Thermedics Inc.

Thermotrex Corporation

Thermo Electron Corporation

L-3 Communications Cyterra Corporation

Trex Medical Corporation

David P Lieb

David P Rounbehler

Eugene K Achter

David H Fine

Anthony J Pellegrino

Daniel N Lyke

Joseph A Buturlia

Eugenie Hainsworth

Gabor Miskolczy

David B Gernes

Alf L Carroll

Abdul Tafreshi

Freeman W Fraim

Herbert A Duvoisin, Iii

Sean Christiansen

Eric J Moy

Edward E A Bromberg

C Andrew Helm

Steven Bullock

Gregory J Wendell

Gregory J Wendel

A method of detecting energetic materials, such as explosives, includes energizing a sample area that contains particles of energetic materials. In the method, temperature characteristics from the sample area are monitored, and a temperature released from exothermic decomposition of the particles is detected. The method further includes analyzing the detected temperature to determine the presence of the exothermic compound which caused the decomposition.

Energetic material detector

Air cross grids, for absorbing scattered secondary radiation and improving radiation imaging in general radiography and in mammography, are provided with a large plurality of open air passages extending through each grid panel. These passages are defined by two large pluralities of substantially parallel partition walls, respectively extending transverse to each other. Each grid panel is made by laminating a plurality of thin metal foil sheets photo-etched to create through openings defined by partition segments. The etched sheets are aligned and bonded to form the laminated grid panel, which is moved edgewise during the radiation exposure to pass primary radiation through the air passages while absorbing scattered secondary radiation arriving along slanted paths.

Air cross grids for X-ray imaging

Air cross grids, for absorbing scattered secondary radiation and improving X-ray imaging in general radiography and in mammography, are provided with a large plurality of open air passages extending through each grid panel. These passages are defined by two large pluralities of substantially parallel partition walls, respectively extending transverse to each other. Each grid panel is made by laminating a plurality of thin metal foil sheets photo-etched to create through openings defined by partition segments. The etched sheets are aligned and bonded to form the laminated grid panel, which is moved edgewise during the X-ray exposure to pass primary radiation through the air passages while absorbing scattered secondary radiation arriving along slanted paths.

Air cross grids for mammography and methods for their manufacture and use

A highly selective, sensitive, fast detection system and method are disclosed for detecting vapors of specific compounds in air. Vapors emanating from compounds such as explosives, or stripped from surfaces using heat and suction from a hand-held sample gun, are collected on surfaces coated with gas chromatograph (GC) material which trap explosives vapors but repel nitric oxide, then are desorbed and concentrated in one or more cold spot concentrators, A high speed gas chromatograph (GC) separates the vapors, after which specific vapors are decomposed in two pyrolyzers arranged in parallel and the resulting nitric oxide is detected, A low temperature pyrolyzer with silver produces NO from nitramines or nitrite esters; a high temperature pyrolyzer decomposes all explosives vapors to permit detection of the remaining explosives, Also disclosed is a series arrangement of pyrolyzers and gas chromatographs and an NO detector to time-shift detection of certain vapors and facilitate very fast GC analyses, The use of hydrogen as a carrier gas, plus unique collectors and concentrators, high speed heaters, NO detectors, and very fast, temperature-programmable GC's enhance selectivity, sensitivity and speed of detection,

Vapor collector/desorber with non-conductive tube bundle

A highly selective, sensitive, fast detection system and method are disclosed for detecting vapors of specific compounds in air. Vapors emanating from compounds such as explosives, or stripped from surfaces using heat and suction from a hand-held sample gun, are collected on surfaces coated with gas chromatograph (GC) material which trap explosives vapors but repel nitric oxide, then are desorbed and concentrated in one or more cold spot concentrators. A high speed gas chromatograph (GC) separates the vapors, after which specific vapors are decomposed in two pyrolyzers arranged in parallel and the resulting nitric oxide is detected. A low temperature pyrolyzer with silver produces NO from nitramines or nitrite esters; a high temperature pyrolyzer decomposes all explosives vapors to permit detection of the remaining explosives. Also disclosed is a series arrangement of pyrolyzers and gas chromatographs and an NO detector to time-shift detection of certain vapors and facilitate very fast GC analyses. The use of hydrogen as a carrier gas, plus unique collectors and concentrators, high speed heaters, NO detectors, and very fast, temperature-programmable GC's enhance selectivity, sensitivity and speed of detection.

Selective detection with high speed gas chromatography

Disclosed are a method and apparatus for high speed, selective detection of vapors of specific compounds, particularly nitrogen-containing compounds, utilizing a bypass branch and high speed gas chromatography for improved selectivity and sensitivity of detection. A system with two gas chromatographs (GC's) alternating in series with two pyrolyzers provides two time intervals of detection in a downstream detector, with the second time interval containing signals delayed and further separated relative to signals from the first time interval. The bypass branch, in diverting a portion of the flow of gas samples from passage through the second gas chromatograph and second pyrolyzer, avoids interferences in the first time interval of detection from non-GC-retained compounds decomposed in the second pyrolyzer. Also disclosed is an arrangement for rapid, precise heating of vapor concentrator tubes in which vapors are rapidly focussed and then injected into a GC, and for rapid, precise heating of the GC's.

Vapor detection with high speed gas chromatography

A method and apparatus for selective, high speed detection of vapors of specific gas-chromatographically-separable compounds. In the disclosed method separate analyses are performed on two portions of a gas sample formed by flash-heating trapped vapors to successively higher temperatures while flowing hydrogen carrier gas over coatings in/on which the vapors are held. Within a total time interval of about twenty seconds 1) two sample portions are formed, 2) each portion is rapidly separated in two series-connected, high speed, temperature-programmed gas chromatographs, and 3) specific compounds are identified by detection of NO gas formed during an oxidative pyrolysis of each separated portion. One application of the described method and apparatus is the rapid, selective, and sensitive detection of nitrogen-containing compounds such as the drugs methamphetamine, cocaine, and heroin.

Selective, high speed detection of vapors with analysis of multiple

A highly selective, sensitive, fast detection system and method are disclosed for detecting vapors of specific compounds in air. Vapors emanating from compounds such as explosives, or stripped from surfaces using heat and suction from a hand-held sample gun, are collected on surface coated with gas chromatograph (GC) material which trap explosives vapors but repel nitric oxide, then are desorbed and concentrated in one or more cold spot concentrators. A high speed gas chromatograph (GC) separates the vapors, after which specific vapors are decomposed in two pyrolyzers arranged in parallel and the resulting nitric oxide is detected. A low temperature pyrolyzer with silver produces NO from nitramines or nitrite esters; a high temperature pyrolyzer decomposes all explosives vapors to permit detection of the remaining explosives. Also disclosed is a series arrangement of pyroloyzers and gas chromatographs and an NO detector to time-shift detection of certain vapors and facilitate very fast GC analyses. The use of hydrogen as a carrier gas, plus unique collectors and concentrators, high speed heaters, NO detectors, and very fast, temperature-programmable GC's enhance selectivity, sensitivity and speed of detection.

Hand-held sample gun for vapor collection

Disclosed are a method and apparatus for high speed, selective detection of vapors of specific compounds, particularly nitrogen-containing compounds, utilizing, a bypass branch and high speed gas chromatography for improved selectively and sensitivity of detection. A system with two gas chromatographs (GC's) alternating in series with two pyrolyzers provides two time intervals of detection in a downstream detector, with the second time interval containing signals delayed and further separated relative to signals from the first time interval. The bypass branch, in diverting a portion of the flow of gas samples from passage through the second gas chromatograph and second pyrolyzer, avoids interferences in the first time interval of detection from non-GC-retained compounds decomposed in the second pyrolyzer. Also disclosed is an arrangement for rapid, precise heating of vapor concentrator tubes in which vapors are rapidly focussed and then injected into a GC, and for rapid, precise heating of the GC's.

Vapor concentrator

Apparatus for detecting the amount of a specific compound in a sample. The apparatus comprises, in combination, a gas chromatograph, a cold trap and a specific gas detector. The cold trap includes means to cool the gas passing therethrough to a predetermined pressure therein, whereby gaseous effluent from the trap substantially consists of the specific gas and an inert gas.

Specific compound detection system

Apparatus for detecting the amount of a specific compound in a sample. The apparatus comprises, in combination, a gas chromatograph, a cold trap and a specific gas detector. The cold trap includes means to cool the gas passing therethrough to a predetermined temperature, and means to maintain a predetermined pressure therein, whereby the chromatograph carrier gas is condensed and the gaseous effluent from the trap substantially consists of the specific gas.

Growing community of inventors

Lexington, MA, United States of America

David P Lieb