) functionalized by the deposition of nanoparticles selected from the group consisting of an elemental metal (e.g., gold or palladium), a doped polymer (e.g., camphor-sulfonic acid doped polyaniline), and a metal oxide (e.g. tin oxide). Depending on the nanoparticles employed in the functionalization, the nanosensor may be used to detect a selected gas, such as hydrogen, mercury vapor, hydrogen sulfide, nitrogen dioxide, methane, water vapor, and/or ammonia, in a gaseous environment.

Methods and apparatus for broad tuning of single wavelength quantum cascade lasers and the use of light output from such lasers for highly sensitive detection of trace gases such as nitrogen dioxide, acetylene, and vapors of explosives such as trinitrotoluene (TNT) and triacetone triperoxide (TATP) and TATP's precursors including acetone and hydrogen peroxide. These methods and apparatus are also suitable for high sensitivity, high selectivity detection of other chemical compounds including chemical warfare agents and toxic industrial chemicals. A quantum cascade laser (QCL) system that better achieves single mode, continuous, mode-hop free tuning for use in L-PAS (laser photoacoustic spectroscopy) by independently coordinating gain chip current, diffraction grating angle and external cavity length is described. An all mechanical method that achieves similar performance is also described. Additionally, methods for improving the sensor performance by critical selection of wavelengths are presented.

The invention provides a smoke catalysis and oxidation denitration process which takes a catalyst using TiO2 or ZrO2-TiO2 as a carrier and Co as active ingredient, uses the oxygen contained in the smoke to oxidate the NO as NO2 which is easy to be dissolved in water, utilizes the alkali solution to absorb the NO2 and remove the NOx. The process of the invention has high denitration efficiency and low cost, can selectively recover the nitrite in the denitration outgrowth and realize the resource utilization of the outcome after controlling the content of the NO2 in the oxidated smoke.

An oxidation catalyst that efficiently promotes oxidation of NO to NO₂ even in a low temperature range, and an exhaust-gas purification system and method that efficiently removes exhaust-gas components even in a low temperature range are provided. This invention provides an oxidation catalyst comprising platinum and palladium as catalytically active components, which promotes oxidation of nitrogen monoxide to nitrogen dioxide, wherein the oxidation catalyst comprises 1 to 55% by weight of the palladium relative to 100% by weight of the platinum.

The invention discloses a wet-method smoke denitration process used for recovering nitrite, comprising the steps as follows: hydrogen peroxide or ozone is taken as oxidant; the oxidant is uniformly sprayed into smoke disposed by pre-dedusting and desulfurizing so as to carry out gas oxidation reaction and lead the NO in the smoke to be oxidated as NO2; subsequently, alkali liquid is taken as absorbent so as to absorb the mixture of the oxidated NO and NO2 and generate the nitrite; the absorbent is concentrated after absorbing the NO and NO2 and cooled and crystallized; after centrifuging separation, the nitrite crystal is gained. The process of the invention can effectively remove the NOx in the smoke, gains the nitrite with high economic values at the same time, and realizes the resource utilization of denitration outgrowth.

A power generating apparatus including a gas turbine engine combusting a fuel in air to produce shaft power and producing a flow of exhaust gases including oxides of nitrogen (NO_x), carbon monoxide (CO) and hydrocarbons (HC). An emissions treatment apparatus includes in the exhaust gas flowpath a CO oxidation catalyst disposed at a location with an exhaust gas temperature for which the CO oxidation catalyst advantageously limits NO₂ production. The emissions treatment apparatus further includes an ammonia injection apparatus, a mixing section, and a selective catalytic reduction element disposed downsteam of the ammonia injection apparatus and adapted for reduction of NO_x.

Several embodiments of a Nitric Oxide Inhaler that uses an electrical spark to produce Nitric Oxide from Air, optimized to maximize the production of Nitric Oxide and minimize the production of Nitrogen Dioxide through hardware and control system. Further disclosed is a system to control such inhalers

A system for the detection of nitric oxide in a gas sample includes a converter for oxidation of nitric oxide to nitrogen dioxide, a nitrogen dioxide sensor including nanostructures and a filtering device to remove at least carbon dioxide from the gas sample positioned upstream of the converter. The nitrogen dioxide sensor can, for example, include a recognition layer on the nanostructures adapted to enhance sensitivity to nitrogen dioxide. A method for detecting nitric oxide in exhaled breath includes detecting nitric oxide in the exhaled breath using a nitric oxide sensor including nanostructures. Another method for detecting nitric oxide in exhaled breath includes filtering the breath to remove at least carbon dioxide from the breath, oxidizing nitric oxide in the exhaled breath to nitrogen dioxide and detecting the nitrogen dioxide using a nitrogen dioxide sensor including nanostructures.

A process for producing saleable liquids from organic material comprising the following steps. Providing organic material and separating it into solids, liquids and vapor. Reacting the liquids, combining it with water vapor and producing a volatized gas stream. Removing nitrogen dioxide from the gas stream to produce a scrubbed volatized gas stream. Reacting the scrubbed volatized gas stream with water vapor to produce a combined volatized gas stream. Removing carbon dioxide from the combined volatized gas stream to produce a subtracted volatized gas stream. Reacting the subtracted volatized gas stream with methanol to produce an enhanced volatized gas stream. Distilling the enhanced volatized gas stream to produce ethanol.

A process for cleaning the waste gas containing high-concentration NOx includes such steps as gathering the fume, coming in rotary filler bed, diffusing into rotary filler, spraying the absorptive liquid to filler, countercurrent absorption, mixing the treated gas with oxidant to oxidize NO to NO2, coming in rotary filler bed, absorbing by absorptive liquid, defrosting, and exhausting. Said absorptive liquid can be cyclically used. Its apparatus is also disclosed.

A dry method for simultaneously desulfurizing and denitrating fume includes using H2O2 or methanol to convert the NO in fume to NO2, using Ca-base particles as desulfurizing agent to react with SO2 to obtain calcium sulfate, and using ammonia water or urea as denitrating agent to react with NO2 to obtain ammonium nitrate and clean fume. Its apparatus is composed of additive sprayer, desulfurizing system and denitrating system.

A method of on-board diagnostic (OBD) catalyst monitoring. Vehicle OBD exhaust systems often include a catalyst, a pre-catalyst exhaust gas oxygen sensor, and a post-catalyst exhaust gas oxygen sensor. A method is provided of monitoring the catalyst which includes the steps of measuring hydrogen or nitrogen dioxide generation by the catalyst, and correlating changes in hydrogen or nitrogen dioxide generation to changes in catalytic conversion efficiency. Because OBD legislation defines catalyst deterioration or malfunction in terms of hydrocarbon or nitrogen oxide emission levels, the method uses hydrogen or nitrogen dioxide generation as a metric for OBD monitoring of the catalyst and offers the advantage of a more direct relationship to catalyst health than conventional methods.