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1

Nonlinearities in Flame Ionization Detector Response  

Science Journals Connector (OSTI)

......ionization detector (FIO) to various hydrocarbons hat been found to be proportional to powers of the concentration which ex- ceed unity In certain ranges. The sample elution rates at which this effect is observed and operating condi- tions employed correspond......

J.H. Bromly; P. Roga

1980-11-01T23:59:59.000Z

2

A Hydrogen Singing-Flame Ionization Detector  

Science Journals Connector (OSTI)

......occurs un- der certain hydrogen, air, and sam- ple...which was the fact that methods of increas- ing ion...inverted glass jar over a hydrogen diffusion flame to demonstrate...optimum in the normal hydrogen diffusion flame and...reasons for the higher ion production. Advantages of the......

L. B. Graiff

1965-05-01T23:59:59.000Z

3

A Novel Miniaturized Flame Ionization Detector for Portable Gas Chromatography  

Science Journals Connector (OSTI)

......the detection of hydrocarbons in portable GC...The air needed for combustion is introduced from...electrical power to heat the detector to...detector is used to heat the detector and...is defined as the hydrocarbon concentra- tion...in Table I. The data in Table I show......

Chunhui Deng; Xiuhan Yang; Ning Li; Yue Huang; Xiangmin Zhang

2005-08-01T23:59:59.000Z

4

Correlation between speciated hydrocarbon emissions and flame ionization detector response for gasoline/alcohol blends .  

SciTech Connect (OSTI)

The U.S. renewable fuel standard has made it a requirement to increase the production of ethanol and advanced biofuels to 36 billion by 2022. Ethanol will be capped at 15 billion, which leaves 21 billion to come from other sources such as butanol. Butanol has a higher energy density and lower affinity for water than ethanol. Moreover, alcohol fueled engines in general have been shown to positively affect engine-out emissions of oxides of nitrogen and carbon monoxide compared with their gasoline fueled counterparts. In light of these developments, the variety and blend levels of oxygenated constituents is likely to increase in the foreseeable future. The effect on engine-out emissions for total hydrocarbons is less clear due to the relative insensitivity of the flame ionization detector (FID) toward alcohols and aldehydes. It is well documented that hydrocarbon (HC) measurement using a conventional FID in the presence of oxygenates in the engine exhaust stream can lead to a misinterpretation of HC emissions trends for alcohol fuel blends. Characterization of the exhaust stream for all expected hydrocarbon constituents is required to accurately determine the actual concentration of unburned fuel components in the exhaust. In addition to a conventional exhaust emissions bench, this characterization requires supplementary instrumentation capable of hydrocarbon speciation and response factor independent quantification. Although required for certification testing, this sort of instrumentation is not yet widely available in engine development facilities. Therefore, an attempt is made to empirically determine FID correction factors for oxygenate fuels. Exhaust emissions of an engine fueled with several blends of gasoline and ethanol, n-butanol and iso-Butanol were characterized using both a conventional FID and a Fourier transform infrared. Based on these results, a response factor predicting the actual hydrocarbon emissions based solely on FID results as a function of alcohol type and content is presented. Finally, the correlation derived from data presented in this study is compared with equations and results found in the literature.

Wallner, T. (Energy Systems)

2011-08-01T23:59:59.000Z

5

The Flame Ionization Detector  

Science Journals Connector (OSTI)

......same as most other hydrocarbons. We are therefore...supported only by data from C2H2, the...the shock tube data, while somewhat...Inter- nat.) on Combustion," Academic Press...formation in those hydrocarbons which display the...the transfer of heat and hydrogen atoms......

A. T. Blades

1973-05-01T23:59:59.000Z

6

Ionizing radiation detector  

DOE Patents [OSTI]

An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.

Thacker, Louis H. (Knoxville, TN)

1990-01-01T23:59:59.000Z

7

Optical ionization detector  

DOE Patents [OSTI]

An optical ionization detector wherein a beam of light is split so that one arm passes through a fiber optics and the other arm passes through a gas-filled region, and uses interferometry to detect density changes in a gas when charged particles pass through it. The gas-filled region of the detector is subjected to a high electric field and as a charged particle traverses this gas region electrons are freed from the cathode and accelerated so as to generate an electron avalanche which is collected on the anode. The gas density is effected by the electron avalanche formation and if the index or refraction is proportional to the gas density the index will change accordingly. The detector uses this index change by modulating the one arm of the split light beam passing through the gas, with respect to the other arm that is passed through the fiber optic. Upon recombining of the beams, interference fringe changes as a function of the index change indicates the passage of charged particles through the gaseous medium. 3 figures.

Wuest, C.R.; Lowry, M.E.

1994-03-29T23:59:59.000Z

8

Optical ionization detector  

DOE Patents [OSTI]

An optical ionization detector wherein a beam of light is split so that one arm passes through a fiber optics and the other arm passes through a gas-filled region, and uses interferometry to detect density changes in a gas when charged particles pass through it. The gas-filled region of the detector is subjected to a high electric field and as a charged particle traverses this gas region electrons are freed from the cathode and accelerated so as to generate an electron avalanche which is collected on the anode. The gas density is effected by the electron avalanche formation and if the index or refraction is proportional to the gas density the index will change accordingly. The detector uses this index change by modulating the one arm of the split light beam passing through the gas, with respect to the other arm that is passed through the fiber optic. Upon recombining of the beams, interference fringe changes as a function of the index change indicates the passage of charged particles through the gaseous medium.

Wuest, Craig R. (Danville, CA); Lowry, Mark E. (Castro Valley, CA)

1994-01-01T23:59:59.000Z

9

Modulated voltage metastable ionization detector  

SciTech Connect (OSTI)

Metastable ionization detectors used for chromatographic analysis usually employa fixed high voltage for the ionization potential. For this reason, the operating range is limited to about three orders of magnitude. By use of the technique disclosed in the instant invention, operating ranges of about nine orders of magnitude are obtained. The output current from a metastable ionization detector (MID) is applied to a modulation voltage circuit. An adjustment is made to balance out the background current, and an output current, above background, is applied to an input of a strip chart recorder. For low level concentrations, i.e., low detected output current, the ionization potential will be at a maximum and the metastable ionization detector will operate at its most sensitive level. When the detected current from the metastable ionization detector increases above a predetermined threshold level, a voltage control circuit is activated which turns on a high voltage transistor which acts to reduce the ionization potential. The ionization potential applied to the metastable ionization detector is then varied so as to maintain the detected signal level constant. The variation in ionization potential is now related to the concentration fo the constituent and a representative amplitude is applied to another input of said strip chart recorder.

Carle, G. C.; Humphry, D. E.; Kojiro, D. R.

1985-08-27T23:59:59.000Z

10

Neutron And Gamma Detector Using An Ionization Chamber With An...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting...

11

A Universal Detector for Liquid Chromatography: The Flame Aerosol Detector  

Science Journals Connector (OSTI)

......a turbu- lent air-hydrogen flame into which the...application of calibration methods similar to those often...of the flame as one method of production of charged droplets...case. In the air-hydrogen flame of a conventional......

Stephen A. Wise; Richard A. Mowery; Jr; Richard S. Juvet; Jr

1979-11-01T23:59:59.000Z

12

Use of laser-induced ionization to detect soot inception in premixed flames  

SciTech Connect (OSTI)

Experimental measurements of laser-induced ionization were performed for ethene-air premixed flames operated near the soot inception point. Soot was ionized with a pulsed laser operated at 532 nm. The ionization signal was collected with a tungsten electrode located in the postflame region. Ionization signals were collected by use of both single-electrode and dual-electrode configurations. Earlier laser-induced- ionization studies focused on the use of a single biased electrode to generate the electric field, with the burner head serving as the path to ground. In many practical combustion systems, a path to ground is not readily available. To apply the laser-induced- ionization diagnostic to these geometries, a dual-electrode geometry must be employed. The influence of electrode configuration, flame equivalence ratio, and flame height on ionization signal detection was determined. The efficacy of the laser-induced-ionization diagnostic in detecting soot inception in the postflame region of a premixed flame by use of a dual-electrode configuration was investigated. Of the dual-electrode configurations tested, the dual-electrode geometry oriented parallel to the laser beam was observed to be most sensitive for detecting the soot inception point in a premixed flame.

Manzello, Samuel L.; Lee, Eui Ju; Mulholland, George W

2005-08-20T23:59:59.000Z

13

The Effect of the Carrier Gas on Flame lonization Detector Sensitivity  

Science Journals Connector (OSTI)

......fraction of the hydrocarbon converted to CH...ion formation in hydrocarbon flames. The CH...1 ". While no data is presently available...12) that the heats of formation of...chemi-ionization in hydrocarbon flames appears to...International on Combustion, Academic Press......

A.T. Blades

1976-01-01T23:59:59.000Z

14

TIME-VARYING FLAME IONIZATION SENSING APPLIED TO NATURAL GAS AND PROPANE BLENDS IN A PRESSURIZED LEAN PREMIXED (LPM) COMBUSTOR  

SciTech Connect (OSTI)

In-situ monitoring of combustion phenomena is a critical need for optimal operation and control of advanced gas turbine combustion systems. The concept described in this paper is based on naturally occurring flame ionization processes that accompany the combustion of hydrocarbon fuels. Previous work has shown that flame ionization techniques may be applied to detect flashback, lean blowout, and some aspects of thermo-acoustic combustion instabilities. Previous work has focused on application of DC electric fields. By application of time-varying electric fields, significant improvements to sensor capabilities have been observed. These data have been collected in a lean premixed combustion test rig operating at 0.51-0.76 MPa (5-7.5 atm) with air preheated to 588 K (600°F). Five percent of the total fuel flow is injected through the centerbody tip as a diffusion pilot. The fuel composition is varied independently by blending approximately 5% (volume) propane with the pipeline natural gas. The reference velocity through the premixing annulus is kept constant for all conditions at a nominal value of 70 m/s. The fuel-air equivalence ratio is varied independently from 0.46 – 0.58. Relative to the DC field version, the time-varying combustion control and diagnostic sensor (TV-CCADS) shows a significant improvement in the correlation between the measured flame ionization current and local fuel-air equivalence ratio. In testing with different fuel compositions, the triangle wave data show the most distinct change in flame ionization current in response to an increase in propane content. Continued development of this sensor technology will improve the capability to control advanced gas turbine combustion systems, and help address issues associated with variations in fuel supplies.

D. L. Straub; B. T. Chorpening; E. D. Huckaby; J. D. Thornton; W. L. Fincham

2008-06-13T23:59:59.000Z

15

Neutron And Gamma Detector Using An Ionization Chamber With An Integrated  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. Available for thumbnail of Feynman Center (505) 665-9090 Email Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. A conductive neutron-capturing layer is disposed on the interior surface of the cathode and a plastic housing surrounds the cathode. A plastic lid is attached to the housing and encloses the interior volume of the cathode forming an

16

High resolution resonance ionization imaging detector and method  

DOE Patents [OSTI]

A resonance ionization imaging device (RIID) and method for imaging objects using the RIID are provided, the RIID system including a RIID cell containing an ionizable vapor including monoisotopic atoms or molecules, the cell being positioned to intercept scattered radiation of a resonance wavelength .lambda..sub.1 from the object which is to be detected or imaged, a laser source disposed to illuminate the RIID cell with laser radiation having a wavelength .lambda..sub.2 or wavelengths .lambda..sub.2, .lambda..sub.3 selected to ionize atoms in the cell that are in an excited state by virtue of having absorbed the scattered resonance laser radiation, and a luminescent screen at the back surface of the RIID cell which presents an image of the number and position of charged particles present in the RIID cell as a result of the ionization of the excited state atoms. The method of the invention further includes the step of initially illuminating the object to be detected or imaged with a laser having a wavelength selected such that the object will scatter laser radiation having the resonance wavelength .lambda..sub.1.

Winefordner, James D. (Gainesville, FL); Matveev, Oleg I. (Gainesville, FL); Smith, Benjamin W. (Gainesville, FL)

1999-01-01T23:59:59.000Z

17

An Improved Thermionic Ionization Detector for Gas Chromatography  

Science Journals Connector (OSTI)

......through two of the holes and is used as the heater element. A fine platinum wire runs through...LOW DENSITY Cs HIGH DENSITY Cs NICHROME HEATER GAS ENVIRONMENT DILUTE H2/AIR N2 Figure...Patterson. Selective responses of a flameless thermionic detector. J. Chromatogr......

P.L. Patterson; R.A. Gatten; C. Ontiveros

1982-03-01T23:59:59.000Z

18

MICE: the Muon Ionization Cooling Experiment. Step I: First Measurement of Emittance with Particle Physics Detectors  

E-Print Network [OSTI]

The Muon Ionization Cooling Experiment (MICE) is a strategic R&D project intended to demonstrate the only practical solution to providing high brilliance beams necessary for a neutrino factory or muon collider. MICE is under development at the Rutherford Appleton Laboratory (RAL) in the United Kingdom. It comprises a dedicated beamline to generate a range of input muon emittances and momenta, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. The emittance of the incoming beam will be measured in the upstream magnetic spectrometer with a scintillating fiber tracker. A cooling cell will then follow, alternating energy loss in Liquid Hydrogen (LH2) absorbers to RF cavity acceleration. A second spectrometer, identical to the first, and a second muon identification system will measure the outgoing emittance. In the 2010 run at RAL the muon beamline and most detectors were fully commissioned and a first measurement of the emittance of the muon beam with particle physics (time-of-flight) detectors was performed. The analysis of these data was recently completed and is discussed in this paper. Future steps for MICE, where beam emittance and emittance reduction (cooling) are to be measured with greater accuracy, are also presented.

U. Bravar; M. Bogomilov; Y. Karadzhov; D. Kolev; I. Russinov; R. Tsenov; L. Wang; F. Y. Xu; S. X. Zheng; R. Bertoni; M. Bonesini; R. Mazza; V. Palladino; G. Cecchet; A. de Bari; M. Capponi; A. Iaciofano; D. Orestano; F. Pastore; L. Tortora; S. Ishimoto; S. Suzuki; K. Yoshimura; Y. Mori; Y. Kuno; H. Sakamoto; A. Sato; T. Yano; M. Yoshida; F. Filthaut; M. Vretenar; S. Ramberger; A. Blondel; F. Cadoux; F. Masciocchi; J. S. Graulich; V. Verguilov; H. Wisting; C. Petitjean; R. Seviour; M. Ellis; P. Kyberd; M. Littlefield; J. J. Nebrensky; D. Forrest; F. J. P. Soler; K. Walaron; P. Cooke; R. Gamet; A. Alecou; M. Apollonio; G. Barber; A. Dobbs; P. Dornan; A. Fish; R. Hare; A. Jamdagni; V. Kasey; M. Khaleeq; K. Long; J. Pasternak; H. Sakamoto; T. Sashalmi; V. Blackmore; J. Cobb; W. Lau; M. Rayner; C. D. Tunnell; H. Witte; S. Yang; J. Alexander; G. Charnley; S. Griffiths; B. Martlew; A. Moss; I. Mullacrane; A. Oats; S. York; R. Apsimon; R. J. Alexander; P. Barclay; D. E. Baynham; T. W. Bradshaw; M. Courthold; R. Edgecock T. Hayler; M. Hills; T. Jones; N. McCubbin; W. J. Murray; C. Nelson; A. Nicholls; P. R. Norton; C. Prior; J. H. Rochford; C. Rogers; W. Spensley; K. Tilley; C. N. Booth; P. Hodgson; R. Nicholson; E. Overton; M. Robinson; P. Smith; D. Adey; J. Back; S. Boyd; P. Harrison; J. Norem; A. D. Bross; S. Geer; A. Moretti; D. Neuffer; M. Popovic; Z. Qian; R. Raja; R. Stefanski; M. A. C. Cummings; T. J. Roberts; A. DeMello; M. A. Green; D. Li; A. M. Sessler; S. Virostek; M. S. Zisman; B. Freemire; P. Hanlet; D. Huang; G. Kafka; D. M. Kaplan; P. Snopok; Y. Torun; Y. Onel; D. Cline; K. Lee; Y. Fukui; X. Yang; R. A. Rimmer; L. M. Cremaldi; T. L. Hart; D. J. Summers; L. Coney; R. Fletcher; G. G. Hanson; C. Heidt; J. Gallardo; S. Kahn; H. Kirk; R. B. Palmer

2011-10-09T23:59:59.000Z

19

Determinations of Carbon Dioxide and Methane by Dual Catalyst Flame Ionization Chromatography and Nitrous Oxide by Electron Capture Chromatography  

Science Journals Connector (OSTI)

......thermistor has a low thermal mass and the circuit...and have longer thermal exchange times will...detectors such as the thermal conductivity detector...equatorial Pacific Ocean during a 24 day...Department of Energy. References Journal...Methanizer" catalytic converter. 5. W.E. Wentworth......

Ray F. Weiss

1981-12-01T23:59:59.000Z

20

Flame Chemistry and Diagnostics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Details Photoionization Mass Spectrometer Flame Conditions Flame Chemistry Insights (n-butanol flame) Experiment vs. Model Fuel-Consumption Pathways...

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Physics studies with ICARUS and a hybrid ionization and scintillation fiber detector  

SciTech Connect (OSTI)

We discuss the physics possibilities for the ICARUS detector currently being tested at CERN. The physics potential goes from a massive proton decay detector to the study of solar neutrinos. In addition, the detection of {nu}{sub {mu}} {yields} {nu}{sub {tau}} and {nu}{sub e} {yields} {nu}{sub {tau}} will be possible with such a detector. One major topic involves the possibility of a complete determination of the MSW solar neutrino parameters with the ICARUS. The possibility of detecting WIMPS with a scintillating fiber liquid Argon (Ar) detector or fiber Xenon (Xe) detector doped with Ar is also described. Some comments on the measurement of the {sup 42}Ar level from an experiment at the Gran Sasso will be made.

Cline, D.B.

1992-12-31T23:59:59.000Z

22

Effective ionization coefficients, electron drift velocities, and limiting breakdown fields for gas mixtures of possible interest to particle detectors  

SciTech Connect (OSTI)

We have measured the gas-density, N, normalized effective ionization coefficient, {bar a}/N, and the electron drift velocity, w, as a function of the density-reduced electric field, E/N, and obtained the limiting, (E/N){sub lim}, value of E/N for the unitary gases Ar, CO{sub 2}, and CF{sub 4}, the binary gas mixtures CO{sub 2}:Ar (20: 80), CO{sub 2}:CH{sub 4} (20:80), and CF{sub 4}:Ar (20:80), and the ternary gas mixtures CO{sub 2}:CF{sub 4}:Ar (10:10:80) and H{sub 2}O: CF{sub 4}:Ar (2:18:80). Addition of the strongly electron thermalizing gas CO{sub 2} or H{sub 2}O to the binary mixture CF{sub 4}:Ar (1) cools'' the mixture (i.e., lowers the electron energies), (2) has only a small effect on the magnitude of w(E/N) in the E/N range employed in the particle detectors, and (3) increases {bar a}/N for E/N {ge} 50 {times} 10{sup {minus}17} V cm{sup 2}. The increase in {bar a}/N, even though the electron energies are lower in the ternary mixture, is due to the Penning ionization of CO{sub 2}(or H{sub 2}O) in collisions with excited Ar* atoms. The ternary mixtures -- being fast, cool, and efficient -- have potential for advanced gas-filled particle detectors such as those for the SCC muon chambers. 17 refs., 8 figs., 1 tab.

Datskos, P.G. (Tennessee Univ., Knoxville, TN (United States). Dept. of Physics); Christophorou, L.G.; Carter, J.G. (Oak Ridge National Lab., TN (United States))

1991-01-01T23:59:59.000Z

23

Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe  

DOE Patents [OSTI]

An optimized examination system and method based on the Reverse Geometry X-Ray{trademark} (RGX{trademark}) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging. 5 figs.

Majewski, S.; Kross, B.J.; Zorn, C.J.; Majewski, L.A.

1996-10-22T23:59:59.000Z

24

detectors  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Detectors are made of many layers specialized to identify and record Detectors are made of many layers specialized to identify and record information about the many particles that result from a collision of a proton and an antiproton. A sphere would be the best shape to surround the collision point, but it is cheaper to make cylindrical detectors. Because the particles in the Fermilab accelerator have so much energy, detectors may be 3-5 stories high. The layers of a generic detector: (Run the cursor over the names.) Beam Pipe Tracker Electromagnetic Calorimeter Hadron Calorimeter Magnet Muon Detector Anatomy of a Detector - Identifying Particles - CDF Detector - D0 Detector - Links Project Contact: Thomas Jordan - jordant@fnal.gov Web Maintainer: qnet-webmaster@fnal.gov Last Update: April 13, 2001 http://quarknet.fnal.gov/run2/news

25

Detectors  

DOE Patents [OSTI]

The apparatus and method provide techniques through which both alpha and beta emission determinations can be made simultaneously using a simple detector structure. The technique uses a beta detector covered in an electrically conducting material, the electrically conducting material discharging ions generated by alpha emissions, and as a consequence providing a measure of those alpha emissions. The technique also offers improved mountings for alpha detectors and other forms of detectors against vibration and the consequential effects vibration has on measurement accuracy.

Orr, Christopher Henry (Calderbridge, GB); Luff, Craig Janson (Calderbridge, GB); Dockray, Thomas (Calderbridge, GB); Macarthur, Duncan Whittemore (Los Alamos, NM); Bounds, John Alan (Los Alamos, NM); Allander, Krag (Los Alamos, NM)

2002-01-01T23:59:59.000Z

26

Detectors  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Detectores Detectores Avanzar Volver Principal ESTOY PERDIDO!!! Rutherford utilizó el sulfuro de zinc para detectar la presencia de partículas alfa invisibles, y mediante este conocimiento pudo determinar las trayectorias de las partículas alfa; del mismo modo los físicos modernos deben observar los productos, resultantes del decaimiento de las partículas, y deducir así la existencia de partículas. Para detectar las distintas partículas y los productos de decaimiento, los físicos han diseñado detectores multicomponentes que examinan diferentes aspectos de un evento. Cada componente de un detector moderno se emplea para medir la energía y el ímpetu de una partícula, y/o para distinguir entre sí partículas de diferentes tipos. Cuando todos los componentes

27

Electrical probe diagnostics for the laminar flame quenching distance  

SciTech Connect (OSTI)

A simplified theory, previously developed for the general case of weakly ionized gas flow, is used to predict electrical probe response when the flame is quenched on the probe surface. This theory is based on the planar model of space charge sheaths around the measuring electrode. For the flame quenching case, by assuming that the sheath thickness is comparable with the thermal boundary layer thickness, probe current can be related to flame quenching distance. The theoretical assumptions made to obtain the analytical formulation of probe current were experimentally proved by using direct visualization and high-frequency PIV. The direct visualization method was also used to validate the results of flame quenching distance values obtained with electrical probe. The electrical probe diagnostics have been verified for both head-on and sidewall flame quenching regimes and for stoichiometric methane/air and propane/air mixtures in a pressure range of 0.05-0.6 MPa. (author)

Karrer, Maxime; Makarov, Maxime [Renault Technocentre, 78288 Guyancourt Cedex (France); Bellenoue, Marc; Labuda, Sergei; Sotton, Julien [Laboratoire de Combustion et de Detonique, CNRS, 86961 Futuroscope Chasseneuil (France)

2010-02-15T23:59:59.000Z

28

Flame front geometry in premixed turbulent flames  

SciTech Connect (OSTI)

Experimental and numerical determinations of flame front curvature and orientation in premixed turbulent flames are presented. The experimental data is obtained from planar, cross sectional images of stagnation point flames at high Damkoehler number. A direct numerical simulation of a constant energy flow is combined with a zero-thickness, constant density flame model to provide the numerical results. The computational domain is a 32{sup 3} cube with periodic boundary conditions. The two-dimensional curvature distributions of the experiments and numerical simulations compare well at similar q{prime}/S{sub L} values with means close to zero and marked negative skewness. At higher turbulence levels the simulations show that the distributions become symmetric about zero. These features are also found in the three dimensional distributions of curvature. The simulations support assumptions which make it possible to determine the mean direction cosines from the experimental data. This leads to a reduction of 12% in the estimated flame surface area density in the middle of the flame brush. 18 refs.

Shepherd, I.G. (Lawrence Berkeley Lab., CA (United States)); Ashurst, W.T. (Sandia National Labs., Livermore, CA (United States))

1991-12-01T23:59:59.000Z

29

The Chemi-Ionization Detector: A Flameless Ionization Detector  

Science Journals Connector (OSTI)

......phos- JOURNAL OF CHROMATOGRAPHIC SCIENCE VOL 8 AUGUST 1970 465 0 0 0 0000000 0 0 O C g 0 0 20 0 CsBr HEATER ON SAMPLE HEATER ON 60 SAMPLE HEATER OFF SAMPLE HEATER ON CsBr HEATER OFF 4 20 24 NAR I RITE VYCOR TUBE 00000000/100000000000 N2......

Martin Scolnick

1970-08-01T23:59:59.000Z

30

The Chemi-Ionization Detector: A Flameless Ionization Detector  

Science Journals Connector (OSTI)

......compared to similar data obtained with the...is insensitive to hydrocarbons. The use of electric...compared to similar data obtained with the...is insensitive to hydrocarbons. The use of electric...large enough to heat the electrode to...following way. The combustion prod- ucts of phosphorus......

Martin Scolnick

1970-08-01T23:59:59.000Z

31

Effects of oxygen concentration on radiative loss from normal-gravity and microgravity methane diffusion flames  

SciTech Connect (OSTI)

Laminar diffusion flames of methane, burning in quiescent oxidizing environments at atmospheric pressure, have been studied under both normal-gravity and microgravity conditions. Radiation from these flames is measured using a wide-view-angle, thermopile detector radiometer. The oxidizer was 18, 21, and 30 percent oxygen in nitrogen. 17 refs.

Bahadori, M.Y.; Edelman, R.B.; Stocker, D.P.; Sotos, R.G.; Vaughan, D.F. (Science Applications International Corp., Torrance, CA (United States) Rockwell International Corp., Rocketdyne Div., Canoga Park, CA (United States) NASA, Lewis Research Center, Cleveland, OH (United States))

1992-01-01T23:59:59.000Z

32

Comparison of ultraviolet and ultraviolet-infrared flame detection systems  

E-Print Network [OSTI]

detectors view a s1ngle area and a majority of detectors must sense a fire to signal an alarm) and time delay ci r- cu1ts, sensitivity adjustments, and integral self-test lamps and circuitry. Infrared detectors were improved by the addition of vot1ng... have been improved through an evolutionary process to the point where they have become highly reliable, stable and sensitive detectors of flames. With the recent advances in micro- processor based e'lectronics, it has become possible to combine both...

Dayton, Robert Mark

2012-06-07T23:59:59.000Z

33

Gas Filled Detectors counting & tracking of  

E-Print Network [OSTI]

Gas Filled Detectors counting & tracking of particles energy loss generation of electron-ion+ pairs #12;Gas Filled Detectors Primary and Total Ionization fast charged particles ionize the atoms of a gas fraction of resulting primary electrons have enough kinetic energy to ionize other atoms #12;Gas Filled

Peletier, Reynier

34

Resonance ionization detection of combustion radicals  

SciTech Connect (OSTI)

Fundamental research on the combustion of halogenated organic compounds with emphasis on reaction pathways leading to the formation of chlorinated aromatic compounds and the development of continuous emission monitoring methods will assist in DOE efforts in the management and disposal of hazardous chemical wastes. Selective laser ionization techniques are used in this laboratory for the measurement of concentration profiles of radical intermediates in the combustion of chlorinated hydrocarbon flames. A new ultrasensitive detection technique, made possible with the advent of tunable VUV laser sources, enables the selective near-threshold photoionization of all radical intermediates in premixed hydrocarbon and chlorinated hydrocarbon flames.

Cool, T.A. [Cornell Univ., Ithaca, NY (United States)

1993-12-01T23:59:59.000Z

35

Dynamics and structure of stretched flames  

SciTech Connect (OSTI)

This program aims to gain fundamental understanding on the structure, geometry, and dynamics of laminar premixed flames, and relate these understanding to the practical issues of flame extinction and stabilization. The underlying fundamental interest here is the recent recognition that the response of premixed flames can be profoundly affected by flame stretch, as manifested by flow nonuniformity, flame curvature, and flame/flow unsteadiness. As such, many of the existing understanding on the behavior of premixed flames need to be qualitatively revised. The research program consists of three major thrusts: (1) detailed experimental and computational mapping of the structure of aerodynamically-strained planar flames, with emphasis on the effects of heat loss, nonequidiffusion, and finite residence time on the flame thickness, extent of incomplete reaction, and the state of extinction. (2) Analytical study of the geometry and dynamics of stretch-affected wrinkled flame sheets in simple configurations, as exemplified by the Bunsen flame and the spatially-periodic flame, with emphasis on the effects of nonlinear stretch, the phenomena of flame cusping, smoothing, and tip opening, and their implications on the structure and burning rate of turbulent flames. (3) Stabilization and blowoff of two-dimensional inverted premixed and stabilization and determining the criteria governing flame blowoff. The research is synergistically conducted through the use of laser-based diagnostics, computational simulation of the flame structure with detailed chemistry and transport, and mathematical analysis of the flame dynamics.

Law, C.K. [Princeton Univ., NJ (United States)

1993-12-01T23:59:59.000Z

36

Flame front structure of turbulent premixed flames of syngas oxyfuel mixtures  

Science Journals Connector (OSTI)

Abstract In order to investigate oxyfuel combustion characteristics of typical composition of coal gasification syngas connected to CCS systems. Instantaneous flame front structure of turbulent premixed flames of CO/H2/O2/CO2 mixtures which represent syngas oxyfuel combustion was quantitatively studied comparing with CH4/air and syngas/air flames by using a nozzle-type Bunsen burner. Hot-wire anemometer and OH-PLIF were used to measure the turbulent flow and detect the instantaneous flame front structure, respectively. Image processing and statistical analyzing were performed using the Matlab Software. Flame surface density, mean progress variable, local curvature radius, mean flame volume, and flame thickness, were obtained. Results show that turbulent premixed flames of syngas possess wrinkled flame front structure which is a general feature of turbulent premixed flames. Flame surface density for the CO/H2/O2/CO2 flame is much larger than that of CO/H2/O2/air and CH4/air flames. This is mainly caused by the smaller flame intrinsic instability scale, which would lead to smaller scales and less flame passivity response to turbulence presented by Markstain length, which reduce the local flame stretch against turbulence vortex. Peak value of Possibility Density Function (PDF) distribution of local curvature radius, R, for CO/H2/O2/CO2 flames is larger than those of CO/H2/O2/air and CH4/air flames at both positive and negative side and the corresponding R of absolute peak PDF is the smallest. This demonstrates that the most frequent scale is the smallest for CO/H2/O2/CO2 flames. Mean flame volume of CO/H2/O2/CO2 flame is smaller than that of CH4/air flame even smaller than that of CO/H2/O2/air flame. This would be due to the lower flame height and smaller flame wrinkles.

Meng Zhang; Jinhua Wang; Jin Wu; Zhilong Wei; Zuohua Huang; Hideaki Kobayashi

2014-01-01T23:59:59.000Z

37

Recent Advances in Thermionic Ionization Detection for Gas Chromatography  

Science Journals Connector (OSTI)

......and catalytic combustion modifier/thermionic...be comparable to hydrocarbons by a judicious selection...because the flame heat w o u l d otherwise...elec tronegative combustion products by means...the bulk o f the hydrocarbon ionization pro duced...The applications data presented in this......

P.L. Patterson

1986-02-01T23:59:59.000Z

38

A surface ionization source  

E-Print Network [OSTI]

The Einzel Lens. 2 The Quadrupole Triplet . . 3. The Beam Scanner. . . 4 The Four-plate Detectors and Faraday Cups. III TESTING AND OPTIMIZING THE BEAM LINE 10 12 13 A. Initial Results. IV THE THEORY OF SURFACE IONIZATION . . . . . V ION SOURCES. 21... aperture and through a beam scanner. The scanner translates the beam's cross-section to an image visible on the oscilloscope A movable Faraday cup connected to a sensitive electrometer is used to maximize the beam transmission at the opening into the 2...

Buzatu, Daniel J.

2012-06-07T23:59:59.000Z

39

Ionization chamber  

DOE Patents [OSTI]

An ionization chamber has separate drift and detection regions electrically isolated from each other by a fine wire grid. A relatively weak electric field can be maintained in the drift region when the grid and another electrode in the chamber are connected to a high voltage source. A much stronger electric field can be provided in the detection region by connecting wire electrodes therein to another high voltage source. The detection region can thus be operated in a proportional mode when a suitable gas is contained in the chamber. High resolution output pulse waveforms are provided across a resistor connected to the detection region anode, after ionizing radiation enters the drift region and ionize the gas.

Walenta, Albert H. (Port Jefferson Station, NY)

1981-01-01T23:59:59.000Z

40

Improved gaseous leak detector  

DOE Patents [OSTI]

In a short path length mass-spectrometer type of helium leak detector wherein the helium trace gas is ionized, accelerated and deflected onto a particle counter, an arrangement is provided for converting the detector to neon leak detection. The magnetic field of the deflection system is lowered so as to bring the nonlinear fringe area of the magnetic field across the ion path, thereby increasing the amount of deflection of the heavier neon ions.

Juravic, F.E. Jr.

1983-10-06T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Cal Flame: Order (2015-CE-14015)  

Broader source: Energy.gov [DOE]

DOE ordered Cal Flame to pay a $8,000 civil penalty after finding Cal Flame had failed to certify that refrigerator basic model BBQ09849P-H complies with the applicable energy conservation standards.

42

Investigation on characteristics of ionization current in a spark-ignition engine fueled with natural gas–hydrogen blends with BSS de-noising method  

Science Journals Connector (OSTI)

Investigation on ionization current characteristic in a spark-ignition engine fueled with natural gas, natural gas–hydrogen bends and gasoline was conducted. Blind Source Separation (BSS) de-noising method is employed to separate the ionization current signal from the interference of spark tail generated by ignition discharge. Cylinder pressure was recorded, and local temperature at spark plug gap is calculated using AVL-FIRE simulation code. Results show that the simulated cylinder pressures are in good agreement with those of measured and the spark tail and ionization current can be separated using BSS method. Front flame stage and post flame stage in ionization current can be used to analyze the combustion characteristics of natural gas–hydrogen blends. De-noised current shows that the appearance of front flame stage and post flame stage (including the peaks in the stages) fueled with natural gas is postponed and compared with that fueled with gasoline, and the appearance of front flame stage and post flame stage advance with the increase of hydrogen fraction in natural gas–hydrogen blends. In addition, the amplitude of ionization currents in both front flame and post flame (including the two peaks) fueled with natural gas gives lower values compared with those fueled with gasoline and hydrogen addition can increase the amplitude. Maximum post flame current shows similar trend to maximum cylinder pressure and it has good correlation between the timing of maximum post flame current and the timing of maximum cylinder pressure. High correlation coefficient between maximum post flame current and maximum pressure is presented.

Zhongquan Gao; Xiaomin Wu; Hui Gao; Bing Liu; Jie Wang; Xiangwen Meng; Zuohua Huang

2010-01-01T23:59:59.000Z

43

Production Of Fullerenic Soot In Flames  

DOE Patents [OSTI]

A method for the production of fullerenic nanostructures is described in which unsaturated hydrocarbon fuel and oxygen are combusted in a burner chamber at a sub-atmospheric pressure, thereby establishing a flame. The condensibles of the flame are collected at a post-flame location. The condensibles contain fullerenic nanostructures, such as single and nested nanotubes, single and nested nanoparticles and giant fullerenes. The method of producing fullerenic soot from flames is also described.

Howard, Jack B. (Winchester, MA); Vander Sande, John B. (Newbury, MA); Chowdhury, K. Das (Cambridge, MA)

2000-12-19T23:59:59.000Z

44

Production of fullerenic nanostructures in flames  

DOE Patents [OSTI]

A method for the production of fullerenic nanostructures is described in which unsaturated hydrocarbon fuel and oxygen are combusted in a burner chamber at a sub-atmospheric pressure, thereby establishing a flame. The condensibles of the flame are collected at a post-flame location. The condensibles contain fullerenic nanostructures, such as single and nested nanotubes, single and nested nanoparticles and giant fullerenes. The method of producing fullerenic soot from flames is also described.

Howard, Jack B. (Winchester, MA); Vander Sande, John B. (Newbury, MA); Chowdhury, K. Das (Cambridge, MA)

1999-01-01T23:59:59.000Z

45

Premixed-gas flames Paul D. Ronney  

E-Print Network [OSTI]

Premixed-gas flames Paul D. Ronney Department of Aerospace and Mechanical Engineering University of Southern California, Los Angeles, CA 90089-1453 USA ronney@usc.edu Keywords: Microgravity; premixed-gas; cool flames; turbulence. Reference: Ronney, P. D., "Premixed-Gas Flames," in: Microgravity Combustion

46

Semiconductor radiation detector  

DOE Patents [OSTI]

A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

Bell, Zane W. (Oak Ridge, TN); Burger, Arnold (Knoxville, TN)

2010-03-30T23:59:59.000Z

47

E-Print Network 3.0 - area position-sensitive ionization Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

coefficient of positional... photoelectron focusing and high electron transmission efficiency from the gas ionization area to the detector... their spectral resolution and...

48

Clothes That Care -- Flame Resistant Protection.  

E-Print Network [OSTI]

.. 8-1272 othes That Care- Flame Resistant Protection" TOoe ZTA245.7 8873 NQ.'2'T2 Texas Agricultural Extension Service . The Texas A&M University System Daniel C. Pfannstiel, Director, College Station, Texas , ? Clothes That Care- Flame... Resistant Protection Claudia Kerbel * Concern for a safer environment has led to changes in many of the everyday products we use , including clothing . In the' past dec ade, flame-resistant (FR) garments and fabrics have become more available than ever...

Kerbel, Claudia

1980-01-01T23:59:59.000Z

49

High-Pressure Flame Speed Measurements  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

addition on flame speeds of hydrocarbon fuels 3. Soot formation and explosive gasification in burning droplets of dieselbiodieselethanol blends C. K. Law Princeton...

50

Flame retardant finishing of cotton fleece.  

E-Print Network [OSTI]

??In this research, an inorganic phosphorus-containing flame retardant system was developed for cotton fleece. The aluminum hydroxyphosphate (AHP) formed in situ on cotton by the… (more)

Wu, Xialing

2008-01-01T23:59:59.000Z

51

Glow discharge detector  

DOE Patents [OSTI]

A highly sensitive electronic ion cell for the measurement of trace elements in He carrier gas which involves glow discharge. A constant wave (CW) glow discharge detector which is controlled through a biased resistor, can detect the change of electron density caused by impurities in the He carrier gas by many orders of magnitude larger than that caused by direct ionization or electron capture. The glow discharge detector utilizes a floating pseudo-electrode to form a probe in or near the plasma. By using this probe, the large variation of electron density due to trace amounts of impurities can be directly measured.

Koo, Jackson C. (San Ramon, CA); Yu, Conrad M. (Antioch, CA)

2002-01-01T23:59:59.000Z

52

Response of the Flame lonization Detector to Nitrogenous Compounds  

Science Journals Connector (OSTI)

......Of the response data for various nitrogen...Internat.) on Combustion, Academic Press...positive ions from hydrocarbons (11). Of the...31,1972 *The heat of hydration of...ternat.) on Combustion, 647 (Academie...Internat.) on Combustion, 155 (Wil- liams......

A. T. Blades

1972-11-01T23:59:59.000Z

53

The Cool Flame Combustion of Ethanol  

Science Journals Connector (OSTI)

...research-article The Cool Flame Combustion of Ethanol J. Brown C. F. H. Tipper The kinetics...products of the cool flame combustion of ethanol between about 280 and 330 C have been...much less for a 1 : 2 than for a 1 : 1 ethanol/oxygen mixture at constant T and varied...

1969-01-01T23:59:59.000Z

54

Polymer combustion: effects of flame emissivity  

Science Journals Connector (OSTI)

...gas phase. Polymer combustion chemistry is modelled...investigating polymer combustion it has proven advantageous...properties and treat the heat flux from the ignition...luminous flames from hydrocarbon fuels, it is common...A (1999) Polymer combustion: effects of flame emissivity...

1999-01-01T23:59:59.000Z

55

On the extraction of laminar flame speed and Markstein length from outwardly propagating spherical flames  

SciTech Connect (OSTI)

Large discrepancies among the laminar flame speeds and Markstein lengths of methane/air mixtures measured by different researchers using the same constant-pressure spherical flame method are observed. As an effort to reduce these discrepancies, one linear model (LM, the stretched flame speed changes linearly with the stretch rate) and two non-linear models (NM I and NM II, the stretched flame speed changes non-linearly with the stretch rate) for extracting the laminar flame speed and Markstein length from propagating spherical flames are investigated. The accuracy and performance of the LM, NM I, and NM II are found to strongly depend on the Lewis number. It is demonstrated that NM I is the most accurate for mixtures with large Lewis number (positive Markstein length) while NM II is the most accurate for mixtures with small Lewis number (negative Markstein length). Therefore, in order to get accurate laminar flame speed and Markstein length from spherical flame experiments, different non-linear models should be used for different mixtures. The validity of the theoretical results is further demonstrated by numerical and experimental studies. The results of this study can be used directly in spherical flame experiments measuring the laminar flame speed and Markstein length. (author)

Chen, Zheng [State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Aerospace Engineering, College of Engineering, Peking University, Beijing 100871 (China)

2011-02-15T23:59:59.000Z

56

Model flames in the Boussinesq limit: Rising Natalia Vladimirova  

E-Print Network [OSTI]

Model flames in the Boussinesq limit: Rising bubbles Natalia Vladimirova ASC/Flash Center the Boussinesq buoyancy approximation, we study a bubble of reaction products rising in the reactant fluid under with a specified speed. The flame speed, although known for laminar flame, is #12;Model flames in the Boussinesq

Vladimirova, Natalia

57

Numerical studies of flames in wide tubes:?Stability limits of curved stationary flames  

Science Journals Connector (OSTI)

Flame dynamics in wide tubes with ideally adiabatical and slip walls is studied by means of direct numerical simulations of the complete set of hydrodynamical equations including thermal conduction, fuel diffusion, viscosity, and chemical kinetics. Stability limits of curved stationary flames in wide tubes and the hydrodynamic instability of these flames (the secondary Darrieus-Landau instability) are investigated. The stability limits found in the present numerical simulations are in a very good agreement with the previous theoretical predictions. It is obtained that close to the stability limits the secondary Darrieus-Landau instability results in an extra cusp at the flame front. It is shown that the curved flames subject to the secondary Darrieus-Landau instability propagate with velocity considerably larger than the velocity of the stationary flames.

O. Yu. Travnikov; V. V. Bychkov; M. A. Liberman

2000-01-01T23:59:59.000Z

58

Aromatics oxidation and soot formation in flames  

SciTech Connect (OSTI)

This project is concerned with the kinetics and mechanisms of aromatics oxidation and soot and fullerenes formation in flames. The scope includes detailed measurements of profiles of stable and radical species concentrations in low-pressure one-dimensional premixed flames. Intermediate species identifications and mole fractions, fluxes, and net reaction rates calculated from the measured profiles are used to test postulated reaction mechanisms. Particular objectives are to identify and to determine or confirm rate constants for the main benzene oxidation reactions in flames, and to characterize fullerenes and their formation mechanisms and kinetics.

Howard, J.B.; Pope, C.J.; Shandross, R.A.; Yadav, T. [Massachusetts Institute of Technology, Cambridge (United States)

1993-12-01T23:59:59.000Z

59

The Cryogenic Dark Matter Search: First 5-Tower Data and Improved Understanding of Ionization Collection  

SciTech Connect (OSTI)

The Cryogenic Dark Matter Search (CDMS) is searching for Weakly Interacting Massive Particles (WIMPs) with cryogenic particle detectors. These detectors have the ability to discriminate between nuclear recoil candidate and electron recoil background events by collecting both phonon and ionization energy from recoils in the detector crystals. The CDMS-II experiment has completed analysis of the first data runs with 30 semiconductor detectors at the Soudan Underground Laboratory, resulting in a world leading WIMP-nucleon spin-independent cross section limit for WIMP masses above 44 GeV/c{sup 2}. As CDMS aims to achieve greater WIMP sensitivity, it is necessary to increase the detector mass and discrimination between signal and background events. Incomplete ionization collection results in the largest background in the CDMS detectors as this causes electron recoil background interactions to appear as false candidate events. Two primary causes of incomplete ionization collection are surface and bulk trapping. Recent work has been focused on reducing surface trapping through the modification of fabrication methods for future detectors. Analyzing data taken with test devices has shown that hydrogen passivation of the amorphous silicon blocking layer worsens surface trapping. Additional data has shown that the iron-ion implantation used to lower the critical temperature of the tungsten transition-edge sensors causes a degradation of the ionization collection. Using selective implantation on future detectors may improve ionization collection for events near the phonon side detector surface. Bulk trapping is minimized by neutralizing ionized lattice impurities. Detector investigations at testing facilities and in situ at the experimental site have provided methods to optimize the neutralization process and monitor running conditions to maintain full ionization collection. This work details my contribution to the 5-tower data taking, monitoring, and analysis effort as well as the SuperCDMS detector development with the focus on monitoring and improving ionization collection in the detectors.

Bailey, Catherine N.; /Case Western Reserve U.

2010-01-01T23:59:59.000Z

60

Enol Intermediates Unexpectedly Found in Flames  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Enol Intermediates Unexpectedly Found in Flames Print Enol Intermediates Unexpectedly Found in Flames Print For those studying flame chemistry and the properties of combustion intermediates by means of molecular beam mass spectrometry, the addition of tunable vacuum ultraviolet (VUV) from a synchrotron to photoionize the beam for mass spectrometry makes for a powerful technique capable of differentiating between isomers with the same molecular weight and composition. With the help of a unique experimental apparatus, an international team of American, Chinese, and German researchers has exploited this selectivity to identify chemical compounds known as enols as apparently ubiquitous intermediates in flames burning a variety of fuels. This surprising observation will require combustion modelers to revise their models to account for the presence of these compounds.

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Enol Intermediates Unexpectedly Found in Flames  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Enol Intermediates Unexpectedly Found in Flames Print Enol Intermediates Unexpectedly Found in Flames Print For those studying flame chemistry and the properties of combustion intermediates by means of molecular beam mass spectrometry, the addition of tunable vacuum ultraviolet (VUV) from a synchrotron to photoionize the beam for mass spectrometry makes for a powerful technique capable of differentiating between isomers with the same molecular weight and composition. With the help of a unique experimental apparatus, an international team of American, Chinese, and German researchers has exploited this selectivity to identify chemical compounds known as enols as apparently ubiquitous intermediates in flames burning a variety of fuels. This surprising observation will require combustion modelers to revise their models to account for the presence of these compounds.

62

Enol Intermediates Unexpectedly Found in Flames  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Enol Intermediates Unexpectedly Found in Flames Print Enol Intermediates Unexpectedly Found in Flames Print For those studying flame chemistry and the properties of combustion intermediates by means of molecular beam mass spectrometry, the addition of tunable vacuum ultraviolet (VUV) from a synchrotron to photoionize the beam for mass spectrometry makes for a powerful technique capable of differentiating between isomers with the same molecular weight and composition. With the help of a unique experimental apparatus, an international team of American, Chinese, and German researchers has exploited this selectivity to identify chemical compounds known as enols as apparently ubiquitous intermediates in flames burning a variety of fuels. This surprising observation will require combustion modelers to revise their models to account for the presence of these compounds.

63

The structure of the carbon black flame  

E-Print Network [OSTI]

THE STRUCTURE OF THE CARBON BLACK FLAME A Dissertation By W1 111 ami Kermit Anderson THEHSR UCOF Approval as to style and content recommended Head of tiie Department of Chemistry A Dissertation Submitted to the Faculty of the Agricultural... and Mechanical College of. Texas in Parti ail Fulfilment of the Requirements for the Degree of Doctor of Philosophy THE STRUCTURE OF THE CARBON BLACK FLAME Major Subject: Chemistry AB William Hermit Anderson:\\ t * August 1945 THE STRUCTURE OF THE. CARBON...

Anderson, W. Kermi

1945-01-01T23:59:59.000Z

64

NO concentration imaging in turbulent nonpremixed flames  

SciTech Connect (OSTI)

The importance of NO as a pollutant species is well known. An understanding of the formation characteristics of NO in turbulent hydrocarbon flames is important to both the desired reduction of pollutant emissions and the validation of proposed models for turbulent reacting flows. Of particular interest is the relationship between NO formation and the local flame zone, in which the fuel is oxidized and primary heat release occurs. Planar imaging of NO provides the multipoint statistics needed to relate NO formation to the both the flame zone and the local turbulence characteristics. Planar imaging of NO has been demonstrated in turbulent flames where NO was seeded into the flow at high concentrations (2000 ppm) to determine the gas temperature distribution. The NO concentrations in these experiments were significantly higher than those expected in typical hydrocarbon-air flames, which require a much lower detectability limit for NO measurements. An imaging technique based on laser-induced fluorescence with sufficient sensitivity to study the NO formation mechanism in the stabilization region of turbulent lifted-jet methane flames.

Schefer, R.W. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

65

Characterisation of an oxy-coal flame through digital imaging  

SciTech Connect (OSTI)

This paper presents investigations into the impact of oxy-fuel combustion on flame characteristics through the application of digital imaging and image processing techniques. The characteristic parameters of the flame are derived from flame images that are captured using a vision-based flame monitoring system. Experiments were carried out on a 0.5 MW{sub th} coal combustion test facility. Different flue gas recycle ratios and furnace oxygen levels were created for two different coals. The characteristics of the flame and the correlation between the measured flame parameters and corresponding combustion conditions are described and discussed. The results show that the flame temperature decreases with the recycle ratio for both test coals, suggesting that the flame temperature is effectively controlled by the flue gas recycle ratio. The presence of high levels of CO{sub 2} at high flue gas recycle ratios may result in delayed combustion and thus has a detrimental effect on the flame stability. (author)

Smart, John; Riley, Gerry [RWE npower plc, Windmill Hill Business Park, Whitehill Way, Swindon SN5 6PB (United Kingdom); Lu, Gang; Yan, Yong [Instrumentation, Control and Embedded Systems Research Group, School of Engineering and Digital Arts, University of Kent, Canterbury, Kent CT2 7NT (United Kingdom)

2010-06-15T23:59:59.000Z

66

Blowoff dynamics of bluff body stabilized turbulent premixed flames  

SciTech Connect (OSTI)

This article concerns the flame dynamics of a bluff body stabilized turbulent premixed flame as it approaches lean blowoff. Time resolved chemiluminescence imaging along with simultaneous particle image velocimetry and OH planar laser-induced fluorescence were utilized in an axisymmetric bluff body stabilized, propane-air flame to determine the sequence of events leading to blowoff and provide a quantitative analysis of the experimental results. It was found that as lean blowoff is approached by reduction of equivalence ratio, flame speed decreases and the flame shape progressively changes from a conical to a columnar shape. For a stably burning conical flame away from blowoff, the flame front envelopes the shear layer vortices. Near blowoff, the columnar flame front and shear layer vortices overlap to induce high local stretch rates that exceed the extinction stretch rates instantaneously and in the mean, resulting in local flame extinction along the shear layers. Following shear layer extinction, fresh reactants can pass through the shear layers to react within the recirculation zone with all other parts of the flame extinguished. This flame kernel within the recirculation zone may survive for a few milliseconds and can reignite the shear layers such that the entire flame is reestablished for a short period. This extinction and reignition event can happen several times before final blowoff which occurs when the flame kernel fails to reignite the shear layers and ultimately leads to total flame extinguishment. (author)

Chaudhuri, Swetaprovo; Kostka, Stanislav; Renfro, Michael W.; Cetegen, Baki M. [Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Road, U-3139, Storrs, CT 06269 (United States)

2010-04-15T23:59:59.000Z

67

Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame  

E-Print Network [OSTI]

Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame S. E of these regions can be supersonic and could initiate a detonation. Subject headings: supernovae: general a late time transition of the thermonuclear burning to a detonation wave (e.g., Hoflich et al. 1995

68

Characterization of syngas laminar flames using the Bunsen burner configuration  

Science Journals Connector (OSTI)

Laminar flame speeds of syngas mixtures (H2/CO/Air) have been studied using the Bunsen flame configuration with both straight and nozzle burners. The flame surface area and flame cone angle methodologies, respectively based on the OH* chemiluminescence and Schlieren imaging techniques, have been performed to extract flame speeds for a wide range of equivalence ratios (0.3 syngas flames with 0.6 < ? < 1.0 and 10% < %H2 < 70% is proposed. A particular attention has been devoted to the development and validation of the OH* chemiluminescence methodology with the identification of important parameters governing the measurement accuracy.

N. Bouvet; C. Chauveau; I. Gökalp; S.-Y. Lee; R.J. Santoro

2011-01-01T23:59:59.000Z

69

Synergistic effect of nanosilica aerogel with phosphorus flame retardants on improving flame retardancy and leaching resistance of wood  

Science Journals Connector (OSTI)

Nanosilica (Nano-SiO2) sol fabricated by a sol-gel process was introduced into wood modification with phosphorus flame retardants to improve the flame retardancy and leaching resistance of wood. The obtained materials were characterized by ...

Xiaodan Zhu, Yiqiang Wu, Cuihua Tian, Yan Qing, Chunhua Yao

2014-01-01T23:59:59.000Z

70

White Flame Energy switches to backhoes  

SciTech Connect (OSTI)

The mountaintop coal operator, White Flame Energy has switched to different truck-shovel arrangement. Along with many surface mining operations throughout central Appalachia, the company is using hoe-configured hydraulic excavators as opposed to the traditional front-shovel arrangements. Located in Varney, WV, White Flame Energy uses two Terex O & K mining shovels, an RH170 and an RH 200, which have the capacity to move 2 million cu yards per month from five seams, primarily the Coalburg, Stockton, and No 5 Block and associated rider seams. The article records conversations on the operations with Mike Vines, the general manager, and Don Nicewonder, the owner of White Flame Energy. 2 photos.

Fiscor, S.

2005-06-01T23:59:59.000Z

71

Investigations of swirl flames in a gas turbine model combustor  

SciTech Connect (OSTI)

The thermochemical states of three swirling CH{sub 4}/air diffusion flames, stabilized in a gas turbine model combustor, were investigated using laser Raman scattering. The flames were operated at different thermal powers and air/fuel ratios and exhibited different flame behavior with respect to flame instabilities. They had previously been characterized with respect to their flame structures, velocity fields, and mean values of temperature, major species concentrations, and mixture fraction. The single-pulse multispecies measurements presented in this article revealed very rapid mixing of fuel and air, accompanied by strong effects of turbulence-chemistry interactions in the form of local flame extinction and ignition delay. Flame stabilization is accomplished mainly by hot and relatively fuel-rich combustion products, which are transported back to the flame root within an inner recirculation zone. The flames are not attached to the fuel nozzle, and are stabilized approximately 10 mm above the fuel nozzle, where fuel and air are partially premixed before ignition. The mixing and reaction progress in this area are discussed in detail. The flames are short (<50 mm), especially that exhibiting thermoacoustic oscillations, and reach a thermochemical state close to adiabatic equilibrium at the flame tip. The main goals of this article are to outline results that yield deeper insight into the combustion of gas turbine flames and to establish an experimental database for the validation of numerical models.

Meier, W.; Duan, X.R.; Weigand, P. [Institut fuer Verbrennungstechnik, Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Pfaffenwaldring 38, D-70569 Stuttgart (Germany)

2006-01-01T23:59:59.000Z

72

Flame Spectra in the Photographic Infra-Red  

Science Journals Connector (OSTI)

...H O bands in the flame of moist carbon monoxide indicates that in this flame the excitation is a result of the combustion processes; this agrees with earlier theories on the formation of vibrationally activated molecules of CO in this flame...

1942-01-01T23:59:59.000Z

73

Device for detecting ionizing radiation  

SciTech Connect (OSTI)

The present invention relates to ionizing radiation sensors, and , more particularly, to semiconductor spectrometers with thermoelectric cooling, and can most advantageously be used in mineral raw material exploration and evaluation under field conditions. The spectrometer comprises a vacuum chamber with an entrance window for passing the radiation therethrough. The vacuum chamber accommodates a thermoelectric cooler formed by a set of peltier elements. A heat conducting plate is mounted on the cold side of the thermoelectric cooler, and its hot side is provided with a radiator. Mounted on the heat conducting plate are sets of peltier elements, integral with the thermoelectric cooler and independent of one another. The peltier elements of these sets are stacked so as to develop the minimum temperature conditions on one set carrying a semiconductor detector and to provide the maximum refrigeration capacity conditions on the other set provided with the field-effect transistor mounted thereon.

Anatychuk, L.I.; Kharitonov, J.P.; Kusniruk, V.F.; Meir, V.A.; Melnik, A.P.; Ponomarev, V.S.; Skakodub, V.A.; Sokolov, A.D.; Subbotin, V.G.; Zhukovsky, A.N.

1980-10-28T23:59:59.000Z

74

Molecular Characterization of Organic Content of Soot along the Centerline of a Coflow Diffusion Flame  

SciTech Connect (OSTI)

High-resolution mass spectrometry coupled with nanospray desorption electrospray ionization was used to probe chemical constituents of young soot particles sampled along the centerline of a coflow diffusion flame of a three-component Jet-A1 surrogate. In lower positions where particles are transparent to light extinction (n= 632.8 nm), peri-condensed polycyclic aromatic hydrocarbons (PAHs) are found to be the major components of the particle material. These particles become enriched with aliphatic components as they grow in mass and size. Before carbonization occurs, the constituent species in young soot particles are aliphatic and aromatic compounds 200-600 amu in mass, some of which are oxygenated. Particles dominated by PAHs or mixtures of PAHs and aliphatics can both exhibit liquid-like appearance observed by electron microscopy and be transparent to visible light. The variations in chemical composition observed here indicate that the molecular processes of soot formation in coflow diffusion flames may be more complex than previously thought. For example, the mass growth and enrichment of aliphatic components in an initially, mostly aromatic structure region of the flame that is absent of H atoms or other free radicals indicates that there must exist at least another mechanism of soot mass growth in addition to the hydrogen-abstraction-carbon addition mechanism currently considered in fundamental models of soot formation.

Cain, Jeremy P.; Laskin, Alexander; Kholghy, Mohammad Reza; Thomson, Murray; Wang, Hai

2014-10-29T23:59:59.000Z

75

Computatonal and experimental study of laminar flames  

SciTech Connect (OSTI)

This research has centered on an investigation of the effects of complex chemistry and detailed transport on the structure and extinction of hydrocarbon flames in counterflow, cylindrical and coflowing axisymmetric configurations. The authors have pursued both computational and experimental aspects of the research in parallel. The computational work has focused on the application of accurate and efficient numerical methods for the solution of the one and two-dimensional nonlinear boundary value problems describing the various reacting systems. Detailed experimental measurements were performed on axisymmetric coflow flames using two-dimensional imaging techniques. In particular, spontaneous Raman scattering and laser induced fluorescence were used to measure the temperature, major and minor species profiles.

Smooke, M.D.; Long, M.B. [Yale Univ., New Haven, CT (United States)

1993-12-01T23:59:59.000Z

76

Ionization and scintillation of nuclear recoils in gaseous xenon  

E-Print Network [OSTI]

Ionization and scintillation produced by nuclear recoils in gaseous xenon at approximately 14 bar have been simultaneously observed in an electroluminescent time projection chamber. Neutrons from radioisotope $\\alpha$-Be neutron sources were used to induce xenon nuclear recoils, and the observed recoil spectra were compared to a detailed Monte Carlo employing estimated ionization and scintillation yields for nuclear recoils. The ability to discriminate between electronic and nuclear recoils using the ratio of ionization to primary scintillation is demonstrated. These results encourage further investigation on the use of xenon in the gas phase as a detector medium in dark matter direct detection experiments.

J. Renner; V. M. Gehman; A. Goldschmidt; H. S. Matis; T. Miller; Y. Nakajima; D. Nygren; C. A. B. Oliveira; D. Shuman; V. Álvarez; F. I. G. Borges; S. Cárcel; J. Castel; S. Cebrián; A. Cervera; C. A. N. Conde; T. Dafni; T. H. V. T. Dias; J. Díaz; R. Esteve; P. Evtoukhovitch; L. M. P. Fernandes; P. Ferrario; A. L. Ferreira; E. D. C. Freitas; A. Gil; H. Gómez; J. J. Gómez-Cadenas; D. González-Díaz; R. M. Gutiérrez; J. Hauptman; J. A. Hernando Morata; D. C. Herrera; F. J. Iguaz; I. G. Irastorza; M. A. Jinete; L. Labarga; A. Laing; I. Liubarsky; J. A. M. Lopes; D. Lorca; M. Losada; G. Luzón; A. Marí; J. Martín-Albo; A. Martínez; A. Moiseenko; F. Monrabal; M. Monserrate; C. M. B. Monteiro; F. J. Mora; L. M. Moutinho; J. Muñoz Vidal; H. Natal da Luz; G. Navarro; M. Nebot-Guinot; R. Palma; J. Pérez; J. L. Pérez Aparicio; L. Ripoll; A. Rodríguez; J. Rodríguez; F. P. Santos; J. M. F. dos Santos; L. Seguí; L. Serra; A. Simón; C. Sofka; M. Sorel; J. F. Toledo; A. Tomás; J. Torrent; Z. Tsamalaidze; J. F. C. A. Veloso; J. A. Villar; R. C. Webb; J. White; N. Yahlali

2014-09-09T23:59:59.000Z

77

A Numerical Study of the Superadiabatic Flame Temperature Phenomenon in HN3 Flame O. P. Korobeinichev,a  

E-Print Network [OSTI]

@cua.edu #12;2 ABSTRACT The phenomenon of superadiabatic flame temperature (SAFT) was discovered the revised mechanism. The results demonstrate presence of the SAFT phenomenon in the HN3/N2 flame. Analysis of the flame structure and the kinetic mechanism indicates that the cause of SAFT is in the kinetic mechanism

Knyazev, Vadim D.

78

Risks from ionizing radiation  

Science Journals Connector (OSTI)

... RADON indoors now accounts for nearly half of the average UK population exposure to ionizing radiation ... exposure to ionizing radiation. We believe that the extent of the variation in exposure to radon in the United Kingdom and else-where and its magnitude in relation to exposures from ...

R. H. Clarke; T. R. E. Southwood

1989-03-16T23:59:59.000Z

79

Measurement of the radiation field surrounding the Collider Detector at Fermilab  

SciTech Connect (OSTI)

We present here the first direct and detailed measurements of the spatial distribution of the ionizing radiation surrounding a hadron collider experiment. Using data from two different exposures we measure the effect of additional shielding on the radiation field around the Collider Detector at Fermilab (CDF). Employing a simple model we parameterize the ionizing radiation field surrounding the detector.

K. Kordas et al.

2004-01-28T23:59:59.000Z

80

Superheated microdrops as cold dark matter detectors J. I. Collar*  

E-Print Network [OSTI]

to distinguish nuclear recoils in the keV energy range from similar energy depo- sitions by minimum ionizing of the medium, the bubbles remain fixed in it, providing a visual record of the radiation dose and simple a detector based on superheated liquid droplets. Such devices are totally insensitive to minimum ionizing

Collar, Juan I.

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Power-Law Wrinkling Turbulence-Flame Interaction Model for Astrophysical Flames  

E-Print Network [OSTI]

We extend a model for turbulence-flame interactions (TFI) to consider astrophysical flames with a particular focus on combustion in type Ia supernovae. The inertial range of the turbulent cascade is nearly always under-resolved in simulations of astrophysical flows, requiring the use of a model in order to quantify the effects of subgrid-scale wrinkling of the flame surface. We provide implementation details to extend a well-tested TFI model to low-Prandtl number flames for use in the compressible hydrodynamics code FLASH. A local, instantaneous measure of the turbulent velocity is calibrated for FLASH and verification tests are performed. Particular care is taken to consider the relation between the subgrid rms turbulent velocity and the turbulent flame speed, especially for high-intensity turbulence where the turbulent flame speed is not expected to scale with the turbulent velocity. Finally, we explore the impact of different TFI models in full-star, three-dimensional simulations of type Ia supernovae.

Jackson, Aaron P; Calder, Alan C

2014-01-01T23:59:59.000Z

82

Increased Cytotoxicity of Oxidized Flame Soot  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Increased Cytotoxicity of Oxidized Flame Soot Increased Cytotoxicity of Oxidized Flame Soot Title Increased Cytotoxicity of Oxidized Flame Soot Publication Type Journal Article Year of Publication 2012 Authors Holder, Amara L., Brietta J. Carter, Regine Goth-Goldstein, Donald Lucas, and Catherine P. Koshland Journal Atmospheric Pollution Research Volume 3 Start Page 25 Issue 1 Pagination 25-31 Date Published 01/2012 Keywords health effects, ozone, soot, toxicity Abstract Combustion-generated particles released into the atmosphere undergo reactions with oxidants, which can change the particles' physiochemical characteristics. In this work, we compare the physical and chemical properties and cellular response of particles fresh from a flame with those oxidized by ozone and nitrogen dioxide. The reaction with ozone and nitrogen dioxide does not significantly modify the physical characteristics of the particles (primary particle size, fractal dimension, and surface area). However, oxidation affects the chemical characteristics of the particles, creating more oxygen and nitrogen containing functional groups, and increases their hydrophilicity. In addition, oxidized soot generates more reactive oxygen species, as measured by the dithiothreitol (DTT) assay. Furthermore, oxidized soot is 1.5-2 times more toxic than soot that was not reacted with ozone, but the inflammatory response, measured by interleukin-8 (IL-8) secretion, is unchanged. These results imply that combustion-generated particles released into the atmosphere will have an increased toxicity on or after high ozone days.

83

Spectrum of the Flame of Ethylene  

Science Journals Connector (OSTI)

1 December 1934 research-article Spectrum of the Flame of Ethylene W. M. Vaidya The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences. www.jstor.org

1934-01-01T23:59:59.000Z

84

Electrochemistry Discovery Laboratory | JCESR  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

For routine and robust analysis, gas chromatography with both flame ionization (FID) and thermal conductivity (TCD) detectors provides reliable data for detection of possible...

85

Flame quality monitor system for fixed firing rate oil burners  

DOE Patents [OSTI]

A method and apparatus for determining and indicating the flame quality, or efficiency of the air-fuel ratio, in a fixed firing rate heating unit, such as an oil burning furnace, is provided. When the flame brightness falls outside a preset range, the flame quality, or excess air, has changed to the point that the unit should be serviced. The flame quality indicator output is in the form of lights mounted on the front of the unit. A green light indicates that the flame is about in the same condition as when the burner was last serviced. A red light indicates a flame which is either too rich or too lean, and that servicing of the burner is required. At the end of each firing cycle, the flame quality indicator goes into a hold mode which is in effect during the period that the burner remains off. A yellow or amber light indicates that the burner is in the hold mode. In this mode, the flame quality lights indicate the flame condition immediately before the burner turned off. Thus the unit can be viewed when it is off, and the flame condition at the end of the previous firing cycle can be observed.

Butcher, Thomas A. (Pt. Jefferson, NY); Cerniglia, Philip (Moriches, NY)

1992-01-01T23:59:59.000Z

86

MS Detectors  

SciTech Connect (OSTI)

Good eyesight is often taken for granted, a situation that everyone appreciates once vision begins to fade with age. New eyeglasses or contact lenses are traditional ways to improve vision, but recent new technology, i.e. LASIK laser eye surgery, provides a new and exciting means for marked vision restoration and improvement. In mass spectrometry, detectors are the 'eyes' of the MS instrument. These 'eyes' have also been taken for granted. New detectors and new technologies are likewise needed to correct, improve, and extend ion detection and hence, our 'chemical vision'. The purpose of this report is to review and assess current MS detector technology and to provide a glimpse towards future detector technologies. It is hoped that the report will also serve to motivate interest, prompt ideas, and inspire new visions for ion detection research.

Koppenaal, David W.; Barinaga, Charles J.; Denton, M Bonner B.; Sperline, Roger P.; Hieftje, Gary M.; Schilling, G. D.; Andrade, Francisco J.; Barnes IV., James H.

2005-11-01T23:59:59.000Z

87

Turbulent Nonpremixed Flames (TNF): Experimental Data Archives and Computational Submodels  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

In the 1990s an international collaboration formed around a series of workshops that became known collectively as the International Workshop on Measurement and Computation of Turbulent Non-Premixed Flames (TNF). An online library, hosted by Sandia National Laboratory (California) was established that provides data sets and submodels or "mechanisms" for the study of turbulence-chemistry interactions in turbulent nonpremixed and partially premixed combustion. Data are organized by flame types: simple jet flames, piloted jet flames, bluff body flames, and swirl flames. These data sets provide a means for collaborative comparisons of both measured and simulated/modeled research results and also assist scientists in determining priorities for further research. More than 20 data sets or databases are available from this website, along with various downloadable files of chemical mechanisms. The website also provides an extensive bibliography and the proceedings of the workshops themselves from 1996 through 2012. Information continues to be added to this collection.

88

New developments in the theory of flame propagation  

SciTech Connect (OSTI)

Two topics in combustion fluid mechanics are discussed. The first is a theory of the outward propagating spherical flame in the regime of well-developed hydrodynamic instability. In a qualitative agreement with experimental observations it is shown that the flame assumes a fractal-like wrinkled structure resulting in the overall burning rate acceleration. In contrast to hydrodynamically unstable flames, the expanding flame subject exclusively to the effect of diffusive instability does not indicate any disposition toward acceleration. The second topic concerns the dynamics of diffusively unstable flames subjected to radiative heat losses. At high enough heat losses the flame breaks up into separate self-propagating cap-like flamelets while a significant portion of the fuel remains unconsumed.

Sivashinsky, G.I. [City College of the City Univ. of New York, NY (United States)

1996-12-31T23:59:59.000Z

89

The advanced flame quality indicator system  

SciTech Connect (OSTI)

By combining oil tank monitoring, systems diagnostics and flame quality monitoring in an affordable system that communicates directly with dealers by telephone modem, Insight Technologies offers new revenue opportunities and the capability for a new order of customer relations to oil dealers. With co-sponsorship from New York State Energy Research and Development Authority, we have incorporated several valuable functions to a new product based on the original Flame Quality Indicator concept licensed from the US DOE`s Brookhaven National Laboratory. The new system is the Advanced Flame Quality Indicator, or AFQI. As before, the AFQI monitors and reports the intensity of the burner flame relative to a calibration established when the burner is set up at AFQI installation. Repairs or adjustments are summoned by late-night outgoing telephone calls when limits are exceeded in either direction, indicating an impending contamination or other malfunction. A independently, a pressure transducer for monitoring oil tank level and filter condition, safety lockout alarms and a temperature monitor; all reporting automatically at instructed intervals via an on-board modem to a central station PC computer (CSC). Firmware on each AFQI unit and Insight-supplied software on the CSC automatically interact to maintain a customer database for an oil dealer, an OEM, or a regional service contractor. In addition to ensuring continuously clean and efficient operation, the AFQI offers the oil industry a new set of immediate payoffs, among which are reduced outages and emergency service calls, shorter service calls from cleaner operation, larger oil delivery drops, the opportunity to stretch service intervals to as along as three years in some cases, new selling features to keep and attract customers, and greatly enhanced customer contact, quality and reliability.

Oman, R.; Rossi, M.J.; Calia, V.S.; Davis, F.L.; Rudin, A. [Insight Technologies, Inc., Bohemia, NY (United States)

1997-09-01T23:59:59.000Z

90

Advancing predictive models for particulate formation in turbulent flames via massively parallel direct numerical simulations  

Science Journals Connector (OSTI)

...gaseous flames in gas turbine combustion chambers...using a flamelet/progress variable approach...flame of natural gas. Combust. Flame...and R Suntz. 2002 Progress in characterization...calculations. Technical report, University of Technology...

2014-01-01T23:59:59.000Z

91

Flame-wall interaction simulation in a turbulent channel flow  

SciTech Connect (OSTI)

The interaction between turbulent premixed flames and channel walls is studied. Combustion is represented by a simple irreversible reaction with a large activation temperature. A low heat release assumption is used, but feedback to the flowfield can be allowed through viscosity changes. The effect of wall distance on local and global flame structure is investigated. Quenching distances and maximum wall heat fluxed computed in laminar cases are compared to DNS results. It is found that quenching distances decrease and maximum heat fluxes increase relative to laminar flame values, scaling with the turbulent strain rate. It is shown that these effects are due to large coherent structures which push flame elements towards the wall. The effect of wall strain in flame-wall interaction is studied in a stagnation line flow; this is used to explain the DNS results. The effects of the flame on the flow through viscosity changes is studied. It is also shown that remarkable flame events are produced by flame interaction with a horseshoe vortex: burned gases are pushed towards the wall at high speed and induce quenching and high wall heat flux while fresh gases are expelled from the wall region and form finger-like structures. Effects of the wall on flame surface density are investigated.

Bruneaux, G.; Akselvoll, K.; Poinsot, T.; Ferziger, J.H.

1996-10-01T23:59:59.000Z

92

Surface wettability studies of PDMS using flame plasma treatment .  

E-Print Network [OSTI]

??The flame plasma treatment studied in this thesis was able to oxidize the surface of Polydimethylsiloxane (PDMS) in a fraction of a second. It was… (more)

Wang, Xin C

2009-01-01T23:59:59.000Z

93

FIELD TEST OF THE FLAME QUALITY INDICATOR  

SciTech Connect (OSTI)

The flame quality indicator concept was developed at BNL specifically to monitor the brightness of the flame in a small oil burner and to provide a ''call for service'' notification when the brightness has changed from its setpoint, either high or low. In prior development work BNL has explored the response of this system to operational upsets such as excess air changes, fouled atomizer nozzles, poor fuel quality, etc. Insight Technologies, Inc. and Honeywell, Inc. have licensed this technology from the U.S. Department of Energy and have been cooperating to develop product offerings which meet industry needs with an optimal combination of function and price. Honeywell has recently completed the development of the Flame Quality Monitor (FQM or Honeywell QS7100F). This is a small module which connects via a serial cable to the burners primary operating control. Primary advantages of this approach are simplicity, cost, and ease of installation. Call-for-service conditions are output in the form of front panel indicator lights and contact closure which can trigger a range of external communication options. Under this project a field test was conducted of the FQM in cooperation with service organizations in Virginia, Pennsylvania, New Jersey, New York, and Connecticut. At total of 83 field sites were included. At each site the FQM was installed in parallel with another embodiment of this concept--the Insight AFQI. The AFQI incorporates a modem and provides the ability to provide detailed information on the trends in the flame quality over the course of the two year test period. The test site population was comprised of 79.5% boilers, 13.7% warm air furnaces, and 6.8% water heaters. Nearly all were of residential size--with firing rates ranging from 0.6 gallons of oil per hour to 1.25. During the course of the test program the monitoring equipment successfully identified problems including: plugged fuel lines, fouled nozzles, collapsed combustion chambers, and poor fuel pump cut-off. Service organizations can use these early indications to reduce problems and service costs. There were also some ''call-for-service'' indications for which problems were not identified. The test program also showed that monitoring of the flame can provide information on burner run times and this can be used to estimate current oversize factors and to determine actual fuel usage, enabling more efficient fuel delivery procedures.

Andrew M. Rudin; Thomas Butcher; Henry Troost

2003-02-04T23:59:59.000Z

94

Photon detectors  

SciTech Connect (OSTI)

J. Seguinot and T. Ypsilantis have recently described the theory and history of Ring Imaging Cherenkov (RICH) detectors. In this paper, I will expand on these excellent review papers, by covering the various photon detector designs in greater detail, and by including discussion of mistakes made, and detector problems encountered, along the way. Photon detectors are among the most difficult devices used in physics experiments, because they must achieve high efficiency for photon transport and for the detection of single photo-electrons. For gaseous devices, this requires the correct choice of gas gain in order to prevent breakdown and wire aging, together with the use of low noise electronics having the maximum possible amplification. In addition, the detector must be constructed of materials which resist corrosion due to photosensitive materials such as, the detector enclosure must be tightly sealed in order to prevent oxygen leaks, etc. The most critical step is the selection of the photocathode material. Typically, a choice must be made between a solid (CsI) or gaseous photocathode (TMAE, TEA). A conservative approach favors a gaseous photocathode, since it is continuously being replaced by flushing, and permits the photon detectors to be easily serviced (the air sensitive photocathode can be removed at any time). In addition, it can be argued that we now know how to handle TMAE, which, as is generally accepted, is the best photocathode material available as far as quantum efficiency is concerned. However, it is a very fragile molecule, and therefore its use may result in relatively fast wire aging. A possible alternative is TEA, which, in the early days, was rejected because it requires expensive CaF{sub 2} windows, which could be contaminated easily in the region of 8.3 eV and thus lose their UV transmission.

Va`vra, J.

1995-10-01T23:59:59.000Z

95

Effect of Blending on High-Pressure Laminar Flame Speed Measurements, Markstein Lengths, and Flame Stability of Hydrocarbons  

E-Print Network [OSTI]

, 5, and 10 .................................................. 40 Figure 26 Pure CH3OCH3 results for initial pressures of 1, 5, and 10 atm ................................................ 41 Figure 27 Flame speed results for 80/20 CH4/C2H6... .............................................................................................. 44 Figure 30 Flame speed results for 80/20 CH4/CH3OCH3 at initial pressures of 1, 5, and 10 atm compared to modeled results .................................................................................. 45 Figure 31 Flame speed results...

Lowry, William Baugh

2012-02-14T23:59:59.000Z

96

E-Print Network 3.0 - atomic absorption flame Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

flame Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic absorption flame Page: << < 1 2 3 4 5 > >> 1 Appendix 1: Experimental Studies...

97

(Resonance ionization spectroscopy)  

SciTech Connect (OSTI)

J. P. Young attended the Fifth International Symposium on Resonance Ionization Spectroscopy and presented an invited oral presentation on research he and coworkers had carried out in applying diode lasers to resonance ionization mass spectrometry. A summary of the conference is given along with an assessment of some of the presentations that the author found of interest. Young also visited Professor Marassi at the University of Camerino to present a seminar and discuss mutual interests in a new molten salt research project of the author. Some of the studies at Camerino are described. Ideas concerning the author's research that came from private discussions are also presented here.

Young, J.P.

1990-10-11T23:59:59.000Z

98

Ionizing radiation effects on silicon test structures  

SciTech Connect (OSTI)

The effects of {sup 60}Co gamma irradiation on MOSCAPS and special junction diode detectors have been studied. The capacitors were used to ellicit the charge accumulation and anneal in two types of thermally grown oxides representative of those used in routine detector processing. Ion implanted, oxide passivated junction detectors having 0.25 and 1 cm{sup 2} areas and perimeter to area ratios of 1 (a square), 2 and 5 were designed and constructed to amplify the ionizing effects expected to largely affect junction edges through changes in fixed oxide charges. Detectors were exposed to over 4 Mrad and showed clear increases in leakage current in proportion to the junction edge length. Annealing schedules were determined to provide a continuous response to incremental irradiations and subsequent room temperature anneals of leakage current. Besides an increase in gate threshold, little effect on the C(V) response was found. PISCES simulation of the edge fields using different fixed oxide charge revealed regions of very high lateral fields near the junction edges for fixed charges in the 2 {times} 10{sup 12}/cm{sup 2} range expected from the capacitor studies which could be responsible for the observed leakage currents.

Kraner, H.W.; Beuttenmuller, R.; Chen, W.; Kierstead, J.A.; Li, Z.; Zhang, Y. [Brookhaven National Lab., Upton, NY (United States); Dou, L. [Wayne State Univ., Detroit, MI (United States); Fretwurst, E.; Lindstroem, G. [Univ. of Hamburg (Germany)

1993-12-01T23:59:59.000Z

99

Introduction HYBRID FLAME: combustion of a combustible gas and  

E-Print Network [OSTI]

in numerous cases (e.g. explosion in coal mines) QUENCHING DISTANCES: narrowest passage through which aflame due to the difficulty of obtaining a hybrid flame. Setup Methodology Dust fed by actuator with methane Future Work Verify data obtained for methane and aluminum flame Run test with constant equivalence ratio

Barthelat, Francois

100

Low-Temperature Oxidation and Cool Flames of Propane  

Science Journals Connector (OSTI)

...1954 research-article Low-Temperature Oxidation and Cool Flames of Propane J. H. Knox R. G. W. Norrish A detailed analytical study of the cool-flame oxidation of propane has been carried out using a continuous-flow technique with a view...

1954-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Author's personal copy Combustion and Flame 151 (2007) 104119  

E-Print Network [OSTI]

Author's personal copy Combustion and Flame 151 (2007) 104­119 www May 2007 Available online 28 June 2007 Abstract Laminar flame speeds of lean H2/CO/CO2 (syngas) fuel but overpredict the measurements at higher temperatures. © 2007 The Combustion Institute. Published by Elsevier

Lieuwen, Timothy C.

102

Analyzing and Tracking Burning Structures in Lean Premixed Hydrogen Flames  

E-Print Network [OSTI]

of premixed burners capable of stably burning ultra-lean hydrogen-air fuel mixtures. Such burners couldAnalyzing and Tracking Burning Structures in Lean Premixed Hydrogen Flames Peer-Timo Bremer, Member demonstrate our approach by analyzing three numerical simulations of lean hydrogen flames subject to different

Pascucci, Valerio

103

On the Evolution of Thermonuclear Flames on Large Scales  

Science Journals Connector (OSTI)

The thermonuclear explosion of a massive white dwarf in a Type Ia supernova explosion is characterized by vastly disparate spatial and temporal scales. The extreme dynamic range inherent to the problem prevents the use of direct numerical simulation and forces modelers to resort to subgrid models to describe physical processes taking place on unresolved scales. We consider the evolution of a model thermonuclear flame in a constant gravitational field on a periodic domain. The gravitational acceleration is aligned with the overall direction of the flame propagation, making the flame surface subject to the Rayleigh-Taylor instability. The flame evolution is followed through an extended initial transient phase well into the steady state regime. The properties of the evolution of flame surface are examined. We confirm the form of the governing equation of the evolution suggested by Khokhlov in 1995. The mechanism of vorticity production and the interaction between vortices and the flame surface are discussed. Previously observed periodic behavior of the flame evolution is reproduced and is found to be caused by the turnover of the largest eddies. The characteristic timescales are found to be similar to the turnover time of these eddies. Relations between flame surface creation and destruction processes and basic characteristics of the flow are discussed. We find that the flame surface creation strength is associated with the Rayleigh-Taylor timescale. Also, in fully developed turbulence, the flame surface destruction strength scales as 1/L3, where L is the turbulent driving scale. The results of our investigation provide support for Khokhlov's self-regulating model of turbulent thermonuclear flames. Based on these results, one can revise and extend the original model. The revision uses a local description of the flame surface enhancement and the evolution of the flame surface since the onset of turbulence, rendering it free from the assumption of an instantaneous steady state of turbulence. This new model can be applied to the initial transient phase of the flame evolution, where the self-regulation mechanism yet to be fully established. Details of this new model will be presented in a forthcoming paper.

Ju Zhang; O. E. Bronson Messer; Alexei M. Khokhlov; Tomasz Plewa

2007-01-01T23:59:59.000Z

104

Investigations of swirl flames in a gas turbine model combustor  

SciTech Connect (OSTI)

A gas turbine model combustor for swirling CH{sub 4}/air diffusion flames at atmospheric pressure with good optical access for detailed laser measurements is discussed. Three flames with thermal powers between 7.6 and 34.9 kW and overall equivalence ratios between 0.55 and 0.75 were investigated. These behave differently with respect to combustion instabilities: Flame A burned stably, flame B exhibited pronounced thermoacoustic oscillations, and flame C, operated near the lean extinction limit, was subject to sudden liftoff with partial extinction and reanchoring. One aim of the studies was a detailed experimental characterization of flame behavior to better understand the underlying physical and chemical processes leading to instabilities. The second goal of the work was the establishment of a comprehensive database that can be used for validation and improvement of numerical combustion models. The flow field was measured by laser Doppler velocimetry, the flame structures were visualized by planar laser-induced fluorescence (PLIF) of OH and CH radicals, and the major species concentrations, temperature, and mixture fraction were determined by laser Raman scattering. The flow fields of the three flames were quite similar, with high velocities in the region of the injected gases, a pronounced inner recirculation zone, and an outer recirculation zone with low velocities. The flames were not attached to the fuel nozzle and thus were partially premixed before ignition. The near field of the flames was characterized by fast mixing and considerable finite-rate chemistry effects. CH PLIF images revealed that the reaction zones were thin (=<0.5 mm) and strongly corrugated and that the flame zones were short (h=<50 mm). Despite the similar flow fields of the three flames, the oscillating flame B was flatter and opened more widely than the others. In the current article, the flow field, structures, and mean and rms values of the temperature, mixture fraction, and species concentrations are discussed. Turbulence intensities, mixing, heat release, and reaction progress are addressed. In a second article, the turbulence-chemistry interactions in the three flames are treated.

Weigand, P.; Meier, W.; Duan, X.R.; Stricker, W.; Aigner, M. [Institut fuer Verbrennungstechnik, Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Pfaffenwaldring 38, D-70569 Stuttgart (Germany)

2006-01-01T23:59:59.000Z

105

Diamonds as timing detectors for MIP: The HADES proton-beam monitor and start detectors  

E-Print Network [OSTI]

This paper gives an overview of a recent development of measuring time of flight of minimum-ionizing particles (MIP) with mono-crystalline diamond detectors. The application in the HADES spectrometer as well as test results obtained with proton beams are discussed.

J. Pietraszko; L. Fabbietti; W. Koenig

2009-11-02T23:59:59.000Z

106

Diamonds as timing detectors for MIP: The HADES proton-beam monitor and start detectors  

E-Print Network [OSTI]

This paper gives an overview of a recent development of measuring time of flight of minimum-ionizing particles (MIP) with mono-crystalline diamond detectors. The application in the HADES spectrometer as well as test results obtained with proton beams are discussed.

,

2009-01-01T23:59:59.000Z

107

Trapping and aerogelation of nanoparticles in negative gravity hydrocarbon flames  

SciTech Connect (OSTI)

We report the experimental realization of continuous carbon aerogel production using a flame aerosol reactor by operating it in negative gravity (?g; up-side-down configuration). Buoyancy opposes the fuel and air flow forces in ?g, which eliminates convectional outflow of nanoparticles from the flame and traps them in a distinctive non-tipping, flicker-free, cylindrical flame body, where they grow to millimeter-size aerogel particles and gravitationally fall out. Computational fluid dynamics simulations show that a closed-loop recirculation zone is set up in ?g flames, which reduces the time to gel for nanoparticles by ?10{sup 6}?s, compared to positive gravity (upward rising) flames. Our results open up new possibilities of one-step gas-phase synthesis of a wide variety of aerogels on an industrial scale.

Chakrabarty, Rajan K., E-mail: rajan.chakrabarty@gmail.com [Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130 (United States); Laboratory for Aerosol Science, Spectroscopy, and Optics, Desert Research Institute, Nevada System of Higher Education, Reno, Nevada 89512 (United States); Novosselov, Igor V. [Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States); Enertechnix Inc., Maple Valley, Washington 98068 (United States); Beres, Nicholas D.; Moosmüller, Hans [Laboratory for Aerosol Science, Spectroscopy, and Optics, Desert Research Institute, Nevada System of Higher Education, Reno, Nevada 89512 (United States); Sorensen, Christopher M. [Condensed Matter Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506 (United States); Stipe, Christopher B. [TSI Incorporated, 500 Cardigan Rd, Shoreview, Minnesota 55126 (United States)

2014-06-16T23:59:59.000Z

108

Turbulence-Flame Interactions in Type Ia Supernovae  

E-Print Network [OSTI]

The large range of time and length scales involved in type Ia supernovae (SN Ia) requires the use of flame models. As a prelude to exploring various options for flame models, we consider, in this paper, high-resolution three-dimensional simulations of the small-scale dynamics of nuclear flames in the supernova environment in which the details of the flame structure are fully resolved. The range of densities examined, 1 to $8 \\times 10^7$ g cm$^{-3}$, spans the transition from the laminar flamelet regime to the distributed burning regime where small scale turbulence disrupts the flame. The use of a low Mach number algorithm facilitates the accurate resolution of the thermal structure of the flame and the inviscid turbulent kinetic energy cascade, while implicitly incorporating kinetic energy dissipation at the grid-scale cutoff. For an assumed background of isotropic Kolmogorov turbulence with an energy characteristic of SN Ia, we find a transition density between 1 and $3 \\times 10^7$ g cm$^{-3}$ where the nature of the burning changes qualitatively. By $1 \\times 10^7$ g cm$^{-3}$, energy diffusion by conduction and radiation is exceeded, on the flame scale, by turbulent advection. As a result, the effective Lewis Number approaches unity. That is, the flame resembles a laminar flame, but is turbulently broadened with an effective diffusion coefficient, $D_T \\sim u' l$, where $u'$ is the turbulent intensity and $l$ is the integral scale. For the larger integral scales characteristic of a real supernova, the flame structure is predicted to become complex and unsteady. Implications for a possible transition to detonation are discussed.

A. J. Aspden; J. B. Bell; M. S. Day; S. E. Woosley; M. Zingale

2008-11-17T23:59:59.000Z

109

Hysteresis of ionization waves  

SciTech Connect (OSTI)

A quasi-logistic, nonlinear model for ionization wave modes is introduced. Modes are due to finite size of the discharge and current feedback. The model consists of competing coupled modes and it incorporates spatial wave amplitude saturation. The hysteresis of wave mode transitions under current variation is reproduced. Sidebands are predicted by the model and found in experimental data. The ad hoc model is equivalent to a general--so-called universal--approach from bifurcation theory.

Dinklage, A. [Max-Planck-Institut fuer Plasmaphysik, EURATOM-Association, Wendelsteinstr. 1, 17491 Greifswald (Germany); Bruhn, B.; Testrich, H. [Institut fuer Physik, E.-M.-Arndt Universitaet Greifswald, Felix-Hausdorff-Str. 6, 17487 Greifswald (Germany); Wilke, C. [Leibniz-Institut fuer Plasmaforschung und Technologie, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

2008-06-15T23:59:59.000Z

110

Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

Electrospray Ionization (ESI) is a process whereby gas phase ions are created from molecules in solution. As a solution exits a narrow tube in the presence of a strong electric field, an aerosol of charged droplets are is formed that produces gas phase ions as they it desolvates. ESI-MS comprises the creation of ions by ESI and the determination of their mass to charge ratio (m/z) by MS.

Kelly, Ryan T.; Marginean, Ioan; Tang, Keqi

2014-06-13T23:59:59.000Z

111

Neutron detector  

DOE Patents [OSTI]

A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

Stephan, Andrew C. (Knoxville, TN); Jardret; Vincent D. (Powell, TN)

2011-04-05T23:59:59.000Z

112

REAL TIME FLAME MONITORING OF GASIFIER BURNER AND INJECTORS  

SciTech Connect (OSTI)

This report is submitted to the United States Department of Energy in partial fulfillment of the contractual requirements for Phase I of the project titled, ''Real Time Flame Monitoring of Gasifier Burner and Injectors'', under co-operative agreement number DE-FS26-02NT41585. The project is composed of three one-year budget periods. The work in each year is divided into separate Tasks to facilitate project management, orderly completion of all project objectives, budget control, and critical path application of personnel and equipment. This Topical Report presents results of the Task 1 and 2 work. The 2 D optical sensor was developed to monitor selected UV and visible wavelengths to collect accurate flame characterization information regarding mixing, flame shape, and flame rich/lean characteristic. Flame richness, for example, was determined using OH and CH intensity peaks in the 300 to 500 nanometer range of the UV and visible spectrum. The laboratory burner was operated over a wide range of air to fuel ratio conditions from fuel rich to fuel lean. The sooty oxygen enriched air flames were established to test the sensor ability to characterize flame structures with substantial presence of hot solid particles emitting strong ''black body radiation''. The knowledge gained in these experiments will be very important when the sensor is used for gasifier flame analyses. It is expected that the sensor when installed on the Global Energy gasifier will be exposed to complex radiation patterns. The measured energy will be a combination of spectra emitted by the combusting gases, hot solid particulates, and hot walls of the gasifier chamber. The ability to separate flame emissions from the ''black body emissions'' will allow the sensor to accurately determine flame location relative to the gasifier walls and the injectors, as well as to analyze the flame's structure and condition. Ultimately, this information should enable the gasification processes to be monitored and controlled and as a result increase durability and efficiency of the gasifier. To accomplish goals set for Task 2 GTI will utilize the CANMET Coal Gasification Research facility. The Entrained Coal Gasifier Burner Test Stand has been designed and is currently under construction in the CANMET Energy Technology Center (CETC), the research and technology arm of Natural Resources Canada (NRCan). This Gasifier Burner Stand (GBS) is a scaled-down mock-up of a working gasifier combustion system that can provide the flexible platform needed in the second year of the project to test the flame sensor. The GBS will be capable of simulating combustion and gasification processes occurring in commercial gasifiers, such as Texaco, Shell, and Wabash River.

James Servaites; Serguei Zelepouga; David Rue

2003-10-01T23:59:59.000Z

113

THE DEPLOYMENT OF ZIP NON-EQUILIBRIUM PHONON DETECTORS IN CDMS II  

E-Print Network [OSTI]

operating these Si and Ge Z-sensitive Ionization and Phonon (ZIP) detectors at the Stanford Underground Facility are reported. 1 Surface electron events The Cryogenic Dark Matter Search (CDMS) 1 utilizes

California at Berkeley, University of

114

Pulsed-Discharge Electron-Capture Detector: Kinetic Model, Response Factors, and Temperature Dependence  

Science Journals Connector (OSTI)

......competing with the electron capture processes for some compounds and dictated...the detector were made in the process of commercialization. The studies using methane...thermalized. A potential competing process is the ionization of the sample......

W.E. Wentworth; Y. Wang; Wayne Odegard; E.C.M. Chen; Stanley D. Stearns

1996-08-01T23:59:59.000Z

115

Device for calibrating a radiation detector system  

DOE Patents [OSTI]

A device is disclosed for testing a radiation detector system that includes at least two arrays of radiation detectors that are movable with respect to each other. The device includes a ''shield plate'' or shell, and an opposing ''source plate'' containing a source of ionizing radiation. Guides are attached to the outer surface of the shell for engaging the forward ends of the detectors, thereby reproducibly positioning the detectors with respect to the source and with respect to each other, thereby ensuring that a predetermined portion of the radiation emitted by the source passes through the shell and reaches the detectors. The shell is made of an hydrogenous material having approximately the same radiological attenuation characteristics as composite human tissue. The source represents a human organ such as the lungs, heart, kidneys, liver, spleen, pancreas, thyroid, testes, prostate, or ovaries. The source includes a source of ionizing radiation having a long half-life and an activity that is within the range typically searched for in human subjects. 3 figures.

McFee, M.C.; Kirkham, T.J.; Johnson, T.H.

1994-12-27T23:59:59.000Z

116

Device for calibrating a radiation detector system  

DOE Patents [OSTI]

A device for testing a radiation detector system that includes at least two arrays of radiation detectors that are movable with respect to each other. The device includes a "shield plate" or shell, and an opposing "source plate" containing a source of ionizing radiation. Guides are attached to the outer surface of the shell for engaging the forward ends of the detectors, thereby reproducibly positioning the detectors with respect to the source and with respect to each other, thereby ensuring that a predetermined portion of the radiation emitted by the source passes through the shell and reaches the detectors. The shell is made of an hydrogenous material having approximately the same radiological attenuation characteristics as composite human tissue. The source represents a human organ such as the lungs, heart, kidneys, heart, liver, spleen, pancreas, thyroid, testes, prostate, or ovaries. The source includes a source of ionizing radiation having a long half-life and an activity that is within the range typically searched for in human subjects.

Mc Fee, Matthew C. (New Ellenton, SC); Kirkham, Tim J. (Beech Island, SC); Johnson, Tippi H. (Aiken, SC)

1994-01-01T23:59:59.000Z

117

Study on laminar flame speed and flame structure of syngas with varied compositions using OH-PLIF and spectrograph  

Science Journals Connector (OSTI)

Various Bunsen flame information of premixed syngas/air mixtures was systematically collected. A CCD camera was used to capture the flame images. The OH-PLIF technique was applied to obtain the flame OH distribution and overall flame radiation spectra were measured with a spectrograph. Experiments were conducted on a temperature un-controlled burner and syngas over a wide range of H2/CO ratios (from 0.25 to 4) and equivalence ratios (from 0.5 to 1.2). Results show that increasing hydrogen fraction ( X H 2 ) extends the blow-off limit significantly. The measured laminar flame speed using cone-angle method based on CCD flame imaging and OH-PLIF images increases remarkably with the increase of X H 2 , and these measurements agrees well with kinetic modeling predictions through Li's mechanism when the temperature for computation is corrected. Kinetic study shows that as X H 2 increases, the production of H and OH radicals is accelerated. Additionally, the main H radical production reaction (or OH radical consumption reactions) changes from R29 (CO + OH = CO2 + H) to R3 (H2 + OH = H2O + H) as X H 2 increases. Sensitivity analysis was conducted to access the dominant reactions when X H 2 increases. The difference on flame color for different X H 2 mixtures is due to their difference in radiation spectrum of the intermediate radicals produced in combustion.

Jin Fu; Chenglong Tang; Wu Jin; Luong Dinh Thi; Zuohua Huang; Yang Zhang

2013-01-01T23:59:59.000Z

118

Plasma Production via Field Ionization  

SciTech Connect (OSTI)

Plasma production via field ionization occurs when an incoming particle beam is sufficiently dense that the electric field associated with the beam ionizes a neutral vapor or gas. Experiments conducted at the Stanford Linear Accelerator Center explore the threshold conditions necessary to induce field ionization by an electron beam in a neutral lithium vapor. By independently varying the transverse beam size, number of electrons per bunch or bunch length, the radial component of the electric field is controlled to be above or below the threshold for field ionization. Additional experiments ionized neutral xenon and neutral nitric oxide by varying the incoming beam's bunch length. A self-ionized plasma is an essential step for the viability of plasma-based accelerators for future high-energy experiments.

O'Connell, C.L.; Barnes, C.D.; Decker, F.; Hogan, M.J.; Iverson, R.; Krejcik, P.; Siemann, R.; Walz, D.R.; /SLAC; Clayton, C.E.; Huang, C.; Johnson, D.K.; Joshi, C.; Lu,; Marsh, K.A.; Mori, W.; Zhou, M.; /UCLA; Deng, S.; Katsouleas, T.; Muggli, P.; Oz, E.; /Southern California U.

2007-01-02T23:59:59.000Z

119

Theoretical Adiabatic Temperature and Chemical Composition of Sodium Combustion Flame  

SciTech Connect (OSTI)

Sodium fire safety analysis requires fundamental combustion properties, e.g., heat of combustion, flame temperature, and composition. We developed the GENESYS code for a theoretical investigation of sodium combustion flame.Our principle conclusions on sodium combustion under atmospheric air conditions are (a) the maximum theoretical flame temperature is 1950 K, and it is not affected by the presence of moisture; the uppermost limiting factor is the chemical instability of the condensed sodium-oxide products under high temperature; (b) the main combustion product is liquid Na{sub 2}O in dry air condition and liquid Na{sub 2}O with gaseous NaOH in moist air; and (c) the chemical equilibrium prediction of the residual gaseous reactants in the flame is indispensable for sodium combustion modeling.

Okano, Yasushi; Yamaguchi, Akira [O-arai Engineering Center (Japan)

2003-12-15T23:59:59.000Z

120

The effect of fuel composition on flame dynamics  

SciTech Connect (OSTI)

As fuel sources diversify, the gas turbine industry is under increasing pressure to develop fuel-flexible plants, able to use fuels with a variety of compositions from a large range of sources. However, the dynamic characteristics vary considerably with composition, in many cases altering the thermoacoustic stability of the combustor. We compare the flame dynamics, or the response in heat release rate of the flame to acoustic perturbations, of the three major constituents of natural gas: methane, ethane, and propane. The heat release rate is quantified using OH* chemiluminescence and product gas temperature. Gas temperature is measured by tracking the absorption of two high-temperature water lines, via Tunable Diode Laser Absorption Spectroscopy. The flame dynamics of the three fuels differ significantly. The changes in flame dynamics due to variations in fuel composition have the potential to have a large effect on the thermoacoustic stability of the combustor. (author)

Hendricks, Adam G.; Vandsburger, Uri [Department of Mechanical Engineering - 0238, Virginia Tech, Blacksburg, VA 24061 (United States)

2007-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Probing flame chemistry with MBMS, theory, and modeling  

SciTech Connect (OSTI)

The objective is to establish kinetics of combustion and molecular-weight growth in C{sub 3} hydrocarbon flames as part of an ongoing study of flame chemistry. Specific reactions being studied are (1) the growth reactions of C{sub 3}H{sub 5} and C{sub 3}H{sub 3} with themselves and with unsaturated hydrocarbons and (2) the oxidation reactions of O and OH with C{sub 3}`s. This approach combines molecular-beam mass spectrometry (MBMS) experiments on low-pressure flat flames; theoretical predictions of rate constants by thermochemical kinetics, Bimolecular Quantum-RRK, RRKM, and master-equation theory; and whole-flame modeling using full mechanisms of elementary reactions.

Westmoreland, P.R. [Univ. of Massachusetts, Amherst (United States)

1993-12-01T23:59:59.000Z

122

Fuel Properties to Enable Lifted-Flame Combustion  

Broader source: Energy.gov (indexed) [DOE]

Page 1 E.Kurtz File Name.pptx Fuel Properties to Enable Lifted Flame Combustion Eric Kurtz Ford Motor Company June 19, 2014 FT017 This presentation does not contain any...

123

Stability Regimes of Turbulent Nitrogen-Diluted Hydrogen Jet Flames  

SciTech Connect (OSTI)

One option for combustion in zero-emission Integrated Gasification Combined Cycle (IGCC) power plants is non-premixed combustion of nitrogen-diluted hydrogen in air. An important aspect to non-premixed combustion is flame stability or anchoring, though only a few fundamental stability studies of these flames have taken place to date. The following paper presents the results of experiments investigating the effects of nitrogen diluent fraction, jet diameter, and exit velocity on the static stability limits of a turbulent hydrogen jet flame issuing from a thin-lipped tube into a quiescent atmosphere. Four different stability limits are observed: detachment from the burner lip, reattachment to the burner lip, transition from a laminar lifted flame base to blowout or to a turbulent lifted flame, and transition from a turbulent lifted flame to blowout. The applicability of existing theories and correlations to the stability results is discussed. These results are an important step in assessing the viability of a non-premixed combustion approach using hydrogen diluted with nitrogen as a fuel.

Weiland, N.T.; Strakey, P.A.

2007-03-01T23:59:59.000Z

124

Modeling variable density effects in turbulent flames -- Some basic considerations  

SciTech Connect (OSTI)

The paper discusses the basic physical phenomena involved in pressure-density interactions, and presents models of pressure-velocity, pressure-scalar, baroclinic and dilatation effects for variable density low Mach-number turbulence. Their implementation in the {kappa}-{epsilon} framework is then described and their performance evaluated. The models assume that both scalar transport and turbulence generation arising from pressure-density interactions in flames are caused by the motion of large scale turbulent thermals superposed on the normal turbulence mechanism. The velocity of the thermals is related directly to the mean pressure gradient and local density differences in the flames. It is furthermore assumed that the correction for dilatation effects in the {kappa}-{epsilon} system can be determined from the constraint of conservation of the angular momentum of turbulence per unit mass. Simple corrections of the {kappa}-{epsilon} system are proposed for fast chemistry diffusion and premixed flames subject to variable pressure gradients, which offer substantial improvements in the predictions of the flames. some problems remain, particularly in predictions of turbulence in premixed flames, owing to large scale instabilities of the flames observed in the experiments.

Chomiak, J.; Nisbet, J.R. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Thermo and Fluid Dynamics] [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Thermo and Fluid Dynamics

1995-08-01T23:59:59.000Z

125

Noise in non?premixed turbulent syngas flames  

Science Journals Connector (OSTI)

A turbulent syngas flame may generate acoustic noise of high acoustic intensity in a combustion chamber. This may lead to the failure of construction components in a gas turbine engine in periods of the order of 1–100 hours. The research as described in the literature has almost exclusively been performed on the generation of noise in premixed methane or propane flames. Syngas fuel is a mixture of hydrogen and carbon monoxide and the burners used are of the non?premixed type. In this research the effect of turbulence and syngas composition on noise generation is investigated. A laboratory is set up to test syngas flames of a thermal power of 50 kW in a cylindrical air?cooled combustion chamber. Experiments are performed at several fuel compositions and burner inlet conditions. The flame sound intensity is measured in the combustion chamber equipped with acoustic dampers. The paper discusses the measured sound spectra. A model is derived for the generation of sound in a turbulent non?premixed flame. In this model it is shown that the sound generation is related to the dependence of density on mixture fraction in a flame with fast chemistry. A fluctuation in mixture fraction will lead to sound generation.

Sikke A. Klein; Jim B. W. Kok

1998-01-01T23:59:59.000Z

126

On the Evolution of Thermonuclear Flames on Large Scales  

E-Print Network [OSTI]

The thermonuclear explosion of a massive white dwarf in a Type Ia supernova explosion is characterized by vastly disparate spatial and temporal scales. The extreme dynamic range inherent to the problem prevents the use of direct numerical simulation and forces modelers to resort to subgrid models to describe physical processes taking place on unresolved scales. We consider the evolution of a model thermonuclear flame in a constant gravitational field on a periodic domain. The gravitational acceleration is aligned with the overall direction of the flame propagation, making the flame surface subject to the Rayleigh-Taylor instability. The flame evolution is followed through an extended initial transient phase well into the steady-state regime. The properties of the evolution of flame surface are examined. We confirm the form of the governing equation of the evolution suggested by Khokhlov (1995). The mechanism of vorticity production and the interaction between vortices and the flame surface are discussed. The results of our investigation provide the bases for revising and extending previous subgrid-scale model.

Ju Zhang; O. E. Bronson Messer; Alexei M. Khokhlov; Tomasz Plewa

2006-10-05T23:59:59.000Z

127

Longevity effects on the performance of fire detectors  

E-Print Network [OSTI]

Detector Sensitivity 6. Light Obscuration Type Photoelectric Smoke Detector 10 7. Angular Patterns of Scattered Intensity from Particles of Three Sizes 8. Detection Systems Present in the State of Texas for 1991 13 9. Ionization Flow Chart 19 10.... Photoelectric Flow Chart 11. Smoke Chamber: Orientation Drawing 20 25 12. Smoke Chamber: Plan View 13. Smoke Chamber: Cross Section 14. Smoke Chamber: Elevation Side 1 15. Smoke Chamber: Elevation Side 2 16. Smoke Chamber: Elevation Side 3 17. Smoke...

Dedear, Timothy Keith

1993-01-01T23:59:59.000Z

128

Oscillator detector  

SciTech Connect (OSTI)

An alien liquid detector employs a monitoring element and an oscillatory electronic circuit for maintaining the temperature of the monitoring element substantially above ambient temperature. The output wave form, eg., frequency of oscillation or wave shape, of the oscillatory circuit depends upon the temperaturedependent electrical characteristic of the monitoring element. A predetermined change in the output waveform allows water to be discriminated from another liquid, eg., oil. Features of the invention employing two thermistors in two oscillatory circuits include positioning one thermistor for contact with water and the other thermistor above the oil-water interface to detect a layer of oil if present. Unique oscillatory circuit arrangements are shown that achieve effective thermistor action with an economy of parts and energizing power. These include an operational amplifier employed in an astable multivibrator circuit, a discrete transistor-powered tank circuit, and use of an integrated circuit chip.

Potter, B.M.

1980-05-13T23:59:59.000Z

129

Design and Prototyping of an Ionization Profile Monitor for the SNS Accumulator Ring  

SciTech Connect (OSTI)

An ionization profile monitor (IPM) has been designed for the Spallation Neutron Source (SNS) accumulator ring. Utilizing ionized electrons produced by beam-gas ionization, the SNS IPM uses a 120 kV bias potential to overcome beam space charge and accelerate electrons towards a movable particle detector. A 300 G magnetic field is used to confine the transverse electron motion, resulting in profile errors at the estimated 7% level. With a system bandwidth of 17.5 MHz. The SNS IPM is capable of measuring turn-by-turn beam profiles for a fully accumulated beam. This paper presents a description of the system and design.

Bartkoski, Dirk A [ORNL; Deibele, Craig E [ORNL; Polsky, Yarom [ORNL

2014-01-01T23:59:59.000Z

130

Proteasome Structures Affected by Ionizing Radiation  

Science Journals Connector (OSTI)

...Effect of ionizing radiation on 26S but...radiation doses, and immediately...the dose range 1 to 20 Gy...ionizing radiation induced a...38), ionizing radiation (39...over a wide range of radiation doses and further...

Milena Pervan; Keisuke S. Iwamoto; and William H. McBride

2005-07-01T23:59:59.000Z

131

RHIC | PHENIX Detector  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

The PHENIX Detector The PHENIX detector records many different particles emerging from RHIC collisions, including photons, electrons, muons, and quark-containing particles called...

132

Investigation of H2 Concentration and Combustion Instability Effects on the Kinetics of Strained Syngas Flames  

SciTech Connect (OSTI)

The flame extinction limits of syngas (H{sub 2}-CO) flames were measured using a twin-flame-counter-flow burner. Plots of Extinction limits vs. global stretch rates were generated at different mixture compositions and an extrapolation method was used to calculate the flame extinction limit corresponding to an experimentally unattainable zero-stretch condition. The zero-stretch extinction limit of H{sub 2}-CO mixtures decreases (from rich to lean) with the increase in H{sub 2} concentration in the mixture. The average difference between the measured flame extinction limit and the Le Chatelier's calculation is around {approx} 7%. The measured OH{sup -} chemiluminescent data indicates that regardless of mixture compositions the OH radical concentration reduces (within the experimental uncertainties) to an extinction value prior to the flame extinction. Flame extinction limits of H{sub 2}-CO mixtures measured in a flat-flame burner configuration also show a similar relation. Additionally, the measured laminar flame velocity close to the extinction indicates that regardless of fuel composition the premixed flame of hydrogen fuel blends extinguishes when the mixture laminar flame velocity falls below a critical value. The critical laminar flame velocity at extinction for H{sub 2}-CO premixed flames (measured in the flat flame burner configuration) is found to be 3.77({+-}0.38) cm/s. An externally perturbed H{sub 2}-CO twin flame was not experimentally achievable for the mixture conditions used in the present investigation. A slightest perturbation in the flow-field distorts the H{sub 2}-CO twin-flame. The flame becomes highly unstable with the introduction of an externally excited flow oscillation.

Ahsan R. Choudhuri

2006-08-07T23:59:59.000Z

133

DEVELOPMENT OF PHONON-MEDIATED CRYOGENIC PARTICLE DETECTORS WITH  

E-Print Network [OSTI]

of detectors which are able to reject background events by simultane- ously measuring energy deposited into phonons versus electron hole pairs. By using the phonon sensors with the ionization sensors to compare (background radiation) and nuclear recoil events (dark matter events). These detec- tors with built

California at Berkeley, University of

134

Turbulent flame speed for syngas at gas turbine relevant conditions  

Science Journals Connector (OSTI)

Modifications of conventional natural-gas-fired burners for operation with syngas fuels using lean premixed combustion is challenging due to the different physicochemical properties of the two fuels. A key differentiating parameter is the turbulent flame velocity, ST, commonly expressed as its ratio to the laminar flame speed, SL. This paper reports an experimental investigation of premixed syngas combustion at gas turbine like conditions, with emphasis on the determination of ST/SL derived as global fuel consumption per unit time. Experiments at pressures up to 2.0 MPa, inlet temperatures and velocities up to 773 K and 150 m/s, respectively, and turbulence intensity to laminar flame speed ratios, u?/SL, exceeding 100 are presented for the first time. Comparisons between different syngas mixtures and methane clearly show much higher ST/SL for the former fuel. It is shown that ST/SL is strongly dependent on preferential diffusive-thermal (PDT) effects, co-acting with hydrodynamic effects, even for very high u?/SL. ST/SL increases with rising hydrogen content in the fuel mixture and with increasing pressure. A correlation for ST/SL valid for all investigated fuel mixtures, including methane, is proposed in terms of turbulence properties (turbulence intensity and integral length scale), combustion properties (laminar flame speed and laminar flame thickness) and operating conditions (pressure and inlet temperature). The correlation captures effects of preferential diffusive-thermal and hydrodynamic instabilities.

S. Daniele; P. Jansohn; J. Mantzaras; K. Boulouchos

2011-01-01T23:59:59.000Z

135

Grid resolution effects on LES of a piloted methane-air flame K. A. Kemenov  

E-Print Network [OSTI]

not only for canonical geome- tries like laboratory jet flames but also for complex ones like gas-turbine in the flame shows some residual grid dependence. Introduction Large Eddy Simulation (LES) has proved

136

Layer-by-Layer Nanocoatings with Flame Retardant and Oxygen Barrier Properties: Moving Toward Renewable Systems  

E-Print Network [OSTI]

) clay to create a renewable flame retardant nanocoating for polyurethane foam. This coating system completely stops the melting of a flexible polyurethane foam when exposed to direct flame from a butane torch, with just 10 bilayers (~ 30 nm thick...

Laufer, Galina 1985-

2012-10-23T23:59:59.000Z

137

The fabrication and properties characterization of wood-based flame retardant composites  

Science Journals Connector (OSTI)

Wood-based flame retardant composites were fabricated based on vacuum-pressure impregnating method after high intensive microwave pretreatment. The effects of ammonium polyphosphate (APP) and modified nano-zinc borate (nZB) addition on flame-retardation ...

Xia He, Xianjun Li, Zhu Zhong, Yongli Yan, Qunying Mou, Chunhua Yao, Chun Wang

2014-01-01T23:59:59.000Z

138

E-Print Network 3.0 - aerosol flame deposition Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

search results for: aerosol flame deposition Page: << < 1 2 3 4 5 > >> 1 Flame aerosol nano-technology has been developed to preparation of thin and defect-free porous membrane...

139

Photon Sciences Directorate | 2010 Annual Report | Detector R&D  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Detector R&D Detector R&D ionization chamber A miniature four-channel ionization chamber that was developed at NSLS Detectors sit at the very end of the intricate systems that constitute light sources like NSLS and NSLS-II. Because detectors are where the science gets done, detector research and development can enable new science. For the user community, NSLS-II will offer a significantly higher degree of coherence in its beams than most other synchrotrons, so imaging techniques that take advantage of that superiority are at the forefront of detector R&D. The CHX beamline, one of six project beamlines being built for NSLS-II, uses photon correlation spectroscopy. The goal is to detect the arrival time of photons with the highest possible resolution over the largest

140

Metrological tool for the characterization of flame fronts based on the coupling of heat  

E-Print Network [OSTI]

° flame inclination angle due to wind [ ]th i W theoretical radiative heat flux received by the ith target

Boyer, Edmond

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Detectors (XSD) | Advanced Photon Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the APS Detector Pool; conducts R&D in x-ray detectors; and operates several x-ray generators. diffuse Detector Pool The Detectors Group operates the APS Detector Pool. Submit a...

142

Flame Synthesis of One-Dimensional Metal Oxide Nanomaterials  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Synthesis of One-Dimensional Metal Oxide Nanomaterials Synthesis of One-Dimensional Metal Oxide Nanomaterials Alexei V. Saveliev Dept. of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA Robust, scalable, and energy efficient methods of nanomaterial synthesis are needed to meet the demands of current and potential applications. Flames have been successfully applied for the synthesis of metal oxide and ceramic nanopowders largely composed of spherical particles and their aggregates. In recent years, premixed and diffusion flames have been employed for the synthesis of 1-D carbon nanoforms such as carbon fibers and carbon nanotubes. The extension of flame methods to gas phase and solid support synthesis of 1-D inorganic nanoforms is of great interest and significance. This talk presents

143

Resonance Ionization Laser Ion Sources  

E-Print Network [OSTI]

The application of the technique of laser resonance ionization to the production of singly charged ions at radioactive ion beam facilities is discussed. The ability to combine high efficiency and element selectivity makes a resonance ionization laser ion source (RILIS) an important component of many radioactive ion beam facilities. At CERN, for example, the RILIS is the most commonly used ion source of the ISOLDE facility, with a yearly operating time of up to 3000 hours. For some isotopes the RILIS can also be used as a fast and sensitive laser spectroscopy tool, provided that the spectral resolution is sufficiently high to reveal the influence of nuclear structure on the atomic spectra. This enables the study of nuclear properties of isotopes with production rates even lower than one ion per second and, in some cases, enables isomer selective ionization. The solutions available for the implementation of resonance laser ionization at radioactive ion beam facilities are summarized. Aspects such as the laser r...

Marsh, B

2013-01-01T23:59:59.000Z

144

Field ionization from carbon nanofibers  

E-Print Network [OSTI]

The Micro Gas Analyzer project aims to develop power-efficient, high resolution, high sensitivity, portable and real-time gas sensors. We developed a field ionizer array based on gated CNTs. Arrays of CNTs are used because ...

Adeoti, Bosun J

2008-01-01T23:59:59.000Z

145

Ionizing Radiation Injury (South Carolina)  

Broader source: Energy.gov [DOE]

This legislation applies to employers that have more than one employee who engages in activities which involve the presence of ionizing radiation. Employers with less than three employees can...

146

LES/probability density function approach for the simulation of an ethanol spray flame  

E-Print Network [OSTI]

LES/probability density function approach for the simulation of an ethanol spray flame Colin Heye a an experimental pilot-stabilized ethanol spray flame. In this particular flame, droplet evaporation occurs away: Large-eddy simulation; Probability density function; Flamelet/progress variable approach; Ethanol

Raman, Venkat

147

Radiation-Driven Flame Spread Over Thermally-Thick Fuels in Quiescent Microgravity Environments  

E-Print Network [OSTI]

Radiation-Driven Flame Spread Over Thermally-Thick Fuels in Quiescent Microgravity Environments-non-premixed, flame-spread Submitted to Twenty-Ninth International Symposium on Combustion, Sapporo, Japan, July 21 ­ July 26, 2002. #12;Radiation-Driven Flame Spread Over Thermally-Thick Fuels in Quiescent Microgravity

148

Prediction of oxy-coal flame stand-off using high-fidelity thermochemical models  

E-Print Network [OSTI]

Prediction of oxy-coal flame stand-off using high-fidelity thermochemical models and the one Abstract An Eulerian one-dimensional turbulence (ODT) model is applied to simulate oxy-coal combustion temperature and mixing rate on oxy-coal flame is simulated and discussed where flame stand-off is used

149

Turbulent Oxygen Flames in Type Ia Supernovae A. J. Aspden1  

E-Print Network [OSTI]

Turbulent Oxygen Flames in Type Ia Supernovae A. J. Aspden1 , J. B. Bell1 , and S. E. Woosley2 oxygen flames. The two aims of the paper are to examine the response of the inductive oxygen flame to intense levels of turbulence, and to explore the possibility of transition to detonation in the oxygen

150

Real Time Flame Monitoring of Gasifier Burner and Injectors  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Real Time Flame Monitoring of Gasifier Real Time Flame Monitoring of Gasifier Burner and Injectors Background The Gasification Technologies Program at the National Energy Technology Laboratory (NETL) supports research and development (R&D) in the area of gasification-a process whereby carbon-based materials (feedstocks) such as coal are converted into synthesis gas (syngas), which is separated into hydrogen (H 2 ) and carbon dioxide (CO 2 ) gas streams in a combustion turbine-generator as a way to generate clean electricity while

151

Oxy-fuel Combustion of Ethanol in Premixed Flames  

Science Journals Connector (OSTI)

(11-14) First, measurements using a heat flux setup for liquid fuels were studied on ethanol + air combustion. ... The heat flux method builds on the principle that heat is transferred to the unburnt gas, cooling the plate, while heat transfer from the flame heats the plate. ... A detailed kinetic scheme was compiled using known data on EtOH kinetics and is self-consistent in that it closely predicts laminar flame speed of EtOH, CH4, MeOH, and C2-hydrocarbons. ...

Jenny D. Nauclér; Moah Christensen; Elna J. K. Nilsson; Alexander A. Konnov

2012-06-19T23:59:59.000Z

152

Detection of single atoms by resonance ionization spectroscopy  

SciTech Connect (OSTI)

Rutherford's idea for counting individual atoms can, in principle, be implemented for nearly any type of atom, whether stable or radioactive, by using methods of resonance ionization. With the RIS technique, a laser is tuned to a wavelength which will promote a valence electron in a Z-selected atom to an excited level. Additional resonance or nonresonance photoabsorption steps are used to achieve nearly 100% ionization efficiencies. Hence, the RIS process can be saturated for the Z-selected atoms; and since detectors are available for counting either single electrons or positive ions, one-atom detection is possible. Some examples are given of one-atom detection, including that of the noble gases, in order to show complementarity with AMS methods. For instance, the detection of /sup 81/Kr using RIS has interesting applications for solar neutrino research, ice-cap dating, and groundwater dating. 39 refs., 7 figs., 2 tabs.

Hurst, G.S.

1986-01-01T23:59:59.000Z

153

Muon Collider Machine-Detector Interface  

SciTech Connect (OSTI)

In order to realize the high physics potential of a Muon Collider (MC) a high luminosity of {mu}{sup +}{mu}{sup -}-collisions at the Interaction Point (IP) in the TeV range must be achieved ({approx}10{sup 34} cm{sup -2}s{sup -1}). To reach this goal, a number of demanding requirements on the collider optics and the IR hardware - arising from the short muon lifetime and from relatively large values of the transverse emittance and momentum spread in muon beams that can realistically be obtained with ionization cooling should be satisfied. These requirements are aggravated by limitations on the quadrupole gradients as well as by the necessity to protect superconducting magnets and collider detectors from muon decay products. The overall detector performance in this domain is strongly dependent on the background particle rates in various sub-detectors. The deleterious effects of the background and radiation environment produced by the beam in the ring are very important issues in the Interaction Region (IR), detector and Machine-Detector Interface (MDI) designs. This report is based on studies presented very recently.

Mokhov, Nikolai V.; /Fermilab

2011-08-01T23:59:59.000Z

154

Intensity Characteristics of S2 Emission for Sulfur Compounds with Flame Photometric Detector  

Science Journals Connector (OSTI)

......necessary to determine this range now that high speed liquid chromatography is carried out largely at pressures which sometimes ex- ceed 300 bars. In the following, we shall study the effect of pres- sure on the compressibility and on the viscosity of the mobile......

Toshiaki Sugiyama; Yoshihito Suzuki; Tsugio Takeuchi

1973-12-01T23:59:59.000Z

155

Experimental study of industrial gas turbine flames including quantification of pressure influence on flow field, fuel/air premixing and flame shape  

Science Journals Connector (OSTI)

Abstract A commercial swirl burner for industrial gas turbine combustors was equipped with an optically accessible combustion chamber and installed in a high-pressure test-rig. Several premixed natural gas/air flames at pressures between 3 and 6 bar and thermal powers of up to 1 MW were studied by using a variety of measurement techniques. These include particle image velocimetry (PIV) for the investigation of the flow field, one-dimensional laser Raman scattering for the determination of the joint probability density functions of major species concentrations, mixture fraction and temperature, planar laser induced fluorescence (PLIF) of OH for the visualization of the flame front, chemiluminescence measurements of OH* for determining the lift-off height and size of the flame and acoustic recordings. The results give insights into important flame properties like the flow field structure, the premixing quality and the turbulence–flame interaction as well as their dependency on operating parameters like pressure, inflow velocity and equivalence ratio. The 1D Raman measurements yielded information about the gradients and variation of the mixture fraction and the quality of the fuel/air mixing, as well as the reaction progress. The OH PLIF images showed that the flame was located between the inflow of fresh gas and the recirculated combustion products. The flame front structures varied significantly with Reynolds number from wrinkled flame fronts to fragmented and strongly corrugated flame fronts. All results are combined in one database that can be used for the validation of numerical simulations.

Ulrich Stopper; Wolfgang Meier; Rajesh Sadanandan; Michael Stöhr; Manfred Aigner; Ghenadie Bulat

2013-01-01T23:59:59.000Z

156

GADRAS Detector Response Function.  

SciTech Connect (OSTI)

The Gamma Detector Response and Analysis Software (GADRAS) applies a Detector Response Function (DRF) to compute the output of gamma-ray and neutron detectors when they are exposed to radiation sources. The DRF is fundamental to the ability to perform forward calculations (i.e., computation of the response of a detector to a known source), as well as the ability to analyze spectra to deduce the types and quantities of radioactive material to which the detectors are exposed. This document describes how gamma-ray spectra are computed and the significance of response function parameters that define characteristics of particular detectors.

Mitchell, Dean J.; Harding, Lee; Thoreson, Gregory G; Horne, Steven M.

2014-11-01T23:59:59.000Z

157

Small-scale Interaction of Turbulence with Thermonuclear Flames in Type Ia Supernovae  

E-Print Network [OSTI]

Microscopic turbulence-flame interactions of thermonuclear fusion flames occuring in Type Ia Supernovae were studied by means of incompressible direct numerical simulations with a highly simplified flame description. The flame is treated as a single diffusive scalar field with a nonlinear source term. It is characterized by its Prandtl number, Pr << 1, and laminar flame speed, S_L. We find that if S_L ~ u', where u' is the rms amplitude of turbulent velocity fluctuations, the local flame propagation speed does not significantly deviate from S_L even in the presence of velocity fluctuations on scales below the laminar flame thickness. This result is interpreted in the context of subgrid-scale modeling of supernova explosions and the mechanism for deflagration-detonation-transitions.

J. C. Niemeyer; W. K. Bushe; G. R. Ruetsch

1999-05-07T23:59:59.000Z

158

NETL: Investigation on Flame Characteristics and Burner Operability Issues  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Investigation on Flame Characteristics and Burner Operability Issues of Oxy-Fuel Combustion Investigation on Flame Characteristics and Burner Operability Issues of Oxy-Fuel Combustion Project No.: DE-FE0002402 NETL has partnered with the University of Texas at El Paso (UTEP) to investigate the characteristics of oxy-fuel flames and assess their impact on the operability of oxy-fuel combustion systems. The examination of fundamental flame characteristics data and related burner operability parameters are essential for designing and developing oxy-fuel combustion systems for new power plants and retrofitting existing power generation units. In an oxy-fuel system, coal is combusted in an enriched oxygen environment using pure oxygen diluted with recycled CO2 or water vapor (H2O), resulting in a flue stream consisting only of CO2 and H2O (no other co-contaminants) (Figure 1). Oxy-fuel combustion is promising for CCUS applications because water can be condensed out of the CO2/H2O flue stream to produce a relatively pure CO2 end product for capture. Oxy-fuel combustion and subsequent CO2 capture is currently being considered by the DOE's Innovations for Existing Plants Program as having the potential to meet the goal of 90 percent CO2 capture without increasing the cost of electricity more than 35 percent.

159

Ignition and Flame Quenching of Quiescent Fuel Mists  

Science Journals Connector (OSTI)

...Ignition and Flame Quenching of Quiescent Fuel Mists D. R. Ballal A. H. Lefebvre A...the ignition of quiescent multidroplet fuel mists which assumes that chemical reaction...spark, of an adequate concentration of fuel vapour in the ignition zone. From analysis...

1978-01-01T23:59:59.000Z

160

Flame Contact, a New Departure in Water Heating1  

Science Journals Connector (OSTI)

... paper. We can, by a modification of this experiment, measure the depth of the flameless space, as the copper, if placed against the paper before it has time to ... gum, which is liable to swell and force the paper past the limit of the flameless space, and also to allow the paste to dry before applying the flame, as ...

1886-07-08T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Measurements of Laminar Flame Velocity for Components of Natural Gas  

E-Print Network [OSTI]

gas in combustion engines and power generation systems. The main hydrocarbon included in natural gas, BP 20451, 1 Rue Grandville, 54001 Nancy, France 2 Division of Combustion Physics, Lund University performed by the heat flux method using a newly built flat flame adiabatic burner at atmospheric pressure

Paris-Sud XI, Université de

162

Formation mechanism for polycyclic aromatic hydrocarbons in methane flames  

E-Print Network [OSTI]

aromatic hydrocarbons PAHs up to 788 amu (C64H20) were detected in the combustion gases. Only the most applications including heating systems and gas turbines for electric power generation.62­64 The combustionFormation mechanism for polycyclic aromatic hydrocarbons in methane flames K. Siegmanna) Swiss

Sattler, Klaus

163

Treating Unresolvable Flame Physics in Simulations of Thermonuclear Supernovae  

Science Journals Connector (OSTI)

Due to the small width of the subsonic burning front (flame) in thermonuclear supernovae, micrometers to centimeters, and the influence of turbulence, which adds structure to this front on a broad range of scales, it won't be possible in the foreseeable ... Keywords: Computational astrophysics, combustion, turbulence

Dean M. Townsley

2009-03-01T23:59:59.000Z

164

Paper # A02 Topic: Laminar Flames US Combustion Meeting  

E-Print Network [OSTI]

been focused on synthetic fuel gas (syngas) combustion. Syngas is derived from coal throughPaper # A02 Topic: Laminar Flames 1 5th US Combustion Meeting Organized by the Western States Section of the Combustion Institute and Hosted by the University of California at San Diego March 25

Seitzman, Jerry M.

165

Analyzing and Tracking Burning Structures in Lean Premixed Hydrogen Flames  

E-Print Network [OSTI]

- bly burning ultra-lean hydrogen-air fuel mixtures. Such burners could, for example, be used as oneAnalyzing and Tracking Burning Structures in Lean Premixed Hydrogen Flames P.-T. Bremer1, G. Weber2 of the temporal behavior. We demonstrate our approach by analyzing three numerical simulations of lean hydrogen

166

Real Time Flame Monitoring of Gasifier and Injectors  

SciTech Connect (OSTI)

This project is a multistage effort with the final goal to develop a practical and reliable nonintrusive gasifier injector monitor to assess burner wear and need for replacement. The project team included the National Energy Technology Laboratory (NETL), Gas Technology Institute (GTI), North Carolina State University, and ConocoPhillips. This report presents the results of the sensor development and testing initially at GTI combustion laboratory with natural gas flames, then at the Canada Energy Technology Center (CANMET), Canada in the atmospheric coal combustor as well as in the pilot scale pressurized entrained flow gasifier, and finally the sensor capabilities were demonstrated at the Pratt and Whitney Rocketdyne (PWR) Gasifier and the Wabash River Repowering plant located in West Terre Haute, IN. The initial tests demonstrated that GTI gasifier sensor technology was capable of detecting shape and rich/lean properties of natural gas air/oxygen enriched air flames. The following testing at the Vertical Combustor Research Facility (VCRF) was a logical transition step from the atmospheric natural gas flames to pressurized coal gasification environment. The results of testing with atmospheric coal flames showed that light emitted by excited OH* and CH* radicals in coal/air flames can be detected and quantified. The maximum emission intensities of OH*, CH*, and black body (char combustion) occur at different axial positions along the flame length. Therefore, the excitation rates of CH* and OH* are distinct at different stages of coal combustion and can be utilized to identify and characterize processes which occur during coal combustion such as devolatilization, char heating and burning. To accomplish the goals set for Tasks 4 and 5, GTI utilized the CANMET Pressurized Entrained Flow Gasifier (PEFG). The testing parameters of the PEFG were selected to simulate optimum gasifier operation as well as gasifier conditions normally resulting from improper operation or failed gasifier injectors. The sensor developed under previous tasks was used to assess the spectroscopic characteristics of the gasifier flame. The obtained spectral data were successfully translated into flame temperature measurements. It was also demonstrated that the reduced spectral data could be very well correlated with very important gasification process parameters such as the air/fuel and water/fuel ratio. Any of these parameters (temperature, air/fuel, and water/fuel) is sufficient to assess burner wear; however, the tested sensor was capable of monitoring all three of them plus the flame shape as functions of burner wear. This will likely be a very powerful tool which should enable significant improvements in gasifier efficiency, reliability, and availability. The sensor technology was presented to the projectâ??s industrial partner (ConocoPhillips). The partner expressed its strong interest in continuing to participate in the field validation phase of GTI's Flame Monitor Project. Finally the sensor was tested in the PWR (Pratt & Whitney Rocketdyne) gasification plant located at GTIâ??s research campus and at the ConocoPhillips industrial scale gasifier at Wabash River Indiana. The field trials of the GTI Gasifier sensor modified to withstand high temperature and pressure corrosive atmosphere of the industrial entrain flow gasifier. The project team successfully demonstrated the Gasifier Sensor system ability to monitor gasifier interior temperature maintaining unobstructed optical access for in excess of six week without any maintenance. The sensor examination upon completion of the trial revealed that the system did not sustain any damage and required minor cleanup of the optics.

Zelepouga, Serguei; Saveliev, Alexei

2011-12-31T23:59:59.000Z

167

Performance parameters of a liquid filled ionization chamber array  

SciTech Connect (OSTI)

Purpose: In this work, the properties of the two-dimensional liquid filled ionization chamber array Octavius 1000SRS (PTW-Freiburg, Germany) for use in clinical photon-beam dosimetry are investigated.Methods: Measurements were carried out at an Elekta Synergy and Siemens Primus accelerator. For measurements of stability, linearity, and saturation effects of the 1000SRS array a Semiflex 31013 ionization chamber (PTW-Freiburg, Germany) was used as a reference. The effective point of measurement was determined by TPR measurements of the array in comparison with a Roos chamber (type 31004, PTW-Freiburg, Germany). The response of the array with varying field size and depth of measurement was evaluated using a Semiflex 31010 ionization chamber as a reference. Output factor measurements were carried out with a Semiflex 31010 ionization chamber, a diode (type 60012, PTW-Freiburg, Germany), and the detector array under investigation. The dose response function for a single detector of the array was determined by measuring 1 cm wide slit-beam dose profiles and comparing them against diode-measured profiles. Theoretical aspects of the low pass properties and of the sampling frequency of the detector array were evaluated. Dose profiles measured with the array and the diode detector were compared, and an intensity modulated radiation therapy (IMRT) field was verified using the Gamma-Index method and the visualization of line dose profiles.Results: The array showed a short and long term stability better than 0.1% and 0.2%, respectively. Fluctuations in linearity were found to be within ±0.2% for the vendor specified dose range. Saturation effects were found to be similar to those reported in other studies for liquid-filled ionization chambers. The detector's relative response varied with field size and depth of measurement, showing a small energy dependence accounting for maximum signal deviations of ±2.6% from the reference condition for the setup used. The ?-values of the Gaussian dose response function for a single detector of the array were found to be (0.72 ± 0.25) mm at 6 MV and (0.74 ± 0.25) mm at 15 MV and the corresponding low pass cutoff frequencies are 0.22 and 0.21 mm{sup ?1}, respectively. For the inner 5 × 5 cm{sup 2} region and the outer 11 × 11 cm{sup 2} region of the array the Nyquist theorem is fulfilled for maximum sampling frequencies of 0.2 and 0.1 mm{sup ?1}, respectively. An IMRT field verification with a Gamma-Index analysis yielded a passing rate of 95.2% for a 3 mm/3% criterion with a TPS calculation as reference.Conclusions: This study shows the applicability of the Octavius 1000SRS in modern dosimetry. Output factor and dose profile measurements illustrated the applicability of the array in small field and stereotactic dosimetry. The high spatial resolution ensures adequate measurements of dose profiles in regular and intensity modulated photon-beam fields.

Poppe, B.; Stelljes, T. S.; Looe, H. K.; Chofor, N. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg 26121 (Germany)] [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg 26121 (Germany); Harder, D. [Prof. em., Medical Physics and Biophysics, Georg August University, Göttingen 37073 (Germany)] [Prof. em., Medical Physics and Biophysics, Georg August University, Göttingen 37073 (Germany); Willborn, K. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121 (Germany)] [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121 (Germany)

2013-08-15T23:59:59.000Z

168

THE EFFECTS OF FLAME TEMPERATURE, PARTICLE SIZE AND EUROPIUM DOPING CONCENTRATION ON THE PROPERTIES OF Y2O3:EU PARTICLES FORMED IN A FLAME AEROSOL PROCESS  

E-Print Network [OSTI]

ix LIST OF FIGURES FIGURE Page 1 Schematic of flame spray pyrolysis apparatus... 2 O 3 :Eu 9, 10 . A number of methods may be used to synthesize Y 2 O 3 :Eu particles, including colloidal methods 11-13 , combustion in fuel-oxidizer mixture 14 , evaporation? condensation 15, 16 , furnace spray pyrolysis 17 . Flame aerosol...

Yim, Hoon

2010-07-14T23:59:59.000Z

169

The BABAR Detector  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

BABAR Detector BABAR Detector This page provides background information on HEP detectors in general and the BaBar detector in particular. A Technical Introduction to Particle-Physics Experiments A particle physics experiment has two basic components: an accelerator and a detector. The particle accelerator's job is to produce the high-energy particles. It does this by taking a particle, speeding it up using electromagnetic fields, and crashing it into another particle. At first, only one or two high-energy particles are produced, but these soon decay to many more lower-energy particles, so you end up with lots of particles shooting out from the collision point. The detector's job is to record information about the particles. A typical particle detector consists of several subdetectors, each of which performs a different type of measurement. Particles from the collision pass through and interact with each subdetector, and the results are recorded.

170

A reversible time-of-flight detector for use in pseudocontinuous resonance enhanced multiphoton (pc-REMPI) detection  

SciTech Connect (OSTI)

A time-of-flight coincidence detector is demonstrated. This detector is optimized for use in a pseudocontinuous resonance enhanced multiphoton ionization scheme that requires photoelectrons and photoions to be detected in coincidence. The detector utilizes two simultaneously operating charged particle detectors, one for the detection of electrons and the other for the detection of ions. In order to allow for field reversal, the detectors are physically identical, differing only by the value of applied voltages. Particular attention is given to the implementation of a charge-to-voltage transducer that allows for subnanosecond detection of both electrons and ions.

McRaven, C. P.; Shafer-Ray, N. E. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019 (United States)

2011-02-15T23:59:59.000Z

171

Electron impact ionization of neutral and ionized fullerenes: ionization cross–sections and kinetic energy release  

Science Journals Connector (OSTI)

...and 1000 eV, with an energy spread of approximately...exit electrode by an electric field penetrating from...measurements of appearance energies and ionization cross-sections...measurements have been car- ried out (in both...cross-sections versus electron energy from threshold up to...

1999-01-01T23:59:59.000Z

172

Real Time Flame Monitoring of Gasifier Burner and Injectors  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

8 8 Gasification Technologies contacts Gary J. stiegel Gasification Technology Manager National Energy Technology Laboratory 626 Cochrans Mill Road P.O. Box 10940 Pittsburgh, PA 15236 412-386-4499 gary.stiegel@netl.doe.gov Jenny tennant Project Manager National Energy Technology Laboratory 3610 Collins Ferry Road P.O. Box 880 Morgantown, WV 26507 304-285-4830 jenny.tennant@netl.doe.gov David Rue Principal Investigator Gas Technology Institute 1700 South Mount Prospect Road Des Plaines, IL 60018 847-768-0508 david.rue@gastechnology.org Real Time Flame moniToRing oF gasiFieR BuRneR and injecToRs Description Combustion scientists and engineers have studied radiant emissions of various flames for many years. For some time, technologists have understood the rich potential for

173

High-pressure xenon detector development at Constellation Technology Corporation  

Science Journals Connector (OSTI)

Xenon-filled ionization detectors, due to their high atomic number fill gas (Z=54), moderate densities (?0.3–0.5 g/cm3) and good energy resolution (2–4% at 662 keV), fill an important niche between more familiar technologies such as NaI(Tl) scintillators and germanium detectors. Until recently, difficulties with obtaining sufficient xenon purity, reducing microphonic sensitivity, and developing low-noise electronics compatible with small ionization signals have hampered the development of this nuclear detection field. Constellation Technology Corporation, whose experience with xenon detectors goes back to the mid 1990s, has made significant progress in these areas and has developed a commercial line of detectors with active volumes ranging from small (35 g Xe) to large (1400 g Xe). Current applications for Constellation's detectors are principally in the area of defense (Unmanned Aerial Vehicles and Advanced Spectroscopic Portals), but as awareness of this technology grows, it will surely find applications in a much expanded range of fields.

Robert A. Austin

2007-01-01T23:59:59.000Z

174

Phonon Quasidiffusion in Cryogenic Dark Matter Search Large Germanium Detectors  

E-Print Network [OSTI]

We present results on quasidiffusion studies in large, 3 inch diameter, 1 inch thick [100] high purity germanium crystals, cooled to 50 mK in the vacuum of a dilution refrigerator, and exposed with 59.5 keV gamma-rays from an Am-241 calibration source. We compare data obtained in two different detector types, with different phonon sensor area coverage, with results from a Monte Carlo. The Monte Carlo includes phonon quasidiffusion and the generation of phonons created by charge carriers as they are drifted across the detector by ionization readout channels.

S. W. Leman; B. Cabrera; K. A. McCarthy; M. Pyle; R. Resch; B. Sadoulet; K. M. Sundqvist; P. L. Brink; M. Cherry; E. Do Couto E Silva; E. Figueroa-Feliciano; N. Mirabolfathi; B. Serfass; A. Tomada

2011-07-18T23:59:59.000Z

175

Fuel effects on flame lift-off under diesel conditions  

SciTech Connect (OSTI)

An apparent relation between the lift-off length under diesel conditions and the ignition quality of a fuel has previously been reported. To cast light on the underlying mechanism, the current study aims to separate flame lift-off effects of the chemical ignition delay from those of other fuel properties under diesel conditions. Flame lift-off was measured in an optical diesel engine by high-speed video imaging of OH-chemiluminescence. Fuel and ambient-gas properties were varied during the experiment. Only a weak correlation was found between ignition delay and lift-off length. The data indicate that this correlation is due to a common, stronger correlation with the ambient oxygen concentration. The chemical ignition delay and the fuel type had similar, weak effects on the lift-off length. A recently proposed mechanism for lift-off stabilization was used to interpret the results. It assumes that reactants approaching the lift-off position of the jet are mixed with high-temperature products found along the edges of the flame, which trigger autoignition. In this picture, the fuel effect is most likely due to differences in the amount of mixing with high-temperature products that is required for autoignition. In the current experiment, all lift-off effects seem to arise from variations in the reactant and product temperatures, induced by fuel and ambient properties. (author)

Persson, Helena; Andersson, Oeivind; Egnell, Rolf [Lund University (Sweden). Dept. of Energy Sciences

2011-01-15T23:59:59.000Z

176

Flame propagation enhancement by plasma excitation of oxygen. Part I: Effects of O{sub 3}  

SciTech Connect (OSTI)

The thermal and kinetic effects of O{sub 3} on flame propagation were investigated experimentally and numerically by using C{sub 3}H{sub 8}/O{sub 2}/N{sub 2} laminar lifted flames. Ozone produced by a dielectric barrier plasma discharge was isolated and measured quantitatively by using absorption spectroscopy. Significant kinetic enhancement by O{sub 3} was observed by comparing flame stabilization locations with and without O{sub 3} production. Experiments at atmospheric pressures showed an 8% enhancement in the flame propagation speed for 1260 ppm of O{sub 3} addition to the O{sub 2}/N{sub 2} oxidizer. Numerical simulations showed that the O{sub 3} decomposition and reaction with H early in the pre-heat zone of the flame produced O and OH, respectively, from which the O reacted rapidly with C{sub 3}H{sub 8} and produced additional OH. The subsequent reaction of OH with the fuel and fuel fragments, such as CH{sub 2}O, provided chemical heat release at lower temperatures to enhance the flame propagation speed. It was shown that the kinetic effect on flame propagation enhancement by O{sub 3} reaching the pre-heat zone of the flame for early oxidation of fuel was much greater than that by the thermal effect from the energy contained within O{sub 3}. For non-premixed laminar lifted flames, the kinetic enhancement by O{sub 3} also induced changes to the hydrodynamics at the flame front which provided additional enhancement of the flame propagation speed. The present results will have a direct impact on the development of detailed plasma-flame kinetic mechanisms and provided a foundation for the study of combustion enhancement by O{sub 2}(a{sup 1}{delta}{sub g}) in part II of this investigation. (author)

Ombrello, Timothy; Won, Sang Hee; Ju, Yiguang [Department of Mechanical and Aerospace Engineering, Engineering Quadrangle, Olden Street, Princeton, NJ 08544 (United States); Williams, Skip [Air Force Research Laboratory, Propulsion Directorate, 1950 Fifth Street, Wright-Patterson AFB, OH 45433 (United States)

2010-10-15T23:59:59.000Z

177

Turbulent Flame Speeds and NOx Kinetics of HHC Fuels with Contaminants and High Dilution Levels  

SciTech Connect (OSTI)

This final report documents the technical results of the 3-year project entitled, “Turbulent Flame Speeds and NOx Kinetics of HHC Fuels with Contaminants and High Dilution Levels,” funded under the NETL of DOE. The research was conducted under six main tasks: 1) program management and planning; 2) turbulent flame speed measurements of syngas mixtures; 3) laminar flame speed measurements with diluents; 4) NOx mechanism validation experiments; 5) fundamental NOx kinetics; and 6) the effect of impurities on NOx kinetics. Experiments were performed using primary constant-volume vessels for laminar and turbulent flame speeds and shock tubes for ignition delay times and species concentrations. In addition to the existing shock- tube and flame speed facilities, a new capability in measuring turbulent flame speeds was developed under this grant. Other highlights include an improved NOx kinetics mechanism; a database on syngas blends for real fuel mixtures with and without impurities; an improved hydrogen sulfide mechanism; an improved ammonia kintics mechanism; laminar flame speed data at high pressures with water addition; and the development of an inexpensive absorption spectroscopy diagnostic for shock-tube measurements of OH time histories. The Project Results for this work can be divided into 13 major sections, which form the basis of this report. These 13 topics are divided into the five areas: 1) laminar flame speeds; 2) Nitrogen Oxide and Ammonia chemical kinetics; 3) syngas impurities chemical kinetics; 4) turbulent flame speeds; and 5) OH absorption measurements for chemical kinetics.

Peterson, Eric; Krejci, Michael; Mathieu, Olivier; Vissotski, Andrew; Ravi, Sankat; Plichta, Drew; Sikes, Travis; Levacque, Anthony; Camou, Alejandro; Aul, Christopher

2013-09-30T23:59:59.000Z

178

E-Print Network 3.0 - atomic-absorption flame photometry Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic-absorption flame photometry Page: << < 1 2 3 4 5 > >> 1 MICROCHEMICALJOURNAL33,304-...

179

IGNITION PROCESSES AND FLAME SPREADING IN A GRANULAR SOLID PROPELLANT BED.  

E-Print Network [OSTI]

??Understanding the detailed ignition, flame spreading, and combustion processes inside of a granular solid propellant bed is vital for accurate internal ballistic modeling and development… (more)

Colletti, Alexander

2010-01-01T23:59:59.000Z

180

E-Print Network 3.0 - advanced flame quality Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

paper overviews the dynamics of bluff body... stabilized flames and describes the phenomenology of the blowoff process. The first section of the paper Source: Lieuwen, Timothy C....

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Detectors (5/5)  

ScienceCinema (OSTI)

This lecture will serve as an introduction to particle detectors and detection techniques. In the first lecture, a historic overview of particle detector development will be given. In the second lecture, some basic techniques and concepts for particle detection will be discussed. In the third lecture, the interaction of particles with matter, the basis of particle detection, will be presented. The fourth and fifth lectures will discuss different detector types used for particle tracking, energy measurement and particle identification.

None

2011-10-06T23:59:59.000Z

182

Detectors (4/5)  

ScienceCinema (OSTI)

This lecture will serve as an introduction to particle detectors and detection techniques. In the first lecture, a historic overview of particle detector development will be given. In the second lecture, some basic techniques and concepts for particle detection will be discussed. In the third lecture, the interaction of particles with matter, the basis of particle detection, will be presented. The fourth and fifth lectures will discuss different detector types used for particle tracking, energy measurement and particle identification.

None

2011-10-06T23:59:59.000Z

183

Lesson 4 - Ionizing Radiation | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

4 - Ionizing Radiation 4 - Ionizing Radiation Lesson 4 - Ionizing Radiation Lesson Three showed that unstable isotopes emit energy as they become more stable. This energy is known as radiation. This lesson explores forms of radiation, where radiation is found, how we detect and measure radiation, what sources of radiation people are exposed to, whether radiation is harmful, and how we can limit our exposure. Specific topics covered in this lesson include: Types of radiation Non-ionizing Ionizing Forms of ionizing radiation Alpha particles Beta particles Gamma rays Radiation Decay chain Half-life Dose Radiation measurements Sources of radiation Average annual exposure Lesson 4 - Ionizing Radiation.pptx More Documents & Publications DOE-HDBK-1130-2008 DOE-HDBK-1130-2008 DOE-HDBK-1130-2007

184

Adaptors for radiation detectors  

DOE Patents [OSTI]

Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

Livesay, Ronald Jason

2014-04-22T23:59:59.000Z

185

Effects of Combustor Geometry on the Flowfields and Flame Properties of A  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Effects of Combustor Geometry on the Flowfields and Flame Properties of A Effects of Combustor Geometry on the Flowfields and Flame Properties of A Low-Swirl Injector Title Effects of Combustor Geometry on the Flowfields and Flame Properties of A Low-Swirl Injector Publication Type Journal Article Year of Publication 2008 Authors Cheng, Robert K., and David Littlejohn Journal Proceedings of the Combustion Institute Type of Article Conference Paper Abstract The Low-swirl injector (LSI) is a novel dry-low NOx combustion method that is being developed for gas turbines to burn a variety of gaseous fuels including natural gas, low-Btu fuels, syngases and hydrogen. Its basic principle is described by a top level analytical model that relates the flame position to the flowfield similarity parameters and the turbulent flame speed correlation. The model was based on experimental measurements in open laboratory flames. It has been useful for guiding hardware development. As the LSI is being adapted to different engine configurations, one open question is how the combustor geometry and size affect its basic operating principle. The objective of this paper is to investigate these effects by conducting Particle Image Velocimetry (PIV) measurements in open and enclosed flames produced by a 6.35 cm diameter LSI using two quartz cylinders of 15.5 and 20 cm diameter to simulate the combustor casing. Results from 18 methane-air flames show that the enclosures do not alter the flame properties or the nearfield flow structures. The differences occur mostly in the farfield where the tighter enclosure deters the formation of a weak recirculation zone. The enclosure effects on hydrogen and hydrogen-methane flames were studies using the 20 cm cylinder. The results show that the outer recirculation zone generated at the corner of the dump plane promotes the formation of attached flames. However, the properties and nearfield flow features of the attached flames are similar to those of the lifted flames. At higher stoichiometries, the attached flame collapses to form a compact disc shaped flame that has very different flowfield structures. These results show that the enclosure effects on the LSI are strongly coupled to the fuel type and dump plane geometry but are less dependent on the enclosure size. These observations will provide the basis for developing computational methods that can be used as design tools for LSI adaptation

186

Investigation of the nonlinear response of turbulent premixed flames to imposed inlet velocity oscillations  

SciTech Connect (OSTI)

Acoustically forced lean premixed turbulent bluff-body stabilized flames are investigated using turbulent combustion CFD. The calculations simulate aspects of the experimental investigation by Balachandran et al. [R. Balachandran, B. Ayoola, C. Kaminski, A. Dowling, E. Mastorakos, Combust. Flame 143 (2005) 37-55] and focus on the amplitude dependence of the flame response. For the frequencies of interest in this investigation an unsteady Reynolds-averaged Navier-Stokes (URANS) approach is appropriate. The combustion is represented using a modified laminar flamelet approach with an algebraic representation of the flame surface density. The predictions are compared with flame surface density (FSD) and OH* chemiluminescence measurements. In the experiments the response of the flame has been quantified by means of a number of single-frequency, amplitude-dependent transfer functions. The predicted flame shape and position are in good agreement with the experiment. The dynamic response of the flame to inlet velocity forcing is also well captured by the calculations. At moderate frequencies nonlinear behavior of the transfer functions is observed as the forcing amplitude is increased. In the experiments this nonlinearity was attributed in part to the rollup of the reacting shear layer into vortices and in part to the collision of the inner and outer flame sheets. This transition to nonlinearity is also observed in the transfer functions obtained from the predictions. Furthermore, the vortex shedding and flame-sheet collapse may be seen in snapshots of the predicted flow field taken throughout the forcing cycle. The URANS methodology successfully predicts the behavior of the forced premixed turbulent flames and captures the effects of saturation in the transfer function of the response of the heat release to velocity fluctuations. (author)

Armitage, C.A.; Mastorakos, E.; Cant, R.S. [Department of Engineering, Trumpington Street, University of Cambridge, Cambridge, CB2 1PZ (United Kingdom); Balachandran, R. [Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE (United Kingdom)

2006-08-15T23:59:59.000Z

187

Effects of fuel type and equivalence ratios on the flickering of triple flames  

SciTech Connect (OSTI)

An experimental study has been conducted in axisymmetric, co-flowing triple flames with different equivalence ratios of the inner and outer reactant streams (2<{phi}{sub in}<3 and 0{<=}{phi}{sub out}<0.7). Different fuel combinations, like propane/propane, propane/methane or methane/methane in the inner and outer streams respectively, have been used in the experiments. The structures of the triple flames have been compared for the different fuel combinations and equivalence ratios. The conditions under which triple flames exhibit oscillation have been identified. During the oscillation, the non-premixed flame and the outer lean premixed flame flicker strongly, while the inner rich premixed flame remains more or less stable. The flickering frequency has been evaluated through image processing and fast Fourier transform (FFT) of the average pixel intensity of the image frames. It is observed that, for all the fuel combinations, the frequency decreases with the increase in the outer equivalence ratio, while it is relatively invariant with the change in the inner equivalence ratio. However, an increase in the inner equivalence ratio affects the structure of the flame by increasing the heights of the inner premixed flame and non-premixed flame and also enlarges the yellow soot-laden zone at the tip of the inner flame. A scaling analysis of the oscillating flames has been performed based on the measured parameters, which show a variation of Strouhal number (St) with Richardson number (Ri) as St {proportional_to} Ri{sup 0.5}. The fuel type is found to have no influence on this correlation. (author)

Sahu, K.B.; Kundu, A.; Ganguly, R.; Datta, A. [Department of Power Engineering, Jadavpur University, Salt Lake Campus, Kolkata 700098 (India)

2009-02-15T23:59:59.000Z

188

Determinations of Carbon Dioxide and Methane by Dual Catalyst Flame Ionization Chromatography and Nitrous Oxide by Electron Capture Chromatography  

Science Journals Connector (OSTI)

......equilibrate with atmospheric pressure through...applications involving atmospheric analyses, the instrument...electrolytically from distilled water by a General Electric...Massachusetts) hydrogen generator. The gas is further...the analysis. The water formed by the palladium...737-1-B "clean air generator," a preparative......

Ray F. Weiss

1981-12-01T23:59:59.000Z

189

Determinations of Carbon Dioxide and Methane by Dual Catalyst Flame Ionization Chromatography and Nitrous Oxide by Electron Capture Chromatography  

Science Journals Connector (OSTI)

......reduced by introducing additional fuel hydrogen before the palladium...smaller sample size is that the consumption of standards in long-term...1979 aboard the Research Vessel Wecoma during Leg 9 of the...because of its low rate of consumption of standard gases, but also......

Ray F. Weiss

1981-12-01T23:59:59.000Z

190

Determination of Free Amino Compounds in Betalainic Fruits and Vegetables by Gas Chromatography with Flame Ionization and Mass Spectrometric Detection  

Science Journals Connector (OSTI)

Bright Lights] petioles and red and yellow beets (B. vulgaris L. ssp. ... Burpee's Golden, Chenopodiaceae) were sown in May 2004 in the Experimental Station for Horticulture of Hohenheim University, and fully developed hypocotyls were harvested in July 2004. ... (>40 °C), but more stable at 40 °C with the exclusion of light and air. ...

Florian Kugler; Stephan Graneis; Pat P.-Y. Schreiter; Florian C. Stintzing; Reinhold Carle

2006-05-19T23:59:59.000Z

191

The Analysis of Hydrocarbon Types — Saturates, Aromatics and Olefins—by Selective Chemical Absorption and Flame Ionization Detection  

Science Journals Connector (OSTI)

......n-heptane calibration; (2).--Synthetic gasoline; (3).--Commercial gasoline; (4).--Propylene. ; 2 1 capacity packed...samples were prepared from a dearomatized straight run gasoline (S), a polymerization gasoline (0) containing......

Nestor L. Soulages; Antonio M. Brieva

1971-08-01T23:59:59.000Z

192

Making a Low-Cost Soda Can Ethanol Burner for Out-of-Laboratory Flame Test Demonstrations and Experiments  

Science Journals Connector (OSTI)

Making a Low-Cost Soda Can Ethanol Burner for Out-of-Laboratory Flame Test Demonstrations and Experiments ... Video clips for the three flame tests shown in Figure 3, and for turning the burner on and off. ...

Henson L. Lee Yu; Perfecto N. Domingo, Jr.; Elliard Roswell S. Yanza; Armando M. Guidote, Jr.

2014-10-13T23:59:59.000Z

193

THE IMPACT OF VARIOUS OXIDIZERS ON THE OVERALL PERFORMACE OF A DIRECT FLAME SOLID OXIDE FUEL CELL.  

E-Print Network [OSTI]

??The power output of a direct-flame solid oxide fuel cell (SOFC) was studied using hydrogen (H2) as the fuel for the flame and various oxidizers,… (more)

Donadio, Nicholas

2010-01-01T23:59:59.000Z

194

Speciated Engine-Out Organic Gas Emissions from a PFI-SI Engine Operating on Ethanol/Gasoline Mixtures  

E-Print Network [OSTI]

Engine-out HC emissions from a PFI spark ignition engine were measured using a gas chromatograph and a flame ionization detector (FID). Two port fuel injectors were used respectively for ethanol and gasoline so that the ...

Kar, Kenneth

195

A COMPARATIVE STUDY OF THE FORMATION OF AROMATICS IN RICH METHANE FLAMES DOPED BY UNSATURATED COMPOUNDS  

E-Print Network [OSTI]

unsaturated hydrocarbons: allene and propyne, because they are precursors of propargyl radicals which are well as the background gas makes these flames more representative of the combustion of a real fuel compared to a flame by passing through a single pass heat exchanger [14]. Temperature profiles were obtained using a PtRh 3 hal

Boyer, Edmond

196

Large eddy simulation of one diffusion swirling flame European Combustion Meeting 2011  

E-Print Network [OSTI]

.5 7200 75900 Numerical method This research use large eddy simulation (LES) in software ANASYS FLUENT Simulations of Swirling Non-premixed Flames With Flamelet Models: A Comparison of Numerical Methods. FlowLarge eddy simulation of one diffusion swirling flame European Combustion Meeting 2011 Introduction

Berning, Torsten

197

Combustion and Flame 156 (2009) 771779 Contents lists available at ScienceDirect  

E-Print Network [OSTI]

Combustion and Flame 156 (2009) 771­779 Contents lists available at ScienceDirect Combustion Cylindrical chamber Flow correction Hydrogen Syngas High pressure The effect of nonspherical (i.e. cylindrical are measured for hydrogen and syngas mixtures at atmospheric and elevated pressures. Flow-corrected flame

Ju, Yiguang

198

Kinetic effects of non-equilibrium plasma-assisted methane oxidation on diffusion flame extinction limits  

E-Print Network [OSTI]

. The prod- ucts of plasma assisted CH4 oxidation were measured using the Two-photon Absorption Laser to understand the role of plasma generated species on ignition, flame speed, and flame stabilization. For ignition studies, the reduction of ignition delay time by non-equilibrium nanosecond pulsed discharges

Ju, Yiguang

199

Sample Desorption/Ionization From Mesoporous Silica  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sample Desorption/Ionization From Mesoporous Silica Sample Desorption/Ionization From Mesoporous Silica Sample Desorption/Ionization From Mesoporous Silica Mesoporous silica is shown to be a sample holder for laser desorption/ionization of mass spectrometry. Available for thumbnail of Feynman Center (505) 665-9090 Email Sample Desorption/Ionization From Mesoporous Silica Mesoporous silica is shown to be a sample holder for laser desorption/ionization of mass spectrometry. Supported mesoporous silica was prepared by coating an ethanolic silicate solution having a removable surfactant onto a substrate to produce a self-assembled, ordered, nanocomposite silica thin film. The surfactant was chosen to provide a desired pore size between about 1 nanometer diameter and 50 nanometers diameter. Removal of the surfactant resulted in a mesoporous silica thin

200

Scalar dissipation rate based flamelet modelling of turbulent premixed flames  

E-Print Network [OSTI]

curves of ??+ vs N+c conditioned on the progress variable ? for three cases: (a) methane–air, ? = 0.6, Le = 0.96, (b) propane–air, ? = 0.8, Le = 1.83 and (c) methane–air, ? = 1.4, Le = 1.17 . The ? = 0.7 curve for the propane–air case is shown in (d... closure for two mixtures: stoichiometric methane–air with K = 1.0 (•) and lean propane–air with KLe = 1.0 (?). The experimental data of Abdel- Gayed et al. (1987) for K = 1.0 are also shown (?). . . . . . . . . 111 7.9 The comparisons of flame speeds...

Kolla, Hemanth

2010-03-16T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Metal rich stars in omega Cen: preliminary FLAMES GTO results  

E-Print Network [OSTI]

I present preliminary results for a sample of ~700 red giants in omega Cen, observed during the Ital-FLAMES Consortium GTO time in May 2003, for the Bologna Project on omega Cen. Preliminary Fe and Ca abundances confirm previous results: while the metal-poor and intermediate populations show a normal halo alpha-enhancement of [alpha/Fe]=$+0.3, the most metal-rich stars show a significantly lower [alpha/Fe]=+0.1. If the metal-rich stars have evolved within the cluster in a process of self-enrichment, the only way to lower their alpha-enhancement would be SNe type Ia intervention.

Pancino, E

2004-01-01T23:59:59.000Z

202

Metal rich stars in omega Cen: preliminary FLAMES GTO results  

E-Print Network [OSTI]

I present preliminary results for a sample of ~700 red giants in omega Cen, observed during the Ital-FLAMES Consortium GTO time in May 2003, for the Bologna Project on omega Cen. Preliminary Fe and Ca abundances confirm previous results: while the metal-poor and intermediate populations show a normal halo alpha-enhancement of [alpha/Fe]=$+0.3, the most metal-rich stars show a significantly lower [alpha/Fe]=+0.1. If the metal-rich stars have evolved within the cluster in a process of self-enrichment, the only way to lower their alpha-enhancement would be SNe type Ia intervention.

E. Pancino

2004-10-28T23:59:59.000Z

203

Polybrominated diphenyl ether flame retardants in the antarctic environment  

E-Print Network [OSTI]

, the historical record of dioxins, PCBs and DDTs in the same cores showed a decreasing trend. At present, PBDEs are recognized as a worldwide pollution problem since they have reached remote areas such as the deep ocean, the Arctic and Antarctica (de Boer et al... that cheerful and warm Brazilian spirit. You are my Aggie family! viii NOMENCLATURE #1; critical value of a statistical test used to reject the null hypothesis ANOVA Analysis of Variance BDE Brominated Diphenyl Ether BFR Brominated Flame Retardant DC...

Yogui, Gilvan Takeshi

2009-05-15T23:59:59.000Z

204

An analytical model for flame propagation in low-Mach-number, variable-density flow  

SciTech Connect (OSTI)

Flame propagation is relevant in many practical applications involving heat transfer and the conversion of heat into mechanical work. Examples of such applications include spark-ignition engines, turbojets, ramjets, afterburners and rockets, although these devices may exhibit nonlocal and nonpropagating combustion phenomena as well. Here, a simple model problem is formulated to describe the coupling between premixed-flame and flow-field dynamics resulting from gas expansion within the flame. The energy conservation equation is integrated analytically across the flame in order to reduce the number of governing equations for the computational problem. A system of six equations and associated boundary conditions are formulated for computation of the time evolution of an initially prescribed three-dimensional velocity field and the flame surface.

Aldredge, R.C. [Univ. of California, Davis, CA (United States). Dept. of Mechanical and Aeronautical Engineering] [Univ. of California, Davis, CA (United States). Dept. of Mechanical and Aeronautical Engineering

1997-12-01T23:59:59.000Z

205

Dynamics of premixed flames in a narrow channel with a step-wise wall temperature  

SciTech Connect (OSTI)

The effect of channel height, inflow velocity and wall temperature on the dynamics and stability of unity Lewis number premixed flames in channels with specified wall temperature is investigated with steady and transient numerical simulations using a two-dimensional thermo-diffusive model. The simplified model is capable of capturing many of the transitions and the combustion modes observed experimentally and in direct numerical simulations in micro- and meso-scale channels, and indicates that the thermal flame/wall interaction is the mechanism leading to the observed flame instabilities. Finally, an ad-hoc one-dimensional model based on the flame-sheet approximation is tested in its capacity to reproduce some of the flame dynamics of the two-dimensional thermo-diffusive model. (author)

Kurdyumov, Vadim N. [Department of Energy, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Pizza, Gianmarco [Aerothermochemistry and Combustion Systems Laboratory, Swiss Federal Institute of Technology, Zurich CH-8092 (Switzerland); Combustion Research, Paul Scherrer Institute, Villigen CH-5232 (Switzerland); Frouzakis, Christos E. [Aerothermochemistry and Combustion Systems Laboratory, Swiss Federal Institute of Technology, Zurich CH-8092 (Switzerland); Mantzaras, John [Combustion Research, Paul Scherrer Institute, Villigen CH-5232 (Switzerland)

2009-11-15T23:59:59.000Z

206

Characterization of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion  

SciTech Connect (OSTI)

This study details the characterization and implementation of a burner designed to simulate solid propellant fires. The burner was designed with the ability to introduce particles (particularly aluminum) into a gas flame. The aluminized flame conditions produced by this burner are characterized based on temperature and heat flux measurements. Using these results, flame conditions are quantified in comparison to other well-characterized reactions including hydrocarbon and propellant fires. The aluminized flame is also used to measure the burning rate of the particles. This work describes the application of this burner for re-creating small-scale propellant flame conditions and as a test platform for experiments that contribute to the development of a particle combustion model, particularly in propellant fires. (author)

Jackson, Matt [Engineering Department, West Texas A and M University, Canyon, TX 79016 (United States); Pantoya, Michelle L. [Mechanical Engineering Department, Texas Tech University, Lubbock, TX 79409 (United States); Gill, Walt [Sandia National Laboratories, Albuquerque, NM 87185 (United States)

2008-04-15T23:59:59.000Z

207

Effects of copper catalytic reactions on the development of supersonic hydrogen flames  

SciTech Connect (OSTI)

Copper species are present in hydrogen flames in arc heated supersonic ramjet testing facilities. Homogeneous and heterogeneous copper catalytic reactions may affect the flame development by enhancing the recombination of hydrogen atoms. Computer simulation is used to investigate the effects of the catalytic reactions on the reaction and ignition times of the flames. The simulation uses a modified general chemical kinetics computer program to simulate the development of copper-contaminated hydrogen flames under scramjet testing conditions. Reaction times of hydrogen flames are found to be reduced due to the copper catalytic effects, but ignition times are much less sensitive to such effects. The reduction of reaction time depends on copper concentration, particle size (if copper is in the condensed phase), and Mach number (or initial temperature and pressure). As copper concentration increases or the particle size decreases, reaction time decreases. As Mach number increases (or pressure and temperature decrease), the copper catalytic effects are greater.

Chang, S.L.; Lottes, S.A.; Berry, G.F.

1992-10-01T23:59:59.000Z

208

Ionization probes of molecular structure and chemistry  

SciTech Connect (OSTI)

Various photoionization processes provide very sensitive probes for the detection and understanding of the spectra of molecules relevant to combustion processes. The detection of ionization can be selective by using resonant multiphoton ionization or by exploiting the fact that different molecules have different sets of ionization potentials. Therefore, the structure and dynamics of individual molecules can be studied even in a mixed sample. The authors are continuing to develop methods for the selective spectroscopic detection of molecules by ionization, and to use these methods for the study of some molecules of combustion interest.

Johnson, P.M. [State Univ. of New York, Stony Brook (United States)

1993-12-01T23:59:59.000Z

209

WOLTE_8 Abstract -Workshop on Low Temperature Electronics -June 22-25, 2008 CMOS Charge amplifier for liquid argon Time Projection Chamber detectors  

E-Print Network [OSTI]

, on a system of wires at the sides of the detector, the electric charges from the ionization losses Charge) with a detector capacitance of 250pF. The distribution of charges collected by the wires which decreases with temperature. However, the circuit should dissipate as little heat as possible

Boyer, Edmond

210

Reaction Mechanism in an lonization Detector with Tunable Selectivity for Carbon, Nitrogen and Phosphorus  

Science Journals Connector (OSTI)

......in this detector will obviously need a red-glowing metal surface for further ionization...In this way it is possible to investi- gate independently the influence of the hydrogen...1975). 5. R. Greenhalch and P.J. Wood. /. Chromatog. 82: 410 (1973). 6......

B. Kolb; M. Auer; P. Pospisil

1977-02-01T23:59:59.000Z

211

LET Estimation of Heavy Ion Particles based on a Timepix-Based Si Detector  

E-Print Network [OSTI]

of ionizing radiation as expressed in dosimetric endpoints such as Dose-equivalent. Pixel detectors from the raw Timepix outputs. Dose is defined as the energy deposited by a source of radiation per unit of the dose caused by a particular type of particle for radiation protection purposes. To calculate the Dose

Vilalta, Ricardo

212

A Novel Detector Design for Imaging Low-Intensity Diffuse Ion Beams  

E-Print Network [OSTI]

A Novel Detector Design for Imaging Low- Intensity Diffuse Ion Beams J. Schmidt, R. de Souza, S for signal processing To image the beam scintillating fibers are used. Ionizing particles, when incident readouts for each dimension. Right: example of a beam profile. Above: EZ10EN drive electronics to control

de Souza, Romualdo T.

213

Statistical errors in the fractal analysis of flame boundaries  

SciTech Connect (OSTI)

A high speed tomographic technique is used to evaluate the effect of spatial resolution, and requirements for statistical convergence on the fractal analysis of a turbulent, premixed, stoichiometric methane/air flame at high Damkoehler number. The gas velocity at the nozzle exit is 5 m/s, the turbulence intensity is 7%, the integral length scale 3 mm and hence the turbulence Reynolds number is 70. The light source is a copper vapor laser which produces 20ns, 5 mJ pulses at a 4KHz repetition rate. Cylindrical lenses transform the 38mm circular laser beam to a sheet 50 mm high and 0.6 mm thick. A high speed Fastax camera is used to record the tomographic images formed by the scattering of light from oil droplets seeded in the reactant flow. The films are digitized and the flame front extracted from the images by a thresholding technique. Digitization noise, which appears in the fractal plots at approximately twice the pixel resolution, can obscure the inner cutoff. Simple smoothing can remove this problem if the spatial resolution is sufficient. At insufficient resolution smoothing produces plausible resolutes are produced which in fact erroneous. If the inner cutoff is ambiguous the range over which the fractal dimension is determined will be unclear. The wide distribution of fractal dimensions obtained from the individual images indicates the necessity of ensemble averaging the fractal plots if reliable statistical results are to be obtained. 8 refs., 6 figs.

Shepherd, I.G.; Cheng, R.K.

1990-10-01T23:59:59.000Z

214

Flame–vortex interaction in a reacting vortex ring  

Science Journals Connector (OSTI)

Direct numerical simulations are used to study the flame–vortex interaction in a laminar reacting vortex ring. The chemical reaction occurs by a one-step Arrhenius-type reaction that mimics the combustion of typical hydrocarbon and air. The ring is generated by an axisymmetric jet that is impulsed to emit a cold fuel through a nozzle. The fuel enters a quiescent ambient at a much higher temperature. By adjusting the ratio of the ambient and fuel temperatures the ignition either occurs during the formation or post-formation phase of the ring. When ignition occurs during the formation phase of the ring the bulk of combustion is by a flame at the front of the vortex bubble. When ignition is delayed until after the formation phase most of the reaction occurs inside the vortex ring. It is found that premixing the fuel and the oxidizer enhances the amount of product formation. The heat released from the reaction significantly affects production redistribution and diffusion of the vorticity throughout the field. The results of the simulations also reveal that the heat of reaction affects the strain rate fields differently depending on when the ignition of the ring occurs.

J. S. Hewett; C. K. Madnia

1998-01-01T23:59:59.000Z

215

Pocket formation and the flame surface density equation  

SciTech Connect (OSTI)

The occurrence and properties of singularities in the equation for the surface density function {sigma} {triple_bond}{vert_bar}{del}{Phi}{vert_bar} are analyzed analytically and numerically using data from two dimensional direct numerical simulation (DNS) of pocket formation in a premixed methane-air flame. The various stages and the relevant time scales associated with pocket formation were determined in a previous study. It was found that isolated pockets form if and only if a nondegenerate critical point of a saddle point type appears. The appearance of a singularity in the isoline representing the flame front may have implications to modeling of the terms in the surface density function (sdf) approach during such transient events as pocket formation. The sink and source terms in sdf are evaluated in the neighborhood of a critical point using DNS data during pocket formation, and an analytic representation of a scalar in the vicinity of the critical point which allows for the computation of all kinematic properties. The analytic and computational results show that the normal restoration and dissipation terms in the sdf become singular at the critical point when the pocket emerges. Furthermore, the analytic results show that the singularities exactly cancel, and therefore, the main conclusion is that it is unnecessary to model the singular behavior of these terms at critical points. However, closure of their sum is recommended.

Kollman, W. [Univ. of California, Davis, CA (United States); Chen, J.H. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility

1998-03-01T23:59:59.000Z

216

A model of particle nucleation in premixed ethylene flames  

SciTech Connect (OSTI)

A detailed model of particle inception is proposed to delve into the physical structure and chemistry of combustion-formed particles. A sectional method is used, from a previously developed kinetic mechanism of particle formation with a double discretization of the particle phase in terms of C and H atom number. The present model also distinguishes between different particle structures based on their state of aggregation; single high molecular mass molecules, cluster of molecules and aggregates of clusters. The model predicts the mass of particles, hydrogen content and internal structure. It represents a first approach in following the chemical evolution and internal structure of the particles formed in flames, coupled with the main pyrolysis and oxidation of the fuel. The model is tested in atmospheric premixed flat flames of ethylene and the effect of fuel equivalence ratio on particle morphology is analyzed. Molecular weight growth of aromatic compounds and the inception of particles are predicted. The morphology of the particles and the number of molecules in the clusters at particle inception are also indicated. (author)

D'Anna, Andrea; Sirignano, Mariano [Dipartimento di Ingegneria Chimica, Universita di Napoli ''Federico II'', Napoli (Italy); Kent, John [School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney (Australia)

2010-11-15T23:59:59.000Z

217

Preliminary results of a WIMP search with EDELWEISS-II cryogenic detectors  

E-Print Network [OSTI]

The EDELWEISS-II experiment uses cryogenic heat-and-ionization detectors in order to detect the rare interactions from possible WIMP dark matter particles on Germanium nuclei. Recently, new-generation detectors with an interleaved electrode geometry were developped and validated, enabling an outstanding rejection of gamma-rays and surface interactions. We present here preliminary results of a one-year WIMP search carried out with ten of such detectors in the Laboratoire Souterrain de Modane. A sensitivity to the spin-independent WIMP-nucleon cross-section of 5 \\times 10-8 pb was achieved using a 322 kg

E. Armengaud; for the EDELWEISS collaboration

2010-11-10T23:59:59.000Z

218

Space-based detectors  

Science Journals Connector (OSTI)

The parallel session C5 on Space-Based Detectors gave a broad overview over the planned space missions related to gravitational wave detection. Overviews of the revolutionary science to be expected from LISA was ...

A. Sesana; W. J. Weber; C. J. Killow…

2014-11-01T23:59:59.000Z

219

Pocked surface neutron detector  

DOE Patents [OSTI]

The detection efficiency, or sensitivity, of a neutron detector material such as of Si, SiC, amorphous Si, GaAs, or diamond is substantially increased by forming one or more cavities, or holes, in its surface. A neutron reactive material such as of elemental, or any compound of, .sup.10 B, .sup.6 Li, .sup.6 LiF, U, or Gd is deposited on the surface of the detector material so as to be disposed within the cavities therein. The portions of the neutron reactive material extending into the detector material substantially increase the probability of an energetic neutron reaction product in the form of a charged particle being directed into and detected by the neutron detector material.

McGregor, Douglas (Whitmore Lake, MI); Klann, Raymond (Bolingbrook, IL)

2003-04-08T23:59:59.000Z

220

Modular optical detector system  

DOE Patents [OSTI]

A modular optical detector system. The detector system is designed to detect the presence of molecules or molecular species by inducing fluorescence with exciting radiation and detecting the emitted fluorescence. Because the system is capable of accurately detecting and measuring picomolar concentrations it is ideally suited for use with microchemical analysis systems generally and capillary chromatographic systems in particular. By employing a modular design, the detector system provides both the ability to replace various elements of the detector system without requiring extensive realignment or recalibration of the components as well as minimal user interaction with the system. In addition, the modular concept provides for the use and addition of a wide variety of components, including optical elements (lenses and filters), light sources, and detection means, to fit particular needs.

Horn, Brent A. (Livermore, CA); Renzi, Ronald F. (Tracy, CA)

2006-02-14T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Ultrafast neutron detector  

DOE Patents [OSTI]

A neutron detector of very high temporal resolution is described. It may be used to measure distributions of neutrons produced by fusion reactions that persist for times as short as about 50 picoseconds.

Wang, C.L.

1985-06-19T23:59:59.000Z

222

Flexible Composite Radiation Detector  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Flexible Composite Radiation Detector Flexible Composite Radiation Detector Flexible Composite Radiation Detector A flexible composite scintillator was prepared by mixing fast, bright, dense rare-earth doped powdered oxyorthosilicate (such as LSO:Ce, LSO:Sm, and GSO:Ce) scintillator with a polymer binder. Available for thumbnail of Feynman Center (505) 665-9090 Email Flexible Composite Radiation Detector A flexible composite scintillator was prepared by mixing fast, bright, dense rare-earth doped powdered oxyorthosilicate (such as LSO:Ce, LSO:Sm, and GSO:Ce) scintillator with a polymer binder. The binder is transparent to the scintillator emission. The composite is seamless and can be made large and in a wide variety of shapes. Importantly, the composite can be tailored to emit light in a spectral region that matches the optimum

223

Understanding and predicting soot generation in turbulent non-premixed jet flames.  

SciTech Connect (OSTI)

This report documents the results of a project funded by DoD's Strategic Environmental Research and Development Program (SERDP) on the science behind development of predictive models for soot emission from gas turbine engines. Measurements of soot formation were performed in laminar flat premixed flames and turbulent non-premixed jet flames at 1 atm pressure and in turbulent liquid spray flames under representative conditions for takeoff in a gas turbine engine. The laminar flames and open jet flames used both ethylene and a prevaporized JP-8 surrogate fuel composed of n-dodecane and m-xylene. The pressurized turbulent jet flame measurements used the JP-8 surrogate fuel and compared its combustion and sooting characteristics to a world-average JP-8 fuel sample. The pressurized jet flame measurements demonstrated that the surrogate was representative of JP-8, with a somewhat higher tendency to soot formation. The premixed flame measurements revealed that flame temperature has a strong impact on the rate of soot nucleation and particle coagulation, but little sensitivity in the overall trends was found with different fuels. An extensive array of non-intrusive optical and laser-based measurements was performed in turbulent non-premixed jet flames established on specially designed piloted burners. Soot concentration data was collected throughout the flames, together with instantaneous images showing the relationship between soot and the OH radical and soot and PAH. A detailed chemical kinetic mechanism for ethylene combustion, including fuel-rich chemistry and benzene formation steps, was compiled, validated, and reduced. The reduced ethylene mechanism was incorporated into a high-fidelity LES code, together with a moment-based soot model and models for thermal radiation, to evaluate the ability of the chemistry and soot models to predict soot formation in the jet diffusion flame. The LES results highlight the importance of including an optically-thick radiation model to accurately predict gas temperatures and thus soot formation rates. When including such a radiation model, the LES model predicts mean soot concentrations within 30% in the ethylene jet flame.

Wang, Hai (University of Southern California, Los Angeles, CA); Kook, Sanghoon; Doom, Jeffrey; Oefelein, Joseph Charles; Zhang, Jiayao; Shaddix, Christopher R.; Schefer, Robert W.; Pickett, Lyle M.

2010-10-01T23:59:59.000Z

224

New developments in biochemical mass spectrometry: Electrospray ionization  

SciTech Connect (OSTI)

The principles, development, and recent application of electrospray ionization-mass spectrometry (ESI-MS) to biological compounds are reviewed. ESI-MS methods now allow determination of accurate molecular weights for proteins extending to over 50,000, and in some cases well over 100,000. Similar capabilities are being developed for oligonucleotides. The instrumentation used for ESI-MS is briefly described and it is shown that, although ionization efficiency appears to be uniformly high, detector sensitivity may be directly correlated with molecular weight. The use of tandem mass spectrometry (e.g., MS/MS) for extending collision-induced dissociation (CID) methods to the structural studies of large molecules is described. For example, effective CID of various albumin species (molecular weight {approximately}66,000) can be obtained, far larger than obtainable for singly charged molecular ions. The combination of capillary electrophoresis, in both free solution zone electrophoresis and isotachophoresis formats, as well as microcolumn liquid chromatography with ESI-MS, provides the capability for on-line separation and analysis of subpicomole quantities of proteins. These and other new developments related to ESI-MS are illustrated by a range of examples. Fundamental considerations suggest even more impressive developments may be anticipated related to detection sensitivity and methods for obtaining structural information.

Smith, R.D.; Loo, J.A.; Edmonds, C.G.; Barinaga, C.J.; Udseth, H.R. (Pacific Northwest Laboratory, Richland, WA (USA))

1990-05-01T23:59:59.000Z

225

Ionization tube simmer current circuit  

DOE Patents [OSTI]

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

Steinkraus, Jr., Robert F. (Livermore, CA)

1994-01-01T23:59:59.000Z

226

Ionization tube simmer current circuit  

DOE Patents [OSTI]

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

Steinkraus, R.F. Jr.

1994-12-13T23:59:59.000Z

227

Measurement of the ionization yield of nuclear recoils in liquid argon at 80 and 233 keV  

E-Print Network [OSTI]

The energy calibration of nuclear recoil detectors is of primary importance to rare-event experiments such as those of direct dark matter search and coherent neutrino-nucleus scattering. In particular, such a calibration is performed by measuring the ionization yield of nuclear recoils in liquid Ar and Xe detection media, using neutron elastic scattering off nuclei. In the present work, the ionization yield for nuclear recoils in liquid Ar has for the first time been measured in the higher energy range, at 80 and 233 keV, using a two-phase Cryogenic Avalanche Detector (CRAD) and DD neutron generator. The ionization yield in liquid Ar at an electric field of 2.3 kV/cm amounted to 7.8+/-1.1 and 9.7+/-1.3 e-/keV at 80 and 233 keV respectively. The Jaffe model for nuclear recoil-induced ionization, in contrast to that Thomas-Imel, can probably consistently describe the energy dependence of the ionization yield.

A. Bondar; A. Buzulutskov; A. Dolgov; E. Grishnyaev; S. Polosatkin; L. Shekhtman; E. Shemyakina; A. Sokolov

2014-09-23T23:59:59.000Z

228

Finite-rate chemistry and transient effects in direct numerical simulations of turbulent nonpremixed flames  

SciTech Connect (OSTI)

Three-dimensional direct numerical simulations (DNS) of turbulent nonpremixed flames including finite-rate chemistry and heat release effects were performed. Two chemical reaction models were considered: (1) a single-step global reaction model in which the heat release and activation energy parameters are typical combustion applications, and (2) a two-step reaction model to stimulate radical production and consumption and to compare against the single-step model. The model problem consists of the interaction between an initially unstained laminar diffusion flame and a three-dimensional field of homogeneous turbulence. Conditions ranging from fast chemistry to the pure mixing limit were studied by varying a global Damkoehler number. Results suggest that turbulence-induced mixing acting along the stoichiometric line leads to a strong modification of the inner structure of the turbulent flame compared with a laminar strained flame, resulting in intermediate species concentrations well above the laminar prediction. This result is consistent the experimental observations. Comparison of the response of the turbulent flame structure due to changes in the scalar dissipation rate with a steady strained laminar flame reveals that unsteady strain rates experienced by the turbulent flame may be responsible for h3e observed high concentrations of reaction intermediates.

Mahalingam, S. [Univ. of Colorado, Boulder, CO (United States). Center for Combustion Research] [Univ. of Colorado, Boulder, CO (United States). Center for Combustion Research; Chen, J.H. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility] [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility; Vervisch, L. [CORIA, Rouen (France). Laboratoire de Mechanique des Fluides Numeriques] [CORIA, Rouen (France). Laboratoire de Mechanique des Fluides Numeriques

1995-08-01T23:59:59.000Z

229

Multi-anode ionization chamber  

DOE Patents [OSTI]

The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

Bolotnikov, Aleksey E. (South Setauket, NY); Smith, Graham (Port Jefferson, NY); Mahler, George J. (Rocky Point, NY); Vanier, Peter E. (Setauket, NY)

2010-12-28T23:59:59.000Z

230

Simulations of flame acceleration and deflagration-to-detonation transitions in methane-air systems  

SciTech Connect (OSTI)

Flame acceleration and deflagration-to-detonation transitions (DDT) in large obstructed channels filled with a stoichiometric methane-air mixture are simulated using a single-step reaction mechanism. The reaction parameters are calibrated using known velocities and length scales of laminar flames and detonations. Calculations of the flame dynamics and DDT in channels with obstacles are compared to previously reported experimental data. The results obtained using the simple reaction model qualitatively, and in many cases, quantitatively match the experiments and are found to be largely insensitive to small variations in model parameters. (author)

Kessler, D.A.; Gamezo, V.N.; Oran, E.S. [Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory, Washington, DC (United States)

2010-11-15T23:59:59.000Z

231

CONTROL OF POLLUTANT EMISSIONS IN NATURAL GAS DIFFUSION FLAMES BY USING CASCADE BURNERS  

SciTech Connect (OSTI)

The goal of this exploratory research project is to control the pollutant emissions of diffusion flames by modifying the air infusion rate into the flame. The modification was achieved by installing a cascade of venturis around the burning gas jet. The basic idea behind this technique is controlling the stoichiometry of the flame through changing the flow dynamics and rates of mixing in the combustion zone with a set of venturis surrounding the flame. A natural gas jet diffusion flame at burner-exit Reynolds number of 5100 was examined with a set of venturis of specific sizes and spacing arrangement. The thermal and composition fields of the baseline and venturi-cascaded flames were numerically simulated using CFD-ACE+, an advanced computational environment software package. The instantaneous chemistry model was used as the reaction model. The concentration of NO was determined through CFD-POST, a post processing utility program for CFD-ACE+. The numerical results showed that, in the near-burner, midflame and far-burner regions, the venturi-cascaded flame had lower temperature by an average of 13%, 19% and 17%, respectively, and lower CO{sub 2} concentration by 35%, 37% and 32%, respectively, than the baseline flame. An opposite trend was noticed for O{sub 2} concentration; the cascaded flame has higher O{sub 2} concentration by 7%, 26% and 44%, in average values, in the near-burner, mid-flame and far-burner regions, respectively, than in the baseline case. The results also showed that, in the near-burner, mid-flame, and far-burner regions, the venturi-cascaded flame has lower NO concentrations by 89%, 70% and 70%, in average values, respectively, compared to the baseline case. The numerical results substantiate that venturi-cascading is a feasible method for controlling the pollutant emissions of a burning gas jet. In addition, the numerical results were useful to understand the thermo-chemical processes involved. The results showed that the prompt-NO mechanism plays an important role besides the conventional thermal-NO mechanism. The computational results of the present study need to be validated experimentally.

Dr. Ala Qubbaj

2001-12-30T23:59:59.000Z

232

Photo double ionization of ethylene and acetylene near threshold  

E-Print Network [OSTI]

Photo double ionization of ethylene and acetylene nearcomplete measurements of the photo double ionization ofkinetic energy of the photo electrons and the nuclear

Gaire, B.

2014-01-01T23:59:59.000Z

233

Direct Experimental Observation of the Low Ionization Potentials...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Observation of the Low Ionization Potentials of Guanine in Free Oligonucleotides by Using Photoelectron Direct Experimental Observation of the Low Ionization Potentials of Guanine...

234

Photo double ionization of ethylene and acetylene near threshold  

E-Print Network [OSTI]

double ionization of ethylene and acetylene near thresholdphoto double ionization of ethylene (dou- ble CC bond) andsimilar yields of metastable ethylene dications produced by

Gaire, B.

2014-01-01T23:59:59.000Z

235

Applications of High-Resolution Electrospray Ionization Mass...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

High-Resolution Electrospray Ionization Mass Spectrometry to Measurements of Average Oxygen to Carbon Ratios in Applications of High-Resolution Electrospray Ionization Mass...

236

Ambient Ionization Mass Spectrometry Analysis Pertaining To Biofuel Process Development.  

E-Print Network [OSTI]

??Mass spectrometry (MS) has undergone a revolution with the introduction of a new group of desorption/ionization (DI) techniques known collectively as Ambient Ionization mass spectrometry.… (more)

Dendukuri, Sushma

2012-01-01T23:59:59.000Z

237

An Inverted Co-Flow Diffusion Flame for Producing Soot  

SciTech Connect (OSTI)

We developed an inverted, co-flow, methane/air/nitrogen burner that generates a wide range of soot particles sizes and concentrations. By adjusting the flow rates of air, methane, and nitrogen in the fuel, the mean electric mobility diameter and number concentration are varied. Additional dilution downstream of the flame allows us to generate particle concentrations spanning those produced by spark-ignited and diesel engines: particles with mean diameters between 50 and 250 nm and number concentrations from 4.7 {center_dot} 10{sup 4} to 10{sup 7} cm{sup -3}. The range of achievable number concentrations, and therefore volume concentrations, can be increased by a factor of 30 by reducing the dilution ratio. These operating conditions make this burner valuable for developing and calibrating diagnostics as well as for other studies involving soot particles.

Stipe, Christopher B.; Higgins, Brian S.; Lucas, Donald; Koshland, Catherine P.; Sawyer, Robert F.

2005-06-21T23:59:59.000Z

238

Reaction zone visualisation in swirling spray n-heptane flames  

E-Print Network [OSTI]

process and consumed in the subsequent high temperature oxidation. Formaldehyde LIF was used for autoignition of methane jets [6], methanol, ethanol and acetone spray jet flames [7,8], and diesel fuel [9-11] and n-heptane [11,12] in HCCI engines. Najm... intensifier was 30,000 FL/FC and 80,000 FL/FC for CH2O and OH respectively. The laser powers were 12 mJ/pulse for OH PLIF and 300 mJ/pulse for CH2O PLIF. The intensifiers were triggered off the Q switch of each laser 6 with a gate of 220 ns. The CH2O PLIF...

Yuan, R.; Kariuki, J.; Dowlut, A.; Balachandran, R.; Mastorakos, E.

2014-06-26T23:59:59.000Z

239

Mechanisms governing fine particulate emissions from coal flames  

SciTech Connect (OSTI)

The primary objective of this program was to provide a basic understanding of the principal processes that govern the formation of particulate matter in the 0.5--10 {mu}m size range in pulverized coal flames. The mechanism that produces ash particles in this size range is not clear. Particle sizes smaller than the 0.5--10 {mu}m size range are generally accepted to result from a vaporization/condensation mechanism while particles larger than this size result from the coalescence of ash in coal particles which may breakup as they burn. This program combined experimental and theoretical studies to understand the mechanisms which control the production of ash in the 0.5--10 {mu}m size range. (VC)

Newton, G.H.; Schieber, C.; Socha, R.G.; Kramlich, J.C.

1990-04-01T23:59:59.000Z

240

Mechanisms governing fine particulate emissions from coal flames. Final report  

SciTech Connect (OSTI)

The primary objective of this program was to provide a basic understanding of the principal processes that govern the formation of particulate matter in the 0.5--10 {mu}m size range in pulverized coal flames. The mechanism that produces ash particles in this size range is not clear. Particle sizes smaller than the 0.5--10 {mu}m size range are generally accepted to result from a vaporization/condensation mechanism while particles larger than this size result from the coalescence of ash in coal particles which may breakup as they burn. This program combined experimental and theoretical studies to understand the mechanisms which control the production of ash in the 0.5--10 {mu}m size range. (VC)

Newton, G.H.; Schieber, C.; Socha, R.G.; Kramlich, J.C.

1990-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

NO{sub x} control by flame management  

SciTech Connect (OSTI)

In the control of emissions from power generation boilers combustion modification, in the form of low NO{sub x} burner (LNB) design, is recognized as the basic and economic technique for minimising NO{sub x} production. Depending upon the application LNB`s alone may offer sufficient NO{sub x} control or may be used in conjunction with changes in boiler operating techniques to achieve ultra-low NO{sub x} operation. LNB designs are based on well established principles of fuel and air staging which control the mixing of fuel and combustion air in order to establish the flame chemistry and temperature conditions conducive to minimising NO{sub x} formation. These mixing processes need to be considered in conjunction with the fuel characteristics for maximum effectiveness.

Allen, J.W.; Beal, P.R. [International Combustion Ltd., Derby (United Kingdom)

1995-12-31T23:59:59.000Z

242

Semiconductor radiation detector  

DOE Patents [OSTI]

A semiconductor radiation detector is provided to detect x-ray and light photons. The entrance electrode is segmented by using variable doping concentrations. Further, the entrance electrode is physically segmented by inserting n+ regions between p+ regions. The p+ regions and the n+ regions are individually biased. The detector elements can be used in an array, and the p+ regions and the n+ regions can be biased by applying potential at a single point. The back side of the semiconductor radiation detector has an n+ anode for collecting created charges and a number of p+ cathodes. Biased n+ inserts can be placed between the p+ cathodes, and an internal resistor divider can be used to bias the n+ inserts as well as the p+ cathodes. A polysilicon spiral guard can be implemented surrounding the active area of the entrance electrode or surrounding an array of entrance electrodes.

Patt, Bradley E. (Sherman Oaks, CA); Iwanczyk, Jan S. (Los Angeles, CA); Tull, Carolyn R. (Orinda, CA); Vilkelis, Gintas (Westlake Village, CA)

2002-01-01T23:59:59.000Z

243

Photo-Electric Ionization of Caesium Vapor  

Science Journals Connector (OSTI)

Measurement of photo-electric ionization in gases.—The current from a filament, normally limited by space change, is increased by the presence of positive ions. As shown by Kingdon this effect may be greatly magnified if a small cathode is practically enclosed by the anode so that the ions are imprisoned. This method was used for the detection of photo-electric ionization. Besides possessing extreme sensitivity it is unaffected by photo-electric emission from the electrodes.Photo-electric effect in caesium vapor.—The change in thermionic current with the unresolved radiation from a mercury arc was measured as functions of the applied voltage, filament temperature, and vapor pressure. Then the photo-electric effect as a function of wave-length was studied using a monochromatic illuminator to disperse light from the arc or a Mazda lamp. The ionization per unit flux was found to increase with increasing wave-length to a sharp maximum at the limit 1s=3184A of the principal series, as is required by the Bohr theory. For longer wave-lengths the ionization decreased to about 10 percent at 3400A. Photo-excitation. The simple theory does not admit of ionization by wave-lengths greater than 3184A but the data are in qualitative agreement with the hypothesis that such radiation produces excited atoms which upon collision with other atoms acquire sufficient additional energy to become ionized. Hence, unlike an x-ray limit, the photo-ionization effect for a valence electron is not sharply discontinuous at the true threshold for direct ionization.Photo-ionization photometer and intensitometer. A tube of the type described, with suitable gases for the range of wave-length involved, may be used as a photometer or may be calibrated to measure intensity of radiation directly.

Paul D. Foote and F. L. Mohler

1925-08-01T23:59:59.000Z

244

Ionization threshold of crystalline LiF  

Science Journals Connector (OSTI)

The ionization threshold for crystalline LiF is calculated using a cluster embedded model. The experimental ionization threshold is 9.8 eV; however, previous band and cluster model calculations gave 14–15 eV. These earlier calculations used a crystal having a perfect lattice. In the present work, a crystal with lattice defects is introduced. The calculated surface and bulk ionization thresholds are 8.1 and 8.7 eV, respectively, showing good correspondence with experiment. The electron affinity and other band parameters are also studied.

Hiroshi Tatewaki

1999-08-01T23:59:59.000Z

245

Fissile material detector  

DOE Patents [OSTI]

A detector for fissile materials which provides for integrity monitoring of fissile materials and can be used for nondestructive assay to confirm the presence of a stable content of fissile material in items. The detector has a sample cavity large enough to enable assay of large items of arbitrary configuration, utilizes neutron sources fabricated in spatially extended shapes mounted on the endcaps of the sample cavity, incorporates a thermal neutron filter insert with reflector properties, and the electronics module includes a neutron multiplicity coincidence counter.

Ivanov, Alexander I. (Dubna, RU); Lushchikov, Vladislav I. (Dubna, RU); Shabalin, Eugeny P. (Dubna, RU); Maznyy, Nikita G. (Dubna, RU); Khvastunov, Michael M. (Dubna, RU); Rowland, Mark (Alamo, CA)

2002-01-01T23:59:59.000Z

246

Ultrasonic liquid level detector  

DOE Patents [OSTI]

An ultrasonic liquid level detector for use within a shielded container, the detector being tubular in shape with a chamber at its lower end into which liquid from in the container may enter and exit, the chamber having an ultrasonic transmitter and receiver in its top wall and a reflector plate or target as its bottom wall whereby when liquid fills the chamber a complete medium is then present through which an ultrasonic wave may be transmitted and reflected from the target thus signaling that the liquid is at chamber level.

Kotz, Dennis M. (North Augusta, SC); Hinz, William R. (Augusta, GA)

2010-09-28T23:59:59.000Z

247

A DNS study on the stabilization mechanism of a turbulent lifted ethylene jet flame in highly-heated coflow  

SciTech Connect (OSTI)

Direct numerical simulation (DNS) of the near-field of a three-dimensional spatially-developing turbulent ethylene jet flame in highly-heated coflow is performed with a reduced mechanism to determine the stabilization mechanism. The DNS was performed at a jet Reynolds number of 10,000 with over 1.29 billion grid points. The results show that auto-ignition in a fuel-lean mixture at the flame base is the main source of stabilization of the lifted jet flame. The Damkoehler number and chemical explosive mode (CEM) analysis also verify that auto-ignition occurs at the flame base. In addition to auto-ignition, Lagrangian tracking of the flame base reveals the passage of large-scale flow structures and their correlation with the fluctuations of the flame base similar to a previous study (Yoo et al., J. Fluid Mech. 640 (2009) 453-481) with hydrogen/air jet flames. It is also observed that the present lifted flame base exhibits a cyclic 'saw-tooth' shaped movement marked by rapid movement upstream and slower movement downstream. This is a consequence of the lifted flame being stabilized by a balance between consecutive auto-ignition events in hot fuel-lean mixtures and convection induced by the high-speed jet and coflow velocities. This is confirmed by Lagrangian tracking of key variables including the flame-normal velocity, displacement speed, scalar dissipation rate, and mixture fraction at the stabilization point.

Yoo, Chun S [Sandia National Laboratories (SNL)

2011-01-01T23:59:59.000Z

248

On The Toxicity of Flame Retardants in Buildings and What Can Be Done About  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

On The Toxicity of Flame Retardants in Buildings and What Can Be Done About On The Toxicity of Flame Retardants in Buildings and What Can Be Done About It Speaker(s): Arlene Blum Date: November 3, 2010 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: William Fisk Polystyrene, polyisocyanurate, and polyurethane are insulation materials that increase energy efficiency and whose use in buildings, especially energy efficient buildings, is growing rapidly. At the same time, the flame retardants currently in use with these materials are often chemicals that are known to be toxic or have not been adequately evaluated for their impact on human health and the environment. For example, all polystyrene foam insulation used in buildings is treated with HBCD, a persistent, bioaccumulative, and toxic flame retardant. The impacts of exposure to

249

Coal Particle Measurement in a Pulverized Coal Flame with Digital Inline Holography  

Science Journals Connector (OSTI)

Digital inline holography with pulse illumination was applied to measure the 3D position and size of the burning coal particles in a laboratory-scale pulverized coal flame under strong...

Wu, Yingchun; Wu, Xuecheng; Zhou, Binwu; Yang, Jing; Chen, Linghong; Peng, Yueyu; Qiu, Kunzan; Grehan, Gerard; Cen, Kefa

250

Investigation of the Syngas Flame Characteristics at Elevated Pressures Using Optical and Laser Diagnostic Methods  

Science Journals Connector (OSTI)

The effect of pressure on the characteristics of syngas flames is investigated under gas turbine relevant...*...chemiluminescence imaging. An optically accessible combustor fitted with a swirl burner was operated...

Rajesh Sadanandan; Peter Kutne; Adam Steinberg…

2012-09-01T23:59:59.000Z

251

Synthesis of Highly Efficient Flame Retardant High-Density Polyethylene Nanocomposites with Inorgano-Layered Double  

E-Print Network [OSTI]

Synthesis of Highly Efficient Flame Retardant High-Density Polyethylene Nanocomposites, Harbin 150080, P. R. China ABSTRACT: High-density polyethylene (HDPE) polymer nanocomposites containing. INTRODUCTION High density polyethylene (HDPE) has good electrical proper- ties, high stiffness, and tensile

Guo, John Zhanhu

252

Method for determining effective flame emissivity in a rotary kiln incinerator burning solid waste  

Science Journals Connector (OSTI)

Temperature is the most important parameter for the improvement of combustion efficiency and the control of pollutants. In order to obtain accurate flame temperatures in a rotary kiln incinerator using non-int...

Jin-cai Du; Qun-xing Huang; Jian-hua Yan

2012-12-01T23:59:59.000Z

253

Effect of Plasma Pretreatment Followed by Nanoclay Loading on Flame Retardant Properties of Cotton Fabric  

Science Journals Connector (OSTI)

In this research work the effect of plasma treatment with nitrogen gas followed by nanoclay treatment on flame retardancy of cotton fabrics ... , nitrogen plasma pretreatment has synergistic effect on nanoclay fo...

Sheila Shahidi; Mahmood Ghoranneviss

2014-02-01T23:59:59.000Z

254

Multifractal detrended fluctuation analysis of combustion flames in four-burner impinging entrained-flow gasifier  

E-Print Network [OSTI]

On a laboratory-scale testing platform of impinging entrained-flow gasifier with four opposed burners, the flame images for diesel combustion and gasification process were measured with a single charge coupled device (CCD) camera. The two-dimensional multifractal detrended fluctuation analysis was employed to investigate the multifractal nature of the flame images. Sound power-law scaling in the annealed average of detrended fluctuations was unveiled when the order $q>0$ and the multifractal feature of flame images were confirmed. Further analyses identified two multifractal parameters, the minimum and maximum singularity $\\alpha_{\\min}$ and $\\alpha_{\\max}$, serving as characteristic parameters of the multifractal flames. These two characteristic multifractal parameters vary with respect to different experimental conditions.

Niu, Miao-Ren; Yan, Zhuo-Yong; Guo, Qing-Hua; Liang, Qin-Feng; Wang, Fu-Chen; Yu, Zun-Hong

2007-01-01T23:59:59.000Z

255

Large eddy simulations of premixed turbulent flame dynamics : combustion modeling, validation and analysis  

E-Print Network [OSTI]

High efficiency, low emissions and stable operation over a wide range of conditions are some of the key requirements of modem-day combustors. To achieve these objectives, lean premixed flames are generally preferred as ...

Kewlani, Gaurav

2014-01-01T23:59:59.000Z

256

The Plasma Flame: Development and Application of a Hybrid Plasma at Atmospheric Pressure.  

E-Print Network [OSTI]

??The focus of this work was to develop a hybrid plasma at atmospheric pressure, which we have deemed the “plasma flame†. This discharge is… (more)

King, Matthew Russell

2009-01-01T23:59:59.000Z

257

Laser induced spark ignition of coaxial methane/oxygen/nitrogen diffusion flames  

Science Journals Connector (OSTI)

We report the laser induced spark ignition (LSI) of coaxial methane/oxygen/nitrogen diffusion flames using the 1064 nm output of a Q-switched Nd:YAG laser. The minimum ignition energy...

Li, Xiaohui; Yu, Yang; Yu, Xin; Liu, Chang; Fan, Rongwei; Chen, Deying

2014-01-01T23:59:59.000Z

258

THE COMBUSTION OF SOLVENT REPINED COAL IN AN OPPOSED FLOW DIFFUSION FLAME  

E-Print Network [OSTI]

R.F. (1977). Combustion of coal in an opposed flow diffusionpulverized, solvent-refined coal. ASME Paper No. 76-WA/FU-6.OF SOLVENT REFINED COAL IN AN OPPOSED FLOW DIFFUSION FLAME*

Chin, W.K.

2011-01-01T23:59:59.000Z

259

Non-adiabatic flamelet modeling for combustion processes of oxy-natural gas flame  

Science Journals Connector (OSTI)

In order to realistically predict the combustion characteristics of the oxy-fuel flame, the present study employs the non-adiabatic flamelet approach. In this combustion model, the detailed equilibrium chemist...

Gunhong Kim; Yongmo Kim

2005-09-01T23:59:59.000Z

260

DEPFET—detectors: New developments  

Science Journals Connector (OSTI)

The Depleted Field Effect Transistor (DEPFET) detector–amplifier structure forms the basis of a variety of detectors being developed at the MPI semiconductor laboratory. These detectors are foreseen to be used in astronomy and particle physics as well as other fields of science. The detector developments are described together with some intended applications. They comprise the X-ray astronomy missions XEUS and SIMBOL-X as well as the vertex detector of the planned International Linear Collider (ILC). All detectors are produced in the MPI semiconductor laboratory that has a complete silicon technology available.

G. Lutz; L. Andricek; R. Eckardt; O. Hälker; S. Hermann; P. Lechner; R. Richter; G. Schaller; F. Schopper; H. Soltau; L. Strüder; J. Treis; S. Wölfl; C. Zhang

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

EIS-0351: Operation of Flaming Gorge Dam, Colorado River Storage Project, Colorado River, UT  

Broader source: Energy.gov [DOE]

The Secretary of the United States Department of the Interior (Secretary), acting through the Bureau of Reclamation (Reclamation), is considering whether to implement a proposed action under which Flaming Gorge Dam would be operated to achieve the flow and temperature regimes recommended in the September 2000 report Flow and Temperature Recommendations for Endangered Fishes in the Green River Downstream of Flaming Gorge Dam (2000 Flow and Temperature Recommendations), published by the Upper Colorado River Endangered Fish Recovery Program (Recovery Program).

262

6 - Industrial Applications of Ionizing Radiation  

Science Journals Connector (OSTI)

The chapter summarizes the industrial applications of ionizing radiation. Ionizing radiation finds use in a variety of industrial applications such as wire and cable insulation, tire manufacturing, production of polymeric foams, heat-shrinkable films and tubings, curing of coatings, adhesives and composites, printing, and other technological development. It provides extensive information on EB process in wire and cable and tire technology. The chapter also provides discussion on EB process in the manufacture of polyolefin foams and heat-shrinkable materials. Detailed discussion on cross-linked PE pipes (PEX) including methods for production, irradiation, and its advantages, is presented. Other applications for ionizing radiation include sterilization of medical devices, hydrogels, radiation curing of polymeric composites, production of fluoroadditives, radiation-cured flexography, coatings, adhesives, paints, and printing inks. Keywords Ionizing radiation; tire manufacturing; wire and cable insulations; printing inks; polyolefin foams; heat-shrinkable materials; cross-linked PE pipes (PEX); hydrogels; flexography

Jiri George Drobny

2013-01-01T23:59:59.000Z

263

Electrical conductivity of nondegenerate, fully ionized plasmas  

Science Journals Connector (OSTI)

Within a virial expansion of the electrical conductivity of a fully ionized plasma, which takes into account many-particle effects, different limiting cases are considered. An appropriate interpolation formula is compared with experimental values.

G. Röpke and R. Redmer

1989-01-15T23:59:59.000Z

264

Note on accelerated detectors  

Science Journals Connector (OSTI)

The Unruh result, on the thermal-like behavior of particle detectors under a uniformly accelerated state of motion, is found by a different method which does not involve field quantization in a metric with a horizon. The result is extended to other situations.

P. Meyer

1978-07-15T23:59:59.000Z

265

Directional gamma detector  

DOE Patents [OSTI]

An improved directional gamma radiation detector has a collector sandwiched etween two layers of insulation of varying thicknesses. The collector and insulation layers are contained within an evacuated casing, or emitter, which releases electrons upon exposure to gamma radiation. Delayed electrons and electrons entering the collector at oblique angles are attenuated as they pass through the insulation layers on route to the collector.

LeVert, Francis E. (Downers Grove, Knoxville, TN); Cox, Samson A. (Downers Grove, IL)

1981-01-01T23:59:59.000Z

266

The BABAR Detector  

E-Print Network [OSTI]

BABAR, the detector for the SLAC PEP-II asymmetric e+e- B Factory operating at the upsilon 4S resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagentic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems, VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.

The BABAR Collaboration

2001-05-16T23:59:59.000Z

267

The CLIC Vertex Detector  

E-Print Network [OSTI]

The precision physics needs at TeV-scale linear electron-positron colliders (ILC and CLIC) require a vertex-detector system with excellent flavour-tagging capabilities through a meas- urement of displaced vertices. This is essential, for example, for an explicit measurement of the Higgs decays to pairs of b-quarks, c-quarks and gluons. Efficient identification of top quarks in the decay t ? W b will give access to the ttH-coupling measurement. In addition to those requirements driven by physics arguments, the CLIC bunch structure calls for hit tim- ing at the few-ns level. As a result, the CLIC vertex-detector system needs to have excellent spatial resolution, full geometrical coverage extending to low polar angles, extremely low material budget, low occupancy facilitated by time-tagging, and sufficient heat removal from sensors and readout. These considerations challenge current technological limits. A detector concept based on hybrid pixel-detector technology is under development for the CLIC ver- tex det...

Dannheim, D.

2014-01-01T23:59:59.000Z

268

Semiconductor Radiation Detectors  

Science Journals Connector (OSTI)

...detector in which the material is not fully depleted. 284 SCIENCE, VOL. 170 (77 K), reduces...isotopes produced in fragmentation of uranium nuclei by 5-Gev protons as observed...staff of the U.S. De-partment of Health, Education, and Welfare National Air...

Fred S. Goulding; Yvonne Stone

1970-10-16T23:59:59.000Z

269

Direct numerical simulations of type Ia supernovae flames I: The landau-darrieus instability  

SciTech Connect (OSTI)

Planar flames are intrinsically unstable in open domains due to the thermal expansion across the burning front--the Landau-Darrieus instability. This instability leads to wrinkling and growth of the flame surface, and corresponding acceleration of the flame, until it is stabilized by cusp formation. We look at the Landau-Darrieus in stability for C/O thermonuclear flames at conditions relevant to the late stages of a Type Ia supernova explosion. Two-dimensional direct numerical simulations of both single-mode and multi-mode perturbations using a low Mach number hydrodynamics code are presented. We show the effect of the instability on the flame speed as a function of both the density and domain size, demonstrate the existence of the small scale cutoff to the growth of the instability, and look for the proposed breakdown of the non-linear stabilization at low densities. The effects of curvature on the flame as quantified through measurements of the growth rate and computation of the corresponding Markstein number. While accelerations of a few percent are observed, they are too small to have any direct outcome on the supernova explosion.

Bell, J.B.; Day, M.S.; Rendleman, C.A.; Woosley, S.E.; Zingale, M.

2003-11-24T23:59:59.000Z

270

Optical determination of incipient soot particle concentrations in ethene laminar diffusion flames.  

SciTech Connect (OSTI)

Recent studies in premixed flames have shown the existence of ''transparent particles.'' These particles, 2 nm in size and in high number densities are considered to be a phase transitional between the gas phase PAH species and particulate soot. In the present study, various optical diagnostics were evaluated for measuring the concentration of these particles in situ, Through such evaluations, a technique using extinction at two wavelengths was found to be ideal. While employing such a technique, the volume fractions of these particles in an ethene laminar diffusion flame were measured. Low in the flame, these particles were found to be concentrated in the fuel rich core, while at higher locations, they could be found with appreciable volume fractions even in the soot laden regions. Having given due consideration for the errors due to uncertainties in the optical constants, we report the existence of these particles in an ethene flame with volume fractions comparable to those of soot. Also, similar measurements performed in a low sooting ethene/methanol flame show the concentration of these particles to be of the same order of magnitude as in a pure ethene flame.

Gupta, S. B.; Santoro, R. J.

1999-07-06T23:59:59.000Z

271

Autoignited laminar lifted flames of propane in coflow jets with tribrachial edge and mild combustion  

SciTech Connect (OSTI)

Characteristics of laminar lifted flames have been investigated experimentally by varying the initial temperature of coflow air over 800 K in the non-premixed jets of propane diluted with nitrogen. The result showed that the lifted flame with the initial temperature below 860 K maintained the typical tribrachial structure at the leading edge, which was stabilized by the balance mechanism between the propagation speed of tribrachial flame and the local flow velocity. For the temperature above 860 K, the flame was autoignited without having any external ignition source. The autoignited lifted flames were categorized in two regimes. In the case with tribrachial edge structure, the liftoff height increased nonlinearly with jet velocity. Especially, for the critical condition near blowout, the lifted flame showed a repetitive behavior of extinction and reignition. In such a case, the autoignition was controlled by the non-adiabatic ignition delay time considering heat loss such that the autoignition height was correlated with the square of the adiabatic ignition delay time. In the case with mild combustion regime at excessively diluted conditions, the liftoff height increased linearly with jet velocity and was correlated well with the square of the adiabatic ignition delay time. (author)

Choi, B.C.; Kim, K.N.; Chung, S.H. [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744 (Korea)

2009-02-15T23:59:59.000Z

272

Detectors (XSD) | Advanced Photon Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

APS Detector Pool (X-ray Science Division) The Detector Pool provides many different types of x-ray detectors to beamline scientists at the Advanced Photon Source. These detectors are made available for short term loans (typically several days to a week or two, but this is flexible). The detector pool also coordinates loans between sectors, helps sectors repair equipment, and coordinates group purchases. Depending on budgets, we purchase new equipment, based largely on suggestions from the beamline scientists. Requests for detectors are submitted by beamline scientists at the sectors on behalf of general users. General Users are free to contact us regarding detector capabilities and other questions. The Detector Pool is staffed during normal working hours,

273

Near infrared detectors for SNAP  

E-Print Network [OSTI]

Near Infrared Detectors for SNAP M. Schubnell a , N. Barron1k × 1k and 2k × 2k) near infrared detectors manufactured byas part of the near infrared R&D e?ort for SNAP (the Super-

2006-01-01T23:59:59.000Z

274

Cherenkov detectors in particle physics  

Science Journals Connector (OSTI)

The most impressive examples of the application of Cherenkov detectors in modern-physics experiments are considered.

Yu. K. Akimov

2004-07-01T23:59:59.000Z

275

IONIZATION IN ATMOSPHERES OF BROWN DWARFS AND EXTRASOLAR PLANETS. V. ALFVÉN IONIZATION  

SciTech Connect (OSTI)

Observations of continuous radio and sporadic X-ray emission from low-mass objects suggest they harbor localized plasmas in their atmospheric environments. For low-mass objects, the degree of thermal ionization is insufficient to qualify the ionized component as a plasma, posing the question: what ionization processes can efficiently produce the required plasma that is the source of the radiation? We propose Alfvén ionization as a mechanism for producing localized pockets of ionized gas in the atmosphere, having sufficient degrees of ionization (?10{sup –7}) that they constitute plasmas. We outline the criteria required for Alfvén ionization and demonstrate its applicability in the atmospheres of low-mass objects such as giant gas planets, brown dwarfs, and M dwarfs with both solar and sub-solar metallicities. We find that Alfvén ionization is most efficient at mid to low atmospheric pressures where a seed plasma is easier to magnetize and the pressure gradients needed to drive the required neutral flows are the smallest. For the model atmospheres considered, our results show that degrees of ionization of 10{sup –6}-1 can be obtained as a result of Alfvén ionization. Observable consequences include continuum bremsstrahlung emission, superimposed with spectral lines from the plasma ion species (e.g., He, Mg, H{sub 2}, or CO lines). Forbidden lines are also expected from the metastable population. The presence of an atmospheric plasma opens the door to a multitude of plasma and chemical processes not yet considered in current atmospheric models. The occurrence of Alfvén ionization may also be applicable to other astrophysical environments such as protoplanetary disks.

Stark, C. R.; Helling, Ch.; Rimmer, P. B. [SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS (United Kingdom); Diver, D. A., E-mail: craig.stark@st-andrews.ac.uk [SUPA, School of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow, G12 8QQ (United Kingdom)

2013-10-10T23:59:59.000Z

276

Synthesis and thermal studies of flexible polyurethane nanocomposite foams obtained using nanoclay modified with flame retardant compound  

Science Journals Connector (OSTI)

This work presents thermal studies of nanocomposites based on the flexible polyurethane (PU) matrix and filled using montmorillonite organically modified with organophosphorus flame retardant compound. Flexibl...

?ukasz Piszczyk; Magdalena Danowska…

2014-11-01T23:59:59.000Z

277

Aerogel for FARICH detector  

Science Journals Connector (OSTI)

Abstract We present our current experience in preparation of focusing aerogels for the Focusing Aerogel RICH detector. Multilayer focusing aerogel tiles have been produced in Novosibirsk by a collaboration of the Budker Institute of Nuclear Physics and Boreskov Institute of Catalysis since 2004. We have obtained 2–3–4-layer blocks with the thickness of 30–45 mm. In 2012, the first samples of focusing blocks with continuous density (refractive index) gradient along thickness were produced. This technology can significantly reduce the contribution from the geometric factor of the radiator thickness to the resolution of the measured Cherenkov angle in the FARICH detector. The special installation was used for automatic control of reagents ratio during the synthesis process. The first samples were tested using the digital radiography method and on the electron beam with the FARICH prototype.

A.Yu. Barnyakov; M.Yu. Barnyakov; V.S. Bobrovnikov; A.R. Buzykaev; V.V. Gulevich; A.F. Danilyuk; S.A. Kononov; E.A. Kravchenko; I.A. Kuyanov; S.A. Lopatin; A.P. Onuchin; I.V. Ovtin; N.A. Podgornov; V.V. Porosev; A.Yu. Predein; R.S. Protsenko

2014-01-01T23:59:59.000Z

278

Liquid level detector  

DOE Patents [OSTI]

A liquid level detector for conductive liquids for vertical installation in a tank, the detector having a probe positioned within a sheath and insulated therefrom by a seal so that the tip of the probe extends proximate to but not below the lower end of the sheath, the lower end terminating in a rim that is provided with notches, said lower end being tapered, the taper and notches preventing debris collection and bubble formation, said lower end when contacting liquid as it rises will form an airtight cavity defined by the liquid, the interior sheath wall, and the seal, the compression of air in the cavity preventing liquid from further entry into the sheath and contact with the seal. As a result, the liquid cannot deposit a film to form an electrical bridge across the seal.

Tshishiku, Eugene M. (Augusta, GA)

2011-08-09T23:59:59.000Z

279

Ultrafast neutron detector  

DOE Patents [OSTI]

The invention comprises a neutron detector (50) of very high temporal resolution that is particularly well suited for measuring the fusion reaction neutrons produced by laser-driven inertial confinement fusion targets. The detector comprises a biased two-conductor traveling-wave transmission line (54, 56, 58, 68) having a uranium cathode (60) and a phosphor anode (62) as respective parts of the two conductors. A charge line and Auston switch assembly (70, 72, 74) launch an electric field pulse along the transmission line. Neutrons striking the uranium cathode at a location where the field pulse is passing, are enabled to strike the phosphor anode and produce light that is recorded on photographic film (64). The transmission line may be variously configured to achieve specific experimental goals.

Wang, Ching L. (Livermore, CA)

1987-01-01T23:59:59.000Z

280

Development of a New Flame Speed Vessel to Measure the Effect of Steam Dilution on Laminar Flame Speeds of Syngas Fuel Blends at Elevated Pressures and Temperatures  

E-Print Network [OSTI]

, including the H2O. .............................................................................................................................................. 35 Table 6 Standard L9 DOE test matrix for four factors (A-D) at three levels (1-3) (Ross... sensitivity analysis based on the maximum difference between the averaged laminar flame speeds at each DOE level (1, 2, or 3) for four oxygen equivalence ratios. ...................................................................................... 41 Table...

Krejci, Michael

2012-07-16T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Flame structure of wall-impinging diesel fuel sprays injected by group-hole nozzles  

SciTech Connect (OSTI)

This paper describes an investigation of the flame structure of wall-impinging diesel sprays injected by group-hole nozzles in a constant-volume combustion vessel at experimental conditions typical of a diesel engine. The particular emphasis was on the effect of the included angle between two orifices (0-15 deg. in current study) on the flame structure and combustion characteristics under various simulated engine load conditions. The laser absorption scattering (LAS) technique was applied to analyze the spray and mixture properties. Direct flame imaging and OH chemiluminescence imaging were utilized to quantify the ignition delay, flame geometrical parameters, and OH chemiluminescence intensity. The images show that the asymmetric flame structure emerges in wall-impinging group-hole nozzle sprays as larger included angle and higher engine load conditions are applied, which is consistent with the spray shape observed by LAS. Compared to the base nozzle, group-hole nozzles with large included angles yield higher overall OH chemiluminescence intensity, wider flame area, and greater proportion of high OH intensity, implying the better fuel/air mixing and improved combustion characteristics. The advantages of group-hole nozzle are more pronounced under high load conditions. Based on the results, the feasibility of group-hole nozzle for practical direct injection diesel engines is also discussed. It is concluded that the asymmetric flame structure of a group-hole nozzle spray is favorable to reduce soot formation over wide engine loads. However, the hole configuration of the group-hole nozzle should be carefully considered so as to achieve proper air utilization in the combustion chamber. Stoichiometric diesel combustion is another promising application of group-hole nozzle. (author)

Gao, Jian; Moon, Seoksu; Nishida, Keiya; Matsumoto, Yuhei [Department of Mechanical System Engineering, University of Hiroshima, Higashi-Hiroshima, 739-8527 (Japan); Zhang, Yuyin [Department of Mechanical Engineering, Tokyo Denki University, Tokyo, 101-8457 (Japan)

2009-06-15T23:59:59.000Z

282

Mobility of Negative Ions in Flames by the Hall Effect Method  

Science Journals Connector (OSTI)

Variation with potential gradient of mobility of negative flame ions.—Using a flat salted flame, previously described by Wilson, between the poles of an electromagnet giving a field of 5000 gauss, the horizontal potential gradient X due to the current sent between two Pt electrodes and also the vertical potential gradient Y due to the Hall effect, were measured by means of two Pt sounding wires which could be rotated about a horizontal axis and which were connected to a quadrant electrometer. For a flame containing potassium carbonate the mobility k2=YHX was found to decrease from 26 m/sec for 1 volt/cm when the potential gradient was 1 volt/cm, to 16 m/sec for a gradient of 30 volts/cm. For a flame free from salt the mobility was some-what greater, decreasing from 26.5 m/sec for 5 volts/cm to 16 m/sec for 50 volts/cm. However, wide variation of concentration produced so little effect on the mobility that it could not be detected with certainty. The magneto-resistance effect which Heaps1 has shown enters into the mobility equation, was so small as to be negligible.Asymmetry of the Hall effect in flames.—The Hall effect was found to vary slightly with the direction of the magnetic field, the asymmetry being greater the greater the amount of salt in the flame. This asymmetry was probably due to the effect of the magnetic field on the upward velocity of the flame gases, which was evident in these experiments.

J. S. Watt

1925-01-01T23:59:59.000Z

283

Sensor readout detector circuit  

DOE Patents [OSTI]

A sensor readout detector circuit is disclosed that is capable of detecting sensor signals down to a few nanoamperes or less in a high (microampere) background noise level. The circuit operates at a very low standby power level and is triggerable by a sensor event signal that is above a predetermined threshold level. A plurality of sensor readout detector circuits can be formed on a substrate as an integrated circuit (IC). These circuits can operate to process data from an array of sensors in parallel, with only data from active sensors being processed for digitization and analysis. This allows the IC to operate at a low power level with a high data throughput for the active sensors. The circuit may be used with many different types of sensors, including photodetectors, capacitance sensors, chemically-sensitive sensors or combinations thereof to provide a capability for recording transient events or for recording data for a predetermined period of time following an event trigger. The sensor readout detector circuit has applications for portable or satellite-based sensor systems. 6 figs.

Chu, D.D.; Thelen, D.C. Jr.

1998-08-11T23:59:59.000Z

284

Sensor readout detector circuit  

DOE Patents [OSTI]

A sensor readout detector circuit is disclosed that is capable of detecting sensor signals down to a few nanoamperes or less in a high (microampere) background noise level. The circuit operates at a very low standby power level and is triggerable by a sensor event signal that is above a predetermined threshold level. A plurality of sensor readout detector circuits can be formed on a substrate as an integrated circuit (IC). These circuits can operate to process data from an array of sensors in parallel, with only data from active sensors being processed for digitization and analysis. This allows the IC to operate at a low power level with a high data throughput for the active sensors. The circuit may be used with many different types of sensors, including photodetectors, capacitance sensors, chemically-sensitive sensors or combinations thereof to provide a capability for recording transient events or for recording data for a predetermined period of time following an event trigger. The sensor readout detector circuit has applications for portable or satellite-based sensor systems.

Chu, Dahlon D. (Albuquerque, NM); Thelen, Jr., Donald C. (Bozeman, MT)

1998-01-01T23:59:59.000Z

285

Nanowire-based detector  

DOE Patents [OSTI]

Systems, articles, and methods are provided related to nanowire-based detectors, which can be used for light detection in, for example, single-photon detectors. In one aspect, a variety of detectors are provided, for example one including an electrically superconductive nanowire or nanowires constructed and arranged to interact with photons to produce a detectable signal. In another aspect, fabrication methods are provided, including techniques to precisely reproduce patterns in subsequently formed layers of material using a relatively small number of fabrication steps. By precisely reproducing patterns in multiple material layers, one can form electrically insulating materials and electrically conductive materials in shapes such that incoming photons are redirected toward a nearby electrically superconductive materials (e.g., electrically superconductive nanowire(s)). For example, one or more resonance structures (e.g., comprising an electrically insulating material), which can trap electromagnetic radiation within its boundaries, can be positioned proximate the nanowire(s). The resonance structure can include, at its boundaries, electrically conductive material positioned proximate the electrically superconductive nanowire such that light that would otherwise be transmitted through the sensor is redirected toward the nanowire(s) and detected. In addition, electrically conductive material can be positioned proximate the electrically superconductive nanowire (e.g. at the aperture of the resonant structure), such that light is directed by scattering from this structure into the nanowire.

Berggren, Karl K; Hu, Xiaolong; Masciarelli, Daniele

2014-06-24T23:59:59.000Z

286

Conceptual design for a fast neutron ionization chamber for fusion reactor plasma diagnostics  

SciTech Connect (OSTI)

A conceptual design for a radiation-hard ``pointing`` fast neutron ionization chamber that is capable of delivering a 1 MHz countrate of T(D,n) events at ITER is given. The detector will use a {approximately}1 cm{sup 3} volume of CO{sub 2} fill gas at 0.1 bar pressure in a 500 V/cm electric field. The pulse widths will be {approximately}10 ns, enabling it to operate in a flux of {approximately} 6 {times} 10{sup 13} DT n/cm{sup 2}/sec. A special collimator design is used, giving an estimated angular resolution of 4.5 degrees HWHM.

Sailor, W.C.; Barnes, C.W.

1994-06-01T23:59:59.000Z

287

Analysis of two alternative organophosphorus flame retardants in electronic and plastic consumer products: Resorcinol bis-(diphenylphosphate) (PBDPP) and bisphenol A bis (diphenylphosphate) (BPA-BDPP)  

Science Journals Connector (OSTI)

Abstract Following the phase-out of polybrominated diphenyl ethers (PBDEs), organophosphorus flame retardants (PFRs) are increasingly used as alternative flame retardants in many products. Data on the presence of two alternative \\{PFRs\\} in consumer products, resorcinol bis (diphenylphosphate) (PBDPP or RDP) and bisphenol A bis (diphenylphosphate) (BPA-BDPP or BDP) is still scarce or non-existing. In this study we propose a simple extraction method and analysis by liquid chromatography–atmospheric pressure chemical ionization (APCI) coupled to a high resolution time-of-flight mass spectrometry (TOF) for plastic consumer products. Detection limits were low enough for trace quantitation in plastic or electronic samples (0.001% and 0.002% w/w for PBDPP and BPA-BDPP, respectively). The APCI source provided better sensitivity and matrix effects than the commonly used ESI source for the analysis of these PFRs. Both PBDPP and BPA-BDPP were detected in 7 of the 12 products purchased in 2012 (at 0.002–0.3% w/w for PBDPP and 0.02–0.18% w/w for BPA-BDPP) while only PBDPP was found in 4 of the 13 products purchased before 2006 (0.005–7.8% w/w). In newly purchased products, PBDPP, BPA-BDPP and triphenyl phosphate (TPHP) were the most frequently detected PFRs. These results support the recent findings of our research group about high concentration levels of PBDPP and BPA-BDPP up to 0.5–1 mg g?1 in house dust collected on electronic equipment and highlights the need for further research on these two novel PFRs.

A. Ballesteros-Gómez; S.H. Brandsma; J. de Boer; P.E.G. Leonards

2014-01-01T23:59:59.000Z

288

Multiphoton ionization of large water clusters  

SciTech Connect (OSTI)

Water clusters are multimers of water molecules held together by hydrogen bonds. In the present work, multiphoton ionization in the UV range coupled with time of flight mass spectrometry has been applied to water clusters with up to 160 molecules in order to obtain information on the electronic states of clusters of different sizes up to dimensions that can approximate the bulk phase. The dependence of ion intensities of water clusters and their metastable fragments produced by laser ionization at 355 nm on laser power density indicates a (3+1)-photon resonance-enhanced multiphoton ionization process. It also explains the large increase of ionization efficiency at 355 nm compared to that at 266 nm. Indeed, it was found, by applying both nanosecond and picosecond laser ionization with the two different UV wavelengths, that no water cluster sequences after n = 9 could be observed at 266 nm, whereas water clusters up to m/z 2000 Th in reflectron mode and m/z 3000 Th in linear mode were detected at 355 nm. The agreement between our findings on clusters of water, especially true in the range with n > 10, and reported data for liquid water supports the hypothesis that clusters above a critical dimension can approximate the liquid phase. It should thus be possible to study clusters just above 10 water molecules, for getting information on the bulk phase structure.

Apicella, B., E-mail: apicella@irc.cnr.it [Combustion Research Institute, IRC–C.N.R., P.le Tecchio 80, 80125 Napoli (Italy); Li, X. [Key Laboratory of Power Machinery and Engineering, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240 (China); Passaro, M. [CNISM and Chemical Engineering, Materials and Industrial Production Department, University of Naples “Federico II,” P.le Tecchio 80, 80125 Napoli (Italy); Spinelli, N. [CNISM and Physics Department, University of Naples “Federico II,” Via Cintia, 80124 Napoli (Italy); Wang, X. [SPIN–C.N.R., Via Cintia, 80124 Napoli (Italy)

2014-05-28T23:59:59.000Z

289

Liquid Xenon Detectors for Particle Physics and Astrophysics  

E-Print Network [OSTI]

This article reviews the progress made over the last 20 years in the development and applications of liquid xenon detectors in particle physics, astrophysics and medical imaging experiments. We begin with a summary of the fundamental properties of liquid xenon as radiation detection medium, in light of the most current theoretical and experimental information. After a brief introduction of the different type of liquid xenon detectors, we continue with a review of past, current and future experiments using liquid xenon to search for rare processes and to image radiation in space and in medicine. We will introduce each application with a brief survey of the underlying scientific motivation and experimental requirements, before reviewing the basic characteristics and expected performance of each experiment. Within this decade it appears likely that large volume liquid xenon detectors operated in different modes will contribute to answering some of the most fundamental questions in particle physics, astrophysics and cosmology, fulfilling the most demanding detection challenges. From experiments like MEG, currently the largest liquid xenon scintillation detector in operation, dedicated to the rare mu -> e + gamma decay, to the future XMASS which also exploits only liquid xenon scintillation to address an ambitious program of rare event searches, to the class of time projection chambers like XENON and EXO which exploit both scintillation and ionization of liquid xenon for dark matter and neutrinoless double beta decay, respectively, we anticipate unrivaled performance and important contributions to physics in the next few years.

E. Aprile; T. Doke

2009-10-26T23:59:59.000Z

290

Study of the performance of three micromixing models in transported scalar PDF simulations of a piloted jet diffusion flame ('Delft Flame III')  

SciTech Connect (OSTI)

Numerical simulation results are presented for a turbulent nonpremixed flame with local extinction and reignition. The transported scalar PDF approach is applied to the turbulence-chemistry interaction. The turbulent flow field is obtained with a nonlinear two-equation turbulence model. A C{sub 1} skeletal scheme is used as the chemistry model. The performance of three micromixing models is compared: the interaction by exchange with the mean model (IEM), the modified Curl's coalescence/dispersion model (CD) and the Euclidean minimum spanning tree model (EMST). With the IEM model, global extinction occurs. With the standard value of model constant C{sub f}=2, the CD model yields a lifted flame, unlike the experiments, while with the EMST model the correct flame shape is obtained. However, the conditional variances of the thermochemical quantities are underestimated with the EMST model, due to a lack of local extinction in the simulations. With the CD model, the flame becomes attached when either the value of C{sub f} is increased to 3 or the pilot flame thermal power is increased by a factor of 1.5. With increased value of C{sub f} better results for mixture fraction variance are obtained with both the CD and the EMST model. Lowering the value of C{sub f} leads to better predictions for mean temperature with EMST, but at the cost of stronger overprediction of mixture fraction variance. These trends are explained as a consequence of variance production by macroscopic inhomogeneity and the specific properties of the micromixing models. Local time stepping is applied so that convergence is obtained more quickly. Iteration averaging reduces statistical error so that the limited number of 50 particles per cell is sufficient to obtain accurate results. (author)

Merci, Bart [Department of Flow, Heat and Combustion Mechanics, Ghent University-UGent, B-9000 Ghent (Belgium); Roekaerts, Dirk [Department of Multi-Scale Physics, Delft University of Technology, Delft (Netherlands); Naud, Bertrand [CIEMAT, Madrid (Spain)

2006-02-01T23:59:59.000Z

291

An Investigation into the Quantitative Gas Chromatographic Analysis of Metal Chelates using a Hydrogen-Flame lonization Detector  

Science Journals Connector (OSTI)

......60 mesh firebrick. The acetylacetonate complexes were obtained...the three ligands. The acetylacetonate and trifluoroacetylacetonate...Comparable experiments with the acetylacetonate and hexa- fluoroacetylacetonate...aluminum, copper (II) and iron (III) trifluoroacetylaceton......

R. D. Hill; H. Gesser

1963-10-01T23:59:59.000Z

292

The Determination of Trace Mercaptans and Sulfides in Natural Gas by a Gas Chromatography-Flame Photometric Detector Technique  

Science Journals Connector (OSTI)

......choice for the analysis of tetrahydrothiophene, one of the organic sulfur...SCIENCE VOL. 14 Figure 4A. Tetrahydrothiophene peak with Teflon lined column (140 C). Figure 4B. Tetrahydrothiophene peak with stainless steel......

C. David Pearson

1976-03-01T23:59:59.000Z

293

MUCOOL: Ionization Cooling R&D  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Laboratory Laboratory MUCOOL Muon Ionization Cooling R&D Welcome to the muon ionization cooling experimental R&D page. The MuCool collaboration has been formed to pursue the development of a muon ionization cooling channel for a high luminosity muon collider. For more information please contact Alan Bross (Spokesperson: bross@fnal.gov), Rick Fernow (BNL Contact person: fernow1@bnl.gov), or Mike Zisman (LBNL Contact person: mszisman@lbl.gov). General MUCOOL Telephone Book MUCOOL Notes MUCOOL Collaborating Institutes and Interests Useful Links Link to IIT MUCOOL page Meetings Muon Collaboration Friday Meetings Fermilab Muon Group Monday Meetings MTA RF Workshop (August 22, 2007 - Fermilab) Low Emittance Muon Collider Workshop (February 12-16, 2007, Fermilab) Low Emittance Muon Collider Workshop (February 6-10, 2006, Fermilab)

294

Weak interaction studies using resonance ionization spectroscopy  

SciTech Connect (OSTI)

Important developments in laser sources for the vacuum ultraviolet (VUV) region of the spectrum are making it possible to carry out resonance ionization of some of the noble gases. It has already been shown that xenon can be ionized in a two-photon allowed excitation from the ground state. Recently a new method of generating radiation by four-wave mixing in mercury vapor enables excitation of xenon in a one-photon resonance process. With these new laser sources we expect to have effective ionization volumes of 10/sup -3/ to 10/sup -2/ cm/sup 3/ for the cases of argon, krypton, and xenon. This has important consequences in weak interaction physics and environmental research.

Payne, M.G.; Hurst, G.S.

1982-01-01T23:59:59.000Z

295

A lattice Boltzmann algorithm for calculation of the laminar jet diffusion flame  

SciTech Connect (OSTI)

A new two-distribution lattice Boltzmann equation (LBE) algorithm is presented to solve the laminar diffusion flames within the context of Burke-Schumann flame sheet model. One distribution models the transport of the Schvab-Zeldovich coupling function, or the mixture fraction to combine the energy and species equations. The other distribution models the quasi-incompressible Navier-Stokes equations with the low Mach number approximation. In the quasi-incompressible flows, the thermodynamics quantities depend on the coupling function but not on the hydrodynamic pressure, and the fluid components are assumed to be compressible only in the mixing/reaction region. A systematic and consistent approach to deriving LBEs for the general advection-diffusion equation and the quasi-incompressible Navier-Stokes equations are also presented. The streaming step of the LBEs are discretized by the total variation diminishing (TVD) Lax-Wendroff scheme. Numerical simulations are carried out to reproduce the low frequency flame oscillation (or flame flicker) of buoyant jet diffusion flame. Comparison between the quasi-incompressible model and the incompressible model is presented and the role of non-solenoidal velocity is examined.

Lee, T. [Department of Mechanical and Industrial Engineering, IIHR - Hydroscience and Engineering, University of Iowa, Iowa City, IA 52242-1527 (United States)]. E-mail: thlee@ccny.cuny.edu; Lin, C.-L. [Department of Mechanical and Industrial Engineering, IIHR - Hydroscience and Engineering, University of Iowa, Iowa City, IA 52242-1527 (United States)]. E-mail: ching-long-lin@uiowa.edu; Chen, L.-D. [Department of Mechanical and Industrial Engineering, National Advanced Driving Simulator, University of Iowa, Iowa City, IA 52242-1527 (United States)]. E-mail: lea-der-chen@uiowa.edu

2006-06-10T23:59:59.000Z

296

areaDetector: Software for 2-D Detectors in EPICS  

SciTech Connect (OSTI)

areaDetector is a new EPICS module designed to support 2-D detectors. It is modular C++ code that greatly simplifies the task of writing support for a new detector. It also supports plugins, which receive detector data from the driver and process it in some way. Existing plugins perform Region-Of-Interest extraction and analysis, file saving (in netCDF, HDF, TIFF and JPEG formats), color conversion, and export to EPICS records for image display in clients like ImageJ and IDL. Drivers have now been written for many of the detectors commonly used at synchrotron beamlines, including CCDs, pixel array and amorphous silicon detectors, and online image plates.

Rivers, M. (UC)

2011-09-23T23:59:59.000Z

297

areaDetector: Software for 2-D Detectors in EPICS  

SciTech Connect (OSTI)

areaDetector is a new EPICS module designed to support 2-D detectors. It is modular C++ code that greatly simplifies the task of writing support for a new detector. It also supports plugins, which receive detector data from the driver and process it in some way. Existing plugins perform Region-Of-Interest extraction and analysis, file saving (in netCDF, HDF, TIFF and JPEG formats), color conversion, and export to EPICS records for image display in clients like ImageJ and IDL. Drivers have now been written for many of the detectors commonly used at synchrotron beamlines, including CCDs, pixel array and amorphous silicon detectors, and online image plates.

Rivers, Mark L. [Center for Advanced Radiation Sources and Department of Geophysical Sciences, University of Chicago, Argonne, IL 60439 (United States)

2010-06-23T23:59:59.000Z

298

Liquid level detector  

DOE Patents [OSTI]

A liquid level detector for low pressure boilers. A boiler tank, from which apor, such as steam, normally exits via a main vent, is provided with a vertical side tube connected to the tank at the desired low liquid level. When the liquid level falls to the level of the side tube vapor escapes therethrough causing heating of a temperature sensitive device located in the side tube, which, for example, may activate a liquid supply means for adding liquid to the boiler tank. High liquid level in the boiler tank blocks entry of vapor into the side tube, allowing the temperature sensitive device to cool, for example, to ambient temperature.

Grasso, Albert P. (Vernon, CT)

1986-01-01T23:59:59.000Z

299

Avalanche semiconductor radiation detectors  

SciTech Connect (OSTI)

Operation of novel avalanche semiconductor detector, produced on the basis of heterojunctions Si-SiC and Si-Si{sub x}O{sub y} is described. A uniform avalanche process with gain from 10{sup 3} to 10{sup 5} can be reached depending on the conductivity of SiC and Si{sub x}O{sub y} layers. Two types of avalanche photodetectors designed for applications in wavelength range 500--10,00 nm with quantum efficiency 60 {+-} 10% (650 nm) and 200--700 nm with quantum efficiency 60 {+-} 15% (450 nm) are presented.

Sadygov, Z.Y. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)] [Joint Inst. for Nuclear Research, Dubna (Russian Federation); [Azerbaijan Academy of Sciences, Baku (Azerbaijan). Physics Inst.; Zheleznykh, I.M.; Kirillova, T.A. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. for Nuclear Research] [Russian Academy of Sciences, Moscow (Russian Federation). Inst. for Nuclear Research; Malakhov, N.A.; Jejer, V.N. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)] [Joint Inst. for Nuclear Research, Dubna (Russian Federation)

1996-06-01T23:59:59.000Z

300

Liquid level detector  

DOE Patents [OSTI]

A liquid level detector for low pressure boilers. A boiler tank, from which vapor, such as steam, normally exits via a main vent, is provided with a vertical side tube connected to the tank at the desired low liquid level. When the liquid level falls to the level of the side tube vapor escapes therethrough causing heating of a temperature sensitive device located in the side tube, which, for example, may activate a liquid supply means for adding liquid to the boiler tank. High liquid level in the boiler tank blocks entry of vapor into the side tube, allowing the temperature sensitive device to cool, for example, to ambient temperature.

Grasso, A.P.

1984-02-21T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Pyroelectric demodulating detector  

DOE Patents [OSTI]

A pyroelectric demodulating detector (also termed a pyroelectric demodulator) is disclosed which utilizes an electrical resistor stacked upon a pyroelectric element to demodulate an rf or microwave electrical input signal which is amplitude-modulated (AM). The pyroelectric demodulator, which can be formed as a hybrid or a monolithic device, has applications for use in AM radio receivers. Demodulation is performed by feeding the AM input signal into the resistor and converting the AM input signal into an AM heat signal which is conducted through the pyroelectric element and used to generate an electrical output signal containing AM information from the AM input signal.

Brocato, Robert W. (Sandia Park, NM)

2008-07-08T23:59:59.000Z

302

LHC Beam Loss Detector Design Simulations and Measurements  

E-Print Network [OSTI]

The Beam Loss Monitoring (BLM) system is integrated in the active equipment protection system of the LHC. It determines the number of particles lost from the primary hadron beam by measuring the radiation field of the shower particles outside of the vacuum chamber. The LHC BLM system will use ionization chambers as its standard detectors but in the areas where very high dose rates are expected, the Secondary Emission Monitor (SEM) chambers will be additionally employed because of their high linearity, low sensitivity and fast response.The sensitivity of the SEM was modeled in Geant4 via the Photo-Absorption Ionization module together with custom parameterization of the very low energy secondary electron production. The prototypes were calibrated by proton beams. For the calibration of the BLM system the signal response of the ionization chamber is simulated in Geant4 for all relevant particle types and energies (keV to TeV range). The results are validated by comparing the simulations to measurements using pr...

Dehning, B; Emery, J; Ferioli, G; Holzer, E B; Kramer, Daniel; Ponce, L; Stockner, M; Zamantzas, C

2007-01-01T23:59:59.000Z

303

M AT E R I A L S S C I E N C E Making Flame  

E-Print Network [OSTI]

. The best materials showed heat resistance up to 400°C. All the materials tested had little residual charM AT E R I A L S S C I E N C E Making Flame Retardant Polymeric flame-retardant materials after heat- ing to 1200°C, indicating al- most complete decomposi- tion, and produced no toxic materials

Blower, Sally

304

Feature Article Negative pressure dependence of mass burning rates of H2/CO/O2/diluent flames  

E-Print Network [OSTI]

with predominantly CO, CO2, and H2O) as a fuel itself as synthetic gas or ``syngas" from coal or biomass gasification of burning rates, analysis of the key reactions and kinetic pathways, and modeling studies were performed and temperature dependence compared to Ar-diluted flames of the same flame temperature. Simulations were performed

Ju, Yiguang

305

Progress on a Cavity with Beryllium Walls for Muon Ionization Cooling Channel R&D.  

E-Print Network [OSTI]

WITH BERYLLIUM WALLS FOR MUON IONIZATION COOLING CHANNELNY 11973, USA Abstract The Muon Accelerator Program (MAP)an ionization cooling channel for muon beams. An ionization

Bowring, D.L.

2014-01-01T23:59:59.000Z

306

Experimental Endeavour on a Pillar of Flame: Space Shuttle Rises with  

Broader source: Energy.gov (indexed) [DOE]

Experimental Endeavour on a Pillar of Flame: Space Shuttle Rises Experimental Endeavour on a Pillar of Flame: Space Shuttle Rises with Ambitious Technology Aboard Experimental Endeavour on a Pillar of Flame: Space Shuttle Rises with Ambitious Technology Aboard May 17, 2011 - 5:15pm Addthis Smoke cloud from Endeavour's Final Launge | Photo: NASA, Troy Cryder Smoke cloud from Endeavour's Final Launge | Photo: NASA, Troy Cryder Charles Rousseaux Charles Rousseaux Senior Writer, Office of Science What are the key facts? Space Shuttle Endeavour, which lifted off on its final mission Monday, carrying the Alpha Magnetic Spectrometer (AMS) experiment. In addition to measuring how cosmic rays flow and what they are made of, the AMS will also search for cosmic rays made of a special form of matter known as antimatter. By looking for new particles in space via the AMS, scientists might

307

Experimental Endeavour on a Pillar of Flame: Space Shuttle Rises with  

Broader source: Energy.gov (indexed) [DOE]

Experimental Endeavour on a Pillar of Flame: Space Shuttle Rises Experimental Endeavour on a Pillar of Flame: Space Shuttle Rises with Ambitious Technology Aboard Experimental Endeavour on a Pillar of Flame: Space Shuttle Rises with Ambitious Technology Aboard May 17, 2011 - 5:15pm Addthis Smoke cloud from Endeavour's Final Launge | Photo: NASA, Troy Cryder Smoke cloud from Endeavour's Final Launge | Photo: NASA, Troy Cryder Charles Rousseaux Charles Rousseaux Senior Writer, Office of Science What are the key facts? Space Shuttle Endeavour, which lifted off on its final mission Monday, carrying the Alpha Magnetic Spectrometer (AMS) experiment. In addition to measuring how cosmic rays flow and what they are made of, the AMS will also search for cosmic rays made of a special form of matter known as antimatter. By looking for new particles in space via the AMS, scientists might

308

Measurement of temperature distributions in large pool fires with the use of directional flame thermometers  

SciTech Connect (OSTI)

Temperatures inside the flame zone of large regulatory pool fires measured during tests of radioactive materials packages vary widely with both time and position. Measurements made with several Directional Flame Thermometers, in which a thermocouple is attached to a thin metal sheet that quickly approaches flame temperatures, have been used to construct fire temperature distributions and cumulative probability distributions. As an aid to computer simulations of these large fires, these distributions are presented. The distributions are constructed by sorting fire temperature data into bins 10 C wide. A typical fire temperature distribution curve has a gradual increase starting at about 600 C, with the number of observations increasing to a peak near 1000 C, followed by an abrupt decrease in frequency, with no temperatures observed above 1200 C.

KOSKI,JORMAN A.

2000-05-09T23:59:59.000Z

309

Detailed modeling and laser-induced fluorescence imaging of nitric oxide in a NH3-seeded non-premixed methane/air flame  

E-Print Network [OSTI]

non-premixed methane/air flame John B. Bell, Marcus S. Day, Joseph F. Grcar Computing Sciences-induced fluorescence imaging of nitric oxide in a NH3-seeded non-premixed methane/air flame Abstract In this paper we study the formation of NO in laminar, nitrogen diluted methane diffusion flames that are seeded

Bell, John B.

310

A Centrality Detector Concept  

E-Print Network [OSTI]

The nucleus-nucleus impact parameter and collision geometry of a heavy ion collision are typically characterized by assigning a collision "centrality". In all present heavy ion experiments centrality is measured indirectly, by detecting the number of particles or the energy of the particles produced in the interactions, typically at high rapidity. Centrality parameters are associated to the measured detector response using the Glauber model. This approach suffers from systematic uncertainties related to the assumptions about the particle production mechanism and limitations of the Glauber model. In the collider based experiments there is a unique possibility to measure centrality parameters by registering spectator fragments remaining from the collision. This approach does not require model assumptions and relies on the fact that spectators and participants are related via the total number of nucleons in the colliding species. This article describes the concept of the centrality detector for heavy ion experiment, which measures the total mass number of all fragments by measuring their deflection in the magnetic field of the collider elements.

Sourav Tarafdar; Zvi Citron; Alexander Milov

2014-06-07T23:59:59.000Z

311

Laser-saturated fluorescence of nitric oxide and chemiluminescence measurements in premixed ethanol flames  

SciTech Connect (OSTI)

In this study, nitric oxide laser-saturated fluorescence (LSF) measurements were acquired from premixed ethanol flames at atmospheric pressure in a burner. NO-LSF experimental profiles for fuel-rich premixed ethanol flames ({phi} = 1.34 and {phi} = 1.66) were determined through the excitation/detection scheme of the Q{sub 2}(26.5) rotational line in the A{sup 2}{sigma}{sup +} - X{sup 2}{pi} (0,0) vibronic band and {gamma}(0,1) emission band. A calibration procedure by NO doping into the flame was applied to establish the NO concentration profiles in these flames. Chemiluminescent emission measurements in the (0, 0) vibronic emission bands of the OH{sup *} (A{sup 2}{sigma}{sup +} - X{sup 2}{pi}) and CH{sup *}(A{sup 2}{delta} - X{sup 2}{pi}) radicals were also obtained with high spatial and spectral resolution for fuel-rich premixed ethanol flames to correlate them with NO concentrations. Experimental chemiluminescence profiles and the ratios of the integrated areas under emission spectra (A{sub CH*}/A{sub CH*}(max.) and A{sub CH*}/A{sub OH*}) were determined. The relationships between chemiluminescence and NO concentrations were established along the premixed ethanol flames. There was a strong connection between CH{sup *} radical chemiluminescence and NO formation and the prompt-NO was identified as the governing mechanism for NO production. The results suggest the optimum ratio of the chemiluminescence of two radicals (A{sub CH*}/A{sub OH*}) for NO diagnostic purposes. (author)

Marques, Carla S.T.; Barreta, Luiz G.; Sbampato, Maria E.; dos Santos, Alberto M. [Aerothermodynamic and Hypersonic Division, Institute of Advanced Studies - General Command of Aerospatial Technology, Rodovia dos Tamoios, km 5.5, 12228-001 Sao Jose dos Campos - SP (Brazil)

2010-11-15T23:59:59.000Z

312

Mitigation of thermoacoustic instability utilizing steady air injection near the flame anchoring zone  

SciTech Connect (OSTI)

The objective of this work is to investigate the effectiveness of steady air injection near the flame anchoring zone in suppressing thermoacoustic instabilities driven by flame-vortex interaction mechanism. We perform a systematic experimental study which involves using two different configurations of air injection in an atmospheric pressure backward-facing step combustor. The first configuration utilizes a row of micro-diameter holes allowing for air injection in the cross-stream direction just upstream of the step. The second configuration utilizes an array of micro-diameter holes located on the face of the step, allowing for air injection in the streamwise direction. The effects of each of these configurations are analyzed to determine which one is more effective in suppressing thermoacoustic instabilities at different operating conditions. The tests are conducted while varying the equivalence ratio and the inlet temperature. The secondary air temperature is always the same as the inlet temperature. We used pure propane or propane/hydrogen mixtures as fuels. Combustion dynamics are explored through simultaneous pressure and heat release-rate measurements, and high-speed video images. When the equivalence ratio of the reactant mixture is high, it causes the flame to flashback towards the inlet channel. When air is injected in the cross-stream direction, the flame anchors slightly upstream of the step, which suppresses the instability. When air is injected in the streamwise direction near the edge of step, thermoacoustic instability could be eliminated at an optimum secondary air flow rate, which depends on the operating conditions. When effective, the streamwise air injection prevents the shedding of an unsteady vortex, thus eliminating the flame-vortex interaction mechanism and resulting in a compact, stable flame to form near the step. (author)

Murat Altay, H.; Hudgins, Duane E.; Speth, Raymond L.; Annaswamy, Anuradha M.; Ghoniem, Ahmed F. [Massachusetts Institute of Technology, Department of Mechanical Engineering, Cambridge, MA 02139 (United States)

2010-04-15T23:59:59.000Z

313

Efficiencies of Quantum Optical Detectors  

E-Print Network [OSTI]

We propose a definition for the efficiency that can be universally applied to all classes of quantum optical detectors. This definition is based on the maximum amount of optical loss that a physically plausible device can experience while still replicating the properties of a given detector. We prove that detector efficiency cannot be increased using linear optical processing. That is, given a set of detectors, as well as arbitrary linear optical elements and ancillary light sources, it is impossible to construct detection devices that would exhibit higher efficiencies than the initial set.

Daniel Hogg; Dominic W. Berry; A. I. Lvovsky

2014-12-15T23:59:59.000Z

314

Composite scintillators for detection of ionizing radiation  

DOE Patents [OSTI]

Applicant's present invention is a composite scintillator having enhanced transparency for detecting ionizing radiation comprising a material having optical transparency wherein said material comprises nano-sized objects having a size in at least one dimension that is less than the wavelength of light emitted by the composite scintillator wherein the composite scintillator is designed to have selected properties suitable for a particular application.

Dai, Sheng (Knoxville, TN) [Knoxville, TN; Stephan, Andrew Curtis (Knoxville, TN) [Knoxville, TN; Brown, Suree S. (Knoxville, TN) [Knoxville, TN; Wallace, Steven A. (Knoxville, TN) [Knoxville, TN; Rondinone, Adam J [Knoxville, TN

2010-12-28T23:59:59.000Z

315

Salt Tolerance of Desorption Electrospray Ionization (DESI)  

SciTech Connect (OSTI)

Suppression of ion intensity in the presence of high salt matrices is common in most mass spectrometry ionization techniques. Desorption electrospray ionization (DESI) is an ionization method that exhibits salt tolerance, and this is investigated. DESI analysis was performed on three different drug mixtures in the presence of 0, 0.2, 2, 5, 10, and 20% NaCl:KCl weight by volume from seven different surfaces. At physiological concentrations individual drugs in each mixture were observed with each surface. Collision-induced dissociation (CID) was used to provide additional confirmation for select compounds. Multiple stage experiments, to MS5, were performed for select compounds. Even in the absence of added salt, the benzodiazepine containing mixture yielded sodium and potassium adducts of carbamazepine which masked the ions of interest. These adducts were eliminated by adding 0.1% 7M ammonium acetate to the standard methanol:water (1:1) spray solvent. Comparison of the salt tolerance of DESI with that of electrospray ionization (ESI) demonstrated much better signal/noise characteristics for DESI in this study. The salt tolerance of DESI was also studied by performing limit of detection and dynamic range experiments. Even at a salt concentration significantly above physiological concentrations, select surfaces were effective in providing spectra that allowed the ready identification of the compounds of interest. The already high salt tolerance of DESI can be optimized further by appropriate choices of surface and spray solution.

Jackson, Ayanna U. [Purdue University; Talaty, Nari [Purdue University; Cooks, R G [Purdue University; Van Berkel, Gary J [ORNL

2007-01-01T23:59:59.000Z

316

Muon Cooling via Ionization Andrea Kay Forget  

E-Print Network [OSTI]

1 Muon Cooling via Ionization Andrea Kay Forget Department of Physics, Wayne State University, Detroit, Michigan 48202 Dated: August 7, 2006 Muons only live a few microseconds before they ultimately, and laser cooling) cannot be used to properly cool muons that are being used in proposed accelerators

Cinabro, David

317

Studies of Anomalous Ionization Edgar Y. Choueiri  

E-Print Network [OSTI]

Laboratory (EPPDyL) Princeton University, Princeton NJ 08544. Hideo Okuda Princeton Plasma Physics LabStudies of Anomalous Ionization Edgar Y. Choueiri Electric Propulsion and Plasma Dynamics., Princeton University Princeton, NJ. 08544 AIAA Paper: AIAA-94-2465 Abstract In order to improve the accuracy

Choueiri, Edgar

318

A laser and molecular beam mass spectrometer study of low-pressure dimethyl ether flames  

SciTech Connect (OSTI)

The oxidation of dimethyl ether (DME) is studied in low-pressure flames using new molecular beam mass spectrometer and laser diagnostics. Two 30.0-Torr, premixed DME/oxygen/argon flames are investigated with stoichiometries of 0.98 and 1.20. The height above burner profiles of nine stable species and two radicals are measured. These results are compared to the detailed chemical reaction mechanism of Curran and coworkers. Generally good agreement is found between the model and data. The largest discrepancies are found for the methyl radical profiles where the model predicts qualitatively different trends in the methyl concentration with stoichiometry than observed in the experiment.

Andrew McIlroy; Toby D. Hain; Hope A. Michelsen; Terrill A. Cool

2000-12-15T23:59:59.000Z

319

Reduction of Emissions from a Syngas Flame Using Micromixing and Dilution with CO2  

Science Journals Connector (OSTI)

Hydrogen-rich syngas can be burned stably in the designed combustor, and each suite of nozzles forms a flame surface. ... The smaller dilution ratio and the higher fuel heating value means the fuel can be burned quickly after it leaves the nozzles, resulting in strong heat release in the frontal section of the burner. ... There are, however, gaps in the fundamental understanding of syngas combustion and emissions, as most previous research has focused on flames burning individual fuel components such as H2 and CH4, rather than syngas mixts. ...

Yongsheng Zhang; Tianming Yang; Xueqi Liu; Long Tian; Zhongguang Fu; Kai Zhang

2012-10-25T23:59:59.000Z

320

Method for producing flame retardant porous products and products produced thereby  

DOE Patents [OSTI]

A method for fire retarding porous products used for thermal energy storage and products produced thereby is provided. The method includes treating the surface of the phase change material-containing porous products with a urea fire-retarding agent. Upon exposure to a flame, the urea forms an adduct with the phase change material which will not sustain combustion (is self-extinguishing) in air. No halogens or metal oxides are contained in the fire retardant, so no potentially noxious halide smoke or fumes are emitted if the product is continuously exposed to a flame. 1 fig.

Salyer, I.O.

1998-08-04T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Method for producing flame retardant porous products and products produced thereby  

DOE Patents [OSTI]

A method for fire retarding porous products used for thermal energy storage and products produced thereby is provided. The method includes treating the surface of the phase change material-containing porous products with a urea fire-retarding agent. Upon exposure to a flame, the urea forms an adduct with the phase change material which will not sustain combustion (is self-extinguishing) in air. No halogens or metal oxides are contained in the fire retardant, so no potentially noxious halide smoke or fumes are emitted if the product is continuously exposed to a flame.

Salyer, Ival O. (Dayton, OH)

1998-08-04T23:59:59.000Z

322

Method for Producing Flame Retardant Porous Products and Products Produced Thereby  

DOE Patents [OSTI]

A method for fire retarding porous products used for thermal energy storage and products produced thereby is provided. The method includes treating the surface of the phase change material-containing porous products with a urea fire-retarding agent. Upon exposure to a flame, the urea forms an adduct with the phase change material which will not sustain combustion (is self-extinguishing) in air. No halogens or metal oxides are contained in the fire retardant, so no potentially noxious halide smoke or fumes are emitted if the product is continuously exposed to a flame.

Salyer, Ival O. (Dayton, OH)

1998-08-04T23:59:59.000Z

323

Comparison of the combustion behavior of Orimulsion{trademark} and heavy fuel oil in 70 MW flames  

SciTech Connect (OSTI)

Results of an experimental study are shown in this publication to compare the combustion behavior of heavy fuel oil (HFO) and Orimulsion in 70 MW flames. The investigation was carried out with the use of the combustion test rig at the International Combustion Limited in Derby, UK. The main objective of this test work was to quantify the extent of differences in flame properties, particulate and gaseous emissions of Orimulsion and HFO. Under identical combustion conditions, axial profiles of flame temperature and radiation heat flux were determined at 70 MW thermal input and 1% O{sub 2} for both fuels. Gas compositions at flame tail and furnace exit were obtained to estimate flame length and emission of gaseous pollutants. Stack concentration, carbon content, size and chemical composition of fly ash were also measured. The effect of excess air level on exit NOx and CO concentration were studied. Results of detailed flame measurements and the parametric study have shown that orimulsion fuel can be burnt with 99.97% efficiency at 1% exit O{sub 2} with a modified burner system of Dunamenti Power Station. However, significant implications of Orimulsion firing were observed. Gas temperature data and CO concentrations at flame tail have indicated a 1.5--2 m longer flame for Orimulsion. At flame tail, gas temperature in the Orimulsion flame was higher by 100 C than that for HFO. Lower radiant heat flux was measured in the near burner region for Orimulsion. Higher SO{sub 3}, SO{sub 2} and lower NOx emission were found when firing Orimulsion. Despite the higher ash content of Orimulsion, its combustion resulted in smaller particulate emission, which might be due to fly ash deposition in the furnace.

Barta, L.E. [Inst. for Energy, Budapest (Hungary); Horvath, G. [Hungarian Power Companies, Ltd., Budapest (Hungary); Allen, J.W.; Darar, J.S.; Wright, J.A. [International Combustion Ltd., Derby (United Kingdom). Rolls Royce Industrial Power Group; Szederkenyi, S.

1996-12-31T23:59:59.000Z

324

Detoxification of Salmonella typhimurium Lipopolysaccharide by Ionizing Radiation  

Science Journals Connector (OSTI)

...efficiency of ionizing radiation in detoxifying...decreased with doses above 1 Mrad...efficiency of ionizing radiation in detoxifying...decreased with doses above 1 Mrad...the visible range. After radiation, the general...radiation doses through 20...

Joseph J. Previte; Y. Chang; H. M. El-Bisi

1967-05-01T23:59:59.000Z

325

Oligonucleotide microarray analysis of low-dose ionizing radiation exposure  

Science Journals Connector (OSTI)

...health risk due to low-dose ionizing radiation is still debated. Functional...pathways that are induced by ionizing irradiation (IR...transcriptionally regulated by low-dose IR in occupationally...and showed different ranges of accumulated doses...

Paola Silingardi; Elena Morandi; Cinzia Severini; Daniele Quercioli; Monica Vaccari; Wolfango Horn; Maria Concetta Nucci; Vittorio Lodi; Francesco Violante; Sandro Grilli; and Annmaria Colacci

2007-05-01T23:59:59.000Z

326

Ionizing Radiation Activates the Nrf2 Antioxidant Response  

Science Journals Connector (OSTI)

...Scientific). Results Ionizing radiation does not activate ARE-reporter...determine if exposure to varying doses of ionizing radiation would activate the Nrf2-ARE pathway. The radiation dose range was extended below that used...

J. Tyson McDonald; Kwanghee Kim; Andrew J. Norris; Erina Vlashi; Tiffany M. Phillips; Chann Lagadec; Lorenza Della Donna; Josephine Ratikan; Heather Szelag; Lynn Hlatky; and William H. McBride

2010-11-01T23:59:59.000Z

327

High explosives vapor detection by atmospheric sampling glow discharge ionization/tandem mass spectrometry  

SciTech Connect (OSTI)

The combination of atmospheric sampling glow discharge ionization with tandem mass spectrometry for the detection of traces of high explosives is described. Particular emphasis is placed on use of the quadrupole ion trap as the type of tandem mass spectrometer. Atmospheric sampling glow discharge provides a simple, rugged, and efficient means for anion formation while the quadrupole ion trap provides for efficient tandem mass spectrometry. Mass selective ion accumulation and non-specific ion activation methods can be used to overcome deleterious effects arising from ion/ion interactions. Such interactions constitute the major potential technical barrier to the use of the ion trap for real-time monitoring of targeted compounds in uncontrolled and highly variable matrices. Tailored waveforms can be used to effect both mass selective ion accumulation and ion activation. Concatenated tailored waveforms allow for both functions in a single experiment thereby providing the capability for monitoring several targeted species simultaneously. The combination of atmospheric sampling glow discharge ionization with a state-of-the-art analytical quadrupole ion trap is a highly sensitive and specific detector for traces of high explosives. The combination is also small and inexpensive relative to virtually any other form of tandem mass spectrometry. The science and technology underlying the glow discharge/ion trap combination is sufficiently mature to form the basis for an engineering effort to make the detector portable. 85 refs.

McLuckey, S.A.; Goeringer, D.E.; Asano, K.G. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.

1996-02-01T23:59:59.000Z

328

Detectors - Instrument Support | ORNL Neutron Sciences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Detectors Detectors Detectors The detector design group, led by Yacouba Diawara is responsible for supporting the design of HFIR and SNS instruments by developing the necessary infrastructure and acquiring detector components that will be used to complete the functionality of the instruments. The group's mission also includes supporting detector research and development (R&D) for the various instruments and their different needs. The support effort for instrument design entails monitoring detector development worldwide as neutron facilities around the globe are getting upgraded and adopting the newest technologies. Detector group technician Ted Visscher inspects a parahedreal lens on an Anger camera Detector group technician Ted Visscher inspects a parahedreal lens on an

329

Imaging alpha particle detector  

DOE Patents [OSTI]

A method and apparatus for detecting and imaging alpha particles sources is described. A dielectric coated high voltage electrode and a tungsten wire grid constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source to be quantitatively or qualitatively analyzed. A thin polyester film window allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

Anderson, D.F.

1980-10-29T23:59:59.000Z

330

Imaging alpha particle detector  

DOE Patents [OSTI]

A method and apparatus for detecting and imaging alpha particles sources is described. A conducting coated high voltage electrode (1) and a tungsten wire grid (2) constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source (3) to be quantitatively or qualitatively analyzed. A thin polyester film window (4) allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

Anderson, David F. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

331

Particle detector spatial resolution  

DOE Patents [OSTI]

Method and apparatus for producing separated columns of scintillation layer material, for use in detection of X-rays and high energy charged particles with improved spatial resolution. A pattern of ridges or projections is formed on one surface of a substrate layer or in a thin polyimide layer, and the scintillation layer is grown at controlled temperature and growth rate on the ridge-containing material. The scintillation material preferentially forms cylinders or columns, separated by gaps conforming to the pattern of ridges, and these columns direct most of the light produced in the scintillation layer along individual columns for subsequent detection in a photodiode layer. The gaps may be filled with a light-absorbing material to further enhance the spatial resolution of the particle detector.

Perez-Mendez, Victor (Berkeley, CA)

1992-01-01T23:59:59.000Z

332

Fiber optic fluid detector  

DOE Patents [OSTI]

Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.

Angel, S.M.

1987-02-27T23:59:59.000Z

333

Event counting alpha detector  

DOE Patents [OSTI]

An electrostatic detector is disclosed for atmospheric radon or other weak sources of alpha radiation. In one embodiment, nested enclosures are insulated from one another, open at the top, and have a high voltage pin inside and insulated from the inside enclosure. An electric field is produced between the pin and the inside enclosure. Air ions produced by collision with alpha particles inside the decay volume defined by the inside enclosure are attracted to the pin and the inner enclosure. With low alpha concentrations, individual alpha events can be measured to indicate the presence of radon or other alpha radiation. In another embodiment, an electrical field is produced between parallel plates which are insulated from a single decay cavity enclosure. 6 figs.

Bolton, R.D.; MacArthur, D.W.

1996-08-27T23:59:59.000Z

334

Temperature profile detector  

DOE Patents [OSTI]

Disclosed is a temperature profile detector shown as a tubular enclosure surrounding an elongated electrical conductor having a plurality of meltable conductive segments surrounding it. Duplicative meltable segments are spaced apart from one another along the length of the enclosure. Electrical insulators surround these elements to confine molten material from the segments in bridging contact between the conductor and a second electrical conductor, which might be the confining tube. The location and rate of growth of the resulting short circuits between the two conductors can be monitored by measuring changes in electrical resistance between terminals at both ends of the two conductors. Additional conductors and separate sets of meltable segments operational at differing temperatures can be monitored simultaneously for measuring different temperature profiles. 8 figs.

Tokarz, R.D.

1983-10-11T23:59:59.000Z

335

Photo-Ionization and the Electrical Breakdown of Gases  

Science Journals Connector (OSTI)

25 June 1953 research-article Photo-Ionization and the Electrical Breakdown...theoretical investigation is made of the role of photo-ionization of the gas in the development...obtained experimentally. It is shown that photo-ionization can lead to electrical breakdown...

1953-01-01T23:59:59.000Z

336

Epidemiological Studies of Leukemia in Persons Exposed to Ionizing Radiation  

Science Journals Connector (OSTI)

...exposed to ionizing radiation, the author...the higher dose range regardless...low dose range, it is emphasized...possibility of radiation hazards existing at low doses should not...exposed to ionizing radiation...exposed to ionizing radiation, the author...the higher dose range regardless...

L. H. Hempelmann

1960-01-01T23:59:59.000Z

337

Critical Behavior of Electron Impact Ionization of Atoms  

E-Print Network [OSTI]

Critical Behavior of Electron Impact Ionization of Atoms IMAD LADADWA,1,2 SABRE KAIS1 1 Department of the electron impact ionization for different atoms are calculated numerically in the Born approximation as a function of both the incident electron energy and the nuclear charge Z of the ionized atom. We show

Kais, Sabre

338

A numerical scheme for ionizing shock waves  

SciTech Connect (OSTI)

A two-dimensional (2D) visual computer code to solve the steady state (SS) or transient shock problems including partially ionizing plasma is presented. Since the flows considered are hypersonic and the resulting temperatures are high, the plasma is partially ionized. Hence the plasma constituents are electrons, ions and neutral atoms. It is assumed that all the above species are in thermal equilibrium, namely, that they all have the same temperature. The ionization degree is calculated from Saha equation as a function of electron density and pressure by means of a nonlinear Newton type root finding algorithms. The code utilizes a wave model and numerical fluctuation distribution (FD) scheme that runs on structured or unstructured triangular meshes. This scheme is based on evaluating the mesh averaged fluctuations arising from a number of waves and distributing them to the nodes of these meshes in an upwind manner. The physical properties (directions, strengths, etc.) of these wave patterns are obtained by a new wave model: ION-A developed from the eigen-system of the flux Jacobian matrices. Since the equation of state (EOS) which is used to close up the conservation laws includes electronic effects, it is a nonlinear function and it must be inverted by iterations to determine the ionization degree as a function of density and temperature. For the time advancement, the scheme utilizes a multi-stage Runge-Kutta (RK) algorithm with time steps carefully evaluated from the maximum possible propagation speed in the solution domain. The code runs interactively with the user and allows to create different meshes to use different initial and boundary conditions and to see changes of desired physical quantities in the form of color and vector graphics. The details of the visual properties of the code has been published before (see [N. Aslan, A visual fluctuation splitting scheme for magneto-hydrodynamics with a new sonic fix and Euler limit, J. Comput. Phys. 197 (2004) 1-27]). The two-dimensional nature of ION-A was presented by a planar shock wave propagating over a circular obstacle. It was demonstrated that including the effects of ionization in calculating complex flows is important, even when they appear initially negligible. This code can be used to accurately simulate the nonlinear time dependent evolution of neutral or ionized plasma flows from supersonic to hypersonic regimes.

Aslan, Necdet [Yeditepe University, Physics Department, Kayisda g-circumflex i, 34755 Istanbul (Turkey)]. E-mail: naslan@yeditepe.edu.tr; Mond, Michael [Ben Gurion University, Mechanical Engineering Department, Beer Sheva (Israel)

2005-12-10T23:59:59.000Z

339

E-Print Network 3.0 - assisted resonance ionization Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ionization PADIACplasma43 Dielectricbarrierdischarge... Matrix-assisted ionization ... Source: Oak Ridge National Laboratory Fossil Energy Program Collection: Fossil Fuels 28...

340

Applications of Noble Gas Radiation Detectors to Counter?terrorism  

Science Journals Connector (OSTI)

Radiation detectors are essential tools in the detection analysis and disposition of potential terrorist devices containing hazardous radioactive and/or fissionable materials. For applications where stand?off distance and source shielding are limiting factors large detectors have advantages over small ones. The ability to distinguish between Special Nuclear Materials and false?positive signals from natural or man?made benign sources is also important. Ionization chambers containing compressed noble gases notably xenon and helium?3 can be scaled up to very large sizes improving the solid angle for acceptance of radiation from a distant source. Gamma spectrometers using Xe have a factor of three better energy resolution than NaI scintillators allowing better discrimination between radioisotopes. Xenon detectors can be constructed so as to have extremely low leakage currents enabling them to operate for long periods of time on batteries or solar cells. They are not sensitive to fluctuations in ambient temperature and are therefore suitable for deployment in outdoor locations. Position?sensitive 3He chambers have been built as large as 3000 cm2 and with spatial resolution of less than 1 mm. Combined with coded apertures made of cadmium they can be used to create images of thermal neutron sources. The natural background of spallation neutrons from cosmic rays generates a very low count rate so this instrument could be quite effective at identifying a man?made source such as a spontaneous fission source (Pu) in contact with a moderator (high explosive).

Peter E. Vanier; Leon Forman

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Flame-driven deflagration-to-detonation transitions in Type Ia supernovae?  

E-Print Network [OSTI]

Although delayed detonation models of thermonuclear explosions of white dwarfs seem promising for reproducing Type Ia supernovae, the transition of the flame propagation mode from subsonic deflagration to supersonic detonation remains hypothetical. A potential instant for this transition to occur is the onset of the distributed burning regime, i.e. the moment when turbulence first affects the internal flame structure. Some studies of the burning microphysics indicate that a deflagration-to-detonation transition may be possible here, provided the turbulent intensities are strong enough. Consequently, the magnitude of turbulent velocity fluctuations generated by the deflagration flame is analyzed at the onset of the distributed burning regime in several three-dimensional simulations of deflagrations in thermonuclear supernovae. It is shown that the corresponding probability density functions fall off towards high turbulent velocity fluctuations much more slowly than a Gaussian distribution. Thus, values claimed to be necessary for triggering a detonation are likely to be found in sufficiently large patches of the flame. Although the microphysical evolution of the burning is not followed and a successful deflagration-to-detonation transition cannot be guaranteed from simulations presented here, the results still indicate that such events may be possible in Type Ia supernova explosions.

F. K. Roepke

2007-09-26T23:59:59.000Z

342

Response of a laminar premixed flame to flow oscillations: A kinematic model and thermoacoustic instability results  

SciTech Connect (OSTI)

Combustion instability is a resonance phenomenon that arises due to the coupling between the system acoustics and the unsteady heat release. The constructive feedback between the two processes, which is known to occur as a certain phase relationship between the pressure and the unsteady heat release rate is satisfied, depends on many parameters among which is the acoustic mode, the flame holder characteristics, and the dominant burning pattern. In this paper, the authors construct an analytical model to describe the dynamic response of a laminar premixed flame stabilized on the rim of a tube to velocity oscillation. They consider uniform and nonuniform velocity perturbations superimposed on a pipe flow velocity profile. The model results show that the magnitude of heat release perturbation and its phase with respect to the dynamic perturbation dependent primarily on the flame Strohal number, representing the ratio of the dominant frequency times the tube radius to the laminar burning velocity. In terms of this number, high-frequency perturbations pass through the flame while low frequencies lead to a strong response. The phase with respect to the velocity perturbation behaves in the opposite way. Results of this model are shown to agree with experimental observations and to be useful in determining how the combustion excited model is selected among all the acoustic unstable modes. The model is then used to obtain a time-domain differential equation describing the relationship between the velocity perturbation and the heat release response over the entire frequency range.

Fleifil, M.; Annaswamy, A.M.; Ghoneim, A.F. [Massachusetts Inst. of Technology, Cambridge, MA (United States)] [Massachusetts Inst. of Technology, Cambridge, MA (United States); Ghoneim, Z.A. [Ain Shams Univ., Abassia (Egypt)] [Ain Shams Univ., Abassia (Egypt)

1996-09-01T23:59:59.000Z

343

Syngas production from burner-stabilized methane/air flames: The effect of preheated reactants  

Science Journals Connector (OSTI)

The effect of preheated reactants on syngas production from a methane/air flame was investigated over a range of inlet temperatures up to 630 K. In addition to experimental measurements, the results from a burner-stabilized flame and freely-propagating flame models are presented. A comparison of the modeling and experimental results in terms of flame standoff distance, stability limit conditions and species yields show excellent agreement across a broad range of equivalence ratios and preheat temperatures. Preheating of reactants increased the rich limit for stable operation from 1.26 to 1.75 for a given inlet velocity, and syngas yields were shown to increase with equivalence ratio. The preheat temperature of the reactants was shown to have little impact on syngas yields beyond extending the limits of stable operation. The results of this study are useful for the design and analysis of heat recirculating reactors and other reactors that are designed for producing syngas through the combustion of rich mixtures.

Colin H. Smith; Daniel I. Pineda; Janet L. Ellzey

2013-01-01T23:59:59.000Z

344

Heat Transfer from Augmented Flames and Plasma Jets Based on Magnetically Rotated Arcs  

Science Journals Connector (OSTI)

...November 1971 research-article Heat Transfer from Augmented Flames and Plasma...Jones F. J. Weinberg Rates of heat transfer to the inner surface of a surrounding...experimental data on a computer to yield heat transfer coefficients is developed on this...

1971-01-01T23:59:59.000Z

345

Carbon nanotubes grow in combustion flames Issued on March 31, 2014  

E-Print Network [OSTI]

Carbon nanotubes grow in combustion flames Issued on March 31, 2014 Quantum chemical simulations reveal an unprecedented relationship between the mechanism of carbon nanotube growth and hydrocarbon of carbon nanotube (CNT) growth and hydrocarbon combustion actually share many similarities. In studies

Takahashi, Ryo

346

Visualization of Turbulent Flame Fronts with Planar Laser-Induced Fluorescence  

Science Journals Connector (OSTI)

...TWO-DIMENSIONAL GAS CONCENTRATION MEASUREMENTS...flames at atmospheric pressure. More-over, the...carried out at constant pressure and the molecular...win-dows in the combustor. A simple fused...because ofthe often high and rapid-ly fluctuating...made it an ideal natural laboratory for the...

GEORGE KYCHAKOFF; ROBERT D. HOWE; RONALD K. HANSON; MICHAEL C. DRAKE; ROBERT W. PITZ; MARSHALL LAPP; C. MURRAY PENNEY

1984-04-27T23:59:59.000Z

347

Advancing predictive models for particulate formation in turbulent flames via massively parallel direct numerical simulations  

Science Journals Connector (OSTI)

...147. The pressure is atmospheric. The gas-phase hydrodynamics...formulation is the high-order inter...aeroderivative combustors, while the...fraction is highest (figure-4...scavenging gas-phase precursors...flame of natural gas and air...based on the high Da number...

2014-01-01T23:59:59.000Z

348

VisionGuided Flame Control Using Fuzzy Logic and Neural Networks  

E-Print Network [OSTI]

of the combustion processes are not amenable to mathematical modeling based on simple physical and chemical laws to a vision­guided closed loop control for stationary luminous flames. The image processing technique is used automatically. 2 #12; 1 Introduction Combustion, as one of the most important industrial processes, is a very

349

Testing of a Hydrogen Diffusion Flame Array Injector at Gas Turbine Conditions  

SciTech Connect (OSTI)

High-hydrogen gas turbines enable integration of carbon sequestration into coal-gasifying power plants, though NO{sub x} emissions are often high. This work explores nitrogen dilution of hydrogen diffusion flames to reduce thermal NO{sub x} emissions and avoid problems with premixing hydrogen at gas turbine pressures and temperatures. The burner design includes an array of high-velocity coaxial fuel and air injectors, which balances stability and ignition performance, combustor pressure drop, and flame residence time. Testing of this array injector at representative gas turbine conditions (16 atm and 1750 K firing temperature) yields 4.4 ppmv NO{sub x} at 15% O{sub 2} equivalent. NO{sub x} emissions are proportional to flame residence times, though these deviate from expected scaling due to active combustor cooling and merged flame behavior. The results demonstrate that nitrogen dilution in combination with high velocities can provide low NO{sub x} hydrogen combustion at gas turbine conditions, with significant potential for further NO{sub x} reductions via suggested design changes.

Weiland, Nathan T.; Sidwell, Todd G.; Strakey, Peter A.

2013-07-03T23:59:59.000Z

350

Synthesis of carbon nanotubes on metal alloy substrates with voltage bias in methane inverse diffusion flames  

E-Print Network [OSTI]

of the hydrocarbon fuel intrinsically provides not only the source of process heat to establish the requisite; Catalytically grown carbon; Combustion; Raman spectroscopy 1. Introduction Since IijimaÃ?s discovery [1] of CNTs-volume production, without the need for expensive starting materi- als. In flame synthesis, combustion

Tse, Stephen D.

351

Numerical simulation of Lewis number effects on lean premixed turbulent flames  

E-Print Network [OSTI]

turbulent flames for lean hydrogen, propane and methane mixtures in two dimensions. Each simulation or syngas, obtained from coal gasification, has sparked interest in the development of burners that can for propane, methane and hydrogen using de- tailed chemistry and transport, corresponding to Le > 1, Le 1

352

Flame-Retardant Epoxy Resin Nanocomposites Reinforced with Polyaniline-Stabilized Silica Nanoparticles  

E-Print Network [OSTI]

, Henry A. Colorado, Suying Wei,*,# and Zhanhu Guo*, Integrated Composites Lab (ICL), Dan F. Smith silsesquioxanes (POSS) reinforced epoxy composites.10 For the third method, the inorganic nanoparticles are often (ATH),13 silica (SiO2),14 nanoclay,15 and newly developed phosphorus- containing flame retardants 9

Guo, John Zhanhu

353

PHYSICAL REVIEW E 86, 036314 (2012) ac electric fields drive steady flows in flames  

E-Print Network [OSTI]

PHYSICAL REVIEW E 86, 036314 (2012) ac electric fields drive steady flows in flames Aaron M. Drews June 2012; published 20 September 2012) We show that time-oscillating electric fields applied-averaged force that drives the steady flows observed experimentally. A quantitative model describes the response

Heller, Eric

354

A combined computational and experimental characterization of lean premixed turbulent low swirl laboratory flames.  

E-Print Network [OSTI]

of these alternate fuels will vary significantly with the type of feedstocks and their treatment processes , Vince Beckner1 and Robert Cheng3 , 1 Center for Computational Sciences and Engineering, Lawrence, and then use the simulation data to further probe the time-dependent, 3D structure of the flames

Bell, John B.

355

Cellular burning in lean premixed turbulent hydrogen-air flames: coupling experimental and  

E-Print Network [OSTI]

of burners, particularly for alternative fuels, depends on improving our understanding of basic flame. Beckner1, M. J. Lijewski1 1 Center for Computational Science and Engineering, Lawrence Berkeley National for burning the fuel-lean mixtures of hydrogen or hydrogen-rich syngas fuels obtained from the gasification

356

Electric fields effect on liftoff and blowoff of nonpremixed laminar jet flames in a coflow  

SciTech Connect (OSTI)

The stabilization characteristics of liftoff and blowoff in nonpremixed laminar jet flames in a coflow have been investigated experimentally for propane fuel by applying AC and DC electric fields to the fuel nozzle with a single-electrode configuration. The liftoff and blowoff velocities have been measured by varying the applied voltage and frequency of AC and the voltage and the polarity of DC. The result showed that the AC electric fields extended the stabilization regime of nozzle-attached flame in terms of jet velocity. As the applied AC voltage increased, the nozzle-attached flame was maintained even over the blowout velocity without having electric fields. In such a case, a blowoff occurred directly without experiencing a lifted flame. While for the DC cases, the influence on liftoff was minimal. There existed three different regimes depending on the applied AC voltage. In the low voltage regime, the nozzle-detachment velocity of either liftoff or blowoff increased linearly with the applied voltage, while nonlinearly with the AC frequency. In the intermediate voltage regime, the detachment velocity decreased with the applied voltage and reasonably independent of the AC frequency. At the high voltage regime, the detachment was significantly influenced by the generation of discharges. (author)

Kim, M.K.; Ryu, S.K.; Won, S.H. [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea); Chung, S.H. [Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

2010-01-15T23:59:59.000Z

357

Strategies for laser-induced fluorescence detection of nitric oxide in high-pressure flames.  

E-Print Network [OSTI]

engines and gas turbines where the combustion chamber is at high pressure. Despite the use of catalyticStrategies for laser-induced fluorescence detection of nitric oxide in high-pressure flames. II. A combustion systems3�13 and thus develop new schemes to mini- mize NO effluent. The high operating pressure

Lee, Tonghun

358

Copyright 2007 by ASME1 Laminar Flame Speeds and Strain Sensitivities of Mixtures of H2  

E-Print Network [OSTI]

to rich. [Keywords: Syngas, laminar flame speed, reactant preheat, CO2 dilution, N2 dilution] INTRODUCTION Technologies such as integrated gasification combined cycle (IGCC) plants enable combustion of coal, biomass emissions. Synthetic gas (syngas) fuels derived from coal are particularly promising in this regard. Syngas

Seitzman, Jerry M.

359

EFFECT OF FUEL TYPE ON FLAME IGNITION BY TRANSIENT PLASMA Jianbang Liu1,2  

E-Print Network [OSTI]

to electrical energy consumed to produce the discharge.) Consequently, ignition by laser sources has beenEFFECT OF FUEL TYPE ON FLAME IGNITION BY TRANSIENT PLASMA DISCHARGES Jianbang Liu1,2 , Fei Wang1 with air ignited by transient plasma discharge were investigated and compared with spark discharge ignition

360

Flame Front Matching and Tracking in PLIF Images Using Geodesic Paths and Level Sets  

E-Print Network [OSTI]

. Successive images of the combustion process captured in controlled experiments are smoothed by non combustion processes of varying types and turbulence levels. The local intensity in the recorded images) imaging of OH radicals in combustion processes. The data includes both premixed flames subjected

Hamarneh, Ghassan

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Combustion and Flame 151 (2007) 235244 www.elsevier.com/locate/combustflame  

E-Print Network [OSTI]

Combustion and Flame 151 (2007) 235­244 www.elsevier.com/locate/combustflame Effect of ethanol Available online 26 July 2007 Abstract The effect of fuel-side ethanol addition on the chemical structure of average structural parameters. The results indicate that the ethanol effect on the aromatic components

Utah, University of

362

Ionization cross sections of gases for protons at kinetic energies between 20 MeV and 385 GeV, and applications to vacuum gauges in superconducting accelerators  

Science Journals Connector (OSTI)

Measurements have been made of the ionization cross sections of air, hydrogen, and argon by use of the KEK 500-MeV booster, the KEK 12-GeV main ring, and the Fermilab main ring. Within the beam duct of each of those accelerators, we placed a gas ionization monitor and recorded the current in the monitor as a function of the time elapsed since the beam injection for each pulse. This time is uniquely related to the instantaneous kinetic energy of protons. Because gas pressure in the monitor was kept sufficiently low (about 10-5 Torr), the current is attributable to single ionizing collisions of protons with molecules and is therefore proportional to the specific primary ionization, or the ionization cross section (rather than the total ionization). The dependence of the cross section on proton kinetic energy, measured for air, hydrogen, and argon, agrees closely with the prediction of the Bethe theory, and is represented by a straight line on the Fano plot. The data were tested for consistency with other measurements for electrons and protons at lower kinetic energies. Implications of the work for the design of accelerator vacuum components and of particle detectors are included. For instance, the technique used in the present measurements can be readily applied to the determination of the pressure distribution in a beam duct at liquid-helium temperature of an accelerator using superconducting magnets.

Hajime Ishimaru; Shinkichi Shibata; Mitio Inokuti

1995-06-01T23:59:59.000Z

363

Microsoft Word - Red Detector Tests _3_.doc  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Red Detector Tests May 5 ed -2006 1. Black Body @ 900F, Comparison between red and blue detectors: Table 1: Detector's signal with and without filters -BB at 900F Filter(micron)...

364

ATLAS Inner Detector Event Data Model  

E-Print Network [OSTI]

offline/? cvsroot=atlas : InnerDetector/InDetRawEvent/ATLAS Inner Detector Event Data Model F. Akesson 1 , M.J.the Inner Detector of the ATLAS experiment is presented. Di?

Costa, M.J.; ATLAS

2009-01-01T23:59:59.000Z

365

Stability characteristics of non-premixed turbulent jet flames of hydrogen and syngas blends with coaxial air  

Science Journals Connector (OSTI)

The stability characteristics of attached hydrogen (H2) and syngas (H2/CO) turbulent jet flames with coaxial air were studied experimentally. The flame stability was investigated by varying the fuel and air stream velocities. Effects of the coaxial nozzle diameter, fuel nozzle lip thickness and syngas fuel composition are addressed in detail. The detachment stability limit of the syngas single jet flame was found to decrease with increasing amount of carbon monoxide in the fuel. For jet flames with coaxial air, the critical coaxial air velocity leading to flame detachment first increases with increasing fuel jet velocity and subsequently decreases. This non-monotonic trend appears for all syngas composition herein investigated (50/50 ? 100/0% H2/CO). OH? chemiluminescence imaging was performed to qualitatively identify the mechanisms responsible for the flame detachment. For all fuel compositions, local extinction close to the burner rim is observed at lower fuel velocities (ascending stability limit), while local flame extinction downstream of the burner rim is observed at higher fuel velocities (descending stability limit). Extrema of the non-monotonic trends appear to be identical when the nozzle fuel velocity is normalized by the critical fuel velocity obtained for the single jet cases.

Jeongjae Hwang; Nicolas Bouvet; Kitae Sohn; Youngbin Yoon

2013-01-01T23:59:59.000Z

366

Soot formation in aerodynamically strained methane-air and ethylene-air diffusion flames with chloromethane addition  

SciTech Connect (OSTI)

The effects of chloromethane (CH{sub 3}Cl) addition on soot inception in methane-air and ethylene-air counterflow diffusion flames were investigated by varying the concentrations of chloromethane and nitrogen in the fuel stream. Experiments showed a monotonic increase in the critical sooting stretch rate for methane-air flames when methane was replaced by chloromethane, while ethylene and chloromethane flames exhibited a larger sooting tendency than flames under comparable conditions and burning either ethylene or chloromethane alone. For the conditions investigated, the critical sooting stretch rates of methane-chloromethane-nitrogen flames were shown to be primarily a function of the chloromethane loading in the fuel stream. The structure of these flames was modeled using detailed chemistry and transport. Modeling results suggested that the enhancement of soot formation in ethylene-chloromethane flames may be a combined result of increased concentrations of C{sub 2} species and chlorinated C{sub 1} radicals (CH{sub 2}Cl and CHCl). A large rate of the reactions among these species may be the first steps in the molecular growth processes, which leads to the inception of soot particles. (author)

Leylegian, J.C. [ATK GASL NY Operations, 77 Raynor Avenue, Ronkonkoma, NY 11779-6648 (United States)

2008-01-15T23:59:59.000Z

367

Photo-Ionization of Molecules near Threshold  

Science Journals Connector (OSTI)

An orthogonalized Coulomb-wave method for the construction of continuum wave functions of molecules is described. Hydrogenic functions of definite angular momentum, which transform according to the irreducible representations of the point group of the molecule, are phenomenologically used as trial functions. Corrections to the trial functions are made by orthogonalizing them to charge rearrangement states of the molecule. The photo-ionization cross section is obtained by summing over the asymptotic angular-momentum quantum number. The method is exemplified by calculation of the photo-ionization cross sections of the ground and first excited states of the anthracene molecule in the range of 1.5 eV above threshold.

John P. Hernandez

1968-03-05T23:59:59.000Z

368

Photo-Auger ionization of lithiumlike ions  

Science Journals Connector (OSTI)

The photo-Auger ionization process is a higher-order contribution to the direct photoelectric effect in which photoexcitation of an inner-shell electron is followed by the emission of an Auger electron. The frequency-integrated photo-Auger ionization cross section for ions of the lithium isoelectronic sequence is calculated in the isolated resonance approximation. The effects of transitions into all accessible intermediate states are explicitly included. Results are compared with the frequency-integrated direct photoionization cross section. The relative contribution of the photo-Auger effect for three-electron ions is a maximum in the Ne(7 +) region, where it is of order 70% of the direct process.

K. J. LaGattuta and Yukap Hahn

1982-01-01T23:59:59.000Z

369

External ionization mechanisms for advanced thermionic converters  

SciTech Connect (OSTI)

This work investigates ion generation and recombination mechanisms in the cesium plasma as they pertain to the advanced mode thermionic energy converter. The changes in plasma density and temperature within the converter have been studied under the influence of several promising auxiliary ionization candidate sources. Three novel approaches of external cesium ion generation have been investigated in some detail, namely vibrationally excited N/sub 2/ as are energy source of ionization of Cs ions in a dc discharge, microwave power as a means of resonant sustenance of the cesium plasma, and ion generation in a pulse N/sub 2/-Cs mixture. The experimental data obtained and discussed in this work show that all three techniques - i.e. the non-LTE high-voltage pulsing, the energy transfer from vibrationally excited diatomic gases, and the external pumping with a microwave power - have considerable promise as schemes in auxiliary ion generation applicable to the advanced thermionic energy converter.

Hatziprokopiou, M.E.

1981-01-01T23:59:59.000Z

370

Photo-Ionization of Crystalline Anthracene  

Science Journals Connector (OSTI)

The photo-ionization spectra of the ground, first singlet, and first triplet states of crystalline anthracene are calculated assuming transitions to a simple continuum. The calculations neglect vibrational-overlap factors which will reduce the cross sections perhaps by as much as a factor of 10. Recombination is also neglected, and is blamed for discrepancies between the calculation and experiments which measure photo-currents. Kepler has reported a cross section of 2×10-19 cm2 from the first singlet, Courtens et al., one of 0.6×10-19; the calculation gives 6×10-18. Holzman et al. report 10-20 cm2 from the first triplet; the calculation gives 6×10-18. If one accounted for vibrational overlap and recombination (which will be larger in the second experiment, because of the smaller kinetic energy), the agreement would be good. The agreement is not so good with the magnitude of transitions from the ground state, though the energy dependence gives a good fit. The discrepancy may be due to the (neglected) influence of auto-ionizing states on the final-state wave functions. Based on a theory by Choi, the singlet exciton-exciton ionization rate constant is calculated to be 2×10-9 cm3 sec-1 (vibrations and recombination neglected) compared with Silver's experimental value of 0.8×10-10; again the agreement is good. Finally, the time needed for a photo-ionized electron to lose kinetic energy by exciting a triplet is calculated to be 10-9 sec or longer, so this mechanism is ruled out as an energy-loss process in comparison with the emission of optical vibrations, which has been estimated to take about 10-13 sec.

John P. Hernandez

1968-05-15T23:59:59.000Z

371

The multiphoton ionization of uranium hexafluoride  

SciTech Connect (OSTI)

Multiphoton ionization (MPI) time-of-flight mass spectroscopy and photoelectron spectroscopy studies of UF{sub 6} have been conducted using focused light from the Nd:YAG laser fundamental ({lambda}=1064 nm) and its harmonics ({lambda}=532, 355, or 266 nm), as well as other wavelengths provided by a tunable dye laser. The MPI mass spectra are dominated by the singly and multiply charged uranium ions rather than by the UF{sub x}{sup +} fragment ions even at the lowest laser power densities at which signal could be detected. The laser power dependence of U{sup n+} ions signals indicates that saturation can occur for many of the steps required for their ionization. In general, the doubly-charged uranium ion (U{sup 2+}) intensity is much greater than that of the singly-charged uranium ion (U{sup +}). For the case of the tunable dye laser experiments, the U{sup n+} (n = 1- 4) wavelength dependence is relatively unstructured and does not show observable resonance enhancement at known atomic uranium excitation wavelengths. The dominance of the U{sup 2+} ion and the absence or very small intensities of UF{sub x}{sup +} fragments, along with the unsaturated wavelength dependence, indicate that mechanisms may exist other than ionization of bare U atoms after the stepwise photodissociation of F atoms from the parent molecule.

Armstrong, D.P. (Oak Ridge K-25 Site, TN (United States). UEO Enrichment Technical Operations Div.) [Oak Ridge K-25 Site, TN (United States). UEO Enrichment Technical Operations Div.

1992-05-01T23:59:59.000Z

372

Ionization photophysics and spectroscopy of dicyanoacetylene  

SciTech Connect (OSTI)

Photoionization of dicyanoacetylene was studied using synchrotron radiation over the excitation range 8–25 eV, with photoelectron-photoion coincidence techniques. The absolute ionization cross-section and detailed spectroscopic aspects of the parent ion were recorded. The adiabatic ionization energy of dicyanoacetylene was measured as 11.80 ± 0.01 eV. A detailed analysis of the cation spectroscopy involves new aspects and new assignments of the vibrational components to excitation of the quasi-degenerate A{sup 2}?{sub g}, B{sup 2}?{sub g}{sup +} states as well as the C{sup 2}?{sub u}{sup +} and D{sup 2}?{sub u} states of the cation. Some of the structured autoionization features observed in the 12.4–15 eV region of the total ion yield spectrum were assigned to vibrational components of valence shell transitions and to two previously unknown Rydberg series converging to the D{sup 2}?{sub u} state of C{sub 4}N{sub 2}{sup +}. The appearance energies of the fragment ions C{sub 4}N{sup +}, C{sub 3}N{sup +}, C{sub 4}{sup +}, C{sub 2}N{sup +}, and C{sub 2}{sup +} were measured and their heats of formation were determined and compared with existing literature values. Thermochemical calculations of the appearance potentials of these and other weaker ions were used to infer aspects of dissociative ionization pathways.

Leach, Sydney, E-mail: Sydney.Leach@obspm.fr, E-mail: Martin.Schwell@lisa.u-pec.fr; Champion, Norbert [LERMA UMR CNRS 8112, Observatoire de Paris-Meudon, 5 place Jules-Jansen, 92195 Meudon (France)] [LERMA UMR CNRS 8112, Observatoire de Paris-Meudon, 5 place Jules-Jansen, 92195 Meudon (France); Schwell, Martin, E-mail: Sydney.Leach@obspm.fr, E-mail: Martin.Schwell@lisa.u-pec.fr; Bénilan, Yves; Fray, Nicolas; Gazeau, Marie-Claire [LISA UMR CNRS 7583, Université Paris-Est Créteil and Université Paris Diderot, Institut Pierre Simon Laplace, 61 Avenue du Général de Gaulle, 94010 Créteil (France)] [LISA UMR CNRS 7583, Université Paris-Est Créteil and Université Paris Diderot, Institut Pierre Simon Laplace, 61 Avenue du Général de Gaulle, 94010 Créteil (France); Garcia, Gustavo A.; Gaie-Levrel, François [Synchrotron SOLEIL, L’Orme des Merisiers, St. Aubin, B.P. 48, 91192 Gif-sur-Yvette Cedex (France)] [Synchrotron SOLEIL, L’Orme des Merisiers, St. Aubin, B.P. 48, 91192 Gif-sur-Yvette Cedex (France); Guillemin, Jean-Claude [Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France)] [Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France)

2013-11-14T23:59:59.000Z

373

Reference Handbook: Pressure detectors  

SciTech Connect (OSTI)

The purpose of this handbook is to provide Rocky Flats personnel with the information necessary to understand pressure detection. Upon completion of this handbook you should be able to do the following: Define pressure in terms of force and area. Describe the basic operating principles of the U-Tube Manometer. Demonstrate proper techniques for reading Manometers. Describe the basic operating principles of the three types of Bourdon Tubes. Explain the difference between diaphragm. and bellows-type pressure measurement devices. This handbook is designed for use by experienced Rocky Flats operators to reinforce and improve their current knowledge level, and by entry-level operators to ensure that they possess a minimum level of fundamental knowledge. Pressure Detectors is applicable to many job classifications and can be used as a reference for classroom work or for self-study. Although this reference handbook is by no means all-encompassing, you will gain enough information about this subject area to assist you in contributing to the safe operations of Rocky Flats Plant.

Not Available

1990-11-09T23:59:59.000Z

374

Optical transcutaneous bilirubin detector  

DOE Patents [OSTI]

This invention consists of a transcutaneous bilirubin detector comprising a source of light having spectral components absorbable and not absorbable by bilirubin, a handle assembly, electronic circuitry and a fiber optic bundle connecting the assembly to the light source and circuitry. Inside the assembly is a prism that receives the light from one end of the fiber optic bundle and directs it onto the skin and directs the reflected light back into the bundle. The other end of the bundle is trifucated, with one end going to the light source and the other two ends going to circuitry that determines how much light of each kind has been reflected. A relatively greater amount absorbed by the skin from the portion of the spectrum absorbable by bilirubin may indicate the presence of the illness. Preferably, two measurements are made, one on the kneecap and one on the forehead, and compared to determine the presence of bilirubin. To reduce the impact of light absorption by hemoglobin in the blood carried by the skin, pressure is applied with a plunger and spring in the handle assembly, the pressure limited by points of a button slidably carried in the assembly that are perceived by touch when the pressure applied is sufficient.

Kronberg, J.W.

1991-03-04T23:59:59.000Z

375

Seal system with integral detector  

DOE Patents [OSTI]

There is disclosed a seal system for materials where security is of the essence, such as nuclear materials, which is tamper-indicating, which indicates changes in environmental conditions that evidence attempts to by-pass the seal, which is unique and cost effective, said seal system comprised of a seal where an optical signal is transmitted through a loop, with a detector to read said signal, and one or more additional detectors designed to detect environmental changes, these detectors being operatively associated with the seal so that detection of a break in the optical signal or detection of environmental changes will cause an observable change in the seal.

Fiarman, Sidney (Port Jefferson, NY)

1985-01-01T23:59:59.000Z

376

Solid state neutron detector array  

DOE Patents [OSTI]

A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors.

Seidel, John G. (Pittsburgh, PA); Ruddy, Frank H. (Monroeville, PA); Brandt, Charles D. (Mount Lebanon, PA); Dulloo, Abdul R. (Pittsburgh, PA); Lott, Randy G. (Pittsburgh, PA); Sirianni, Ernest (Monroeville, PA); Wilson, Randall O. (Greensburg, PA)

1999-01-01T23:59:59.000Z

377

ATLAS Forward Detectors and Physics  

E-Print Network [OSTI]

In this communication I describe the ATLAS forward physics program and the detectors, LUCID, ZDC and ALFA that have been designed to meet this experimental challenge. In addition to their primary role in the determination of ATLAS luminosity these detectors - in conjunction with the main ATLAS detector - will be used to study soft QCD and diffractive physics in the initial low luminosity phase of ATLAS running. Finally, I will briefly describe the ATLAS Forward Proton (AFP) project that currently represents the future of the ATLAS forward physics program.

N. Soni

2010-06-28T23:59:59.000Z

378

Oxygen contamination in liquid Argon: combined effects on ionization electron charge and scintillation light  

E-Print Network [OSTI]

A dedicated test of the effects of Oxygen contamination in liquid Argon has been performed at the INFN-Gran Sasso Laboratory (LNGS, Italy) within the WArP R&D program. Two detectors have been used: the WArP 2.3 lt prototype and a small (0.7 lt) dedicated detector, coupled with a system for the injection of controlled amounts of gaseous Oxygen. Purpose of the test with the 0.7 lt detector is to detect the reduction of the long-lived component lifetime of the Argon scintillation light emission at increasing O2 concentration. Data from the WArP prototype are used for determining the behavior of both the ionization electron lifetime and the scintillation long-lived component lifetime during the O2-purification process activated in closed loop during the acquisition run. The electron lifetime measurements allow to infer the O2 content of the Argon and correlate it with the long-lived scintillation lifetime data. The effect of Oxygen contamination on the scintillation light has been thus measured over a wide range of O2 concentration, spanning from about 10^-3 ppm up to about 10 ppm. The rate constant of the light quenching process induced by Oxygen in LAr has been found to be k'(O2)=0.54+-0.03 micros^-1 ppm^-1.

R. Acciarri; M. Antonello; B. Baibussinov; M. Baldo-Ceolin; P. Benetti; F. Calaprice; E. Calligarich; M. Cambiaghi; N. Canci; F. Carbonara; F. Cavanna; S. Centro; A. G. Cocco; F. Di Pompeo; G. Fiorillo; C. Galbiati; V. Gallo; L. Grandi; G. Meng; I. Modena; C. Montanari; O. Palamara; L. Pandola; F. Pietropaolo; G. L. Raselli; M. Roncadelli; M. Rossella; C. Rubbia; E. Segreto; A. M. Szelc; F. Tortorici; S. Ventura; C. Vignoli

2008-04-08T23:59:59.000Z

379

Detector Advisory Panel (DAP) Report  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ATLAS Project Manager's Review ATLAS Project Manager's Review 1-2 April 2010 Panel Members Lothar Bauerdick, FNAL Ray Larsen, SLAC Ronald Lipton, FNAL David Morrison, BNL Robert Roser, FNAL Steve Wolbers, FNAL Brookhaven National Laboratory Upton, New York 10 May 2010 Executive Summary The Detector and Computing Advisory Panels (DAP and CAP) reviewed the status and plans of the US-ATLAS Program at Brookhaven National Laboratory on April 1-2, 2010. The Panel was extremely pleased to hear of the highly successful commissioning of the ATLAS detector during early LHC collisions. The detector operated successfully, with no worse than 97% active channel count in any subsystem, from the start of collisions. There appears to be an excellent understanding of the detector performance via simulations. The BNL computing center has

380

Physics with the MAC detector  

SciTech Connect (OSTI)

New results, obtained during the previous year at the PEP colliding beam rings with the MAC detector at a center of mass energy of 29 GeV, are presented.

Ford, W.T.; Read, A.L. Jr., Smith, J. G.

1982-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Neutron detectors comprising boron powder  

SciTech Connect (OSTI)

High-efficiency neutron detector substrate assemblies comprising a first conductive substrate, wherein a first side of the substrate is in direct contact with a first layer of a powder material comprising .sup.10boron, .sup.10boron carbide or combinations thereof, and wherein a conductive material is in proximity to the first layer of powder material; and processes of making said neutron detector substrate assemblies.

Wang, Zhehui; Morris, Christopher; Bacon, Jeffrey Darnell; Makela, Mark F; Spaulding, Randy Jay

2013-05-21T23:59:59.000Z

382

STAR Vertex Detector Upgrade Development  

SciTech Connect (OSTI)

We report on the development and prototyping efforts undertaken with the goal of producing a micro-vertex detector for the STAR experiment at the RHIC accelerator at BNL. We present the basic detector requirements and show a sensor development path, conceptual mechanical design candidates and readout architecture. Prototyping and beam test results with current generation MimoSTAR-2 sensors and a readout system featuring FPGA based on-the-fly hit finding and data sparsification are also presented.

Greiner, Leo C.; Matis, Howard S.; Stezelberger, Thorsten; Vu,Chinh Q.; Wieman, Howard; Szelezniak, Michal; Sun, Xiangming

2008-01-28T23:59:59.000Z

383

Ignition of Deflagration and Detonation Ahead of the Flame due to Radiative Preheating of Suspended Micro Particles  

E-Print Network [OSTI]

We study a flame propagating in the gaseous combustible mixture with suspended inert solid micro particles. The gaseous mixture is assumed to be transparent for thermal radiation emitted by the hot combustion products, while particles absorb and reemit the radiation. Thermal radiation heats the particles, which in turn transfer the heat to the surrounding unburned gaseous mixture by means of thermal heat transfer. Different scenarios are possible depending on the spatial distribution of the particles, their size and the number density. In the case of uniform spatial distribution the radiation absorption ahead of the flame causes a modest increase of the combustion wave velocity. On the contrary, in the case of non-uniform distribution of the particles, such that the particles number density increases far ahead of the flame, the preheating caused by the thermal radiation may trigger additional source of ignition. Far enough ahead of the flame, where number density of particles is higher, the temperature due to...

Ivanov, M F; Liberman, M A

2014-01-01T23:59:59.000Z

384

A study of the phenomenon of liquid-flame combustion; I. Visual examinations and high-speed photography  

SciTech Connect (OSTI)

A liquid-flame combustion phenomenon, which has been revealed for pressed mixtures of tetrazole and sodium tetrazolate, was studied using high-speed photography and photography of high spatial resolution. New, previously unknown, peculiarities of the origin and development of the liquid-flame structure, pertinent, in particular, to its external texture and interaction with the melt on the pellet surface, as well as some features of the dispersion of condensed products were found.

Astashinsky, V.M.; Kostyukevich, E.A. (Byelorussian Academy of Science, Minsk (Belarus). Inst. of Molecular and Atomic Physics); Ivashkevich, O.A.; Lesnikovich, A.I.; Krasitsky, V.A. (Byelorussian State Univ., Minsk (Belarus))

1994-02-01T23:59:59.000Z

385

Evolution of soot size distribution in premixed ethylene/air and ethylene/benzene/air flames: Experimental and modeling study  

SciTech Connect (OSTI)

The effect of benzene concentration in the initial fuel on the evolution of soot size distribution in ethylene/air and ethylene/benzene/air flat flames was characterized by experimental measurements and model predictions of size and number concentration within the flames. Experimentally, a scanning mobility particle sizer was used to allow spatially resolved and online measurements of particle concentration and sizes in the nanometer-size range. The model couples a detailed kinetic scheme with a discrete-sectional approach to follow the transition from gas-phase to nascent particles and their coagulation to larger soot particles. The evolution of soot size distribution (experimental and modeled) in pure ethylene and ethylene flames doped with benzene showed a typical nucleation-sized (since particles do not actually nucleate in the classical sense particle inception is often used in place of nucleation) mode close to the burner surface, and a bimodal behavior at greater height above burner (HAB). However, major features were distinguished between the data sets. The growth of nucleation and agglomeration-sized particles was faster for ethylene/benzene/air flames, evidenced by the earlier presence of bimodality in these flames. The most significant changes in size distribution were attributed to an increase in benzene concentration in the initial fuel. However, these changes were more evident for high temperature flames. In agreement with the experimental data, the model also predicted the decrease of nucleation-sized particles in the postflame region for ethylene flames doped with benzene. This behavior was associated with the decrease of soot precursors after the main oxidation zone of the flames. (author)

Echavarria, Carlos A.; Sarofim, Adel F.; Lighty, JoAnn S. [Department of Chemical Engineering, University of Utah, Salt Lake City, UT (United States); D'Anna, Andrea [Dipartimento di Ingegneria Chimica, Universita ''Federico II'' di Napoli, Naples (Italy)

2011-01-15T23:59:59.000Z

386

Ionization Chambers in the FLASH Dump Line  

E-Print Network [OSTI]

. 7, 2010FLASH Seminar, Dec. 7, 2010 BPM 13DUMP Dump Line Upgrade 2009Dump Line Upgrade 2009 BPM 9DUMP BPM 5DUMP Toroid 9DUMP OTR screen 9DUMP BLM 14DUMP BLM 13.1DUMP 13.2DUMP BLM 9DUMP BLM 6DUMP BLM 1.1DUMP 1.2DUMP BPM 10DUMP BPM 16DUMP 8 x BHM 16DUMP BLM 14R.DUMP 14L.DUMP 14U.DUMP 14D.DUMP Ionization

387

(Resonance ionization spectroscopy and its applications)  

SciTech Connect (OSTI)

The field of Resonance Ionization Spectroscopy grew out of work done in the Photophysics Group at Oak Ridge National Laboratory. As one of the original developers of this field the traveler has continued to attend this meeting on a regular basis. The traveler was originally asked to present an invited talk and to present part of a short course offered to graduate students attending the conference. Subsequently, the traveler was also asked to chair a session and to be a judge of the students papers entered in a contest for a $1000 first prize.

Payne, M.G.

1990-10-05T23:59:59.000Z

388

Three-dimensional simulations of cellular non-premixed jet flames  

SciTech Connect (OSTI)

The formation, dynamics and structure of cellular flames in circular non-premixed jets are examined with three-dimensional numerical simulations incorporating detailed descriptions of chemistry and transport. Similar to past experiments reported in the literature, CO{sub 2}-diluted hydrogen in diluted or pure oxygen co-flowing streams in the proximity of the extinction limit are considered. As in the experiments, several preferred cellular states are found to co-exist with the particular state realized depending on initial conditions as well as on the jet characteristics. The simulations provide additionally the temporal transitions to different stationary or rotating cellular flames, their detailed structure, and the dependence of the scaling of the realized number of cells with the vorticity thickness. (author)

Valaer, A.L.; Frouzakis, C.E.; Boulouchos, K. [Aerothermochemistry and Combustion System Laboratory, Swiss Federal Institute of Technology, CH-8092 Zurich (Switzerland); Papas, P. [Division of Engineering, Colorado School of Mines, Golden, CO 80401 (United States); Tomboulides, A.G. [Department of Engineering and Management of Energy Resources, University of Western Macedonia, 50100 Kozani (Greece)

2010-04-15T23:59:59.000Z

389

Development of flame retarded self-reinforced composites from automotive shredder plastic waste  

Science Journals Connector (OSTI)

Multilayered self-reinforced composites were developed from a density-separated light fraction of automotive shredder waste of high polyolefin content, which can fulfil the current technical, safety and environmental requirements of structural materials. The significantly enhanced mechanical properties of the recycled composites were ensured by polypropylene fabric reinforcement; meanwhile, reduced flammability was obtained by modifying the matrix layers, made of secondary raw materials, with phosphorous-containing flame retardant additive. The results of the new flame retarded composite systems allowed the discussion of a novel mechanistic observation. The mechanical and flammability properties of the prepared self-reinforced composites are compared to conventional glass fabric reinforced composites and to compounds without reinforcement.

Katalin Bocz; Andrea Toldy; Ákos Kmetty; Tamás Bárány; Tamás Igricz; György Marosi

2012-01-01T23:59:59.000Z

390

Development of an energy efficient curtain flame ignition system for sintering of iron ore fines  

Science Journals Connector (OSTI)

Research and Development Centre for Iron and Steel (RDCIS) of Steel Authority of India Limited (SAIL) has developed a 'curtain flame' ignition system for sinter mix ignition. Conventionally, either horizontal fired burners or top fired or a combination of both are used for ignition of sinter mix. These burners big in size but few in number are mounted on a rectangular box type furnace. This is associated with non-uniform heating of sinter mix. In the new system, small capacity burners are installed on the roof across the sinter bed in a single row. Here, the top layer of the sinter bed gets heated by the direct impingement of the flame. This has resulted in reduction in specific fuel gas consumption by more than 30% and savings in refractory consumption. Implementation of the system led to reduction in green house gas (GHG) emission also.

V.T. Selvan; T.S. Reddy; A. Das

2012-01-01T23:59:59.000Z

391

Dielectric liquid ionization chambers for detecting fast neutrons  

E-Print Network [OSTI]

Three ionization chambers with different geometries have been constructed and filled with dielectric liquids for detection of fast neutrons. The three dielectric liquids studied were Tetramethylsilane (TMS), Tetramethylpentane ...

Boyd, Erin M

2008-01-01T23:59:59.000Z

392

Needs of the Chromatographer—Detectors  

Science Journals Connector (OSTI)

......synthetic fuels from coal or oil shale, are undesirable...or a change in flame chemistry. Therefore, it is...stable inorganic forms by combustion or hydrogenolysis...Sulfur is detected by combustion to form SO. and SO...SOj, NH3, or HCl by combustion or catalytic hydrogenolysis......

Harry V. Drushel

1983-08-01T23:59:59.000Z

393

IONIZATION OF EXTRASOLAR GIANT PLANET ATMOSPHERES  

SciTech Connect (OSTI)

Many extrasolar planets orbit close in and are subject to intense ionizing radiation from their host stars. Therefore, we expect them to have strong, and extended, ionospheres. Ionospheres are important because they modulate escape in the upper atmosphere and can modify circulation, as well as leave their signatures, in the lower atmosphere. In this paper, we evaluate the vertical location Z{sub I} and extent D{sub I} of the EUV ionization peak layer. We find that Z{sub I{approx}}1-10 nbar-for a wide range of orbital distances (a = 0.047-1 AU) from the host star-and D{sub I}/H{sub p{approx}}>15, where H{sub p} is the pressure scale height. At Z{sub I}, the plasma frequency is {approx}80-450 MHz, depending on a. We also study global ion transport, and its dependence on a, using a three-dimensional thermosphere-ionosphere model. On tidally synchronized planets with weak intrinsic magnetic fields, our model shows only a small, but discernible, difference in electron density from the dayside to the nightside ({approx}9 x 10{sup 13} m{sup -3} to {approx}2 x 10{sup 12} m{sup -3}, respectively) at Z{sub I}. On asynchronous planets, the distribution is essentially uniform. These results have consequences for hydrodynamic modeling of the atmospheres of close-in extrasolar giant planets.

Koskinen, Tommi T. [Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ (United States); Cho, James Y-K. [Astronomy Unit, School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Achilleos, Nicholas; Aylward, Alan D., E-mail: tommi@lpl.arizona.ed [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

2010-10-10T23:59:59.000Z

394

Heat transfer characteristics of laminar methane/air flame impinging normal to a cylindrical surface  

SciTech Connect (OSTI)

An experimental study has been conducted to determine the heat transfer characteristics of methane/air laminar flames impinging normal to a cylindrical surface. Effects of variations in the values of Reynolds number (Re = 600-1300), equivalence ratio ({phi} = 0.8-1.3), dimensionless separation distance (H/d = 1-5), and burner diameter to cylinder diameter ratio (d/D = 0.0538-0.1076) have been investigated. Three important configurations, viz., flame inner reaction zone far away, just touching and intercepted by the impingement surface, were examined in detail. High stagnation point heat fluxes were obtained when tip of the flame inner reaction zone just touched the target surface. Stagnation point heat fluxes were either zero or negative when the inner reaction zone was intercepted by the impingement surface. An off-stagnation peak in heat flux was obtained at moderate separation distances above the flame tip. Both stagnation point and peak heat fluxes increased with Re when the inner reaction zone length was less than the separation distance. Heat fluxes in the wall-jet region were high at high Re. Maximum heat fluxes were obtained for initially fuel-rich mixture conditions due to entrainment of the surrounding air. Smaller burner diameters produced high heat flux at the stagnation region for fixed Reynolds number and opposite trends were seen in the wall-jet region. A secondary rise in stagnation point heat flux was obtained at larger separation distances. This secondary rise in heat flux was quite significant for larger burner diameters and at low flow rates. Correlations were developed for stagnation point heat flux. Results were also compared with flat plate under identical operating conditions. (author)

Chander, Subhash; Ray, Anjan [Department of Mechanical Engineering, Indian Institute of Technology, Delhi, New Delhi 110 016 (India)

2007-11-15T23:59:59.000Z

395

Similarity solutions and applications to turbulent upward flame spread on noncharring materials  

SciTech Connect (OSTI)

The primary achievement in this work has been the discovery that turbulent upward flame spread on noncharring materials (for pyrolysis lengths less than 1.8m) can be directly predicted by using measurable flammability parameters. These parameters are: a characteristic length scale which is proportional to a turbulent combustion and mixing related length scale parameter ({dot q}{double_prime}{sub net}({Delta}H{sub c}/{Delta}H{sub v})){sup 2}, a pyrolysis or ignition time {tau}{sub p}, and a parameter which determines the transient pyrolysis history of a non-charring material: {lambda} = L/c{Delta}T{sub p} = ratio of the latent heat to the sensible heat of the pyrolysis temperature of the material. In the length scale parameter, {dot q}{double_prime}{sub net} is the total net heat flux from the flames to the wall (i.e., total heat flux minus reradiation losses), {Delta}H{sub c} is the heat of combustion and {Delta}H{sub v} is an effective heat of gasification for the material. The pyrolysis or ignition time depends (for thermally thick conditions) on the material thermal inertia, the pyrolysis temperature, and the total heat flux from the flames to the wall, {dot q}{double_prime}{sub fw}. The present discovery was made possible by using both a numerical simulation, developed earlier, and exact similarity solutions, which are developed in this work. The predictions of the analysis have been validated by comparison with upward flame spread experiments on PMMA.

Delichatsios, M.A.; Delichatsios, M.; Chen, Y. [Factory Mutual Research Corporation, Norwood, MA (United States)] [Factory Mutual Research Corporation, Norwood, MA (United States); Hasemi, Y. [Ministry of Construction, Tsukuba (Japan). Building Research Inst.] [Ministry of Construction, Tsukuba (Japan). Building Research Inst.

1995-08-01T23:59:59.000Z

396

Mechanism for Inhibition of Atmospheric-Pressure Syngas/Air Flames by Trimethylphosphate  

Science Journals Connector (OSTI)

Gasification processes allow for a wide range of solid combustibles, including coal, biomass, and municipal solid wastes, to be converted into syngas mixtures that can be burned in gas turbines to generate electricity. ... Burning velocity was measured using a Mache–Hebra nozzle burner(22) and the total area method(23) from flame images, as was performed by Linteris and Truett. ... Recommendations are made as to the most suitable methods of measuring burning velocity for both closed vessels and burners. ...

Vladimir M. Shvartsberg; Andrey G. Shmakov; Tatyana A. Bolshova; Oleg P. Korobeinichev

2012-08-10T23:59:59.000Z

397

Low and High Temperature Combustion Chemistry of Butanol Isomers in Premixed Flames and Autoignition Systems  

SciTech Connect (OSTI)

Butanol is a fuel that has been proposed as a bio-derived alternative to conventional petroleum derived fuels. The structural isomer in traditional 'bio-butanol' fuel is n-butanol, but newer conversion technologies produce iso-butanol as a fuel. In order to better understand the combustion chemistry of bio-butanol, this study presents a comprehensive chemical kinetic model for all the four isomers of butanol (e.g., 1-, 2-, iso- and tert-butanol). The proposed model includes detailed high temperature and low temperature reaction pathways. In this study, the primary experimental validation target for the model is premixed flat low-pressure flame species profiles obtained using molecular beam mass spectrometry (MBMS). The model is also validated against previously published data for premixed flame velocity and n-butanol rapid compression machine and shock tube ignition delay. The agreement with these data sets is reasonably good. The dominant reaction pathways at the various pressures and temperatures studied are elucidated. At low temperature conditions, we found that the reaction of alphahydroxybutyl with O{sub 2} was important in controlling the reactivity of the system, and for correctly predicting C{sub 4} aldehyde profiles in low pressure premixed flames. Enol-keto isomerization reactions assisted by HO{sub 2} were also found to be important in converting enols to aldehydes and ketones in the low pressure premixed flames. In the paper, we describe how the structural features of the four different butanol isomers lead to differences in the combustion properties of each isomer.

Sarathy, S M; Pitz, W J; Westbrook, C K; Mehl, M; Yasunaga, K; Curran, H J; Tsujimura, T; Osswald, P; Kohse-Hoinghaus, K

2010-12-12T23:59:59.000Z

398

Flame Evolution During Type Ia Supernovae and the Deflagration Phase in the Gravitationally Confined Detonation Scenario  

E-Print Network [OSTI]

We develop an improved method for tracking the nuclear flame during the deflagration phase of a Type Ia supernova, and apply it to study the variation in outcomes expected from the gravitationally confined detonation (GCD) paradigm. A simplified 3-stage burning model and a non-static ash state are integrated with an artificially thickened advection-diffusion-reaction (ADR) flame front in order to provide an accurate but highly efficient representation of the energy release and electron capture in and after the unresolvable flame. We demonstrate that both our ADR and energy release methods do not generate significant acoustic noise, as has been a problem with previous ADR-based schemes. We proceed to model aspects of the deflagration, particularly the role of buoyancy of the hot ash, and find that our methods are reasonably well-behaved with respect to numerical resolution. We show that if a detonation occurs in material swept up by the material ejected by the first rising bubble but gravitationally confined to the white dwarf (WD) surface (the GCD paradigm), the density structure of the WD at detonation is systematically correlated with the distance of the deflagration ignition point from the center of the star. Coupled to a suitably stochastic ignition process, this correlation may provide a plausible explanation for the variety of nickel masses seen in Type Ia Supernovae.

D. M. Townsley; A. C. Calder; S. M. Asida; I. R. Seitenzahl; F. Peng; N. Vladimirova; D. Q. Lamb; J. W. Truran

2007-06-07T23:59:59.000Z

399

Nanoengineering core/shell structured brucite@polyphosphate@amine hybrid system for enhanced flame retardant properties  

Science Journals Connector (OSTI)

Abstract A novel organic-inorganic hybrid flame retardant consisting of a brucite core and a dodecylamine polyphosphate shell was synthesized by a facile nanoengineering route. The flammability characterization and synergistic flame retardant mechanism of the core/shell flame retardant (CFR) in ethylene-vinyl acetate (EVA) blends had been compared with EVA/physical mixture (PM, with the given proportion of brucite and dodecylamine polyphosphate as well as CFR) and EVA/brucite blends. With the same loading amount (40 wt%) of fillers in EVA, the peak heat release rate and smoke production rate of EVA/CFR blends were significantly reduced to 49% and 48% of that of EVA/PM blends, respectively. Meanwhile, the limiting oxygen index (LOI) was increased up to 32 (14.3% higher than that of EVA/PM blends) and the UL-94 test could achieve the V-0 rating. These remarkable properties were obtained just by nanoengineeing the core/shell structured brucite@polyphosphate@amine hybrid system, facilitating the formation of intact and compact residue with fence structure in process of polymer composite burning.

Xuesong Wang; Hongchang Pang; Wendan Chen; Yuan Lin; Guiling Ning

2013-01-01T23:59:59.000Z

400

Flame propagation and counterflow nonpremixed ignition of mixtures of methane and ethylene  

SciTech Connect (OSTI)

The ignition temperature of nitrogen-diluted mixtures of methane and ethylene counterflowing against heated air was measured up to five atmospheres. In addition, the stretch-corrected laminar flame speeds of mixtures of air, methane and ethylene were determined from outwardly-propagating spherical flames up to 10 atmospheres, for extensive range of the lean-to-rich equivalence ratio. These experimental data, relevant to low- to moderately-high-temperature ignition chemistry and high-temperature flame chemistry, respectively, were subsequently compared with calculations using two detailed kinetic mechanisms. A chemical explosive mode analysis (CEMA) was then conducted to identify the dominant ignition chemistry and the role of ethylene addition in facilitating nonpremixed ignition. Furthermore, the hierarchical structure of the associated oxidation kinetics was examined by comparing the sizes and constituents of the skeletal mechanisms of the pure fuels and their mixtures, derived using the method of directed relation graph (DRG). The skeletal mechanism was further reduced by time-scale analysis, leading to a 24-species reduced mechanism from the detailed mechanism of USC Mech II, validated within the parameter space of the conducted experiments. (author)

Liu, W.; Kelley, A.P.; Law, C.K. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States)

2010-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Evidence of thermonuclear flame spreading on neutron stars from burst rise oscillations  

E-Print Network [OSTI]

Burst oscillations during the rising phases of thermonuclear X-ray bursts are usually believed to originate from flame spreading on the neutron star surface. However, the decrease of fractional oscillation amplitude with rise time, which provides a main observational support for the flame spreading model, have so far been reported from only a few bursts. Moreover, the non-detection and intermittent detections of rise oscillations from many bursts are not yet understood considering the flame spreading scenario. Here, we report the decreasing trend of fractional oscillation amplitude from an extensive analysis of a large sample of Rossi X-ray Timing Explorer Proportional Counter Array bursts from ten neutron star low-mass X-ray binaries. This trend is 99.99% significant for the best case, which provides, to the best of our knowledge, by far the strongest evidence of such trend. Moreover, it is important to note that an opposite trend is not found from any of the bursts. The concave shape of the fractional ampli...

Chakraborty, Manoneeta

2014-01-01T23:59:59.000Z

402

Rotational effects in thermonuclear Type I Bursts: equatorial crossing and directionality of flame spreading  

E-Print Network [OSTI]

In a previous study on thermonuclear (Type I) Bursts on accreting neutron stars we addressed and demonstrated the importance of the effects of rotation, through the Coriolis force, on the propagation of the burning flame. However, that study only analysed cases of longitudinal propagation, where the Coriolis force coefficient $2\\Omega\\cos\\theta$ was constant. In this paper, we study the effects of rotation on propagation in the meridional (latitudinal) direction, where the Coriolis force changes from its maximum at the poles to zero at the equator. We find that the zero Coriolis force at the equator, while affecting the structure of the flame, does not prevent its propagation from one hemisphere to another. We also observe structural differences between the flame propagating towards the equator and that propagating towards the pole, the second being faster. In the light of the recent discovery of the low spin frequency of burster IGR~J17480-2446 rotating at 11 Hz (for which Coriolis effects should be negligib...

Cavecchi, Yuri; Levin, Yuri; Braithwaite, Jonathan

2014-01-01T23:59:59.000Z

403

Determination of Aromatics in Jet and Diesel Fuels by Supercritical Fluid Chromatography with Flame Ionization Detection (SFC—FID): A Quantitative Study  

Science Journals Connector (OSTI)

......fuels (2). However, these techniques are not generally used in routine analysis because of the high initial capital expenditure and the require ment of highly skilled operators. Liquid chromatography ( L C ) has been used extensively in the......

F.P. Di Sanzo; R.E. Yoder

1991-01-01T23:59:59.000Z

404

Determination of Total Biodiesel Fatty Acid Methyl, Ethyl Esters, and Hydrocarbon Types in Diesel Fuels by Supercritical Fluid Chromatography-Flame Ionization Detection  

Science Journals Connector (OSTI)

......Research and Engineering, Paulsboro...determining total biodiesel methyl and...in diesel fuels by supercritical...mixture. Introduction The proposed use of biodiesel esters derived...as diesel fuel blending...of Total Biodiesel Fatty Acid...in Diesel Fuels by Supercritical...Research and Engineering, Paulsboro......

John W. Diehl; Frank P. DiSanzo

405

Determination of Total Biodiesel Fatty Acid Methyl, Ethyl Esters, and Hydrocarbon Types in Diesel Fuels by Supercritical Fluid Chromatography-Flame Ionization Detection  

Science Journals Connector (OSTI)

......Determination of Total Biodiesel Fatty Acid Methyl...vortex mixer. This process produced solutions ranging...D5186 indicated that the biodiesel esters were not eluted...0%. For further evaluation, the quantitative analysis...determination of the biodiesel ester components by......

John W. Diehl; Frank P. DiSanzo

406

Performance of a Large Area Avalanche Photodiode in a Liquid Xenon Ionization and Scintillation Chamber  

E-Print Network [OSTI]

Scintillation light produced in liquid xenon (LXe) by alpha particles, electrons and gamma-rays was detected with a large area avalanche photodiode (LAAPD) immersed in the liquid. The alpha scintillation yield was measured as a function of applied electric field. We estimate the quantum efficiency of the LAAPD to be 45%. The best energy resolution from the light measurement at zero electric field is 7.5%(sigma) for 976 keV internal conversion electrons from Bi-207 and 2.6%(sigma) for 5.5 MeV alpha particles from Am-241. The detector used for these measurements was also operated as a gridded ionization chamber to measure the charge yield. We confirm that using a LAAPD in LXe does not introduce impurities which inhibit the drifting of free electrons.

K. Ni; E. Aprile; D. Day; K. L. Giboni; J. A. M. Lopes; P. Majewski; M. Yamashita

2005-02-14T23:59:59.000Z

407

First measurement of the ionization yield of nuclear recoils in liquid argon  

SciTech Connect (OSTI)

Liquid phase argon has long been used as a target medium for particle detection via scintillation light. Recently there has been considerable interest in direct detection of both hypothetical darkmatter particles and coherent elastic neutrino nucleus scattering. These as-yet unobserved neutral particle interactions are expected to result in a recoiling argon atom O(keV), generally referred to in the literature as a nuclear recoil. This prompts the question of the available electromagnetic signal in a liquid argon detector. In this Letter we report the first measurement of the ionization yield (Qy), detected electrons per unit energy, resulting from nuclear recoils in liquid argon, measured at 6.7 keV. This is also the lowest energy measurement of nuclear recoils in liquid argon.

Joshi, T. [Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering; Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Sangiorgio, Samuele [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Bernstein, A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Foxe, Michael P. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering; Hagmann, Chris [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Jovanovic, Igor [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering; Kazkaz, K. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Mozin, Vladimir V. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Norman, E. B. [Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering; Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Pereverzev, S. V. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Rebassoo, Finn O. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Sorensen, Peter F. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

2014-05-01T23:59:59.000Z

408

High efficiency direct detection of ions from resonance ionization of sputtered atoms  

DOE Patents [OSTI]

A method and apparatus are provided for trace and other quantitative analysis with high efficiency of a component in a sample, with the analysis involving the removal by ion or other bombardment of a small quantity of ion and neutral atom groups from the sample, the conversion of selected neutral atom groups to photoions by laser initiated resonance ionization spectroscopy, the selective deflection of the photoions for separation from original ion group emanating from the sample, and the detection of the photoions as a measure of the quantity of the component. In some embodiments, the original ion group is accelerated prior to the RIS step for separation purposes. Noise and other interference are reduced by shielding the detector from primary and secondary ions and deflecting the photoions sufficiently to avoid the primary and secondary ions.

Gruen, D.M.; Pellin, M.J.; Young, C.E.

1985-01-16T23:59:59.000Z

409

PIN detector arrays and integrated readout circuitry on high-resistivity float-zone silicon  

SciTech Connect (OSTI)

A new silicon PIN-diode-based pixel detector for ionizing particles integrating a two-dimensional array of detecting elements with readout circuitry has been developed and extensively tested. The signal charge is collected on a low-capacitance electrode avoiding loss of charge into the local readout circuitry within each pixel. The spatial resolution for a given circuitry size is optimized. The approach required back side patterning of the wafer, the only nonconventional part in the Stanford BiCMOS based manufacturing process. Thirteen masks on the front side of the wafer and three on the back yielded both CMOS readout circuitry and detecting elements. A gettering step helped obtain a high minority carrier lifetime (500 [mu]s). Test results obtained by infrared illumination, gamma rays, and high-energy particles, which have been described in detail elsewhere, will be summarized. They include a signal to single-channel-noise performance of about 150 to 1 for a minimum ionizing particle, which is an order of magnitude better than silicon strip detectors currently used, and a record-breaking spatial resolution in the direction of smallest pixel pitch (standard deviation of about 1.8 [mu]m). The authors describe the device and chip operation of the new detector in detail.

Snoeys, W.; Plummer, J. (Stanford Univ., CA (United States). Center for Integrated Systems); Parker, S.; Kenney, C. (Univ. of Hawaii, Honolulu, HI (United States). Dept. of Physics)

1994-06-01T23:59:59.000Z

410

Al/Al2O3 Composite Coating Deposited by Flame Spraying for Marine Applications: Alumina Skeleton Enhances Anti-Corrosion and Wear Performances  

Science Journals Connector (OSTI)

Here we report aluminum-alumina composite coatings fabricated by flame spraying for potential marine applications against both corrosion and wear. Microstructure examination suggested dense coating structures and...

Jing Huang; Yi Liu; Jianhui Yuan; Hua Li

2014-04-01T23:59:59.000Z

411

Pulse Rise Time Characterization of a High Pressure Xenon Gamma Detector for use in Resolution Enhancement  

SciTech Connect (OSTI)

High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% {at} 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma photons. Time discrimination was used to characterize the pulse rise time versus photo peak position and resolution. These data were collected to investigate the effect of pulse rise time compensation on resolution and efficiency.

TROYER, G.L.

2000-08-25T23:59:59.000Z

412

Silicon Detector Letter of Intent  

SciTech Connect (OSTI)

This document presents the current status of SiD's effort to develop an optimized design for an experiment at the International Linear Collider. It presents detailed discussions of each of SiD's various subsystems, an overview of the full GEANT4 description of SiD, the status of newly developed tracking and calorimeter reconstruction algorithms, studies of subsystem performance based on these tools, results of physics benchmarking analyses, an estimate of the cost of the detector, and an assessment of the detector R&D needed to provide the technical basis for an optimised SiD.

Aihara, H.; Burrows, P.; Oreglia, M.

2010-05-26T23:59:59.000Z

413

1. Introduction Alanine-based ionizing radiation dosimetry is firmly  

E-Print Network [OSTI]

1. Introduction Alanine-based ionizing radiation dosimetry is firmly woven into the fabric of high-dose System and Its Implications in High-Dose Ionizing Radiation Metrology Volume 113 Number 2 March.g., radiochromic dosimetry). From the NMI's perspective, the broad absorbed- dose range of the alanine system

414

Electron Capture in a Fully Ionized Plasma  

E-Print Network [OSTI]

Properties of fully ionized water plasmas are discussed including plasma charge density oscillations and the screening of the Coulomb law especially in the dilute classical Debye regime. A kinetic model with two charged particle scattering events determines the transition rate per unit time for electron capture by a nucleus with the resulting nuclear transmutations. Two corrections to the recent Maiani et al. calculations are made: (i) The Debye screening length is only employed within its proper domain of validity. (ii) The WKB approximation employed by Maiani in the long De Broglie wave length limit is evidently invalid. We replace this incorrect approximation with mathematically rigorous Calogero inequalities in order to discuss the scattering wave functions. Having made these corrections, we find a verification for our previous results based on condensed matter electro-weak quantum field theory for nuclear transmutations in chemical batteries.

A. Widom; J. Swain; Y. N. Srivastava

2014-09-17T23:59:59.000Z

415

Photo-Ionization of the Hydrogen Molecule  

Science Journals Connector (OSTI)

One-center wave functions are employed to investigate the photo-ionization of the hydrogen molecule from its ground state X(1s??g1+), from 700 to 300 Å. It is assumed that the residual ion is left in its ground state, and the free electron is in a p? or p? orbital. Using the one-center wave functions for H2+ for the internuclear distance equal to 1. 4a0, the free-electron wave functions are obtained by solving the integrodifferential equations in exchange and polarized-orbital approximations. The oscillator strengths obtained in the polarized-orbital approximation are found to be in satisfactory agreement with the experimental data.

S. P. Khare

1968-09-05T23:59:59.000Z

416

Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation Print Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation Print Understanding charge-transfer processes at the atomic level of nanoscale systems is of the utmost importance for designing nanodevices based on quantum-dot structures, nanotubes, or two-dimensional graphene sheets. Researchers from Western Michigan University, Berkeley Lab, and other international research facilities investigated charge-transfer processes and subsequent ion fragmentation dynamics in nanoclusters composed of argon (Ar) shells and xenon (Xe) cores. The clusters were site-selectively ionized (i.e, ionization took place either in the xenon core or in the argon shell). Using a high-resolution photoelectron-ion coincidence technique at ALS Beamlines 10.0.1 and 11.0.2, the researchers concluded that charge-transfer processes and fragmentation dynamics are strongly influenced by the environment of the initially ionized atoms.

417

Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation Print Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation Print Understanding charge-transfer processes at the atomic level of nanoscale systems is of the utmost importance for designing nanodevices based on quantum-dot structures, nanotubes, or two-dimensional graphene sheets. Researchers from Western Michigan University, Berkeley Lab, and other international research facilities investigated charge-transfer processes and subsequent ion fragmentation dynamics in nanoclusters composed of argon (Ar) shells and xenon (Xe) cores. The clusters were site-selectively ionized (i.e, ionization took place either in the xenon core or in the argon shell). Using a high-resolution photoelectron-ion coincidence technique at ALS Beamlines 10.0.1 and 11.0.2, the researchers concluded that charge-transfer processes and fragmentation dynamics are strongly influenced by the environment of the initially ionized atoms.

418

Laser plasma formation assisted by ultraviolet pre-ionization  

SciTech Connect (OSTI)

We present experimental and modeling studies of air pre-ionization using ultraviolet (UV) laser pulses and its effect on laser breakdown of an overlapped near-infrared (NIR) pulse. Experimental studies are conducted with a 266?nm beam (fourth harmonic of Nd:YAG) for UV pre-ionization and an overlapped 1064?nm NIR beam (fundamental of Nd:YAG), both having pulse duration of ?10?ns. Results show that the UV beam produces a pre-ionized volume which assists in breakdown of the NIR beam, leading to reduction in NIR breakdown threshold by factor of >2. Numerical modeling is performed to examine the ionization and breakdown of both beams. The modeled breakdown threshold of the NIR, including assist by pre-ionization, is in reasonable agreement with the experimental results.

Yalin, Azer P., E-mail: ayalin@engr.colostate.edu; Dumitrache, Ciprian [Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Wilvert, Nick [Sandia Laboratory, Albuquerque, New Mexico 87123 (United States); Joshi, Sachin [Cummins Inc., Columbus, Indiana 47201 (United States); Shneider, Mikhail N. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

2014-10-15T23:59:59.000Z

419

A comprehensive range of X-ray ionized reflection models  

E-Print Network [OSTI]

X-ray ionized reflection occurs when a surface is irradiated with X-rays so intense that its ionization state is determined by the ionization parameter xi propto F/n, where F is the incident flux and n the gas density. It occurs in accretion, onto compact objects including black holes in both active galaxies and stellar-mass binaries, and possibly in gamma-ray bursts. Computation of model reflection spectra is often time-consuming. Here we present the results from a comprehensive grid of models computed with our code, which has now been extended to include what we consider to be all energetically-important ionization states and transitions. This grid is being made available as an ionized-reflection model, REFLION, for XSPEC.

R. R. Ross; A. C. Fabian

2005-01-07T23:59:59.000Z

420

Near-threshold positron impact ionization of hydrogen  

SciTech Connect (OSTI)

The hyperspherical hidden crossing method (HHCM) is used to investigate positron impact ionization of hydrogen near threshold. An important feature of this method is that it can provide valuable insight into scattering processes. In the calculation of positron-hydrogen ionization, the adiabatic Hamiltonian is expanded about the Wannier saddle point; anharmonic corrections are treated perturbatively. The S-wave results are consistent with the Wannier threshold law and with the extended threshold law that was previously derived using the HHCM. We have extended the previous HHCM calculation to higher angular momenta L and have calculated the absolute ionization cross-section for L = 0, 1 and 2. The HHCM calculation confirms that the S-wave ionization cross-section is small and provides the reason why it is small. The HHCM ionization cross-section (summed over the lowest partial waves) is compared with a convergent close-coupling calculation, a 33-state close-coupling calculation and experimental data.

Macek, Joseph H [ORNL; Ward, S.J. [University of North Texas; Jansen, Krista [University of North Texas; Shertzer, J. [College Holy Cross, Worcester, MA

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Direct detector for terahertz radiation  

DOE Patents [OSTI]

A direct detector for terahertz radiation comprises a grating-gated field-effect transistor with one or more quantum wells that provide a two-dimensional electron gas in the channel region. The grating gate can be a split-grating gate having at least one finger that can be individually biased. Biasing an individual finger of the split-grating gate to near pinch-off greatly increases the detector's resonant response magnitude over prior QW FET detectors while maintaining frequency selectivity. The split-grating-gated QW FET shows a tunable resonant plasmon response to FIR radiation that makes possible an electrically sweepable spectrometer-on-a-chip with no moving mechanical optical parts. Further, the narrow spectral response and signal-to-noise are adequate for use of the split-grating-gated QW FET in a passive, multispectral terahertz imaging system. The detector can be operated in a photoconductive or a photovoltaic mode. Other embodiments include uniform front and back gates to independently vary the carrier densities in the channel region, a thinned substrate to increase bolometric responsivity, and a resistive shunt to connect the fingers of the grating gate in parallel and provide a uniform gate-channel voltage along the length of the channel to increase the responsivity and improve the spectral resolution.

Wanke, Michael C. (Albuquerque, NM); Lee, Mark (Albuquerque, NM); Shaner, Eric A. (Albuquerque, NM); Allen, S. James (Santa Barbara, CA)

2008-09-02T23:59:59.000Z

422

Escherichia coli Genes and Pathways Involved in Surviving Extreme Exposure to Ionizing Radiation  

Science Journals Connector (OSTI)

...doses of ionizing radiation does not depend on...the effects of high doses of ionizing radiation (IR). The repair...IR resistance. A range of modern screening...survive increasing doses of ionizing radiation in comparison to...

Rose T. Byrne; Stefanie H. Chen; Elizabeth A. Wood; Eric L. Cabot; Michael M. Cox

2014-07-21T23:59:59.000Z

423

Backward Raman amplification in a partially ionized gas A. A. Balakin,1  

E-Print Network [OSTI]

was accessed 10,11 . The experimental success was achieved using a gas jet of propane, subse- quently ionized of propane opens up the question of coupling in a partially ionized gas. Any additional ionization during

424

Neutron coincidence detectors employing heterogeneous materials  

DOE Patents [OSTI]

A neutron detector relies upon optical separation of different scintillators to measure the total energy and/or number of neutrons from a neutron source. In pulse mode embodiments of the invention, neutrons are detected in a first detector which surrounds the neutron source and in a second detector surrounding the first detector. An electronic circuit insures that only events are measured which correspond to neutrons first detected in the first detector followed by subsequent detection in the second detector. In spectrometer embodiments of the invention, neutrons are thermalized in the second detector which is formed by a scintillator-moderator and neutron energy is measured from the summed signals from the first and second detectors.

Czirr, J. Bartley (Mapleton, UT); Jensen, Gary L. (Orem, UT)

1993-07-27T23:59:59.000Z

425

E-Print Network 3.0 - assisted laser ionization Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: of a high power pulsed far-infrared laser. Furthermore, impurity ionization with terahertz radiation can... of ionization capture processes due to the Poole-Frenkel...

426

E-Print Network 3.0 - activities involving ionizing Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Collection: Physics 62 Magnetic field effect on tunnel ionization of deep impurities by terahertz radiation S.D. Ganichev1 Summary: Magnetic field effect on tunnel ionization of...

427

scienceessays IDTL personnel and detector characterization  

E-Print Network [OSTI]

, and this training will ultimately benefit the development and operation of the JWST and future missions. NASA hasnews 3 scienceessays IDTL personnel and detector characterization system. From left to right to select the best flight detector designs for JWST by evaluating prototype near-infrared detectors. Second

Figer, Donald F.

428

A mobile antineutrino detector with plastic scintillators  

E-Print Network [OSTI]

We propose a new type segmented antineutrino detector made of plastic scintillators for the nuclear safeguard application. A small prototype was built and tested to measure background events. A satisfactory unmanned field operation of the detector system was demonstrated. Besides, a detailed Monte Carlo simulation code was developed to estimate the antineutrino detection efficiency of the detector.

Yasuhiro Kuroda; Shugo Oguri; Yo Kato; Ryoko Nakata; Yoshizumi Inoue; Chikara Ito; Makoto Minowa

2012-06-28T23:59:59.000Z

429

Sandia Neutron Detector Is Based on Polyacetylene  

Science Journals Connector (OSTI)

Sandia Neutron Detector Is Based on Polyacetylene ... It also might form the basis of an electrically readable dosimeter that records neutron flux (measured as neutrons per square centimeter) as well as a detector that could provide a cross-sectional image of neutron flux with high spatial resolution. ... Hence, most neutron detectors use a converter material that converts the neutrons to charged particles. ...

RUDY BAUM

1987-02-09T23:59:59.000Z

430

The Harris Corner Detector Konstantinos G. Derpanis  

E-Print Network [OSTI]

will result in a significant increase; this indicates a corner. References [1] C. Harris and M.J. StephensThe Harris Corner Detector Konstantinos G. Derpanis kosta@cs.yorku.ca October 27, 2004 In this report the derivation of the Harris corner detector [1] is presented. The Harris corner detector

Salvaggio, Carl

431

Plasmadynamics and ionization kinetics of thermionic energy conversion  

SciTech Connect (OSTI)

To reduce the plasma arc-drop, thermionic energy conversion is studied with both analytical and numerical tools. Simplifications are made in both the plasmadynamic and ionization-recombination theories. These are applied to a scheme proposed presently using laser irradiation to enhance the ionization kinetics of the thermionic plasma and thereby reduce the arc-drop. It is also predicted that it is possible to generate the required laser light from a thermionic-type cesium plasma. The analysis takes advantage of theoretical simplifications derived for the ionization-recombination kinetics. It is shown that large laser ionization enhancements can occur and that collisional cesium recombination lasing is expected. To complement the kinetic theory, a numerical method is developed to solve the thermionic plasma dynamics. To combine the analysis of ionization-recombination kinetics with the plasma dynamics of thermionic conversion, a finite difference computer program is constructed. It is capable of solving for both unsteady and steady thermionic converter behavior including possible laser ionization enhancement or atomic recombination lasing. A proposal to improve thermionic converter performance using laser radiation is considered. In this proposed scheme, laser radiation impinging on a thermionic plasma enhances the ionization process thereby raising the plasma density and reducing the plasma arc-drop. A source for such radiation may possibly be a cesium recombination laser operating in a different thermionic converter. The possibility of this being an energy efficient process is discussed. (WHK)

Lawless, J.L. Jr.; Lam, S.H.

1982-02-01T23:59:59.000Z

432

Nonlinearity 10 (1997) 12. Printed in the UK PII: S0951-7715(97)79608-7 Cover illustration: Non-premixed hydrocarbon flame  

E-Print Network [OSTI]

by the density difference from the combustion heat release and resulting temperature rise. The Reynolds number Publishing Ltd and LMS Publishing Ltd 1 #12;2 P E Dimotakis Combustion in non-premixed hydrocarbon flames-premixed hydrocarbon flame Paul E Dimotakis Graduate Aeronautical Laboratories, California Institute of Technology

Dimotakis, Paul E.

433

EFFECTIVENESS OF ELECTROSTATIC SHIELDING AND ELECTRONIC SUBTRACTION TO CORRECT FOR THE HOLE TRAPPING IN CDZNTE SEMICONDUCTOR DETECTORS.  

SciTech Connect (OSTI)

CdZnTe (CZT) is a very promising material for nuclear-radiation detectors. CZT detectors operate at ambient temperatures and offer high detection efficiency and excellent energy resolution, placing them ahead of high-purity Ge for those applications where cryogenic cooling is problematic. The progress achieved in CZT detectors over the past decade is founded on the developments of robust detector designs and readout electronics, both of which helped to overcome the effects of carrier trapping. Because the holes have low mobility, only electrons can be used to generate signals in thick CZT detectors, so one must account for the variation of the output signal versus the locations of the interaction points. To obtain high spectral resolution, the detector's design should provide a means to eliminate this dependence throughout the entire volume of the device. In reality, the sensitive volume of any ionization detector invariably has two regions. In the first, adjacent to the collecting electrode, the amplitude of the output signal rapidly increases almost to its maximum as the interaction point is located farther from the anode; in the rest of the volume, the output signal remains nearly constant. Thus, the quality of CZT detector designs can be characterized based on the magnitude of the signals variations in the drift region and the ratio between the volumes of the driR and induction regions. The former determines the ''geometrical'' width of the photopeak i.e., the line width that affects the total energy resolution and is attributed to the device's geometry when all other factors are neglected. The latter determines the photopeak efficiency and the area under the continuum in the pulse-height spectra. In this work, we describe our findings from systematizing different designs of CZT detectors and evaluating their performance based on these two criteria.

BOLOTNIKOV,A.E.; CAMARDA, G.S.; HOSSAIN, A.; CUI, Y.; JAMES, R.B.

2007-08-26T23:59:59.000Z

434

Linear eddy mixing based tabulation and artificial neural networks for large eddy simulations of turbulent flames  

SciTech Connect (OSTI)

A large eddy simulation (LES) sub-grid model is developed based on the artificial neural network (ANN) approach to calculate the species instantaneous reaction rates for multi-step, multi-species chemical kinetics mechanisms. The proposed methodology depends on training the ANNs off-line on a thermo-chemical database representative of the actual composition and turbulence (but not the actual geometrical problem) of interest, and later using them to replace the stiff ODE solver (direct integration (DI)) to calculate the reaction rates in the sub-grid. The thermo-chemical database is tabulated with respect to the thermodynamic state vector without any reduction in the number of state variables. The thermo-chemistry is evolved by stand-alone linear eddy mixing (LEM) model simulations under both premixed and non-premixed conditions, where the unsteady interaction of turbulence with chemical kinetics is included as a part of the training database. The proposed methodology is tested in LES and in stand-alone LEM studies of three distinct test cases with different reduced mechanisms and conditions. LES of premixed flame-turbulence-vortex interaction provides direct comparison of the proposed ANN method against DI and ANNs trained on thermo-chemical database created using another type of tabulation method. It is shown that the ANN trained on the LEM database can capture the correct flame physics with accuracy comparable to DI, which cannot be achieved by ANN trained on a laminar premix flame database. A priori evaluation of the ANN generality within and outside its training domain is carried out using stand-alone LEM simulations as well. Results in general are satisfactory, and it is shown that the ANN provides considerable amount of memory saving and speed-up with reasonable and reliable accuracy. The speed-up is strongly affected by the stiffness of the reduced mechanism used for the computations, whereas the memory saving is considerable regardless. (author)

Sen, Baris Ali; Menon, Suresh [School of Aerospace Engineering, Georgia Institute of Technology, 270 Ferst Drive, Atlanta, GA 30332-0150 (United States)

2010-01-15T23:59:59.000Z

435

On molecular transport effects in real gas laminar diffusion flames at large pressure  

Science Journals Connector (OSTI)

Direct numerical simulations are conducted of unsteady exothermic and one-dimensional laminar diffusionflames at large pressures. The simulations are used to assess the impact of molecular diffusion and real gas effects under high pressure conditions with simplified chemical kinetics. The formulation includes the fully compressible form of the governing equations real gas effects modeled by the cubic Peng–Robinson equation of state and a generalized form of the Soret and Dufour mass and heat diffusion vectors derived from nonequilibrium thermodynamics and fluctuation theory. The cross diffusion fluxes are derived for a ternary species system and include the effects of both heat and mass diffusion in the presence of temperature concentration and pressure gradients (i.e. Soret and Dufour diffusion). The ternary species formulation is applied to a simplified single step reaction elucidating molecular and thermodynamic effects apparent in general combustion. Realistic models for pressure temperature and species dependent heat capacities viscosities thermal conductivities and mass diffusivities are also included. Three different model reactions are simulated both including and neglecting Soret and Dufour cross diffusion. The simulation results show that Soret and Dufour effects are negligible for reactions comprised of species with equal or near equal molecular weights. However Soret diffusion effects are apparent when species with nonequal molecular weights are involved in the reaction and result in reductions of the peak flame temperature. In addition it is shown that neglect of cross diffusion leads to deviations in the predicted flame thicknesses with under predictions for a hydrogen-oxygen system and over predictions for a heavy hydrocarbon reaction. These effects are explained in detail through examinations of the individual heat and mass flux vectors as well as through associated thermodynamic properties. A parametric study addresses the effects of the ambient pressure the initial “flame Reynolds number ” the Damkohler number and the heat release parameter.

Sridhar Palle; Christopher Nolan; Richard S. Miller

2005-01-01T23:59:59.000Z

436

Scaling and efficiency of PRISM in adaptive simulations of turbulent premixed flames  

SciTech Connect (OSTI)

The dominant computational cost in modeling turbulent combustion phenomena numerically with high fidelity chemical mechanisms is the time required to solve the ordinary differential equations associated with chemical kinetics. One approach to reducing that computational cost is to develop an inexpensive surrogate model that accurately represents evolution of chemical kinetics. One such approach, PRISM, develops a polynomial representation of the chemistry evolution in a local region of chemical composition space. This representation is then stored for later use. As the computation proceeds, the chemistry evolution for other points within the same region are computed by evaluating these polynomials instead of calling an ordinary differential equation solver. If initial data for advancing the chemistry is encountered that is not in any region for which a polynomial is defined, the methodology dynamically samples that region and constructs a new representation for that region. The utility of this approach is determined by the size of the regions over which the representation provides a good approximation to the kinetics and the number of these regions that are necessary to model the subset of composition space that is active during a simulation. In this paper, we assess the PRISM methodology in the context of a turbulent premixed flame in two dimensions. We consider a range of turbulent intensities ranging from weak turbulence that has little effect on the flame to strong turbulence that tears pockets of burning fluid from the main flame. For each case, we explore a range of sizes for the local regions and determine the scaling behavior as a function of region size and turbulent intensity.

Tonse, Shaheen R.; Bell, J.B.; Brown, N.J.; Day, M.S.; Frenklach, M.; Grcar, J.F.; Propp, R.M.

1999-12-01T23:59:59.000Z

437

Lattice Boltzmann method for weakly ionized isothermal plasmas  

Science Journals Connector (OSTI)

In this paper, a lattice Boltzmann method (LBM) for weakly ionized isothermal plasmas is presented by introducing a rescaling scheme for the Boltzmann transport equation. Without using this rescaling, we found that the nondimensional relaxation time used in the LBM is too large and the LBM does not produce physically realistic results. The developed model was applied to the electrostatic wave problem and the diffusion process of singly ionized helium plasmas with a 1–3% degree of ionization under an electric field. The obtained results agree well with theoretical values.

Huayu Li and Hyungson Ki

2007-12-21T23:59:59.000Z

438

Lattice Boltzmann method for weakly ionized isothermal plasmas  

SciTech Connect (OSTI)

In this paper, a lattice Boltzmann method (LBM) for weakly ionized isothermal plasmas is presented by introducing a rescaling scheme for the Boltzmann transport equation. Without using this rescaling, we found that the nondimensional relaxation time used in the LBM is too large and the LBM does not produce physically realistic results. The developed model was applied to the electrostatic wave problem and the diffusion process of singly ionized helium plasmas with a 1-3% degree of ionization under an electric field. The obtained results agree well with theoretical values.

Li Huayu; Ki, Hyungson [Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan 48824-1226 (United States)

2007-12-15T23:59:59.000Z

439

Photo-double-ionization of the nitrogen molecule  

Science Journals Connector (OSTI)

The triple differential cross sections of the photo-double-ionization of the nitrogen molecule to the X 1?+g and a3?u N22+ states have been measured at about 20 eV above their respective ionization thresholds in the equal energy sharing kinematics and calculated using a model which makes use of correlated two-center double continuum wave functions. The comparison of the results with those obtained by the Gaussian parametrization method applied in the past with success to heliumlike targets shows the influence of the molecular nature of the N2 target in the photo-double-ionization.

P. Bolognesi; B. Joulakian; A. A. Bulychev; O. Chuluunbaatar; L. Avaldi

2014-05-07T23:59:59.000Z

440

The Density Effect for the Ionization Loss in Various Materials  

Science Journals Connector (OSTI)

The density effect for the ionization loss of charged particles has been calculated for a number of metals, scintillating materials, gases at various pressures, and photographic emulsion, using a dispersion model involving an appropriate number of dispersion oscillators for each substance. The results are presented in the form of graphs which can be used to correct the ionization loss for the density effect. The theoretical curves for silver chloride and anthracene are in reasonable agreement with experiments on the ionization loss of ?-mesons. A general derivation of the equations for the density effect is given.

R. M. Sternheimer

1952-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "flame ionization detector" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Microgap x-ray detector  

DOE Patents [OSTI]

An x-ray detector which provides for the conversion of x-ray photons into photoelectrons and subsequent amplification of these photoelectrons through the generation of electron avalanches in a thin gas-filled region subject to a high electric potential. The detector comprises a cathode (photocathode) and an anode separated by the thin, gas-filled region. The cathode may comprise a substrate, such a beryllium, coated with a layer of high atomic number material, such as gold, while the anode can be a single conducting plane of material, such as gold, or a plane of resistive material, such as chromium/silicon monoxide, or multiple areas of conductive or resistive material, mounted on a substrate composed of glass, plastic or ceramic. The charge collected from each electron avalanche by the anode is passed through processing electronics to a point of use, such as an oscilloscope.

Wuest, Craig R. (Danville, CA); Bionta, Richard M. (Livermore, CA); Ables, Elden (Livermore, CA)

1994-01-01T23:59:59.000Z

442

Superconducting transmission line particle detector  

DOE Patents [OSTI]

A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non- superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propagating in a superconducting transmission line are used to resolve N/sup 2/ ambiguity of charged particle events. 6 figs.

Gray, K.E.

1988-07-28T23:59:59.000Z

443

Superconducting transmission line particle detector  

DOE Patents [OSTI]

A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non-superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propogating in a superconducting transmission line are used to resolve N.sup.2 ambiguity of charged particle events.

Gray, Kenneth E. (Naperville, IL)

1989-01-01T23:59:59.000Z

444

Large Aperture Electrostatic Dust Detector  

SciTech Connect (OSTI)

Diagnosis and management of dust inventories generated in next-step magnetic fusion devices is necessary for their safe operation. A novel electrostatic dust detector, based on a fine grid of interlocking circuit traces biased to 30 or 50 ? has been developed for the detection of dust particles on remote surfaces in air and vacuum environments. Impinging dust particles create a temporary short circuit and the resulting current pulse is recorded by counting electronics. Up to 90% of the particles are ejected from the grid or vaporized suggesting the device may be useful for controlling dust inventories. We report measurements of the sensitivity of a large area (5x5 cm) detector to microgram quantities of dust particles and review its applications to contemporary tokamaks and ITER.

C.H. Skinner, R. Hensley, and A.L Roquemore

2007-10-09T23:59:59.000Z

445

Demonstration of triple pump coherent anti-Stokes Raman scattering in a jet diffusion flame  

E-Print Network [OSTI]

. A. Theory 1. Coherent anti-Stokes Raman scattering basics B. Dual-pump and triple-pump CARS processes 1. Dual-pump CARS 2. Triple pump CARS C. Thermometry and species detection EXPERIMENTAL APPARATUS A. Initial experimental system 1. Laser.... Laser Alignment and Performance I . Nd: YAG laser 2. Narrow band dye laser (ND6000) alignment 3. Broad-band dye laser alignment B. Triple-pump CARS set-up 1. CARS phase-matching alignment 2. Diffusion flame burner C. Results I. Results from first...

Velur Natarajan, Viswanathan

2012-06-07T23:59:59.000Z

446

Fiber optic spectroscopic digital imaging sensor and method for flame properties monitoring  

DOE Patents [OSTI]

A system for real-time monitoring of flame properties in combustors and gasifiers which includes an imaging fiber optic bundle having a light receiving end and a light output end and a spectroscopic imaging system operably connected with the light output end of the imaging fiber optic bundle. Focusing of the light received by the light receiving end of the imaging fiber optic bundle by a wall disposed between the light receiving end of the fiber optic bundle and a light source, which wall forms a pinhole opening aligned with the light receiving end.

Zelepouga, Serguei A. (Hoffman Estates, IL); Rue, David M. (Chicago, IL); Saveliev, Alexei V. (Chicago, IL)

2011-03-15T23:59:59.000Z

447

A Study of Gasification of Municipal Solid Waste Using a Double Inverse Diffusion Flame Burner  

Science Journals Connector (OSTI)

A Study of Gasification of Municipal Solid Waste Using a Double Inverse Diffusion Flame Burner ... Furthermore, the experiences of the waste incineration industry driven in the past by regulatory as well as technical issues may facilitate their commercial potentials outside the common market, especially in highly populated developing countries such as Korea with scarce landfill sites. ... Recently, several new technologies that involve gasification or combinations of pyrolysis, combustion, and gasification processes are currently being brought into the market for energy-efficient, environmentally friendly and economically sound methods of thermal processing of wastes. ...

Tae-Heon Kwak; Seungmoon Lee; Sanjeev Maken; Ho-Chul Shin; Jin-Won Park; Young Done Yoo

2005-08-24T23:59:59.000Z

448

Particle Detector / Beam Current Transformer  

E-Print Network [OSTI]

Particle Detector / Beam Current Transformer Analysis December 8, 2009 Harold G. Kirk #12;ShotSignal,A.U. Proton Bunch Number Beam Current Transformer - 17011 0 2 4 6 8 0 2 4 6 8 10 12 14 16 18 20 Integrated Transformer Pump 187829 (au) Probe 196504 (au) Ratios: Beam Current 1.046 SF 1.019 2.9% difference #12;Shot

McDonald, Kirk

449

Systems and methods for cylindrical hall thrusters with independently controllable ionization and acceleration stages  

DOE Patents [OSTI]

Systems and methods may be provided for cylindrical Hall thrusters with independently controllable ionization and acceleration stages. The systems and methods may include a cylindrical channel having a center axial direction, a gas inlet for directing ionizable gas to an ionization section of the cylindrical channel, an ionization device that ionizes at least a portion of the ionizable gas within the ionization section to generate ionized gas, and an acceleration device distinct from the ionization device. The acceleration device may provide an axial electric field for an acceleration section of the cylindrical channel to accelerate the ionized gas through the acceleration section, where the axial electric field has an axial direction in relation to the center axial direction. The ionization section and the acceleration section of the cylindrical channel may be substantially non-overlapping.

Diamant, Kevin David; Raitses, Yevgeny; Fisch, Nathaniel Joseph

2014-05-13T23:59:59.000Z

450

RHIC DETECTOR ADVISORY COMMITTEE Report  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

RHIC RHIC DETECTOR ADVISORY COMMITTEE Report of Review on Nov. 22, 2003 at BNL 1. Introduction The committee, consisting of Peter Braun-Munzinger (chair), Russell Betts, Carl Haber, Berndt Mueller, Rick Van Berg, and Jerry Va'vra 1 , met for the second time on Nov. 22, 2003 at BNL, chiefly to evaluate proposals by the STAR collaboration on their "MRPC TOF Detector" and by the PHENIX collaboration on their "Si-Tracker". Brief reports were also heard on the progress of the various R&D efforts in STAR and PHENIX but time was too short to make a detailed assessment of those. This report will hence concentrate on the main proposals. At the end we will make some remarks on the status of R&D in general and on some technical aspects we heard in the open session. 2. STAR MRPC TOF Detector The development of a detailed proposal for a TOF in STAR, based on the MRPC tech- nology, is

451

Current status of Japanese detectors  

E-Print Network [OSTI]

Current status of TAMA and CLIO detectors in Japan is reported in this article. These two interferometric gravitational-wave detectors are being developed for the large cryogenic gravitational wave telescope (LCGT) which is a future plan for detecting gravitational wave signals at least once per year. TAMA300 is being upgraded to improve the sensitivity in low frequency region after the last observation experiment in 2004. To reduce the seismic noises, we are installing new seismic isolation system, which is called TAMA Seismic Attenuation System, for the four test masses. We confirmed stable mass locks of a cavity and improvements of length and angular fluctuations by using two SASs. We are currently optimizing the performance of the third and fourth SASs. We continue TAMA300 operation and R&D studies for LCGT. Next data taking in the summer of 2007 is planned. CLIO is a 100-m baseline length prototype detector for LCGT to investigate interferometer performance in cryogenic condition. The key features of CLIO are that it locates Kamioka underground site for low seismic noise level, and adopts cryogenic Sapphire mirrors for low thermal noise level. The first operation of the cryogenic interferometer was successfully demonstrated in February of 2006. Current sensitivity at room temperature is close to the target sensitivity within a factor of 4. Several observation experiments at room temperature have been done. Once the displacement noise reaches at thermal noise level of room temperature, its improvement by cooling test mass mirrors should be demonstrated.

Daisuke Tatsumi; Ryutaro Takahashi; Koji Arai; Noriyasu Nakagawa; Kazuhiro Agatsuma; Toshitaka Yamazaki; Mitsuhiro Fukushima; Masa-Katsu Fujimoto; Akiteru Takamori; Alessandro Bertolini; Virginio Sannibale; Riccardo DeSalvo; Szabolcs Marka; Masaki Ando; Kimio Tsubono; Tomomi Akutsu; Kazuhiro Yamamoto; Hideki Ishitsuka; Takashi Uchiyama; Shinji Miyoki; Masatake Ohashi; Kazuaki Kuroda; Norichika Awaya; Nobuyuki Kanda; Akito Araya; Souichi Telada; Takayuki Tomaru; Tomiyoshi Haruyama; Akira Yamamoto; Nobuaki Sato; Toshitaka Suzuki; Takakazu Shintomi

2007-04-22T23:59:59.000Z

452

Ionization and transmission efficiency in an electrospray ionization-mass spectrometry interface  

SciTech Connect (OSTI)

The efficiency of sample ionization by electrospray ionization (ESI) and the transmission of the charged droplets and gas-phase ions through an ESI interface were investigated in order to advance the understanding of how these factors affect mass spectrometry (MS) sensitivity. In addition, the effects of the ES emitter distance to the inlet, solution flow rate, and inlet temperature to the ionization and transmission efficiency were characterized. Quantitative measurements of ES current loss throughout the ESI interface were accomplished by electrically isolating the front surface of the interface from the inner wall of the heated inlet capillary, enabling losses on the two surfaces to be distinguished. The ES current lost to the front surface of the ESI interface was also spatially profiled with a linear array of 340-µm-dia. electrodes placed adjacent to the inlet capillary entrance. Current transmitted as gas-phase ions was differentiated from charged droplets and solvent clusters by directly measuring sensitivity with a single quadrupole mass spectrometer. The study has revealed a large sampling efficiency into the inlet capillary (>90% at an emitter distance of 1 mm), a global rather than a local gas dynamic effect on the shape of the ES plume due to the gas flow conductance limit of the inlet capillary, a large (>80%) loss of analyte after transmission through the inlet due to incomplete desolvation at a solution flow rate of 1.0 µL/min, and a decrease in analyte peak intensity at lower temperatures, despite a large increase in ES current transmission efficiency. These studies provide a clearer understanding of the parameters affecting ion transmission into the mass spectrometer, and will serve to guide the design of more efficient instrument interfaces.

Page, Jason S.; Kelly, Ryan T.; Tang, Keqi; Smith, Richard D.

2007-09-01T23:59:59.000Z

453

Characterization of nonpolar lipids and steroids by using laser-induced acoustic desorption/chemical ionization, atmospheric pressure chemical ionization, and electrospray ionization mass spectrometry  

SciTech Connect (OSTI)

Laser-induced acoustic desorption (LIAD) combined with ClMn(H{sub 2}O){sup +} chemical ionization (CI) was tested for the analysis of nonpolar lipids and selected steroids in a Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR). The nonpolar lipids studied, cholesterol, 5?-cholestane, cholesta-3,5-diene, squalene, and ?-carotene, were found to solely form the desired water replacement product (adduct-H{sub 2}O) upon reaction with the ClMn(H{sub 2}O){sup +} ions. The steroids, androsterone, dehydroepiandrosterone (DHEA), estrone, estradiol, and estriol, also form abundant adduct-H{sub 2}O ions, but less abundant adduct-2H{sub 2}O ions were also observed. Neither (+)APCI nor (+)ESI can ionize the saturated hydrocarbon lipid, cholestane. APCI successfully ionizes the unsaturated hydrocarbon lipids to form exclusively the intact protonated analytes. However, it causes extensive fragmentation for cholesterol and the steroids. The worst case is cholesterol that does not produce any stable protonated molecules. On the other hand, ESI cannot ionize any of the hydrocarbon analytes, saturated or unsaturated. However, ESI can be used to protonate the oxygen-containing analytes with substantially less fragmentation than for APCI in all cases except for cholesterol and estrone. In conclusion, LIAD/ClMn(H{sub 2}O){sup +} chemical ionization is superior over APCI and ESI for the mass spectrometric characterization of underivatized nonpolar lipids and steroids.

Jin, Z.; Daiya, S.; Kenttämaa, Hilkka I.

2011-01-01T23:59:59.000Z

454

Conditional Moment Closure Modeling for a Three-Dimensional Turbulent Non-premixed Syngas Flame with a Cooling Wall  

Science Journals Connector (OSTI)

Conditional Moment Closure Modeling for a Three-Dimensional Turbulent Non-premixed Syngas Flame with a Cooling Wall ... In the experiment,(13) the burner is mounted to an air-cooled combustion chamber and the burner consists of a central fuel tube and an annular air tube. ... It can be seen that the velocity field at the pure-mixing entrance region is highly deflected by the flame holder, and the burned mixtures are partially impinged on the cooling wall (Tw = 600 K). ...

Gunhong Kim; Sungmo Kang; Yongmo Kim; Kwan-Soo Lee

2008-09-13T23:59:59.000Z

455

Detectors - Instrument Support | ORNL Neutron Sciences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Detectors › R & D 100 Award Detectors › R & D 100 Award ORNL team wins R&D 100 award for wavelength-shifting scintillator detector Neutron facilities, national security monitoring will benefit from high-accuracy detector June 2012, Written by Agatha Bardoel A team of eight scientists and technicians in the Neutron Sciences Directorate has won a prestigious R&D 100 Award from R&D Magazine for developing a highly efficient new detector system that helps take pressure off dwindling worldwide supplies of 3He as an active neutron converter. Members of the team receiving an R&D 100 Award for the wavelength-shifting scintillator detector Members of the team receiving an R&D 100 Award for the wavelength-shifting scintillator detector are shown with their invention. They are (from left)

456

Rules and Regulations for Control of Ionizing Radiation (Arkansas) |  

Broader source: Energy.gov (indexed) [DOE]

Rules and Regulations for Control of Ionizing Radiation (Arkansas) Rules and Regulations for Control of Ionizing Radiation (Arkansas) Rules and Regulations for Control of Ionizing Radiation (Arkansas) < Back Eligibility Utility Program Info State Arkansas Program Type Environmental Regulations Siting and Permitting Provider Department of Health The Rules and Regulations for Control of Ionizing Radiation are the Arkansas state laws made in accordance the federal Nuclear Regulatory Commission Rules. Any contractor with the US DOE or US Nuclear Regulatory Commission is exempt from the state laws. This set of rules and regulations basically restates the federal policy to ensure that Arkansas is in compliance with the federal standards governing nuclear energy. Specifically the State rules are equivalent to Nuclear Regulatory

457

The Degradation of Solid Polymethylmethacrylate by Ionizing Radiation  

Science Journals Connector (OSTI)

...Polymethylmethacrylate by Ionizing Radiation P. Alexander A. Charlesby...inversely proportional to the radiation dose (plus a small quantity of...of measuring high-energy radiation doses in the range of about 1 million rontgens...

1954-01-01T23:59:59.000Z

458

Ionizing Radiation Induces Delayed Hyperrecombination in Mammalian Cells  

Science Journals Connector (OSTI)

...instability is critical to radiation risk assessment and for determining...the many delayed effects of radiation, chromosomal instability is...detrimental effects over a range of doses of ionizing radiation. Furthermore, a rapid and...

Lei Huang; Suzanne Grim; Leslie E. Smith; Perry M. Kim; Jac A. Nickoloff; Olga G. Goloubeva; William F. Morgan

2004-06-01T23:59:59.000Z

459

22.01 Introduction to Ionizing Radiation, Fall 2003  

E-Print Network [OSTI]

Introduction to basic properties of ionizing radiations and their uses in medicine, industry, science, and environmental studies. Discusses natural and man-made radiation sources, energy deposition and dose calculations, ...

Coderre, Jeffrey A.

460

Laser Multiphoton Ionization of Tetrakis(dimethylamino)ethylene  

Science Journals Connector (OSTI)

(4) Also, TDAE has found a place in current plasma research as it can produce plasmas at densities approaching 1013 charges per cm3 via ionization with 193 nm light. ...

Byron H. Smith; Robert N. Compton

2014-02-22T23:59:59.000Z

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461

Comparative study of micromixing models in transported scalar PDF simulations of turbulent nonpremixed bluff body flames  

SciTech Connect (OSTI)

Numerical simulation results are presented for turbulent jet diffusion flames with various levels of turbulence-chemistry interaction, stabilized behind a bluff body (Sydney Flames HM1-3). Interaction between turbulence and combustion is modeled with the transported joint-scalar PDF approach. The mass density function transport equation is solved in a Lagrangian manner. A second-moment-closure turbulence model is applied to obtain accurate mean flow and turbulent mixing fields. The behavior of two micromixing models is discussed: the Euclidean minimum spanning tree model and the modified Curl coalescence dispersion model. The impact of the micromixing model choice on the results in physical space is small, although some influence becomes visible as the amount of local extinction increases. Scatter plots and profiles of conditional means and variances of thermochemical quantities, conditioned on the mixture fraction, are discussed both within and downstream of the recirculation region. A distinction is made between local extinction and incomplete combustion, based on the CO species mass fraction. The differences in qualitative behavior between the micromixing models are explained and quantitative comparison to experimental data is made. (author)

Merci, Bart [Department of Flow, Heat and Combustion Mechanics, Ghent University-UGent, Ghent (Belgium); Roekaerts, Dirk [Department of Multi-Scale Physics, Delft University of Technology, Delft (Netherlands); Naud, Bertrand [CIEMAT, Madrid (Spain); Pope, Stephen B. [Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY (United States)

2006-07-15T23:59:59.000Z

462

Effects of radiation on NO kinetics in turbulent hydrogen/air diffusion flames  

SciTech Connect (OSTI)

The authors describe a coupled radiation and NO kinetics calculation of turbulent hydrogen/air diffusion flame properties. Transport equations for mass, momentum, mixture fraction, enthalpy (sensible + chemical) including gas band radiation, and NO mass fraction are solved. NO kinetics is described by a one step thermal production mechanism. The local temperature is obtained by solving the enthalpy equation taking radiation loss from H{sub 2}O into consideration. Radiation/turbulence and chemical kinetics/turbulence interactions are treated using a clipped Gaussian probability density function (PDF) for the mixture fraction, and a delta PDF for the enthalpy. The source terms in the enthalpy and mass fraction of NO equations are treated using assumed PDF integration over the mixture fraction space. The results of the simulation are compared with existing measurements of the Emission Indices of NO (EINO) in turbulent H{sub 2}/air diffusion flames. The major conclusion of the paper is that coupled turbulence/radiation interactions should be taken into account while computing the EINO.

Sivathanu, Y.R.; Gore, J.P.; Laurendeau, N.M.

1997-07-01T23:59:59.000Z

463

Transported PDF Modeling of Nonpremixed Turbulent CO/H-2/N-2 Jet Flames  

SciTech Connect (OSTI)

Turbulent CO/H{sub 2}/N{sub 2} (“syngas”) flames are simulated using a transported composition probability density function (PDF) method. A consistent hybrid Lagrangian particle/Eulerian mesh algorithm is used to solve the modeled PDF transport equation. The model includes standard k–? turbulence, gradient transport for scalars, and Euclidean minimum spanning tree (EMST) mixing. Sensitivities of model results to variations in the turbulence model, the treatment of radiation heat transfer, the choice of chemical mechanism, and the PDF mixing model are explored. A baseline model reproduces the measured mean and rms temperature, major species, and minor species profiles reasonably well, and captures the scaling that is observed in the experiments. Both our results and the literature suggest that further improvements can be realized with adjustments in the turbulence model, the radiation heat transfer model, and the chemical mechanism. Although radiation effects are relatively small in these flames, consideration of radiation is important for accurate NO prediction. Chemical mechanisms that have been developed specifically for fuels with high concentrations of CO and H{sub 2} perform better than a methane mechanism that was not designed for this purpose. It is important to account explicitly for turbulence–chemistry interactions, although the details of the mixing model do not make a large difference in the results, within reasonable limits.

Zhao, xinyu; Haworth, D. C.; Huckaby, E. David

2012-01-01T23:59:59.000Z

464

Polymer/clay aerogel composites with flame retardant agents: Mechanical, thermal and fire behavior  

Science Journals Connector (OSTI)

Abstract Aerogel is a class of material characterized by its high void content and extreme lightness. Different polymer/clay aerogels have been prepared by a simply freeze–thaw process from a suspension with poly(vinyl alcohol) (PVOH) and clay (Na+-MMT). Low density polymer/clay aerogels modified with flame retardant agents were prepared using a similar approach. The addition of flame retardant agents slightly increased the apparent density of the final composites whereas the compression properties were reduced due to the decrease in the polymer/clay interfacial bonding. An exception was the sample containing Al(OH)3 that exhibited higher modulus and stress at maximum deformation. Regarding thermal properties, the presence of ammonium polyphosphate (APP) or silica gel (SG) significantly slowed the rate of aerogel decomposition at the temperature range from 250 °C to 500 °C while the onset of polymer decomposition was not affected. Fire behavior was analyzed through cone calorimeter suggesting that either the presence of Al(OH)3 or APP reduced the heat release rate of PVOH/clay systems.

Liang Wang; Miguel Sánchez-Soto; Maria Lluisa Maspoch

2013-01-01T23:59:59.000Z

465

Chemical kinetic considerations for postflame synthesis of carbon nanotubes in premixed flames using a support catalyst  

SciTech Connect (OSTI)

Multiwalled carbon nanotubes (MWCNTs) on a grid supported cobalt nanocatalyst were grown, by exposing it to combustion gases from ethylene/air rich premixed flames. Ten equivalence ratios ({phi}) were investigated, as follows: 1.37, 1.44, 1.47, 1.50, 1.55, 1.57, 1.62, 1.75, 1.82, and 1.91. MWCNT growth could be observed for the range of equivalence ratios between 1.45 and 1.75, with the best yield restricted to the range 1.5-1.6. A one-dimensional premixed flame code with a postflame heat loss model, including detailed chemistry, was used to estimate the gas phase chemical composition that favors MWCNT growth. The results of the calculations show that the mixture, including the water gas shift reaction, is not even in partial chemical equilibrium. Therefore, past discussions of compositional parameters that relate to optimum carbon nanotube (CNT) growth are revised to include chemical kinetic effects. Specifically, rapid departures of the water gas shift reaction from partial equilibrium and changes in mole fraction ratios of unburned C{sub 2} hydrocarbons to hydrogen correlate well with experimentally observed CNT yields. (author)

Gopinath, Prarthana; Gore, Jay [School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 (United States)

2007-11-15T23:59:59.000Z

466

Synergistic flame retardant effect of metal hydroxide and nanoclay in EVA composites  

Science Journals Connector (OSTI)

This study focused on the flame retardancy of ethylene-vinyl acetate copolymer (EVA) in combination with metal hydroxide and nanoclay. Fire tests, such as limiting oxygen index (LOI), flammability (UL-94), cone calorimeter, and smoke density chamber were employed to evaluate the effect of composition variation for the metal hydroxide and the nanoclay in EVA composites. The experimental results showed that when the nanoclay of 1 or 2 weight per cent was substituted for the aluminum hydroxide or magnesium hydroxide in EVA blends, the LOI value was significantly improved while the V-0 rating was maintained. The data obtained from the cone calorimeter test indicated that the peak heat release rate (pk-HRR) is reduced by about 28%–47%. The smoke density data (maximal smoke density, Dm) showed a reduction by about 16%–25%. The thermogravimetric analysis (TGA) data also showed that the nanoclay increased the thermal stability and char residue of the EVA samples. Hence, it is suggested that the metal oxide layer on the burning surface is reinforced by the formation of silicate layer, which is both structured and compacted and acts as the insulation, and the newly formed layer responds to the synergistic effect of flame retardancy as well as smoke suppression observed in the EVA blends.

Ynh-Yue Yen; Hsin-Ta Wang; Wen-Jen Guo

2012-01-01T23:59:59.000Z

467

Modeling of the formation of short-chain acids in propane flames  

E-Print Network [OSTI]

In order to better understand their potential formation in combustion systems, a detailed kinetic mechanism for the formation of short-chain monocarboxylic acids, formic (HCOOH), acetic (CH3COOH), propionic (C2H5COOH) and propenic (C2H3COOH)) acids, has been developed. Simulations of lean (equivalence ratios from 0.9 to 0.48) laminar premixed flames of propane stabilized at atmospheric pressure with nitrogen as diluent have been performed. It was found that amounts up to 25 ppm of acetic acid, 15 ppm of formic acid and 1 ppm of C3 acid can be formed for some positions in the flames. Simulations showed that the more abundant C3 acid formed is propenic acid. A quite acceptable agreement has been obtained with the scarce results from the literature concerning oxygenated compounds, including aldehydes (CH2O, CH3CHO) and acids. A reaction pathways analysis demonstrated that each acid is mainly derived from the aldehyde of similar structure.

Battin-Leclerc, Frédérique; Jaffrezo, J L; Legrand, M

2009-01-01T23:59:59.000Z

468

Proceedings of the international workshop on measurement and computation of turbulent nonpremixed flames  

SciTech Connect (OSTI)

This report documents the proceedings of the International Workshop on Measurement and Computation of Turbulent Nonpremixed Flames, held in Naples, Italy on July 26--27, 1996. Contents include materials that were distributed to participants at the beginning of the workshop, as well as a Summary of Workshop Accomplishments that was generated at the close to this Naples meeting. The Naples workshop involved sixty-one people from eleven countries. The primary objectives were: (1) to select a set of well-documented and relatively simple flames that would be appropriate for collaborative comparisons of model predictions; and (2) to specify common submodels to be used in these predictions, such that models for the coupling of turbulence and chemistry might be isolated and better understood. Studies involve hydrogen and natural gas fuels. These proceedings are also published on the Web and those interested in the ongoing process of data selection and model comparison should consult the workshop page for the most recent and complete information on these collaborative research efforts. The URL is: http://www/ca.sandia/gov/tdf/Workshop.html.

Barlow, R.S. [ed.

1996-10-01T23:59:59.000Z

469

Thermonuclear Flame Spreading on Rapidly Spinning Neutron Stars: Indications of the Coriolis Force?  

E-Print Network [OSTI]

Millisecond period brightness oscillations during the intensity rise of thermonuclear X-ray bursts are likely caused by an azimuthally asymmetric, expanding burning region on the stellar surface. The time evolution of the oscillation amplitude during the intensity rise encodes information on how the thermonuclear flames spread across the stellar surface. This process depends on properties of the accreted burning layer, surface fluid motions, and the surface magnetic field structure, and thus can provide insight into these stellar properties. We present two examples of bursts from different sources that show a decrease in oscillation amplitude during the intensity rise. Using theoretical modeling, we demonstrate that the observed amplitude evolution of these bursts is not well described by a uniformly expanding circular burning region. We further show that by including in our model the salient aspects of the Coriolis force (as described by Spitkovsky, Levin, and Ushomirsky) we can qualitatively reproduce the observed evolution curves. Our modeling shows that the evolutionary structure of burst oscillation amplitude is sensitive to the nature of flame spreading, while the actual amplitude values can be very useful to constrain some source parameters.

Sudip Bhattacharyya; Tod E. Strohmayer

2007-08-27T23:59:59.000Z

470

Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Site-Selective Ionization in Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation Site-Selective Ionization in Nanoclusters Affects Subsequent Fragmentation Print Wednesday, 30 June 2010 00:00 Understanding charge-transfer processes at the atomic level of nanoscale systems is of the utmost importance for designing nanodevices based on quantum-dot structures, nanotubes, or two-dimensional graphene sheets. Researchers from Western Michigan University, Berkeley Lab, and other international research facilities investigated charge-transfer processes and subsequent ion fragmentation dynamics in nanoclusters composed of argon (Ar) shells and xenon (Xe) cores. The clusters were site-selectively ionized (i.e, ionization took place either in the xenon core or in the argon shell). Using a high-resolution photoelectron-ion coincidence technique at ALS Beamlines 10.0.1 and 11.0.2, the researchers concluded that charge-transfer processes and fragmentation dynamics are strongly influenced by the environment of the initially ionized atoms.

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