2292results about "Chemical analysis using combustion" patented technology

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 (NOx) generating apparatus (140,190,210,240) and is arranged to supply NOx into the combustion chamber. A yield of sulphur dioxide in the combustion products may thereby be improved. The NOx generating apparatus may be operated at a raised working temperature. The NOx generating apparatus may be provided by an ozonator with a supply of nitrogen and oxygen. A Venturi tube arrangement (246) may draw the generated NOx 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 NOx and ozone may be supplied by a single device (210,240).

A photoelectrochemical assay apparatus for determining chemical oxygen demand (COD) of a water sample which consists of a) a measuring cell for holding a sample to be analysed b) a titanium dioxide nanoparticle photoelectric working electrode and a counter electrode disposed in said cell, c) a UV light source adapted to illuminate the photoelectric working electrode d) control means to control the illumination of the working electrode e) potential measuring means to measure the electrical potential at the working and counter electrodes f) analysis means to derive a measure of oxygen demand from the measurements made by the potential measuring means. The method of determining chemical oxygen demand of a water sample, comprises the steps of a) applying a constant potential bias to a photoelectrochemical cell, containing a supporting electrolyte solution; b) illuminating the working electrode with a UV light source and recording the background photocurrent produced at the working electrode from the supporting electrolyte solution; c) adding a water sample, to be analysed, to the photoelectrochemical cell; d) illuminating the working electrode with a UV light source and recording the total photocurrent produced; e) determining the chemical oxygen demand of the water sample according to the type of degradation conditions employed. The determination may be under exhaustive degradation conditions, in which all organics present in the water sample are oxidised or under non-exhaustive degradation conditions, in which the organics present in the water sample are partially oxidised.

A hydrogen gas sensor and / or switch fabricated from arrays nanowires composed of metal or metal alloys that have stable metal hydride phases. The sensor and / or switch response times make it quite suitable for measuring the concentration of hydrogen in a flowing gas stream. The sensor and / or switch preferably operates by measuring the resistance of several metal nanowires arrayed in parallel in the presence of hydrogen gas. The nanowires preferably comprise gaps or break junctions that can function as a switch that closes in the presence of hydrogen gas. Consequently, the conductivity of the nanowires of the sensor and / or switch increases in the presence of hydrogen

In certain embodiments, an apparatus includes an oxygen depletion sensor (ODS) includes a thermocouple, a first nozzle configured to direct heat from combustion of a first gas, liquid, or combination thereof to the thermocouple, a second nozzle configured to direct heat from combustion of a second gas, liquid, or combination thereof to the thermocouple, and a first igniter.

A method and apparatus for interfacing a plurality of gas measurement systems, including a mainstream and a sidestream gas measurement system, to a host system via an interface unit. The present invention also pertains to a sidestream gas measurement system that output signals emulating the signals output by a mainstream gas measurement system or portion thereof, so that the sidestream gas measurement system can seamlessly communicate with a host system configured to communicate only a mainstream gas measurement system or a portion thereof.

A portable monitor used to measure landfill gas and landfill well parameters. The portable monitor includes a control unit and a measuring unit that can communication wirelessly with one another. The control unit and / or measuring unit can includes a heating arrangement to increase the temperature of one or more components in the control unit and / or measuring unit in cold environments.

The system and method for explosives detection may be used for detecting the presence of explosive elements. A testing device may have a case with a cover. A sample holder may be disposed in the case for receipt of a sample element and may have a sample retainer. The sample element may have a swipe pad attached to a backing element a heater may be disposed in the sample holder wherein the heater may be below the swipe pad adjacent the backing element when the sample element may be positioned in the sample holder. The heater may be in communication with an electric power source. The case may have a plurality of cavities formed therein for receipt of a plurality of fluid containers. The plurality of fluid containers may have at least a first reagent fluid and a second reagent fluid.

A method of assaying the antioxidant capacity of a sample, the method including preparing an extraction solution including a solubility enhancing compound, adding the sample to the extraction solution, extracting the antioxidants present in the sample, adding a fluorescent probe to the extract, adding a free radical generator to the extract, detecting the fluorescence intensity decay of the probe in the presence of the sample over time, and calculating the antioxidant capacity of the sample based on the fluorescence intensity decay of the probe in the presence of the sample.

The invention discloses a testing device of gunpowder combustion characteristics in vacuum, which mainly comprises a combustion chamber, a vacuum pump, an electric heater, a thermoelectric couple, a high speed camera and a data acquisition and processing system; wherein, the vacuum pump provides vacuum environment for the combustion chamber; by controlling the heating current and the heating time of the electric heater, different ignition isoperibols can be provided for tested gunpowder samples in the combustion chamber; and the data acquisition and processing system collects the test data generated by the thermoelectric couple and the gunpowder combustion images shot by the high speed camera when the tested gunpowder samples combust, and finally obtains the combustion characteristics of the tested gunpowder samples through corresponding processing and calculation. The invention not only can be used for testing the parameters such as combustion speed, combustion surface temperature and combustion heat and the like of the gunpowder in vacuum, but also can be used for the generation and collection of the combustion products of the gunpowder under different vacuum conditions. The invention has the overriding advantages of high integration level, obtaining various parameters by one testing and low testing expenses.

An apparatus and method for monitoring microbiological activity in a process stream by measuring dissolved oxygen is disclosed. Bulk microbiological activity and surface associated biological activity are measured using this apparatus and method.

A compact scanning apparatus has an infrared laser adapted to emit light. The light is delivered as a beam by an optical system to illuminate an interrogation area on the surface of an object being scanned. Such illumination has sufficient intensity and duration to cause selective desorption of molecules of the contraband substance, which are present on the surface, without substantially damaging the surface. A collection system collects at least a portion of the desorbed molecules. At least a portion of the collected molecules is thermally decomposed to form NO2 and transferred to a reaction cell containing an aqueous, alkaline, luminol-containing solution. The NO2 reacts with the luminol to produce light by chemiluminescence. A light detector registers the presence of this light as indicative of the detection of the contraband substance, and activates a signaling device to provide an audible or visible alarm. The apparatus rapidly detects the presence of a wide variety of contraband substances in an accurate, reliable manner. It provides for automated screening, with the result that vagaries of human performance are virtually eliminated. False alarms are reduced and detection efficacy is increased. A traceable residue of the detected contraband is left on the article for use in forensic analysis.

A vapor analysis system comprising a vapor analyzer capable of collecting and analyzing a vapor sample for detection of a compound that may be contained within the vapor sample. A controller is coupled to the vapor analyzer. The controller is programmed to produce an indicator signal indicative of a relative concentration of the compound detected by the vapor analyzer within the vapor sample. A sample probe includes a housing containing a vapor channel through which the vapor sample is collected, and a vapor cable couples the sample probe to the vapor analyzer to allow collection and channeling of the vapor sample to the vapor analyzer. A multi-dimensional user indicator is disposed on the housing of the sample probe receives and operates in response to the indicator signal to indicate the relative concentration of the compound detected within the vapor sample for presentation via a multi-directional stimulus to a user of the vapor analysis system. Users are able to create user-defined fields in a route entry database and are able to edit route entries while using the vapor analysis system in the field.

A headspace instrument (10, 70) operates to equilibrate a vapor phase of a headspace sample in a sample loop (40, 74). The sample is equilibrated by flow through the headspace between variable volume chambers (28, 50, 86, 90). The volume of the variable volume chambers are changed in coordinated relation so that a constant total volume is always maintained. An aliquot of the equilibrated sample in the sample loop is delivered to an analytical instrument. The headspace instrument enables delivering a vapor sample from a headspace under conditions which do not disturb the thermodynamic equilibrium between the vapor phase and the non-vapor phase of the sample and avoids having the sampling process impact the results of the analysis. Alternative forms of the headspace instrument enable the conduct of concentration dependent processes and absorption and desorption experiments.

It is an adiabatic test method and its apparatus for stimulating the coal autoignition process, which is to locate an adiabatic coal sample jar served as coal low temperature oxidation reaction and to let the gas in the jar firstly go through the copper gas guide pipe in the gas bath temperature control box for preheating and the environment temperature in the box of the reaction always traces the temperature changes in the coal sample jar. It adopts preheat gas path apparatus, gas bath temperature control box, adiabatic coal jar in the temperature control box, temperature control system, which makes the heat generated during the reaction remain in the coal sample to stimulate the coal autoignition process.

The invention discloses a constant volume combustion bomb and a liquid fuel combustion performance testing method. The constant volume combustion bomb comprises a combustion bomb, an evaporator, a heating device and a vacuum suction device, a discharge outlet of the evaporator is connected to the combustion bomb by a discharge pipe, and a flow control valve is installed on the discharge pipe. The liquid fuel combustion performance testing method realizes complete vaporization of liquid fuel, accurate calculation of the amount of fuel fed into the constant volume combustion bomb by a partial pressure method, and gas distribution by a high-precision electronic pressure gauge so that an air-fuel ratio of the combustible gas mixture in the constant volume combustion bomb is accurately controlled. The constant volume combustor can be operated conveniently and controlled accurately. The liquid fuel combustion performance testing method fully utilizes the existing equipment and realizes combustion of liquid fuel in the combustion bomb and accurate control of a combustible gas mixture equivalence ratio by reasonable use.

Methods and kits that use nucleotide analogs to confer increased accuracy and improved resolution in the analysis and sequencing of oligonucleotide mixtures are provided.

The catalytic combustion type gas sensor includes a sensing element, a heat conducting layer of which includes boron nitride. The boron nitride content is from 30 wt % to 100 wt % of a material (such as alumina) that would be a base material having the highest proportion in a conventional heat conducting layer without boron nitride. A catalyst layer of the sensing element also includes boron nitride. The boron nitride content is from 10 wt % to 80 wt % of a material (such as tin oxide) that would be a base material having the highest proportion in a conventional catalyst layer without boron nitride.

Disclosed herein is a method and apparatus for analyzing, sensing and measuring the concentrations of various gases, including NOx, hydrocarbons, carbon monoxide and oxygen, in a multi-component gas system using chemical sensors and chemical sensor arrays. The sensors and sensor arrays use chemo / electro-active materials to analyze and detect the presence of gases.

The present invention discloses an apparatus and method for rapid analysis of members of a combinatorial library. The apparatus includes a plurality of vessels for containing individual library members and a fluid handling system that apportions a test fluid about equally between each of the vessels. This allows for simultaneous screening of library members by detecting changes in test fluid following contact with individual library members. Fluid flow through each of the vessels is controlled using passive flow restrictors or active flow controllers to ensure that each library member contacts approximately the same amount of test fluid per unit time. The disclosed apparatus is especially useful for screening library members based on their ability to catalyze the conversion of fluid reactants.

A hydrogen gas indicator system that provides various substrate materials (4) that support hydrogen gas sensor (1) materials with discrete indicia (7) that provide information separate from any change in the physical properties of the hydrogen gas sensor itself.

A hydrogen sensor 25 has a fitting base plate 29 in which a gas-sensing chamber 34 is formed, a specimen gas intake 35 formed on said fitting base plate 29, opening toward an exit passage 24 and introducing hydrogen gas into the gas-sensing chamber 34, a gas-sensing element 39 held in the gas-sensing chamber 34 and adapted to sense hydrogen gas, and a water-repelling filter 44 covering the specimen gas intake 35.

A hydrogen gas sensor and / or switch fabricated from arrays nanowires composed of metal or metal alloys that have stable metal hydride phases. The sensor and / or switch response times make it quite suitable for measuring the concentration of hydrogen in a flowing gas stream. The sensor and / or switch preferably operates by measuring the resistance of several metal nanowires arrayed in parallel in the presence of hydrogen gas. The nanowires preferably comprise gaps or break junctions that can function as a switch that closes in the presence of hydrogen gas. Consequently, the conductivity of the nanowires of the sensor and / or switch increases in the presence of hydrogen

A dust monitor is disclosed that is suitably deployed in dusty environments and capable of providing near real-time indications of exposure to airborne particulates. The monitor includes a filter and filter assembly made of materials that do not interfere with subsequent instrumental (such as spectrometric) analysis for detecting and / or quantitating an analyte. In some disclosed embodiments, the filter is made of nylon or other material that is readily subjected to thermal destruction prior to spectrometric analysis. The dust monitor also includes a humidity correction feature that permits the filter to be made of ashable organic materials even if those materials are not highly hydrophobic. Transport devices are provided for shipment of the filter and / or filter assembly to an analytical laboratory which prevent loss of particulate matter and which facilitate an accurate analysis procedure.

The invention discloses a device for realizing a turbulent flame and shock wave visual constant volume combustion test. The device comprises a firebomb body, a fuel supply system, a heating system, an igniting system, a high-speed photography system, an air inlet and outlet system, a pressure acquisition system, a synchronous controller and a single-chip microcomputer control system. The device also comprises orifice plates with different amounts of porosity and aperture sizes. In each test, the cross section of the firebomb body is provided with one of the orifice plates through an orifice plate slot. The method utilizes hydrogen as fuel. Through use of the orifice plates with different amounts of porosity and aperture sizes, turbulent flame with different intensities is obtained and visible shock wave is produced. The invention researches interaction of reflection shock wave and flame and interaction-caused influence on pressure fluctuation in a cylinder. The method and device provide theoretical thinking for pressure fluctuation phenomenon in an enclosed space and knocking of a small reinforced gasoline engine. The device and method realize full transparent visualization of the whole combustion chamber and clear and visual shooting of the whole flame development process.

The invention relates to a sample application device for a gas chromatograph, having an evaporator (1) which can be cooled, can be heated in a temperature-controlled manner, is provided with a carrier-gas feed and has a valve head (11) for holding an exchangeable sampling tube (27), a receiving chamber (4) for the sampling tube (27), a column exit (18) and, if appropriate, a splitter exit (31). In this device, a pyrolyser tube (20), which is coupled to the carrier-gas feed and is held by the valve head (11), is arranged in the receiving chamber (4), in which there is a heating coil (26) into which the sampling tube (27) can be fitted and to which current can be applied by means of a heating conductor (25) which is guided outwards through the valve head (11).

A hydrogen sensor 25 has a fitting base plate 29 in which a gas-sensing chamber 34 is formed, a specimen gas intake 35 formed on said fitting base plate 29, opening toward an exit passage 24 and introducing hydrogen gas into the gas-sensing chamber 34, a gas-sensing element 39 held in the gas-sensing chamber 34 and adapted to sense hydrogen gas, and a water-repelling filter 44 covering the specimen gas intake 35.

PCT No. PCT / SE95 / 01084 Sec. 371 Date Jun. 19, 1997 Sec. 102(e) Date Jun. 19, 1997 PCT Filed Sep. 22, 1995 PCT Pub. No. WO96 / 09534 PCT Pub. Date Mar. 28, 1996A gas sensing device having a semiconductor substrate, wherein the semiconductor substrate is covered by an insulator layer, on which an intermediate layer is formed, and subsequently covered by a gas sensing catalytic layer, wherein the intermediate layer and the catalytic layer are made of different materials. The gas sensing device may optionally have dispersed between the insulator layer and the intermediate layer a catalytic metal layer. The gas sensing device provides improved stability and speed of response, even when used at high ambient temperatures, such as temperatures found in combustion systems. A method for making the gas sensing device is also disclosed.

The invention provides a testing device for the combustion rate of combustibles in a plateau artificial oxygen-enriched environment, belonging to a field of fire safety. The testing device consists of the following seven parts: a combustion chamber, a positioning mechanism, an air distribution system, an airflow-circulation and concentration-monitoring system, a vacuum-pumping system, an ignition system and a data acquisition system. A sample is arranged on a sample support by a sample clamper, and then vacuum-pumping is carried out to a sealed chamber by the vacuum-pumping system; each single high-purity gases are mixed in the sealed chamber after passing through a mass flowmeter and a flow regulating valve; the total pressure of the gases is displayed by a high-precision vacuum manometer; when the requirements of the total pressure of the gases and gas compositions are met, a micro-air pump is started to mix the airflow in the sealed chamber; a laser light source is started to ignite the sample after the concentration of the gas compositions is steady; the sample combustion flame passes through two thermocouples sequentially; temperature change curves of the thermocouples are obtained by A / D conversion and the data acquisition system; and the time between two maximum temperature points of the curves corresponding to the two thermocouples is taken as the combustion time of the sample between the thermocouples with fixed distance, thus obtaining the combustion rate of the sample under the total pressure of the gases and the concentration of the gas compositions. The testing device has stable and reliable testing performance, and is simple and convenient.